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120224 City Council Business Meeting Packet- General Sewer Plan
HomeMy WebLinkAbout120224 City Council Business Meeting Packet- General Sewer Plan
MAY 2024
AGENCY REVIEW DRAFT MAY 2024
FINAL JULY 2024
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MAY 2024
FINAL JULY2024
Mayor
David Faber
Deputy Mayor
Amy Howard
City Council
Aislinn Palmer
Ben Thomas
Libby Urner Wennstrom
Monica MickHager
Owen Rowe
Public WorksDirector
Steve King, PE
Wastewater Operations Manager
Bliss Morris
Streets and Collections Manager
Brian Reid
City ofPort Townsend
250 Madison Street
PortTownsend, WA 98368
Prepared By
RH2 Engineering, Inc.
th
22722 29Drive SE, Suite 210
Bothell, WA 98021
Contact:Dan Mahlum, PE
(425)951-5340
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CERTIFICATION
This General Sewer Plan for the City of Port Townsend was prepared under the direction
of the following registered professional engineers.
05/07/2024
_____________________________________
Eric Smith, PE
Chapter 8
05/07/2024
_____________________________________
John Hendron, PE
Collections System
05/07/2024
_____________________________________
Dan Mahlum, PE
Principal
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City of Port TownsendGeneral Sewer Plan
Table of Contents
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EExecutiveSummary.......................................................................................................E-1
PURPOSE OF THE PLAN..........................................................................................................................E-1
SUMMARY OF KEY ELEMENTS...............................................................................................................E-1
Sewer Service Area, Land Use, and Population.................................................................................E-1
Existing Facilities and Discharge Regulations....................................................................................E-2
Existing Wastewater Flow and Loading.............................................................................................E-6
Inflow and Infiltration........................................................................................................................E-8
Peaking Factors.................................................................................................................................E-8
Projected Wastewater Flow..............................................................................................................E-9
Projected Wastewater Quality........................................................................................................E-10
Policies and Design Criteria.............................................................................................................E-12
Operation and Maintenance...........................................................................................................E-13
Summary of Improvements.............................................................................................................E-13
1|Introduction..................................................................................................................1-1
SEWER SYSTEM OWNERSHIP AND MANAGEMENT...............................................................................1-1
OVERVIEW OF EXISTING SYSTEM..........................................................................................................1-1
AUTHORIZATION AND PURPOSE...........................................................................................................1-2
PREVIOUS PLANNING EFFORTS.............................................................................................................1-3
SUMMARY OF PLAN CONTENTS............................................................................................................1-3
LIST OF ABBREVIATIONS........................................................................................................................1-3
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2SewerSystemDescriptionandDischargeRegulations...................................................2-1
INTRODUCTION.....................................................................................................................................2-1
SEWER SERVICE AREA............................................................................................................................2-1
History...............................................................................................................................................2-1
Geology..............................................................................................................................................2-2
Topography.......................................................................................................................................2-2
Climate..............................................................................................................................................2-3
Water Bodies and Floodplains...........................................................................................................2-3
City Limits, Urban Growth Area, and Sewer Service Area Boundary................................................2-4
EXISTING SEWER FACILITIES..................................................................................................................2-5
Sewer Drainage Basins......................................................................................................................2-5
Gravity Sewer Collection Piping........................................................................................................2-6
Force Mains.......................................................................................................................................2-8
Lift Stations........................................................................................................................................2-9
Low Pressure Sewer Systems..........................................................................................................2-12
Wastewater Treatment and Disposal Facilities...............................................................................2-14
DISCHARGE AND DISPOSAL REGULATIONS AND PERMITS..................................................................2-15
WWTF NPDES Permit and Regulations............................................................................................2-15
Future City NPDES Permit Effluent Limits (Outfall No. 001) Changes.............................................2-16
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City of Port Townsend General Sewer Plan
Table of Contents
Other Regulations and Required Permits ........................................................................................ 2-17
ADJACENT SEWER SYSTEMS ................................................................................................................ 2-23
CITY OF PORT TOWNSEND AND ADJACENT WATER SYSTEMS ............................................................ 2-23
City of Port Townsend ..................................................................................................................... 2-23
Adjacent Water Systems ................................................................................................................. 2-26
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3 Land Use and Population ............................................................................................... 3-1
INTRODUCTION ..................................................................................................................................... 3-1
COMPATIBILITY WITH OTHER PLANS AND POLICIES ............................................................................. 3-1
Growth Management Act .................................................................................................................. 3-1
Port Townsend Comprehensive Plan ................................................................................................ 3-2
Jefferson County County-wide Planning Policies .............................................................................. 3-2
Jefferson County Comprehensive Plan ............................................................................................. 3-3
LAND USE ............................................................................................................................................... 3-3
POPULATION .......................................................................................................................................... 3-5
Household Trends ............................................................................................................................. 3-5
Historical and Future City Population ............................................................................................... 3-5
Sewer System Population .................................................................................................................. 3-7
Distribution of Population Assumptions ........................................................................................... 3-8
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4 Flow and Loading Analyses ............................................................................................ 4-1
INTRODUCTION ..................................................................................................................................... 4-1
SEWER SERVICE CONNECTIONS AND RESIDENTIAL POPULATION ........................................................ 4-1
Sewer Service Connections ............................................................................................................... 4-1
Sewer Service Population .................................................................................................................. 4-2
EXISTING WASTEWATER FLOW AND LOADING ..................................................................................... 4-3
Wastewater Flow .............................................................................................................................. 4-3
Wastewater Loading ......................................................................................................................... 4-4
INFLOW AND INFILTRATION .................................................................................................................. 4-6
Inflow ................................................................................................................................................. 4-6
Infiltration .......................................................................................................................................... 4-7
PROJECTED WASTEWATER FLOW AND LOADING ................................................................................. 4-7
Peaking Factors ................................................................................................................................. 4-8
Projected Wastewater Flow Rates .................................................................................................... 4-9
Historical Wastewater Flow by Basin .............................................................................................. 4-12
Projected Wastewater Flow by Basin .............................................................................................. 4-13
Lift Station Hydraulic Capacity Analyses ......................................................................................... 4-14
Projected Wastewater Loading Capacity ........................................................................................ 4-15
SUMMARY ........................................................................................................................................... 4-22
5 | Policies and Collection System Design Criteria ............................................................... 5-1
INTRODUCTION ..................................................................................................................................... 5-1
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City of Port Townsend General Sewer Plan
Table of Contents
REGULATIONS........................................................................................................................................5-2
National Pollutant Discharge Elimination System Permit.................................................................5-2
Other Regulations and Required Permits..........................................................................................5-2
CUSTOMER SERVICE POLICIES...............................................................................................................5-2
Existing Sewer Service and Connection.............................................................................................5-2
Proposed Sewer Service and Connection Policies.............................................................................5-3
Septic System Policies.......................................................................................................................5-4
COLLECTION SYSTEM POLICIES AND DESIGN CRITERIA.........................................................................5-5
Sanitary Sewer Design Criteria..........................................................................................................5-5
Gravity Sewer Design Criteria............................................................................................................5-5
Design Flow Rates.............................................................................................................................5-6
Separation Between Sanitary Sewer and Other Utilities..................................................................5-6
Design Period.....................................................................................................................................5-6
Force Main Design Criteria................................................................................................................5-7
Low Pressure Sewer Design Criteria..................................................................................................5-7
Side Sewer Design Criteria................................................................................................................5-7
LIFT STATION POLICIES AND DESIGN CRITERIA.....................................................................................5-7
OPERATIONAL POLICIES.........................................................................................................................5-8
Facilities Maintenance.......................................................................................................................5-8
Collection System Maintenance........................................................................................................5-8
Temporary and Emergency Services.................................................................................................5-9
Reliabilities........................................................................................................................................5-9
ORGANIZATIONAL POLICIES..................................................................................................................5-9
Staffing..............................................................................................................................................5-9
FINANCIAL POLICIES.............................................................................................................................5-10
General............................................................................................................................................5-10
Connection Charges........................................................................................................................5-12
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6SewerCollectionSystemEvaluation..............................................................................6-1
INTRODUCTION.....................................................................................................................................6-1
COLLECTION SYSTEM ANALYSIS.............................................................................................................6-1
Hydraulic Model................................................................................................................................6-1
Hydraulic Analyses Results................................................................................................................6-2
Other Existing Gravity Collection System Deficiencies......................................................................6-8
LIFT STATION ANALYSIS.......................................................................................................................6-10
Lift Station Capacity.........................................................................................................................6-10
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7ExistingTreatmentFacilitiesAssessment.......................................................................7-1
BACKGROUND........................................................................................................................................7-1
History and Introduction...................................................................................................................7-1
System Overview...............................................................................................................................7-1
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Historical WWTF Performance .......................................................................................................... 7-2
WWTF EXISTING PROCESS UNITS EVALUATION .................................................................................... 7-4
Introduction ....................................................................................................................................... 7-4
Influent Pump Station ....................................................................................................................... 7-4
Headworks ......................................................................................................................................... 7-5
Activated Sludge System ................................................................................................................... 7-7
Sludge Holding, Dewatering, and Disposal ...................................................................................... 7-10
Odor Control System ....................................................................................................................... 7-11
Electrical and SCADA Existing Systems Evaluation .......................................................................... 7-12
COMPOST FACILITY EXISTING SYSTEMS EVALUATION ........................................................................ 7-15
Overview ......................................................................................................................................... 7-15
Condition Assessment ..................................................................................................................... 7-17
Summary of Major Findings ............................................................................................................ 7-18
TREATMENT FACILITIES ASSESSMENT CONCLUSION .......................................................................... 7-18
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8 Treatment Facilities Analysis ......................................................................................... 8-1
INTRODUCTION ..................................................................................................................................... 8-1
MAJOR CONSIDERATIONS FOR WWTF IMPROVEMENTS ...................................................................... 8-1
Growth in Flow and Loading ............................................................................................................. 8-1
Regulatory Changes Nitrogen Reduction ....................................................................................... 8-2
WWTF Site Footprint ......................................................................................................................... 8-3
Age and Condition ............................................................................................................................. 8-5
APPROACH TO WWTF ANALYSES .......................................................................................................... 8-5
ACTIVATED SLUDGE SYSTEM ................................................................................................................. 8-6
Existing Activated Sludge System ...................................................................................................... 8-6
Screening of Nitrogen Treatment Options ...................................................................................... 8-10
Improvements to the Existing Oxidation Ditch System ................................................................... 8-14
Replacement of the Existing Oxidation Ditch System ..................................................................... 8-17
Activated Sludge System Recommendations .................................................................................. 8-20
PRELIMINARY TREATMENT .................................................................................................................. 8-22
Summary of Analysis ....................................................................................................................... 8-22
Recommendations .......................................................................................................................... 8-23
EFFLUENT DISINFECTION ..................................................................................................................... 8-24
Summary of Analysis ....................................................................................................................... 8-24
Recommendations .......................................................................................................................... 8-25
OUTFALL .............................................................................................................................................. 8-25
TERTIARY TREATMENT WATER REUSE/RECLAMATION .................................................................... 8-26
SOLIDS HANDLING ............................................................................................................................... 8-28
On-Site WWTF Solids Handling System ........................................................................................... 8-28
Off-Site Compost Facility ................................................................................................................. 8-30
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City of Port Townsend General Sewer Plan
Table of Contents
ELECTRICAL AND CONTROLS...............................................................................................................8-31
REFERENCES.........................................................................................................................................8-33
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9OperationsandMaintenance........................................................................................9-1
INTRODUCTION.....................................................................................................................................9-1
NORMAL OPERATIONS..........................................................................................................................9-1
City Personnel....................................................................................................................................9-1
Personnel Responsibilities.................................................................................................................9-2
Certification of Personnel..................................................................................................................9-3
Available Equipment.........................................................................................................................9-4
Routine Operations...........................................................................................................................9-4
Continuity of Service.........................................................................................................................9-5
Routine Wastewater Quality Sampling.............................................................................................9-5
EMERGENCY OPERATIONS.....................................................................................................................9-5
Capabilities........................................................................................................................................9-5
PREVENTIVE MAINTENANCE.................................................................................................................9-7
Wastewater Division.........................................................................................................................9-7
STAFFING...............................................................................................................................................9-9
Current Staff......................................................................................................................................9-9
Proposed Staffing..............................................................................................................................9-9
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10CapitalImprovementPlan...........................................................................................10-1
INTRODUCTION...................................................................................................................................10-1
DESCRIPTION OF IMPROVEMENTS......................................................................................................10-2
5-YearSystem Improvements.........................................................................................................10-2
6-to 10-YearSystem Improvements ..............................................................................................10-9
11-to 20-YearSystem Improvements (Long-Term PlanningCapital Improvements)..................10-10
Planning Improvements................................................................................................................10-13
ESTIMATING COSTS OF IMPROVEMENTS..........................................................................................10-13
PRIORITIZING IMPROVEMENTS.........................................................................................................10-15
SCHEDULE OF IMPROVEMENTS.........................................................................................................10-15
Future Project Cost Adjustments..................................................................................................10-15
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11FinancialAnalysis........................................................................................................11-1
INTRODUCTION...................................................................................................................................11-1
FINANCIAL HISTORY.............................................................................................................................11-1
CAPITAL FUNDING RESOURCES...........................................................................................................11-3
Grant and Low-Cost Loan Programs................................................................................................11-3
System Development Charges (SDCs).............................................................................................11-3
Bonds...............................................................................................................................................11-5
CURRENT REVENUE.............................................................................................................................11-5
Financial Policies..............................................................................................................................11-6
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Revenue Requirement ................................................................................................................... 11-12
CURRENT AND PROJECTED SEWER RATES......................................................................................... 11-13
Utility Rate Affordability Analysis .................................................................................................. 11-14
CONCLUSION ..................................................................................................................................... 11-20
TABLES
Table ES-1 Land Use Inside Future Wastewater Service Area .................................................................. E-2
Table ES-2 2021 City Sewer System Data .................................................................................................. E-3
Table ES-3 Gravity Sewer Collection Piping Inventory Diameter ........................................................... E-3
Table ES-4 Force Main Inventory Diameter ........................................................................................... E-4
Table ES-5 Lift Station Characteristics ....................................................................................................... E-4
Table ES-6 WWTF Permitted Flow and Loading Design Criteria ............................................................... E-5
Table ES-7 SWDP SBR Effluent Limits ........................................................................................................ E-6
Table ES-8 SWDP Wetland Effluent Limits ................................................................................................ E-6
Table ES-9 Historical WWTF Influent Flow Summary ............................................................................... E-7
Table ES-10 Historical WWTF Influent BOD Loading Summary ............................................................... E-7
5
Table ES-11 Historical WWTF Influent TSS Loading Summary .................................................................. E-7
Table ES-12 WWTF Peaking Factor Summary for Flows ........................................................................... E-9
Table ES-13 WWTF Peaking Factor Summary for Loadings ...................................................................... E-9
Table ES-14 Total Projected WWTF Flow including Special Study Area Expansion ................................ E-10
Table ES-15 Total Projected WWTF BOD Loading including Special Study Area Expansion .................. E-11
5
Table ES-16 Total Projected WWTF Influent TSS Loading including Special Study Area Expansion ....... E-12
Table ES-17 Proposed CIP Implementation Schedule ............................................................................. E-15
Table 1-1 2021 City Sewer System Data ................................................................................................... 1-2
Table 1-2 Abbreviations ............................................................................................................................ 1-4
Table 2-1 Gravity Sewer Collection Piping Inventory Diameter ............................................................. 2-7
Table 2-2 Gravity Sewer Collection Piping Inventory Material .............................................................. 2-7
Table 2-3 Gravity Sewer Collection Piping Inventory Installation Year .................................................. 2-8
Table 2-4 Force Main Inventory Diameter ............................................................................................. 2-8
Table 2-5 Force Main Inventory Material .............................................................................................. 2-9
Table 2-6 Force Main Inventory Installation Year .................................................................................. 2-9
Table 2-7 Lift Station Characteristics ...................................................................................................... 2-10
Table 2-8 WWTF Permitted Flow and Loading Design Criteria ............................................................... 2-16
Table 2-9 NPDES Permit Effluent Limits .................................................................................................. 2-16
Table 2-10 Comparison of City NPDES Permit and PSNGP Monitoring Requirements for WWTF
Influent ................................................................................................................................. 2-20
Table 2-11 Comparison of City NPDES Permit and PSNGP Monitoring Requirements for WWTF
Effluent ................................................................................................................................. 2-20
Table 2-12 Compost Facility Flow and Loading Design Criteria .............................................................. 2-22
Table 2-13 State Waste Discharge Permit SBR Effluent Limits ............................................................... 2-22
Table 2-14 State Waste Discharge Permit Wetland Effluent Limits ....................................................... 2-22
Table 2-15 Booster Pump Station Facilities Summary ............................................................................ 2-25
Table 2-16 Storage Facilities Summary ................................................................................................... 2-25
Table 3-1 Land Use Inside Future Wastewater Service Area .................................................................... 3-4
Table 3-2 Population Trends within the City Limits .................................................................................. 3-5
Table 3-3 Population Projections .............................................................................................................. 3-6
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Table 4-1 Historical Sewer Connections Summary...................................................................................4-2
Table 4-2 Historical Sewer Service Population.........................................................................................4-3
Table 4-3 Historical WWTF Influent Flow Summary.................................................................................4-4
Table 4-4 Historical WWTF Influent BODLoading Summary...................................................................4-5
5
Table 4-5 Historical WWTF Influent TSS Loading Summary......................................................................4-5
Table 4-6 Peaking Factor Summary for Flows...........................................................................................4-8
Table 4-7 Peaking Factor Summary for Loadings......................................................................................4-9
Table 4-8 Projected WWTF Influent Flow for Sewer System Population Within City Limits..................4-10
Table 4-9 Projected WWTF Influent Flow for Sewer System Special Study AreaExpansion..................4-11
Table 4-10 Total Projected WWTF Flowincluding Special Study Area Expansion..................................4-12
Table 4-11 Historical AAF and PHF Rates by Lift Station.........................................................................4-13
Table 4-12 Existing and Projected AAF and PHF Rates by Basin.............................................................4-14
Table 4-13 Current AAF and PHF Rates and Remaining Capacity by Lift Station....................................4-14
Table 4-14 Projected WWTF Influent BODLoading for Sewer System Population Within City Limits..4-16
5
Table 4-15 Projected WWTF Influent BODLoading for Sewer System Special Study AreaExpansion.4-17
5
Table 4-16 Total Projected WWTF BODLoadingincludingSpecial Study Area Expansion...................4-18
5
Table 4-17 Projected WWTF Influent TSS Loading for Sewer System Population Within City Limits.....4-19
Table 4-18 Projected WWTF Influent TSS Loading for Sewer SystemSpecial Study Area Expansion....4-20
Table 4-19 Total Projected WWTF TSS Loadingincluding Special Study Area Expansion......................4-21
Table 4-20 Summary of Existing and Projected Flow and Loading at the WWTF...................................4-22
Table 7-1 WWTF Performance Based on NPDES Permit Effluent Limits (2019-2022)..............................7-3
Table 7-2 Monthly Nitrogen Sampling Results.........................................................................................7-3
Table 8-1 Projected Influent Flow and Loading........................................................................................8-2
Table 8-2 Original Oxidation Ditch Design Criteria...................................................................................8-6
Table 8-3 Original Facility Design Flow and Load......................................................................................8-7
Table 8-4 Predicted Clarifier SLR for Existing Activated Sludge System at MLSS 2,800 mg/L..................8-8
Table 8-5 Preliminary Treatment Design Criteria from 1990 Project.....................................................8-23
Table 8-6 Disinfection System Design Criteria from 1990 Project..........................................................8-24
Table 8-7 Aerobic Holding Tank Design Criteria from 1990 Project.......................................................8-29
Table 8-8 Dewatering System Design Criteria from 1990 Project..........................................................8-29
Table 9-1 Personnel Certification..............................................................................................................9-3
Table 9-2 Wastewater Division Equipment List........................................................................................9-4
Table 9-3 Utility and Agency Contacts......................................................................................................9-6
Table 10-1 Gravity Sewer Pipe Unit Costs for Open-Cut Construction.................................................10-14
Table 10-2 Gravity Sewer Pipe Unit Costs for Cured-in-Place Pipe.......................................................10-14
Table 10-3 Proposed CIP Implentation Schedule..................................................................................10-17
Table 11-1 Summary of Historical Financial Performance ($000s).........................................................11-2
Table 11-2 Sewer SDC Calculation..........................................................................................................11-4
Table 11-3 Capital Cost Forecast.............................................................................................................11-9
Table 11-4 Capital Funding Strategy.....................................................................................................11-11
Table 11-5 Projected Financial Performance and Revenue Requirements ($000s).............................11-13
Table 11-6 Sewer Rate Forecast............................................................................................................11-14
Table 11-7 Combined Utility Bill Forecast.............................................................................................11-15
Table 11-8 Monthly Utility Bill as a Percentageof Median Household Income...................................11-16
Table 11-9 Rate Affordability Assessment Based on HM and AR.......................................................11-18
20
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Table 11-10 Summary of Rate Burden Evaluation Based on EPA Methodology .................................. 11-19
Table 11-11 Rate Burden Assessment Based on EPA Methodology ..................................................... 11-20
CHARTS
Chart 3-1 Population Projections .............................................................................................................. 3-7
Chart 4-1 2021 Sewer Service Connections by Customer Class ................................................................ 4-2
FIGURES
Figure 2-1 Existing Sewer System
Figure 2-2 Sewer Drainage Basins
Figure 2-3 Sewer Drainage Basins Schematic
Figure 2-4 Pipe Material
Figure 2-5A Known Pipe Age
Figure 2-5B Assumed Pipe Age
Figure 2-6 Wastewater Treatment Facilities in Vicinity
Figure 2-7 Existing Sewer and Water System
Figure 2-8 Topography Map
Figure 3-1 Existing Land Use Map
Figure 3-2 Possible Service Area Expansion
Figure 3-3 Allocation of Future Population by Planning Area
Figure 6-1 CIP SM1
Figure 6-2 CIP SM2
Figure 6-3 CIPs SM3 and SM4
Figure 6-4 CIP SM5
Figure 6-5 CIP SM6
Figure 6-6 CIP SM7
Figure 6-7 CIP SM10
Figure 6-8 Washington Sewer Street with Cracks
Figure 6-9 CIP SM9
Figure 7-1 Existing WWTF Overall Site Plan
Figure 7-2 Existing WWTF Process Schematic
Figure 7-3 Existing Compost Facility Overall Site Plan
Figure 7-4 Existing Compost Facility Process Schematic
Figure 8-1 WWTF and Surrounding Parcels
Figure 8-2 WWTF Site Aerial
Figure 8-3 Existing Oxidation Ditch Configuration
Figure 8-4 Current Operation of Existing Oxidation Ditch with Aerator at Low Speed
Figure 8-5 Conceptual Conversion of Existing Oxidation Ditches to MLE Configuration
Figure 8-6 Conceptual Conversion of Existing Oxidation Ditches to Cyclic Operation
Figure 8-7 Sea Level Rise Projects for 17% Probability of Exceedance including Storm Surge
Figure 8-8 WWTF and Surrounding Parcels
Figure 8-9 Adjacent Parcel Acquisition Considerations
Figure 8-10 Basic Configuration of Expanded WWTF
Figure 8-11 Approximate Outfall Configuration
Figure 9-1 Wastewater Division Organization Chart
Figure 10-1 Capital Improvement Plan Map Collection System
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APPENDICES
Appendix A 2019 Stormwater Management Plan
Appendix B 2012 Mill Road Pump Station and Force Main Predesign Report by CH2M HILL
Appendix C NPDES Permit
Appendix D PSNGP
AppendixE State Waste Discharge Permit
Appendix F SEPA Checklist/DNS and SERP/Affirmed Determination
Appendix G City Wastewater Engineering Standards
Appendix H 2016 to 2021 WWTF Influent Flow and Loading Summaries
Appendix IHydraulic Model Data
Appendix JMill Site Lift Station Sizing Analysis
Appendix K2022 City of Port Townsend Sea Level Rise and Coastal Flooding Risk Assessment
Appendix L2019 Port Townsend Condition Assessment Summary Report by Jacobs
Appendix MCity Resolutions and Ordinances
Appendix NFunding Program Summary
Appendix OPort Townsend Sewer Rate Model
Appendix P Agency Review Correspondence
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EEXECUTIVESUMMARY
PURPOSEOFTHEPLAN
The City of (City) sewer system is a major infrastructure, most of which is
invisible to the customers it serves.The sewer system requires qualified staff to operate and
maintain an ongoing capital improvement planto replace old components to meet the
requirements mandated by federal and state laws.General
SewerPlan (GSP) is to identify and schedule sewer system improvements that correct existing
deficiencies and ensure a safe and reliable sewer system forcurrent and future customers.This
GSP has beenprepared in accordance with Washington Administrative Code (WAC)
173-240-050.
SUMMARYOFKEYELEMENTS
SewerServiceArea,LandUse,andPopulation
The City limits coincide with the Urban Growth Area (UGA) boundary, and encompassan area
ofapproximately 7.4square miles.Approximately 50percent of the land within the City
future wastewater service areais designated for residential use,while the remaining land is
designated for other uses such as open space/parks,commercial use,public/infrastructure use,
and other land uses.TableES-1 presents the land uses within the future wastewater service
area.Chapter 3 provides more information regarding the population projections and
2021population was 10,220people, which is expected to grow to 13,300people by
2043.The are comprised of single-family homes, with
approximately75percent of the housing units being single-family residences.The 2021sewer
service population is estimated at approximately 9,829 people.
population is expected to grow to12,720people in 2033and to 15,242people by 2043. The
residential populationestimate is based on anaverage single-family household size of
1.9persons per householdin the City.
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EXECUTIVE SUMMARYCITY OF PORT TOWNSENDGENERAL SEWER PLAN
Table ES-1
Land Use Inside Future Wastewater Service Area
Mixed Use
Commercial
2.3%
Marine-Related Use
4.6%
1.9%
Public/Infrastructure
3.4%
Undesignated
24.2%
Park/Open Space
13.2%
Residential
50.5%
ExistingFacilitiesandDischargeRegulations
The sewer system includes a gravity collection and conveyance system, sevenwastewater
lift stations, force mains, thewastewater treatment facility (WWTF), a Compost Facility, and an
outfall.A summary of the sewer system characteristics is provided in TableES-2.Chapter 2
gravitycollection and conveyancesystem, lift station, and general WWTF
characteristics.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
Table ES-2
2021 CitySewerSystem Data
Gravity Sewer Collection Piping
14sewerdrainage basins.Approximately
75.2miles of gravity sewer piping,ranging in size from 6 to 30inches,serves the sewer
system customers.As shown in Table ES-3, most of the sewer pipe (approximately 60percent)
within the sewer service area is 8-inchdiameter.
Table ES-3
Gravity Sewer Collection Piping InventoryDiameter
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
The City also has 2.2 miles of force mains. A summary of the force mains by diameter is
provided in Table ES-4.
Table ES-4
Force Main Inventory Diameter
Lift Stations
The City currently owns, operates, and maintains seven wastewater lift stations. The
characteristics of the lift stations are summarized in Table ES-5.
Table ES-5
Lift Station Characteristics
Lift StationPumps
Design
Force Main Design Firm
Diameter No. of Horsepower TDH Capacity Capacity
Year Constructed(inches)PumpsTypeManufacturer(hp)(feet)(gpm)(gpm)
Lift Station Name
1,050
1967 - Constructed
Gaines Street Lift Station63SubmersibleFlygt601072,100
1,050
2022 - Upgrade
1,050
600
1965 - Constructed
Monroe Street Lift Station103Dry PitChicago151,200
600
2008 - Upgrade
600
200
Port Lift Station196762SubmersibleCornell5200
200
100
31st Street Lift Station199642SubmersibleGorman-Rupp3100
100
1985 - Constructed100
Island Vista Lift Station42SubmersibleFlygt6.5100100
2004 - Upgrade
100
1975 - Constructed150
Point Hudson Lift Station42SubmersiblePeabody Barnes1.5150
1988 - Upgrade
150
250
Hamilton Heights Lift Station199762SubmersibleFairBanks Morse1058250
250
Wastewater Treatment and Disposal Facilities
WWTF is located just west of Fort Worden in the North Beach neighborhood. The
WWTF originally was constructed in 1967 and provided primary treatment and disinfection
using chlorine gas. The WWTF was expanded in 1993 to provide secondary treatment.
Raw wastewater enters the WWTF from two gravity sewers, and an influent pump station lifts
the wastewater to the headworks. Within the headworks, a bar screen removes rags and
floating debris, and then a grit classifier settles out the sand and heavy materials. The flow rate
of the screened and de-gritted influent is measured in a Parshall flume and the liquid then flows
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
to the oxidation ditches. In the oxidation ditches, surface mixers stir air into the liquid,
promoting the growth of microbiological cultures that consume thebiochemical oxygen
demand in the mixture and form a solution known as mixed liquor. The mixed liquor flows to
the secondary clarifier, where the biological solids settle out. The clarified effluent flows to the
chlorination basins, where it is chlorinated using liquid sodium hypochlorite. The biological
solids (liquid sludge) produced during secondary clarification are pumped to the small aerobic
digesters for a short stabilization period. The liquid sludge is then pumped to the control
building, where it is blended with polymer and dewatered using a belt filter press.
Descriptions of processes and further details of the WWTF are presented in Chapter 7.
NPDES Regulations and City Permit
The City has aNational Pollutant Discharge Elimination System (NPDES)Permitissued by the
Washington State Department of Ecology (Ecology). The permit includes effluent limits for
in the Strait of Juan de Fuca in Puget Sound. In
addition, the permit includes facility flow and loading design criteria for the WWTF asshown in
Table ES-6.
Table ES-6
WWTF Permitted Flow and Loading Design Criteria
Compost Facility and Solids Handling
The Compost Facility has been successfully operating since 1993.Dewatered biosolids,
dewatered septage,and ground yard waste are composted to produce a product used for soil
conditioning.
biosolids as defined in the federal 40 CFR 503 regulationsand is covered under a State Waste
Discharge Permit (SWDP). The SWDP effluent limits for the sequencing batch reactor (SBR) and
wetlands are shown in Tables ES-7 and ES-8.
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table ES-7
SWDP SBR Effluent Limits
Table ES-8
SWDP Wetland Effluent Limits
Existing Wastewater Flow and Loading
Flow and load values in a sewer system are used to determine the size of gravity collection
piping, lift station facilities, and force main piping, and the size and type of treatment facilities
needed. This information also is NPDES Permit,
which is required by Ecology. Chapter 4 presents the historical and projected WWTF flow and
loading rates.
The total influent flow to the WWTF is made up of wastewater flow from primarily residential
customers but also includes flow from a number of commercial, hospitality, and retail
businesses, schools, and the Jefferson Healthcare Medical Center. The historical 2016 through
2021 influent average annual flow (AAF), maximum month average flow (MMF), and maximum
day flow (MDF) (including infiltration and inflow) is summarized in Table ES-9. The 2021 AAF
was 0.84 million gallons per day (MGD).
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
Table ES-9
Historical WWTFInfluent Flow Summary
Table ES-10 summarizes the historical 5-day biochemical oxygen demand (BOD),and
5
TableES-11 summarizes the historical total suspended solids (TSS) loadings for 2016 through
2021 inpounds per day (ppd) and pounds per capita per day (ppcd).
Table ES-10
Historical WWTF Influent BODLoadingSummary
5
Table ES-11
Historical WWTFInfluent TSSLoadingSummary
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Inflow and Infiltration
Inflow and infiltration is the combination of groundwater and surface water that enters the
sewer system. The U.S. Environmental Protection Agency (EPA) published a report in May 1985,
Infiltration/Inflow, I/I Analysis and Project Certification, that developed guidelines to help
determine what amount of inflow and infiltration (I/I) is considered to be excessive and what
amount can be cost-effectively removed.
Inflow is considered to be non-excessive if the average daily flow during periods of heavy
rainfall or spring thaw does not exceed 275 gallons per capita per day (gpcd). The peak
recorded flow data in the 6 years of data analyzed for the City was 2.37 MGD. This peak inflow
event equates to 243 gpcd, which is below the EPA maximum guideline of 275 gpcd. The City
did no
should continue to monitor inflow throughout the system, particularly in areas over 50 years
old that previously may have been combined collection systems.
The determination of non-excessive infiltration was based on the national average for dry
weather flow of 120 gpcd. In order for the amount of infiltration to be considered
non-excessive, the average daily flow must be less than 120 gpcd. The peak dry weather flow
period in the last 6 years (2016 through 2021) of record for the City, occurring after a few
consecutive days of rain, was the 5-day period from January 22 through January 26, 2016. This
period also was directly preceded by heavy rains, and yielded an average flow of 1.20 MGD,
equating to 128 gpcd. The second highest peak dry weather flow period occurred in February
2018 and yielded an average flow of 124 gpcd. The third highest peak dry weather flow period
occurred during a 14-day period in February 2020, resulting in an average flow of 121 gpcd. All
three events are slightly
of infiltration is considered excessive. The City should continue to monitor infiltration
throughout the system.
Peaking Factors
Projected flows are used to analyze how well the existing sewer system will perform in the
future and determine improvements required to maintain or improve system function. Peaking
factors are needed to establish projected flow scenarios for the sewer system, which are then
applied to future flow rates. Table ES-12 shows a summary of peaking factors for flows at the
WTF for the 2016 through 2021 period.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
Table ES-12
WWTF Peaking Factor Summary for Flows
Peaking factors also are developed to determine maximum month average BODand TSS
5
loading projections, as shown in Table ES-13.These loading peaking factors are the average
historic maximum month to average annual loadings from 2016 to 2019. Data obtained during
the COVID pandemic (2020 and 2021) may not represent normal flow and load conditions.
Table ES-13
WWTF Peaking Factor Summary for Loadings
ProjectedWastewaterFlow
5,683additional persons by 2043using
2018 as the base year.Table ES-14 provides a summary of the projected flows for the WWTF.
According to these projections, the WWTF will not exceed the NPDES permit maximum month
limit capacity during the 20-year planning period. However, the City should evaluate the WWTF
for upgrades when the average MMF exceeds 85percentof the NPDES Permit limit. According
to these projections(based on flow), the City should prepare for WWTF upgrades by 2038.
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table ES-14
Total Projected WWTF Flow including Special Study Area Expansion
Projected Wastewater Quality
Projected BOD and TSS loadings are presented in Tables ES-15 and ES-16. According to these
5
projections, the WWTF will exceed the NPDES Permit maximum month limit capacity for BOD
5
during the 20-year planning period. However, the City should prepare the WWTF for upgrades
when the maximum month average BOD load exceeds 85 percent of the NPDES permit limit.
5
According to these projections (based on BOD load), the City should begin planning and
preparing for WWTF upgrades by 2027. Near-term upgrades will be completed to enable the
City to reach 100-percent capacity. However, the WWTF will not exceed the NPDES Permit
maximum month limit capacity for TSS during the 20-year planning period. The City should
prepare the WWTF for upgrades when the maximum month average TSS load exceeds
85 percent of the NPDES Permit limit. According to these projections, the City should prepare
for WWTF upgrades for TSS by 2041. Capital improvement plan projects for WWTF upgrades
are included in Chapter 10.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
Table ES-15
Total Projected WWTFBODLoadingincluding Special Study Area Expansion
5
Projected Max.
Projected Average
Percent of NPDES
Equivalent Sewer
Month Average
Annual BOD
Permit Max.
System
5
BOD
5
3
1
Population
Month Limit
(ppd)
2
(ppd)
Year
20189,5592,5092,96879%
2019 (Baseline)9,6692,5912,71872%
20209,7572,1472,42265%
20219,8292,2212,50067%
20229,9812,6542,93978%
202310,1342,6842,97379%
202410,2892,7153,00780%
202510,5532,7683,06682%
202610,8192,8213,12583%
202711,0862,8753,18485%
202811,3542,9283,24386%
202911,6242,9823,30388%
203011,8963,0373,36390%
203112,1693,0913,42491%
203212,4443,1463,48593%
2033 (+ 10 years)12,7203,2023,54694%
203412,9273,2433,59296%
203513,1403,2863,63997%
203613,3613,3303,68898%
203713,6033,3783,741100%
203813,8533,4283,797101%
203914,1113,4803,854103%
204014,3793,5333,913104%
204114,6563,5893,975106%
204214,9443,6464,039108%
2043 (+ 20 years)15,2423,7064,105109%
Buildout25,8065,8196,445172%
1 = Projected average annual BOD loadings were estimated by adding City limit and sewer system expansion loadings together.
5
2 = Projected maximum month average BOD loadings were estimated by adding City limit and sewer system expansion loadings
5
together.
3 = The City's WWTF is permitted for a maximum month average influent BOD loading of 3,754 ppd.
5
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table ES-16
Total Projected WWTF Influent TSS Loading including Special Study Area Expansion
Projected Max.
Projected Average
Percent of NPDES
Equivalent Sewer
Month Average
Annual TSS
Permit Max.
System
TSS
3
1
Population
Month Limit
(ppd)
2
(ppd)
Year
2018 (Baseline)9,5592,4932,79961%
20199,6692,4372,68659%
20209,7572,1882,72560%
20219,8292,1462,48154%
20229,9812,5772,86263%
202310,1342,6082,89663%
202410,2892,6392,93064%
202510,5532,6922,98965%
202610,8192,7453,04867%
202711,0862,7983,10768%
202811,3542,8523,16769%
202911,6242,9063,22771%
203011,8962,9603,28772%
203112,1693,0153,34773%
203212,4443,0703,40875%
2033 (+ 10 years)12,7203,1253,47076%
203412,9273,1673,51677%
203513,1403,2093,56378%
203613,3613,2533,61279%
203713,6033,3023,66680%
203813,8533,3523,72181%
203914,1113,4033,77983%
204014,3793,4573,83884%
204114,6563,5133,90085%
204214,9443,5703,96487%
2043 (+ 20 years)15,2423,6304,03088%
Buildout25,8065,7426,376140%
1 = Projected average annual TSS loadings were estimated by adding City limit and sewer system expansion loadings together.
2 = Projected maximum month average TSS loadings were estimated by adding City limit and sewer system expansion loadings
together.
3 = The City's WWTF is permitted for a maximum month average influent TSS loading of 4,568 ppd.
Policies and Design Criteria
The City operates and plans sewer service for the City and associated sewer service area
residents and businesses according to the design criteria, laws, and policies that originate from
the EPA and Ecology.
These laws, design criteria,
The
overall objective is to ensure that the City provides high quality sewer service at a fair and
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CITY OF PORT TOWNSENDGENERAL SEWER PLANEXECUTIVE SUMMARY
reasonable cost to its customers. They also set the standards the City must meet to ensure that
the sewer system is adequate to meet existing and future flows.The collection
to handlethese flows is detailed in Chapter 6,and the recommended improvements are
identified in Chapter 10.The City Council adopts regulations and policies.The policies
cannot be less stringent or in conflict with those established by federal and state governments.
,and operational procedures, many
of which are summarized in Chapter5.
The City will maintain an updated GSPthat is coordinated with the Land Use Element of the
Comprehensive Plan, so that new development will be located where sufficient sewer
system capacity exists or can be efficiently and logically extended.
OperationandMaintenance
Chapter 9 addresses the operation and maintenance (O&M) WTF and
collection system. Currently, there are approximately 8personnelfunded and assigned to the
.
The collection systemand WWTFwill continue to expand with population growth,and the City
will need additional staff to continue maintainingthe gravity sewers, force mains, and lift
stations. For O&Mneeds, the City recommends a total of 2.6 full-time employees (FTEs) for the
wastewater collections. The City also has requested and is planning to add 1.0 FTE for the
WWTF and Compost Facility. This results ina total of approximately 10 FTEs for the O&M of the
SummaryofImprovements
A general description of improvements and an overview of the deficiencies they will resolve are
presented in Chapter 10.Some of the improvements are necessary to resolve existing system
deficiencies.Thesewer system improvements were identified from the results of the collection
system evaluationpresentedin Chapter 6 andthe WWTF and Compost Facilityevaluation
presented in Chapters7 and 8.The sewer system improvements were sized to meet the
projected2043demand conditions.
Collection system improvements to accommodate new growth are not shown in detail in this
CIP. It is assumed that most of the new growth will occur at or near the Mill site. This CIP
includes a liftstation to allow development of the Mill site and conveyance for the new lift
It is intended that this GSP contain an inclusive list of recommended system improvements;
however,additional projects may need to be added or removed from the list as growth occurs
or conditions change.The City will evaluate the capacity of the wastewater collection system,
WWTF, and Compost Facilityas growth occurs and as development permits are received.
Project costs for the proposed improvements were estimated based on costs of similar recently
constructed sewer projects around the Puget Sound area and are presented in 2023dollars.
The cost estimates includethe estimatedconstruction costs and indirect costs.The existing
system improvements were prioritized by the City based on a perceived need for the
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EXECUTIVE SUMMARY CITY OF PORT TOWNSEND GENERAL SEWER PLAN
improvement to be completed prior to projects with fewer deficiencies or less risk of damage
due to failure of the system. A general schedule has been established for planning purposes;
the schedule should be modified based on City preferences, budget, or as development
fluctuates. In addition, the City retains the flexibility to reschedule, expand, or reduce the
projects presented in Table ES-17 when new information becomes available for review and
analysis.
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1|INTRODUCTION
SEWERSYSTEMOWNERSHIPANDMANAGEMENT
The City of Port Townsend (City), located in JeffersonCounty(County), is a municipal
corporation that provides wastewater collection and treatment, among other municipal
services. The City owns, operates, and maintains the sewer system. Ownership information,
,is as follows.
Physical Address:
250 Madison Street, Suite 2R
PortTownsend, WA 98368
Authorized Representative Name and Phone Number: City Manager, John Mauro,
(360)349-5043
Operation and management of the sewer system is provided by thewastewaterdivision of the
with the following contacts:
City Public Works Director, Steve King, (360) 379-5090
Wastewater Treatment and Compost Operations Manager, Bliss Morris, (360) 344-3043
Streets and Collection Operations Manager, Brian Reid, (360) 385-3197
OVERVIEWOFEXISTINGSYSTEM
of a wastewater treatment facility(WWTF), 7 sewer lift
stations, and approximately 77.4 miles of gravity and force main pipes. The City also owns and
operates a Compost Facility for solids from the WWTF, and septage receiving station and
separate WWTF at the Compost Facility. The City provided wastewater collection and
treatment to an estimated9,829peoplein 2021,compared 10,220.
Currently,206propertieswithin the City limits are using on-site septic systems.As of 2021, the
Citywastewaterservice customer connections wasapproximately 4,710
sewer planningarea is the same as itsUrban Growth Area(UGA).
The main WWTF consists of an Influent Pump Station (IPS),headworks, oxidation ditches,
secondary clarifiers, and chlorine contact basins. Waste sludge is captured in theaerobic sludge
holding tanks. The WWTFis permitted for amaximum
month average flow (MMF) of 2.05million gallons per day(MGD).The Compost Facility
septage in a sequencing batch reactor with disinfection and disposal to constructed wetlands
and infiltration.
A summary of theCitysewer system data is provided in Table 1-1.
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CHAPTER 1 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 1-1
2021 City Sewer System Data
AUTHORIZATION AND PURPOSE
The City authorized RH2 Engineering, Inc., (RH2) to prepare a General Sewer Plan (GSP) in
accordance with Washington Administrative Code (WAC) 173-240-050. The previous
Wastewater Comprehensive Plan was prepared by CH2MHILL for the City in 1999 and was
approved by the Washington State Department of Ecology (Ecology) in 2000. In addition, a
Wastewater Facilities Plan was completed in 2000 by Gray & Osborne, Inc., to address Ecology
comments on the Wastewater Comprehensive Plan and focus on major system components
with a capital program.
The purpose of this updated GSP is as follows:
the future population and employment
Planning and Community Development Department.
To evaluate existing sewer flow and loading data and project future flows and loadings.
To analyze the existing sewer system to determine if it meets minimum requirements
mandated by Ecology
To determine the overall reliability and vulnerability of the existing wastewater lift
stations.
To evaluate the existing WWTF to determine if the treatment facility meets
National Pollutant Discharge Elimination System Permit requirements.
To identify sewer system collection improvements that will resolve existing system
deficiencies and accommodate future needs of the system.
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CITY OF PORT TOWNSENDGENERAL SEWERPLANINTRODUCTION
To identify WWTFimprovements that will resolve existing system deficiencies and
accommodate future wastewater treatment needs.
To prepare a schedule of improvements that meets the
program.
PREVIOUSPLANNINGEFFORTS
sewer
system.
1999 Wastewater Comprehensive Plan
2000 Wastewater Facilities Plan
2009 Southwest Sewer Basin Study
2012 Mill Road Pump Station and Force Main Predesign Report
2019 Port Townsend Condition Assessment Summary Report
SUMMARYOFPLANCONTENTS
A brief summary of the content of the chapters in this GSP is as follows:
Chapter 1 introduces the reader to the sewersystem, the objectives of the GSP,
and the GSP organization.
Chapter 2 presents the sewerservice area and describes the existing sewer system.
Chapter 3 presents related plans, land use,and population characteristics.
Chapter 4 identifies existing wastewater flowand loadingrates and projects futureflow
and loadingrates.
Chapter 5
Chapter 6 discusses the wastewater collectionsystem analyses and deficiencies.
Chapter 7 discusses the existing WWTFandCompost Facilityanalyses and deficiencies.
Chapter 8 evaluates future improvement needsfortheWWTF and Compost Facility to
address existing and projected deficiencies.
Chapter 9 discussesthe
Chapter 10 presents the proposed Capital Improvement Plan (CIP),including
wastewater collection system,WWTF, and Compost Facilityimprovements, their
estimated costs, and a schedule for implementation.
Chapter11 summarizes the financial status of the sewer utilityand presents a plan for
funding the sewer improvements.
LISTOFABBREVIATIONS
The abbreviations listed in Table 1-2 are used throughout this GSP.
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CHAPTER 1 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 1-2
Abbreviations
Description
Abbreviation
AACEAssociation of Cost Engineers
AAFaverage annual flow
ACasbestos cement
AKARTall known, available, and reasonable treatment
BOD
5-day biochemical oxygen demand
5
CIcast iron
CIPCapital Improvement Plan
CIPPcured-in-place pipe
CityCity of Port Townsend
CountyJefferson County
CWAClean Water Act
DIductile iron
DMRDischarge Monitoring Report
EcologyWashington State Department of Ecology
EPAU.S. Environmental Protection Agency
FRPfiberglass reinforced plastic
FTEfull-time staff equivalents
GMAGrowth Management Act
gpcdgallons per capita per day
GSPGeneral Sewer Plan
HDPEhigh-density polyethylene
IFASintegrated fixed film activated sludge
I/IInflow and Infiltration
IPSInfluent Pump Station
LAMIRDlocal area of more intense rural development
lflinear feet
LIDLocal Improvement District
MABRmembrane aeration biofilm reactors
MCCMotor Control Center
MDFmaximum day flow
MGmillion gallons
MGDmillion gallons per day
mg/Lmilligrams per liter
MLEModified Ludzach-Ettinger
MLSSmixed liquor suspended solids
MMDFmaximum month design flow
MMFmaximum month average flow
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CITY OF PORT TOWNSENDGENERAL SEWERPLANINTRODUCTION
Table 1-2
Abbreviations (Continued)
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|
2SEWERSYSTEMDESCRIPTIONANDDISCHARGE
REGULATIONS
INTRODUCTION
This chapter describes the City of (City)sewerservice area, wastewater
collection and treatment system,liftstations, and discharge and disposal regulations and
permits.
climate to provide a better understanding of the physical characteristics of the City. A brief
so is presented.
Analysis of the existing sewer system ispresented in Chapter 4. The results of the evaluation
and analyses of the existing sewersystem arepresented in Chapter 6.Evaluation of the existing
treatment facilitiesis presented in Chapter 7. Improvements to address treatment facility
deficiencies are presented in Chapter 8.
SEWERSERVICEAREA
History
The City's sewer system was originally constructed as combined wastewater and stormwater
sewers serving each small drainage area. There was no requirement for treatment of this
combined sewage, so there were many outfalls to Port Townsend Bay and Admiralty Inlet.
In the 1960s, the City responded to new Washington State requirements to provide primary
treatment for all combined sewage. Interceptors, lift stations, and the Citys first wastewater
treatment facility were constructed and placed in service, and the existing outfall was extended
in 1967.
In the early 1970s, the Federal Government established new standards requiring higher levels
of treatment for municipal wastewater. For most cities, including Port Townsend, these higher
standards meant that additional (secondary) treatment facilities would be required.
In 1976, the City completed a Wastewater Facilities Plan under the guidelines issued by the U.S.
Environmental Protection Agency. The plan evaluated the requirements to upgrade the facility
to secondary treatment and was approved by the Washington State Department of Ecology
(Ecology). The plan recommended adding sludge dewatering facilities and an oxidation ditch for
secondary treatment and conversion to secondary clarifiers. Upon completion of the plan, the
City applied for funding from Ecology to implement the plan. Ecology did not assist the Citywith
funding at that time;therefore,no improvements were made.
In 1982 and 1983, the City prepared and submitted an Application for Modification of
Secondary Treatment Requirements for Discharge into Marine Waters, as allowed under
Section 301(h) of the Clean Water Act. The waiver of secondary treatment was denied by state
and federal agencies.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
The City later entered into a consent agreement with Ecology to have secondary treatment
facilities operational by 1993. In 1987, engineering for upgrading the wastewater treatment
facility (WWTF) to secondary treatment began. In 1989 and 1990, several permit issues
surfaced and a citizens group filed an action against the City to stop construction. The City and
the citizens group worked cooperatively to resolve the permit issues through design changes.
The City commenced construction, and the new secondary wastewater treatment facility was
installed at the same site as the original plant. The new facility began service in July of 1993.
The City originally disposed of the biosolids produced by the WWTF at the Jefferson County
(County) landfill until 1991 when the landfill was closed. Biosolids were then hauled to
Bremerton as an interim biosolids disposal method. The City explored a number of alternative
methods for disposal of the generated biosolids and septage, ranging from forest application
and incineration to lime and kiln dust stabilization. After a detailed analysis and substantial
public involvement, composting was chosen as the preferred approach to biosolids
management. The Compost Facility has been successfully operating since 1993. Dewatered
biosolids, dewatered septage, and yard waste are composted to produce a product used for soil
conditioning. The finished compost meets federal 40 CFR 503 regulations for a class A product
and is thus allowed for unrestricted use.
The City has been growing steadily since the original interceptors, lift stations, and WWTF were
constructed in 1967. Since that time, improvements to the collection system have consisted of
regular maintenance and repair activities at the lift stations and expansion of the collection
system to serve unsewered areas. Most of the collection system improvements identified in the
2000 Wastewater Facilities Plan have been completed. The work performed over the last
20 years was funded through loan and grant contributions, along with sewer rates. Figure 2-1
shows the extents of the sewer collection system.
Geology
The soils in the Port Townsend area are primarily of the Clallam-Hoypus-Dick association, which
are composed of gravel, loam, and sand. These soils vary from 20 to 60 inches in depth, and
most areas are well drained. Compact gravelly sand and glacial till underlie these soils. Till is a
deposit of unsorted material that has been densely compacted under the weight of a glacier.
The service area has undergone repeated glacial advances and retreats until as recently
as 10,000 years ago. Glacial till is relatively impermeable and is the cause of many on-site septic
system problems over the years. There are many small, isolated areas across the City where the
glacial till is exposed and the soils are poorly drained. Drainage in these areas is problematic
with many perched, wet areas that further complicate the application of on-site septic systems.
Topography
Figures 2-2 and 2-8 show the topography and natural drainage basins with the City limits. The
City has several high hills and steep bluffs, and elevations range from sea level to just over
300 feet. The undulating topography creates many isolated areas of low spots. These areas can
be challenging to sewer with gravity mains, but in general, the large amount of relief over the
City allows many sewers to be placed at steeper than minimum grades, reducing required
sewer sizes and the required time for wastewater to get to the treatment facility.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
Unfortunately, there are several areas that drain naturally to local low points away from the
WWTF, where lift stations already exist or may be necessary in the future to provide sewer
service to those areas.
Climate
The northern end of the Quimper Peninsula, where the City is located, does not typically
receive heavy precipitation common in other parts of the Olympic Peninsula and Puget Sound
lowlands. The City lies in the rain shadow of the Olympic Mountains. As a result, the City
receivesrelatively little precipitation in the summer months when prevailing winds are from the
west. T
maximum precipitation are approximately 12 inches and 27 inches, respectively. Average daily
minimum and maximum precipitation rangesfrom approximately 0.4 to 0.8 inches per day,
respectively.
Sea Level Rise
The City and the County joined forces to develop a Climate Action Committee. This committee
has worked diligently to develop several reports and studies associated with the following:
Modeling County carbon dioxide equivalent emissions with the goal of reducing and
measuring greenhouse gas emissions produced in the County overtime.
Addressing the need to adapt to climate change in terms of impacts to weather patterns
and the hydrology of the area.
Addressing the impacts of Sea Level Rise and developing forecastingtools to assess the
impacts of Sea Level Rise on City infrastructure.
The City of Port Townsend Sea Level Rise and Coastal Flooding Risk Assessment (2022, Cityof
Port Townsendand Cascadia Consulting Group) (Appendix K)incorporates the best available
science and information concerning climate change, and specifically Sea L
these facilities incorporates this understanding,with the long-term goal of moving or
transitioning sewer facilities to become more resilient to Sea Level Rise. The City already has
experienced impacts of king tides, with one of the largest king tides occurring on
December27,2022. This king tide event flooded a portion of the Port of Port Townsend Boat
Haven Marina boat yard and contributed to the collapse of an asbestos cement (AC) gravity
sewer pipe, which settled due toahigh water table caused by the king tide and the backup of
water i
damage, but this event illustrates how close the City is to experiencing the effects of Sea Level
Rise combined with a king tide event.
WaterBodiesandFloodplains
The City is bounded by the Salish Sea with Port Townsend Bay to the south, Admiralty Inlet to
the east, and the Strait of Juan de Fuca to the north. The natural drainage basins within the
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
sewer service area drain primarily to the sea, Kah Tai Lagoon, or Chinese Gardens Lagoon.
These natural drainage basins are shown in a 2019 Stormwater
Management Plan in Appendix A. Both the Kah Tai and the Chinese Gardens Lagoons are
somewhat tidally influenced through pipe connections to the Salish Sea. There are no rivers or
streams located within the City limits, although there are a number of small, natural ponds or
depressions throughout the area, as well as several wetlands. The 2019 Stormwater
Management Plan addresses how surface water is dealt with within the City. A map of the
existing stormwater facilities is presented in Appendix A.
A small portion of the City is located within the 100-year floodplain along its marine shorelines,
including the Point Hudson and Boat Haven, Kah Tai Lagoon, and the
Lincoln Beach area. Furthermore, there are several small wetlands and riparian areas
throughout the City. These sensitive areas and steep slopes limit the buildable area.
Given the City is surrounded by the Salish Sea, the City coordinates with the County Marine
to the Salish Sea and/or the impacts of the sea on the operations and development of the
sewer system.
City Limits, Urban Growth Area, and Sewer Service Area Boundary
The sewer service area coincides with the Urban Growth Area (UGA) boundary, which is also
the City limits, and encompasses an area of approximately 7.4 square miles. The majority of the
developed area within the City limits is currently served by
Within the sewer service area, approximately 5 percent of residences are served by privately
owned and operated on-site sewage systems (i.e. septic tanks with drain fields). Currently,
211 properties within the City limits are on on-site systems. planning area
(i.e. future sewer service area) includes (Figure 2-1).
The Glen Cove area directly adjacent and southwest of the City limits has been designated as a
Special Study Area for possible future inclusion in the . The primary basis for
allowing this area to be incorporated into the City sewer service area is based on the following
factors:
1. The Glen Cove industrial area is a Type 3 Local Area of More Intense Rural Development
(LAMIRD) intended for light industrial and limited commercial use that could benefit
from the presence of sewer. Currently, all uses in this area are required to have an
on-site septic system, which may be limiting industrial activities and potentially resulting
in environmental degradation. LAMIRDs are permitted to be served by sanitary sewer
per the Growth Management Act (Washington Administrative Code (WAC)
365-196-425(6)(c), Rural Element).
2. In this area, the Port Townsend Paper Mill currently has an industrial waste treatment
system and a domestic waste treatment system, both of which discharge to Port
Townsend Bay. The City may consider allowing the domestic system to connect to the
the environmental benefit of eliminating a discharge to Port
Townsend Bay. This option would need to be approved by Ecology and the Department
of Commerce before executing a sewer service agreement for the Paper Mill.
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3.Through a UGAexpansion or swap in cooperation withthe County. Based on existing,
more intense development patterns,the Glen Cove Area may be deemed a key area to
serve existing and future uses to support the local economy given the lack of industrially
zoned properties and the need for housing within the City.An additional 20-acre parcel
directly adjacent to the City is owned by theCounty and is serving as a homeless
shelter.This parcel serves key public needs of providing for the poor and infirm.Sewer
service to this property may be of great benefit to the community and may serve as a
basis for a UGA expansion.
4.A portion of the area within the Glen Cove drainage basin is already in the City limits and
does not have access to sewer without the installation of a sewer lift station. Therefore,
locating a sewer lift station in an appropriate area that keeps options open will allow the
City to make sewer service available for unsewered areas within the City limits while
allowingFactors 1 through 3 above to be considered.
All fourof these factorsinvolve the City and County working closely together to evaluate
impacts of sewer extension.The purpose of the Special Study Area is to document the sewer
basin planning process performed in 2012 as outlined in the Mill Road Pump Station and Force
Main Predesign Report(Appendix B).The City has funding to site a lift station in the Mill Road
area to serve the current UGA. Siting of this lift station, whichcould serve as described above,is
an important consideration for this Special Study Area to guide public investment of
approximately $4 million.
This General Sewer Plan(GSP) will address service needs in the Glen Cove Areaandaccount for
inclusion in the UGA.
EXISTINGSEWERFACILITIES
The City owns, operates,and maintains the wastewater system,which includes a gravity
collectionand conveyancesystem, sevenwastewater liftstations, force mains, a WWTF,and an
outfall.
SewerDrainageBasins
The existing sewer service area is comprised of14sewer drainage basinsthat flow by
gravity to the 7 lift stations and WWTF, as shown in Figure2-2.
The wastewater from the eastern part of the City is conveyed by the Point Hudson Lift Station
andthe Monroe Lift Station,where flow is then conveyed to the Gaines Street Lift Station
before traveling by gravity main to .In other words, all of the sewer flow from
uptown, downtown, and the eastern shoreline is routed through the Gaines Street Lift Station.
Southern flows from the Port Lift Station also are conveyedto the Gaines Street Lift Station
.Wastewater from the western portion of the City isconveyed
st
to the Hamilton Heights Lift Station and the 31Street Lift Station,which both then route
wastewater flows by gravity to the WWTF.A small portion of wastewater in the southwestern
portion of the Cityissent to the Island Vista Lift Station,where itthen flowsby gravity to the
WWTF. All other wastewater collected in the City flows via gravity to the WWTF,where it is
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
pumped to the outfall. Figure 2-3 shows a schematic representation of the general location and
flow path for each of the primary sewer drainage basins.
Figure 2-3
Sewer Drainage Basins Schematic
Gravity Sewer Collection Piping
The City has 75.2 miles of gravity sewer piping, including collection sewers and interceptors and
treated effluent sewers from the WWTF. A majority of the system is 8-inch-diameter gravity
main, totaling 45.3 miles. The predominant material used in the system, accounting for
approximately 54 percent of gravity piping, is polyvinyl chloride (PVC).
Approximately 72 . Assumptions of
pipe ages based upon the material were made in an effort to determine the general age of the
collection system piping. AC was a popular material in sewer pipe construction between the
years of 1950 and 1970. A median installation year of 1960 was assumed for AC pipe where the
actual year is unknown. Both cast iron (CI) and vitrified clay (VC) were materials used primarily
before the 1950s. Ductile iron (DI) and high-density polyethylene (HDPE) use rises in popularity
in 1980 and is still used in present day, although largely for deep sewer pipe construction. A
median installation year of 2000 was assumed for DI and HDPE pipe where the actual year is
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unknown. Reinforced concrete pipe (RCP) is another older material where the use ranged from
1940 to 1960. A median installation year of 1950 was assumed for RCPpipe where the actual
year is unknown.
Table 2-1 summarizes the sewer system pipe by diameter, Table 2-2 summarizes the pipe by
material, and Table 2-3 summarizes the pipe by installation year. Figure2-1 illustrates pipe
sizesand locations,and Figure 2-4 illustrates pipe material.Figure 2-5(a)illustrates the pipe
installation year with the known information. Figure 2-5(b)illustrates the assumed pipe
installation year based upon known information and pipe material, as described previously.
Table 2-1
Gravity Sewer Collection Piping InventoryDiameter
Table 2-2
Gravity Sewer Collection Piping Inventory Material
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Table 2-3
Gravity Sewer Collection Piping Inventory Installation Year
Force Mains
The City has approximately 2.2 miles of force mains. Table 2-4 summarizes the force mains by
diameter, Table 2-5 summarizes the force mains by material, and Table 2-6 summarizes the
force mains by installation year. Figure 2-1 illustrates the force main locations.
Approximately 41 percent of the force main installation years are unknown. Assumptions of the
pipe ages based upon the material were made in an effort to determine the general age of the
collection system piping.
Table 2-4
Force Main Inventory Diameter
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Table 2-5
Force Main Inventory Material
Table 2-6
Force Main Inventory Installation Year
LiftStations
The City currently owns,operates,and maintainssevenwastewater liftstations.The
characteristics of the liftstationsaresummarized in Table 2-7, and a description of each lift
station follows.
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Table 2-7
Lift Station Characteristics
Gaines Street Lift Station
The Gaines Street Lift Station was originally constructed
in 1967, and the pumps were upgraded in 2022. The
station is located at 201 Gaines Street and is equipped
with three 60 horsepower (hp) Flygt submersible pumps.
The station has a firm design capacity of 2,100 gallons
per minute (gpm) and is a conventional wet well/dry well
station. The Gaines Street Lift Station collects
wastewater from its sewer basin along with wastewater
from the Port, Monroe Street, and Port Hudson Lift
Gaines Street Lift Station
Stations in the southeastern portion of the system and
conveys it through the gravity collection system to the WWTF. Back-up power is provided by a
generator. The lift station is connected by radio communication supervisory
control and data acquisition (SCADA) system.
Monroe Street Lift Station
The Monroe Street Lift Station, last upgraded in 2008,
pumps wastewater from the gravity collection system to
the Gaines Street Lift Station. The Monroe Street Lift
Station is equipped with three 15 hp Chicago dry pit
pumps that discharge into a 10-inch-diameter force
main. The lift station is connected by radio
communication SCADA system. The lift
station has a hookup for a temporary generator, and
response time is less than 30 minutes to connect power.
The City is alerted when power is out by the SCADA
Monroe Street Lift Station
system, and this is the first lift station responded to.
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Port Lift Station
The Port Lift Station is located in the Port Townsend Boat
Haven Marina. Constructed in 1967, this submersible
stationis equipped with two5hp Cornellpumps and has
a design firm pumping capacity of 200gpm. All
wastewater from the Port Lift Stationis pumped to the
Gaines Street Lift Station through a 6-inch-diameter force
mainbefore being conveyed to the WWTF. The lift station
is connected by radio communication SCADA
system. The lift station has a hookup for a temporary
generator, and staff generally have around 60 minutes to
Port LiftStation
connect power. The City is alerted when power is out by
the SCADA system, and this is the second lift station responded to.
st
31Street Lift Station
st
The 31Street Lift Station wasconstructed in 1996and is located
st
at 1920 31Street. This submersible lift station is equipped with
two 3hp Gorman-Ruppsubmersible pumpsthatdischarge into a
st
4-inch-diameter force main. The designcapacity of the 31Street
Lift Stationis 100gpm. Wastewater from the lift station mostly
consists of infiltration and inflow and is conveyed via gravity mains
The lift station is connected by radio to the
st
SCADA system. The 31Street Lift Station has a hookup for a
temporary generator. The City is alerted when power is out by the
SCADA system, and operators generally pump this out once or
twice in 24 hours.
st
31Street Lift Station
Island Vista LiftStation
The Island Vista Lift Stationis located at 112 Vista Boulevard, was
constructed in 1985,and was upgraded in 2004. This submersible
station collects wastewater and pumps it throughthe gravity
collection system to the WWTF.The lift station consists of two
Flygt submersible pumps that are each 6.5 hp with 100 gpm
capacity. The lift station is connected by radio
system. This lift station has a hookup for a temporary generator.
The City is alerted when power is out by the SCADA system, and
operators generally pump this out once or twice in 24 hours.
Island Vista Lift Station
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Point Hudson Lift Station
Originally constructed in 1967, the Point Hudson Lift Station was
most recently upgraded in 1988. The Point Hudson Lift Station
collects wastewater that is conveyed to the Monroe Street Lift
Station before flowing to the Gaines Street Lift Station and
This submersible lift station has
two 1.5 hp Peabody Barnes pumps that have a capacity of
150
SCADA system. The Point Hudson Lift Station has a hookup for a
temporary generator. The City is alerted when power is out by
the SCADA system, and operators generally pump this out once
or twice in 24 hours.
Point Hudson Lift Station
Hamilton Heights Lift Station
The Hamilton Heights Lift Station is located near
2500 Howard Street and was constructed in 1997. This
submersible lift station consists of two 10 hp FairBanks
Morse pumps and has a design capacity of 250 gpm.
Wastewater from this lift station is conveyed through a
6-inch force main before flowing by gravity main to the
The lift station is connected by radio to the
The Hamilton Heights Lift Station
has a permanent backup generator.
Hamilton Heights Lift Station
Low Pressure Sewer Systems
The City has permitted a small number of low pressure sewers over the last 20 years. Low
pressure sewers consist of a private single pump lift station located at a residential structure
with a small force main that ultimately connects to gravity sewer. Often, multiple private
pumps will discharge into a shared private force main as illustrated in the schematic that
follows.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
Shared force
main
Private grinder sewer
pump system
Private lateral
Low Pressure Sewer System Schematic. Image credit: Environmental One website.
Historically, the City has only allowed low pressure sewers if they were entirely privately
maintained, including the force main. The City generally discouraged this approach to sewer
service as technology was still under scrutiny and private ownership of pump stations was
considered problematic due to pump failures and the inability to quickly fix the problem. Failure
of private pumps also leads to sewer overflows. Manycities have not taken on ownership of
these private pumps due to the massive impact on city maintenance costs given the pumps
were considered unreliable.
The technology and reliability of low pressure sewer pump systems has improved considerably
and now failures of the pump systems are rare. Many municipalities are now embracing the
application of low pressure sewers in areas that are hard to serve due to undulating topography
where gravity sewer is not feasible.
This GSPsuggests there are areas within the City that would benefit greatly from the
installation of low pressure sewer pump systems. Recommended standards for low pressure
sewers are included in Chapter 5.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Wastewater Treatment and Disposal Facilities
Existing System
WWTF is located just west of Fort Worden in
the North Beach neighborhood. The WWTF was
originally constructed in 1967 and provided only primary
treatment and disinfection using chlorine gas. The facility
was expanded in 1993 to provide secondary treatment.
Raw wastewater enters the WWTF from two gravity
sewers, and an influent pump station lifts the
wastewater to the headworks. Within the headworks, a
bar screen removes rags and floating debris, and then a
grit classifier settles out the sand and heavy materials.
WWTF Oxidation Ditches
The flow rate of the screened and de-gritted influent is
measured in a Parshall flume and the liquid then flows to
the oxidation ditches. In the oxidation ditches, surface
mixers stir air into the liquid, promoting the growth of
microbiological cultures that consume the biochemical
oxygen demand (BOD) in the mixture and form a solution
known as mixed liquor. The mixed liquor flows to the
secondary clarifier, where the biological solids settle out.
The clarified effluent flows to the chlorination basins,
where it is chlorinated using liquid sodium hypochlorite.
Effluent is retained in the chlorine contact chambers for
WWTF Chlorine Pumping Room
at least 20 minutes to ensure complete disinfection.
The biological solids (liquid sludge) produced during secondary clarification are pumped to the
small aerobic digesters for a short stabilization period. The liquid sludge is then pumped to the
control building, where it is blended with polymer and dewatered using a belt filter press.
Treated Wastewater Discharge and Solids Handling
WWWTF, resulting in treated water
and digested sludge. The treated effluent is dechlorinated using liquid sodium bisulfite and
discharged to the Strait of Juan de Fuca via a 2,300-foot-long, 18-inch-diameter pipeline and
outfall ending 700 feet offshore.
The dewatered sludge is Compost Facility at the
Jefferson County Waste Management Facility site. Sludge from the WWTF is composted at the
facility in combination with dewatered septage, yard waste, and other wood wastes. Liquids
from the process are treated in a sequencing
batch reactor and constructed wetlands and discharged to infiltration basins for additional
treatment and ultimate disposal.
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DISCHARGEANDDISPOSALREGULATIONSANDPERMITS
WWTFNPDESPermitandRegulations
Fand treated plant effluent water discharged
to the StraitNational Pollutant
Discharge Elimination System (NPDES)Permit.
The federal Clean Water Act (CWA, 1972, and later modifications, 1977, 1981, and 1987)
established water quality goals for the navigable (surface) waters of the United States:
objective of the CWA is the restoration and maintenance of the chemical, physical, and
define the waterquality standards (within the limits set by the water quality goals) within its
jurisdiction and enforce them. Water quality standards for surface waters in Washington State
have been established (Chapter 173-201A WAC) and are enforced by Ecology(Chapter90.48
Revised Code of Washington (RCW)). The purpose of the water quality standards is to provide
state is identified as fresh water or marine
water and designated for one or more uses, which then determines the specific water quality
standards that apply to that water.
The state also has established a permit program for implementation of the NPDES Permit
Programcreated by the CWA. The program requires a discharge permit for any point source,
such as a domestic wastewater treatment plant, and discharge of pollutants to surface waters
of the state for the purpose of maintaining the water quality standards. Each permit is renewed
on roughly a 5-year cycle. The permit and accompanying fact sheet include information on
discharge limits, monitoring schedules, and general and special conditions that apply to the
applicable point source.
Thecurrent NPDES Permit (Permit No.WA0037052) has an effective date of
December1,2015, and expired onNovember 30, 2020.The WWTFcontinues to operate under
this permit as Ecology is currently reviewing and has not issued a revised NPDES permit since
the expiration date.Copies of the permit and accompanying fact sheet are included as
Appendix C.
Facility Design Criteria
The permitted facility flow and loading design criteria for the WWTFare included in Table 2-8.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 2-8
WWTF Permitted Flow and Loading Design Criteria
Effluent Limits
Treated plant effluent water is discharged to the Strait of Juan de Fuca through a piped outfall,
which is designated as Outfall No. 001 in the NPDES Permit. The effluent limits for Outfall
No. 001 are summarized in Table 2-9.
Table 2-9
NPDES Permit Effluent Limits
ParameterAverage MonthlyAverage Weekly
30 mg/L
45 mg/L
Biochemical Oxygen Demand (5-Day) (BOD) 513 ppd
5
769 ppd
85% removal of influent BOD
5
30 mg/L
45 mg/L
Total Suspended Solids (TSS)513 ppd
769 ppd
85% removal of influent TSS
Total Residual Chlorine0.5 mg/L0.75 mg/L
ParameterMinimumMaximum
pH6.0 standard units9.0 standard units
ParameterMonthly Geometric MeanWeekly Geometric Mean
Fecal Coliform Bacteria200/100 mL400/100 mL
mg/L = milligrams per liter
mL = milliliters
Future City NPDES Permit Effluent Limits (Outfall No. 001) Changes
Ecology can change water quality standards or NPDES Permit effluent limits (the latter for the
purpose of maintaining water quality standards). Known future changes to water quality
standards and NPDES Permit effluent limits that are applicable to Outfall No. 001 at the WWTF
are summarized in this section.
Bacterial Indicator Effluent Limits
The receiving water of the Strait of Juan de Fuca at Outfall No. 001 is designated for Primary
Contact Recreational Use (WAC 173-201A-612, Table 612). To protect water contact recreation
in marine water, such as the receiving water, bacterial indicator criteria (standards) are defined
(WAC 173-201A-210(3)(b)). Ecology is reviewing adding an E. coli standard in future permits.
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The E. coli and fecal coliform bacterial indicator criteria are both defined in the current version
of WAC 173-201A-210(3)(b).
mit for Outfall No. 001. An E. coli
bacteria effluent limit for Outfall No. 001 will be evaluated and further monitoring will be
required when the permit is renewed. As Ecology continues to review, the current fecal
coliform bacteria effluent limit will remain effective.
OtherRegulationsandRequiredPermits
WWTF Puget Sound Nutrient General Permit
Section 303(d) of the CWA establishes a process to identify and cleanup surface waters that do
not meet the applicable water quality standards. Everyfew years, Ecology performs a water
quality assessment using collected data to determine whether water quality of the surface
waters meetsthe standards. Based on the assessment, each surface water is placed into one of
five categories that describesthe status of the water quality and rangesfrom meeting the
standards (Category 1) to impaired (i.e. polluted) and requiring a water improvement project
(Category 5). Surface waters placed into Category 5 are listed on the s
polluted waters, which is named after the referenced section of the CWA.
At certain times of the year, dissolved oxygen levels in a large number of locations throughout
Puget Sound do not meet the applicable water quality standards, and in many other locations
show evidence of not meeting the standards in the future. The surface waters within Puget
Sound that are not meeting thedissolved oxygen standards are listed in the s
Ecology initiated the Puget Sound Nutrient Reduction Project (Project) in the spring of 2017 to
address the problem of human sources of nutrients contributing to the low and decreasing
dissolved oxygen levels throughout Puget Sound. As a result of modeling, Ecology believes
discharges of nutrients to Puget Sound from domestic wastewater treatment plants are
significantly contributing to the problem. The goal of the Project is to develop a nutrient source
reduction strategy, which includes reducing nutrient levels discharged from domestic
wastewater treatment plants.
Ecology has been utilizing a model of Puget Sound to understand the problem and simulate
potential improvements. Ecology has identified nitrogen as the limiting nutrient, with inorganic
nitrogen, consisting of nitrate-rm. Ecology
is performing additional modeling for optimization scenarios; however, results from completed
modeling are being used to determine effluent nitrogen permit limits fordomestic wastewater
treatment plants with outfalls to Puget Sound (identifiedas marine sources), which includes the
F.Individual NPDES permits for the same treatment plants will continue
independently of, but in conjunction with, the general permit and may be modified as
necessary to include facility-specific nutrient-related requirements.
In January 2021, Ecology released a preliminary draft of the Puget Sound Nutrient General
Permit (PSNGP) for public comment. The public comment period ended on March 15, 2021, and
Ecology has proceeded with developing a formal version,which became effective January 1,
2022,and expires December 31, 2026. Copies of the final PSNGP (Permit No. WAG994538) and
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
accompanying fact sheet are included as Appendix D. The following descriptions summarize the
final PSNGP, including anticipated permit limits specific F.
Notice of Intent
The City has filed a Notice of Intent for coverage under the PSNGP and will submit Discharge
Monitoring Reports (DMRs) as required by the permit and as discussed as follows.
Nitrogen Optimization Requirements
The City must submit an annual Nitrogen Optimization Plan (NOP) to Ecology no later than
March 31, 2026, as defined in the PSNGP. Optimization refers to short-term actions (low-cost
controls and process changes) focused on improving existing performance. Optimization
processes do not include large scale capital investments. The City must begin optimization
immediately upon coverage under the PSNGP.
The NOP must include the following components:
1. Treatment Process Performance Assessment
Assess the nitrogen removal potential of the current treatment process and have the
ability to evaluate optimization strategies prior to implementation.
a. Evaluation. Develop a treatment process assessment method for the purposes of
evaluating optimization approaches during the permit term. This will include an
evaluation of current (pre-optimization) process performance to determine the
empirical Total Inorganic Nitrogen (TIN) removal rate for the WWTF. The assessment
must include an evaluation of possible optimization strategies at the WWTF prior to
and after implementation. Determine the optimization goal for the WWTF and
develop a list of optimization strategies capable of achieving the optimization goal
for the WWTF. Update this list as necessary to continuously maintain a selection of
strategies for achieving each optimization goal identified. Any optimization strategy
may be excluded from the initial selection if it is found to exceed a reasonable
implementation cost or timeframe. Documentation must be provided that includes
an explanation of the rationale and financial criteria used for the exclusion
determination.
b. Initial Selection. Identify the optimization strategy selected for implementation.
Document the expected percentage of TIN removal (or the expected reduction in
effluent load) for the optimization strategy prior to implementation.
2. Optimization Implementation
The City must document implementation of the selected optimization strategy, which
includes the following:
a. Strategy Implementation. Describe how the selected strategy was implemented
during the reporting period, initial implementation costs, length of time to
implement (including start date), anticipated and unanticipated challenges, and
impacts to the overall treatment performance due to optimization process changes.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
b.Load Evaluation. The City must review effluent data collected during the reporting
period to determine whether TIN loads are increasing. This includes using all
accredited monitoring data to
concentration and load for each year during the reporting period. The City also must
with the pre-optimization rate previously identified.
c.Strategy Assessment. The City must quantify the results of the implemented strategy
and compare them to the expected percentage of TIN removal previously identified.
If the TIN loading increased, apply adaptive management, and re-evaluate the
optimization strategies and the resulting performance to identify the reason. From
this, select a new optimization strategy or revise the implementation for better
performance. Document any updates to the implementation schedule and overall
plan.
3.Influent Nitrogen Reduction Measures/Source Control
The City must investigate opportunities to reduce influent TIN loads from septage
handling practices, commercial, dense residential,and industrial sources and submit
documentation with the Annual Report. This includes the following:
a.Review non-residential sources of nitrogen and identify any possible pretreatment
opportunities.
b.Identify strategies for reducing TIN from new multi-family/dense residential
developments and commercial buildings.
AKART Analysis
Under the PSNGP, all permittees classified as Small Loaders must prepare and submit an
approvable all known, available,and reasonable treatment (AKART) analysis to Ecology for the
purposes of evaluating reasonable treatment alternatives capable of reducing TIN. Permittees
that maintain an annual TIN average of less than 10 milligrams per liter (mg/L) and do not
document an increase in load through their DMRs are excluded from this requirement and do
not have to submit this analysis.
Monitoring Requirements
The PSNGP will create additional monitoring requirements for the City. These requirements do
t. The City will need to
comply with both permits separately. Recorded monitoring data should be submitted monthly
on the electronic DMR form provided by Ecology within the Water Quality Permitting Portal.
The City may use the monitoring locations identified in the NPDES Permitto collect samples for
the PSNGP, but must still prepare two separate monthly DMR submittals (one for each permit).
Samples must be representative of the flow and characteristics of the discharge,and sampling
is not required outside of normal working hours or during unsafe conditions. For each sample
taken, the City must record the sample date and time, location, method of sampling, and
individual who performed the sampling. The City must use appropriate flow measurement and
methods consistent with accepted scientific practices, including proper installation, calibration,
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
and maintenance of all measurement devices. A summary of the anticipated monitoring
Tables 2-10 and 2-11.
Table 2-10
Comparison of City NPDES Permit and PSNGP Monitoring Requirements for WWTF Influent
Table 2-11
Comparison of City NPDES Permit and PSNGP Monitoring Requirements for WWTF Effluent
Units and Minimum Sampling Minimum Sampling
ParameterSample Type
SpecificationFrequency (NPDES)Frequency (PSNGP)
FlowMGD-2/monthMetered/Recorded
BOD
mg/L1/week
5-24-Hour Composite
BOD
ppd1/week
-Calculated
5
BOD
% removal1/week
-Calculated
5
-24-Hour Composite
TSSmg/L1/week
-Calculated
TSSppd1/week
-Calculated
TSS% removal1/week
Chlorine (Total Residual)mg/L1/week
-Grab
Fecal Coliform#/100 ml1/week-Grab
-Grab
pHStandard Units1/day
CBOD
mg/L-2/month24-Hour Composite
5
Total Organic Carbonmg/L-1/quarter24-Hour Composite
mg/L as N-2/month24-Hour Composite
Total Ammonia
mg/L as N-2/month24-Hour Composite
Nitrate plus Nitrite
mg/L as N-1/month24-Hour Composite
Total Kjeldahl Nitrogen
mg/L as N-2/monthCalculated
Total Inorganic Nitrogen (TIN)
ppd-2/monthCalculated
TIN
Average Monthly TINlbs-1/monthCalculated
lbs-1/monthCalculated
Annual TIN, year to date
m by the
th
15 day of the following month. Any pollutant monitoring data collected more frequently than
the permit stipulates must be used in calculations and submitted in the DMR.
After 12 months of monitoring, the City may request a reduction in sampling frequency from
Ecology if it can demonstrate that the distribution of concentrations can be accurately
represented with a lower sampling frequency.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
Additional Requirements
The City must retain records of monitoring information or documentation pertaining to permit
requirements for a minimum of 5 years following termination of permit coverage.If the City is
unable to comply with the conditions of the permit, it must notify Ecology within 24 hours and
submit a written report to Ecology via the WQWebPortal within 5 days describing the
noncompliance event and duration, and how steps will be taken to correct it.The City must
keep the following documentation onsite or within reasonable access to the site: Permit
Coverage Letter, PSNGP, DMRs, and attachments to the NOP.
Compost Facility Regulations for Biosolids
Chapter 173-308 WAC isthe basis forthe state-wide biosolids management program.Facilities
that are subject to the permit program apply for coverage under the existing state-wide general
permit.The state biosolids program regulates facilities that produce, treat, or land apply
sewage sludge or biosolids for beneficial use. The CityCompost Facility is covered under the
general permit to produce Class A biosolids as defined in the federal 40 CFR 503 regulations.
Biosolids quality is measured using three parameters: pathogen reduction, vector attraction
reduction, and pollutant concentration. Pathogen reduction uses accepted treatment processes
or requires measurement of pathogen concentration to determine compliance.To receive
classification as Class A, biosolids must go through a rigorous process called a Process to
Further Reduce Pathogens. This reduces pathogens below detectable limits. Operators must
test all Class A biosolids for pathogens and indicator organisms.
Vector attraction is related to odor control and can be thought of as the appeal that the
biosolids present to organisms (e.g., flies) that may transmit pathogens, if pathogens were
present in the biosolids. Reduction of vector attraction can be achieved through lime
stabilization, reducing volatile solids content, or physical mixing processes.
Pollutant concentration refers to the pollutant limits established in WAC 173-308-160. This sets
a ceiling concentration limit for each pollutant, meaning the maximum allowable concentration
in biosolids. It also lists the pollutant concentration limit, which is lower than the ceiling limit.
Biosolids with pollutants above the pollutant concentration limit are subject to cumulative
loading limits on application sites.
Chapter 7. Proposed solids handling
improvements are discussed in Chapter 8.
Compost Facility State Waste Discharge Permit
Compost Facility containsaSequencing Batch Reactor (SBR) that treats liquids from
the composting process and discharges to
constructed wetlands and then infiltration basins for further treatment and disposal. The
s WWTF is covered under the State Waste Discharge Permit (SWDP), which
regulates the flow and loading of the SBR and adjacent wetlands.Thecurrent SWDP
(Permit No.ST 6127) has an effective date of July 1, 2019, and expires on June 30, 2024.Copies
of the permit and accompanying fact sheet are included as Appendix E.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Facility Design Criteria
The permitted flow and loading design criteria for the Compost Facility are included in
Table 2-12.
Table 2-12
Compost Facility Flow and Loading Design Criteria
Effluent Limits
SBR effluent water is discharged to infiltration basins, designated as wetlands in the SWDP,
west of the Compost Facility. The effluent limits for the SBR and wetland influent and effluent
are summarized in Tables 2-13 and 2-14.
Table 2-13
State Waste Discharge Permit SBR Effluent Limits
Table 2-14
State Waste Discharge Permit Wetland Effluent Limits
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
ADJACENTSEWERSYSTEMS
There are no municipal sewer service systemsadjacent to the City.The closest wastewater
treatment plant to the City is the Port Townsend Paper Corporation just south of the City limits.
The surrounding areasof unincorporated Jefferson Countydo not have sewer service,and
wastewater is managed with on-site septic systems, community drain fields, or alternative
sewage treatment technologies. However, the County is in the process of constructing a sewer
plant and collection system in Hadlock that will allow for conversion of existing septic systems
to public sewer and growth of housing and businesses within the Hadlock UGA.
Figure 2-6 shows thewastewater treatment facilities within 20 miles of the City.
CITYOFPORTTOWNSENDANDADJACENTWATERSYSTEMS
CityofPortTownsend
11.2square
miles, is shown on Figure 2-7 The existing retail service area includes the current Citylimits and
adjacent lands to the west and south of the City limits.
This section provides a brief description of the existing water system and the current operation
of the facilities. The water service area, facilities, and supply sources are shown in Figure 2-7.
by the Big Quilcene and Little Quilcene Rivers.
The City's wastewater facilities are all separated from major drinking water facilities for the City
andadjacent drinking water purveyors. As a result of this separation, the City's wastewater
facilities are unlikely to conflict with or impact the drinking water facilities or supplies for the
City or neighboring purveyors.
Pressure Zones
The City dividesthe water system into twodifferent pressure zones
.Prior to 1998, the City was served from a single pressure zone (the Low Zone).
Service pressures ranged from above 130 pounds per square inch (psi)near the shoreline of
Puget Sound to less than 20 psi at the higher elevations within the service area. To increase
system pressures, the City installed a new, taller storage tank, which provides higher service
pressures in areas of the City with higher elevations,creating the initial phase of the High Zone.
The High Zone serves areas generally above 210 feet of elevation, resulting in a typical High
Zone pressure range of 35 psi to 70 psi (although there are localized areas over 70 psi). The City
expanded the extent of the High Zone to adjacent northwest areas of similarly higher elevation
in 2004 to ensure service pressures in that area were maintained above the Washington State
Department of Healthminimum criterion of 30 psi. The revised Low Zone pressure range is
typically from about 50 psi to above 130 psi, butthere are localized areas under 50 psi.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Supply Facilities
Introduction
The City water system is supplied by surface water from the Big Quilcene and Little Quilcene
Rivers, which are located approximately 30 and 20 miles south of the City, respectively. The
diversions at the Little Quilcene and Big Quilcene Rivers provide flow to Lords Lake and to City
Lake, which are both man-made impoundments. The headwaters of each river originate within
the Olympic National Forest and Olympic National Park. The U.S. Forest Service manages most
of the municipal watershed and the City has a good working relationship with them. The Big
Quilcene River is the primary water supply for the City. Water from the Little Quilcene River
diversion is used to fill Lords Lake, which has a capacity of approximately 500 million gallons
(MG). Lords Lake also can
supplies are high quality and generally very low in turbidity. When the Big and Little Quilcene
Rivers experience high turbidity events, the City and the Port Townsend Paper Corporation use
water stored in Lords Lake or City Lake. The entire system operates by gravity from both of the
diversions, to Lords Lake, City Lake, and the City. City Lake functions as a raw water equalizing
reservoir with approximately 140 MG of storage.
Water Treatment
Prior to treatment, water from City Lake flows through two sets of mesh screen, which prevents
3
objects larger than /inch from entering the Olympic Gravity Water System pipeline below
32
City Lake. The new water treatment facility (WTF), completed in 2017, is located adjacent to the
Raw water flow and pressure control valves.
Mechanical micro-screens for removing algae and larger-sized sediment.
Pressure ultrafiltration membranes for the removal of microbial pathogens (Giardia and
cryptosporidium), sediment, and semi-colloidal particles.
Sodium hypochlorite feed to provide primary disinfection and a chlorine residual in the
finished water throughout the distribution system.
Potassium permanganate injection system for treatment of algal toxins in the event
toxins are detected in the raw water supply.
Automated control system.
Standby power generator.
Pump Station Facilities
two booster pump station (BPS) facilities. The Morgan Hill BPS,
constructed in 2004, has two domestic flow pumps (one service, one standby), three high flow
pumps (two service, one standby), and emergency power (Table 2-15). The BPS serves a closed
distribution system with 2,000 gallons of storage via a hydro-pneumatic tank on top of the hill.
The second BPS is located at the WTF and pumps water into the High Zone and 1 MG Standpipe
reservoir.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER SYSTEMDESCRIPTIONAND DISCHARGE REGULATIONS
Table 2-15
Booster Pump Station Facilities Summary
Storage Facilities
two facilities that provide storage to the water system(Table 2-16).
A 37-foot-tall,160-foot-diameter 5MG
elevation zone,and an 84-foot-tall,47-foot-diameter 1MG
high elevation zone. Both reservoirs have baffles to increase the contact time (CT) in the
reservoir in order to meet CT requirements.
Table 2-16
Storage Facilities Summary
Distribution and Transmission System
The Ci110miles of water main ranging in size from
2inches to 36inches. Most of the water main (approximately 33percent) within the system is
6inches in diameter or less.Approximately 56 percent of the distributionsystem is constructed
of ACpipe. The majority of the remainder ofthe piping system is constructed of PVC pipe. The
City hascomplied with water quality testing requirements for asbestos in the water system,
demonstrating that concentrations are below state and federal standards.
Water System Interties
Water system interties are physical connections between two adjacent water systems. Interties
normally are separated by a closed isolation valve or control valve. Emergency supply interties
provide water from one system to another during emergency situations only. An emergency
situation may occur when a water system loses its main source of supply or a major
transmission main, or during firefighting situations, and is unable to provide a sufficient
quantity of water to its customers. Normal supply interties provide water from one system to
another during non-emergency situations and are typically supplying water at all times.
The Citydoes not have any intertieswith any adjacent water systems.
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CHAPTER 2 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Adjacent Water Systems
is shown in Figure 2-7. Three water systems share a boundary with
the City: Deaner Line, Jamie Kozelisky, and Quimper (Jefferson County Public Utility District
(PUD) No.1). Other purveyors located on the Quimper Peninsula, but not sharing a boundary
with the City, include Jefferson County PUD No. 1 Vandecar, Cape George, and Jefferson County
PUD No. 1 Valiani.
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|
3LANDUSEANDPOPULATION
INTRODUCTION
The State of Washington Growth Management Act (GMA)requires, among other things,
consistency between land use and utility plans and their implementation.This chapter
demonstrates the compatibility of the City of (City)General SewerPlan (GSP)
with other plans, identifies the designated land uses within the existing and future service area,
and presents population
COMPATIBILITYWITHOTHERPLANSANDPOLICIES
To ensure that the GSP is consistent with the land use policies that guide it and other related
plans, the following planning documents were examined.
State of Washington Growth Management Act
tƚƩƷ ƚǞƓƭĻƓķ /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ
Jefferson County County-wide Planning Policies
WĻŅŅĻƩƭƚƓ/ƚǒƓƷǤ/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ
GrowthManagementAct
The State of Washington GMAof 1990 (and its multipleamendments) defined four goals
relevant to this GSP:
1.Growth should be in urban areas;
2.There should be consistency between land use and utility plans and their
implementation;
3.There should be concurrency of growth withpublic facilities and services; and
4.Critical areas should be designated and protected.
Urban Growth Area
The GMA requires that JeffersonCounty (County) designate an Urban Growth Area (UGA)
where most future urban growth and development will be directed. The Countywide UGA is
defined in the WĻŅŅĻƩƭƚƓ /ƚǒƓƷǤ/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ and encompasses the area where this
urban growth anddevelopment is projected to occur over the 20-year planning period. The
current Jefferson County UGA boundaries in the vicinity of the City areshown on Figure 3-1.
Consistency
The GMA requires planning consistency from two perspectives.First, it requires the consistency
of plans between jurisdictions.This means that plans and policies of the City and County must
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CHAPTER 3 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
be consistent per Revised Code of Washington (RCW) 36.70A.100. Second, the GMA requires
that the implementation of the GSP be consistent with comprehensive plans (RCW 36.70A.120).
Concurrency
Concurrency means that adequate public facilities and services be provided at the time that
growth occurs. For example, growth should not occur where schools, roads, and other public
facilities are overloaded. To achieve this objective, the GMA directs growth to areas already
served or readily served by public facilities and services (RCW 36.70A.110). It also requires that
when public facilities and services cannot be maintained at an acceptable level of service, the
new development should be prohibited (RCW 36.70A.110).
Critical Areas
The GMA requires that critical areas be designated and protected. Critical areas include aquifer
recharge areas, wetlands, frequently flooded areas, streams, wildlife habitat, landslide hazard
areas, seismic hazard areas, and steep slopes. The City has adopted development regulations
identifying and protecting critical areas as required. The State Environmental Policy Act (SEPA)
Checklist in Appendix F addresses other environmental concerns.
Port Townsend Comprehensive Plan
The tƚƩƷ ƚǞƓƭĻƓķ /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ was last adopted in 2016. The plan was developed to
describe the vision for the 20-year planning period and to provide goals and policies for
achieving the vision, as well as to meet the requirements of the GMA.
/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ
development should occur over a 20-year horizon. While the Land Use Element goals and
policies set forth general standards for locating land uses, the Land Use Map (Figure 4-1)
indicates geographically where current and future land uses may be appropriate. The Land Use
Map is a blueprint for the development of an area. own in
Figure 3-1.
The Land Use Element considers the general location of land uses, as well as the appropriate
intensity and density of land uses given the current development trends of the City. The
Transportation, Utilities, and Capital Facilities Elements ensure that new development will be
served adequately without compromising adopted levels of service, which is consistent with the
principal of concurrency as defined in the GMA.
Jefferson County County-wide Planning Policies
Jefferson County and the City adopted a joint resolution establishing the County-wide Planning
Policies on December 21, 1992. The policies are intended to ensure that County and City
comprehensive plans are consistent in accordance with the GMA. The County-wide Planning
Policies are organized into policies related to UGAs, development and urban services, siting of
public facilities, County-wide transportation facilities, affordable housing, economic
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CITY OF PORT TOWNSENDGENERAL SEWERPLANLAND USE AND POPULATION
development and employment, and rural areas. equired to
be consistent with the County-wide Planning Policies.
JeffersonCountyComprehensivePlan
The current version of the WĻŅŅĻƩƭƚƓ /ƚǒƓƷǤ/ƚƒƦƩĻŷĻƓƭźǝĻtƌğƓ was last updatedin 2018.
Chapters include the following.
Land Use
Natural Resources
Housing
Open Space, Parks & Recreation, Historic & Cultural Preservation
Environment
Transportation
Economic Development
Capital Facilities & Utilities
Tis focused on ten framework goals, as follows.
I.Preserving Rural Character
II.Sustainable and Suitable Growth Patterns
III.Enhancement of the Rural Economy
IV.Housing Variety and Affordability
V.Allocation of Land to Meet Anticipated Needs
VI.Environmental Consideration
VII.Mobility
VIII.Active and Healthy Living
IX.Continuous and Ongoing Public Involvement
X.Compliant with GMA
The WĻŅŅĻƩƭƚƓ /ƚǒƓƷǤ /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ guides development and designates land use in
unincorporated Jefferson County. County Land Useinside the wastewater service
area (which includestheis shown in Figure 3-1; the WĻŅŅĻƩƭƚƓ /ƚǒƓƷǤ
/ƚƒƦƩĻŷĻƓƭźǝĻtƌğƓ can be referenced for County Land Use outside the future
wastewater service area.
LANDUSE
Thewastewater service area includes the City A boundary, for
a total of approximately 7.0square miles. TheLand UseMap,as shown in Figure 3-1, guides
development and canbe used to forecast future wastewater flows and loadings. Land use
outside the Cityis designated by theCounty, as shown in Figure 3-1.
Approximately 50.5percent of the area within the future wastewaterservice area is
designated for residential use, as indicated in Table 3-1. Approximately 13.2percent of the
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CHAPTER 3CITY OF PORT TOWNSENDGENERAL SEWERPLAN
future wastewater service area is designated for open space/parks; approximately 4.6percent
is designated for commercial use; approximately 3.4percent is designated for
public/infrastructureuse;and approximately28.3percent is designated for other land uses or is
undesignated.
designated as public right-of-
right-of-way, leaving nearly half the land undevelopable. This is a resultof the pre-platted
nature of the City and the 200-foot by 200-foot block pattern. This factor will be a key item of
discussion in the next /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ update and impacts the amount of land generating
demand on the utility systems.
Table3-1
Land Use Inside Future Wastewater Service Area
Mixed Use
Commercial
2.3%
Marine-Related Use
4.6%
1.9%
Public/Infrastructure
3.4%
Undesignated
24.2%
Park/Open Space
13.2%
Residential
50.5%
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CITY OF PORT TOWNSENDGENERAL SEWERPLANLAND USE AND POPULATION
POPULATION
HouseholdTrends
areas are largely comprisedof single-family residences. T2016
/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ estimated that there were over 5,300housing units in the City. Of these,
approximately 4,006housing units (75.2percent) were single-family residences, approximately
1,101housing units (20.7percent)weremulti-family residences, and 219 housing units
(4.1percent) were other types of residences such as mobile homes, boats, and RVs.
average household size is estimated to be 1.90persons per household based on the 2020 U.S.
Census Bureau data.
HistoricalandFutureCityPopulation
The City has experiencedsteadypopulation growth since 2000. The population of the City has
increased by approximately 23percent over thelast 20 years.Table 3-2 illustrates the historical
population growth since 1995.The historical population shown in Table 3-2 represents the
population within the City limits. The sources of the historical population numbers are the
decennial census and Office of Financial Management (OFM)intercensal estimates.
Table 3-2
Population Trendswithin the City Limits
YearCity Population
19958,165
20008,334
20018,441
20048,543
20078,945
20109,113
20119,240
20129,299
20139,320
20149,504
20159,579
20169,805
20179,871
20189,950
201910,060
202010,148
202110,220
Projected future population growth withinthe CityLimits, shown in Table 3-3 and Chart 3-1, is
2016 tƚƩƷ ƚǞƓƭĻƓķ/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ. The City
is projected to have a population of 13,300people in 2043.The buildout population shown in
Table3-3
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CHAPTER 3 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
The City is currently discussing an expansion to its sewer service area. Chapter 2 describes
factors to consider in serving a Special Study Area and the expansion that would result. The
expansion of the service area is dependent on coordination with the County, the Department of
Commerce, and the Department of Ecology to ensure compliance with the GMA. The Special
Study Area expansion will extend service to two new sewer basins already inside the City limits
and could serve the Glen Cove Local Area of More Intense Rural Development (LAMIRD) just
outside the City limits. The Special Study Area boundary is approximately shown in Figure 3-2.
For the purposes of estimating demand on the sewer system, an equivalent population for the
industrial area was estimated. The additional population outside of the City limits this
expansion would introduce to the sewer service area is included in Table 3-3 under the
assumption the expansion would start in 2025. Note, the actual population growth would be
considerably less given business customers do not necessarily add more population to the City.
Table 3-3
Population Projections
Sewer Service
Sewer System
Expansion Equivalent
City SewerPopulation ServedPopulation with
1
System Populationby Septic SystemsPopulationExpansion
YearCity Population
20159,5799,188391----
20169,8059,414391----
20179,8719,480391----
20189,9509,559391----
201910,0609,669391----
202010,1489,757391----
202110,2209,829391----
202210,3399,981359----
202310,46010,134326----
202410,58210,289294010,289
202510,70610,44526110810,553
202610,83110,60322821610,819
202710,95810,76219632411,086
202811,08610,92316343211,354
202911,21511,08513054011,624
203011,34611,2489864811,896
203111,47911,4136575512,169
203211,61311,5803386312,444
2033 (+10 years)11,74811,748097112,720
203411,88611,88601,04112,927
203512,02512,02501,11613,140
203612,16512,16501,19613,361
203712,32112,32101,28213,603
203812,47912,47901,37413,853
203912,63912,63901,47214,111
204012,80112,80101,57814,379
204112,96512,96501,69114,656
204213,13213,13201,81214,944
2043 (+20 years)13,30013,30001,94315,242
Buildout23,03523,03502,77125,973
1 = Equivalent population is shown based upon the projected flow and is representative of the growth in terms of population.
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CITY OF PORT TOWNSENDGENERAL SEWERPLANLAND USE AND POPULATION
Chart 3-1
Population Projections
SewerSystemPopulation
wastewater system is different than the
population of the City limits. The City currently provides sewerservice to the entire population
within the City limits,except for206residential properties that currently are unsewered. The
unsewered population and the sewer system population insidethe City limits was calculated by
multiplying the estimated number of connections by the average household size for the City. As
shownin Table 3-3, the estimated population served by the sewersystem in 2021was 9,829.
Sewersystem population projections through 2043are shown in Table 3-3. It was assumed that
by 2033,the currentunsewered properties in the City limits would be connected
wastewater system. The wastewater system is expected to provide service to approximately
15,242people in 2043.
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CHAPTER 3 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Distribution of Population Assumptions
City planning staff made an estimate of where future growth might occur within the existing
sewer service area as shown in the map in Figure 3-3. This population forecast was used to
allocate future flows in the sewer hydraulic model for the 5-year, 6- to 10-year, and 11- to
20-year design horizons. Flow contributions from the Special Study Area expansion to the Glen
Cove Area to be served by the proposed Mill Lift Station are in addition to these allocations.
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|
4FLOWANDLOADINGANALYSES
INTRODUCTION
A detailed analysis of flow and loading is crucial to the planning efforts of a sewer service
provider.When analyzing a sewer system, the first step is to identify current flow and load
values to determine if the existing system can provide adequate service to its existing
customers under the most crucial conditions in accordance with federal and state laws.A
projected sewer system analysis identifies projected flow and loadvaluesto determine where
the system will need to be improved to satisfy projectedgrowth while continuing to meet
federal and state laws.
Flow and load values in a sewer system are used to determine the size of gravity collection
piping, lift station facilities,and force main piping, as well asthe size and type of treatment
facilities needed.This information also is
Pollutant Discharge Elimination System (NPDES) waste discharge permit, which is required by
the Washington State Department of Ecology(Ecology).Several different flow scenarios were
analyzed for the City of Port Townsend(City) sewer system and are addressed in this chapter,
including average annual flow(AAF), maximum month average flow(MMF), maximum day flow
(MDF), peak hour flow (PHF),and projected flows.astewater treatment facility
(WWTF) loading, inflowand infiltration (I/I), and peaking factorsalso are presented.
System design criteria and standards have been developed to ensure that a consistent
minimum level of
planning, design,and construction of sewer system projects. Engineering
DesignStandards Manual isincluded in AppendixG. Design requirements for sewer systems
are Criteria for Sewage Works Design (commonly known as the Orange
Book).
SEWERSERVICECONNECTIONSANDRESIDENTIALPOPULATION
SewerServiceConnections
Table 4-1 presents the sewer service connections for 2015 through 2021. As of
2021, there were approximately 4,710
system. Of these connections, 4,265were residential servicesand 445were
commercial/government services. A breakdown of the sewer service connections by customer
class is shown in Chart 4-1.
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CHAPTER 4CITY OF PORT TOWNSENDGENERAL SEWER PLAN
Table 4-1
Historical Sewer Connections Summary
Chart 4-1
2021 Sewer Service Connections by Customer Class
Commercial/Government
9.5%
Residential
90.5%
SewerServicePopulation
As presented in Chapter 3 2021 sewer service area population is estimated to be
9,829people. Thisestimate is based on 10,220for 2021, and an
average household size of 1.90for areas in the Citylimitsmultiplied by206unsewered
residential properties in the City limits. The average household size for areas in the City limits is
Comprehensive Plan, whichwas amended in 2016. Table 4-2 presents the
historical sewer population for 2015through 2021.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-2
Historical Sewer Service Population
Urban Growth Area (UGA).
There are parcels within the Citylimitsthat are served by on-site septic systems.Once these
wastewater system if the parcelis located within 500 feetof the wastewater collection system.
It is assumed for this General Sewer Plan (GSP)that all of these parcels in the City limits will be
connected to by 2033,and the sewer service
population will be the same as the UGA population by 2043. This will ensure that the City has
the infrastructure in place to serve the entire UGA population.
EXISTINGWASTEWATERFLOWANDLOADING
WastewaterFlow
The total influent flow to the WWTFis made up of untreatedflow from primarily residential
customers, but also includes flow from a number of commercial, hospitality, and retail
businesses, schools, and the Jefferson Healthcare Medical Center.The City
system flow rates were estimated using theWWTFdischarge monitoring reportsand lift station
run time data for the 2016 through 2021 period.
basins are shown in Figure 2-1.
discharge monitoring reportshave been reviewed and analyzed to determine current
wastewater characteristics and influent loadings.Table 4-3 summarizes the historicalWWTF
AAFs, MMFs,MDFs(including I/I), and PHFson an annual basis for the 2016through 2021
period.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-3
Historical WWTF Influent Flow Summary
The monthly average and maximum influent wastewater flows recorded on the WWTF
discharge monitoring reports for the 2016 through 2021 period are summarized in Appendix H.
Data from 2020 and 2021 were not included in the historical averages and maximums in
Table 4-3 due to probable shifts in typical wastewater patterns due to the COVID pandemic.
In the 2016 to 2019 period, the average annual flow for the WWTF is 0.84 million gallons per
day (MGD), with the highest AAF of 0.87 MGD occurring in 2018. The AAF for 2016 through
2018 has remained at or above the 4-year average. In 2019, the AAF dropped to 0.78 MGD. The
MDF for the WWTF has varied from year to year over the same 4-year period, with the lowest
MDF of 1.12 MGD occurring in 2019, and the highest MDF of 1.99 MGD occurring in 2016.
The WWTF is currently permitted for a MMF of 2.05 NPDES permit stipulates
that the City shall submit a plan and schedule for continuing to maintain capacity when the flow
reaches 85 percent of the permitted flow for 3 consecutive months; 85 percent of the
permitted flow is approximately 1.74 MGD. As Table 4-3 and Appendix H show, this limit has
not been exceeded in the 2016 through 2019 period. The highest MMF of 1.16 MGD
(57 percent of the permitted flow) occurred in 2018. A significant increase in the MMF occurred
from 2017 to 2018; however, the MMF dropped again in 2019 to flows similar to 2017.
Wastewater Loading
wastewater characteristics and influent loadings. The 2016 through 2021 historical average
annual and maximum month average 5-day biochemical oxygen demand (BOD) and total
5
suspended solids (TSS) loadings in pounds per day (ppd) and pounds per capita per day (ppcd)
are summarized in Tables 4-4 and 4-5, respectively.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-4
Historical WWTFInfluent BODLoadingSummary
5
Table 4-5
HistoricalWWTFInfluent TSSLoadingSummary
The average annual and maximum month average BODand TSS loadingsin Tables 4-4 and 4-5
5
were estimated from 2016through 2019data. Data from 2020 and 2021 are not included in the
historical averages due to the COVID pandemic. The monthly average and maximum influent
loadings recorded at the WWTFfor the 2016through 2019period are summarized in
AppendixH.
In the 2016through2019period, the average annual influent BODloading has increased
5
overall; however, there have been fluctuations throughout that time period with both
significant increases and decreases from year to year. The average annual influent BODand
5
TSS loadings significantly increased from 2017to 2018. Average annual BODand TSS loadings
5
were relatively consistent in 2016and 2017, before increasing in 2018. As Tables 4-4 and 4-5
show, the average annual BODand TSS loadingare relatively similar.
5
The WWTF currently has a permitted capacity for BODinfluent maximum month average
5
loading of 3,754 ppdand a TSS influent maximum month averageloadingof 4,568 ppd. The
maintain capacity when the loading reaches 85percent of the permitted loading for
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
3 consecutive months; 85 percent of the permitted loading is 3,191 ppd for BOD and 3,883 ppd
5
for TSS.
As Tables 4-4 and 4-5 show, the BOD and TSS influent limits have not been exceeded in the
5
2016 through 2019 time period. The highest maximum month average BOD loading of
5
2,968 ppd (79 percent of the permitted BOD loading) and the highest maximum month
5
average TSS loading of 2,799 ppd (61 percent of the permitted TSS loading) both occurred in
2018.
INFLOW AND INFILTRATION
I/I is the combination of groundwater and surface water that enters the sewer system.
Infiltration is groundwater entering the sewer system through defects in the sewer system
infrastructure, such as fractured pipes and leaking maintenance holes and pipe joints. Inflow is
surface water that enters the sewer system from sources such as roof and street drains and
leaky maintenance hole covers.
A sanitary sewer system must be able to carry the domestic wastewater generated by utility
customers and the extraneous I/I that is a part of every sewer collection system. Excessive I/I in
the sewer collection system can lead to serious issues within the collection system that may
include wastewater system backups and overflows, accelerating the structural deficiencies of
the collection system. Excessive I/I also can inflate capacity requirements of the proposed
collection and treatment system infrastructure.
Reducing I/I in a sewer collection system can reduce the risk of sanitary sewer overflows and
the cost of treating wastewater. By reducing or eliminating I/I sources, the extraneous water
that previously occupied the conveyance and treatment system can now be occupied by
sewage flows. This leads to delaying conveyance and treatment projects that were needed
because of the extraneous I/I water.
The U.S. Environmental Protection Agency (EPA) published a report in May 1985,
Infiltration/Inflow, I/I Analysis and Project Certification, which developed guidelines to help
determine what amount of I/I is considered to be excessive and what amount can be
cost-effectively removed. The report established I/I flow rates that are considered normal or
acceptable based on surveys and statistical evaluations of data from hundreds of cities across
the nation.
Precipitation and temperature data were compiled from the National Oceanic and Atmospheric
Administration (NOAA) website for weather stations in and near the City.
Inflow
The EPA report gives guidelines for determining whether inflow can be classified as
non-excessive. Inflow is considered to be non-excessive if the average daily flow during periods
of heavy rainfall or spring thaw (i.e. any event that creates surface ponding and surface runoff)
does not exceed 275 gallons per capita per day (gpcd). The peak recorded daily flow in the
6 years analyzed for the City (2016 through 2021) was 2.37 MGD, which occurred on
February 5, 2020. Per the weather data obtained from NOAA, this day was recorded as having
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
0.95inches of precipitation. This peakinflow event equates to a 243gpcd flow rate, which is
belowthe EPAmaximum of 275gpcd. The second peak recorded daily flow was 2.36MGD,
which occurred on the followingday, February 6, 2020.This day was recorded as having
0.4inches of precipitation.Thispeak inflow event equates to a 242 gpcd flow rate, which does
not exceed the EPA maximum. The third highest recorded daily flow was 2.18MGD, which
occurred on January 4, 2021.This day was recorded as having0.64inches of precipitationand a
peak inflowequatingto 222gpcd, which is belowthe EPAinflow guideline.
non-excessive. The City should continue to monitor inflow throughout the system, particularly
in areas over 50 years oldthatpreviously may have been combined collection systems.
Infiltration
guideline for determination of non-excessive infiltration was based on the national
average for dryweather flow of 120 gpcd.In order for the amount of infiltration to be
considered non-excessive, the average daily flow must be less than 120 gpcd(i.e. a 7-to 14-day
average measured during periods of seasonal high groundwater).Although it can be difficult to
discern between inflow and infiltration, peak inflow will generally occur immediately during or
just after a significant rain event, while peak infiltration will occur during the high groundwater
period that follows prolonged precipitation events.
The peak dry weather flow period in the last 6years (2016through 2021) of record for the City,
occurring after a few consecutive days of rain, was the 5-day period from January22,through
January26,2016. This period also was directly preceded by heavy rains, and yielded an average
flow of 1.20MGD, equating to 128gpcd. The second highest peak dry weather flow period
occurred during a 13-day period from February 4,throughFebruary16,2018. This period was
preceded by moderate rainfall andyielded an average flow of 124gpcd. The third highest peak
dry weather flow period occurred during a 14-day period from February 7,through February
21,2020. This period directly followed a period of heavy rainfall andyielded an average flow of
121gpcd. All three events areslightlyabove
therefore, the amount of infiltration is considered excessive. The City should continue to
monitor infiltration throughout the system.
Any I/I studies that are conducted in the future should follow the guidelines defined in Chapter
C-1of Criteria for Sewage Works Design
Emphasis should be placed on older sections of the City with concrete, vitrifiedclay,and
asbestoscement mains or in areas suspected of being combined sewers. Lawrence Street is
believed to convey both storm and sanitary sewer. Chapter 10 discussesremediation of this
defect..
PROJECTEDWASTEWATERFLOWANDLOADING
o add a total of 5,850additional persons by 2043, using
2018as the base year.This increase in population includes the sewer system expansion as
discussed in Chapter 3.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Peaking Factors
Once existing flow rates are measured and defined, projected flow rates can be developed.
Projected flows are used to analyze how well the existing system will perform in the future and
determine improvements required to maintain or improve system function. In order to
establish projected flow scenarios for a sewer system, peaking factors need to be determined
for the existing system, which can then be applied to projected flow rates. Peaking factors are
the ratio of higher flows, such as MDF to AAF.
A maximum peak hour flow of 3.34 MGD, based on the highest PHF from the flow data
analyzed for this GSP, occurred in 2020 during the COVID pandemic. The AAF for 2020 was
lower than typical so the peaking factors were estimated by finding the ratio of the 2020 PHF to
the 2016 to 2019 average AAF, establishing a PHF/AAF of 4.00 for the WWTF. Table 4-6 shows a
Table 4-6
Peaking Factor Summary for Flows
Peaking factors also are developed to determine maximum month average BOD and TSS
5
loading projections. These loading peaking factors are the average historic maximum month to
average annual loadings from 2016 to 2019. Data obtained during the COVID pandemic (2020
and 2021) may not represent normal flow and load conditions. For instance, the data from
these years shows a wider variability in peaking factors; therefore, it is not included in this
calculation. Table 4-7 shows a summary of the peaking factors for loading at WTF
for the 2016 through 2021 period.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-7
Peaking Factor Summary for Loadings
The peaking factorspresentedin Tables4-6 and 4-7 were used to project flows and loadings in
the following sections.
ProjectedWastewaterFlowRates
Once existing flow rates are measured and defined, projected flow rates can be developed.
Projected flows are used to analyze how well the existing system will perform in the future and
determine improvements required to maintain or improve system function.
The projected flows at the WWTFweredeveloped using the following information:
Projected AAFs were estimated using the2018 AAF, which is approximately 0.87MGD,
as the existingbaseline. Year 2018was used as the existing baseline for flow projections
because this was the highest AAF over the last 4 yearsanalyzed.
The highest AAF per capita for 2016 through 2019 was 91gpcd (Table 4-3), which
includes I/I and commercial wastewater flows. This value was used for projecting how
much additional wastewater flow the projected population growth would contribute to
The flow peaking factorsshown in Table 4-6 were used for estimatingMMFs, MDFs, and
PHFs from projected AAFs.
From 2025to buildout, the population and projected flows include the growth as a
result of expanding the sewer service area as described in Chapter 3.
Summaries of the projected flowsfor the sewer system population within the City limits,
additional sewer expansion,and the total of the two populations, arepresented in Tables4-8
through 4-10, respectively.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-8
Projected WWTF Influent Flow for Sewer System Population Within City Limits
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-9
Projected WWTFInfluent Flow for Sewer System Special Study Area Expansion
Equivalent Sewer
Projected AAFProjected MMFProjected MDFProjected PHF
System
1234
(MGD)(MGD)(MGD)(MGD)
Year
Population
2018 (Baseline)----------
2019----------
2020----------
2021----------
2022----------
2023----------
202400.000.000.000.00
20251080.010.020.040.07
20262160.030.040.080.14
20273240.040.050.120.21
20284320.050.070.150.28
20295400.070.090.190.35
20306480.080.110.230.42
20317550.100.130.270.49
20328630.110.150.310.56
2033 (+ 10 years)9710.120.160.350.63
20341,0410.130.170.370.68
20351,1160.140.190.400.72
20361,1960.150.200.430.77
20371,2820.160.220.460.82
20381,3740.170.230.490.88
20391,4720.190.250.530.94
20401,5780.200.270.561.00
20411,6910.210.280.601.07
20421,8120.230.300.651.14
2043 (+ 20 years)1,9430.240.330.691.22
Buildout2,7710.290.390.831.43
1 = Projected AAFs are based upon the calculated 2033, 2043, and Buildout expansion flows as the baseline. 2024 to 2033 flows were projected with a
straight-line appreciation in conjunction with the City's preference on projected equivalent population growth as a result of the sewer expansion.
2 = Projected MMFs were estimated by multiplying the projected AAF by the highest historic MMF/AAF peaking factor from 2016 through 2019, which was
1.33 in 2018.
3 = Projected MDFs were estimated by multiplying the projected AAF by the MDF/AAF peaking factor of 2.83.
4 = Projected PHFs are based upon the calculated 2033, 2043, and Buildout expansion flows as the baseline. 2024 to 2033 flows were projected with a
straight-line appreciation in conjunction with the City's preference on projected equivalent population growth as a result of the sewer expansion.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-10
Total Projected WWTF Flow including Special Study Area Expansion
According to these projections, the WWTF will not exceed the NPDES permit maximum month
limit capacity for flow during the 20-year planning period. However, the City should evaluate
the WWTF for upgrades when the average MMF exceeds 85 percent of the NPDES permit limit.
According to these projections, the City should prepare to plan and design WWTF upgrades for
flow by 2038.
Historical Wastewater Flow by Basin
Table 4-11 shows the historical lift station AAF and PHF rates over the 2016 through
2020 period. These flow rates were developed using the run time records and pumping
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-11
Historical AAF and PHF Rates by Lift Station
2016 to 2020
20162017201820192020Average
Existing Design
AAFPHFAAFPHFAAFPHFAAFPHFAAFPHFAAFPHF
Firm Capacity
1
(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)(gpm)
Lift Station(gpm)
Gaines Street1,5002031,1201881,0271899821718531731,0471851,006
3
Monroe Street857
990
144135990136990124916127990133990
23143211432185192222016321151
Port195
Island Vista135418429547538320431
Hamilton Heights250103810331033103311331034
215212213213217214
31st Street100
2
150
------------------------------------
Point Hudson
593---5821,9406042,1275451,6315572,3235552,005
WWTF---
1 = Highlighted flows in gray exceed current firm pumping capacity.
2 = Point Hudson Lift Station is not connected to the City's SCADA system.
3 = 990 gpm, estimated from existing pump curves, is representative of all three pumps in the Monroe Street Lift Station running simultaneously.
The peak hour flowrates for the Gaines Street and Monroe Street LiftStations are surprisingly
close in magnitude considering that the GainesStreetbasinis larger. The Gaines Street basin
serves approximately 500 equivalent residential units(ERUs)more thantheMonroeStreet
basin, whichindicates theflowrate per ERU in the Monroe Street basin is much higher than the
GainesStreetbasin. As portions of the Lawrence Street sewer are still combined storm and
sanitarysewerconveyance, this would correlate to higher flows in the Monroe Street basin.
Recorded data from the pump stationsupervisory control and data acquisition(SCADA)
systemswas used to calculate the base flows for each pump station. Base flow information for
the GainesStreetLiftStation is based on a magnetic flow meter that records daily totalized
flows. For the Monroe Street LiftStation, timed flow tests were usedto ver
discharge capacity. Runtime records were used to multiply the measured flow rates by the run
totalizations at the Gaines Street LiftStation on an hourly basis to provide an improved
calculation of the peak hour flow.
ProjectedWastewaterFlowbyBasin
The City is planning for additional growth;however,it is uncertain where growth will occur
within the UGA.City planning staff made anestimate of where the future growth mightoccur
asshown in Figure 3-3. This population forecastwas used to allocate future flows inthe sewer
hydraulic model for 5-, 10-and 20-year design horizons, as shown in Table 4-12.The additional
flow associated with the projected population, allocated as shown in Figure 3-3, was calculated
using the per capita domestic and I/I ratesdeveloped in Chapter 3 withapeak hour factor of 4.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-12
Existing and Projected AAF and PHF Rates by Basin
Refer to Chapter 3 for more information regarding the development of population growth.
Refer to Chapter 6 for more information regarding the collection system evaluation.
Lift Station Hydraulic Capacity Analyses
Current lift station pumping capacities based on the calculated and measured flow rates, as well
as the remaining capacity of each lift station, are provided in Table 4-13.
The remaining capacity is presented in terms of the remaining population each lift station is
capable of supporting and is based upon a maximum per capita AAF of 91 gpcd and a PHF/AAF
peaking factor of 4.00.
Table 4-13
Current AAF and PHF Rates and Remaining Capacity by Lift Station
As indicated in Table 4-13, all lift stations, with the exception of Monroe Street, have the
capacity to support existing flows from their basins. There are many instances of all three
pumps in the Monroe Street Lift Station running, which may be indicative of the lift station
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
being unable toconvey the peakflows using only two ofthe threepumps in the station (the
desired standard).Capacity upgrades to this lift station willbe necessary in the future to handle
projected flows. The Monroe Street basinalsoexperiencesthe greatest levels ofI/Irelative to
other basins in the City. Operations staff states that the Monroe Street Lift Stationdischarge
surcharges with three pumps operating simultaneously during peak flows but does not
overflow.
TheCity is planning to perform an I/I study to identify improvements that could reduce I/I in the
sewer system. These I/I improvements could reduce or mitigate the I/I component of the PHFs
For
example, it is known that Lawrence Street has storm inlets connected to the sanitary sewer.
Capacity upgrades to the Monroe Street Lift Station should be performed following with the
removal ofupstream inflow sources.
Besidesthe Monroe Street LiftStation, liftstations have ample capacity to convey
future flowsfor the 20-year design horizon (Table 4-13). Most of the projected growth will
originate in the Mill site area and be pumped by the new Mill LiftStation. All of the discharge
from this station will flow by gravity to the WWTF, posing no new loads toexisting liftstations.
Gravity conveyance upgrades will be substantial, but liftstation capacity upgrades will not.
t these
costs will be covered under a maintenance line item as described in the Capital Improvement
Plan in Chapter 10.
ProjectedWastewaterLoadingCapacity
Once existing influentloadings are determined, projected loading capacitiescan be developed.
Projected loadingsare used to projectfuture WWTF loading capacities and determine
improvements required to increase treatment capacity.
The projected BODand TSS loadings at the WWTF were developed using the following
5
information:
Average annual BODloadings were projected using the 2019average annual loadings
5
as the baseline and adding 0.20ppcd, which isthe average annual BODloading per
5
capita per day defined in the Orange Book, multiplied by the projected increase in sewer
population from 2019.This estimation from the Orange Book represents residential
contributions to loading,and it isassumed edpopulation growth
will bemainly residential.
Average annual TSS loadings were projected using the 2018 average annual loadings as
the baseline and adding 0.20ppcdmultiplied by the projected increase in sewer
population from 2018, similar to the BODloading projections.
5
The loadingpeaking factorsshown in Table 4-7 were used for estimating maximum
month average loadings from projected average annual loadings.
From 2025to buildout, the population includes the growth as a result of expanding the
sewer service area as described in Chapter 3.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Summaries of the projected BOD and TSS loadings for the sewer system population within City
5
limits, additional sewer expansion, and the total of the two populations, are presented in
Tables 4-14 through 4-19, respectively.
Table 4-14
Projected WWTF Influent BOD Loading for Sewer System Population Within City Limits
5
Projected Max.
Projected Average
Percent of NPDES
Equivalent Sewer
Month Average
Annual BOD
Permit Max.
System
5
BOD
5
3
1
Population
Month Limit
(ppd)
2
(ppd)
Year
20189,5592,5092,96879%
2019 (Baseline)9,6692,5912,71872%
20209,7572,1472,42265%
20219,8292,2212,50067%
20229,9812,6542,93978%
202310,1342,6842,97379%
202410,2892,7153,00780%
202510,4452,7473,04281%
202610,6032,7783,07782%
202710,7622,8103,11283%
202810,9232,8423,14884%
202911,0852,8753,18485%
203011,2482,9073,22086%
203111,4132,9403,25787%
203211,5802,9743,29388%
2033 (+ 10 years)11,7483,0073,33189%
203411,8863,0353,36190%
203512,0253,0633,39290%
203612,1653,0913,42391%
203712,3213,1223,45892%
203812,4793,1533,49393%
203912,6393,1853,52894%
204012,8013,2183,56495%
204112,9653,2513,60096%
204213,1323,2843,63797%
2043 (+ 20 years)13,3003,3183,67498%
Buildout23,0355,2655,831155%
1 = Projected average annual BOD loadings were estimated by using the 2019 average annual BOD loading as the baseline and
55
adding 0.20 ppcd (which is the BOD loading per capita per day as defined in Ecology's Criteria for Sewage Works Design) multiplied
5
by the projected increase in sewer population from 2019.
2 = Projected maximum month average BOD loadings were estimated by multiplying the projected average annual BOD loading by
55
the average historic maximum month to average annual BOD loading peaking factor from 2016 through 2019, which was 1.11.
5
3 = The City's WWTF is permitted for a maximum month average influent BOD loading of 3,754 ppd.
5
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-15
Projected WWTFInfluent BODLoadingfor Sewer System Special Study Area Expansion
5
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-16
Total Projected WWTF BOD Loading including Special Study Area Expansion
5
Projected Max.
Projected Average
Percent of NPDES
Equivalent Sewer
Month Average
Annual BOD
Permit Max.
System
5
BOD
5
3
1
Population
Month Limit
(ppd)
2
(ppd)
Year
20189,5592,5092,96879%
2019 (Baseline)9,6692,5912,71872%
20209,7572,1472,42265%
20219,8292,2212,50067%
20229,9812,6542,93978%
202310,1342,6842,97379%
202410,2892,7153,00780%
202510,5532,7683,06682%
202610,8192,8213,12583%
202711,0862,8753,18485%
202811,3542,9283,24386%
202911,6242,9823,30388%
203011,8963,0373,36390%
203112,1693,0913,42491%
203212,4443,1463,48593%
2033 (+ 10 years)12,7203,2023,54694%
203412,9273,2433,59296%
203513,1403,2863,63997%
203613,3613,3303,68898%
203713,6033,3783,741100%
203813,8533,4283,797101%
203914,1113,4803,854103%
204014,3793,5333,913104%
204114,6563,5893,975106%
204214,9443,6464,039108%
2043 (+ 20 years)15,2423,7064,105109%
Buildout25,8065,8196,445172%
1 = Projected average annual BOD loadings were estimated by adding City limit and sewer system expansion loadings together.
5
2 = Projected maximum month average BOD loadings were estimated by adding City limit and sewer system expansion loadings
5
together.
3 = The City's WWTF is permitted for a maximum month average influent BOD loading of 3,754 ppd.
5
According to these projections, the WWTF will exceed the NPDES permit maximum month limit
capacity for BOD during the 20-year planning period. However, the City should prepare the
5
WWTF for upgrades when the maximum month average BOD load exceeds 85 percent of the
5
NPDES permit limit. According to these projections, the City will need to start planning and
designing WWTF upgrades by 2027. If the special study area expansion is not implemented,
then these upgrades will be delayed until 2029.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-17
Projected WWTF Influent TSS Loading for Sewer System Population Within City Limits
Projected Max.
Projected Average
Percent of NPDES
Month Average
Equivalent Sewer
Annual TSS
Permit Max.
TSS
System
3
1
Month Limit
(ppd)
2
Population
(ppd)
Year
2018 (Baseline)9,5592,4932,79961%
20199,6692,4372,68659%
20209,7572,1882,72560%
20219,8292,1462,48154%
20229,9812,5772,86263%
202310,1342,6082,89663%
202410,2892,6392,93064%
202510,4452,6702,96565%
202610,6032,7023,00066%
202710,7622,7343,03566%
202810,9232,7663,07167%
202911,0852,7983,10768%
203011,2482,8313,14369%
203111,4132,8643,18070%
203211,5802,8973,21770%
2033 (+ 10 years)11,7482,9313,25471%
203411,8862,9583,28572%
203512,0252,9863,31573%
203612,1653,0143,34773%
203712,3213,0453,38174%
203812,4793,0773,41675%
203912,6393,1093,45276%
204012,8013,1413,48876%
204112,9653,1743,52477%
204213,1323,2083,56178%
2043 (+ 20 years)13,3003,2413,59979%
Buildout23,0355,1885,760126%
1 = Projected average annual TSS loadings were estimated by using the 2018 average annual TSS loading as the baseline and adding
0.20 ppcd (which is the TSS loading per capita per day as defined in Ecology's Criteria for Sewage Works Design) multiplied by the
projected increase in sewer population from 2018.
2 = Projected maximum month average TSS loadings were estimated by multiplying the projected average annual TSS loading by the
average historic maximum month to average annual TSS loading peaking factor from 2016 through 2019, which was 1.11.
3 = The City's WWTF is permitted for a maximum month average influent TSS loading of 4,568 ppd.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 4-18
Projected WWTF Influent TSS Loading for Sewer System Special Study Area Expansion
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CITY OF PORT TOWNSENDGENERAL SEWER PLANFLOW AND LOADING ANALYSES
Table 4-19
Total Projected WWTF TSS Loadingincluding Special Study Area Expansion
Projected Max.
Projected Average
Percent of NPDES
Equivalent Sewer
Month Average
Annual TSS
Permit Max.
System
TSS
3
1
Population
Month Limit
(ppd)
2
(ppd)
Year
2018 (Baseline)9,5592,4932,79961%
20199,6692,4372,68659%
20209,7572,1882,72560%
20219,8292,1462,48154%
20229,9812,5772,86263%
202310,1342,6082,89663%
202410,2892,6392,93064%
202510,5532,6922,98965%
202610,8192,7453,04867%
202711,0862,7983,10768%
202811,3542,8523,16769%
202911,6242,9063,22771%
203011,8962,9603,28772%
203112,1693,0153,34773%
203212,4443,0703,40875%
2033 (+ 10 years)12,7203,1253,47076%
203412,9273,1673,51677%
203513,1403,2093,56378%
203613,3613,2533,61279%
203713,6033,3023,66680%
203813,8533,3523,72181%
203914,1113,4033,77983%
204014,3793,4573,83884%
204114,6563,5133,90085%
204214,9443,5703,96487%
2043 (+ 20 years)15,2423,6304,03088%
Buildout25,8065,7426,376140%
1 = Projected average annual TSS loadings were estimated by adding City limit and sewer system expansion loadings together.
2 = Projected maximum month average TSS loadings were estimated by adding City limit and sewer system expansion loadings
together.
3 = The City's WWTF is permitted for a maximum month average influent TSS loading of 4,568 ppd.
According to these projections, the WWTF will not exceed the NPDES permit maximum month
limit capacityfor TSSduring the 20-year planning period. However, the City should preparethe
WWTF for upgrades when the maximum month average TSSload exceeds 85percentof the
NPDES permit limit. According to these projections, the City should prepare for WWTF upgrades
for TSS by 2041.
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CHAPTER 4 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
SUMMARY
Table 4-20 provides a summary of the existing, 10-year (2033), planning year (2043), and
buildout flow, and BOD and TSS loadings and treatment
5
systems.
Table 4-20
Summary of Existing and Projected Flow and Loading at the WWTF
Flow
(MGD)
ExistingProjectedProjectedProjected
(2018)20332043Buildout
Average Annual Flow0.871.191.462.39
Max. Month Average Flow1.161.591.943.19
Max. Day Flow1.823.384.126.77
Peak Hour Flow3.064.916.069.82
BOD
5
(ppd)
ExistingProjectedProjectedProjected
(2019)20332043Buildout
Average Annual BOD
2,5913,2023,7065,819
5
Max. Month Average BOD
2,7183,5464,1056,445
5
TSS
(ppd)
ExistingProjectedProjectedProjected
(2018)20332043Buildout
Average Annual TSS2,4933,1253,6305,742
Max. Month Average TSS2,7993,4704,0306,376
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5|POLICIESANDCOLLECTIONSYSTEMDESIGN
CRITERIA
INTRODUCTION
The City of Port Townsend(City) operates and plans sewer service for the City and associated
sewer service area residents and businesses according to the design criteria, laws,and policies
that originate from the U.S.Environmental Protection Agency(EPA)and the Washington State
Department of Ecology(Ecology).
These laws, design criteria,
sewer system on a daily basis, for growth and improvements.The
overall objective is to ensure that the City provides high quality sewer service at a fair and
reasonable cost to its customers. These laws, design criteria, and policies alsoset the standards
the City must meet to ensure that the sewer system is adequate to meet existing and future
flows.The collection Chapter 6,and the
analysis of the existing wastewater treatment system is detailed in Chapter 7.The
recommended improvements for the collection system and wastewater treatment systems are
identified in Chapter 10.
The City Council adopts regulationsand policiesthatcannot be less stringent or in conflict with
those established by the federaland state governments.
ordinances, memoranda,and operational procedures,many of which are summarizedin this
chapter.
The City will maintain an updated General Sewer Plan(GSP)that is coordinated with the Land
Use Element of the /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ so that new development will be located where
sufficient sewer system capacity exists orwhere the collection systemcan be efficiently and
logically extended.
The policies associated with the following categories are presented in this chapter.
Regulations
Customer Service
Collection System
Lift Stations
Operational
Organizational
Financial
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
REGULATIONS
National Pollutant Discharge Elimination System Permit
Wastewater discharge into surface waters of the State shall have a National Pollutant Discharge
Elimination System (NPDES) permit from Ecology. Refer to Chapter 2
NPDES permit. The permit contains a flow limit, influent and effluent quality standards,
monitoring requirements, pretreatment requirements, and system maintenance requirements.
A copy of the NPDES permit is included in Appendix C.
Other Regulations and Required Permits
Refer to Chapter 2
Wastewater Treatment Facility (WWTF). In addition, Chapter 173-240 Washington
Administrative Code (WAC) defines requirements for wastewater facilities plans and reports,
and the City follows the guidelines in 2008 /ƩźƷĻƩźğ ŅƚƩ {ĻǞğŭĻ ƚƩƉƭ 5ĻƭźŭƓ (Orange
Book).
CUSTOMER SERVICE POLICIES
Evaluate the prioritization of capital facilities to serve the housing and density needs of
the City based on the upcoming 2025 periodic update. This likely will replace the current
Policy 14.2, concerning tiers, in the Land Use Element of the /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ.
Existing Sewer Service and Connection
Prioritize capital facilities, services, and utilities within the urban growth tiers per Policy
14.2 of the /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ and Title 13 of the Port Townsend Municipal Code
(PTMC). PTMC 13.01.120 addresses City participation when funds are available as
identified in the 6-year capital facilities plan. Chapter 13.23 specifies that in Tier 1, the
City will participate in sewer extensions when existing structures connected to an
on-site septic system benefit. Historic implementation of the tiering system has not
occurred due to the lack of funding for such sewer extensions. As a result, sewer
extensions have occurred at the cost of the developer who often has utilized the
latecomer fee process for potential reimbursement from benefiting properties.
Increase the capacity of the collection system and WWTF to reflect increased usage
/ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ Land Use Element.
Urban Growth Area (UGA)
sewer service shall not extend beyond the City limits.
Provide sewer service to properties within the sewer service area, provided all
policies related to service can be met. Ensure that existing and new developments
within the UGA have WWTF and collection line capacities to meet their needs, as well as
State and federal discharge standards.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
Chapter 13.22 PTMC requires allproperties that develop or redevelop within the City
limitsto connect when the development is located within
260feet of a wastewater collection line with the following exception: new single-family
residences that are more than 260feet from the nearest City sewer main and are
subject to review under Chapter 19.05PTMC, Critical Areas, and the impacts of the
system are adequately mitigatedand conditioned through critical areas review. Any
development thatis a subdivision, short plat, or Planned Unit Development subjectto
PTMC Title 18, a land use or permit approval that requires a threshold determination
under Chapter 19.04 PTMC, or structures (other than single-family residences) subject
to the CriticalAreas ordinance all require sewer connection regardless of location.
Additionally, any on-site septic systemsmust be approved by the Jefferson County
PublicHealthand be on a lot of sufficient size to meet the requirements for on-site
systems.
Sewer system extensions,required to provide sewer service to proposed developments,
shall be approved by the Department of Public Works and must comply withthe City
most current, adopted Engineering Design Standards, PTMCTitle 13, all applicable
Revised Codesof Washington(RCWs)and WACs, guidance administered byEcology, and
the WSDOT/APWA Standard Specifications.All costs of the extension shall be borne by
the developer or applicant.Theng Standards areincluded in
AppendixG.
For sewer service applications within the City limits, the City will review the availability
for sewerservice at the time of utility development permit review.During the utility
developmentpermitting process, theCity will determine if sewer is available for the site
and will address the sizing and locationof the sewer extension.
Sewer collection system, lift station,and WWTFcapacitywill be considered when
providing sewer availability to applicants.
Seweravailability shall expire at the time that theutility developmentpermit expires.
Time extensions in regard toseweravailability shall be granted in accordance with the
associated permit requirementsand PTMC.
Chapters 13.21 through 13.24PTMC
system.
ProposedSewerServiceandConnectionPolicies
The following proposed policies are part of this GSPthrough its adoption by the City Council
and approval by Ecology. These proposed policies will need to be memorialized as part of the
2025 periodic /ƚƒƦƩĻŷĻƓƭźǝĻ tƌğƓ adoption, as well as updates to the PTMC and the
Engineering Design Standards.
s
sewer service shall not extend beyond the City limits except as permitted by the Growth
Management Act and governing laws according to the Special Study Area expansion
described in Chapter 2.
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Remove and replace the ineffective tiering system with an alternative approach to
achieving the goals of the City concerning sewer extensions.
Develop policies and incentives to maximize density, including multi-family
development.
Develop policies and incentives to support affordable and attainable housing. For the
purpose of this policy, attainable housing will need to be defined in terms of
affordability levels or housing type.
Develop policies to minimize the use of on-site septic systems while recognizing the
requirements of WAC 246-272A-0025, which the local health officer is required to
follow. This WAC allows for the development of on-site septic systems when a property
is located more than 200 feet from a public sewer main. This provision does not apply to
land use actions such as subdivisions.
Develop sewer extension regulations related to pre-platted plots incentivizing
development of density on pre-platted lots or preservation of pre-platted lots for future
development. This goal is to discourage the combination of pre-platted lots.
Septic System Policies
Currently, 211 properties within the City limits have been identified as using on-site
sewage systems. According to the Growth Management Act, no new on-site septic
sewage systems should be allowed in the UGA as new development is intended to be at
urban densities that require sewers. In addition, Chapter 70.118 RCW requires counties
to develop and implement management plans for on-site sewage systems.
No new on-site septic systems are allowed inside the City limits on properties where
existing City sewer main is within 260 feet of the boundary of the subject property
according to PTMC.
Existing single-family homes with septic systems are required
sewer system unless the nearest sewer main is greater than 260 feet. All septic systems
in the City shall be monitored per Jefferson County Public Health regulations.
All non-developing properties that annex into the City are encouraged to phase out their
Property owners with a failing septic system, as documented by Jefferson County Public
Health, shall connect to the sewer system unless the parcel is greater than
260 feet from the nearest existing sewer main, in which case the septic system may be
repaired.
The City is aware of Engrossed Senate Bill (ESB) 5871, which became effective on
July 24, 2015, and requires cities, towns, and counties to offer an administrative appeals
process to consider denials of permit applications to repair or replace a septic system
where connection to a sewer system is required for single-family residences. The City
will review appeals to repair or replace septic systems as they are submitted in
accordance with ESB 5871.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
COLLECTIONSYSTEMPOLICIESANDDESIGNCRITERIA
SanitarySewerDesignCriteria
Standards for sewer system facilities are defined by WAC173-240-050.
All sewer lines and facilities within the City shall be designed in accordance with good
engineering practice by a professional engineer with the minimum design criteria
presented in the /ƩźƷĻƩźğ ŅƚƩ {ĻǞğŭĻ ƚƩƉƭ 5ĻƭźŭƓ,prepared by Ecology,August 2008,
or as superseded by subsequent updates.Chapter C1of this documentincludes
standards and guidelines for design considerations (e.g.,minimum pipe sizes, pipe
slopes,and wastewater velocities), maintenance considerations, estimating wastewater
flow rates, maintenance hole locations, leak testing,and separation from other
underground utilities.These criteria have been establishedto ensure that the sanitary
sewers convey the sewage and protect the public health and environment.The sewer
lines alsoshallconform to the latest regulatory requirements relating to design.
Sewers shall be designed and constructed in accordance with the Citmost current
WastewaterEngineering Standards.
GravitySewerDesignCriteria
All sewers shall be designed as a gravity sewer whenever feasibleand buried at a
minimum depth of 5 feet.Exceptions to depth requirements may be made on a limited
basisto facilitate gravity sewer extension.
The layout forextensions shall provide for the future continuation of the existing system
as determined by the City.The smallest diameter sewer allowed is 8 inches for gravity
mains. A6-inch sewer may be approved when expansion to serve future customers is
not expected.
Side sewer connection laterals within City rights-of-way shall be 6 inches at a minimum,
and side sewer laterals on private property shall be 4 inches at a minimum, in
accordance with the Standard Details.
A 6-inch-diameter lateral is required at a minimum for all commercial, industrial, and
multi-family connections.A larger diameter lateral may be required based on the
projected wastewater flows from the connection.
Maintenance holes shall be a minimum of 48 inches in diameterand will be spaced at
intervalsideally at every blockas set forth in the WastewaterEngineering
Standards.City blocks are typically 260 feet long. On occasion, maintenance holes may
be spaced at 520 feet subject to City Engineer approval. Only new polyvinyl chloride
(PVC)pipes will be considered for extending the maintenance hole interval.
Maintenance holes also shall be located at changes in grade, direction,andpipesize,
and at intersections.Maintenance holes located in areas subject to inflow may be
required to include a watertight insert at the request of the Public Works Director.
New mains connecting to an existing main shall be made via a new or existing
maintenance hole.
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
The minimum sewer main slope shall be 0.40feet per100feet for 8-inch-diameter
sewer lines. The minimum slope may be reduced if approved by the City Engineer.
Sewers shall have a uniform slope between maintenance holes.
Testing of the gravity sewer lines and maintenance holes shall be completed in the
presence of the City. Testing shall be performed in accordance with WSDOT/APWA
Standard Specifications Section 7-17.3(2).
Design Flow Rates
All new gravity sewers shall be designed and constructed to have a minimum velocity of
2 feet per second when flowing full.
Existing sewers may surcharge up to 1-foot over the crown of the pipe during the peak
hour flow caused by a 20-year, 24-hour storm before requiring replacement. This
criterion shall not apply if this storm produces overflows onto the finished floors of any
customers. New sewers shall be designed to be no more than 75-percent full during the
same storm over the 50-year design life of the main.
No overflows will be permitted.
This GSP did not analyze every sub-basin and instead focused on trunkline sewers.
When development occurs within a sub-basin, staff and developers will need to check
the capacity of the sub-e City generally result in
gravity sewers being steeper than minimum slopes. For reference, an 8-inch gravity
sewer at 0.4 percent generally will serve 300 single-family units. This is a conservative
rule of thumb to check when developing an infrastructure
pre-platted environment and for densification of housing.
Separation Between Sanitary Sewer and Other Utilities
A minimum horizontal separation of 10 feet and a minimum vertical separation of 3 feet
is required between sewer and domestic water lines (edge to edge).
Wastewater Engineering Standards (Appendix G) will be followed, and the
/ƩźƷĻƩźğ ŅƚƩ {ĻǞğŭĻ ƚƩƉƭ 5ĻƭźŭƓ should be followed
for difficult spacing or other situations.
Design Period
The design period is the length of time that a given facility will provide safe, adequate,
and reliable service. The design period selected is based on the economic life of a given
facility, which is determined by the structural integrity of the facility, the rate of
degradation, the replacement cost, the cost of increasing the capacity of the facility, and
the projected population growth rate serviced by the facility.
The life expectancy for new sanitary sewers, using current design practices, is in excess
of 50 years.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
ForceMainDesignCriteria
All force mains within the City shall be designed in accordance with good engineering
practice by a professional engineer with the minimum design criteria presented in the
/ƩźƷĻƩźğ ŅƚƩ {ĻǞğŭĻ ƚƩƉƭ 5ĻƭźŭƓ,prepared by Ecology, August 2008, oras superseded
by subsequent updates.Chapter C2of this documentcontains design considerations for
force mains.
LowPressureSewerDesignCriteria
Formalizing the use of low pressure sewer installation is necessary for effective
implementation. The recommended policy and engineering standards for low pressure sewers
should include the following principles:
Low pressure sewers should only be used where gravity sewers are not reasonably
feasible.
Low pressure sewers should only be used in single-family residential zones where
growth is predictable.
Low pressure sewers should not be used in multi-family zones.
Low pressure sewer pumps need to be owned and maintained by the property owners.
The pump system should be of sufficient quality and contain alarms to minimize the
chance of sewer overflow.
Low pressure laterals are to be privately owned and maintained.
Low pressure forcemains should be designed to City standards and be City owned and
maintained.
Engineering design standardsfor low pressure sewer mains should specify durable
materials such as high-density polyethylene (HDPE)pipe, have ample clean out and
flushing ports, and be sized to accommodate entire areas where gravity sewer is not
feasible.
A master plan of locationswhere low pressure sewers are allowed should be developed
as incorporated into the Engineering Design Standards.
SideSewerDesignCriteria
Side sewersshall be constructedin accordance with all applicable City, local, and State
regulations. Refer to the PTMCandStandards
(Appendix G)forspecific criteria.
LIFTSTATIONPOLICIESANDDESIGNCRITERIA
most current Wastewater
Engineering Standardsand the Ecology/ƩźƷĻƩźğŅƚƩ{ĻǞğŭĻ ƚƩƉƭ 5ĻƭźŭƓ.
Lift stations are expensive to operate and maintain; therefore, their installation should
be limitedto locations where gravity is not reasonably feasible only.
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
OPERATIONAL POLICIES
Facilities Maintenance
Facility maintenance is performed by the Wastewater and Compost Facility divisions of Public
Works. This includes the maintenance of the WWTF, the Compost Facility, and all lift stations.
Equipment breakdown is given the highest maintenance priority, and repairs should be
made as soon as possible.
Equipment should be replaced when it becomes obsolete.
Worn parts should be repaired, replaced, or rebuilt before they represent a high failure
probability.
Equipment that is out of service should be returned to service as soon as possible.
A preventive maintenance schedule shall be established for all facilities, equipment, and
processes.
Spare parts shall be stocked for all equipment items whose failure will impact the ability
to meet other policy standards.
Tools shall be obtained and maintained to repair all items whose failure will impact the
ability to meet other policy standards.
Dry, heated shop space should be available to all maintenance personnel to maintain
equipment and store parts.
Written records and reports will be maintained on each facility and item of equipment
showing its operation and maintenance history.
Collection System Maintenance
The collection system is maintained by the Streets Maintenance and Collections Division of
Public Works.
At a minimum, all existing gravity mains shall be video inspected every 10 years.
The target gravity main video inspection interval is 5 years based on the need to
rehabilitate much of the gravity system.
Gravity mains that experience periodic problems shall be video inspected every 1 to
3 years depending on the documented history of problems.
Video inspection records will be maintained and incorporated into prioritization of
either pipeline replacement or in-situ rehabilitation.
Cleaning or jetting of sewer lines shall occur based on video inspection records.
Root cutting of sewer lines shall be based on video inspection records and historical
sewer blockage trends. Many gravity sewer lines in the City require annual root cutting.
These sewer lines should be prioritized for rehabilitation.
Many maintenance holes in the collection system are aging past their design life and
experiencing corrosion. Some maintenance holes are still mortared rock or brick.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
Rehabilitation and replacement of maintenance holes on a systematic basis should be
implemented based on inspection records.
TemporaryandEmergencyServices
Compliance with construction standards (not water quality standards)may be deferred
for temporary sewer service.Provisions for reliability is necessary for temporary service
to reasonably prevent system failures such as overflows.
Compliance withall standards may be deferred for emergency sewer service.
Compliance with all applicable NPDESwaste dischargepermit requirements must be
met.
Reliabilities
The City shall invest sufficient resources toensure that the sewer system is constructed,
operated,and maintained to ensure consistent and reliable service is provided to its
customers.
Reliability is achieved through investment in rehabilitation or replacement of collection
system components, as well as redundant systems. For example, including back-up
generators for critical lift stations improves reliability.
The entire WWTF is builtwith redundant systems to ensure reliable operations. When
redundant systems are compromised or need repair, restoring redundant systems
should be prioritized.
ORGANIZATIONALPOLICIES
Staffing
The sewer treatment and collection systems operate based on the good work of staff.
Therefore, adequate staffing with appropriate training and skills is a key to success. The City
createda skills development program for the Department of Public Works staff to improve skills
and address succession planning. The 2024 budget reflects the addition of awastewater
treatment apprentice position, as well as restoration of a frozenposition in the Streets
Maintenanceand Collections Division. The following staffing policies are included in this GSP:
The sewer utility staffing levels are established by the City Council based on the financial
resources of the City and needs of the sewer utility.Staffing investments are a key
portion of the periodic sewer rate modeling and projections. Staffing, capital
improvements, and required operational costs are to be balanced based on rates set by
City Council.
The City has three Group IIcertified wastewater treatmentplantoperatorsat the WWTF
andtwo Group Icertified wastewater treatmentplantoperatorsat the Compost Facility.
Staffing must comply with the permit-required certification levels associated with both
treatment facilities. Both the WWTF and the Compost Facility are Group II operator
facilities. The staffing objective is as follows:
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
o WWTF Three certified Group II operators, one of which serves as crew chief for
both the WWTF and the Compost Facility.
o Compost Facility Two certified Group II operators.
o WWTF and Compost Facility A shared entry level position serves as an
o Within the City Certified electrician capable of working with 480 volt, three-
Resources Division,
Wastewater Division, and Compost Facility Division of Public Works.
Personnel certification and training will comply with State-established standards. The
City job descriptions reflect the state certification requirements. The City encourages
and supports training in terms of continuing education and skill development to work in
concert with State certification requirements.
FINANCIAL POLICIES
General
The sewer utility is an enterprise business unit of the City. Enterprise business units by
definition are required to be fiscally sustainable in terms of self-supporting through rates and
charges. Rates and charges need to be analyzed periodically to ensure revenues match
expenses of operations and investment in infrastructure. A balanced approach to establishing
reasonably affordable rates along with the needs of the sewer system to ensure compliance
with public health and safety laws is the focus of periodic rate reviews. The following fiscal
policies help establish this balance. Note, that a number of fiscal assumptions are included in
Chapter 11 with respect to rate setting. The following policies and assumptions in Chapter 11
must align.
The City will set rates, charges, and fees to maintain sufficient funds to operate,
maintain, and upgrade its sewer system as necessary to provide safe and reliable sewer
service to its customers. These rates will comply with State regulations and be evaluated
in conjunction with the annual budget process to ensure that forecasted expenses and
impacts of regulations are reflected in the rate structure. Typically, rates are established
for a 5-year period and then re-evaluated against actual operational costs and capital
infrastructure needs. The GSP will be reviewed every 5 years and no less than every
10 years. The annual budgeting process refers to the projected expenses included in the
Each developed lot or parcel with active water service (excluding irrigation) is required
to be connected to subject to the presence of an existing on-site
septic system permitted by Jefferson County Public Health. Each property shall be
subjected to a monthly sewer charge whether or not such lot or parcel of real property
is actually connected to the sewer system when there is an active domestic water
account. The purpose of this policy is financial sustainability of the sewer system to
ensure that all developed properties pay a base fee whether discharging to the sewer
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
systemor not. This base fee provides stable funding for the fixed costs incurred by the
City for operating a sewer system for the overall benefit of community public health.
All new development shall be connected to the sewer system unless meeting the
exemption requirements outlined in PTMC and state law. Note, that per PTMC, all
subdivisions shall be required to provide sewer to all newly created or altered lots
intended for commercial and/or residential development.
The system developmentcharge(SDC)and all applicable connection fees must be paid
at the time a sewer connection is obtained. SDCs and fees shall be paid prior to issuance
of a finalpermit approval or prior to occupancy, whichever comes first,accordance with
The City shall collect sewer extension charges for owners of properties that individually
benefit from publicly built sewer extension facilities, except for those property owners
who previously paid for their fair share of such an extension through a Local
Improvement District (LID) or ULID. This program has not been established and this
policy is recommended to be implemented as away to create a revolving revenue
source to facilitate sewer extensions. The cost of sewer extensions paid by the City can
be recovered through Local Facility Charges, frontage fees, or LIDs.
System development charges should be used to offset rate impacts for capital
improvements and not fund debt service.
Deferral of SDCsshould be considered in the setting of system development charge
levels to make sure financial objectives are met. For example, if 10of 50 new housing
units per year are affordable, SDCswould need to account for a 20-percent decrease in
revenue.
City Council adopted an income-based discount program. This program should be
monitored over time to evaluate participation levels and impacts on rates. The purpose
of the income-based discount program is to lower the rate impact to community
members burdened by the cost of housing and associated costs.
standards and
shall be responsible for any portion of the costs that are attributable to general facilities,
such as over-sizing or over-depth requirements,and offer latecomers fees to
developers. PerRCW, the City may participate in developer extension projects and
practice has not been implemented in the past and is recommended as a future way to
recover costs and contribute to revolving investment in sewer infrastructure extensions.
If written application for service is approved by the City, the application shall be
considered as a contract in which the applicant agrees to abide by such rates, rules, and
regulations in effect at the time of signing the application or as may be adopted
thereafter by the City and to pay all charges, rates, and fees promptly.
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
In addition to all other user rates and service connection fees required to be paid to the
City, service call fees may apply when made at the request of the owner or occupant of
the premises for assistance in locating and/or repairing a plugged sanitary sewer drain in
The City shall manage its income and expenses in a self-supporting manner in
compliance with applicable laws and regulations and its own financial policies.
The City shall establish a CIP that describes the anticipated improvements or
modifications to the sewer system, planned replacement of aging facilities, upgrades to
existing facilities to provide additional capacity for projected growth, and construction
of general facilities to aid growth. The CIP will be updated at a minimum on a 2-year
basis associated with the requirement of the Growth Management Act and maintaining
a current Capital Facilities Plan.
The City shall maintain reserves for operations consistent with City reserve policies. The
reserves should consider emergencies, bad debts, existing debt coverage, reserve
requirements, and fluctuations in revenue.
The City will maintain information systems that provide sufficient financial and statistical
information to ensure conformance with rate-setting policies and objectives.
Currently, the sewer utility is part of a combined utility with the water utility. It is the
policy of the City to separate these utilities into separate funds to ensure accurate cost
accounting and sustainability of both utilities.
Connection Charges
Connection fees are an important source of revenue for the sewer, water, and stormwater
utilities. The owners of properties that have not been assessed, charged, or borne an equitable
share of the cost of the sewer collection system and WWTF pay connection fees for their
equitable share of connecting to the system. Connection fees help reduce the burden to
existing rate payers. It is noted that some of these charges, such as SDCs for qualifying low
income housing, can be deferred according to PTMC. While connection charges are an
important source of resources for the sewer utility, SDC levels should be evaluated for impacts
on housing and land prices. Higher SDCs combined with other permitting and connection fees
typically drive down the price of land to meet market conditions. However, in some cases, land
prices do not come down, thereby impacting the total cost of housing. The primary challenge
with connection charges for Port Townsend is that much of the City is currently inaccessible to
sewer per state and City codes, and many of the pre-platted rights-of-way do not currently have
sewer pipes within them. Sewer extensions are costly, and the City sewer utility is already
stressed in terms of required upgrades and repairs. Thus, there is a tradeoff between
connections fees and housing affecting rates and financial sustainability. One possible
approach, when legally allowed, is to expand the City deferral program to more housing
options, sizes, and affordability levels or to find additional general fund sources to support
objectives.
The following connection fees are available to the City to assist in sewer utility financial
sustainability. Some of these strategies have been utilized in the past and others have not.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANPOLICIES ANDCOLLECTION SYSTEMDESIGN CRITERIA
1.Latecomers Fees(also known as Developer Extension Charges): Latecomers fees are
negotiated with the City, developers,and property owners for the reimbursement of a
pro rata portion of the original costs of sewer system extensions and facilities and are
documented in a Developer Extension Agreement, depending on the application.
Latecomer fees have been the primary tool for developers to obtain partial
reimbursement for their costs of installing or extending sewer mains. Many latecomers
have been filed with the City in the last 20 years. Latecomer reimbursements are due for
any new connections to sewer in which an agreement is in place for a period of
20years.
2.Local Facilities Charges: If applicable, Local Facilities Charges may be due based on
established fees by ordinance for specific facilities benefiting specific properties. Pursue
the use of Local Facilities Charges for specific system infrastructure, such as trunkline
extensions, trunkline upsizing, and lift stations. Local Facilities Charges should be used in
areas where new connections are expected. Local Facilities Charges have not been used
historically in the City.
3.Frontage Charges: If applicable, Frontage Charges may be due to reimburse the City for
investment of sewer pipelines benefiting undeveloped properties. Frontage Charges
have not been used historically in the City.
4.LIDAssessments: If applicable, these assessments are often paid at the time of
connection as required by lending institutions. These assessments take priority lien
status right behind taxes. LIDscan be implemented by City Council Resolution or by
petition of property owners. LIDs have not been used historically in the City.
5.SDCs: Connection chargesshall be assessed against any property connecting to the
sewer system.This charge is for the major facilities that deliver the sewage to the
WWTFand for the facilities to treat and dispose of the sewage.This charge reimburses
customers who have paid for the facilities described and for building capacity to
accommodate growth.
6.Outstanding charges resulting from account delinquency.
This GSP recommends the City develop a connection policy reflecting its housing objectives.
Examples include the following strategies as detailed previously.
The City developed an issue paper (white paper) in 2023suggesting expanding the
deferral program for SDCsto housing that is affordable andhouseholds earning as much
as 200percentof the Area Median Income. Further study is necessary to determine the
appropriate affordability level to ensure gifting of public funds prohibitions are not
violated. The intent of this issue paper is to address the inability for many households to
obtain housing,including workforce, fixed income, and other situations thatresult in
incomes that cannot afford housing in the City.
Set SDClevels tied to household size,such asthoseadopted by Oak Harbor. This
recognizes that a small house has less impact on the sewer system than a large house.
Port Angeles set up a program to reduce fees for middle housing.
A deferral program or SDCtied to infill housing would recognize the benefit of new
housing and rate payers connecting to the system where infrastructure already exists.
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CHAPTER 5 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Consider developing a front footage connectionfee for all pipes installed by the City to
develop a revolving fund for the installation of sewers.
Using LIDs for new sewer extensions can be a useful tool that captures all benefited
properties. This is especially beneficial where there are large unsewered areas of
undeveloped properties or where existing septic systems are experiencing failures. LIDs
could be implemented in a manner to incentivize development of underutilized
property.
Formalization of connection fee policies occurs through City Council adoption of various
connection fee levels or programs.
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|
6SEWERCOLLECTIONSYSTEMEVALUATION
INTRODUCTION
This chapter presents the analysis of the existing City of Port Townsend(City)wastewater
collection system. Individual sewer system components were analyzed to determine their
ability to meet policies and design criteria under both existing and projected flow conditions.
The policies and design criteria are presented in Chapter 5,and the wastewatersystem flow
and loading analysis is presented in Chapter 4. A description of the existing wastewatersystem
facilities and current operation is presented in Chapter 2.A distribution of growth map for the
purpose of hydraulic modeling of trunklines is included in Chapter 3. Thecapital improvement
projects resulting from the existing and projected flow condition analysesarepresented in
Chapter 10.
COLLECTIONSYSTEMANALYSIS
HydraulicModel
Background
A computer-based hydraulic model of the existing sewer system was created using the
®
SewerGEMSprogram developed by Bentley Systems.The entire sewer collection systemwas
modeled, including gravity mains, force mains,and sewer lift stations.The hydraulic model was
created usingthe bestinformationavailable and dataprovided by the City.Pipe locations,
lengths, diameters,and materialswere addedbased on the previous hydraulic sewer model,
GIS data, as-built drawings,various system maps,survey information, and informationacquired
from the City.Maintenance hole invert and rim elevation data from and survey
information was used, ifavailable. The remaining elevation data was extracted from Jefferson
County topographic data.Minimum slope and cover values also were used in the development
of the modelandare annotated in the data files.The output from this model was used to
evaluate the capacity of the existing collection system and identify improvements that will be
required to handle wastewater flows.The model can be updated and maintained for use as a
tool to aid in future planning.Refer to Appendix I for basic data used to construct the model.
Model Limitations
Due to the number of data gaps and assumptions used in the model, the accuracy of the model
should be confirmed prior to undertaking any replacement or rehabilitation projects,especially
for projects not located alonga major trunk sewer. The results of the modeling should be
considered approximate,and additional investigations, such as field surveys, flow monitoring,
and lift station pump down tests,should be performed in the vicinity of any proposed
improvements prior todesign and construction. If it is found that the input information differs
significantly from actual conditions, the model should be updated accordingly and rerun to
confirm the original results.
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
Modeling was performed using a steady-state analysis, which shows all flows reaching all
downstream points simultaneously. This is conservative and not truly representative of
conditions that occur, since it takes some time for wastewater to travel downstream through
the sewer system, which stores and attenuates peak flows.
Flow Data
Existing and projected flow rates for the sewer drainage basins were developed in Chapter 4.
The total existing flows are shown in Table 4-3, and the projected total system flows are shown
in Table 4-10 in Chapter 4. Table 4-11 in Chapter 4 details existing average annual flow and
peak hour flow (PHF) for each sewer lift station. As discussed in Chapter 4
wastewater flow by basin was estimated from population growth per basin as provided by City
planning staff (Figure 3-3) and calculated from peaking factors and per capita flows as
estimated in Chapter 4. The total existing and projected flows by basin are shown in Table 4-12
in Chapter 4. It is recommended that the City obtain additional flow data from the sewer
drainage basins to accurately evaluate capacity in areas with suspected deficiencies for future
planning and design.
Facilities
The hydraulic model of the existing system contains all active existing system facilities.
Available information for the lift stations, such as pump capacity, total dynamic head,
horsepower, wet well diameter, wet well depth, and force main diameter, is included in the
model. For simplicity, the existing lift stations were modeled as having variable frequency drives
(VFDs) on the pumps so that they discharge at the same rate as the influent flow rate regardless
of head conditions.
Hydraulic Analyses Results
Hydraulic analyses were performed based on the existing flow rates (2018), as well as projected
flow rates for 2028, 2033, and 2043. In the evaluation, the criteria for listing an existing sewer
pipe as deficient is that the upstream maintenance hole is surcharged more than 1 foot during
the estimated PHF. The results for the 2028, 2033, and 2043 modeling are included in
Appendix I.
Pipe Capacity Deficiencies
It is intended that this General Sewer Plan (GSP) contain an inclusive list of recommended
system improvements; however, additional projects may need to be added or removed from
the list as growth occurs or conditions change. The City will evaluate the capacity of the
wastewater collection system as growth occurs and development applications are received.
Existing System
Currently, the existing gravity sewers do not have deficient conveyance capacity. That is, no
maintenance hole surcharges over 1 foot above the crown of the pipe during existing peak
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER COLLECTION SYSTEM EVALUATION
flows.Surcharging
only occurs at the discharge of the Monroe Street Lift Station force main to the gravity sewer
on Water Street.Design of a new and larger Water Street gravity sewermainto receive the
flow is underway;therefore, it isnot included in the Capital Improvement Plan (CIP) in
Chapter10.
Future Analyses
The primary driver of gravity main capacity improvements for the 5-year,6-to10-year,and
11-to20-year planning periods are the projected flows from the proposed development of the
Mill site.Fortunately, this flow will be conveyed by gravity to the wastewater treatment facility
(WWTF)following discharge from the proposed Mill Lift Station force main.Existing lift stations
will not be taxed by these additional flows; however, substantial investment in the upsizing of
existing pipelines will be required over the next 20 years to convey these flows to the WWTF.
The following sections providea summary of gravity conveyance deficiencies for the 5-, 10-,
and 20-year design horizons.The colors of the mains to be upsized are red, green,and blue,
respectively,for the 5-, 10-,and 20-year scenariospresentedhere and in Chapter 10.
ЎΏĻğƩCƚƩĻĭğƭƷIǤķƩğǒƌźĭ 5ĻŅźĭźĻƓĭźĻƭ
Figure 6-1 showsCIP SM1. Thesepipelines are estimated to be hydraulically deficient within the
next 5years after the construction of the Mill LiftStation. The pipelines, shown in red, may
need their alignment shifted from existing to get moredistance from existing structures.
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
Figure 6-1 CIP SM1
CIP SM1 must be upgraded simultaneously with the construction of the Mill Lift Station.
ЏΏ Ʒƚ ЊЉΏĻğƩ CƚƩĻĭğƭƷ
The growth of the Mill site will warrant upsizing the gravity pipelines shown in green in
Figures 6-2 and 6-3 by the year 2033.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER COLLECTION SYSTEM EVALUATION
Figure 6-2 CIP SM2
Figure 6-3 CIPs SM3 and SM4
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
ЊЊΏ Ʒƚ ЋЉΏĻğƩ CƚƩĻĭğƭƷ
Sewer mains shown in blue in Figures 6-4 through 6-6 are anticipated to need upgrades by
2043 to be able to convey anticipated flows without causing the pipelines to flow more than
75-percent full.
Figure 6-4 CIP SM5
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER COLLECTION SYSTEM EVALUATION
Figure 6-5 CIP SM6
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
Figure 6-6 CIP SM7
Other Existing Gravity Collection System Deficiencies
The City does not have complete knowledge about the condition of its collection system
because of antiquated and broken video inspection equipment. During the attempted
inspection of the Water Street gravity main in 2023, a contracted video inspection company
recorded mains suspected of being structurally deficient. The results of these inspections were
alarming, as some pipelines contained earthen sediments (Water Street) and others were
cracked, crushed, and becoming oval in cross-section (Washington Street; Figures 6-7 and 6-8).
Only a small sampling
defects were found. It is imperative that the City begin a systematic inspection plan with a goal
of viewing the interior of all pipes and maintenance holes within the next 5 to 10 years. As
these inspections are performed, pipe materials
system to improve system records. Many pipelines are of unknown material, making pipe
lifespan predictions difficult. Gaining knowledge about the existing collection system will allow
the City to identify those mains that are most urgently in need of repair or replacement and will
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CITY OF PORT TOWNSENDGENERAL SEWER PLANSEWER COLLECTION SYSTEM EVALUATION
helpprevent occurrences like the collapse of the Water Streetgravity seweron
December27,2022.
greatly aided by recording pipe materialsand conditionsand storing this information in the GIS
system it hasestablished.Purchase of modern inspection equipment and committing
employees to the inspection of pipelines will yield savings and prevent future wastewater
overflows.
Figure 6-7 CIP SM10
This section of pipe in Washington Street is in danger of imminent collapse.
Figure 6-8 Washington Street Sewer with Cracks
Longitudinal cracks and deformation in Washington Street sewer portend collapse.
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
LIFT STATION ANALYSIS
Lift Station Capacity
Existing System
(Table 4-12) shows that only the Monroe
Street Lift Station does not have adequate capacity. As discussed previously, capacity analyses
of each lift station are based on estimated PHF. According to discussions with the system
during
current operating conditions except for the Monroe Street Lift Station. These deficiencies are
discussed later in this chapter.
2028, 2033, and 2043 Lift Station Needs
Only modest population growth is forecast within the current City limits and it is dispersed
throughout the City as shown in Figure 3-3. Of this growth, less than 20 percent is forecast to
occur in the existing lift station basins. The remainder will flow by gravity to the WWTF. There
will be small, incremental increases to each existing lift station over the next 20 years, leaving
the total flow to be pumped by each station below each their firm capacities. None of the
existing lift stations are forecast to have capacity shortfalls, except for the Monroe Street Lift
Station. The station handling most of the new growth will be the proposed Mill Lift Station.
Predesign studies show that a 1,062 gallons per minute (gpm) capacity is required. Refer to
Appendix J for an estimation of the flows for this lift station. Capacity upgrades are needed for
the Mill and Monroe Street Lift Stations.
aƚƓƩƚĻ {ƷƩĻĻƷ \[źŅƷ {ƷğƷźƚƓ
The Monroe Street Lift Station is currently under capacity and regularly has all three of the
stations pumps operating to convey peak flows. The station has not overflowed, but it is the
with one redundant pump to accommodate PHFs. For this
reason, the capacity must be increased, or the peak flow tributary to the station must be
reduced. As part of the Water Street Sewer Replacement project, scheduled for 2024, new
pump impellers will be installed for each of the pumps. The existing electric motors
have spare capacity to accommodate larger impellers that could deliver approximately 100 gpm
more from the station. However, this will not be enough to bring the lift station into compliance
with desired capacity standards. RH2 Engineering, Inc., (RH2) recommends that inflow in the
basin draining to the lift station be reduced to decrease the load on the lift station.
Lawrence Street, between Fillmore and Monroe Streets, has stormwater inlets connecting to
the gravity sewer (Figure 6-9). This is a likely cause for the Monroe Street Lift Station
overload. This inflow also taxes the capacity of the WWTF unnecessarily with stormwater.
Separation of the storm and sanitary sewer could possibly reduce the hydraulic loads entering
the Monroe Street Lift Station. Smoke testing and video inspection of the sewer main in
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Lawrence Street should be performed to locate the connections between the storm and
sanitary sewer systems.
Figure 6-9 CIP SM9
The sanitary and storm sewers in Lawrence Street must be separated to reduce hydraulic
loads on wastewater facilities.
In addition to capacity shortfalls, the Monroe Street Lift Station is aging andnear the shoreline,
placing it at risk for flooding due to forecasted sea level rise. The City of Port Townsend Sea
Level Rise and Coastal Flooding Risk Assessment (City of Port Townsend & Cascadia Consulting
Group, 2022)(Appendix K) lists the Monroe Street Lift Station as a public facility at risk of
The lift station access hatches must be
elevated or the lift station must be relocated to higher ground.All pumps, pipes, valves,
electrical panels,and controls must be replaced with new units to increase the reliability of this
vital lift station.Flow measurement also should be added to the station to assist the City in
quantifying the inflow tributary to the lift station.
Hydraulically, the lift
condition.It is approaching 60 years in age,and record drawings show that it is cast ironpipe.
When the existing 10-inch cast iron force main is exposed for any reason, theexterior should be
inspected for pitting and corrosion.Cast iron pipe from the 1960s came with cement mortar
lining,and the main could still be in good condition.Out of caution,theCity should monitor the
discharge pressure characteristics of the liftstation closely. Sudden decreases in pressure could
indicate a breach in the pipe. Increases show occlusion of the pipeline due to corrosion or
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CHAPTER 6 CITY OF PORT TOWNSEND GENERAL SEWER SYSTEM PLAN
sediment deposition. The City should
deterioration since exterior corrosion of the iron main is a risk in the marine environment.
Work to separate the Lawrence Street storm and sanitary sewers should be completed prior to
designing improvements for the Monroe Street Lift Station. This will allow the pumps to be
sized appropriately if inflow is substantially reduced. RH2 suspects that PHF could drop
dramatically with the storm inlets removed from the sanitary sewer. This may be adequate to
provide a temporary solution to the Monroe Street Lift s capacity problem. This
temporary solution may allow the full lift station rehabilitation or relocation to be delayed by
5 to 10 years.
hƷŷĻƩ \[źŅƷ {ƷğƷźƚƓ LƒƦƩƚǝĻƒĻƓƷƭ
A budget will be set aside in the CIP for minor repairs and replacements of pump motors, pump
impellers, telemetry unit replacement, valve overhauls, panel replacements, generator
replacements, force main repairs, and other minor improvements to keep the existing lift
stations operating reliably. The City has two existing major lift stations: Monroe Street and
Gaines Street. Gaines Street was upgraded in 2021, and Monroe Street will be scheduled for
upgrades as discussed previously. The Mill site will add another major lift station within the
next 2 to 3 years. All major lift stations will be relatively new and/or rehabilitated in the 2020s,
and no additional capacity or significant upgrades will be needed during the 20-year planning
horizon. The remaining lift stations are small with minor replacement needs. The CIP will
include a general allowance to cover these needs.
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7EXISTINGTREATMENTFACILITIESASSESSMENT
BACKGROUND
HistoryandIntroduction
Theoriginal wastewater treatment facility (WWTF) was constructed
in 1967to receive wastewater from approximately 90nd to
provide primary treatmentand disinfection with chlorine gas. The WWTF was expanded in 1993 to
provide full secondary treatment. This expansion included a new Headworksfacility, oxidation
ditches, secondary clarifiers, chlorine contact basins, conversion of the original plant primary
treatment tanksto aerobic sludge holding tanks, a Control building, and electrical and supervisory
control and data acquisition (SCADA)systemimprovements.
Compost Facility is located at the Jefferson County Landfill and receives dewatered
biosolids from the WWTF,as well as dewatered septage from Jefferson County(County), yard
waste from the City and County, and other wood wastes.Liquidsgenerated from these processes,
including septage filtrate, contaminated stormwater runoff, and compost aeration condensate,are
treated in a separate wastewater treatment facility consisting of a sequencing batch reactor (SBR)
with disinfection and effluent disposal to constructed wetlands followed by discharge to infiltration
basins for ultimate disposal.
This chapter presents the evaluationsof the existingWWTFand Compost Facility conditions,
includingtheexisting liquid stream andsolids handling processes. It also presents an evaluation of
theelectrical and SCADA systems. Deficiencies identified from the evaluations are described, and
recommendations for capital improvementsare summarized. The analyses of needed
improvements to the treatment facilities for water quality and capacity are provided in Chapter 8.
All WWTF capital improvements are identified in Chapter 10.
SystemOverview
WWTFand flows via gravity to the
InfluentPump Station located on the WWTF site. Wastewater from the InfluentPump Station,
which also includes facility-generated wastewater and process drains,is pumped to the inlet of the
Headworks.From the Headworks, wastewater entersthe oxidation ditches, secondary clarifiers,
and chlorine contact basinsbefore heading to the Strait of Juan de Fuca through an outfall
structure. Waste sludge is capturedin the aerobic sludge holding tanks and pumped to the belt
Compost Facility.An important
consideration in a wastewater treatment system is that virtually allof the system components must
have redundant or back-up components. For example, the plant must be able to run with one
clarifier out of service. Thus, upgrades to a system also requireupgrades to the redundant
components. This adds to the cost of upgrades significantly butis a requirement to ensure that the
plant operates reliably.
The approximate locations of major WWTF process units are outlinedin Figure 7-1 and shown
schematically in Figure 7-2.
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Figure 7-1 Existing WWTF Overall Site Plan
Non-Potable Water Pumps
Secondary
Chlorine Contact Basins
Clarifier No. 1
Aerobic
Secondary
Holding Tanks
Clarifier No. 2
Control
Building
Influent Pump Station
Oxidation Ditches
Headworks
Figure 7-2 Existing WWTF Process Schematic
Historical WWTF Performance
The historical performance of the WWTF from 2019 through 2022 is compared to the
National Pollutant Discharge Elimination System (NPDES) Permit limits as shown in Table 7-1.
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Table 7-1
WWTF Performance Based on NPDES Permit Effluent Limits (2019-2022)
As shown in the table, the City has maintained compliance with itsNPDES Permit limits and no
exceedances of the permit were reported for the last 4years.As required by the NPDES Permit, the
City also monitors priority nutrients, priority pollutants, and other parameters and undergoes
whole effluent toxicity testing in the winter and summer of the final year of each permit cycle.
None of these items have prompted additional activities or permit actions in recent years.The
WWTF is well maintained and earned the Washington State Department of EcologyOutstanding
th
Performance Award for the 25consecutive yearin 2022.
As noted in Chapter 2, the City also is subject to the Puget Sound Nutrient General Permit (PSNGP).
Starting in February 2022, the City was required to monitor and report nitrogen compounds on its
Discharge Monitoring Reports. Table 7-2 is a summary of the monthly sampling results for 2022.
Table 7-2
Monthly Nitrogen Sampling Results
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The average annual Total Inorganic Nitrogen (TIN) is well below 10 milligrams per liter (mg/L). Only
two samples exceeded 10 mg/L in the sampling period.
WWTF EXISTING PROCESS UNITS EVALUATION
Introduction
The WWTF secondary treatment expansion in 1993 was the last major improvement or expansion
to the facility. This section provides a review of the general conditions of each major process or
area within the WWTF. The analyses and findings provided herein were based on observation of
visible areas around the WWTF, discussions with City operations and maintenance staff, and a
2019 Condition Assessment Summary Report performed by Jacobs (Appendix L).
Although most equipment and processes continue to function satisfactorily and meet existing
demands, several of these systems are nearing the end of their design life and need to be replaced
or upgraded. In general, these include major improvements to the Influent Pump Station,
Headworks, secondary clarifiers, oxidation ditches, and electrical and SCADA systems. Other minor
improvements that were previously noted are also described in this chapter.
Overall, the visible elements of the WWTF generally appear to be in good physical condition except
where noted otherwise. The age of the equipment and processes is one of the main drivers for the
WWTF improvements, and details are provided in the subsequent sections.
Influent Pump Station
Overview
T includes two influent gravity sewer mains that enter the Influent Pump
Station (IPS), which is located near the center of the WWTF site. The IPS also receives various
WWTF process drains.
The IPS consists of a below-grade, cast-in-place concrete structure that houses 3 submersible
influent pumps, each with a nominal capacity of 2,250 gallons per minute. Each of the three pumps
have below-grade check valve systems outside of the wet well. Downstream of the check valve
systems, the discharge piping from the pumps combines to a common force main that directs flow
up to the elevated Headworks channels.
Under normal operating conditions, one pump operates as the lead pump, a second lag pump turns
on during extreme flow events, and the third pump serves as a redundant pump. The pumps are
cycled weekly to avoid overuse of any single pump and to prolong the service life of all three
pumps.
Condition Assessment
IPS Structure
The existing IPS structure was constructed as part of the 1993 secondary treatment expansion
project. The interior liner is detaching from the concrete and portions of the cast-in-place concrete
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walls and ceiling are corroding.There is notable exposed aggregateand the surfaces need to be
rehabilitated in the near term to prolongtheuseful lifeof thisstructure.
IPS Mechanical
The original submersible pumps from the 1993 WWTF secondary treatment expansion project
experienced corrosion and were replaced after the expansionwith Flygt N-style impeller pumps.
Since then, minimal corrosion has been noted and no major repairshave been necessary for the
Flygt pumps. The stainlesssteel pump guide rails are generally in satisfactory condition with only
minor corrosion. Due to the IPS needing to remainin operation, the pump discharge piping and
fittings were not able to be observed. However, due to the age and condition of the IPS
infrastructure, it is recommendedto further evaluate this systemduring other improvement work
in the IPS andprioritizereplacing mechanical components if determined necessary.
Major Electrical and Control Equipment
Major improvements to the IPS electrical and control equipmentare expected during the planning
period due to significant corrosion and aging infrastructure. The junction boxes, conduits, and level
instrumentation directly inside the IPS, as well as the power raceways and variable frequency
drives (VFDs) from the electrical room need to be replacedin the near term. Additionally, one of
theelectrical conduits has corroded to the point where one of the pumps is now out of service. In
an emergency, this pump can be brought back into service by a quick pump wiring change;
however, this is an example of the urgency needed to rebuild theIPS. The power and control cables
of the pumps are connected to plugs located near the top of the IPS. These plugs are accessible and
should be maintained to allow WWTF staff to efficiently disconnect and remove pumps from the
IPS if needed.
Summaryof Major Findings
Based on the conditionsassessment, a summary of the recommendations for major improvements
to the IPS is as follows:
1.Rehabilitate theconcreteinfrastructureinside the IPS wetwell. Coatthe interior walls and
ceilingfor future corrosion protection.
2.Evaluate the condition of the mechanical equipment in the IPS and replace itif necessary.
3.Replace the electrical equipment associated with the IPS, including raceways, VFDs, and
instrumentation.
Headworks
Overview
The Headworks building was constructed as part of the 1993 WWTF secondary treatment
expansion project to include a mechanical bar screen in thecovered concrete influent channel. In
approximately 2009, the original screen was replaced with a new automatic Parkson Aqua Guard
mechanical bar screenthat has a 66-inch nominal width. The IPS discharges raw water into the
influent channel throughthe bar screen.Screenings are dewatered ina compactor system that
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discharges to the screenings and grit hopper in the Headworks building before being disposed
offsite. A bypass channel is adjacent to the main influent channel and houses a manual bar screen
that can be isolated with stop gates.
Screened influent enters the original Smith and Loveless Pistagrit vortex-style grit removal chamber
located on the northern side of the Headworks building. The grit chamber is 10 feet in diameter
and is nominally rated at 7 million gallons per day. Screened influent also can be diverted to bypass
the grit chamber if necessary. De-gritted influent from the grit chamber flows through a
1-foot-wide Parshall flume in a separate concrete channel and combines with return activated
sludge (RAS) at the end of the Headworks before entering the oxidation ditches. The settled grit
slurry in the grit removal chamber is directed to the grit classifier, which dewaters and washes the
grit, before being discharged to the screenings and grit hopper and disposed offsite. The grit
classifier was replaced around 2009 and is located on the main level of the Headworks building.
The Headworks screen and grit removal system is an important part of the plant operation.
However, failures in the system do not disrupt plant operation. The result of a Headworks
equipment failure is that grit is transferred to the oxidation ditches, which creates the need for
additional cleaning. Careful maintenance and inspection of the equipment, maximizing the life of
the equipment, can extend when equipment replacement would be needed. There is budget
provided in the Capital Improvement Plan (CIP) for replacement if needed. However, given the
Headworks ultimately will be replaced, if staff can extend the life of this equipment to the time of
the Headworks building replacement, savings in the overall CIP will be realized.
Condition Assessment
Headworks Influent Channels Structure
The influent channels are cast-in-place concrete. These structures appear to be in satisfactory
condition, requiring only some rehabilitation work relating to the interior liner system. The
embedded liner was not adequately installed on a concrete support column in the RAS return basin
and is peeling away at the corners of the column. Liner failure also was observed previously near
the temporary gates. Significant liner failures exist over the RAS and influent splitter weirs and
under the cover of the influent wet well, which will need to be improved. Concrete corrosion has
been noted previously at the bottom of the Parshall flume; however, the Parshall flume and
associated instrumentation appear to provide accurate influent flow readings.
Mechanical Screens
The mechanical screen appears to be functioning well with minimal corrosion observed. Other
components, including channel covers and gates, appear to be in good condition. Near the screen,
a short section of ductile iron non-potable water pipe was previously observed to be uncoated and
moderately corroded where there was no thermal insulation.
Grit Removal Chamber and Grit Room
The original vortex grit unit appears to be functioning well with minor wearing that are not
uncommon or of concern. However, the grit unit was not dewatered and out of service during the
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site visit, so submerged components could not be reviewed. No significant grit accumulation
downstream of the grit unit has been reported. The air lift tube and cyclone have been rebuilt
previously due to the original units wearing out and appear to be in good condition. Thescreenings
compactor and compactor tube have been noted to be in good condition;overall, no corrosion
issues have been observed in the grit room.
Summary of Major Findings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the Headworks is as follows:
1.Repairtheembedded plastic liner on the concrete columns and wallsin the Headworks
influent channels. These improvements should be included with the IPS concrete liner
system improvementsas previously discussed. These improvements should occur in the
near term and more details are included in Chapter 10(CIP F1).
2.Due to the age ofinfrastructure, it is recommended to plan for the replacement of the
screen and grit removal equipment within the next 5 to 10 years.More details are included
in Chapter 10.
Summary of Minor Findings
Based on the conditions assessment, a summary of the recommendations for minor improvements
to the Headworks is as follows:
1.Repair and coat the ductile iron non-potable water pipe near themechanical screen.
2.Perform minor repairs to Headworks equipment to extendits life until the Headworks
building is replaced.
ActivatedSludgeSystem
Overview
Prior to the addition of secondary treatment to the WWTF, the facility provided treatment utilizing
two primary treatment tanksand chlorine disinfection.During the secondary treatment
improvements in 1993, the activated sludge system was added to the WWTFand includedtwo
oxidation ditches and two secondary clarifiers. The existing primary treatment tankswere
converted into aerobic sludge holding tanks. The current activated sludge system isa suspended
growth system that utilizes microorganismsin the liquid of the oxidation ditches to provide
biological treatment of the wastewater. The oxidation ditches and secondary clarifiers were
configured within the hydraulic profile such that influent could flowby gravityfrom the Headworks
to the oxidation ditches, the secondaryclarifiers, and then the chlorine contact basin before
reachingthe outfall.Each of the activated sludge components isdiscussed in greater detail as
follows.
Oxidation Ditches
The oxidation ditches are where biological treatment occurs. This system utilizes a combination of
mixing wastewaterandoxygen tobreak down organics.The ditches alsoareoperated such that a
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
small anaerobic zone provides some nitrogen removal. Wastewater from the Headworks and RAS
processes combine and flow to the two oxidation ditches using isolation gates. The oxidation
ditches are original Eimco Carrousel Systems, each with a nominal volume of 0.57 million gallons.
Each ditch contains a deck-mounted vertical paddle mixer/aerator that supplies dissolved oxygen
into the ditch. These mixer/aerators operate on a two-speed mode, high and low, and each utilizes
a 75-horsepower motor. The gearbox assemblies for the mixer shafts are housed in noise enclosure
structures on top of the ditches. The mixed liquor enters the oxidation ditches, flows around the
Carrousel system, and exits over adjustable weirs to downstream processes.
Secondary Clarifiers and Processes
Clarifiers serve the purpose of separating solids from water after the biological treatment has
occurred in the oxidation ditches. After exiting the oxidation ditches, the mixed liquor is split
between two 50-foot-diameter Eimco secondary clarifiers. The two secondary clarifiers are circular
concrete tanks that are identical in size and construction. The secondary clarifier mechanisms are
original, each operating on a 0.75-horsepower drive motor. Each clarifier mechanism directs settled
mixed liquor to three RAS pumps that return to the splitter box downstream of the Headworks
Parshall flume. Each mechanism also collects floatable items (referred to herein as scum) and
directs the collected material to a scum box in each clarifier. An existing scum pump conveys scum
to the aerobic holding tanks. Settled sludge from the clarifiers also is pumped to the aerobic
holding tanks using two waste activated sludge (WAS) pumps. Clarified effluent exits over the
clarifier weirs and discharges to the chlorine contact basins.
Chlorine Contact Basins
Prior to discharge to the Strait of Juan de Fuca, treated water must be disinfected. The current
system utilizes a chlorination system approach to disinfection. The clarified effluent from the
secondary clarifiers enters the chlorine contact basins and is disinfected with chlorine,
dechlorinated with sodium bisulfite, and finally discharged through the outfall of the WWTF. The
two chlorine contact chamber structures are original, and two feed pumps are used to dose liquid
sodium hypochlorite into the clarified effluent. The original fiberglass reinforced plastic (FRP) tank
holding the hypochlorite was previously replaced with a 6,200-gallon high density polyethylene
(HDPE) tank. Once dosed with hypochlorite, the effluent flows through a serpentine path
throughout the chlorine contact basins to meet contact time requirements. The effluent is then
dechlorinated with liquid sodium bisulfite before being discharged through the outfall. The sodium
bisulfite is held in a 1,100-gallon tank manufactured by Chemical Proof Corporation. Two Peabody
Floway non-potable water pumps at the end of the chlorine contact basins supply part of the
effluent back throughout the plant for various processes. Scum also is collected near the end of
these basins and pumped to the aerobic holding tanks.
Condition Assessment
Oxidation Ditches
The visible concrete of the oxidation ditches generally appeared to be in good condition; however,
submerged concrete was not observed due to both ditches remaining in operation. The
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mixer/aeratorsappear to be in good condition with minimal vibrationand both gearbox enclosures
appear to be sufficiently ventilated.The paddle of one mixer/aeratorwasreplaced previouslyand
there is a spare motor available. Further assessment of the ditches is provided in Chapter 8.
Secondary Clarifiers and Processes
The original clarifier mechanisms appear to be in satisfactory condition andthe original drives and
motors are still in service. These items have been in service for over 30 years now, and have
reached their expected design life. However, with careful monitoring and maintenance, the design
life can be extended. Minor corrosion has been noted on the mechanism in areas with coating
defects that have become noticeable over time; however, no major mechanical or capacity issues
have previously been noted. The original carbon steel fasteners on the mechanisms were replaced
previously with stainless steel hardware due to past failures, and other carbon steel support
brackets have been previously observed tobe corroding.Minimal corrosion issues have been noted
on the concrete floor inside the secondary clarifiers,with only minor leaching and exposed
aggregate observed in the clarifier launders. The steel walkway, FRP weirs,and baffles of the
clarifiers all appear to be in sufficient condition.
There have been no major concerns with theWAS/RAS station between the two secondary
clarifiers as the piping and appurtenances arein a good overallcondition. Only minor replacement
and maintenance work has been required in the past. No major capacity, functionality, or
conditions-basedissues have been observed for the RAS, WAS, and scum systems.
Chlorine Contact Basins
Overall, the chlorine contact basins are in satisfactory condition with only a few issues noted. The
gate operator stems have been observed to be corroding at the water surface and a few wood
planks above the water are rotting. The conditions of the planks below water have not been
observed. No major capacity, functionality, or conditions-basedissues were observedwith these
basins.No corrosion issues have been noted for the sodium hypochlorite or sodium bisulfite
systems, and no issues have been noted on the HDPE hypochlorite storage tank.The City has
observedpreviouslythat the existing non-potable water pumps have corrosion issues.
Discharge Outfall
The existing discharge outfall into the Strait of Juan de Fuca was not evaluated as part of this
General Sewer Plan (GSP). The City is separately actively working with the Washington State
Department of Ecology (Ecology)and Jacobson the outfall replacement/upgrade,and that work
was in progress at the time of this GSP.Further discussion is contained within Chapter 8.
Summary of Major Findings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the activated sludge system is as follows.
Oxidation Ditches
Chapter 8 discusses operational modifications to maintain nutrient reduction within the existing
system capacityand improve actual treatment capacity. Ultimately, the oxidation ditches will have
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
to be replaced with larger ditches to address increasing demands on the system and nutrient
removal. Interim improvements will be needed for nutrient removal. The evaluation in Chapter 8
provides the recommended next steps for improvements on the oxidation ditches; more details are
provided in Chapters 8 and 10.
Secondary Clarifiers and Processes
Clarifier upgrades are included in the CIP. The clarifiers need to be maintained as they are not
planned to be replaced in the next 20 years. Extending the life of the clarifiers provides significant
savings over the long term.
1.Re-coat the concrete launders of both secondary clarifiers.
2.The existing mechanisms of both secondary clarifiers are at or nearing the end of their
design life. Continue to monitor mechanisms annually and at manufacturer recommended
frequency on drive units and consider oil testing as recommended by the manufacturer.
Plan to replace the mechanisms and replace or rehabilitate the drive units.
Chlorine Contact Basins
Continued maintenance of the chlorine contact basins is recommended as these facilities are not
planned to be replaced in the next 20 years.
1.Replace the non-potable water pumps in-kind and associated electrical equipment in the
near term.
Summary of Minor Findings
Based on the conditions assessment, a summary of the recommendations for minor improvements
to the activated sludge system is as follows.
Secondary Clarifiers and Processes
1.Replace the carbon steel weir support brackets with stainless steel brackets in the near
term.
2.Re-coat areas of the mechanisms that have notable spot corrosion.
Chlorine Contact Basins
1.Repair or replace gate operator stems with notable corrosion.
2.Evaluate the condition of all wood planks associated with the chlorine contact basins and
repair or replace components as necessary.
Sludge Holding, Dewatering, and Disposal
Overview
The WAS pumped from the secondary clarifiers enters the aerobic holding tanks that provide
sludge storage prior to dewatering. The sludge in these holding tanks is aerated to stay mixed and
aerobic. Rotary lobe blowers located in the lower level of the Control building supply the air into
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the holding tanks. Decanting isrequired to thicken the sludge before it is pumped to the belt filter
press for dewatering. This process is facilitated by the addition of polymer solution into the feed
sludge for enhanced dewatering.The dewatered sludge produced from the WWTF is loadedonto a
sludgehaulingtruck via a shaftless screw conveyor and delivered offsite to theCompost
Facility.
Condition Assessment
No major capacity or conditions-based issues have been observedin either the aerobic holding
tanks or the blower room.The rotary lobe blowers have been noted to be in good overall condition
with adequate capacity. Some coarse bubble diffusers alsohavebeen previously noted to be
missing. The aerobic holding tanks were converted from the original primary treatment tanks and a
thorough evaluation is recommended to evaluate the structural integrity of the infrastructure.
The belt press is original and appears to be in good conditionwith no significant corrosion. The belt
press room is well ventilated with only minor corrosion previously noted at the entrance steel door
base frame and on light fixture metal housings. The aluminum platforms and grating are in good
condition,but the grout under the aluminum column bases has deteriorated.No issues have been
noted with the shaftless screw conveyorfor sludge disposal.
Summary of MajorFindings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the sludge holding system is as follows:
1.Due to aging infrastructure,it is recommended to plan for upgrades to the solids handling
equipment,including the existing rotary lobeblowers, WAS pumps, and belt press unit
withinthe next 5 to 10 years. More details are provided in Chapter 8.
2.Evaluate the structural integrity of the aerobic holding tanks and plan for repairswithin the
next 5 to 10 years. More details are provided in Chapter 8.
Summary of Minor Findings
Based on the conditions assessment, a summary of the recommendations for minor improvements
to the sludge holding system is as follows:
1.Identify coarse bubble diffusers that are potentially missing and replace as needed.
2.Repair the grout under the aluminum column bases in the belt filter press room.
3.Repair minor corrosion within the belt filter press room as needed.
OdorControlSystem
Overview
The odor control system focuses on removing foul air from the most odoriferous locations in the
treatment process, including the IPS, Headworks, and grit and screenings holding room. The
original odor control system directs air from the Headworks influent channel, influent wet well, and
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
grit room to a carbon scrubber vessel located outside and adjacent to the Headworks building. The
odor control fan for pulling this air is located adjacent to the carbon scrubber vessel.
Condition Assessment
As described previously, severe corrosion and degradation of the concrete liner within the
Headworks has been noted, indicating the potential build-up of sulfuric gases. Historically, there
have been infrequent off-site odor complaints, indicating there may be sufficient air exchange to
contain odors but not enough to reduce sulfuric gas formation on contact surfaces. Spot
penetrations have been noted along the ducting from the Headworks to the carbon vessel, which
could be a result of internal corrosion. The carbon scrubber vessel that holds activated carbon
appears to be in good physical condition.
Summary of Major Findings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the odor control system is as follows:
1.Upgrade the odor control fan and activated carbon system to increase treatment capacity.
2.Replace the odor control ducting from the top of the Headworks to the carbon scrubber
vessel.
Electrical and SCADA Existing Systems Evaluation
Electrical Components
Overview
Wastewater treatment plants are highly dependent on electricity. Electrical systems, including
back-up power, deserve critical attention to avoid system failures. The existing electrical service
and distribution equipment dates back to the 1993 WWTF expansion and upgrades. Electrical utility
service is supplied to the facility by Jefferson County Public Utility District (PUD) from a PUD-owned
1,000 kilovolt-amperes pad-mounted transformer. The secondary electrical service to the facility is
a 1,600 Amperes (A) service with the main service disconnect located within Motor Control Center
(MCC) No. 1. MCC No. 1 resides in the ground level of the Headworks building. Located within MCC
No. 1 are feeder circuit breakers that feed power to other MCCs located throughout the WWTF.
MCC No. 1 feeds power to MCC No. 1X, which also is located on the ground level of the Headworks
building, MCC No. 2 is located in the RAS/WAS pump station, MCC No. 3 is located in the Control
building, and MCC No. 4 is located at the digesters. The MCCs are used to distribute power to all
motors and equipment throughout the facility. Critical electrical loads and equipment that require
backup power are supplied from MCC No. 1X. MCC No. 1X includes a 600 A automatic transfer
switch (ATS) for automatically switching to backup power in the event of a power failure. A
475 kilowatt standby diesel generator, manufactured by Caterpillar, is located in the ground level
of the Headworks building. This generator is connected to the ATS in MCC No. 1X and supplies
backup power to all the electrical loads and equipment powered out of MCC No. 1X. The existing
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MCC equipment throughout the facility is manufactured by Cutler-Hammer/Eaton and are Unitrol
model MCCs.
Some of the motors throughout the facility utilize variable frequency drives (VFDs) for modulating
motor speed.These motors include the influent pumps, RAS pumps, and the belt press feed pump.
The VFDs are manufactured by Reliance Electric.
Condition Assessment
The existing MCC equipment looks to be well maintained and in good condition considering
the age of the equipment.This equipment is approximately 30 years old and is nearing the
end of its expected lifespan.The typical lifespan for similar electrical equipment is
approximately 25to 40 years.One of the issues with maintaining older equipment is
locating replacement parts when equipment fails.Fortunately for the City, Eaton has robust
aftermarket support and is still able to supportreplacement of components for the Unitrol
model MCC.However, that may not be the case for long.It is estimated that this equipment
has approximately 5to 10 years of life remaining.
ger supported and are
obsolete.Reliance Electric was purchased by Rockwell Automation in 1996,and Rockwell
Automation no longer supports these drives.Replacement of all seven VFDs at the WWTF is
recommended.
An Arc Flash Analysis has not been performed for the existing electrical distribution system,
which is required by the National Electrical Code (NEC) for services of this size.It is
recommended that a plantwide electrical short circuit, protective device coordination, and
arc flash analysis be completed soon.These studies need to be completed to be in
compliance with the NEC and need to be updated every 5 years.
The standby generator,while also nearing the end of its expected 25-to 40-year lifespan,
looks to have been maintained well and is in good working condition.Similar to the MCC
equipment, it is estimated that this equipment has approximately 5to 10 years of life
remaining.
Significant corrosion was observed on the conduits and conduit supports inside the IPS.
Replacement of the conduits, supports, conductors, and cables inside the IPS is
recommended.
Some corrosion and rust were observed throughout the WWTF on various enclosures,
flexible conduits, and fittings.It is recommended to remove this rust where able to do so
and add rust protectant coating to extend the life of these components.Full replacement
may be needed in some areas if corrosion is severe enough.
Summary of Major Findings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the electrical systemis as follows:
1.Plan for MCC and standby generator replacement within the next 5to 10 years.
2.Budget for near-term replacement of all seven VFDs.
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
3.Perform a short circuit, protective device coordination, and arc flash analysis on the
electrical distribution system.
4.Replace conduits, supports, conductors, and cables inside the IPS.
5.Address electrical enclosure and conduit corrosion as needed throughout the WWTF.
Central SCADA System
Overview
The SCADA system is the computer and electronic control element of the plant. SCADA allows for
automation of system processes and monitoring and is the system that enables plant operators to
control physical processes within the plant. The central components of the SCADA system and
instruments are from the 1993 WWTF upgrades. The existing SCADA system consists of three
control panels located throughout the facility that are interconnected via a DH+ serial
communication protocol. A SCADA human machine interface (HMI) computer located at the WWTF
allows the City to monitor and control the system. The HMI computer was last upgraded around
2017. The three control panels include the Main Control Panel, CP-3, which is located in the Control
building. The other two control panels are considered Remote Input/Output (I/O) panels as they do
not contain a central processing unit (CPU) and instead allow for an I/O extension to the Main
Control Panel. The first Remote I/O panel, CP-1, is located on the ground level of the Headworks
building. The second Remote I/O panel, CP-2, is located in the RAS/WAS pump station.
Condition Assessment
All three control panels are equipped with obsolete Allen-Bradley PLC-5 programmable logic
controller (PLC) equipment. These were considered obsolete by Allen-Bradley in 2011, so
parts are difficult and expensive to obtain. Replacement of these components with
Allen-Bradley ControlLogix PLC equipment is recommended.
The SCADA HMI computer does not require major additional upgrades at this time. The
computer hardware should be replaced within the next 5 years. The typical lifespan of
SCADA computer hardware is 5 to 10 years. The Factory Talk View SE software currently
installed can be reinstalled on the new hardware.
Uninterruptible power supply (UPS) equipment located within each of the control panels is
well maintained but has exceeded its useful expected life. Replacement of the UPS
equipment is recommended.
PLC and UPS replacements should occur as soon as possible.
The communication network infrastructure is using an outdated serial network platform.
The new PLC CPUs require Ethernet-based communications instead of serial
communication. Replacement of the existing serial communication network with an
Ethernet-based network is required when the PLCs are updated. This network can be either
a copper-based Ethernet network or a fiber optic based Ethernet network. A fiber optic
network is recommended as it is not subject to electrical interference or lightning, it can be
installed at longer distances, and it will provide the City with a higher speed network.
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The Parshall flume flow meter transmitter (FIT-460) has issues with the LCD display. The
original manufacturer,Magnetrol,no longer supports replacements,so this meter should
be replaced as soon as possible.
The instruments inside the IPS are corroded and need to be replaced. The gas transmitter
inside the wet well is extremely corroded and there is no reading on the panel meter,which
indicates failure.
Many instruments have been abandoned in place,including:
o Network radio antenna;
o Milltronics MultiRanger Plus transmitter (previously used for hypochlorite tank level
measurement); and
o De-energized Dechlor controller (Strantrol 190-300).
Summary of Major Findings
Based on the conditions assessment, a SCADA system overhaul is recommended in the near term. A
summary of the recommendations for major improvements to the central SCADA system is as
follows:
Replace existing LE and LIT-210 wet well level instruments with a single-sealed unit, equal to
VegaPLUS WL61.
Replace existing LSH and LSL-210 wet well low-leveland high-level float switches with new
switches, Intrinsic Safety Barriers, and 316L SST mounting pole.
Replace existing AE and AIT-240 wet well explosive gas sensor instrumentswith a new
remote sensor that draws and returns samples to the wet well.
Replace all conduit inside the wet well and under buried conditions with handhole access
and sealed transitions to protect all cables.
Replace obsolete Allen-Bradley PLC-5 system with ControlLogix PLC equipment.
Replace Serial Remote I/O network with Ethernet Device Level Ring network.Fiber optic
cable is recommended.
Replace existing UPSs at the three control panels.
Replace the Parshall flume flow meter with a new FIT-460.
Plan for replacement oftheSCADA HMI computer hardware.
COMPOSTFACILITYEXISTINGSYSTEMSEVALUATION
Overview
The Compost Facility is located at the Jefferson County Transfer Station Siteand handles yard
wasteand septageaccepted from boththe Countyand the City.Thedewatered sludge generated
from the WWTF also is delivered to this facility. The compost mixtures incorporate dewatered
biosolids and yard waste to produce compost piles that areaerated. The compostistransferred
with a front-endloader to becuredbefore itis screened and preparedfor distribution in
conformance with Ecologyrequirements.
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CHAPTER 7CITY OF PORT TOWNSENDGENERAL SEWERPLAN
Theseptage received at the Compost Facility isscreened in a septage screening vault and held in
two steel, aerated10,000-gallon tanks. The septage is then dewatered and the filtrate from this
process, as well as all other liquid wastestreams around the facility,drain to a sequencing batch
reactor (SBR) for treatment.
previously discussed. The SBR is approximately 42,000gallons and consists of a submerged turbine
aerator, methanol feed pump, WAS pump, and supernatant pump station.The WAS from the SBR is
pumped back to the septage screening vault,while the supernatant is disinfected with sodium
hypochlorite and discharged to constructed wetlands for further treatment. The constructed
wetlands are made up of two cells, each with an area of approximately 6,500 square feet,thathave
a combined approximate maximum detention time of 17 total days. The treated effluent from
these wetlands enters a flow control structure and discharges to the infiltration basinsfor final
disposal.
Odors resulting from the septage holding tanks and compost aeration system are treated with
biofilter media. This media consists of finished compost, soil and/or wood chips, and ground yard
waste, and it is monitored for temperature, moisture content, and pH for process control and
operation. A fan provides air pressure to discharge odorous air through the biofilter media evenly.
Figure 7-3 shows the approximate locations of the major Compost Facility processes,and
Figure7-4 shows the general process schematicofthe Compost Facility.
Figure 7-3Existing Compost FacilityOverall Site Plan
SBR Disposal
System
SBR and Related
Treatment System
Composting Area
Composting
Barns
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Figure 7-4Existing Compost Facility Process Schematic
ConditionAssessment
SolidsHandlingInfluentSystem
Septage haulers manually rake the bar screen and wash down the septage receiving area and
screening vault. From the initial screening, septage is sent to one of two holding tanks. A significant
amount of grit has been noted in one of the two 10,000-gallon septage holding tanks such that only
the other tank is usable and is limiting the overall holding capacity. Grit is difficult to remove from
these tanks. A new holding tank with a larger capacity should be installed, along with associated
blowers to provide aeration into the holding tank.The influent system should be automated by
installing a new packaged septage screening and grit removal system with an influent meter to
monitor flow.
Septage Treatment System
The existing SBR appeared to be in good physical conditionand continues to provide sufficient
treatment. However, the blowers, pumps, and other associated equipment are aging and should be
considered for replacement in the future.
Compost Facility Infrastructure
Due to the age of infrastructure and equipment, the composting screen, front-end loader, and
aeration blowers associated with the composting process are nearing the end of their useful life
and should be replaced.The concrete supports of the compost pole building havenotable
deterioration and need to be refurbished. Around the facility, the asphalt has degraded and should
be repaired. In the existing pole building, the lighting is insufficient.Adequate accommodationsand
sufficient on-site fire flow capacity should be available to operational staff who will be present
regularly.
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CHAPTER 7 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Summary of Major Findings
Based on the conditions assessment, a summary of the recommendations for major improvements
to the Compost Facility is as follows. Refer to the Proposed CIP Implementation Schedule in
Chapter 10 for the timeframes of the recommendations.
Solids Handling Influent System
1.Install an automated, packaged septage screening and grit removal system.
2.Install an influent meter to monitor flow.
Septage Treatment System
1.Remove the two existing septage holding tanks and install a new larger septage holding
tank.
2.Install new aeration blowers for the new septage holding tank.
3.Replace aging SBR equipment.
4.Replace the WAS, chlorination, and wetland disposal pumps.
Compost Facility Infrastructure
1.Replace the composting screen.
2.Replace the composting front-end loader.
3.Replace the composting aeration blowers.
4.Refurbish the compost holding bay concrete supports.
5.Repair and seal asphalt around the facility.
6.Install new lighting inside the existing pole building.
7.Install a new hydrant connected to the water main feeding the facility.
8.Construct a new office for staffing accommodations.
TREATMENT FACILITIES ASSESSMENT CONCLUSION
This chapter describe
Compost Facility based on an evaluation of existing conditions. Given the major capital
improvements and impacts on City operations, the next three chapters provide a basis for a capital
improvement plan. Alternatives analyses for major capital improvements are presented in
Chapter 8, and the recommended capital improvement projects are identified and further detailed
in Chapter 10. Chapter 9.
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8TREATMENTFACILITIESANALYSIS
INTRODUCTION
The future regulatory requirements for the wastewater treatment facility (WWTF)are outlined in
Chapter 2 of this General Sewer Plan(GSP). Chapter 4 projectsgrowthof the influent flowand
loading.Chapter 7 evaluates theconditionof the existing facilities. In addition to these items, this
chapter evaluates the ability of the WWTF to reliably meet the
requirements of its National Pollutant Discharge Elimination System (NPDES) Permitthrough the
planning periodgiven the major considerations presented in previous chapters. This chapter
analyzes alternativesto meet the needs of the WWTF through the planning periodand provides
recommendationsforimprovements.
MAJORCONSIDERATIONSFORWWTFIMPROVEMENTS
Based on the analyses of the previous chapters,the major factors influencing the WWTFplanning
are:
Growth;
Future regulations, specifically nitrogen removal requirements;
Footprint constraints of the WWTF;
Age and condition of the existing facility components.
Each factor is briefly introduced in the following sections.
GrowthinFlowandLoading
The existing and projected flow and loading is defined in Chapter 4.The projected values are
summarized in Table 8-1, along with the current rated capacity of the WWTFper the NPDES Permit.
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 8-1
Projected Influent Flow and Loading
As shown in the table, the projected 2043 flow and biochemical oxygen demand (BOD) loading is
very near to the permitted capacity of the WWTF. Further, the projected 2033 BOD loading exceeds
85 percent of the rated capacity. TPermit requires the City to begin planning for an
expansion of facility capacity when flow and loading exceeds 85 percent of the permitted maximum
month value for 3 consecutive months. It takes considerable time (up to 10 years) to properly plan
for and permit major treatment plant expansion, and as such, it is recommended that the City
begin planning for such an expansion in the first 5 years of the planning period.
Regulatory Changes Nitrogen Reduction
As discussed in Chapter 2, the future regulations that will most significantly influence WWTF
planning are the nitrogen limits proposed by the Puget Sound Nutrient General Permit (PSNGP),
which became effective in 2022. The City WWTFs with small
\[Total Inorganic Nitrogen\] by the PSNGP. As detailed in Chapter 2, the PSNGP requires
dischargers in this category to:
Develop and implement a Nitrogen Optimization Plan (NOP). The general intent of the NOP
is to assess and recommend optimization strategies to maximize TIN removal at the existing
WWTF primarily through operational changes, minor on-site improvements, and off-site
source control. The dischargers were required to select an initial optimization strategy by
December 31, 2022. The NOP should analyze and document the performance of the
selected optimization strategy. The NOP must be submitted by March 31, 2026; and
Complete an all known available and reasonable methods of prevention, control, and
treatment (AKART) analysis that evaluates reasonable treatment alternatives that will
maintain the WWTF annual average effluent TIN below 10 milligrams per liter (mg/L). This
analysis must include wastewater characterization, analysis of treatment technologies,
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economic evaluation, environmental justice review, recommendation of the most
reasonable treatment alternative,and an implementation schedule. The AKART analysis
must be submitted by December 31, 2025.Notably, the PSNG
maintain an annual TIN average of < 10 mg/L and do not document an increase in load
through their \[Discharge Monitoring Reports\]
Meet additional monitoring and record retention requirements as discussed in Chapter 2.
Forthe purposes of this GSP, an annual average effluent TIN below 10 mg/L isconsideredthe
benchmark for analyzingalternatives for improvements to the WWTF. The existing WWTF was not
designed with a dedicated denitrification process, which would be necessary to reliably provide TIN
reduction at the permitted flow and loading conditions. Upgrading the WWTF to provide TIN
reduction at the permitted flow and loading would necessitate amajor reconfiguration of the
facility.
It is understood that continued modeling by the Washington State Department of Ecology (Ecology)
or other factors may change the structure of the final TIN limit. It should be noted that the final TIN
limit may be different from an annual average of 10 mg/L for the City,and as such, it is likely in the
deferthe need
to make major improvements until the future effluent nitrogen limits have been finalized. As
discussed inthe Activated Sludge System section, the City is currentlyutilizing an optimization
strategy to meet a TIN limit of 10 mg/L. This chapter discussesimprovements of limited mechanical
and structural scope that could be made to allow the TIN limit to continue to be reliably met for at
least a portion of the planning period.
It should be noted that ifregulatory conditions result in more stringentlimits, the timeline for
planningimprovements may be acceleratedand capital costsincreased,which would require either
significant grant resources and/or largerrate increases.
WWTFSiteFootprint
One of the major factors influencingWWTF planning is the constrained nature of the existing
WWTF site. The site is bounded tothe east by the body of water referred to as the Chinese
Gardens. To the west, the site is bounded by Kuhn Street. Figure 8-1 shows the existing site aerial
with parcel lines and ownership,as well as the surrounding areas.
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CHAPTER 8CITY OF PORT TOWNSENDGENERAL SEWERPLAN
Figure 8-1WWTFand Surrounding Parcels
Parcel owned
N
Port Townsend
by City
WWTF
Kuhn St.
Vacant ROW
The WWTF occupiestwo parcels transected by platted right-of-way (ROW) extending from
rd
53Street. The City owns an additional parcel to the south of the WWTFthatcontains a single
structure(house converted to an office).This parcel is separated from the WWTF parcels by
platted, vacantROW. Similarly, a plattedstrip of vacantROW lies immediately north of the
northmost WWTF parcel. To the north and south beyond are private parcels.
The plattedandvacant ROW sectionnorth and south of the WWTF parcelmust be maintained for
public access to the waterfrontperRevised Code of Washington(RCW)35.79.035. Thisarea
potentiallycouldbe used for below-grade utilities, but it is not prudent to plan any above-grade
tankage and infrastructure in these areas.
Figure 8-2 shows the current WWTF and parcels.
Figure 8-2WWTF Site Aerial
N
Kuhn St.
On Figure 8-2, there are three general spaces within theexisting WWTF footprintthat are not
occupied with permanent, above-grade WWTF infrastructure:
Thenortheast corner of the site, north of the existing sludge holding tanks, is vacant and
could be utilized. However,this area is relatively small andisisolated from the main
process piping and interconnections. This space may be used for ancillary improvements.
However, this space does not readily facilitate any significant expansion of the WWTF;
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The southmost parcel, which contains one existing building, could potentially be
repurposed forexpansion of the WWTF. However, as previously stated, the southern
section of unused ROW cannot be used for permanent, above-grade infrastructure.As
such, this parcel will remain somewhat isolated from the main WWTF infrastructure.
Relative to the size of the existing WWTF, the parcel is also relatively small and could
support only limited new infrastructure. Similar to the northeast corner of the WWTF, this
parcel does not readily facilitate any significant expansion of the WWTF; and
The paved area north of the oxidation ditches isrelatively small andencumbered by
significant below-grade utilities.The area also is used for parking and vehicle access. This
area does not readily facilitate any significant expansion of the WWTF.
In general, the existing WWTF infrastructure occupies most of the area included in theCity parcels
and there is not sufficient available space on these parcels to plan for a major expansion of the
WWTF.
AgeandCondition
Chapter 7 summarizedthe existing conditions of the major unit processes and areas of the WWTF.
Thefacilityhas beenexceptionally well maintained. However, the last major improvements to the
facility were made over 30years agoandnumerous improvements will be needed during the
planning period due to the ageof the infrastructure.It is known that major changes to thefacility
will be needed during the planning period to meet new regulations and growth. The
recommendations in this chapter seek to avoid unnecessarily investing in the rehabilitation of aging
items that are likely to be substantially reconfigured or replaced later in the planning period. The
intent is to make improvements that maintain the operability and reliabilityof the WWTF and
extend its useful life while avoidingmajorsunk costs for such improvements.
Due to its size, the concrete oxidation ditch tankage is the largest and most valuable asset at the
WWTF. Understanding the remaining useful life of this tankage is critical in analyzing the activated
sludge system improvements. As noted in Chapter 7, the existing oxidation ditch concrete appears
to be in good physical condition. However, these tanks were designed over 30 years ago and will be
over 50 years of age at the end of the planning period. Further, the tankage was not designed to
currentcodesand may not meet current requirements for seismic conditions, as an example. As
discussed in the Activated Sludge System section, major improvements will be needed later in the
planning period to expand facility capacity while meeting nitrogen reduction requirements.Some
options fortheseimprovements include reuse of the existing oxidation ditch tankage. It should be
noted that any significant reconfiguration of the oxidation ditches will require substantial structural
modifications to meet current codes. This likely will be very costly and may not be prudent given
the advanced age of the structure at the time of the improvements. This factor warrants significant
consideration when analyzing activated sludge system improvements in the subsequent sections of
this chapter.
APPROACHTOWWTFANALYSES
Improvementsto the activated sludge system (oxidation ditches and clarifiers) are needed for
nitrogen reductionand to expand WWTF capacity. These improvementsare expected to have the
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
largest impact on WWTF planning; therefore, the major WWTF processes are reviewed in the
following order:
1.Activated sludge system.
2.Preliminary treatment system.
3.Effluent disinfection system.
4.Solids handling system.
ACTIVATED SLUDGE SYSTEM
Existing Activated Sludge System
Original Design Criteria
The existing activated sludge system consists of two oxidation ditches and two secondary clarifiers.
Each ditch contains a single two-speed mechanical surface aerator (referred to herein as
mixer/aerators). The design criteria for the oxidation ditches is included in Table 8-2 from the
original construction drawings.
Table 8-2
Original Oxidation Ditch Design Criteria
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The original design criteria shown in Table 8-2 assumes two basins are online. At the average
annual condition, with a solids retention time (SRT) of 15 days, the predicted mixed liquor
suspended solids (MLSS) concentration is2,800 mg/L with two basins online. The original design
loading for the WWTF is included in Table 8-3.
Table 8-3
Original Facility Design Flow and Load
It should be noted that the 20-year design values (2013 values) shown in the table areslightly
below the currently permitted values shownin Table 8-1.For the purposes of this chapter, the
permitted values generallyareusedfor the subsequent analyses.
Capacity Analysis
The ability to settle the biological floc of an activated sludge system in the secondary clarifiers
typically constrainsthe capacity of the system. The solids loading rate (SLR) to the clarifiers
represents the allowable solids load per unit of clarifier operating surface area. The typical
secondary clarifier SLRdesign criteriaisan average of25 pounds per square foot per day (lb/sf/d)
and a peak SLR of 40 lb/sf/d for conventional activated sludge. As the microbial population
increases in the oxidation ditches (represented by the MLSSconcentration), clarifier SLRgenerally
increases proportionally. As SRT increases, so does the MLSS concentration due to the extended
time available for microbial growth. As such, the SRT and MLSS are both indirectly limited by the
settleability of the activated sludge.The existing WWTF includes two 50-foot diameter secondary
clarifiers. Table 8-4 shows thecalculated SLR for operating scenarios with one or two clarifiers
online. This table assumes both oxidation ditches are online and the MLSS is constant at 2,800 mg/L
for all conditions.
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Table 8-4
Predicted Clarifier SLR for Existing Activated Sludge System at MLSS 2,800 mg/L
As shown in the table, at the original maximum month design condition of 1.81 million gallons per
day (MGD), as well as at the permitted maximum month condition of 2.05 MGD, the clarifier SLR is
below the recommended range with two oxidation ditches and two clarifiers in service. However, if
one clarifier is out of service, as must be considered for normal maintenance or a failure, the SLR
will exceed the recommended range. Although not shown in the table, a similar result would be
expected if one oxidation ditch is out of service with two clarifiers online.
Due to the existing constraints presented in the WWTF Site Footprint section, there appears to be
no simple method to add a third clarifier to the site, which would otherwise alleviate the potential
single clarifier condition. The third clarifier would most practically be located immediately adjacent
to the existing clarifiers to facilitate the large and complex pipe connections. This is not feasible
with the current oxidation ditches and parcel boundaries.
As shown in this analysis, the clarifier SLR effectively limits the WWTF capacity approximately at the
current WWTP rating. Further, there is no readily available location to add a third clarifier on the
site to alleviate this capacity restraint.
Current Strategy for Nitrogen Reduction
The original activated sludge system was designed and expected to produce fully nitrified effluent
(ammonia converted to nitrate). At the design loading with the existing aerators at full speed, there
should be sufficient oxygen transfer and SRT to allow for full nitrification. However, in this
configuration, minimal denitrification is likely to occur, which is necessary to convert nitrate to
nitrogen gas to reduce overall nitrogen in the effluent. At the time the WWTF was designed,
denitrification was not a consideration. For denitrification to occur, an anoxic environment must be
provided in the system. No dedicated anoxic environment was provided in the oxidation ditches as
originally configured. The oxidation ditches each consist of an entirely aerated, closed loop reactor
as shown in Figure 8-3.
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Figure 8-3ExistingOxidation Ditch Configuration
Note: Single ditch shown.
The result of this configurationis minimal TIN reductionin the effluent. Further, nitrification
consumes alkalinity and without denitrification it can be difficult to maintain effluent pH within
NPDES Permit limits without supplementing alkalinity to the process.
As previously noted, the WWTFis required to implement and monitor an optimization strategy to
reduce effluent TINas required by the PSNGP.When operated as designed, the aeratorsprovide
sufficient oxygen to maintain adequatedissolved oxygen(DO)concentration throughout the
entirety of the reactor. As an optimization strategy, the operators are currently operating the
aerator for each ditch in low speed. By doing this, the oxygen transfer is limited, which allows for
the creation of an anoxic area that is low or devoid of oxygenon the downstream end of the
reactorloop. This configuration is similar to that described inTable 8-24, row (o)of Wastewater
th
Engineering: Treatment and Resource Recovery, 5edition (2013, Metcalf & Eddy).Figure8-4
illustrates this configuration.
Figure 8-4Current Operation of Existing Oxidation Ditch with Aerator at Low Speed
Note: Single ditch shown.
This approach has generally allowed the operators to reliably maintain effluent TIN below 10 mg/L
at the current flow and loading conditions. However, this approach has several drawbacks, which
arediscussed as follows:
Reduction in capacity: By limiting the aerators to low speed, the capacity of the oxidation
ditchesis effectively reduced. The oxidation ditch design criteria (Table 8-2) assumedthat
the aerators are operating at a high speed to provide peak oxygen transfer. Maintaining the
aerators at a low speed, to create theanoxic zone, reduces the capacity of the system to
oxidize influent constituents and significantly reduces the design capacity forBOD removal.
Currently, the influent is below the design BOD load, but with growth, it is expected that the
aerators will need to run athigh speed more consistently to meet BOD demand. Without a
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
dedicated anoxic zone, the entire ditch volume is expected to be aerobic with the aerators
in high speed and TIN reduction will not substantially occur.
Anoxic zone variability: Currently, there is no automation that would control the
mixer/aerator speed between low and high speed based on loading conditions and the
resulting DO demand. As such, the aerators are operated manually and predominately in
low speed. With the normal diurnal variability in loading and subsequent DO utilization, the
size of the anoxic zone may vary significantly and is generally uncontrolled. This issue will be
exacerbated as flow and loading increases and will make reliably meeting the permit limits
more challenging.
Anoxic zone location: In the current optimization strategy, the anoxic zone is inherently at
the downstream end of the reactor. Typically, activated sludge systems designed for
nitrogen removal include anoxic zones upstream of oxic zones such that some influent
carbon can be used by organisms to perform denitrification. This configuration allows for
efficient use of carbon and a higher rate of denitrification. The current optimization strategy
does not allow for this approach.
Filamentous Organism Growth: Filamentous organisms can reduce the settleability of
activated sludge significantly, which, as previously discussed, restrains the capacity of
activated sludge systems. These organisms can thrive in low DO environments and should
be a significant concern with the current optimization strategy, which inherently creates
areas of low DO. The current sludge volume index values, which measure the
settleability of the activated sludge, tend to be in the range of 150 to 250. These values
generally are considered to be indicative of relatively poor settling sludge. This issue will be
of further concern with growth in flow and loading.
The current optimization strategy is reducing effluent TIN substantially and has been implemented
without incurring capital expenditures. The operators are effectively managing the system to
reliably produce TIN below 10 mg/L. While this approach has been valuable to the City in meeting
the initial PSNGP requirements, for the reasons previously stated, it is not recommended that this
strategy be relied upon for more than approximately the next 5 years (2028).
It is in the best Cmaintain TIN reduction going forward. The current optimization
strategy should continue to be utilized, but more permanent improvements should be prioritized in
the next 5 years. Given this, the remaining analyses of this chapter review improvements of limited
scope that can be made soon to continue to provide TIN reduction, extend the useful life of the
activated sludge system, and allow for deferral of significant improvements to the WWTF.
Screening of Nitrogen Treatment Options
Nitrogen is reduced via biological treatment of wastewater through aerobic activated sludge
treatment as discussed previously. Aerobic activated sludge systems have been utilized for this
purpose in a variety of configurations. To support nitrogen reduction, each process seeks to
provide nitrification though an aerobic system and denitrification through an environment low in,
or devoid of, dissolved oxygen. There are two general categories of activated sludge systems:
suspended growth and attached growth. Within these categories and subcategories, many
variations exist.
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Suspended GrowthProcesses
Suspended growth processes are detailed in Chapter 8 of Metcalf & Eddy (2013) and generally
include the basic subcategories for each system aslisted.
Complete-mix systems Large, single stage tanks with substantial mixing/recirculation
equipment to dilute influent into the tank and avoid short circuiting.
o The existing oxidation ditch system is an extended aeration system that constitutes a
special type of complete-mix system. An oxidation ditchis completely mixed due to
the highrate of recycle but also contains of single point of aeration that creates an
oxygen gradient along the flow path of the reactor.
Plug flow, staged systemsTypically consist of long, narrow basins with multiple zones.
Sequencing batch reactors(SBRs)Consist of two or more tanks to which batches of
influent are cycled for treatment.
Of the three general subcategories of suspended growth processes, complete-mix and plug flow,
staged systems are applicable for analysis at this site as discussed further in this chapter. Improving
the existing oxidation ditchsystem is reviewed first inthe Improvements to Existing Oxidation
DitchSystem section. Implementing a plug flow, staged system would constitute complete
replacement of the existing activated sludge system and is evaluated inthe Replacement of the
Existing Oxidation System section.
SBRs are not considered practical to implement at the existing WWTF site as they represent an
entirely new process configuration with new tankage. As previously establishedinthe WWTF Site
Footprint section, there is not sufficient available space on thesitetomaintain the operation of the
existing systemwhile adding the new tankage that would be necessary for an SBR system.
Attached Growth Processes
Attached growth processes are detailed in Chapter 9of Metcalf & Eddy (2013) and generally
include the basic subcategories for each system as listed.
Standard biofilm processesVarious configurations in which flow passes through either
stationary or moving carriers to which biofilm is attached.
Integrated biofilm and activated sludge processesVarious configurations in whicheither
stationary or moving biofilm carriers are utilized with suspended growth activated sludge to
provide treatment.
Similarto SBRs, most standard biofilm processes are not practical for consideration atthe existing
site.However, one standard biofilm processand three integrated processes are screened for
applicability in this section. These systems typicallyarepromoted as supplemental equipment
options intended to represent minimally invasiveimprovements to existing activated sludge
systemsandincludethe following.
Integrated biofilm and activated sludge processes
o Integrated fixed film activated sludge (IFAS)
o Membrane aerated biofilm reactors (MABR)
o Mobile organic biofilm (MOB)
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Standard biofilm processes
o Denitrification filters for tertiary treatment
Attached Growth IFAS
IFAS is a biological treatment that integrates suspended growth activated sludge with fixed film
growth. IFAS adds inert carriers, typically plastic, to the activated sludge system to facilitate fixed
film growth. A screen retains the carriers in the reactors while suspended growth is carried through
the normal flow path to the secondary clarifiers and returned by the return activated sludge (RAS)
or wasted. Multiple manufacturers provide IFAS systems, with many proven installations. The
typically stated benefits of this system include:
Biomass density can be increased through the addition of fixed film organisms without
proportionally increasing the secondary clarifier SLR;
Simultaneous nitrification and denitrification can potentially occur within the biofilm;
however, there is not enough information to verify that this can reliably be achieved at all
operating conditions;
Nitrification and denitrification can be achieved at SRTs lower than conventional flocculant
sludge;
The likelihood of microbial washout at high flows is decreased due to the retention of the
fixed film organisms; and
Reduced yield of waste sludge.
However, IFAS is not considered compatible with a closed loop oxidation ditch system and surface
aerators. Floor-mounted diffused aeration is necessary to ensure that the media remains
adequately suspended throughout the reactor. Further, multiple partitioned zones would be
necessary to ensure that the media remains evenly distributed along the length of the reactor.
These requirements would incur a high capital cost and would be difficult to implement. Further,
the system likely would only incrementally increase the overall capacity of the activated sludge
system. This option is not considered further.
Attached Growth MABR
MABR is biological treatment that integrates suspended growth activated sludge with fixed film
growth. In this system, cassettes of membranes are installed into one or more zones of an
activated sludge system. The membrane cassettes are similar to those used in membrane
bioreactor systems; however, with MABR, the membranes are used as both a fixed biofilm carrier
and an aeration device. The membranes are stationary in the tank and biofilm attaches to the
surface of the membranes. The membranes are used to transfer oxygen directly to the biofilm.
Suspended growth activated sludge develops in the bulk liquid, is passed to subsequent zones, and
is returned from the secondary clarifiers. The MABR process has been characterized in
Criteria for Sewage Works Design as a new and developmental technology as defined in Section
G1-5.4.1.
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The typically stated benefits of MABR include:
Biomass density can be increased through the addition of fixed film organisms without
proportionally increasing the clarifier SLR;
The total system oxygen transfer efficiency is increased as a portion of the total oxygen is
delivered through the membranes directly to the biomass in lieu of passing through the
bulk liquid;
Simultaneous nitrification and denitrification potentially can occur within the biofilm, but
there is not enough information to verify that this can be achieved reliably at all operating
conditions;
Nitrification and denitrification can be achieved at SRTs lower than conventional flocculant
sludge;
The likelihood of microbial washout at high flows is decreased due to the retention of the
fixed film organisms; and
Reduced yield of waste sludge.
The primary difficulty with implementing MABR into the existing WWTFis that MABR cassettes
typicallyareinstalled within the initial partitioned zone of a plug flow system. It is unlikely that
MABR could be integrated into a closed loop oxidation ditch system. Implementing this system
would require many of the same elements as IFAS; therefore, this option is not considered further.
Attached Growth MOB
MOB is a biological treatment process intended to enhance suspended growth activated sludge
systems. Nuvoda is currently the only company known to sell such systems. The MOB process
consists of adding small organic carriers to an activated sludge system to facilitate biofilm
development. The porous organic carriers are manufactured from Kenaf plant stalks. The carriers
vary in size but are generally near 1 millimeter in diameter. These organic carriers have a very high
surface area relative to the particle size and facilitate faster settling compared to conventional
flocculant sludge. As such, the process intends to intensify activated sludge systems by adding a
biofilm component to increase biomass concentration while increasing settleability. The carriers
are removed from the RAS stream via a rotary drum screen and returned to the basins.
The MOB process has been implemented at a few municipal facilities over approximately the last
5years. Notably, demonstration of the Nuvoda process was undertaken at the Edmonds WWTFin
Washington and the Forest Grove WWTFin Oregon in recent years. However,neither of these
facilities include oxidation ditches, sothe findings are not directly applicable to the City.
By adding MOB directly to the existing oxidation ditch, the carriers should add a biofilm component
to the activated sludge, which may allow for some denitrification within the anoxic environment
internal to the biofilm. However, the relative effectthat thiswill have on effluent TIN is difficult to
predict based on the limited data from similar operating facilities. Further, the system requires
screening to be added to the RAS system, which will require additional process building spacethat
will be costly and challenging to implementon the already constrained site. For these reasons, the
is not recommended to be an early adopter of this technology.
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Attached Growth Denitrification Filters for Tertiary Treatment
Various tertiary treatment systems exist for the purposes of removing nutrients from the
secondary effluent. The existing oxidation ditches are shown to full nitrify the effluent at design
conditions; therefore, a tertiary treatment system that provides denitrification may be considered
for this facility. Denitrification filters are the logical technology to review. These filters are a subset
of biofilm processes that can be used as a tertiary treatment process to aid in effluent TIN
reduction. In this process, nitrified effluent (in which most ammonia has been converted to nitrate)
is passed through a filter bed containing heterotrophic organisms that metabolized nitrate into
nitrogen gas in the anoxic conditions of the filter bed. This typically requires a carbon feed ahead of
the filter as most of the influent carbon has been reduced through the preceding secondary
process.
For this technology to be applied at the City, an effluent pump station would be required to lift
secondary effluent from downstream end of the clarifiers to the denitrification filters. This is not
recommended as the construction of an effluent pump station and filters on the existing site would
be extremely difficult to configure and implement, would be costly, and would further reduce the
available footprint at the WWTF. Further, implementation of a tertiary treatment system of any
sort will not inherently increase the WWTF capacity as it will not improve the activated sludge
system. As such, tertiary treatment systems, such as denitrification filters, are not considered
further for this facility.
Improvements to the Existing Oxidation Ditch System
Based on the analyses of the previous section, improving the existing oxidation ditch system is
likely to be the only feasible approach that does not constitute a complete replacement of the
existing system. The intent of this section is to review options for improving the existing system
that include limited mechanical and structural improvements, are relatively low cost, would extend
the useful life of the existing infrastructure, and would delay the need for major improvements.
The applicable options include:
1.The addition of anoxic tankage external to the oxidation ditches;
2.The creation of a dedicated anoxic zone internal to the oxidation ditches; and
3.Cyclic aeration of the oxidation ditches.
The anoxic zone tankage would need to equate to approximately 20 to 30 percent of the volume of
the existing ditches. There is no feasible method to add external anoxic tankage of this size to the
site based on the constraints identified in the WWTF Site Footprint. As such, the first option is not
considered applicable.
The two remaining options are analyzed in the following sections.
Creation of Dedicated Anoxic Zone Internal to Oxidation Ditches
The existing optimization strategy represents one method of creating an anoxic zone within the
oxidation ditches by reducing aeration to create a zone relatively devoid of oxygen. As previously
discussed, this configuration has significant limitations that preclude relying on this option through
the planning period.
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Another option consists of physically partitioning an anoxic zone and adding new equipment to the
system. The Modified Ludzack-Ettinger (MLE) processthat fits this approach is one of the most
commonactivated sludge processesused for biological nitrogen removal. This process is shown in
Table 8-24, row (b)of Metcalf & Eddy (2013). The MLEconfiguration creates a dedicated anoxic
zone upstream of the aerobic zone. An internal recycle pump returns mixed liquor from the
downstream end of the aerobic zone to the anoxic zone atahigh rate (typically 3to 5 times the
influent flow rate) toreturn the nitrate for denitrification in the anoxic zone. Placement of the
anoxic zone upstream of the aerobic zone allows for influent carbon to be utilized for
denitrification.
Toimplement this configuration within the existing tankage at the WWTF, an anoxic zone would be
created withaphysical partition within the ditch as shown in Figure 8-5.
Figure 8-5ConceptualConversion of Existing Oxidation Ditches to MLE Configuration
Note: Single ditch shown.
As shown in the figure, this fundamental change to the ditch configuration essentially converts the
ditch from a closed-loop reactor to a staged, continuous flow reactor. The mixer/aerator, which is
necessary to provide a highdegree of mixing and recirculation in a closed-loop reactor, would be
removed. The MLE configuration would utilize an internal recycle pump, newmixing equipment in
the anoxic zone,and diffused aeration withexternalblowersfor the oxic zone. Additionally, it
would be prudentto place the partition adjacent to the mixed liquor outfall and relocate the
influent/RAS discharge locationas shown in the figureto make the best usage of the tankage
volume.
These changes would consist primarily of mechanical equipment additions. There would be
significantnewmotor loads for the aeration blowers, mixing equipment,and internal recycle
pumps that likely would promptmajor electricalsystem changes. Any approachthat continuesto
utilize the existing aerators and minimize equipment additions would be less costly than conversion
to theMLE configurationshown.
Further, these improvements would not be expected tosignificantly expand the systemcapacity
beyond the projected 2043 loading values. The system will remain inherently limited by the SLR
capacity of the two clarifiers.The MLE system could allow for modest improvements in aeration
system oxygen transfer and mixed liquor settleability,but thesewould only be expected to
incrementally increase the capacity of the activated sludge system with the existing two clarifiers.
The cost and complexity ofthis configuration, coupled with the minimal capacity expansion that it
affords, preclude this option from further consideration.
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Cyclical Operation of the Oxidation Ditches
As previously discusse
environment in the oxidation ditches by operating the aerators in low speed. This approach creates
an anoxic zone internal to the ditch without necessitating physical partitions and other
improvements discussed in the Creation of Dedicated Anoxic Zone Internal to Oxidation Ditches
section.
Another approach to creating an anoxic environment in the ditches without physical partitions is to
create anoxic cycles by cyclically turning off the aerator periodically each day. This approach has
been utilized in multiple similar facilities to reduce TIN below 10 mg/L or less and is described in
Table 8-24, row (p) of Metcalf & Eddy (2013). This approach is readily applicable for retrofitting
facilities with two oxidation ditches. At a minimum, it would be necessary to add the following
items to the existing ditches:
Mechanical mixing equipment for each ditch to maintain the activated sludge in suspension
during the anoxic cycles when the mixer/aerators are offline. This equipment likely would
consist of one or two low speed, large blade, submersible mixers.
Oxidation-reduction potential control equipment to determine when the nitrate is depleted
to suspend the anoxic cycle.
Figure 8-6 illustrates the cyclical operation of the two oxidation ditches.
Figure 8-6 Conceptual Conversion of Existing Oxidation Ditches to Cyclic Operation
Note: Single ditch shown in either oxic or anoxic cycle.
There are some significant benefits to this approach. First, it represents limited structural and
mechanical improvements consisting primarily of small equipment additions and control system
programming. Further, it allows for continued use of the mixer/aerators, which decreases the cost
of this option relative to conversion to an MLE process. Lastly, this option could be implemented
with a relatively short outage of the existing tankage and by taking each ditch offline in series.
Conversion to cyclic operation generally should regain most of the permitted capacity of the WWTF
while providing for TIN reduction to below 10 mg/L. It is recommended that the capacity of this
system be based on an average annual clarifier SLR of 25 lb/d/sf. Based on Table 8-4, this would
equate to 1.40 MGD with one clarifier online, which is approximately the same as the current rated
capacity of the WWTF (1.44 MGD average annual). An average annual flow of 1.4 MGD is projected
to occur in approximately 2040 per Table 8-1. As previously noted, the City must begin planning for
an expansion of WWTF capacity when the facility exceeds 85 percent of its rated capacity.
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Assuming acapacity of 1.4MGD with cyclical ditch operation, 85percent would equal an
approximate average annual flow of 1.20MGD,which is projected to occurby2033.
Implementing cyclic operation is recommended soon as it will assist the WWTF in maintaining TIN
below 10 mg/L as growth in flow and loading occurs. These improvements are of limited
mechanical and structural scope and represent a relatively low-cost approach toregaining WWTF
capacityand maintaining TIN reduction with the existing system. Further, the ultimate TIN
requirements of the PSNGP are not yet finalized; therefore,delaying major improvements by
extending the useful life of the existing infrastructure is in the best interest of the ratepayers. This
approach is predicatedonmajor improvements to the activated sludge system likely occurring
between 2033 and 2040,as 85percent of the WWTF capacity is expected to be exceeded by 2033.
ReplacementoftheExistingOxidationDitchSystem
The analyses of the previous sections resulted in recommendingcyclical operation of the oxidation
ditches as a near-term improvement that is minimally invasive to the WWTF. As discussed,this
approach mayprovide reliable TIN reduction as the City grows, although major improvements
should be planned and implemented to ensure continued, reliable treatment. Major improvements
also are anticipated given the age of the infrastructure. The useful life and capacity of this
infrastructure could be extended to approximately 2040 by making improvements to implement
cyclical oxidation ditch operationin the next 5 years. The City is fortunate to be able to get
extended life out of the oxidation ditches and replacement will be timely in addressing its age and
growth concurrently.
None of the optionspreviously analyzedwere shown to meet the TIN objectives at the flow and
loading levels expected at the end of the planning period due to the SLR limitation of the two
secondary clarifiers.Based on the initial review of alternatives inthe Screening of Nitrogen
Treatment Options section, conversion to aplug flow,staged systemis the only other practical
alternative thatshould be consideredfor the longer term improvements and capacity expansion of
the WWTF.
Plug flow, stagedsystems have been configured to provide a much higher rate of treatment
relativetooxidation ditches. A prudently designed plug flow system can allow for treatment
capacity that is double that of an oxidation ditch system with a similar footprint. The activated
sludge in a plug flow system should have substantially improved settleabilitycompared to that of
an oxidation ditch system, which allows for a much higher clarifier SLR to be achieved. This enables
significantly increased MLSS concentrations to be achieved, which allows for a higher rate of
biological treatment per reactorarea.
In 2022, the City commissioned a study on sea level rise impacts on Port Townsend, including
wastewater infrastructure. The City of Port Townsend Sea Level Rise and Coastal Flooding Risk
Assessment(Cascadia Consulting Group, 2022) is containedin Appendix K. As noted in the study, in
the long term, there will be impacts that could affect wastewater infrastructure. Any future
planning for improvements intended to last beyond the next 20 years should factor this study and
latest available information on sea level rise into the siting and hydraulicsof the proposed
improvements.Figure 8-7 illustrates an open water connection between the Strait and Chinese
Garden Lagoon. This plan for future improvements (lasting beyond 20 years) takes into account this
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
probability of sea level rise as illustrated in Figure 8-10. Refer to the Outfall section in this chapter
for further discussion on sea level rise.
Figure 8-7 Sea Level Rise Projects for 17% Probability of Exceedance including Storm Surge
Open water
connection to Chinese
Garden Lagoon
WWTF
Given the effects of sea level rise, site constraints, and the need to apply the best known and
available technology to replace aging infrastructure and to improve the capacity of the WWTF,
options for replacing the oxidation ditches with a plug flow system are reviewed in this section.
On-Site Implementation of Plug Flow Reactors Replace Existing Oxidation Ditches
It is likely that the only location plug flow reactors could be constructed onsite are within the
existing footprint of the oxidation ditches. Various methods of constructing such basins were
considered. The two primary approaches consist of the following:
Option 1 Conversion of each ditch, in series, into a plug flow aeration basin with multiple
partitioned zones, floor-mounted diffused aeration, internal recycle, and other
improvements.
Option 2 Complete demolition of the existing oxidation ditches and reconstruction of plug
flow aeration basins in this location.
The result of these analyses is that neither option is recommended for similar reasons noted in the
analyses of converting the existing oxidation ditches to an MLE or similar process. Substantial
structural improvements would be necessary for each ditch to ensure reliability and longevity.
There also would be significant new equipment, access platforms, electrical, and control items to
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install. These items necessitate months of construction, resulting inan extendedoutageperiod for
each ditch. This outagewould reduce the reliability and redundancy of the existingactivated sludge
system and expose the City to substantial risk of permit violation for an extended period.
Further, this approach would not facilitate thefuture construction of a thirdclarifier as itwould be
unlikely to create additional unused space on the WWTFsite.
This approach is not considered further.
Off-Site Implementation of Plug Flow Reactors
Thepreviousanalyseshave not identifiedapracticalapproachto provide sufficient treatment
capacity withTIN reduction atthe existing WWTF beyond approximately 2040.As flow and loading
growth continues, constructing major improvementson the existing site becomes even more
challenging as the existing tankage must be maintained in operation through construction to
provide reliable treatment. As previously noted, limited improvements for cyclical ditch operation
should allow for continued use of the existing WWTF infrastructure to approximately 2040, which
will allow the City to begin planning for a majorexpansion of the WWTF. It is recommended that
this expansion be planned to be offsite and near the existing WWTF.
Figure 8-8 shows the existing site aerial with parcel lines and ownership,as well as the surrounding
areas.
Figure 8-8WWTF and SurroundingParcels
N
Port
Townsend
WWTF
Vacant ROW
Kuhn St.
Vacant parcels
(two)
Two parcelsimmediately west of Kuhn Streetwiththesame ownercouldprovide sufficient space
for an expansion of the WWTF. The utilization of these parcels most likelywouldinclude
construction of activated sludgesystem tankage, specifically plug flow aeration basins, at this
location.
nd
In addition to procuringthese parcels,vacating the 52Street ROWseparating both parcels for the
purposes of providing a single contiguous parcelwould help provide ample space for new oxidation
ditches and future facilities that may be needed well beyond the planning period.
Figure 8-9 showsthese major considerations.
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CHAPTER 8CITY OF PORT TOWNSENDGENERAL SEWERPLAN
Figure 8-9AdjacentParcel Acquisition Considerations
Potential future
extents of WWTF
property
Chinese
nd
Gardens
Vacate 52
St. ROW?
City-owned
future operator
residence
N
ActivatedSludgeSystemRecommendations
The previous analyses resulted inthe followingmajor findings:
The facility is projected to exceed 85percent of the permitted BODloading by 2033.
The facility flow and loading is projected to reach its rated capacity at approximately 2043.
The current optimization strategy effectively reduces TIN below 10 mg/L but results in a
significant reduction in the realistic capacity of the activated sludge system.
Implementation of cyclical oxidationditch operation, as an alternative to the current
optimization strategy,would be a relatively low cost approach to maintaining TIN reduction
until the expansion can occur.
Providing TIN reduction at the flow and loading projected late in the planning period would
necessitate a major expansionof the WWTF that will be most effectively completed through
the acquisition of off-site adjacent parcels.
The recommended basic approach and phasing of the WWTF improvements follows.
Years 0to 5 (2024to 2028)
In the next 5 years, the City will need to coordinate withEcologyand the requirements of the Puget
Sound NutrientGeneral Permit,which may require the need to implement cyclical oxidation ditch
operation to ensure continued TIN reduction and maintain the existing activated sludge system
capacity. The City also shouldbegin the early work preparing for the future major expansion of the
WWTF. This work generallyshouldincludethe following:
Complete a preliminary design for the cyclical oxidation ditch improvements(Capital
Improvement Project(CIP) F8 in Chapter 10). Determine if an Engineering Report meeting
the requirements ofWashington Administrative Code(WAC)240-173-060 will berequired
by Ecology.
Complete improvements to implement cyclical oxidation ditch operation (CIP F8 in
Chapter10).
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Complete a Nitrogen Optimization Plan per the PSNGP and submit to Ecology byMarch 31,
2026.
Complete other WWTF rehabilitation work to extend the life of the existing infrastructure in
the most economical manner feasible to avoid significant capital costs for items that will be
removed or reconfigured with the major expansion of the WWTF (Chapter10).
Acquire parcels of land to support themajor expansion of the WWTF (CIP F11 in
Chapter10).
Years 6to 10 (2028to 2033)
Complete an Engineering Report per WAC 173-240-060 for the major expansion of the
WWTF. Submit the report for review and approval by Ecology(CIP F12 in Chapter 10).
Commence permitting, preliminary design,and funding acquisitionrelated to the major
expansion of the WWTF (CIP F12 in Chapter 10).
Years 11to 20 (2034to 2043)
During this period, the design and construction of the major expansion of the WWTF (CIP F12 in
Chapter 10)should be completed. A basic description of the proposed major improvements is
discussed in this section.
Pending the land acquisition and configuration of the new parcels, at a minimum,anew activated
sludgesystem would be constructed on the new parcels. The existing secondary clarifiers likely
could remain at the current location. With the implementation of biological treatment on the new
parcels, the existing oxidation ditches could be removed. This would allow for future secondary
clarifiers to be constructed within the footprint of the demolished oxidation ditches.
To provide TIN reduction, a conservative approach to planning the new activated sludge system
consists of two plug flow, stagedaeration basins on the new parcels. The exact size, configuration,
and equipment options would be analyzed thoroughly and determined in a future Engineering
Report.
All influent flow by gravity to the existing WWTF is collected at the Influent Pump Station (IPS)and
pumped to theexistingHeadworks, with subsequent gravity flow to the oxidation ditches. The
proposed future configuration of the WWTF, with biological treatment on the higher ground of the
new parcels, will prompt significant changes to the hydraulic profile of the WWTF. Influent will
need to be lifted to thenewaeration basins. In order to avoid an additional pump station between
the existing Headworks and the new basins, it wouldbe most practical to construct a new
Headworks on the new parcels and refurbish or replace the existing IPSat or near its existing
location. This is further discussed in the following Preliminary Treatment section.
Figure 8-10 schematically displays a conceptual reconfiguration of the WWTF utilizingthe currently
undeveloped parcels west of Kuhn Street.
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CHAPTER 8CITY OF PORT TOWNSENDGENERAL SEWERPLAN
Figure 8-10BasicConfiguration of Expanded WWTF
Space for
Remove existing
additional
Headworks
clarifiers
building
Kuhn St.
New Headworks
New aeration
building
basins
N
PRELIMINARYTREATMENT
Chapter 7 identified improvements to rectify conditions-based needs for the IPSand Headworks.
The most significant of these improvements include:
1.Wet well rehabilitation, piping and pump replacement, and electrical raceway replacement
at the IPS; and
2.In-kind replacement of the existing screenand grit equipment,and concrete channel
rehabilitationat the Headworks.
SummaryofAnalysis
Table 8-5 shows thedesign criteria for the existing IPS and Headworks from the original
construction drawings.
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CITY OF PORT TOWNSEND GENERAL SEWER PLANTREATMENT FACILITIES ANALYSIS
Table 8-5
Preliminary Treatment Design Criteria from 1990 Project
As shown, two pumps in service should provide a nominal flow of 4,500 gallons per minute (gpm)
(6.48 MGD). This is in excess of theprojected 2043 peak hour flow of 6.06 MGD with one pump out
of service. The IPS should provide sufficient capacity and redundancy through the planning period.
In general, the Headworks equipment and channels were designed for a peakflow of
approximately 7 MGD, which is above the projected 2043 peak hour flow of 6.06 MGD. The
Headworks includes a single mechanical bar screen and a back-up channel with a manually raked
bar screen. However, the mechanical screen should provide sufficient capacityand the back-up
screen provides sufficient redundancy.As previously noted, a budgetary allocation is established
for the in-kind replacement of the screen if needed during the planning period.
Similarly, the grit removal system is expected to provide sufficient capacity through the planning
period,and any improvements needed will be for the in-kind replacement of aging equipment as
previously noted.
Recommendations
Based on this review, the existing IPS and Headworks should not require replacements during the
planning periodto increase capacity or redundancy. As noted in Chapter 7, age and condition may
require replacementor repair in the next 5 to 10 years.However, as discussed inthe Activated
Sludge System section, future replacement of the activated sludge system likely would provide the
opportune time to replace the existing preliminary treatment system. The overall approach to the
activated sludge system improvements involves constructing new aeration basins offsite, on the
currently vacant parcels west of Kuhn Street. As noted, this likely would necessitate constructing a
new Headworks facility on the new parcels, adjacent to the new aeration basins. With this
configuration, it is most likely that the IPSwould be significantly changed or replaced and
potentially relocated. The IPSwould lift all influent and return flows up to the new Headworks
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
location. The configuration of this infrastructure would be analyzed thoroughly in the future
Engineering Report as discussed in the Activated Sludge System section. Given that the preliminary
treatment system is expected to be replaced in conjunction with the activated sludge system
improvements planned for the second half of the planning period, it is prudent to extend the life of
this infrastructure through limited rehabilitation while avoiding significant sunk costs in improving
this system.
Further, the new Headworks will allow for improvements over the existing configuration. For
instance, the new Headworks should include mechanical fine screening, which will provide
2-dimensional screening with much improved screenings capture compared to the existing
1-dimensional bar screen. The fine screens would provide a minimum of -inch screening, and
¼-inch screening could be considered. Additionally, two mechanical screens could be included in
the new Headworks for redundancy and to reduce operational labor in the event of an outage of a
single mechanical screen. Similarly, a new grit removal system would present opportunities for
improvements relative to the existing grit system. Such improvements are not feasible to make to
the existing Headworks; therefore, it is prudent to extend the life of the existing infrastructure as
feasible while planning for a future new, off-site Headworks.
EFFLUENT DISINFECTION
Chapter 7 identified relatively minor repair and replacement needs for the existing chlorination
system. Replacement of the non-potable water pumps also was recommended and represents the
only capital improvement project identified based on the conditions assessment of the disinfection
system.
Summary of Analysis
The design criteria for the existing chlorine contact chambers is compared to the 2043 average and
peak hour flow values in Table 8-6.
Table 8-6
Disinfection System Design Criteria from 1990 Project
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The typical design range for disinfection contact time based on average design flow is 30 to
120minutes per Metcalf & Eddy(2013).With two contact tanks online at the 2043 average annual
flow of 1.46 MGD, there is96 minutes of contact time,which is well within the accepted range.
With one tank offline, the contact time would be approximately 48 minutes, which is still within the
recommended range.
Typical design ranges for disinfection contact time based on peak design flow is 15to90minutes
per Metcalf & Eddy(2013). The contacttime of 23 minutes with two tanks online at the projected
2043 peak hour flow is within the recommended range. With one tank out of service, the contact
time would be reduced to approximately 12 minutes. While this is below the recommended range
andcould cause an increase in coliform discharge, it is likely that weekly and monthlyaverage
coliform values would remain below permit limitsas the average contact times are sufficient.
Based on this analysis, expanding capacity, or improving redundancy ofthe chlorination system,
should not be required during the planning period.
Recommendations
No major improvements appear to be needed for the effluent disinfection system during the
planning period. Minor repairs and rehabilitation should be completed as necessaryto maintain
reliable operation of the system.However, future sea level rise and other considerations may in the
long term require improvements to, or replacement of, the existing disinfectionsystem.
OUTFALL
The City has received funding and is actively working with Ecology and Jacobs Engineering Group on
an evaluation and modifications to the existing outfall.The project is currently under further
alternatives evaluation. Initial evaluations of the outfall dating back to the 2000 Wastewater
Facilities Plan suggest that slipliningand pumping would be the least cost option. Since that time,
significant work has been completed,including the approval of aFacilities Plan Amendmentin 2019
by Ecology. This amendment recommends digging in a parallel pipe to the existing pipe and
replacing the diffusers. This option has been recommended as the least cost option. Prior to
entering the permitting phase of the project, resource agencies and the public spoke out against
the project due to potential impacts to eel grass and kelp beds. Figure 8-11 illustrates the
approximate outfall configuration. Note, the difference betweentheChinese Garden Lagoon and
the WWTF outfall. The Chinese Garden Lagoon outfall often is exposed on the beach and is
confused by the public as being the WWTF outfall.
fall is always submerged; however, storms periodically expose and damage
the existing concrete pipe on the beach. Staff immediately repairs the concrete when damaged.
One need for the outfall project, no matter the solution,is to replace the beach section of pipe and
protect it against heavy North Beach surf.
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Figure 8-11 Approximate Outfall Configuration
WWTF
Outfall
Chinese Garden
Lagoon Outfall
Staff is re-evaluating possible solutions, including sliplining the pipe. Staff also is considering the
impact of sea level rise on the Chinese Garden Lagoon. Currently, the outfall does not use the
Chinese Garden Lagoon; however, at a Marine Resources Committee meeting, a suggestion was
made to look for environmental improvements of combining the sewer outfall with the Chinese
Garden Lagoon.
Given this work is already underway, further evaluation in this GSP is not included and will be
handled in separate documents that will be submitted to Ecology for review and approval.
TERTIARY TREATMENT WATER REUSE/RECLAMATION
The City currently discharges all of its effluent to the existing outfall. The City frequently hears from
the community about its desire to implement water reuse practices in the name of water
conservation and environmental stewardship. A detailed description of water reuse as it relates to
regulations and standards is included in Chapter 4 of the adopted 2019 Water System Plan (WSP)
(available on the City website). Given water reuse begins at the WWTF, the following information is
provided concerning the application of water reuse opportunities in the City, as well as financial
limitations.
How would reclaimed water from the WWTF be used in Port Townsend? Chapter 4 of the WSP,
specifically Table 4-7, lists all of the allowable uses and the associated class of reclaimed water
allowable for such use. In general, higher levels of treatment are required for reclaimed water
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where there is a potential for human exposure,such as irrigation water. What is the greatest
environmental and societal benefit? How is water reuse helpful in the light of climate change and
sea level rise? These are all very good questions. The WSPoutlines that the cost would be
prohibitive, thus no specific actions or investments are included in the WSP. This GSPoutlines the
most common comments heard by the City and likely the most probableapplications of water
reuse,recognizing that there is benefit to seeking opportunities. Practically, this GSPdoes not
include specific investments in the CIPgiven the rate impacts. However, staff recommends keeping
water reuse on the horizon and lookingfor grant opportunities to negate the capital cost of
operating a water reuse system. The following brief discussion of potential water reuse applications
provides very high level considerations.
Water reuse for industrial process water is oneoption available. This option requires the
least amount of treatment because industrial water is non-contact use. Giventhatthe City
has a huge industrial water user, the Port TownsendPaper Mill, this thought was brought
up in the recent Water Supply Agreement discussions. The City could reliably provide
approximately 900,000 gallons of the m
reclaimed water pipeline would have to be constructed across the City from the WWTF to
the Paper Mill. This water supply pipeline would cost in thetensof millions to construct.
Depending on whether or not workers were exposed to the water determines the level of
treatment required. Likely, Class A treatment would be required. If tertiary or enhanced
treatment is required, funding for an order of magnitude cost estimate of $20 million
would be needed.
Irrigation is the most common beneficial use of reclaimed wastewater. Due to human
exposure in parks and to food in gardens, Class A reclamation standards must be met. To
make reclaimed water available throughout the City, a second water system would need to
be created. These systems are constructed of purple pipe to reduce the chance of
accidental cross connection. Cities with reclaimed water available for irrigation also require
extensive investment at each property for cross-connection prevention as required by the
Washington State Department of Health. A more likely beneficial use of reclaimed irrigation
water is to focus on the large expanses of irrigated areas such as the Fort, golf course,
parks, and school play fields. This would help reduce peak water use by the City during the
summer months when irrigation demands increase water consumption from 1 MGDto
nearly 2 MGD. Note, water reclamation is limited to the irrigation season between May and
October for this application. Dedicated water pipelines, reservoirs,and pumps stations are
required to accomplish any type of irrigation use. The cost of this infrastructure is in
addition to the cost of enhanced or tertiary treatment. Given tertiary or enhanced
treatment is required, funding for an order of magnitude cost estimate of $20to
$50million would be required to build an irrigation system. Irrigation of the Fort, Jefferson
County fairgrounds,and nearby schools would require the least amount of infrastructure
development.
Water reclamation for environmental benefit might be the most practical implementation
strategy. For example, the City is currently exploring options for enhancing the water
quality of the Chinese Garden Lagoon given its propensity for algae blooms. With sealevel
rise, the lagoon will ultimately connect with the Strait of Juan de Fuca and provide an
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
inland estuary that will result in great habitat enhancements. The question for this
application would be whether accelerating this connection would make sense or not with
wastewater discharge to the lagoon.
Water reclamation for groundwater augmentation could be another practical use.
Groundwater injection occurs through either direct injection or percolation. The aquifer
under the City is not a drinking water supply and is approximately at sea level. A number of
irrigation wells exist within the City, including one owned by the City. Pumping of this
aquifer invites salt water intrusion on all three sides of the City. Infiltration of reclaimed
water can offset the impact of pumping. The exact configuration of the aquifer is not
readily known; therefore, a great amount of research would be required to validate this
approach for reclaimed water reuse. Depending on the level of treatment, investment
levels likely approach $10 million for this option.
All of the applications discussed require extensive permitting to ensure unintended consequences
are not a result. Given the extensive needs of investment in the foundational systems of the WWTF
and collection system, the rate payers may not be willing to pay for a reclaimed water system at
this time. Adding reclaimed water to the capital plan would require nearly doubling the investment
levels, which would more than triple current sewer rates. Therefore, this GSP recommends
expending resources on water reuse only if an environmental improvement grant makes it
financially feasible.
The improvements noted in the previous sections and in the Chapter 10 CIP will still need to be
implemented, even if the City decides to pursue tertiary treatment for water reclamation. Given
the space limitations and capital cost concerns, pursuing this further at this time is not feasible.
SOLIDS HANDLING
The conditions assessment in Chapter 7 identified primarily minor improvements to maintain
reliable operation of the solids handling system during the planning period. This chapter reviews
the potential improvements needed to ensure sufficient system capacity and redundancy is
available with this system. The analyses are divided between the on- and off-site solids handling
system components.
On-Site WWTF Solids Handling System
The existing on-site solids handling system includes two aerobic holding tanks followed by sludge
dewatering via a single belt press. The aerobic holding tanks where retrofitted during the
1990 project to provide waste activated sludge (WAS) storage. These concrete tanks originally were
constructed in approximately 1970. The dewatering system was installed in the 1990 project.
Dewatered sludge is composted as discussed in the Off-Site Compost Facility section.
Summary of Analysis
The on-site solids handling system is not intended to provide substantial stabilization of the WAS as
the solids are stabilized via off-site composting. As currently configured, the on-site system is
generally intended to equalize and store WAS to enable periodic operation of the dewatering belt
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CITY OF PORT TOWNSEND GENERAL SEWER PLANTREATMENT FACILITIES ANALYSIS
press during normal staffhours. As such, the aerobic holding tanks are not required to provide
significant volatile solids destruction,andthe dewatered sludge is not intended to meet Class B
requirements. The design criteria from the 1990 project for the existing aerobic holding tanks is
shown in Table 8-7.
Table 8-7
Aerobic Holding Tank Design Criteria from 1990 Project
At the 2043 maximum month loading condition, the WWTF is expected to produce WAS at
approximately 4,000 pounds per day (ppd) total solids. At an average concentration of 8,000 mg/L,
this equates to 60,000 gallons per day (gpd). As shown in Table 8-7, thetwo aerobic holding tanks
provide a total volume of approximately 360,000 gallons. With one tank offline, the system should
provide approximately 3 days of storage volumewithout thickening. The operators currently
decant the tanks to increase the solids concentration and reduce the volume fed to the belt press.
With or without decanting, 3 days should be sufficient equalization for the dewatering system
should one tank be offline. The aeration system also appears sufficiently sized to maintain an
aerobic environment in the tanks without allowing significant volatile solids destruction. By utilizing
the composting system to provide sludge stabilization, the aerobic holding tank system is expected
to provide sufficient capacity and redundancy in WAS storage through the planning period.
The design criteria from the 1990 project for thedewatering system is shown in Table 8-8.
Table 8-8
Dewatering SystemDesign Criteria from 1990 Project
The belt press is currently operated up to3 days per week for approximately 8-hour shifts. Based
on staff input, it is preferred thatthe belt press be operated no more than 4days per week for
8hours per day. Given this, the belt press is operating at about 75percentor less of the allowable
operating time per week. Based on the projected increase in flow and loading in Table 8-1, sludge
production would be expected to increase approximately 20percentby 2033 and 40percentby
2043 compared to existing levels. As such, it is likely that the belt provides sufficient capacity to
approximately 2033 by operating up to 4 days per week. Beyond 2033, the belt press may need to
be operated up to 5 days per week to provide sufficient capacityor be replaced with a larger unit.
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It should be noted that the City has a single belt press, so there is no inherent dewatering system
redundancy. If needed, the City could rent a mobile dewatering unit to process sludge.
Appropriately sized units for should be readily available for rental in an
emergency.
Recommendations
As noted in Chapter 7, the existing on-site solids handling system is generally in good condition. As
needs. However, the aerobic holding system tankage is expected to be over 70 years of age at the
end of the planning period, while the belt press and ancillary equipment will generally be over
50 years of age by 2043. It is prudent to plan for replacement of the major mechanical equipment
for the solids handling equipment, such as the belt press, sludge pumps, blowers, etc., as well as
other refurbishments, such as the aerobic holding tankage, late in the planning period. It is difficult
to predict the scope of this work. Further, the WWTF is expected to be significantly reconfigured by
the end of the planning period as discussed in the Activated Sludge System section. Based on these
factors, it is recommended that the City establish a budgetary allocation for on-site solids handling
system improvements late in the planning period. As an initial allocation, $3 million is
recommended. The scope of the improvements and associated costs should be reviewed
thoroughly in the future, likely as part of the Engineering Report that will be required for the major
WWTF expansion project.
Off-Site Compost Facility
The City operates a Compost Facility at the Jefferson County (County) Transfer Station site. The City
transports dewatered sludge from the WWTF to the facility for composting. An aerial image of the
facility is included in the Chapter 7.
Summary of Analysis
The composting system utilizes the aerated static pile method. The facility includes two covered
are.The south barn occupies approximately 11,000 square feet (sf) and is
used for the aerated static piles. The north barn is 8,000 sf and is primarily used as a
finishing/storage barn. The City received carbon in the form of yard wa
solid waste hauler and provided by self-haulers at the Jefferson County transfer station. The City
chips yard waste annually for use as a bulking agent in the composting process. The City owns
screening equipment, a front-end loader, and other heavy equipment necessary to operate the
composting system.
Based on the projected increase in loading shown in Table 8-1, sludge hauled to the compost
facility would be expected to increase approximately 20 percent by 2033 and 40 percent by 2043
compared to existing levels.
The City is also contracting to take waste activated sludge from the new Port Hadlock WWTF. Port
Hadlock will purchase and operate a gravity dewatering system and haul the dewatered sludge to
the Compost Facility. The City will mix with the Port Hadlock sludge with the to
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compost on site.It is estimated that Port Hadlock will supply a 5 yard load approximately 8 times
per year.
The Compost Facilitysitehas ample space for the existing operation and has sufficient available
space to expand in the future if desired. As growth occurs, the City likelywill convert the north barn
firstto house additional aerated static piles. At a minimum, this would consist of adding aeration
equipment to this barn.An additional barnlikelywouldbe the next major addition with growth.
Septage Receiving System
As discussed in Chapter 7, the City also receivesseptage to the Compost Facility from the County,
which necessitates a small SBRtreatment plant at the facility.The SBR system discharges to an
engineered wetland treatment system west of the Compost Facility. As noted in Chapter 7, some
improvements to the SBR are required to replace and rehabilitate aging items. Septage solids are
mixed with City sludge and composted. Forthepurposes of this GSP, it is assumed that if septage
receiving were expanded, the overall impact on the solids portion of the composting operation
would not be significantly impacted. On the other hand, if septage receiving was expanded,
significant improvements to the liquid treatment potion of the compost facility would be required.
The current CIP in Chapter 10 includes operations and maintenanceandrepair/replacement
projects to keep the existing septage facility running for the next 20 years. This would keep the
system functioning at the same treatment capacity as current. However, the City was approached
by the
percent
total annual septage generation. The remainderis trucked to facilities outside of the County for
treatment. Whenincluding 20 years of growth, the facility would need to treat a maximum month
average daily flow of 6,500 gpd, and a peak day of 10,000 gallons. This is significantly higher than
the rated capacity of the existing facility.
Alternatives were analyzed,including upgrading the on-
WWTF, and building a pump station and pumping from the septage facility to the main WWTF. The
recommended alternative was to expand capacity at the site, as the other alternatives were much
more costly or unfeasible. The upgrade alternative would cost approximately $4M (2023 dollars).
This information was presented to County staff and County Commissioners for review.
The County is considering their optionsand the availability of funding. The next step for this
upgradewould be a dedicated Engineering Report to analyze and recommend the SBR
improvements and detail the associated costs.
As noted previously, this GSP only includes repair/replacement projects at this time.If expansion is
decided upon, and funding is found by the County, then a separate amendment would be
submitted.
ELECTRICALANDCONTROLS
Chapter 7 identified necessary improvements for the electrical and controlsystems. Chapter 10
includes the CIP projects for these items to maintain the reliability and operability of these systems.
However, one of the main considerations for electrical improvements is the timing of the
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CHAPTER 8 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
recommended motor control center (MCC) and generator replacements due to these items nearing
the end of their useful life. As discussed in this chapter, a major reconfiguration of the WWTF is
planned to support the necessary treatment objectives. As noted in the Activated Sludge System
Recommendations, the major improvements to the WWTF are likely to consist of abandonment of
the existing Headworks and oxidation ditches and replacement with a new Headworks and plug
flow aeration basins on adjacent property. Additionally, the IPS will be reconfigured or replaced to
pump to the new Headworks at a higher elevation than the existing Headworks. The project also
may include, or at least allow provisions for, an additional secondary clarifier on the existing site.
The improvements associated with the major reconfiguration of the WWTF will significantly impact
the electrical system at the WWTP by decommissioning major motor loads through removal of
existing processes, as well as adding new motor loads associated with the new systems. It would be
most economical for the City to maintain the existing MCCs and generator until they are completely
replaced through the major reconfiguration project. However, Chapter 7 conservatively
recommended replacement of this equipment in 5 to 10 years. This timing may be slightly in
advance of the major improvements that are expected to occur between 10 and 20 years. For
conservative planning purposes, it is recommended that the City budget for replacement of this
equipment in 5 to 10 years. However, pending the progress on the major improvements project, as
well as continued spare parts availability for the existing electrical equipment, it may be possible to
forego some of the recommended in-kind electrical equipment replacements prior to the major
reconfiguration project.
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REFERENCES
Metcalf & Eddy Inc., Tchobanoglous, G., Burton, F. L., Tsuchihashi, R., & Stensel, H.D. (2013).
th
Wastewater engineering: Treatment and resource recovery (5ed.). McGraw-Hill
Professional.
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9OPERATIONSANDMAINTENANCE
INTRODUCTION
The City of (City) wastewater operations and maintenance (O&M) program
consists of the following elements:
1.Normal operation of the wastewater collection system,wastewater treatment facility
(WWTF), and Compost Facility.
2.Emergency operation of the wastewater collection system,WWTF, and Compost
Facility, when one or more of the components is not available for normal use due to
natural or human-made events.
3.A preventive maintenance program to ensure that the wastewater system is receiving
maintenance in accordance with generally accepted standards.
NORMALOPERATIONS
CityPersonnel
provisionsof the National Pollutant
Discharge Elimination System (NPDES)Permit and the direction of the Public Works Director.
Wastewater treatment facilitieshave special employment requirements for staff as outlined in
Chapter70A.212 Revised Code of Washington (RCW).
In accordance with the RCW, it shall be unlawful for any person, firm, corporation, municipal
corporation, or other governmental subdivision or agency to operate or maintain a wastewater
treatment facilityunless the individual persons performing the duties of an operator as defined
in NPDES Permit S.5.3.B, or in any lawful rule, order, or regulation,without being duly certified
under the provisions of thechapter.
The municipality is required to designate a person onsite at itsWWTFas the operator in
responsible command of the operation and maintenance of the system. This person is required
to becertified at a level equal to or higher than the classification rating of the facility,or
GroupIIfor the City.
The WWTF also is required, while staffed on more than one daily shift, to have a shift
supervisor designated in charge of each shift at a level no lower than one level lower than the
classification rating of II for the City. Based on the RCW, all staff shall be subordinate to the
operator in responsible charge.
The current wastewater divisionorganization structure is as shown in Figure 9-1. Staff must:
1.Institute adequate O&Mprogramsfor the entire sewage system;
2.Keep maintenance records on all major electrical, supervisory control and data
acquisition (SCADA),and mechanical components of the WWTF, as well as the
collections system and pumping stations. Such records must clearly specify the
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CHAPTER 9 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
frequency and type of maintenance recommended by the manufacturer and must show
the frequency and type of maintenance performed;
3.Ensure all operations and maintenance tasks done on the WWTF process equipment or
systems are operated or supervised by an operator certified by the State of Washington.
The Permittee may allow qualified mechanics, programmers, network engineers,
electricians, or other trained tradespersons appropriate for specific tasks to perform
work on equipment as long as a certified operator is on site to supervise, authorize, and
verify that the work performed does not adversely impact facility operations, effluent
quality, or process monitoring and alarm reliability; and
4.Make maintenance records available for inspection at all times.
Figure 9-1
Wastewater Division Organization Chart
Personnel Responsibilities
The key responsibilities of the wastewater O&M staff are summarized as follows.
Public Works Director Under the direction of the City Manager, the Public Works Director
leads or facilitates planning, implements capital improvement projects, and directs the
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CITY OF PORT TOWNSENDGENERAL SEWER PLANOPERATIONS AND MAINTENANCE
long-termprograms of the department, including Engineering and Construction, Streets
Maintenance and Collections, Stormwater, Transportation, Water Resources, Wastewater,
Compost Facility, Parks, Facilities, and contractual management of Trash Collection/Recycling.
Operations Manager Under the direction of the Public Works Director, the Operations
Manager provides oversight anwastewaterdivision. Thisposition
coordinates planning objectives, capital improvement projects,and O&M plans to implement
City-defined objectives for the wastewater division. The Operations Manager coordinates
closely with other divisions and City departments to develop operational strategies, budgets,
and long-rangeplanning efforts.The Operations Manager also serves as Operator in Charge
when there are vacant positions.
WWTFOperatorCrew Chief The Operator Crew Chief serves to assist the Operations
Managerin the leadership and management of the WWTF. This position provides backup and
support when the Operations Manageris unavailable or on leave.
WWTF Operators The Operatoris a fully skilled journeylevel position capable of operating
and maintaining all functional areas of the WWTF with minimal guidance or direction.
Compost FacilityOperator The Operator is a fully skilled journey level position capable of
operating and maintaining all functional areas of the Compost Facility with minimal guidance or
direction.
Wastewater Seasonal and/or Apprentice The Apprentice will serve both the Compost Facility
and the WWTF to help with additional work and receive training to become a certified
Operator. This position will be especially importantduring construction of the WWTF upgrades,
when staff is stressed with additional work caused by construction disruptions.
CertificationofPersonnel
Table 9-1 WWTF and Compost FacilityO&M staff.
Table 9-1
Personnel Certification
It is City policy to maintain a well-qualified, technically trained staff. The City annually allocates
funds for personnel training, certification, and membership in professional organizations. The
City believes that the time and money invested in training, certification,and professional
organizations are necessary to providesafetyand meet permit compliance.
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CHAPTER 9 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Available Equipment
The wastewater division has several types of equipment available for daily routine O&M of the
wastewater system. If additional equipment is required for specific projects, the City will rent or
contract with a local contractor for the services needed. A stock of supplies in sufficient
quantities for normal system O&M and anticipated emergencies are stored at each facility. A
list of major equipment and chemicals used in the normal operation of the wastewater division
can be found in Table 9-2.
Table 9-2
Wastewater Division Equipment List
The following representatives typically provide supplies and chemicals to the City.
Supplies: MASCO Petroleum, 727 Marine Drive, Port Angeles, WA 98363, (360) 640-4444
Equipment: NAPA Auto Parts, 2321 W Sims Way, Port Townsend, WA 98368,
(360) 385-3131
Equipment: McGuire Bearing Company, 915 S Center Street, Tacoma, WA 98409,
(253) 572-2700
Wastewater division employees are equipped with cell phones. The phones provide the
capability for personnel to communicate with other cities and Jefferson County as needed.
Routine Operations
Routine operations involve the analysis, formulation, and implementation of procedures to
ensure that the facilities are functioning efficiently and treating sewer to meet discharge
standards.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANOPERATIONS AND MAINTENANCE
ContinuityofService
As the local sewer authorityand publicly owned treatment works, the City shall maintaina
structureof authority and responsibility to ensure that wastewater service is continuous. For
example, changes in City Council or staff shalllevel
of treatment in terms of meeting the requirements of the NPDES Permit and water quality
standards.
RoutineWastewaterQualitySampling
The Washington State Department of Ecology (Ecology) has adopted federal regulations that
specify minimum monitoring requirements for the wastewater system. There are two types of
reporting at the treatment facility:process and compliance reporting. Process reporting
involves collecting data by analyzing samples collected in the facility and reporting the data to
the operations team. The data is used by the operations team to evaluate the facilit
performance, monitor trends, and make appropriate daily adjustments. These minor daily
adjustments ensure the facility is continuously operated meeting the discharge limits identified
in the NPDES Permit. Compliance testing includes analytical and recorddata reported to
Ecology that demonstrates theCity is compliantwith the discharge limits. Reporting
requirements are contained in the NPDESPermit,a copy of which is included in Appendix C.
EMERGENCYOPERATIONS
Capabilities
The City is well equipped to accommodate short-term system failures and abnormalities. Its
capabilities are as follows.
Emergency Equipment
The City is equipped with the necessary tools to deal with common emergencies. If a more
serious emergency should develop, the City will hire a local contractor who has a stock of spare
parts necessary to make repairs to alleviate the emergency condition.The primary emergency
response tool for the collection system are two Vactor trucks and a portable back-up generator.
The WWTF and lift stations are monitored by staff through the Mission telemetry system.
Emergency Telephone
The wastewater divisionhas an emergency phone number for publicor City staffto directly
contact sewer department personnel after normal business hours. The number is
(360)344-9779.
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CHAPTER 9 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Standby Personnel
The designated standby person can generally respond to a call within 30 minutes. A list of
emergency telephone numbers is provided to each on-call employee. New employees will be
added to the e
Contacts
The City maintains a list of utility and agency contacts for routine and emergency use as shown
in Table 9-3.
Table 9-3
Utility and Agency Contacts
Material Readiness
Some critical repair parts, tools, and equipment are on-hand and kept in fully operational
condition. As repair parts are used, they are re-ordered. Inventories are kept current and
adequate for most common emergencies that reasonably can be anticipated. The City has ready
access to an inventory of repair parts, including parts required for repair of each type and size
of pipe within the service area. Additionally, the City has been provided with after-hours
emergency contact phone numbers for key material suppliers, which gives the City 24-hour
access to parts not kept in inventory. -hour contact at Ferguson is Daryl Clark at
(360) 340-8088.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANOPERATIONS AND MAINTENANCE
PREVENTIVEMAINTENANCE
Each year the Public Works Department cleansapproximately one-
lines. This process begins in March and is completed by the end of October.
The sewer lines are cleaned with a cleaning nozzle that is propelled from one maintenance hole
to the next using water under high pressure (1,500 to 2,000 pounds per square inch). The
nozzle is then pulled back to the starting maintenance hole. As the nozzle is pulled back, water
scours the inside of the sewer pipe. Any debris in the pipe is pulled back with the water. The
debris is removed from the maintenance hole with a vacuum unit. If roots are found, they are
cut with a root cutter. The City cleans and root cuts any problem areas once ortwiceper year.
City sewer lines requiring a higher level of maintenance are cleaned annually or semi-annually.
Per the recommendations in Chapter 6, the City will begin a video inspectionprogram with the
goal of viewing the interior of all pipes and maintenance holes within the next 5 to 10 years.
This program will help identify mains most urgently in need of repairs or replacement and will
help prevent overflows.
The lift stations are checked three times weekly and include wireless monitoring and alarm
equipment for flows, backups,and power outages.
recommendations should be followed where conflict exists.
WastewaterDivision
Wastewater Treatment Facility
FrequencyTask or Activity
DailySample influent and effluent water quality per state and federal requirements.
As NeededAdjust the treatment process in the field as influent wastewater quality or
quantity changesto maintain high quality effluent.
As NeededDewater the biosolids produced at the WWTF and haul the dewatered biosolids
to the Compost Facility.
As NeededRepair, maintain, and replace WWTF equipment.
As NeededClean, paint, and perform small repairs atthe WWTF buildings.
As NeededClean and perform small repairs for the WWTF vehicles.
As NeededWater, mow, and trim the landscaping.
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CHAPTER 9 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Compost Facility
Frequency Task or Activity
Grease blowers, mixer, screen, and rotary screen thickener (RST). Check
Monthly
mixer gear box and fill, if needed.
Monthly Run bio-filter fans and grease, if needed.
Monthly Exercise valves, spin blower shafts, and lift station heaters.
Monthly Fill shower drain and flush with hot water. Inspect fire extinguishers.
Monthly Change dissolved oxygen membrane and loader bucket pin.
Every 2 Months Spray down sequencing batch reactor (SBR).
Every 2 Months Sample compost for finished product quality.
Quarterly Sample water quality at the facility per state and federal requirements.
Quarterly Inspect the first aid kit.
Quarterly Clean the bar screen. Drain and clean the RST flock mixer tank.
Every 4 Months Clean catch basins and septage holding tanks.
Every 6 Months Grease motor control center room vent fan.
Every 6 Months Change oil for septage blower nos. 1 and 2 and the SBR blower.
Annually Sample water quality at the facility per state and federal requirements.
Perform an annual safety inspection of the facility. Change batteries in the
Annually
smoke detectors.
Grease screens and bio-filter fans. Change oil for the septage pump, air
Annually
filters, and tractor. Change fluids for the SBR mixer.
Annually Deep clean the RST and inspect lube latches.
Every 2 Years Change fuel at the filter diesel tank.
Change oil for the pond pump, waste pump, filtrate pump, air compressor,
Every 2 Years
and pressure washer.
As Needed Water, mow, and trim the landscaping.
Sewage Lift Stations
Frequency Task or Activity
3 Times per Inspect and maintain the Gaines Street, Monroe Street, and Port Lift
Week Stations.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANOPERATIONS AND MAINTENANCE
WeeklyInspect and maintain the remaining smaller lift stations.
As NeededPerform routine maintenance on the pumps, valves, and controls.
As NeededPerform routine maintenance of lift station structures and surrounding site.
Collection System
FrequencyTask or Activity
Semi-AnnuallyClean identified problem sewer lines of clogs and debris. Cut roots if found.
AnnuallyClean approximately 2.4 milesof sewers not identified as problem lines.
As NeededInspect, clean, and evaluate maintenance holes and sewer pipeline condition
when hours are available for the program.
As NeededPerform unscheduled cleaning of periodic clogs and backups in the sewer
system.
As NeededPerform minor construction to maintain the existing system, including
maintenance hole cover replacements, maintenance hole replacements, and
spot pipe repairs.
STAFFING
The preventive maintenance procedures, as well as the normal and emergency operations of
the utility, are described in the previous sections. The hours of labor and supervisory activity
required to effectively provide this ongoing maintenance and operations schedule forms the
basis for determining adequate staffing levels.
CurrentStaff
Thewastewater division staff currently includesapproximatelyeightpersonnel assigned
to the operation and maintenance of the sewer system. The staff is made up of management
personnel and operatorsas shown in Figure 9-1.
Currently, thtewater collections, which is part of the Streets Maintenance and
Collections crew, consists of 2.23 full-time equivalents (FTEs). In addition, the WWTF has a total
of 3.5 FTEs, and the Compost Facility has a total of 2.5 FTEs.
ProposedStaffing
The City currently is preparing a rate study for the wastewater division. The following FTEs will
be planned for as part of this study.
The 2024 budget includesaposition to increase the wastewater collections FTE count to 2.56.
In addition, the City is hoping to retain two seasonal positions, which would equate to 0.33 FTE
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CHAPTER 9 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
annually, for seasonal assistance with the collections system. Therefore, a total of 2.6 FTEs is
recommended for the wastewater collections.
The City has budgeted in 2024 to add 1.0 FTE for the WWTF and Compost Facility. This new
position would be a shared maintenance worker with the ability to become an operator. This
position also is intended to help with the additional workload caused by projects being
performed at the WWTF. As a result, 0.5 FTE would be added to the WWTF, for a total of
5.0 FTEs. The other 0.5 FTE would assist with the Compost Facility, for a total of 3.0 FTEs.
Finally, the City has budgeted for a full-time electrician to be shared between the Facilities
(0.5), Water (0.2), and Wastewater (0.3) divisions.
After positions have been filled according to the 2024 budget, the following FTE counts apply
-rated portion):
Wastewater Collections 2.6
WWTF 5.0
Compost Facility 3.0
Total is 10.6 FTEs
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|
10CAPITALIMPROVEMENTPLAN
INTRODUCTION
This chapter presents proposed improvements to the City of (City)sewer
system that are necessary to resolve existing system deficiencies andplan for the projected
sewer system growth.The sewer system improvements were identified from the results of the
collection system evaluation presented in /ŷğƦƷĻƩ Џ,the Wastewater Treatment Facility
(WWTF)and Compost Facility evaluation presented in /ŷğƦƷĻƩА, andWWTF improvements
alternatives analyses presented in /ŷğƦƷĻƩБ.The sewer system improvements were sized to
meet the projected2040flow and loadingconditions.
A Capital Improvement Plannumber, herein referred to as a CIP number, has been assigned to
each improvement.The improvements are organized and presented in this chapter according
to the followingprimarycategories.bƚƷĻʹŷĻ ƓǒƒĬĻƩ ƭǤƒĬƚƌ Ǟźƌƌ ĬĻ ƩĻƦƌğĭĻķ ǞźƷŷ ğ
ĭƚƩƩĻƭƦƚƓķźƓŭ źƒƦƩƚǝĻƒĻƓƷ ƓǒƒĬĻƩ źƓƷŷĻķĻƭĭƩźƦƷźƚƓƭ͵
5-YearSystem Improvements
o Wastewater TreatmentFacilityImprovements(CIP F#)
o Compost Facility and Solids HandlingImprovements (CIP C#)
o Lift Stationand Miscellaneous Collection System Improvements (CIP WW#)
o Sewer MainImprovements (CIP SM#)
6-to 10-YearSystem Improvements
o Wastewater Treatment FacilityImprovements (CIP F#)
o Sewer Main Improvements (CIP SM#)
11-to 20-YearSystem Improvements(long-term planningcapital improvements)
o Wastewater Treatment FacilityImprovements (CIP F#)
o Compost Facility and Solids HandlingImprovements (CIP C#)
o Sewer Main Improvements (CIP SM#)
Planning Improvements
o Miscellaneous and Planning Improvements(CIP M#)
The remainder of this chapter presents a brief description of each group of improvements, the
criteria for prioritization, the basis for the cost estimates,and theschedule forimplementation.
For planning purposes, the improvement projects described herein are based on one
alternative route or conventional concept for providing the necessary improvement.Other
methods of achieving the same result, such as obtaining flow capacity increases by adding one
large gravity main versususingmultiple gravity pipes, force main/gravity main combinations,or
multiple force mains,should be considered during design to ensure the best and lowestcost
alternative design is selected.Further evaluation should be performed when more information
is available regarding when and where futuredevelopments will occur.
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
DESCRIPTION OF IMPROVEMENTS
This section provides a general description of each group of improvements and an overview of
the system deficiencies they will resolve. Some of the improvements are necessary to resolve
existing system deficiencies. These improvements are discussed in /ŷğƦƷĻƩƭ Џ, А, and Б.
Collection system improvements to accommodate new growth are not shown in detail in this
CIP. It is assumed that most of the new growth will occur at or near the Mill site. This CIP
includes a lift station to allow development of the Mill site and conveyance for the new lift
s discharge throughout the existing collection system.
It is intended that this General Sewer Plan (GSP) contain an inclusive list of recommended
system improvements; however, additional projects may need to be added or removed from
the list as growth occurs or conditions change. The City will evaluate the capacity of the
wastewater collection system, WWTF, and Compost Facility as growth occurs and as
development permits are received.
5-Year System Improvements
The following improvements were identified by City staff, from the results of the WWTF and
system analyses, and from previously prepared CIPs, as discussed in /ŷğƦƷĻƩƭ Џ, А, and Б. These
improvements are primarily necessary to serve the existing sewer service area. The
improvements include the major pipeline and facility construction that is required to properly
serve the existing sewer service area now and within the next 5 years. The improvement costs
shall be borne by the existing customers unless over-sizing of the improvements provides a
benefit to developers, in which case the City may pass those costs on depending on goals and
policies for development, especially as it relates to housing.
The improvements are based on existing peak hour flow rates; however, the proposed pipe
diameters for recommended replacement pipelines are based on peak hour flow projections.
The proposed system improvements are illustrated in CźŭǒƩĻ ЊЉΏЊ. (RH2)
analysis shows the best apparent replacement alignment for the collection system
improvements based on information currently available. A variety of alternatives are possible
for the collection system CIP projects listed, and alternatives should and will be considered
during the design of each project.
Wastewater Treatment Facility Improvements (F#)
CIP F1 Influent Pump Station and Odor Control Improvements
5ĻŅźĭźĻƓĭǤ: Portions of the Influent Pump Station (IPS) are heavily corroded, and the interior
liner is detaching from the concrete. The electrical conduits and equipment inside the pump
station also have corroded severely. In addition, a 2019 conditions assessment by Jacobs
Engineering Group (Jacobs) recommended odor control system improvements to increase
treatment capacity.
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CITY OF PORT TOWNSENDGENERAL SEWER PLANCAPITAL IMPROVEMENT PLAN
LƒƦƩƚǝĻƒĻƓƷ:Repair the concrete liner system within the IPS and Headworks channels.Repair
the ductwork ofthe odor control system,upsizethe fan,andadda new carbon tank.A full
conditions assessment of the mechanical components inside the IPSis recommended to
determine if the pipes and fittings need to be replaced. Replace the electricalandsupervisory
control and data acquisition(SCADA)equipment and instrumentation inside the IPS. All flows
entering the IPS will need to be temporarily bypassed while improvements within the IPS are
being performed.
/ƚƭƷ:$2,120,000
CIP F5 Non-Potable WaterPump Replacements(City to Install)
5ĻŅźĭźĻƓĭǤ:The existing non-potable water (NPW) pumps located at the end of the chlorine
contact basins are heavily corroded and in need of replacement.
LƒƦƩƚǝĻƒĻƓƷ:Replace the NPW pumps in-kind. Provide equipment and instrumentation
necessary to allow a fully functional and integrated system. This work is anticipatedto be
completed by City staff.
/ƚƭƷ:$120,000
CIP F6 SCADA Upgrades
5ĻŅźĭźĻƓĭǤ:The existing SCADA system at the WWTF is aging and in need of replacementas
spare parts become harder to acquire. The existing software is outdated and needs updating.
LƒƦƩƚǝĻƒĻƓƷ:Replace the programmable logic controller (PLC) and uninterruptible power
supply (UPS) equipment in all three control panelsand replace the existing SCADA human
machine interface (HMI) computerhardware. Upgrade the network toanEthernet Device Level
Ring network and convert the existing Allen-Bradley PLC-5 system to ControlLogix PLC
equipment.
/ƚƭƷ:$1,140,000
CIP F7 Electrical Upgrades
5ĻŅźĭźĻƓĭǤ:Most of the existing electrical equipment and instrumentation is original to the
WWTF and is recommended to be upgraded or replaced as failures occur.
LƒƦƩƚǝĻƒĻƓƷ:Replace aging electrical equipment as failures occur and/or stock up on spare
parts. Replaceall variable frequency drives(VFDs),aging field instrumentation, and
miscellaneous panel components.
/ƚƭƷ:$630,000
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
CIP F8 Near-Term Oxidation Ditch Improvements
5ĻŅźĭźĻƓĭǤ: Near-term improvements are recommended to upgrade the equipment at the
oxidation ditch. The system is losing treatment capacity due to the nitrogen removal operations
at the WWTF.
LƒƦƩƚǝĻƒĻƓƷ: Upgrade the oxidation ditches to replace one of the mixer aerators in-kind, and
install independent mechanical mixers and instrumentation and access platforms at both
ditches. Install the necessary equipment and instrumentation to automate flow isolation into
the ditches. These improvements will enable cyclical operation of the ditches by alternating
between oxic and anoxic cycles as discussed in /ŷğƦƷĻƩ Б. A preliminary design for the ditches is
recommended before implementing the improvements. While the improvements are being
performed within the ditches, rehabilitate the structures and remove sludge and grit as
necessary.
Note that the engineering will begin in the 5-year plan, but the City has currently budgeted
construction in the 6- to 10-year CIP for purposes of rate mitigation. However, if funding can be
procured, this project should be constructed sooner to minimize potential risk.
/ƚƭƷ: $2,940,000
CIP F9 Outfall Upgrades
5ĻŅźĭźĻƓĭǤ: The existing outfall needs to be replaced due to the age of the infrastructure.
LƒƦƩƚǝĻƒĻƓƷ: Plan and design a replacement outfall project.
/ƚƭƷ: $4,000,000
CIP F11 Land Acquisition for WWTF Expansion
5ĻŅźĭźĻƓĭǤ: The WWTF will require additional footprint to construct additional infrastructure
necessary for providing sufficient long-term treatment capacity.
LƒƦƩƚǝĻƒĻƓƷ: In anticipation of the future WWTF expansion, acquire additional parcels of land
as described in /ŷğƦƷĻƩ Б.
/ƚƭƷ: $2,000,000
Compost Facility and Solids Handling Improvements (C#)
CIP C1 Solids Handling Influent Screening and Grit Removal
5ĻŅźĭźĻƓĭǤ: The bar screens currently are manually raked and washed down by haulers. This
process should be automated and grit should be removed in the process.
LƒƦƩƚǝĻƒĻƓƷ: Install a packaged septage screening and grit removal system with a new
influent meter to monitor flow.
/ƚƭƷ: $890,000
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CITY OF PORT TOWNSENDGENERAL SEWER PLANCAPITAL IMPROVEMENT PLAN
CIP C2 Solids Handling Tank Replacement and Mechanical Upgrades
5ĻŅźĭźĻƓĭǤ:One of the two existing septage holding tankshas accumulated a significant amount
of grit, making only onetankoperable.The equipment associated with the septage treatment
system also needsto be replaced due toitsage.
LƒƦƩƚǝĻƒĻƓƷ:Replace the existing solids handling tankswith a larger 50,000-gallon holding
tankwith new blowers.Replace the pumps for thewaste activated sludge (WAS), chlorination,
and wetland disposalprocesses, and replace thesequencing batch reactor (SBR) blower.
/ƚƭƷ:$700,000
CIP C3 Compost Screen Replacement
5ĻŅźĭźĻƓĭǤ:The existing composting screen is nearing the end of its useful life and is due for
replacement.
LƒƦƩƚǝĻƒĻƓƷ:Install a new compost screen to replace the existing screen.
/ƚƭƷ:$460,000
CIP C4 Compost Case Loader Replacement
5ĻŅźĭźĻƓĭǤ:The existing front-end loader in the Compost Facility is nearing the end of its useful
life and is due for replacement.
LƒƦƩƚǝĻƒĻƓƷ:Replace the existing front-end loader with a new loader.
/ƚƭƷ:$390,000
CIP C5 Compost Blowers Replacements
5ĻŅźĭźĻƓĭǤ:The existing composting aeration blowers are nearing the end of their useful life
and are due for replacement.
LƒƦƩƚǝĻƒĻƓƷ:Replace the existing compost blowers with new compost blowers.
/ƚƭƷ:$80,000
CIP C7 6-Inch Hydrant Line
5ĻŅźĭźĻƓĭǤ:TheCompost Facility needs additional water supply to meet process demands.
LƒƦƩƚǝĻƒĻƓƷ:Install approximately 1,100 linear feet (lf) of 6-inch water main
primary water main and connect to ahydrant located on the Compost Facility site.
/ƚƭƷ:$670,000
CIP C8 Office with Dedicated Lunchroom
5ĻŅźĭźĻƓĭǤ:Expanding the Compost Facility and its associated processes will require more space
for Citystaff.
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
LƒƦƩƚǝĻƒĻƓƷ: Add an office space with a dedicated lunchroom for City operators and staff use.
/ƚƭƷ: $300,000
Lift Station and Miscellaneous Collection System Improvements (WW#)
CIP WW1 Existing Monroe Street Lift Station Improvements
5ĻŅźĭźĻƓĭǤ: The existing Monroe Street Lift Station does not have adequate pumping capacity
to meet existing hydraulic loads. The sewers on Lawrence Street, tributary to the Monroe Street
Lift Station, are still combined and the station is overwhelmed by stormwater inflow during
peak rainfall events. These extreme events cause all three pumps at the station to run. The
pump capacity deficiency could be mitigated by the separation of storm sewers from sanitary
sewers on Lawrence Street. For this reason, the upgrade of the lift station should be performed
after the Lawrence Street sewer separation project (CIP SM9) and after flows into the Monroe
Street Lift Station have been observed for at least 2 years.
The station must be relocated or elevated to prevent the access hatches from being inundated
as sea level continues to rise.
LƒƦƩƚǝĻƒĻƓƷ: Relocate the station to a new site that minimizes the risk of flooding over a
75-year design life. Rebuild the Monroe Street Lift Station with pumps, valves, and electrical
gear capable of handling the higher flow rates being received. Begin predesign for this project
after the Lawrence Street storm and sanitary sewer separation project has been completed and
influent flows have been analyzed. It is possible that influent flows to the Monroe Street Lift
Station could be significantly reduced with the Lawrence Street improvement project.
/ƚƭƷ: $5,000,000
CIP WW2 Sewer Camera Van, Video Camera and Tractor, Recording Software and
Hardware, and Staff Training
5ĻŅźĭźĻƓĭǤ: existing video inspection equipment is outdated and no longer
functioning. New pipeline video equipment is needed to allow the City to inspect every pipe in
its system at least once every 10 years, and preferably every 5 years. Lack of functioning video
inspection equipment leaves the City unaware of the condition of its aging collection system.
The Water Street collapse may have been avoided if the City were able to see its deteriorating
condition. Knowledge of pipeline condition is an essential component of an asset management
system to schedule and budget repairs and replacements of aging mains and maintenance
holes.
LƒƦƩƚǝĻƒĻƓƷ: Procure new video camera, camera tractor, and software to record, store, and
annotate digital videos. Procure a van to house the equipment with power supply, cable reels,
and workstation with multiple monitor screens. This CIP item also includes training for the new
equipment.
/ƚƭƷ: $300,000
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CITY OF PORT TOWNSENDGENERAL SEWER PLANCAPITAL IMPROVEMENT PLAN
CIP WW3 General Lift Station Improvements
5ĻŅźĭźĻƓĭǤ:Replace components at various liftstations asneededdue to aging partsand
equipmentfailures.
LƒƦƩƚǝĻƒĻƓƷ:Replacepumps, generators, valves, electrical power supply equipment,and
other essential liftstation componentsas needed.
/ƚƭƷ:$1,000,000
CIP WW4 MillLift Station
5ĻŅźĭźĻƓĭǤ:Currently,there is no sewer service at the Mill site. This liftstation and force main
will allowfordevelopment of the Mill siteto its potential.
LƒƦƩƚǝĻƒĻƓƷ:Procure property and constructasubmersible liftstation with an ultimatefirm
capacity of 1,062gallons per minute.The stationis to includebackup power generation and a
4,500-foot-long,10-inch-diameter force main as shown in CźŭǒƩĻ ЊЉΏЊ.Costs also include gravity
piping in the area to supply the lift station.
/ƚƭƷ:$6,300,000
Sewer MainImprovements(SM#)
CIP SM1 Sims Way Crossing and Wilson Street Realignment
5ĻŅźĭźĻƓĭǤ:Theconcretegravity sewer main in W Sims Wayand Wilson Street lacks the
hydraulic capacity to convey the projected 5-year flows from the proposed Mill LiftStation.
Furthermore, portions of this pipeline pass beneath an existing residence.
LƒƦƩƚǝĻƒĻƓƷ:Replace approximately786lfof existing 8-inch gravity pipe with new 18-inch
gravity sewer in a different alignment on an easement to be procured. This project must be
completed concurrently with the construction of the Mill LiftStation(CIP WW4).
/ƚƭƷ:$1,212,000
CIP SM8 Sewer System Defect Investigation and Repair
5ĻŅźĭźĻƓĭǤ:There are a number of known structural deficiencies throughout the sewer system,
particularly in the older parts of the sewer collection system.The degree of structural
degradation at sites the City was able to videoinspect indicate there may be additional
structural defects in other areas of the system.
LƒƦƩƚǝĻƒĻƓƷ:Systematically investigate and repair highpriority,compromised sewer mains
with an emphasis on the areas of known structuraldegradation.Investigationswill include
video inspections withsome smoke testing of gravity sewer mains in areas where defects are
collectionsoperations staff. Replacements will be made to the extent
allowed by the yearly collection system repair budget.
/ƚƭƷ:$3,300,000
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
CIP SM9 Lawrence Street Combined Sewer Separation
5ĻŅźĭźĻƓĭǤ: The Lawrence Street sewer combines sanitary sewer and stormwater in the same
pipe. Stormwater peak flows impose significant hydraulic loads on the sanitary sewer collection
system and the Monroe Street Lift Station and consumes treatment capacity at the WWTF.
LƒƦƩƚǝĻƒĻƓƷ: Reconstruct the storm and sanitary sewer collection pipelines in Lawrence
Street from Fillmore Street to Monroe Street to fully separate the storm drains. Perform smoke
testing and video inspection of the Lawrence Street sewer first to determine the level of
connectivity between the storm and sanitary sewers. The amount of asphalt disturbance will
require full street repaving and modification of street geometric design to provide Americans
with Disabilities Act compliant ramps at intersections. This project is split evenly
stormwater division because of the magnitude of the cost and the equal benefit received by the
wastewater and stormwater divisions. The cost shown is the half share to be funded by the
wastewater division.
/ƚƭƷ: $2,826,000
CIP SM10 Suitcase Pipe Replacement on Washington Street
5ĻŅźĭźĻƓĭǤ: During a video inspection in 2023, it was observed that the vitrified clay pipe in
Washington Street between Taylor and Adams Streets was becoming crushed and in imminent
danger of collapse. The video
observed These cracks were acting like
hinges, allowing the pipe to slowly close like a suitcase. Replacement of this main is urgent to
prevent it from completely losing its ability to convey wastewater.
LƒƦƩƚǝĻƒĻƓƷ: Replace the existing pipeline with new 8-inch polyvinyl chloride (PVC) pipe by
open-cut methods.
/ƚƭƷ: $399,000
CIP SM12 Water Street Sewer Replacement
5ĻŅźĭźĻƓĭǤ: The existing 14-inch-diameter, asbestos cement pipe in Water Street collapsed
during a king tide on December 27, 2022. After an emergency repair of the collapse, video
inspection of the 14-inch gravity sewer detected corrosion, broken pipe, and sediment
accumulation in the main, indicating a breach in the pipeline. The sediment prevented a full
pipeline inspection and hydraulic cleaning methods were abandoned because of the risk to the
fragile main. In early 2023, the City deemed the main to be in immediate need of replacement
and applied for funding. The City received funding from the
Board in August 2023, and design has been underway since that time with the intent of
constructing the project in 2024.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 1,600 lf of existing 14-inch gravity pipe by extending the
Monroe Street Lift Station force main by approximately 1,600 feet. This extension will be made
by horizontal directional drilling (HDD). Approximately 350 feet of the gravity main will be
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converted to force main by pipe bursting or slipliningthe existing gravity main. Four service
laterals,currently connected to the gravity mainbeing converted to a force main,will be
transferred to an 8-inch main sliplined into the failing 14-inch gravity sewer.
/ƚƭƷ:$2,100,000
6-to10-YearSystemImprovements
The 6-to 10-yearimprovements were identified from the results of the WWTF and system
analyses discussed in /ŷğƦƷĻƩƭЏ and А and the WWTF improvements alternatives analyses
presented in /ŷğƦƷĻƩБ.
The6-to 10-yearsystem improvements are illustrated in CźŭǒƩĻ ЊЉΏЊ.Alternatives forthe
collection systemimprovements are possible,and further evaluation should be performed
when more information is available regarding when and where futuredevelopments will occur.
Wastewater TreatmentFacilityImprovements(CIP F#)
CIP F2: Headworks Rehabilitation
5ĻŅźĭźĻƓĭǤ:The existing Headworks screen and grit mechanism are aging and in need of
replacement.
LƒƦƩƚǝĻƒĻƓƷ:Install a new replacement screen and remove the existing grit mechanism to
install a new mechanism and appurtenances. Increase the power feeder size and provide
instrumentation for a fully integrated system.
/ƚƭƷ:$1,200,000
CIP F3 Clarifier No. 1 Improvements
5ĻŅźĭźĻƓĭǤ:The original secondary clarifier mechanisms are reaching the end of their useful life
and are in need of replacement. Improvements are planned to be phased so that one clarifier
can remain online.
LƒƦƩƚǝĻƒĻƓƷ:Replace the existing Clarifier No. 1 mechanism with a stainlesssteelmechanism,
replace the drive unit, and recoat the launder. Remove the existing power feeder conductors
and re-land the conductors after the mechanism replacement iscomplete. Perform a conditions
assessment to determine if other improvements are needed.
/ƚƭƷ:$1,250,000
CIP F4 Clarifier No. 2 Improvements
5ĻŅźĭźĻƓĭǤ:The original secondary clarifier mechanisms are reaching the end of their useful life
and are in need of replacement. Improvements are planned to be phased so that one clarifier
can remain online.
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LƒƦƩƚǝĻƒĻƓƷ: Replace the existing Clarifier No. 2 mechanism with a stainless steel mechanism,
replace the drive unit, and recoat the launder. Remove the existing power feeder conductors
and re-land the conductors after the mechanism replacement is complete. Perform a conditions
assessment to determine if other improvements are needed.
/ƚƭƷ: $1,250,000
Sewer Main Improvements (CIP SM#)
CIP SM2 Howard Street and S Park Avenue
5ĻŅźĭźĻƓĭǤ: The gravity sewer main in Howard Street and S Park Avenue has hydraulic capacity
deficiencies, and a portion of these sewer mains need to be upsized.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 1,079 lf of existing 8-inch gravity pipe with new 15-inch
gravity sewer pipe by open-cut methods as shown in CźŭǒƩĻ ЊЉΏЊ.
/ƚƭƷ: $1,578,000
rd
CIP SM3 Sims Way, 3 Street, and Gise Street
rd
5ĻŅźĭźĻƓĭǤ: The gravity sewer mains in Sims Way, 3 Street, and Gise Street have hydraulic
capacity deficiencies, and a portion of these sewer mains need to be upsized.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 273 lf of existing 8-inch gravity pipe with new 18-inch
gravity sewer pipe, and replace approximately 523 lf of existing 8-inch gravity pipe with new
15-inch gravity sewer pipe by open-cut methods as shown in CźŭǒƩĻ ЊЉΏЊ.
/ƚƭƷ: $1,186,000
CIP SM4 Holcomb Street
5ĻŅźĭźĻƓĭǤ: The gravity sewer main in Holcomb Street has hydraulic capacity deficiencies and a
portion of the sewer main needs to be upsized.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 531 lf of existing 12-inch gravity pipe with new 18-inch
gravity sewer pipe by open-cut methods as shown in CźŭǒƩĻ ЊЉΏЊ.
/ƚƭƷ: $819,000
11- to 20-Year System Improvements (Long-Term Planning Capital
Improvements)
The long-term improvements were identified from the results of the WWTF and system
analyses discussed in /ŷğƦƷĻƩƭ Џ and А and the WWTF improvements alternatives analyses
presented in /ŷğƦƷĻƩ Б. These improvements are necessary to serve projected population
growth in the City and expansion areas. The improvements include the major facility and
conveyance construction that will be required to serve those areas.
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The additional system improvements required for long-term improvementsare illustrated in
CźŭǒƩĻ ЊЉΏЊ.
Wastewater TreatmentFacilityImprovements(CIP F#)
CIP F12Long-Term WWTF Expansion(Budgetary Estimate)
5ĻŅźĭźĻƓĭǤ:Long-term, major expansion of the WWTF isrequiredto providebiological
treatment for the projected flow and loadsand to provide nitrogen removal.
LƒƦƩƚǝĻƒĻƓƷ:Construct a new activated sludge systemconsisting of aeration basins and
secondary clarifiers. This involves constructing new aeration basinson the newly acquired
parcels andremoving the existing oxidation ditchesto construct future secondary clarifiers
within the existingfootprint. Modify the hydraulics of the WWTF such thatinfluent flow is lifted
to the new aerationbasins. This may involve constructing a new Headworks and refurbishingor
replacingthe existing IPS.
/ƚƭƷ:$30,000,000
Compost Facility and Solids Handling Improvements (C#)
CIP C6 Compost Facility Infrastructure Upgrades
5ĻŅźĭźĻƓĭǤ:The Compost Facility needs infrastructure upgrades to bring the facility up to
current codes and to ensure safety for the operators.
LƒƦƩƚǝĻƒĻƓƷ:Perform infrastructure upgrades at the Compost Facility, including repairing and
sealing the asphaltaround the facility, adding lights to the barns, and reinforcing the existing
concrete support polesof the barns.
/ƚƭƷ:$410,000
Sewer Main Improvements (SM#)
CIP SM5Howard Street, S Park Avenue, and McPherson Street
5ĻŅźĭźĻƓĭǤ:The gravity sewer mainsin Howard Street, S Park Avenue, and McPherson Street
have hydraulic capacity deficiencies, and a portion of these sewer mains need to be upsized.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 1,685 lf of existing 8-inch sewer with new 15-inch gravity
sewer pipe by open-cut methods as shown in CźŭǒƩĻЊЉΏЊ.
/ƚƭƷ:$2,463,000
rd
CIP SM6West Sims Way and 3Street
rd
5ĻŅźĭźĻƓĭǤ:The existing 8-inch concrete gravity sewer mains in West Sims Way and 3Street
have hydraulic capacity deficiencies, and a portion of these sewer mains need to be upsized.
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 1,150 lf of existing 8-inch concrete sewer main with new
15-inch gravity sewer pipe by open-cut methods as shown in CźŭǒƩĻ ЊЉΏЊ.
/ƚƭƷ: $1,679,000
CIP SM7 Future Interceptor Sizing
5ĻŅźĭźĻƓĭǤ: Existing 8-, 10-, 12-, and 18-
failing and has hydraulic capacity deficiencies. Portions of the sewer interceptor need to be
upsized.
LƒƦƩƚǝĻƒĻƓƷ: Replace approximately 3,785 lf of existing 10-, 12-, and 18-inch sewer
interceptor. Install approximately 220 lf of new 15-inch sewer interceptor, approximately
1,365 lf of new 18-inch sewer interceptor, approximately 1,165 lf of new 24-inch sewer
interceptor, and approximately 1,035 lf of new 30-inch sewer interceptor by open-cut methods
as shown in CźŭǒƩĻ ЊЉΏЊ.
/ƚƭƷ: $6,722,000
CIP SM11 Long-Term Sewer System Investigation and Refurbishment
5ĻŅźĭźĻƓĭǤ:
collection system. There are several known structural deficiencies, particularly in the older parts
of the collection system that have been video inspected. The degree of structural degradation
observed (such as Water and Washington Streets) indicates there are other structurally
deficient mains in the older parts of the sewer collection system. The condition of the collection
system is not well known because of a lack of adequate inspection equipment. The pipe
material and age of many of the mains is also unknown because of incomplete record drawings.
RH2 believes that many structurally deficient mains will be discovered once the City begins a
regular video inspection program and many of these mains will need to be replaced or repaired.
LƒƦƩƚǝĻƒĻƓƷ: Systematically investigate all un-inspected sewer mains with an emphasis on the
areas of known structural degradation that pose a threat of imminent pipe collapse. Replace or
line the existing mains and maintenance holes that are structurally deficient. The cost
vitrified clay, asbestos cement, or unknown material are assumed to be deficient and will need
lining using cured-in-place pipe (CIPP) starting in 10 years. The estimated cost could be reduced
if vitrified clay pipes are still in good condition or if unknown pipes are made of PVC. If pipes are
in such dire condition that they cannot be lined (like the Water Street sewer in 2023), a more
expensive open-cut replacement method will be required. To be conservative, RH2 has
estimated that all pipes of substandard or unknown material will be lined with CIPP.
/ƚƭƷ: $56,000,000
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PlanningImprovements
Miscellaneousand PlanningImprovements (CIP M#)
CIP M1Arc Flash Analysis
LƒƦƩƚǝĻƒĻƓƷ:Perform an electrical short circuit, protective device coordination, and arc flash
report summarizing the calculations and recommendations for protective device settings and
Personal Protective Equipment requirements.
CIP M2 Public Works Shop (Sewer Collection Share)
5ĻŅźĭźĻƓĭǤ: The City Shops is home to the water, streets, stormwater, and wastewater
collections maintenance crews and equipment. The shops are in disrepair and a new
maintenance facility is needed. The first step is to do a schematic design and needs assessment.
LƒƦƩƚǝĻƒĻƓƷ:The
estimated cost for the sewer utility portion of this assessment is $100,000.
CIP M3General Sewer Plan Update
5ĻŅźĭźĻƓĭǤ:
System Plan update.
LƒƦƩƚǝĻƒĻƓƷ:The City plans to update its GSP every 10 years. In addition, the City may review
the GSP at the 5-year mark and adjust the projections and improvements as necessary. This
may be completed between 2032 and 2033, and 2042 and 2043.
CIP M4 Downtown Restrooms
LƒƦƩƚǝĻƒĻƓƷ:The
estimated sewer fund cost is $250,000. Costs may vary depending on the location and size of
the facility. This estimate is planning-level only and anticipates use of other funding sources to
assist in the project development.
ESTIMATINGCOSTSOFIMPROVEMENTS
Project costs for the proposed improvements were estimated based on costs of similar recently
constructed sewer projects around the Puget Sound areaand are presented in 2023dollars.
The unit costs for each pipe size are based on estimates of all construction-related
improvements, such as materials and labor for installation, services, maintenance holes,
connections to the existing system, trench restoration, asphalt surface restoration,and other
work for a complete installation. Project cost estimates for sewer pipe projects were
determined from the unit costs (i.e., cost per foot-length) shown in ğĬƌĻƭЊЉΏЊ and ЊЉΏЋ and
the proposed diameter and approximate length of each improvement.The costs shownin
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
ğĬƌĻƭ ЊЉΏЊ and ЊЉΏЋ include indirect costs estimated at 50 percent of the construction cost for
engineering preliminary design, final design, construction contract administration, project
administration, permitting, and legal and administrative services.
ğĬƌĻ ЊЉΏЊ
DƩğǝźƷǤ {ĻǞĻƩ tźƦĻ
ƓźƷ /ƚƭƷƭ ŅƚƩ hƦĻƓΏ/ǒƷ /ƚƓƭƷƩǒĭƷźƚƓ
ğĬƌĻ ЊЉΏЋ
DƩğǝźƷǤ {ĻǞĻƩ tźƦĻ
ƓźƷ /ƚƭƷƭ ŅƚƩ /ǒƩĻķΏźƓΏtƌğĭĻ tźƦĻ
The cost estimates shown in ğĬƌĻ ЊЉΏЌ include the estimated construction cost of the
improvement and indirect costs estimated at 50 percent of the construction cost for
engineering preliminary design, final design, construction contract administration, project
administration, permitting, and legal and administrative services. The construction cost
estimates include a sales tax of 8.6 percent.
Cost estimates prepared by RH2 for projects in the CIP are Class 5 estimates, based on
standards established by the American Association of Cost Engineers (AACE). Class 5 estimates
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are described as generally being prepared with limited information and subsequently have wide
accuracy ranges. The typical accuracy range for this cost estimate class is from -20 percent
to -50percent on the low side and from +30 percent to +100percent on the high side.
The final cost of the projects will depend on actual labor and material costs, actual site
conditions, productivity, competitive market conditions, final project scope, final project
schedule, and other variable factors. As a result, the final project costs likely will vary from
those presented. Because of these factors, funding needs must be reviewedcarefullyprior to
making specific financial decisions or establishing final budgets.
PRIORITIZINGIMPROVEMENTS
The existing system improvements were prioritized by the City based on the perceived need for
the improvement to be completed prior to projects with fewer deficienciesor less risk of
damage due to failure of the system.Priority and schedule forany futuredeveloper-funded
projects is dependenton the timing and design of specific developments areas.
CIPmay become necessary.Such
projects may be required to remedy an emergency situationor address unforeseen problems.
Due to budgetary constraints, the completion of such projects may require modifications to the
recommended CIP.The City retains the flexibility to reschedule, expand,or reduce the projects
included in the CIP and to add new projects to the CIP, as best determined by rate payers and
the City Council, when new information becomes available for review and analysis.
SCHEDULEOFIMPROVEMENTS
The results of prioritizing the improvements were used to assist in establishing an
implementation schedule that can be used by the City for preparing its CIP.The implementation
schedule for the proposed improvements is shown in ğĬƌĻ ЊЉΏЌ.It should be noted that the
implementation schedule shown is,to some extent, flexible.The implementation schedule
should be modified based on City preferences, budget,or as development fluctuates.The City
should review ğĬƌĻ ЊЉΏЌ at least annually and reprioritize as necessary to match budget,
growth, flows,and other City conditions/priorities.This provides the City with the flexibility to
coordinate these projects with road or other projects within the same area.
FutureProjectCostAdjustments
All cost estimates shown in the tables are presented in 2023dollars.Therefore, it is
recommended that future costs be adjusted to account for the effects of inflation and changing
construction market conditions at the actual time of project implementation.Future costs can
be estimated using the Engineering News Record Construction Cost Index for the Seattle area or
by applying an estimated rate of inflation that reflects the current and anticipated future
market conditions.
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CHAPTER 10 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
The CIP presented in ğĬƌĻ ЊЉΏЌ is based on the information currently available. As the City
implements the recommendations, the cost and timing of projects may be revised.
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11 FINANCIAL ANALYSIS
INTRODUCTION
The financial analysis assesses the ability of the City of Port Townsend (City) sewer utility to
remain financially viable during the planning period, considering its recent historical performance
at existing levels and with any rate increases needed to support the planned capital program.
FINANCIAL HISTORY
The City tracks the financial activities of its water and sewer utilities in a set of joint funds.
Water/Sewer Operating Fund (411) Water/Sewer Debt Reserve Fund (430)
Water/Sewer Capital Fund (415) System Development Charge Fund (495)
Olympic Gravity Water System Fund (417)
The City has historically recovered the cost of ongoing operations and maintenance through a
combination of base fees and volume fees, imposing a separate capital surcharge to recover costs
associated with debt service and capital investment. Though the City originally introduced the
capital surcharge in 2013 to communicate the rate impacts of major capital projects to ratepayers,
is an ongoing obligatio
Table 11-1 through
2023, given its allocated share of revenues, expenses, and reserve balances from each of the funds
listed above. Key findings include:
Though the City historically transferred utility taxes directly to its General Fund, it began to
account for utility tax revenue in Fund 411 in 2019. Excluding the impacts of this change in
percent from
2018 to
sewer base fees and volume fees by a total of approximately 9 percent during this period.
;
he sewer
enses increased by about 38 percent from 2018 to 2023. Inflation
likely contributed significantly toward this increase, as the Consumer Price Index for the
Seattle-Tacoma-Bellevue area increased by 26 percent during this period. In addition, labor
costs, including salaries and benefits, have increased at a rate exceeding inflation;
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PREPARED BY FCS GROUP
CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 11-1
Summary of Historical Financial Performance ($000s)
Fund Resources and Uses Arising from 2018 2019 2020 2021 2022 2023
Cash Transactions Sewer Utility Share Actual Actual Actual Actual Actual Budget
Beginning Cash & Investments ($000s) $2,160 $1,803 $2,288 $3,142 $4,057 $4,767
Operating Revenues
Intergovernmental $ - $ - $ 0 $ 0 $ - $ -
Rate Revenue 2,626 3,168 3,080 3,251 3,414 3,450
Other Charges for Services 258 285 190 200 198 222
Miscellaneous 3 10 8 10 13 2
Total ($000s) $2,886 $3,463 $3,279 $3,461 $3,625 $3,675
Operating Expenses
General Government $ 221 $ 217 $ 228 $ 0 $ - $ -
Utility Operations 1,885 2,527 2,477 2,911 3,067 3,456
Total ($000s) $2,106 $2,743 $2,704 $2,911 $3,067 $3,456
Net Operating Income (Loss) $780 $720 $575 $550 $558 $219
hƦĻƩğƷźƓŭ wğƷźƚ Њ͵ЌА Њ͵ЋЏ Њ͵ЋЊ Њ͵ЊВ Њ͵ЊБ Њ͵ЉЏ
Other Increases (Decreases) in Fund Resources
Capital Revenues 19 544 396 495 617 259
Custodial Activities (Net) (1) - - - - -
Debt Proceeds - - 189 - 2 -
Net Transfers In (Out) (236) (90) 32 115 743 (8)
Debt Service (168) (167) (113) (119) (64) (52)
Capital Expenditures (751) (484) (224) (126) (1,175) (339)
Net Other Resources (Uses) 0 (38) - - 28 -
Net Change in Fund Position ($000s) (357) 485 855 915 710 80
Ending Cash & Investments ($000s) $1,803 $2,288 $3,142 $4,057 $4,767 $4,847
5ğǤƭ ƚŅ /ğƭŷ ƚƓ IğƓķ ЌЊЌ ЌЉЍ ЍЋЍ ЎЉВ ЎЏА ЎЊЋ
The operating ratio provides a means of evaluating the self-
utility as an enterprise, measuring the ability of annual operating revenues to cover annual
is collecting exactly
enough revenue to pay for its operating costs. Table 11-1 indicates that while the sewer
utility was generally able to cover its operating expenses from 2018 to 2023, there was a
net cash flow deficiency in 2018 for the sewer funds overall after capital expenditures and
interfund transfers had been covered; and
Days of cash on hand is a measure of financial security, quantifying how long the City
sewer utility would be able to fund daily operating and maintenance costs if it received no
additional revenue. It is calculated by dividing unrestricted cash by the average daily cost of
operations. While there is no formal minimum standard for this metric, bond rating
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
agencies have recently expressed a preference for a minimum of 180 days of cash on hand
for utilities seeking the highest bond ratings. Considering its operating and capital reserves,
the sewer utility maintained over 300 days of cash on hand between 2018 and 2023.
CAPITAL FUNDING RESOURCES
Other than cash financing, the City may fund the sewer Capital Improvement Plan (CIP) from a
variety of sources, described in further detail below.
Grant and Low-Cost Loan Programs
Historically, federal and state grant programs were available to local utilities for capital funding
assistance. However, these assistance programs have been mostly eliminated, substantially
reduced in scope and amount, or replaced by loan programs. Remaining miscellaneous grant
programs are generally lightly funded and heavily subscribed. Nonetheless, the benefit of
low-interest loans makes the effort of applying worthwhile. Appendix N includes a document
published by the Washington State Department of Commerce that outlines state programs,
eligibility requirements, and contact information.
System Development Charges (SDCs)
SDCs are a form of connection charge authorized in Revised Code of Washington (RCW) 35.92.025.
The City imposes SDCs on development seeking to connect (or upsize an existing connection) to its
sewer system as a condition of service, and are in addition to any other costs of connection.
Typically based on a blend of historical and planned future capital investment in system
infrastructure, the underlying premise is that growth (future customers) will pay for growth-related
costs that the utility has incurred (or will incur) to provide capacity to serve new customers. The
key components of the SDC calculation are described below.
Existing Cost Basis: The SDC recovers a proportionate share of the cost of existing assets
from growth. City records indicate a cumulative investment of $26.7 million in existing
assets.
Interest: RCW 35.92.025 allows up to 10 years of interest accrued on existing assets to be
included in the cost basis. Based on the original cost and acquisition date of the sewer
.
Future System Costs: The SDC recovers a proportionate share of costs associated with
future capital projects from growth to recognize that growth either directly drives or
otherwise benefits from these projects. Table 10-3 indicates a total projected capital cost of
$115.7 million in 2023 dollars the SDC cost basis is adjusted to exclude $6.8 million in
costs that the City expects to fund with grants and other sources external to the sewer
utility on the premise that the SDC should only recover a share of the investment made in
the sewer system by the utility and its ratepayers. In addition, the SDC calculation deducts a
provision for future asset retirements to recognize that certain projects in the CIP will
replace existing assets. This adjustment intends to avoid double charging development for
an asset and its replacement concurrently, recognizing that the assets added through the
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
CIP will generally cost more than the historical acquisition costs of the existing assets. Based
on the projected cost of replacement projects and the expected life of the facilities being
replaced, the estimated provision for asset retirements is $3.6 million.
System Capacity: The City imposes sewer SDCs based on water meter size as a
representation of how much wastewater a connection could generate, using
meter-and-service equivalent (MSE) ratios published by the American Water Works
Association (AWWA) to assign equivalent residential units (ERUs) to each meter size.
(AWWA also publishes equivalency ratios based on maximum continuous flow capacity,
which the City uses to assign ERUs to water service connections because water meters are
often sized to meet demands that do not enter the sewer system, such as irrigation and fire
The SDC analysis estimates the ERU capacity of the sewer system by:
1. Estimating the number of existing ERUs using utility billing records. Based on a
current inventory of sewer customers by meter size, the City serves an estimated
4,781 ERUs;
2. Estimating the average flow/loading contributions per ERU using influent data from
the to 2021 data suggests
that an ERU contributes 174 gallons per day (gpd) of flow on an annual average
basis, 216 gpd of flow on a maximum month basis, 0.54 pounds per day of maximum
month 5-day Biochemical Oxygen Demand, and 0.55 pounds per day of maximum
month total suspended solids; and
3. Equating the design capacity of the wastewater treatment plant to an equivalent
number of ERUs, given the constraining measure of capacity. Based on the unit
flows/loadings summarized above, the wastewater treatment plant can
accommodate an estimated 6,673 ERUs based on annual average daily flow capacity
of 1.44 million gallons per day.
Table 11-2 summarizes the sewer SDC calculation.
Table 11-2
Sewer SDC Calculation
Sewer SDC Cost Basis ($000s)
Existing Assets as of 12/31/22 $ 26,685
Plus: Estimated 2023 Expenditures (Net of 50% Grant Funding) 300
Less: Estimated Cost of Assets Being Retired Through CIP Projects (3,567)
Plus: Interest on Existing Assets 14,905
Future Capital Projects (2023 Dollars) 115,128
Less: Projects Funded by Grants or External Contributions (6,796)
Net SDC Cost Basis $146,655
System Capacity in ERUs 6,673
Maximum Sewer SDC per ERU $21,978
Table 11-2 indicates that the City could justify increasing its sewer SDC to $21,978 per ERU.
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
adopted the following changes effective April 1, 2024 (Ordinance 3330):
Increasing the sewer SDC from $3,758 to $5,258 per ERU based on inflation in the
Engineering News-Record Construction Cost Index (20-City Average) from 2013 (when the
SDC had last been updated) to 2023. The financial plan assumes that beginning in 2025, the
City will adjust the sewer SDC annually for inflation.
Establishing an alternate methodology for assigning ERUs to single-family connections
based on house size (excluding garages). Parcel data from the Jefferson County Assessor
informed the proposed structure, which includes five tiers based on square footage:
Residential Single-Unit and Mobile Home
House Size in Square Feet (SF) Number of ERUs SDC
Up to 750 SF 0.36 $1,871
751 1,500 SF 0.70 $3,676
1,501 1,900 SF 1.00 $5,258
1,901 2,600 SF 1.30 $6,819
Larger Than 2,600 SF 1.90 $10,011
Bonds
While general obligation bonds pledge the full faith and credit of the issuing entity, revenue bonds
are typically secured by utility revenues. With this limited commitment, revenue bonds normally
bear higher interest rates than other types of debt and also require additional security conditions
intended to protect bondholders from default risk. These conditions may include the maintenance
of dedicated reserves and minimum standards of financial performance (e.g., debt service
coverage).
Revenue bonds can be issued in Washington State without a public vote. While there is no explicit
statutory bonding limit, the conditions that come with revenue bonds often impose practical limits
phase in rate increases, also resulting in a higher overall cost of capital investment given the related
coverage when assigning a rating higher levels of indebtedness make it more difficult for a utility
to meet the coverage ratios that the rating agencies require for the highest ratings (and the lowest
interest rates). In recent years, these coverage ratios have often exceeded the minimum legal
standards outlined in the applicable bond covenants.
CURRENT REVENUE
The primary goal of the financial analysis is to develop a viable financial plan to support execution
of the planned capital projects while funding ongoing operations and maintaining affordable rates.
including:
Operation and maintenance costs;
Administrative and overhead costs;
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Policy-based needs (e.g., reserve funding);
Capital costs; and
Existing/new debt service obligations.
The City operates its sewer utility as an enterprise, relying on revenue from its sewer rates (as
opposed to taxes or other external resources) to cover the expenses outlined above. The
rate-setting process includes both operating and capital elements.
Financial Policies
The ensuing discussion summarizes the key financial policies used in this analysis.
Utility Reserves
Reserves are a key component of any utility financial strategy, as they provide the flexibility to
manage variations in costs and revenues that could otherwise have an adverse impact on
ratepayers. The financial analysis separates resources into the following funds:
Operating Reserve: Providing an unrestricted cash balance to accommodate the short-term
cycles of revenues and expenses, these reserves are intended to address variations in
revenues and expenses (including anticipated variations in billing/receipt cycles, as well as
unanticipated variations due to weather or economic conditions). The financial analysis
assumes a minimum balance target of 60 days of operating expenses for this reserve, which
based on projected 2024 operating expenses equates to about $725,000.
Capital Reserve: Providing a source of cash for emergency asset replacements or capital
project overruns, this reserve enforces an appropriate segregation of resources restricted or
designated for capital purposes. This analysis does not include a minimum balance for this
reserve, assuming that the City would be able to delay or seek external funding for capital
projects as needed.
Bond Reserve: Bond covenants establish reserve requirements as a means of protecting
bondholders against the risk of nonpayment. While the City
currently have outstanding debt that requires such a reserve, the forecast assumes a
minimum balance equal to debt service payment for future revenue bonds.
Recognizing that revenue bonds will likely be needed to fund at least part of the projected capital
costs, this analysis also targets a combined unrestricted cash balance (including both operating and
capital reserves, but not restricted bond reserves) of 180 days of operating expenses. Though not a
formal requirement, this policy is based on recommendations from the bond rating agencies for
borrowers seeking to optimize their bond ratings. Given the near-term expense forecast, the
combined target balance would be roughly $2,178,000 in 2024.
Financial Performance Standards
The financial plan (revenue requirement analysis) uses a pair of sufficiency tests to establish the
amount of revenue needed to meet the annual financial obligations .
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
Cash Flow Test: To satisfy this test, operating revenues must be adequate to fund all known
cash requirements, including operations and maintenance (O&M) expenses, debt service,
rate-funded capital outlays, and reserve funding.
Coverage Test: Though the sewer utility currently has no debt requiring coverage, the
finan
equal to 1.25 times annual parity debt service (based on the requirements typically outlined
in bond covenants) in the event of future debt issuance.
The annual revenue requirement is broadly defined as the amount of revenue needed to satisfy
both of these tests. Short-term cash flow deficits may occur as part of a strategy to phase rate
increases in, as long as the utility has sufficient reserves on hand to absorb them; however, any
applicable debt service coverage requirements must always be met.
Capital Funding Plan
As shown in Table 11-3, the -year CIP includes $115.1 million in project costs (in
2023 dollars) with $51.9 million expected to occur in the next 10 years (2024 to 2033). Based on
input from City staff, the financial plan assumes construction cost inflation of 5 percent for 2024
and 4 percent per year thereafter. Adjusting for inflation, Table 11-3 shows a total 20-year capital
expenditure of $180.1 million, of which $63.8 million is projected to occur within the next 10 years.
Note that Table 11-3 only includes $21.3 million of the $56.0 million estimated for the long-term
sewer system refurbishment program due to financing constraints, the remainder will either need
to be funded by grants or delayed beyond the 20-year period.
Shown in further detail in Table 11-4, the capital funding plan for the 10-year CIP (2024 to 2033)
consists of the following components:
$6.3 million in grant funding, including $4.1 million for the Mill Road Lift Station,
$1.2 million for the Lawrence Street Combined Sewer Separation, and $1.1 million for the
Water Street Sewer Replacement (in addition to $300,000 in grant funding attributable to
2023 expenditures on the Water Street project).
or the
fund of the City that is external to the sewer utility).
$1.1 million in Public Works Trust Fund loans for the Water Street Sewer Replacement. At
an interest rate of 0.86 percent, the annual payment on this loan (including an additional
$300,000 attributable to 2023 expenditures on this project) would be about $80,000.
A $4.5 million State Revolving Fund (SRF) loan for the outfall upgrades. At an interest rate of
1.2 percent, the annual payment on this 20-year loan would be about $253,000.
$30.9 million in revenue bond proceeds to fund various capital projects over the 10-year
planning period. With interest rates of 3.5 to 4.0 percent, the annual payment on these
20-year bonds would increase to $2.3 million by the end of the planning period.
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
$2.0 million in Local Facilities Charges imposed on properties in the area benefitting from
the Mill Road Lift Station at the time of connection.
$18.6 million in sewer utility cash resources, including $3.1 million in SDCs and $15.5 million
of cash contributions generated through rates.
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9
-
819399300120630
11
1,5781,1862,4631,6796,7223,3002,8262,1005,0001,0006,3002,1201,2001,2501,2501,1402,944
21,250
Total
$ 1,212
-
------------------
500
2,4631,6796,722
Future
21,250
FINANCIAL ANALYSIS
$
-
------------------
50
886669350
2033
1,178
$
-
------------------
50
400300150350
2032
$
-
-----------------
50
350600625625
2031
1,222
$
-
----------------
50
350500475475
2030
3,5001,072
$
-
----------------
50
350100150150150
2029
1,000
$
-
3
-------------------
-
50
350500400
2028
$
-
--------------------
Table 11
50
350
2027
1,163
$
Capital Cost Forecast
----------------
5060
350990630
2026
1,1632,000
$ 506
---------------
50
350500399150100
2025
3,2001,820
)
$ 606
----------------
5060
150300300
PLAN
2024
2,1001,100
$ 100
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\\
WIP
\\
Street
rd
10 REPORTS
\\
0226
-
21
\\
Term Oxidation Ditch Improvements
Term Sewer System Refurbishment
--
rovements
TWNSD
\\
RealignmentSt.RepairSeparationWashington St.ImprovementsTractorImp
Sims Way Crossing & Wilson Street Howard Street & South Park AvenueSims Way, Third Street, & Gise StreetHolcomb StreetHoward St., South Park Ave, & McPherson West Sims Way & 3Future
Interceptor UpsizingSewer System Defect Investigation & Lawrence Street Combined Sewer Suitcase Pipe Replacement on LongWater Street Sewer ReplacementExisting Monroe St. Pump Station
Sewer Camera Van, Video Camera, & General Lift Station ImprovementsMill Road Lift StationInfluent Pump Station & Odor Control Headworks RehabilitationClarifier No. 1 ImprovementsClarifier
No. 2 ImprovementsNPW Pump ReplacementsSCADA UpgradesElectrical UpgradesNear
DATA
\\
Capital Project Expenditures ($000s)Sewer Main Improvements Lift Station Improvements Wastewater Facility Improvements
CITY OF PORT TOWNSEND GENERAL SEWER J:PREPARED BY FCS GROUP
)
PLAN
8090
890700460390410670300250250
Total
4,0003,0002,0002,850
30,000 180,067
$115,128$
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-------------
395250
63,259
Future
30,000 116,270
$
$
GENERAL SEWER
15
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\\
9 840
--------------
32
2033
WIP
2,750
\\
$5,$8,
10 REPORTS
282 842
---------------
\\
32
2032
$1,$1,
0226
-
21
\\
04
0
--------------
TWNSD
32
CITY OF PORT TOWNSEND\\
6,914
2031
1,500
$5,$
DATA
\\
J:
302
754
--------------
32
2030
1,300
$ 7,
$10,
182 787
--------------
32
200
2029
$2,$2,
95
3
-
7 205
--------------
365130
2028
$1,$2,
------------
Table 11
23
365130285
2027
$2,366$2,795
-----------
19
160130285
2026
2,900
$ 9,243
$10,497
Capital Cost Forecast (Continued)
89
1 218
-----
191590
600150390100300100250
2025
2,000
$11,$12,
-------------
19
500460
2024
$5,139$5,396
11
Term WWTP Expansion
-
10
Inch Hydrant Line
-
-
RemovalUpgradesShare)
Outfall UpgradesOnsite Solids HandlingLand Acquisition for WWTP ExpansionLongSolids Handling Influent Screening & Grit Solids Handling Tank Repl. & Mechanical Compost Screen ReplacementCompost
Case Loader ReplacementCompost Blower ReplacementsCompost Facility Infrastructure Upgrades6Office with Dedicated LunchroomArc Flash AnalysisPublic Works Shop (Sewer Collection General
Sewer Plan UpdateDowntown Restrooms
Capital Project Expenditures ($000s) Compost Facility & Solids Handling Improvements Miscellaneous & Planning Improvements Total (2023 Dollars)Total
Projected Expenditures (with Inflation)
CHAPTER 11
11
-
)
11
03
2033
8
-
802483
Total
4,1001,1631,0501,0504,4743,1032,000
$ 259
63,796
30,90016,216$1,
(
2024
)
3
03
8
-------
FINANCIAL ANALYSIS
23840
89
197200
5,924
2033
4,
$$1,
(8,
)
273
-------
842
64
188200
5,924
2032
3,040
$4,$
(1,
)
48
6273
------
534
25
180200
2031
6,6002,6,914
$1,$4,
(
)
48
6
302
-------
47
644
1173200
9,786
2030
1,
$
$ 1,
(10,
)
-------
64
787
1813448200
9,786
2029
10,948
$
(2,
$
)
00
502
3
1
------
204
2
903425200
2028
10,948
10,
(2,
$ 1,
$
4
-
8
2
783
------
,502
4
58228403200
2027
$2,$1
(2,795)
Table 11
0
309
783
------
37
175816382200
2026
$ 2,
$11,
(10,497)
Capital Funding Strategy
)
00
309
2218
-----
75
5,019
570363200
2025
3,100
14,
$
$11,
(12,
)
--
4
483344200
5,019
2024
1,0001,0501,0504,4741,552
$
(5,396)
$ 259
PLAN
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Street Sewer
Compost Screen
Water Street Sewer
Outfall Upgrades
Projections ($000s)
10 REPORTS
Mill Lift Station ProjectLawrence Street Sewer Water
\\
Earnings
0226
-
21
\\
TWNSD
\\
Capital Reserve Beginning BalancePlus: Interest Plus: Grants Plus: Grants Separation ProjectPlus: Grants ReplacementPlus: PWTF Loan ReplacementPlus: SRF Loan Plus: Revenue BondsPlus:
ERR Reserves ReplacementPlus: Transfer from Operating Fund Plus: Transfer from SDC FundPlus: Local SDC for Mill Road Lift Station ProjectLess: Capital ExpendituresEnding Balance
DATA
\\
CITY OF PORT TOWNSEND GENERAL SEWER J:PREPARED BY FCS GROUP
CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Revenue Requirement
projected costs
under its currently adopted rates. In the event of any projected deficiencies, this analysis will serve
as the basis for a strategy of recommended rate revenue adjustments.
Projected Financial Performance
The revenue requirement analysis is
assumptions:
The forecast of sewer rate revenue is based on 2023 budgeted revenue provided by the
City, adjusted for customer growth. Based on
presented in Table 3-3, the analysis assumes growth of about 1.4 percent per year (the
long-term annual average growth rate) through 2029 and 0.5 percent annual growth
thereafter. These projections are somewhat lower than the population projections
presented in Table 3-3, recognizing the difference between conservatism for financial
structure;
Interest earnings are calculated on the sewer utilityrojected fund balances assuming an
annual interest earnings rate of 1.5 percent;
The operating forecast generally holds most of the revenues
at 2023 levels moving forward;
The forecast of operating expenses generally adjusts the 2023 budgeted expenditures for
inflation assuming 5.0-percent inflation for 2024 and 4.0-percent inflation thereafter.
Though lower than recent inflation observed in the Consumer Price Index, these inflation
assumptions intend to recognize longer-term inflationary trends while maintaining a
reasonable degree of conservatism; and
Taxes are calculated based on the projected revenues and prevailing rates:
o City Utility Tax: 16.0 percent;
o State Excise Tax (Sewer): 3.852 percent; and
o Business & Occupation (B&O) Tax: 1.75 percent.
Table 11-5
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
Table 11-5
Projected Financial Performance and Revenue Requirements ($000s)
2024 2025 2026 2027 2028 2029 2030 2031 2032 2033
Revenue
Rate Revenue at 2023 Rates $3,072 $3,114 $3,156 $3,199 $3,243 $3,287 $3,304 $3,321 $3,337 $3,354
Other Operating Revenues 237 237 237 237 237 237 237 237 237 237
Use of Fund 430 for Debt Service 18 83 873 - - - - - - -
Total Revenues $3,327 $3,433 $4,266 $3,436 $3,480 $3,524 $3,541 $3,558 $3,574 $3,591
Expenses
Operating Expenses $4,417 $4,061 $4,210 $4,364 $4,525 $4,692 $4,812 $4,985 $5,165 $ 5,351
Debt Service 69 335 1,421 1,421 1,420 2,230 2,230 2,229 2,758 2,758
Direct Funding for Capital Projects - - - - - - 169 - - 2,627
Additions to Operating Reserve - - 24 25 26 27 20 29 29 31
Total Expenses $4,487 $4,397 $5,655 $5,810 $5,971 $6,949 $7,231 $7,243 $7,952 $10,767
Net Cash Flow ($1,160) ($964) ($1,389) ($2,374) ($2,491) ($3,425) ($3,690) ($3,685) ($4,378) ($7,176)
1
Annual Rate Increase 39.7% 13.0% 13.0% 13.0% 13.0% 13.0% 13.0% 13.0% 13.0% 13.0%
Rate Revenue After Rate Increases $3,986 $4,915 $5,630 $6,449 $7,387 $8,462 $9,609 $10,913 $12,393 $14,074
Net Cash Flow After Rate Increases ($411) $512 $662 $313 $930 $841 $1,495 $2,563 $3,070 $1,637
Debt Coverage After Rate Increases (N/A) (N/A) 1.62 1.98 2.54 1.92 2.19 2.59 2.46 2.96
Projected Ending Balances (Sewer Share)
Operating Fund $ 726 $ 668 $ 692 $ 717 $ 744 $ 771 $ 791 $ 819 $ 849 $ 880
Capital Fund 5,019 11,309 2,783 1,502 10,948 9,786 1,648 4,273 5,924 1,803
Total $5,745 $11,977 $3,475 $2,220 $11,692 $10,558 $2,439 $5,093 $6,773 $2,683
ЊͲЉАЏ
Combined Balance as Days of O&M ЍАЎ 5ğǤƭ ЌЉЊ 5ğǤƭ ЊБЏ 5ğǤƭ ВЍЌ 5ğǤƭ БЋЊ 5ğǤƭ ЊБЎ 5ğǤƭ ЌАЌ 5ğǤƭ ЍАВ 5ğǤƭ ЊБЌ5ğǤƭ
5ğǤƭ
1. ease over the total existing sewer bill.
Table 11-5 ufficient to cover the
with inflation, projected increases in debt service, and capital funding
needs, the cash-flow deficiency generally grows larger over time (except in 2025, when total
operating expenses are expected to decrease after accounting for several one-time expenses built
into the 2024 projections). Table 11-5 shows a strategy of 13.0-percent annual rate increases from
2024 to 2033, which are projected to enable the sewer utility to cover the projected needs while
maintaining a combined fund balance of at least 180 days of operating expenses. The City Council
passed Ordinance 3332 at its February 20, 2024, meeting, adopting the rate increases for 2024
(effective April 1, 2024) through 2028 the City intends to revisit the sewer financial plan in 2028
and assess whether the rate increases shown for 2029 and future years are still needed given any
capital funding assistance (e.g., grants, low-cost loans, forgivable principal loans) that the City is
able to obtain.
CURRENT AND PROJECTED SEWER RATES
The City imposes a two-tiered base rate on residential users, with residences using more than
3,000 gallons paying a higher base rate than those using 3,000 gallons or less. Multi-family,
commercial, and governmental users pay a base rate based on their water meter size and a volume
rate per thousand gallons of water usage. Effective April 1, 2024, the City eliminated the capital
surcharge and increased the rest of the sewer rate structure proportionately to maintain revenue
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
neutrality. Table 11-6 shows the sewer rate schedule adopted by the City Council on
February 20, 2024.
Table 11-6
Sewer Rate Forecast
Sewer Rate Structure Jan-Mar Apr-Dec
2025 2026 2027 2028
(Including Utility Tax) 2024 2024
Monthly Base Rate
Residential (Including Duplexes)
$46.46 $63.36 $71.60 $80.91 $91.42 $103.31
Usage > 3,000 Gallons $57.44 $78.33 $88.51 $100.02 $113.02 $127.71
Multi-Family/Commercial/Government:
$41.18 $56.16 $63.46 $71.71 $81.03 $91.57
$61.77 $84.23 $95.18 $107.56 $121.54 $137.34
1- $102.94 $140.37 $158.62 $179.24 $202.55 $228.88
$157.84 $215.24 $243.23 $274.84 $310.57 $350.95
$576.48 $786.12 $888.32 $1,003.80 $1,134.29 $1,281.75
$645.11 $879.72 $994.08 $1,123.31 $1,269.34 $1,434.35
$960.80 $1,310.22 $1,480.55 $1,673.02 $1,890.51 $2,136.28
$1,317.67 $1,796.87 $2,030.46 $2,294.42 $2,592.69 $2,929.74
Volume Rate per 1,000 Gallons
Multi-Family (3+ Units) $4.73 $6.45 $7.29 $8.24 $9.31 $10.52
$6.38 $8.70 $9.83 $11.11 $12.55 $14.18
$4.18 $5.70 $6.45 $7.28 $8.23 $9.30
Government $6.24 $8.51 $9.62 $10.87 $12.29 $13.88
Capital Surcharge per Month
Standard $9.00 - - - - -
Low-Income $4.50 - - - - -
Utility Rate Affordability Analysis
A
capital improvement projects while maintaining reasonable sewer rates. Recognizing that a holistic
assessment of rate affordability must consider the total utility bill, Table 11-7 shows a forecast of
combined utility bills under the adopted rates for a residential customer using 3,000 gallons of
water per month.
The City has historically offered citizens with income levels at or below 150 percent of the poverty
level (PL) for Jefferson County a 50-percent discount on their water base charge (excluding volume
charges), their sewer charge, and their stormwater charge. Effective April 1, 2024, the City replaced
its low-income discount program with an income-based discount program consisting of the
following tiers:
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Income Level Discount to Water Base Charge, Sewer Charge, and Stormwater Charge
> 350% of PL 0% (Customer Pays 100% of Charges)
300% 350% of PL 25% (Customer Pays 75% of Charges)
200% 300% of PL 50% (Customer Pays 50% of Charges)
75% (Customer Pays 25% of Charges)
Table 11-7 shows the bills for residential customers using 3,000 gallons of water per month under
each of these income thresholds.
Table 11-7
Combined Utility Bill Forecast
Average Monthly Jan-Mar Apr-Dec
2025 2026 2027 2028
Residential Bill @ 3,000 Gallons 2024 2024
Income > 350% of PL
1
Water $ 70.84 $ 74.31 $ 76.86 $ 77.79 $ 80.90 $ 84.14
Sewer 55.46 63.36 71.60 80.91 91.42 103.31
Stormwater 16.89 20.05 22.01 24.41 27.02 29.62
Total $143.19 $157.72 $170.47 $183.11 $199.34 $217.07
Change from Prior Year +$14.53 +$12.75 +$12.64 +$16.23 +$17.73
Percent Change from Prior Year +10.1% +8.1% +7.4% +8.9% +8.9%
Income Between 300% 350% of PL
1
Water (25% Discount to Base Charge) $ 70.84 $ 59.14 $ 61.14 $ 61.91 $ 64.39 $ 66.96
Sewer (25% Discount) 55.46 47.52 53.70 60.68 68.57 77.48
Stormwater (25% Discount) 16.89 15.04 16.51 18.31 20.27 22.22
Total $143.19 $121.70 $131.35 $140.90 $153.23 $166.66
Change from Prior Year ($21.49) +$9.65 +$9.55 +$12.33 +$13.43
Percent Change from Prior Year -15.0% +7.9% +7.3% +8.8% +8.8%
Income Between 200% 300% of PL
1
Water (50% Discount to Base Charge) $ 70.84 $43.97 $45.43 $46.04 $ 47.88 $ 49.80
Sewer (50% Discount) 55.46 31.68 35.80 40.46 45.71 51.66
Stormwater (50% Discount) 16.89 10.03 11.01 12.21 13.51 14.81
Total $143.19 $85.68 $92.24 $98.71 $107.10 $116.27
Change from Prior Year ($57.51) +$6.56 +$6.47 +$8.39 +$9.17
Percent Change from Prior Year -40.2% +7.7% +7.0% +8.5% +8.6%
1
Water (75% Discount to Base Charge) $42.40 $28.79 $29.72 $30.16 $31.37 $32.62
Sewer (75% Discount) 27.73 15.84 17.90 20.23 22.86 25.83
Stormwater (75% Discount) 8.27 5.01 5.50 6.10 6.76 7.41
Total $78.40 $49.64 $53.12 $56.49 $60.99 $65.86
Change from Prior Year ($28.76) +$3.48 +$3.37 +$4.50 +$4.87
Percent Change from Prior Year -36.7% +7.0% +6.3% +8.0% +8.0%
1. Assumes 4% inflationary increases for 2027 and 2028; the City has only adopted water rates through 2026.
-cost
on median household income (MHI) to
define a threshold beyond which utility rates impose financial hardship on ratepayers. The
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
benchmark most often used in this evaluation is 4.5 percent of the median household income in
the relevant demographic area for the combined water/sewer bill. The 2022 American Community
Survey indicates a median income of $59,193 (in 2022 dollars) for households in the City of Port
Townsend adjusting for increases in the state minimum wage from 2022 to 2024 (12.3 percent),
the equivalent 2024 median income level would be $66,505. Table 11-8 summarizes the
Table 11-8
Monthly Utility Bill as a Percentage of Median Household Income
Jan-Mar Apr-Dec
2025 2026 2027 2028
2024 2024
WaterBill @ 3,000 Gallons $ 70.84 $ 74.31 $ 76.86 $ 77.79 $ 80.90 $ 84.14
Sewer Bill @ 3,000 Gallons 55.46 63.36 71.60 80.91 91.42 103.31
Combined Monthly Water/Sewer Bill $126.30 $137.67 $148.46 $158.70 $172.32 $187.45
1
Annual MHI $66,505 $66,505 $69,166 $71,932 $74,809 $77,802
Combined Bill as Percent of MHI 2.3% 2.5% 2.6% 2.6% 2.8% 2.9%
1. Assumes that MHI increases annually with inflation at 4% per year.
Table 11-8 shows that the combined water/sewer bill at 3,000 gallons is expected to remain within
the range of 2.5 to 3.0 percent of MHI through 2028 even without the assumed inflationary
adjustments to MHI, the combined bill would only reach about 3.4 percent of MHI by 2028. Though
here has been a growing
consensus in the industry that median household income is of limited value in assessing the
impacts of utility rates on customers with income levels far below the area median. As discussions
about rate affordability continue to evolve, two alternative metrics have been gaining traction as
providing a more meaningful basis for evaluating affordability:
Hours at Minimum Wage (HM)
HM quantifies the amount of time that someone earning minimum wage (currently $16.28 per
hour in Washington State) would need to work in order to pay their combined water/sewer bill,
assuming that thper capita per day (gpcd). Based on the
month per household (for simplicity, this assessment rounds the usage level up to 3,000 gallons per
month). The literature discussing HM recommends 8.0 hours as a threshold for defining
th
Affordability Ratio at the 20 Income Percentile (AR)
20
AR expresses the combined water/sewer bill (at 50 gpcd) as a percentage of the net disposable
20
th
income (NDI) of a household in the 20 income percentile after accounting for the cost of food,
housing, power, healthcare, and taxes.
Based on data from the American Community Survey, the estimated gross income of a
th
household at the 20 income percentile is about $25,113 (roughly $2,100 per month).
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
estimated annual expenditures for the essential needs listed above add up to $20,605 for a
household of two and $15,852 for a household of three. Though it is somewhat
counterintuitive that a household of two would spend ƒƚƩĻ than a household of three on
these essential needs, the Consumer Expenditure Survey data suggests that on average, a
household of three gets a greater tax refund than a household of two (possibly due to
dependent tax credits) and spends less on healthcare despite spending more in most other
areas.
th
The parameters above suggest that the NDI for a household in the 20 income percentile falls into
the range of $376 to $772 per month, depending on whether the expense estimates for the
two-person or three-person household (which is more common for households in Washington
State) are used. The literature discussing AR recommends 10.0 percent of NDI as a threshold for
20
Both HM and AR focus specifically on the combined water/sewer bill and do not explicitly account
20
for stormwater charges. While this is possibly because residential stormwater charges have
historically been low compared to water and sewer charges, stormwater rate increases driven by
infrastructure investments and water quality improvements are at a point where they arguably
should be considered in an affordability assessment. It is reasonable to expect that the
methodology for determining these metrics (as well as the suggested affordability thresholds) may
evolve over time as a result of stormwater rate increases. With this caveat, Table 11-9 summarizes
the affordability analysis for low-income residents based on the current definitions of HM and AR.
20
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 11-9
Rate Affordability Assessment Based on HM and AR
20
Jan-Mar Apr-Dec
2025 2026 2027 2028
2024 2024
Residential (Income > 350% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $137.67 $148.46 $158.70 $172.32 $187.45
7.8 Hours 8.5 Hours 8.8 Hours 9.0 Hours 9.4 Hours 9.8 Hours
16.4 17.8 19.2 20.6 22.3 24.3
Bill as % of NDI (AR
20
33.6% 36.6% 39.5% 42.2% 45.8% 49.9%
Residential (Income Between 300 350% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $106.66 $114.84 $122.59 $132.96 $144.44
7.8 Hours 6.6 Hours 6.8 Hours 7.0 Hours 7.3 Hours 7.6 Hours
16.4 13.8 14.9 15.9 17.2 18.7
Bill as % of NDI (AR
20
33.6% 28.4% 30.5% 32.6% 35.4% 38.4%
Residential (Income Between 200 300% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $75.65 $81.23 $86.50 $93.59 $101.46
7.8 Hours 4.6 Hours 4.8 Hours 4.9 Hours 5.1 Hours 5.3 Hours
16.4 9.8 10.5 11.2 12.1 13.1
Bill as % of NDI (AR
20
33.6% 20.1% 21.6% 23.0% 24.9% 27.0%
Monthly Water/Sewer Bill @ 3,000 Gallons $70.13 $44.63 $47.62 $50.39 $54.23 $58.45
4.3 Hours 2.7 Hours 2.8 Hours 2.9 Hours 3.0 Hours 3.1 Hours
9.1 5.8 6.2 6.5 7.0 7.6
Bill as % of NDI (AR
20
18.7% 11.9% 12.7% 13.4% 14.4% 15.5%
1
Projected Minimum Hourly Wage $16.28 $16.28 $16.93 $17.61 $18.31 $19.05
$376 $376 $376 $376 $376 $376
th2
Monthly NDI of Household @ 20 Percentile
$772 $772 $772 $772 $772 $772
1
Assumes that minimum wage increases annually with inflation (assumed to be 4% per year) per RCW 49.46.020.
2
Range based on two-person and three-person homes; remains the same since both income and expenses are assumed to increase with inflation.
Table 11-9
customers with annual income above 350 percent of PL), the bill for a residential customer using
3,000 gallons per month generally exceeds the suggested affordability thresholds based on HM and
AR-based discount program in April 2024 appears to
20
materially improve the affordability of rates for customers below 350 percent of PL. It is worth
th
noting that the estimated annual income for a household in the City at the 20 income percentile
($25,113) represents approximately 123 percent of the 2024 Federal Poverty Guideline of $20,440
for a household of two in Table 11-9, this household would fall into the lowest income category
(150 percent of PL).
Rate Burden (EPA Methodology)
The U.S. Environmental Protection Agency (EPA) has developed a method for evaluating the
household burden of utility rates associated with water utilities. The framework for measuring
household affordability and financial capability include:
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1. The Household Burden Indicator (HBI), defined as basic water service costs (includes water,
th
wastewater, and stormwater combined) as a percent of the 20 percentile household
income (i.e., the Lowest Quintile of Income (LQI) for the Service Area); and
2. The Poverty Prevalence Indicator (PPI), defined as the percentage of community households
at or below 200 percent of the Federal Poverty Level (FPL).
Table 11-10
methodology.
Table 11-10
Summary of Rate Burden Evaluation Based on EPA Methodology
HBI Water Costs as a PPI Percent of Households Below 200% of FPL
Percent of Income at LQI
20 35% < 20%
Very High Burden High Burden Moderate-High Burden
7 10% High Burden Moderate-High Burden Moderate-Low Burden
< 7% Moderate-High Burden Moderate-Low Burden Low Burden
high burden if total basic water costs are a relatively high
percentage of household income for the LQI household, and a relatively large proportion of the
community households are economically challenged. However, if less than 20 percent of
households are below 200 percent of FPL, the community as a whole may be affluent enough to
pay for water at a relatively cost without it becoming a high burden (although some households
might still struggle). This approach also suggests that utility service may be highly burdensome and
200 percent of FPL,
even if water bills are a relatively low percent of LQI (the lower-left portion of Table 11-10).
City staff estimated that approximately 29.5 percent of households in the City have income levels
below 200 percent of FPL. Table 11-11 summarizes the evaluation of rate burden under the EPA
methodology.
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CHAPTER 11 CITY OF PORT TOWNSEND GENERAL SEWER PLAN
Table 11-11
Rate Burden Assessment Based on EPA Methodology
Jan-Mar Apr-Dec
2025 2026 2027 2028
2024 2024
th1
Annual Income at 20 Income Percentile $25,113 $25,113 $26,118 $27,162 $28,249 $29,379
th1
Monthly Income at 20 Income Percentile $2,093 $2,093 $2,176 $2,264 $2,354 $2,448
Residential (Income > 350% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $137.67 $148.46 $158.70 $172.32 $187.45
th
Bill as % of Monthly Income @ 20 Percentile 6.8% 7.5% 7.8% 8.1% 8.5% 8.9%
Rate Burden Mod. Low Mod. High Mod. High Mod. High Mod. High Mod. High
Residential (Income Between 300 350% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $106.66 $114.84 $122.59 $132.96 $144.44
th
Bill as % of Monthly Income @ 20 Percentile 6.8% 5.8% 6.0% 6.2% 6.5% 6.8%
Rate Burden Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low
Residential (Income Between 200 300% of PL)
Monthly Water/Sewer Bill @ 3,000 Gallons $126.30 $75.65 $81.23 $86.50 $93.59 $101.46
th
Bill as % of Monthly Income @ 20 Percentile 6.8% 4.1% 4.2% 4.4% 4.5% 4.7%
Rate Burden Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low
Monthly Water/Sewer Bill @ 3,000 Gallons $70.13 $44.63 $47.62 $50.39 $54.23 $58.45
th
Bill as % of Monthly Income @ 20 Percentile 3.7% 2.4% 2.4% 2.5% 2.6% 2.7%
Rate Burden Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low Mod. Low
1
Assumes that minimum wage increases annually with inflation (assumed to be 4% per year) per RCW 49.46.020.
Table 11-11 residential rate schedule (applicable to customers
with annual income above 350 percent of PL), the bill for a residential customer using 3,000 gallons
-
income-based discount program in April 2024 appears to help alleviate the burden to an extent,
-. Given the expected rate increases
shown in Table 11-5 for 2029 and future years, it is reasonable to expect that the rate burden may
shift to higher levels over time unless the City can secure additional grant funding for the capital
plan.
Table 11-11 (as well as Table 11-9) show affordability assessments under each of the levels in the
-based discount program to recognize that: (a) not all qualifying customers will enroll
in the program; and (b) customers with below-average income levels that exceed the
th
20 percentile might also be burdened by rates.
CONCLUSION
Table 11-5 indicates that the City will need to increase its sewer rates significantly in order to cover
projected debt service payments on debt issued to fund several of the upcoming capital
projects. In addition to debt service, this rate strategy also considers the need to keep up with
rising operating costs. The recommended strategy envisions rate increases of 13 percent per year
and inflationary incprovide additional funds to offset system
capital costs.
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CITY OF PORT TOWNSEND GENERAL SEWER PLAN FINANCIAL ANALYSIS
on lower-income citizens. By expanding its rate discount program, the City has taken a significant
step to alleviate the rate burden for customers that qualify for and enroll in the program.
Though the City Council has adopted sewer rates through 2028, the City may be able to reduce
future rate increases if it is successful in obtaining additional funding assistance for its capital
program. It would be prudent for the City to regularly monitor the financial position of its sewer
ues remain
sufficient to meet its financial obligations.
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Stormwater Management Plan
Prepared for
City of Port Townsend
Prepared by
Parametrix
719 2nd Avenue, Suite 200
Seattle, WA 98104
T. 206.394.3700 F. 1.855.542.6353
www.parametrix.com
January 2019 553-2836-004
CITATION
Parametrix. 2019. Stormwater
Management Plan. Prepared by
Parametrix, Seattle, WA. January 2019.
Stormwater Management Plan
City of Port Townsend
TABLE OF CONTENTS
1. INTRODUCTION AND PURPOSE ............................................................................................. 1-1
1.1 Public Input Process ...................................................................................................................... 1-1
1.2 Introduction .................................................................................................................................. 1-1
1.3 Comprehensive Program Mission ................................................................................................. 1-2
1.4 Plan Outline ................................................................................................................................... 1-2
1.5 Plan Resources .............................................................................................................................. 1-3
2. THE WATERSHEDS AND BASINS ............................................................................................ 2-1
2.1 Project Area Description ............................................................................................................... 2-1
2.2 Physical Conditions of the Area .................................................................................................... 2-1
2.2.1 Topography and Drainage................................................................................................ 2-1
2.2.2 Local Geology ................................................................................................................... 2-2
2.2.3 Soils .................................................................................................................................. 2-9
2.3 Area Climate and Hydrology ......................................................................................................... 2-9
2.3.1 Hydrology ......................................................................................................................... 2-9
2.4 Water Quality .............................................................................................................................. 2-10
2.5 Climate Change ........................................................................................................................... 2-10
3. THE BUILT ENVIRONMENT .................................................................................................... 3-1
3.1 Land Use ........................................................................................................................................ 3-1
3.1.1 Existing Land Cover .......................................................................................................... 3-2
3.1.2 Future Land Use and Land Cover ..................................................................................... 3-9
3.1.3 Estimating Runoff Potential ........................................................................................... 3-15
3.1.4 Catchments with Largest Increase Potential ................................................................. 3-25
3.2 Stormwater System Operation and Maintenance ...................................................................... 3-27
3.2.1 Asset Identification ........................................................................................................ 3-28
3.2.2 Level of Service .............................................................................................................. 3-28
3.2.3 Reporting ....................................................................................................................... 3-28
4. BASIN PLANNING .................................................................................................................. 4-1
4.1 Planning Objectives ....................................................................................................................... 4-1
4.2 Drainage Connectivity ................................................................................................................... 4-1
4.2.1 Drainage System Hierarchy .............................................................................................. 4-2
4.2.2 Drainage System Connectivity ......................................................................................... 4-6
4.2.3 Drainage System Protection ............................................................................................ 4-6
4.2.4 Evaluating Potential Capacity Needs and Impacts ........................................................... 4-8
4.2.5 Drainageway Potential Impact Assessment ................................................................... 4-21
4.2.6 Potential Impacts to Closed System Wetlands .............................................................. 4-25
4.3 Drainage System Stormwater Improvements ............................................................................ 4-25
4.4 Roadway Inventory for Upgrade Opportunities ......................................................................... 4-26
January 2019 553-2836-004 i
Stormwater Management Plan
City of Port Townsend
TABLE OF CONTENTS (CONTINUED)
5.CAPITAL PROJECTS PLAN.......................................................................................................5-1
5.1 Proposed Capital Projects ............................................................................................................. 5-1
5.2 Proposed Recurring Capital Projects ............................................................................................ 5-5
6. IMPLEMENTATION ................................................................................................................ 6-1
6.1 Capital Plan Priorities and Schedule ............................................................................................. 6-1
6.1.1 Capital Projects for Existing Flood Control ...................................................................... 6-1
6.1.2 Non-Capital Recurring Projects ........................................................................................ 6-2
6.2 Stormwater Control Standards and Policies ................................................................................. 6-3
6.2.1 Stormwater Control from New Development ................................................................. 6-3
6.2.2 Drainage System Protection ............................................................................................ 6-4
6.2.3 Drainage System Review and Upgrades .......................................................................... 6-7
6.2.4 Other Drainage System Protection Measures ................................................................. 6-8
6.3 Funding and Resources ............................................................................................................... 6-10
6.3.1 Capital Projects .............................................................................................................. 6-10
6.4 Summary Implementation Plan .................................................................................................. 6-12
7. REFERENCES ......................................................................................................................... 7-1
LIST OF FIGURES
1 Stormwater Drainage Basins ......................................................................................................... 2-3
2 Drainage Basins Discharge Locations ............................................................................................ 2-4
3 Topography ................................................................................................................................... 2-5
4 Flood Hazard Zones ....................................................................................................................... 2-6
5 Area Geology ................................................................................................................................. 2-7
6 Annual Water Budget ................................................................................................................... 2-8
7 Hydrologic Soil Groups ................................................................................................................ 2-11
8 Drainage Catchment Areas ........................................................................................................... 3-7
9 Land Use ...................................................................................................................................... 3-11
10 Vacant Lands and Development Potential .................................................................................. 3-12
11 Catchment Nodes ....................................................................................................................... 3-17
12 Stormwater Facilities .................................................................................................................... 4-3
13 Stormwater System Levels ............................................................................................................ 4-4
14a Pipe Capacity “Look Up Table” ..................................................................................................... 4-9
14b Ditch Capacity “Look up Table” .................................................................................................. 4-10
15 Long Paths, CDCs & KDs .............................................................................................................. 4-11
16 Roadway Drainage for Long Path Conveyance Sizing ................................................................. 4-19
17 CDCs & KDs High Velocity Reaches ............................................................................................. 4-23
18 Future Impact Estimate Wetland Footprints .............................................................................. 4-27
19 Capital Projects ............................................................................................................................. 5-3
ii January 2019 553-2836-004
Stormwater Management Plan
City of Port Townsend
TABLE OF CONTENTS (CONTINUED)
LIST OF TABLES
2-1 Rainfall Depths for 24-Hour Events .............................................................................................. 2-9
3-1 Existing Land Cover ....................................................................................................................... 3-2
3-2 Existing Land Use Model Inputs .................................................................................................... 3-4
3-3 Future Land Use Model Inputs ................................................................................................... 3-13
3-4 Buildable Area – Impervious Comparison................................................................................... 3-19
3-5a Peak Runoff at Nodes or for Total Catchment – Existing ............................................................ 3-23
3-5b Peak Runoff at Nodes or for Total Catchment – Future ............................................................. 3-24
3-6 Potential Change in Peak Flows by Catchment Area .................................................................. 3-25
3-7 Existing Inventory of Public Facilities .......................................................................................... 3-29
3-8 Maintenance Frequency and Personnel ..................................................................................... 3-30
4-1 Basins and Disposition or Discharge Point .................................................................................... 4-2
4-2a Pipe Capacity for Reaches of Different Slopes .............................................................................. 4-9
4-2b Ditch Capacity for Reaches of Different Slopes ............................................................................ 4-9
4-3 Catchment Area Peak flows and Maximum Required Drainage Conveyance ............................ 4-13
4-4 Drainage Facility Size Estimates for Drainage Paths Exceeding Minimum Conveyance Sizing .. 4-15
4-5 Peak Flows in Reaches for Structure Sizing ................................................................................. 4-17
4-6 Peak flows in Reaches for Long-Path Conveyance Sizing ........................................................... 4-18
4-7 Peak Flow Increase at Key Nodes due to future Development .................................................. 4-21
4-8 CDC and KD Velocity Thresholds ................................................................................................. 4-22
4-9 Potentially Impacted Wetlands................................................................................................... 4-25
5-1 Capital Projects ............................................................................................................................. 5-2
5-2 Other Built Capital Projects ........................................................................................................... 5-5
6-1 Capital Projects Rankings and Priority .......................................................................................... 6-1
6-2 Summary of the Roadway Drainage Improvement Plan .............................................................. 6-2
6-3 Summary of Stormwater Control and Drainage Protection ......................................................... 6-6
6-4 Summary of Drainage System Review and Upgrades ................................................................... 6-7
6-5 Summary of Other Drainage System Protection Measures .......................................................... 6-9
6-7 Summary Cost Plan – Capital (2019-2024) ................................................................................. 6-10
6-8 Summary Cost Plan - Resources .................................................................................................. 6-11
6-9 Summary Implementation Schedule .......................................................................................... 6-12
6-10 Updated CIP with $6 Surcharge and Development Fee.............................................................. 6-15
January 2019 553-2836-004 iii
Stormwater Management Plan
City of Port Townsend
TABLE OF CONTENTS (CONTINUED)
APPENDICES
A Kickoff Meetings
B Public Input Process
C FEMA Flood Mapping
D Modeling Analysis
E Roadway Inventory
F Small-Site Stormwater Management Guide
G Capital Projects Worksheets
H Stormwater Manual Comparison
I Updated Capital Improvements Plan
iv January 2019 553-2836-004
Stormwater Management Plan
City of Port Townsend
ACRONYMS AND ABBREVIATIONS
BMPbest management practice
CAO Critical Area Ordinance
CDC Critical Drainage Corridors
Ecology Washington State Department of Ecology
EDS Engineering Design Standards
FTE full time equivalent
HSG hydrologic soil groups
KD Key Drainageway
LID low impact development
MEP maximum extent practicable
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollution Discharge Elimination System
NRCS Natural Resources Conservation Service
PTMC Port Townsend Municipal Code
RSL relative sea level
SMP Stormwater Management Plan
SWMMWW Stormwater Management Manual for Western Washington
USDA U.S. Department of Agriculture
January 2019 553-2836-004 v
Stormwater Management Plan
City of Port Townsend
1. INTRODUCTION AND PURPOSE
1.1 Public Input Process
The planning process included public participation via public open house, public comment periods and a
technical advisory task force committee. The first SMP Technical Advisory Task Force meeting was held
on August 30, 2017. The purpose of the Task Force was to provide a wide variety of perspectives on the
City’s existing stormwater utility and input on the creation and adoption of the SMP. A second task force
meeting was held on November 2, 2017. Materials provided in the two meetings are included in
Appendix A.
A public open house was held between the two Task Force meetings to present the plan purpose and
findings (to date) and solicit input from the general public, such as known flooding problems for capital
project.
During the SMP adoption process there were two public comment periods. The first comment period
was early in the process and the goal was to gain feedback on what topics the public would like to see
covered in the SMP and what was important regarding stormwater. The second comment period was to
provide comments on the draft version of the SMP
The input provided throughout the public participation process was reviewed by the Plan team and
included where appropriate in this final draft. The materials and minutes from city council sub-
committee meetings, planning commission meetings and workshops, and the city council meetings and
workshop are included in Appendix B.
1.2 Introduction
The City of Port Townsend is unique in many ways, notably when it comes to climate, landscape, and
history of its development. Annual rainfall of about 17 inches is 70 percent of the amount that falls in
Port Angeles, just 30 miles to the west, and 25 percent of Quilcene’s, 23 miles to the south. There are no
“streams” in our common understanding of the term and the City is surrounded on three sides by water:
the Strait of Juan de Fuca, Admiralty Inlet, and Port Townsend Bay (all parts of the Salish Sea). Much of
the land was platted in the 1890s, with no regard to topography, drainage patterns, or infrastructure.
These conditions result in challenges for the City and property owners to follow natural drainage
patterns, control changes from new development, and apply western Washington stormwater manual
standards that were developed for wetter climates with streams and more traditional land development
approaches.
In 1986, the City prepared the “Comprehensive Storm Water Drainage Plan for Port Townsend”
(CH2MHill et al. 1987) which was used as the basis for establishing the City’s municipal stormwater utility.
Deficiencies in this plan were noted when preparing the Growth Management Plan in the early 1990s,
which resulted in initiating a new comprehensive plan (Port Townsend 1996) and an updated Stormwater
Management Plan (SMP) (Port Townsend 1999). Notable in the draft 1999 SMP was the idea of a “natural
drainage systems” approach, which included the mapping of “Critical Drainage Corridors”. The draft 1999
plan was never adopted; however, the natural drainage systems approach was adopted through the 1996
Comprehensive Plan through policies and goals in both the Land Use and Utility Elements of the 1996
Comprehensive Plan. The Critical Drainage Corridors were protected through regulatory language in the
city’s Critical Area Ordinance (CAO).
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This SMP update addresses ongoing management of the existing system and plots a course for the
future of the system. While there are many pieces already in place—system mapping, adopted
standards, and a recognized need to consider development and protect resources—the SMP includes
analyses, approaches, priorities, specific projects, mechanisms, updated performance standards, and an
implementation plan. In addition, since stormwater practice and regulations continue to evolve and the
approach and responsibility of municipalities to control stormwater discharges and manage
infrastructure increases, this Plan recommends policy and regulatory updates. The SMP is an important
tool for the City to use for day-to-day development review, operations, and long-term planning.
The objectives of the SMP include:
Updating and defining drainage connectivity and mapping;
Preparing updated policies for protecting the natural and built drainage system;
Describing approaches to protect and improve the existing roadway drainage system;
Preparing standard designs for future road drainage infrastructure;
Assessing the existing impacts and potential changes due to new development;
Preparing concept designs for capital projects to address existing stormwater problem areas;
and
Preparing site development information and review materials, including low impact development
(LID) measures, redevelopment, new site development, and water quality retrofitting.
The SMP presents the background objectives existing conditions summary, basin analysis, consideration
of future land use, recommended stormwater controls, and capital projects to address existing
stormwater problems.
1.3 Comprehensive Program Mission
The project kick-off with both the City and Parametrix teams was held on June 20, 2017. The purpose of
the kickoff was to develop the Plan vision and team mission to complete the plan, brainstorm the Plan
needs and goals, discuss risks and threats to project success, and finalize the schedule and work plan for
the adoption of an updated SMP. The team agreed on the following Vision and Mission statement:
A fully functional, achievable, and sustainable stormwater system that is integrated
into the landscape, supports envisioned growth, protects residents, and nurtures the
environment.
Additional information to help guide plan preparation was collected by the team. The kick-off meeting
day included a field tour of key areas and problem areas in the city. Notes from the meeting
brainstorming are provided in Appendix A.
1.4 Plan Outline
The Plan structure follows this general outline: Section 2 describes the study area, with a discussion of
the physical setting and natural drainage system; Section 3 describes the current built environment in
the context of how it affects water resources, such as land cover and stormwater facilities; Section 4
describes the basis for stormwater planning, establishes stormwater control targets, and presents the
proposed SMP approaches; Section 5 describes the proposed capital projects; and Section 6 includes the
implementation plan.
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1.5 Plan Resources
The City prepared the Draft Storm Water Management Plan in 1999 (Port Townsend 1999). This plan
was very thorough and provides a strong platform on which this SMP plan update was built. Key
material used for a starting point includes the original drainage basin mapping and critical drainage
corridors (CDC) map.
The existing available GIS mapping from the city was used extensively, including topography, the
mapped drainage basins, CDCs, road network, drainage patterns and conveyance, wetlands, floodplains
and soils mapping. The City staff also prepared new information for this plan, such as a roadway
inventory, new and revised catchment inventory, and updated CDC and key drainageway (KD) mapping.
Other information, such as water quality sampling and some rainfall data, was provided by the City.
Other geology and climate data were collected from reliable Internet sources.
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2. THE WATERSHEDS AND BASINS
2.1 Project Area Description
The City is located on the Quimper Peninsula, surrounded on three sides by the Strait of Juan de Fuca,
Admiralty Inlet, and Port Townsend Bay, all parts of the Salish Sea. Figure 1 shows the city limits, streets,
named receiving waters, wetlands and potential wetlands, CDCs, KDs, and drainage basins. There are no
well-defined perennial or named streams. There is a long linear depression that generally drains toward
“Chinese Gardens” which contains a connected series of wetlands and a designated floodplain. CDCs are
regulated by the City’s Critical Areas ordinance. KDs are defined in this Plan and regulated by
stormwater codes and design standards.
The general disposition of surface waters is shown on Figure 2. Drainage basins in the City drain either to
closed depressions or directly to the ocean. The basins that discharge to the ocean are via a storm sewer
system, flow through surface ravines or through outlets from the two large named wetlands, Chinese
Gardens and Kah Tai Lagoon. The closed basins discharge into groundwater at small wetlands. Additional
detailed discussion of the drainage basins is provided in the 1987 Comprehensive Stormwater Drainage
Plan (CH2M Hill et al. 1987).
2.2 Physical Conditions of the Area
2.2.1 Topography and Drainage
The landscape and general topography of the City indicates irregular and undulating slopes. Figure 3 is a
topographic map of the City which shows the location of the low-lying areas, closed depressions and
geologic drainage features. Generally, there are relatively flat “plateaus” along the east and west sides
of the City with a valley (low lands) going through the middle. High bluffs dominate the ocean edge.
Strong erosional drainage patterns are not well-seen and are generally limited to drainage from the
plateau, notably in the southwest corner of the city. The formation of the large-scale landforms found
are an outcome of many processes, including deposition by advancing and receding glaciers, changing
sea levels, isostatic rebound after the glaciers have gone, and other apparent significant land forming
events. However, there is little evidence of landscape-level changes due to streams and flowing water
over the last several thousand years since the glaciers retreated, other than very local drainage patterns.
The topography of the City indicates low-lying areas and subtle drainage paths to form the natural
drainage disposition shown on Figures 2 and 3. Topographic maps and the built environment (i.e., both
built drainage network and existing roads) were used to define the drainage basins and their discharge
location. Figure 3 indicates by shading the location of low-lying drainage patterns within the major
drainage basins that lead to receiving water. The drainage patterns described in this section and shown
on Figures 1 through 3 form the drainage network on which the stormwater planning is based.
As shown on Figure 2, stormwater runoff drains directly to: the ocean either via storm sewers (pipes) or
from the two large named wetlands (Chinese Gardens and Kah Tai Lagoon) via an overflow pipe or to
closed basins that discharge into the groundwater, often at small wetlands and surface ravines. The flow
path and disposition of stormwater is an important factor in the stormwater impact analysis, future
control decisions and policies and potential basin retrofitting.
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Designated floodplains and coastal flood hazard zones as mapped by FEMA exist in the low coastline
areas along the entire City shoreline (Figure 4). The only non-coastal floodplain in the City has also been
mapped in Drainage Basin 4, for which detailed information can be found in Appendix C (Polaris 1996).
Wetlands have also been mapped throughout the city annotated as “wetlands” or “potential wetlands”
(Figure 4). A wetland has been delineated by a wetland specialist and documented by a wetland report;
a potential wetland is identified through aerial mapping by a topographic depression or wet area in the
landscape and does not have a delineation wetland report and has not been field verified.
2.2.2 Local Geology
The geology and climate of the area contribute substantially to defining stormwater planning
approaches for the City. The relatively poorly defined natural drainage paths are a direct result of the
recent geologic past and the lack of rainfall to form drainage patterns and provide perennial streams.
The dominant geologic formation that resulted in local landforms is known as the Vashon recessional
drift, made up of sediments deposited during and after the last retreat of the Puget Lobe glacier. The
landforms are made up of a combination of materials deposited during previous advances as till,
outwash coming from the glacier as it retreated, and materials left behind as the ice stagnated and
melted. Because the Vashon recessional drift is the last deposit left by the melting glacier, it is relatively
undisturbed (Washington State Department of Ecology \[Ecology\] 1981). No interpretations of the
existing smaller-scale landforms in the City were found, and virtually all of the City is mapped as “Vashon
Till (Qvt)” on the Surficial Geologic Map of the Port Townsend Quadrangle (Pessl et al. 1989) (Figure 5).
Small areas of “Marsh, Swamp, or Bog” (Qm), “Recessional-Continental” deposits (Qvrc) and “Advance
Outwash” (Qva) are also found. This mixture of material sources, depositional environments, and
geologic processes demonstrates that highly variable landforms.
As described earlier, annual rainfall in the City is very low when compared to nearby areas due to the
Olympic Mountains rain shadow. In addition, the historical forest cover before the arrival of European
settlement resulted in low basin response and runoff from the rain that does fall. Consequently, there
was limited water available to carve drainage channels. Low areas that appear to have been created by
water are present (see Figure3) and may have resulted from the last processes of the melting glaciers or
in the slow response to several thousand years of rainfall since the glaciers melted.
Ecology conducted a study of ground water resources in eastern Jefferson County (Ecology 1981) and
developed a compelling analysis of the annual water budgets for the Port Townsend area that
demonstrates the amount of water typically available for surface water runoff. Figure 6, replicated here
from Ecology 1981, shows the relative percentages of average annual rainfall needed to replenish soil
moisture and the resultant remaining water surplus available for runoff. The results show that the
average annual excess water available (water surplus) for runoff is just 0.6 inches (precipitation minus
evapotranspiration), although under seasonally variable infiltration and evapotranspiration or in
different locations, it could be more or less. This is a very small amount of water available for runoff. By
comparison, the excess available runoff (water surplus) in Quilcene, just 30 miles south of the City, is
29.7 inches (Ecology 1981). This excess runoff in Quilcene is also reflected in local drainage patterns and
development of channels in the same glacial materials. As the amount of average annual precipitation
increases moving south from Port Townsend, the number of streams also increases to the south
(Ecology 1981).
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Stormwater Management Plan
City of Port Townsend
2.2.3 Soils
Soils in the area were mapped by the Natural Resources Conservation Service (NRCS), as shown on
Figure 7. The NRCS divides soils into four hydrologic soil groups (HSG) defined by the expected rainfall
infiltration and runoff response. These soils categories provide information for hydrologic modeling and
planning-level information regarding localized infiltration potential (or lack thereof). These data will be
used for testing potential impacts described in Section 4 below. Figure 7 has highlighted HSG “A” and
HSG “D” which represents the soils most likely to have high infiltration and low infiltration respectively.
The hydrologic soil groups will be used to support on-site infiltration feasibility7.
2.3 Area Climate and Hydrology
2.3.1 Hydrology
Port Townsend is located in the rain shadow of the Olympic Mountains. The precipitation in the area
usually falls as rain, with about 65 percent of the yearly precipitation occurring between October and
March. Current hydrological parameters in the City are:
Average annual rainfall: 17.64 inches
Mean storm events: 50
1
Mean storm depth: 0.266 inches
1
Data from the Port Townsend Station located at latitude 48.07, longitude 122.45 (Perrich 1992).
Rainfall depths for selected 24-hour storm events are shown in Table 2-1.
2
Table 2-1. Rainfall Depths for 24-Hour Events
Return Frequency Precipitation Depth (inches)
2-year 1.17
10-year 1.72
25-year 2.03
100-year 2.50
2
Data taken from National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce (reference needed)
Hydrologic modeling is used to predict runoff from under different land use scenarios. Modeling for this
Plan was done using MGSFlood. The predicted runoff rates are used for sizing conveyance structures such
as culverts and ditches. Stormwater models use the long-term regional rainfall records which are tailored
to the specific location being analyzed (i.e., Port Townsend). The maximum adjustment in the rainfall
record allowed by Ecology is a factor of 0.78, which does not fully reflect the reduction needed when
comparing Port Townsend rainfall records to nearby stations used in the long-term model record.
Consequently, the modeled rainfall amounts used, and the resultant peak flow rates (described in
sections below), may be higher than observed amounts. Because of this, conveyance structures may be
larger than needed for the design storms used. However, the structure sizing is not that sensitive to
modest changes in rainfall extremes, therefore the overall effect on results is expected to be minor. Also,
the impact analysis is comparative, using the same rainfall record, which means the existing and future
conditions are similarly different (high or low) but the comparative difference is reasonably accurate.
The rational method is another appropriate approach for calculating peak flows in for conveyance
design. However, the rainfall intensity numbers used in the rational method also rely on location-specific
rainfall data. These data have not been calculated for Port Townsend and the available nearby rainfall
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stations do not have the type of data or length of records needed to be appropriate data sources.
Similar adjustments can be made to nearby available rainfall data if this method is used but is also
expected to over-predict runoff rates.
2.4 Water Quality
No stormwater quality data has been collected by the City at city outfalls. The Jefferson County Health
Department collected dry and wet weather samples to evaluate e coli from storm sewer outfalls in 2013
and 2014. The samples can inform some elements of stormwater planning which would be focused on
education (usually pet waste), source controls, and illicit discharges. There is insufficient available data
to inform a basin or outfall-specific stormwater quality retrofit prioritization plan, which is the norm, not
the exception, in most of Puget Sound communities. However, stormwater is a presumptive practice;
therefore, a surrogate such as the percentage of roadways and intensity of development in a basin can
be used to prioritize locations for stormwater treatment retrofits to improve water quality.
2.5 Climate Change
Change in climate is expected to result in more extreme weather such as larger storms of greater
intensity, changes in seasonal rainfall patterns, more extreme difference between wet and dry years, or
changes in snow and snow melt patterns. In addition, warming weather is resulting in higher sea levels
which can impact coastal communities, such as Port Townsend.
F to
F by 2050 in the Puget Sound Region and more extreme weather may be expected. For example,
according to a study done by University of Washington (Mauger et al. 2015), the wettest days
(99th percentile of 24-hour precipitation totals) in the Pacific Northwest are projected to increase in
precipitation by 22 percent by the 2080s and the frequency of those events are predicted to increase
from 2 days per year historically (1970-1999) to 7 days per year in the future (2070-2099). According to
some models, around the Puget Sound watershed and Port Townsend, the maximum 24-hour
precipitation event is projected to have an increase precipitation of 6 percent to 10 percent by 2040,
and 10 percent to 11.5 percent by 2080.
Precipitation in general is projected to increase in fall, winter and spring and decrease in summer.
Around the Puget Sound watershed and Port Townsend, it is projected that winter precipitation will
increase on average of 7 percent to 8.5 percent by 2040, while summer precipitation will decrease on
average by 10 percent to 11.5 percent. Additionally, the average snowpack is predicted to decline in the
Puget Sound region, causing the spring peak in streamflow to occur earlier in the year and decreasing
summer minimum flows.
In addition, warming weather is resulting in higher sea levels which can impact coastal communities
such as Port Townsend. Based on a University of Washington study on projected sea level rise
(Miller et al. 2018), around Port Townsend there is a 99 percent probability that relative sea level (RSL)
will increase by 0.1 feet by 2030 and a 50 percent probability that RSL will increase by 0.4 feet. By 2070,
that increases to a 99 percent probability that the RSL will rise by 0.4 feet and 50 percent probability of
over 1.3 feet. These projections all assume high greenhouse gas scenario. In a low greenhouse gas
scenario, the projections remain the same for 2030, and decrease slightly to a 99 percent probability of
RSL rises by 0.3 feet and 50 percent probability of over 1.1 feet in 2070. Looking farther ahead, in 2150
there is a 99 percent probability that RSL will increase by 0.3 feet and 50 percent probability that RSL
will increase by 2.8 feet. Furthermore, in the event of a subduction zone earthquake, some parts of
Washington coast may be subject to land level changes, based on multiple seismic deformation models,
of 0 to 0.3 feet subduction.
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Stormwater Management Plan
City of Port Townsend
3. THE BUILT ENVIRONMENT
Stormwater plans are prepared to addressbothcurrent and proposed conditions:the effects of land
conversion on stream hydrology and the impacts of pollution-generating activities on water quality.
Land drainage has been included in design for centuries; stormwater management has been the norm
for the past several decades in Washington and continues to evolve as the practice learns from the past
and new issues come to the forefront. Existing land use and land cover have created drainage conditions
observed today, including some localized flooding and erosion impacts. Development of vacant
undeveloped lands, redevelopment, and infill will bring future potential impacts, if not properly
controlled. The measures and standards for control to be used in Port Townsend will follow the general
approach for stormwater management used elsewhere in western Washington, with adjustments due to
local conditions found in Port Townsend.
As described before, the City will be unique in its approach to addressing stormwater management
because of the following unique local conditions: there are no natural streams but there are obvious
pathways, drainage basins, and receiving waters; new development will be predominantly infill into pre-
platted areas with or without existing opened rights-of-way; rainfall is relatively low; and the road
system is the dominant drainage conveyance network.
In this section, existing land use (as defined by imperviousness) is estimated to evaluate existing
drainage needs, primarily in the road system, and identify areas with potentially high stormwater quality
impacts. There are no reliable mapped data for determining existing imperviousness, therefore
estimates were made using approaches described below. Future land use is estimated by both the
development potential and estimated allowable development. This generally tends to over predict
future impacts, which means the planning outcomes tend to be reliably protective.
Runoff modeling requires soils and land cover data. Figure 7 provides the source for soils data. Land
cover refers to the general type and condition of vegetated surfaces, such as forests, pastures, and open
landscapes, each of which has a different runoff response to precipitation. The City used visual
estimates for land cover data. In low precipitation areas with moderate soil runoff response such as Port
Townsend, runoff rates are relatively insensitive to land cover.
In addition, for purposes of hydrologic modeling, each drainage basin in the City was further divided into
subbasins, referred to as “catchment” areas as shown on Figure 8. The catchment boundaries are
defined by both topography and the built environment—existing roads and stormwater infrastructure.
3.1 Land Use
An inventory of impervious area and land cover, described in terms of aerial coverage within a
catchment, is needed to prepare modeling or characterization analyses that relate runoff potential or
quality characteristics to a point in the conveyance system. Impervious land cover can include amounts
and types of impervious surface, for example roads, sidewalks, rooftops, or parking lots, or a stormwater
management description like pollution generating or “effective” impervious surface. Available data to
make these characterizations varies widely between different jurisdictions. Fortunately, there are a
number of approaches to either translate available data into categories that are useful for stormwater
management or basin planning evaluations. Data are needed to characterize existing conditions and to
project the changes that could occur due to new development.
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3.1.1 Existing Land Cover
Existing land use and imperviousness is estimated to evaluate existing conditions to determine drainage
needs, primarily in the road system, identify areas with potentially high stormwater quality impacts, and
provide a baseline for modeling existing runoff conditions. For the modeling analysis, imperviousness is
calculated for each catchment within a drainage basin. The approach for estimating existing
imperviousness is described below.
For rights-of-way, two categories were identified: opened rights-of-way (which means an existing public
road is present) and unopened rights-of-way (an undeveloped, platted right-of-way with no public road).
For opened rights-of-way, the length of roadways in the catchments were measured and multiplied by
22-feet to estimate the area of impervious surface. The right-of-way per catchment is shown in Table 3-
1. The opened rights-of-way are an estimated 40 percent imperviousness based on a typical roadway
width of 22-feet of pavement in a 60-foot wide platted right-of-way, plus some consideration of
sidewalks and driveways in the right-of-way. For unopened rights-of-way, imperviousness is assumed to
be zero.
The remaining land (i.e., not platted rights-of-way) was classified into developed land, critical areas
(undevelopable land including steep slopes, wetlands, and CDCs), or vacant land. For developed land,
the estimated imperviousness is 37 percent of the developed land area. Vacant land was further divided
into conservation or public lands (which are assumed will remain undeveloped) underdeveloped land
(which are large tracts with little development or a single house) and undeveloped (developable land
either platted land or not). For vacant land, the estimated imperviousness was assumed to be zero for
current baseline conditions.
Runoff modeling requires land cover data and soils types. Land cover refers to the general type and
condition of vegetated surfaces, such as forests, pastures, and open landscapes, each of which has a
different runoff response to precipitation. Visual estimates were used to provide data for land cover. In
low precipitation areas with moderate soil runoff response such as Port Townsend, runoff rates are
relatively insensitive to land cover. Figure 7 provides the source for soils data. Tables 3-1 and 3-2
provides a breakdown of total catchment area breakdown (see Figure 8), rights-of-way impervious area,
rights-of-way unopened area, developed area, critical areas, vacant conservation/public land and vacant
underdeveloped/developable land.
Table 3-1. Existing Land Cover
Remaining Land
Right-of-Way Vacant
Total
Area
Open Unopened Developed Critical Areas Underdeveloped/
Catchment (ac.) (ac.) (ac.) (ac.) (ac.) Conservation/public Developable
1 12.80.0 0.0 0.0 12.8 0.0 0.0
2 62.713.7 4.8 15.1 2.0 24.1 3.4
3 19.10.0 0.0 0.0 10.9 0.0 8.1
4a 46.50.0 0.0 0.0 46.5 0.0 0.0
4b 80.30.1 0.2 0.9 7.1 0.8 71.2
4c 122.4 15.0 4.2 7.4 8.9 21.9 65.0
4d 47.40.1 0.0 0.0 8.6 0.1 38.6
4e 26.74.6 1.0 5.2 1.5 7.9 6.7
4f83.78.5 2.3 13.3 6.3 52.5 1.0
4g 107.6 17.5 15.2 27.6 19.8 25.4 2.2
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Table 3-1. Existing Land Cover (continued)
Remaining Land
Right-of-Way Vacant
Total
Area Open Unopened Developed Critical Areas Underdeveloped/
Catchment(ac.)(ac.)(ac.)(ac.)(ac.)Conservation/public Developable
4h 46.42.8 4.2 8.2 3.0 1.2 27.0
4i 114.2 7.2 26.8 43.3 11.3 9.9 15.7
4j 38.02.3 0.2 33.5 2.0 0.0 0.0
4k 129.9 13.9 24.1 66.3 11.2 13.6 0.8
4l 314.8 22.9 45.7 160.2 37.3 25.6 23.2
4m 38.43.7 8.6 16.3 1.7 8.1 0.0
5a 85.71.5 14.0 65.5 1.2 1.7 1.9
5b 54.82.6 1.9 17.8 9.5 23.0 0.0
5c 36.93.1 4.3 8.0 9.5 4.7 7.3
5d 61.41.8 17.9 34.4 2.4 1.8 3.1
6a 80.418.4 6.7 25.0 2.9 26.9 0.5
6b 14.63.6 1.3 5.7 0.0 4.0 0.0
6c 5.8 0.9 1.0 0.3 1.2 2.3 0.0
7a 19.63.4 2.0 4.6 3.1 6.4 0.0
7b 7.4 0.0 0.0 0.2 0.0 7.2 0.0
7c 48.516.5 3.1 5.8 0.7 22.4 0.0
7d 26.07.1 1.0 3.9 1.6 11.0 1.3
7e 18.81.4 0.5 13.0 0.1 3.9 0.0
7f6.6 0.1 0.0 4.9 0.9 0.6 0.0
8a 70.813.7 4.2 11.7 0.9 40.1 0.2
8b 107.3 14.2 3.6 14.3 9.6 37.8 27.9
8c 61.912.3 6.3 18.4 3.3 21.2 0.5
8d 8.0 3.4 0.3 1.9 0.2 2.2 0.0
8e 2.7 0.6 0.0 1.1 0.0 0.9 0.0
8f31.99.6 4.5 4.0 0.0 13.8 0.0
8g 13.93.1 0.9 3.3 0.2 5.6 0.8
8h 5.7 0.3 0.1 4.4 0.0 0.9 0.0
8i 50.64.7 8.3 30.1 0.4 6.6 0.4
8j 18.44.3 2.0 7.4 0.5 4.2 0.0
8k 32.62.8 4.3 13.8 8.4 3.0 0.2
9a 46.40.0 0.0 0.0 46.4 0.0 0.0
9b 137.7 34.6 16.2 33.5 1.3 52.0 0.0
9c 30.58.6 3.3 5.0 1.0 12.4 0.1
9d 39.013.6 1.0 2.0 0.1 22.2 0.0
9e 13.85.8 1.1 0.8 1.7 3.4 1.7
9f108.8 24.2 16.3 11.5 7.7 35.2 21.4
9g 26.20.4 0.0 0.0 0.0 0.0 25.7
9h 39.97.4 0.5 6.6 0.0 25.4 0.0
9i 25.17.2 2.3 2.9 0.0 12.4 0.2
9j 99.616.3 6.3 35.0 13.2 28.7 0.0
9k 15.93.3 1.2 1.4 0.0 10.0 0.0
9l 49.316.4 4.1 10.4 0.2 18.2 0.0
553-2836-004 3-3
Stormwater Management Plan
City of Port Townsend
Table 3-1. Existing Land Cover (continued)
Remaining Land
Right-of-Way Vacant
Total
Area Open Unopened Developed Critical Areas Underdeveloped/
Catchment(ac.)(ac.)(ac.)(ac.)(ac.)Conservation/public Developable
9m 17.17.0 0.1 0.8 0.2 9.1 0.0
10a 103.9 24.7 6.3 15.1 12.0 45.7 0.1
10b 23.53.9 0.7 5.3 3.8 9.8 0.0
10c 51.02.2 1.3 0.0 1.0 46.5 0.0
10d 21.45.2 0.8 0.0 0.3 15.1 0.0
11a 72.12.0 9.8 41.2 14.9 3.5 0.7
11b 76.717.8 6.5 10.4 5.4 33.6 3.0
11c 28.85.5 1.5 7.4 6.8 7.7 0.0
11d 3.7 0.0 0.0 0.0 3.7 0.0 0.0
11e 26.74.4 1.5 4.7 9.3 6.2 0.6
11f 33.66.3 2.7 10.3 1.4 12.9 0.0
12a 86.632.9 3.8 4.4 2.0 43.5 0.1
12b 20.14.3 1.2 0.5 3.1 10.5 0.4
12c 26.910.9 0.5 0.4 1.6 13.4 0.1
12d 30.813.0 0.4 2.1 1.2 13.4 0.7
12e 13.53.6 0.4 0.6 1.3 6.7 0.9
12f 112.2 38.6 0.7 9.5 1.6 57.2 4.6
12g 14.32.0 0.1 1.3 0.5 10.5 0.0
13a 44.85.4 0.8 3.4 2.1 30.0 3.1
13b 51.915.9 1.1 4.1 1.6 24.5 4.6
13c 18.80.6 0.8 1.8 10.7 4.4 0.5
14 193.6 10.3 4.9 11.6 21.9 13.0 131.8
15a 131.7 5.1 7.8 77.8 30.1 10.9 0.0
15b 24.64.0 1.3 13.8 0.6 4.4 0.6
15c 24.01.3 0.3 12.0 2.3 4.2 3.8
16a 42.96.7 5.8 14.5 6.1 9.3 0.5
16b 62.78.3 5.4 22.5 6.6 19.9 0.0
16c 7.5 1.6 1.1 0.9 0.1 3.7 0.0
17a 53.77.0 5.5 34.1 0.7 6.4 0.0
17b 46.45.8 1.2 15.7 6.4 16.4 0.9
18a 141.6 5.0 4.4 105.0 15.1 12.1 0.0
18b 84.62.9 7.7 61.8 9.4 0.3 2.7
Table 3-2. Existing Land Use Model Inputs
Pervious (ac.)
Total Area Impervious Percent Hydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.)ImperviousType A -Forest Type C - Forest Type D - Forest
1 12.8 0.00 0.0% 11.5 1.30.0
2 62.7 11.1 17.7% 35.1 16.5 0.0
3 19.1 0.01 0.1% 19.0 0.00 0.0
4a 46.5 0.00 0.0% 2.1 2.142.3
3-4 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 3-2. Existing Land Use Model Inputs (continued)
Pervious (ac.)
Total Area Impervious Percent Hydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.)ImperviousType A -Forest Type C - Forest Type D - Forest
4b 80.3 0.3 0.3% 66.8 11.80 1.4
4c 122.4 18.2 14.8% 47.9 53.35 2.9
4d47.40.20.4%16.322.08.9
4e 26.7 3.7 13.7% 17.7 3.61.8
4f 83.7 10.4 12.4% 40.1 32.5 0.8
4g107.613.812.8%27.166.70.0
4h 46.4 1.2 2.5% 32.8 12.4 0.0
4i 114.2 5.4 4.7% 87.3 21.6 0.0
4j 38.0 1.9 4.9% 10.7 25.5 0.0
4k 129.9 7.5 5.8% 107.1 15.3 0.0
4l 314.8 15.1 4.8% 274.0 0.025.8
4m 38.4 2.8 7.3% 14.7 20.9 0.0
5a 85.7 1.0 1.2% 30.5 54.3 0.0
5b 54.8 4.3 7.9% 12.5 38.0 0.0
5c 36.9 2.7 7.4% 20.6 10.1 3.5
5d 61.4 1.3 2.1% 23.8 36.4 0.0
6a 80.4 13.8 17.2% 33.9 32.7 0.0
6b 14.6 2.3 16.0% 5.6 6.70.0
6c 5.8 0.9 14.7% 0.0 5.00.0
7a 19.6 2.5 12.9% 13.7 3.30.0
7b 7.4 1.5 20.2% 0.0 5.90.0
7c 48.5 11.5 23.7% 26.4 10.6 0.0
7d 26.0 5.6 21.5% 8.7 12.1 0.0
7e 18.8 1.5 8.1% 4.6 12.7 0.0
7f 6.6 0.2 3.1% 0.0 6.40.0
8a 70.8 10.5 14.9% 60.1 0.20.0
8b 107.3 11.0 10.3% 42.2 54.1 0.0
8c61.910.216.4%42.49.40.0
8d 8.0 2.1 26.6% 3.7 2.10.0
8e 2.7 0.6 21.4% 0.0 2.10.0
8f 31.9 6.0 18.7% 22.3 3.60.0
8g 13.9 2.1 15.0% 0.4 11.5 0.0
8h 5.7 1.2 21.4% 0.0 4.50.0
8i 50.6 3.6 7.1% 0.0 47.1 0.0
8j 18.4 3.6 19.7% 14.8 0.00.0
8k 32.6 2.1 6.5% 30.2 0.00.3
9a 46.4 0.0 0.0% 0.0 5.540.9
9b 137.7 23.5 17.1% 102.6 11.6 0.0
9c 30.5 5.6 18.3% 22.7 2.20.0
9d 39.0 9.4 24.2% 25.6 4.00.0
9e 13.8 3.2 23.1% 3.5 7.10.0
9f 108.8 16.1 14.8% 46.4 44.8 1.5
9g 26.2 7.2 27.6% 8.0 11.0 0.0
553-2836-004 3-5
Stormwater Management Plan
City of Port Townsend
Table 3-2. Existing Land Use Model Inputs (continued)
Pervious (ac.)
Total Area Impervious Percent Hydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.)ImperviousType A -Forest Type C - Forest Type D - Forest
9h 39.9 6.6 16.6% 33.3 0.00.0
9i 25.1 8.3 32.9% 0.0 16.9 0.0
9j99.69.59.5%90.20.00.0
9k 15.9 6.3 39.2% 9.5 0.20.0
9l 49.3 9.0 18.2% 19.8 20.5 0.0
9m17.113.377.9%3.50.30.0
10a 103.9 11.5 11.0% 91.5 1.00.0
10b 23.5 4.6 19.7% 9.2 9.70.0
10c 51.0 6.1 12.0% 44.9 0.00.0
10d 21.4 2.3 10.7% 19.1 0.00.0
11a 72.1 9.6 13.3% 62.4 0.00.0
11b 76.7 8.6 11.2% 68.1 0.00.0
11c 28.8 2.9 10.0% 25.9 0.00.0
11d 3.7 1.1 30.6% 2.6 0.00.0
11e 26.7 6.0 22.3% 20.6 0.20.0
11f 33.6 13.7 40.9% 19.6 0.30.0
12a 86.6 15.5 17.9% 68.4 2.70.0
12b 20.1 6.1 30.3% 14.0 0.00.0
12c 26.9 8.1 30.0% 18.8 0.00.0
12d 30.8 6.0 19.5% 24.8 0.00.0
1 1
12e13.5 15.2112.7%-1.72 0.00.0
12f 112.2 17.5 15.6% 90.7 4.10.0
12g 14.3 5.5 38.6% 3.7 5.20.0
13a 44.8 9.3 20.7% 35.5 0.00.0
13b 51.9 8.1 15.5% 43.9 0.00.0
13c 18.8 6.0 32.0% 12.5 0.30.0
14.00 193.6 12.2 6.3% 161.7 19.7 0.0
15a131.73.22.4%102.425.30.8
15b 24.6 2.8 11.2% 15.3 6.60.0
15c 24.0 2.6 10.7% 12.5 9.00.0
16a 42.9 8.6 20.0% 34.3 0.00.0
16b 62.7 4.0 6.4% 58.7 0.00.0
16c 7.5 2.4 32.1% 5.1 0.00.0
17a 53.7 6.8 12.7% 46.9 0.00.0
17b 46.4 5.6 12.0% 40.8 0.00.0
18a 141.6 2.6 1.8% 119.8 19.2 0.0
18b 84.6 1.6 1.9% 83.0 0.00.0
1
The approach used to calculate existing impervious area resulted in an area larger than the basin. These numbers were adjusted to show the maximum area
possible.
3-6 553-2836-004
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Stormwater Management Plan
City of Port Townsend
3.1.2 Future Land Use and Land Cover
Existing land use, as described above, is used in runoff models to evaluate existing drainage conditions
and needs and identify areas with potential stormwater impacts. Future land use, mainly in the form of
new impervious surfaces and converted land cover, is used to predict future potential runoff impacts.
Future potential impact areas are the focus of the SMP.
The unopened rights-of-way and the “developable land” categories are where the potential runoff
changes will occur. For planning purposes, potential land conversion estimates are made for full build-
out to predict where impacts could occur which then point to the need for measures to minimize or
manage those impacts.
For unopened rights-of-way, the total potential conversion of land area is estimated to be 40 percent
impervious, following the assumption used for existing opened rights-of-way in Section 3.1.1. Some of
the unopened rights-of-way are located adjacent to public and conservation lands and may never be
opened, resulting in an over-estimation of future imperviousness, thus the modeling results can be
considered conservative.
For vacant land, public and conservation lands are expected to remain pervious and undeveloped.
Underdeveloped and remaining developable lands are assumed to be developed to their full, allowable
potential. The estimated future fully developed impervious percentage is 37 percent, which was
provided by City staff to use in runoff modeling. This is a typical approach in stormwater planning,
although it has been found to overpredict actual development that occurs.
Larger tracts that will construct new roads within new rights-of-way use an estimate of 37 percent
future impervious (which is the same percent used for future developable land), while existing
unopened rights-of-way will use 40 percent imperviousness. The 3 percent difference is small and is not
expected to result in significantly different modeling outcomes.
Land cover conversion will assume that the remaining uncovered pervious lands will be “pasture” (which
includes lawns and non-forested open spaces; this is a modeling convention term) and or remain in part
forest. The land cover is visually estimated from recent aerial photos. For the model it will be assumed
that 50 percent of the forest in developable land will convert to pasture, and that pasture will remain
pasture.
The potential development and conversion to impervious surfaces described here are used to model
and predict the highest potential for future impacts to the natural drainage ways, drainage systems, and
existing wetlands. However, the reality is that runoff would be controlled to some extent at each site,
with full control following the stormwater manual at larger sites and to the maximum extent practicable
at small sites or individual platted lots. The amount of control or runoff reduction is catchment-specific,
considering soils conditions and developable tract types. In the modeling results, if the potential for
future impacts is found or exceeds thresholds, a closer catchment-specific analysis and adjustment may
be made if the conservative assumptions (developable and underdeveloped lands developed to their
full, allowable potential with no stormwater controls) result in an impact. Catchments that still could
have impacts after these adjustments are applied may become candidates for regional control facilities.
Existing Land Use is shown on Figure 9. Vacant lands and development potential are shown in Figure 10.
Soils mapping and potential for good infiltration conditions are shown in Figure 7. Using this
information, the estimates for future conditions for full buildout for the MGSFlood model are shown in
Table 3-3.
553-2836-004 3-9
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Q:\\Facilities\\Storm\\MasterPlan2017\\Figures\\09-Land-Use.mxd 3/4/2019
Q:\\Facilities\\Storm\\MasterPlan2017\\Figures\\10-Vacant-Lands-Development-Potential.mxd 3/4/2019
Stormwater Management Plan
City of Port Townsend
Table 3-3. Future Land Use Model Inputs
Pervious (ac.)
Total Area Impervious PercentHydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.) Impervious Type A - Forest Type C - Forest Type D - Forest
1 12.8 0.1 7.6% 10.6 1.2 0.0
2 62.7 27.7 44.2% 23.8 11.2 0.0
3 19.1 0.00 0.1% 19.0 0.0 0.0
4a 46.5 0.1 0.3% 2.1 2.1 42.2
4b80.30.11.2%66.211.71.4
4c 122.4 30.7 25.1% 42.2 46.9 2.6
4d 47.4 0.2 0.5% 16.3 21.1 8.9
4e 26.7 8.9 33.3% 13.7 2.8 1.4
4f 83.7 35.8 42.8% 26.2 21.2 0.5
4g 107.6 41.6 38.7% 19.1 46.9 0.0
4h 46.4 6.3 13.7% 29.1 10.1 0.0
4i 114.2 36.5 31.9% 62.4 15.4 0.0
4j 38.0 14.4 37.7% 7.0 16.7 0.0
4k 129.9 48.1 37.0% 71.6 10.2 0.00
4l 314.8 106.8 33.9% 190.2 0.0 17.9
4m 38.4 15.3 39.8% 9.5 13.6 0.0
5a 85.7 31.5 36.8% 19.5 34.7 0.0
5b 54.8 20.2 36.8% 8.6 26.0 0.0
5c 36.9 9.9 26.8% 16.3 7.1 2.8
5d 61.4 21.1 35.8% 15.6 23.9 0.0
6a 80.4 35.1 44.7% 22.6 21.9 0.0
6b 14.6 6.4 44.1% 3.8 4.4 0.0
6c 5.8 2.4 40.5% 0.0 3.5 0.0
7a 19.6 7.6 38.9% 9.6 2.3 0.0
7b 7.4 4.2 57.1% 0.0 3.2 0.0
7c 48.5 23.2 47.9% 18.0 7.3 0.0
7d 26.0 11.5 44.4% 5.8 8.6 0.0
7e 18.8 7.7 42.3% 2.9 8.0 0.0
7f 6.6 2.3 34.3% 0.0 4.3 0.0
8a 70.8 31.4 44.3% 39.3 0.2 0.0
8b 107.3 32.1 29.9% 32.1 42.3 0.0
8c 61.9 27.5 44.4% 28.2 6.3 0.0
8d 8.0 3.8 47.4% 2.7 1.5 0.0
8e 2.7 1.3 49.7% 0.0 1.4 0.0
8f 31.9 14.4 45.0% 15.1 2.5 0.0
3-13 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 3-3. Future Land Use Model Inputs (continued)
Pervious (ac.)
Total Area Impervious PercentHydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.) Impervious Type A - Forest Type C - Forest Type D - Forest
8g 13.9 5.8 41.5% 0.3 7.9 0.0
8h 5.7 3.2 56.2% 0.0 2.5 0.0
8i 50.6 20.5 40.5% 0.0 30.1 0.0
8j 18.4 8.8 47.7% 9.6 0.0 0.0
8k 32.6 10.5 32.1% 21.9 0.0 0.2
9a 46.4 1.9 4.1% 0.0 5.3 39.2
9b 137.7 61.6 44.8% 68.3 7.7 0.0
9c 30.5 13.6 44.5% 15.5 1.5 0.0
9d 39.0 18.8 48.3% 17.5 2.7 0.0
9e 13.8 5.3 38.6% 2.8 5.7 0.0
9f 108.8 41.2 37.9% 33.9 32.7 1.1
9g 26.2 7.2 27.7% 7.1 10.1 0.0
9h 39.9 18.7 46.8% 21.2 0.0 0.0
9i 25.1 14.9 59.2% 0.0 10.2 0.0
9j 99.6 36.1 36.2% 63.6 0.0 0.0
9k 15.9 10.9 68.7% 4.9 0.1 0.0
9l 49.3 21.2 43.0% 13.8 14.3 0.0
9m 17.1 17.0 99.5% 0.1 0.0 0.0
10a 103.9 37.3 35.9% 65.9 0.7 0.0
10b 23.5 10.5 44.6% 6.3 6.7 0.0
10c 51.0 23.9 46.8% 27.2 0.0 0.0
10d 21.4 8.2 38.4% 13.2 0.0 0.0
11a 72.1 31.4 43.6% 40.6 0.0 0.0
11b 76.7 27.8 36.2% 48.9 0.0 0.0
11c 28.8 9.4 32.7% 19.4 0.0 0.0
11d 3.7 1.2 30.7% 2.6 0.0 0.0
11e 26.7 11.5 42.9% 15.2 0.2 0.0
11f33.6 23.4 69.7% 10.1 0.2 0.0
12a 86.6 34.9 40.3% 49.7 1.1 0.0
12b 20.1 10.9 54.1% 9.2 0.0 0.0
12c 26.9 13.5 50.3% 13.3 0.0 0.0
12d 30.8 11.1 38.8% 18.8 0.0 0.0
12e 13.5 13.5 100.0% 0.0 0.0 0.0
12f112.2 42.5 37.9% 66.7 3.0 0.0
12g 14.3 9.9 69.1% 1.8 2.6 0.0
13a 44.8 22.2 49.5% 22.7 0.0 0.0
13b 51.9 19.1 36.8% 32.8 0.0 0.0
3-14 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 3-3. Future Land Use Model Inputs (continued)
Pervious (ac.)
Total Area Impervious PercentHydrologic Soil Hydrologic Soil Hydrologic Soil
Catchment (ac.) (ac.) Impervious Type A - Forest Type C - Forest Type D - Forest
13c 18.8 9.9 52.6% 8.7 0.2 0.0
14.00 193.6 23.6 12.2% 151.5 18.5 0.0
15a 131.7 40.3 30.6% 72.8 17.1 0.6
15b 24.6 10.1 40.9% 10.2 4.4 0.0
15c 24.0 8.7 36.2% 8.9 6.4 0.0
16a 42.9 20.3 47.1% 22.7 0.0 0.0
16b 62.7 22.1 35.2% 40.6 0.0 0.0
16c 7.5 4.6 61.2% 2.9 0.0 0.0
17a 53.7 24.1 44.9% 29.6 0.0 0.0
17b 46.4 18.0 38.9% 28.3 0.0 0.0
18a 141.6 47.7 33.7% 80.9 13.0 0.0
18b 84.6 28.1 33.2% 56.5 0.0 0.0
3.1.3 Estimating Runoff Potential
As described in previous sections, the City has: low rainfall depth and intensity when compared to
elsewhere in western Washington, areas of relatively low runoff soils and land cover, and small
catchments with poorly defined natural drainage paths. These factors converge to result in a relatively
narrow range of peak flow rates, which often means that similar drainage infrastructure is needed in
many different locations. Modeling the entire system would be costly; a generalized modeling approach
can address much of the City’s system need. To define this need and confirm the expectation that
similar runoff results can be found across the city, some generalized runoff modeling was performed.
The land cover conversion analysis results, previously described in this section, are input into the
hydrologic model to find future peak runoff potential from the basin. The location at which this peak
flow rate occurs is described as “key locations” in the drainage system. In some catchments, the peak
flow rate is the entire runoff potential from the catchment, with no specific geographic location. An
example would be in Catchment 1, which has runoff that generally flows toward the Strait of Juan de
Fuca and discharges at multiple points. In the catchments where there is a defined location at which all
of the runoff is directed, a “node” is defined as the specific location of the calculated peak flow rate, as
shown on Figure 11. Table 3-4 lists the catchment area name, total catchment area in acres, percentage
of existing and future impervious area, and distribution of land cover.
Existing and future peak runoff for the 2-, 10-, 25-, and 100-year events were determined at the
catchment nodes shown on Figure 11 (unless there is no node, which means that the peak runoff rate is
total runoff potential from the entire basin). These modeling results will be used to define potentially
impacted areas. The future peak flows for the 25-year event will be used to assess drainage conveyance
needs in the roadway system, notably where the road drainage becomes the main flow path in the
basin. The 25-year peak flows will be used to assess potential impacts from future development to CDCs
and KDs as defined in Section 4. A comparison between existing (Table 3-5a) and future (Table 3-5b)
conditions for selected events (2-, 10-, 25-, and 100-year storm events) is also used to assess wetland
receiving waters, notably in Basins 4 through 9. The peak runoff modeling results for Existing and Future
Conditions are shown in Tables 3-5a and Table 3-5b, respectively.
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Q:\\Facilities\\Storm\\MasterPlan2017\\Figures\\11-Catchment-Nodes.mxd 3/4/2019
Stormwater Management Plan
City of Port Townsend
Table 3-4. Buildable Area – Impervious Comparison
Existing Impervious (ac.) Future Impervious (ac.)
Total Area Buildable Total Impervious BuildableTotal Impervious
Catchment (ac.) ROW Area Percent ROWArea Percent
1 12.8 0.0 0.0 0.0%1.0 0.0 7.6%
2 62.7 13.7 5.6 30.7% 15.8 20.0 57.2%
3 19.1 0.0 0.0 0.1%0.0 0.0 0.1%
4a 46.5 0.0 0.0 0.0%0.1 0.0 0.3%
4b80.30.10.30.5%0.20.91.3%
4c 122.4 15.0 7.8 18.7% 16.7 18.6 28.9%
4d 47.4 0.1 0.1 0.4%0.1 0.1 0.5%
4e 26.7 4.6 1.6 23.2% 5.0 6.4 42.7%
4f 83.7 8.5 6.1 17.4% 9.6 30.4 47.7%
4g 107.6 17.5 5.7 21.5% 25.7 25.3 47.3%
4h 46.4 2.8 0.3 6.6%4.5 3.7 17.7%
4i 114.2 7.2 2.6 8.6% 18.6 22.3 35.8%
4j 38.0 2.3 0.6 7.8%2.4 13.0 40.7%
4k 129.9 13.9 1.7 12.0% 24.9 31.3 43.2%
4l 314.8 22.9 5.6 9.1% 45.8 74.4 38.2%
4m 38.4 3.7 1.3 12.9% 7.2 10.3 45.4%
5a 85.7 1.5 0.3 2.1%7.2 25.2 37.7%
5b 54.8 2.6 2.8 9.9%3.4 17.9 38.8%
5c 36.9 3.1 1.4 12.1% 5.5 6.1 31.5%
5d 61.4 1.8 0.4 3.6%9.1 13.8 37.3%
6a 80.4 18.4 6.3 30.6% 21.3 25.5 58.1%
6b 14.6 3.6 1.2 32.8% 4.2 4.7 60.8%
6c 5.8 0.9 0.5 23.2% 1.4 1.4 48.9%
7a 19.6 3.4 1.1 23.2% 4.4 5.2 49.2%
7b 7.4 0.0 1.1 15.5% 0.0 3.9 52.4%
7c 48.5 16.5 4.6 43.4% 17.8 15.0 67.6%
7d 26.0 7.1 2.5 36.6% 7.5 8.0 59.6%
7e 18.8 1.4 1.0 12.8% 1.6 7.2 47.0%
7f 6.6 0.1 0.2 4.2% 0.1 2.2 35.4%
8a 70.8 13.7 4.4 25.6% 15.4 23.6 55.0%
8b 107.3 14.2 5.9 18.7% 16.0 25.1 38.3%
8c 61.9 12.3 4.2 26.6% 14.9 18.9 54.6%
8d 8.0 3.4 0.5 48.0% 3.5 2.0 68.8%
8e 2.7 0.6 0.3 35.8% 0.6 1.1 64.1%
8f 31.9 9.6 2.6 38.3% 11.4 9.2 64.6%
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City of Port Townsend
Table 3-4. Buildable Area – Impervious Comparison (continued)
Existing Impervious (ac.) Future Impervious (ac.)
Total Area Buildable Total Impervious BuildableTotal Impervious
Catchment (ac.) ROW Area Percent ROWArea Percent
8g 13.9 3.1 1.1 29.9% 3.5 4.4 56.5%
8h 5.7 0.3 1.1 25.2% 0.4 3.1 60.0%
8i 50.6 4.7 1.4 12.2% 8.1 15.0 45.7%
8j 18.4 4.3 1.3 30.0% 5.1 5.6 58.0%
8k 32.6 2.8 1.0 11.9% 5.0 7.3 37.5%
9a 46.4 0.0 0.0 0.0%1.9 0.0 4.1%
9b 137.7 34.6 10.3 32.6% 41.1 41.9 60.3%
9c 30.5 8.6 2.5 36.2% 10.1 9.0 62.3%
9d 39.0 13.6 3.8 44.6% 14.0 12.8 68.7%
9e 13.8 5.8 0.7 47.0% 6.4 2.3 62.5%
9f 108.8 24.2 7.6 29.2% 32.0 24.9 52.3%
9g 26.2 0.4 6.7 27.2% 0.4 6.7 27.2%
9h 39.9 7.4 2.8 25.7% 7.6 14.6 55.8%
9i 25.1 7.2 5.9 52.5% 8.2 11.6 78.9%
9j 99.6 16.3 2.1 18.5% 19.3 25.7 45.2%
9k 15.9 3.3 4.9 51.4% 3.8 9.1 80.8%
9l 49.3 16.4 2.7 38.8% 18.0 13.3 63.6%
9m 17.1 7.0 10.1 99.9% 7.1 13.7 121.5%
10a 103.9 24.7 2.5 26.2% 28.1 25.0 51.1%
10b 23.5 3.9 3.1 29.8% 4.2 8.7 54.8%
10c 51.0 2.2 2.3 8.9%2.8 19.5 43.6%
10d 21.4 5.2 0.2 25.3% 5.5 5.8 52.9%
11a 72.1 2.0 8.1 14.1% 7.3 24.6 44.4%
11b 76.7 17.8 1.8 25.6% 20.7 18.1 50.6%
11c 28.8 5.5 0.0 19.0% 6.4 5.6 41.7%
11d 3.7 0.0 1.1 30.6% 0.0 1.1 30.7%
11e 26.7 4.4 3.8 30.8% 5.8 7.9 51.3%
11f33.6 6.3 11.2 52.2% 7.4 19.8 81.0%
12a 86.6 32.9 4.3 42.9% 34.5 22.0 65.3%
12b 20.1 4.3 4.7 44.8% 5.0 8.8 68.5%
12c 26.9 10.9 4.1 55.9% 11.2 9.2 76.2%
12d 30.8 13.0 1.4 46.9% 13.2 7.2 66.2%
1
12e13.5 3.6 13.5 100.0% 3.8 16.6 151.6%
12f112.2 38.6 1.5 35.7% 38.9 26.2 58.0%
12g 14.3 2.0 4.3 44.5% 2.1 8.7 74.9%
13a 44.8 5.4 5.5 24.3% 5.9 17.9 53.0%
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Table 3-4. Buildable Area – Impervious Comparison (continued)
Existing Impervious (ac.) Future Impervious (ac.)
Total Area Buildable Total Impervious BuildableTotal Impervious
Catchment (ac.) ROW Area Percent ROWArea Percent
13b 51.9 15.9 0.9 32.5% 16.4 11.5 53.8%
13c 18.8 0.6 5.9 34.7% 2.2 8.2 55.4%
14.00 193.6 10.3 0.9 5.8% 12.5 10.0 11.7%
15a 131.7 5.1 0.3 4.1% 9.5 33.1 32.3%
15b 24.6 4.0 0.2 17.1% 4.6 7.0 46.8%
15c 24.0 1.3 1.6 12.4% 1.5 7.6 37.9%
16a 42.9 6.7 4.6 26.3% 9.5 13.4 53.4%
16b 62.7 8.3 0.5 14.1% 10.6 16.2 42.9%
16c 7.5 1.6 2.1 48.8% 2.0 3.8 77.9%
17a 53.7 7.0 3.8 20.1% 9.3 18.7 52.2%
17b 46.4 5.8 2.6 18.0% 6.4 14.4 44.9%
18a 141.6 5.0 0.5 3.9% 6.7 43.9 35.7%
18b 84.6 2.9 0.0 3.4% 6.5 23.0 34.8%
1
Impervious area and impervious percent were changed to full basin area.
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City of Port Townsend
3.1.4 Catchments with Largest Increase Potential
The existing and future peak runoff determined in Table 3-5a and Table 3-5b above provide an indicator
of where the highest potential impacts could occur or where there are priorities for further evaluation
or improvements. Table 3-6 shows the peak 25-year runoff rates under existing and future conditions
and the percent change. The highest potential changes shown can provide a basis for prioritizing other
improvements that may be identified in Section 4.
Table 3-6. Potential Change in Peak Flows by Catchment Area
Existing Peak 25-year Future Peak 25-year Rank (highest
Catchment Number Flow (cfs) Flow (cfs) Percent Change change)
1 0.2 0.4 160% 10
2 3.9 7.3 84% 33
3 0.4 0.4 0% 82
4a 0.0 0.0 0% 83
4b 1.7 1.7 5% 77
4c 6.6 9.3 42% 72
4d 0.5 0.5 2% 79
4e 1.4 2.3 67% 52
4f 3.8 10.1 162% 8
4g 4.6 10.1 122% 13
4h 1.1 1.6 45% 69
4i3.5 7.4 111% 19
4j 0.7 0.8 3% 78
4k 4.6 8.7 88% 29
4l10.8 18.5 71% 46
4m 1.1 3.0 177% 6
5a 0.6 2.6 317% 2
5b 1.4 4.4 214% 4
5c 1.0 2.3 133% 12
5d 0.6 3.0 427% 1
6a 4.9 8.7 79% 42
6b 0.8 1.4 81% 39
6c 0.3 0.7 140% 11
7a 1.0 2.0 96% 25
7b 0.4 1.2 233% 3
7c 3.9 6.9 76% 44
7d 1.8 3.3 77% 43
7e 0.5 1.0 90% 27
7f 0.1 0.1 106% 22
8a 4.2 8.9 113% 18
8b 4.1 8.8 117% 15
8c 3.8 6.8 80% 40
8d 0.7 1.0 43% 70
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City of Port Townsend
Table 3-6. Potential Change in Peak Flows by Catchment Area (continued)
Existing Peak 25-year Future Peak 25-year Rank (highest
Catchment Number Flow (cfs) Flow (cfs) Percent Change change)
8e 0.2 0.3 59% 56
8f 2.2 4.2 93% 26
8g 0.7 1.4 118% 14
8h 0.4 0.5 31% 74
8i1.1 3.0 162% 9
8j 1.3 2.0 50% 62
8k1.22.067%51
9a 0.0 0.0 0% 84
9b 8.9 16.3 84% 36
9c 2.1 3.9 86% 32
9d 3.3 5.9 79% 41
9e 1.0 1.6 55% 60
9f 5.9 12.2 106% 21
9g 2.4 2.4 0% 81
9h 2.6 5.4 108% 20
9i2.6 4.4 67% 50
9j 4.5 8.2 84% 35
9k 2.1 3.4 63% 54
9l3.0 5.6 86% 31
9m 4.2 5.3 25% 75
10a 4.9 10.7 115% 16
10b1.6 2.8 76% 45
10c 2.6 7.8 206% 5
10d1.0 2.7 164% 7
11a 3.9 5.8 49% 65
11b3.8 8.1 115% 17
11c 1.3 2.4 82% 37
11d0.4 0.4 0% 80
11e2.23.248%66
11f4.5 6.3 40% 73
12a 5.9 11.0 87% 30
12b 2.1 3.5 67% 49
12c 2.7 4.4 59% 57
12d2.2 3.7 65% 53
12e 2.1 3.3 56% 59
12f6.8 12.9 89% 28
12g1.8 3.0 68% 48
13a 3.4 6.8 103% 23
13b3.2 5.8 84% 34
13c 2.0 3.0 50% 64
14 7.3 8.6 18% 76
15a 3.1 5.0 61% 55
15b1.1 1.7 59% 58
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Table 3-6. Potential Change in Peak Flows by Catchment Area (continued)
Existing Peak 25-year Future Peak 25-year Rank (highest
Catchment Number Flow (cfs) Flow (cfs) Percent Change change)
15c 1.0 1.5 50% 63
16a 3.2 4.9 55% 61
16b2.5 5.0 99% 24
16c 0.8 1.4 70% 47
17a 2.9 4.2 47% 67
17b2.3 4.2 81% 38
18a3.55.147%68
18b2.3 3.3 42% 71
3.2 Stormwater System Operation and Maintenance
Proper operation and maintenance of the stormwater system is necessary to prolong life and
effectiveness of the system as well as reduce the potential for flooding and improve water quality. There
are several sources and guidelines as well as direct experience used to develop the City’s stormwater
practices.
Ecology provides guidance on best management
practices (BMPs) for municipal operations in the
Stormwater Management Manual for Western
Washington (SWMMWW). This manual was developed
in response to federal requirements and tailored to
conditions in the Pacific Northwest.
Below are the recommended BMPs from the SWMMWW the City of Port Townsend uses for guidance
for stormwater system maintenance.
Maintenance of Public and Private Utility Corridors and Facilities
Maintenance of Roadside Ditches
Maintenance of Stormwater Drainage and Treatment Systems
Spills of Oil and Hazardous Substances
Urban Streets
Recommendations for Management of Street Wastes.
The operation and maintenance of the stormwater system is funded by a stormwater utility fund and
includes 3.55 full time equivalents (FTEs) distributed amongst several employees. This number is likely to
increase as the stormwater system is extended or enhanced, increasing the need for maintenance.
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Maintenance of the stormwater system includes:
Cleaning, repairing and replacing ditches, swales, and storm drains;
Cleaning and maintaining catch basins;
Filter inspection and cleaning;
Street sweeping to improve water quality;
Maintaining stormwater ponds and infiltration galleries;
Vegetation control;
Repairing roadways damaged by stormwater;
Checking for illicit discharges to the stormwater system;
Stormwater utility locates; and
Emergency response.
The City owns and operates the equipment necessary for most stormwater system maintenance such as
vacuum truck for removing debris from catch basins, a street sweeper, dump trucks, various heavy
equipment and related tools and implements.
The City of Port Townsend has developed a process over the years to identify, track and schedule
stormwater system operation and maintenance activities. Listed below are current elements and
activities.
3.2.1 Asset Identification
Most all stormwater system assets have been identified or are in the process of being identified and
mapped and are available electronically and summarized in Table 3-7. Mapping includes the location of
catch basins, culverts, detention ponds, biofiltration swales, infiltration trenches, drain pipe, rain
gardens, compost filters and roadside ditches. Roadside areas that do not have adequate drainage are
also noted. Data can be accessed electronically with a computer or device or available in printed map
sets. Streets, roadways, trails and open space are all considered part of the stormwater system.
3.2.2 Level of Service
The level of service is measured by frequency and labor requirements as suggested by Department of
Ecology guidelines and is listed in Table 3-8 for the City of Port Townsend.
3.2.3 Reporting
Most all work is issued via work order and reported and coded to the utility on timesheets. Summary
reports can be generated from work orders and timesheets to update the level and cost of service.
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Table 3-7. Existing Inventory of Public Facilities
Facility Type Quantity Measurement Unit
Streets Swept
Street Swept 30 Miles
Total All Roads 94Miles
Catch Basins 1,468 Each
Maintenance Holes 114 Each
Infiltration Trenches/Perforated Pipes0.9Miles
Solid Pipes 25 Miles
Swales 4.1 Miles
Detention Ponds/Retention7Each
Culverts 3,183 Linear Feet (LF)
Storm Filters 7 Each
Stormwater Pump Facilities 2 Each
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Table 3-8. Maintenance Frequency and Personnel
Facility TypeFrequency Level of Effort
Street Sweeping
Downtown 52 times/year 1 Maintenance Worker, 1 Sweeper
Arterials12 times/year 1 Maintenance Worker, 1 Sweeper
Catch Basin
Cleaning 1 time/year 2 Maintenance Workers, 1 Vactor, 1 truck
3 Maintenance Workers1 Backhoe,
Repair/Replace 1 time/3o years
1 Dumptruck, 1 truck Traffic Control
Maintenance Holes
Cleaning 1 time/year 2 Maintenance Workers, 1 Vactor, 1 truck
3 Maintenance Workers1 Backhoe,
Repair/Replace 1 time/30 years
1 Dumptruck, 1 truck Traffic Control
Infiltration Trenches
Cleaning 1 time/year 2 Maintenance Workers, 1 Vactor, 1 truck
Repair/Replace 1 time/15 years 3 Maintenance Workers,
1 Backhoe, 1 Dumptruck, 1 truck Traffic Control
Pipes
Flushing/Vactor 1 time/3 years 2 Maintenance Workers, 1 Vactor, 1 truck
Repair 1time/50 years 3 Maintenance Workers
1 Backhoe, 1 Dump truck, 1 truck Traffic Control
Swales
Vegetation/Cleaning 4 time/year 2 Maintenance Workers, 1 Vactor, 1 truck
Repair/Replace 1 time/10 years 3 Maintenance Workers, 1 Backhoe, 1 Dumptruck
Detention Ponds/Retention
Control Structure
Cleaning 1 time/year 2 Maintenance Workers, 1 Vactor, 1 truck
3 Maintenance Workers,
Repair/Replace 1 time/30 years
1 Backhoe, 1 Dump truck, 1 truck
Pond
Cleaning/Vegetation 3 times/year 1 Maintenance Worker, 1 Weed Whip
Remove Sediment 1 time/5 years 3 Maintenance Workers,
1 Backhoe, 1 Dump truck, 1 truck
Ditches
Vegetation Control 3 times/year 2 Maintenance Workers, 1 Mower
Clean, Reshape, Remove
1 time/5 years 4 Maintenance Workers, 1 Backhoe, 2 Dump trucks
Sediment
Culverts
Clean 1 time/3 years 2 Maintenance Workers, 1 Vactor, 1 truck
Clean Inlets2 times per year 2 Maintenance Workers, 1 truck
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4. BASIN PLANNING
4.1 Planning Objectives
Stormwater planning needs and objectives were discussed with City staff and the task force during early
phases of the project. Technical assessments of the physical setting and watersheds were made, as
described in Section 2. Section 3 describes existing conditions and development potential. This section
describes the findings and recommended approaches to addressing existing and potential impacts to the
drainage and natural systems, based on the analysis in Chapter 3.
The following sections describe the systems and needs for which approaches have been developed to
maintain, protect, control, and upgrade natural and built stormwater systems, including:
Assessing drainage connectivity and providing for protection of the natural and built drainage
system;
Identifying potential impacts to drainage systems, natural drainage courses, and wetlands, and
techniques for reducing impact from future development (i.e., using LID to the maximum
practicable extent);
Defining future road drainage guidelines;
Identifying potential future impacts to the natural drainage system; and
Identifying roadway water quality improvements in the right-of-way.
4.2 Drainage Connectivity
The City has been divided into 19 drainage basins, originally delineated using the boundaries in the 1987
Plan, and updated based on better topographic information, the roadside drainage network, and the
drainage flow path in existing pipes and swales (Figure 12). Each of the numbered basins has a final
disposition or discharge to a receiving water or location, except basin 17, which drains to basin 9.
Figure 2 shows the numbered basins and their disposition and Table 4-1 lists the basin number and the
discharge point. Several basins directly runoff or are conveyed via storm sewers to the Salish Sea
without entering natural drainage paths or wetlands. Two receiving waters, Kah Tai Lagoon and Chinese
Gardens, also discharge to the Salish Sea.
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City of Port Townsend
Table 4-1. Basins and Disposition or Discharge Point
1
Receiving Water or Discharge Point Basin Number Note
Sheet flow or storm sewer, often via multiple
Salish Sea, direct 1, 2, 3, 10, 12, 13, 14
discharge points
Ravines, unnamed channel 11, 16 Flows to points outside of city limits
Chinese Gardens4
Kah Tai Lagoon 9 Basin 17 flows through Basin 9 to Kah Tai
Lagoon
2
Here is no surface water outlet from these
Closed wetland or groundwater 5, 6, 7, 8, 19
basins to the ocean
Jefferson County 15, 17, 18 Ultimate disposition was not determined
1
Receiving Water—a named or known “water of the state” or the Salish Sea.
2
Basin 5 can connect to Basin 4 if the water level rises high enough. There is no record of it doing so.
4.2.1 Drainage System Hierarchy
A key objective of the Plan is to define, provide, and protect a connected and well-defined built and
natural drainage system. One challenge of doing so in Port Townsend is the almost complete lack of
natural drainage systems such as streams and rivers. Without obvious natural watercourses and with
the extensive land pre-platting that has occurred, the flow paths to collect and carry stormwater to the
ocean are not well-structured and, in many cases, have no outlet to the ocean. Special measures are
needed to define and protect the built and natural drainage system. Consequently, a hierarchy to define
the drainage network was developed to describe its components and provide measures for protecting,
controlling, or improving a segment in a way that is consistent with its position in the network and
hierarchy. The recommended protection measures may include new or modified ordinances and
standards identifying mitigation or protection measures outlined in development guidance materials.
A system with four “levels” to define the drainage network was developed (Figure 13). Like a stream
ordering system, the highest level provides the backbone or trunk of the system (the highest order in
the hierarchy), while each subsequent level typically drains to the next higher numbered level in the
system. For Port Townsend, the levels are defined as follows:
Level 1 Receiving Locations – Level 1 are the terminus for each basin and includes all natural waters
(usually named), “waters of the state” or “waters of the United States”. Level 1 are the “Receiving
Waters” and includes the Salish Sea (Strait of Juan de Fuca, Admiralty Inlet, and Port Townsend Bay);
Chinese Gardens; Kah Tai Lagoon; named wetlands in Basins 5, 6, 7, and 8 (Blue Heron, 35th Street Park,
Froggy Bottoms, Glasbell, and Hastings Pond); the basin 5 terminus to groundwater; and the Quimper
Wildlife Corridor (as defined by the 100-year floodplain (see Figure 4). The extent or limits of a Level 1
water is the ordinary high-water line.
Level 2 Natural Drainage – Level 2 includes natural, piped, or planned main connectors to the Level 1
receiving locations for stormwater. They are the branches that connect to the trunk, often natural paths,
delivering runoff to Level 1 waters. Generally, they are located at the lowest point of the basins, or along
a main road in the basin. All Level 2 waters drain to or connect with Level 1 waters. The Level 2 Natural
Drainage hierarchy is divided into two types: Level 2a CDCs and Level 2b KDs. CDCs are protected
through the City’s CAO. The KDs are regulated through the Stormwater Plan and the City’s Engineering
Design Standards. They are both important connecting features of the City’s stormwater drainage
network (see Figure 13).
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Stormwater Management Plan
City of Port Townsend
Level 2a and 2b routes were determined for this Plan by following the apparent center line of flow paths
using the topographic map of the city and connecting to Level 1 waters. In some instances, the Level 2a
CDCs cross built areas or roads; the CDC is considered continuous. The Level 2b KDs can follow a
constructed drainage path, usually a road drainage system, for part of its path.
Level 2a CDCs – Level 2a areas are defined in the City’s Critical Area Ordinance and includes natural low
areas and depressions in the landscape, often linear, and are characterized as a year-round or
intermittent naturally flowing watercourse which exhibits but is not limited to one or more of the
following characteristics:
a. A stream or watercourse formed by nature or modified by humans;
b. Generally consisting of a defined channel with a bed for a substantial portion of its length on the lot;
and
c. Perched ponds, ravines or other natural drainage features.
All CDCs (Level 2a drainage) are continuous and unbroken from its starting point downstream to its
connection with a Level 1 water. To provide network continuity for the purposes of this SMP, a CDC or
Level 2a water is considered continuous over and through wetlands that are encountered.
Level 2b KDs – Level 2b areas includes natural low areas and depressions in the landscape, to where
water would flow if enough runoff was generated by a storm, but moving water is not routinely seen or
has not been observed. In some instances, the Level 2b is a constructed drainage feature, for example a
road drainage system, for part of its path. Level 2b waters generally drain to or connect with Level 1
receiving locations.
Level 3 Connecting Drainage Paths and Infrastructure – Level 3 includes flow paths that connect the
built environment with the Level 1 waters or Level 2a and 2b drainageways. They provide continuity and
connectivity for drainage created by the roadways and land development to the natural topographic
flow paths. Level 3 drainage tends to be local and relatively short segments that include formal
(man-made ditches and storm sewers) and informal (poorly defined) flow paths and channels. Level 3
segments are not depicted on a figure, as they are ongoing and newly defined elements of the mapped
drainage system when identified and described. Level 3 segments can be defined by the city at any time
when a detailed drainage analysis or review is made for new development. The long-term objective of
defining and identifying Level 3 segments is for the city to gain control via easement or right-of-way to
allow for protection, improvement, operation and maintenance of those segments. The Level 3
connectors may need to be constructed by new developments, through off-site mitigation, where no
connection between a Level 2 or Level 4 exists.
Level 4a and 4b Constructed Drainage System – Level 4 includes the constructed drainage systems in
the road rights-of-way. Level 4 represents the constructed drainage infrastructure that follows the
roadway system and is either well-defined by ditches, swales, curbs, storm sewers and culverts or less
well-defined roadside drainage. Level 4 has been divided into Level 4a and 4b; Level 4a represents a
defined network of key constructed drainage pathways along major roads (e.g., arterials and collectors)
and Level 4b represent the rest of the road network (e.g., local access and neighborhood roads) where
the roadway drainage may be poorly defined or non-existent. Level 4 roadway drainage provides the
primary disposition for site drainage for development. Level 4 should connect to a higher Level for
disposition to a receiving water.
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City of Port Townsend
4.2.2 Drainage System Connectivity
The 19 basins were additionally broken down into catchment areas as shown on Figure 11. These areas
were defined by topography and the configuration and disposition of the drainage system as currently
understood and mapped. The CDCs and KDs (Levels 2a and 2b) provide a foundation for the network of
natural drainage patterns defined by topography and provide connectivity to Level 1 receiving waters.
The built drainage is almost completely located within the roadway network (Level 4). The network
shown in the hierarchy system shows connectivity, but it does not indicate the size, capacity, or
performance of the drainage system. To do so would require intensive data collection and modelling
which is outside the scope of this analysis and is not needed to provide guidance to inform the planning
effort.
Figures 8 and 13 show the catchment areas and associated KDs. The location of the peak flow rate in
each drainage path is indicated at the downstream end where it discharges into a different catchment.
4.2.3 Drainage System Protection
The purpose of the drainage system definition and connectivity system described above was to provide
a framework for analysis, protection, planning, and operations. Higher level systems (e.g., Level 1 and 2)
may need greater protection; lower level systems (e.g., Level 3 and 4) need more improvements and
maintenance. The following is general outline of key drainage resources needing protection and an
approach to evaluating those protections.
Level 1 Receiving Waters
Protection:
Most or all Level 1 receiving waters have protections through the Shoreline Management Plan, critical
areas ordinances, and floodplain management.
Guidelines:
Ordinance and Code should have language to protect the conveyance, flood control, water quality, and
hydrologic aspects of the resource (Port Townsend Municipal Code \[PTMC\] 19.05).
Provide measures for mitigating and providing the conveyance, flood control, and water quality aspects
of Level 1 at road crossings in unopened rights-of-way
Evaluation and Improvements:
Review protection guidelines
Prepare guidance for providing conveyance, flood control, and water quality mitigation measures when
impacts to Level 1 resource cannot be avoided.
Level 2 Natural Drainage via Critical Drainage Corridors or Key Drainageways
Protection:
Critical Drainage Corridors are protected by the critical areas ordinance.
Key Drainageways are defined and regulated by stormwater standards.
Guidelines:
CDC Ordinance and Code should have language to protect the conveyance, flood control, water quality,
and hydrologic aspects of the resource (PTMC 19.05).
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City of Port Townsend
KD should identify and protect the conveyance, flood control, water quality, and hydrologic aspects of
the resource, and provide measures to quantify and mitigate unavoidable impacts. Key Drainageways
may be modified by development provided the functionality is maintained.
Evaluation and Improvements:
Review and update KD maps as needed.
Provide definition, standards and review guidelines; prepare process for evaluating modifications; and
prepare standards for mitigating unavoidable impacts to Level 2 resources; and prepare guidance for
providing the conveyance and water quality aspects of Level 2 resources.
Level 3 Connecting Drainage
Protection:
Level 3 drainage connections should be identified and protected through easements, fee purchase, or
other related permission to maintain and protect drainage connectivity.
Guidelines:
Create requirement and approach to identify Level 3 connections during the development review
process.
Identify and catalogue Level 3 connections for prioritization and protection.
Evaluation and Improvements:
Review and update Level 3 connections maps or list as needed.
Prioritize Level 3 connections for protection.
Level 4 Constructed Drainage System
Protection:
Level 4 drainage is included in rights-of-way; no further ownership or regulation is needed.
Standards for right-of-way use are needed.
Guidelines:
Create or update right-of-way use permits.
Use sizing guidelines prepared in Section 4 for pipe size, ditch size, and minimum drainage
requirements.
Prepare Level 4b development requirements and funding strategy.
Prepare development review and fees for Level 4b program.
Evaluation and Improvements:
Inventory pipe and ditch deficiencies in Level 4a.
Prioritize Level 4a upgrade or repair needs.
Prioritize Level 4b upgrade and repair needs.
Prepare a strategy for regular improvements in Level 4a and 4b.
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4.2.4 Evaluating Potential Capacity Needs and Impacts
In Section 3, basin characteristics were identified to estimate existing and future runoff in the basins.
Tables 3-5a (existing peak runoff) and 3-5b (future peak runoff) show the results of the modeling. The
analysis is used to determine two planning needs: where are there expected impacts due to existing and
future development and what pipe and ditch capacity is needed for roadway drainage. Details of runoff
modeling and conveyance capacity analysis are presented in Appendix D. The impact analysis and
drainage capacity were evaluated by modeling the catchment areas for the existing and future
(uncontrolled) runoff (see Tables 3-5a and 3-5b). The peak flows shown occur at the catchment area
nodes shown on Figure 11. Use of these data for drainage capacity and impact analysis are described in
the following sections.
4.2.4.1 Drainage Capacity
Drainage capacity refers to the size and configuration of the conveyance ways and drainage systems for
conveying stormwater to receiving waters, including the Level 1, 2, and 4 drainage paths. Modeling the
entire city drainage system would be a very costly task and is rarely done in smaller cities. Modeling the
Level 1 and Level 2a and 2b (CDCs and KD) for drainage capacity has limited utility as the corridors are
very large relative to the flows, although an impact analysis is important and described below in Section
4.2.5. In lieu of modeling all of the Level 4 drainage paths and systems, a generalized runoff and capacity
analysis was completed to provide information on pipe sizing under normal conditions. The results are
not expected to vary greatly from one location in the City to another due the low rainfall, similar
roadside conditions, and relatively insensitivity of standard pipe sizing to small flow differences.
The approach taken to evaluating drainage capacity is to consider the typical “long path” of drainage
within a catchment basin and use that as a basis for the peak flows expected in any drainage system in
the catchment. The peak runoff from the catchment was determined for different design storms, with
the understanding that the runoff from the entire catchment would always be greater than or equal to
the runoff from the longest drainage segment in the drainage area. Table 3-5b shows the peak runoff for
future uncontrolled runoff generated by a catchment.
To evaluate drainage needs, standard pipe slopes and roadside ditch configurations were considered.
The minimum pipe size allowed by current City Code (Engineering Design Standards) is 12-inches. The
standard roadside ditch has a bottom width between 2- and 8-feet with 3:1 slide slopes. Table 4-2a
shows the capacity of the standard minimum allowable pipes per slope percentage. Figure 14a is a
graphic representation of Table 4-2a, or “look-up table” which is used to select a pipe size when the
peak flow and slope are known. To use Figure 14a, enter the x-axis with the conveyance or existing ditch
slope and move vertically to the intercept with the peak design flow. The region of this intercept
indicates the pipe size needed. Table 4-2b shows the capacity of different ditch widths per slope
percentage. Figure 14b is a “look-up table” for ditch width and is used the same way as Figure 14a.
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Table 4-2a. Pipe Capacity for Reaches of Different Slopes
1
Slope (percent) Capacity of 12" Pipe (cfs) Capacity of 18" Pipe (cfs)
0-25.0 14.9
2-47.1 21.0
4-68.7 25.7
6-810.1 29.7
8-10 11.3 33.2
1
This value is the minimum capacity of the standard required drainage conveyance systems
50
45
>18"pipe size required
40
35
30
25
18" pipe size required
20
Flow (cfs)
15
10
5
12" pipe size required
0
0246810
Slope (%)
Capacity of 12" Pipe (cfs)Capacity of 18" Pipe (cfs)
Figure 14a. Pipe Capacity “Look Up Table”
Table 4-2b. Ditch Capacity for Reaches of Different Slopes
1
Capacity of 4-foot ditch Capacity of 6-foot ditch Capacity of 8-foot ditch
Slope
Capacity of 2-foot Ditch
(cfs) (cfs) (cfs)
(percent)
(cfs)
0-2 1.8 3.2 4.7 6.1
2-4 2.5 4.6 6.6 8.7
4-6 3.1 5.6 8.1 10.6
6-8 3.6 6.4 9.3 12.3
8-10 4.0 7.2 10.4 13.7
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40
35
>8' ditch needed, further
30
evaluation needed
25
8' ditch required
20
Flow (cfs)
15
6' ditch required
10
4' ditch required
5
2' ditch required
0
0246810
Slope (%)
Capacity of 2' Ditch (cfs)Capacity of 4' Ditch (cfs)
Capacity of 6' Ditch (cfs)Capacity of 8' Ditch (cfs)
Figure 14b. Ditch Capacity “Look up Table”
4.2.4.2 Standard Drainage System Sizing
When designing or improving drainage in the roadway system, such as the Level 4 drainage system, the
peak expected flow rate and channel slope are needed to design the pipe or ditch sizes needed. The City
has standard minimum sizes for pipes (12-inch) and ditches (2-foot bottom), therefore many of
roadways will use the minimum conveyance sizes. The drainage system capacity should include future
conditions, which are not always known by persons proposing pipes in the right-of-way or the City when
improvements are needed.
Table 4-3 shows the 25-year peak flows expected in all catchments under future uncontrolled
conditions. This would be the largest peak flow expected at any location in the catchment except for
reaches that pass through the catchment that have accumulated upstream flows (Figure 15). A reach is
the primary path in which runoff is collected and conveyed in a catchment to the next downstream
catchment and reach. The flow rate in a reach with an upstream catchment is higher than the flows
generated by the catchment alone. Therefore, if the largest design peak flow in a catchment is smaller
than the minimum allowable pipe or ditch capacity, no additional calculations need to be made to size
conveyance systems in the roadside channels. The rows noted in Table 4-3 indicated by “Yes” means
that the maximum expected stormwater flow in the catchment can be handled by the minimum sizes,
and therefore no further evaluation of potential capacity is needed. The slope used for each catchment
is estimated from available topographic mapping provided by the City at the locations shown on
Figure 15. Note that the 2-foot ditch width fails in a majority of catchments. It is recommended that the
2-foot minimum ditch no longer be used unless site or project-specific calculations are made to
demonstrate that it provides adequate capacity.
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Table 4-3. Catchment Area Peak flows and Maximum Required Drainage Conveyance
Pass Pass Pass Pass
Catchment Estimated Future 25-year Pass Criteria
Criteria for Criteria for Criteria for Criteria for
Node Slope (ft/ft) Peak Flow (cfs) for 2' Ditch
12" Pipe 4' Ditch 6' Ditch 8' Ditch
14.0%0.4YesYesYesYesYes
2 4.4% 7.3 Yes No No Yes Yes
3 4.0% 0.4 Yes Yes Yes Yes Yes
4a4a is a wetland
4b 4.0% 1.7 Yes Yes Yes Yes Yes
4c 2.9% 9.3 No No No No No
4d4.0%0.5YesYesYesYesYes
4e 2.3% 2.3 Yes Yes Yes Yes Yes
4f 2.5% 10.1 No No No No No
4g 2.0% 10.1 No No No No No
4h 5.3% 1.6 Yes Yes Yes Yes Yes
4i 1.7% 7.4 No No No No No
4j 2.0% 0.8 Yes Yes Yes Yes Yes
4k 1.5% 8.7 No No No No No
4l 3.6% 18.5 No No No No No
4m 9.0% 3.0 Yes Yes Yes Yes Yes
5a 2.1% 2.6 Yes No Yes Yes Yes
5b 1.0% 4.4 Yes No No Yes Yes
5c 2.0% 2.3 Yes Yes Yes Yes Yes
5d 6.7% 3.0 Yes Yes Yes Yes Yes
6a 2.0% 8.7 No No No No Yes
6b 1.3% 1.4 Yes Yes Yes Yes Yes
6c 1.2% 0.7 Yes Yes Yes Yes Yes
7a 1.3% 2.0 Yes No Yes Yes Yes
7b 3.3% 1.2 Yes Yes Yes Yes Yes
7c 1.7% 6.9 No No No No No
7d 4.8% 3.3 Yes No Yes Yes Yes
7e 1.7% 1.0 Yes Yes Yes Yes Yes
7f 1.0% 0.1 Yes Yes Yes Yes Yes
8a 2.8% 8.9 No No No No No
8b 4.4% 8.8 Yes No No No Yes
8c 4.3% 6.8 Yes No No Yes Yes
8d 6.9% 1.0 Yes Yes Yes Yes Yes
8e 3.3% 0.3 Yes Yes Yes Yes Yes
8f 6.2% 4.2 Yes No Yes Yes Yes
8g 4.0% 1.4 Yes Yes Yes Yes Yes
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Table 4-3. Catchment Area Peak flows and Maximum Required Drainage Conveyance (continued)
Pass Pass Pass Pass
Catchment Estimated Future 25-year Pass Criteria
Criteria for Criteria for Criteria for Criteria for
Node Slope (ft/ft) Peak Flow (cfs) for 2' Ditch
12" Pipe 4' Ditch 6' Ditch 8' Ditch
8h 0.5 Yes Yes Yes Yes Yes
4.0%
8i 1.8% 3.0 Yes No Yes Yes Yes
8j 0.4% 2.0 Yes No Yes Yes Yes
8k 2.0 Yes No Yes Yes Yes
1.0%
9a 9a is a wetland
9b 2.1% 16.3 No No No No No
9c 3.9 Yes No Yes Yes Yes
4.8%
9d 5.2% 5.9 Yes No No Yes Yes
9e 4.5% 1.6 Yes Yes Yes Yes Yes
9f 12.2 No No No No No
0.7%
9g 6.7% 2.4 Yes Yes Yes Yes Yes
9h 2.0% 5.4 Yes No No Yes Yes
9i 4.4 Yes No Yes Yes Yes
2.4%
9j 1.5% 8.2 No No No No No
9k 1.4% 3.4 Yes No No Yes Yes
9l 5.6 Yes No No Yes Yes
2.4%
9m 4.7% 5.3 Yes No Yes Yes Yes
10a 5.4% 10.7 No No No No No
10b 2.8 Yes No Yes Yes Yes
3.3%
10c 0.8% 7.8 No No No No No
10d 1.3% 2.7 Yes No Yes Yes Yes
11a 5.8 No No No No Yes
0.7%
11b2.2%8.1NoNoNoNoYes
11c 1.3% 2.4 Yes No Yes Yes Yes
11d 0.4 Yes Yes Yes Yes Yes
1.3%
11e 1.0% 3.2 Yes No No Yes Yes
11f7.3% 6.3 Yes No Yes Yes Yes
12a 11.0 No No No No No
3.4%
12b 0.2% 3.5 Yes No No Yes Yes
12c 3.4% 4.4 Yes No Yes Yes Yes
12d 3.7 Yes No Yes Yes Yes
7.0%
12e 1.4% 3.3 Yes No No Yes Yes
12f3.9% 12.9 No No No No No
12g 3.0 Yes Yes Yes Yes Yes
8.0%
13a 7.5% 6.8 Yes No No Yes Yes
13b 8.9% 5.8 Yes No Yes Yes Yes
13c 3.0 Yes Yes Yes Yes Yes
4.0%
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Table 4-3. Catchment Area Peak flows and Maximum Required Drainage Conveyance (continued)
Pass Pass Pass Pass
Catchment Estimated Future 25-year Pass Criteria
Criteria for Criteria for Criteria for Criteria for
Node Slope (ft/ft) Peak Flow (cfs) for 2' Ditch
12" Pipe 4' Ditch 6' Ditch 8' Ditch
14 8.6 No No No No Yes
3.3%
15a 4.7% 5.0 Yes No Yes Yes Yes
15b 4.7% 1.7 Yes Yes Yes Yes Yes
15c 1.5 Yes Yes Yes Yes Yes
0.9%
16a 0.1% 4.9 Yes No No No Yes
16b 1.7% 5.0 No No No No Yes
16c 1.4 Yes Yes Yes Yes Yes
2.5%
17a 6.3% 4.2 Yes No Yes Yes Yes
17b 3.0% 4.2 Yes No Yes Yes Yes
18a 5.1 Yes No No Yes Yes
3.4%
18b 4.1% 3.3 Yes No Yes Yes Yes
4.2.4.3 Drainage System Sizing for Non-Standard Catchments
Table 4-4 lists the catchment areas where the 25-year peak flow in the catchment exceeds the minimum
pipe or ditch size capacity (catchments with “no” in Table 4-3) and may require a larger culvert or ditch
section for drainage in the catchment. The required screening-level pipe or ditch size is shown. It should
be noted that the longest path of drainage for this analysis may not include all of the drainage from the
catchment, and the peak flows are actually lower. When applying the screening-level data to a specific
catchment or drainage path, Table 4-3 should be reviewed to determine if pipe up-sizing is needed.
Figure 14a or 14b can be used if reduced peak flows are known. Generally, if the proportion of the
catchment actually draining to the pipe or ditch location is known, the peak flows shown in Table 4-3
can be adjusted by that proportion. In catchments that exceed the maximum ditch width of 8 feet, the
ditch should be piped using the size shown.
In addition, the peak flows shown are for uncontrolled future runoff. In reality, individual sites will be
infiltrating runoff to the maximum practical extent and larger developments will control flows, so the
actual accumulated peak flows will be lower. The approach to on-site controls to the maximum
practicable extent is shown in Appendix F. Site and project-specific analysis can be used for sizing;
however, future conditions should be applied and the same modeling assumptions used.
Table 4-4. Drainage Facility Size Estimates for Drainage Paths Exceeding Minimum Conveyance Sizing
Future 25-year Peak Pass Criteria for 12" Pipe or 2’ Predicted Pipe Size Minimum Ditch bottom
Catchment
Flow (cfs) Ditch? (in) Size
2 7.3 No 6.4
4c 9.3 No 15 10.2
4f 10.1 No 15 12.0
4g 10.1 No 18 13.4
4i 7.4 No 15 10.6
4k 8.7 No 18 13.4
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Table 4-4. Drainage Facility Size Estimates for Drainage Paths Exceeding Minimum Conveyance Sizing
(continued)
Future 25-year Peak Pass Criteria for 12" Pipe or 2’ Predicted Pipe Size Minimum Ditch bottom
Catchment
Flow (cfs) Ditch? (in) Size
4l 18.5 No 18 18.5
5a 2.6 No 3.1
5b 4.4 No 8.1
6a 8.7 No 15 11.5
7a 2.0 No 3.0
7c 6.9 No 15 9.9
7d 3.3 No 2.5
8a 8.9 No 15 9.9
8b 8.8 No 7.7
8c 6.8 No 6.0
8f 4.2 No 2.8
8i 3.0 No 3.9
8j 2.0 No 5.7
8k 2.0 No 3.5
9b 16.3 No 18 21.3
9c 3.9 No 3.0
9d 5.9 No 4.6
9f 12.2 No 24 27.7
9h 5.4 No 7.0
9i 4.4 No 5.1
9j 8.2 No 15 12.6
9k 3.4 No 5.2
9l 5.6 No 6.6
9m 5.3 No 4.3
10a 10.7 No 15 8.5
10b 2.8 No 2.6
10c 7.8 No 18 16.5
10d 2.7 No 4.2
11a 5.8 No 15 13.0
11b 8.1 No 15 10.2
11c 2.4 No 3.7
11e 3.2 No 5.8
11f6.3 No 6.2
12a 11.0 No 15 11.2
12b 3.5 No 14.7
12c 4.4 No 4.2
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Table 4-4. Drainage Facility Size Estimates for Drainage Paths Exceeding Minimum Conveyance Sizing
(continued)
Future 25-year Peak Pass Criteria for 12" Pipe or 2’ Predicted Pipe Size Minimum Ditch bottom
Catchment
Flow (cfs) Ditch? (in) Size
12d 3.7 No 2.3
12e 3.3 No 5.0
12f12.9 No 15 12.3
13a 6.8 No 4.4
13b 5.8 No 3.4
14 8.6 No 15 8.8
15a 5.0 No 4.1
16a 4.9 No 29.5
16b 5.0 No 15 7.0
17a 4.2 No 2.8
17b 4.2 No 4.3
18a 5.1 No 5.0
18b 3.3 No 2.7
4.2.4.4 Drainage System Sizing for Basin Reaches
Most of the 19 basins in the plan are defined around a principal drainage course that can convey
stormwater runoff to the receiving waters. The drainage reaches, defined and named for the catchment
in which they convey stormwater, are connected together and convey stormwater, adding the
cumulative flows from upstream of the catchment nodes (see Figure 11). Figure 15 shows the drainage
path for connected reaches.
Table 4-5 lists the peak flows at node points (see Figure 11) at the downstream end of the reach in the
catchment for which it is named and the catchments contributing runoff to these nodes. This
information is used for sizing culverts that are placed in the longer, connected reaches (usually CDCs and
KDs), such as at road crossings, or for storm drains and roadside ditches in the road drainage system
that conveys area-wide runoff. It should be noted that the culvert sizes shown are for uncontrolled
future development flow and that actual flows in the future may be lower. Also, the flow rates can be
used to size different types of structures.
Table 4-5. Peak Flows in Reaches for Structure Sizing
Estimated Required
Catchments Future 25-year Predicted
Reach/Node Slope Channel Width
Contributing to Node Peak Flow (cfs) Pipe Size (in)
(ft/ft) (ft)
4k 4k 7.4% 8.7 12 <1.0
4l 4k, 4l 3.6% 27.2 24 2.8
4i 4k, 4l, 4i 1.7% 34.6 30 6.8
4h 4k, 4l, 4i, 4h 5.3% 36.2 24 3.3
4j 4k, 4l, 4i, 4h, 4j 2.0% 37.0 30 6.7
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Table 4-5. Peak Flows in Reaches for Structure Sizing (continued)
Estimated Required
Catchments Future 25-year Predicted
Reach/Node Slope Channel Width
Contributing to Node Peak Flow (cfs) Pipe Size (in)
(ft/ft) (ft)
4g4k, 4l, 4i, 4h, 4j, 4g 2.0% 47.1 30 8.9
4f 4f 0.5% 10.1 24 2.8
4e 4e, 4f 2.5% 12.4 18 <1.0
5c 5c 3.3% 2.3 12 <1.0
5d 5c, 5d 6.7% 5.3 12 <1.0
5a 5c, 5d, 5a 2.1% 7.9 15 <1.0
7e7a, 7c, 7e, 7d1.7%13.118<1.0
8b 8b 4.2% 8.8 15 <1.0
8c 8c 1.0% 6.8 18 <1.0
8i 8i 3.0% 3.0 12 <1.0
9b 9j, 9h, 9b 2.1% 29.9 24 4.9
9c 9j, 9h, 9b, 9c 4.1% 33.7 24 3.6
9e 9l, 9e 4.1% 7.3 12 <1.0
11a 11a 0.7% 5.8 18 <1.0
11c 11a, 11c 1.3% 8.2 18 <1.0
11b 11a, 11c, 11b 2.2% 16.3 24 1.7
11e 11a, 11c, 11b, 11e 1.0% 19.5 24 4.5
11f 11f 7.3% 6.3 12 <1.0
16a 16a 7.0% 4.9 12 <1.0
16b 16b 1.5% 5.3 15 <1.0
This analysis was also used to evaluate the largest potential threats to the roadway drainage system that
carries area-wide runoff. For reaches in catchments with long segments in the built system, additional
analysis was prepared to determine where future runoff would exceed the minimum ditch and pipe
thresholds (Figure 16). Segments where the ditch or pipe size would increase are shown in Table 4-6
Table 4-6. Peak flows in Reaches for Long-Path Conveyance Sizing
Predicted
Catchments Estimated Future 25-year Predicted
Node Ditch Size
Contributing to Node Slope (ft/ft) Peak Flow (cfs) Pipe Size (in)
(ft)
9h 9h2.0% 5.4 15 <1.0
9b 9h, 9b 2.1% 21.624 3.1
8a/ 9l 9h, 9b, 8a, 9l 2.8% 36.224 5.2
8f 9h, 9b, 8a, 9l, 8f 6.2% 40.424 3.5
10a 10a 5.4% 10.715 <1.0
9k 10a, 9k 1.4% 14 24 2.0
10c 10a, 9k, 10c 1.4% 21.824 4.2
10d10a, 9k, 10c, 10d 1.4% 24.524 4.9
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The greatest threats to the overall drainage system can be predicted by finding the node points with the
greatest peak flow change that could occur with full development. Table 4-7 shows the greatest percent
change in peak flows at the key node points. Table 4-5 can be used for sizing future drainage structures
at full build-out.
Table 4-7. Peak Flow Increase at Key Nodes due to future Development
Catchments Estimated Existing Percent
Future 25-year
Node Contributing to Slope 25 year change
Peak Flow (cfs)
Node (ft/ft) (cfs)
4k 4k 7.4% 3.8 8.7 56%
4l 4k, 4l 3.6% 15.4 27.2 43%
4i4k, 4l, 4i1.7%19.034.645%
4h 4k, 4l, 4i, 4h 5.3% 20.1 36.2 44%
4j 4k, 4l, 4i, 4h, 4j 2.0% 20.8 37.0 44%
4g 4k, 4l, 4i, 4h, 4j, 4g 2.0% 25.4 47.1 46%
4f 4f 0.5% 3.8 10.1 62%
4e 4e, 4f 2.5% 5.2 12.4 58%
5c 5c 3.3% 1.0 2.3 57%
5d 5c, 5d 6.7% 1.5 5.3 72%
5a 5c, 5d, 5a 2.1% 2.2 7.8 72%
7e 7a, 7c, 7e, 7d 1.7% 7.3 13.1 44%
8b 8b 4.2% 4.1 8.8 53%
8c 8c 1.0% 3.8 6.8 44%
8i 8i 3.0% 1.1 3.0 63%
9b 9j, 9h, 9b 2.1% 15.9 29.9 47%
9c 9j, 9h, 9b, 9c 4.1% 18.0 33.7 47%
9e9l, 9e4.1%4.17.344%
11a 11a 0.7% 3.9 5.8 33%
11c 11a, 11c 1.3% 5.2 8.2 37%
11b 11a, 11c, 11b 2.2% 8.9 16.3 45%
11e 11a, 11c, 11b, 11e 1.0% 11.1 19.5 43%
11f 11f 7.3% 4.5 6.3 29%
16a 16a 7.0% 3.2 4.9 35%
16b 16b 1.5% 2.5 5.3 53%
4.2.5 Drainageway Potential Impact Assessment
Because there are no streams or typical natural drainageways in the City, it is difficult to use metrics
commonly used for evaluating potential impacts such as flow-frequency increases or stream hydrology
changes (i.e., pulse counts and duration, flashiness indices). The existing natural drainage system,
represented in the City by Levels 1, 2a (CDCs) and 2b (KDs) were evaluated to determine if future
physical impacts to the natural drainage system could be expected due to anticipated growth and build-
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out.The metric chosen for screening CDCs and KDs is based on the potential for exceeding channel
erosion thresholds that could cause the natural earthen channels found in the CDCs and KDs to erode
(USDA 2007). If future uncontrolled peak flows exceed the velocity threshold for the 25-year peak flow,
those affected CDCs and KDs are included in the Section 6 implementation plan as needing additional
hydrologic evaluation (i.e., peak flows may be lower due to stormwater controls or they nearly meet the
25-year threshold) or are threatened by future development and may require additional basin controls.
For the analysis, a typical standard CDC or KD channel section was defined (10-foot bottom, 3:1 side
slopes, 1-foot flow depth as shown in Appendix D) and reach-specific slopes were used. Channel reaches
that exceed the selected velocity threshold of 3.75 feet/second at the respective flow return frequency
are shown in Table 4-8 and Figure 17. The detailed channel conveyance and erosion analysis is provided
in Appendix D. The reaches not shown on the table but included in Figure 17 all pass the threshold
value.
Table 4-8. CDC and KD Velocity Thresholds
Estimated Estimated Estimated
Velocity for Velocity for Estimated Velocity for
Catchments Estimated Future 25-
10-year 25-year Velocity for100-year
Reach Contributing to Slope year Peak
Storm Storm 50-year Storm Storm
Reach (ft/ft) Flow (cfs)
Event Event Event (ft/sec) Event
(ft/sec) (ft/sec) (ft/sec)
4l 4k, 4l 5.2% 27.2 4.21 4.47 4.59 4.74
4i 4k, 4l, 4i1.2% 34.6 2.80 2.96 2.74 3.13
4h 4k, 4l, 4i, 4h 36.2 2.84 3.00 3.07 3.17
1.2%
4g 4k, 4l, 4i, 4h, 4j, 4g 6.5%47.1 5.50 5.79 5.93 6.11
5d 5c, 5d 7.8% 5.3 2.69 2.82 2.94 3.06
5a 5c, 5d, 5a 7.9 1.73 2.09 2.15 2.24
1.9%
5b 5c, 5d, 5a 1.6% 7.9 1.88 1.98 2.04 2.12
9c 9j, 9h, 9b, 9c 8.5% 39.4 5.47 5.65 5.76 5.97
11b 11a, 11c, 11b16.3 3.18 3.32 3.38 3.51
3.6%
11e 11a, 11c, 11b, 11e 5.2% 19.5 3.83 3.98 4.06 4.22
The reaches shown which exceed the 25-year 3.75 feet/second velocity threshold were further
examined for their location in the system and their actual potential threat. The Basin 4 reaches (4l and
4g) have fairly steep segments that account for the velocity failure. The change in runoff from
development is moderate (see Table 3-6) and there is extensive storage in wetlands throughout the
system. This is a lower priority for future analysis of additional stormwater controls or a regional system.
Reaches 9c and 11e have a higher potential for future impacts and are included in the implementation
plan as higher priority for additional analysis or regional controls. The remaining CDCs and KDs should
continue to be inspected and reviewed for observed impacts.
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4.2.6 Potential Impacts to Closed System Wetlands
Depending on their size and the relative size of the drainage area, wetlands may be sensitive to
impervious surface changes in the basin. The drainage basins with discharges to wetlands—Basins 4
through 9—were assessed for potential impacts from new development. The analysis approach was
based on the 2005 SWMMWW Appendix 1-D and is summarized in Appendix D. New impervious
surfaces increase runoff to wetlands, potentially affecting peak stages and stage duration that can
change the wetland. Wetlands with surface outlets are less likely to change, while closed wetlands with
no surface outlet are more susceptible to change.
For the wetland impact potential analysis, an impact level of 1-foot increase was used, and the area of
new impervious surface in the basin that would result in this change was determined. The results are
shown in Table 4-9. Basins 6 and 8 show that potential impacts from new basin development could
occur. The wetland (Froggy Bottoms) in Catchment 6a has an outlet, so the potential for impact is
lessened. The approach to further evaluating potential impacts or mitigation of impacts is to reduce
allowable new development in those areas, provide additional controls through infiltration potential,
increase the protection area around the wetland to allow it to increase in size, or provide for a high-level
overflow of the wetlands—as is available in the Basin 6 wetland. Figure 18 shows the potential increased
footprint for wetlands in basins 5, 6, 7, and 8 at full buildout with no development controls.
Table 4-9. Potentially Impacted Wetlands
Wetland Area Allowable Additional Estimated Future Impervious
Wetland Name
(ac.) Impervious Percent Percent Change
Wetland 4a 46.5 30 >30
Wetland 5b5.2 5 >70
Wetland 6a 1.3 3 >70
Wetland 7f 0.9 2 >40
Wetland 8b5.3 5 >40
Wetland 9a 46.4 37 >30
4.3 Drainage System Stormwater Improvements
The existing constructed drainage system is predominantly part of the road system, which collects and
conveys runoff from roadways and development to natural drainage areas and receiving waters.
Figure 15 shows the key drainage paths and Table 3-5 shows the estimated peak flow rates at catchment
node points (see Figure 11). In addition to drainage capacity, the roadway drainage system is also the
predominant location for existing incidental stormwater quality via runoff flowing through existing
grassy ditches or swales. As described in the previous section, modeling the entire drainage system for
capacity was not completed due to the relative homogeneity of the drainage areas and subsequent
runoff rates (see Table 3-5). Instead “typical” conveyance size for the design storm flow capacity was
defined and the findings can be applied to all drainage conveyance channels or ditches.
The prioritization for future implementation will be made by City staff based on known needs. For
example, the first priority is to upgrade roadside “ditches” to properly performing swales based on
conveyance needs and road condition. Often inadequate roadside drainage leads to premature road
failure. Level 4a roadways have not been assessed for existing capacity, which would be done by
applying the catchment flow results to each drainage reach. Generally, culverts must be a minimum of
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12-inches in all systems except Discovery Road, Sims Way, and Hastings Avenue or ditches lessthan the
sizes indicated would be considered deficient.
Water quality sizing and the typical water quality roadway ditch section is smaller than that needed for
the peak conveyance flow. Upgrades to meet the minimum conveyance capacity will address water
quality. Road improvements are usually required to retrofit for flow control and water quality; having
funding available to achieve this will be a key part of the implementation plan. If new storm sewers are
proposed or constructed in Level 4a or 4b road segments, water quality treatment for that roadway
segment will be required per the Manual, usually in the form of bioretention or modular treatment.
The Level 4b road system will also need upgrades, although their role is to provide local drainage to
other levels, not to provide regional drainage. Consequently, the maximum design flow rates are
expected to be smaller. The minimum pipe size is 12-inches, which can handle all likely peak flows from
the Level 4b roadways (see Table 4-3). The minimum standard ditch section for conveyance is also
approximately the same as the required biofiltration section for these flows, therefore treatment will be
provided.
4.4 Roadway Inventory for Upgrade Opportunities
The Level 4a roadways were inventoried to determine where space was available for future drainage or
water quality improvements could be made. The inventory includes information on right-of-way and
pavement width, sidewalks, curb and gutter or ditch, and existing swales. Additional information for
each roadway segment is included in Appendix E.
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5. CAPITAL PROJECTS PLAN
Capital projects are identified in basin plans to describe, estimate, and provide a basis for design of
proposed constructed facilities to address the stormwater needs identified in the plan. Most stormwater
capital project plans include:
Solutions for chronic, known flooding and drainage problems;
Typical concept designs and unit costs for improvements, such as roadway conveyance and
water quality retrofitting;
Regional or neighborhood stormwater management facilities to support existing and future
development;
Basin-specific stormwater retrofit projects to retroactively address stormwater impacts from
existing development;
Basin planning studies; and
Capital acquisition, such as land or equipment
Preliminary engineering is prepared for the constructed capital projects to develop planning-level cost
assumptions for programming and planning these projects. The implementation plan to prioritize and
schedule the capital projects is described in Section 6.
5.1 Proposed Capital Projects
A meeting between Parametrix and the City on June 20, 2017, revealed several known problem areas in
varied locations within the city limits. Five capital projects were identified by the City to be included in
the Plan, covering some of the typical categories listed above (Figure 19). Each problem area was visited
in the field on November 2, 2017 to collect data to aid in determining appropriate solutions. Preliminary
solutions were designed using information gathered in the field and in discussions with the City.
A brief description of the problem and proposed solution for each project is shown in Table 5-1. Project
plan sheets showing the preliminary design approach and planning-level costs are provided in Appendix G.
The total project costs are based on the conceptual plan layouts shown in Appendix G. Material
quantities, labor, mobilization costs (approximately 15 percent of subtotal), traffic control costs (a
minimum of 2 percent of the subtotal), and erosion and sedimentation control (a minimum of 2 percent
of the subtotal) were estimated. In addition, environmental permitting and documentation,
administration, and design and management costs have been considered. Lastly, a contingency factor of
30 percent has been added to the final cost.
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Table 5-1. Capital Projects
Estimated
Project No. and Title Cost Problem Description Proposed Solution
1 16th Street – $187,000 Site consists of an undeveloped right-of-Install a closed conveyance system along the
Sheridan Street to way. Stormwater from Sheridan Street, 17th Street Right-of-way between Gise
Landes Street 14th Street, and 16th Street is conveyed Street and Hill Street while maintaining
through a closed system to an outfall some flow in the 16th Street corridor.
located at 16th Street and Gise Street,
where severe erosion has occurred in
16th Street.
2 12th Street ROW, $614,000 Several flooding issues occur near the Construct roadside bioswales to convey
Logan Street, and wetland located at McPherson Street and drainage from between McPherson St and
14th Street the 12th Street right-of-way and at 14th Logan St to a new storm sewer pipe that will
and McPherson Streets. convey stormwater south along Thomas St
to an existing wetland. Runoff on 14th St
from Logan St to Rosecrans St will be
conveyed through proposed bioswales
directing runoff to an existing conveyance
system that discharges to a critical drainage
area on 16th St and Gise St. Additionally, an
existing swale from the 12th St ROW will be
connected to a proposed closed storm
system that will convey stormwater south to
an existing conveyance system before
discharge to a CDC.
3 Center Street – $432,000 There exists a low point (sump) condition Construct roadside drainage ditches and
San Juan Avenue along Center St between San Juan Ave culverts per a standard roadway section
to Olympic and Spruce St, along with a lack of well-with closed conveyance to a wetland located
Avenue developed roadside drainage south of Cedar Street.
infrastructure, which creates flooding
issues.
4 Hancock Street $188,000 Poor drainage exists along Hancock Street Construct bioswales per standard roadway
and in the intersection of Hancock Street
and 32nd Street section with a proposed culvert beneath
and 32nd Street. Ponding occurs in 32nd Street to convey drainage north and
roadway. Catch basin connected to west to a critical drainage area. Stormwater
sanitary sewer system exists, and City currently captured by an existing catch basin
tied existing sanitary system at 31st Street
intends to separate.
and Hancock Street to be conveyed west
along 31st Street to critical drainage area.
5 Lawrence Street $858,000 Storm sewer catch basins located on Construct new stormwater conveyance
at intersections of Lawrence Street at the intersections of system with trunk-line running north along
Polk Street, Taylor Polk Street, Taylor Street, and Tyler Street Lawrence Street with lateral pipes and catch
Street, and Tyler are currently directly connected to basins to collect stormwater on both sides
Street sanitary sewer system. City intends to of Lawrence Street. A downstream capacity
separate stormwater from sanitary sewer analysis is necessary to verify the
system. practicability of this approach.
6 Rainier Street
Regional
Underway in 2019
Stormwater
Project
7 Logan Street
Stormwater Pond Underway in 2019
Overflow
Total Cost $2,279,000
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5.2 Proposed Recurring Capital Projects
The plan has considered the potential need for drainage improvements in the Level 4a and 4b road
systems. Deficiencies and priorities in these systems will be developed by an on-going and regular
evaluation by City maintenance and engineering staff. Funds to make repairs are needed to address the
program developed by staff. A lump cost was identified; the funding is identified in Table 5-2.
Table 5-2. Other Built Capital Projects
Estimated
Cost total
Project Title over 6 years Distribution
1 Roadside $300,000 Allocate $300,000 every 6 years starting
Conveyance in 2021, to align with street upgrade
Improvements – projects.
Major Collectors
and Minor Arterials
(Level 4a)
2 Roadside $100,000 Allocate $100,000 every 6 years starting
Conveyance in 2022.
Improvements –
Local Access Streets
(level 4b)
Total Cost $400,000
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6. IMPLEMENTATION
The implementation plan summarizes specific plan actions, capital projects, policy needs, an
implementation schedule, and an itemized cost for each item. There are few outside drivers to plan
implementation, therefore it is likely to be executed as resources are applied or come available. Plan
costs for capital projects are estimated and a suggested annual cost for implementing recurring projects
and upgrades is provided. However, no final timeline is included for delivery of capital projects because
available funding stream information is still under evaluation and is not available.
6.1 Capital Plan Priorities and Schedule
Capital projects are identified in basin plans to address known flooding problems; capital improvements,
upgrades or repairs; new facilities, such as regional stormwater ponds or retrofitting projects; land
purchase and protection; and restoration or mitigation. The SWMP is primarily addressing flooding
problems and future projects to improve street drainage. Table 6-1 shows the relative ratings and
ranking for implementation priority.
6.1.1 Capital Projects for Existing Flood Control
The Capital Projects Plan includes 20 proposed capital projects. These projects include repair and
minimization of existing flooding problem areas; new regional facilities for retrofitting and new
development; and upgrades to existing facilities. The projects were ranked and prioritized according to
four categories:
Area benefitted—the number of parcels or land area served
Need/severity—the need for the solution or project to facilitate other work and the seriousness
of the problem
Cost—low or no cost or many benefits for cost
Opportunity—the project is ready to go, the land is owned by the City, and there are no
concerns or issues with implementation
Table 6-1. Capital Projects Rankings and Priority
Item Project Area Need or Opportunity or Rank
Number Number Project Name Benefitted Severity Cost/Benefit Constraints Total Rank
6.1.1 1 16th Street – Sheridan MED HIGH MED LOW 8 3
Street to Landes Street
6.1.2 2 12th Street ROW, LOW HIGH LOW LOW 6 7
Logan Street, and 14th
Street
6.1.3 3 Center Street – San MED LOW HIGH MED 8 3
Juan Avenue to
Olympic Avenue
6.1.4 4 Hancock Street and LOW MED MED MED 7 6
32nd Street
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Table 6-1. Capital Projects Rankings and Priority (continued)
Item Project Area Need or Opportunity or Rank
Number Number Project Name Benefitted Severity Cost/Benefit Constraints Total Rank
6.1.5 5 Lawrence Street at MED MED MED MED 8 3
intersections of Polk
Street, Taylor Street,
and Tyler Street
6.1.6 6 Rainier Street Regional HIGH MED HIGH MED 10 1
Stormwater Project
Logan Street
6.1.7 7 HIGH LOW MED HIGH 9 2
Stormwater Pond
Overflow
N/A means projects not ranked.
6.1.2 Non-Capital Recurring Projects
Non-capital recurring projects, in the context of this plan, means minor, local, ongoing improvements,
upgrades, repairs, and replacements of the drainage system. They are often completed as part of a
larger project or are identified by a complaint. In addition, it can include systematic improvements or
upgrades to a part of the system that has been neglected or is changing due to new development. An
example of this is the Level 4b roadway network.
The analyses prepared in Section 4 identified future drainage system need on 4a and 4b roadways, on
continuous reaches of roadway drainage, crossings for long drainage reaches, and potential impacts on
CDCs and KDs. The analysis identified threats and areas for additional study; specific needs and found
problem areas was outside the scope of this plan. However, planning for future needs based on the
identified deficiencies is included in this implementation plan.
Table 6-2. Summary of the Roadway Drainage Improvement Plan
Plan
Section Effort and Timeline
Item No.No.Action What it is Quantity Cost Priority
Future system Provide a fund to 3 drainage
6.1.8 4.2.4 Moderate Annual
upgrades in make roadway upgrades per year
Level 4a drainage that require new
improvements when pipes or
acute problems occur structures.
in the Level 4a system
6.1.9 4.2.4 Future system Provide a fund to 500 feet of ditch Moderate Annual
upgrades in make roadway drainage upgrades
Level 4b drainage per year and 500
improvements when feet of 12” pipe
acute problems occur per year.
in the Level 4a system
Future system Provide a plan and
6.1.10 4.2.3 1 Plan. Low Annual
upgrades in fund to make
Level 1-2 drainage
improvements when
acute problems occur
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Table 6-2. Summary of the Roadway Drainage Improvement Plan (continued)
Plan
Section Effort and Timeline
No. Cost Priority
Item No.Action What it is Quantity
6.1.11 4.2.4.4 Long-path road Review the structures One study Low Early and
drainage and ditch in the long-Moderate
upgrade analysis path drainage
systems. Prepare a
needs assessment and
add to Capital
Projects Plan
6.1.12 4.2.4.4 Long-path road Implement identified 1 drainage High Annual
drainage capital projects; up to upgrade per year starting in
upgrades 4 anticipated Year 5;
Moderate
CDC and KD Review the 4 CDCs or Early and
6.1.13 4.2.5 One study Low
impact KDs with potential Moderate
mitigation impacts. Identify
analysis actual threat and
prepare scenarios for
mitigation
6.1.14 4.2.5 CDC and KD Implement study One Plan High Year 3 and
impact results Low
mitigation
6.1.15 4.2.6 Closed Wetland Review the 4 One study Moderate Year 3 and
System impact wetlands with Moderate
and mitigation potential impacts.
analysis Identify actual threat
and prepare scenarios
for mitigation
6.1.16 4.2.6 Closed Wetland Implement study One Plan High Year 5 and
System impact results Low
mitigation
6.2 Stormwater Control Standards and Policies
Basin planning is used to assess existing and future threats to the City’s ability to provide a level of
service to the community to protect the resource, minimize flooding and drainage problems, and
maintain safety. The nature of most threats are new development that increases runoff; changes in flow
paths and capacity; and/or a degrading and failing existing system that is not properly maintained. This
section describes measures to protect the existing system from new development.
6.2.1 Stormwater Control from New Development
Runoff from new development is usually controlled by using a system to minimize runoff changes from a
site or by constructing stormwater controls that serve multiple sites, such as a subdivision or regional
stormwater facility. Most stormwater in western Washington in National Pollution Discharge Elimination
System (NPDES) Municipal Permit communities is controlled by following Ecology’s SWMMWW or an
approved equivalent manual, which applies to new development or significant redevelopment
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proposals. The City is using the 2005 SWMMWW(the City is not an NPDES community). A review
comparing the 2005 and 2014 SWMMWWs was made and the findings are shown in Appendix H. We
recommend that the City continue to use the 2005 SWMMWW for new development and
redevelopment that triggers review under the manual.
As described earlier, the City has areas with platted lots, often 5,000 square feet in size and rights-of-
way that are not developed. Proposed development or redevelopment of these lots may or may not
exceed SWMMWW thresholds for stormwater control. As described in the analysis in Section 4,
uncontrolled development of these areas does result in increased flows and can cause impacts. These
areas should control runoff to the maximum extent practicable (MEP). Policies and guidelines for
landowners with development projects that do not trigger SWMMWW thresholds are included in
Appendix F.
6.2.2 Drainage System Protection
Receiving waters (Level 1), Critical Drainage Corridors, and Key Drainageways (Level 2) were defined in
Section 4. These are areas that could be impacted by future uncontrolled stormwater or direct impacts
to their conveyance pathway. The following describes protection for Level 1 and 2 drainage, example
guidelines, and measures for protecting these resources.
Level 1 Receiving Waters
Protection:
Most or all Level 1 receiving waters have protections through critical areas ordinances
and floodplain management.
Guidelines:
Ordinance and Code should have language to protect the conveyance, flood control,
water quality, and hydrologic aspects of the resource.
Provide measures for mitigating and providing conveyance, flood control, and water
quality aspects of Level 1 at road crossings in unopened rights-of-way.
Evaluation and Improvements:
Review ordinances and protection guidelines
Prepare guidance for providing conveyance, flood control, and water quality measures
when Level 1 resource impacts cannot be avoided.
Level 2 Natural Drainage via Critical Drainage Corridors or Key Drainageways
Protection:
CDC are protected by the critical areas ordinance
Key Drainageways are defined and protected through the stormwater code Guidelines:
CDC Ordinance and Code should have language to protect the conveyance, flood
control, water quality, and hydrologic aspects of the resource.
KD should identify and protect the conveyance, flood control, water quality, and
hydrologic aspects of the resource and provide measures to quantify and protect or
mitigate unavoidable impacts.
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Evaluation and Improvements:
Review and update KD maps as needed.
Review and update the stormwater code to incorporate the regulatory framework for
protection and regulation of the KDs.
Review and update the Engineering Design Standards (EDS) to reflect guidelines in this
Plan.
Provide review ordinances guidelines.
Prepare process for evaluating modifications and standards for mitigating and providing
the conveyance, flood control, and water quality aspects of Level 2 at road crossings in
unopened rights-of-way
Level 3 drainage connections, as described in Section 4.1, also need identification and protection
measures, as described below.
Level 3 Connecting Drainage
Protection:
Level 3 drainage connections should be identified and protected through easements, fee
purchase, or other related permission to maintain and protect drainage connectivity
Guidelines:
Create requirement and approach to identify Level 3 connections during site plan review.
Identify and catalogue Level 3 connections for prioritization and protection
Evaluation and Improvements:
Prioritize Level 3 connections for protection.
Level 4 drainage, which is collection and conveyance in the existing (and future) road system, requires
standards for allowable modifications, crossing standards, conveyance sizing for new roads, and
guidance for defining and upgrading deficient systems. Measures for defining and protecting this
drainage level include:
Level 4 Constructed Drainage System
Protection:
Level 4 drainage is included in rights-of-way; no further ownership or regulation is
needed.
Standards for right-of-way use permits
Guidelines:
Update right-of-way use permits if needed.
Use sizing guidelines prepared in Section 4 for pipe size, ditch size, and minimum
drainage requirements.
Prepare Level 4b development requirements and funding strategy.
Prepare development review and fees for Level 4b program.
Review and update the EDS to reflect guidelines in this Plan.
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Evaluation and Improvements:
Inventory pipe and ditch deficiencies in Level 4a.
Prioritize Level 4a upgrade or repair needs.
Prioritize Level 4b upgrade and repair needs.
Prepare a strategy for regular improvements in Level 4a and 4b.
Table 6-3. Summary of Stormwater Control and Drainage Protection
Plan
Section Effort and Timeline
Item No. No. Action What it is Benefit Cost Priority
Guidance for Establish basin
6.2.1 4.2.3 Adopt basin plan Moderate Early and High
stormwater specific City
management, approaches and
policy, land use priorities.
recommendations,
and capital
projects.
6.2.2 Continue to use The stormwater In use and is None; existing N/A
2005 Ecology manual for new applicable and action
Manual development and appropriate to City
redevelopment system
6.2.3 Adopt guidance for Adopt “maximum Stormwater Low Early and High
individual lot extent controls will be
stormwater controls practicable” applied that are
stormwater commensurate with
controls focused MEP and address
on sites below the pre-platted lots
stormwater
manual threshold
6.2.4 4.2.3 Adopt drainage level A hierarchy to Streamline Moderate Early and High
designations as define the development
defined in the drainage network process
SWMP in codes and to provide for
standardsprotecting,
controlling, or
improving a
segment
6.2.5 4.2.3 Update codes and Align Level 2b Have a process for Moderate Early and High
standards to waters with the regulating Level 2b
implement stormwater plan (KDs)
protection measures recommendations
for Level 2b Key
Drainageways
6.2.6 4.2.3 Implement Level 3 system Connectivity will be Moderate Year 1 and
identification, connects the built maintained Moderate
protection system drainage
measures, and to the natural
prioritization for drainage system
Level 3 drainage
6.2.7 4.2.3 Implement Level 4 drainage Connectivity will be High Year 1 and
guidelines, permits, provides the built maintained, Moderate
inventory, system drainage drainage provided
prioritization, and for all development,
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Table 6-3. Summary of Stormwater Control and Drainage Protection (continued)
Plan
Section Effort and Timeline
No. Cost Priority
Item No. Action What it is Benefit
funding measures via the road a system for
for Level 4 drainage network upgrades is
provided
6.2.8 4.2.4 Adopt drainage An analysis of the Design calculations Low Early and High
capacity analysis general capacity and drainage needs
and design tools and drainage are standardized
sizing across the city;
requirements for sizing is consistent
roadway drainage for future buildout
6.2.3 Drainage System Review and Upgrades
The existing constructed drainage system is predominantly part of the road system, which collects and
conveys runoff from roadways and development to natural drainage areas and receiving waters.
Drainage capacity refers to the size and configuration of the conveyance ways and drainage systems for
conveying stormwater to receiving waters, including the Level 1, 2, and 4 drainage paths. The capacity of
the existing system was evaluated under future development conditions and the findings are provided in
Section 4. This section provides a summary of actions for continued evaluation and upgrades to the
system to repair existing deficiencies, inspect for ongoing problems, and prepare for future capacity.
Table 6-4. Summary of Drainage System Review and Upgrades
Plan
Section Effort and Timeline
Item No. No. Action What it is Benefit Cost Priority
6.2.10 4.2.4.4 Review capacity Analyses for the drainage Plan for upgrades Moderate Year 2 and
analysis in Table 4-5 network were evaluated. before flooding Moderate
and 4-6 for existing Deficiencies can be occurs now or in
system deficiencies documented. the future
6.2.11 4.2.4.4 Review capacity Analyses for future peak Plan for upgrades Moderate Year 4 and
analysis in Table 4-7 flows from future before flooding Moderate
for drainage nodes development were occurs now or in
with the greatest determined. The highest the future
potential for increase potential for future drainage
and future impacts needs can be seen
6.2.12 4.2.5 Prepare alternative Threats to the CDCs and KDs Plan for High Year 4 and
analysis for protecting from accumulated future protection and or Moderate
potential future drainage increase were avoidance before
impacts on CDCs and defined in Table 4.8. A plan flooding or
KDs from future to address alternatives is impacts occur.
development needed
6.2.13 4.2.5 Inspect CDCs and KDs Threats calculated are Avoiding severe Low Early and
for observable theoretical. Actual threats impacts will be Moderate
impacts could be observed and may more cost-
need earlier protection. A effective than
hierarchy to define the repairing them
drainage network to provide
for protecting, controlling,
or improving a segment
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Table 6-4. Summary of Drainage System Review and Upgrades (continued)
Plan
Section Effort and Timeline
No. Cost Priority
Item No. Action What it is Benefit
6.2.14 4.2.6 Prepare alternative Threats to some receiving Plan for High Year 4 and
analysis for protecting water wetlands from protection and or Moderate
potential future accumulated future avoidance before
impacts on wetlands drainage were defined in
flooding or
defined in Table 4-9 Table 4.9. A plan to address impacts occur.
alternatives is needed
Implement guidelines, Level 4 drainage provides Connectivity will Year 1 and
6.2.15 4.3 High
permits, inventory, the built system drainage via be maintained, Moderate
prioritization, and the road network drainage
funding measures for provided for all
Level 4 drainage development, a
system for
upgrades is
provided
6.2.4 Other Drainage System Protection Measures
The future impacts analysis evaluated the potential stormwater runoff changes due to the full potential
buildout of all private developable lands and unopened right-of-way. The timeline for full-build-out was
not considered; consequently, applying a timeline or priority for new or upgraded infrastructure is not
included. Priorities will be made by City staff based on ongoing observations and the capacity is provided
by the identified scope of needs outlined in the plan.
The calculations for future runoff provided in Section 4 do not consider the benefits of stormwater
measures required by the Ecology Manual, thus the results are conservative and more protective than
the standard. Development and buildout of individual lots are generally under the stormwater control
requirement thresholds in the manual, although City code will require infiltration and control to the
maximum extent practicable, therefore these results are also conservative.
Reductions in allowable land use changes or changed thresholds for required stormwater controls are
other measures the City can take to control future stormwater impact potential. The greatest potential
for change in stormwater runoff due to new, uncontrolled development is show in Table 3-6. These data
could provide a basis for where allowable land use or additional controls could be focused.
Potential stormwater runoff increase due solely to climate change were not evaluated. While increased
storm size and annual precipitation is expected (see Section 2.4), the impacts of this change on the
systems will vary. In general, the level of service may be reduced. However, the drainage system pipe
and ditch sizes are not sensitive to small changes in peak runoff, therefore the need to increase drainage
system sizes should be made on a project by project basis, using the tools provided in Section 4.2.
Drainage structure impacts due to rising sea level were outside the scope of this study and no other
existing drainage infrastructure analyses were completed.
6-8 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 6-5. Summary of Other Drainage System Protection Measures
Item No. Plan
Section
Effort and Timeline
No. Action What it is Benefit Cost Priority
Review areas Investigate if future
6.2.16 Control impacts by Moderate Year 5 and
with large allowable land use reducing land use or Moderate
expected runoff with large potential providing additional
changes using runoff changes are controls when
Table 3-6. compatible with the needed to protect
existing drainage
infrastructure or
system or natural natural resources
system capacity.
6.2.17 Model the Future peak flows Plan for upgrades High Year 5 and
catchment peak from future before flooding Moderate
flows and development may occurs now or in
drainage be higher due to the future
conveyance climate change and
capacity (Tables may require added
4-4 through 4-8) capacity.
using future
rainfall
projections
considering
climate change
6.2.18 Review drainage CDCs and KDs, storm Plan for protection High Year 5 and
infrastructure drainage systems and or avoidance High
(built and near the ocean, and before flooding or
natural) that low elevation impacts occur.
could be wetlands could be
impacted by impacted and cause
higher sea levels flooding
553-2836-004 6-9
Stormwater Management Plan
City of Port Townsend
6.3 Funding and Resources
6.3.1 Capital Projects
Table 6-7 includes the cost distribution plan for the initial implementation years. Additional Information
and years is provided in Appendix I. Table 6-8 provides a summary of when staff resources are needed
for implementation.
Table 6-7. Summary Cost Plan – Capital (2019-2024)
Item
No.
Title Total Cost 2019 2020 2021 2022 2023 2024
$ 808,000.00 $ 808,000.00
6.1.6 Rainier Street
Regional
Stormwater
Project
$ 50,000.00 $10,000.00$ 50,000.00
6.1.7 Logan Street
Stormwater
Pond Overflow
$210,000.00 $ 60,000.00 $ 150,000.00
6.1.1 16th Street –
Sheridan Street
to Landes Street
$ 550,000.00
6.1.2 12th Street
ROW, Logan
Street, and 14th
Street
$ 600,000.00
6.1.8 Future system $300,000.00
upgrades in
Level 4a -
Implement
$ 200,000.00
6.1.9 Future system $100,000.00
upgrades in
Level 4b -
Implement
$ 180,000.00
6.1.4 Hancock Street
and 32nd Street
$ 400,000.00
6.1.3 Center Street –
San Juan Avenue
to Olympic
Avenue
$ 850,000.00
6.1.5 Lawrence Street
at intersections
of Polk Street,
Taylor Street,
and Tyler Street
6-10 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 6-8. Summary Cost Plan - Resources
Total
Item No. Title Effort2019 2020 2021 2022 2023 2024
6.2.1 PrepareBasin Plans X
Adopt guidance for individual lot
6.2.3 X
stormwater controls
Adopt drainage level
6.2.4 X
designations as defined in the
SWMP
6.2.8 Adopt drainage capacity analysis X
and design tools
6.2.5 Review and implement X
protection measures for Level 2b
receiving waters
6.1.9 Future system upgrades in Level X
4b – Plan
6.1.10 Future system upgrades in Level X
1-2 -Plan
Long-path road drainage upgrade
6.1.11 X
analysis
6.1.13 CDC and KD impact mitigation X
analysis
6.2.15 Implement guidelines, permits, X
inventory, prioritization, and
funding measures for Level 4
drainage
6.2.13 Inspect CDCs and KDs for X
observable impacts
Implement identification,
6.2.6 X
protection measures, and
prioritization for Level 3 drainage
6.2.10 Review capacity analysis in X
Tables 4-5 and 4-6 for existing
system deficiencies
6.1.15 Closed Wetland System impact X
Review capacity analysis in Table
6.2.11 X
4-7 for drainage nodes with the
greatest potential for increase
and future impacts
6.2.12 Prepare alternative analysis for X
protecting potential future
impacts on CDCs and KDs from
future development
6-11 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 6-8. Summary Cost Plan – Resources (continued)
Total
Item No. Title Effort2019 2020 2021 2022 2023 2024
6.2.14 Prepare alternative analysis for X
protecting potential future
impacts on wetlands defined in
Table 4-9
6.2.16 Review areas with large expected X
runoff changes using Table 3-6
Review areas with large expected
6.2.17 X
runoff changes using Table 3-6
6.2.18Review drainage infrastructure X
(built and natural) that could be
impacted by higher sea levels
6.4 Summary Implementation Plan
The Basin Plan Program elements have been summarized in an implementation schedule in order of
anticipated priority and timeline in Table 6-9. This is recommended for planning purposes to determine
the relative costs and effort levels that may need to be applied. It is anticipated that some elements may
be moved up the list because of changing needs or opportunities that arise and may need to be delayed
over a longer time frame due to lack of available resources. Table 6-10 shows the 2019-2029 Capital
Program if a $6.00 surcharge and development fee are applied.
Table 6-9. Summary Implementation Schedule
Item
Number
Time Action Effort Timeline Priority
First 6.2.1 Adopt Basin Plan Moderate High
Actions
Adopt guidance for individual lot stormwater
6.2.3 Low High
controls
6.2.4 Adopt drainage level designations as defined in Moderate High
the SWMP
6.2.9 Adopt drainage capacity analysis and design tools Low High
6.2.5 Update Codes for Level 2b Key Drainageways Moderate Moderate
Year 0-1 Implement Rainier Street Regional Stormwater
6.1.6 High High
(2019) Project
6.2.6 Review and implement protection measures for Moderate Moderate
Level 3 Drainage
6.1.8 Future system upgrades in Level 4a - Plan Moderate Moderate
6.1.9 Future system upgrades in Level 4b – Plan Moderate Moderate
6.1.10 Future system upgrades in Level 1-2 - Plan Low Low
6.1.11 Long-path road drainage upgrade analysis Moderate Low
6.1.13 CDC and KD impact mitigation analysis Moderate Low
6-12 553-2836-004
Stormwater Management Plan
City of Port Townsend
Table 6-9. Summary Implementation Schedule (continued)
Item
Time Number Action Effort Timeline Priority
6.2.15 Implement guidelines, permits, inventory, High Moderate
prioritization, and funding measures for Level 4
drainage
6.2.13 Inspect CDCs and KDs for observable impacts Low Moderate
6.2.7 Implement identification, protection measures, High Moderate
and guidelines for Level 4 drainage
Year 2 6.1.8 Future system upgrades in Level 4a - Implement Moderate Moderate
(2020)
6.1.7 Logan Street Stormwater Pond Overflow High High
6.1.9 Future system upgrades in Level 4b - Implement Moderate Moderate
6.1.10 Future system upgrades in Level 1 - Implement Low Low
Year 3 6.1.1 16th Street – Sheridan Street to Landes Street High High
(2021)
6.1.8 Future system upgrades in Level 4a - Implement Moderate Moderate
6.2.10 Review capacity analysis in Tables 4-5 and 4-6 for Moderate Moderate
existing system deficiencies
6.1.9 Future system upgrades in Level 4b - Implement Moderate Moderate
6.1.10 Future system upgrades in Level 1 - Implement Low Low
Year 4 16th Street – Sheridan Street to Landes Street
6.1.1 High High
(2022) (cont.)
6.1.14 CDC and KD impact mitigation – Implement study High Low
results
6.1.15 Closed Wetland System impact Moderate Moderate
6.1.8 Future system upgrades in Level 4a - Implement Moderate Moderate
6.1.9 Future system upgrades in Level 4b - Implement Moderate Moderate
6.1.10 Future system upgrades in Level 1 - Implement Low Low
6.2.11 Review capacity analysis in Table 4-7 for drainage Moderate High
nodes with the greatest potential for increase
and future impacts
6.2.12 Prepare alternative analysis for protecting Moderate Moderate
potential future impacts on CDCs and KDs from
future development
6.2.14 Prepare alternative analysis for protecting High Moderate
potential future impacts on wetlands defined in
Table 4-9
Year 5 6.1.3 Center Street – San Juan Avenue to Olympic High High
Avenue
(2023)
6.1.5 Lawrence Street at intersections of Polk Street, High High
Taylor Street, and Tyler Street
6.1.12 Long-path road drainage upgrades High Moderate
6.1.8 Future system upgrades in Level 4a - Implement Moderate Moderate
6.1.9 Future system upgrades in Level 4b - Implement Moderate Moderate
553-2836-004 6-13
Stormwater Management Plan
City of Port Townsend
Table 6-9. Summary Implementation Schedule (continued)
Item
Time Number Action Effort Timeline Priority
6.1.10 Future system upgrades in Level 1 - Implement Low Low
6.1.16 Closed Wetland System impact mitigation High Low
6.2.16 Review areas with large expected runoff changes Moderate High
using Table 3-6.
Review areas with large expected runoff changes
6.2.17 High Moderate
using Table 3-6.
6.2.18 Review drainage infrastructure (built and natural) High High
that could be impacted by higher sea levels
Year 6 Plus 6.1.2 12th Street ROW, Logan Street, and 14th Street High High
6.1.4 Hancock Street and 32nd Street High High
6-14 553-2836-004
Stormwater Management Plan
City of Port Townsend
7. REFERENCES
Ecology (Washington State Department of Ecology). 1981. Geology and Ground-Water Resources of
Eastern Jefferson County, Washington. Olympia, WA. April 1981.
Mauger, G.S., J.H. Casola, H.A. Morgan, R.L. Strauch, B. Jones, B. Curry, T.M. Busch Isaksen, L. Whitely
Binder, M.B. Krosby, and A.K. Snover. 2015. State of Knowledge: Climate Change in Puget Sound.
Report prepared for the Puget Sound Partnership and the National Oceanic and Atmospheric
Administration. Climate Impacts Group, University of Washington, Seattle. doi:10.7915/CIG93777D.
Miller, I.M., H. Morgan, G. Mauger, T. Newton, R. Weldon, D. Schmidt, M. Welch, E. Grossman. 2018.
Projected Sea Level Rise for Washington State – A 2018 Assessment. A collaboration of Washington
Sea Grant, University of Washington Climate Impacts Group, Oregon State University, University of
Washington, and US Geological Survey. Prepared for the Washington Coastal Resilience Project.
Pessl, F., D.P. Dethier, D.B. Booth, J.P. Minard. 1989. Surficial Geology of the Port Townsend 1:100,000
Quadrangle, Washington. U.S. Geological Survey Miscellaneous Investigations Map I-1198F.
USDA (U.S. Department of Agriculture). 2007. Threshold Channel Design. Stream Restoration Design
National Engineering Handbook, 8.1-8.43.
553-2836-004 7-1
Port Townsend 2017 Stormwater Management Plan (SWMP)
Project Kick-off Meeting
June 20, 2017 9:30 AM – 4:30PM
9:30–9:45Introductionsand roles; meeting purposeGroup
9:45–10:00Project summarySamantha and Paul
10:00-10:30Scope,Schedule,and CommunicationsPaul
10:30-11:30Project needs and information brainstormingPaul leads Group
11:30-12:30Working lunchGroup
12:00 -12:30Project Vision and Mission (part of working lunch)Group
12:30 -1:00Project risk reviewGroup
1:00–2:00Operations, maintenance, information,and systemsCity staff
2:00 –2:45Problem area and priority project reviewCity staff
2:45–4:30Field review of problem areas and key featuresCity staff
4:30Adjourn
SURFACE WATER PROGRAM VISION AND MISSION STATEMENTS
Vision
A fully functional, achievable, and sustainable stormwater system that is integrated into the
landscape, supports envisioned growth, protects residents, and nurtures the environment.
Mission
Safeguard public safetyand minimize property damage
Improve qualityofstormwater runoff
Prepare, implement and update a comprehensive plan to evaluate, measure, protect, design, and
construct a system for current and future needs
Use appropriate, technologically sound, and cost-effective stormwater control solutions
Define and protect the natural and built drainage systems
Consider, accommodate, and direct future development
Protect and improve existing water quality
Correct existing drainage and stormwater management problems
Protect, upgrade, and optimize the existing stormwater infrastructure
Define appropriate measures to manage, optimize, and protect the roadway drainage and
stormwater system
Operate, inspect, maintain, and repair the City’s existing stormwater infrastructure to continue
effective operation
Protect wetlands, marine waters, and habitat
Proactively address the City’s surface water needs for all existing and future customers and
accommodate system growth and expansion.
Control temporary impacts from construction
Consider and account for future changes in sea level and climate change
Develop strategies to resolve existing flooding problems
Determine the City staff and funding needed to accomplish the program mission
Create an outreach plan that informs and engages residents to participate and stokes the willingness
to work together
MEETING NOTES
City of Port Townsend
Stormwater Management Plan
Things that you do well
Coordinated and cooperative
Do well with what you have
Stormwater is not noticed and cared about
WSU and Mater Gardeners coordinate and provide funding support
Community interest in caring for stormwater facilities
Low rain, no streams
Attractive community
Good GIS
MEETING NOTES
City of Port Townsend
Stormwater Management Plan
Notes
Higher intensity and stormwater compatibility
What does stormwater need to serve?
What are stormwater utility expectations for delivery?
Design facilities for climate change
Design selection for lifecycle/maintenance
Good CIP list
Streets/stormwater undermaintained
Setting thresholds for redevelopment
Retrofitting to maximum extent practical (redevelopment)
Opportunistic stormwater management/retrofitting
Develop regulations – policy decisions
Public property use – use natural drainage systems
Integrated stormwater facilities – integrated into landscape
What is a “critical drainage corridor” (CDC)?
Should standards be changed?
Utility crossings of CDC
CDC should be better defined – different policy and standards
Infill development – what should the stormwater standards be? Thresholds?
What should single lot standards be?
NPDES?
Follow up/follow through on stormwater construction and implementation
Inflow and infiltration into sanitary sewer
Storm discharges to sanitary sewer
Community and City maintenance of LID/GSI
Skills/equipment/funding for stormwater maintenance
Should LID maintenance selection match funding for stormwater maintenance?
Existing stormwater BMPs in special FHA
Plan review and system capacity
Critical areas – stormwater facilities are regional
Skills (engineers, contractors) to implement
Demand for LID/GSI in the wrong locations
Picking LID/GSI – how?
Learning and experience on past LID/GSI – next project
2005 stormwater manual
No stream
Stormwater fee $25/month (last increased 4-5 years ago, 3,000 ft ERU, no discount, port not
included)
Pet waste – some EDU
No IDDE
RISK REGISTER
City of Port Townsend Stormwater Management Plan
Potential Risks Identified (at kickoff meeting) Likelihood Impact Mitigation
Samantha moves away H H Keep other City staff
members engaged (and
plan is too good to
miss)
Provide timelines and
Staff priorities change H H
critical path for timely
input.
Stormwater/land use incompatible H H This is a key plan
element for
consideration
Inadequate data – delays, incomplete H H Identify potential data
gaps in early project
phase – during map
and data review (by
July 14)
Allocation of problems (existing pushed to new) H H This is a key plan
element for
consideration
Geologic uncertainty H H Develop plan
contingencies
Citizen challenges H M Stakeholder review
group
Projects (CIP) are not implementable (pre-plats, cost, M H
land, geology)
Development constraints are large M H
Plan too complex or unimplementable, daunting M H
Samantha/staff time M M
Inconsistencies created M M
Adoption/review process M M
BAS issues (schedule) M M
Climate change M M
Site design standards incompatible with stormwater M M
needs due to cost
GMA goals not met L H
Stormwater utility fee controversy L M
Changes in leadership L M
Land constraints on waterfront L M
MEETING NOTES
City of Port Townsend
Stormwater Management Plan
Stakeholders
Hospital
WSU Extension
Beach Watchers
Marine resource community
Olympic Environmental Council
Puget Sound Partnership
o Local integrating organization (Strait and Hood Canal)
Contractors and landscapers
Wetlands/critical areas consultants
Realtors
Friends of Kah-Tai
Developers
Jefferson County Land Trust
Climate Action Committee
Master Builder Association
City Departments
o Engineering/Capital Projects
o Planning
o Operations
o Parks
o Finance
o Administration
o Attorney
Jefferson County Health Department (sampling)
Washington State Department of Ecology
Design engineers/geotechs
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¸
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
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¸
p
p
p
p
p
p
p
p
p
p
p
p
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SURFACE WATER PROGRAM VISION AND MISSION STATEMENTS
Vision
A fully functional, achievable, and sustainable stormwater system that is integrated into the
landscape, supports envisioned growth, protects residents, and nurtures the environment.
Mission
Safeguard public safetyand minimize property damage
Improve qualityofstormwater runoff
Prepare, implement and update a comprehensive plan to evaluate, measure, protect, design, and
construct a system for current and future needs
Use appropriate, technologically sound, and cost-effective stormwater control solutions
Define and protect the natural and built drainage systems
Consider, accommodate, and direct future development
Protect and improve existing water quality
Correct existing drainage and stormwater management problems
Protect, upgrade, and optimize the existing stormwater infrastructure
Define appropriate measures to manage, optimize, and protect the roadway drainage and
stormwater system
Operate, inspect, maintain, and repair the City’s existing stormwater infrastructure to continue
effective operation
Protect wetlands, marine waters, and habitat
Proactively address the City’s surface water needs for all existing and future customers and
accommodate system growth and expansion.
Control temporary impacts from construction
Consider and account for future changes in sea level and climate change
Develop strategies to resolve existing flooding problems
Determine the City staff and funding needed to accomplish the program mission
Create an outreach plan that informs and engages residents to participate and stokes the willingness
to work together
Appendix I-D Guidelines for
WAC.
1.5.1, 1.6.10.
in the manual.
including LID BMPs.
BMPs in the manual.
Sound Action Agenda.
new LID requirements.
Reasoning or Comments
Management Plan. Section renamed.
4.1.3 is the third table in Section 4.1).
Wetlands when Managing Stormwater.
their stormwater program requirements.their stormwater program requirements.
and in Sections 2.1, 2.2, 2.5.3, and 2.5.10.
provided information on the public involvement process.
Removed outdated references to the Puget Sound Water Quality
Revised definitions, requirements, supplemental guidance, etc. to
Revised language for changes made in
Revised to provide an overview of the requirements of the current Revised to provide an overview of the requirements of the current
Quality Management Plan and replaced with guidance on the Puget
Summarized the reasons for the update, the uses of the manual and
Added language to refer to Ecology's website and to define UIC well.
Renumbered all tables and figures in all Volumes. The new numbers
Revised incorrect or outdated code references, such as the RCW and
Removed references and guidance related to the Puget Sound Water
Revised for clarity and removed outdate language in Sections 1.2, 1.4,
Construction Stormwater General Permit and their relationship to the
are located. (Eg. Figure 2.4.2 is the second figure in Section 2.4, Table Added guidance referring Phase I Municipal Stormwater Permittees to
Revised for clarity and removed outdated language in the introduction
coordinate tables and figures to the section of the Volume where they Added guidance referring Phase II Municipal Stormwater Permittees to
Language added to categorize On-site Stormwater Management BMPs,
Appendix 1 of the permit for more information on the requirements for Appendix 1 of the permit for more information on the requirements for
correspond to the changes in the Municipal Stormwater Permits and for
Industrial Stormwater General Permit and their relationship to the BMPs
Change
renamed.
references.
Revised language.
guidance removed.guidance removed.
Guidance removed.
Minor language changes.Minor language changes.
Minor language changes.
Added an Executive Summary
Additional guidance provided.
Renumbered Tables and Figures
Update incorrect or outdated code
Significant revisions to add guidance.
Industrial Stormwater General Permit
Revised to coordinate with the current Revised to coordinate with the current
Significant revisions to remove outdated
Construction Stormwater General Permit
guidance and to add new guidance. Section
Additional guidance provided and outdated Additional guidance provided and outdated
YesYesYesYesYes
to Permit
Language
Change Tied
1-6
1-5
1-141-14
Numbers
ES-i and ES-ii
1-1 through 1-261-1 through 1-262-1 through 2-462-1 through 2-46
1-11 through 1-131-13 through 1-141-14 through 1-151-15 through 1-161-18 through 1-19
Approximate Page
BMPs
Permit
General
Location
All Volumes
Authorizations
Inside cover page
Chapter 1 - Introduction
Chapter 1 - Introduction
Section 1.5.4 Flow Control BMPs
Development and RedevelopmentDevelopment and Redevelopment
NPDES Stormwater Municipal Permits
Chapter 2 - Minimum Requirements for New Chapter 2 - Minimum Requirements for New
Section 1.6.4 The Puget Sound Action AgendaSection 1.6.15 Underground Injection Control
Section 1.6.5 Phase I - NPDES and State Waste
Section 1.6.7 Municipalities Not Subject to the
Section 1.6.6 Phase II - NPDES and State Waste
Section 1.5.5 On-site Stormwater Management Section 1.6.9 Construction Stormwater General
Discharge Stormwater Permits for MunicipalitiesDischarge Stormwater Permits for Municipalities
Section 1.6.8 Industrial Stormwater General Permit
Volume I Minimum Technical Requirements and Site PlanningChapter 1 - IntroductionChapter 2 - Minimum Requirements for New Development and Redevelopment
.
Appendix I-D Guidelines
project.
Stormwater Permits.
perforated stub-outs.
Reasoning or Comments
impervious surfaces to the extent feasible.
for Wetlands when Managing Stormwater
"native" from the land conversion threshold.
manual to the municipal stormwater permits.
for water quality design storm volume and flow rate.
Management Practices, and revision of element #12 to include
and partial dispersion methods, full downspout infiltration and
Added a new statement for the site plan to use site-appropriate addition of element #13 that requires the protection of LID Best
development (LID) guidance and requirements in the Municipal
development principles to retain native vegetation and minimize
Removed outdated references to the Puget Sound Water Quality
related new definitions. Clarifications about the surfaces that the
hard surfaces at new development sites, the deletion of the word
Changes include: revisions to the construction SWPPP elements to
correspond with the Construction Stormwater General Permit, the
Added clarification for peak discharges using 15 minute time steps.
the related new definitions. The intent is to continue to capture the Revisions to acknowledge the use of permeable pavements and the
surfaces, LID, converted vegetation) because of the new low impact
Changes include: the new LID performance standard and list options
Added definitions for a few terms used previously but not previously
intent is to capture the same size and types of projects as previously.
responsibilities for an inspector or CESCL depending on the size of the use types: lawn and landscaped areas; roofs, and other hard surfaces.
Revisions made to acknowledge the use of permeable pavements and
based on project size and location. The lists are divided into three land for each land use type. Some of the BMPs included in the lists are: rain
surfaces, the application of minimum requirements #6 - #9 to replaced
Projects implementing the list option must select the first feasible BMP
Management Plan. Section renamed and focuses on relationship of the
Changes include: the replacement of “impervious” surfaces with “hard”
defined. Other terms have a revised definition or a new definition (hard
requirement applies to, and the use of the 0.10 /0.15 cfs threshold. The
same size and types of projects as previously. More accurate definitions
gardens, permeable pavements, bioretention, soil quality and depth, full
Revisions correspond to the significantly revised
Change
guidelines.guidelines.
Minor additions.
supplemental guidelines.supplemental guidelines.
Added and revised definitions.
Revisions to the thresholds and
development (LID) requirements.standard requirement, additional
Added guidance. Section renamed.
Design Flow Rate, and supplemental
Revised requirements and objective.
Multiple revisions for new low impact
elements, objective, and supplemental
Revised the thresholds for determining
Revisions to the applicability, thresholds,
Reorganized and revisions to: thresholds,
Revisions to the thresholds, Water Quality
development and redevelopment. Revised
general requirements, construction SWPPP
which minimum requirements apply to new
requirements, and supplemental guidelines.
YesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
2-2
2-16
Numbers
2-5 through 2-9
2-9 through 2-16
2-17 through 2-262-27 through 2-282-28 through 2-322-33 through 2-352-35 through 2-402-40 through 2-41
Approximate Page
(SWPP)
Agenda
Outfalls
Location
Protection
Treatment
Flow Control
RequirementsRequirements
Stormwater Management
Preparation of Stormwater Site Plans
Section 2.5.2 Minimum Requirement #2: Section 2.5.4 Minimum Requirement #4:
Section 2.4 Applicability of the Minimum Section 2.5.1 Minimum Requirement #1:
Section 2.3 Definitions Related to Minimum
Preservation of Natural Drainage Systems and
Construction Stormwater Pollution Prevention
Section 2.5.6 Minimum Requirement #6: Runoff Section 2.5.7 Minimum Requirement #7: Runoff
Section 2.5.5 Minimum Requirement #5: On-site
Section 2.5.8 Minimum Requirement #8: Wetlands
Section 2.1 Relationship to the Puget Sound Action
Step V: Select
apply.
facilities.
and in section 3.1.7.
with a reference to Chapter 2 of Volume V.
Reasoning or Comments
applicable minimum requirements.subject to Min. Requirements 1 - 9.
the appendix and retained the rainfall tables.
Appendix 1 of the 2007 municipal stormwater permits.
Changes for clarification and to remove repetitive language.
Significant changes to describe how to prepare the Permanent
requirements. Ecology replaced the language in
Soils reports are necessary part of LID decisions. Declarations of
Revisions and new language especially in Step III for guidance on
Added several LID BMPs that require the submission of as-builts.
Treatment Facilities
the changes in the Municipal Stormwater Permits and for new LID
Stormwater Control Plan that incorporates LID features. Separate
Added language for clarity on use of Basin Planning for addressing
and in particular for LID site design. Split into subsections based on
whether Min. Requirements 1 - 5 apply, or Min. Requirements 1 - 9
LID features, establish maintenance requirements and government
References to on-site BMPs added and preliminary determination of
access for inspections of privately maintained stormwater BMPs and
Revised for clarity and removed outdate language in the introduction
guidance for projects subject to Min. Requirements 1 - 5 and projects
retrofit needs and for developing an alternative flow control strategy.
Removed background and outdated information for brevity. Renamed
Additional guidance details the information necessary for site analysis,
modeling threshold discharge areas. Minor revisions to correspond with
Changed and added language to be consistent with the requirements in
Covenants and Grants of Easement are necessary mechanisms to identify
Change
Volume V.
Step V: Select Treatment
implementation.
Guidance added.Guidance added.
Design Flow Rate.
guidance removed.
Grants of Easement.
with a reference to Chapter 2 of
Minor language changes.
Stormwater Control Plan.
procedures necessary for LID
Additional guidance provided.Additional guidance provided.
Site Hydrology of the Permanent
Significant changes to incorporate
Removed introductory language and
Reference to needed soils report and
background information on the Water
language in
Quality Design Storm and Water Quality
Revisions to all subsections of Developed addition of Declaration of Covenants and
Revised language, proposed replacing the
Facilities
Additional guidance provided and outdated
YesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-17
Numbers
4-1 through 4-4
3-2 through 3-73-7 through 3-8
B-1 through B-5
A-1 through A-3
3-1 through 3-173-8 through 3-12
2-45 through 2-463-13 through 3-143-14 through 3-16
Approximate Page
Plan
Location
Sections 3.1.2 to 3.1.4
Stormwater Control Plan
Section 2.8 Exceptions/Variances
Information on Existing Conditions
Stormwater Pollution Prevention Plan
Requirements Through Basin Planning
Section 3.1.1 Step 1 - Collect and Analyze
Section 3.1.5 Step 5 - Prepare a Permanent
Section 3.2.2 Final Corrected Plan Submittal
Appendix I-B Rainfall Amounts and Statistics
Section 3.1.6 Step 6 - Prepare a Construction
Section 4.2 BMP and Facility Selection Process
Section 3.1.7 Step 7 - Complete Stormwater Site
Chapter 3 - Preparation of Stormwater Site Plans
Appendix I-A Guidance for Altering the Minimum
Chapter 3 - Preparation of Stormwater Site PlansChapter 4 - BMP and Facility Selection Process for Permanent Stormwater Control PlansAppendix I-A Guidance for Altering the Minimum Requirements
Through Basin PlanningAppendix I-B Rainfall Amounts and Statistics
Stormwater Permits.
in Min. Requirement #7.
Reasoning or Comments
than 15% on a monthly basis.
analyses, and to remove reference to a creek in Eastern WA.
development (LID) guidance and requirements in the Municipal
Rewritten to remove outdated information, clarify concepts, and
approach the protection and use of wetlands through controlling
List edited to add additional waters based on specific requests and
definition has been added. A handful of other terms have a revised
There are a few terms, used previously but not defined, for which a
definition, and there are new terms, because of the new low impact
more than 20% on a single event basis, and must not deviate by more
Map shows basins which potentially qualify for use of existing land cover
discharges to wetlands. Total discharges to wetlands must not deviate by as the pre-developed land cover for flow control purposes. See reference
Change
Added Map
stormwater.
Added and revised definitions.
protection of Wetlands when managing
Multiple revisions for the use and/or the
Added and deleted Exempt Surface Waters.
YesYesYes
to Permit
Language
Change Tied
F-1
Numbers
Glossary-47
E-1 through E-4
D-1 through D-18
Glossary-1 through
Approximate Page
Location
Managing Stormwater
Glossary and Notations
impervious area since 1985
Appendix I-F Basins with 40% or more total
Appendix I-D Guidelines for Wetlands when
Appendix I-E Flow Control-Exempt Surface Waters
Appendix I-D Guidelines for Wetlands when Managing StormwaterAppendix I-E Flow Control-Exempt Surface WatersAppendix I-F Feasibility Criteria for Selected Low Impact Development Best
Management PracticesGlossary and Notations
BMPs.
Industrial Permits).
duplicate language.
Reasoning or Comments
Low Impact Development BMPs.
Replaced older figure with an updated one.
Prevention Plan Checklist is still located in Section 3.3.
State, and Local Regulatory Requirements was removed.State, and Local Regulatory Requirements was removed.
Revised this chapter to use simpler and clearer language.
information. Sections 2.1 and 2.2 now go into detail about the element now contains an Additional Guidance section that has
Removed this section by combining it with Section 1.2 to eliminate
Revised this chapter to update this information for revisions to the
Replaced these sections to remove invalid information or duplicate Stormwater Permits, and the Construction BMPs in Chapter 4. Each
Section 3.3. Please note that the Construction Stormwater Pollution
to Section 3.2 for clarity. The Step-By-Step Procedure now follows in
information not required by the permits. Added Element #13 Protect
Revised this chapter to use simpler and clearer language. Information Revised this chapter to use simpler and clearer language. Information
and the requirements for a Stormwater Site Pollution Prevention Plan.
covered in Volume I, Section 1.6 Relationship of the Manual to Federal, covered in Volume I, Section 1.6 Relationship of the Manual to Federal,
Stormwater General Permits (including the Municipal, Construction, and Revised The Construction SWPPP Elements, described in Section 3.3.3 to coordinate with the Construction Stormwater
General Permit, Municipal
Moved The Construction SWPPP Requirements, previously in Section 3.3
relationship of Volume II to the Construction Stormwater General Permit
Revised to incorporate a new element, Protect Low Impact Development
1.2.
Change
reversed.
Replaced.
Renamed.
and brevity.and brevity.and brevity.
SWPPP Elements.
Stormwater Permits.
to the Washington State General
Multiple revisions to the Construction
Previous Sections 3.2 and 3.3 have been
Section 2.1 The Construction Stormwater
in this section is now included in Sections
replace the previous Sections 2.1 and 2.2.
Stormwater Pollution Prevention Plans now
This section was removed. The information
Multiple revisions to coordinate the manual
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
General Permit and Section 2.2 Construction
YesYesYesYes
to Permit
Language
Change Tied
1-31-6
N/A
Numbers
1-1 through 1-92-1 through 2-62-1 through 2-6
2-2 through 2-4
3-1 through 3-323-4 through 3-323-8 through 3-32
Approximate Page
Location
Figure 1.5.1
Implementation
Chapter 3 - Planning
Pollution Prevention
Section 2.1 and Section 2.2Section 3.2 and Section 3.3
Stormwater Pollution Prevention
Section 1.3 How to Use This Volume
Chapter 2 - Regulatory RequirementsChapter 2 - Regulatory Requirements
Construction SWPPP Development and
Section 1.3 Thirteen Elements of Construction
Section 3.3.3 (Previously Section 3.2.3) Step 3 -
Chapter 1 - Introduction Construction Stormwater
Volume II Construction Stormwater Pollution PreventionChapter 1 - Introduction Construction Stormwater Pollution PreventionChapter 2 - Regulatory RequirementsChapter 3 - Planning
equivalent.
field experience.
and field experience.
compost specification.
Reasoning or Comments
discharge to surface or ground water.
comments received and field experience.
Temporary and Permanent Seeding to this BMP.
should be based on the size of the construction site.
Revised this BMP to use simpler and clearer language.
Added Wood Straw and Wood Straw Mulch to the table.
Added guidance previously found in BMP C120: Temporary and
intent of this BMP in a safer and more commonly used manner.
Added minimum mulch thickness based on field experience and for this BMP based on comments received and field experience.
Added guidance to clarify that wheel wash wastewater shall not
Updated figure to provide more details of a typical Wheel Wash.
Ecology revised this chapter to use simpler and clearer language.
Refers to Ecology's website for BMPs that have been approved as
comments. Ecology added guidance previously found in BMP C120:
Ecology added Table 4.1 Source Control BMPs by SWPPP Element to
Removed measures and quantities because measures and quantities
coverings (such as compost and straw) are preferable. Ecology added
Removed the use of plastic sheeting over seeded areas because other Provided a link to composting guidance and removed old reference to
Removed this BMP because BMP C103: High Visibility Fence meets the and removed guidance for this BMP based on comments received and
Revised and reorganized this BMP to use simpler and clearer language.
Permanent Seeding to this BMP. Ecology added and removed guidance
Ecology added and removed additional guidance for this BMP based on
show how the BMPs listed in Section 4.1 relate to the SWPPP Elements.
Added high visibility silt fence because it meets the intent of BMP C103.
Moved some guidance to BMP C121: Mulching or BMP C125: Top soiling.
Added and removed guidance for this BMP based on comments received
Change
removed.
and brevity.
and removed.
SWPPP Element
clarity, and brevity.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Figure was updated
This BMP was removed.
Additional guidance provided.Additional guidance provided.
Suggested measures and quantities
This BMP now includes high visibility silt
Added Table 4.1 Source Control BMPs by
and brevity. Additional guidance provided
Added approved equivalent BMPs Sections.fence. Multiple revisions for plain language, Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Yes
to Permit
Language
Change Tied
4-6
N/A
4-114-21
Numbers
4-1 through 4-2
4-7 through 4-9
4-9 through 4-11
4-1 through 4-1284-13 through 4-194-19 through 4-214-22 through 4-254-25 through 4-274-27 through 4-284-29 through 4-324-42 through 4-43
Approximate Page
Location
Table 4.1.8
and Specifications
BMP C124: Sodding
BMP C121: Mulching
BMP C106: Wheel Wash
Figure 4.1.2 - Wheel Wash
BMP C123: Plastic Covering
BMP C122: Nets and Blankets
BMP C150: Materials on Hand
BMP C103: High Visibility Fence
Section 4.1 Source Control BMPs
BMP C104: Stake and Wire Fence
BMP C125: Top soiling / Composting
BMP C120: Temporary and Permanent Seeding
BMP C105: Stabilized Construction Entrance / Exit
Chapter 4 - Best Management Practices Standards
Chapter 4 - Best Management Practices Standards and Specifications
.
2
areas.
Elements. materials.
prohibited.
experience.
the near future.
(CTAPE) program.
Stormwater General Permit.
Reasoning or Comments
in BMP C252 and in BMP C253.
guidance for neutralizing high pH.
on comment received and field experience.
on neutralizing high pH through the use of CO
to show how the BMPs listed in Section 4.2 relate to the SWPPP
projects needing to perform Erosion and Sediment Control Work. Added guidance for this BMP, previously available online, to
Removed this BMP because it is not applicable to the full range of
both the Municipal Stormwater General Permits and Construction
Construction Stormwater General Permit and to make it clear that
Added sizing criteria for this BMP, previously available online.
Renamed this BMP to include wattles made from compost or other
Removed this BMP because of changes in threshold requirements in
Added guidance for this BMP based on comments received and field
coordinate with the Chemical Technology Assessment Protocol
Added this BMP to provide additional guidance for concrete washout
Added guidance to coordinate this BMP with the requirements of the Concrete spillage or concrete discard to surface waters of the State is
Minimum Requirements for ESC Training and Certification Courses has
Added this BMP, previously available online, to provide guidance
Added guidance for inlet protection of lawn and yard drains and based
been removed. Ecology plans on issuing separate, updated guidance in Revised and reorganized this BMP to use simpler and clearer language.
Added this BMP, previously available online, to provide additional
Added this new BMP for dewatering, Construction SWPPP Element #10.Revised this appendix to coordinate with the new information provided
Removed this BMP because this BMP has been proven to be ineffective.
Added Table 4.2 Runoff Conveyance Treatment BMPs by SWPPP Element
Change
and brevity.
Added this BMP.Added this BMP.Added this BMP.Added this BMP.
guidance removed.
C252 and BMP C53.
This BMP was removed.This BMP was removed.This BMP was removed.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Renamed from Straw Wattles.
Added Table 4.2 Runoff Conveyance
Treatment BMPs by SWPPP Element
Multiple revisions to coordinate with BMP
Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
N/AN/AN/A
4-57
Numbers
B-1 through B-3
4-43 through 4-454-48 through 4-534-54 through 4-554-74 through 4-774-78 through 4-794-90 through 4-954-96 through 4-99
4-100 through 4-1024-112 through 4-1204-120 through 4-1244-125 through 4-127
4-128 through 4-129
Approximate Page
2
Lead
BMPs
Location
TreatmentTreatment
BMP C235: Wattles
Pollution Prevention
BMP C233: Silt Fence
BMP C207: Check Dams
BMP C230: Straw Bale Barrier
BMP C236: Vegetated Spray Fields
BMP C154: Concrete Washout Area
BMP C220: Storm Drain Inlet Protection
BMP C253: pH Control for High pH Water
Sawcutting and Surface Pollution Prevention
BMP C252: High pH Neutralization Using CO
BMP C161: Payment of Erosion Control Work
BMP C151: Concrete Handling and BMP C152:
Section 4.2 Runoff Conveyance and Treatment BMP C250: Construction Stormwater Chemical BMP C251: Construction Stormwater Filtration
BMP C180: Small Project Construction Stormwater
BMP C160: Certified Erosion and Sediment Control
Appendix II-B Background Information on Chemical
purposes.
Minor text change
(WWHM) changes.
guidance was replaced.
Volume I, Appendix 1-D.
trenches and splashblocks.
in the introductory section.
Reasoning or Comments
of Street Wastes in Volume IV.
Permeable Pavement sections.
permeable pavements in introductory section.
and feasibility criteria. Updated design guidance.
guidance for oil control and pre-treatment facilities.
distributed bioretention facilities as indicated in text.
Revised this chapter to use simpler and clearer language. Revised this chapter to use simpler and clearer language.
and feasibility criteria. Improved clarify in design guidance and
and feasibility criteria. Needed better clarity in design guidance
Added references to Minimum Requirement #5, bioretention and
Step 6 for clarity and for meeting MR#5. Revised Step 7 for clarity.
Revised Step 2 to include guidance for meeting MR#5. Significantly
Revised this chapter to use simpler and clearer language. Outdated Added guidance for MR #5 which now includes an LID Performance Expanded purpose statement and clarified in regard to
the types of
Added guidance on upcoming Western Washington Hydrology Model
facilities covered in Section 3.3. Added references to Bioretention and
computer modeling. Added guidance for design criteria for dispersion revised Step 5 for the new guidance provided in section 3.3.6. Revised
Added guidance on precipitation data and upcoming WWHM changes.
Text and figures updated to indicate priorities for handling roof runoff.
design of centralized infiltration facilities. Certain sections also apply to
Text changes for consistency with new priority lists in Min.Req'ment #5
Section 2.2 split into multiple subsections for clarity and for referencing Updated references to revised roof downspout BMPs and Rain Gardens
Text changes for consistency with new priority lists in Min. Req'ment #5 Text changes for consistency with new priority lists in Min. Req'ment #5
Updated Maintenance narrative to refer to Appendix IV-G Management
Standard. Revised the guidance for MR#8 to reflect the changes made in
Made significant changes to all sub-sections. Section pertains primarily to Made clarifications and added language for complying with MR#5. Added
Change
standard.
Req'mt #5Req'mt #5Req'mt #5
Req'mt #5
Req'mt #5.
and brevity.and brevity.and brevity.
Req'mt #5 and LID
Requirements (MR).
Updated references.
revised Min Req'mt #5
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Section significantly rewritten.
guidance removed for Minimum
Revised guidance and reference LID.
Revised several steps for new infiltration
Update text & figure for consistency with
Section 2.2 split into multiple subsections.
Additional guidance provided and outdated Additional guidance provided including Min
rate guidance and the new LID performance
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min
Update text for consistency with revised Min
YesYesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-1
3-353-653-653-66
Numbers
2-5 through 2-82-8 through 2-9
2-4 through 2-92-4 through 2-93-1 through 3-3
2-1 through 2-173-1 through 3-183-4 through 3-10
3-1 through 3-1093-11 through 3-163-17 through 3-183-19 through 3-643-68 through 3-71
3-65 through 3-102
Approximate Page
T5.10A)
WWHM
Facilities
Location
and Treatment
Section 3.3.1 Purpose
Section 3.3.2 Description
Section 3.3.3 Applications
Section 3.2 Detention FacilitiesSection 3.2 Detention Facilities
Chapter 2 - Hydrologic Analysis
Chapter 3 - Flow Control Design
Chapter 3 - Flow Control Design
Section 3.1 Roof Downspout ControlsSection 3.1 Roof Downspout Controls
Section 3.3.4 Steps for Design of Infiltration
Section 3.1.2 Downspout Dispersion Systems
Section 3.1.3 Perforated Stub-out Connections
Section 2.2.2 Assumptions made in creating the
Section 3.3 Infiltration Facilities for Flow Control
Section 2.2.3 Guidance for flow-related standards
Section 2.2 Western Washington Hydrology ModelSection 2.2 Western Washington Hydrology Model
Section 3.1.1 Roof Downspout Full Infiltration (BMP
Volume III Hydrologic Analysis and Flow Control Design / BMPsChapter 2 - Hydrologic AnalysisChapter 3 - Flow Control Design
3.3.6.
Reasoning or Comments
outdated computation steps.
3, and one for upcoming WWHM 2012.
Soil Texture Classification and D10 grain size.
Added guidance for conducting performance testing.
amended drawdown guidance, and verification testing.
for bioretention / rain gardens and permeable pavement.
and maintenance. Made wording clarifications to guidance.
Added a link to a website where isopluvial maps are available.
method for estimating infiltration rates. Deleted infiltration rate
determination sub-section due to redundancy with next section.
Procedures for conducting the PIT have been included within the
instead refers to steps 1-5 in section 3.3.4. Revised Figure 3.27 for
investigation, and determine the saturated hydraulic conductivity;
Removed steps to select location, estimate volume of stormwater, infiltration rate. Added a step for groundwater mounding analysis.
on groundwater monitoring wells and the use of grain size analysis infiltration rates, added a minimum organic content for treatment,
develop a trial infiltration facility geometry, conduct a geotechnical
Replaced "Infiltration Rate" with "Saturated Hydraulic Conductivity"
Updated references, removed unneeded guidance, revised limits on
guidance for the modeling on LID elements and wetlands. Removed
saturated hydraulic conductivity. Added guidance on pilot infiltration
proposed text on “Design Infiltration Rate Determination” in sections
Added guidance on current and upcoming versions of WWHM. Added
testing (PIT), and soil grain size analysis. Revised correction factors for
Text in regard to design guidance removed. All design guidance moved
Added guidance re field tests, computer modeling, and implementation
PIT results and soil grain size method. Removed options based on USDA
Added guidance for sizing for flow control, pretreatment design criteria,
throughout section. Updated the guidelines and criteria for determining
Multiple changes to subsurface characterization include added guidance
to Volume V. Two sets of modeling guidance provided. One for WWHM
updated guidance. Revised guidance for adjusting the preliminary design
Change
Section renamed.
guidance removed.guidance removed.guidance removed.guidance removed.
Appendix removed.
permeable pavement.
Added link to website.
USDA Textural Triangle.
Revised guidance on subsurface
receptor. Removed guidance for
Multiple revisions. Previous steps 1-4
groundwater mounding analysis step.
Added this section for bioretention and
Revisions for determining the saturated
hydraulic conductivity (infiltration rate).
removed. Multiple steps revised. Added
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
hydrogeologic investigation and figure 3.27,
characterization, soil testing, and infiltration
YesYesYes
to Permit
Language
Change Tied
A-1
N/A
Numbers
B-1 through B-13C-1 through C-13
3-72 through 3-753-75 through 3-833-83 through 3-863-86 through 3-903-90 through 3-94
3-103 through 3-109
Approximate Page
Guidance
Location
Infiltration Test
Computation Steps
Permeable Pavement Use
Facilities - Detailed Approach
Conductivity - Guidelines and Criteria
Model - Information, Assumptions, and
Section 3.3.6 Design Saturated Hydraulic
Section 3.3.7 Site Suitability Criteria (SSC)
Section 3.3.5 Site Characterization Criteria
Section 3.3.8 Steps for Designing Infiltration
Construction Criteria for Infiltration Facilities
Appendix III-B Western Washington Hydrology
Appendix III-D Procedure for Conducting a Pilot
Appendix III-C Washington State Department of
Section 3.3.9 General Design, Maintenance, and
Section 3.4 Site Procedures for Bioretention and
Appendix III-A Isopluvial Maps for Design Storms
Ecology Low Impact Development Flow Modeling
Appendix III-A Isopluvial Maps for Design StormsAppendix III-B Western Washington Hydrology Model - Information, Assumptions, and Computation Steps Appendix III-C Washington State Department
of Ecology Low Impact Development Design and Flow Modeling GuidanceAppendix III-D Procedure for Conducting a Pilot Infiltration Test
action.
language.
ISWGP and BGP.
a corrective action.
system to the BMPs.
outdated references.
Stormwater Permits).
Reasoning or Comments
and removed outdated references.
Revised BMPs to use simpler and clearer language.
Revised for clarity and removed outdated language.
Added numbers in the "S400" series to BMPs in Volume IV.
BMPs for facilities covered under the ISWGP (or other General
prevention and cleanup, visual inspections and record keeping.
Revised BMPs to use simpler and clearer language, and removed
in regards to the ISGP, BGP, and S&GP. Added guidance regarding
in regards to the ISGP, BGP, and S&GP. Section renamed to make it
include the addition of vacuum sweeping and pressure washing, spill
Revised wording to clarify where this Section applies. Revised several
clearer that applicable BMPs are Mandatory for permittees under the
Added new guidance clarifying the requirements regarding treatment compost leachate. Revised BMPs to use simpler and clearer language,
regarding boatyard activities. Revised BMPs to use simpler and clearer
(ISWGP), Boatyard General Permit (BGP), and Sand and Gravel General
facilities covered under the ISWGP that trigger a Level 1 or 2 corrective BMPs for clarity and to coordinate with the ISWGP. Significant changes
Revised language because solid waste regulations prohibit discharge of
Permit (S&GP) and the inclusion of "applicable" BMPs from this volume
Clarified guidance describing the requirements under the BGP and ISGP
in Industrial Stormwater Pollution Prevention Plans (Industrial SWPPPs).the ISWGP that trigger a Level 1 or 2 corrective action. Changed the title
Added new guidance describing the use of applicable (mandatory) BMPs Added new guidance describing the use of applicable (mandatory) BMPs
Revised wording to clarify where this Section applies. Added new text on
ISWGP requirements. Added guidance regarding facilities covered under
Added new guidance regarding the Industrial Stormwater General Permit
Added guidance regarding facilities covered under the ISWGP that trigger format for the BMPs to match the other volumes and added a numbering
Change
revisions.
and brevity.and brevity.
BMPs clarified.
Numbered BMPs.
guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.
Additional guidance provided.
guidance removed. Minor formatting
Additional guidance provided and several
Minor revisions for plain language, clarity, Minor revisions for plain language, clarity,
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
YesYes
to Permit
Language
Change Tied
1-2
1-31-4
2-10
Numbers
1-1 through 1-52-7 through 2-9
1-3 through 1-42-1 through 2-22-2 through 2-6
2-1 through 2-662-1 through 2-662-7 through 2-66
2-10 through 2-12
Approximate Page
Sources
Location
Source Control BMPs
Source Control BMPsSource Control BMPsSource Control BMPs
Chapter 1 - Introduction
Maintenance of Boats and Ships
Section 1.6.2 Recommended BMPs
Section 1.3 How to Use this Volume
S403 BMPs for Commercial Composting
S401 BMPs for the Building, Repair, and
Section 2.2 Pollutant Source Specific BMPs
Section 1.6.1 Applicable (Mandatory) BMPs
Section 2.1 Applicable (Mandatory) Operational
Section 1.5 Treatment BMPs for Specific Pollutant
S402 BMPs for Commercial Animal Handling Areas
Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural
Volume IV Source Control BMPsChapter 1 - IntroductionChapter 2 - Selection of Operational and Structural Source Control BMPs
references.references.references.
this volume.
Appendix IV-B.
outdated guidance.
use in street cleaning. the required controls.
vehicles to align with ISGP.
Reasoning or Comments
municipal stormwater permits.
Minor language changes for clarity.
Added "Potential Pollutant Generating Sources"
Minor revisions to the Site Evaluation subsection.
Updated the reference to guidance for Vehicle Recyclers.
Removed outdated guidance and added new guidance in the
process wastewater to ground water or surface water. Removed
Additional guidance provided for the handling of ditch cleanings.
contamination in Street Waste Solids subsection. Reorganized the
Revised language to coordinate with the ISGP. Removed outdated
Updated "applicable BMP" guidance for handling of liquids in scrap
Revised several BMPs for clarity and to coordinate with the ISWGP.
Clarified guidance describing which NPDES permit(s) regulate wood
Minor language changes for clarity. Removed the outdated Table in
Added guidance to clarify that the ISWGP prohibits the discharge of
Added a references to Volume V and Ecology publications for BMPs.
treatment areas. Revised BMPs to use simpler and clearer language.
Clarified that facilities not under the ISWGP may consider some water Edits to make guidance consistent with the most recent industrial and
disposal of street waste liquids subsection, no major content changes.
Figure was unclear and the existing text provided a better description of Edits for clarity and to replace and revise guidance documents and WAC Edits for clarity and to replace and
revise guidance documents and WAC
Added this BMP to provide further guidance consistent with BMPs within
Change
references.
Figure Deleted
BMPs clarified.
guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.Minor language changes.Minor language changes.
Additional guidance provided
Added reference to guidance.
Additional guidance provided.Additional guidance provided.
Updated reference to guidance.
and outdated guidance removed.
Revision for consistency with the ISGP
Additional guidance provided and several
Minor language changes. Removed Table.
and brevity. Additional guidance provided
Additional guidance provided and updated
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
C-1
N/A
A-14
Numbers
E-1 through E-7
B-1 through B-2
D-1 through D-9
A-1 through A-24
G-1 through G-15
2-13 through 2-142-32 through 2-342-35 through 2-372-45 through 2-462-46 through 2-472-48 through 2-492-58 through 2-592-60 through 2-622-63 through 2-642-64 through 2-66
Approximate Page
Permits
Location
Substances
and Equipment
Adverse Impact
of Street Wastes
Generating Sources
Airports and Streets
Fluids/Other Wastes
S430 BMPs for Urban Streets
Impact Stormwater Programs
Commercial Composting - SIC 2875
Figure 2.15 - Uncovered Wash Area
S424 BMPs for Roof/Building Drains at
S432 BMPs for Wood Treatment Areas
S423 BMPs for Recyclers and Scrap Yards
Manufacturing and Commercial Buildings
S426 BMPs for Spills of Oil and Hazardous
Vehicles / Equipment / Building Structures
Appendix IV-C Recycling/Disposal of Vehicle
S431 BMPs for Washing and Steam Cleaning Appendix IV-E NPDES Stormwater Discharge
Appendix IV-D Regulatory Requirements That
Appendix IV-A Urban Land Uses and Pollutant
Appendix IV-B Stormwater Pollutants and Their
S416 BMPs for Maintenance of Roadside Ditches
S405 BMPs for Deicing and Anti-Icing Operations -
S414 BMPs for Maintenance and Repair of Vehicles S433 BMPs for Pools, Spas, Hot Tubs and Fountains
Appendix IV-G Recommendations for Management
Appendix IV-A Urban Land Uses and Pollutant Generating SourcesAppendix IV-B Stormwater Pollutants and Their Adverse ImpactAppendix IV-C Recycling/Disposal of Vehicle Fluids/Other WastesAppendix
IV-D Regulatory Requirements That Impact Stormwater ProgramsAppendix IV-E NPDES Stormwater Discharge PermitsAppendix IV-G Recommendations for Management of Street Wastes
Chapter 2. Chapter 2.
computer models.
outdated references.
Enhanced Treatment.
duplicated from Chapter 2.
Reasoning or Comments
was duplicated from Chapter 2.
Bioretention as a treatment method.
Added paragraph on emerging technology options.
Added paragraph on emerging technology options.
waters triggering enhanced treatment for accuracy.
removed the associated subsection, Pollutants of Concern.
filtration, emerging technologies, and on-line systems. Added
technologies. Deleted the "Where Applied" section since it was
between "bioretention" and "rain gardens." Replaced "Ecology between "bioretention" and "rain gardens." Replaced "Ecology
Removed the Suggested Treatment Options Table and Ability of
Revised BMPs to use simpler and clearer language, and removed
for this treatment), and media filter, added emerging stormwater
Deleted the "Where Applied" section since it was duplicated from
Deleted the "Where Applied" section since it was duplicated from
Revised selection process steps for clarity and to remove outdated
Embankment" with "Media Filter Drain". Added Compost-amended
Removed "rain garden" for consistency with proposal to distinguish
information. Revised the Treatment Facility Selection Flow Chart for
Revised guidance for oil/water separation, pretreatment, infiltration,
treatment technologies. Deleted the "Where Applied" section since it
the TAPE process but Ecology has approved one emerging technology.
revised guidance throughout Volume V. Revised description of surface
Some treatment BMP options removed, emerging technologies added,
Removed amended sand filter (no design criteria have been developed
Vegetated Filter Strip. Removed Bio-infiltration Swale. Added emerging
New guidance more accurately describes how volume is determined by
Revised the performance goal for dissolved metals. Removed Amended
Embankment" with "Media Filter Drain." Added emerging technologies.
one BMP renamed. Added a note for Phosphorous facilities that require
Treatment Facilities Table because they provided limited usefulness and
Removed catch basin inserts and added emerging stormwater treatment Sand Filter. Added "vegetated" to "Compost Amended "Vegetated" Filter
technologies. To date, no catch basin inserts have been approved though Strip. Removed "rain garden" for consistency with proposal to distinguish
Table.
Change
and brevity.
list of options.
with Chapter 2.
guidance removed.
enhanced treatment.
Revised list of options.Revised list of options.Revised list of options.
Additional guidance provided.Additional guidance provided.
Minor revisions to the steps. Revised
Inserted updated modeling guidance.
Revised list of options. Revised waters
Multiple revisions to remove outdated
description of surface waters triggering
guidance and to provide new guidance.
Table, and Ability of Treatment Facilities
Removed the subsection on Pollutants of
triggering enhanced treatment consistent
Minor revisions for plain language, clarity,
Concern, the Suggested Treatment Options
Minor language changes for clarity. Revised
Additional guidance provided and outdated
Yes
to Permit
Language
Change Tied
3-1
2-12-34-1
Numbers
1-2 through 1-43-2 through 3-33-5 through 3-7
1-1 through 1-42-1 through 2-93-3 through 3-43-7 through 3-9
2-9 through 2-11
Approximate Page
Factors
Location
Figure 2.1.1
Treatment Facilities
Chapter 1 - Introduction
Section 3.2 Oil Control Menu
Chapter Introduction Paragraph
Section 1.4.3 Treatment Methods
Section 3.5 Basic Treatment Menu
Section 3.4 Enhanced Treatment Menu
Section 3.3 Phosphorous Treatment Menu
Section 2.1 Step-by-Step Selection Process for Section 2.2 Other Treatment Facility Selection
Chapter 2 - Treatment Facility Selection Process
Section 4.1.1 Water Quality Design Storm Volume
Volume V Runoff Treatment BMPsChapter 1 - Introduction Chapter 2 - Treatment Facility Selection Process Chapter 3 - Treatment Facility Menus Chapter 4 - General Requirements for Stormwater
Facilities
Manual).
#6, and #7.
this chapter.
Rain Gardens.
pretreatment.
Appendix III-C.
and references for clarity.
Revised language for clarity.
Reasoning or Comments
maintenance standards grant.
statement added in BMP T5.40.
Added reference to Chapter 12.
pollution-generating pervious surfaces.
Updated listed BMPs and made minor revisions to text.
Removed "and media filtration" in first bullet for clarity.
Vegetated Filter Strips. Minor additions to the recommended
Changed "StormFilter" to "Manufactured Media Filters", added
Moved Full Dispersion into Section 5.3.1 because the Municipal
Downspout infiltration moved to Volume III. Revised BMP T5.11
Stormwater Permits make it a necessary option in MR #5. Clarifying
Updated figures. Added BMP T5.14A Rain Gardens and BMP T5.14B
Permeable Pavements, BMP T5.16 Tree Retention and Tree Planting,
maintenance tables added. Added placeholders for Bioretention and
Added discussion that there are emerging technologies approved for
permeable pavement pending completion of the development of LID Concentrated Flow Dispersion and BMP T5.12 Sheet Flow Dispersion.
general changes in terminology. Added guidance regarding pollution-
Revised application to refer specifically to Minimum Requirements #5,
the expansion of Chapter 5 and source of additional design details (LID BMP T5.16 Vegetated Roofs, BMP T5.18 Reverse Slope Sidewalks, BMP
Expanded the list of BMPs in sections 5.3.1 and 5.3.2. Revised language
Renamed this Section and added information for the BMPs discussed in
generating hard surfaces, pollution-generating impervious surfaces, and
Bioretention but details are in Volume V of Chapter 7. Added BMP T5.15
information from WSDOT on Media Filter Drains and Compost Amended
Renamed this Section and added information regarding Bioretention and
Revised BMP T5.30 Full Dispersion by incorporating details from previous
T5.19 Minimal Excavation Foundations, BMP T5.20 Rainwater Harvesting.
Replaced "impervious" surfaces with "hard" surfaces in coordination with Add reference to expanded BMP options and LID Manual to acknowledge
5.3.3
Change
Other Practices
list of BMPs provided.
Minor language changes.
to incorporate new terms.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Minor language changes for clarity.
Amend existing BMP's add new BMP's
Added new tables within overall set of operation and maintenance standards
Changed bioinfilltration to bioretention.
Deleted Full Dispersion and section
Minor language changes for clarity. Changes
Additional clarifying guidance provided. Full
YesYesYes
to Permit
Language
Change Tied
5-16-16-17-1 7-1
5-16-1
Numbers
5-3 to 5-39
4-1 through 4-24-2 through 4-45-1 through 5-27-1 through 7-2
4-31 through 4-535-39 through 5-42
Approximate Page
BMPs
Facilities
Location
Pretreatment
Section 6.1 PurposeSection 7.1 Purpose
Section 5.1 Purpose
Section 5.2 ApplicationSection 6.2 Application
Sections 7.3 Applications
Stormwater Management
Section 5.3.2 Site Design BMPs
Sections 7.2 General Considerations
Section 4.1.3 flows Requiring Treatment
Section 4.1.2 Water Quality Design Flow Rate
Section 5.3.1 On-site Stormwater Management
Section 4.6 Maintenance Standards for Drainage
Section 6.3 Best Management Practices (BMPs) for
Section 5.3 Best Management Practices for On-Site
Chapter 5 - On-Site Stormwater ManagementChapter 6 - PretreatmentChapter 7 - Infiltration and Bioretention Treatment Facilities
T8.10.
area of plates.
sand filter vault.
Highway Runoff Manual.
separate BMP for clarity.
objective for sand filters.
Reasoning or Comments
Revised to include media filter drains.
Designers should refer to Basic Filter Strip.
Corrected Stokes Law equation for rise rate.
for Bioretention Cells, Swales, and Planter Boxes.
Design details for these BMPs remain in Volume III.
Revised name from Sand Filtration to just Filtration.
Added reference to Media Filter Drain to description.
Revised list of BMPs. Revised Sizing Criteria table for clarity.
Minor language changes for clarity throughout the chapter.
Added design criteria for new Media Filter Drain (MFD) option
Filter Strips. Treatment via infiltration through amended soils.
No design criteria exists for this BMP to validate basic treatment.
First cell must be lined to be consistent with liner requirements in
Added Media Filter Drain to list of approved technologies. Clarified
for 2-cell ponds. Definition of WQ Design Storm Volume amended.
BMP T8.11 Large Sand Filter Basin was described in the prior manual
under BMP T8.10 Sand Filter Basin. The Large Sand Filter was given a
previous sections 8.5, 8.6, 8.7, & 8.8 become subsections under BMP Replaced sections 12.1 through 12.5 to provide new guidance on the
Added guidance and design criteria for Compost-Amended Vegetated
Technology Assessment Protocol (TAPE) review and approval process.
Added design criteria for sand filter basins. reorganized section so that
(previously referred to as Ecology Embankment). Text matches WSDOT Chapter 4. Added cell requirements for consistency with design criteria Corrected the equation to calculated the projected
(horizontal) surface
Added detailed guidance, design criteria, infeasibilty criteria and figures
Revised the purpose to apply to both sand and media filtration facilities.Added design criteria, construction criteria, and maintenance criteria for
Boxes.
Change
new guidance.
Added this BMP.
within BMP T8.10
Revised guidance.Revised guidance.
Corrected formula.Corrected formula.
guidance removed.
Removed this BMP.
Included new technologies
language changes for clarity.
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Updated references to Volume III
Renamed and reorganized section.
Minor language changes for clarity.Minor language changes for clarity.
Replaced Bio-infiltration Swale with
Changed title and introduced minor
Transferred this BMP from Chapter 9.
Bioretention Cells, Swales, and Planter
Separated out BMP previously reference
Replaced sections 12.1 through 12.5 with
Additional guidance provided and outdated
to Permit
Language
Change Tied
7-28-2
8-18-18-2
N/A
Numbers
8-2 to 8-15
7-3 through 7-258-1 through 8-399-1 through 9-269-1 through 9-26
7-25 through 7-298-16 through 8-178-17 through 8-238-24 through 8-3811-8 through 11-912-1 through 12-6
10-1 through 10-17
11-10 through 11-11
Approximate Page
Boxes
Location
8.1 Purpose
Strips (CAVFS)
8.2 Description
BMP T10.10 Wet Pond
BMP T8.20 Sand Filter Vault
BMP T8.40 Media Filter Drain
Section 7.4 and BMPs 7.10 & 7.20
BMP T8.11 Large Sand Filter Basin
BMP T9.50 Narrow Area Filter Strip
Section 8.3 Performance Objectives
Chapter 12 - Emerging Technologies
Section 9.4 Best Management Practices
Section 8.4 Applications and Limitations
Chapter 8 - Filtration Treatment Facilities
BMP T11.10 API (Baffle type) Separator Bay
Chapter 9 - Biofiltration Treatment Facilities
Sand Filtration / BMP T8.10 Sand Filter Basin
BMP T7.40 Compost-amended Vegetated Filter
BMP T11.11 Coalescing Plate (CP) Separator Bay
BMP T 7.30 Bioretention Cells, Swales, and Planter
Section 8.5 Best Management Practices (BMPs) for
Chapter 8 - Sand Filtration Treatment FacilitiesChapter 9 - Biofiltration Treatment FacilitiesChapter 10- Wetpool FacilitiesChapter 11 - Oil and Water SeparatorsChapter 12 - Emerging
Technologies
Reasoning or Comments
evaluating soils used for bioretention.
previously listed throughout this volume.
Lists of species from City of Seattle guidance.
general procedures in the ASTM method are implemented. This
Removed examples of emerging technologies. Added some examples
test for saturated hydraulic conductivity can be influenced by how the
appendix lays out more specific procedures to help with consistency in
Added Recommended Modifications to ASTM D 2434. The results of this
Corrected several test procedures and geotextile property requirements.
Change
technologies.
Revised Guidance.
Additional guidance provided.
Removed examples of emerging
New appendix pertinent to BMP T5.16
to Permit
Language
Change Tied
N/A
Numbers
E-1 through E-5
C-1 through C-3
B-1 through B-2
Approximate Page
Species
Location
Appendix V-C Geotextile Specifications
for Stormwater Treatment and Control
Conductivity for Bioretention Soil Mixes.
ASTM D 2434 When Measuring Hydraulic
Appendix V-B Recommended Modifications to
Section 12.6 Examples of Emerging Technologies
Appendix V-E Recommended Newly Planted Tree
Appendix V-B Recommended Procedures for ASTM D 2434Appendix V-C Geotextile SpecificationsAppendix V-E Recommended Bioretention Plant Species
Tupsnxbufs!Nbobhfnfou!Qmbo
Qvcmjd!Pqfo!Ipvtf
Date: Tuesday, September 26, 2017
Location: Cotton Building, 607 Water Street, Port Townsend
Be part of the Stormwater Management Plan public process. Come and
give your input on the City’s proposed Stormwater Capital Improvement
projects, the Stormwater Utilities Vision Statement and more.
Gps!npsf!jogpsnbujpo!po!boe!bcpvu!uif!Tupsnxbufs!Nbobhfnfou!Qmbo!qmfbtf!wjtju!uif!Djuzt!Tupsnxbufs!
Nbobhfnfou!Qmbo!xfctjuf!iuuqt;00tupsnxbufsnbobhfnfouqmbo/xpseqsftt/dpn0!!Xijmf!zpv!bsf!wjfxjoh!
uif!xfctjuf!qspwjef!zpvs!fnbjm!bu!uif!cpuupn!pg!uif!nbjo!qbhf!boe!gpmmpx!uif!qspdftt/!!!
AGENDA
Stormwater Management Plan - Advisory Task Force
Workshop 2 | November 2, 2017 | Cotton Building, 607 Water Street, Port Townsend
2:00 –2:15 Welcome and Agenda
2:15 –2:30 Introductions
2:30 –2:45 Meeting Purpose and Goal
2:45 –3:15 Recap from Task Force Meeting #1
3:15 –3:30 Go over public comment to date
3:30 –3:45 Brief overview of the proposed Stormwater Capital
Improvement Program (CIP)
3:45 –4:15 Financing
4:15 –4:30 Development Standards
4:30 –5:00 Meeting Summary
5:00 Adjourn
H
MMM
M
On-goingOn-goingOn-going
in progress
Importance
(High/Med/Low)in the 2018 budget
XXXXXXXX
2017 CIP?
(Select 10)
C
D
2017 Site
Visit Map
Description
Winona Wetland Property Acquisition - Purchased in 1995Hastings to 25th Thomas to Hancock - wetland and critical drainage protection propertyHancock/25th/Sheridan, Pasture - combine
with # 4 under Acquisitions16th Street - Sheridan to LandesDrainage Cooridor between 49th St. and 50th St. and Jackman St. to Gise St. 12th St right-of-way from McPherson to Logan and
Logan Street from 10th to 12th Sts.Golf Course Pond - Needs flow control on the upper elevationCenter St San Juan to Olympic Ave. - Flooding/drainage problemHancock Street and 32nd
Street - Flooding Issues - 31st Street storm water tied into the sewerMcPherson/9th, Stormwater to SSMH tie-in is north of 9th Street14th Street McPherson Street to Rosecrans StreetLogan
Street Stormwater Pond overflow - cross street is 3rd StreetPacific Street - Tremont Street to Milo Street - need storm pipe to Froggy BottomsStorm tied in to sewer on Lawrence Street
at Polk Street, Tyler Street and Taylor StreetGarfield Street Bioswales - Could be part of the removing storm to sewer tie-in on Lawrence StreetRegional Stormwater Facility for Rainier
Street Commercial CorridorMajor Collector and Minor Arterials (Purple Roads) Stormwater ImprovementsLocal Access Street (Brown Roads) Stormwater Improvements
----------
9-29-28-6
4-8
9-204-2111-311-4
1999
2018 - 2023 Stormwater CIP ListProject No.ACQUISITIONSSTORMWATER PROJECTSLocalized Flooding Improve ConveyanceStormwater Tie Into the Sewer SystemImprove Treatment through RetrofitRegional
Stormwater SystemsExisting system improvements
December 11, 2017
City Council Meeting
Plan Briefing
Stormwater Management
Waters
Corridors
Connections
Roadways
Critical Drainage
–
–
Water Bodies and Receiving
Created Drainage
–
–
RPLE
REEN
LUE
INK
BGPU
–––P–
Tier 1 Tier 2 Tier 3 Tier 4
••••
ashington (ECY SWMM) and the 2012 ECY SWMM comparison
2005 Department of Ecology’s Stormwater Management Manual for Western W
•
Curb and Gutter
–
F Street
Road side Swale
–
Discovery Road
Hastings Avenue
Street
Landes
Street
14
Sheridan Street
Street & Rosecrans Street
3
P Street
Street
Hancock Street & 31
Sheridan Street
Haines Street
Street
Landes
Street &
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March 15, 2018
¸
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.
Appendix I-D Guidelines
project.
Stormwater Permits.
perforated stub-outs.
Reasoning or Comments
impervious surfaces to the extent feasible.
for Wetlands when Managing Stormwater
"native" from the land conversion threshold.
manual to the municipal stormwater permits.
for water quality design storm volume and flow rate.
Management Practices, and revision of element #12 to include
and partial dispersion methods, full downspout infiltration and
Added a new statement for the site plan to use site-appropriate addition of element #13 that requires the protection of LID Best
development (LID) guidance and requirements in the Municipal
development principles to retain native vegetation and minimize
Removed outdated references to the Puget Sound Water Quality
related new definitions. Clarifications about the surfaces that the
hard surfaces at new development sites, the deletion of the word
Changes include: revisions to the construction SWPPP elements to
correspond with the Construction Stormwater General Permit, the
Added clarification for peak discharges using 15 minute time steps.
the related new definitions. The intent is to continue to capture the Revisions to acknowledge the use of permeable pavements and the
surfaces, LID, converted vegetation) because of the new low impact
Changes include: the new LID performance standard and list options
Added definitions for a few terms used previously but not previously
intent is to capture the same size and types of projects as previously.
responsibilities for an inspector or CESCL depending on the size of the use types: lawn and landscaped areas; roofs, and other hard surfaces.
Revisions made to acknowledge the use of permeable pavements and
based on project size and location. The lists are divided into three land for each land use type. Some of the BMPs included in the lists are: rain
surfaces, the application of minimum requirements #6 - #9 to replaced
Projects implementing the list option must select the first feasible BMP
Management Plan. Section renamed and focuses on relationship of the
Changes include: the replacement of “impervious” surfaces with “hard”
defined. Other terms have a revised definition or a new definition (hard
requirement applies to, and the use of the 0.10 /0.15 cfs threshold. The
same size and types of projects as previously. More accurate definitions
gardens, permeable pavements, bioretention, soil quality and depth, full
Revisions correspond to the significantly revised
Change
guidelines.guidelines.
Minor additions.
supplemental guidelines.supplemental guidelines.
Added and revised definitions.
Revisions to the thresholds and
development (LID) requirements.standard requirement, additional
Added guidance. Section renamed.
Design Flow Rate, and supplemental
Revised requirements and objective.
Multiple revisions for new low impact
elements, objective, and supplemental
Revised the thresholds for determining
Revisions to the applicability, thresholds,
Reorganized and revisions to: thresholds,
Revisions to the thresholds, Water Quality
development and redevelopment. Revised
general requirements, construction SWPPP
which minimum requirements apply to new
requirements, and supplemental guidelines.
YesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
2-2
2-16
Numbers
2-5 through 2-9
2-9 through 2-16
2-17 through 2-262-27 through 2-282-28 through 2-322-33 through 2-352-35 through 2-402-40 through 2-41
Approximate Page
(SWPP)
Agenda
Outfalls
Location
Protection
Treatment
Flow Control
RequirementsRequirements
Stormwater Management
Preparation of Stormwater Site Plans
Section 2.5.2 Minimum Requirement #2: Section 2.5.4 Minimum Requirement #4:
Section 2.4 Applicability of the Minimum Section 2.5.1 Minimum Requirement #1:
Section 2.3 Definitions Related to Minimum
Preservation of Natural Drainage Systems and
Construction Stormwater Pollution Prevention
Section 2.5.6 Minimum Requirement #6: Runoff Section 2.5.7 Minimum Requirement #7: Runoff
Section 2.5.5 Minimum Requirement #5: On-site
Section 2.5.8 Minimum Requirement #8: Wetlands
Section 2.1 Relationship to the Puget Sound Action
Step V: Select
apply.
facilities.
and in section 3.1.7.
with a reference to Chapter 2 of Volume V.
Reasoning or Comments
applicable minimum requirements.subject to Min. Requirements 1 - 9.
the appendix and retained the rainfall tables.
Appendix 1 of the 2007 municipal stormwater permits.
Changes for clarification and to remove repetitive language.
Significant changes to describe how to prepare the Permanent
requirements. Ecology replaced the language in
Soils reports are necessary part of LID decisions. Declarations of
Revisions and new language especially in Step III for guidance on
Added several LID BMPs that require the submission of as-builts.
Treatment Facilities
the changes in the Municipal Stormwater Permits and for new LID
Stormwater Control Plan that incorporates LID features. Separate
Added language for clarity on use of Basin Planning for addressing
and in particular for LID site design. Split into subsections based on
whether Min. Requirements 1 - 5 apply, or Min. Requirements 1 - 9
LID features, establish maintenance requirements and government
References to on-site BMPs added and preliminary determination of
access for inspections of privately maintained stormwater BMPs and
Revised for clarity and removed outdate language in the introduction
guidance for projects subject to Min. Requirements 1 - 5 and projects
retrofit needs and for developing an alternative flow control strategy.
Removed background and outdated information for brevity. Renamed
Additional guidance details the information necessary for site analysis,
modeling threshold discharge areas. Minor revisions to correspond with
Changed and added language to be consistent with the requirements in
Covenants and Grants of Easement are necessary mechanisms to identify
Change
Volume V.
Step V: Select Treatment
implementation.
Guidance added.Guidance added.
Design Flow Rate.
guidance removed.
Grants of Easement.
with a reference to Chapter 2 of
Minor language changes.
Stormwater Control Plan.
procedures necessary for LID
Additional guidance provided.Additional guidance provided.
Site Hydrology of the Permanent
Significant changes to incorporate
Removed introductory language and
Reference to needed soils report and
background information on the Water
language in
Quality Design Storm and Water Quality
Revisions to all subsections of Developed addition of Declaration of Covenants and
Revised language, proposed replacing the
Facilities
Additional guidance provided and outdated
YesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-17
Numbers
4-1 through 4-4
3-2 through 3-73-7 through 3-8
B-1 through B-5
A-1 through A-3
3-1 through 3-173-8 through 3-12
2-45 through 2-463-13 through 3-143-14 through 3-16
Approximate Page
Plan
Location
Sections 3.1.2 to 3.1.4
Stormwater Control Plan
Section 2.8 Exceptions/Variances
Information on Existing Conditions
Stormwater Pollution Prevention Plan
Requirements Through Basin Planning
Section 3.1.1 Step 1 - Collect and Analyze
Section 3.1.5 Step 5 - Prepare a Permanent
Section 3.2.2 Final Corrected Plan Submittal
Appendix I-B Rainfall Amounts and Statistics
Section 3.1.6 Step 6 - Prepare a Construction
Section 4.2 BMP and Facility Selection Process
Section 3.1.7 Step 7 - Complete Stormwater Site
Chapter 3 - Preparation of Stormwater Site Plans
Appendix I-A Guidance for Altering the Minimum
Chapter 3 - Preparation of Stormwater Site PlansChapter 4 - BMP and Facility Selection Process for Permanent Stormwater Control PlansAppendix I-A Guidance for Altering the Minimum Requirements
Through Basin PlanningAppendix I-B Rainfall Amounts and Statistics
Stormwater Permits.
in Min. Requirement #7.
Reasoning or Comments
than 15% on a monthly basis.
analyses, and to remove reference to a creek in Eastern WA.
development (LID) guidance and requirements in the Municipal
Rewritten to remove outdated information, clarify concepts, and
approach the protection and use of wetlands through controlling
List edited to add additional waters based on specific requests and
definition has been added. A handful of other terms have a revised
There are a few terms, used previously but not defined, for which a
definition, and there are new terms, because of the new low impact
more than 20% on a single event basis, and must not deviate by more
Map shows basins which potentially qualify for use of existing land cover
discharges to wetlands. Total discharges to wetlands must not deviate by as the pre-developed land cover for flow control purposes. See reference
Change
Added Map
stormwater.
Added and revised definitions.
protection of Wetlands when managing
Multiple revisions for the use and/or the
Added and deleted Exempt Surface Waters.
YesYesYes
to Permit
Language
Change Tied
F-1
Numbers
Glossary-47
E-1 through E-4
D-1 through D-18
Glossary-1 through
Approximate Page
Location
Managing Stormwater
Glossary and Notations
impervious area since 1985
Appendix I-F Basins with 40% or more total
Appendix I-D Guidelines for Wetlands when
Appendix I-E Flow Control-Exempt Surface Waters
Appendix I-D Guidelines for Wetlands when Managing StormwaterAppendix I-E Flow Control-Exempt Surface WatersAppendix I-F Feasibility Criteria for Selected Low Impact Development Best
Management PracticesGlossary and Notations
BMPs.
Industrial Permits).
duplicate language.
Reasoning or Comments
Low Impact Development BMPs.
Replaced older figure with an updated one.
Prevention Plan Checklist is still located in Section 3.3.
State, and Local Regulatory Requirements was removed.State, and Local Regulatory Requirements was removed.
Revised this chapter to use simpler and clearer language.
information. Sections 2.1 and 2.2 now go into detail about the element now contains an Additional Guidance section that has
Removed this section by combining it with Section 1.2 to eliminate
Revised this chapter to update this information for revisions to the
Replaced these sections to remove invalid information or duplicate Stormwater Permits, and the Construction BMPs in Chapter 4. Each
Section 3.3. Please note that the Construction Stormwater Pollution
to Section 3.2 for clarity. The Step-By-Step Procedure now follows in
information not required by the permits. Added Element #13 Protect
Revised this chapter to use simpler and clearer language. Information Revised this chapter to use simpler and clearer language. Information
and the requirements for a Stormwater Site Pollution Prevention Plan.
covered in Volume I, Section 1.6 Relationship of the Manual to Federal, covered in Volume I, Section 1.6 Relationship of the Manual to Federal,
Stormwater General Permits (including the Municipal, Construction, and Revised The Construction SWPPP Elements, described in Section 3.3.3 to coordinate with the Construction Stormwater
General Permit, Municipal
Moved The Construction SWPPP Requirements, previously in Section 3.3
relationship of Volume II to the Construction Stormwater General Permit
Revised to incorporate a new element, Protect Low Impact Development
1.2.
Change
reversed.
Replaced.
Renamed.
and brevity.and brevity.and brevity.
SWPPP Elements.
Stormwater Permits.
to the Washington State General
Multiple revisions to the Construction
Previous Sections 3.2 and 3.3 have been
Section 2.1 The Construction Stormwater
in this section is now included in Sections
replace the previous Sections 2.1 and 2.2.
Stormwater Pollution Prevention Plans now
This section was removed. The information
Multiple revisions to coordinate the manual
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
General Permit and Section 2.2 Construction
YesYesYesYes
to Permit
Language
Change Tied
1-31-6
N/A
Numbers
1-1 through 1-92-1 through 2-62-1 through 2-6
2-2 through 2-4
3-1 through 3-323-4 through 3-323-8 through 3-32
Approximate Page
Location
Figure 1.5.1
Implementation
Chapter 3 - Planning
Pollution Prevention
Section 2.1 and Section 2.2Section 3.2 and Section 3.3
Stormwater Pollution Prevention
Section 1.3 How to Use This Volume
Chapter 2 - Regulatory RequirementsChapter 2 - Regulatory Requirements
Construction SWPPP Development and
Section 1.3 Thirteen Elements of Construction
Section 3.3.3 (Previously Section 3.2.3) Step 3 -
Chapter 1 - Introduction Construction Stormwater
Volume II Construction Stormwater Pollution PreventionChapter 1 - Introduction Construction Stormwater Pollution PreventionChapter 2 - Regulatory RequirementsChapter 3 - Planning
equivalent.
field experience.
and field experience.
compost specification.
Reasoning or Comments
discharge to surface or ground water.
comments received and field experience.
Temporary and Permanent Seeding to this BMP.
should be based on the size of the construction site.
Revised this BMP to use simpler and clearer language.
Added Wood Straw and Wood Straw Mulch to the table.
Added guidance previously found in BMP C120: Temporary and
intent of this BMP in a safer and more commonly used manner.
Added minimum mulch thickness based on field experience and for this BMP based on comments received and field experience.
Added guidance to clarify that wheel wash wastewater shall not
Updated figure to provide more details of a typical Wheel Wash.
Ecology revised this chapter to use simpler and clearer language.
Refers to Ecology's website for BMPs that have been approved as
comments. Ecology added guidance previously found in BMP C120:
Ecology added Table 4.1 Source Control BMPs by SWPPP Element to
Removed measures and quantities because measures and quantities
coverings (such as compost and straw) are preferable. Ecology added
Removed the use of plastic sheeting over seeded areas because other Provided a link to composting guidance and removed old reference to
Removed this BMP because BMP C103: High Visibility Fence meets the and removed guidance for this BMP based on comments received and
Revised and reorganized this BMP to use simpler and clearer language.
Permanent Seeding to this BMP. Ecology added and removed guidance
Ecology added and removed additional guidance for this BMP based on
show how the BMPs listed in Section 4.1 relate to the SWPPP Elements.
Added high visibility silt fence because it meets the intent of BMP C103.
Moved some guidance to BMP C121: Mulching or BMP C125: Top soiling.
Added and removed guidance for this BMP based on comments received
Change
removed.
and brevity.
and removed.
SWPPP Element
clarity, and brevity.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Figure was updated
This BMP was removed.
Additional guidance provided.Additional guidance provided.
Suggested measures and quantities
This BMP now includes high visibility silt
Added Table 4.1 Source Control BMPs by
and brevity. Additional guidance provided
Added approved equivalent BMPs Sections.fence. Multiple revisions for plain language, Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Yes
to Permit
Language
Change Tied
4-6
N/A
4-114-21
Numbers
4-1 through 4-2
4-7 through 4-9
4-9 through 4-11
4-1 through 4-1284-13 through 4-194-19 through 4-214-22 through 4-254-25 through 4-274-27 through 4-284-29 through 4-324-42 through 4-43
Approximate Page
Location
Table 4.1.8
and Specifications
BMP C124: Sodding
BMP C121: Mulching
BMP C106: Wheel Wash
Figure 4.1.2 - Wheel Wash
BMP C123: Plastic Covering
BMP C122: Nets and Blankets
BMP C150: Materials on Hand
BMP C103: High Visibility Fence
Section 4.1 Source Control BMPs
BMP C104: Stake and Wire Fence
BMP C125: Top soiling / Composting
BMP C120: Temporary and Permanent Seeding
BMP C105: Stabilized Construction Entrance / Exit
Chapter 4 - Best Management Practices Standards
Chapter 4 - Best Management Practices Standards and Specifications
.
2
areas.
Elements. materials.
prohibited.
experience.
the near future.
(CTAPE) program.
Stormwater General Permit.
Reasoning or Comments
in BMP C252 and in BMP C253.
guidance for neutralizing high pH.
on comment received and field experience.
on neutralizing high pH through the use of CO
to show how the BMPs listed in Section 4.2 relate to the SWPPP
projects needing to perform Erosion and Sediment Control Work. Added guidance for this BMP, previously available online, to
Removed this BMP because it is not applicable to the full range of
both the Municipal Stormwater General Permits and Construction
Construction Stormwater General Permit and to make it clear that
Added sizing criteria for this BMP, previously available online.
Renamed this BMP to include wattles made from compost or other
Removed this BMP because of changes in threshold requirements in
Added guidance for this BMP based on comments received and field
coordinate with the Chemical Technology Assessment Protocol
Added this BMP to provide additional guidance for concrete washout
Added guidance to coordinate this BMP with the requirements of the Concrete spillage or concrete discard to surface waters of the State is
Minimum Requirements for ESC Training and Certification Courses has
Added this BMP, previously available online, to provide guidance
Added guidance for inlet protection of lawn and yard drains and based
been removed. Ecology plans on issuing separate, updated guidance in Revised and reorganized this BMP to use simpler and clearer language.
Added this BMP, previously available online, to provide additional
Added this new BMP for dewatering, Construction SWPPP Element #10.Revised this appendix to coordinate with the new information provided
Removed this BMP because this BMP has been proven to be ineffective.
Added Table 4.2 Runoff Conveyance Treatment BMPs by SWPPP Element
Change
and brevity.
Added this BMP.Added this BMP.Added this BMP.Added this BMP.
guidance removed.
C252 and BMP C53.
This BMP was removed.This BMP was removed.This BMP was removed.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Renamed from Straw Wattles.
Added Table 4.2 Runoff Conveyance
Treatment BMPs by SWPPP Element
Multiple revisions to coordinate with BMP
Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
N/AN/AN/A
4-57
Numbers
B-1 through B-3
4-43 through 4-454-48 through 4-534-54 through 4-554-74 through 4-774-78 through 4-794-90 through 4-954-96 through 4-99
4-100 through 4-1024-112 through 4-1204-120 through 4-1244-125 through 4-127
4-128 through 4-129
Approximate Page
2
Lead
BMPs
Location
TreatmentTreatment
BMP C235: Wattles
Pollution Prevention
BMP C233: Silt Fence
BMP C207: Check Dams
BMP C230: Straw Bale Barrier
BMP C236: Vegetated Spray Fields
BMP C154: Concrete Washout Area
BMP C220: Storm Drain Inlet Protection
BMP C253: pH Control for High pH Water
Sawcutting and Surface Pollution Prevention
BMP C252: High pH Neutralization Using CO
BMP C161: Payment of Erosion Control Work
BMP C151: Concrete Handling and BMP C152:
Section 4.2 Runoff Conveyance and Treatment BMP C250: Construction Stormwater Chemical BMP C251: Construction Stormwater Filtration
BMP C180: Small Project Construction Stormwater
BMP C160: Certified Erosion and Sediment Control
Appendix II-B Background Information on Chemical
purposes.
Minor text change
(WWHM) changes.
guidance was replaced.
Volume I, Appendix 1-D.
trenches and splashblocks.
in the introductory section.
Reasoning or Comments
of Street Wastes in Volume IV.
Permeable Pavement sections.
permeable pavements in introductory section.
and feasibility criteria. Updated design guidance.
guidance for oil control and pre-treatment facilities.
distributed bioretention facilities as indicated in text.
Revised this chapter to use simpler and clearer language. Revised this chapter to use simpler and clearer language.
and feasibility criteria. Improved clarify in design guidance and
and feasibility criteria. Needed better clarity in design guidance
Added references to Minimum Requirement #5, bioretention and
Step 6 for clarity and for meeting MR#5. Revised Step 7 for clarity.
Revised Step 2 to include guidance for meeting MR#5. Significantly
Revised this chapter to use simpler and clearer language. Outdated Added guidance for MR #5 which now includes an LID Performance Expanded purpose statement and clarified in regard to
the types of
Added guidance on upcoming Western Washington Hydrology Model
facilities covered in Section 3.3. Added references to Bioretention and
computer modeling. Added guidance for design criteria for dispersion revised Step 5 for the new guidance provided in section 3.3.6. Revised
Added guidance on precipitation data and upcoming WWHM changes.
Text and figures updated to indicate priorities for handling roof runoff.
design of centralized infiltration facilities. Certain sections also apply to
Text changes for consistency with new priority lists in Min.Req'ment #5
Section 2.2 split into multiple subsections for clarity and for referencing Updated references to revised roof downspout BMPs and Rain Gardens
Text changes for consistency with new priority lists in Min. Req'ment #5 Text changes for consistency with new priority lists in Min. Req'ment #5
Updated Maintenance narrative to refer to Appendix IV-G Management
Standard. Revised the guidance for MR#8 to reflect the changes made in
Made significant changes to all sub-sections. Section pertains primarily to Made clarifications and added language for complying with MR#5. Added
Change
standard.
Req'mt #5Req'mt #5Req'mt #5
Req'mt #5
Req'mt #5.
and brevity.and brevity.and brevity.
Req'mt #5 and LID
Requirements (MR).
Updated references.
revised Min Req'mt #5
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Section significantly rewritten.
guidance removed for Minimum
Revised guidance and reference LID.
Revised several steps for new infiltration
Update text & figure for consistency with
Section 2.2 split into multiple subsections.
Additional guidance provided and outdated Additional guidance provided including Min
rate guidance and the new LID performance
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min
Update text for consistency with revised Min
YesYesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-1
3-353-653-653-66
Numbers
2-5 through 2-82-8 through 2-9
2-4 through 2-92-4 through 2-93-1 through 3-3
2-1 through 2-173-1 through 3-183-4 through 3-10
3-1 through 3-1093-11 through 3-163-17 through 3-183-19 through 3-643-68 through 3-71
3-65 through 3-102
Approximate Page
T5.10A)
WWHM
Facilities
Location
and Treatment
Section 3.3.1 Purpose
Section 3.3.2 Description
Section 3.3.3 Applications
Section 3.2 Detention FacilitiesSection 3.2 Detention Facilities
Chapter 2 - Hydrologic Analysis
Chapter 3 - Flow Control Design
Chapter 3 - Flow Control Design
Section 3.1 Roof Downspout ControlsSection 3.1 Roof Downspout Controls
Section 3.3.4 Steps for Design of Infiltration
Section 3.1.2 Downspout Dispersion Systems
Section 3.1.3 Perforated Stub-out Connections
Section 2.2.2 Assumptions made in creating the
Section 3.3 Infiltration Facilities for Flow Control
Section 2.2.3 Guidance for flow-related standards
Section 2.2 Western Washington Hydrology ModelSection 2.2 Western Washington Hydrology Model
Section 3.1.1 Roof Downspout Full Infiltration (BMP
Volume III Hydrologic Analysis and Flow Control Design / BMPsChapter 2 - Hydrologic AnalysisChapter 3 - Flow Control Design
3.3.6.
Reasoning or Comments
outdated computation steps.
3, and one for upcoming WWHM 2012.
Soil Texture Classification and D10 grain size.
Added guidance for conducting performance testing.
amended drawdown guidance, and verification testing.
for bioretention / rain gardens and permeable pavement.
and maintenance. Made wording clarifications to guidance.
Added a link to a website where isopluvial maps are available.
method for estimating infiltration rates. Deleted infiltration rate
determination sub-section due to redundancy with next section.
Procedures for conducting the PIT have been included within the
instead refers to steps 1-5 in section 3.3.4. Revised Figure 3.27 for
investigation, and determine the saturated hydraulic conductivity;
Removed steps to select location, estimate volume of stormwater, infiltration rate. Added a step for groundwater mounding analysis.
on groundwater monitoring wells and the use of grain size analysis infiltration rates, added a minimum organic content for treatment,
develop a trial infiltration facility geometry, conduct a geotechnical
Replaced "Infiltration Rate" with "Saturated Hydraulic Conductivity"
Updated references, removed unneeded guidance, revised limits on
guidance for the modeling on LID elements and wetlands. Removed
saturated hydraulic conductivity. Added guidance on pilot infiltration
proposed text on “Design Infiltration Rate Determination” in sections
Added guidance on current and upcoming versions of WWHM. Added
testing (PIT), and soil grain size analysis. Revised correction factors for
Text in regard to design guidance removed. All design guidance moved
Added guidance re field tests, computer modeling, and implementation
PIT results and soil grain size method. Removed options based on USDA
Added guidance for sizing for flow control, pretreatment design criteria,
throughout section. Updated the guidelines and criteria for determining
Multiple changes to subsurface characterization include added guidance
to Volume V. Two sets of modeling guidance provided. One for WWHM
updated guidance. Revised guidance for adjusting the preliminary design
Change
Section renamed.
guidance removed.guidance removed.guidance removed.guidance removed.
Appendix removed.
permeable pavement.
Added link to website.
USDA Textural Triangle.
Revised guidance on subsurface
receptor. Removed guidance for
Multiple revisions. Previous steps 1-4
groundwater mounding analysis step.
Added this section for bioretention and
Revisions for determining the saturated
hydraulic conductivity (infiltration rate).
removed. Multiple steps revised. Added
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
hydrogeologic investigation and figure 3.27,
characterization, soil testing, and infiltration
YesYesYes
to Permit
Language
Change Tied
A-1
N/A
Numbers
B-1 through B-13C-1 through C-13
3-72 through 3-753-75 through 3-833-83 through 3-863-86 through 3-903-90 through 3-94
3-103 through 3-109
Approximate Page
Guidance
Location
Infiltration Test
Computation Steps
Permeable Pavement Use
Facilities - Detailed Approach
Conductivity - Guidelines and Criteria
Model - Information, Assumptions, and
Section 3.3.6 Design Saturated Hydraulic
Section 3.3.7 Site Suitability Criteria (SSC)
Section 3.3.5 Site Characterization Criteria
Section 3.3.8 Steps for Designing Infiltration
Construction Criteria for Infiltration Facilities
Appendix III-B Western Washington Hydrology
Appendix III-D Procedure for Conducting a Pilot
Appendix III-C Washington State Department of
Section 3.3.9 General Design, Maintenance, and
Section 3.4 Site Procedures for Bioretention and
Appendix III-A Isopluvial Maps for Design Storms
Ecology Low Impact Development Flow Modeling
Appendix III-A Isopluvial Maps for Design StormsAppendix III-B Western Washington Hydrology Model - Information, Assumptions, and Computation Steps Appendix III-C Washington State Department
of Ecology Low Impact Development Design and Flow Modeling GuidanceAppendix III-D Procedure for Conducting a Pilot Infiltration Test
action.
language.
ISWGP and BGP.
a corrective action.
system to the BMPs.
outdated references.
Stormwater Permits).
Reasoning or Comments
and removed outdated references.
Revised BMPs to use simpler and clearer language.
Revised for clarity and removed outdated language.
Added numbers in the "S400" series to BMPs in Volume IV.
BMPs for facilities covered under the ISWGP (or other General
prevention and cleanup, visual inspections and record keeping.
Revised BMPs to use simpler and clearer language, and removed
in regards to the ISGP, BGP, and S&GP. Added guidance regarding
in regards to the ISGP, BGP, and S&GP. Section renamed to make it
include the addition of vacuum sweeping and pressure washing, spill
Revised wording to clarify where this Section applies. Revised several
clearer that applicable BMPs are Mandatory for permittees under the
Added new guidance clarifying the requirements regarding treatment compost leachate. Revised BMPs to use simpler and clearer language,
regarding boatyard activities. Revised BMPs to use simpler and clearer
(ISWGP), Boatyard General Permit (BGP), and Sand and Gravel General
facilities covered under the ISWGP that trigger a Level 1 or 2 corrective BMPs for clarity and to coordinate with the ISWGP. Significant changes
Revised language because solid waste regulations prohibit discharge of
Permit (S&GP) and the inclusion of "applicable" BMPs from this volume
Clarified guidance describing the requirements under the BGP and ISGP
in Industrial Stormwater Pollution Prevention Plans (Industrial SWPPPs).the ISWGP that trigger a Level 1 or 2 corrective action. Changed the title
Added new guidance describing the use of applicable (mandatory) BMPs Added new guidance describing the use of applicable (mandatory) BMPs
Revised wording to clarify where this Section applies. Added new text on
ISWGP requirements. Added guidance regarding facilities covered under
Added new guidance regarding the Industrial Stormwater General Permit
Added guidance regarding facilities covered under the ISWGP that trigger format for the BMPs to match the other volumes and added a numbering
Change
revisions.
and brevity.and brevity.
BMPs clarified.
Numbered BMPs.
guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.
Additional guidance provided.
guidance removed. Minor formatting
Additional guidance provided and several
Minor revisions for plain language, clarity, Minor revisions for plain language, clarity,
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
YesYes
to Permit
Language
Change Tied
1-2
1-31-4
2-10
Numbers
1-1 through 1-52-7 through 2-9
1-3 through 1-42-1 through 2-22-2 through 2-6
2-1 through 2-662-1 through 2-662-7 through 2-66
2-10 through 2-12
Approximate Page
Sources
Location
Source Control BMPs
Source Control BMPsSource Control BMPsSource Control BMPs
Chapter 1 - Introduction
Maintenance of Boats and Ships
Section 1.6.2 Recommended BMPs
Section 1.3 How to Use this Volume
S403 BMPs for Commercial Composting
S401 BMPs for the Building, Repair, and
Section 2.2 Pollutant Source Specific BMPs
Section 1.6.1 Applicable (Mandatory) BMPs
Section 2.1 Applicable (Mandatory) Operational
Section 1.5 Treatment BMPs for Specific Pollutant
S402 BMPs for Commercial Animal Handling Areas
Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural
Volume IV Source Control BMPsChapter 1 - IntroductionChapter 2 - Selection of Operational and Structural Source Control BMPs
references.references.references.
this volume.
Appendix IV-B.
outdated guidance.
use in street cleaning. the required controls.
vehicles to align with ISGP.
Reasoning or Comments
municipal stormwater permits.
Minor language changes for clarity.
Added "Potential Pollutant Generating Sources"
Minor revisions to the Site Evaluation subsection.
Updated the reference to guidance for Vehicle Recyclers.
Removed outdated guidance and added new guidance in the
process wastewater to ground water or surface water. Removed
Additional guidance provided for the handling of ditch cleanings.
contamination in Street Waste Solids subsection. Reorganized the
Revised language to coordinate with the ISGP. Removed outdated
Updated "applicable BMP" guidance for handling of liquids in scrap
Revised several BMPs for clarity and to coordinate with the ISWGP.
Clarified guidance describing which NPDES permit(s) regulate wood
Minor language changes for clarity. Removed the outdated Table in
Added guidance to clarify that the ISWGP prohibits the discharge of
Added a references to Volume V and Ecology publications for BMPs.
treatment areas. Revised BMPs to use simpler and clearer language.
Clarified that facilities not under the ISWGP may consider some water Edits to make guidance consistent with the most recent industrial and
disposal of street waste liquids subsection, no major content changes.
Figure was unclear and the existing text provided a better description of Edits for clarity and to replace and revise guidance documents and WAC Edits for clarity and to replace and
revise guidance documents and WAC
Added this BMP to provide further guidance consistent with BMPs within
Change
references.
Figure Deleted
BMPs clarified.
guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.Minor language changes.Minor language changes.
Additional guidance provided
Added reference to guidance.
Additional guidance provided.Additional guidance provided.
Updated reference to guidance.
and outdated guidance removed.
Revision for consistency with the ISGP
Additional guidance provided and several
Minor language changes. Removed Table.
and brevity. Additional guidance provided
Additional guidance provided and updated
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
C-1
N/A
A-14
Numbers
E-1 through E-7
B-1 through B-2
D-1 through D-9
A-1 through A-24
G-1 through G-15
2-13 through 2-142-32 through 2-342-35 through 2-372-45 through 2-462-46 through 2-472-48 through 2-492-58 through 2-592-60 through 2-622-63 through 2-642-64 through 2-66
Approximate Page
Permits
Location
Substances
and Equipment
Adverse Impact
of Street Wastes
Generating Sources
Airports and Streets
Fluids/Other Wastes
S430 BMPs for Urban Streets
Impact Stormwater Programs
Commercial Composting - SIC 2875
Figure 2.15 - Uncovered Wash Area
S424 BMPs for Roof/Building Drains at
S432 BMPs for Wood Treatment Areas
S423 BMPs for Recyclers and Scrap Yards
Manufacturing and Commercial Buildings
S426 BMPs for Spills of Oil and Hazardous
Vehicles / Equipment / Building Structures
Appendix IV-C Recycling/Disposal of Vehicle
S431 BMPs for Washing and Steam Cleaning Appendix IV-E NPDES Stormwater Discharge
Appendix IV-D Regulatory Requirements That
Appendix IV-A Urban Land Uses and Pollutant
Appendix IV-B Stormwater Pollutants and Their
S416 BMPs for Maintenance of Roadside Ditches
S405 BMPs for Deicing and Anti-Icing Operations -
S414 BMPs for Maintenance and Repair of Vehicles S433 BMPs for Pools, Spas, Hot Tubs and Fountains
Appendix IV-G Recommendations for Management
Appendix IV-A Urban Land Uses and Pollutant Generating SourcesAppendix IV-B Stormwater Pollutants and Their Adverse ImpactAppendix IV-C Recycling/Disposal of Vehicle Fluids/Other WastesAppendix
IV-D Regulatory Requirements That Impact Stormwater ProgramsAppendix IV-E NPDES Stormwater Discharge PermitsAppendix IV-G Recommendations for Management of Street Wastes
Chapter 2. Chapter 2.
computer models.
outdated references.
Enhanced Treatment.
duplicated from Chapter 2.
Reasoning or Comments
was duplicated from Chapter 2.
Bioretention as a treatment method.
Added paragraph on emerging technology options.
Added paragraph on emerging technology options.
waters triggering enhanced treatment for accuracy.
removed the associated subsection, Pollutants of Concern.
filtration, emerging technologies, and on-line systems. Added
technologies. Deleted the "Where Applied" section since it was
between "bioretention" and "rain gardens." Replaced "Ecology between "bioretention" and "rain gardens." Replaced "Ecology
Removed the Suggested Treatment Options Table and Ability of
Revised BMPs to use simpler and clearer language, and removed
for this treatment), and media filter, added emerging stormwater
Deleted the "Where Applied" section since it was duplicated from
Deleted the "Where Applied" section since it was duplicated from
Revised selection process steps for clarity and to remove outdated
Embankment" with "Media Filter Drain". Added Compost-amended
Removed "rain garden" for consistency with proposal to distinguish
information. Revised the Treatment Facility Selection Flow Chart for
Revised guidance for oil/water separation, pretreatment, infiltration,
treatment technologies. Deleted the "Where Applied" section since it
the TAPE process but Ecology has approved one emerging technology.
revised guidance throughout Volume V. Revised description of surface
Some treatment BMP options removed, emerging technologies added,
Removed amended sand filter (no design criteria have been developed
Vegetated Filter Strip. Removed Bio-infiltration Swale. Added emerging
New guidance more accurately describes how volume is determined by
Revised the performance goal for dissolved metals. Removed Amended
Embankment" with "Media Filter Drain." Added emerging technologies.
one BMP renamed. Added a note for Phosphorous facilities that require
Treatment Facilities Table because they provided limited usefulness and
Removed catch basin inserts and added emerging stormwater treatment Sand Filter. Added "vegetated" to "Compost Amended "Vegetated" Filter
technologies. To date, no catch basin inserts have been approved though Strip. Removed "rain garden" for consistency with proposal to distinguish
Table.
Change
and brevity.
list of options.
with Chapter 2.
guidance removed.
enhanced treatment.
Revised list of options.Revised list of options.Revised list of options.
Additional guidance provided.Additional guidance provided.
Minor revisions to the steps. Revised
Inserted updated modeling guidance.
Revised list of options. Revised waters
Multiple revisions to remove outdated
description of surface waters triggering
guidance and to provide new guidance.
Table, and Ability of Treatment Facilities
Removed the subsection on Pollutants of
triggering enhanced treatment consistent
Minor revisions for plain language, clarity,
Concern, the Suggested Treatment Options
Minor language changes for clarity. Revised
Additional guidance provided and outdated
Yes
to Permit
Language
Change Tied
3-1
2-12-34-1
Numbers
1-2 through 1-43-2 through 3-33-5 through 3-7
1-1 through 1-42-1 through 2-93-3 through 3-43-7 through 3-9
2-9 through 2-11
Approximate Page
Factors
Location
Figure 2.1.1
Treatment Facilities
Chapter 1 - Introduction
Section 3.2 Oil Control Menu
Chapter Introduction Paragraph
Section 1.4.3 Treatment Methods
Section 3.5 Basic Treatment Menu
Section 3.4 Enhanced Treatment Menu
Section 3.3 Phosphorous Treatment Menu
Section 2.1 Step-by-Step Selection Process for Section 2.2 Other Treatment Facility Selection
Chapter 2 - Treatment Facility Selection Process
Section 4.1.1 Water Quality Design Storm Volume
Volume V Runoff Treatment BMPsChapter 1 - Introduction Chapter 2 - Treatment Facility Selection Process Chapter 3 - Treatment Facility Menus Chapter 4 - General Requirements for Stormwater
Facilities
Manual).
#6, and #7.
this chapter.
Rain Gardens.
pretreatment.
Appendix III-C.
and references for clarity.
Revised language for clarity.
Reasoning or Comments
maintenance standards grant.
statement added in BMP T5.40.
Added reference to Chapter 12.
pollution-generating pervious surfaces.
Updated listed BMPs and made minor revisions to text.
Removed "and media filtration" in first bullet for clarity.
Vegetated Filter Strips. Minor additions to the recommended
Changed "StormFilter" to "Manufactured Media Filters", added
Moved Full Dispersion into Section 5.3.1 because the Municipal
Downspout infiltration moved to Volume III. Revised BMP T5.11
Stormwater Permits make it a necessary option in MR #5. Clarifying
Updated figures. Added BMP T5.14A Rain Gardens and BMP T5.14B
Permeable Pavements, BMP T5.16 Tree Retention and Tree Planting,
maintenance tables added. Added placeholders for Bioretention and
Added discussion that there are emerging technologies approved for
permeable pavement pending completion of the development of LID Concentrated Flow Dispersion and BMP T5.12 Sheet Flow Dispersion.
general changes in terminology. Added guidance regarding pollution-
Revised application to refer specifically to Minimum Requirements #5,
the expansion of Chapter 5 and source of additional design details (LID BMP T5.16 Vegetated Roofs, BMP T5.18 Reverse Slope Sidewalks, BMP
Expanded the list of BMPs in sections 5.3.1 and 5.3.2. Revised language
Renamed this Section and added information for the BMPs discussed in
generating hard surfaces, pollution-generating impervious surfaces, and
Bioretention but details are in Volume V of Chapter 7. Added BMP T5.15
information from WSDOT on Media Filter Drains and Compost Amended
Renamed this Section and added information regarding Bioretention and
Revised BMP T5.30 Full Dispersion by incorporating details from previous
T5.19 Minimal Excavation Foundations, BMP T5.20 Rainwater Harvesting.
Replaced "impervious" surfaces with "hard" surfaces in coordination with Add reference to expanded BMP options and LID Manual to acknowledge
5.3.3
Change
Other Practices
list of BMPs provided.
Minor language changes.
to incorporate new terms.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Minor language changes for clarity.
Amend existing BMP's add new BMP's
Added new tables within overall set of operation and maintenance standards
Changed bioinfilltration to bioretention.
Deleted Full Dispersion and section
Minor language changes for clarity. Changes
Additional clarifying guidance provided. Full
YesYesYes
to Permit
Language
Change Tied
5-16-16-17-1 7-1
5-16-1
Numbers
5-3 to 5-39
4-1 through 4-24-2 through 4-45-1 through 5-27-1 through 7-2
4-31 through 4-535-39 through 5-42
Approximate Page
BMPs
Facilities
Location
Pretreatment
Section 6.1 PurposeSection 7.1 Purpose
Section 5.1 Purpose
Section 5.2 ApplicationSection 6.2 Application
Sections 7.3 Applications
Stormwater Management
Section 5.3.2 Site Design BMPs
Sections 7.2 General Considerations
Section 4.1.3 flows Requiring Treatment
Section 4.1.2 Water Quality Design Flow Rate
Section 5.3.1 On-site Stormwater Management
Section 4.6 Maintenance Standards for Drainage
Section 6.3 Best Management Practices (BMPs) for
Section 5.3 Best Management Practices for On-Site
Chapter 5 - On-Site Stormwater ManagementChapter 6 - PretreatmentChapter 7 - Infiltration and Bioretention Treatment Facilities
T8.10.
area of plates.
sand filter vault.
Highway Runoff Manual.
separate BMP for clarity.
objective for sand filters.
Reasoning or Comments
Revised to include media filter drains.
Designers should refer to Basic Filter Strip.
Corrected Stokes Law equation for rise rate.
for Bioretention Cells, Swales, and Planter Boxes.
Design details for these BMPs remain in Volume III.
Revised name from Sand Filtration to just Filtration.
Added reference to Media Filter Drain to description.
Revised list of BMPs. Revised Sizing Criteria table for clarity.
Minor language changes for clarity throughout the chapter.
Added design criteria for new Media Filter Drain (MFD) option
Filter Strips. Treatment via infiltration through amended soils.
No design criteria exists for this BMP to validate basic treatment.
First cell must be lined to be consistent with liner requirements in
Added Media Filter Drain to list of approved technologies. Clarified
for 2-cell ponds. Definition of WQ Design Storm Volume amended.
BMP T8.11 Large Sand Filter Basin was described in the prior manual
under BMP T8.10 Sand Filter Basin. The Large Sand Filter was given a
previous sections 8.5, 8.6, 8.7, & 8.8 become subsections under BMP Replaced sections 12.1 through 12.5 to provide new guidance on the
Added guidance and design criteria for Compost-Amended Vegetated
Technology Assessment Protocol (TAPE) review and approval process.
Added design criteria for sand filter basins. reorganized section so that
(previously referred to as Ecology Embankment). Text matches WSDOT Chapter 4. Added cell requirements for consistency with design criteria Corrected the equation to calculated the projected
(horizontal) surface
Added detailed guidance, design criteria, infeasibilty criteria and figures
Revised the purpose to apply to both sand and media filtration facilities.Added design criteria, construction criteria, and maintenance criteria for
Boxes.
Change
new guidance.
Added this BMP.
within BMP T8.10
Revised guidance.Revised guidance.
Corrected formula.Corrected formula.
guidance removed.
Removed this BMP.
Included new technologies
language changes for clarity.
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Updated references to Volume III
Renamed and reorganized section.
Minor language changes for clarity.Minor language changes for clarity.
Replaced Bio-infiltration Swale with
Changed title and introduced minor
Transferred this BMP from Chapter 9.
Bioretention Cells, Swales, and Planter
Separated out BMP previously reference
Replaced sections 12.1 through 12.5 with
Additional guidance provided and outdated
to Permit
Language
Change Tied
7-28-2
8-18-18-2
N/A
Numbers
8-2 to 8-15
7-3 through 7-258-1 through 8-399-1 through 9-269-1 through 9-26
7-25 through 7-298-16 through 8-178-17 through 8-238-24 through 8-3811-8 through 11-912-1 through 12-6
10-1 through 10-17
11-10 through 11-11
Approximate Page
Boxes
Location
8.1 Purpose
Strips (CAVFS)
8.2 Description
BMP T10.10 Wet Pond
BMP T8.20 Sand Filter Vault
BMP T8.40 Media Filter Drain
Section 7.4 and BMPs 7.10 & 7.20
BMP T8.11 Large Sand Filter Basin
BMP T9.50 Narrow Area Filter Strip
Section 8.3 Performance Objectives
Chapter 12 - Emerging Technologies
Section 9.4 Best Management Practices
Section 8.4 Applications and Limitations
Chapter 8 - Filtration Treatment Facilities
BMP T11.10 API (Baffle type) Separator Bay
Chapter 9 - Biofiltration Treatment Facilities
Sand Filtration / BMP T8.10 Sand Filter Basin
BMP T7.40 Compost-amended Vegetated Filter
BMP T11.11 Coalescing Plate (CP) Separator Bay
BMP T 7.30 Bioretention Cells, Swales, and Planter
Section 8.5 Best Management Practices (BMPs) for
Chapter 8 - Sand Filtration Treatment FacilitiesChapter 9 - Biofiltration Treatment FacilitiesChapter 10- Wetpool FacilitiesChapter 11 - Oil and Water SeparatorsChapter 12 - Emerging
Technologies
Reasoning or Comments
evaluating soils used for bioretention.
previously listed throughout this volume.
Lists of species from City of Seattle guidance.
general procedures in the ASTM method are implemented. This
Removed examples of emerging technologies. Added some examples
test for saturated hydraulic conductivity can be influenced by how the
appendix lays out more specific procedures to help with consistency in
Added Recommended Modifications to ASTM D 2434. The results of this
Corrected several test procedures and geotextile property requirements.
Change
technologies.
Revised Guidance.
Additional guidance provided.
Removed examples of emerging
New appendix pertinent to BMP T5.16
to Permit
Language
Change Tied
N/A
Numbers
E-1 through E-5
C-1 through C-3
B-1 through B-2
Approximate Page
Species
Location
Appendix V-C Geotextile Specifications
for Stormwater Treatment and Control
Conductivity for Bioretention Soil Mixes.
ASTM D 2434 When Measuring Hydraulic
Appendix V-B Recommended Modifications to
Section 12.6 Examples of Emerging Technologies
Appendix V-E Recommended Newly Planted Tree
Appendix V-B Recommended Procedures for ASTM D 2434Appendix V-C Geotextile SpecificationsAppendix V-E Recommended Bioretention Plant Species
APPENDIX D MODELING ANALYSIS
The detailed modeling analysis is available at the Port Townsend City offices for review upon request.
Development Services Department
250 Madison Street, Suite 3
Port Townsend WA 98368
Phone: 360-379-5095
Fax: 360-344-4619
www.cityofpt.us
\[DRAFT\]Street & Utility Development Permit Application
MIP No.SDP No.BLD No.
Applicant:Phone:
Mailing Address:Fax:
City, State, Zip:E-mail:
Property Owner's Name(s):Phone:
Mailing Address:
City, State, Zip:E-mail:
Authorized Representative:Phone:
Address:E-mail:
Property Site Street (and address if assigned):
Zoning District:Parcel #:Parcel #:Parcel #:Parcel #:Parcel #:
Legal Description: Addition:Block:Block:Block:Lot(s):
Water/Sewer/Street ContractorWater/Sewer/Street ContractorWater/Sewer/Street Contractor
Mailing Address:
Phone:Fax:Fax:Fax:Cell Phone:
State License #:Expiration:City Business Lic.#:Expiration:
Estimated value of utility and/or street construction: $
Describe work to be conducted under this permit and purpose:
Describeearth worksuch as landscaping, clearing, grading:
How many acre(s) will be disturbed?Where will the overflow discharge?
Is Latecomer Proposed?For what Utility?
Will trees or vegetation be removed in the right-of-way?o Yes o NoIf yes, Describe & show on site plan.
What is the amount of impervious surface on the property? ___________sq. ft. & _______% of the property.
I hereby certify that the information provided is correct, that I am either the owner or authorized to act on behalf of the owner and that
all the activities associated with this permit will be in accordance with State Laws and the Port Townsend Municipal Code.
Signature of Owner or Authorized RepresentativeDate
______________________________________________
Print Name:
U:\\PSO\\Projects\\Clients\\2836-City of Port Townsend\\553-2836-004 Stormwater Mgmt Plan\\02WBS\\T04_StdsFormsProc\\PublicBooklet\\PDF
Pieces\\Form_SDP-MIP_App20170925.docx\\\\citynas1\\group\\DSD\\Forms\\Right of Way Forms\\SDP.MIP Application.docx (06/22/2016)| 1
Street & Utility Development Permit Application
Infrastructure
The application is not complete without all the items on this checklist complete.
(If not applicable, mark “N/A”)
*All boxes filled in on the front of this application
*City of Port Townsend “Lot Coverage and Impervious Surfaces Worksheet for Applicants”
*Soil percolation test results, based on Port Townsend “Guide to Residential Rainwater
Management”
*Vicinity Map
*Two sets of 8 ½ X 11 drawings showing work proposed under this permit. All dimensions must be
shown - width, length, depth, etc. Include the following drawings:
*Site Plan:
*All lot lines, block number, and lot numbers
*Lot dimensions
*Slopes/Contours (existing and proposed)Slopes/Contours (existing and proposed)Slopes/Contours (existing and proposed)Slopes/Contours (existing and proposed)Slopes/Contours (existing
and proposed)Slopes/Contours (existing and proposed)Slopes/Contours (existing and proposed)
*Area (acres or square feet) and volume (cubic yards) of cut and fillArea (acres or square feet) and volume (cubic yards) of cut and fillArea (acres or square feet) and volume (cubic
yards) of cut and fillArea (acres or square feet) and volume (cubic yards) of cut and fillArea (acres or square feet) and volume (cubic yards) of cut and fillArea (acres or square feet)
and volume (cubic yards) of cut and fillArea (acres or square feet) and volume (cubic yards) of cut and fill
*Outside dimensions of all buildings, including eavesOutside dimensions of all buildings, including eavesOutside dimensions of all buildings, including eavesOutside dimensions of all
buildings, including eavesOutside dimensions of all buildings, including eaves
1
*Dimensions of impervious (hard) surfaces (existing and proposed)
*Edge of street travel way
*Driveway from edge of travel way (dimensions & type of surface material)
*Adjoining street names
*All trees/vegetation proposed for removal in the right-of-way
*Existing or proposed easements
*Existing or proposed water and sewer mains
2
*Proposed connections to existing utilities (sewer, water, power)
*Profile of lots
1 If creating new impervious surfaces, provide square footage of total impervious and percentage of the property using the City of
Port Townsend “Lot Coverage and Impervious Surfaces Worksheet for Applicants”
2 The Public Utility District #1 (PUD #1) provides Port Townsend electrical power; be sure to contact PUD #1 (385-5800) to develop
plans for the electrical service connections for your property. Provide a site plan that clearly shows the power route to your project.
U:\\PSO\\Projects\\Clients\\2836-City of Port Townsend\\553-2836-004 Stormwater Mgmt
Plan\\02WBS\\T04_StdsFormsProc\\PublicBooklet\\PDF Pieces\\Form_SDP-
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*Drainage Plan:
*Have any known wetlands or their buffers been identified on the property?
¨ No o Yes (If yes, you may be required to include a wetland report)
*Are there any steep slopes (greater than 15%) on the property?
¨ No o Yes (If yes, you may be required to include a geotechnical report)
*North Arrow
*Slopes/Contours (existing and proposed) and flow direction arrows
1
*Dimensions of impervious (hard) surfaces (existing and proposed)
*Location(s) where rainwater flows off of the property (existing and proposed)
*Location(s) where rainwater discharges to the City street-side drainage system (catch
basin inlet, swale, ditch, culvert/pipe, etc.)
*Direction of flow of City street-side drainage system
*Dimensions of the on-site stormwater facility (rain garden, dry-well, curtain drain, etc.)Dimensions of the on-site stormwater facility (rain garden, dry-well, curtain drain, etc.)Dimensions
of the on-site stormwater facility (rain garden, dry-well, curtain drain, etc.)
*Location where site flow will enter proposed on-site stormwater facilityLocation where site flow will enter proposed on-site stormwater facilityLocation where site flow will enter proposed
on-site stormwater facilityLocation where site flow will enter proposed on-site stormwater facilityLocation where site flow will enter proposed on-site stormwater facilityLocation where
site flow will enter proposed on-site stormwater facilityLocation where site flow will enter proposed on-site stormwater facility
*Location where water will overflow from on-site stormwater facility and flow to City street-Location where water will overflow from on-site stormwater facility and flow to City street-Location
where water will overflow from on-site stormwater facility and flow to City street-Location where water will overflow from on-site stormwater facility and flow to City street-Location
where water will overflow from on-site stormwater facility and flow to City street-Location where water will overflow from on-site stormwater facility and flow to City street-Location
where water will overflow from on-site stormwater facility and flow to City street-Location where water will overflow from on-site stormwater facility and flow to City street-Location
where water will overflow from on-site stormwater facility and flow to City street-
side drainage system in case of heavy rainsside drainage system in case of heavy rainsside drainage system in case of heavy rainsside drainage system in case of heavy rainsside drainage
system in case of heavy rainsside drainage system in case of heavy rainsside drainage system in case of heavy rainsside drainage system in case of heavy rainsside drainage system in
case of heavy rains
*Temporary Erosion and Sediment Control Plan:Temporary Erosion and Sediment Control Plan:Temporary Erosion and Sediment Control Plan:Temporary Erosion and Sediment Control Plan:Temporary
Erosion and Sediment Control Plan:Temporary Erosion and Sediment Control Plan:Temporary Erosion and Sediment Control Plan:
*North Arrow
*Slopes/Contours (existing and proposed) and flow direction arrowsSlopes/Contours (existing and proposed) and flow direction arrowsSlopes/Contours (existing and proposed) and flow direction
arrowsSlopes/Contours (existing and proposed) and flow direction arrowsSlopes/Contours (existing and proposed) and flow direction arrows
*Location(s) where rainwater flows off of the property (existing and proposed)
*Location(s) where rainwater discharges to the City street-side drainage system (catch
basin inlet, swale, ditch, culvert/pipe, etc.)
*Direction of flow of City street-side drainage system
*Location(s) of temporary erosion and sediment control management features, based on
the Port Townsend Engineering Design Standards Chapter 5.
*If extending water or sewer mains or constructing a new street, 3 sets of plans prepared by a
licensed civil engineer must be submitted with this application.
*Did the applicant complete the process of a Technical Conference in the prior 12 months? If yes,
a credit may be available for a portion of the SDP/MIP permit fee.
U:\\PSO\\Projects\\Clients\\2836-City of Port Townsend\\553-2836-004 Stormwater Mgmt
Plan\\02WBS\\T04_StdsFormsProc\\PublicBooklet\\PDF Pieces\\Form_SDP-
MIP_App20170925.docx\\\\citynas1\\group\\DSD\\Forms\\Right of Way Forms\\SDP.MIP Application.docx (06/22/2016)| 3
DRAINAGE SKETCH
oo
Topography (steep slopes, flow direction)Soil (shovel test, hand texture, perc test)
oo
Vegetation (mature plants/trees, invasives)Water (direction over hard surfaces, standing water, natural springs)
oo
Sensitive Areas (wetlands, setbacks, tree roots)Off-site connections (flow to City street drain, neighbor's property)
50 FEET
Scale: 1 square = 5 ft x 5 ft
13.32 STORMWATER MANAGEMENT REQUIREMENTS
13.32.010 Minimum requirements for drainage improvements.
A.All developments shall comply with the Department of Ecology’s February 2005 Stormwater
Management Manual for Western Washington (“2005 SWMM-WW”), except f or the following:
Section 2.6 – Optional guidance relating to financial liability and off-site analysis and mitigation, city
engineering design standards, city stormwater master plan, and adopted drainage basin plansfor all
clearing and grading activities, for erosion control during construction, and for permanent drainage
system improvements.; except developments shall comply with the following City requirements,
which supersede the 2005 SWMMWW:
1.Section 2.6 – Optional guidance relating to financial liability and off-site analysis and mitigation
2.Engineering Design Standards
3.Stormwater Master Plan, and
1.4.Adopted drainage basin plans
A.B.Surface water entering the subject property shall be received at the naturally occurring locations
and surface water exiting the subject property shall be discharged at the natural locations with
adequate energy dissipaters within the subject property to minimize downstream damage and with
no diversion at any of these points.
B.C.All developments shalldo the necessaryconduct analysis and installthe necessarymitigations to
ensure that stormwater exiting their property is discharged at a safe location which will not impact
other property owners.
C.D.All structures shall be built such that finished floor elevations are in conformance with the
International Building Code as adopted or hereafter amended.
D.E.Building Drainageplans shall clearly show locations of drainage system and stormwater controls
within property limits and any off-site drainage improvements.
E.F.Considerations for the discharge of water off-site include but are not limited to the following:
1.Sufficient capacity of downstream facilities under design conditions;
2.Maintenance of the integrity of the receiving waters;
3.Possibility of adverse effects of retention/detention;
4.Utility of regional retention/detention facilities;
5.Capability of maintenance of the system; and 6. Structural integrity of abutting foundations and
structures.
F.G.All developers not providing permanent stormwater control facilities will be required to sign a no-
protest agreement for future participation in a stormwater-related LID. (Ord. 2915 § 1, 2006; Ord.
2867 § 2, 2004; Ord. 2579 § 1, 1997).
13.32.020 Drainage plan – Submission.
A.All developers applying for any of the following permits and/or approvals may be required to submit
for approval a drainage plan with their application and/or request:
1.Grading permit;
2.Street development permit;
3.Substantial development permit required under Chapter 90.58 RCW (Shoreline Management
Act);
4.Subdivision approval;
5.Short subdivision approval;
6.Commercial, industrial or multifamily site plan approval;
7.Rezones;
8.Conditional use permits;
9.Planned unit developments;
10.Building permits, where the permit either (a) authorizes or is for new construction totaling 40
percent or more of developmental coverage within the subject property; or (b) authorizes or is
for new construction which, together with pre-existing developmental coverage, would result in
40 percent or more developmental coverage within the property or (c) is for development in an
environmentally sensitive area or which has the potential to impact an environmentally
sensitive area;
11.Building permits, where the new development does not involve a change in impervious
coverage of a site but where one of the following conditions exist:
a.The stormwater from the existing development is connected to the sanitary sewer system.
b.The drainage system serving the existing development is inadequate to prevent impacts to
neighboring properties.
c.Water quality issues are a concern either from the existing development or from the
proposed development.
B.In addition, a drainage plan may be required for creation of impervious area, not covered by a
permit, which exceeds either:
1.Five thousand square feet; or
2.Forty percent developmental coverage within the subject property.
C. Construction work done under any of the above permits or applications shall not begin until such
time as final approval of the drainage plan is obtained in accordance with PTMC 13.32.050.
D.The same plan submitted during one permit/approval process may be subsequently submitted with
further required applications. The plan shall be supplemented with such additional information that
is requested by the public works department or required by the provisions of the engineering design
standards manual and/or DOE Stormwater Management Manual for the Puget Sound Basin.
E.Temporary erosion and sediment control measures may be required under Chapter 5 of the
engineering design standards at the discretion of the director for:
1.Site preparation and/or construction of any development; or
2.Creation of impervious area which exceeds either:
a.Five thousand square feet; or
b.Forty percent of the subject property. (Ord. 2687 § 1, 1999; Ord. 2579 § 1, 1997; Ord. 2126 §
1, 1988; Ord. 1957 § 3, 1983).
13.32.030 Drainage plan – Contents.
All persons applying for any of the permits and/or approvals contained in PTMC 13.32.020 shall provide
a drainage plan for surface and pertinent subsurface water flows entering, flowing within, and leaving
the subject property both during and after construction. The detailed form and contents of the drainage
plan shall be described in procedures established by the public works department, or in the engineering
design standards manual and/or DOE Stormwater Management Manual for the Puget Sound Basin. The
engineering design standards manual, and the DOE Manual, will set forth the manner of presenting the
required information which may include but is not limited to the following:
A.Background computations for sizing drainage facilities:
1.Depiction of the drainage area on a topographical map of approved scale and contour interval,
with acreage of the site, development, and developmental coverage indicated;
2.Indications of the peak discharge and volume of surface water currently entering and leaving the
subject property due to the design storm;
3.Indication of the peak discharge and volume of runoff which will be generated due to the design
storm within the subject property if the development or proposed activity is allowed to proceed;
and
4.Determination of the peak discharge and volume of water that will be generated by the design
storm at various points on the subject property;
B.Proposed measures for handling the computed runoff at the detail level specified in the engineering
design standards manual and/or DOE Stormwater Management Manual for the Puget Sound Basin:
1.The design storm peak discharge from the subject property may not be increased by the
proposed development; and
2.Retention/detention facilities must be provided in order to maintain surface water discharge
rates at or below the existing design storm peak discharge; and
C.Proposed Measures for Controlling Runoff During Construction. The requirements of this section
may be modified at the discretion of the city public works department in special cases requiring
more information. (Ord. 2579 § 1, 1997; Ord. 2444 § 2, 1995; Ord. 1957 § 4, 1983).
13.32.040 Development in environmentally sensitive areas or impacting ESAs.
Development in environmentally sensitive areas (ESAs) or development which has the potential to
impact ESAs must meet the requirements of Chapter 19.05 PTMC or other requirements as determined
necessary for the protection of the ESAs as determined by the public works director. (Ord. 2579 § 1,
1997; Ord. 1957 § 6, 1983).
13.32.050 Review and approval of the plan.
All storm drainage plans prepared in connection with any of the permits and/or approvals listed in PTMC
13.32.020 shall be submitted for review by and approval of the public works department in accordance
with the procedures established in the engineering design standards manual and/or DOE Stormwater
Management Manual for the Puget Sound Basin. (Ord. 2579 § 1, 1997; Ord. 2444 § 3, 1995; Ord. 1957 §
7, 1983).
13.32.060 Establishment of regional facilities.
In the event that public benefits would accrue due to modification of the drainage plan for the subject
property to better implement the recommendations of the comprehensive drainage plan, the public
works department may recommend that the city should assume responsibility for the further design,
construction, operation and maintenance of drainage facilities on the subject property. Such decision
shall be made concurrently with review and approval of the plan as specified in PTMC 13.32.050. In the
event that the city decides to assume responsibility for design, construction, operation, and
maintenance of the facilities, the developer will be required to contribute a pro rata share to the
construction cost of the facilities. The developer may be required to supply additional information at the
request of the public works department to aid in the determination by the city. Guidelines for
implementing this section will be defined in the engineering design standards manual and/or DOE
Stormwater Management Manual for the Puget Sound Basin. (Ord. 2579 § 1, 1997; Ord. 1957 § 8, 1983).
13.32.070 Applicability to government entities.
A.All municipal corporations and governmental entities shall be required to submit a drainage plan
and comply with the terms of this chapter when developing and/or improving land including, but
not limited to, road building and widening within the areas of the city.
B.It is recognized that many other city, county, state and federal permit conditions may apply to the
proposed action and that compliance with the provisions of this chapter does not constitute
compliance with such other requirements. (Ord. 2579 § 1, 1997; Ord. 1957 § 12, 1983).
13.32.080 Protection of public/private rights.
Implementation of any provision of this chapter shall not cause nor be construed as an infringement of
the rights of individuals, municipalities, or corporations other than the developer seeking a permit or
approval as described in PTMC 13.32.030. (Ord. 2579 § 1, 1997; Ord. 1957 § 14, 1983).
19.05 - CRITICAL AREAS
19.05.060 Performance standards for development – Mitigation, on-site and off-site, density,
minimum lot size, subdivisions, preferred construction practices, impervious surface standards,
stormwater plans, mitigation plans.
D.The performance standards below apply to any development and to all short plats, subdivisions and
lot line revisions proposed for sites wholly or partially within confirmed critical areas or their buffers
in Port Townsend. These standards are general development practices to minimize problems related
to water quality, stormwater and erosion control, and the placement and construction of
development in the city’s critical areas. In addition to the following general performance standards,
if a site contains a critical area or its buffer, such as a steep slope or a wetland, the applicable set(s)
of regulations outlined in the following sections of this chapter shall also apply.
5.Stormwater and Erosion Control.
a.Stormwater Management Plan.
All development subject to the provisions of this chapter shall comply with the 2005
Department of Ecology Stormwater Management Manual for Western Washington (SWMM-
WW (2005)), city engineering design standards manual, city stormwater master plan, and
adopted drainage basin plans.
i.Stormwater management plans shall be consistent with the standards contained in
the city’s EDS manual and the SWMM-WW (2005), and must be developed on a site-
specific basis and must contain a technical report that identifies existing or
predicted problems and sets forth solutions to each. Off-site measures may be
required to correct existing on-site problems or to prevent new problems from
occurring. Surface water discharge from the site shall not be greater than historic or
predevelopment rates.
ii.If the development does not meet water quality standards established by law or
administrative rules, the city may suspend further development work on the site
until such standards are met.
b.Erosion control practices must be detailed using best management practices for
situation/filtration devices to control surface runoff during construction, and the 2005
Department of Ecology Stormwater Management Manual for Western Washington (SWMM-
WW (2005)).
i.Applicants shall indicate erosion control measures on the site construction plan or
stormwater control management plan, as appropriate for the project.
ii.These requirements shall be in place following the preconstruction meeting outlined
in PTMC 19.05.040(D)(1)(i) and shall be reviewed and approved prior to clearing and
grading.
c.Applicants are also encouraged to consult the recommendations set forth in Chapter 5 of
the Low Impact Development Technical Guidance Manual for the Puget Sound (2004) for
guidance concerning the protection of native soils and vegetation, and retention of
hydrologic function, during clearing and grading for development proposals.
Stormwater Management Plan
City of Port Townsend
Drainage Problem Areas
ID LocationDescription
2-158th St. East of Gise St.Street Flooding
4c-1Admiralty Ave. and Spruce St.Street Flooding
4e-1Admiralty Ave. East of San Juan Ave.Stormwater Drains to Sewer Manhole Lid
4e-2San Juan Ave. at 45th St., East SideWater Over Roadway
4f-1Happy Valley Pond (43rd St.)Water Over Roadway
4f-2Haines St.; 43rd St. to 45th St.No Conveyance
4f-3McNeill St. North of 45th St.No Conveyance
4g-1Landes St. & 49th St.; Northeast CornerStreet Flooding
4h-153rd St. & 49th St.; Northwest CornerNo Conveyance
4l-1Howard St. Trail North of 35th St.Stormwater Eroding Trail
4l-2Cook Ave. West of Seaview Dr.Stormwater Directed to Private Property
4m-1Jackman St.; 47th St. to 49th St., West SideLocal Flooding
6a-1Center St.; San Juan Ave. to Spruce St.Water Ponding at Edge of Roadway
6a-2Center St.; Spruce St. to P St.No Conveyance
6a-3Pacific Ave. and Milo St. IntersectionWater Over Roadway
6a-4Tremont St. West of Pacific Ave.Infiltration System Insufficient
8b-1Fir St. and Benton St.Lack of Conveyance
8c-1Hancock St. & 32nd St. IntersectionPonding in Intersection
8c-21550 31st St.Lack of Conveyance, Property Damage
8c-3Sherman St.; 31st St. to 32nd St.Catch Basin Tied to Sewer System
9c-116th St.; Gise St. to Hill St.Ravine Erosion
9d-1Mountain View Police RoadLack of Conveyance
9f-1Sheridan St. and 12th St.Lack of Conveyance
9f-2Kearney St. and Franklin St.Flooding on Kearney Street
9f-314th St.; Cleveland St. to Landes St.Erosion at Edge of Roadway
9j-1Thomas St. and Hastings Ave., SW CornerFlooding over Thomas Street
9j-2Sherman St. & 27th St., NW CornerInadequate Conveyance
9l-12010 Holcomb St.Street Runoff Flooding Driveway
10b-13rd St. and Grant St.Catch Basin Tied to Sewer System
11a-1Discovery Rd. Northeast of RoundaboutFlooding at Edge of Roadway
11b-1McPherson St.; 9th St. to 11th St.Catch Basin Tied to Sewer System
11c-1McPherson St. and 14th St.Water Ponding at Edge of Intersection
11e-13rd St. and Rosecrans St.Storm Pond Outfall Eroding Bluff
11f-13rd St. and Sherman St.Inadequate Conveyance
12a-11623 Jefferson St.Street Run-off Flooding Garage
12c-1Water St.; Taylor St. to Adams St., (South)Ponding Over Sidewalk
12c-2Fillmore St.; Jefferson St. to Washington St.Erosion at Edge of Roadway
12c-3VanBuren St. and Franklin St.Catch Basin Has No Outlet
12d-1Lawrence St. and Taylor St.Ponding on Southwest Corner
12f-1Tyler St. and Oak St.Trail Erosion From Roadway Runoff
13a-1Lincoln BeachWater Over Roadway
19-1Hancock St. & 31st St.Catch Basin Tied to Sewer System
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Appendix I-D Guidelines
project.
Stormwater Permits.
perforated stub-outs.
Reasoning or Comments
impervious surfaces to the extent feasible.
for Wetlands when Managing Stormwater
"native" from the land conversion threshold.
manual to the municipal stormwater permits.
for water quality design storm volume and flow rate.
Management Practices, and revision of element #12 to include
and partial dispersion methods, full downspout infiltration and
Added a new statement for the site plan to use site-appropriate addition of element #13 that requires the protection of LID Best
development (LID) guidance and requirements in the Municipal
development principles to retain native vegetation and minimize
Removed outdated references to the Puget Sound Water Quality
related new definitions. Clarifications about the surfaces that the
hard surfaces at new development sites, the deletion of the word
Changes include: revisions to the construction SWPPP elements to
correspond with the Construction Stormwater General Permit, the
Added clarification for peak discharges using 15 minute time steps.
the related new definitions. The intent is to continue to capture the Revisions to acknowledge the use of permeable pavements and the
surfaces, LID, converted vegetation) because of the new low impact
Changes include: the new LID performance standard and list options
Added definitions for a few terms used previously but not previously
intent is to capture the same size and types of projects as previously.
responsibilities for an inspector or CESCL depending on the size of the use types: lawn and landscaped areas; roofs, and other hard surfaces.
Revisions made to acknowledge the use of permeable pavements and
based on project size and location. The lists are divided into three land for each land use type. Some of the BMPs included in the lists are: rain
surfaces, the application of minimum requirements #6 - #9 to replaced
Projects implementing the list option must select the first feasible BMP
Management Plan. Section renamed and focuses on relationship of the
Changes include: the replacement of “impervious” surfaces with “hard”
defined. Other terms have a revised definition or a new definition (hard
requirement applies to, and the use of the 0.10 /0.15 cfs threshold. The
same size and types of projects as previously. More accurate definitions
gardens, permeable pavements, bioretention, soil quality and depth, full
Revisions correspond to the significantly revised
Change
guidelines.guidelines.
Minor additions.
supplemental guidelines.supplemental guidelines.
Added and revised definitions.
Revisions to the thresholds and
development (LID) requirements.standard requirement, additional
Added guidance. Section renamed.
Design Flow Rate, and supplemental
Revised requirements and objective.
Multiple revisions for new low impact
elements, objective, and supplemental
Revised the thresholds for determining
Revisions to the applicability, thresholds,
Reorganized and revisions to: thresholds,
Revisions to the thresholds, Water Quality
development and redevelopment. Revised
general requirements, construction SWPPP
which minimum requirements apply to new
requirements, and supplemental guidelines.
YesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
2-2
2-16
Numbers
2-5 through 2-9
2-9 through 2-16
2-17 through 2-262-27 through 2-282-28 through 2-322-33 through 2-352-35 through 2-402-40 through 2-41
Approximate Page
(SWPP)
Agenda
Outfalls
Location
Protection
Treatment
Flow Control
RequirementsRequirements
Stormwater Management
Preparation of Stormwater Site Plans
Section 2.5.2 Minimum Requirement #2: Section 2.5.4 Minimum Requirement #4:
Section 2.4 Applicability of the Minimum Section 2.5.1 Minimum Requirement #1:
Section 2.3 Definitions Related to Minimum
Preservation of Natural Drainage Systems and
Construction Stormwater Pollution Prevention
Section 2.5.6 Minimum Requirement #6: Runoff Section 2.5.7 Minimum Requirement #7: Runoff
Section 2.5.5 Minimum Requirement #5: On-site
Section 2.5.8 Minimum Requirement #8: Wetlands
Section 2.1 Relationship to the Puget Sound Action
Step V: Select
apply.
facilities.
and in section 3.1.7.
with a reference to Chapter 2 of Volume V.
Reasoning or Comments
applicable minimum requirements.subject to Min. Requirements 1 - 9.
the appendix and retained the rainfall tables.
Appendix 1 of the 2007 municipal stormwater permits.
Changes for clarification and to remove repetitive language.
Significant changes to describe how to prepare the Permanent
requirements. Ecology replaced the language in
Soils reports are necessary part of LID decisions. Declarations of
Revisions and new language especially in Step III for guidance on
Added several LID BMPs that require the submission of as-builts.
Treatment Facilities
the changes in the Municipal Stormwater Permits and for new LID
Stormwater Control Plan that incorporates LID features. Separate
Added language for clarity on use of Basin Planning for addressing
and in particular for LID site design. Split into subsections based on
whether Min. Requirements 1 - 5 apply, or Min. Requirements 1 - 9
LID features, establish maintenance requirements and government
References to on-site BMPs added and preliminary determination of
access for inspections of privately maintained stormwater BMPs and
Revised for clarity and removed outdate language in the introduction
guidance for projects subject to Min. Requirements 1 - 5 and projects
retrofit needs and for developing an alternative flow control strategy.
Removed background and outdated information for brevity. Renamed
Additional guidance details the information necessary for site analysis,
modeling threshold discharge areas. Minor revisions to correspond with
Changed and added language to be consistent with the requirements in
Covenants and Grants of Easement are necessary mechanisms to identify
Change
Volume V.
Step V: Select Treatment
implementation.
Guidance added.Guidance added.
Design Flow Rate.
guidance removed.
Grants of Easement.
with a reference to Chapter 2 of
Minor language changes.
Stormwater Control Plan.
procedures necessary for LID
Additional guidance provided.Additional guidance provided.
Site Hydrology of the Permanent
Significant changes to incorporate
Removed introductory language and
Reference to needed soils report and
background information on the Water
language in
Quality Design Storm and Water Quality
Revisions to all subsections of Developed addition of Declaration of Covenants and
Revised language, proposed replacing the
Facilities
Additional guidance provided and outdated
YesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-17
Numbers
4-1 through 4-4
3-2 through 3-73-7 through 3-8
B-1 through B-5
A-1 through A-3
3-1 through 3-173-8 through 3-12
2-45 through 2-463-13 through 3-143-14 through 3-16
Approximate Page
Plan
Location
Sections 3.1.2 to 3.1.4
Stormwater Control Plan
Section 2.8 Exceptions/Variances
Information on Existing Conditions
Stormwater Pollution Prevention Plan
Requirements Through Basin Planning
Section 3.1.1 Step 1 - Collect and Analyze
Section 3.1.5 Step 5 - Prepare a Permanent
Section 3.2.2 Final Corrected Plan Submittal
Appendix I-B Rainfall Amounts and Statistics
Section 3.1.6 Step 6 - Prepare a Construction
Section 4.2 BMP and Facility Selection Process
Section 3.1.7 Step 7 - Complete Stormwater Site
Chapter 3 - Preparation of Stormwater Site Plans
Appendix I-A Guidance for Altering the Minimum
Chapter 3 - Preparation of Stormwater Site PlansChapter 4 - BMP and Facility Selection Process for Permanent Stormwater Control PlansAppendix I-A Guidance for Altering the Minimum Requirements
Through Basin PlanningAppendix I-B Rainfall Amounts and Statistics
Stormwater Permits.
in Min. Requirement #7.
Reasoning or Comments
than 15% on a monthly basis.
analyses, and to remove reference to a creek in Eastern WA.
development (LID) guidance and requirements in the Municipal
Rewritten to remove outdated information, clarify concepts, and
approach the protection and use of wetlands through controlling
List edited to add additional waters based on specific requests and
definition has been added. A handful of other terms have a revised
There are a few terms, used previously but not defined, for which a
definition, and there are new terms, because of the new low impact
more than 20% on a single event basis, and must not deviate by more
Map shows basins which potentially qualify for use of existing land cover
discharges to wetlands. Total discharges to wetlands must not deviate by as the pre-developed land cover for flow control purposes. See reference
Change
Added Map
stormwater.
Added and revised definitions.
protection of Wetlands when managing
Multiple revisions for the use and/or the
Added and deleted Exempt Surface Waters.
YesYesYes
to Permit
Language
Change Tied
F-1
Numbers
Glossary-47
E-1 through E-4
D-1 through D-18
Glossary-1 through
Approximate Page
Location
Managing Stormwater
Glossary and Notations
impervious area since 1985
Appendix I-F Basins with 40% or more total
Appendix I-D Guidelines for Wetlands when
Appendix I-E Flow Control-Exempt Surface Waters
Appendix I-D Guidelines for Wetlands when Managing StormwaterAppendix I-E Flow Control-Exempt Surface WatersAppendix I-F Feasibility Criteria for Selected Low Impact Development Best
Management PracticesGlossary and Notations
BMPs.
Industrial Permits).
duplicate language.
Reasoning or Comments
Low Impact Development BMPs.
Replaced older figure with an updated one.
Prevention Plan Checklist is still located in Section 3.3.
State, and Local Regulatory Requirements was removed.State, and Local Regulatory Requirements was removed.
Revised this chapter to use simpler and clearer language.
information. Sections 2.1 and 2.2 now go into detail about the element now contains an Additional Guidance section that has
Removed this section by combining it with Section 1.2 to eliminate
Revised this chapter to update this information for revisions to the
Replaced these sections to remove invalid information or duplicate Stormwater Permits, and the Construction BMPs in Chapter 4. Each
Section 3.3. Please note that the Construction Stormwater Pollution
to Section 3.2 for clarity. The Step-By-Step Procedure now follows in
information not required by the permits. Added Element #13 Protect
Revised this chapter to use simpler and clearer language. Information Revised this chapter to use simpler and clearer language. Information
and the requirements for a Stormwater Site Pollution Prevention Plan.
covered in Volume I, Section 1.6 Relationship of the Manual to Federal, covered in Volume I, Section 1.6 Relationship of the Manual to Federal,
Stormwater General Permits (including the Municipal, Construction, and Revised The Construction SWPPP Elements, described in Section 3.3.3 to coordinate with the Construction Stormwater
General Permit, Municipal
Moved The Construction SWPPP Requirements, previously in Section 3.3
relationship of Volume II to the Construction Stormwater General Permit
Revised to incorporate a new element, Protect Low Impact Development
1.2.
Change
reversed.
Replaced.
Renamed.
and brevity.and brevity.and brevity.
SWPPP Elements.
Stormwater Permits.
to the Washington State General
Multiple revisions to the Construction
Previous Sections 3.2 and 3.3 have been
Section 2.1 The Construction Stormwater
in this section is now included in Sections
replace the previous Sections 2.1 and 2.2.
Stormwater Pollution Prevention Plans now
This section was removed. The information
Multiple revisions to coordinate the manual
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
General Permit and Section 2.2 Construction
YesYesYesYes
to Permit
Language
Change Tied
1-31-6
N/A
Numbers
1-1 through 1-92-1 through 2-62-1 through 2-6
2-2 through 2-4
3-1 through 3-323-4 through 3-323-8 through 3-32
Approximate Page
Location
Figure 1.5.1
Implementation
Chapter 3 - Planning
Pollution Prevention
Section 2.1 and Section 2.2Section 3.2 and Section 3.3
Stormwater Pollution Prevention
Section 1.3 How to Use This Volume
Chapter 2 - Regulatory RequirementsChapter 2 - Regulatory Requirements
Construction SWPPP Development and
Section 1.3 Thirteen Elements of Construction
Section 3.3.3 (Previously Section 3.2.3) Step 3 -
Chapter 1 - Introduction Construction Stormwater
Volume II Construction Stormwater Pollution PreventionChapter 1 - Introduction Construction Stormwater Pollution PreventionChapter 2 - Regulatory RequirementsChapter 3 - Planning
equivalent.
field experience.
and field experience.
compost specification.
Reasoning or Comments
discharge to surface or ground water.
comments received and field experience.
Temporary and Permanent Seeding to this BMP.
should be based on the size of the construction site.
Revised this BMP to use simpler and clearer language.
Added Wood Straw and Wood Straw Mulch to the table.
Added guidance previously found in BMP C120: Temporary and
intent of this BMP in a safer and more commonly used manner.
Added minimum mulch thickness based on field experience and for this BMP based on comments received and field experience.
Added guidance to clarify that wheel wash wastewater shall not
Updated figure to provide more details of a typical Wheel Wash.
Ecology revised this chapter to use simpler and clearer language.
Refers to Ecology's website for BMPs that have been approved as
comments. Ecology added guidance previously found in BMP C120:
Ecology added Table 4.1 Source Control BMPs by SWPPP Element to
Removed measures and quantities because measures and quantities
coverings (such as compost and straw) are preferable. Ecology added
Removed the use of plastic sheeting over seeded areas because other Provided a link to composting guidance and removed old reference to
Removed this BMP because BMP C103: High Visibility Fence meets the and removed guidance for this BMP based on comments received and
Revised and reorganized this BMP to use simpler and clearer language.
Permanent Seeding to this BMP. Ecology added and removed guidance
Ecology added and removed additional guidance for this BMP based on
show how the BMPs listed in Section 4.1 relate to the SWPPP Elements.
Added high visibility silt fence because it meets the intent of BMP C103.
Moved some guidance to BMP C121: Mulching or BMP C125: Top soiling.
Added and removed guidance for this BMP based on comments received
Change
removed.
and brevity.
and removed.
SWPPP Element
clarity, and brevity.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Figure was updated
This BMP was removed.
Additional guidance provided.Additional guidance provided.
Suggested measures and quantities
This BMP now includes high visibility silt
Added Table 4.1 Source Control BMPs by
and brevity. Additional guidance provided
Added approved equivalent BMPs Sections.fence. Multiple revisions for plain language, Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Yes
to Permit
Language
Change Tied
4-6
N/A
4-114-21
Numbers
4-1 through 4-2
4-7 through 4-9
4-9 through 4-11
4-1 through 4-1284-13 through 4-194-19 through 4-214-22 through 4-254-25 through 4-274-27 through 4-284-29 through 4-324-42 through 4-43
Approximate Page
Location
Table 4.1.8
and Specifications
BMP C124: Sodding
BMP C121: Mulching
BMP C106: Wheel Wash
Figure 4.1.2 - Wheel Wash
BMP C123: Plastic Covering
BMP C122: Nets and Blankets
BMP C150: Materials on Hand
BMP C103: High Visibility Fence
Section 4.1 Source Control BMPs
BMP C104: Stake and Wire Fence
BMP C125: Top soiling / Composting
BMP C120: Temporary and Permanent Seeding
BMP C105: Stabilized Construction Entrance / Exit
Chapter 4 - Best Management Practices Standards
Chapter 4 - Best Management Practices Standards and Specifications
.
2
areas.
Elements. materials.
prohibited.
experience.
the near future.
(CTAPE) program.
Stormwater General Permit.
Reasoning or Comments
in BMP C252 and in BMP C253.
guidance for neutralizing high pH.
on comment received and field experience.
on neutralizing high pH through the use of CO
to show how the BMPs listed in Section 4.2 relate to the SWPPP
projects needing to perform Erosion and Sediment Control Work. Added guidance for this BMP, previously available online, to
Removed this BMP because it is not applicable to the full range of
both the Municipal Stormwater General Permits and Construction
Construction Stormwater General Permit and to make it clear that
Added sizing criteria for this BMP, previously available online.
Renamed this BMP to include wattles made from compost or other
Removed this BMP because of changes in threshold requirements in
Added guidance for this BMP based on comments received and field
coordinate with the Chemical Technology Assessment Protocol
Added this BMP to provide additional guidance for concrete washout
Added guidance to coordinate this BMP with the requirements of the Concrete spillage or concrete discard to surface waters of the State is
Minimum Requirements for ESC Training and Certification Courses has
Added this BMP, previously available online, to provide guidance
Added guidance for inlet protection of lawn and yard drains and based
been removed. Ecology plans on issuing separate, updated guidance in Revised and reorganized this BMP to use simpler and clearer language.
Added this BMP, previously available online, to provide additional
Added this new BMP for dewatering, Construction SWPPP Element #10.Revised this appendix to coordinate with the new information provided
Removed this BMP because this BMP has been proven to be ineffective.
Added Table 4.2 Runoff Conveyance Treatment BMPs by SWPPP Element
Change
and brevity.
Added this BMP.Added this BMP.Added this BMP.Added this BMP.
guidance removed.
C252 and BMP C53.
This BMP was removed.This BMP was removed.This BMP was removed.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Renamed from Straw Wattles.
Added Table 4.2 Runoff Conveyance
Treatment BMPs by SWPPP Element
Multiple revisions to coordinate with BMP
Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
N/AN/AN/A
4-57
Numbers
B-1 through B-3
4-43 through 4-454-48 through 4-534-54 through 4-554-74 through 4-774-78 through 4-794-90 through 4-954-96 through 4-99
4-100 through 4-1024-112 through 4-1204-120 through 4-1244-125 through 4-127
4-128 through 4-129
Approximate Page
2
Lead
BMPs
Location
TreatmentTreatment
BMP C235: Wattles
Pollution Prevention
BMP C233: Silt Fence
BMP C207: Check Dams
BMP C230: Straw Bale Barrier
BMP C236: Vegetated Spray Fields
BMP C154: Concrete Washout Area
BMP C220: Storm Drain Inlet Protection
BMP C253: pH Control for High pH Water
Sawcutting and Surface Pollution Prevention
BMP C252: High pH Neutralization Using CO
BMP C161: Payment of Erosion Control Work
BMP C151: Concrete Handling and BMP C152:
Section 4.2 Runoff Conveyance and Treatment BMP C250: Construction Stormwater Chemical BMP C251: Construction Stormwater Filtration
BMP C180: Small Project Construction Stormwater
BMP C160: Certified Erosion and Sediment Control
Appendix II-B Background Information on Chemical
purposes.
Minor text change
(WWHM) changes.
guidance was replaced.
Volume I, Appendix 1-D.
trenches and splashblocks.
in the introductory section.
Reasoning or Comments
of Street Wastes in Volume IV.
Permeable Pavement sections.
permeable pavements in introductory section.
and feasibility criteria. Updated design guidance.
guidance for oil control and pre-treatment facilities.
distributed bioretention facilities as indicated in text.
Revised this chapter to use simpler and clearer language. Revised this chapter to use simpler and clearer language.
and feasibility criteria. Improved clarify in design guidance and
and feasibility criteria. Needed better clarity in design guidance
Added references to Minimum Requirement #5, bioretention and
Step 6 for clarity and for meeting MR#5. Revised Step 7 for clarity.
Revised Step 2 to include guidance for meeting MR#5. Significantly
Revised this chapter to use simpler and clearer language. Outdated Added guidance for MR #5 which now includes an LID Performance Expanded purpose statement and clarified in regard to
the types of
Added guidance on upcoming Western Washington Hydrology Model
facilities covered in Section 3.3. Added references to Bioretention and
computer modeling. Added guidance for design criteria for dispersion revised Step 5 for the new guidance provided in section 3.3.6. Revised
Added guidance on precipitation data and upcoming WWHM changes.
Text and figures updated to indicate priorities for handling roof runoff.
design of centralized infiltration facilities. Certain sections also apply to
Text changes for consistency with new priority lists in Min.Req'ment #5
Section 2.2 split into multiple subsections for clarity and for referencing Updated references to revised roof downspout BMPs and Rain Gardens
Text changes for consistency with new priority lists in Min. Req'ment #5 Text changes for consistency with new priority lists in Min. Req'ment #5
Updated Maintenance narrative to refer to Appendix IV-G Management
Standard. Revised the guidance for MR#8 to reflect the changes made in
Made significant changes to all sub-sections. Section pertains primarily to Made clarifications and added language for complying with MR#5. Added
Change
standard.
Req'mt #5Req'mt #5Req'mt #5
Req'mt #5
Req'mt #5.
and brevity.and brevity.and brevity.
Req'mt #5 and LID
Requirements (MR).
Updated references.
revised Min Req'mt #5
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Section significantly rewritten.
guidance removed for Minimum
Revised guidance and reference LID.
Revised several steps for new infiltration
Update text & figure for consistency with
Section 2.2 split into multiple subsections.
Additional guidance provided and outdated Additional guidance provided including Min
rate guidance and the new LID performance
Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity, Multiple revisions for plain language, clarity,
Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min Update text for consistency with revised Min
Update text for consistency with revised Min
YesYesYesYesYesYesYesYesYesYes
to Permit
Language
Change Tied
3-1
3-353-653-653-66
Numbers
2-5 through 2-82-8 through 2-9
2-4 through 2-92-4 through 2-93-1 through 3-3
2-1 through 2-173-1 through 3-183-4 through 3-10
3-1 through 3-1093-11 through 3-163-17 through 3-183-19 through 3-643-68 through 3-71
3-65 through 3-102
Approximate Page
T5.10A)
WWHM
Facilities
Location
and Treatment
Section 3.3.1 Purpose
Section 3.3.2 Description
Section 3.3.3 Applications
Section 3.2 Detention FacilitiesSection 3.2 Detention Facilities
Chapter 2 - Hydrologic Analysis
Chapter 3 - Flow Control Design
Chapter 3 - Flow Control Design
Section 3.1 Roof Downspout ControlsSection 3.1 Roof Downspout Controls
Section 3.3.4 Steps for Design of Infiltration
Section 3.1.2 Downspout Dispersion Systems
Section 3.1.3 Perforated Stub-out Connections
Section 2.2.2 Assumptions made in creating the
Section 3.3 Infiltration Facilities for Flow Control
Section 2.2.3 Guidance for flow-related standards
Section 2.2 Western Washington Hydrology ModelSection 2.2 Western Washington Hydrology Model
Section 3.1.1 Roof Downspout Full Infiltration (BMP
Volume III Hydrologic Analysis and Flow Control Design / BMPsChapter 2 - Hydrologic AnalysisChapter 3 - Flow Control Design
3.3.6.
Reasoning or Comments
outdated computation steps.
3, and one for upcoming WWHM 2012.
Soil Texture Classification and D10 grain size.
Added guidance for conducting performance testing.
amended drawdown guidance, and verification testing.
for bioretention / rain gardens and permeable pavement.
and maintenance. Made wording clarifications to guidance.
Added a link to a website where isopluvial maps are available.
method for estimating infiltration rates. Deleted infiltration rate
determination sub-section due to redundancy with next section.
Procedures for conducting the PIT have been included within the
instead refers to steps 1-5 in section 3.3.4. Revised Figure 3.27 for
investigation, and determine the saturated hydraulic conductivity;
Removed steps to select location, estimate volume of stormwater, infiltration rate. Added a step for groundwater mounding analysis.
on groundwater monitoring wells and the use of grain size analysis infiltration rates, added a minimum organic content for treatment,
develop a trial infiltration facility geometry, conduct a geotechnical
Replaced "Infiltration Rate" with "Saturated Hydraulic Conductivity"
Updated references, removed unneeded guidance, revised limits on
guidance for the modeling on LID elements and wetlands. Removed
saturated hydraulic conductivity. Added guidance on pilot infiltration
proposed text on “Design Infiltration Rate Determination” in sections
Added guidance on current and upcoming versions of WWHM. Added
testing (PIT), and soil grain size analysis. Revised correction factors for
Text in regard to design guidance removed. All design guidance moved
Added guidance re field tests, computer modeling, and implementation
PIT results and soil grain size method. Removed options based on USDA
Added guidance for sizing for flow control, pretreatment design criteria,
throughout section. Updated the guidelines and criteria for determining
Multiple changes to subsurface characterization include added guidance
to Volume V. Two sets of modeling guidance provided. One for WWHM
updated guidance. Revised guidance for adjusting the preliminary design
Change
Section renamed.
guidance removed.guidance removed.guidance removed.guidance removed.
Appendix removed.
permeable pavement.
Added link to website.
USDA Textural Triangle.
Revised guidance on subsurface
receptor. Removed guidance for
Multiple revisions. Previous steps 1-4
groundwater mounding analysis step.
Added this section for bioretention and
Revisions for determining the saturated
hydraulic conductivity (infiltration rate).
removed. Multiple steps revised. Added
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
hydrogeologic investigation and figure 3.27,
characterization, soil testing, and infiltration
YesYesYes
to Permit
Language
Change Tied
A-1
N/A
Numbers
B-1 through B-13C-1 through C-13
3-72 through 3-753-75 through 3-833-83 through 3-863-86 through 3-903-90 through 3-94
3-103 through 3-109
Approximate Page
Guidance
Location
Infiltration Test
Computation Steps
Permeable Pavement Use
Facilities - Detailed Approach
Conductivity - Guidelines and Criteria
Model - Information, Assumptions, and
Section 3.3.6 Design Saturated Hydraulic
Section 3.3.7 Site Suitability Criteria (SSC)
Section 3.3.5 Site Characterization Criteria
Section 3.3.8 Steps for Designing Infiltration
Construction Criteria for Infiltration Facilities
Appendix III-B Western Washington Hydrology
Appendix III-D Procedure for Conducting a Pilot
Appendix III-C Washington State Department of
Section 3.3.9 General Design, Maintenance, and
Section 3.4 Site Procedures for Bioretention and
Appendix III-A Isopluvial Maps for Design Storms
Ecology Low Impact Development Flow Modeling
Appendix III-A Isopluvial Maps for Design StormsAppendix III-B Western Washington Hydrology Model - Information, Assumptions, and Computation Steps Appendix III-C Washington State Department
of Ecology Low Impact Development Design and Flow Modeling GuidanceAppendix III-D Procedure for Conducting a Pilot Infiltration Test
action.
language.
ISWGP and BGP.
a corrective action.
system to the BMPs.
outdated references.
Stormwater Permits).
Reasoning or Comments
and removed outdated references.
Revised BMPs to use simpler and clearer language.
Revised for clarity and removed outdated language.
Added numbers in the "S400" series to BMPs in Volume IV.
BMPs for facilities covered under the ISWGP (or other General
prevention and cleanup, visual inspections and record keeping.
Revised BMPs to use simpler and clearer language, and removed
in regards to the ISGP, BGP, and S&GP. Added guidance regarding
in regards to the ISGP, BGP, and S&GP. Section renamed to make it
include the addition of vacuum sweeping and pressure washing, spill
Revised wording to clarify where this Section applies. Revised several
clearer that applicable BMPs are Mandatory for permittees under the
Added new guidance clarifying the requirements regarding treatment compost leachate. Revised BMPs to use simpler and clearer language,
regarding boatyard activities. Revised BMPs to use simpler and clearer
(ISWGP), Boatyard General Permit (BGP), and Sand and Gravel General
facilities covered under the ISWGP that trigger a Level 1 or 2 corrective BMPs for clarity and to coordinate with the ISWGP. Significant changes
Revised language because solid waste regulations prohibit discharge of
Permit (S&GP) and the inclusion of "applicable" BMPs from this volume
Clarified guidance describing the requirements under the BGP and ISGP
in Industrial Stormwater Pollution Prevention Plans (Industrial SWPPPs).the ISWGP that trigger a Level 1 or 2 corrective action. Changed the title
Added new guidance describing the use of applicable (mandatory) BMPs Added new guidance describing the use of applicable (mandatory) BMPs
Revised wording to clarify where this Section applies. Added new text on
ISWGP requirements. Added guidance regarding facilities covered under
Added new guidance regarding the Industrial Stormwater General Permit
Added guidance regarding facilities covered under the ISWGP that trigger format for the BMPs to match the other volumes and added a numbering
Change
revisions.
and brevity.and brevity.
BMPs clarified.
Numbered BMPs.
guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.
Additional guidance provided.
guidance removed. Minor formatting
Additional guidance provided and several
Minor revisions for plain language, clarity, Minor revisions for plain language, clarity,
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance
provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
YesYes
to Permit
Language
Change Tied
1-2
1-31-4
2-10
Numbers
1-1 through 1-52-7 through 2-9
1-3 through 1-42-1 through 2-22-2 through 2-6
2-1 through 2-662-1 through 2-662-7 through 2-66
2-10 through 2-12
Approximate Page
Sources
Location
Source Control BMPs
Source Control BMPsSource Control BMPsSource Control BMPs
Chapter 1 - Introduction
Maintenance of Boats and Ships
Section 1.6.2 Recommended BMPs
Section 1.3 How to Use this Volume
S403 BMPs for Commercial Composting
S401 BMPs for the Building, Repair, and
Section 2.2 Pollutant Source Specific BMPs
Section 1.6.1 Applicable (Mandatory) BMPs
Section 2.1 Applicable (Mandatory) Operational
Section 1.5 Treatment BMPs for Specific Pollutant
S402 BMPs for Commercial Animal Handling Areas
Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural Chapter 2 - Selection of Operational and Structural
Volume IV Source Control BMPsChapter 1 - IntroductionChapter 2 - Selection of Operational and Structural Source Control BMPs
references.references.references.
this volume.
Appendix IV-B.
outdated guidance.
use in street cleaning. the required controls.
vehicles to align with ISGP.
Reasoning or Comments
municipal stormwater permits.
Minor language changes for clarity.
Added "Potential Pollutant Generating Sources"
Minor revisions to the Site Evaluation subsection.
Updated the reference to guidance for Vehicle Recyclers.
Removed outdated guidance and added new guidance in the
process wastewater to ground water or surface water. Removed
Additional guidance provided for the handling of ditch cleanings.
contamination in Street Waste Solids subsection. Reorganized the
Revised language to coordinate with the ISGP. Removed outdated
Updated "applicable BMP" guidance for handling of liquids in scrap
Revised several BMPs for clarity and to coordinate with the ISWGP.
Clarified guidance describing which NPDES permit(s) regulate wood
Minor language changes for clarity. Removed the outdated Table in
Added guidance to clarify that the ISWGP prohibits the discharge of
Added a references to Volume V and Ecology publications for BMPs.
treatment areas. Revised BMPs to use simpler and clearer language.
Clarified that facilities not under the ISWGP may consider some water Edits to make guidance consistent with the most recent industrial and
disposal of street waste liquids subsection, no major content changes.
Figure was unclear and the existing text provided a better description of Edits for clarity and to replace and revise guidance documents and WAC Edits for clarity and to replace and
revise guidance documents and WAC
Added this BMP to provide further guidance consistent with BMPs within
Change
references.
Figure Deleted
BMPs clarified.
guidance removed.guidance removed.guidance removed.guidance removed.
Minor language changes.Minor language changes.Minor language changes.
Additional guidance provided
Added reference to guidance.
Additional guidance provided.Additional guidance provided.
Updated reference to guidance.
and outdated guidance removed.
Revision for consistency with the ISGP
Additional guidance provided and several
Minor language changes. Removed Table.
and brevity. Additional guidance provided
Additional guidance provided and updated
Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated Additional guidance provided and outdated
Multiple revisions for plain language, clarity,
YesYesYes
to Permit
Language
Change Tied
C-1
N/A
A-14
Numbers
E-1 through E-7
B-1 through B-2
D-1 through D-9
A-1 through A-24
G-1 through G-15
2-13 through 2-142-32 through 2-342-35 through 2-372-45 through 2-462-46 through 2-472-48 through 2-492-58 through 2-592-60 through 2-622-63 through 2-642-64 through 2-66
Approximate Page
Permits
Location
Substances
and Equipment
Adverse Impact
of Street Wastes
Generating Sources
Airports and Streets
Fluids/Other Wastes
S430 BMPs for Urban Streets
Impact Stormwater Programs
Commercial Composting - SIC 2875
Figure 2.15 - Uncovered Wash Area
S424 BMPs for Roof/Building Drains at
S432 BMPs for Wood Treatment Areas
S423 BMPs for Recyclers and Scrap Yards
Manufacturing and Commercial Buildings
S426 BMPs for Spills of Oil and Hazardous
Vehicles / Equipment / Building Structures
Appendix IV-C Recycling/Disposal of Vehicle
S431 BMPs for Washing and Steam Cleaning Appendix IV-E NPDES Stormwater Discharge
Appendix IV-D Regulatory Requirements That
Appendix IV-A Urban Land Uses and Pollutant
Appendix IV-B Stormwater Pollutants and Their
S416 BMPs for Maintenance of Roadside Ditches
S405 BMPs for Deicing and Anti-Icing Operations -
S414 BMPs for Maintenance and Repair of Vehicles S433 BMPs for Pools, Spas, Hot Tubs and Fountains
Appendix IV-G Recommendations for Management
Appendix IV-A Urban Land Uses and Pollutant Generating SourcesAppendix IV-B Stormwater Pollutants and Their Adverse ImpactAppendix IV-C Recycling/Disposal of Vehicle Fluids/Other WastesAppendix
IV-D Regulatory Requirements That Impact Stormwater ProgramsAppendix IV-E NPDES Stormwater Discharge PermitsAppendix IV-G Recommendations for Management of Street Wastes
Chapter 2. Chapter 2.
computer models.
outdated references.
Enhanced Treatment.
duplicated from Chapter 2.
Reasoning or Comments
was duplicated from Chapter 2.
Bioretention as a treatment method.
Added paragraph on emerging technology options.
Added paragraph on emerging technology options.
waters triggering enhanced treatment for accuracy.
removed the associated subsection, Pollutants of Concern.
filtration, emerging technologies, and on-line systems. Added
technologies. Deleted the "Where Applied" section since it was
between "bioretention" and "rain gardens." Replaced "Ecology between "bioretention" and "rain gardens." Replaced "Ecology
Removed the Suggested Treatment Options Table and Ability of
Revised BMPs to use simpler and clearer language, and removed
for this treatment), and media filter, added emerging stormwater
Deleted the "Where Applied" section since it was duplicated from
Deleted the "Where Applied" section since it was duplicated from
Revised selection process steps for clarity and to remove outdated
Embankment" with "Media Filter Drain". Added Compost-amended
Removed "rain garden" for consistency with proposal to distinguish
information. Revised the Treatment Facility Selection Flow Chart for
Revised guidance for oil/water separation, pretreatment, infiltration,
treatment technologies. Deleted the "Where Applied" section since it
the TAPE process but Ecology has approved one emerging technology.
revised guidance throughout Volume V. Revised description of surface
Some treatment BMP options removed, emerging technologies added,
Removed amended sand filter (no design criteria have been developed
Vegetated Filter Strip. Removed Bio-infiltration Swale. Added emerging
New guidance more accurately describes how volume is determined by
Revised the performance goal for dissolved metals. Removed Amended
Embankment" with "Media Filter Drain." Added emerging technologies.
one BMP renamed. Added a note for Phosphorous facilities that require
Treatment Facilities Table because they provided limited usefulness and
Removed catch basin inserts and added emerging stormwater treatment Sand Filter. Added "vegetated" to "Compost Amended "Vegetated" Filter
technologies. To date, no catch basin inserts have been approved though Strip. Removed "rain garden" for consistency with proposal to distinguish
Table.
Change
and brevity.
list of options.
with Chapter 2.
guidance removed.
enhanced treatment.
Revised list of options.Revised list of options.Revised list of options.
Additional guidance provided.Additional guidance provided.
Minor revisions to the steps. Revised
Inserted updated modeling guidance.
Revised list of options. Revised waters
Multiple revisions to remove outdated
description of surface waters triggering
guidance and to provide new guidance.
Table, and Ability of Treatment Facilities
Removed the subsection on Pollutants of
triggering enhanced treatment consistent
Minor revisions for plain language, clarity,
Concern, the Suggested Treatment Options
Minor language changes for clarity. Revised
Additional guidance provided and outdated
Yes
to Permit
Language
Change Tied
3-1
2-12-34-1
Numbers
1-2 through 1-43-2 through 3-33-5 through 3-7
1-1 through 1-42-1 through 2-93-3 through 3-43-7 through 3-9
2-9 through 2-11
Approximate Page
Factors
Location
Figure 2.1.1
Treatment Facilities
Chapter 1 - Introduction
Section 3.2 Oil Control Menu
Chapter Introduction Paragraph
Section 1.4.3 Treatment Methods
Section 3.5 Basic Treatment Menu
Section 3.4 Enhanced Treatment Menu
Section 3.3 Phosphorous Treatment Menu
Section 2.1 Step-by-Step Selection Process for Section 2.2 Other Treatment Facility Selection
Chapter 2 - Treatment Facility Selection Process
Section 4.1.1 Water Quality Design Storm Volume
Volume V Runoff Treatment BMPsChapter 1 - Introduction Chapter 2 - Treatment Facility Selection Process Chapter 3 - Treatment Facility Menus Chapter 4 - General Requirements for Stormwater
Facilities
Manual).
#6, and #7.
this chapter.
Rain Gardens.
pretreatment.
Appendix III-C.
and references for clarity.
Revised language for clarity.
Reasoning or Comments
maintenance standards grant.
statement added in BMP T5.40.
Added reference to Chapter 12.
pollution-generating pervious surfaces.
Updated listed BMPs and made minor revisions to text.
Removed "and media filtration" in first bullet for clarity.
Vegetated Filter Strips. Minor additions to the recommended
Changed "StormFilter" to "Manufactured Media Filters", added
Moved Full Dispersion into Section 5.3.1 because the Municipal
Downspout infiltration moved to Volume III. Revised BMP T5.11
Stormwater Permits make it a necessary option in MR #5. Clarifying
Updated figures. Added BMP T5.14A Rain Gardens and BMP T5.14B
Permeable Pavements, BMP T5.16 Tree Retention and Tree Planting,
maintenance tables added. Added placeholders for Bioretention and
Added discussion that there are emerging technologies approved for
permeable pavement pending completion of the development of LID Concentrated Flow Dispersion and BMP T5.12 Sheet Flow Dispersion.
general changes in terminology. Added guidance regarding pollution-
Revised application to refer specifically to Minimum Requirements #5,
the expansion of Chapter 5 and source of additional design details (LID BMP T5.16 Vegetated Roofs, BMP T5.18 Reverse Slope Sidewalks, BMP
Expanded the list of BMPs in sections 5.3.1 and 5.3.2. Revised language
Renamed this Section and added information for the BMPs discussed in
generating hard surfaces, pollution-generating impervious surfaces, and
Bioretention but details are in Volume V of Chapter 7. Added BMP T5.15
information from WSDOT on Media Filter Drains and Compost Amended
Renamed this Section and added information regarding Bioretention and
Revised BMP T5.30 Full Dispersion by incorporating details from previous
T5.19 Minimal Excavation Foundations, BMP T5.20 Rainwater Harvesting.
Replaced "impervious" surfaces with "hard" surfaces in coordination with Add reference to expanded BMP options and LID Manual to acknowledge
5.3.3
Change
Other Practices
list of BMPs provided.
Minor language changes.
to incorporate new terms.
Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.Additional guidance provided.
Minor language changes for clarity.
Amend existing BMP's add new BMP's
Added new tables within overall set of operation and maintenance standards
Changed bioinfilltration to bioretention.
Deleted Full Dispersion and section
Minor language changes for clarity. Changes
Additional clarifying guidance provided. Full
YesYesYes
to Permit
Language
Change Tied
5-16-16-17-1 7-1
5-16-1
Numbers
5-3 to 5-39
4-1 through 4-24-2 through 4-45-1 through 5-27-1 through 7-2
4-31 through 4-535-39 through 5-42
Approximate Page
BMPs
Facilities
Location
Pretreatment
Section 6.1 PurposeSection 7.1 Purpose
Section 5.1 Purpose
Section 5.2 ApplicationSection 6.2 Application
Sections 7.3 Applications
Stormwater Management
Section 5.3.2 Site Design BMPs
Sections 7.2 General Considerations
Section 4.1.3 flows Requiring Treatment
Section 4.1.2 Water Quality Design Flow Rate
Section 5.3.1 On-site Stormwater Management
Section 4.6 Maintenance Standards for Drainage
Section 6.3 Best Management Practices (BMPs) for
Section 5.3 Best Management Practices for On-Site
Chapter 5 - On-Site Stormwater ManagementChapter 6 - PretreatmentChapter 7 - Infiltration and Bioretention Treatment Facilities
T8.10.
area of plates.
sand filter vault.
Highway Runoff Manual.
separate BMP for clarity.
objective for sand filters.
Reasoning or Comments
Revised to include media filter drains.
Designers should refer to Basic Filter Strip.
Corrected Stokes Law equation for rise rate.
for Bioretention Cells, Swales, and Planter Boxes.
Design details for these BMPs remain in Volume III.
Revised name from Sand Filtration to just Filtration.
Added reference to Media Filter Drain to description.
Revised list of BMPs. Revised Sizing Criteria table for clarity.
Minor language changes for clarity throughout the chapter.
Added design criteria for new Media Filter Drain (MFD) option
Filter Strips. Treatment via infiltration through amended soils.
No design criteria exists for this BMP to validate basic treatment.
First cell must be lined to be consistent with liner requirements in
Added Media Filter Drain to list of approved technologies. Clarified
for 2-cell ponds. Definition of WQ Design Storm Volume amended.
BMP T8.11 Large Sand Filter Basin was described in the prior manual
under BMP T8.10 Sand Filter Basin. The Large Sand Filter was given a
previous sections 8.5, 8.6, 8.7, & 8.8 become subsections under BMP Replaced sections 12.1 through 12.5 to provide new guidance on the
Added guidance and design criteria for Compost-Amended Vegetated
Technology Assessment Protocol (TAPE) review and approval process.
Added design criteria for sand filter basins. reorganized section so that
(previously referred to as Ecology Embankment). Text matches WSDOT Chapter 4. Added cell requirements for consistency with design criteria Corrected the equation to calculated the projected
(horizontal) surface
Added detailed guidance, design criteria, infeasibilty criteria and figures
Revised the purpose to apply to both sand and media filtration facilities.Added design criteria, construction criteria, and maintenance criteria for
Boxes.
Change
new guidance.
Added this BMP.
within BMP T8.10
Revised guidance.Revised guidance.
Corrected formula.Corrected formula.
guidance removed.
Removed this BMP.
Included new technologies
language changes for clarity.
Additional guidance provided.Additional guidance provided.Additional guidance provided.
Updated references to Volume III
Renamed and reorganized section.
Minor language changes for clarity.Minor language changes for clarity.
Replaced Bio-infiltration Swale with
Changed title and introduced minor
Transferred this BMP from Chapter 9.
Bioretention Cells, Swales, and Planter
Separated out BMP previously reference
Replaced sections 12.1 through 12.5 with
Additional guidance provided and outdated
to Permit
Language
Change Tied
7-28-2
8-18-18-2
N/A
Numbers
8-2 to 8-15
7-3 through 7-258-1 through 8-399-1 through 9-269-1 through 9-26
7-25 through 7-298-16 through 8-178-17 through 8-238-24 through 8-3811-8 through 11-912-1 through 12-6
10-1 through 10-17
11-10 through 11-11
Approximate Page
Boxes
Location
8.1 Purpose
Strips (CAVFS)
8.2 Description
BMP T10.10 Wet Pond
BMP T8.20 Sand Filter Vault
BMP T8.40 Media Filter Drain
Section 7.4 and BMPs 7.10 & 7.20
BMP T8.11 Large Sand Filter Basin
BMP T9.50 Narrow Area Filter Strip
Section 8.3 Performance Objectives
Chapter 12 - Emerging Technologies
Section 9.4 Best Management Practices
Section 8.4 Applications and Limitations
Chapter 8 - Filtration Treatment Facilities
BMP T11.10 API (Baffle type) Separator Bay
Chapter 9 - Biofiltration Treatment Facilities
Sand Filtration / BMP T8.10 Sand Filter Basin
BMP T7.40 Compost-amended Vegetated Filter
BMP T11.11 Coalescing Plate (CP) Separator Bay
BMP T 7.30 Bioretention Cells, Swales, and Planter
Section 8.5 Best Management Practices (BMPs) for
Chapter 8 - Sand Filtration Treatment FacilitiesChapter 9 - Biofiltration Treatment FacilitiesChapter 10- Wetpool FacilitiesChapter 11 - Oil and Water SeparatorsChapter 12 - Emerging
Technologies
Reasoning or Comments
evaluating soils used for bioretention.
previously listed throughout this volume.
Lists of species from City of Seattle guidance.
general procedures in the ASTM method are implemented. This
Removed examples of emerging technologies. Added some examples
test for saturated hydraulic conductivity can be influenced by how the
appendix lays out more specific procedures to help with consistency in
Added Recommended Modifications to ASTM D 2434. The results of this
Corrected several test procedures and geotextile property requirements.
Change
technologies.
Revised Guidance.
Additional guidance provided.
Removed examples of emerging
New appendix pertinent to BMP T5.16
to Permit
Language
Change Tied
N/A
Numbers
E-1 through E-5
C-1 through C-3
B-1 through B-2
Approximate Page
Species
Location
Appendix V-C Geotextile Specifications
for Stormwater Treatment and Control
Conductivity for Bioretention Soil Mixes.
ASTM D 2434 When Measuring Hydraulic
Appendix V-B Recommended Modifications to
Section 12.6 Examples of Emerging Technologies
Appendix V-E Recommended Newly Planted Tree
Appendix V-B Recommended Procedures for ASTM D 2434Appendix V-C Geotextile SpecificationsAppendix V-E Recommended Bioretention Plant Species
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Page 1of 51
Permit No. WA0037052
Issuance Date: November 13, 2015
Effective Date: December1, 2015
Expiration Date: November 30, 2020
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
WASTE DISCHARGE PERMIT NO. WA0037052
State of Washington
DEPARTMENT OF ECOLOGY
Southwest Regional Office
P.O. Box 47775
Olympia, WA 98504-7775
In compliance with the provisions of
The State of Washington Water Pollution Control Law
Chapter 90.48 Revised Code of Washington
and
The Federal Water Pollution Control Act
(The Clean Water Act)
Title 33 United States Code, Section 1342 et seq.
City of Port Townsend
250 Madison Street, Suite 2R
Port Townsend, WA98368
is authorized to discharge in accordance with the Special and General Conditions that follow.
Plant Location:5300 Kuhn StreetReceiving Water:Strait of Juan de Fuca
Port Townsend, WA 98368
TreatmentType:Activated Sludge
(Oxidation Ditch)
Rich Doenges
Southwest Region Manager
Water Quality Program
Washington State Department of Ecology
Page 2of 51
Permit No. WA0037052
TABLE OF CONTENTS
TABLE OF CONTENTS...........................................................................................................................2
SUMMARY OF PERMIT REPORT SUBMITTALS.............................................................................4
SPECIAL CONDITIONS..........................................................................................................................6
S1.DISCHARGE LIMITS....................................................................................................................6
A.Effluent Limits....................................................................................................................6
B.Mixing Zone Authorization................................................................................................7
S2.MONITORING REQUIREMENTS................................................................................................7
A.Monitoring Schedule...........................................................................................................7
B.Sampling and Analytical Procedures................................................................................10
C.FlowMeasurement, Field Measurement, and Continuous Monitoring Devices..............10
D.Laboratory Accreditation..................................................................................................11
S3.REPORTING AND RECORDING REQUIREMENTS...............................................................11
A.Discharge Monitoring Reports..........................................................................................12
B.Permit Submittals and Schedules......................................................................................13
C.Records Retention.............................................................................................................14
D.Recording of Results.........................................................................................................14
E.Additional Monitoring by the Permittee...........................................................................14
F.Reporting Permit Violations.............................................................................................14
G.Other Reporting................................................................................................................16
H.Maintaining a Copy of this Permit....................................................................................16
S4.FACILITY LOADING..................................................................................................................17
A.Design Criteria..................................................................................................................17
B.Plans for Maintaining Adequate Capacity........................................................................17
C.Duty to Mitigate................................................................................................................18
D.Notification of New or Altered Sources...........................................................................18
E.Infiltration and Inflow Evaluation....................................................................................18
F.Wasteload Assessment......................................................................................................18
S5.OPERATION AND MAINTENANCE.........................................................................................19
A.Certified Operator.............................................................................................................19
B.Operation and Maintenance Program...............................................................................19
C.Short-term Reduction........................................................................................................20
D.Electrical Power Failure....................................................................................................20
E.Prevent Connection of Inflow...........................................................................................20
F.Bypass Procedures............................................................................................................20
G.Operations and Maintenance (O&M) Manual..................................................................23
S6.PRETREATMENT........................................................................................................................24
A.General Requirements.......................................................................................................24
B.Duty to Enforce Discharge Prohibitions...........................................................................24
C.Wastewater Discharge Permit Required...........................................................................25
D.Identification and Reporting of Existing, New, and Proposed Industrial Users...............26
E.Industrial User Survey......................................................................................................26
S7.SOLID WASTES...........................................................................................................................26
A.Solid Waste Handling.......................................................................................................26
Page 3of 51
Permit No. WA0037052
B.Leachate............................................................................................................................26
S8.APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR
FACILITY CHANGES....................................................................................................26
S9.ENGINEERING DOCUMENTS FOR OUTFALL REPLACEMENT.........................................27
S10.ACUTE TOXICITY......................................................................................................................27
A.Testing when there is No Permit Limit for Acute Toxicity..............................................27
B.Sampling and Reporting Requirements............................................................................28
S11.CHRONIC TOXICITY..................................................................................................................29
A.Testing when there is No Permit Limit for Chronic Toxicity...........................................29
B.Sampling and Reporting Requirements............................................................................29
GENERAL CONDITIONS......................................................................................................................31
G1.SIGNATORY REQUIREMENTS.................................................................................................31
G2.RIGHT OF INSPECTION AND ENTRY.....................................................................................32
G3.PERMIT ACTIONS.......................................................................................................................32
G4.REPORTING PLANNED CHANGES..........................................................................................34
G5.PLAN REVIEW REQUIRED.......................................................................................................34
G6.COMPLIANCE WITH OTHER LAWS AND STATUTES.........................................................34
G7.TRANSFER OF THIS PERMIT...................................................................................................34
G8.REDUCED PRODUCTION FOR COMPLIANCE......................................................................35
G9.REMOVED SUBSTANCES.........................................................................................................35
G10.DUTY TO PROVIDE INFORMATION.......................................................................................35
G11.OTHER REQUIREMENTS OF 40 CFR.......................................................................................35
G12.ADDITIONAL MONITORING....................................................................................................35
G13.PAYMENT OF FEES....................................................................................................................35
G14.PENALTIES FOR VIOLATING PERMIT CONDITIONS..........................................................35
G15.UPSET...........................................................................................................................................36
G16.PROPERTY RIGHTS....................................................................................................................36
G17.DUTY TO COMPLY....................................................................................................................36
G18.TOXIC POLLUTANTS.................................................................................................................36
G19.PENALTIES FOR TAMPERING.................................................................................................37
G20.COMPLIANCE SCHEDULES.....................................................................................................37
G21.SERVICE AGREEMENT REVIEW.............................................................................................37
APPENDIX A............................................................................................................................................38
Page 4of 51
Permit No. WA0037052
SUMMARY OF PERMIT REPORT SUBMITTALS
Refer to the Special and General Conditions of this permit for additional submittal requirements.
Permit
SubmittalFrequencyFirst Submittal Date
Section
S3.A.Discharge Monitoring Report(DMR)MonthlyJanuary 15, 2016
Permit Renewal Application Monitoring
S3.A.AnnuallyJanuary 15, 2017
Data
S3.F.Reporting Permit ViolationsAs necessary
S4.B.Plans for Maintaining Adequate CapacityAs necessary
S4.D.Notification of New or Altered SourcesAs necessary
S4.E.Infiltration and Inflow EvaluationAnnuallyJanuary 31, 2016
S4.F.Wasteload AssessmentAnnuallyJanuary 31, 2016
S5.F.Bypass NotificationAs necessary
Notify Ecology when Industrial Users
S6.B.4.As necessary
violate discharge prohibitions
Notify Ecology of any proposed discharger
S6.C.2.As necessary
which may be a SIU
Submit copies of Industrial User
S6.D.As necessary
notifications letters
S6.E.Industrial User Survey Submittal1/permit cycleJanuary 31, 2019
S8.Application for Permit Renewal1/permit cycleJune 1, 2020
Engineering Documentsfor Outfall
S9.A.1/permit cycleDecember 31, 2018
Replacement
Approvable Plans & Specifications1/permit cycleDecember 31, 2019
S9.D.
once in the last
summer and once
in the last winter
Acute Toxicity Effluent Test Results -
S10.prior to June 1, 2020
Submit with Permit Renewal Application
submission of the
application for
permit renewal
once in the last
summer and once
in the last winter
Chronic Toxicity Effluent Test Results with
S11.prior to June 1, 2020
Permit Renewal Application
submission of the
application for
permit renewal
G1.Notice of Change in AuthorizationAs necessary
Page 5of 51
Permit No. WA0037052
Permit
SubmittalFrequencyFirst Submittal Date
Section
G4.Reporting Planned ChangesAs necessary
Engineering Report for Construction or
G5.As necessary
Modification Activities
G7.Notice of Permit TransferAs necessary
G10.Dutyto Provide InformationAs necessary
G20.Compliance SchedulesAs necessary
G21.Contract SubmittalAs necessary
Page 6of 51
Permit No. WA0037052
SPECIAL CONDITIONS
S1.DISCHARGE LIMITS
A.Effluent Limits
All discharges and activities authorized by this permit must comply withthe terms and
conditions of this permit. The discharge of any of the following pollutants more
frequently than, or at a level in excess of, that identified and authorized by this permit
violates the terms and conditions of this permit.
Beginning on the effective date of this permit, the Permittee may dischargetreated
domesticwastewater to the Strait of Juan de Fucaat the permitted location subject to
compliance with the following limits:
Effluent Limits: Outfall 001
Latitude 48.141667N Longitude-122.783333 W
ab
ParameterAverage Monthly Average Weekly
30milligrams/liter (mg/L)
Biochemical Oxygen513pounds/day (lbs/day)45mg/L
Demand (5-day) (BOD)85% removal of influent 769lbs/day
5
BOD
5
30mg/L
513lbs/day45mg/L
Total Suspended Solids (TSS)
85%removal of influent 769lbs/day
TSS
Total Residual Chlorine0.5 mg/L0.75mg/L
ParameterMinimumMaximum
pH6.0Standard Units9.0Standard Units
WeeklyGeometric
ParameterMonthly Geometric Mean
Mean
c
Fecal Coliform Bacteria 200/100 milliliter (mL)400/100 mL
aAverage monthly effluent limit means the highest allowable average of daily
discharges over a calendar month. To calculate the discharge value to compare to the
limit, you add the value of each daily discharge measured duringa calendar month and
divide this sum by the total number of daily discharges measured. See footnote c for
fecal coliform calculations.
bAverage weekly discharge limit means the highest allowable average of daily
discharges over a calendar week, calculated as the sum of all daily discharges
measured during a calendar week divided by the number of daily discharges' measured
during that week. See footnote c for fecal coliform calculations.
cEcology provides directions to calculate the monthly and the weekly geometric mean
in publication No. 04-10-020, Information Manual for Treatment Plant Operators
available at: http://www.ecy.wa.gov/pubs/0410020.pdf
Page 7of 51
Permit No. WA0037052
B.Mixing Zone Authorization
Mixing Zone for Outfall 001
The following paragraphs define the maximum boundariesof the mixing zones:
Chronic Mixing Zone
The mixing zone is a circle with radius of 321feet (97.8meters)measured from
the center of each discharge port. The mixing zone extends fromthe bottom to
the top of the water column. The concentration of pollutants at the edge of the
chronic zone must meet chronic aquatic life criteria and human health criteria.
Acute Mixing Zone
The acute mixing zone is a circle with radius of 32.1feet (9.8meters) measured
from the center of each discharge port.The mixing zone extends from the
bottom to the top of the water column.The concentration of pollutants at the
edge of the acute zone must meet acute aquatic life criteria.
Available Dilution (dilution factor)
Acute Aquatic Life Criteria25
Chronic Aquatic Life Criteria781
Human Health Criteria -Carcinogen781
Human Health Criteria -Non-carcinogen781
S2.MONITORING REQUIREMENTS
A.Monitoring Schedule
The Permittee must monitor in accordance with the following schedule and the
requirements specified in Appendix A.
Minimum
ParameterUnitsSampling Sample Type
Frequency
(1) WastewaterInfluent
Wastewater Influent means the raw sewage flow from the collection system into the
treatment facility. Sample the wastewater entering the headworks of the treatment plant
excluding any side-stream returns from inside the plant.
a
FlowMGDContinuousMetered/Recorded
Composite Sample
b
BODmg/L1/week
5
c
(24-Hour)
bd
BODlbs/day1/weekCalculated
5
Page 8of 51
Permit No. WA0037052
Minimum
ParameterUnitsSampling Sample Type
Frequency
Composite Sample
b
TSSmg/L1/week
c
(24-Hour)
bd
TSSlbs/day1/weekCalculated
(2)Final Wastewater Effluent
Final Wastewater Effluent means wastewaterexitingthe last treatment process or
operation. Typically, this is after or at the exit from the chlorine contact chamber or
other disinfection process. The Permittee may take effluent samples for the BOD
5
analysis before or after the disinfection process. If taken after, the Permittee must
dechlorinate and reseed the sample.Chlorine residual should be taken after
dechlorination.
Composite Sample
b
BODmg/L1/week
5
c
(24-Hour)
bd
BODlbs/day1/weekCalculated
5
be
BOD% removal1/weekCalculated
5
Composite Sample
b
TSSmg/L1/week
c
(24-Hour)
bd
TSSlbs/day1/weekCalculated
be
TSS% removal1/weekCalculated
bf
Chlorine (Total Residual)mg/L1/weekGrab
gbf
Fecal Coliform# /100 ml1/weekGrab
Standard
hf
pH 1/dayGrab
Units
(3) Whole Effluent Toxicity Testing Final Wastewater Effluent
once in the last
Composite Sample
Acute Toxicity Testingwinter & once in
(24-Hour)
the last summer
once in the last
Composite Sample
Chronic Toxicity Testingwinter & once in
(24-Hour)
the last summer
Additional requirements specified in Special Condition S10 and S11.
(4)Permit Renewal Application Requirements Final Wastewater Effluent
The Permittee must record and report the wastewater treatment plant flow discharged on
the day it collects the sample for priority pollutant testing with the discharge monitoring
report.
Degrees Once/July
i
Temperature Measurement
CelsiusOnce/December
Page 9of 51
Permit No. WA0037052
Minimum
ParameterUnitsSampling Sample Type
Frequency
Dissolved Oxygenmg/LOnce per yearGrab
Composite Sample
Total Kjeldahl Nitrogenmg/L as NOnce per year
(24-Hour)
Composite Sample
Total Ammoniamg/L as NOnce per year
(24-Hour)
Composite Sample
Nitrate plus Nitritemg/L as NOnce per year
(24-Hour)
Oil and Greasemg/LOnce per yearGrab
Composite Sample
Phosphorus (Total)mg/L as POnce per year
(24-Hour)
Composite Sample
Total Dissolved Solidsmg/LOnce per year
(24-Hour)
Composite Sample
Total Hardnessmg/LOnce per year
(24-Hour)
micrograms/
CyanideOnce per yearGrab
liter (µg/L)
Total Phenolic Compoundsµg/LOnce per yearGrab
µg/L;
Composite Sample
Priority Pollutants (PP) nanograms
Once per year(24-Hour)
Total Metals(ng/L) for
Grab for Mercury
mercury
PPVolatile Organic
µg/LOnce per yearGrab
Compounds
PPAcid-extractable Composite Sample
µg/LOnce per year
Compounds(24 hour)
PPBase-neutral Composite Sample
µg/LOnce per year
Compounds(24 hour)
aContinuous means uninterrupted except for brief lengths of time for calibration,
power failure, or unanticipated equipment repair or maintenance. The time interval
for the associated data logger must be no greater than 30 minutes. The Permittee
must sample at least four times a daywhen continuous monitoring is not possible.
b1/week means one time during each calendar week.
c24-hour composite means a series of individual samples collected over a 24-hour
period into a single container, and analyzed as one sample.
dCalculated means figured concurrently with the respective sample, using the
following formula: Concentration (in mg/L) X Flow (in MGD) X Conversion Factor
(8.34) = lbs/day
Page 10of 51
Permit No. WA0037052
Minimum
ParameterUnitsSampling Sample Type
Frequency
e% removal = Influent concentration (mg/L) Effluent concentration (mg/L)x 100
Influent concentration (mg/L)
Calculate the percent (%) removal of BODand TSS using the above equation.
5
fGrab means an individual sample collected over a15 minute, or less, period.
g
Information Manual for Wastewater Treatment Plant Operators, Publication Number
04-10-020 available at:http://www.ecy.wa.gov/programs/wq/permits/guidance.html
. Do not report a result as too numerous to count (TNTC).
hReport the daily pH and the minimum and maximum for the monitoring period.
iTemperature grab sampling must occur when the effluent is at or near its daily
maximum temperature, which usually occurs in the late afternoon. If measuring
temperature continuously, the Permittee must determine and report a daily maximum
from half-hour measurements in a 24-hour period.Continuous monitoring
instruments must achieve an accuracy of 0.2 degrees C and the Permittee must verify
accuracy annually.
B.Sampling and Analytical Procedures
Samples and measurements taken to meet the requirements of this permit must represent
the volume and nature of the monitored parameters. The Permittee must conduct
representative sampling of any unusual discharge or discharge condition, including
bypasses, upsets, and maintenance-related conditions that may affect effluent quality.
Sampling and analytical methods used to meet the monitoring requirements specified in
this permit must conform to the latest revision of theGuidelines Establishing Test
Procedures for the Analysis of Pollutantscontained in 40 Code of Federal Regulations
(CFR)Part 136\[or as applicable in 40 CFR subchapters N (Parts 400471)or O (Parts
501-503)\]unless otherwise specified in this permit. The Department of Ecology
(Ecology) may only specifyalternative methods for parameterswithout permit limitsand
for those parameters without an Environmental Protection Agency (EPA)approved test
method in 40 CFR Part 136.
C.FlowMeasurement, Field Measurement,andContinuous Monitoring Devices
The Permittee must:
1.Select and use appropriate flow measurement, field measurement, and continuous
monitoring devicesand methods consistent withaccepted scientific practices.
2.Install, calibrate, and maintain these devices to ensure the accuracy of the
measurements is consistent with the accepted industry standard, the
peration and Maintenance
(O&M)Manual procedures for the device and the wastestream.
Page 11of 51
Permit No. WA0037052
3.Calibrate continuous monitoring instruments weekly unless it can demonstrate a
longer period is sufficient based on monitoring records. The Permittee:
a.May calibrate apparatus for continuous monitoring of dissolved oxygen
by air calibration.
b.Must calibrate continuous pH measurement instruments using a grab
sample analyzed in the lab with a pH meter calibrated with standard
buffers and analyzed within 15 minutes of sampling.
c.Must calibrate continuous chlorine measurement instruments usinga
grab sample analyzed in the laboratory within 15 minutes of sampling.
4.Calibrate micro-recording temperature devices, known as thermistors, using
(Standard Operating Procedures for Continuous Temperature Monitoring of
Fresh Water Rivers and Streams Version 1.0 10/26/2011). This document is
available online at:
http://www.ecy.wa.gov/programs/eap/qa/docs/ECY_EAP_SOP_Cont_Temp_Mo
n_Ambient_v1_0EAP080.pdf. Calibration as specified in this document is not
required if the Permittee uses recording devices certified by the manufacturer.
5.Use field measurement devices as directed by themanufacturer and do not use
reagents beyond their expiration dates.
6.Establish a calibration frequency for each device or instrument in the O&M
Manual that conforms to the frequency recommended by the manufacturer.
7.Calibrate flow-monitoring devices at a minimum frequency of at least one
calibration per year.
8.Maintain calibration records for at least three years.
D.Laboratory Accreditation
The Permittee must ensure that all monitoring data required by Ecology for permit
specified parameters is prepared by a laboratory registered or accredited under the
provisions of chapter 173-50Washington Administrative Code (WAC),Accreditation of
Environmental Laboratories. Flow, temperature, settleable solids, conductivity, pH, and
internal process control parameters are exempt from this requirement. The Permittee
must obtain accreditation for conductivity and pH if it must receive accreditation or
registration for other parameters.
S3.REPORTING AND RECORDING REQUIREMENTS
The Permittee must monitor and report in accordance with the following conditions. Falsification
of information submitted to Ecology is a violation of the terms and conditions of this permit.
Page 12of 51
Permit No. WA0037052
A.Discharge Monitoring Reports
The first monitoring period begins on the effective date of the permit(unless otherwise
specified). The Permittee must:
1.Summarize, report, and submit monitoring data obtained during each monitoring
period on theelectronicDischarge Monitoring Report (DMR) form provided by
Ecologywithin the Water Quality Permitting Portal. Include data for each ofthe
parameters tabulated in Special Condition S2and as required by the form.
Report a value for each day sampling occurred (unless specifically exempted in
the permit) and for the summary values (when applicable) included on the
electronic form.
To find out more information and to sign up for the Water Quality Permitting
Portal go to: http://www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html
2.ENoDreporting code for an entire DMR, for a specific
monitoring point, or for a specific parameter as appropriate, if the Permitteedid
not discharge wastewater or a specific pollutant during a given monitoring
period.
3.Report single analytical valuesbelow detection as less than the detection level
by entering < followed by the numeric valueof the detection level (e.g.<
2.0)on the DMR. If the methoduseddid not meet the minimum DL and
quantitation level (QL)identified in the permit,report the actual QL and DLin
the commentsor in the location provided.
4.Do notreport zero for bacteria monitoring. Report as required by the laboratory
method.
5.Calculate and report an arithmetic average value for each day for bacteria if
multiple samples were taken in one day.
6.Calculate the geometric mean values for bacteria (unless otherwise specified in
the permit) using:
a.The reported numeric value for all bacteria samples measured above the
detection value except when it took multiple samples in one day. If the
Permittee takes multiple samples in one day it must use the arithmetic
average for the day in the geometric mean calculation.
b.The detection value for those samples measured below detection.
7.Report the test method used for analysisin the comments if the laboratoryused
an alternative method not specified in the permit and as allowed in Appendix A.
8.Calculate average valuesand calculated total values(unless otherwise specified
in the permit)using:
Page 13of 51
Permit No. WA0037052
a.The reported numeric value for all parameters measured between the
agency-required detection value and the agency-required quantitation
value.
b.One-half the detection value (for values reported below detection) if the
lab detected the parameter in another sample from the same monitoring
point for the reporting period.
c.Zero (for values reported below detection) if the lab didnot detect the
parameter in another sample for the reporting period.
9.Report single-sample grouped parameters (for example:priority pollutants,
PAHs, pulp and paper chlorophenolics, TTOs) on the WQWebDMRform and
include: sampledate, concentration detected, detection limit (DL)(as necessary),
andlaboratory quantitation level(QL)(as necessary).
The Permittee must also submit an electronic copy of the laboratory reportas an
attachmentusingWQWebDMR.The contract laboratory reportsmust also
include information on the chain of custody, QA/QC results, and documentation
of accreditation for the parameter.
10.Ensure that DMRs are electronically submitted no later than the dates specified
below, unless otherwise specified in this permit.
11.Submit DMRs for parameters with the monitoring frequencies specified in S2
(monthly, quarterly, annual, etc.) at the reporting schedule identified below. The
Permittee must:
th
a.Submit monthlyDMRsby the 15day of the following month.
b.Submit annual DMRs(Permit Renewal Application Requirements),
th
unless otherwise specified in the permit, by January 15for the previous
calendar year. The annual sampling period is the calendar year.
B.Permit Submittals and Schedules
The Permittee must use the Water Quality Permitting Portal Permit Submittals
application (unless otherwise specified in the permit) to submit all other written permit-
required reports by the date specified in the permit.
When another permit condition requires submittal of a paper(hard-copy)report,the
Permittee must ensure that it is postmarked or received by Ecology no later than the dates
specified by this permit.Send thesepaper reports to Ecology at:
Water Quality Permit Coordinator
Department ofEcology
Southwest Regional Office
P.O. Box 47775
Olympia, WA 98504-7775
Page 14of 51
Permit No. WA0037052
C.Records Retention
The Permittee must retain records of all monitoring information for a minimum of three
years. Such information must include all calibration and maintenance records and all
original recordings for continuous monitoring instrumentation, copies of all reports
required by this permit, and records of all data used to complete the application for this
permit. The Permittee must extend this period of retention during the course of any
unresolved litigation regarding the discharge of pollutants by the Permittee or when
requested by Ecology.
D.Recording of Results
For each measurement or sample taken, the Permittee must record the following
information:
1.The date, exact place, method, and time of sampling or measurement.
2.The individual who performed the sampling or measurement.
3.The dates the analyses were performed.
4.The individual who performed the analyses.
5.The analytical techniques or methods used.
6.The results of all analyses.
E.Additional Monitoring by the Permittee
If the Permittee monitors any pollutant more frequently than required by Special
Condition S2 of this permit, then the Permittee must include the results of such
monitoring in the calculation and reporting of the data submitted in the Permittee's DMR
unless otherwise specified by Special Condition S2.
F.Reporting Permit Violations
The Permittee must take the following actions when it violates or is unable to comply
with any permit condition:
1.Immediately take action to stop, contain, and cleanup unauthorized discharges or
otherwise stop the noncompliance and correct the problem.
2.If applicable, immediately repeat sampling and analysis. Submit the results of
any repeat sampling to Ecology within 30 days of sampling.
a.Immediate Reporting
The Permittee must immediatelyreportto Ecology and the Department
of Health, Shellfish Program, and the Local Health Jurisdiction(at the
numbers listed below), all:
Page 15of 51
Permit No. WA0037052
Failuresof the disinfection system.
Collection system overflows.
Plant bypassesdischarging to marine surface waters.
Any other failures of the sewage system (pipe breaks, etc.)
Southwest Regional Office360-407-6300
Department of Health, 360-236-3330 (business hours)
Shellfish Program360-789-8962(after businesshours)
Jefferson County Public 360-385-9444
Health
b.Twenty-Four-Hour Reporting
The Permittee must report the following occurrences of noncompliance
by telephone, to Ecology at the telephone numberlisted above, within 24
hours from the time the Permittee becomes aware of any of the following
circumstances:
i.Any noncompliance that may endanger health or the
environment, unless previously reported under immediate
reporting requirements.
ii.Any unanticipated bypass that causes an exceedance ofan
effluent limit in the permit (See Part S5.F,
iii.Any upset that causes an exceedance of aneffluent limit in the
iv.Any violation of a maximum daily or instantaneous maximum
discharge limit for any of the pollutants in Section S1.A of this
permit.
v.Any overflow prior to the treatment works, whether or not such
overflow endangers health or the environment or exceeds any
effluent limit in the permit.
c.Report within Five Days
The Permittee must also submit a written report within five days of the
time that thePermittee becomes aware of any reportable event under
subparts a or b, above. The report must contain:
i.A description of the noncompliance and its cause.
ii.The period of noncompliance, including exact dates and times.
Page 16of 51
Permit No. WA0037052
iii.The estimated time the Permittee expects the noncompliance to
continue if not yet corrected.
iv.Steps taken or planned to reduce, eliminate, and prevent
recurrence of the noncompliance.
v.If the noncompliance involves an overflow prior to the treatment
works, an estimate of the quantity (in gallons) of untreated
overflow.
d.Waiver of Written Reports
Ecology may waive the written report required in subpart c, above, on a
case-by-case basis upon request if the Permittee has submitted a timely
oral report.
e.All Other Permit Violation Reporting
The Permittee must report all permit violations, which do not require
immediate or within 24 hours reporting, when it submits monitoring
reports for S3.A ("Reporting"). The reports must contain the information
listed in subpart c, above. Compliance with these requirements does not
relieve the Permittee from responsibility to maintain continuous
compliance with the terms and conditions of this permit or the resulting
liability for failure to comply.
G.Other Reporting
1.Spills of Oil or Hazardous Materials
The Permittee must report a spill of oil or hazardous materials in accordance with
the requirements of Revised Code of Washington (RCW)90.56.280 and chapter
173-303-145. You can obtain further instructions at the following website:
http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm.
2.Failure to Submit Relevant or Correct Facts
Where the Permittee becomes aware that it failed to submit any relevant facts in a
permit application, or submitted incorrect information in a permit application, or
in any report to Ecology, it must submit such facts or information promptly.
H.Maintaining a Copy of this Permit
The Permittee must keep a copy of this permit at the facility and make it available upon
request to Ecology inspectors.
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S4.FACILITY LOADING
A.Design Criteria
The flows or waste loads for the permitted facility must not exceed the following design
criteria:
Maximum Month Design Flow (MMDF)2.05MGD
Annual AverageFlow1.44MGD
BODInfluent Loading for Maximum Month3754lbs/day
5
TSS Influent Loading for Maximum Month4568lbs/day
Design Population12,000
B.Plans for Maintaining Adequate Capacity
1.Conditions Triggering Plan Submittal
The Permittee must submit a plan and a schedule for continuing to maintain
capacity to Ecology when:
a.The actual flow or waste load reaches 85 percent of any one of the design
criteria in S4.A for three consecutive months.
b.The projected plant flow or loading would reach design capacity within
five years.
2.Plan and Schedule Content
The plan and schedule must identify the actions necessary to maintain adequate
capacity for the expected population growth and to meet the limits and
requirements of the permit. The Permittee must consider the following topics and
actions in its plan.
a.Analysis of the present design and proposed process modifications
b.Reduction or elimination of excessive infiltration and inflow of
uncontaminated ground and surface water into the sewer system
c.Limits on future sewer extensions or connections or additional waste
loads
d.Modification or expansion of facilities
e.Reduction of industrial or commercial flows or wasteloads
Engineering documents associated with the plan must meet the requirements of
WAC 173-240-060, "Engineering Report," and be approved by Ecology prior to
any construction.
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C.Duty to Mitigate
The Permittee must take all reasonable steps to minimize or prevent any discharge or
sludge use or disposal in violation of this permit that has a reasonable likelihood of
adversely affecting human health or the environment.
D.Notification of New or Altered Sources
1.The Permittee must submit written notice to Ecology whenever any new
discharge or a substantial change in volume or character of an existing discharge
into the wastewater treatment plantis proposed which:
a.Would interfere with the operation of, or exceed the design capacity of,
any portion of the wastewater treatment plant.
b.Is not part of an approved general sewer plan or approved plans and
specifications.
c.Issubject to pretreatment standards under 40 CFR Part 403 and Section
307(b) of the Clean Water Act.
2.This notice must include an evaluation of the ability
to adequately transport and treat the added flow and/or waste load, the quality
and volume of effluent to be discharged to the treatment plant, and the
CFR 122.42(b)\].
E.Infiltration and Inflow Evaluation
1.The Permittee must conduct an infiltration and inflow evaluation. Refer to the
U.S. EPA publication, I/I Analysis and Project Certification, available as
Publication No. 97-03at:
http://www.ecy.wa.gov/programs/wq/permits/guidance.html
2.The Permittee may use monitoring records to assess measurable infiltration and
inflow.
3.The Permittee must prepare a report summarizing any measurable infiltration and
inflow. If infiltration and inflow have increased by more than 15 percent from
that found in the previous report based on equivalent rainfall, the report must
contain a plan and a schedule to locate the sources of infiltration and inflow and
to correct the problem.
4.The Permittee must submit a report summarizing the results of the evaluation and
any recommendations for corrective actions byJanuary 31, 2016,andannually
thereafter.
F.Wasteload Assessment
The Permittee must conduct an annual assessment of itsinfluent flow and waste loadand
submita report to Ecology by January 31, 2016, and annuallythereafter.The report
must contain:
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Permit No. WA0037052
1.A description of compliance or noncompliance with the permit effluent limits.
2.Acomparison between the existing and design:
a.Monthly averagedry weatherand wet weather flows.
b.Peak flows.
c.BODloading.
5
d.Total suspended solids loadings.
3.The percent change in theaboveparameters since the previous report(except for
the first report).
4.The present and design population or population equivalent.
5.The projected population growth rate.
6.Theestimated date upon which the Permittee expectsthe wastewater treatment
plant toreach design capacity, according to the most restrictive of the parameters
above.
Ecology may modify the interval for review and reporting if it determines that a different
frequency is sufficient.
S5.OPERATION AND MAINTENANCE
The Permittee must at all times properly operate and maintain all facilities and systems of
treatment and control (and related appurtenances), which areinstalled to achieve compliance with
the terms and conditions of this permit. Proper operation and maintenance also includes keeping
a daily operation logbook (paper or electronic), adequate laboratory controls, and appropriate
quality assurance procedures. This provision of the permit requires the Permittee to operate
backup or auxiliary facilities or similar systems only when the operation is necessary to achieve
compliance with the conditions of this permit.
A.Certified Operator
This permitted facility must be operated by an operator certified by the state of
Washington for at least a Class IIplant. This operator must be in responsible charge of
the day-to-day operation of the wastewater treatment plant. An operatorcertified for at
least a Class Iplant must be in charge during all regularly scheduled shifts.
B.OperationandMaintenance (O&M) Program
The Permittee must:
1.Institute an adequate operation and maintenance program for the entire sewage
system.
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Permit No. WA0037052
2.Keep maintenance records on all major electrical and mechanical components of
the treatment plant, as well as the sewage system and pumping stations. Such
records must clearly specify the frequency and type of maintenance
recommended by the manufacturer and must show the frequency and type of
maintenance performed.
3.Make maintenance records available for inspection at all times.
C.Short-Term Reduction
The Permittee must schedule any facility maintenance, which might require interruption
of wastewater treatment and degrade effluent quality, during non-critical water quality
periods and carry this maintenance out according to the approved O&M Manual or as
otherwise approved by Ecology.
If a Permittee contemplates a reduction in the level of treatment that would cause a
violation of permit discharge limits on a short-term basis for any reason, and such
reduction cannot be avoided, the Permittee must:
1.Give written notification to Ecology, if possible, 30 days prior to such activities.
2.Detail the reasons for, length of time of, and the potential effects of the reduced
level of treatment.
This notification does not relieve the Permittee of its obligations under this permit.
D.Electrical Power Failure
The Permittee must ensure that adequate safeguards prevent the discharge of untreated
wastes or wastes not treated in accordance with the requirements of this permit during
electrical power failure at the treatment plant and/or sewage lift stations. Adequate
safeguards include, but are not limited to,alternate power sources, standby generator(s),
or retention of inadequately treated wastes.
The Permittee must maintain Reliability Class II (EPA 430-99-74-001)at the wastewater
treatment plant.Reliability Class II requires a backup power source sufficient to operate
all vital components and critical lighting and ventilation during peak wastewater flow
conditions. Vital components used to support the secondary processes (i.e., mechanical
aerators or aeration basin air compressors) need not be operable to full levels of
treatment, but must be sufficient to maintain the biota.
E.Prevent Connection of Inflow
The Permittee must strictly enforce its sewer ordinances and not allow the connection of
inflow (roof drains, foundation drains, etc.) to the sanitary sewer system.
F.Bypass Procedures
This permit prohibits a bypass,which is the intentional diversion of waste streams from
any portion of a treatment facility. Ecology may take enforcement action against a
Permittee for a bypass unless one of the following circumstances (1, 2, or 3) applies.
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Permit No. WA0037052
1.Bypass for essential maintenance without the potential to cause violation of
permit limits or conditions.
This permit authorizes a bypass if it allows for essential maintenance and does
not have the potential to cause violations of limits or other conditions of this
permit, or adversely impact public health as determined by Ecology prior to the
bypass. The Permittee must submit prior notice, if possible, at least 10 days
before the date of the bypass.
2.Bypass which is unavoidable, unanticipated, and results in noncompliance of this
permit.
This permit authorizes such a bypass only if:
a.Bypass is unavoidable to prevent loss of life, personal injury, or severe
damage to property, damage to the treatment facilities which would
cause them to become inoperable, or substantial and permanent loss of
natural resources which can reasonably be expected to occur in the
absence of a bypass.
b.No feasible alternatives to the bypass exist, such as:
The use of auxiliary treatment facilities.
Retention of untreated wastes.
Maintenance during normal periods of equipment downtime, but
not if the Permittee should have installed adequate backup
equipment in the exercise of reasonable engineering judgment to
prevent a bypass.
Transport of untreated wastes to another treatment facility.
c.Ecology is properly notified ofthe bypass as required in Special
Condition S3.Fof this permit.
3.If bypass is anticipated and has the potential to result in noncompliance of this
permit.
a.The Permittee must notify Ecology at least 30 days before the planned
date of bypass. The notice must contain:
A description of the bypass and its cause.
An analysis of all known alternatives which would eliminate,
reduce, or mitigate the need for bypassing.
A cost-effectiveness analysis of alternatives including
comparative resource damage assessment.
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The minimum and maximum duration of bypass under each
alternative.
A recommendation as to the preferred alternative for conducting
the bypass.
The projected date of bypass initiation.
A statement of compliance with State Environmental Policy Act
(SEPA).
A request for modification of water quality standards as provided
for in WAC 173-201A-410, if an exceedance of any water
quality standard is anticipated.
Details of the steps taken or planned to reduce, eliminate, and
prevent reoccurrence of the bypass.
b.For probable construction bypasses, the Permittee must notify Ecology of
the need to bypass as early in the planning process as possible. The
Permittee must consider the analysis required above during the project
planning and design process. The project-specific engineering report or
facilities plan as well as the plans and specifications must include details
of probable construction bypasses to the extent practical.In cases where
the Permittee determines the probable need to bypass early, the Permittee
must continue to analyze conditions up to and including the construction
period in an effort to minimize or eliminate the bypass.
c.Ecology will consider the following prior to issuing an administrative
order for this type of bypass:
If the bypass is necessary to perform construction or
maintenance-related activities essential to meet the requirements
of this permit.
If feasible alternatives to bypass exist, such as the use of
auxiliary treatment facilities, retention of untreated wastes,
stopping production, maintenance during normal periods of
equipment down time, or transport of untreated wastes to another
treatment facility.
If the Permittee planned and scheduled the bypass to minimize
adverse effects on the public and the environment.
After consideration of the above and the adverse effects of the proposed bypass
and any other relevant factors, Ecology will approve or deny the request.
Ecology will give the public an opportunity to comment on bypass incidents of
significant duration, to the extent feasible. Ecology will approve a request to
bypass by issuing an administrative order under RCW 90.48.120.
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G.Operations and Maintenance Manual
1.O&M Manual Submittal and Requirements
The Permittee must:
a.Review the O&M Manual at least annually.
b.Submit to Ecology for review and approval substantial changes or
updates to the O&M Manual whenever it incorporates them into the
manual.
c.Keep the approved O&M Manual at the permitted facility.
d.Follow the instructions and procedures of this manual.
2.O&MManual Components
In addition to the requirements of WAC 173-240-080(1) through (5), the O&M
Manual must be consistent with the guidance in Table G1-3 in the Criteria for
Sewage Works Design(Orange Book), 2008. TheO&M Manual must include:
a.Emergency procedures for cleanup in the event of wastewater system
upset or failure.
b.A review of system components which if failed could pollute surface
water or could impact human health. Provide a procedure for a routine
schedule of checking the function of these components.
c.Wastewater system maintenance procedures that contribute to the
generation of process wastewater.
d.Reporting protocols for submitting reports to Ecology to comply with the
reporting requirements in the discharge permit.
e.Any directions to maintenance staff when cleaning or maintaining other
equipment or performing other tasks which are necessary to protect the
operation of the wastewater system (for example, defining maximum
allowable discharge rate for draining a tank, blocking all floor drains
before beginning the overhaul of a stationary engine).
f.The treatment plant process control monitoring schedule.
g.Minimum staffing adequate to operate and maintain the treatment
processes and carry out compliance monitoring required by the permit.
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Permit No. WA0037052
S6.PRETREATMENT
A.General Requirements
The Permittee must work with Ecology to ensure that all commercial and industrial users
of the Publicly Owned Treatment Works (POTW) comply with the pretreatment
regulations in 40 CFR Part 403 and any additional regulations that the Environmental
Protection Agency (U.S. EPA) may promulgate under Section 307(b) (pretreatment) and
308 (reporting) of the Federal Clean Water Act.
B.Duty to Enforce Discharge Prohibitions
1.Under federal regulations \[40 CFR 403.5(a)and (b)\],the Permittee must not
authorize or knowingly allow the discharge of any pollutants into its POTW
which may be reasonably expected to cause pass-through or interference, or
which otherwise violate general or specific discharge prohibitions contained in
40CFR Part 403.5 or WAC173-216-060.
2.The Permittee must not authorize or knowingly allow the introduction of any of
the following into their treatment works:
a.Pollutants which create a fire or explosion hazard in the POTW
(including, but not limited to waste streams with a closed cup flashpoint
of less than 140 degrees Fahrenheit or 60 degrees Centigrade using the
test methods specified in 40 CFR 261.21).
b.Pollutants which will cause corrosive structural damage to the POTW,
but in no case discharges with pH lower than 5.0, or greater than 11.0
standard units, unless the works are specifically designed to
accommodate such discharges.
c.Solid or viscous pollutants in amounts that could cause obstruction to the
flow in sewers or otherwise interfere with the operationof the POTW.
d.Any pollutant, including oxygen-demandingpollutants, (BOD, etc.)
5
released in a discharge at a flow rate and/or pollutant concentration
which will cause interference with the POTW.
e.Petroleum oil, non-biodegradable cutting oil, or products of mineral
origin in amounts that will cause interference or pass through.
f.Pollutants which result in the presence of toxic gases, vapors, or fumes
within the POTW in a quantity which may cause acute worker health and
safety problems.
g.Heat in amounts that will inhibit biological activity in the POTW
resulting in interference but in no case heat in such quantities such that
the temperature at the POTW headworks exceeds 40 degrees Centigrade
(104 degrees Fahrenheit) unless Ecology, upon request of the Permittee,
approves, in writing, alternate temperature limits.
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Permit No. WA0037052
h.Any trucked or hauled pollutants, except at discharge points designated
by the Permittee.
i.Wastewaters prohibited to be discharged to the POTW by the Dangerous
Waste Regulations (chapter 173-303 WAC), unless authorized under the
Domestic Sewage Exclusion (WAC 173-303-071).
3.The Permittee must also not allow the following discharges to the POTW unless
approved in writing by Ecology:
a.Noncontact cooling water in significant volumes.
b.Stormwater and other direct inflow sources.
c.Wastewaters significantly affecting system hydraulic loading, which do
not require treatment, or would not be afforded a significant degree of
treatment by the system.
4.The Permittee must notify Ecology if any industrial user violates the prohibitions
listed in this section (S6.B), and initiate enforcement action to promptly curtail
any such discharge.
C.Wastewater Discharge Permit Required
The Permittee must:
1.Establish a process for authorizing non-domestic wastewater discharges that
ensures all SIUs in all tributary areas meet the applicable State Waste Discharge
Permit (SWDP)requirements in accordance with chapter 90.48 RCW and
chapter 173-216 WAC.
2.Immediately notify Ecology of any proposed discharge of wastewater from a
source, which may be a Significant Industrial User (SIU) \[see fact sheet
definitions or refer to 40 CFR 403.3(v)(i)(ii)\].
3.Require all SIUs to obtainaSWDPfrom Ecology prior to accepting their non-
domestic wastewater, or require proof that Ecology has determined they do not
require apermit.
4.Require the documentation as described in S6.C.3at the earliest practicable date
as a condition of continuing to accept non-domestic wastewater discharges from
a previously undiscovered, currently discharging and unpermitted SIU.
5.Require sources of non-domestic wastewater, which do not qualify as SIUs but
merit a degree of oversight, to apply for a SWDPand provideit a copy of the
application and any Ecology responses.
6.Keep all records documenting that its users have met the requirements of S6.C.
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Permit No. WA0037052
D.Identification and Reporting of Existing, New, and Proposed Industrial Users
1.The Permittee must take continuous, routine measures to identify all existing,
new, and proposed SIUs and Potential Significant Industrial Users (PSIUs)
discharging or proposing to discharge to the Permittee's sewer system (see
Appendix Cof the fact sheetfor definitions).
2.Within 30 days of becoming aware of an unpermitted existing, new, or proposed
industrial user who may be aSIU, the Permittee must notify such user by
registered mail that, if classified as an SIU, they must apply to Ecology and
obtain a State Waste Discharge Permit. The Permittee must send a copy of this
notification letter to Ecology within this same 30-day period.
3.The Permittee must also notify all PSIUs, as they are identified, that if their
classification should change to an SIU, they must apply to Ecology for a State
Waste Discharge Permit within 30 days of such change.
E.Industrial User Survey
The Permittee must complete an industrial user survey listing all SIUs and PSIUs
discharging to the POTW. The Permittee must submit the survey to Ecology by
January31, 2019. At a minimum, the Permittee must develop the list of SIUs and
PSIUs by means of a telephone book search, a water utility billing records search, and a
physical reconnaissance of the service area. Information on PSIUs must include,at a
minimum,the business name, telephone number, address, description of the industrial
process(s), and the known wastewater volumes and characteristics.
S7.SOLID WASTES
A.Solid Waste Handling
The Permittee must handle and dispose of all solid waste material in such a manner as to
prevent its entry into state ground or surface water.
B.Leachate
The Permittee must not allow leachate from its solid waste material to enter state waters
without providing all known, available,and reasonable methods of treatment, nor allow
such leachate to cause violations of the State Surface Water Quality Standards, Chapter
173-201A WAC, or the State Ground Water Quality Standards, Chapter 173-200 WAC.
The Permittee must apply for a permit or permit modification as may be required for such
discharges to state ground or surface waters.
S8.APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR FACILITY CHANGES
The Permittee must submit an application for renewal of this permit byJune1, 2020.
The Permittee must also submit a new application or supplement at least 180 days prior to
commencement of discharges, resulting from the activities listed below, which may result in
permit violations. These activities include any facility expansions, production increases, or other
planned changes, such as process modifications, in the permitted facility.
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Permit No. WA0037052
S9.ENGINEERING DOCUMENTS FOR OUTFALL REPLACEMENT
A.The Permittee must prepare and submit an approvable engineering report or facility plan
amendment in accordance with chapter 173-240 WAC to Ecology for review and
approval by December 31, 2018.This report shall describe the options for a new outfall
and select an outfall configuration that allows the Permittee to meet applicable State
Water Quality Standards.The report must consider impacts to marine vegetation and
impacts to commercial and/or recreational shellfish resources. Appropriate mitigation for
any construction impacts should be discussed.
B.As required by RCW 90.48.112, the engineering report must address the feasibility of
using reclaimed water as defined in RCW 90.46.010.
C.The report must contain any appropriate requirements as described in the following
guidance:
1.Criteria for Sewage Works Design (Washington State Department of Ecology,
Publication No. 98-37 WQ, 2008)
2.Design Criteria for Municipal Wastewater Land Treatment Systems for Public
Health Protection (Washington State Department of Health, 1994)
3.Guidelines for Preparation of Engineering Reports for Industrial Wastewater
Land Application Systems (Washington State Department of Ecology,
Publication No. 93-36,1993)
4.Water Reclamation and Reuse Standards(Washington State Department of
Ecology and Department of Health Publication No. 97-23, 1997)
D.The Permittee must prepare and submit approvable plans and specificationsto Ecology
for review and approval in accordance with chapter 173-240 WAC by December 31,
2019.In addition to the electronic copy required by Special Condition S3.B, the
Permittee must submit one paper copy to Ecology for its use to the address listed in
Special Condition S3.B. If the Permittee wants Ecology to provide a stamped approved
copy it must submit an additional paper copy (total of 2 paper copies).
E.Prior to the start of construction, the Permittee must submitto Ecology a quality
assurance plan as required by chapter 173-240 WAC.
S10.ACUTE TOXICITY
A.Testing When There is No Permit Limit for Acute Toxicity
The Permittee must:
1.Conduct acute toxicity testing on final effluent once in the last summerand once
in the last winterprior to submission of the application for permit renewal.
2.Conduct acute toxicity testing on a series of at least five concentrations of
effluent, including 100percenteffluent and a control.
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Permit No. WA0037052
3.Use each of the following species and protocols for each acute toxicity test:
Acute Toxicity TestsSpeciesMethod
Fathead minnow 96-hour
Pimephales promelasEPA-821-R-02-012
static-renewal test
Ceriodaphnia dubia,
Daphnid 48-hour static testDaphnia pulex, orEPA-821-R-02-012
Daphnia magna
4.Submit the results to Ecology by June1, 2020(with the permit renewal
application).
B.Sampling andReporting Requirements
1.The Permittee must submit all reports for toxicity testing in accordance with the
most recent version of Ecology Publication No. WQ-R-95-80,Laboratory
Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must
contain toxicity data, bench sheets, and reference toxicant results for test
methods. In addition, the Permittee must submit toxicity test data in electronic
.
2.The Permittee must collect 24-hour composite effluent samples for toxicity
testing. The Permittee must cool the samples to 0 -6 degrees Celsius during
collection and send them to the lab immediately upon completion. The lab must
begin the toxicity testing as soon as possible but no later than 36 hours after
sampling was completed.
3.The laboratory must conduct water quality measurements on all samples and test
solutions for toxicity testing, as specified in the most recent version of Ecology
Publication No. WQ-R-95-80,Laboratory Guidance and Whole Effluent Toxicity
Test Review Criteria.
4.All toxicity tests must meet quality assurance criteria and test conditions
specified in the most recent versions of the EPA methods listed in SubsectionC
and the Ecology Publication No. WQ-R-95-80,Laboratory Guidance and Whole
Effluent Toxicity Test Review Criteria. If Ecology determines any test results to
be invalid or anomalous, the Permittee must repeat the testing with freshly
collected effluent.
5.The laboratory must use control water and dilution water meeting the
requirements of the EPA methods listed in SectionA or pristine natural water of
sufficient quality for good control performance.
6.The Permittee must conduct whole effluent toxicity tests on an unmodified
sample of final effluent.
7.The Permittee may choose to conduct a full dilution series test during compliance
testing in order to determine dose response. In this case, the series must have a
minimum of five effluent concentrations and a control. The series of
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concentrations must include the acute critical effluent concentration (ACEC).
The ACEC equals 0.12percenteffluent.
8.All whole effluent toxicity tests, effluent screening tests, and rapid screening
tests that involve hypothesis testing must comply with the acute statistical power
standard of 29percentasdefined in WAC 173-205-020. If the test does not meet
the power standard, the Permittee must repeat the test on a fresh sample with an
increased number of replicates to increase the power.
S11.CHRONIC TOXICITY
A.Testing When There is No Permit Limit for Chronic Toxicity
The Permittee must:
1.Conduct chronic toxicity testing on final effluent once in the last winter and once
in the last summer prior to submission of the application for permit renewal.
2.Conduct chronic toxicity testing on a series of at least five concentrations of
effluent and a control. This series of dilutions must include the acute critical
effluent concentration (ACEC). The ACEC equals 0.12percenteffluent. The
series of dilutions should also contain the CCEC.
3.Compare the ACEC to the control using hypothesis testing at the 0.05 level of
significance as described in Appendix H, EPA/600/4-89/001.
4.Submit the results to Ecology June1, 2020 (with the permit renewal
application).
5.Perform chronic toxicity tests with all of the followingspecies and the most
recent version of the following protocols:
Saltwater Chronic TestSpeciesMethod
Topsmelt survival and growthAtherinops affinisEPA/600/R-95/136
Americamysis bahia
Mysid shrimp survival and
(formerly Mysidopsis EPA-821-R-02-014
growth
bahia)
B.Sampling and Reporting Requirements
1.The Permittee must submit all reports for toxicity testing in accordance with the
most recent version of Ecology Publication No. WQ-R-95-80,Laboratory
Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must
contain toxicity data, bench sheets, and reference toxicant results for test
methods. In addition, the Permittee must submit toxicity test data in electronic
base.
2.The Permittee must collect 24-hour composite effluent samples for toxicity
testing. The Permittee must cool the samples to 0 -6 degrees Celsius during
collection and send them to the lab immediately upon completion. The lab must
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Permit No. WA0037052
begin the toxicitytesting as soon as possible but no later than 36 hours after
sampling was completed.
3.The laboratory must conduct water quality measurements on all samples and test
solutions for toxicity testing, as specified in the most recent version of Ecology
Publication No.WQ-R-95-80,Laboratory Guidance and Whole Effluent Toxicity
Test Review Criteria.
4.All toxicity tests must meet quality assurance criteria and test conditions
specified in the most recent versions of the EPA methods listed in SectionCand
the Ecology Publication no.WQ-R-95-80,Laboratory Guidance and Whole
Effluent Toxicity Test Review Criteria. If Ecology determines any test results to
be invalid or anomalous, the Permittee must repeat the testing with freshly
collected effluent.
5.The laboratory must use control water and dilution water meeting the
requirements of the EPA methods listed in SubsectionC. or pristine natural water
of sufficient quality for good control performance.
6.The Permittee must conduct whole effluent toxicity tests on an unmodified
sample of final effluent.
7.The Permittee may choose to conduct a full dilution series test during compliance
testing in order to determine dose response. In this case, the series must have a
minimum of five effluent concentrations and a control.The series of
concentrations must include the CCEC and the ACEC. The CCEC and the
ACEC may either substitute for the effluent concentrations that are closest to
them in the dilution series or be extra effluent concentrations.
8.All whole effluent toxicity tests that involve hypothesis testing must comply with
the chronic statistical power standard of 39percentas defined in WAC 173-205-
020.If the test does not meet the power standard, the Permittee must repeat the
test on a fresh sample with an increased number of replicates to increase the
power.
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GENERAL CONDITIONS
G1.SIGNATORY REQUIREMENTS
A.All applications, reports, or information submitted to Ecology must be signed and
certified.
1.In the case of corporations, by a responsible corporate officer.For the purpose of
this section, a responsible corporate officer means:
A president, secretary, treasurer, or vice-president of the corporation in
charge of a principal business function, or any other person who
performs similar policy or decision making functions for the corporation,
or
The manager of one or more manufacturing, production, or operating
facilities, provided, the manager is authorized to make management
decisions which govern the operation of the regulated facility including
having the explicit or implicit duty of making major capital investment
recommendations, and initiating and directing other comprehensive
measures to assure long-term environmental compliance with
environmental laws and regulations; the manager can ensure that the
necessary systems are established or actions taken to gather complete and
accurate information for permit application requirements; and where
authority to sign documents has been assigned or delegated to the
manager in accordance with corporate procedures.
b.In the case of a partnership, by a general partner.
c.In the case of sole proprietorship, by the proprietor.
d.In the case of a municipal, state, or other public facility, by either a principal
executive officer or ranking elected official.
Applications for permits for domestic wastewater facilities that are either owned or
operated by, or under contract to, a public entity shall be submitted by the public entity.
B.All reports required by this permit and other information requested by Ecology must be
signed by a person described above or by a duly authorized representative of that person.
A person is a duly authorized representative only if:
1.The authorization is made in writing by a person described above and submitted
to Ecology.
2.The authorization specifies either an individual or a position having
responsibility for the overall operation of the regulated facility, such as the
position of plant manager, superintendent, position of equivalent responsibility,
or an individual or position having overall responsibility for environmental
matters. (A duly authorized representative may thus be either a named individual
or any individual occupying a named position.)
Page 32of 51
Permit No. WA0037052
C.Changes to authorization. If an authorization under paragraph G1.B, above, is no longer
accurate because a different individual or position has responsibility for the overall
operation of the facility, a new authorization satisfying the requirements of paragraph
G1.B, above, must be submitted to Ecology prior to or together with any reports,
information, or applications to be signed by an authorized representative.
D.Certification. Any person signing a document under this section must make the
following certification:
were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gathered and
evaluated the information submitted. Based on my inquiry of the person
or persons who manage the system or those persons directly responsible
for gathering information, the information submitted is, to the bestof my
knowledge and belief, true, accurate, and complete. I am aware that
there are significant penalties for submitting false information, including
G2.RIGHT OF INSPECTION AND ENTRY
The Permittee must allow an authorized representative of Ecology, upon the presentation of
credentials and such other documents as may be required by law:
A.To enter upon the premises where a discharge is located or where any records must be
kept under the termsand conditions of this permit.
B.To have access to and copy, at reasonable times and at reasonable cost, any records
required to be kept under the terms and conditions of this permit.
C.To inspect, at reasonable times, any facilities, equipment (including monitoring and
control equipment), practices, methods, or operations regulated or required under this
permit.
D.To sample or monitor, at reasonable times, any substances or parameters at any location
for purposes of assuring permit compliance or as otherwise authorized by the Clean
Water Act.
G3.PERMIT ACTIONS
This permit may be modified, revoked and reissued, or terminated either at the request of any
may only be modified, revoked and reissued, or terminated for the reasons specified in 40 CFR
122.62, 40 CFR 122.64 or WAC 173-220-150 according to the procedures of 40 CFR 124.5.
A.The following are causes for terminating this permit during its term, or for denying a
permit renewal application:
1.Violation of any permit term or condition.
2.Obtaining a permit by misrepresentation or failure to disclose all relevant facts.
Page 33of 51
Permit No. WA0037052
3.A material change in quantity or type of waste disposal.
4.A determination that the permitted activity endangers human health or the
environment, or contributes to water quality standards violations and can only be
regulated to acceptable levels by permit modification or termination.
5.A change in any condition that requires either a temporary or permanent
reduction, or elimination of any discharge or sludge use or disposal practice
controlled by the permit.
6.Nonpayment of fees assessed pursuant to RCW 90.48.465.
7.Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090.
B.The following are causes for modification but not revocation and reissuance except when
the Permittee requests or agrees:
1.A material change in the condition of the waters of the state.
2.New information not available at the time of permit issuance that would have
justified the application of different permit conditions.
3.Material and substantial alterations or additions to the permitted facility or
activities which occurred after this permit issuance.
4.Promulgation of new or amended standards or regulations having a direct bearing
upon permit conditions, or requiring permit revision.
5.The Permittee has requested a modification based on other rationale meeting the
criteria of 40 CFR Part 122.62.
6.Ecology has determined that good cause exists for modification of a compliance
schedule, and the modification will not violate statutory deadlines.
7.
permit.
C.The following are causes for modification or alternatively revocation and reissuance:
1.When cause exists for termination for reasons listed in A.1through A.7of this
section, and Ecology determines that modification or revocation and reissuance is
appropriate.
2.When Ecology has received notification of a proposed transfer of the permit. A
permit may also be modifiedto reflect a transfer after the effective date of an
automatic transfer (General Condition G7) but will not be revoked and reissued
after the effective date of the transfer except upon the request of the new
Permittee.
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Permit No. WA0037052
G4.REPORTING PLANNED CHANGES
The Permittee must, as soon as possible, but no later than 180days prior to the proposed changes,
give notice to Ecology of planned physical alterations or additions to the permitted facility,
production increases, or process modification which will result in:
A.The permitted facility being determined to be a new source pursuant to 40 CFR
122.29(b).
B.Asignificant change in the nature or an increase in quantity of pollutants discharged.
C.Aowing such
notice, and the submittal of a new application or supplement to the existing application,
along with required engineering plans and reports, this permit may be modified, or
revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants
not previously limited. Until such modification is effective, any new or increased
discharge in excess of permit limits or not specifically authorized by this permit
constitutes a violation.
G5.PLAN REVIEW REQUIRED
Prior to constructing or modifying any wastewater control facilities, an engineering report and
detailed plans and specifications must be submitted to Ecology for approval in accordance with
chapter 173-240 WAC. Engineering reports, plans, and specifications must be submitted at least
180 days prior to the planned start of construction unless a shorter time is approved by Ecology.
Facilities must be constructed and operated in accordance with the approved plans.
G6.COMPLIANCE WITH OTHER LAWS AND STATUTES
Nothing in this permit excuses the Permittee from compliance with any applicable federal, state,
or local statutes, ordinances, or regulations.
G7.TRANSFER OF THIS PERMIT
In the event of any change in control or ownership of facilities from which the authorized
discharge emanate, the Permittee must notify the succeeding owner or controller of the existence
of this permit by letter, a copy of which must be forwarded to Ecology.
A.Transfers by Modification
Except as provided in paragraph (B) below, this permit may be transferred by the
Permittee to a new owner or operator only if this permit has been modified or revoked
and reissued under 40 CFR 122.62(b)(2), or a minor modification made under 40 CFR
122.63(d), to identify the new Permittee and incorporate such other requirements as may
be necessary under the Clean Water Act.
B.Automatic Transfers
This permit may be automatically transferred to a new Permittee if:
Page 35of 51
Permit No. WA0037052
1.The Permittee notifies Ecology at least 30 days in advance of the proposed
transfer date.
2.The notice includes a written agreement between the existing and new Permittees
containing a specific date transfer of permit responsibility, coverage, and liability
between them.
3.Ecology does not notify the existing Permittee and the proposed new Permittee of
its intent to modify or revoke and reissue this permit. A modification under this
subparagraph may also be minor modification under 40 CFR 122.63. If this
notice is not received, the transfer is effective on the date specified in the written
agreement.
G8.REDUCED PRODUCTION FOR COMPLIANCE
The Permittee, in order to maintain compliance with its permit, must control production and/or all
discharges upon reduction, loss, failure, or bypass of the treatment facility until the facility is
restored or an alternative method of treatment is provided. This requirement applies in the
situation where, among other things, the primary source of power of the treatment facility is
reduced, lost, or fails.
G9.REMOVED SUBSTANCES
Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the
course of treatment or control of wastewaters must not be resuspended or reintroduced to the final
effluent stream for discharge to state waters.
G10.DUTY TO PROVIDE INFORMATION
The Permittee must submit to Ecology, within a reasonable time, all information which Ecology
may request to determine whether cause exists for modifying, revoking and reissuing, or
terminating this permit or to determine compliance with this permit. The Permittee must also
submit to Ecology upon request, copies of records required to be kept by this permit.
G11.OTHER REQUIREMENTS OF 40 CFR
All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference.
G12.ADDITIONAL MONITORING
Ecology may establish specific monitoring requirements in addition to those contained in this
permit by administrative order or permit modification.
G13.PAYMENT OF FEES
The Permittee must submit payment of fees associated with this permit as assessed by Ecology.
G14.PENALTIES FOR VIOLATING PERMIT CONDITIONS
Any person who is found guilty of willfully violating the terms and conditions of this permit is
deemed guilty of a crime, and upon conviction thereof shallbe punished by a fine of up to
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Permit No. WA0037052
$10,000 and costs of prosecution, or by imprisonment in the discretion of the court. Each day
upon which a willful violation occurs may be deemed a separate and additional violation.
Any person who violates the terms and conditions of a waste discharge permit may incur, in
addition to any other penalty as provided by law, a civil penalty in the amount of up to $10,000
for every such violation. Each and every such violation is a separate and distinct offense, and in
case of a continuing violation, every day's continuance is deemed to be a separate and distinct
violation.
G15.UPSET
Definition
noncompliance with technology-based permit effluent limits because of factors beyond the
reasonable control of the Permittee. An upset does not include noncompliance to the extent
caused by operational error, improperly designed treatment facilities, inadequate treatment
facilities, lack of preventive maintenance, or careless or improper operation.
An upset constitutes an affirmative defense to an action brought for noncompliance with such
technology-based permit effluent limits if the requirements of the following paragraph are met.
A Permittee who wishes to establish the affirmativedefense of upset must demonstrate, through
properly signed, contemporaneous operating logs, or other relevant evidence that:
A.An upset occurred and that the Permittee can identify the cause(s) of the upset.
B.The permitted facility was being properly operated at the time of the upset.
C.The Permittee submitted notice of the upset as required in Special Condition S3.E.
D.The Permittee complied with any remedial measures required under S3.E of this permit.
In any enforcement action the Permittee seeking to establish the occurrence of an upset has the
burden of proof.
G16.PROPERTY RIGHTS
This permit does not convey any property rights of any sort, or any exclusive privilege.
G17.DUTY TO COMPLY
The Permittee must comply with all conditions of this permit. Any permit noncompliance
constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit
termination, revocation and reissuance, or modification; or denial of a permit renewal application.
G18.Toxic pollutants
The Permittee must comply with effluent standards or prohibitions established under
Section307(a) of the Clean Water Act for toxic pollutants within the time provided in the
regulations that establish those standards or prohibitions, even if this permit has not yet been
modified to incorporate the requirement.
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Permit No. WA0037052
G19.PENALTIES FOR TAMPERING
The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders
inaccurate any monitoring device or method required to be maintained under this permit shall,
upon conviction, be punished by a fine of not more than $10,000 per violation, or by
imprisonment for not more than two years per violation, or by both. If a conviction of a person is
for a violation committed after a first conviction of such person under this condition, punishment
shall be a fine of not more than $20,000 per day of violation, or by imprisonment of not more
than four years, or by both.
G20.COMPLIANCE SCHEDULES
Reports of compliance or noncompliance with, or any progress reports on, interim and final
requirements contained in any compliance schedule of this permit must be submitted no later than
14 days following each schedule date.
G21.SERVICE AGREEMENT REVIEW
The Permittee must submit to Ecology any proposed service agreements and proposed revisions
or updates to existing agreementsfor the operation of any wastewater treatment facility covered
by this permit. The review is to ensure consistency with chapters 90.46 and 90.48 RCWas
required by RCW 70.150.040(9). In the event that Ecology does not comment within a 30-day
period, the Permittee may assume consistency and proceed with the service agreement or the
revised/updated service agreement.
Page 38of 51
Permit No. WA0037052
APPENDIX A
LIST OF POLLUTANTS WITH ANALYTICAL METHODS, DETECTION LIMITS AND
QUANTITATION LEVELS
The Permittee must use the specified analytical methods, detection limits (DLs) and quantitation levels
(QLs) in the following table for permit and application required monitoring unless:
Another permit condition specifies other methods, detection levels, or quantitation levels.
The method used produces measurable results in the sample and EPA has listed it as an EPA-
approved method in 40 CFR Part 136.
If the Permitteeuses an alternative method, not specified in the permit and as allowed above, it must
report the test method, DL, and QL on the discharge monitoring report or in the required report.
If the Permittee is unable to obtain the required DL and QL in its effluent due to matrix effects, the
Permittee must submit a matrix-specific detection limit (MDL) and a quantitation limit (QL) to Ecology
with appropriate laboratory documentation.
When the permit requires the Permittee to measure the base neutral compounds in the list of priority
pollutants, it must measure all of the base neutral pollutants listed in the table below. The list includes
EPA required base neutral priority pollutants and several additional polynuclear aromatic hydrocarbons
(PAHs). The Water Quality Program added several PAHs to the list of base neutrals below from
to Appendix A that did not increase the overall cost of analysis unreasonably.
-
permit-required monitoring and to measure effluent concentrations near or below criteria values where
possible at a reasonable cost.
The lists below include conventional pollutants (as defined in CWA section 502(6) and 40 CFR Part
122.), toxic or priority pollutants as defined in CWA section 307(a)(1) and listed in 40 CFR Part 122
Appendix D, 40 CFR Part 401.15 and 40 CFR Part 423 Appendix A), and nonconventionals. 40 CFR
Part 122 Appendix D (Table V) also identifies toxic pollutants and hazardous substances which are
required to be reported by dischargers if expected to be present. This permit appendix A list does not
include those parameters.
CONVENTIONAL POLLUTANTS
Pollutant CAS Recommended Detection Quantitation
12
Number Analytical (DL)µg/L Level (QL)
(if Protocolunless µg/L unless
available)specifiedspecified
Biochemical Oxygen DemandSM5210-B2 mg/L
3
SM5210-B2 mg/L
Biochemical Oxygen Demand,
Page 39of 51
Permit No. WA0037052
Soluble
SM 9221E,9222 N/ASpecified in
method -
Fecal Coliform
sample aliquot
dependent
Oil and Grease (HEM) (Hexane 1664 A or B1,4005,000
Extractable Material)
+
pHSM4500-HBN/AN/A
Total SuspendedSolidsSM2540-D5 mg/L
NONCONVENTIONAL POLLUTANTS
Pollutant & CAS No. (if CAS Recommended Detection Quantitation
12
available)Number Analytical (DL)µg/L Level (QL)
(if Protocolunless µg/L unless
available)specifiedspecified
SM2320-B5 mg/L as
Alkalinity, Total
CaCO3
Aluminum, Total 7429-90-5200.82.010
SM4500-NH3-B
Ammonia, Total (as N)20
and C/D/E/G/H
Barium Total 7440-39-3200.80.52.0
BTEX (benzene +toluene + EPA SW 846 1
2
ethylbenzene + m,o,p xylenes)8021/8260
Boron, Total 7440-42-8200.82.010.0
Chemical Oxygen DemandSM5220-D10 mg/L
SM4500-Cl Sample and
ChlorideB/C/D/E and limit
SM4110 Bdependent
Chlorine, Total ResidualSM4500 Cl G50.0
Cobalt, Total 7440-48-4200.80.050.25
ColorSM2120B/C/E10 color units
Page 40of 51
Permit No. WA0037052
NONCONVENTIONAL POLLUTANTS
Pollutant & CAS No. (if CAS Recommended Detection Quantitation
12
available)Number Analytical (DL)µg/L Level (QL)
(if Protocolunless µg/L unless
available)specifiedspecified
Dissolved oxygenSM4500-OC/OG0.2 mg/L
FlowCalibrated device
16984-48-SM4500-F E25
Fluoride 100
8
Hardness, TotalSM2340B200 as CaCO3
Iron, Total 7439-89-6200.712.550
Magnesium, Total 7439-95-4200.71050
Manganese, Total 7439-96-5200.80.10.5
Molybdenum, Total 7439-98-7200.80.10.5
SM4500-NO3-
Nitrate + Nitrite Nitrogen (as N)100
E/F/H
SM4500-NB/C
org
Nitrogen, Total Kjeldahl (as N)and SM4500NH-300
3
B/C/D/EF/G/H
Ecology NWTPH 250
4
NWTPH Dx 250
Dx
Ecology NWTPH 250
5
NWTPH Gx 250
Gx
SM 4500 PB 3
Phosphorus, Total (as P)followed by 10
SM4500-PE/PF
SM2520-B3 practical
salinity units
Salinity
or scale (PSU
or PSS)
SM2540-FSample and
Settleable Solidslimit
dependent
Page 41of 51
Permit No. WA0037052
NONCONVENTIONAL POLLUTANTS
Pollutant & CAS No. (if CAS Recommended Detection Quantitation
12
available)Number Analytical (DL)µg/L Level (QL)
(if Protocolunless µg/L unless
available)specifiedspecified
Soluble Reactive Phosphorus (as SM4500-P E/F/G3
10
P)
Sulfate (as mg/L SO)SM4110-B0.2 mg/L
4
SM4500-
Sulfide (as mg/L S)0.2 mg/L
2
SF/D/E/G
Sulfite (as mg/L SO)SM4500-SO3B2 mg/L
3
Analog recorder or
Use micro-
Temperature (max. 7-day avg.)recording devices 0.2º C
known as
thermistors
Tin, Total 7440-31-5200.80.31.5
Titanium, Total 7440-32-6200.80.52.5
SM 9221B, N/ASpecified in
9222B, 9223Bmethod -
Total Coliform
sample aliquot
dependent
Total Organic CarbonSM5310-B/C/D1 mg/L
Total dissolved solidsSM2540 C20 mg/L
Page 42of 51
Permit No. WA0037052
Quantitati
Detection onLevel
CAS
12
Recommended
(DL)(QL)
PP Number
PRIORITY POLLUTANTSAnalytical
#(if
µg/L unless µg/L
Protocol
available)
specifiedunless
specified
METALS, CYANIDE & TOTAL PHENOLS
Antimony, Total 1147440-36-0200.80.31.0
Arsenic, Total 1157440-38-2200.80.10.5
Beryllium, Total 1177440-41-7200.80.10.5
Cadmium, Total 1187440-43-9200.80.050.25
Chromium (hex) dissolved 11918540-29-9SM3500-Cr C0.31.2
Chromium, Total 1197440-47-3200.80.21.0
Copper, Total 1207440-50-8200.80.42.0
Lead, Total 1227439-92-1200.80.10.5
Mercury, Total 1237439-97-61631E0.00020.0005
Nickel, Total 1247440-02-0200.80.10.5
Selenium, Total1257782-49-2200.81.01.0
Silver, Total 1267440-22-4200.80.040.2
Thallium, Total 1277440-28-0200.80.090.36
Zinc, Total 1287440-66-6200.80.52.5
Cyanide, Total 12157-12-5335.4510
Cyanide, Weak Acid Dissociable121SM4500-CN I510
Cyanide, Free Amenable to 121SM4500-CN G510
Chlorination (Available Cyanide)
Phenols, Total65EPA 420.150
Page 43of 51
Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
ACID COMPOUNDS
2-Chlorophenol 2495-57-86251.02.0
2,4-Dichlorophenol 31120-83-26250.51.0
2,4-Dimethylphenol 34105-67-96250.51.0
4,6-dinitro-o-cresol (2-methyl-60534-52-1625/1625B1.02.0
4,6,-dinitrophenol)
2,4 dinitrophenol 5951-28-56251.02.0
2-Nitrophenol5788-75-56250.51.0
4-Nitrophenol 58100-02-76250.51.0
Parachlorometa cresol (4-2259-50-76251.02.0
chloro-3-methylphenol)
Pentachlorophenol 6487-86-56250.51.0
Phenol 65108-95-26252.04.0
2,4,6-Trichlorophenol 2188-06-26252.04.0
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
VOLATILE COMPOUNDS
Acrolein 2107-02-8624510
Acrylonitrile 3107-13-16241.02.0
Benzene 471-43-26241.02.0
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Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
VOLATILE COMPOUNDS
Bromoform 4775-25-26241.02.0
Carbon tetrachloride 656-23-5624/601 or 1.02.0
SM6230B
Chlorobenzene 7108-90-76241.02.0
Chloroethane 1675-00-3624/6011.02.0
2-Chloroethylvinyl Ether 19110-75-86241.02.0
Chloroform 2367-66-3624 or 1.02.0
SM6210B
Dibromochloromethane 51124-48-16241.02.0
(chlordibromomethane)
1,2-Dichlorobenzene 2595-50-16241.97.6
1,3-Dichlorobenzene 26541-73-16241.97.6
1,4-Dichlorobenzene 27106-46-76244.417.6
Dichlorobromomethane 4875-27-46241.02.0
1,1-Dichloroethane 1375-34-36241.02.0
1,2-Dichloroethane 10107-06-26241.02.0
1,1-Dichloroethylene 2975-35-46241.02.0
1,2-Dichloropropane 3278-87-56241.02.0
1,3-dichloropropene (mixed 33542-75-66241.02.0
isomers)
6
(1,2-dichloropropylene)
Ethylbenzene 38100-41-46241.02.0
Methyl bromide 4674-83-9624/6015.010.0
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Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
VOLATILE COMPOUNDS
(Bromomethane)
Methyl chloride 4574-87-36241.02.0
(Chloromethane)
Methylene chloride 4475-09-26245.010.0
1,1,2,2-Tetrachloroethane 1579-34-56241.92.0
Tetrachloroethylene 85127-18-46241.02.0
Toluene 86108-88-36241.02.0
1,2-Trans-Dichloroethylene 30156-60-56241.02.0
(Ethylene dichloride)
1,1,1-Trichloroethane 1171-55-66241.02.0
1,1,2-Trichloroethane 1479-00-56241.02.0
Trichloroethylene 8779-01-66241.02.0
Vinyl chloride 8875-01-4624/SM6200B1.02.0
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)
Acenaphthene 183-32-96250.20.4
Acenaphthylene 77208-96-86250.30.6
Anthracene 78120-12-76250.30.6
Benzidine 592-87-56251224
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Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)
Benzyl butyl phthalate 6785-68-76250.30.6
Benzo(a)anthracene7256-55-36250.30.6
Benzo(b)fluoranthene (3,4-74205-99-2610/6250.81.6
7
benzofluoranthene)
7
6250.51.0
Benzo(j)fluoranthene 205-82-3
Benzo(k)fluoranthene (11,12-75207-08-9610/6250.81.6
7
benzofluoranthene)
6250.51.0
Benzo(r,s,t)pentaphene 189-55-9
Benzo(a)pyrene 7350-32-8610/6250.51.0
Benzo(ghi)Perylene 79191-24-2610/6250.51.0
Bis(2-chloroethoxy)methane 43111-91-16255.321.2
Bis(2-chloroethyl)ether 18111-44-4611/6250.31.0
Bis(2-chloroisopropyl)ether 4239638-32-96250.30.6
Bis(2-ethylhexyl)phthalate 66117-81-76250.10.5
4-Bromophenyl phenyl ether 41101-55-36250.20.4
2-Chloronaphthalene 2091-58-76250.30.6
4-Chlorophenyl phenyl ether 407005-72-36250.30.5
Chrysene 76218-01-9610/6250.30.6
610M/625M2.510.0
Dibenzo (a,h)acridine 226-36-8
610M/625M2.510.0
Dibenzo (a,j)acridine 224-42-0
Dibenzo(a-h)anthracene 8253-70-36250.81.6
(1,2,5,6-dibenzanthracene)
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Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)
192-65-4610M/625M2.510.0
Dibenzo(a,e)pyrene
189-64-0625M2.510.0
Dibenzo(a,h)pyrene
3,3-Dichlorobenzidine2891-94-1605/6250.51.0
Diethyl phthalate 7084-66-26251.97.6
Dimethyl phthalate 71131-11-36251.66.4
Di-n-butyl phthalate 6884-74-26250.51.0
2,4-dinitrotoluene 35121-14-2609/6250.20.4
2,6-dinitrotoluene 36606-20-2609/6250.20.4
Di-n-octyl phthalate 69117-84-06250.30.6
1,2-Diphenylhydrazine (as37122-66-71625B5.020
Azobenzene)
Fluoranthene 39206-44-06250.30.6
Fluorene 8086-73-76250.30.6
Hexachlorobenzene 9118-74-1612/6250.30.6
Hexachlorobutadiene 5287-68-36250.51.0
Hexachlorocyclopentadiene 5377-47-41625B/6250.51.0
Hexachloroethane 1267-72-16250.51.0
Indeno(1,2,3-cd)Pyrene83193-39-5610/6250.51.0
Isophorone 5478-59-16250.51.0
6252.08.0
3-Methyl cholanthrene 56-49-5
Naphthalene 5591-20-36250.30.6
Page 48of 51
Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)
Nitrobenzene 5698-95-36250.51.0
N-Nitrosodimethylamine 6162-75-9607/6252.04.0
N-Nitrosodi-n-propylamine 63621-64-7607/6250.51.0
N-Nitrosodiphenylamine 6286-30-66250.51.0
6251.97.6
Perylene 198-55-0
Phenanthrene 8185-01-86250.30.6
Pyrene 84129-00-06250.30.6
1,2,4-Trichlorobenzene8120-82-16250.30.6
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
DIOXIN
2,3,7,8-Tetra-Chlorodibenzo-P-1291746-01-61613B1.3 pg/L5 pg/L
Dioxin (2,3,7,8 TCDD)
Page 49of 51
Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
PESTICIDES/PCBs
Aldrin 89309-00-26080.0250.05
alpha-BHC102319-84-66080.0250.05
beta-BHC103319-85-76080.0250.05
gamma-BHC (Lindane)10458-89-96080.0250.05
delta-BHC105319-86-86080.0250.05
8
Chlordane 9157-74-96080.0250.05
-DDT9250-29-36080.0250.05
-DDE9372-55-96080.0250.05
9472-54-86080.0250.05
Dieldrin 9060-57-16080.0250.05
alpha-Endosulfan 95959-98-86080.0250.05
beta-Endosulfan 9633213-65-96080.0250.05
Endosulfan Sulfate 971031-07-86080.0250.05
Endrin 9872-20-86080.0250.05
Endrin Aldehyde 997421-93-46080.0250.05
Heptachlor 10076-44-86080.0250.05
Heptachlor Epoxide 1011024-57-36080.0250.05
9
PCB-124210653469-21-96080.250.5
PCB-125410711097-69-16080.250.5
PCB-122110811104-28-26080.250.5
PCB-123210911141-16-56080.250.5
Page 50of 51
Permit No. WA0037052
Quantitati
Detection
CAS
onLevel
1
Recommended
(DL)
2
Number
(QL)
PRIORITY POLLUTANTSPP #Analytical
(if
µg/L unless
Protocol
µg/L unless
available)
specified
specified
PESTICIDES/PCBs
PCB-124811012672-29-66080.250.5
PCB-126011111096-82-56080.130.5
9
PCB-101611212674-11-26080.130.5
Toxaphene 1138001-35-26080.240.5
1.Detection level (DL)or detection limit means the minimum concentration of an analyte
(substance) that can be measured and reported with a 99% confidence that the analyte
concentration is greater than zero as determined by the procedure given in 40 CFR part 136,
Appendix B.
2.Quantitation Level (QL)also known as Minimum Level of Quantitation (ML) The lowest level
at which the entire analytical system must give a recognizable signal and acceptable calibration
point for the analyte. It is equivalent to the concentration of the lowest calibration standard,
assuming that the lab has used all method-specified sample weights, volumes, and cleanup
procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the
n
number nearest to (1, 2, or 5) x 10, where n is an integer. (64 FR 30417).
ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection
Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended
purpose. (Report of the Federal Advisory Committee on Detection and Quantitation Approaches
and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency
December 2007).
3.Soluble Biochemical Oxygen Demandmethod note: First, filter the sample through a Millipore
Nylon filter (or equivalent) -pore size of 0.45-0.50 um (prep all filters by filtering 250 ml of
laboratory grade deionized water through the filter and discard). Then, analyze sample as per
method 5210-B.
-
4.NWTPH DxNorthwest Total Petroleum Hydrocarbons Diesel Extended Range see
http://www.ecy.wa.gov/biblio/97602.html
5.NWTPH Gx-Northwest Total Petroleum Hydrocarbons Gasoline Extended Range see
http://www.ecy.wa.gov/biblio/97602.html
6.1, 3-dichloroproylene (mixed isomers)You may report this parameter as two separate parameters:
cis-1, 3-dichlorpropropene (10061-01-5)and trans-1, 3-dichloropropene (10061-02-6).
Page 51of 51
Permit No. WA0037052
7.Total Benzofluoranthenes-Because Benzo(b)fluoranthene, Benzo(j)fluoranthene and
Benzo(k)fluoranthene co-elute you may report these three isomers as total benzofluoranthenes.
8.ChlordaneYou may report alpha-chlordane (5103-71-9) and gamma-chlordane (5103-74-2) in
place of chlordane (57-74-9). If you report alpha and gamma-chlordane, the DL/PQLs that apply
are 0.025/0.050.
9.PCB 1016 & PCB 1242You may report these two PCB compounds as one parameter called
PCB 1016/1242.
FACT SHEET FOR CITY OF PORT TOWNSEND WASTEWATER
TREATMENT PLANT NATIONAL POLLUTANT DISCHARGE
ELIMINATION SYSTEM (NPDES) PERMIT NO. WA0037052
Purpose of This Fact Sheet
This fact sheet explains and documents the decisions the Department of Ecology(Ecology)made
in drafting theproposed National Pollutant Discharge Elimination System (NPDES) permitfor
thecity of Port Townsend Wastewater Treatment Plant.
This fact sheet complies with Section 173-220-060 of the Washington Administrative Code
(WAC), which requires Ecology to prepare a draft permit and accompanying fact sheet for public
evaluation before issuing an NPDES permit.
Ecology makesthe draft permit and fact sheet availablefor public reviewand comment at least
30 days before issuingthefinal permit.Copies of the fact sheet and draft permit for the city of
Port Townsend Wastewater Treatment Plant, NPDES permit WA0037052, are available for
public review.For more details on preparing and filing comments about these documents, please
seeAppendix A -Public InvolvementInformation.
The city of Port Townsendreviewed the draft permit and fact sheet for factual accuracy.
Ecology corrected any errors or omissions regarding history, wastewater
discharges,or receiving waterprior to publishing this draft fact sheet for public notice.
After the public comment period closes, Ecology will summarize substantive comments and
provide responses to them. Ecology will includethesummary and responses to commentsin this
fact sheet as AppendixE-Response to Comments, and publish it when issuing the final
NPDES permit. Ecology generally will not revise the rest of the fact sheet. The full document
will become part of the legal history contained in the facility
Summary
The city of Port Townsendoperates an activated sludge wastewater treatment plant that
discharges to the Strait of Juan de Fuca. Ecology issued the previous permit for this facility on
June 4, 2009,and modified it on October 12,2011.
The proposed permit contains the same effluent limits forBiochemical Oxygen Demand, Total
Suspended Solids, Fecal Coliform Bacteria,and pH as the permitissued in 2009. The proposed
permit includes newlimits for Total Residual Chlorine. It doesnot include any other significant
changes.
11/05/15
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
TABLE OF CONTENTS
I.INTRODUCTION...........................................................................................................................1
II.BACKGROUND INFORMATION................................................................................................2
A.Facility Description.............................................................................................................4
History...................................................................................................................4
Collection System Status.......................................................................................4
Treatment Processes..............................................................................................4
Solid Wastes/Residual Solids................................................................................4
Discharge Outfall...................................................................................................5
B.Description of the Receiving Water....................................................................................5
C.Wastewater Influent Characterization.................................................................................5
D.Wastewater Effluent Characterization................................................................................6
E.Summary of Compliance with Previous Permit Issued on June 4, 2009............................6
F.State Environmental Policy Act (SEPA) Compliance........................................................7
III.PROPOSED PERMIT LIMITS.......................................................................................................7
A.Design Criteria....................................................................................................................8
B.Technology-Based Effluent Limits.....................................................................................8
C.Surface Water Quality-Based Effluent Limits..................................................................10
Numerical Criteria for the Protection of Aquatic Life andRecreation................10
Numerical Criteria for the Protection of Human Health......................................10
Narrative Criteria.................................................................................................10
Antidegradation...................................................................................................11
Mixing Zones.......................................................................................................12
D.Designated Uses and Surface Water Quality Criteria.......................................................17
E.Water Quality Impairments...............................................................................................18
F.Evaluation of Surface Water Quality-Based Effluent Limits for Narrative Criteria........18
G.Evaluation of Surface Water Quality-Based Effluent Limits for Numeric Criteria..........18
Reasonable Potential Analysis.............................................................................22
H.Human Health...................................................................................................................22
I.Sediment Quality..............................................................................................................22
J.WholeEffluent Toxicity...................................................................................................23
K.Groundwater Quality Limits.............................................................................................24
L.Comparison of Effluent Limits with the Previous Permit Modified on
October 12, 2011..................................................................................................24
IV.MONITORING REQUIREMENTS..............................................................................................25
A.Wastewater Monitoring....................................................................................................25
B.LabAccreditation.............................................................................................................25
11/05/15
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
C.Effluent Limits Which are Near Detection or Quantitation Levels..................................26
V.OTHER PERMIT CONDITIONS.................................................................................................26
A.Reporting and Record Keeping.........................................................................................26
B.Prevention of Facility Overloading...................................................................................26
C.Operation and Maintenance..............................................................................................27
D.Pretreatment......................................................................................................................27
Duty to Enforce Discharge Prohibitions..............................................................27
Federal and State Pretreatment Program Requirements......................................28
Routine Identification and Reporting of Industrial Users....................................28
Requirements for Performing an Industrial User Survey.....................................28
E.Solid Wastes.....................................................................................................................29
F.Engineering Documents....................................................................................................29
G.General Conditions...........................................................................................................30
VI.PERMIT ISSUANCE PROCEDURES.........................................................................................30
A.Permit Modifications........................................................................................................30
B.Proposed Permit Issuance.................................................................................................30
VII.REFERENCES FOR TEXT AND APPENDICES........................................................................30
APPENDIX A--PUBLIC INVOLVEMENT INFORMATION.................................................................32
APPENDIX B --YOUR RIGHT TO APPEAL...........................................................................................33
APPENDIX C--GLOSSARY.....................................................................................................................34
APPENDIX D--TECHNICAL CALCULATIONS....................................................................................41
APPENDIX E--RESPONSE TO COMMENTS.........................................................................................42
Table 1 -General Facility Information2
Table 2 -Ambient Background Data5
Figure 1 Facility Location Map.....................................................................................................3
11/05/15
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
I.INTRODUCTION
The Federal Clean Water Act (FCWA, 1972, and later amendments in1977, 1981, and 1987) established
water quality goals for the navigable (surface) waters of the United States. One mechanism for achieving
the goals of the Clean Water Act is the National Pollutant Discharge Elimination System (NPDES),
administered by the federal Environmental Protection Agency (EPA). The EPA authorized the state of
Washington to manage the NPDES permit program in our state. Our state legislature accepted the
delegation and assigned the power and duty for conducting NPDES permitting and enforcement to the
Department of Ecology(Ecology). The Legislature defined Ecology's authority and obligations for the
wastewater discharge permit program in 90.48 Revised Code of Washington(RCW).
The following regulations apply to domestic wastewaterNPDES permits:
Procedures Ecology follows for issuing NPDES permits \[chapter 173-220Washington
Administrative Code (WAC)\]
Technical criteria for discharges from municipal wastewater treatment facilities (chapter 173-221
WAC)
Water quality criteria for surface waters (chapter 173-201A WAC)
Water quality criteria for groundwaters (chapter 173-200 WAC)
Whole effluent toxicity testing and limits (chapter 173-205 WAC)
Sediment management standards (chapter 173-204 WAC)
Submission of plans and reports for construction of wastewater facilities (chapter 173-240 WAC)
These rules require any treatment facility owner/operatorto obtain an NPDES permit before discharging
wastewater to state waters. They alsohelp define the basis for limits on each discharge and for
requirements imposed by the permit.
Under the NPDES permit programand in response to a complete and accepted permit application,
Ecology must prepare a draft permit and accompanying fact sheet, and make themavailablefor public
reviewbefore final issuance. Ecology must also publish an announcement (public notice) telling people
where they can read the draft permit, and where to send their comments, during a period of30days
(WAC 173-220-050).(See Appendix A-Public InvolvementInformationfor more detail about the public
notice and comment procedures). After the public comment period ends, Ecology may make changes to
the draft NPDES permitin response to comment(s).Ecology will summarize the responses to comments
and any changes to the permit in Appendix E.
11/05/15Page 1
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
II.BACKGROUND INFORMATION
Table 1-General Facility Information
Facility Information
ApplicantCity of Port Townsend
City of Port Townsend Wastewater Treatment Facility
Facility Name and Address5300 Kuhn Street
Port Townsend, WA 98368
Name:John Merchant, Operations Manager
Contact at Facility
Telephone #:360-379-4432
Name:David Timmons
Title:City Manager
Responsible OfficialAddress:250 Madison Street, Suite 201
Port Townsend, WA 98368
Telephone #:360-379-5043
Type of TreatmentActivated Sludge(Oxidation Ditch)
FacilityLocation(NAD83/WGS84 reference Latitude:48.1384
datum)Longitude:-122.78167
Strait of Juan de Fuca
Discharge Waterbody Name and Location
Latitude:48.141667
(NAD83/WGS84 reference datum)
Longitude:-122.783333
Permit Status
Renewal Date of Previous PermitJuly 1, 2009
Application for Permit Renewal Submittal
December 16, 2013
Date
Date of Ecology Acceptance of ApplicationJanuary 2, 2014
Inspection Status
Date of Last Non-sampling Inspection Date March 3, 2015
11/05/15Page 2
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Figure 1-Facility Location Map
11/05/15Page 3
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
A.Facility Description
History
In 1967, the city of Port Townsend constructed a Wastewater Treatment Plant (WWTP)
that provided primary treatment and disinfection. The system provided primarytreatment
for average flows of 0.61 million gallons per day (MGD). In 1988, Ecology approved an
engineering report for constructing the upgrade to secondary treatment.
The construction of the new activated sludge treatment plant was completed in 1993. No
major changes have been made since initial constructionof the activated sludge treatment
plant.
Collection System Status
The city of Port Townsend (City) sewer system consists of about 76.6 miles of sewer
lines. Of these lines, 70.3 miles are gravity sewers, 2.3 miles are force mains, and 4
miles are sewer mains within Fort Warden State Park. About half of the system was
constructed prior to 1960.
The oldest parts of the collection system are in the downtown area and date back as far as
1908 when construction of the first sanitary sewer was begun. These early systems
included a combination of wastewater and stormwater. The combined sewers in the
downtown area were separated starting in the 1960s. Infiltration and inflow levels have
been maintained at reasonable levels, with additional projects to remove Infiltration and
Inflow (I&I)
Treatment Processes
You can find basic information describing wastewater treatment processes included in a
booklet atthe Water Environment Federation website at:
http://www.wef.org/publicinformation/default.aspx
The facility consists of influent pumping, mechanical cleaned fine screen, grit removal,
flow meter (Parshall flume), activated sludge (two oxidation ditches), two secondary
clarifiers, chlorine contact basins, and an outfall into marine waters.
Solid Wastes/Residual Solids
The treatment facilities remove solids during the treatment of the wastewater at the
headworks (grit and screenings), and at the primary and secondary clarifiers, in addition
to incidental solids (rags, scum, and other debris) removed as part of the routine
maintenance of the equipment. Port Townsenddrains grit, rags, scum,and screenings
and disposes this solid waste at the local landfill. Solids removed from the secondary
clarifiersare treated in two aerobic disaster/holding tanks and a belt gravity filter press is
used for sludge thickening. The solids are then truckedfacility
located at the Jefferson County Waste Management Facility. The composted product is
sold and is applied toland. This facility has met the solid waste requirements for
screening, as required by WAC 173-308-205.
11/05/15Page 4
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Discharge Outfall
The treated and disinfected effluent flows into the Strait of Juan de Fucathrough an old,
leaky outfall.The original section of the outfall was built in the 1940s and was then
extended in 1966 to discharge approximately 700 feet offshore at a depth of about 21 feet
at MLLW. The original section of outfall was constructed with 3-foot lengths of 18-inch
diameter concrete pipe. This original section of pipe is about 450 feet long with about
150 joints, many of which may be leaking. The 1960s extension is 18-inch diameter cast
iron pipe in 18-foot lengths. At about 50 years old, the structuralintegrityof this pipe is
questionable.The diffuser is cast iron with a total of five, 6-inch ports, and spaced9feet
apart.
The useful life expectancyof the off-shore portion of the outfall appears to be coming to
an end. The 2000 Facility Plan first looked at alternatives for the outfall. The City
replaced the on-shore portion of the outfall in 2005. This was needed due to recurrent
blockages caused by root intrusion resulting in surcharging at maintenance holes along
the outfall. A 2009 Facility Plan Amendment recommended replacement of the off-shore
portion of the outfall as well. This work has not been completed yet, but the permit
requires progress to be made in efforts to replace the outfall.
B.Description ofthe Receiving Water
The CityWWTP discharges to the Strait of Juan de Fuca. There is no other nearby point source
outfall. Nearby non-point sources of pollutants include storm water. There are noreceiving
waterbody impairments.
The ambient background data used for this permit includes the following from Ecology marine
water monitoring station ADM002 Admiralty Inlet (north) Quimper Point 2013:
Table 2-Ambient Background Data
ParameterValue Used
o
Temperature (highest annual 1-DADMax)11.1C
o
Temperature (average)8.5C
pH7.5standard units
Dissolved Oxygen6.3mg/L
Density26.4 sigma-t
Salinity31.6 psu
C.Wastewater Influent Characterization
The City reported the concentration of influent pollutants in discharge monitoring reports.The
influent wastewater from 2010 to 2014 is characterized as follows:
11/05/15Page 5
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Average Maximum
ParameterUnits
ValueValue
Biochemical Oxygen Demand (BOD)mg/L
334462
5
BODlbs/day
22283063
5
Total Suspended Solids (TSS)mg/L
343492
TSSlbs/day
22803176
FlowMGD
0.822.03
D.Wastewater Effluent Characterization
The City reported the concentration of pollutants in the discharge in the permitapplication and in
discharge monitoring reports.The tabulated data represents the quality of the wastewater effluent
discharged from 2010 to 2014.The wastewater effluent is characterized as follows:
Maximum
ParameterUnitsAverage Value
Value
BODmg/L
4.27.8
5
BODlbs/day
28.473
5
TSSmg/L
3.37.4
TSSlbs/day
22.570.1
Total Ammoniamg/L
0.371.4
Total Ammonialbs/day
2.3811.1
Total Nitrate + Nitritemg/L
6.115.4
Total Nitrogenmg/L
7.717.1
Total Phosphate (Ortho-phosphate)mg/L
3.98.1
Total Phosphorusmg/L
4.47.7
Maximum Maximum
Monthly Weekly
ParameterUnits
Geometric Geometric
MeanMean
Fecal Coliform#/100 mL22109
Minimum Maximum
ParameterUnits
ValueValue
pHStandard Units
6.57.6
E.Summary of Compliance with Previous Permit Issued on June 4, 2009
The previous permit placed effluent limits onBOD,TSS, Fecal Coliform Bacteria, and pH.
5
11/05/15Page 6
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
The CityWWTPhas complied with the effluent limits and permit conditions throughout the
duration of the permit issued on June 4, 2009. Ecology assessed compliance based on its review
information in the Ecology Permitting and Reporting Information System
(PARIS), Discharge Monitoring Reports (DMRs) and on inspections.
The following table summarizes compliance with report submittal requirements over the permit
term.
Submittal NameDue DateReceived Date
Outfall Evaluation1/1/201412/16/2013
Acute Toxicity Testing1/1/201412/16/2013
Chronic Toxicity Testing1/1/201412/16/2013
Wasteload Assessment1/31/20101/13/2010
Wasteload Assessment1/31/20111/6/2011
Wasteload Assessment1/31/20121/6/2012
Wasteload Assessment1/31/20131/4/2013
Wasteload Assessment1/31/20141/8/2014
Wasteload Assessment1/31/20151/14/2015
Infiltration and Inflow Evaluation1/31/20101/13/2010
Infiltration and Inflow Evaluation1/31/20111/6/2011
Infiltration and Inflow Evaluation1/31/20121/6/2012
Infiltration and Inflow Evaluation1/31/20131/4/2013
Infiltration and Inflow Evaluation1/31/20141/8/2014
Infiltration and Inflow Evaluation1/31/20151/14/2015
Industrial User Survey1/1/201412/16/2013
Application for Permit Renewal1/1/201412/16/2013
F.State Environmental Policy Act (SEPA)Compliance
State law exempts the issuance, reissuance or modification of any wastewater discharge permit
from the SEPA process as long as the permit contains conditions that are no less stringent than
federal and state rules and regulations (RCW 43.21C.0383). The exemption applies only to
existing discharges, not to new discharges.
III.PROPOSED PERMIT LIMITS
Federal andstate regulations require that effluent limits in an NPDES permit must beeither technology-
or water quality-based.
11/05/15Page 7
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Technology-based limits are based uponthe treatment methods available to treat specific
pollutants. Technology-based limitsare set by the EPA and published as a regulation, or Ecology
develops the limit on a case-by-case basis (40 CFR 125.3, and chapter 173-220 WAC).
Water quality-based limitsare calculated so that the effluent will comply with the Surface Water
Quality Standards (chapter 173-201A WAC), Ground Water Standards (chapter 173-200 WAC),
Sediment Quality Standards (chapter 173-204 WAC),or the National Toxics Rule (40 CFR
131.36).
Ecology must apply the most stringent of these limits toeach parameter of concern. These limits
are described below.
The limits in this permit reflect information received in the applicationand from supporting reports
(engineering, hydrogeology, etc.). Ecology evaluated the permit application and determined the limits
needed to comply with the rules adopted by the state of Washington.Ecology does not develop effluent
limits for all reported pollutants. Some pollutants are not treatable at the concentrations reported, are not
controllable at the source, are not listed in regulation, anddo not have a reasonable potential to cause a
water quality violation.
Ecologydoes notusuallydevelop limits for pollutants not reported in the permit applicationbut may be
present in the discharge. The permit does not authorizedischarge of the non-reported pollutants. During
the five-rom those conditions
reported in the permit application. The facility must notify Ecology if significant changes occur in any
constituent \[40 CFR 122.42(a)\]. Until Ecology modifies the permit to reflect additional discharge of
pollutants, a permittedfacility could be violating itspermit.
A.Design Criteria
UnderWAC 173-220-150 (1)(g), flows and waste loadings must not exceed approved design
criteria.Ecologyapproveddesign criteria for this treatment plant inthe facility plan
dated November 2000 and prepared by Gray & Osborne, Inc. The table below includes design
criteria from the referenced report.
Table 6 -Design Criteria for City of Port Townsend WWTP
ParameterDesign Quantity
Maximum Month Design Flow (MMDF)2.05MGD
Average AnnualFlow1.44MGD
BODLoadingfor Maximum Month3754lb/day
5
TSS Loadingfor Maximum Month4568lb/day
Design Population12,000
B.Technology-Based Effluent Limits
Federal and state regulations define technology-based effluent limits for domestic wastewater
treatment plants. These effluent limitsare given in 40 CFR Part 133 (federal) and in chapter 173-
221 WAC (state). These regulations are performance standards that constitute all known,
11/05/15Page 8
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
available, and reasonable methods of prevention,control, and treatment (AKART) for domestic
wastewater.
The table below identifies technology-based limits for pH, fecal coliform, BOD, and TSS, as
5
listed in chapter 173-221 WAC. Section III.F of thisfact sheet describes the potential for water
quality-based limits.
Table 7 -Technology-Based Limits
ParameterAverage Monthly LimitAverage Weekly Limit
BOD
5
30mg/L45mg/L
(concentration)
BODIn addition,the BODeffluent concentration must not exceed
55
(concentration)15percent of the average influent concentration.
TSS
30mg/L45mg/L
(concentration)
TSSIn addition,the TSS effluent concentration must not exceed 15
(concentration)percent of the average influent concentration.
Chlorine0.5mg/L0.75mg/L
Monthly Geometric Mean Weekly Geometric Mean
Parameter
LimitLimit
Fecal Coliform Bacteria200 organisms/100 mL400 organisms/100 mL
ParameterDaily MinimumDaily Maximum
pH6.0Standard Units9.0Standard Units
Ecology derived the technology-based monthly average limit for chlorine from standard operating
practices. The Water Pollution Control Federation's Chlorination of Wastewater(1976) states
that a properly designed and maintained wastewater treatment plant can achieve adequate
disinfection if a 0.5 mg/Lchlorine residual is maintained after fifteen minutes of contact time.
See also Metcalf and Eddy, Wastewater Engineering, Treatment, Disposal and Reuse, Third
Edition, 1991. A treatment plant that provides adequate chlorination contact time can meet the
0.5mg/Lchlorine limit on a monthly average basis. According to WAC 173-221-030(11)(b), the
corresponding weekly average is 0.75 mg/L.
Technology-based mass limits are based on WAC 173-220-130(3)(b) and 173-221-030(11)(b).
Ecology calculated the monthly and weekly average mass limits for BODand Total Suspended
5
Solidsas follows:
Mass Limit=CL x DF x CF
where:
CL=Technology-based concentration limits listed in the above table
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DF=Maximum Monthly Average Design flow (MGD)
CF=Conversion factor of 8.34
Table 8 -Technology-Based Mass Limits
ParameterConcentration Limit Mass Limit
(mg/L)(lbs/day)
BODMonthly Average30513
5
BODWeekly Average45769
5
TSS Monthly Average30513
TSS Weekly Average45769
C.Surface Water Quality-Based Effluent Limits
The Washington State surface water quality standards (chapter 173-201A WAC) are designed to
protect existing water quality and preserve the beneficial uses of Washington's surface waters.
Waste discharge permits must include conditions thatensurethe discharge will meet the surface
water quality standards(WAC 173-201A-510). Water quality-based effluent limitsmay be based
on an individual waste load allocation or on a waste load allocationdeveloped during a basin
wide Total Maximum Daily Load Study (TMDL).
Numerical Criteria for the Protection of Aquatic Life and Recreation
Numerical water quality criteria are listed in the water quality standards for surface
waters (chapter 173-201A WAC). They specify the maximum levelsof pollutants
allowed in receivingwater to protectaquatic lifeand recreation in and on the water.
Ecology uses numerical criteria along with chemical and physical data for the wastewater
and receiving water to derive the effluent limits in the discharge permit. When surface
water quality-based limits are more stringent or potentially more stringent than
technology-based limits,the dischargemust meetthe water quality-based limits.
Numerical Criteria for the Protection of Human Health
The U.S. EPA has published 91 numeric water quality criteria for the protection of
human health that are applicable to dischargers in Washington State (EPA,1992). These
criteria are designed to protect humans from exposure to pollutants linked to cancer and
other diseases, based on consumingfish and shellfish and drinking contaminated surface
waters. The water quality standards also include radionuclide criteria to protect humans
from the effects ofradioactive substances.
Narrative Criteria
Narrative water quality criteria (e.g., WAC 173-201A-240(1); 2006) limit the toxic,
radioactive, or other deleterious material concentrations that the facility may discharge to
levels below those which have the potential to:
Adversely affect designated water uses
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Cause acute or chronic toxicityto biota
Impair aesthetic values
Adversely affect human health
Narrative criteria protect the specific designated uses of all fresh waters (WAC 173-
201A-200, 2006) and of all marine waters (WAC 173-201A-210,2006) in thestate of
Washington.
Antidegradation
Description--The purpose of Washington's Antidegradation Policy(WAC 173-201A-
300-330; 2006)is to:
Restore and maintain the highest possible quality of the surface waters of
Washington.
Describe situations under which water quality may be lowered from its current
condition.
Apply to human activities that are likely to have an impact on the water quality
of surfacewater.
Ensure that all human activities likely to contribute to a lowering of water
quality, at a minimum, apply all known, available, and reasonable methods of
prevention, control, and treatment (AKART).
Apply three tiersof protection(described below)for surface waters of the state.
Tier Iensuresexisting and designated uses are maintained andprotected and applies to all
waters and all sources of pollutions. Tier II ensuresthat waters of a higher quality than
the criteria assigned are not degraded unless such lowering of water quality is necessary
and in the overriding public interest. Tier II applies only to a specific list of polluting
activities. Tier IIIpreventsthe degradation of waters formally listed as "outstanding
resource waters," and applies to all sources of pollution.
A facility must prepare a Tier II analysis when all three of the following conditions are
met:
The facility isplanning anew or expanded action.
Ecology regulatesor authorizesthe action.
The action hasthe potential to cause measurable degradation to existing water
quality at the edge of a chronic mixing zone.
Facility Specific Requirements--This facility must meet Tier I requirements.
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Dischargers must maintain and protect existing and designated uses.Ecology
must not allow any degradation that willinterfere with, or become injurious to,
existing or designated uses, except as provided for in chapter173-201A WAC.
proposed permit conditions will protect existing and designated uses of the receiving
water.
Mixing Zones
A mixing zone is the defined area in the receiving water surrounding the discharge
port(s), where wastewater mixes with receiving water. Within mixing zones the pollutant
concentrations may exceed water quality numeric standards, so long as the discharge
designated uses of the receiving water body (for example,
recreation, water supply, and aquatic life and wildlife habitat, etc.) The pollutant
concentrations outside of the mixing zones must meet water quality numeric standards.
State and federal rules allow mixing zones because the concentrations and effects of most
pollutants diminish rapidly after discharge, due to dilution. Ecology defines mixing zone
sizes to limit the amount of time any exposure to the end-of-pipe discharge could harm
water quality, plants, or fish.
known, available, and reasonable methods of prevention, control,and treatment
(AKART). Mixing zones typically require compliance with water quality criteria within
a specified distance from the point of dischargeandmust not use more than 25percentof
the available width of the water body for dilution\[WAC 173-201A-400 (7)(a)(ii-iii)\].
Ecology uses modeling toestimate the amount of mixing within the mixing zone.
Through modeling Ecology determinesthe potential for violatingthe water quality
standards at the edge of the mixing zone and derivesany necessary effluent limits.
Steady-state models are the most frequently used tools for conducting mixing zone
analyses. Ecology chooses values for each effluent and for receiving water variablesthat
correspond to the time period when the most critical condition is likely to occur(see
s Manual). Each critical condition parameter,by itself,has a
low probability of occurrence and the resulting dilution factor is conservative. The term
reasonable worst-caseappliesto these values.
The mixing zone analysis producesa numerical value called a dilution factor(DF). A
dilution factor represents the amount of mixing of effluent and receiving water that
occurs at the boundary of the mixing zone. For example, a dilution factor of 4meansthe
effluent is 25percentand the receiving water is75percentof the total volumeof water at
the boundary of the mixing zone. Ecology usesdilution factors with the water quality
criteria to calculatereasonable potentials and effluent limits. Waterquality standards
include bothaquatic life-based criteria and human health-based criteria. The former are
applied at both the acute and chronic mixing zone boundaries;the latter are applied only
at the chronic boundary. The concentration of pollutantsat the boundariesof any of these
mixing zones may not exceed the numerical criteria for that zone.
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Each aquatic life acutecriterionis based on the assumption that organisms are not
exposed to that concentration for more than onehour andmore often than one exposure
in three years. Each aquatic life chroniccriterionis based on the assumption that
organisms are not exposed to that concentration for more than four consecutive days and
more often than once in three years.
The two types of human health-based water quality criteria distinguish between those
pollutants linked to non-cancer effects (non-carcinogenic) and those linked to cancer
effects (carcinogenic). The human health-based water quality criteria incorporate several
exposure and riskassumptions.These assumptions include:
A70-year lifetime of daily exposures
An ingestion rate for fish or shellfish measured in kg/day
An ingestion rate of twoliters/day for drinking water
Aone-in-one-million cancer risk for carcinogenic chemicals
This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone
around the point of discharge (WAC 173-201A-400). The water quality standards
impose certain conditions before allowing the discharger a mixing zone:
1.Ecology must specify both the allowed size and location in a permit.
The proposed permit specifies the size and location of the allowed mixing zone
(as specified below).
2.The facility must f,available,and reasonable methods of
prevention, control and to its discharge.
Ecology has determined that the treatment provided at the City of Port Townsend
WWTPmeets-based Limits
3.Ecology must consider critical discharge conditions.
Surface water quality-based limits are derivedfor the water
condition (the receiving water and waste discharge condition with the highest
potential for adverse impact on the aquatic biota, human health, and existing or
designated waterbody uses). The critical discharge condition is often pollutant-
specific or waterbody-specific.
Critical discharge conditions are those conditions that result in reduced dilution
or increased effect of the pollutant. Factors affecting dilution include the depth
of water, the density stratification in the water column, the currents,and the rate
of discharge. Density stratification is determined by the salinity and temperature
of the receiving water. Temperatures are warmer in the surface waters in
summer.Therefore, density stratification is generally greatest during the summer
months. Density stratification affects how far up in the water column a
freshwater plume may rise. The rate of mixing is greatest when an effluent is
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rising. The effluent stops rising when the mixed effluent is the same density as
the surrounding water. After the effluent stops rising, the rate of mixing is much
more gradual. Water depth can affect dilution when a plume might rise to the
surface when there islittle or no stratification. Ecology uses the water depth at
mean lower low water (MLLW)for marine waters
Manual describes additional guidance on criteria/design conditions for
determining dilution factors. The manual can be
website at: https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html.
Table 9 -Critical Conditions Used to Model the Discharge
Critical ConditionValue
Water depth at MLLW28.82feet
Density profile with a difference of 0.85sigma-t units
0 to 0.85 sigma-t
between28feet and the surface
thth
10and90percentile current speeds for acute
0.40 and 0.82 m/sec
mixing zone
50th percentile current speeds for chronic andhuman
0.61m/sec
health mixing zones
Maximum average monthly effluent flow for chronic 2.05 million gallons
and human health non-carcinogenper day (MGD)
Annual average flow for human health carcinogen1.44MGD
Maximum daily flow for acute mixing zone10.65MGD
1 DAD MAX effluent temperature20degrees C
Ecology obtained ambient data at critical conditions in the vicinity of the outfall
from historical data and the monitoring studiesconducted in 1990 and 2008.
Ecology obtained historical ambient data from ambient station ADM002 located
near the outfall.
4.Supporting information must clearly indicate the mixing zone would not:
Have a reasonable potential to cause the loss ofsensitive or important
habitat
Substantially interfere with the existing or characteristic uses
Result in damage to the ecosystem
Adverselyaffect public health
Ecology established Washington State water quality criteria for toxic chemicals
using EPA criteria. EPA developed the criteria using toxicity tests with
numerous organismsand set the criteria to generally protect the species tested
and to fully protect all commercially and recreationally important species.
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EPA sets acute criteria for toxic chemicals assuming organisms are exposed to
the pollutant at the criteriaconcentration for one hour. They set chronic
standards assuming organisms are exposed to the pollutant at the criteria
concentration for fourdays. Dilution modeling under critical conditions
generally shows that both acute and chronic criteria concentrations are reached
within minutes of discharge.
The discharge plume does not impact drifting and non-strong swimming
organisms because they cannot stay in the plume close to the outfall long enough
to be affected. Strong swimming fish could maintain a position within the
plume, but they can also avoidthe discharge by swimming away. Mixing zones
generally do not affect benthic organisms(bottom dwellers) because the buoyant
plume rises in the water column. Ecology has additionally determined that the
effluent will not exceed 33 degrees C for more than twoseconds after discharge;
and that the temperature of the water will not create lethal conditions or
blockages to fish migration.
Ecology evaluates the cumulative toxicity of an effluent by testing the discharge
with whole effluent toxicity (WET) testing.
Ecology reviewed the above information, the specific information on the
characteristics of the discharge, the receiving water characteristics,and the
discharge location. Based on this review,Ecology concludedthat the discharge
does not have a reasonable potential to cause the loss of sensitive or important
habitat, substantially interfere with existing or characteristics uses, result in
damage to the ecosystem,or adversely affect public healthif the permit limits are
met.
5.The discharge/receiving water mixture mustnot exceed water quality criteria
outside the boundary of a mixing zone.
Ecology conducted areasonable potential analysis;using procedures established
by the EPA and by Ecology, foreach pollutantandconcluded the
discharge/receiving water mixture will not violate water quality criteria outside
the boundary of the mixing zoneif permit limits are met.
6.The size of the mixing zone and the concentrations of the pollutants mustbe
minimized.
At any given time, the effluent plume usesonly a portion of the acute and chronic
mixing zone, which minimizes the volume of water involved in mixing. Because
tidal currents change direction, the plume orientation within the mixing zone
changes. The plume mixes as it rises through the water columntherefore much
of the receiving water volume at lower depths inthe mixing zoneis not mixed
with discharge. Similarly, because the dischargemaystop risingat some depth
due to density stratification, waters above that depthwill not mix with the
discharge.Ecology determined it is impractical to specify in the permit the
actual, much more limited volume in which the dilution occurs as the plume rises
and moves with the current.
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Ecology minimizes the size of mixing zones by requiring dischargers to install
diffusers when they are appropriate to the discharge and the specific receiving
waterbody. When a diffuser is installed,the discharge is more completely mixed
with the receiving water in a shorter time. Ecology also minimizes the size of the
mixing zone (in the form of the dilution factor) using design criteria with a low
probability of occurrence. For example, Ecology uses the expected 95th
percentile pollutant concentration, the 90th percentile background concentration,
the centerline dilution factor,and the lowestflow occurring once in every ten
years to perform the reasonable potential analysis.
Because of the above reasons, Ecology haseffectivelyminimized the sizeof the
mixing zone authorized in the proposed permit.
7.Maximum size of mixing zone.
The authorized mixing zone does not exceed the maximum size restriction.
8.Acute mixing zone.
The discharge/receiving water mixture must comply with acute criteria
as near tothe point of discharge as practicably attainable.
Ecology determined the acute criteria will be met at 10percentof the
distance of the chronic mixing zone.
The pollutant concentration, duration, and frequency of exposure to the
discharge will not createa barrier to migration or translocation of
indigenous organisms to a degree that has the potential to cause damage
to the ecosystem.
As described above, the toxicity of any pollutant depends upon the
exposure, the pollutant concentration, and the time theorganism is
exposed to that concentration. Authorizing a limited acute mixing zone
for this discharge assures that it will not create a barrier to migration.
The effluent from this discharge will rise as it enters the receiving water,
assuring that the rising effluent will not cause translocation of indigenous
organisms near the point of discharge (below the rising effluent).
Comply with size restrictions.
The mixing zone authorized for this discharge complies with the size
restrictions published in chapter 173-201A WAC.
9.Overlap of mixing zones.
This mixing zone does not overlap another mixing zone.
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D.Designated Uses and Surface Water Quality Criteria
Applicable designated uses and surface water quality criteria are defined in chapter 173-201A
WAC. In addition, the U.S. EPA sethuman health criteria for toxic pollutants (EPA 1992). The
tablesincluded below summarize the criteria applicable to .
Aquatic life uses are designated using the following general categories. Allindigenous
fish and non-fish aquatic speciesmustbe protected in waters of the state.
1.Extraordinary quality salmonid and other fish migration, rearing, and spawning;
clam, oyster, and mussel rearing and spawning; crustaceans and othershellfish
(crabs, shrimp, crayfish, scallops, etc.) rearing and spawning.
2.Excellent quality salmonid and other fish migration, rearing, and spawning; clam,
oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs,
shrimp, crayfish, scallops, etc.) rearing and spawning.
3.Good quality salmonid migration and rearing; other fish migration, rearing, and
spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other
shellfish (crabs, shrimp, crayfish, scallops, etc.) rearingand spawning.
4.Fair quality salmonid and other fish migration.
The Aquatic Life Usesand the associated criteria for this receiving water are identified
below.
Table 10 -Marine Aquatic Life Uses and Associated Criteria
Extraordinary Quality
Temperature Criteria Highest 1D MAX13°C (55.4°F)
Dissolved Oxygen Criteria Lowest
7.0mg/L
1-Day Minimum
5 NTU over background when the
background is 50 NTU or less; or
Turbidity Criteria
A 10 percent increase in turbidity when
the background turbidity is more than 50
NTU.
pH must be within the range of 7.0 to 8.5
pH Criteriawith a human-caused variation within the
above range of less than 0.2 units.
To protect shellfish harvesting, fecal coliformorganism levels must not exceed a
geometric mean value of 14 colonies/100 mL, andnot have more than 10 percent of all
samples (or any single sample when less than tensample points exist) obtained for
calculating the geometric mean value exceeding 43colonies/100 mL.
The recreational usesare primary contact recreation and secondary contact recreation.
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The recreational uses for this receiving water are identified below.
Table 11 -Recreational Uses
Recreational UseCriteria
Fecal coliform organism levels must not exceed a geometric
mean value of 14 colonies/100 mL, with not more than 10
Primary Contact
percent of all samples (or any single sample when less than ten
Recreation
sample points exist) obtained for calculating the geometric
mean value exceeding 43 colonies /100 mL.
The miscellaneous marine water usesare wildlife habitat, harvesting, commerce and
navigation, boating, and aesthetics.
E.Water Quality Impairments
Ecology has not documented any water quality impairments in the receiving water in the vicinity
of the outfall.
F.Evaluation of Surface Water Quality-Based Effluent Limits for Narrative Criteria
Ecology must consider the narrative criteriadescribed in WAC 173-201A-160when it determines
permit limits and conditions. Narrative water quality criteria limit the toxic, radioactive, or other
deleterious material concentrations that the facility may discharge which have the potential to
adversely affect designated uses, cause acute or chronic toxicity to biota, impair aesthetic values,
or adversely affect human health.
Ecology considers narrative criteria when it evaluates the characteristics of the wastewater and
when itimplements AKARTasdescribed above in the technology-based limits section. When
Ecology determines if a facility is meeting AKART it considersthe pollutants in the wastewater
and the adequacy of the treatment to prevent the violation of narrative criteria.
In addition, Ecology considers the toxicity of the wastewater discharge by requiring WET testing
need for WET testing for this discharge is described later in the fact sheet.
G.Evaluation of Surface Water Quality-Based Effluent Limits for Numeric Criteria
Pollutants in an effluent may affect the aquatic environment near the point of discharge
(near-field) or at a considerable distance from the point of discharge (far-field). Toxic pollutants,
for example, are near-field pollutants;their adverse effects diminish rapidly with mixing in the
receiving water. Conversely,a pollutant such as biochemicaloxygen demand (BOD) is a far-
5
field pollutant whose adverse effect occurs away from the discharge even after dilution has
occurred. Thus, the method of calculating surface water quality-based effluent limits varies with
the point at which the pollutant has its maximum effect.
With technology-based controls (AKART), predicted pollutant concentrations in the discharge
exceed water quality criteria. Ecology therefore authorizes a mixing zone in accordance with the
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geometric configuration, flow restriction, and other restrictions imposed on mixing zones by
chapter 173-201A WAC.
The diffuser at Outfall 001 is 36feet long with a diameter of 18inches. The diffuser has a total
of five 6-inch diameter ports. The distance between ports is ninefeet. The diffuser depth is listed
as 21 to 29feetin various studies. Amean lower low water (MLLW) depth of 21feetwas used
in the permit. Ecology obtained this information from various reports.
Chronic Mixing Zone--WAC 173-201A-400(7)(c) specifies that mixing zones must not extend
in any horizontal direction from the discharge ports for a distance greater than 300 feet plus the
depth of water over the discharge ports as measured during MLLW.
The horizontal distance of the chronic mixing zone is 321 feet. The mixing zone extends from
the bottom to the top of the water column.
AcuteMixing Zone--WAC 173-201A-400(8)(b) specifies that in oceanicwaters a zone where
acute criteria may be exceeded must not extend beyond 10percentof the distance established for
the chronic zone. The horizontal distance of the acute mixing zone is 32.1feet. The mixing zone
extends from the bottom to the top of the water column.
Ecology determined the dilution factors that occur within these zones at the critical condition
using the model PLUMES. The dilution factors are listed below.
Table 12 -Dilution Factors (DF)
CriteriaAcuteChronic
Aquatic Life25781
Human Health, Carcinogen781
Human Health, Non-carcinogen781
Ecology determined theimpacts of dissolved oxygen deficiency, pH, fecal coliform, chlorine,
ammonia, metals, and temperature as described below, using the dilution factors in the above
table.The derivation of surface water quality-based limits also takes into account the variability
of pollutant concentrations in both the effluent and the receiving water.
Dissolved Oxygen--BODand Ammonia Effects--Natural decomposition of organic material in
5
wastewater effluentimpactsdissolved oxygen in the receiving water at distances far outside of
the regulated mixing zone. The BODof an effluent sample indicates the amount of
5
biodegradable material in the wastewater and estimates the magnitude of oxygen consumption the
wastewater will generate in the receiving water. The amount of ammonia-based nitrogen in the
wastewater also provides an indication of oxygen demandpotential in the receiving water.
With technology-based limits, this discharge results in a small amount of BODrelative to the
5
large amount of dilution in the receiving water at critical conditions. Technology-based limits
will ensure that dissolved oxygen criteria are met in the receiving water.
pH--Compliance with the technology-based limits of 6.0 to 9.0 will assure compliance with the
water quality standards of surface waters because of the high buffering capacity of marine water.
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Fecal Coliform--Ecology modeled the numbers of fecal coliform by simple mixing analysis
using the technology-based limit of 400 organisms per 100 mLand a dilution factor of 781.
Under critical conditions, modeling predicts no violation of the water quality criterion for fecal
coliform. Therefore, the proposed permit includes the technology-based effluent limit for fecal
coliform bacteria.
Turbidity--Ecology evaluated the impact of turbidity based on the range of total suspended
solidsin the effluent and turbidity ofthe receiving water. Ecology expects no violations of the
turbidity criteria outside the designated mixing zoneprovided the facility meets its technology-
based total suspended solids permit limits.
Toxic Pollutants--Federal regulations (40 CFR 122.44) require Ecology to place limits in
NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for
those chemicals to exceed the surface water quality criteria. Ecology does not exempt facilities
with technology-based effluent limits from meeting the surface water quality standards.
The following toxic pollutants are present in the discharge: chlorine, ammonia, and (presumably)
heavy metals. Ecology conducted a reasonable potential analysis on ammonia to determine
whether it would require effluent limits in this permit.
Ammonia's toxicity depends on that portion which is available in the unionized form. The
amount of unionized ammonia depends on the temperature, pH, and salinity of the receiving
marine water. To evaluate ammonia toxicity, Ecology used the available receiving water
information for ambient station ADM002 and Ecology spreadsheet tools. We found no potential
for a violation, largely because oflow values in the effluent.
For chlorine, we did not calculate a reasonable potential as the previous permit did not require
chlorine effluent monitoring and, as a result, we do not have data for the calculation. The facility
de-chlorinates before discharge, and it was a reasonable assumption on the part of the previous
permit writer that both the effluent and the receiving water have (at most) low levels of chlorine
such that there is no potential to violate standards. In such a case, we typically would not require
monitoring. However, our current practice is to require effluent monitoring when chlorine is used
for disinfection and the new permit includes that requirement.
Similarly for metals, we did not calculate a reasonable potential for metals as the previous permit
did not require effluent metals monitoring. Wehistoricallydidnot require metals monitoring for
facilities that were not majorsunless we hadreason to believe that there could be a problem due
to, for example, low available dilution. The current permit does require annual effluent metals
monitoring, andit requiresthe Permittee to move forward on diffuser replacement, to ensure that
dilution is in fact available.
Temperature--The state temperature standards \[WAC 173-201A-200-210 and 600-612\]include
multiple elements:
thth
Annual summer maximum threshold criteria (June 15to September 15)
thth
Supplemental spawning and rearing season criteria (September 15to June 15)
Incremental warming restrictions
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Protections Against Acute Effects
Ecology evaluates each criterion independently to determine reasonable potential and
derive permit limits.
Annual Summer Maximum and Supplementary Spawning/Rearing Criteria
Each water body has an annual maximum temperature criterion \[WAC 173-201A-
200(1)(c), 210(1)(c), and Table 602\]. These threshold criteria (e.g., 12, 16, 17.5, 20°C)
protect specific categories of aquatic life by controlling the effect of human actions on
summer temperatures.
Some waters have an additional thresholdcriterion to protect the spawning and
incubation of salmonids (9°C for char and 13°C for salmon and trout) \[WAC 173-201A-
602, Table 602\]. These criteria apply during specific date-windows.
The threshold criteria apply at the edge of the chronic mixing zone. Criteria for most
fresh waters are expressed as the highest 7-Day average of daily maximum temperature
(7-DADMax). The 7-DADMax temperature is the arithmetic average of seven
consecutive measures of daily maximum temperatures. Criteria for marine waters and
some fresh waters are expressed as the highest 1-Day annual maximum temperature (1-
DMax).
Incremental Warming Criteria
The water quality standards limit the amount of warming human sources can cause under
specific situations \[WAC 173-201A-200(1)(c)(i)-(ii), 210(1)(c)(i)-(ii)\]. The incremental
warming criteria apply at the edge of the chronic mixing zone.
At locations and times when background temperatures are cooler than the assigned
threshold criterion, point sources are permitted to warm the water by only a defined
increment. These increments are permitted only to the extent doing so does not cause
temperatures to exceed either the annual maximum or supplemental spawning criteria.
At locations and times when a threshold criterion is being exceeded due to natural
conditions, all human sources, considered cumulatively, must not warm the water more
than 0.3°C above the naturally warm condition.
When Ecology has not yet completed a TMDL, our policy allows each point source to
warm water at the edge of the chronic mixing zone by 0.3°C. This is true regardless of
the background temperature and even if doing so would cause the temperature at the edge
of a standard mixing zone to exceed the numeric threshold criteria. Allowing a 0.3°C
warming for each point source is reasonable and protective where the dilution factor is
based on 25percentor less of the critical flow. This is because the fully mixed effect on
temperature will only be a fraction of the 0.3°C cumulative allowance (0.075°C or less)
for all human sources combined.
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Protections for Temperature Acute Effects
th
Instantaneous lethality to passing fish: The upper 99percentile daily maximum effluent
temperature must not exceed 33°C,unless a dilution analysis indicates ambient
temperatures will not exceed 33°C two seconds after discharge.
General lethality and migration blockage: Measurable (0.3°C) increases in temperature at
the edge of a chronic mixing zone are not allowed when the receiving water temperature
exceeds either a 1DMax of 23°Cor a 7DADMax of 22°C.
Lethality to incubating fish: Human actions must not cause a measurable (0.3°C)
warming above 17.5°C at locations where eggs are incubating.
Reasonable Potential Analysis
Annual Summer Maximum and Incremental Warming Criteria:Ecology calculated the
reasonable potential for the discharge to exceed the annual summer maximumand the
incremental warming criteria at the edge of the chronic mixing zone during critical
conditions. No reasonable potential exists to exceed the temperature criterion where:
(Criterion + 0.3) > \[Criterion + (Teffluent95 Criterion)/DF\].
(13 + 0.3) > (13 + (2513)/781).
Therefore, the proposed permit does not include a temperature limit.Ecology will
reevaluate the reasonable potential during the nextpermit renewal.
H.Human Health
human health-based criteria that
Ecology must considerwhen writingNPDES permits. These criteria were establishedin 1992by
the U.S. EPA in its National Toxics Rule (40 CFR 131.36). The National Toxics Rule allows
states to use mixing zonesto evaluate whetherdischarges comply withhuman health criteria.
Ecologydetermined the applicant's discharge is unlikely to contain chemicals regulated to protect
human health, and does not contain chemicals of concern based on existing effluent data or
knowledgeof discharges to thewastewater treatmentsystem. Ecology will reevaluatethis
dischargefor impactsto human health at the next permit reissuance.
I.Sediment Quality
The aquatic sediment standards (chapter 173-204 WAC) protect aquatic biota and human health.
Under these standards Ecologymay require a facility to evaluate the potential for its discharge to
cause a violation of sedimentstandards (WAC 173-204-400).You can obtain additional
information about sediments at the Aquatic Lands Cleanup Unit website.
http://www.ecy.wa.gov/programs/tcp/smu/sediment.html
Given the plans to replace the outfall and through a review of the discharger characteristics and of
the effluent characteristics, Ecology determinedthat this discharge has no reasonable potential to
violate the sediment management standards.
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
J.Whole Effluent Toxicity
The water quality standards for surface waters forbid discharge of effluent that has the potential
to cause toxic effects in the receiving waters. Many toxic pollutants cannot be measured by
commonly available detection methods. However, laboratory tests can measure toxicity directly
by exposing living organisms to the wastewater and measuring their responses. These tests
measure the aggregate toxicity of the whole effluent, so this approach is calledwhole effluent
toxicity (WET) testing. Some WET tests measure acute toxicity and other WET tests measure
chronic toxicity.
Acute toxicity tests measure mortality as the significant responseto the toxicity of the
effluent. Dischargers who monitor their wastewater with acute toxicity tests find early
indications of any potential lethal effect of the effluent on organisms in the receiving
water.
Chronic toxicity tests measure various sublethal toxic responses, such as reduced growth
or reproduction. Chronic toxicity tests often involve either a complete life cycle test on
an organism with an extremely short life cycle, or a partial life cycle test during a critical
stage of a test organism's life. Some chronic toxicity tests also measure organism
survival.
Laboratories accredited by Ecology for WET testing know how to use the proper WET testing
protocols, fulfill the data requirements, and submit results in the correct reporting format.
Accredited laboratory staff knowsabout WET testing and how to calculate an NOEC, LC50,
EC50, IC25, etc. Ecology gives all accredited labs the most recent version of Ecology
Publication No. WQ-R-95-80,Laboratory Guidance and Whole Effluent Toxicity Test Review
Criteria(https://fortress.wa.gov/ecy/publications/SummaryPages/9580.html), which is referenced
in the permit. Ecology recommends that the City of Port Townsendsend a copy of the acute or
chronic toxicity sections(s) of its NPDES permit to the laboratory.
WET testing conducted during effluent characterization showed no reasonable potential for
effluent discharges to cause receiving water acute toxicity. The proposed permit will not include
an acute WET limit. The city of Port Townsendmust retest the effluent before submitting an
application for permit renewal.
If this facility makes process or material changes which, in Ecology's opinion, increase
the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit
modification, or in the permit renewal) require the facility to conduct additional effluent
characterization. The city of Port Townsendmay demonstrate to Ecology that effluent
toxicity has not increased by performing additional WET testing and/or chemical
analyses after the process or material changes have been made. Ecology recommends
that the Permittee check with it first to make sure that Ecology will consider the
demonstration adequate to support a decision to not require an additional effluent
characterization.
If WET testing conducted for submittal with a permit application fails to meet the
performance standards in WAC 173-205-020, Ecology will assume that effluent toxicity
has increased.
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
WET testing conducted during effluent characterization showed no reasonable potential for
effluent discharges to cause receiving water chronic toxicity. The proposed permit will not
includea chronic WET limit. The City of Port Townsendmust retest the effluent before
submitting an application for permit renewal.
If this facility makes process or material changes which, in Ecology's opinion, increase
the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit
modification, or in the permit renewal) require the facility to conduct additional effluent
characterization
If WET testing conducted for submittal with a permit application fails to meet the
performance standards in WAC 173-205-020, Ecology will assume that effluent toxicity
has increased. The City of Port Townsendmay demonstrate to Ecology that effluent
toxicity has not increased by performing additional WET testing after the process or
material changes have been made.
K.Groundwater Quality Limits
The groundwaterquality standards(chapter 173-200 WAC)protect beneficial uses of
groundwater. Permits issued by Ecologymustnot allow violations of those standards (WAC
173-200-100).
The city of Port Townsenddoes not discharge wastewater to the ground.Nopermit limitsare
required toprotect groundwater.
L.Comparison of Effluent Limits with thePrevious Permit Modified onOctober 12, 2011
Table 13 -Comparison of Previous and Proposed Effluent Limits
PreviousEffluent Limits: ProposedEffluent Limits:
Outfall # 001Outfall # 001
Basis of Average Average Average Average
Parameter
LimitMonthlyWeeklyMonthlyWeekly
30mg/L,30mg/L,
513 lbs/day, 45mg/L&513 lbs/day, 45mg/L&
BODTechnology
5
& 85% 769 lbs/day& 85% 769 lbs/day
removalremoval
30mg/L,30mg/L,
513lbs/day, 45mg/L&513 lbs/day, 45mg/L&
TSSTechnology
& 85% 769 lbs/day& 85% 769 lbs/day
removalremoval
Total Residual
TechnologyNANA0.5 mg/K0.75mg/L
Chlorine
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Weekly
Monthly Weekly Monthly
Geometric
ParameterGeometric Geometric Geometric
Mean
Mean LimitMean LimitMean Limit
Limit
Fecal
Coliform Technology200/100 mL400/100 mL200/100 mL400/100 mL
Bacteria
ParameterLimitLimit
Daily minimum is equal to or
greater than 6.0 and the daily Minimum is 6.0
pHTechnology
maximum is less than or Maximum is 9.0
equal to 9.0
IV.MONITORING REQUIREMENTS
Ecology requires monitoring, recording, and reporting (WAC 173-220-210 and 40 CFR 122.41) to verify
that the treatment process is functioning correctly and that the
effluent limits.
If a facility uses a contract laboratory to monitor wastewater, it must ensure that the laboratory uses the
methods and meets or exceeds the method detection levels required by the permit. The permit describes
when facilities may use alternative methods. It also describes what to do in certain situations when the
laboratory encounters matrix effects. When a facility uses an alternative method as allowed by the
permit, it must report the test method, Detection Level (DL), and Quantitation Level (QL)on the DMRor
in the required report.
A.Wastewater Monitoring
The monitoring schedule is detailed in the proposed permit under Special Condition S2.
Specified monitoring frequencies take into account the quantity and variability of the discharge,
the treatment method, past compliance, significance of pollutants, and cost of monitoring. The
required monitoring frequency is consistent with agency guidance given in the current version of
Permit Writer's Manual(Publication Number 92-09) for oxidation ditches.
Ecology hadincluded some additional monitoring of nutrients in the previouspermit to establish
a baseline for this discharger. It will use this data in the future as it develops TMDLs for
dissolved oxygen and establishes WLAs for nutrients.
Monitoring of sludge quantity and quality is necessary to determine the appropriate uses of the
sludge. Biosolids monitoring is required by the current state and local solid waste management
program andalso by EPA under 40 CFR 503.
B.Lab Accreditation
Ecology requires that facilities must use a laboratory registered or accredited under the provisions
of chapter 173-50 WAC, Accreditation of Environmental Laboratories,to prepare all monitoring
data (with the exception of certain parameters). Ecology accredited the laboratory at this facility
for:
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Table 14 -Accredited Parameters
Matrix
Parameter NameCategoryMethod Name
Description
TSSGeneral ChemistrySM 2540 D-97Non-Potable Water
Total Residual ChlorineGeneral ChemistrySM 4500-Cl G-00Non-Potable Water
pHGeneral ChemistrySM 4500-H+ B-00Non-Potable Water
Dissolved OxygenGeneral ChemistrySM 4500-O G-01Non-Potable Water
BODGeneral ChemistrySM 5210B-01Non-Potable Water
5
SM 9222 D (m-
Fecal ColiformMicrobiologyNon-Potable Water
FC)-97
C.Effluent Limits which are Near Detection or Quantitation Levels
The Method Detection Level (MDL) also known as DL is the minimum concentration of a
pollutant that a laboratory can measure and report with a 99 percent confidence that its
concentration is greater than zero (as determined by a specific laboratory method). The QL is the
level at which a laboratory canreliably report concentrations with a specified level of error.
Estimated concentrations are the values between the DL and the QL. Ecology requires permitted
facilities to report estimated concentrations. When reporting maximum daily effluent
concentra
detection level if the measured effluent concentration falls below the detection level.
V.OTHER PERMIT CONDITIONS
A.Reporting and Record Keeping
Ecology basedSpecial Condition S3 onitsauthority to specify any appropriate reporting and
recordkeeping requirements to prevent and control waste discharges (WAC 173-220-210).
B.Prevention of Facility Overloading
Overloading of the treatment plant is a violation of the terms and conditions of the permit. To
prevent this from occurring, RCW 90.48.110 and WAC 173-220-150 requires the City of Port
Townsendto:
Take the actions detailed in proposed permit Special Condition S.4.
Design and construct expansions or modifications before the treatment plant reaches
existing capacity.
Report and correct conditions that could result in new or increased discharges of
pollutants.
Special Condition S4 restricts the amount of flow.
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
If a municipality intends to apply for Ecology-administered funding for the design or construction
-
98-
State Environmental Review Process (SERP) documentation to demonstrate compliance with 40
CFR 35.3140 and 40 CFR 35.3145, and a cost effectiveness analysisas required by WAC 173-
98-730.
planning a project that may include Ecology-administered funding.
C.Operation and Maintenance
The proposed permit contains Special Condition S.5as authorized under RCW 90.48.110, WAC
173-220-150, chapter 173-230 WAC, and WAC 173-240-080. Ecology included it to ensure
proper operation and regular maintenance of equipment, and to ensure that the city of Port
Townsendtakes adequate safeguards sothat it uses constructed facilities to their optimum
potential in terms of pollutant capture and treatment.
D.Pretreatment
Duty to Enforce Discharge Prohibitions
This provision prohibits the Publicly Owned Treatment Works (POTW)from authorizing
or permitting an industrial discharger to discharge certain types of waste into the sanitary
sewer.
The first section of the pretreatment requirements prohibits the POTW from
pass-
prohibition is from 40 CFR §403.5(a). Appendix Cof this fact sheet defines
these terms.
The second section reinforces a number of specific state and federal pretreatment
prohibitions found in WAC 173-216-060 and 40 CFR §403.5(b). These reinforce
that the POTW may not accept certain wastes, which:
1.Are prohibited due to dangerous waste rules
2.Are explosive or flammable
3.Have too high or low of a pH (too corrosive, acidic or basic)
4.May cause a blockage such as grease, sand, rocks, or viscous materials
5.Are hot enough to cause a problem
6.Are of sufficient strength or volume to interfere with treatment
7.Contain too much petroleum-based oils,mineral oil, or cutting fluid
8.Create noxious or toxic gases at any point
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
40 CFR Part 403 contains the regulatory basis for these prohibitions, with the
exception of the pH provisions which are based on WAC 173-216-060.
The third section of pretreatment conditions reflects state prohibitions on the
POTW accepting certain types of discharges unless the discharge has received
prior written authorization from Ecology. These discharges include:
1.Cooling water in significantvolumes
2.Stormwater and other direct inflow sources
3.Wastewaters significantly affecting system hydraulic loading,which do
not require treatment
Federal andState Pretreatment Program Requirements
Ecology administers the Pretreatment Program under the terms of the addendum to the
403. Underthis delegation of authority, Ecology issues wastewater discharge permits for
significant industrial users (SIUs) discharging to POTWs which have not been delegated
authority to issue wastewater discharge permits. Ecology must approve, condition, or
deny new discharges or a significant increase in the discharge for existing significant
industrial users (SIUs) \[40 CFR 403.8 (f)(1)(i) and(iii)\].
Industrial dischargers must obtain a permit from Ecology before discharging waste to the
city of Port Townsend WWTP\[WAC 173-216-110(5)\]. Industries discharging
wastewater that is similar in character to domestic wastewater do not require a permit.
Routine Identification and Reporting of Industrial Users
The permit requires non-
identify all existing, new, and proposed significant industrial users (SIUs) and potential
f such
routine measures include regular review of water and sewer billing records;business
license and building permit applications, advertisements, and personal reconnaissance.
System maintenance personnel should be trained on what to look for so they can identify
and report new industrial dischargers in the course of performing their jobs. The POTW
may not allow SIUs to discharge prior to receiving a permit, and must notify all industrial
dischargers (significant or not) in writing of their responsibility to apply for a State Waste
Discharge Permit. The POTW must send a copy of this notification to Ecology.
Requirements for Performing an Industrial User Survey
This POTW has the potential to serve significant industrial or commercial users and must
conduct an Industrial User (IU) survey.The purpose of the IU Survey is to identify all
facilities that may be subject to pretreatment standards or requirements so that Ecology
can take appropriate measures to control these discharges. The POTW should identify
each such user, and require them to apply for a permit before allowing their discharge to
the POTW to commence. ForSIUs, the POTW must require they actually are issued a
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
permit prior to accepting their discharge. The steps the POTW must document in their IU
Survey submittal include:
1.The POTW must develop a master list of businesses that may be subject to
pretreatment standards and requirements and show their disposition. This list
must be based on several sources of information including business licenses, and
water and sewer billing records.
2.The POTW must canvas all the potential sources, having them either complete a
survey form or ruling them out by confirming they only generate domestic
wastewater.
3.The POTW must develop a list of the SIUs and potential SIUs in all areas served
by the POTW. The list must contain sufficient information on each to allow
Ecology to decide which discharges merit further controls such as a state waste
discharge permit.
Ecology describes the information needed in IUSurvey submittals to allow Ecology to
Properly completing an Industrial User Survey helps Ecology control discharges that may
otherwise harm the POTW including its collection system, processes, and receiving
waters. Where surveys are incomplete, Ecology may take such enforcement as
appropriate and/or require the POTW to develop a fully delegated pretreatment program.
The proposed permit requires the city of Port Townsendto conduct an industrial user
survey to determine the extent of compliance of all industrial users of the sanitary sewer
and wastewater treatment facility with federal pretreatment regulations \[40 CFR Part 403
and Sections 307(b) and 308 of the Clean Water Act)\], with state regulations (chapter
90.48 RCW and chapter 173-216 WAC), and with local ordinances.
E.Solid Wastes
To prevent water quality problems the facilityis required in permit Special Condition S7to store
and handle all residual solids (grit, screenings, scum, sludge, and other solid waste) in accordance
with the requirements of RCW 90.48.080 and state water quality standards.
The final use and disposal of sewage sludge from this facility is regulated by U.S. EPA under 40
CFR 503, and by Ecology under chapter 70.95J RCW, chapter 173-308 W
hapter 173-The disposal of
other solid waste is under the jurisdiction of the JeffersonCounty Health Department.
Requirements for monitoring sewage sludge and recordkeeping are included in this permit.
Ecology will use this information, requiredunder 40 CFR 503, to develop or update local limits.
F.Engineering Documents
The proposed permit includes a schedule for completion and submittal of engineering documents
for outfall replacement. The city of Port Townsend had submitted a 2009 Facility Plan
Amendment that selected a shorter outfall than the existing outfall as the preferred alternative for
outfall replacement. State agencies did not feel the plan considered impacts to marine vegetation
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
or shellfish resources. The feasibility of using reclaimed water should have also been discussed.
A new plan needs to be developed that addressesstated concerns and allows the outfall
replacement to move forward.
G.General Conditions
Ecology bases the standardized General Conditions on state and federal law and regulations.
They are included inall individual domestic wastewaterNPDES permits issued by Ecology.
VI.PERMIT ISSUANCE PROCEDURES
A.Permit Modifications
Ecologymay modify this permit to impose numerical limits, if necessary to comply with water
quality standardsfor surface waters, with sediment quality standards, or with water quality
standards for groundwaters, based onnewinformation from sources such as inspections, effluent
monitoring, outfall studies, and effluent mixing studies.
Ecologymay also modify this permit to comply withnew or amended state or federal regulations.
B.Proposed Permit Issuance
This proposed permit meets all statutory requirements for Ecology to authorize a wastewater
discharge.The permit includes limitsand conditions to protect human healthand aquatic life,
and the beneficial uses of waters of the state of Washington. Ecologyproposes to issue this
permit fora term offiveyears.
VII.REFERENCES FOR TEXT AND APPENDICES
CH2MHILL
2009.Facilities Plan for a
New Off-Shore Outfall.
Environmental Protection Agency (EPA)
1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992.
1991.Technical Support Document for Water Quality-based Toxics Control. EPA/505/2-90-001.
1988.Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling.
USEPA Office of Water, Washington, D.C.
1985.Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in
Surface and Ground Water. EPA/600/6-85/002a.
1983.Water Quality Standards Handbook. USEPA Office of Water, Washington, D.C.
Gray & Osborne, Inc.
2000.City of Port Townsend Wastewater Facilities Plan
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Moran, Bridget and Birch, Peter
2010. Letter to David Timmons, City of Port Townsend City Manager. Subject: Port Townsend
Sewage Outfall Replacement.
Tsivoglou, E.C., and J.R. Wallace.
1972.Characterization of Stream Reaeration Capacity. EPA-R3-72-012. (Cited in EPA 1985 op.cit.)
Washington State Department of Ecology.
December 2011.. Publication Number 92-109
(https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html)
September 2011. Water Quality Program Guidance Manual Supplemental Guidance on
Implementing Tier II Antidegradation. Publication Number 11-10-073
(https://fortress.wa.gov/ecy/publications/summarypages/1110073.html)
October 2010 (revised). Water Quality Program Guidance Manual Procedures to Implement the
. Publication Number 06-10-100
(https://fortress.wa.gov/ecy/publications/summarypages/0610100.html)
Laws and Regulations(http://www.ecy.wa.gov/laws-rules/index.html)
Permit and Wastewater Related Information
(http://www.ecy.wa.gov/programs/wq/permits/guidance.html)
Water Pollution Control Federation.
1976.Chlorination of Wastewater.
Wright, R.M., and A.J. McDonnell.
1979.In-stream Deoxygenation Rate Prediction. Journal Environmental Engineering Division,
ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
APPENDIX A--PUBLIC INVOLVEMENT INFORMATION
Ecologyproposesto reissue a permit to the city of Port Townsend Wastewater Treatment Plant. The
permit includeswastewater discharge limitsand other conditions. This fact sheet describes the facility
.
Ecology placed a Public Notice ofApplication on June 12, 2013; June 19, 2013;June 11, 2014; and
June18, 2014,in the Port Townsend Leaderto inform the public about the submitted application and to
invite comment on the reissuance of this permit.
Ecologywill place a Public Notice of Draft onJuly 29, 2015,in the Port Townsend Leader to inform the
public and to invite comment on the proposed draftNational Pollutant Discharge Elimination System
permit and fact sheet.
The notice:
Tells where copies of the draft permit and fact sheetare available for public evaluation(a local
public library, the closest regional or field office, posted on our website).
Offers to provide the documents in an alternate format to accommodate special needs.
Asks people to tell us how well the proposed permit would protect the receiving water.
Invites people to suggest fairer conditions, limits, and requirements for the permit.
I
Urges people to submit their comments, in writing, before the end of the comment period.
Tells how to request a public hearing about the proposed NPDES permit.
Explains the next step(s) in the permitting process.
Ecology has published a document entitled Frequently Asked Questions about Effective Public
Commenting,which is available on our website at
https://fortress.wa.gov/ecy/publications/SummaryPages/0307023.html.
You may obtain further information from Ecologyby telephone, 360-407-6278,by email at
carey.cholski@ecy.wa.gov,or by writing to the address listed below.
Water Quality Permit Coordinator
Department of Ecology
Southwest Regional Office
P.O. Box 47775
Olympia, WA98504-7775
The primary author of this permit and fact sheetis Dave Dougherty.
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
APPENDIX B --YOUR RIGHT TO APPEAL
You have a right to appeal this permit to the Pollution Control Hearing Board (PCHB) within 30 days of
the date of receipt of the final permit. The appeal process is governedby chapter43.21B RCW and
chapter 371-CW 43.21B.001(2)(see glossary).
To appeal you must do the following within 30 days of the date of receipt of this permit:
File your appeal and a copy of this permit with the PCHB (see addresses below). Filing means
actual receipt by the PCHB during regular business hours.
Serve a copy of your appeal and this permit on Ecology in paper form -by mail or in person.
(See addresses below.) E-mail is not accepted.
You must also comply with other applicable requirements in chapter 43.21B RCW and chapter 371-08
WAC.
ADDRESS AND LOCATION INFORMATION
Street Addresses
Mailing Addresses
Department of EcologyDepartment of Ecology
Attn: Appeals Processing DeskAttn: Appeals Processing Desk
300 Desmond Drive SoutheastP.O.Box 47608
Lacey, WA 98503Olympia, WA 98504-7608
Pollution Control Hearings Board Pollution Control Hearings Board
1111 Israel RoadSouthwest, Suite 301PO Box 40903
Tumwater, WA 98501Olympia, WA 98504-0903
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WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
APPENDIX C--GLOSSARY
1-DMax or 1-day Maximum Temperature --The highest water temperature reached on any given day.
This measure can be obtained using calibrated maximum/minimum thermometers or continuous
monitoring probes having sampling intervals of thirty minutes or less.
7-DADMax or 7-day Average Of The Daily Maximum Temperatures--The arithmetic average of
seven consecutive measures of daily maximum temperatures. The 7-DADMax for any individual
day is calculated by averaging that day's daily maximum temperature with the daily maximum
temperatures of the threedays prior and the three days after that date.
Acute Toxicity --The lethal effect of a compound on an organism that occurs in a short time period,
usually 48 to 96 hours.
AKART--n, control and
-based approach to limiting pollutants from wastewater
discharges, which requires an engineering judgment and an economic judgment. AKART must
be applied to all wastes and contaminants prior to entry into waters of the state in accordance with
RCW 90.48.010 and 520, WAC 173-200-030(2)(c)(ii), and WAC 173-216-110(1)(a).
Alternate Point of Compliance--An alternative location in the ground water from the point of
compliance where compliance with the ground water standards is measured. It may be established
in the ground water at locations some distance from the discharge source, up to, but not exceeding
the property boundary and is determined on a site specific basis following an AKART analysis.
of compliance must be determined and approved in accordance with WAC 173-200-060(2).
Ambient Water Quality--The existing environmental condition of the water in a receiving water body.
Ammonia--Ammonia is produced by the breakdown of nitrogenous materials in wastewater. Ammonia
is toxic to aquatic organisms, exerts an oxygen demand, and contributes to eutrophication. It also
increases the amount of chlorine needed to disinfect wastewater.
Annual Average Design Flow(AADF --average of the daily flow volumes anticipated to occur over a
calendar year.
Average Monthly Discharge Limit--The average of the measured values obtained over a calendar
month's time.
Background Water Quality--The concentrations of chemical, physical, biological or radiological
constituents or other characteristics in or of ground water at a particular point in time upgradient
of an activity that has not been affected by that activity, \[WAC 173-200-020(3)\]. Background
water quality for any parameter is statistically defined as the 95percentupper tolerance interval
with a 95percentconfidence based on at least eight hydraulically upgradient water quality
samples. The eight samples are collected over a period of at least one year, with no more than
one sample collected during any month in a single calendar year.
Best Management Practices(BMPs) --Schedules of activities, prohibitions of practices, maintenance
procedures, and other physical, structural and/or managerial practices to prevent or reduce the
pollution of waters of the state. BMPs include treatment systems, operating procedures, and
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FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage
from raw material storage. BMPs may be further categorized as operational, source control,
erosion and sediment control, and treatment BMPs.
BOD5--Determining the five-day Biochemical Oxygen Demand of an effluent is an indirect way of
measuring the quantity of organic material present in an effluent that is utilized by bacteria. The
BOD5 is used in modeling to measure the reduction of dissolved oxygen in receiving waters after
effluent is discharged. Stress caused by reduced dissolved oxygen levels makes organisms less
competitive and less able to sustain their species in the aquatic environment. Although BODis
5
not a specific compound, it is defined as a conventional pollutant under the federal Clean Water
Act.
Bypass--The intentional diversion of waste streams from any portion of a treatment facility.
Categorical Pretreatment Standards --National pretreatment standards specifying quantities or
concentrations of pollutants or pollutant properties, which may be discharged to a POTW by
existing or new industrial users in specific industrial subcategories.
Chlorine--A chemical used to disinfect wastewaters of pathogens harmful to human health. It is also
extremely toxic to aquatic life.
Chronic Toxicity--The effect of a compound on an organism over arelatively long time, often 1/10 of
an organism's lifespan or more. Chronic toxicity can measure survival, reproduction or growth
rates, or other parameters to measure the toxic effects of a compound or combination of
compounds.
Clean Water Act(CWA --The federal Water Pollution Control Act enacted by Public Law 92-500, as
amended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq.
Compliance Inspection-Without Sampling--A site visit for the purpose of determining the compliance
of a facility with the terms and conditions of its permit or with applicable statutes and regulations.
Compliance Inspection-With Sampling--A site visit for the purpose of determining the compliance of
a facility with the terms and conditions of its permit or with applicable statutes and regulations.
In addition it includes as a minimum, sampling and analysis for all parameters with limits in the
permit to ascertain compliance with those limits; and, for municipal facilities, sampling of
influent to ascertain compliance with the 85 percent removal requirement. Ecology may conduct
additional sampling.
Composite Sample--A mixture of grab samples collected at the same sampling point at different times,
formed either by continuous sampling or by mixing discrete samples. May be "time-composite"
(collected at constant time intervals) or "flow-proportional" (collected either as a constant sample
volume at time intervals proportional to stream flow, or collected by increasing the volume of
each aliquot as the flow increased while maintaining a constant time interval between the
aliquots).
Construction Activity--Clearing, grading, excavation, and any other activity, which disturbs the surface
of the land. Such activities may include road building; construction of residential houses, office
buildings, or industrial buildings; and demolition activity.
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NPDES PERMIT NO. WA0037052
Continuous Monitoring--Uninterrupted, unless otherwise noted in the permit.
Critical Condition--The time during which the combination of receiving water and waste discharge
conditions have the highest potential for causing toxicity in the receiving water environment.
This situation usually occurs when the flow within a water body is low, thus, its ability to dilute
effluent is reduced.
Date of Receipt This is defined in RCW 43.21B.001(2) as five business days after the date of mailing;
or the date of actual receipt, when the actual receipt date can be proven by a preponderance of the
evidence. The recipient's sworn affidavit or declaration indicating the date of receipt, which is
unchallenged by the agency, constitutes sufficient evidence of actual receipt. The date of actual
receipt, however, may not exceed 45days from the date of mailing.
Detection Limit--See Method Detection Level.
Dilution Factor (DF)--A measure of the amount of mixing of effluent and receiving water that occurs at
the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction, for
example, adilution factor of 10 means the effluent comprises 10percentby volume and the
receiving water 90percent.
Distribution Uniformity --The uniformity of infiltration (or application in the case of sprinkle or trickle
irrigation) throughout the field expressed as a percent relating to the average depth infiltrated in
the lowest one-quarter of the area to the average depth of water infiltrated.
Early Warning Value--The concentration of a pollutant set in accordance with WAC 173-200-070 that
is a percentageof an enforcement limit. It may be established in the effluent, ground water,
surface water, the vadose zone or within the treatment process. This value acts as a trigger to
detect and respond to increasing contaminant concentrations prior to the degradation of a
beneficial use.
Enforcement Limit--The concentration assigned to a contaminant in the ground water at the point of
compliance for the purpose of regulation, \[WAC 173-200-020(11)\]. This limit assures that a
ground water criterion will not be exceeded and that background water quality will be protected.
Engineering Report--A document that thoroughly examines the engineering and administrative aspects
of a particular domestic or industrial wastewater facility. The report must contain the appropriate
information required in WAC 173-240-060 or 173-240-130.
Fecal Coliform Bacteria--Fecal coliform bacteria are used as indicators of pathogenic bacteria in the
effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are controlled
by disinfecting the wastewater. The presence of high numbers of fecal coliform bacteria in a
water body can indicate the recent release of untreated wastewater and/or the presence of animal
feces.
Grab Sample--A single sample or measurement taken at a specific time or over as short a period of time
as is feasible.
Groundwater--Water in a saturated zone or stratum beneath the surface of land or below a surface
water body.
11/05/15Page 36
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Industrial User--A discharger of wastewater to the sanitary sewer that is not sanitary wastewater or is
not equivalent to sanitary wastewater in character.
Industrial Wastewater--Water or liquid-carried waste from industrial or commercial processes, as
distinct from domestic wastewater. These wastes may result from any process or activity of
industry, manufacture, trade or business; from the development of any natural resource; or from
animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated
storm water and, also, leachate from solid waste facilities.
Interference --A discharge which, alone or in conjunction with a discharge or discharges from other
sources, both:
Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge
processes, use or disposal; and
Thereforeis a cause of a violation of any requirement of the POTW's NPDES permit
(including an increase in the magnitude or duration of a violation) or of the prevention of
sewage sludge use or disposal in compliance with the following statutory provisions and
regulations or permits issued thereunder (or more stringent State or local regulations):
Section 405 of the Clean Water Act, the Solid Waste Disposal Act (SWDA) (including
title II, more commonly referred to as the Resource Conservation and Recovery Act
(RCRA), and including State regulations contained in any State sludge management plan
prepared pursuant to subtitle D of the SWDA), sludge regulations appearing in 40 CFR
Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine
Protection, Research and Sanctuaries Act.
Local Limits --Specific prohibitions or limits on pollutants or pollutant parameters developed by a
POTW.
Major Facility--A facility discharging to surface water with an EPA rating score of > 80 points based
on such factorsas flow volume, toxic pollutant potential, and public health impact.
Maximum Daily Discharge Limit--The highest allowable daily discharge of a pollutant measured
during a calendar day or any 24-hour period that reasonably represents the calendar day for
purposes of sampling. The daily discharge is calculated as the average measurement of the
pollutant over the day.
Maximum Day Design Flow (MDDF)--The largest volume of flow anticipated to occur during a one-
day period, expressed as a daily average.
Maximum Month Design Flow (MMDF)--The largest volume of flow anticipated to occur during a
continuous 30-day period, expressed as a daily average.
Maximum Week Design Flow (MWDF)--The largest volume of flow anticipated to occur during a
continuous seven-day period, expressed as a daily average.
Method Detection Level (MDL)--The minimum concentration of a substance that can be measured and
reported with 99 percent confidence that the pollutant concentration is above zero and is
determined from analysisof a sample in a given matrix containing the pollutant.
11/05/15Page 37
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Minor Facility--A facility discharging to surface water with an EPA rating score of < 80 points based
on such factors as flow volume, toxic pollutant potential, and public health impact.
Mixing Zone--An area that surrounds an effluent discharge within which water quality criteria may be
exceeded. The permit specifies the area of the authorized mixing zone that Ecology defines
following procedures outlined in state regulations (chapter 173-201A WAC).
National Pollutant Discharge Elimination System (NPDES)--The NPDES (Section 402 of the Clean
Water Act) is the federal wastewater permitting system for discharges to navigable waters of the
United States. Many states, including the state of Washington, have been delegated the authority
to issue these permits. NPDES permits issued by Washington State permit writers are joint
NPDES/State permits issued under both state and federal laws.
pH--The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the hydrogen
ion concentration. A pH of 7.0is defined as neutral and large variations above or below this value
are considered harmful to most aquatic life.
Pass-through --A discharge which exits the POTW into waters of the State in quantities or
concentrations which, alone or in conjunction with a discharge or discharges from other sources,
is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase
in the magnitude or duration of a violation), or which is a cause of a violation of State water
quality standards.
Peak Hour Design Flow (PHDF)--The largest volume of flow anticipated to occur during a
one-hour period, expressed as a daily or hourly average.
Peak Instantaneous Design Flow (PIDF)--The maximum anticipated instantaneous flow.
Point of Compliance--The location in the ground water where the enforcement limit must not be
exceeded and a facility must comply with the Ground Water Quality Standards. Ecology
determines this limiton a site-specific basis.Ecology locates the point of compliance in the
ground water as near and directly downgradient from the pollutant source as technically,
hydrogeologically, and geographically feasible, unless it approves an alternative point of
compliance.
Potential Significant Industrial User (PSIU) --A potential significant industrial user is defined as an
Industrial User that does not meet the criteria for a Significant Industrial User, but which
discharges wastewater meeting one or more of thefollowing criteria:
ğ.Exceeds 0.5 percentof treatment plant design capacity criteria and discharges <25,000
gallons per day or;
b.Is a member of a group of similar industrial users which, taken together, have the
potential to cause pass through or interference at the POTW (e.g. facilities which develop
photographic film or paper, and car washes).Ecology may determine that a discharger
initially classified as a potential significant industrial user should be managed as a
significant industrial user.
Quantitation Level (QL)--Also known as Minimum Level of Quantitation (ML) The lowest level at
which the entire analytical system must give a recognizable signal and acceptable calibration
11/05/15Page 38
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
point for the analyte. It is equivalent to the concentration of the lowest calibration standard,
assuming that the lab has used all method-specified sample weights, volumes, and cleanup
procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the
n
number nearest to (1,2,or 5) x 10, where n is an integer (64 FR 30417). ALSO GIVEN AS:
The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the
accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of the
Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water
Act Programs Submitted to the US Environmental Protection Agency December 2007).
Reasonable Potential--A reasonable potential to cause a water quality violation, or loss of sensitive
and/or important habitat.
Responsible Corporate Officer--A president, secretary, treasurer, or vice-president of the corporation
in charge of a principal business function, or any other person who performs similar policy-or
decision-making functions for the corporation, or the manager of one or more manufacturing,
production, or operating facilities employing more than 250 persons or have gross annual sales or
expenditures exceeding $25 million (in second quarter 1980 dollars), if authority to sign
documents has been assigned or delegated to the manager in accordance with corporate
procedures (40 CFR 122.22).
Significant Industrial User (SIU) --
a.All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6
and 40 CFR Chapter I, Subchapter N;and
b.Any other industrial user that: discharges an average of 25,000 gallons per day or more of
process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler
blow-down wastewater); contributes a process wastestream that makes up 5 percent or
more of the average dry weather hydraulic or organic capacity of the POTW treatment
plant; or is designated as such by the Control Authority* on the basis that the industrial
user has a reasonable potential for adversely affecting the POTW's operation or for
violating any pretreatment standard or requirement \[in accordance with 40 CFR
403.8(f)(6)\].
Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no reasonable
potential for adversely affecting the POTW's operation or for violating any pretreatment standard
or requirement, the Control Authority* may at any time, on its own initiative or in response to a
petition received from an industrial user or POTW, and in accordance with 40 CFR 403.8(f)(6),
determine that such industrial user is not a significant industrial user.
*The term "Control Authority" refers to the Washington State Department of Ecology in the case
of non-delegated POTWs or to the POTW in the case of delegated POTWs.
SlugDischarge --Any discharge of a non-routine, episodic nature, including but not limited to an
accidental spill or a non-customary batch discharge to the POTW. This may include any
pollutant released at a flow rate that may cause interference or pass through with the POTW or in
Soil Scientist --An individual who is registered as a Certified or Registered Professional Soil Scientist or
as a Certified Professional Soil Specialist bythe American Registry of Certified Professionals in
11/05/15Page 39
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
Agronomy, Crops, and Soils or by the National Society of Consulting Scientists or who has the
credentials for membership. Minimum requirements for eligibility are: possession of a
baccalaureate, masters, or doctorate degree from a U.S. or Canadian institution with a minimum
of 30 semester hours or 45 quarter hours professional core courses in agronomy, crops or soils,
and have five,three,or oneyears, respectively, of professional experience working inthe area of
agronomy, crops, or soils.
Solid Waste--All putrescible and non-putrescible solid and semisolid wastes including, but not limited
to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and construction
wastes, abandoned vehicles or parts thereof, contaminated soils and contaminated dredged
material, and recyclable materials.
Soluble BOD--Determining the soluble fraction of Biochemical Oxygen Demand of an effluent is an
5
indirect way of measuring the quantity of soluble organic material present in an effluent that is
utilized by bacteria. Although the soluble BODtest is not specifically described in Standard
5
Methods, filtering the raw sample through at least a 1.2 um filter prior to running the standard
BODtest is sufficient to remove the particulate organic fraction.
5
State Waters--Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all
other surface waters and watercourses within the jurisdiction of the state of Washington.
Stormwater--That portion of precipitation that does not naturally percolate into the ground or evaporate,
but flows via overland flow, interflow, pipes, and other features of a storm water drainage system
into a defined surface water body, or a constructed infiltration facility.
Technology-Based Effluent Limit --A permit limit based on the ability of a treatment method to reduce
thepollutant.
Total Coliform Bacteria--A microbiological test, which detects and enumerates the total coliform group
of bacteria in water samples.
Total Dissolved Solids--That portion of total solids in water or wastewater that passes through a specific
filter.
Total Suspended Solids (TSS)--Total suspended solids is the particulate material in an effluent. Large
quantities of TSS discharged to a receiving water may result in solids accumulation. Apart from
any toxic effects attributable to substances leached out by water, suspended solids may kill fish,
shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills and
respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen out light
and can promote and maintain the development of noxious conditions through oxygen depletion.
Upset --An exceptional incident in which there is unintentional and temporary noncompliance with
technology-based permit effluent limits because of factors beyond the reasonable control of the
Permittee. An upset does not include noncompliance to the extent caused by operational error,
improperly designed treatment facilities, lack of preventative maintenance, or careless or
improper operation.
Water Quality-Based Effluent Limit--A limit imposed on the concentration of an effluent parameter to
prevent the concentration of that parameter from exceeding its water quality criterion after
discharge into receiving waters.
11/05/15Page 40
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
APPENDIX D--TECHNICAL CALCULATIONS
Several of the
water quality standards can be found in the PermitCalc workbook webpage at:
http://www.ecy.wa.gov/programs/wq/permits/guidance.html.
Simple Mixing:
Ecology uses simple mixing calculations to assess the impacts of certain conservative pollutants,
such as the expected increase in fecal coliform bacteria at the edge of the chronic mixingzone
boundary. Simple mixing uses a mass balance approach to proportionally distribute a pollutant
load from a discharge into the authorized mixing zone. The approach assumes no decay or
generation of the pollutant of concern within the mixing zone. The predicted concentration at the
edge of a mixing zone (C) is based on the following calculation:
mz
C=
mz
where
Ce = Effluent Concentration
:
Ca = Ambient Concentration
DF = Dilution Factor
Reasonable Potential Analysis:
The spreadsheets Input 2 Reasonable Potential, and LimitCalcPermitCalc
Workbook determine reasonable potential (to violate the aquatic life and human health water
quality standards) and calculate effluent limits. The process and formulas for determining
reasonable potential and effluent limits in these spreadsheets are taken directly from the
Technical Support Document for Water Quality-based Toxics Control, (EPA 505/2-90-001). The
adjustment for autocorrelation is from EPA (1996a), and EPA (1996b).
11/05/15Page 41
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
APPENDIX E--RESPONSE TO COMMENTS
A public comment period was held from July 29, 2015, to August 28, 2015. During the comment period,
the following comments were received from Mr. Kenneth Clow, Public Works Director, City of Port
Townsend (City).
Comment 1:
Special Condition S5 -Operation and Maintenance. The final sentence of the introductory
paragraph This provision of the permit requires the Permittee to operate backup or auxiliary
facilities or similar systems only when the operation is necessary to achieve compliance with
conditions of this permitis unclear. We are not sure what this requirement allows or does not
allow the Permittee to do. Please clarify what this means for the operation of our wastewater
treatment and collection systems.
Response 1:
The sentence is part of the standard boilerplate language used for NPDES permits. The final
sentence appears to clarify the first sentence of the same paragraph. The first sentence reads: The
Permittee must at all times properly operate and maintain all facilities and systems of treatment
and control (and related appurtenances), which are installed to achieve compliance with the
terms and conditions of this permit.This first sentence could be construed as meaning even
redundant backup or auxiliary systems would need to be operated at all times. The final sentence
in question therefore clarifies that backup or auxiliary systems only need to operate as necessary.
If the Permittee is still not sure how to apply this requirement, Ecology would be happy to discuss
further the application to specific components of the wastewater treatment and collection systems.
Comment 2:
Special Condition S9 Engineering Documents for Outfall Replacement Concern with
schedule. Currently, the City has identified this project in our six-year Capital Improvements
Program (CIP) with engineering/design scheduled in 2019 and construction to begin in 2020.
One reason for this schedule concerns the impact of the project cost on City utility ratepayers.
The City is preparing to break ground on a new water treatment facility mandated by federal and
state regulations and a replacement for our 5 million gallon water storage reservoir. These new
facilities are expected to cost in the neighborhood of
approximately 4700 water customers. New surcharges to pay for the water projects will nearly
double the water charges paid by our customers. We are trying to avoid adding to the rates for
sewer projects for as long as reasonably possible. With that in mind the City desires to maintain
our current schedule of engineering/design completion in 2019 and construction initiation in
2020. Also the exact schedule for securing funding for this project has not been developed.
Funding cycles for Public Works Trust Fund and other grant and loan programs need to be taken
into account as the wastewater utility fund does not have sufficient cash on hand to fully pay for a
project of this scope.
We recognize that the proposedcompletion date for an approvable engineering report of
this date remains in the permit the City requests that the submission date for approvable plans and
specifications of June 30, 2019 (Special Condition S9.D) be extended by six months to December
31, 2019. Given the regulatory climate, intergovernmental/tribal coordination, and permitting
11/05/15Page 42
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
requirements for this type of project we believe that six months is not sufficient time to produce
the project documents that would conform to the permit conditions as these conditions evolve
throughout the design process.
Response 2:
Ecology changed the due date for plans and specifications in Special Condition S9.D to
December 31, 2019, as requested. Ecology realizes it may take time to work through the
permitting and funding issues associated with the outfall. Ecology would also be willing to help
the Permittee with grant and loan programs. Ecology administers the Clean Water State
Revolving Fund and the Centennial Clean Water Fund with application periods each fall.
Funding for planning and design is available and can be applied for in the fall and then funds
would become available the following July. The permit does not include a deadline for outfall
construction, as Ecology understands that the schedule for final construction may depend on
success in securing funding.
Comment 3:
Special Condition S9 Engineering Documents for Outfall Replacement Alternative Selection
for a new outfall and select an alternative that is an improvement over the present discharge
The City takes exceptionto the highlighted criteria. The project is
being undertaken because the existing outfall is reaching the end of its useful life and is failing.
We are not aware that the current location of the outfall is a problem. We recognize that the
design of a new outfall is subject to a variety of factors functional, environmental, and
economic. The best alternative will meet the state and federal design requirements for outfall
structures while minimizing the impacts to the surrounding environment and to theutility
Response3:
s report shall describe the options for a new outfall and select an outfall configuration that
allows the Permittee to meet applicable State Water Quality Standards
for Special Condition S9 was taken from the February22, 2010,joint letter from Washington
State Department of Natural Resources (DNR) and the Department of Fish and Wildlife (DFW)
to David Timmons of the c
order to protect marine vegetation and re-open North Beach to shellfish harvest, we believe that
animprovement over the present locationwas a paraphrase of the letter conclusion. While
Ecology changed the permit to better reflect our issues, the Permittee needs to meet the
requirements of all agencies, and should realize that some of the mitigation required for
construction impacts may involve an ultimate outcome that is an improvement of thepresent
condition.
Comment 4:
Given the scope and complexity of the outfall project from a technical, permitting, and funding
perspective we believe that the best solution would be to remove Special Condition S9 from the
11/05/15Page 43
FACT SHEET FOR CITY OF PORT TOWNSEND
WASTEWATER TREATMENT PLANT
NPDES PERMIT NO. WA0037052
permit completely and to addressthe Department of Ecology concerns with the outfall through a
separate Administrative Order process. This would give the Department and the City sufficient
time to work together to develop appropriate, realistic schedules and the project scope.
Response4:
Ecology tried to develop Special Condition S9 as a reasonable schedule to complete outfall
construction, taking into consideration the complexity of the outfall project. The schedule is also
intended as a means to enforce the schedule that the Permittee already seemed to be on.
started again. At this point, an Adminstrive Order would be additional work and delay that would
not seem to provide any benefit over the present permit condition.
These were the only comments received during the 30-day public comment period. After the comment
period closed, some comments from Richard A. Smith on behalf of Puget Soundkeeper Alliance were
submitted. As these comments did not cause any changes to the permit or fact sheet,and were not
submitted during the comment period, they were responded to in a separate letter.
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Page 1of 44
Permit No. ST 6127
Issuance Date: May 28, 2019
Effective Date: July 1, 2019
Expiration Date: June 30, 2024
STATE WASTE DISCHARGE PERMIT NUMBER ST6127
State of Washington
DEPARTMENT OF ECOLOGY
Southwest Regional Office
PO Box 47775
Olympia, WA 98504-7775
In compliance with the provisions of the
State of Washington Water Pollution Control Law
Chapter 90.48 Revised Code of Washington, as amended,
City of Port Townsend Compost Facility
250 Madison Street, Suite 2R
Port Townsend, WA 98368
is authorized to discharge wastewater in accordance with the special and general conditions
which follow.
Plant Location:Discharge Location:
603 County Landfill RoadLegal Description : SE ¼ SW ¼ Section8,
Port Townsend, WA 98368Range1W, Township30N
Treatment Type
Sequencing Batch Reactor (SBR) with Wetlands and Rapid Infiltration
Originally-Signed Permit is in Public Files
Richard Doenges
Southwest Region Manager
Water Quality Program
Washington State Department of Ecology
Page 2of 44
Permit No. ST 6127
TABLE OF CONTENTS
SUMMARY OF PERMIT REPORT SUBMITTALS.............................................................................4
SPECIAL CONDITIONS..........................................................................................................................5
S1.DISCHARGE LIMITS....................................................................................................................5
A.Effluent Limits....................................................................................................................5
B.Best Management Practices/Pollution Prevention..............................................................6
S2.MONITORING REQUIREMENTS................................................................................................6
A.Wastewater Monitoring......................................................................................................6
B.Groundwater Monitoring....................................................................................................7
C.Sampling and Analytical Procedures..................................................................................8
D.Flow MeasurementandField Measurement Devices.........................................................9
E.Laboratory Accreditation....................................................................................................9
S3.REPORTING AND RECORDING REQUIREMENTS.................................................................9
A.Discharge Monitoring Reports..........................................................................................10
B.Permit Submittals and Schedules......................................................................................11
C.Records Retention.............................................................................................................12
D.Recording of Results.........................................................................................................12
E.Additional Monitoring by the Permittee...........................................................................12
F.Reporting Permit Violations.............................................................................................12
G.Other Reporting................................................................................................................14
H.MAINTAINING A COPY OF THIS PERMIT................................................................15
S4.FACILITY LOADING..................................................................................................................15
A.Design Criteria..................................................................................................................15
B.Plans for Maintaining Adequate Capacity........................................................................15
C.Duty to Mitigate................................................................................................................16
D.Notification of New or Altered Sources...........................................................................16
E.Wasteload Assessment......................................................................................................16
S5.OPERATION AND MAINTENANCE.........................................................................................17
A.Certified Operator.............................................................................................................17
B.Operation and Maintenance Program...............................................................................17
C.Short-Term Reduction......................................................................................................17
D.Electrical Power Failure....................................................................................................18
E.Bypass Procedures............................................................................................................18
F.Operations and Maintenance Manual...............................................................................20
G.InfiltrationLand Application Best Management Practices...............................................21
S6.PRETREATMENT........................................................................................................................22
A.General Requirements.......................................................................................................22
B.Duty to Enforce Discharge Prohibitions...........................................................................22
S7.SOLID WASTES.............................................................................................................................23
A.Solid Waste Handling.......................................................................................................23
B.Leachate............................................................................................................................24
S8.APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR
FACILITY CHANGES....................................................................................................24
Page 3of 44
Permit No. ST 6127
GENERAL CONDITIONS......................................................................................................................25
G1.SIGNATORY REQUIREMENTS.................................................................................................25
G2.RIGHT OF ENTRY.......................................................................................................................25
G3.PERMIT ACTIONS.......................................................................................................................26
G4.REPORTING A CAUSE FOR MODIFICATION........................................................................26
G5.PLAN REVIEW REQUIRED.......................................................................................................26
G6.COMPLIANCE WITH OTHER LAWS AND STATUTES.........................................................26
G7.TRANSFER OF THIS PERMIT...................................................................................................26
G8.PAYMENT OF FEES....................................................................................................................27
G9.PENALTIES FOR VIOLATING PERMIT CONDITIONS..........................................................27
G10.DUTY TO PROVIDE INFORMATION.......................................................................................27
G11.DUTY TO COMPLY....................................................................................................................27
G12.SERVICE AGREEMENT REVIEW.............................................................................................27
APPENDIX A............................................................................................................................................28
Page 4of 44
Permit No. ST 6127
SUMMARY OF PERMIT REPORT SUBMITTALS
Refer to the Special and General Conditions of this permit for additional submittal requirements.
Permit
SubmittalFrequencyFirst Submittal Date
Section
S3.ADischarge Monitoring Report (DMR)MonthlyAugust 15, 2019
S3.ADischarge Monitoring Report (DMR)QuarterlyOctober 15, 2019
S3.ADischarge Monitoring Report (DMR)AnnualJanuary 15, 2021
S3.FReporting Permit ViolationsAs necessary
S4.BPlans for Maintaining Adequate CapacityAs necessary
S4.DNotification of New or Altered SourcesAs necessary
S4.EWasteload Assessment1/permit cycleJune 1, 2022
S5.FReporting BypassesAs necessary
Operations and Maintenance Manual
S5.GAs necessary
Update
S8.Application for Permit Renewal1/permit cycleFebruary 1, 2024
G1Notice of Change in AuthorizationAs necessary
Permit Application for Substantive
G4As necessary
Changes to the Discharge
Engineering Report for Construction or
G5As necessary
Modification Activities
G7Notice of Permit TransferAs necessary
G10Duty to Provide InformationAs necessary
G12Contract SubmittalAs necessary
Page 5of 44
Permit No. ST 6127
SPECIAL CONDITIONS
S1.DISCHARGE LIMITS
A.Effluent Limits
All discharges and activities authorized by this permit must comply with the terms and
conditions of this permit. The discharge of any of the following pollutants more frequently
than, or at a concentration in excess of, that authorized by this permit violates the terms
and conditions of this permit.Wastewater flows and loadings must not exceed the Design
Criteria specified in Section S4.
Beginning on the effective date, the Permittee is authorized to discharge treated domestic
wastewater to infiltration basinsat the permitted location subject to the following limits:
Effluent Limits: SBR Effluent
Latitude48.10117Longitude-122.83416
ab
ParameterAverage Monthly Average Weekly
30milligrams/liter (mg/L)
Biochemical Oxygen 45mg/L
1 pound/day (lbs/day)
Demand (BOD)1.5lbs/day
5
85% removal of influent BOD
5
30 mg/L
Total Suspended Solids 45mg/L
1 lbs/day
(TSS)1.5lbs/day
85% removal of influent TSS
d
ParameterMinimumMaximum
e
pH 6.0Standard Units(SU)9.0SU
Effluent Limits: Wetland Influent
7-dayGeometric
ParameterMonthly Geometric Mean
Mean
c
Fecal Coliform 200 col./100 mL400 col./10 mL
ab
ParameterAverage Monthly Average Weekly
Total Residual Chlorine0.5 mg/L0.75 mg/L
Effluent Limit: Wetland Effluent
ab
ParameterAverage Monthly Average Weekly
Nitrate10 mg/L as N-----
aAverage monthly effluent limit means the highest allowable average of daily
discharges over a calendar month. To calculate the discharge value to compare to the
limit, you add the value of each daily discharge measured during a calendar month
and divide this sum by the total number of daily discharges measured.
bAverage weekly discharge limit means the highest allowable average of daily
discharges over a calendar week, calculated as the sum of all daily discharges
measured during a calendar week divided by the number of daily discharges measured
during that week. See footnote c for fecal coliform calculations.
Page 6of 44
Permit No. ST 6127
Effluent Limits: SBR Effluent
Latitude48.10117Longitude-122.83416
cThe Department of Ecology (Ecology) provides directions to calculate the monthly
and the 7-day geometric mean in publication No. 04-10-020, Information Manual
for Treatment Plant Operators available at:
https://fortress.wa.gov/ecy/publications/SummaryPages/0410020.html
dMaximum daily effluent limit means the highest allowable daily discharge. The daily
discharge means the maximum discharge of a pollutant measured during a calendar
day. For pollutants with limits expressed in units of mass, calculate the daily
discharge as the total mass of the pollutant discharged over the day. For other units
of measurement, the daily discharge is the average measurement of the pollutant over
the day. This does not apply to pH or temperature.
eThe Permittee must report the instantaneous maximum and minimum pH monthly.
Do not average pH.
B.Best Management Practices/Pollution Prevention
The Permittee must comply with the following Best Management Practices to prevent
pollution to waters of the State:
1.Do notdischarge in excess of the hydraulic capacity of the infiltration basins so
that the pond overflows.
2.Do notdischarge priority pollutants, dangerous wastes, or toxics in toxic amounts.
S2.MONITORING REQUIREMENTS
A.Wastewater Monitoring
The Permittee must monitor the wastewater prior to discharging into the infiltration basins.
The Permittee must monitor in accordance with the following schedule and the
requirements specified in Appendix A.
Minimum
ParameterUnitsSampling Sample Type
Frequency
(1) Wastewater Influent
Wastewater Influent means flow from into the SBR, excluding any side-stream returns from
inside the plant.
ab
BODmg/L2/monthGrab
5
ac
BODlbs/day2/monthCalculated
5
ab
TSSmg/L2/monthGrab
ac
TSSlbs/day2/monthCalculated
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Permit No. ST 6127
Minimum
ParameterUnitsSampling Sample Type
Frequency
(2)SBR Effluent
SBR Effluent means wastewater which is exiting, or has exited, the SBR.
Daily or Per
Flowgallons/day (gpd)Measurement
Batch
ab
BODmg/L2/month Grab
5
ac
BODlbs/day2/month Calculated
5
ad
BOD% Removal2/month Calculated
5
ab
TSSmg/L2/month Grab
ac
TSSlbs/day2/month Calculated
ad
TSS% Removal2/month Calculated
ab
pHSU2/month Grab
(3)Wetland Influent
Chlorine (Total
ab
mg/L2/month Grab
Residual)
#Organisms /100
ab
Fecal Coliform2/month Grab
ml
(4)Wetland Effluent Final Wastewater Effluent
ab
Nitrate (as N)mg/L as N2/month Grab
ab
pHStandard Units2/month Grab
aTwo (2)/month is defined as two times during each calendar month.
bGrab means an individual sample collected over a 15 minute, or less,period.
cCalculation means figured concurrently with the respective sample, using the following
formula: Concentration (in mg/L) X Flow (in MGD) X Conversion Factor (8.34) =
lbs/day
dPercent (%)removal = (Influent concentration (mg/L) Effluent concentration (mg/L)
x 100Influent BOD(mg/L)
5
Calculate the percent (%) removal of BODand TSS using the above equation.
5
B.Groundwater Monitoring
The Permittee must monitor groundwater at monitoring wellMW-1-93in accordance
with the following schedule and the requirements specified in Appendix A.
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Permit No. ST 6127
Units & Sampling
ParameterSample Type
SpeciationFrequency
ba
pHSUQuarterly Grab
ba
ConductivityMicromho/cmQuarterly Grab
cba
Total Coliform #/100 mLQuarterly Grab
Measured Depth to Feet
ba
Quarterly Grab
Groundwater(nearest 0.1 ft)
b
TemperatureDegrees CQuarterly Field Measurement
b
Nitrate (as N)mg/L as NQuarterly Field Measurement
da
Chloridemg/LAnnually Grab
da
Sulfatemg/LAnnually Grab
Total Dissolved
da
mg/LAnnually Grab
Solids
da
Iron (Total)mg/LAnnually Grab
da
Manganesemg/LAnnually Grab
da
Leadmg/LAnnually Grab
da
Chromiummg/LAnnually Grab
da
Arsenicmg/LAnnually Grab
aGrab means an individual sample collected over a 15 minute, or less, period.
bQuarterly is defined as January March, April June, July September, and
October December,starting July 1, 2019.
cReport a numerical value for Total Coliforms following the procedures in
Publication Number 04-10-020 available at:
https://fortress.wa.gov/ecy/publications/SummaryPages/0410020.html.Do not
report a result as Too Numerous To Count (TNTC).
dAnnually is defined as January December,starting January 1, 2020.
C.Sampling and Analytical Procedures
Samples and measurements taken to meet the requirements of this permit must represent
the volume and nature of the monitored parameters, including representative sampling of
any unusual discharge or discharge condition, including bypasses, upsets and maintenance-
related conditions affecting effluent quality.
Groundwatersampling must conform to the latest protocols in the Implementation
Guidance for the Ground Water Quality Standards, (Ecology 1996).
Sampling and analytical methods used to meet the water and wastewater monitoring
requirements specified in this permit must conform to the latest revision of thefollowing
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Permit No. ST 6127
rules and documents unless otherwise specified in this permit or approved in writing by the
Department of Ecology(Ecology).
Guidelines Establishing Test Procedures for the Analysis of Pollutants contained
in 40 Code of Federal Regulation (CFR)Part 136
Standard Methods for the Examination of Water and Wastewater (APHA)
The Permittee must conduct and report all soil analysis in accordance with the Western
States Laboratory Plant, Soil and Water Analysis Manual, Soil, Plant And Water Reference
Methods for The Western Region, 4th Edition,2013. You can find more information at:
http://www.naptprogram.org/files/napt/publications/method-papers/western-states-
methods-manual-2013.pdf.
D.FlowMeasurementandField Measurement Devices
The Permittee must:
1.Select and use appropriate flow measurementand field measurement devicesand
methods consistent with accepted scientific practices.
2.Install, calibrate, and maintain these devices to ensure the accuracy of the
measurements is consistent with the accepted industry standard, the
peration and Maintenance
(O&M) Manual procedures for the device and the wastestream.
3.Use field measurement devices as directed by the manufacturer and do not use
reagents beyond their expiration dates.
4.Establish a calibration frequency for each device or instrument in the O&M manual
that conforms to the frequency recommended by the manufacturer.
5.Calibrate flow monitoring devices at a minimum frequency of at least one
calibration per year.
6.Maintain calibration records for at least three years.
E.Laboratory Accreditation
The Permittee must ensure that all monitoring data required by Ecology for permit
specified parameters is prepared by a laboratory registered or accredited under the
provisions of chapter 173-50Washington Administrative Code (WAC),Accreditation of
Environmental Laboratories. Flow, temperature, Settleable Solids,conductivity, pH, and
internal process control parameters are exempt from this requirement.The Permittee must
obtain accreditation for conductivity and pH if it must receive accreditation or registration
for other parameters.
S3.REPORTING AND RECORDING REQUIREMENTS
The Permittee must monitor and report in accordance with the following conditions. Falsification
of information submitted to Ecology is a violation of the terms and conditions of this permit.
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Permit No. ST 6127
A.Discharge Monitoring Reports
The first monitoring period begins on the effective date of the permit (unless otherwise
specified).The Permittee must:
1.Summarize, report, and submit monitoring data obtained during each monitoring
period on the electronic Discharge Monitoring Report (DMR) form provided by
Ecology within the Water Quality Permitting Portal. Include data for each of the
parameters tabulated in Special Condition S2 and as required by the form. Report
a value for each day sampling occurred (unless specifically exempted in the
permit) and for the summary values (when applicable) included on the electronic
form.
To find out more information and to sign up for the Water Quality Permitting
Portal go to: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-
assistance/Water-quality-permits-guidance/WQWebPortal-guidance.
2.No Discharge
monitoring point, or for a specific parameter as appropriate, if the Permittee did
not discharge wastewater or a specific pollutant during a given monitoring period.
3.Detection Level
vel (e.g. <
2.0) on the DMR.If the method used did not meet the minimum DL and
Quantitation Level (QL) identified in the permit, report the actual QL and DL in
the comments or in the location provided.
4.Do notreportzero for bacteria monitoring. Report as required by the laboratory
method.
5.Calculate and report an arithmetic average value for each day for bacteria if
multiple samples were taken in one day.
6.Calculate the geometric mean values for bacteria (unless otherwise specified in the
permit) using:
a.The reported numeric value for all bacteria samples measured above the
detection value except when it took multiple samples in one day. If the
Permittee takes multiple samples in one day it must use the arithmetic
average for the day in the geometric mean calculation.
b.The detection value for those samples measured below detection.
7.Report the test method used for analysis in the comments if the laboratory used an
alternative method not specified in the permit and as allowed inAppendix A.
8.Calculate average values and calculated total values (unless otherwise specified in
the permit) using:
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Permit No. ST 6127
a.The reported numeric value for all parameters measured between the
agency-required detection value and the agency-required quantitation
value.
b.One-half the detection value (for values reported below detection) if the
lab detected the parameter in another sample from the same monitoring
point for the reporting period.
c.Zero (for values reported below detection) if the lab did not detect the
parameter in another sample for the reporting period.
9.Report single-sample grouped parameters (for example: priority pollutants, PAHs,
pulp and paper chlorophenolics, TTOs) on the WQWebDMR form and include:
sample date, concentration detected, DL (as necessary), and laboratory QL (as
necessary).
The Permittee must also submit an electronic copy of the laboratory report as an
attachment using WQWebDMR. The contract laboratory reports must also include
information on the chain of custody, QA/QC results, and documentation of
accreditation for the parameter.
10.Ensure that DMRs are electronically submitted no later than the dates specified
below, unless otherwise specified in this permit.
11.Submit DMRs for parameters with the monitoring frequencies specified in S2
(monthly, quarterly, annual, etc.) at the reporting schedule identified below. The
Permittee must:
th
a.Submit monthlyDMRs by the 15day of the following month.
b.Submit quarterlyDMRs, unless otherwise specified in the permit, by the
th
15day of the month following the monitoring period.
c.Submit annualDMRs, unless otherwise specified in the permit, by
th
January 15for the previous calendar year.
B.Permit Submittals and Schedules
The Permittee mayuse the Water Quality Permitting Portal Permit Submittals application
(unless otherwise specified in thepermit) to submit all other writtenpermit-required reports
by the date specified in the permit.
When another permit condition requires submittal of a paper(hard-copy)report, the
Permittee must ensure that it is postmarked or received by Ecology no later than the dates
specified by this permit. Send these paper reports to Ecology at:
Water Quality Permit Coordinator
Department of Ecology
Southwest Regional Office
POBox 47775
Olympia, WA 98504-7775
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Permit No. ST 6127
C.Records Retention
The Permittee must retain records of all monitoring information for a minimum of three
years. Such information must include all calibration and maintenance records and all
original recordings for continuous monitoring instrumentation, copies of all reports
required by this permit, and records of all data used to complete the application for this
permit. The Permittee must extend this period of retention during the course of any
unresolved litigation regarding the discharge of pollutants by the Permittee or when
requested by Ecology.
The Permittee must retain all records pertaining to the monitoring of sludge for a minimum
of five years.
D.Recording of Results
For each measurement or sample taken, the Permittee must record the following
information:
1.The date, exact place and time of sampling.
2.The individual who performed the sampling or measurement.
3.The dates the analyses were performed.
4.The individual who performed the analyses.
5.The analytical techniques or methods used.
6.The results of all analyses.
E.Additional Monitoring by the Permittee
If the Permittee monitors any pollutant more frequently than required by Special Condition
S2 of this permit, then the Permittee must include the results of such monitoring in the
calculation and reporting of the datasubmitted in the Permittee's DMRunless otherwise
specified by Special Condition S2.
F.Reporting Permit Violations
The Permittee must take the following actions when it violates or is unable to comply with
any permit condition:
1.Immediately take action to stop, contain, and cleanup unauthorized discharges or
otherwise stop the noncompliance and correct the problem.
2.If applicable, immediately repeat sampling and analysis. Submit the results of any
repeat sampling to Ecology within 30 days of sampling.
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Permit No. ST 6127
a.Immediate Reporting
The Permittee must immediately report to Ecology (at the number listed
below), all:
Failures of the disinfection system
Collection system overflows
Plant bypasses resulting in a discharge
Any other failures of the sewage system (pipe breaks, etc)
Overflows or leaks of transmission or irrigation pipelines that
discharge to a waterbody used as a source of drinking or irrigation
water.
Southwest Regional Office360-407-6300
b.Twenty-Four-Hour Reporting
The Permittee must report the following occurrences of noncompliance by
telephone, to Ecology at the telephone numberlisted above, within 24
hours from the time the Permittee becomes aware of any of the following
circumstances:
i.Any noncompliance that may endanger health or the environment,
unless previously reported under immediate reporting
requirements.
ii.Any unanticipated bypass that causes an exceedance of aneffluent
iii.Any upset that causes an exceedance of aneffluent limit in the
permit. Upset means an exceptional incident in which there is
unintentional and temporary noncompliance with technology-
based permit effluent limits because of factors beyond the
reasonable control of the Permittee. An upset does not include
noncompliance to the extent caused by operational error,
improperly designed treatment facilities, inadequate treatment
facilities, lack of preventive maintenance, or careless or improper
operation.
iv.Any violation of a maximum daily or instantaneous maximum
discharge limit for any of the pollutants in Section S1.A of this
permit.
v.Any overflow prior to the treatment works, whether or not such
overflow endangers health or the environment or exceeds any
effluent limit in the permit.
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Permit No. ST 6127
c.Report Within Five Days
The Permittee must also submit a written report within five days of the
time that the Permittee becomes aware of any reportable eventunder
subparts a or b, above. The report must contain:
i.A description of the noncompliance and its cause.
ii.Maps, drawings,aerial photographs,or pictures to show the
location and cause(s) of the non-compliance.
iii.The period of noncompliance, including exact dates and times.
iv.The estimated time the Permittee expects the noncompliance to
continue if not yet corrected.
v.Steps taken or planned to reduce, eliminate, and prevent
recurrence of the noncompliance.
vi.If the noncompliance involves an overflow prior to the treatment
works, an estimate of the quantity (in gallons) of untreated
overflow.
d.Waiver of Written Reports
Ecology may waive the written report required in subpart c, above, on a
case-by-case basis upon request if the Permittee has submitted a timely
oral report.
e.All Other Permit Violation Reporting
The Permittee must report all permit violations, which do not require
immediate or within 24 hours reporting, when it submits monitoring
reports for S3.A ("Reporting"). The reports must contain the information
listed in subpart c, above. Compliance with theserequirements does not
relieve the Permittee from responsibility to maintain continuous
compliance with the terms and conditions of this permit or the resulting
liability for failure to comply.
G.Other Reporting
1.Spills of Oil or Hazardous Materials
ThePermittee must report a spill of oil or hazardous materials in accordance with
the requirements of Revised Code of Washington (RCW)90.56.280 and chapter
173-303-145. You can obtain further instructions at the following website:
https://ecology.wa.gov/About-us/Get-involved/Report-an-environmental-
issue/Report-a-spill.
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Permit No. ST 6127
2.Failure to Submit Relevant or Correct Facts
Where the Permittee becomes aware that it failed to submit any relevant facts in a
permit application, or submitted incorrect information in a permit application, or
in any report to Ecology, it must submit such facts or information promptly.
H.Maintaining aCopy of this Permit
The Permittee must keep a copy of this permit at the facility and make it available upon
request to Ecology inspectors.
S4.FACILITY LOADING
A.Design Criteria
The flows or waste loads for the permitted facility must not exceed the following design
criteria:
Maximum Month Design Flow (MMDF)4,000 gpd
Daily Maximum Flow6,200 gpd
B.Plans for Maintaining Adequate Capacity
1.Conditions Triggering Plan Submittal
The Permittee must submit a plan and a schedule for continuing to maintain
capacity to Ecology when:
a.The actual flow or waste load reaches 85 percent of any one of the design
criteria in S4.A for three consecutive months.
b.The projected plant flow or loading would reach design capacity within
five years.
2.Plan and Schedule Content
The plan and schedule must identify the actions necessary to maintain adequate
capacity for the expected population growth and to meet the limits and
requirements of the permit. The Permittee must consider the following topics and
actions in its plan.
a.Analysis of the present design and proposed process modifications.
b.Reduction or elimination of excessive infiltration and inflow of
uncontaminated ground and surface water into the sewer system.
c.Limits on future sewer extensions or connections or additional waste loads
d.Modification or expansion of facilities.
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Permit No. ST 6127
e.Reduction of industrial or commercial flows or waste loads.
Engineering documents associated with the plan must meet the requirements of WAC
173-240-060, "Engineering Report," and be approved by Ecology prior to any
construction.
C.Duty to Mitigate
The Permittee must take all reasonable steps to minimize or prevent any discharge or
sludge use or disposal in violation of this permit that has a reasonable likelihood of
adversely affecting human health or the environment.
D.Notification of New or Altered Sources
1.The Permittee must submit written notice to Ecology whenever any new discharge
or a substantial change in volume or character of an existing discharge into the
wastewater treatment plant is proposedwhich:
a.Would interfere with the operation of, or exceed the design capacity of,
any portion of the wastewater treatment plant.
b.Is not part of an approved general sewer plan or approved plans and
specifications.
c.Is subject to pretreatment standards under 40 CFR Part 403 and Section
307(b) of the Clean Water Act.
2.
to adequately transport and treat the added flow and/or wasteload, the quality and
volume of effluent to be discharged to the treatment plant, and the anticipated
CFR 122.42(b)\].
E.Wasteload Assessment
The Permittee must conduct an assessment of itsinfluent flow and wasteload and submit a
report to Ecology byJune 1, 2022.
The report must contain:
1.A description of compliance or noncompliance with the permit effluent limits.
2.A comparison between the existing and design:
a.Monthly AverageDry Weather andWet Weather Flows
b.Peak Flows
c.BODLoading
5
d.Total Suspended Solids Loadings
Page 17of 44
Permit No. ST 6127
3.The percent change in the above parameters since the previous report (except for
the first report).
4.The present and design population or population equivalent.
5.The projected population growth rate.
6.The estimated date upon which the Permittee expects the wastewater treatment
plant to reach design capacity, according to the most restrictive of the parameters
above.
Ecology may modify the interval for review and reporting if it determines that a different
frequency is sufficient.
S5.OPERATION AND MAINTENANCE
The Permittee must, at all times, properly operate and maintain all facilities or systems of treatment
and control (and related appurtenances), whichare installed to achieve compliance with the terms
and conditions of this permit. Proper Operation and Maintenance (O&M) also includes keeping a
daily operation logbook (paper or electronic), adequate laboratory controls, and appropriate quality
assurance procedures. This provision of the permit requires the Permittee to operate backup or
auxiliary facilities or similar systems only when the operation is necessary to achieve compliance
with the conditions of this permit.
A.Certified Operator
An operator certified for at least a Class II plant by the State of Washington must be in
responsible charge of the day-to-day operation of the wastewater treatment plant. An
operator certified for at least a Class II plant must be in charge during all regularly
scheduled shifts.
B.O&MProgram
The Permitteemust:
1.Institute an adequate operation and maintenance program for the entire sewage
system.
2.Keep maintenance records on all major electrical and mechanical components of
the treatment plant, as well as the sewage system and pumping stations. Such
records must clearly specify the frequency and type of maintenance recommended
by the manufacturer and must show the frequency and type of maintenance
performed.
3.Make maintenance records available for inspection at all times.
C.Short-Term Reduction
The Permittee must schedule any facility maintenance, which might require interruption of
wastewater treatment and degrade effluent quality, during non-critical water quality
Page 18of 44
Permit No. ST 6127
periods and carry this maintenance out according to the approved O&M Manual or as
otherwise approved by Ecology.
If a Permittee contemplates a reduction in the level of treatment that would cause a
violation of permit discharge limits on a short-term basis for any reason, and such reduction
cannot be avoided, the Permittee must:
1.Give written notification to Ecology, if possible, 30 days prior to such activities.
2.Detail the reasons for, length of time of, and the potential effects of the reduced
level of treatment.
This notification does not relieve the Permittee of its obligations under this permit.
D.Electrical Power Failure
The Permittee must ensure that adequate safeguards prevent the discharge of untreated
wastes or wastes not treated in accordance with the requirements of this permit during
electrical power failure at the treatment plant and/or sewage lift stations. Adequate
safeguards include, but are not limited toalternate power sources, standby generator(s), or
retention of inadequately treated wastes. The Permittee must maintain Reliability Class II
(EPA 430-99-74-001) at the wastewater treatment plant, which requires primary
sedimentation and disinfection.
E.Bypass Procedures
This permit prohibits a bypass, which is the intentional diversion of waste streams from
any portion of a treatment facility. Ecology may take enforcement action against a
Permittee for a bypass unless one of the following circumstances (1, 2, or 3) applies.
1.Bypass for essential maintenance without the potential to cause violation of permit
limits or conditions.
This permit authorizes a bypass if it allows for essential maintenance and doesnot
have the potential to cause violations of limits or other conditions of this permit,
or adversely impact public health as determined by Ecology prior to the bypass.
The Permittee must submit prior notice, if possible, at least 10 days before the date
of the bypass.
2.Bypass which is unavoidable, unanticipated, and results in noncompliance of this
permit.
This permit authorizes such a bypass only if:
a.Bypass is unavoidable to prevent loss of life, personal injury, or severe
damage to property, damage to the treatment facilities which would cause
them to become inoperable, or substantial and permanent loss of natural
resources which can reasonably be expected to occur in the absence of a
bypass.
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Permit No. ST 6127
b.No feasible alternatives to the bypass exist, such as:
The use ofauxiliary treatment facilities
Retention of untreated wastes
Maintenance during normal periods of equipment downtime, but
not if the Permittee should have installed adequate backup
equipment in the exercise of reasonable engineering judgment to
prevent a bypass.
Transport of untreated wastes to another treatment facility
c.Ecology is properly notified of the bypass as required in Special Condition
S3.Fof this permit.
3.If bypass is anticipated and has the potential to result in noncompliance of this
permit.
a.The Permittee must notify Ecology at least 30 days before the planned date
of bypass. The notice must contain:
A description of the bypass and its cause
An analysis of all known alternatives which would eliminate,
reduce, or mitigate the need for bypassing
A cost-effectiveness analysis of alternatives including
comparative resource damage assessment
The minimum and maximum duration of bypassunder each
alternative
A recommendation as to the preferred alternative for conducting
the bypass
The projected date of bypass initiation
A statement of compliance with State Environmental Policy Act
(SEPA)
A request for modification of Water Quality Standards as provided
for in WAC 173-201A-410, if an exceedance of any water quality
standard is anticipated.
Details of the steps taken or planned to reduce, eliminate, and
prevent reoccurrence of the bypass.
b.For probable construction bypasses, the Permittee must notifyEcology of
the need to bypass as early in the planning process as possible. The
Permittee must consider the analysis required above during the project
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Permit No. ST 6127
planning and design process. The project-specific engineering report or
facilities plan as well as theplans and specifications must include details
of probable construction bypasses to the extent practical. In cases where
the Permittee determines the probable need to bypass early, the Permittee
must continue to analyze conditions up to and including the construction
period in an effort to minimize or eliminate the bypass.
c.Ecology will consider the following prior to issuing an administrative
order for this type of bypass:
If the bypass is necessary to perform construction or maintenance-
related activitiesessential to meet the requirements of this permit.
If feasible alternatives to bypass exist, such as the use of auxiliary
treatment facilities, retention of untreated wastes, stopping
production, maintenance during normal periods of equipment
down time, or transport of untreated wastes to another treatment
facility.
If the Permittee planned and scheduled the bypass to minimize
adverse effects on the public and the environment.
After consideration of the above and the adverse effects of the proposed bypass
and any other relevant factors, Ecology will approve or deny the request. Ecology
will give the public an opportunity to comment on bypass incidents of significant
duration, to the extent feasible. Ecology will approve a request to bypass by
issuing an administrative order under RCW 90.48.120.
G.Operations and Maintenance (O&M) Manual
1.O&M Manual Submittal and Requirements
The Permittee must:
a.As needed, update O&M Manual that meets the requirements of WAC
173-240-080.
b.Review the O&M Manual at least annually.
c.Submit to Ecology for review and approval substantial changes or updates
to the O&M Manual whenever it incorporates them into the manual.
d.Keep the approved O&M Manual at the permitted facility.
e.Follow the instructions and procedures of this Manual.
2.O&M Manual Components
In addition to the requirements of WAC 173-240-080(1) through (5), the O&M
Manual must be consistent with the guidance in Table G1-3 in the Criteria for
Sewage Works Design(Orange Book), 2008. The O&M Manual must include:
Page 21of 44
Permit No. ST 6127
a.Emergency procedures for plant shutdown and cleanup in event of
wastewater system upset or failure, or infiltration systemleak.
b.Infiltration basinsystem operational controls and procedures.
c.Wastewater system maintenance procedures that contribute to the
generation of wastewater.
d.Reporting protocols for submitting reports to Ecology to comply with the
reporting requirements in the discharge permit.
e.Any directions to maintenance staff when cleaning, or maintaining other
equipment or performing other tasks which are necessary to protect the
operation of the wastewater system (for example, defining maximum
allowable discharge rate for draining a tank, blocking all floor drains
before beginning the overhaul of a stationary engine.)
f.Treatment plant process control monitoring schedule.
g.Wastewater sampling protocols and procedures for compliance with the
sampling and reporting requirements in the wastewater discharge permit.
h.Minimum staffing adequate to operate and maintain the treatment
processes and carry out compliance monitoring required by the permit.
i.Protocols and procedures for groundwatermonitoring network, vadose
zone, and soil sampling and testing.
j.Protocols and procedures for double-lined evaporation pond leak system,
sampling and testing.
G.Infiltration Land Application Best Management Practices
The Permittee must:
1.Operate the infiltration basinsto protect the existing and future beneficial uses of
the groundwater, and not cause a violation of the groundwater standards.
2.Not allow practices to result in runoff of wastewater to any surface waters of the
state or to any land not owned by or under its control.
3.Use recognized good practices, and all available and reasonable procedures to
control odors from the infiltration basinsystem.
4.Implement measures to reduce odors to a reasonable minimum when notified by
Ecology.
5.Not apply wastewater to the infiltration basinsin quantities that:
a.Significantly reduce or destroy the long-term infiltration rate of the soil.
Page 22of 44
Permit No. ST 6127
b.Would cause long-term anaerobic conditions in the soil.
c.Would cause ponding of wastewater and produce objectionable odors or
support insects or vectors.
d.Would cause leaching losses of constituents of concern beyond the
treatment zone or in excess of the approved design. Constituents of
concern are constituents in the wastewater, partial decomposition
products, or soil constituents that would alter groundwaterquality in
amounts that would affect current and future beneficial uses.
6.Maintain all agreements for lands not owned for the duration of the permit cycle.
Any reduction in infiltration lands by termination of any irrigation agreements may
result in permit modification or revocation.
7.Immediately inform Ecology in writing of any proposed changes to existing
irrigation agreements.
8.Discontinue operation during periods of heavy or prolonged rainfall to prevent
ground saturation and runoff.
S6.PRETREATMENT
A.General Requirements
The Permittee must work with Ecology to ensure that all commercial and industrial users
of the Publicly Owned Treatment Works (POTW) comply with the pretreatment
regulations in 40 CFR Part 403 and any additional regulations that the Environmental
Protection Agency (U.S. EPA) may promulgate under Section 307(b) (pretreatment) and
308 (reporting) of the Federal Clean Water Act.
B.Duty to Enforce Discharge Prohibitions
1.Under federal regulations \[40 CFR 403.5(a) and (b)\], the Permittee must not
authorize or knowingly allow the discharge of any pollutants into its POTW which
may be reasonably expected to cause pass through or interference, or which
otherwise violate general or specific discharge prohibitions contained in 40 CFR
Part 403.5 or WAC 173-216-060.
2.The Permittee must not authorize or knowingly allow the introduction of any of
the following into their treatment works:
a.Pollutants which create a fire or explosion hazard in the POTW (including,
but not limited to waste streams with a closed cup flashpoint of less than
140 degrees Fahrenheit or 60 degrees Centigrade using the test methods
specified in 40 CFR 261.21).
b.Pollutants which will cause corrosive structural damage to the POTW, but
in no case discharges with pH lower than 5.0, or greater than 11.0 Standard
Units, unless the works are specifically designed to accommodate such
discharges.
Page 23of 44
Permit No. ST 6127
c.Solid or viscous pollutants in amounts that could cause obstruction to the
flow in sewers or otherwise interfere with the operation of the POTW.
d.Any pollutant, including oxygen-demanding pollutants, (BOD, etc.)
5
released in a discharge at a flow rate and/or pollutant concentration which
will cause interference with the POTW.
e.Petroleum oil, non-biodegradable cutting oil, or products of mineral origin
in amounts that will cause interference or pass through.
f.Pollutants which result in the presence of toxic gases, vapors, or fumes
within the POTW in a quantity which may cause acute worker health and
safety problems.
g.Heat in amounts that will inhibit biological activity in the POTW resulting
in interference butin no case heat in such quantities such that the
temperature at the POTW headworks exceeds 40 degrees Centigrade (104
degrees Fahrenheit) unless Ecology, upon request of the Permittee,
approves, in writing, alternate temperature limits.
h.Any trucked or hauled pollutants, except at discharge points designated by
the Permittee.
i.Wastewaters prohibited to be discharged to the POTW by the Dangerous
Waste Regulations (chapter 173-303 WAC), unless authorized under the
Domestic Sewage Exclusion (WAC 173-303-071).
3.The Permittee must also not allow the following discharges to the POTW unless
approved in writing by Ecology:
a.Noncontact cooling water in significant volumes
b.Stormwater and other direct inflow sources
c.Wastewaters significantly affecting system hydraulic loading, which do
not require treatment, or would not be afforded a significant degree of
treatment by the system.
4.The Permittee must notify Ecology if any industrial user violates the prohibitions
listed in this section (S6.B), and initiate enforcement action to promptly curtail any
such discharge.
S7.SOLID WASTES
A.Solid Waste Handling
The Permittee must handle and dispose of all solid waste material in such a manner as to
prevent its entry into state ground or surface water.
Page 24of 44
Permit No. ST 6127
B.Leachate
The Permittee mustnot allow leachate from its solid waste material to enter state waters
without providing all known, available,and reasonable methods of treatment, nor allow
such leachate to cause violations of the State Surface Water Quality Standards, Chapter
173-201A WAC, or the State Ground Water Quality Standards, Chapter 173-200 WAC.
S8.APPLICATION FOR PERMIT RENEWAL OR MODIFICATION FOR FACILITY CHANGES
The Permittee must submit an application for renewal of this permit byFebruary 1, 2024.
The Permittee must also submita new application or addendumat least 180 days prior to
commencement of discharges, resulting from the activities listed below, which may result in permit
violations.These activities include any facility expansions, production increases, or other planned
changes, such as process modifications, in the permitted facility.
Page 25of 44
Permit No. ST 6127
GENERAL CONDITIONS
G1.SIGNATORY REQUIREMENTS
All applications, reports, or information submitted to Ecology must be signed as follows:
A.All permit applications must be signed by either a principal executive officer or ranking
elected official.
B.All reports required by this permit and other information requested by Ecology must be
signed by a person described above or by a duly authorized representative of that person.
A person is a duly authorized representative only if:
1.The authorization is made in writing by the person described above and is
submitted to Ecology at the time of authorization, and
2.The authorization specifies either a named individual or anyindividual occupying
a named position.
C.Changes to authorization. If an authorization under paragraph G1.Babove is no longer
accurate because a different individual or position has responsibility for the overall
operation of the facility, a new authorization must be submitted to Ecology prior to or
together with any reports, information, or applications to besigned by an authorized
representative.
D.Certification. Any person signing a document under this section must make the following
certification:
"I certify under penalty of law, that this document and all attachments were
prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gathered and
evaluated the information submitted. Based on my inquiry of the person
or persons who manage the system or those persons directly responsible
for gathering information, the information submitted is, to the best of my
knowledge and belief, true, accurate, and complete. I am aware that there
are significant penalties for submitting false information, including the
possibility of fine and imprisonment for knowing violations."
G2.RIGHT OF ENTRY
Representatives of Ecology have the right to enter at all reasonable times in or upon any property,
publicor privatefor the purpose of inspecting and investigating conditions relating to the pollution
or the possible pollution of any waters of the state. Reasonable timesincludenormal business
hours; hours during which production, treatment, or discharge occurs; or times when Ecology
suspects a violation requiring immediate inspection. Representatives of Ecology must be allowed
to have access to, and copy at reasonable cost, any records required to be kept under terms and
conditions of the permit; to inspect any monitoring equipment or method required in the permit;
and to sample the discharge, waste treatment processes, or internal waste streams.
Page 26of 44
Permit No. ST 6127
G3.PERMIT ACTIONS
This permit is subject to modification, suspension, or termination, in whole or in part by Ecology
for any of the following causes:
A.Violation of any permit term or condition;
B.Obtaining a permit by misrepresentation or failure to disclose all relevant facts;
C.A material change in quantity or type of waste disposal;
D.A material change in the condition of the waters of the state; or
E.Nonpayment of fees assessed pursuant to RCW 90.48.465.
Ecology may also modify this permit, including the schedule of compliance or other conditions, if
it determines good and valid cause exists, including promulgation or revisions of regulations or
new information.
G4.REPORTING A CAUSE FOR MODIFICATION
The Permittee must submit a new application at least 180days before it wants to discharge more
of any pollutant, a new pollutant, or more flow than allowed under this permit. The Permittee
should use the State Waste Discharge Permit application, and submit required plans at thesame
time. Required plans include an Engineering Report, Plans and Specifications, and O&M Manual,
(see Chapter 173-240 WAC). Ecology may waive these plan requirements for small changes, so
contact Ecology if they do not appear necessary. The Permitteemust obtain the written concurrence
of the receiving POTW on the application before submitting it to Ecology. The Permittee must
continue to comply with the existing permit until it is modified or reissued. Submitting a notice of
dangerous waste discharge (to comply with Pretreatment or Dangerous Waste rules) triggers this
requirement as well.
G5.PLAN REVIEW REQUIRED
Prior to constructing or modifying any wastewater control facilities, an Engineering Report and
detailed Plans and Specifications must be submitted to Ecology for approval in accordance with
Chapter 173-240 WAC. Engineering Reports, Plans, and Specifications should be submitted at
least 180 days prior to the planned start of construction. Facilities must be constructed and operated
in accordance with the approved plans.
G6.COMPLIANCE WITH OTHER LAWS AND STATUTES
Nothing in this permit excuses the Permittee from compliance with any applicable federal, state, or
local statutes, ordinances, or regulations.
G7.TRANSFER OF THIS PERMIT
This permit is automatically transferred to a new owner or operator if:
A.A written agreement between the old and new owner or operator containing a specific date
for transfer of permit responsibility, coverage, and liability is submitted to Ecology;
Page 27of 44
Permit No. ST 6127
B.A copy ofthe permit is provided to the new owner and;
C.Ecology does not notify the Permittee of the need to modify the permit.
Unless this permit is automatically transferred according to Section 1above, this permit may be
transferred only if it is modified to identify the new Permittee and to incorporate such other
requirements as determined necessary by Ecology.
G8.PAYMENT OF FEES
The Permittee must submit payment of fees associated with this permit as assessed by Ecology.
Ecology may revoke this permit if the permit fees established under Chapter 173-224 WAC are not
paid.
G9.PENALTIES FOR VIOLATING PERMIT CONDITIONS
Any person who is found guilty of willfully violating the terms and conditions of this permit is
guilty of a crime, and upon conviction thereof shallbe punished by a fine of up to $10,000and
costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a
willful violation occurs may be deemed a separate and additional violation.
Any person who violates the terms and conditions of a waste discharge permit incurs, in addition
to any other penalty as provided by law, a civil penalty in the amount of up to $10,000for every
such violation. Each and every such violation is a separate and distinct offense, and in case ofa
continuing violation, every day's continuance is considered a separate and distinct violation.
G10.DUTY TO PROVIDE INFORMATION
The Permittee must submit to Ecology, within a reasonable time, all information which Ecology
may request to determine whether cause exists for modifying, revoking and reissuing, or
terminating this permit or to determine compliance with this permit. The Permittee must also
submit to Ecology upon request, copies of records required to be kept by this permit.
G11.DUTY TO COMPLY
The Permittee must comply with all conditions of this permit. Any permit noncompliance
constitutes a violation of chapter 90.48 RCW and is grounds for enforcement action; for permit
termination, revocation and reissuance, or modification; or denial of apermit renewal application.
G12.SERVICE AGREEMENT REVIEW
The Permittee must submit to Ecology any proposed service agreements and proposed revisions or
updates to existing agreementsfor the operation of any wastewater treatment facility covered by
this permit. The review is to ensure consistency with chapters 90.46 and 90.48 RCW as required
by RCW 70.150.040(9). In the event that Ecology does not comment within a 30-day period, the
Permittee may assume consistency and proceed with the service agreement or the revised/updated
service agreement.
scharge
44
of
28
rs if expected to be
ntionals. 40 CFR Part
specific detection limit
Page Permit No. ST 6127
g table for permit and
-
polynuclear aromatic hydrocarbons
required monitoring and to measure effluent
-
utants, it must measure all of the base neutral
approved method in 40 CFR Part 136.
-
-
ue to matrix effects, the Permittee must submit a matrix
APPENDIX A
(as defined in CWA section 502(6) and 40 CFR Part 122.), toxic or priority pollutants as defined in CWA
nitoring unless:
an alternative method, not specified in the permit and as allowed above, it must report the test method, DL, and QL on the di
LIST OF POLLUTANTS WITH ANALYTICAL METHODS, DETECTION LIMITS AND QUANTITATION LEVELS
The Water Quality Program added several
Another permit condition specifies other methods, detection levels, or quantitation levels.The method used produces measurable results in the sample and EPA has listed it as an EPA
Appendix D (Table V) also identifies toxic pollutants and hazardous substances which are required to be reported by discharge
The Permittee must use the specified analytical methods, detection limits (DLs) and quantitation levels (QLs) in the followinapplication required moIf the Permittee usesmonitoring report
or in the required report.If the Permittee is unable to obtain the required DL and QL in its effluent d(MDL) and a QL to Ecology with appropriate laboratory documentation.When the permit
requires the Permittee to measure the base neutral compounds in the list of priority pollpollutants listed in the table below. The list includes EPA required base neutral priority
pollutants and several additional(PAHs). It only added those PBT parameters of interest to Appendix A that did not increase the overall cost of analysis unreasonably.Ecology added this
appendixconcentrations near or below criteria values where possible at a reasonable cost.The lists below include conventional pollutantssection 307(a)(1) and listed in 40 CFR Part 122
Appendix D, 40 CFR Part 401.15 and 40 CFR Part 423 Appendix A), and nonconve122present. This permit appendix A list does not include those parameters.
-
44
10
N/A
of µg/L unless
5,000
µg/L unless
2 mg/L2 mg/L5 mg/L
2
2
specified
specified
dependent
29
sample aliquot
5 mg/L as CaCO3
(QL)
(QL)
Quantitation Level
Quantitation Level
Specified in method
Page Permit No. ST 6127
1
1
N/AN/A
2.0
1,400
specified
specified
µg/L unless
µg/L unless
Detection (DL)
Detection (DL)
3
B
+
B
D
B
-
-B
-
H
-
-
200.8
Protocol
Protocol
SM5210
SM2540
1664 A or B
SM5210
SM2320
SM4500
SM 9221E,9222
Recommended Analytical
Recommended Analytical
5
-
90
-
7429
CONVENTIONAL POLLUTANTS
(if available)
(if available)
CAS Number CAS Number
NONCONVENTIONAL POLLUTANTS
Pollutant
Pollutant & CAS No. (if available)
Biochemical Oxygen DemandBiochemical Oxygen Demand, SolubleFecal ColiformOil and Grease (HEM) (Hexane Extractable Material)pHTotal Suspended SolidsAlkalinity, TotalAluminum, Total
44
2
2050
2.0
100
10.050.00.25
of
µg/L unless
2
10 mg/L
0.2 mg/L
specified
dependent
30
10 color units
200 as CaCO3
Sample and limit
(QL)
Quantitation Level
Page Permit No. ST 6127
1
1
25
0.52.0
0.0512.5
specified
µg/L unless
Detection (DL)
B and
-D
-
F E
-
OC/OG
-
NH3
-
200.8200.8200.8200.7
Cl B/C/D/E and
-
Protocol
SM2340B
SM4110 B
SM5220
C/D/E/G/H
SM4500
SM4500 Cl G
SM2120 B/C/E
SM4500
Calibrated device
SM4500
EPA SW 846 8021/8260
SM4500
Recommended Analytical
8
3846
-
----
48
39424889
-
----
7440744074407439
16984
(if available)
CAS Number
NONCONVENTIONAL POLLUTANTS
Pollutant & CAS No. (if available)
Ammonia, Total (as N)Barium Total BTEX (benzene +toluene + ethylbenzene + m,o,p xylenes)Boron, Total Chemical Oxygen DemandChlorideChlorine, Total ResidualCobalt, Total ColorDissolved
oxygenFlowFluoride Hardness, TotalIron, Total
44
501010
0.50.5
100300250250
of
µg/L unless
or PSS)
2
0.2 mg/L
specified
dependent
31
Sample and limit
3 practical salinity
(QL)
units or scale (PSU
Quantitation Level
Page Permit No. ST 6127
1
33
10
0.10.1
250250
specified
µg/L unless
Detection (DL)
-
3
E/F/H
F
BB
-
-
--
B/C and
PE/PF
-
P E/F/G
org
-
N
NO3
-
-
200.7200.8200.8
Protocol
SM2520SM4110
SM2540
SM4500NH
B/C/D/EF/G/H
SM4500
SM4500
Ecology NWTPH DxEcology NWTPH Gx
SM4500
SM4500
SM 4500 PB followed by
Recommended Analytical
457
---
959698
---
743974397439
(if available)
CAS Number
NONCONVENTIONAL POLLUTANTS
)
4
45
Total (as P)
mg/L SO
Pollutant & CAS No. (if available)
Magnesium, Total Manganese, Total Molybdenum, Total Nitrate + Nitrite Nitrogen (as N)Nitrogen, Total Kjeldahl (as N)NWTPH Dx NWTPH Gx Phosphorus, SalinitySettleable SolidsSoluble Reactive
Phosphorus (as P)Sulfate (as
-
44
1.52.5
of
µg/L unless
0.2º C
2 mg/L1 mg/L
2
20 mg/L
0.2 mg/L
specified
dependent
32
sample aliquot
(QL)
Quantitation Level
Specified in method
Page Permit No. ST 6127
1
0.30.5
N/A
specified
µg/L unless
Detection (DL)
SO3B
F/D/E/G
B/C/D
-
2
-
S
-
200.8200.8
Protocol
SM2540 C
recording devices
-
SM4500
SM5310
SM4500
known as thermistors
Analog recorder or Use
micro
SM 9221B, 9222B, 9223B
Recommended Analytical
56
--
3132
--
74407440
(if available)
CAS Number
NONCONVENTIONAL POLLUTANTS
day avg.)
-
)
3
Pollutant & CAS No. (if available)
Sulfide (as mg/L S)Sulfite (as mg/L SOTemperature (max. 7Tin, Total Titanium, Total Total ColiformTotal Organic CarbonTotal dissolved solids
2
44
1.00.50.51.21.02.00.50.51.00.22.5
0.250.36
0.0005
of
specified
µg/L unless
Level (QL)
Quantitation
33
Page Permit No. ST 6127
1
0.30.10.10.30.20.40.10.11.00.5
0.050.040.09
0.0002
specified
µg/L unless
Detection (DL)
Cr C
-
200.8200.8200.8200.8200.8200.8200.8200.8200.8200.8200.8200.8
1631E
SM3500
Recommended
Analytical Protocol
9
0279381602406
-
-------------
29
36384143475092970249222866
-
-------------
available)7440744074407440744074407439743974407782744074407440
18540
CAS Number (if
114115117118119119120122123124125126127128
PP #
POLLUTANTS
PRIORITY
METALS, CYANIDE & TOTAL PHENOLSAntimony, Total Arsenic, Total Beryllium, Total Cadmium, Total Chromium (hex) dissolved Chromium, Total Copper, Total Lead, Total Mercury, Total Nickel,
Total Selenium, TotalSilver, Total Thallium, Total Zinc, Total
2
2
10101050
4472
9.98.18.1
126
of
specified
specified
µg/L unless
µg/L unless
Level (QL)
Level (QL)
Quantitation
Quantitation
34
Page Permit No. ST 6127
1
1
555
2442
3.32.72.7
specified
specified
µg/L unless
µg/L unless
Detection (DL)
Detection (DL)
CN I
CN G
-
-
335.4
625.1625.1625.1625.1
EPA 420.1
625.1/1625B
SM4500
SM4500
Recommended
Recommended
Analytical Protocol
Analytical Protocol
291
585
---
---
836752
125728
---
---
579551
120105534
available)available)
CAS Number (if CAS Number (if
65
1211211212431346059
PP #
PP #
-
4,6,
-
methyl
POLLUTANTS
-
cresol (2
-
o
Cyanide)
-
PRIORITY
PRIORITY POLLUTANTS
Dichlorophenol Dimethylphenol dinitro
---
Chlorophenol
-
METALS, CYANIDE & TOTAL PHENOLSCyanide, Total Cyanide, Weak Acid DissociableCyanide, Free Amenable to Chlorination (Available Phenols, TotalACID COMPOUNDS22,42,44,6dinitrophenol)2,4
dinitrophenol
22
4410
7.29.04.58.12.0
10.810.813.2
of
specifiedspecified
µg/L unless µg/L unless
Level (QL)Level (QL)
QuantitationQuantitation
35
Page Permit No. ST 6127
11
5
3.62.43.03.61.52.71.04.4
specifiedspecified
µg/L unless µg/L unless
Detection (DL)Detection (DL)
624624
625.1625.1625.1625.1625.1625.1624.1
Recommended Recommended
Analytical ProtocolAnalytical Protocol
7281
57522
----
-----
02950213
7550860643
----
-----
8859878871
100108107107
available)available)
CAS Number (if
CAS Number (if
234
575822646521
PP #
PP #
-
3
-
chloro
-
PRIORITY POLLUTANTS
PRIORITY POLLUTANTS
Trichlorophenol
-
NitrophenolNitrophenol
--
ACID COMPOUNDS24Parachlorometa cresol (4methylphenol)Pentachlorophenol Phenol 2,4,6VOLATILE COMPOUNDSAcrolein Acrylonitrile Benzene
2
44
8.42.02.04.89.37.67.66.68.48.4
14.118.017.614.1
of
specified
µg/L unless
Level (QL)
Quantitation
36
Page Permit No. ST 6127
1
4.72.86.01.01.01.63.11.91.94.42.24.72.82.8
specified
µg/L unless
Detection (DL)
624624624624
624.1624.1624.1624.1624.1624.1624.1
624/601
Recommended
624.1 or SM6210B
Analytical Protocol
624.1/601 or SM6230B
781172
25331434
------
--------
907548734606
2523006650273435
------
--------
7556756795757575
108110124541106107
available)
CAS Number (if
67
471619235125262748131029
PP #
PRIORITY POLLUTANTS
Dichlorobenzene Dichlorobenzene Dichlorobenzene Dichloroethane Dichloroethane Dichloroethylene
------
Chloroethylvinyl Ether
-
VOLATILE COMPOUNDSBromoform Carbon tetrachloride Chlorobenzene Chloroethane 2Chloroform Dibromochloromethane (chlordibromomethane)1,21,31,4Dichlorobromomethane 1,11,21,1
2
44
2.08.44.85.72.0
18.015.021.610.020.712.318.011.415.0
of
specified
µg/L unless
Level (QL)
Quantitation
37
Page Permit No. ST 6127
1
6.05.07.25.01.02.86.94.16.01.63.85.01.91.0
specified
µg/L unless
Detection (DL)
624
624.1624.1624.1624.1624.1624.1624.1624.1624.1624.1624.1
624/601
624/SM6200B
Recommended
Analytical Protocol
64435
593256564
-----
---------
7541188860
878387093455000101
-----
---------
787474757971797975
542100127108156
available)
CAS Number (if
3233384645441585863011148788
PP #
6
Dichloroethylene (Ethylene
PRIORITY POLLUTANTS
-
Tetrachloroethane
-
Trichloroethane Trichloroethane
--
dichloropropylene)
-
Dichloropropane dichloropropene (mixed isomers)Trans
---
VOLATILE COMPOUNDS1,21,3(1,2Ethylbenzene Methyl bromide (Bromomethane)Methyl chloride (Chloromethane)Methylene chloride 1,1,2,2Tetrachloroethylene Toluene 1,2dichloride)1,1,11,1,2Trichloroethylene
Vinyl chloride
2
44
5.75.77.51.07.55.07.5
132
10.523.414.412.315.9
of
specified
µg/L unless
Level (QL)
Quantitation
38
Page Permit No. ST 6127
1
44
1.93.51.92.57.84.80.52.51.32.54.15.3
specified
µg/L unless
Detection (DL)
625625
625.1625.1625.1625.1625.1625.1625.1
610/625.1610/625.1610/625.1610/625.1
Recommended
Analytical Protocol
39
872921
95738
--------
-----
8255
961299082491
3287685532
--------
-----
8392855650
208120205205207189191111
available)
CAS Number (if
15
777867727475737943
PP #
-
benzofluoranthene)
-
7
methane
7
)Perylene
PRIORITY POLLUTANTS
)anthracene)pyrene
aaghi
chloroethoxy)
-
2
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)Acenaphthene Acenaphthylene Anthracene Benzidine Benzyl butyl phthalate Benzo(Benzo(b)fluoranthene (3,4 7 Benzo(j)fluoranthene
Benzo(k)fluoranthene (11,12benzofluoranthene) Benzo(r,s,t)pentaphene Benzo(Benzo(Bis(
2
44
1.07.55.75.77.57.55.7
17.112.610.010.010.010.049.5
of
specified
µg/L unless
Level (QL)
Quantitation
39
Page Permit No. ST 6127
1
5.70.52.51.91.94.22.52.52.52.52.52.51.9
16.5
specified
µg/L unless
Detection (DL)
625
625.1625.1625.1625.1625.1625.1
625M
611/625.1610/625.1605/625.1
610M/625M610M/625M610M/625M
Recommended
Analytical Protocol
9
3
-
80
473940
-
7312
--------
----
32
72
-
3642
448155016564
-
58709466
--------
----
91539184
111117101218226224192189
available)7005
39638
CAS Number (if
18426641204076822870
PP #
-
)ether
)ether
)phthalate
)anthracene (1,2,5,6
h
-
PRIORITY POLLUTANTS
chloroethylchloroisopropylethylhexyl
dibenzanthracene)
---
222
Dichlorobenzidine
-
Bromophenyl phenyl ether Chloronaphthalene Chlorophenyl phenyl ether
---
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)Bis(Bis(Bis(424Chrysene Dibenzo (a,h)acridine Dibenzo (a,j)acridine Dibenzo(aDibenzo(a,e)pyrene Dibenzo(a,h)pyrene 3,3Diethyl
phthalate
2
4420
4.87.55.77.56.65.75.72.74.04.86.68.0
17.111.1
of
specified
µg/L unless
Level (QL)
Quantitation
40
Page Permit No. ST 6127
1
1.62.55.71.92.55.02.21.91.90.92.01.63.72.22.0
specified
µg/L unless
Detection (DL)
625
625.1625.1625.1625.1625.1625.1625.1625.1
1625B
609/625.1609/625.1612/625.1610/625.1
1625B/625
Recommended
Analytical Protocol
32207015
5
273411
--------
-------
1114208466447439
49
747368477259
--------
-------
84868777677856
131121606117122206118193
available)
CAS Number (if
9
71683536693739805253128354
PP #
)
as Azobenzene
)Pyrene
cd
-
PRIORITY POLLUTANTS
1,2,3
butyl phthalate octyl phthalate
--
dinitrotoluene dinitrotoluene Diphenylhydrazine (
nn
---
--
Methyl cholanthrene
-
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)Dimethyl phthalate Di2,42,6Di1,2Fluoranthene Fluorene Hexachlorobenzene Hexachlorobutadiene Hexachlorocyclopentadiene Hexachloroethane
Indeno(Isophorone 3
22
44
4.85.74.01.02.07.65.75.7
16.2
5 pg/L
of
specifiedspecified
µg/L unless µg/L unless
Level (QL)Level (QL)
QuantitationQuantitation
41
Page Permit No. ST 6127
11
1.61.92.00.51.01.95.41.91.9
1.3 pg/L
specifiedspecified
µg/L unless µg/L unless
Detection (DL)Detection (DL)
625625
625.1625.1625.1625.1625.1
1613B
607/625607/625
Recommended Recommended
Analytical Protocol
Analytical Protocol
6
0
701
-
33968
----
-----
01
55
640082
-
2095753001
----
-----
9198628685
621198129120
available)available)1746
CAS Number (if CAS Number (if
8
55566163628184
129
PP #
PP #
Dioxin
-
P
-
propylamine
-
Chlorodibenzo
-
n
-
PRIORITY POLLUTANT
PRIORITY POLLUTANTS
Tetra
-
Trichlorobenzene
-
Nitrosodimethylamine NitrosodiNitrosodiphenylamine
---
BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs)Naphthalene Nitrobenzene NNNPerylene Phenanthrene Pyrene 1,2,4DIOXIN2,3,7,8(2,3,7,8 TCDD)
2
ng/L
44
1218 ng/L12 ng/L27 ng/L42 ng/L36 ng/L12 ng/L33 ng/L42 ng/L12 ng/L18 ng/L
of
9.0 ng/L6.0 ng/L
specified
198 ng/L
µg/L unless
Level (QL)
Quantitation
42
Page Permit No. ST 6127
1
11ng/L
14 ng/L12 ng/L14 ng/L66 ng/L
4.0 ng/L3.0 ng/L6.0 ng/L4.0 ng/L9.0 ng/L4.0 ng/L2.0 ng/L4.0 ng/L6.0 ng/L
specified
µg/L unless
Detection (DL)
608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3
Recommended
Analytical Protocol
9
8
-
26788
-
9939818
-----
-------
65
07
-
0084858698
-
89742955545720
-----
-------
58575072726072
309319319319959
available)1031
33213
CAS Number (if
89919293949095969798
102103104105
PP #
8
PRIORITY POLLUTANTS
BHC (Lindane)
-
BHCEndosulfan
BHC
--
BHCEndosulfan
-
DDT DDE
--
--
PESTICIDES/PCBsAldrin alphabetagammadeltaChlordane Dieldrin alphabetaEndosulfan Sulfate Endrin
2
dix B.
44
0.1950.1950.1950.1950.1950.1950.195
70 ng/L
of
9.0 ng/L
specified
249 ng/L720 ng/L
µg/L unless
Level (QL)
Quantitation
43
Page Permit No. ST 6127
1
calibration standard,
0.0650.0650.0650.0650.0650.0650.065
23 ng/L83 ng/L
3.0 ng/L
specified
240 ng/L
µg/L unless
Detection (DL)
608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3608.3
Recommended
The lowest level at which the entire analytical system must give
Analytical Protocol
analyte (substance) that can be measured and reported with a 99
, where n is an integer. (64 FR 30417).
n
9125652
432
-------
---
8
-
21692816298211
935735
-------
---
44
-
76
available)742110248001
53469110971110411141126721109612674
CAS Number (if
of Quantitation (ML)
99
100101106107108109110111112113
PP #
specified sample weights, volumes, and cleanup procedures. The QL is calculated by multiplying the
-
also known as Minimum Level
or detection limit means the minimum concentration of an
b has used all method
99
confidence that the analyte concentration is greater than zero as determined by the procedure given in 40 CFR part 136, Appen
PRIORITY POLLUTANTS
1242125412211232124812601016
-------
Detection level (DL)percentQuantitation Level (QL)a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest assuming
that the laMDL by 3.18 and rounding the result to the number nearest to (1, 2, or 5) x 10
PESTICIDES/PCBsEndrin Aldehyde Heptachlor Heptachlor Epoxide PCBPCBPCBPCBPCBPCBPCBToxaphene
1.2.
-
and
5)
-
44
01
-
of
44
sample as per
achieves the
pore size of 0.45
-
9). If you report
-
Page Permit No. ST 6127
74
es and Uses in Clean
-
elute you may report these three
-
dichlorpropropene (10061
-
1, 3
-
1016/1242.
2) in place of chlordane (57
-
74
-
see
see
chlordane (5103
-
9) and gamma
-
71
-
You may report this parameter as two separate parameters: cis
method note: First, filter the sample through a Millipore Nylon filter (or equivalent)
lordane (5103
6).
-
Report of the Federal Advisory Committee on Detection and Quantitation Approach
ch
-
02
-
Because Benzo(b)fluoranthene, Benzo(j)fluoranthene and Benzo(k)fluoranthene co
-
You may report these two PCB compounds as one parameter called PCB
Submitted to the US Environmental Protection Agency December 2007).
chlordane, the DL/PQLs that apply are 14/42 ng/L.
-
Northwest Total Petroleum Hydrocarbons Gasoline Extended Range
B.
Northwest Total Petroleum Hydrocarbons Diesel Extended Range
You may report alpha
-
-
-
dichloropropene (10061
-
1, 3
um (prep all filters by filtering 250 ml of laboratory grade deionized water through the filter and discard). Then, analyze
-
dichloroproylene (mixed isomers)
-
rans
ALSO GIVEN AS:The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) objectives of the intended purpose. (Water
Act Programs Soluble Biochemical Oxygen Demand0.50method 5210NWTPH Dxhttps://fortress.wa.gov/ecy/publications/documents/97602.pdfNWTPH Gxhttps://fortress.wa.gov/ecy/publications/documents/97602.pdf1
, 3tTotal Benzofluoranthenesisomers as total benzofluoranthenes.Chlordanealpha and gammaPCB 1016 & PCB 1242
3.4.5.6.7.8.9.
ADDENDUM TO THE FACT SHEET FOR
CITY OF PORT TOWNSEND COMPOST FACILITY
STATE WASTE DISCHARGE PERMIT ST0006127
1.GENERAL INFORMATION
Facility:City of Port Townsend Compost Facility
603County Landfill Road
Port Townsend, WA 98368
2.APPLICATION AND COMPLIANCE REVIEW
The city of Port Townsend submitted an application to the Department of Ecology (Ecology) on
November 6, 2017,for permit reissuance, and Ecology accepted it on December 7, 2017. Ecology
conditions in the previous permit. Ecology has sufficiently reviewed the application, discharge
monitoring reports, and other facility information inenough detail to ensure that:
The city of Port Townsend Compost Facilityhas compliedwith all of the terms, conditions,
requirements and schedules of compliance of the expired permit.
Ecology has up-to date information on the cityof Port Townsend Compost Facility
treatment practices;and the nature, content, volume, and frequency of its discharge.
The discharge meetsapplicableeffluent standards and limits,ground water quality
standards, and other legally applicable requirements(see more information in Section 4).
Since the issuance of the current permit, Ecology has not received any additional information,
which indicates that environmental impacts from the discharge warrant a complete renewal of the
permit. Therefore, Ecologychose to reauthorize this permit.
3.PERMIT REAUTHORIZATION
When Ecology reauthorizes a discharge permit it essentially reissuesthe permit with the existing
limits, terms and conditions. Alternatively, when Ecology renewsa permit it re-evaluates the
impact of the discharge on the ground water,which may lead to changes in the limits, terms and
conditions of the permit.
The permit reauthorization process, along with the renewal of high priority permits, allows Ecology
to reissue permits in a timely manner and minimize the number of active permits that have passed
their expiration dates. Ecology assesses each permit that is expiring and due for reissuance and
compares it with other permits due for reissuancewhen it plans its workloadfor the upcoming year.
This fact sheet addendum accompanies the permit, which Ecology proposes to reauthorize forthe
discharge of wastewater to groundwater. The previous fact sheet explains the basis for the
discharge limits and conditions of the reauthorized permit and remains as part of the administrative
record.
5/15/19
FACT SHEET ADDENDUM FOR
CITY OF PORT TOWNSEND
BIOSOLIDS COMPOST FACILITY
STATE WASTE DISCHARGE PERMIT ST 6127
4.PERMIT LIMITS AND CONDITIONS
The reauthorized permit is virtually identical to the previous permit issued on June 10, 2013,with
a few exceptions identified below. Ecology removed the completed report requirements that do
not require additional or continued assessment. The proposed reauthorized permit includes:
The discharge limits and conditions in effect at the time of expiration of the previous
permit.
Changes to the submittal dates for reports from those in the previous permit.
Adjusted dates for the other necessary compliance and submittal requirements carried over
from the past permit.
Appendix A, which identifies the required test methods, detection levels and quantitation
levels for the monitoring required in the proposed permit.
5.PUBLIC PROCESS
Ecology public noticesthe availability of the draft reauthorized permit at least 30 days before it
reissuesthe permit. Ecology invites you to review and comment on its decisionto reauthorize the
permit(see Appendix A-Public Involvement Informationfor more detail on the Public Notice
procedures).
After the public comment period has closed, Ecologywill prepare a Response to Comments
document andattachitto this fact sheet addendum. Ecology will respond to each comment and
describe the resultant changes to the permit in this document.Ecology sends a copy of the Response
to Commentsto all parties that submitted comments.
6.PERMIT APPEAL PROCESS
Appendix Bdescribes the permit appeal process.
7.RECOMMENDATION FOR PERMIT ISSUANCE
Ecologyproposes to reissue this permit for fiveyears.
5/15/19Page 2
FACT SHEET ADDENDUM FOR
CITY OF PORT TOWNSEND
BIOSOLIDS COMPOST FACILITY
STATE WASTE DISCHARGE PERMIT ST 6127
APPENDIX A--PUBLIC INVOLVEMENT INFORMATION
Ecology proposes to reissuea permit to the city of Port Townsend Compost Facility. The permit includes
wastewat
reasons for requiring permit conditions.
Ecology will place a Public Notice of Draft on April 10, 2019in Port Townsend Leader to inform the public
and to invite comment on the proposed draft state waste discharge permit and fact sheet.
The notice:
Tells where copies of the draft permit and fact sheet are available for public evaluation (a local
public library, the closest regional or field office, posted on our website).
Offers to provide the documents in an alternate format to accommodate special needs.
Asks people to tell us how well the proposed permit would protect the receiving water.
Invites people to suggest fairer conditions, limits, and requirements for the permit.
Urges people to submit their comments, in writing, before the end of the comment period.
Tells how to request a public hearing about the proposed State Waste Dischargepermit.
Explains the next step(s) in the permitting process.
Ecology has published a document entitled Frequently Asked Questions about Effective Public
Commenting,whichis available on our website.
You may obtain further information from Ecology by telephone, 360-407-6278, or by writing to the address
listed below.
Water Quality Permit Coordinator
Department of Ecology
Southwest Regional Office
PO Box 47775
Olympia, WA 98504-7775
The primary authorsofthepermit and fact sheet addendum are Carey Cholski and Dave Dougherty.
5/15/19Page 3
FACT SHEET ADDENDUM FOR
CITY OF PORT TOWNSEND
BIOSOLIDS COMPOST FACILITY
STATE WASTE DISCHARGE PERMIT ST 6127
APPENDIX B --YOUR RIGHT TO APPEAL
You have a right to appeal this permit to the Pollution Control Hearing Board (PCHB) within 30 days of
the date of receipt of the final permit. The appeal process is governedby chapter43.21B RCW and chapter
371-CW 43.21B.001(2) (see glossary).
To appeal you must do the following within 30 days of the date of receipt of this permit:
File your appeal and a copy of this permit with the PCHB (see addresses below). Filing means
actual receipt by the PCHB during regular business hours.
Serve a copy of your appeal and this permit on Ecology in paper form -by mail or in person. (See
addresses below.) E-mail is not accepted.
You must also comply with other applicable requirements in chapter 43.21B RCW and chapter 371-08
WAC.
ADDRESS AND LOCATION INFORMATION
Street Addresses
Mailing Addresses
Department of EcologyDepartment of Ecology
Attn: Appeals Processing DeskAttn: Appeals Processing Desk
300 Desmond Drive SoutheastPO Box 47608
Lacey, WA 98503Olympia, WA 98504-7608
Pollution Control Hearings Board Pollution Control Hearings Board
1111 Israel RoadSouthwest, Suite301PO Box 40903
Tumwater, WA 98501Olympia, WA 98504-0903
5/15/19Page 4
FACT SHEET ADDENDUM FOR
CITY OF PORT TOWNSEND
BIOSOLIDS COMPOST FACILITY
STATE WASTE DISCHARGE PERMIT ST 6127
APPENDIX CRESPONSE TO COMMENTS
No comments were received.
5/15/19Page 5
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To be Provided Later
SEPA
DETERMINATION OF NONSIGNIFICANCE
_________________________________________________________________
Proposal: City of Port Townsend 2024 General Sewer Plan (GSP) Update - The City of Port
Townsend is proposing a 2024 General Sewer Plan update. Updates to the City of Port
improvements that are correcting deficiencies and ensure a safe and reliable sewer system for
current and future customers. This GSP has been prepared in accordance with Washington
Administrative Code (WAC) 173-240-050.
File References: LUP 24-045
Location/Legal Description: Proposed code amendments will apply city-wide.
Proponent: City of Port Townsend Public Works Department
250 Madison Street Suite 2R
Port Townsend, WA 98368
Lead Agency: City of Port Townsend, Planning & Community Development Department (PCD)
Determination of Nonsignificance: The City of Port Townsend, as SEPA lead agency for this
project, has determined that the proposal will not have a probable significant adverse impact on
the environment and issued a Determination of Nonsignificance under the State Environmental
Policy Act Rules (WAC 197-11-340). This determination was made after a review of a completed
environmental checklist and other information on file with the City of Port Townsend which can
be obtained from the address shown below.
SEPA Public Comment/Appeal Period: Written comments/appeals concerning the
environmental analysis and SEPA determination must be submitted to the Development Services
Department no later than 4:00 p.m., October 23, 2023. This comment period will be the only
time to comment on the environmental impacts of the proposed project. Any appeal of a
Threshold SEPA determination for Type V applications is heard by the City Council. Please
address SEPA comments/appeals to the staff contact listed below.
Staff Contact: Jenny Murphy, Associate Planner
Email: jmurphy@cityofpt.us.
Address: City Hall, Suite 3
250 Madison Street
Port Townsend, WA 98368
Signature: ___________________________ Date: October 8, 2024
Emma Bolin, AICP
Director of Planning & Community Development
1
TO: All Permit and Review Authorities
ENVIRONMENTAL RECORD
The environmental review consisted of analysis based on the following documents included in
the environmental record.
DOCUMENTS/REFERENCES:
Exhibit A: Environmental Checklist
Exhibit B: Draft 2024 General Sewer Plan
Exhibit C: Notice of Determination of Non-Significance (October 8, 2024)
Unless otherwise noted, the above information is available for review at the Planning and
Community Development Department, City Hall, 250 Madison Street, Suite 3, between the hours
of 9 am to 1 pm Monday through Thursday.
I. PROPOSAL DESCRIPTION
The Environmental Checklist adequately describes the proposal. In short, the primary purpose
of the plan is to help identify and schedule sewer system improvements that are correcting
deficiencies and ensure a safe and reliable sewer system for current and future customers.
II. PERMITS/APPROVALS REQUIRED PRIOR TO CONSTRUCTION
The 2024 General Sewer Plan is a non-project action requiring City Council approval.
Subsequent project actions (e.g. construction/repair projects) implementing the plan may be
subject to further project-level SEPA review unless they are found to be categorically exempt
under Chapter 197-11-800 WAC. Project actions may also require:
1)
2)
Master Program
3) A construction permit from the Department of Ecology
4)
5)
6)
III. PUBLIC COMMENT
The SEPA Comment period ends on October 23, 2024 (Ex. C).
The following discussion is intended to address potential environmental impacts not addressed
by the environmental checklist (Exhibit A).
2
The checklist covers the potential significant environmental impacts resulting from adoption of
the 2024 General Sewer Plan. Future SEPA reviews may be required for project actions
undertaken to implement the adopted Plan (i.e., construction of capital facilities).
V. ANALYSIS AND THRESHOLD DETERMINATION
The Environmental Checklist (Ex. A) adequately addresses the environmental impacts of the
proposed Plan. The General Sewer Plan is one tool to help implement the land use element of
the comprehensive plan. Subsequent project actions (e.g. construction/repair projects) may
require further project-level under SEPA, Critical Areas (PTMC 19.05), or Shorelines Master
Program.
No probable significant adverse impact on the environment have been identified from the
proposed 2024 General Sewer Plan, therefore issuance of a Determination of Non-significance is
warranted.
3
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THIS PAGE INTENTIONALLY LEFT BLANK
CITY OF PORT TOWNSEND
DEPARTMENT OF PUBLIC WORKS
ENGINEERING
DESIGN STANDARDS
MANUAL
April 1997
Robert L. Wheeler, P. E., Director of Public Works
David L. Peterson, P.E., City Engineer
Colette Kostelec, P.E. Development Review Engineer
WASTEWATER
Chapter 3
WASTEWATER
1. General Requirements
a. Wastewater systems refer to the facilities that transport, treat, and discharge
water-carried waste materials from domestic, commercial, and industrial sources.
This chapter of the Standards addresses service connections to the existing mains
as well as extensions, repairs, lift stations, and other system improvements.
b. Any extension, replacement, or other improvement of the Port Townsend
Wastewater System must be approved by the Department of Public Works and all
extensions must conform to the current standards of the City of Port Townsend
and to Department of Ecology regulations. The material contained in these
Standards shall be used in conjunction with the Washington State Department of
Ecology regulations to develop all plans and specification for construction of
wastewater facilities. Where there are conflicts or differences between these
standards, DOH regulations and city ordinances, the DOH regulations shall apply
followed in order of precedence by city ordinances and these Standards.
c. City sewer service shall not be extended outside the city limits.
d. In designing and planning for any development, it is the developer’s
responsibility to see that adequate wastewater systems are provided. The
developer must show, in the proposed plans, how the development will be served
by sewers and whether the existing system can adequately handle the flows and
loads. Improvements necessary to assure that the existing system will not be
adversely impacted are the responsibility of the developer. A detailed analysis of
the system may be required to evaluate the capacity of the existing hydraulic
system to handle the new loads.
e. Anyone that wishes to extend or connect to the city’s wastewater system should
contact the Department of Public Works for preliminary information and
discussion of the extension proposed. The design of wastewater system
improvements is the responsibility of the Developer proposing the construction
and upgrading of the public wastewater system.
f. Prior to acceptance by the city and the discharge of any wastewater, all
improvements must be completed and approved, as-builts submitted, all rights-of-
way or easements filed, and all applicable fees as set forth in Chapter 3.36 PTMC
must be paid.
g. Issuance of building permits for new construction of single family residences
within new subdivisions shall not occur until final Public Works approval of all
improvements is given unless otherwise allowed through an approved
improvement methods report and/or construction bond. For commercial projects,
building permits may be issued upon completion and approval by the Public
Works Director of a Wastewater Discharge Plan (including pretreatment when
necessary). Certificates of occupancy will not be granted until final Public Works
approval and acceptance of all wastewater system improvements is given.
h. All requests for inspections and for witnessing tests shall be scheduled with the
City of Port Townsend 3-1 April 1997
Engineering Design Standards
WASTEWATER
Public Works Department 24 hours in advance. Failure to give adequate advance
notice may result in delays to the contractor for required inspections.
i.Warranty: The developer shall warranty sewer mains and other wastewater
system improvements for one year after installation, approval and acceptance by
the City and shall be responsible for one year for any unanticipated settling of
excavations or repairs to restored street surfaces. All necessary repairs shall be
performed immediately or the city shall perform the repairs at the developer’s
expense.
j.Traffic Control: For work in opened streets and rights-of-way, the contractor shall
follow procedures described in Chapter 1 of these standards.
k.Approval for Construction Outside of Business Hours: Any work performed in
any street right of way at any time other than Monday through Friday 7 am to 6
pm must have the approval of the Public Works Department.
l.Noncompliance Penalty: Utility development permits may be revoked from any
contractor not complying with these specifications.
m. Survey: See Chapter 1 of these standards.
n.Standard Details: All construction shall comply with city Standard Details.
2. Design Standards
a. The design, construction, and maintenance and operation of wastewater systems
shall be in compliance with the city engineering design standards, the sewer code,
the wastewater system master plan, the requirements of Jefferson County
Environmental Health Department, Washington State Departments of Health and
Ecology, any applicable federal regulations, and the WSDOT/APWA Standard
Specifications.
b. The layout and sizing of extensions shall provide for the future continuation of
the existing system as determined by the Director. All sewers shall be designed
as a gravity sewer whenever physically and/or economically feasible or as
outlined in the Wastewater System Master Plan.
c. The following GENERAL CONDITIONS shall apply to all work on the
wastewater system, and, together with those in Chapter 1, Section 2a, shall be
included on any plans dealing with the wastewater system construction:
i. All work and materials shall conform to the City of Port Townsend
Standards and WSDOT/APWA Standard Specifications.
ii. The city shall be given 72 hours notice prior to scheduling a diversion of
flows in the wastewater system.
iii. During the construction of mains and services, the contractor shall cap,
plug, or secure the ends of such lines whenever the project is shut down at
the end of the day so that contaminates will not enter the lines.
iv. All lines shall be tested in conformance with the standard specifications.
Prior to final acceptance of all installations, the city reserves the right to
conduct an inspection of all main lines by the use of television equipment.
v. The city construction inspector shall be notified a minimum of 24 hours
in advance of the time that a service connection to an existing main is
City of Port Townsend 3-2 April 1997
Engineering Design Standards
WASTEWATER
needed so that city inspection may be scheduled for the work. The
inspector shall be present at the time of the tap.
vi. Prior to backfilling, all sewer lines and appurtenances shall be inspected
and approved by the city’s inspector. Approval shall not relieve the
contractor for correction of any deficiencies and/or failure as determined
by subsequent testing and inspections. It shall be the contractor’s
responsibility to notify the city for the required inspections.
vii. Approximate locations of existing utilities have been obtained from
available records and are shown for convenience. The contractor shall be
responsible for verification of locations and to avoid damage to any
additional utilities not shown. If conflicts with existing utilities arise
during construction, the contractor shall notify the public works inspector
and any changes required shall be approved by the Public Works Director
prior to commencement of related construction on the project.
viii. All sewer main extensions within the public right-of-way or in easements
must be staked by survey for line and grade prior to starting construction.
3. Sewer Service Connections
a. All new developments within the city limits are required to connect to the city’s
sewer system with the following exception:
i. New single-family residential development occurring on parcels equal to
or greater than one acre in size: a) which is more than 500 feet from the
nearest city sewer main, and b) which is not subject to review and
threshold determination under the State Environmental Policy Act
Implementing Ordinance, Chapter 19.04 PTMC, or c) which is not subject
to the permit requirements of the Environmentally Sensitive Areas
Ordinance, Chapter 19.05 PTMC.
b. Managed individual or group on-site septic systems are allowed for new
development which meets the requirements of subsection a.i, provided the
following conditions are met:
i. The soil conditions and parcel size will support the use of an on-site septic
system until connection to the city’s sewer system;
ii. The system is designed to be efficiently converted to the city’s sewer
system;
iii. The developer enters into a no protest agreement with the City (i.e.,
requiring connection to the city’s sewer system within two year(s) of
when a sewer main is within 260 feet of the property line, and/or
participation in a Local Improvement District (“LID”) which may include
installation of sewer mains, interceptors, pump stations and/or Latecomer
Agreement paybacks), filed on record title, as a condition of any building
or development permit; and
iv. The septic system is approved by the Jefferson County Environmental
Health Department.
c. Existing parcels containing an on-site septic system are required to connect to the
City of Port Townsend 3-3 April 1997
Engineering Design Standards
WASTEWATER
city’s sewer system by July 2002.
d. After July 2002, any parcel containing an on-site septic system will be required to
connect to the city’s sewer system unless the nearest sewer main is greater than
260 feet (i.e., one city block measured along public rights-of-way) from the
nearest portion of the subject parcel (in which case connection is required within
two years of when the sewer is within 260 feet).
e. Notwithstanding subsections, c and d above, if an on-site septic system fails
connection is required unless the nearest portion of the subject parcel is greater
than 500 feet from the nearest sewer main, in which case the septic system may
be repaired to serve the subject property.
4. Sewer Main Extensions and other System Improvements
a. When Required. A main extension, main replacement, pump station, maintenance
hole, force main or other system improvement may be required for any of the
following reasons to mitigate the direct impacts of the proposed development:
i. Whenever a customer requests service and the premises to be served does
not abut a sewer main;
ii. Whenever the existing sewer main(s) is not adequate to provide the
necessary service;
iii. Whenever the development cannot be served by a gravity system;
iv. Where other components of the sewer system are inadequate to handle the
increased wastewater discharges;
v. Whenever necessary to handle wastewater from the development; or
vi. Whenever necessary to protect public health and safety.
b. Right-of-way acquisition. When sufficient right-of-way does not exist, the
customer shall provide sufficient right-of-way or utility easements where
necessary to serve the needs of the development and for the maintenance and
orderly growth of the system.
.
5. Procedural Requirements
a.Public Works Technical Conference. Anyone wishing to connect to or extend the
city’s water system is encouraged to request a meeting with Public Works staff to
obtain preliminary information of the location of existing facilities and to review
water system extension requirements. A technical conference will generally be
required for anyone proposing a main extension.
b.Application for sewer service. Any person seeking to connect to the City’s water
system shall submit an application to the Public Works Department on forms
provided by the city.
i. Information required for the sewer service application shall include:
(1) The name of the owner or agent and his or her mailing address, the
street address or name of the premises to be served, and the legal
description of the premises to be served.
(2) An estimate of wastewater volumes for all subdivisions, multi-
family, mixed use, commercial and manufacturing proposals.
City of Port Townsend 3-4 April 1997
Engineering Design Standards
WASTEWATER
(3) A site plan and details showing the proposed location for the
service connection.
(4) Upon request by the director, a hydraulic analysis and assessment
of the ability of the collection system and treatment facilities to
handle the wastewater discharges and proposed mitigations if
required.
(5) Proposed pretreatment facilities and best management practices for
commercial and manufacturing facilities.
(6) Any other information deemed reasonably necessary by the
director to review the application for compliance with Title 13
PTMC and these Standards or required by other provisions of the
City’s code, Department of Health requirements, SEPA, permit
conditions, or city ordinance.
(7) The design drawings and specifications for the water system
improvements required under “item d” below.
ii. Complete Application Required. The city will not process any application
unless and until the information required by this section is substantially
complete. The public works director may reject an application as
incomplete within a reasonable time of review, in which case the director
shall return it to the applicant with an indication of the additional
information needed to make the application complete.
c.Utility Development Permit. A Utility Development Permit is required for any
sewer main extension, replacement, and other system improvements:
i. The Utility Development Permit shall contain all design drawings and
information necessary for the Public Works Department to determine
compliance with these Standards and the applicable codes and standards
incorporated by reference into these Standards.
ii. When the City receives the application, the application will first be
checked for completeness. Once it is determined to be complete the City
will begin its review of the application.
iii. Utility Development Permits are reviewed and approved by the Public
Works Department. Construction shall not commence until the permit is
approved by the Director.
d.Construction Drawings and Engineered Plans. All applicants for sewer system
connections and improvements shall furnish drawings and specifications
necessary to describe and illustrate the proposed sewer system improvements. If
base maps prepared by a licensed land surveyor are available, the design and
construction plans shall be submitted on such maps. If base maps are unavailable,
the public works director may require a survey to avoid conflicts with existing
facilities, to determine elevations and contours, and to determine the limits of the
right-of-way.
i. All plans for sewer main extensions and other sewer system improvements
shall be prepared, signed and stamped by a civil engineer licensed in the
State of Washington.
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ii. For main extensions and replacements of 260 feet (one city block) or less
in Tier 1 which do not require plans under another authority of the PTMC,
the developer has the option of the city performing the engineering for the
fee identified in Chapter 3.36 PTMC. Alternatively, the developer may
pay for his or her own engineering with the full cost to be borne by the
developer.
iii. All design and construction plans and specifications shall be prepared in
accordance with current DOT/APWA standard specifications and the
city’s engineering design standards. If discrepancies exist in the standards
and specifications, the city engineering design standards shall take
precedence.
iv. The requirement for engineered plans may be waived in certain instances
as defined by the PTMC and approved by the City Engineer for minor
improvements to the sewer system that can be adequately inspected and
certified by the City Engineer and that will still assure the long-term
integrity of the system. As-builts must still be submitted.
v. All plans must be reviewed and approved by the Director prior to
proceeding with construction.
vi. Plans should be prepared on plan/profile type sheets and show both plan
and profile views. Other utilities are to be shown in profile view and in
plan view.
vii. Plans shall include specific city standards for such items as maintenance
holes, drop connections, side sewers, etc.
viii. Plans shall show invert elevations of the main at the outlet and all inlets of
each maintenance hole, slope of the main, and surface elevations of the
maintenance hole lid. In the profile view, the finish ground elevation over
the pipe shall be shown as well as crossings of other existing or proposed
utilities. Stationing of side sewers from the downhill maintenance hole is
required. Drawings shall show mainline connection depth and distance
from nearest maintenance hole, the street that mainline connection is made
in and the nearest cross street shall be identified. Drawings will show and
label all connections and pipe diameters.
ix. In all cases where a line is to be placed in an easement, the easement is to
be shown with measurement information to accurately lay it out prior to
constructing the pipe line.
e.Inspection: All sewer system installations shall be inspected and approved by the
City. It is the responsibility of the developer or contractor to notify the city 24
hours in advance of necessary inspections at the proper point in construction. All
excavations must be left open until inspection is complete.
f.Approval, Acceptance, Conveyance and As-Builts: Certificates of occupancy will
not be granted until final Public Works approval and acceptance of all
improvements is given easements filed, all applicable fees paid and as-built
drawings are received.
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6. Gravity Sewer Mains
a.Size
i. Sewer mains shall be sized for the ultimate development of the tributary
area.
ii. New gravity systems shall be designed on the basis of an average daily per
capita flow of not less than 100 gallons per capita per day. The table
“Design Basis for Sewage Works” from the DOE Manual is assumed to
cover normal infiltration, but additional allowances shall be made where
conditions dictate. Generally, laterals and submain sewers should be
designed to carry, when running full, not less than 400 gallons daily per
capita contributions of sewage. When deviations from these per capita
rates are used, a description of the procedure used shall be submitted to
the City Engineer for review and approval. Nothing shall preclude the
city from requiring the installation of larger mains if the city determines
that a larger size is needed to meet requirements for future service. The
developer may be eligible for a Utility Latecomer Agreement.
iii. The minimum pipe size for sanitary sewer mains shall be 8 inches in
diameter, except that a 6-inch sewer may be approved in limited instances
where the sewer has no potential to be extended to serve future customers.
iv. The minimum size service connection lateral in the street right-of-way
shall be 6 inches and the minimum size for a service lateral on private
property shall be 4 inches in accordance with the Standard Details. The
depth at the property line shall be 5 feet, except as approved by the City
Engineer. Sewer connections to the main shall be made with a wye
connection. All new main connections to existing mains shall require the
installation of a new maintenance hole if not made at an existing
maintenance hole.
v. All nonferrous pipe shall be installed with metal wire and tracer tape as
shown on the Standard Details and described in Chapter 1.
vi. Gravity sewer mains shall typically have a depth of 5 feet. Actual depth
will be determined by the slope, flow, velocity, and elevation of the
existing system as proposed by the applicant and approved by the City.
b.Slope
i. All sewers shall be designed and constructed to give mean velocities,
when flowing full, of not less than 2.0 feet per second, based on
Mannings’ formula using an “n” value of 0.013. The following are
minimum slopes which should be provided; however slopes greater than
these are desirable.
(1) 8-inch Mains: 0.40 feet per 100 feet.
(2) 10-inch Mains: 0.28 feet per 100 feet.
(3) 12-inch Mains: 0.22 feet per 100 feet.
(4) 15-inch mains: 0.15 feet per 100 feet.
(5) 18-inch mains: 0.12 feet per 100 feet.
(6) 21-inch mains: 0.10 feet per 100 feet.
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(7) 24-inch mains: 0.08 feet per 100 feet.
(8) 30-inch mains: 0.06 feet per 100 feet.
(9) 36-inch mains: 0.05 feet per 100 feet.
ii. Under special conditions, slopes slightly less than those required for the
2.0 feet per second velocity requirement may be permitted by the City
Engineer upon request by the applicant with engineering documentation.
iii. Sewers shall be laid with a uniform slope between maintenance holes.
iv. Sewers with slopes greater than 6.0 percent slope, or where groundwater
may travel as a conduit, may require check dams. Such dams shall be
noted on the drawings.
v. Sewer mains on slopes of 20% or greater shall be securely anchored per
WSDOT/APWA standards.
c.Materials: Materials for sanitary sewer pipe shall meet the requirements of the
following:
i. Sanitary Sewer Pipe - Preferred:
(1) PVC Ringtight ASTM D3034, SDR 35 or ASTM F789 with joints
and gaskets conforming to ASTM D3212 and ASTM F477.
(2) Ductile Iron Pipe shall conform to ANSI A 21.51 or AWWA C151
and shall be cement mortar lined with push-on joint or mechanical
joint. The ductile iron pipe shall be Class 52, unless otherwise
approved.
ii. Sanitary Sewer Pipe - For repair only:
(1) Concrete Sewer Pipe shall meet the requirements of ASTM C14
Class 3, unless otherwise approved.
(2) Reinforced Concrete Sewer Pipe shall conform to ASTM
Designation C76 and shall be of the class specified on the plans.
iii. Pipe Zone Material - see drawings
d.Connections to Existing System
i. All new sewer connections to the existing system shall be physically
plugged until all tests have been completed and the city approves the
removal of the plug.
ii. Connection of the new sewer mains to existing maintenance holes shall be
core drilled for connection by the contractor. The base shall be
rechanneled so as to provide smooth transitions into existing flows.
iii. Connection of a new sewer onto an existing sewer main where a
maintenance hole is not available shall be accomplished by pouring a
concrete base and setting maintenance hole sections around the existing
pipe. For extending onto the end of a pipe, a precast base may be used.
iv. Straight grades between the invert out of the new maintenance hole and
the invert out of the existing maintenance are preferred over drops.
v. An outside drop connection shall be constructed per the Drawings for a
sewer entering a maintenance hole whenever the elevation of the entering
sewer is 24 inches or more above the maintenance hole invert. Where the
difference is less than 24 inches a fillet shall be poured below the entering
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pipe to prevent solids deposition.
vi. Connections when a building sewer is the same size as the existing sewer
main shall be accomplished by installation of a new maintenance hole,
unless otherwise approved in writing by the City.
e.Taps: Taps shall be a gasketed saddle wye or wye with a couplet. Taps shall not
protrude into the existing sewer main. All taps shall be by the contractor. The
contractor shall notify the city inspector at least 24 hours prior to the tap. All tap
installation shall be witnessed by the city inspector.
f.Location: Parallel water and sewer lines shall be laid at least 10 feet apart
horizontally. If this is impractical, the water line shall be at least three (3) feet
above the top of the sewer line. Wherever it is necessary for sewer and water
lines to cross each other, the crossings shall be made at an angle of approximately
90 degrees, and the sewer shall be located three or more feet below the water line
if possible. See Chapter 2 “Water and Sewer Main Separation” for additional
requirements.
g.Installation
i.General
(1) Installation of gravity mains shall be per WSDOT/APWA Standard
Specifications Section 7-17 and 7-08.3.
(2) For typical trench details see Standard Details.
(3) Excavations shall be kept free of water.
(4) Safety is the responsibility of the contractor. Contractor(s) must
conform to WISHA standards when working in excavations.
(5) All crossings and patches of city streets will be made to City
standards and the contractor will be held responsible for the
integrity of the patch for one full year.
(6) All new sewer services will be equipped with backflow
preventer(s) when required by the City because of the floor
elevation of the house relative to the sewer, or due to sewer main
surcharging.
ii.Pipe Bedding and Pipe Zone
(1) The pipe bed shall be prepared per WSDOT/APWA 7-08.3(1)C.
(2) Pipe bedding and pipe zone material shall be per the
WSDOT/APWA Standard Specifications Section 9-03.9(3).
(3) Bedding and pipe zones shall be as shown on the Standard
Drawings.
(4) Bedding and pipe zone material shall be placed in more than one
lift. The first lift, to provide at least 4 inches thickness under the
pipe, shall be placed before the pipe is installed and shall be spread
and compacted so that the pipe is uniformly supported.
Subsequent lifts of not more than 6 inches thickness shall be
installed to the crown of the pipe A further 12 inch lift of
moderately compacted material shall be placed over the crown of
the pipe prior to the start of backfilling the trench.
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(5) Compact all pipe zone and bedding material to 95% density as
determined by ASTM D698.
iii.Backfill
(1) Backfill material shall be per WSDOT/APWA 7-08(3) and as
shown on the standard Drawings
(2) Backfill shall be compacted to 95% density under roadways and
traveled ways. Controlled density backfill may be proposed as an
alternate for road cuts. Compaction to 90% may be allowed where
no roadways, driveways or vehicular travel will occur.
(3) Backfill to the elevation necessary to apply required surface
treatment
iv.Surface Treatment
(1) Repair surface to original condition, including all driveways,
culverts, curbs, gutters, sidewalks or other facilities damaged by
the construction
(2) Street repair shall be per Chapter 6.
(3) Any drainage ditches damaged or disturbed during construction
shall be pulled, dug, or otherwise repaired to restore storm
drainage flow.
(4) Any disturbed vegetation shall be restored.
h.Laying the Sewer Pipe
i. Per WSDOT/APWA 7-083(2).
ii. All sewer main installations shall have line and grade stakes or hubs set
prior to construction.
iii. The contractor may use any method such as “swede line and batter board”
and “laser beam” etc., which would allow him to accurately transfer the
control points provided by the surveyor in laying the pipe to the
designated alignment and grade.
iv. When using the “swede line and batter board” method, the contractor shall
transfer line and grade into the ditch where they shall be carried by means
of a taut grade line supported on firmly set batter boards at intervals of not
more than 30 feet. Not less than three batter boards shall be in use at one
location. Grades shall be constantly checked and in event the batter
boards do not line up, the work shall be immediately stopped and the
cause remedied before proceeding with the work.
v. When using a “laser beam” to set pipe alignment and grade, the contractor
shall constantly check the position of laser beam from surface hubs
provided by the surveyor to ensure the laser beam is still on alignment and
grade. In the event the laser beam is found out of position, the contractor
shall stop work and make necessary corrections to the laser beam
equipment and pipe installed.
i.Inspections
i. Pipe and connections shall remain exposed until inspected by the City.
ii. The contractor or his/her representative will be on-site at the time of the
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inspection.
j.Plugs and Connections
i. All fittings shall be capped or plugged with a plug of an approved material
gasketed with the same gasket material as the pipe unit; or shall be fitted
with an approved mechanical stopper; or shall have an integrally cast
knock-out plug. The plug shall be able to withstand all test pressures
without leaking, and when later removed, shall permit continuation of
piping with jointing similar to joints in the installed line.
k.Jointing
i. Where it is necessary to break out or connect to an existing sewer during
construction, only new pipe having the same inside diameter will be used
in reconnecting the sewer. Where joints must be made between pipes with
a mismatched wall thickness, the contractor shall use flexible gasketed
coupling adaptor to make a watertight joint. Couplings shall be those
manufactured by “Romac,” “Smith Blair,” or approved equal for
reinforced pipes and “Fernco” or approved equal for non-reinforced pipes.
l.Cleaning and Testing
i. All sanitary sewer pipe installations shall be cleaned and tested in
accordance with WSDOT/APWA Standard Specifications Section 7-
17.3(2). A copy of this testing procedure is included at the end of this
Section. Sewers and appurtenances shall be cleaned and tested after
backfilling by either the exfiltration or low pressure air method at the
option of the contractor, except where the groundwater table is such that
the Public Works Director may require the infiltration test.
7. Alignment Tolerance
a. The maximum deviation from established line and grade shall not be greater than
1/32 inch per inch of pipe diameter and not to exceed 1/2 inch per pipe length.
b. No adverse grade in any pipe length will be permitted.
c. The difference in deviation from established line and grade between two
successive joints shall not exceed 1/3 of the amounts specified above.
8. Maintenance holes
Maintenance holes shall be installed in accordance with these Standards, the Standard
Details and WSDOT/APWA Standard Specifications Section 7-05. Where conflicts
occur, these Standards shall have precedence over WSDOT/APWA Standard
Specifications Section 7-05.
a.Materials:
i. Precast maintenance holes shall meet the requirements of ASTM C478
with either a precast base or a cast-in-place base made from 3,000 psi
minimum structural concrete. Maintenance holes shall be as shown on the
Standard Details and WSDOT drawing B-23a. Any deviations from the
Standard Details will be subject to review of a shop drawing submitted by
the contractor and approved by the Public Works Director.
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ii. The minimum diameter of maintenance holes shall be 48 inches; larger
diameters are preferable for large diameter sewers.
iii. Joints between maintenance hole elements shall be rubber gasketed
conforming to ASTM C443.
iv. All pre-cast concrete shall be Class 4000. Maintenance hole channels
shall be Class 3000 concrete. Concrete blocks or concrete (masonry) rings
may be used for adjustment of the casting to final street grade.
v. Standard precast cones shall provide eccentric reduction from 48 inches to
24 inches with height of not less than 18 inches and 54 to 24 inches with
height of not less than 24 inches. The eccentric cone shall be offset so as
not to be located in the tire track or a traveled lane and shall be in line
with the steps.
vi. Maintenance hole frames and covers shall be cast iron conforming to the
requirements of ASTM A536, Grade 80-55-06, Olympic foundry Type
MH 30D/T, or approved equal. The minimum clear opening in the frame
shall be 24 inches. Grade rings and covers shall be machine-finished or
ground-on seating surfaces so as to assure non-rocking fit in any position.
The public works director may require that maintenance holes located in
areas subject to inflow shall be equipped with a PRECO sewer guard
watertight insert, or approved equal. All casting shall be coated with
bituminous coating prior to delivery to the job site.
vii. Safety steps shall be fabricated of polypropylene conforming to ASTM D-
4101, injection molded around a 1/2 inch ASTM A-615 grade steel bar
with anti-slip tread. Steps shall project uniformly from the inside of the
wall. Steps shall be installed per WSDOT/APWA Standard Plan B-24a.
b.Spacing and location:
i. Maintenance holes shall be provided at a maximum spacing of 300 feet.
Intervals at distances greater than 300 feet require the approval of the
Public Works Director.
ii. Maintenance holes shall be provided at intersections, and at all changes in
direction, grade or pipe size.
iii. All maintenance holes are to be accessible to maintenance vehicles.
iv. Maintenance holes are not allowed in a fill section unless base is on a cut
section.
v. A maintenance hole is required at the ends of all sewer mains, unless
approved by the City.
c.Construction Requirements:
i.Bedding: Unless otherwise directed by the Public Works Director,
maintenance holes shall be constructed with pre-cast base sections or cast-
in-place to grade upon a 6 inch minimum depth of Crushed Surfacing Base
Course meeting the requirements of WSDOT/APWA Standard
Specifications Section 9.03.9(3). \[verify ref.\] The Crushed Surfacing Base
Course shall be compacted to 95% maximum density.
ii.Joints: Shop drawings of the joint design shall be submitted to the Public
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Works Director for approval, prior to manufacture. Completed joints shall
show no visible leakage and shall conform to the dimensional
requirements of ASTM 478. Joints shall be grouted from the inside.
iii.Lift holes: Shall be grouted from the outside and the inside of the
maintenance hole.
iv.Maintenance hole channels: All maintenance holes shall be channeled
unless otherwise approved in writing by the Public Works Director.
Maintenance hole channels shall be made to conform accurately to the
sewer grade and shall be brought together smoothly with well rounded
junctions. Channel sides shall be carried up vertically to the crown
elevation of the various pipes, and the concrete shelf between channels
shall be smoothly finished and warped evenly with slope to drain.
v.Maintenance hole pipe connections:
(1) All pipes except PVC pipe entering or leaving the maintenance
hole shall be provided with flexible joints within 1/2 of a pipe
diameter or 12 inches, whichever is greater, from the outside face
of the maintenance hole structure and shall be placed on firmly
compacted bedding, particularly within the area of the maintenance
hole excavation which normally is deeper than that of the sewer
trench. Special care shall be taken to see that the openings through
which pipes enter the maintenance hole are completely and firmly
rammed full of non-shrink grout to ensure water tightness.
(2) PVC pipe connected to maintenance holes shall be provided with a
maintenance hole adaptor complete with gasket and approved by
the Public Works Director. No pipe joint in PVC shall be placed
within 10 feet of the outside face of the maintenance hole.
vi.Connections to existing maintenance holes:
(1) The contractor shall verify invert elevations prior to construction.
The crown elevation of laterals shall be the same as the crown
elevation of the incoming pipe unless specified. The existing base
shall be reshaped to provide a channel equivalent to that specified
for a new maintenance hole.
(2) The maintenance hole shall be kept in operation at all times and
the necessary precautions shall be taken to prevent debris or other
material from entering the sewer, including a tight pipeline bypass
through the exiting channel if required.
(3) The contractor shall core drill, line drill or wall saw an opening to
match the size of pipe to be inserted. Where line drilling is the
method used, the drilled holes must be interconnected. Line
drilling shall be accomplished by the use of a small core drill or a
rotary hammer. Jackhammer shall not be used. All openings must
provide a minimum of 1 inch and a maximum of 2 inches
clearance around the circumference of the pipe. Upstream pipes,
except PVC pipe, penetrating the walls of maintenance holes shall
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be placed with the bell facing out such that the bell is placed snug
against the outside wall of the structure as the angle of penetration
allows. Pipe, except PVC pipe, leaving or entering maintenance
holes shall be provided with a flexible joint within 1/2 of a pipe
diameter, or 12 inches, whichever is greater. After pipes have
been placed to their final position, they shall be grouted tight with
non-shrink grout in a workmanlike manner. PVC pipe connecting
to existing maintenance hole shall be installed using gasketed
inserts as approved by the Director.
(4) The contractor shall comply with all safety requirements for
confined space entry.
9. Service Connection, Side Sewer, Building Sewer
A service connection for sewer (including the side sewer and building sewer) refers to the
extension from the building plumbing at a point two feet from the outside of the outside
of the outer foundation wall of the structure to the public sewer main. The service
connection within the public right-of-way is considered the side sewer; the building
sewer connects from the building to the side sewer.
a.General
i. Prior to construction a side sewer permit must be obtained from the City.
During the permit process the City may request additional information
about the type and amount of flows anticipated to the sewer system.
ii. Drawings for side sewers shall be required on forms provided by the city
during the permit process. Information to be supplied is specified on the
form. If the service connection does not involve extension of a main,
design of the side sewer by a licensed engineer is not required.
iii. A separate and independent side sewer shall be constructed for every
premises, except where multiple connections are approved by the Public
Works Director.
iv. All side sewer service connections shall gravity flow into the City’s
wastewater system unless otherwise approved.
v. The construction of sewer service connections and side sewers shall
conform to the latest edition of the Uniform Plumbing Code,
WSDOT/APWA 7-18, and to the other Sections of these Standards.
Where inconsistencies exist, these Standards for side sewers shall apply
alike to all side sewers on public rights-of-way and private property.
vi. Maintenance of the sewer service connection is the sole responsibility of
the owner of the premises served.
vii. Side sewer locations shown on the drawings shall be subject to relocation
in the field after construction starts.
viii. If a side sewer is to serve two houses a six-inch clean out extending to
within 12 inches of the ground surface will be required at the wye where
the upper-grade connections are made.
ix. Side sewers are not permitted to cross a public right-of-way or run parallel
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to the right-of-way centerline. All lots must front on a public sanitary
system in order to be served.
x. If a building sewer is to serve more than one property, by joint agreement
of the owners, an approved document insuring that all properties involved
shall have perpetual use of the side sewer, and having provisions for
maintenance and for access for repair purposes, shall be signed by the
recorded owner. This document shall be notarized and recorded with the
county auditor and shall be referred to as an “easement.”
b.Size
i. The minimum size for side sewers in the public right-of-way is 6-inches in
diameter.
ii. The minimum size for a single family residential building sewer shall be
4-inch diameter.
iii. The minimum size of a dual residential, commercial/industrial and multi-
family building sewer is 6-inches in diameter. A larger size may be
required as determined by projected wastewater flows from the service.
c.Slope
i. The minimum slope on side sewers and building sewers shall be 2 percent.
d.Installation
i. Installation of service lines shall be the same as Water Main - Installation
above.
ii. No side sewer connection shall be made to the public sewer until that
section of sewer main has been approved by the city for side sewer
connections.
iii. Connections to mainline will be sanitary tee or wye; 45 and 22 degree
wyes may also be used depending on the situation. Connection to
mainline will be either saddled, strapped and gasketed or installed with
rubber repair coupler with stainless bands. Cutting in a ringtight sanitary
tee or wye is also an option. No glue joints are allowed. No 90 degree
bends are allowed. All right angle bends will be made with a combination
of two 45 degree bends.
iv. In the event that there is no suitable tee or stub out, a tap to the main may
be made by a licensed contractor, under the direct supervision of the
Public Works Director. The tap shall be made with the approved rubber
joint saddles on all types of sewer main. Grouting in a tee or wye is not
permitted. Great care shall be taken in cutting a neat hole into the sewer
main, and in the event of breakage of the sewer main, the broken section
shall be removed and replaced at no cost to the city. \[Alternate to iii\]
v. The contractor shall prevent entrance of all foreign material into the pipe.
vi. The type of joint to be used for connecting the side sewer pipe to the tee or
stub out shall be that for which the wye was designed. Rubber or plastic
joint adapters shall be used as required to connect pipes and wyes of
different materials or joint designs. Selected bedding material shall be
hand-tamped in a moist condition under and around the wye and
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connection to the wye made so as to prevent any pressure on the wye.
Care shall be taken to prevent the dislodging of this hand-tamped material
during the balance of the backfill and water settling operation.
vii. A cleanout shall be provided within three (3) feet of the building or
structure served. The cleanout shall be a wye from the service line with a
branch installed upward. The wye connection shall be of the same size as
the service run. A vertical riser shall be installed in the wye. This riser
shall be brought to within 12 inches of the finish grade and capped with an
approved cast iron plug or plastic plug with metal for detection. The plug
shall be machined to fit the standard joint of the pipe being used, with the
standard gasket.
viii. The connection to the building sewer shall be suitable rubber gasket
sleeve or adapter. Grout joints will not be allowed. In exceptional cases,
the Public Works Director may allow a connection using a hot pour
jointing material JC 60 or approved equal.
ix. Where any property served by a side sewer carries industrial waste, the
owner or occupant shall install a control maintenance hole in the side
sewer to facilitate observation, sampling and measurement of the wastes
when the same may be required by the Public Works Director. Such
maintenance hole shall be accessibly and safely located and shall require
plans approved prior to installation by the Public Works Director, and
shall be maintained and installed by the owner or occupant at his/her sole
expense.
e.Excavation, Bedding, Backfill and Compaction:
i. Follow procedures for sewer mains
ii. It shall be the responsibility of the licensed contractor to cut the road
surface, dig a trench, lay the pipe, make the connection to the sewer or
wye and backfill the trench within the limits of any public thoroughfare or
right-of-way.
iii. The contractor shall restore all roadways, drainage features, culverts, and
all other disturbed features to their original condition or as shown on the
drawings.
iv. The contractor shall prevent any damage to the sewer main, tee or stub
out, and shall so conduct his/her trenching operations as to prevent the
possibility of damage occurring. Undercutting of sewer main and wye is
prohibited.
v. The bottom of the trench must be smooth and free of large rocks which
may injure the side sewer pipe. Where unsuitable bedding is found, as
determined by the Public Works Director, the contractor shall over-
excavate and prepare a bedding.
vi. Minimum cover for side sewers shall be five feet in the right-of-way
unless otherwise approved.
f.Special discharge situations:
i. In any case where the house or building drain is too low to permit gravity
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flow to the public sewer, the same may be lifted by an individually-owned
pumping facility that discharges to the side sewer or the sanitary sewer.
ii. A backwater valve may be prescribed by the Public Works Director where
elevations of the sewer require it.
(1) The effective operation of any backwater valve shall be the
responsibility of the owner of the side sewer.
g.Pipe Materials: the following pipe may be used between the sewer main and the
property line and shall be used between the property line and the building drain:
i. Preferred: PVC
ii. Other: Cast Iron, Concrete Pipe
iii. The concrete pipe shall be rubber gasket pipe using "Tylox," "Flex-Tite,"
"Press Seal" or other approved units. The cast iron pipe shall have
mechanical joints or "o" ring rubber gasket joints Tylon or equal.
h.Testing:
i. All side sewers shall be tested before backfill but after piping is suitably
anchored. Side sewers that are reconstructed or repaired to a length of 10
feet or more shall be tested for water tightness. Testing of newly
reconstructed sections of side sewers consisting of a single length of pipe
will not be required. Testing shall be performed in the presence of the
City Inspector in accordance with WSDOT Standard Specifications. A
copy of this testing procedure is included at the end of this Section.
ii. When a new side sewer is installed, the entire length of new pipe shall be
tested. In cases where a new tap is made on the main, the first joint of
pipe off the main shall be installed with a test tee, so that an inflatable
rubber ball can be inserted for sealing off the side sewer installation for
testing. In cases where the side sewer stub is existing to the property line,
the test ball may be inserted through the clean-out wye to test the new
portion of the side sewer installation.
10. Grease Traps
Grease traps shall be required for all restaurants and other food processing facilities.
Grease traps shall be cleaned at least once per year. All maintenance and cleaning costs
are the responsibility of the property owner/operator.
11. Pump Stations
Any pump station which is intended to be conveyed to the City for operation and
maintenance shall meet the following requirements.
a.Pump Station (General): Pump stations must be designed and installed to take
into account pressure and hydraulics of distribution system, safety and aesthetics.
b.Noise Control: The following shall be provided for noise abatement and control:
i. All pump stations will be provided with adequate noise control to meet
state noise guidelines.
ii. Pumps shall be housed in a concrete or equivalent structure with sound
attenuation provided.
City of Port Townsend 3-17 April 1997
Engineering Design Standards
WASTEWATER
iii. Pump stations shall be located away from residences where feasible.
c.Plans: The plans for lift stations shall include the following:
i. An overall site drawing of the lift station showing the location of all
components including elevations;
ii. Service size, voltage and enclosure type and location in relation to the
pump station;
iii. A list of specific materials used including quantity description and
manufacturer names;
iv. A schematic and line diagram of the service and motor control center and
lift station;
v. All applicable telemetry installation with schematics;
d.Operations and Maintenance Manual: Three sets of the Operation and
Maintenance manual from the lift station manufacturer shall be supplied.
e.Design Report: A design report shall be submitted with each lift station
demonstrating its conformance with the standards and shall address the following
items:
i.Pump Data: size and type, horsepower, pump curves, head capacity,
velocity
ii.Motor: size and type, cycle length, type of motor
iii.Controls: type
iv.Telemetry: alarm system compatible with City system
v.Housing: size and type, ventilation, humidity control, interior lighting,
access
vi.Well sizing: type, storage capacity
vii.Maintenance: warranty, tools and equipment required
viii.Electrical Service: size and type, source
ix.Corrosion Protection: type of materials, coatings, linings, maintenance
x.Site Layout: location of lift station on property
xi.Testing: operational, pressure
xii.Piping and Valves: size and type
f. Pumps are to be engineered and manufactured under a written Quality Assurance
program. The Quality Assurance program is to be in effect for at least five (5)
years, to include a written record of periodic internal and external audits to
confirm compliance with UL Quality Assurance specifications.
g. Lift stations must be either a wet well/dry well type or submersible type.
h.Location:
i. Lift station structures and electrical and mechanical equipment shall be
protected from the 100 year flood.
ii. Lift stations shall be readily accessible by maintenance vehicles during all
weather conditions. The facility should be located off the traffic way of
streets and alleys.
i.Emergency Power:
i. Lift stations must be provided with an emergency power source or
auxiliary pumping equipment to ensure continuous operability unless
City of Port Townsend 3-18 April 1997
Engineering Design Standards
WASTEWATER
experience has shown the frequency and duration of outage to be low and
the lift station and/or sewers provide storage sufficient for expected
interruptions in power service.
ii. Provision of an emergency power supply may be accomplished by
connection of the station to at least two independent public utility sources,
or by provision of portable or in-place internal combustion engine
equipment that will generate electrical or mechanical energy, or by the
provision of portable pumping equipment.
iii. Emergency power shall be provided that, alone or combined with storage,
will prevent overflows from occurring during any power outage that is
equal to the maximum outage in the immediate area during the last 10
years. If available data are less than 10 years, an evaluation of a similar
area served by the power utility for 10 years would be appropriate.
iv.In-Place Equipment:
Where in-place internal combustion equipment is utilized, the following
will apply:
(1) The unit shall be bolted in place. Facilities shall be provided for
unit removal for purposes of major repair or routine maintenance.
(2) Provision shall be made for automatic and manual startup and cut-
in.
(3) Unit size shall be adequate to provide power for lighting and
ventilating systems and such further systems that affect capability
and safety as well as the pumps.
(4) The unit internal combustion engine should be located above
grade, with suitable and adequate ventilation of exhaust gases.
(5) If diesel fuel is used there shall be a containment area for 125% of
the diesel fuel tank capacity.
v.Portable Equipment:
Where portable equipment is utilized, the following apply:
(1) Pumping units shall have the capability to operate between the wet
well and the discharge side of the station and the station shall be
provided with permanent fixtures that will facilitate rapid and easy
connection of lines.
(2) Electrical energy generating units should be protected against
burnout when normal utility services are restored, and should have
sufficient capacity to provide power for lighting and ventilating
systems and any other station systems affecting capability and
safety, in addition to the pumping units.
vi.Storage:
Where storage is provided in lieu of an emergency power supply, wet well
and tributary main capacity above the high-level alarm should be
sufficient to hold the peak flow expected during the maximum power
outage duration during the last 10 years.
j.Telemetry:
City of Port Townsend 3-19 April 1997
Engineering Design Standards
WASTEWATER
A telemetry system shall be installed at the lift station which shall be
connected to and compatible with the existing city alarm system for
transferring alarm conditions from the lift station to the central alarm
monitor.
k.Automated Controls:
A comprehensive automation system for the lift station shall be supplied.
The equipment provided shall be a completely integrated control system
consisting of the required power equipment (motor starters, circuit
breakers, etc.), automation and monitoring equipment in a factory wired
and tested assembly. The submersible level transducer and solid-state
controller shall be standard catalogued products of the system supplier to
assure one source responsibility, proper system interconnections and
reliable, long term operation. The city will accept a Bulletin
A1000/D152/F100 Control system as manufactured by Consolidated
Electric Company, or equal. Float switches shall not be used.
l.Pump Features:
i. The following Submersible pumps are acceptable: Flight, Gorman-Rupp,
Fairbanks & Morse, or equal.
ii. Heavy duty, nonclog submersible capable of passing a minimum of 3"
spheres.
iii. Oil-filled, double mechanical shaft seals.
iv. Integral over temperature and moisture protection.
v. Rail mounted; stainless steel Schedule 40 pipe.
vi. Pump Sizing: Minimum two pumps. Sized to handle peak flow with one
pump out of service.
vii. Pump Accessories: All accessories shall be constructed of Type 304
stainless steel.
viii. Pump safety chain: Able to lift pumps from wet well. Three-eight inch
(3/8”) diameter 18” stainless steel chain, then stainless steel cable to top of
rail. Safety chain clip; eye bolt for safety chain (304 SST)
ix. Intermediate guide bar bracket: Provide if guide bar exceeds 20’ in length
x. Lifting lugs: Provide if equipment exceeds 70 lbs.
xi. Anchor bolts: 316 stainless steel, at least 1” diameter
xii. Pump Installation: Pumps shall be automatically connected to the
discharge connection elbow when lowered into place.
xiii. Spare Parts / Special Tools: Supply the following: 1 set special tools, 1
set upper and lower seal assembly per pump, 1 wear ring per pump, 1
complete O-ring set per pump, 1 set upper and lower bearings, 1
mechanical set seals.
xiv. Pump Painting
(1) Preparation: Abrasive Blast or centrifugal wheel blast (SP 5)
(2) Paint Material: Polyamide, anti-corrosive, epoxy primer.
(3) Min. Coats, cover: 1 coat, 2.5 MDFT
m. Instrumentation and Control: Provide heavy-duty waterproof control and power
City of Port Townsend 3-20 April 1997
Engineering Design Standards
WASTEWATER
cable, motor temperature sensors for thermal overload detection. Stainless steel
control panels required.
n.Special Construction: Equipment suitable for Class I, Division I, Group C and D
hazardous location.
12. Individual Sewage Disposal Systems
The type, capacities, location and layout of a private sewage system shall comply with all
Department of Public Health of the State of Washington, or other state regulatory agency,
and to the regulations of the city. No septic tank or cesspool shall be permitted to
discharge to any public sewer or natural outlet or to the ground surface. The owner shall
operate and maintain the private sewage disposal facilities in a sanitary manner at all
times at no expense to the city. All private septic tanks shall be thoroughly pumped a
minimum of one time during any three-year period.
City of Port Townsend 3-21 April 1997
Engineering Design Standards
WASTEWATER
CHAPTER 3 - APPENDIX
Exhibit # Standard Detail # Title
1 SS- 1A Single Sewer Service
2 SS - 1B Dual Sewer Service
3 SS - 1C Deep Trench Service Connection
4 SS - 2A Trench Section Trenching Pavement Restoration
5 SS - 2B Pipe Bedding
6 SS - 3 Standard Maintenance Hole/New Maintenance Hole
on Existing Sewer
7 SS - 4 Sewer Cleanout Detail
8 SS - 5 24" Maintenance Hole Frame and Lid
9 SS - 6 Drop Connection for Sanitary Sewer
10 SS - 7 Pavement and Installation Underground
Maintenance Hole
11 SS - 8 Typical Sewer Connection to Existing Sewer Mains
12 SS - 9 Pipe Anchor Detail For Slopes Greater Than 20%
13 SS - 10 Check Valve Assembly for Joint Use Side Sewer
14 SS - 11 Polypropylene Ladder and Maintenance Step
15 Cleaning and Testing (3 Pages)
City of Port Townsend 3-22 April 1997
Engineering Design Standards
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
ESBGU
THIS PAGE INTENTIONALLY LEFT BLANK
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Page 1 of 41
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00
0.0020.0060.0050.0040.0061.6010.0040.9650.0430.5770.0180.3030.4530.0051.4552.7716.5520.1254.2080.0060.0030.7740.0092.3280.0090.3380.8840.439
69.33711.29888.50667.43569.48546.13897.16735.32950.14616.85480.28338.04221.664
285.605119.185164.828
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
00
0.74
1.9160.914
0.33241.92530.76760.24723.76040.79231.19643.31925.32634.80010.91961.69823.76855.17231.03741.16190.72162.31934.408210.4181.26280.44110.65030.44111.20874.15080.91930.97910.53884.35412.06321.41031.50561
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176.69315.489639.4206
1,737.564,751.69
252.2698568.5213
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0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
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886888688686688866866686888886688886888688
10121030
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00000000000000
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0.4022.5290.4010.3980.4011.2510.3990.3990.4250.0470.3849.7460.401
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188.75
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Λ/ğƌĭǒƌğƷĻķΜ
555789
121212131314141415
4.24.75.66.17.57.98.18.18.38.48.48.78.99.29.49.69.6
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244
8.2231.25.087.3799.117.147.1
35.6665.6463.1457.5331.4349.42118.691.5495.2852.1290.2357.53
160.15227.84238.29232.16189.16229.23230.38106.35241.06102.73207.81245.52
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
8
6865
977709375430423379576395443
130113041139129611601203109813961256138410961188136712161175129113691371122210961252
MH-7253MH-7255MH-7251MH-7260MH-7264MH-7267MH-7268MH-7278MH-7282MH-7283MH-7286
W-Island Vista
W-Point Hudson
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000000000
0.035.287.41
65.6899.22241.157.5854.0817.1191.5995.2890.2857.59
230.42106.39102.77209.12244.06
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
777263532125386444
14081075137112761422133313701235
MH-7233MH-7237MH-7238MH-7236MH-7240MH-7241MH-7242MH-7246MH-7249MH-7251MH-7252MH-7254MH-7256MH-7257MH-7258MH-7259MH-7261MH-7263MH-7269MH-7272MH-7270MH-7271MH-7275MH-7276MH-7277MH-7279MH-7280MH-7284MH-
7281MH-7285MH-7287MH-7288
ƦƭƷƩĻğƒ bƚķĻ
914909108
3541629563097697628643492661394180504601696827445378256876644682524342777075508352937767510456188090443740746445763640204652562743952299626576376780665576634701482240735025
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ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 2 of 41
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1.610.59
82.970.01122.660.2170.0080.0293.3328.4890.0030.1140.0930.0120.0040.1120.0020.0060.1090.5480.0130.0360.0545.0640.0240.0248.1330.00878.69
20.25278.66513.41245.32514.19539.91330.48110.97212.242
603.801177.202186.952109.239656.526151.453
1,227.191,567.09
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5.30483.44
2.08941.06190.57061.09861.14520.44112.29094.26631.03160.40380.38270.45661.03161.14140.76992.50420.87251.08141.13319.07038.06051.00512.18543.51840.44110.76761.29470.93984.26770.3083
32.746711.909130.904195.228117.955416.533257.042739.4638
5,374.322,112.77
921.7406140.5805318.9053568.4034
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6668688668688688886886668666888686686
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78.82651.30364.056
954.232754.961
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1.560.821.615.953.62
76.94108.962.27107.1118.662.8238.0815.6533.3454.0812.9760.7122.7790.02
237.45185.87134.11227.58224.94230.47229.99229.72207.93216.24
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38
624498892579636528783178538857490714974181509457118586708
14201156121812161214123213331070138210501328
MH-7292MH-7299MH-7301MH-7304MH-7311MH-7315MH-7272MH-7320MH-7324MH-7322MH-7328MH-7330MH-7331
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000000000000000000000000000
1.610.850.821.685.973.68
75.6738.1612.04229.854.1413.05165.922.7990.12
115.86185.94145.64200.67
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96
41
857783869850987849377
149014241148145812111233
MH-7289MH-7290MH-7291MH-7293MH-7294MH-7295MH-7296MH-7297MH-7298MH-7300MH-7302MH-7303MH-7305MH-7306MH-7307MH-7308MH-7309MH-7310MH-7314MH-7316MH-7317MH-7318MH-7319MH-7323MH-7321MH-7325MH-7326MH-7327MH-
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81
118117
6544808243307457509531704658625680934427509046537339396162503171691780301415478462596656685276448004263639496444462877433804722539484797719547931175663965266779200271924085
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1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 3 of 41
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2.3110.0076.3330.0421.4734.4624.9350.4640.2530.0221.0134.3530.1160.0151.7150.0050.0060.4730.7530.0420.2880.2410.2894.067
75.512177.4425.05947.44726.66616.62328.19618.135336.7875.15823.269
102.885162.389140.024672.561197.345161.125990.159
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10.087115.316711.981436.820386.467612.697710.702919.598428.883343.3371
4,845.871,206.812,280.77
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Asbestos CementAsbestos Cement
68868886868688688866886686888886868648686
3018101018
ΛźƓΜ
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0.4010.1221.5230.4010.2911.8632.1980.3990.4140.118
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47.67322.04711.28339.369
216.568104.037
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
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25262729293134
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24.724.724.725.525.525.625.826.226.226.526.826.926.927.327.727.728.247.228.428.529.530.130.130.230.430.431.131.532.332.732.833.133.133.333.533.733.833.9
254.2
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2.7937.179.51.7543.31.6113.8
16.0438.59210.4245.513.0590.1234.13163.444.4818.1556.6886.4933.3419.5864.23
182.45244.91117.39129.09144.34218.49244.61226.02119.88187.63
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887618725475129325159631326396898511818724544594954857509518970
1174108611641279124312411159122510621158140312931073
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5ƚǞƓƭƷƩĻğƒ bƚķĻ
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6.21.7
2.891.83
16.0738.6955.2813.1690.2390.9356.8186.6219.7213.8464.36
210.79118.13142.13150.56168.73245.17226.73153.85189.42
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
7971
726158630513819782595858657259516252918
10871255108811251310142313071380
MH-7333MH-7334MH-7335MH-7336MH-7338MH-7339MH-7340MH-7341MH-7342MH-7344MH-7282MH-7346MH-7320MH-7348MH-7347MH-7350MH-7324MH-7352MH-7353MH-7354MH-7356MH-7358MH-7360
ƦƭƷƩĻğƒ bƚķĻ
34
848908776
529043934017279156115080281154304164110438064905543249046778116123354348379864283221469721887602545239543963722423446440394543468029631777283172627366523950653634443785
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 4 of 41
/Lt
0.380.21
0.0414.2840.1750.0090.0060.0080.0080.3171.3640.7790.1170.4820.0180.23324.960.17943.710.4130.0060.4470.0390.0050.3080.3090.5610.00423.550.0070.0185.187
28.26128.78145.44528.76760.30613.87912.95630.69470.76778.28675.866
120.931135.437581.416
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
7.77
0.4010.3671.3033.8388.261
1.34861.56091.06191.14440.79791.06196.55867.34541.03163.52882.17290.76763.27071.07691.06190.62867.78722.37060.70270.71181.93550.24721.06190.89310.51921.27720.40381.77882.1805
20.835817.453731.532733.4697
4,808.664,846.271,820.35
104.7266112.9794180.3517151.8432
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcrete
Ductile IronDuctile Iron
Vitrified ClayVitrified ClayVitrified Clay
688886888888668868686888866888888886888886
30183012
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.4
ΛіΜ
0.8544.2190.5240.7042.4470.1132.252
{ƌƚƦĻ
20.32167.08664.249
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
353637383940404243
ΛŅƷΜ
35.135.435.635.936.837.137.137.537.637.938.138.338.137.139.439.539.839.839.940.440.540.741.642.142.142.742.743.143.243.443.643.644.144.244.444.644.7
\[ĻƓŭƷŷ
000000000000
4.8
233256
16.759.68.3468.335.46.085.8343.39.54
59.55263.2237.342.9940.9291.59228.548.9124.49228.529.54171.7242.7212.115.9989.0412.79
167.92224.41145.64242.34221.44
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
68104474
914142610848324240986598809519250136828190862908481409
134812091215120013591231141712311173118710761315137311581073
MH-7363MH-7300MH-7370MH-7276MH-7375MH-7378MH-7383MH-7394MH-7570
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000000000060000
17
61.28.314.975.72
270.423.8841.07256.291.7474.5668.1410.6216.0490.0412.97
145.79242.62242.87
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
67
530651984249411817189867479
135411521377139312281406135214871091115110861382
MH-7362MH-7365MH-7364MH-7366MH-7367MH-7368MH-7369MH-7371MH-7374MH-7376MH-7377MH-7379MH-7380MH-7382MH-7384MH-7387MH-7388MH-7389MH-7390MH-7391MH-7392MH-7393MH-7395MH-7396
ƦƭƷƩĻğƒ bƚķĻ
382458
137915140107813938
7582432339571695462376913811782173384737804875937887477336858078199340523080477440987597441345073029120439966742768042764809434542824018213639537744
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 5 of 41
/Lt
SM 1
0.040.96
0.1521.7880.0631.6420.0558.1492.8420.0091.15419.580.0210.0560.0110.9573.1120.0110.0564.6350.2770.0231.1530.0462.9910.0410.035
56.74570.57499.02838.882172.7940.96450.45335.42146.28458.20415.85718.01927.43242.292
102.362505.847791.556606.349109.123
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.86
4.7921.9211.5832.748
0.48474.82241.77732.49382.57784.35131.03162.08186.53850.63224.52620.33244.07551.06193.15671.53010.45381.11665.98641.31563.28351.48771.205932.8854.27720.44112.15654.09325.00644.76451.6838
84.705627.434319.933610.6764
1,200.584,888.912,288.014,897.34
191.0272113.7888
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
4666666688866868868686688888888868886866
181830121830
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000000
0.41.10.40.40.40.40.4
ΛіΜ
5.1350.4290.2770.5390.4231.9660.4280.396
{ƌƚƦĻ
20.487
159.225169.573461.678402.843
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
45505051535456
ΛŅƷΜ
45.445.546.346.246.246.746.946.946.948.248.248.848.849.749.850.451.351.651.751.752.653.153.353.253.453.653.954.254.555.155.455.656.479.357.157.958.258.1
265.8
\[ĻƓŭƷŷ
000000000000000000
5.9733.28.83
15.1895.2815.5278.4631.6218.0123.8486.0286.06123.229.5413.71
123.66232.63233.93240.86215.13230.12207.55240.14109.67164.08247.75117.92216.42
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
6331621814
975987157303413406319951534841424195811592622395723120
1294108911891112123713201171114913871314115614181322139111651187
MH-7397MH-7399MH-7402MH-7404MH-7409MH-7415MH-7348
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000000000000
8.3479.59.04
87.42124.895.2815.6568.1431.8318.5686.2333.4197.3413.94
234.19241.06216.12245.52123.42247.99227.39118.24
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
241576
583986156818405356253535762682399318
1303107012961335131712641071131512221486132311661239
MH-7400MH-7398MH-7278MH-7401MH-7405MH-7264MH-7406MH-7407MH-7408MH-7410MH-7411MH-7412MH-7413MH-7414MH-7416MH-7418MH-7419MH-7420
ƦƭƷƩĻğƒ bƚķĻ
46
627906213339536752247249
6281510041303684761711595626525241426285241737686662510339466436438122916304311272587810152364344331511830858073652954657824436420154853450817841150
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 6 of 41
/Lt
0.520.012.123.560.020.07
2.3651.1710.4060.0480.0370.0740.3832.2760.1260.0940.0580.0350.0131.4090.3681.0350.7689.8160.3080.9851.5040.6483.7170.005
54.97459.79370.87344.14816.26397.76279.25533.96314.15320.87264.24611.82424.252
574.095223.584106.085
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.1180.8822.3835.302
7.52169.25022.44324.62620.78071.979823.8191.50583.84383.62420.20059.55782.54461.10991.90371.64810.95753.37665.75351.22340.76761.13940.24723.04475.15540.64133.75965.73842.22281.31530.5072
31.135712.1259890.25333.592312.215163.4843
4,029.47
143.9761116.4817170.5141219.6691
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcrete
Ductile Iron
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
8868886868868686868888886868688866688888888
301510
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.40.40.4
ΛіΜ
5.720.150.69
2.1232.6940.2330.2460.9120.3970.4950.4959.919
{ƌƚƦĻ
44.203
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
5960606162626264656769
ΛŅƷΜ
58.258.459.459.860.360.460.360.360.760.761.162.362.862.963.564.264.564.765.366.166.266.166.466.366.466.666.667.467.968.568.768.769.369.769.9
\[ĻƓŭƷŷ
000000000000
0.8
85.874.52.2147.1
204.6202.425.2559.5565.6879.3817.8664.7898.23168.812.4785.7686.2366.4812.1774.7876.98
229.42240.77216.24116.09165.16227.09224.51174.73201.47228.88113.91222.79
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
4
89
173188215914975118232489440738456843205665562
113012061190107713091416111413451121130612081262107212781401128511751229
MH-7422MH-7252MH-7425MH-7428MH-7432MH-7299MH-7433MH-7436MH-7408MH-7442MH-7444
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000000
204
3.380.892.48
204.465.9218.0165.0398.4886.0686.0286.4966.7412.6347.4477.26
230.66240.91227.68174.99104.57229.22120.79
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
3145
167640508978650793591438554971781203200567
1316121213401266107811451342130514501368
MH-7421MH-7423MH-7424MH-7429MH-7427MH-7426MH-7431MH-7415MH-7434MH-7435MH-7409MH-7437MH-7438MH-7357MH-7439MH-7440MH-7441MH-7443MH-7445MH-7447
ƦƭƷƩĻğƒ bƚķĻ
26
341254116
417812653198462671565190452233805377400623226003369675984149664811735464641875373929631572574614402539716653209353637984611217052302533180626671439412871011233022854768
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 7 of 41
/Lt
SM 1
SM 10
0.061.4680.20.02
39.160.3111.3170.0330.0510.4872.3170.0080.2560.6542.53319.580.1260.1020.0410.6230.6813.7860.0740.0280.0080.8155.91345.410.4060.251
23.99940.96444.92930.35520.43961.47343.64569.26724.60177.86116.58442.46230.425
160.951508.869197.569
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.118
82.3431.03162.12388.72912.09721.41814.083929.5750.51470.76762.70969.35828.29574.03381.06190.20059.07031.42020.99152.33742.32482.30290.14170.76764.34969.41892.462810.7151.74470.64624.2207
30.878210.234526.086886.267127.598220.0258
1,532.145,120.784,750.892,281.534,864.94
116.1651107.8214145.0379
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
8688866888868686686886888668888886888868
183030183010
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000
0.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.350.280.86
0.5230.4985.5380.20540.790.4880.6531.6140.1150.7739.605
{ƌƚƦĻ
15.01525.39120.537
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
70727373748081
ΛŅƷΜ
70.370.470.971.571.771.773.372.172.873.373.374.274.474.774.874.975.175.275.876.176.476.676.877.677.878.178.277.979.179.998.580.380.480.380.381.581.681.7
265.7
\[ĻƓŭƷŷ
00000000000
12
116260
1.138.345.9715.91.83
237.3254.2155.6144.4215.1232.233.7176.9417.3178.7519.21253.165.0964.78202.4
242.59214.12124.36200.67113.21227.99259.37227.68120.79212.61240.14244.06
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
2867
824217160536728191986447180987168225216575254659782797873518305106
1184121513611364121112831350129714161074110413051149141812351206
MH-7451MH-7455MH-7458MH-7463MH-7468MH-7445
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000
1.416.1265.42.05
19.1795.7817.5779.0530.6619.58260.565.0915.9932.22
117.39242.87254.57148.44124.66113.51253.41229.23260.05121.11240.77244.39210.25
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
861729
159537981540491917423804612304215
141513001319113513491073110512581205
MH-7448MH-7449MH-7450MH-7452MH-7454MH-7456MH-7457MH-7459MH-7460MH-7461MH-7462MH-7359MH-7464MH-7466MH-7467MH-7468MH-7469MH-7470MH-7471MH-7508MH-7255MH-7473MH-7474
ƦƭƷƩĻğƒ bƚķĻ
33
959335619508601
4488129146361260227741321773805862933683647150614867421810013160509476261290166846273628313860257578629039873988291141196314628422565093256637871230807048234613
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 8 of 41
/Lt
SM 10
1.010.010.430.28
8.3232.9130.5050.0920.0554.1944.2050.0280.8224.3560.5047.3163.4090.0170.7820.0183.1230.8520.0470.4350.0071.3060.2033.735
28.11774.81612.88646.139108.5931.66158.29760.59461.30421.67727.28814.15394.187
123.373445.432443.595620.447595.569
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
6.678
1.52498.38092.50234.78710.92753.10690.79732.38751.30941.73070.39681.46815.42894.78130.82753.32481.37466.12133.61250.67254.97481.35721.17561.56139.67350.49442.45772.07981.47996.52510.76765.1082
13.258812.761117.789261.306920.143824.157724.058133.649632.3003
4,771.85
174.6994207.8421179.9106
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos Cement
8686888846686868868688888888686886888688888
301218
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000000
0.40.40.40.40.40.40.40.40.4
ΛіΜ
0.120.770.78
0.6536.2910.7622.0852.4011.044
{ƌƚƦĻ
45.31735.041
240.821156.909
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
858888899091
ΛŅƷΜ
205
82.182.484.384.284.484.583.384.784.785.586.587.187.687.887.988.288.688.689.289.289.790.288.390.890.690.691.291.591.592.192.392.592.893.693.793.593.993.793.9
\[ĻƓŭƷŷ
00000000000000000000
1717
6.9910.44.648.31
65.68218.563.8889.6710.2377.2614.8232.8215.46
234.64165.16235.19222.88192.04197.59235.19104.57230.02159.78222.23
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
66753366
551401989402785323725560200689712602185402316668436321654670703984
111313451131132111411395119614221080
MH-7478MH-7480MH-7481MH-7487MH-7488MH-7490MH-7441MH-7869MH-7405MH-7495
5ƚǞƓƭƷƩĻğƒ bƚķĻ
W-Hamilton Heights
000000000005000000000000
12
17.17.6434.79.29
66.0164.2390.0215.7677.6115.1841.17144.914.57222.632.82
235.19210.84223.56237.31104.94230.38
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
65332174
553402144993873988831606394878317320258136919
1114127011851077125011951326132213271118119614941108
MH-7477MH-7479MH-7361MH-7483MH-7330MH-7485MH-7484MH-7486MH-7397MH-7489MH-7260MH-7492MH-7493MH-7494
ƦƭƷƩĻğƒ bƚķĻ
44
918354261251946355907
41501598211375383673211241795487378365274143449416564229101519914000206078455010226645382110655232693773223865281392382066142246412545391201808942902634
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 9 of 41
/Lt
SM 2
0
0.041.870.010.04
4.1980.4660.2740.4230.0040.37919.587.3038.4493.7191.3213.7140.3520.0354.3530.0430.3320.1770.6360.3380.0635.6850.96515.240.7890.14419.58
43.078134.4431.00455.61911.31138.55431.00713.29380.587
155.627107.903447.561438.024
1,087.97
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0
0.74178.44032.71730.94062.96240.67410.30327.29131.67691.06192.97853.01654.33931.20631.68161.63466.93381.29781.13943.20850.72090.53880.76764.37063.93281.73590.30839.852824.2724.36321.0619
14.4005108.85311.629413.459312.755218.012512.741327.398117.049911.270812.895123.7559
208.9265892.9447
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos Cement
868868886888886686886888866688886888886666868
15
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000
0.40.40.40.80.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.6670.4190.3670.638
{ƌƚƦĻ
11.11116.44142.106
191.218
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
9595979798
ΛŅƷΜ
152100100101103
94.294.294.694.594.995.495.595.695.795.995.496.797.497.797.998.198.498.699.199.599.9
100.2100.5100.4100.7100.8100.6100.6100.9101.5102.2102.6102.5102.4102.9102.9
\[ĻƓŭƷŷ
000004000000000
175
4.146.08
72.5337.04249.1259.665.29186.572.3869.3424.53206.6134.863.1438.69
115.51212.33198.98107.33224.51133.72226.73115.11127.38236.33105.95142.64108.73128.73148.98
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
2037598711
382542588360460271398897606558196644213574333770249414627609622206632516380
12071208116713511307129012561076
MH-7497MH-7374MH-7449MH-7507MH-7511MH-7424MH-7336MH-7527
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000
260
3.614.5355.56.49
72.9137.4265.68237.369.74
115.88199.74182.45107.71249.74134.11227.09115.51127.77186.89106.35186.17109.13171.84
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
1358
455618551641638576599251212511
11681350109713411306121512911067110112751146
MH-7496MH-7498MH-7500MH-7499MH-7501MH-7502MH-7503MH-7504MH-7505MH-7301MH-7422MH-7497MH-7509MH-7510MH-7514MH-7515MH-7513MH-7512MH-7375MH-7516MH-7520MH-7522MH-7521
ƦƭƷƩĻğƒ bƚķĻ
730350204866426812160775
79766334237246121896242922594625436275794802202852127601218010626316216423334635233862632354225138871929653818822280788650821683560912963997225552924243
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 10 of 41
/Lt
4.8
0.12
0.0670.9670.3380.1290.0040.1480.2410.0234.0944.99763.810.0150.0240.0466.8220.5150.0562.1710.6314.37868.360.1913.0113.8076.129
85.24197.07332.83132.60530.07351.41217.51672.26718.02732.68138.07552.44117.23345.78937.19162.603
123.344146.634197.844
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
4.6230.8232.065
4.34743.31576.68952.24381.78060.44110.16387.53110.38381.85056.51977.95853.46070.44111.17361.81991.85473.61679.562220.5791.70722.84411.80811.44720.93461.72151.50864.79550.9366
10.729923.406357.915912.746318.561913.058311.9144
1,204.812,114.304,907.304,889.72
137.6047115.1032890.0525
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
888888888888868668686888888688888688666868
18301830
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
0.830.170.18
5.2371.4990.0940.6060.4980.2690.3510.6257.6751.1720.6119.825
{ƌƚƦĻ
206.1911.738
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
103106106107109112113
103.4104.1105.2105.6106.9107.2107.3107.4107.6108.1107.9108.1108.7108.8109.2109.4110.4110.5110.5110.5111.1111.1110.8111.9111.9113.2113.3113.5114.3114.5114.7115.1115.2116.5116.3116.4116.9116.7116.8
\[ĻƓŭƷŷ
00000000000000
22.68.380.89
-0.18
96.7478.1295.7812.4711.0935.6663.9466.0114.95
147.39253.49118.13235.75244.54254.57135.17247.06133.28229.22227.84172.86248.56230.12107.78249.53105.51161.53216.39
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
80
477543158521246384834491614387655707203453813990637760607327977708756306793553546117
1065109414151421112113041245128211981068
MH-7534MH-7870MH-7543MH-7548MH-7552MH-7553MH-7555
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000
162
22.70.268.831.09
97.17255.112.76135.611.4872.6466.4815.16
253.91123.66237.34245.19133.72227.84185.87249.26231.45108.73250.23116.83216.24
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
251146
841549157385833398708811926636758416753996784652118
136014931120141013041246127712781069
MH-7528MH-7530MH-7533MH-7472MH-7535MH-7540MH-7539MH-7541MH-7542MH-7545MH-7546MH-7547MH-7455MH-7549MH-7550MH-7551MH-7554
ƦƭƷƩĻğƒ bƚķĻ
2
54
311768763516
3111310724251160309427423065405375918086278339282349210320278052262646051286212875966308303334707599210178414692262749467595599732883780531724897370218224791176
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 11 of 41
/Lt
0.470.370.34
2.4351.5310.0150.4440.0821.6174.7770.5960.1310.0690.0610.0250.0130.2571.6250.4063.4734.4990.0120.10611.040.5970.4880.01173.6635.695.1154.1830.0350.206
27.49827.38387.85412.74134.24126.59238.86115.97570.49226.62375.252
116.155395.781
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
8.3522.5751.857
1.71521.08840.70792.89321.49131.48516.29960.45052.62474.02951.65130.42532.80311.44222.10765.57570.86640.64625.53030.90931.77520.90031.44390.95040.77650.76761.93562.692721.4653.92750.3276
14.435414.896427.455315.434757.4437
4,845.474,891.74
179.4695230.6338173.8464126.9753188.0177
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
88866688888888888888888686886686688888886
1812103030
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
1.210.280.13
0.2340.7280.1224.534
{ƌƚƦĻ
19.92749.28920.952
114.073197.288
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
119120122123125126126
117.1117.2117.2117.3117.7117.6117.9118.1118.5118.8119.5119.5119.4120.1119.9119.7120.3120.7120.7120.9121.1120.9121.2121.2121.7121.7121.6121.9122.3122.6131.5122.8122.5122.6122.9123.5123.6123.6124.1
\[ĻƓŭƷŷ
0000000000000
175
6.929.295.612.8584.94.21
41.5416.6528.7841.1725.6961.1175.3213.84228.516.0714.79
212.33207.93108.73232.78149.27217.98178.41244.06227.99249.74172.86100.44214.57174.61222.79
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
11
247838408109919566177995780426770450587125976339750428893916918637687542487757198
120713261179123511681230111910871311124911071229
MH-7438MH-7552MH-7559MH-7562MH-7566MH-7570
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000
6.1
7.398.5459.23.224.72
109.265.2517.5229.2627.1561.5975.81228.516.2214.95200.5228.5
212.28149.74218.26137.95244.55173.35100.93244.91
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
278864
842108619563997425126916338745696419755197
12101238105113981181112212971279123113851068120411061230
MH-7556MH-7557MH-7558MH-7560MH-7561MH-7563MH-7564MH-7565MH-7567MH-7569MH-7568MH-7572MH-7571MH-7573MH-7444
ƦƭƷƩĻğƒ bƚķĻ
6
72
441668879911514
311846101750484611402635196474912066365714137858208219286551180244584156126234372228482422952063404343614261476577702340301464302480667062614607411547661257
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 12 of 41
/Lt
SM 2SM 2
0.195.17
2.1351.9320.0184.5580.0991.1097.1090.0464.5580.0144.7244.6640.2320.3433.6640.0150.1570.25984.740.0180.0890.8636.1290.1430.3380.0311.5720.6121.5025.3459.4990.0240.351
66.98850.13746.62355.06838.79245.29347.73444.46677.007
259.314109.643
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.134
2.37783.63310.66480.24721.11311.766141.1293.40920.24721.03162.71912.52867.52371.38680.36964.36371.06190.88220.41182.45641.13582.71235.94648.82710.33245.34812.77441.06192.41165.39021.93930.975495.5575
3.3761.10458.3403
22.099216.236215.997312.566162.076838.1846
2,156.37
917.9251859.9427
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcrete
Vitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88888866888886686888866886888886886688888
1018151518
ΛźƓΜ
5źğƒĻƷĻƩ
000000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
1.083.562.293.44
3.6435.3382.4010.3465.5090.6660.3860.7693.624
{ƌƚƦĻ
19.852
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
127127128130132
125.7126.3126.5126.2126.6126.7127.2127.1127.1127.3127.9128.5135.8128.7128.9128.6129.2129.6129.7129.7247.7130.3130.1130.7130.4131.5131.5131.5131.3336.7131.4132.1132.6132.7132.6132.7133.1133.4133.5133.
2133.2
\[ĻƓŭƷŷ
0000000000000
193100
62.61.418.8362.25.97
20.7824.3761.7985.2555.7474.8121.9976.41121.862.37237.329.6290.3425.64
235.67234.08106.39231.18231.18168.11192.87210.79242.47207.98205.41197.59
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
12867660
955334262912335806715552603503227494811204204705458116726966425237297669987415186185791701
133410561276139011241325124712151267
MH-7577MH-7569MH-7580
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000
27.41.939.346.99
25.3669.3425.2585.7656.1875.32106.921.9583.53123.262.72238.632.6390.87203.1
232.83215.47208.51197.59202.43
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
7559
956333602517347199363492210706107723967378236989185183702
12471190112713461391137814191128
MH-7578MH-7436MH-7579MH-7581MH-7582MH-7583MH-7566MH-7584MH-7585MH-7586MH-7588MH-7587MH-7589MH-7590MH-7592MH-7591MH-7593
ƦƭƷƩĻğƒ bƚķĻ
45
748202624867430
3703388839344971452113693896417045031702350921741401112050383149278475601289781713014162654526212004117228104972768434398072407913293764163536824174125811992592
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 13 of 41
/Lt
0.090.12
0.0890.87797.270.2780.0110.2411.0451.2568.0530.68610.670.0890.0790.0620.1341.0371.0190.7570.1441.4020.3390.1260.0790.0460.1220.9840.0150.0120.6760.256
60.37112.04676.82317.12117.72463.89929.53665.373
336.662217.172152.073103.716124.112134.452
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
5.6256.277
8.47813.14492.98994.98610.76763.27420.38422.01442.35394.45362.76525.60681.24956.51145.98226.73116.11161.60923.13754.81013.39932.89574.79467.29191.64633.07047.91111.06876.68740.40380.90762.56385.4272
11.778219.186219.167827.6202
2,045.014,844.91
696.4732186.3035167.7499126.2077133.7734
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcrete
Vitrified ClayVitrified Clay
Asbestos CementAsbestos Cement
6888888668688886888888688868888888688668888
101830
ΛźƓΜ
5źğƒĻƷĻƩ
00000000
0.40.40.40.40.4
ΛіΜ
0.537.29
0.3950.4060.08113.610.1171.1315.9873.2642.2171.7243.4230.6970.489
{ƌƚƦĻ
10.90310.36580.63515.247
153.953
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
134135136136138139
133.8133.6134.1134.3133.9133.9134.4134.4134.5134.4135.6134.5135.2135.2135.5135.7135.7135.6136.3136.1136.5136.4136.6136.2136.9136.6136.9137.7137.9146.3137.7137.8138.2138.1138.5138.5138.6138.8138.6139.
1
\[ĻƓŭƷŷ
0000000000
5561
82.25.0791.484.924.933.4
56.9890.8722.09205.468.1415.3673.6692.6123.71204.2233.216.2264.36223.4200.522.09205.616.7934.13
116.38186.17234.13215.47248.38218.45174.03254.05231.48
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
9364858135
212236529721411871321243351262691654211520176723419435529336431248441807963364617371941
10821169122110931204106710601159
MH-7596MH-7540MH-7360MH-7389
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000000000
91.422.896.85.6174.243.582.2
68.6891.9593.1523.8298.9116.3872.5355.55253.1
204.68109.67235.67227.86218.49202.86219.47212.57232.16
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
1869805062
243903893322352904486692374806514382724417228727503375
1083122012531447128713861339109512831292131312741221
MH-7594MH-7562MH-7595MH-7597MH-7598MH-7599MH-7601MH-7602MH-7603MH-7604
ƦƭƷƩĻğƒ bƚķĻ
211415912807517595902
129240044372133223684639143676614097404437971336389231222127255317116242780627853012378411632809280123714076602419742151626220326297643334425291433619774638
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 14 of 41
/Lt
0.020.030.191.7225.1
0.1360.034612.22.3392.7310.2870.1690.6260.0820.0050.8350.3720.3398.3389.1160.4612.2090.2851.1310.2650.1060.4541.0820.6970.0510.853
95.21275.47516.87661.33511.00129.85957.037111.4999.95534.054
172.841137.857637.503208.397
1,588.20
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.96
5.5186.7541.211
2.39774.09341.54468.84699.37398.02450.98591.36730.99741.35590.24722.12381.61943.89041.43637.47664.03572.73978.53650.49443.27386.04661.50991.36133.88061.31561.83221.72274.92995.44522.51727.1522
39.995515.416955.162657.243219.514116.893611.3023
165.3728131.0316118.2889
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
668868886868668888886688688868868888868468888
10
ΛźƓΜ
5źğƒĻƷĻƩ
000000000000000
0.40.40.40.40.40.4
ΛіΜ
0.280.41
3.2652.2230.1867.9544.4245.1890.5551.6992.389
{ƌƚƦĻ
64.32610.29817.28315.344
143.905167.169
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
141141142143145145146146
139.4140.1140.2140.6140.6140.6140.6140.4140.9140.7141.2140.8141.4141.4141.8141.8141.7142.1143.3143.2143.6143.7143.9144.5144.8145.5145.6145.7145.8145.6146.1148.4146.6146.2146.2146.3146.3146.5
\[ĻƓŭƷŷ
00000000000000000
1.9
33.237.53.22
37.7971.7150.62144.9204.428.3431.0395.2883.2328.7827.1427.56249.9
227.86135.17219.22210.84230.02104.94249.26174.03201.29245.52177.84251.55
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
12
363689313524949195882778496614369584668572580704878940758384441555361840122764968591588973538802
1325133911851327128813851316124812221363
MH-7462MH-7323MH-7277
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000000
3.622.49
202.433.7651.1852.0450.3789.6729.36253.129.62250.5
232.45162.38135.73237.45207.55254.78105.51249.53106.81178.65255.05
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
624528707175520194877666691939756397627434560360121966587974539800
120611231420132813141308121311981299122313811362
MH-7607MH-7606MH-7610MH-7608MH-7609MH-7548MH-7611MH-7612MH-7613MH-7580MH-7615MH-7577
ƦƭƷƩĻğƒ bƚķĻ
809751489749
706621912625712137884615340022741210326014331876235013794495661380812057643563402241255226134550361445024518228121192184499931196292470011452051343824193630758922792847
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 15 of 41
/Lt
SM 2
0.279.49
19.683.0322.8750.0283.5340.1740.0160.0760.0280.8280.2563.7670.0022.4152.5680.0332.0590.1520.6831.5030.0980.1130.0211.2710.888
68.26449.84125.14242.29420.86841.38211.55416.55649.96460.04843.19517.59480.89597.94353.117
526.294131.091115.332204.195
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.946
3.70221.06738.24919.71827.10962.70311.25371.36355.62891.82092.29381.13181.03161.92951.04218.64524.238612.9192.90440.14178.28262.11613.27930.24221.08831.25821.51222.03725.31192.12481.80371.25720.51474
.35865.0832
28.543286.668116.9287146.90886.279615.831611.0744
4,941.88
909.8006118.4983
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88888888866888686888868888666666868888888
1210151230
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000000
0.40.40.40.40.40.40.4
ΛіΜ
0.22
0.2520.3883.7059.2840.2810.5280.1778.7280.2551.115
{ƌƚƦĻ
17.505
111.233
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
147147147147148149150152152153
146.9146.9146.7146.8146.9147.2147.8147.9147.5147.6148.3148.3148.4148.9148.8148.6148.6149.1148.6149.1149.6149.7149.5149.7150.2150.5342.9152.2152.2151.9152.4153.2152.7153.4153.6153.4
\[ĻƓŭƷŷ
0000000000000000
3.541.4221.362.2
20.2298.9125.6414.9689.74233.211.9830.1624.4110.2376.3723.98
232.39160.95219.23148.98251.55202.43198.66260.05209.04118.24186.89235.75181.73191.96
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
21
748589905410615486506658701549311432802464183842201792238132789638589211294942137790319111124194
12841275105813331105123910011124114113081178
MH-7400MH-7469
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000000
4.141.7562.8
20.5928.7890.33165.921.7238.5930.43195.110.6276.9825.69
232.96161.53207.93118.84187.49235.01235.75
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
89
749543412743433379754181361196788237133920633208327913326105
12481150114212811179
MH-7511MH-7559MH-7487MH-7616MH-7617MH-7555MH-7618MH-7351MH-7619MH-7349MH-7620MH-7622MH-7624MH-7623MH-7625MH-7626MH-7337MH-7629MH-7534MH-7630
ƦƭƷƩĻğƒ bƚķĻ
164260838509630973798
607722303139229322487464199424485072135023062084298317651198214612566953542441181330113824741367355150182337225039664444382933623819114442255881634110104461
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 16 of 41
/Lt
SM 3
1.4873.0640.0340.8660.1030.2531.3280.4540.2470.3530.0190.8561.4690.23746.960.0740.0710.0261.0850.0210.0863.7330.067
69.47653.73637.93790.20869.75631.69728.43811.42926.61912.12154.06518.32134.77625.06236.746692.3478.27418.10533.48573.63169.288
566.445221.848
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.749620.3921.56131.37942.91430.16380.40352.05754.89241.76441.75671.47471.71781.16032.93531.71914.91974.43472.546818.2030.87582.20721.35920.92544.79071.62611.43081.97122.42825.94544.27041.7449
30.720810.512611.831819.304210.122837.548649.357412.0318
1,021.71
109.8846142.9142125.4401125.2007278.3145
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos Cement
86888686688886868888888686866868888686868868
1512
ΛźƓΜ
5źğƒĻƷĻƩ
000000000000000
0.40.40.40.42.70.40.40.40.4
ΛіΜ
0.980.34
6.3940.5121.2093.7440.3810.5080.4251.5940.2530.4750.486
{ƌƚƦĻ
11.896
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
154155158160160160162
153.9153.7153.9154.1154.7154.5154.7155.4155.3155.2156.1156.2156.3156.5157.1157.2157.8157.3157.6158.6158.5159.2159.1244.8159.6160.4160.9160.9161.5161.4161.6161.5162.3162.4162.1162.6162.4169.1164.5
\[ĻƓŭƷŷ
000000000000000
204
9.044.44
25.3665.0368.14119.5158.3205.760.11258.860.46176.8209.532.7611.4874.13
111.73169.15198.66148.88185.87240.91202.86224.58250.23248.19204.32229.22215.05222.17
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
1392443445
839615956762650526411545788146636557946235900127417747374753182226184265926420715884719
1177120113881144135712121234126612881077
MH-7419MH-7871
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000000
9.665.07
35.1965.6468.76120.3186.560.71259.661.0933.3111.8974.78
169.77202.85150.77164.16222.79242.47177.84205.41229.99215.84
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
12913744
838610957550733145700562435871122415598801225980714716
1389105013511229126712891082
MH-7631MH-7632MH-7253MH-7633MH-7634MH-7635MH-7636MH-7637MH-7402MH-7638MH-7639MH-7495MH-7641MH-7640MH-7643MH-7442MH-7644
ƦƭƷƩĻğƒ bƚķĻ
7
2527
623203805439120518989360
22493542445121602414409945863123781944434236113122863681758647672798221551923227114722296240171070813159120235993471172128273249280723624001
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 17 of 41
/Lt
0.7814.5
23.860.3094.1474.0570.0319.4490.4410.1470.7420.104140.90.2910.1447.9771.16827.070.4540.0570.6220.3365.0650.0410.1251.6510.2230.051
60.74740.31920.90888.18423.47766.95237.46611.96932.47321.50622.91539.29946.21714.30994.481
529.713193.811198.762
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.8815.8652.728
0.49140.40382.67231.13391.51141.74013.63114.57237.64166.46054.30541.86051.76121.46810.98972.50663.60480.99050.53582.39072.62862.23981.16915.1241
15.139228.728674.530934.001610.511241.055729.150710.779819.8828
4,780.662,041.33
105.7582302.7699104.5397140.7903120.6059323.8952261.1116118.9394
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified Clay
Asbestos Cement
86188886888888688888888868888688888668886688
3018
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
0.48
0.1830.6680.4731.9174.1614.7890.2410.3430.6182.3527.7124.4142.3490.524
{ƌƚƦĻ
16.70330.226
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
166168169
164.1164.7167.6164.8164.8164.8165.2165.8165.3165.8165.5165.6165.9166.3165.8166.2166.6166.7166.3166.9166.9166.7167.2167.9167.7168.3168.6169.2168.8168.9169.6169.2169.8169.4169.9170.2169.9170.2170.6170.
2171.1171.3170.9
\[ĻƓŭƷŷ
00000000000
179126
16.73.5434.80.0324.530.7
262.1194.7186.148.5449.5422.2277.0726.1727.56107.127.14
218.45204.32239.39148.49234.07142.13242.47209.12117.39222.88236.76231.68229.04129.73229.23193.76
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
67782623
201431114420187533147901404549630385779444798947660822159401713539423844973579968736
13561180140811221267117614001337111511451253128613181425
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000
17
193100
4.210.6924.9
263.276.4126.1777.7430.16
219.23197.86240.05156.42234.64132.17243.27210.15126.67130.39230.34229.72130.41230.12107.78
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
66
198432112865186534149248401705629626494791445797656155711400942542424512
1348126812841286125211841282
MH-7648MH-7650MH-7649MH-7651MH-7652MH-7653MH-7655MH-7654MH-7311MH-7657MH-7343MH-7463MH-7658MH-7659
ƦƭƷƩĻğƒ bƚķĻ
73
917513402
758510724460230711803195415718471269207022921158312121142620246651914416274179822297297061182328301941391189688742382108502444873615227879984268229415503648372645717079
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 18 of 41
/Lt
SM 3
0.0534.1
6.8710.0914.2610.2960.0340.0150.3255.18248.980.0877.8048.6058.5760.7980.0920.0210.1210.16862.570.68221.350.0740.0510.1330.4340.5380.9160.2770.0220.7350.1181.572
29.27757.90755.69420.39128.20275.64725.00884.78329.63239.01829.812
220.612
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.0530.118
1.58781.13411.45830.47112.07620.95756.09231.40251.11381.74131.52954.10272.73581.31634.59821.06191.60711.92433.39354.38521.15791.89842.35971.48720.85721.39081.37372.11615.52631.61680.4035
23.570111.964824.7029260.224116.97784.264562.087329.411813.182612.0146
1,536.15
263.1013271.2562
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
88888668888686688888888888688686888688888886
1812
ΛźƓΜ
5źğƒĻƷĻƩ
0000004000000
0.40.40.40.40.40.40.40.40.4
ΛіΜ
0.961.77
5.3090.7732.5530.4566.9444.4416.5131.9219.217
{ƌƚƦĻ
11.97712.02710.646
136.828
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
172172173273176178178179179
171.5171.9171.3171.6171.7172.6172.8173.3173.4177.6174.7175.1175.3175.6175.4175.9175.6176.5176.1176.1176.9176.8176.9177.4177.7177.2177.8177.6177.7178.3177.9178.5178.6178.5178.5178.8178.9
\[ĻƓŭƷŷ
0000000000000
7.6985.12.574.64
25.6928.7831.8376.3790.9327.1587.4283.5392.2866.74
222.88125.52224.56223.55213.24136.12109.03111.58215.84126.67212.28161.24256.38123.66187.63260.37137.95227.09175.47
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
8880
613812306712584780177307100161385896356550823656194140819997583313653492157345795126309461554
117913241186119113381210108011811293130610841395
MH-7437
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000
99
116
8.3834.885.85.685.36
236.449.54214.932.6377.0735.0492.99178.983.23
126.21224.89222.88127.38224.51112.27257.09142.64188.34260.23
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
87
813305779218101160357559712816644822141590744805129311555
118013371242120810811102118211101085
MH-7660MH-7662MH-7661MH-7663MH-7664MH-7665MH-7666MH-7667MH-7433MH-7668MH-7553MH-7671MH-7669MH-7670MH-7672MH-7673MH-7674
ƦƭƷƩĻğƒ bƚķĻ
440804963520622427
1686303437764459280422636530490221431164374911674498119446902282136636116889305523324609400811521934414144573289134722393907627229321261631837772476400278442183
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 19 of 41
/Lt
0.970.030.78
0.1910.0580.0460.9527.4450.3790.0321.2552.5470.4860.00320.490.2680.6120.3270.0442.2060.0390.4520.0580.1140.3380.2410.2070.216
51.78124.67435.03221.88419.15536.20120.84410.60677.60559.56720.49861.29172.13734.80664.65130.415
588.249411.694
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.44
3.9960.7321.491
2.80831.33820.30482.34222.85619.61010.88220.40381.99958.72371.66611.18691.03880.19150.91161.476222.3284.20880.51623.32411.81661.83261.88633.506312.6590.93532.51160.20052.71747.44282.89741.20350.7417
31.903382.267910.5617204.329258.15512.4951
170.9552107.1009253.3014
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
8868888686868888868868886868888888688688668
101010
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000000
0.40.40.40.40.40.4
ΛіΜ
1.12
3.4640.3990.6960.2831.0320.6221.0671.8012.4491.0495.354
{ƌƚƦĻ
16.492
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
182184184184187
179.7179.7179.8179.5179.7180.5180.4181.1181.8182.6183.1183.1183.2183.1182.4183.7184.1184.2184.8185.2185.2185.5185.5185.3186.2186.4186.5186.6186.6187.2187.4187.6187.4188.7188.7188.6189.2188.7189.3189.
8189.8
\[ĻƓŭƷŷ
0000000000500000
204
31.70.7343.3
82.7611.8989.0110.8919.7238.2987.05214.972.38225.7171.747.4441.0716.4852.04
105.51100.19232.78233.24187.49237.34234.93244.91230.34167.93115.86
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
2559
559741495408241166567980245239870272137910252189231483508546831267101710711190134322
11981172111812121292112711061148113213681406115811231424
MH-7681MH-7500
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000000000
1.475.7431.262.2
89.01232.289.7412.1720.2439.44227.849.4241.83
106.23188.23239.24216.89238.29234.93116.62
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
568742239168976238541188221502552830266202709547710324
1117128512631290115611331367116011241496
MH-7677MH-7675MH-7676MH-7543MH-7678MH-7679MH-7680MH-7682MH-7490MH-7683MH-7684MH-7685MH-7686MH-7687MH-7688MH-7690MH-7689MH-7691
ƦƭƷƩĻğƒ bƚķĻ
30
803405433125625865
223345512003160513283969439122843436456927901331442834304785392631291023344951051768305135986264417111662802411622882803418176356982114943413796433441618094
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 20 of 41
/Lt
0.110.030.050.03
28.270.5890.3130.4923.7110.4026.3230.0320.1550.7943.1340.1310.0561.3770.6610.4121.2050.0130.0940.0470.9310.0740.0231.6760.0320.9720.6070.978
30.68513.17429.38163.17481.93321.44672.03691.424
222.248611.246258.273773.593111.466143.326
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
10.3
6.5043.4740.691
2.44450.49781.68921.53521.45010.24651.59353.42624.60044.44363.06310.92487.56513.53854.54874.13222.80660.79793.60942.18390.57153.19521.88061.81410.64021.39082.30230.68022.08323.3532
12.053528.386768.708233.150513.828319.481317.290317.8575
2,063.48
321.4861114.0413322.8332
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
88688688886888886686888888888866686668688888
1018
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000
0.40.40.40.40.40.4
ΛіΜ
0.473.07
4.3970.5861.2150.4960.6850.2811.1432.4117.7040.1541.0260.9744.1383.6170.401
{ƌƚƦĻ
18.455
130.004108.498120.476
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
204190191192193196196196197199
190.4189.4190.7191.5191.2191.8191.6194.2192.9192.5192.7192.7193.5193.6193.2193.4193.7194.4194.6194.9195.1194.9195.2196.1195.9197.4197.7198.2198.1198.3198.4198.9199.2198.9199.5199.4
\[ĻƓŭƷŷ
00000000000000
3.41.6
27.40.6961.8
28.78255.123.25238.632.6323.4135.66124.8240.8165.945.9191.46218.530.6622.82
145.37247.99132.17102.77213.62212.59137.95130.39245.38199.65146.72255.05
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
6857
152629780328263171126273876773612517578978967155522977156891107515943679730599800564917261865349
11661312136013781108126413741061123313301131
MH-7367
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000
256236
4.1837.32.381.4962.6
249.129.54213.923.79240.833.3435.6623.71126.8242.792.25225.7
153.74132.99105.09214.57145.37253.42253.49212.61
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
98
150294681170274622509977613915152262154889106799250868334
11671311135913741107107211091373106512401132
MH-7692MH-7693MH-7696MH-7697MH-7292MH-7698MH-7399MH-7699MH-7274MH-7700MH-7701MH-7425MH-7702MH-7480MH-7703
ƦƭƷƩĻğƒ bƚķĻ
1187436324671426383022106431112311167592273452491948225376824289745621563972352024333382118831504122340563067681310632701171490127394796340914784329423966542848235741803443242331943889
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 21 of 41
/Lt
SM 3SM 4
0.57
6.9395.4650.0330.0420.6990.0570.3830.1030.6750.1870.3150.2940.3625.4362.2430.0513.0330.8378.6070.0252.7835.3010.5850.1382.5030.108
38.07670.74912.19236.15546.25824.73838.64240.61475.82951.628369.2841.83426.47857.75925.945
114.175575.803557.606153.534
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
3.8372.5450.4721.4368.587
1.98282.87530.66121.11260.71012.12387.65950.16382.50882.69031.95990.50251.133182.7091.10951.33330.44112.26889.54582.24928.32680.8076
41.570113.659816.940928.629331.228327.246920.027713.707730.241424.4432629.208
5,116.834,886.001,716.78
297.2713256.3986995.3274363.6812169.5781
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88888686886688886684888868688888888888
1015303010181212
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
0.02
0.3711.5421.0450.9020.5397.3483.7190.4680.1232.3945.5390.4982.7430.7230.5024.0350.1670.219
{ƌƚƦĻ
28.44110.333
100.597
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
200203203203204205206206209
199.4200.1199.8199.8200.5200.2200.3200.8201.4200.9278.4201.5201.3201.9202.1202.6202.8204.1203.8204.2204.7204.2530.6206.3206.6207.1207.1207.5207.1207.5208.9208.6209.4208.9209.5209.7210.5
\[ĻƓŭƷŷ
00000000000
55
4.7261.89.2827.433.46.672.795.72
214.966.9110.6213.16117.966.9565.2597.4215.6532.63241.483.93123.862.8982.8717.5248.0716.15
248.56253.42240.14200.73230.12148.44101.88247.06
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
5
779953
336760101110807310874197547349488563424517358967810390875885887387867528997292
1109115114181397133611401070131910561388109712441228
MH-7341MH-7291MH-7384
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000
7.5
5.5274.515.93.626.56
55.7467.7170.4662.8965.2998.2310.2338.2984.75145.263.9491.3217.8748.9116.61
201.29217.98242.24203.24132.79159.78104.52247.06248.56
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
9452
335840759177109308585557485558231436533193387880130611760859501527998
141712441401114110741057139411551245
MH-7705MH-7704MH-7706MH-7708MH-7707MH-7428MH-7552MH-7709MH-7710MH-7711MH-7714MH-7378
ƦƭƷƩĻğƒ bƚķĻ
4189
943429617820966144
38972100116511413001381632784281807111333936228749487983206566684224394039821724360920903440210432553623323712007823226532362102494731854738232136653678
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 22 of 41
/Lt
SM 5SM 5
0.140.312.11
0.0770.0540.0740.7690.8850.8260.8890.0570.6073.7940.3471.3270.1870.2251.7610.02648.350.4470.5290.6299.4480.6780.0140.0430.906
15.51319.02152.74333.58514.09856.85850.83342.82674.52476.86874.19529.49634.09813.84119.632
606.701101.402144.981
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.1187.8636.016
4.13710.40381.52051.03161.40932.83171.41772.69292.30280.76466.04260.55257.89572.75690.642632.9041.62152.80511.48715.02354.04180.84324.16891.86841.06454.33320.76760.49447.57010.7646
10.3412103.695341.08281.385719.6668
4,941.144,733.93
101.8916944.8505626.6187223.4767916.4694149.4296
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
886886686888866688866868688688888886866
12301510153010
ΛźƓΜ
5źğƒĻƷĻƩ
000000000
0.40.40.40.40.40.40.40.40.4
ΛіΜ
1.4670.2223.9960.2590.9420.4010.4894.1295.5858.1790.2820.4270.0643.1094.0954.5460.6531.3870.3580.437
{ƌƚƦĻ
28.50774.87119.95974.314
Min. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
212212218215216
71.286.6
210.7211.4211.5258.6211.2211.8212.5212.4214.4213.9214.9214.8214.8214.5214.9215.1215.7215.9216.5216.6217.5217.7218.5218.1218.6218.7219.2218.7219.8220.2219.7220.5220.6220.9220.5221.2221.8221.5222.2
\[ĻƓŭƷŷ
00000000000
3.9537.50.82
279.416.6135.0411.9221.9991.3279.17238.717.7284.11270.457.59238.720.7840.51
209.12143.41166.79133.89222.71212.57107.42121.11190.32169.15232.83171.71165.72165.46223.73232.96109.67
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
3
523018
444623826911165227501881982496296174783210677771690228290470174955769737412153
13551182137012721265130013131423126112581201108310811354
MH-7723MH-7287
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000
4.8
1.4341.3
282.517.0843.4812.4722.8580.0338.36233.217.8690.91279.458.4723.84
144.44227.17134.74223.38160.15213.62100.19108.28133.28207.98170.02215.13166.59175.47240.14233.93165.16
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
5157
828164495655979321669372211291461951368738406
135311831121130113121495132013091084135514181345
MH-7394MH-7715MH-7717MH-7716MH-7718MH-7719MH-7720MH-7721MH-7722MH-7724MH-7725MH-7596MH-7726MH-7727MH-7728MH-7730MH-7731
ƦƭƷƩĻğƒ bƚķĻ
8898
330425340815822
229875836288445676627620512930544155112562946432809223205102324123293634214738212342458516073965221719532538400323703600757646891311369334461441223541681192
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 23 of 41
/Lt
0.1919.7212.1441.2050.0632.9890.0678.0580.0210.5270.9091.5661.5090.7660.0710.4028.1330.0950.0220.8636.5460.0441.1870.6110.2241.3530.0190.2030.023
14.92723.28740.35263.18798.96961.18914.69810.95319.02114.56843.83370.75347.35745.906
152.063151.908474.793
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0.594
0.30480.80963.41520.68622.61920.22348.24710.83961.44722.49412.40391.21941.50224.98560.44118.23875.24333.31861.18742.96211.99141.03161.89112.09446.28672.37733.83721.15611.04971.43041.2572
39.805713.313711.9033151.19950.410915.032283.150125.750111.7822
106.7898138.3974217.4728348.9395261.4038
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
688868868888866668688888888888888688888886888
10
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.57
0.7154.1514.0632.50111.973.9710.4035.2250.4230.3372.5791.0361.686
{ƌƚƦĻ
26.696
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
224224225226227227229230
222.8222.8223.7223.8223.7223.8224.7224.8224.4225.2224.7225.1225.5225.6226.1227.1227.5227.7227.2227.3227.6227.7228.3228.2228.7228.9228.5228.8230.5228.5228.8229.5229.9229.9229.8230.4230.7232.7
\[ĻƓŭƷŷ
000000000000
236162234100
2.4885.139.60.73
58.33260.598.4835.19236.4165.963.4534.1381.3832.6344.48
153.85183.54116.55104.52189.42135.73175.77234.19147.39156.38149.74210.86235.75235.35244.61
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
60
244619957437691193299133652657879781896329686939515405477794768791561270348448357870939393315954692102586790765
13801349136612421240119712381062
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000000
8661
59.63.3933.41.66
262.199.3744.48245.5166.8162.964.3540.5180.9750.41
154.74189.16131.43244.91190.32136.63187.63148.35100.91150.66213.24239.24
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
6056
240628954430192310131764476796767370573353440504358941316948100766
13561243108912411293
MH-7732MH-7733MH-7734MH-7735MH-7723MH-7736MH-7737MH-7738MH-7739MH-7740MH-7741MH-7745MH-7744MH-7527MH-7481MH-7747MH-7746
ƦƭƷƩĻğƒ bƚķĻ
3293
786818709130262
222113352424757776333641490326628099490037621136220932512426325020503254242733661646196529102080205934313885209476033610203532253613377436401168199920721764
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 24 of 41
/Lt
0.5
2.910.674.611.08
0.0970.4230.38128.370.4260.3750.0210.0231.6940.3370.1790.5920.5370.9540.3570.1961.4681.0980.0691.1370.0240.461
60.78858.47116.03550.98427.34512.20448.81972.403102.5844.05717.91816.94489.155
370.201479.202189.803395.271985.886
2,017.29
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
6.5262.719
3.29684.00330.67411.47254.10880.40384.38011.28394.77989.95410.79971.10874.57591.22942.56921.823350.8010.79715.56344.37071.51941.10954.48051.74913.07491.06197.34076.11833.1568
20.077625.989279.180217.566427.179112.715428.537420.657721.135824.827415.9644
2,169.79
355.3717119.3508570.8041
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified Clay
Asbestos CementAsbestos Cement
8868688868666888688686668888686688688688888
101018
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000000
0.40.40.40.40.4
ΛіΜ
4.08
3.9625.3353.5971.1510.6480.4350.7162.9662.25311.740.2660.4081.092
{ƌƚƦĻ
10.28480.65592.27711.736
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
232236
230.6231.4231.5231.3231.4232.6232.9232.3233.3233.4232.9233.6233.2233.2233.3233.7234.7234.3234.5235.3235.4235.7235.1235.7235.4235.4236.2235.7236.3236.5236.5236.8236.3236.1236.3236.4237.1236.4237.2237.
1237.7237.9238.2238.5
\[ĻƓŭƷŷ
00000000000000000
3.7
112
74.415.9
34.1319.1744.9516.48117.256.8141.9319.5950.4135.19
132.79101.82134.98245.38248.38256.92234.13255.05101.88106.39161.24178.41153.74243.64216.39
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
2485
645485625279533484400524981581771367116322578647797352800680810979359863140426902599150948957117
11591217106110601125107412761064
MH-7293MH-7368MH-7753MH-7354
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000
43.3
27.5623.98249.945.9781.3857.7631.4320.2260.1137.79
102.75147.39188.13248.07216.39257.86235.82260.37118.14107.33206.25244.61212.58
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
348420
642330477391973223117323581794348795809883526260139418905148946949119
1273115811001178114713631126118811491062
MH-7748MH-7750MH-7751MH-7754MH-7458MH-7752MH-7755MH-7757MH-7756MH-7758
ƦƭƷƩĻğƒ bƚķĻ
36
819957
2223178550533531632743352107362922672075215744624643424631097588360311784131379441652270257929093893297120463032344132352415451739812041115320833141225211853639311036381177
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 25 of 41
/Lt
SM 5SM 5
0.830.11
5.7859.5710.3220.0850.0960.5930.0550.2150.0310.5568.1330.10329.220.0270.1260.0573.1320.6920.6750.6360.4921.4551.5535.9340.299
13.26464.31741.74413.43114.02988.47515.72642.98999.75217.98540.66449.47444.495
195.649329.334280.291529.005592.249133.423
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
5.413.36
4.2861.3170.354
8.15856.05635.22120.57010.94472.32661.27538.92840.76090.44111.37864.79840.20050.98577.05854.27522.63111.01230.97541.77432.20547.65152.91692.6832
78.246665.681580.944610.610917.861253.9474900.78128.690210.691632.120311.8444
5,117.08
227.4958106.4935111.9478179.0284899.0828
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
888668886888888888868886886686888888886
10103012151815
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000000
0.40.40.40.40.4
ΛіΜ
6.221.28
0.4870.3853.2817.1350.4250.4430.2460.4990.5220.3966.0262.3970.4432.2530.8260.4093.2270.486
{ƌƚƦĻ
10.021
103.504
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
240240241241244
238.6238.1238.9238.3239.4239.3238.7239.8239.7239.1239.1240.2239.9239.8239.9240.2240.8240.5241.2240.6241.6241.5130.2242.5242.6242.8242.4251.6242.8243.3243.2242.9243.7243.9244.1243.5244.2243.6244.5131.
8244.8
\[ĻƓŭƷŷ
00000000000000
41.38.226.568.54
206.666.9199.2231.03134.821.06256.284.76203.192.9460.7125.1355.28
135.92107.33218.26160.44113.67143.74235.82207.93120.79235.01203.24189.16136.12223.38235.69
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
8120888494
414874368473777457940373474609965939859181619556259208838739646776281506164969581207464
111111391083135211281186105010511255
MH-7445MH-7764MH-7249
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000
9.287.529.54
68.0742.2231.62257.485.73227.4204.293.9161.7927.1463.14
221.44143.74247.75124.36219.28114.63238.89121.75235.69204.32141.94228.88236.33
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
93
409888222474776575176820607938860689848660207975837420593747283912205968908592213453
1165117211401112135811291256
MH-7322MH-7759MH-7761MH-7363MH-7760MH-7762MH-7763MH-7767MH-7765MH-7768
ƦƭƷƩĻğƒ bƚķĻ
35
129442214965635787
211632763607212119097600439921244223165225852260364640053680318475871012199214912327396741753084113244992232217552943545333721521314353239315081226939682129
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 26 of 41
/Lt
SM 5SM 5SM 5
0.630.131.485.42
6.8080.2160.4630.64267.276.3083.6060.2657.22630.311.9330.0670.9420.2363.9061.0521.1890.9913.1670.2391.9910.314
91.78314.15373.88226.18620.35724.69598.22510.88911.97623.74727.453
471.291161.097111.025181.026141.108107.774168.999609.793
2,293.66
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
10.788.7373.1355.2434.093
4.97781.61523.13610.76763.64837.14350.90771.86051.42026.02147.65291.676157.7615.84510.59056.03154.25593.17041.07847.9887
25.560232.150112.368924.894213.771510.430413.397220.226174.627840.6879114.84311.992818.593633.0717
1,184.84
301.4242853.2185931.4395288.3217319.3623945.9123
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos Cement
88888888888866888688688868688888868868688
1215151015
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
4.370.58
0.0850.2191.5581.8710.9431.7262.4915.6864.9475.7440.3921.8880.595
{ƌƚƦĻ
19.346
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
246248254248250250250250
245.4245.6246.4246.1246.5245.9246.3246.6246.9274.5247.4247.2246.9201.5247.4247.7241.7248.5248.8248.2248.4249.4249.4249.3248.9249.6249.8249.9249.7249.5250.4254.3250.4249.9241.3250.1255.9250.6
\[ĻƓŭƷŷ
00000000000000
4.9724.5
14.9577.59168.8240.216.7941.57221.890.9556.18213.911.4840.51
245.17236.16210.15191.69215.21223.38160.95185.69126.67153.74128.73148.88227.58181.73217.91229.99100.86100.91
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
79504135
327962388271445138337817232963748649164658377451656220150163632515572808146178478347111138172714170616370926573
1068105913761273
MH-7339
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000000
240
5.96
15.4978.69242.121.06229.4222.857.1641.54
245.38226.02173.42161.94174.73167.92129.73161.24229.03105.31222.71231.48101.82101.91
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
61774916
961688270340763234965645173596359142206701578807140179471346110137165371169625566839
106112981116137512621425
MH-7331MH-7770MH-7772MH-7771MH-7773MH-7753MH-7774MH-7764
ƦƭƷƩĻğƒ bƚķĻ
80
872404942284806834504636594
368735363108248235396291664338943083315176851786362022241264216220014245203311861313233622713030115412703725209938951142119011261979112230962477
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 27 of 41
/Lt
SM 5SM 5
0.2
0.960.530.111.112.87
2.9512.4170.7470.3380.2770.0331.5960.3890.0340.7160.6430.1844.1370.4660.2430.4750.3911.1897.6283.2330.2420.362
86.02233.96363.89370.64939.51715.64772.61917.17939.79821.13716.99423.19424.755
219.005358.799192.195
1,236.901,658.02
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.374.84
1.8420.118
7.76223.84893.94793.67824.66531.81642.24291.30069.03563.00643.92923.46521.02345.37752.90035.03030.93170.74172.29232.36296.80065.97314.41411.37266.1321
17.665111.877631.148715.331923.110241.753759.731179.621312.149736.9383
4,892.14
357.2322920.5337173.5661854.2804128.6216346.5858
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos Cement
886688888866868888868688886688686886666688
15301510
ΛźƓΜ
5źğƒĻƷĻƩ
000000000
0.40.40.40.40.40.40.4
ΛіΜ
2.2231.2184.4054.0372.2253.1363.4760.3730.8698.4750.6461.0614.1833.2410.1340.5480.2713.0373.8950.2273.9820.2945.0566.664
{ƌƚƦĻ
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
251
250.3250.6251.1250.6250.7250.7251.6251.7250.8250.9251.7251.9251.9256.3251.7252.3251.9252.3252.5251.9252.8252.4253.2275.7253.5254.3253.4253.9253.9253.9291.9254.1254.9255.2255.2255.2255.5255.8255.7255.
3255.3255.5255.9255.8256.8
\[ĻƓŭƷŷ
000000000
99
8.8
9.4759.224.9
13.7414.9638.08209.5131.7213.990.0437.7915.07203.562.87229.414.45238.626.2444.3789.36
173.42168.15132.79222.23224.89135.92159.92131.87123.85174.61171.84106.35216.12162.38148.35
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
399636
234964693590450842277490182377569170949403960615485670332173218473584620746994697702366434597576877248476
109914071378139812591317
MH-7872MH-7521
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000
179
9.81
16.7925.0839.09215.1221.846.5416.0184.3314.79240.210.1666.9544.9599.54107.1163.4
169.15110.06134.98223.24231.18227.58146.56168.15132.89133.79172.86229.04165.46
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
3895
963600449219276180589163465944392861950484331204178466586693687992621704367698637579898506470
117612011260138713251376139712491318
MH-7383MH-7776MH-7777MH-7778
ƦƭƷƩĻğƒ bƚķĻ
17
665600506486817
4417362221662062214121492732214411962258510111216062780936372111804936902247203022451128131513162122226221682481768359067860217326003604211822542355643732612153
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 28 of 41
/Lt
0.260.481.779.05
0.7730.5510.15863.630.8420.1138.3881.1510.6410.43925.250.3660.4321.1461.7950.3040.4640.9758.3280.2570.393122.60.1840.4792.163
45.54353.69313.37269.63714.56714.28639.56258.48910.70736.85634.14213.45138.372
129.165540.726578.992
1,149.67
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.475.12
4.545
2.65147.00525.66293.77675.96831.88353.45092.077473.9565.85274.36462.14563.17215.41332.56413.93087.99675.71489.28765.96921.420229.3262.81851.90676.64912.77865.323313.3741.85172.0811
69.608540.038745.102228.502462.351431.4013
4,941.63
107.4061317.2385143.9739180.1572149.5972184.2822
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos Cement
8888888888886888888888686888888868888688888
301010
ΛźƓΜ
5źğƒĻƷĻƩ
000000000000
0.41.20.40.40.8
ΛіΜ
0.250.283.641.04
3.5944.8360.3265.5740.2774.0751.5795.3670.6755.9060.3986.1473.8610.8129.2896.381
{ƌƚƦĻ
17.93511.48513.64819.451
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
259260
256.1256.8256.1256.9257.1257.1256.5256.5257.4256.7256.9257.7257.2258.3241.7258.6257.8258.7258.2258.3259.2258.3258.3259.2259.4258.7259.4258.9258.7259.5259.6259.8259.7259.7259.4260.2260.2260.3259.7260.
2260.2259.5260.5260.5
\[ĻƓŭƷŷ
000000000000000
1.7
234
96.81.4161.837.1
25.0810.6222.53126.850.3712.96171.722.1388.5419.17108.949.4220.1780.9798.91
197.59164.46167.92144.47214.73155.73143.41210.25131.43171.71
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
138671
219740271270154983314185972190772751327142981768447676349278191858623192649677353283303486761
114211621213100210921220121811721367105311741205
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000
46
175112
26.113.822.82.4535.447.13.81
11.2623.2562.8229.54186.192.61106.262.8352.12171.7155.677.59
136.04181.83235.75230.02144.45212.33222.23115.53
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
431970
496741273272151982313184970187275770750135983825790446668350279190191670337302480803
11431163121411871093121912171173136910541175120212071053
MH-7780
ƦƭƷƩĻğƒ bƚķĻ
2042
958512349
21482234422635493538115636354356463037751259368945061203355520794055222746401184363246422095439822423890763435471205354343963188701146111206221840233544381721262981
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 29 of 41
/Lt
9.48
3.6931.2031.6757.7310.3911.0810.0499.8450.8090.2670.0385.7820.1530.7950.3186.5283.3285.2993.72989.980.0650.347174.30.05165.160.397
19.49221.99481.46474.43471.45614.07364.76775.35214.15223.71615.36661.518
249.964251.775255.566521.489178.099
1,326.611,154.22
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
4.88
1.179
5.88184.25482.66756.29483.18818.42082.48942.77622.47711.33771.323331.1514.41814.53055.30091.79953.51266.43592.70349.65919.45311.87643.53393.19023.3364
12.313371.947760.452162.598613.654939.061544.117746.821468.862473.708812.790828.282673.214486.4879
4,843.48
137.0624136.7941946.9742117.1448
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos Cement
666668886888888888888868688688868888888
10101010301012
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000000
0.40.40.40.40.40.40.4
ΛіΜ
1.9712.2630.3279.5642.0042.9231.5522.5281.5535.5030.2525.7420.2840.1221.8210.2770.4520.2272.201
{ƌƚƦĻ
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
260260260262262264264264
259.9260.4260.4260.8260.7259.9261.1260.1260.9260.2260.8260.2260.5260.3260.4261.1260.5260.4261.2260.8261.9261.6261.3257.3262.5262.5262.6262.8262.7262.7262.3262.5262.3263.1263.8263.7263.1263.2
\[ĻƓŭƷŷ
00000000000000
112
8.6228.222.8
168.837.0476.53111.818.03231.3203.554.3416.3824.3330.4323.84
174.73118.56118.84170.67193.75214.73224.94235.35135.91117.51120.87143.29153.47141.94122.44205.41
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
8343961569
684144564991676722232360277654765454276324836339937463465275472312774593281449160467415913951304
126213791153121711031054
MH-7624MH-7781MH-7784
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000000
55
9.4735.816.7
239.738.0877.57118.623.5325.06206.631.0329.65
175.77123.68119.88171.71199.65174.03239.39235.35217.91118.56135.91144.34146.72
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
4278146890
686694677138730569994441490278649886381303325765172336454452396464314295773299235922414940945740
11541216137910091330
MH-7355MH-7782MH-7304MH-7478
ƦƭƷƩĻğƒ bƚķĻ
19
250916
2034770024362435119131252358353322442817315221454321273322256252207146442088383637952073112738982555209721332731217021313815382620772171382517381042272923132117336336921349
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 30 of 41
/Lt
SM 6SM 6
0
0.224.570.64
0.7480.0530.2120.0742.6514.2793.1160.4371.8251.0721.0610.2330.50573.194.6094.7511.1019.2280.2985.584
29.53859.22253.60743.22734.14379.71243.85413.58556.18816.36769.62489.35828.34513.67417.528
120.091176.589155.653358.064338.288116.191
1,441.21
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0
6.5139.553
4.10392.61369.57722.90738.44171.56693.67552.34449.01714.32318.05814.96479.09527.32893.04730.93529.97513.96946.24670.88771.75330.7416
78.1633176.57511.442110.688126.159715.584980.062418.346936.508332.406831.654415.380559.9225
1,187.825,118.57
314.7502172.2446953.4136110.9162702.6439161.7244
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos Cement
888888888688886888888668888688888868888
15151030101012
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000000
0.40.4
ΛіΜ
3.861.44
1.0250.3028.61782.910.6340.5620.5426.9831.8341.6237.5860.3590.5462.1341.5821.0940.0970.5210.3781.1910.333
{ƌƚƦĻ
11.55911.341
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
265266266266268269
27.146.2
263.5264.7264.1264.8264.9264.4264.7264.4264.4265.8265.2266.2265.5265.6265.9265.9266.8266.1266.8266.1267.3267.3267.8267.3267.5267.4267.6267.6268.6267.8268.7268.5268.9269.7269.8269.4270.3270.3
\[ĻƓŭƷŷ
0000000000000000
46
8.5
5.2880.331.26.744.4418.7
106.2220.477.6123.8843.41253.115.07257.419.5850.02
175.47232.45146.56148.49147.02203.24254.56159.78173.42164.46239.39243.64
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
21
41959478
461310809541175776466147660755537436234853272772998330960467900302355
1219117010751111126312241163136511521223116010851137135813091064
MH-7485
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000000000700
256
6.0830.728.220.65.5219.6
108.9220.4203.5178.328.7844.3720.7834.13258.853.24
185.69100.44234.13148.88148.08178.41110.55254.56243.64
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
3985962681
451312808548775457146472761736426233780366771267306955531890737343999
1218117110761162111911701399122511641257115312241064115911381357
MH-7785MH-7786
ƦƭƷƩĻğƒ bƚķĻ
18
816951954487
46414380376330312360399543574379207421231157213279161129227646984358208539647632432231173605414046992076328638353694311343404007231542217580313332241351311439223667
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 31 of 41
/Lt
SM 6SM 6SM 6
1.360.73
2.9940.4210.3351.5426.4361.9020.0532.8242.30929.220.1160.5051.7691.0710.3453.6450.3690.9660.0531.6120.5180.0670.9150.0281.0662.017
76.14489.61827.48553.54464.46524.77522.22914.90338.07832.544
482.662509.863220.101105.348186.926313.536
1,135.801,824.09
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.24
7.877
4.10721.14976.629928.8190.94925.54280.86973.49625.71350.804533.3016.34713.95182.503331.0783.66083.31252.43311.78792.32896.9201
26.176970.535527.652175.298528.297523.720710.137882.444478.739117.004461.599117.500142.663311.165345.9358
5,119.955,119.411,178.10
122.8402310.0496109.7474996.3894998.5797
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos Cement
8888888888686888686688888888886888886
303010121510101515
ΛźƓΜ
5źğƒĻƷĻƩ
000000000
0.40.40.40.40.4
ΛіΜ
1.140.482.691.12
0.1330.0960.6795.7413.2350.6294.6537.8063.5880.2213.4362.1482.4720.1420.2893.3494.0051.8773.7310.815
{ƌƚƦĻ
11.00440.792
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
270271271272274274274275
269.8270.9270.2271.1271.1270.4270.4271.4271.3271.4271.6271.2271.8271.1271.4272.1271.7272.9272.4272.3273.2272.4273.2273.4248.7273.4273.6272.9273.4274.1273.6274.4273.9273.9275.3250.4274.9275.9
\[ĻƓŭƷŷ
00000050000
67
6.126.4835.42.210.35
20.3849.5496.3342.9996.3332.8848.5489.2645.9750.41
105.31227.39188.87221.44143.74231.48150.56150.53234.64161.24197.28153.47160.58202.43182.45223.73148.08198.69190.85
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
837952471295399128779409582510381371843747582525446505535293401140864223948831459462569774634471183618769103581123
11351136117310661260127013101399
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000000000
234
6.486.7437.12.810.736.09
22.2250.6296.8797.4290.35241.446.7659.55
120.87236.16191.96234.07117.51153.47232.78159.92156.38167.93164.46165.72111.73149.18200.73193.94
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
22353699
835947463315388124778404937774588408854748403515620448536390134870354914832450572772690768639584115
11361137117411991200133614001177
MH-7788
ƦƭƷƩĻğƒ bƚķĻ
1
263593
4219422019593535209838142431118221424397211520614553457820862441198031532231521520672432200020962154229021051151328336023670305047192031237520782539445220812331113422681118
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 32 of 41
/Lt
SM 6
6.271.86
3.0130.5942.6099.9443.7950.0870.0630.4383.9783.80931.114.8961.0410.3331.8890.7877.2160.5411.3766.6581.1250.1198.9750.2470.3141.228
41.77217.57139.58327.35614.11724.88314.24343.01227.36218.87336.24634.00230.254
124.426369.165634.034104.686222.328
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
6.0674.961
6.74824.66476.06971.69643.24416.33569.90322.12620.68913.47736.28565.300910.6041.79241.57682.08854.1202
30.065520.021428.061366.990136.057418.920273.461674.203259.010212.048535.863815.966811.491835.4965631.36712.0578
5,117.57
174.0959165.6141139.7284997.4512264.6481659.5042223.2762311.1115135.4808126.1135
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88868888888866866688888866866688888868
1030181510101010
ΛźƓΜ
5źğƒĻƷĻƩ
00000
0.40.40.40.40.4
ΛіΜ
3.020.282.460.54
3.3849.7373.9331.1810.4430.1383.0690.4240.3621.5820.6457.2650.2810.2790.6580.3323.7182.5051.3834.5982.3390.5910.5321.2372.4350.555
{ƌƚƦĻ
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
277279282283
276.3275.2275.2275.9275.4276.1275.5275.5276.7276.8276.2276.1277.2276.4277.3300.3285.7278.6279.2279.7295.7279.9279.6279.6279.8280.8281.1281.3280.6281.6280.8281.4282.1282.1281.8282.5282.7282.1282.2283.
1282.7282.8
\[ĻƓŭƷŷ
007000
30.735.821.31.43
62.8346.7610.5123.5363.6784.7625.1810.1646.5479.1772.5316.79203.179.3860.1176.94
203.24228.28135.91160.44243.37250.23175.47227.17193.94197.86123.68181.83177.84197.86245.19206.25106.29242.87246.71207.93
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
4
9417
304751673350354909454457736801461115661112556851372694992944135122112833613881418382675963946251498181
1138126811541009100110631128
MH-7716MH-7308
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000
67
244
8.2231.745.52.2180.3
73.6650.0210.89144.4168.824.3364.7886.5622.1311.0956.9879.13204.682.87209.5
212.59255.14244.54228.28198.69204.73125.52188.87181.73246.71219.22107.42248.38
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
15
171739654663351910447232834245462673103104365843990128111116615369959735499182
1139141612361002132411691063136513311261106011301066
MH-7790MH-7789MH-7784MH-7791MH-7286
ƦƭƷƩĻğƒ bƚķĻ
967511811
1130134822262237389136014222392520913162135449422989203722161135273021611170484423243556160825565425331643731183126311793064225713631380203841333621132341763095393321581197
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 33 of 41
/Lt
SM 7SM 7SM 7
19
3.72
0.5741.8930.6340.6020.5142.6850.161504.30.0969.5038.7570.0820.7627.6330.8321.6723.7490.3080.7349.843
49.86355.74613.27489.17445.32538.81335.42243.57618.14816.55957.77546.82483.80133.50761.06835.57824.768
614.834111.852106.889109.729113.486377.318299.434
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
6.92775.07254.28377.12484.27656.01770.32766.15482.45821.05149.46362.12622.66255.97192.36331.69864.54491.81733.27841.5379
20.379833.345149.589611.571884.186182.562430.036420.463634.150116.239662.251186.032451.2129
4,734.961,023.084,941.392,043.172,113.542,160.771,814.60
169.1908570.9221151.9786535.6961303.8318122.0409
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88888868888888888888666888888868
1030101030101810301010301024
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
4.961.720.280.940.28
0.3911.1982.1740.0533.1150.2320.3292.6682.1750.2365.2430.2071.0310.0872.3650.2791.0370.0630.6790.521
{ƌƚƦĻ
47.392
Min. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
80
ΛŅƷΜ
284284290292
283.6281.8283.6282.8283.7283.9284.4283.7284.8284.6284.5284.5284.7285.8285.6286.4286.5287.3287.9287.9288.4288.5289.8289.9289.9290.1290.5290.2290.6290.8290.3290.2291.4291.3159.1291.1291.8291.6292.8292.
5174.8
\[ĻƓŭƷŷ
0000000000
3.42.93.4
-0.8
5.835.5222.71.413.68
12.6374.5618.5297.3417.5776.9811.2623.8216.0133.3455.41239.721.7220.2255.5583.9390.04
189.16131.24167.93231.45106.29232.45160.58149.18191.96237.31
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
6
29897786
971862430605320682596134887866416675869530175890904502950509876535634639895307920124394905611875479
10911143128710951100
MH-7435MH-7472MH-7782
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000400000
3.43.74.5
9.230.356.6724.52.5785.1
13.7488.5498.48134.817.72176.878.1211.92238.748.5422.7762.2722.53194.720.3257.5390.95
195.31136.12232.39113.91163.57150.34240.86240.33
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
30
964894429319296609127876863911410665864220174885901500731505897538643892309823271114389906617561896478
1092118613661421123712881096
MH-7795MH-7328MH-7796MH-7797
ƦƭƷƩĻğƒ bƚķĻ
336790810960
362740513282214022073771376113652261114832383186443542272326318911623272397017672813369121553240228921676525242232284845377835501181210931426241226440752058196332572135
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 34 of 41
/Lt
SM 7SM 7SM 7
0.072.191.010.69
5.9071.4888.7791.8761.2590.7764.5831.7041.1263.2985.5681.3150.1680.0580.0450.3980.0227.8326.3520.2390.1610.3450.1950.1260.117
42.81516.20621.68647.56416.90613.03118.26710.61912.66511.21124.18721.37719.62220.40210.797
240.912774.906
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.3650.401
3.43925.02547.29925.72225.23085.25321.19788.86848.28441.67690.20051.69721.06194.56848.78941.31183.72051.21146.13761.32330.66921.88311.1065
20.261816.364152.838221.998415.754913.065721.390966.036965.905212.474835.127642.026560.8658
1,822.171,833.94
694.4141129.3259123.2813182.4922160.9772101.0149
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
8888686666686686888888688688888888888
101524121010101224
ΛźƓΜ
5źğƒĻƷĻƩ
00000
0.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.280.22
4.1110.3750.3134.6752.1656.6191.7773.4020.6851.8086.2593.4076.6680.3040.9870.6950.3340.3028.2172.6890.5010.7147.5910.3272.976
{ƌƚƦĻ
24.707
Min. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
298299
293.1293.1293.7217.3293.7293.8293.4293.3294.1294.5294.8294.5290.6294.5295.1294.6295.5295.9295.4296.1296.3296.3295.8296.8296.9297.7288.5297.7297.9297.8298.2298.1299.2299.6299.8299.2301.1299.8300.5299.
7299.6299.9300.8300.6
\[ĻƓŭƷŷ
001000
2.91.64.8
-1.4-0.2
9.2322.86.6719.62.0560.838.384.97.64
53.2477.5775.8132.2287.0577.5762.4815.0387.46146.1165.686.5615.49120.397.34
131.24117.51239.39143.74150.56195.31116.16245.19191.69207.11210.25
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
7854
894605343903937886885696381483886570671958565429480999855866891828833685242258688732487854279993520682852
1310110010591236119313891205
MH-7508MH-7469
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000001
233
-0.2
10.433.420.52.185.832.792.855.9961.88.62
54.3423.4883.9379.1795.2889.0478.7563.6720.38205.487.4662.8916.15121.887.05
143.29131.24148.98160.58105.95135.92166.79193.76215.17106.29
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
53
339525605875881393364380634481577661952574721473845862887829844349565729483852281991519675855
132111031189136410001272119213901209
MH-7798MH-7799MH-7570MH-7800MH-7801
ƦƭƷƩĻğƒ bƚķĻ
9290
507808
327321723908236720683256324220692026323920872169213732532273309036162353279721253537249031903271205630533073243431241317246262784535197878182138315435464608353422202491
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 35 of 41
/Lt
SM 7
0.770.34
0.1810.5674.1113.5344.7360.0910.0413.8992.02112.070.9342.16148.850.3210.0870.0331.2191.1160.1540.3020.2770.99776.45
16.96210.44812.38458.09915.82419.56951.79235.04911.94426.95144.09533.01427.93212.01913.803
105.152125.926335.376599.977560.801200.957
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.1433.2421.778
1.41586.82951.94675.62941.7006160.732.49824.65493.98421.10241.61111.94096.31891.41470.94924.12434.1462
27.014235.835819.725554.274913.634622.402719.688318.188941.118116.962915.109175.061514.122610.898824.9639176.81140.246871.8279
2,172.52
653.9198210.4864123.7224140.2346151.2532215.1859199.3432
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
6868688668868688866688868888886688888
103010121010101010
ΛźƓΜ
5źğƒĻƷĻƩ
000000
0.40.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.280.28
9.6880.4011.7350.2315.3740.2641.6590.2640.5620.4240.4031.4442.8694.5350.5660.4140.3810.7440.581
{ƌƚƦĻ
11.113
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
302302305306306306
300.5310.1300.7301.4301.2301.2315.1300.9302.4302.5302.6302.3303.2303.1303.4302.7304.1304.1304.5305.3305.5305.6326.6305.9305.4305.3306.5305.6307.8306.5306.9306.7307.6307.8307.9309.2309.1308.4309.6309.
6
\[ĻƓŭƷŷ
0400000
1.74.7
59.66.4920.55.723.810.7336.5
57.7619.7290.33178.313.6229.65178.987.9190.0413.7413.8442.9975.6762.2779.13204.692.2857.1679.05242.784.33
101.82113.91197.28192.87199.74146.25248.38107.69175.36
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
6
55
858625513883240665252237814233897945683459479500964918511892867848458455345482346468870331306
111010001228133111301202106013731194
MH-7295MH-7610MH-7459MH-7806
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000
2.94.75.51.6
245
60.87.6921.36.9593.55.0838.3
58.9619.5991.5414.8245.9192.9415.0315.0776.9476.5363.5887.91218.558.3380.2885.56
131.87115.11183.54198.98197.28201.47108.93
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
8
235554
866697899242902812437683943646672460384958960498507872570856524459456344244467891307
100110991131120313721193
MH-7507MH-7488MH-7802MH-7781MH-7803MH-7804MH-7805MH-7807
ƦƭƷƩĻğƒ bƚķĻ
3791
503109620628666
318720423245133420393140303631611360370224753668413420432310213427433618344521592190327732302469316923124135417723114602131813263258741423147677322645363779
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 36 of 41
/Lt
SM 7SM 7
0.040.3740.61.41
0.0280.1810.1680.3140.4080.3380.0220.3912.1350.9280.90534.871.8620.42740.783.8910.4411.5150.3810.0693.0110.1810.5821.1970.168
19.84462.76941.13462.18238.86944.68191.17335.08718.87624.82314.19578.85213.96910.79447.707
350.676
1,244.80
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.1080.2367.256
1.32363.08770.26820.64977.02881.85721.56591.06192.07273.40023.18353.74976.38741.46362.21179.25842.36685.51113.75145.32822.20194.83584.79464.27650.61921.99522.58742.6466
13.717119.0187309.10530.061267.511172.967241.1953
1,558.812,159.31
163.8857215.3128263.4977567.0321279.3461150.7235
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
88688868686886888888866668888888868888868
1218103010
ΛźƓΜ
5źğƒĻƷĻƩ
00000000
0.40.40.40.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
1.926.66
9.9370.2670.9530.5840.5481.9410.8930.1124.5372.0854.3063.8333.5020.2820.4955.7988.439
{ƌƚƦĻ
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
310310315317326326
309.5311.1310.4311.4310.9311.4312.5313.4313.3314.6313.9314.8314.6314.3315.5317.7315.8315.9317.2318.2317.8483.2318.6318.5318.9319.6319.6318.7319.9319.4319.7319.6319.8320.5320.4322.6323.4325.1325.1325.
9
\[ĻƓŭƷŷ
00000000
8892
61.23.397.52
17.8786.51225.498.7250.0294.4754.1420.32117.255.41206.283.5662.2961.5969.3494.7225.06206.270.46
228.26166.33201.29185.69214.12244.54132.17223.56107.29204.73105.09110.55201.29142.13
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
71
421695998764451728507834629678290162104288214681906680895840442341274343860338630209333342922442268585
13931299105712511250125711161392
MH-7810MH-7317
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000
92
8.8
18.74.64
87.7599.9889.26225.451.2895.7455.4120.8656.68117.294.7283.5662.8770.6396.0125.9889.36119.5
167.57191.69135.17109.03210.86107.93131.65215.05218.45143.41207.81
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
422355725328497614293161102289216674895362699680719431342277341332623217923443269597
1392139510591113125110901403140711151388
MH-7808MH-7809MH-7432MH-7811MH-7812MH-7813MH-7814MH-7815
ƦƭƷƩĻğƒ bƚķĻ
682683403664681522
2303782225573666281230743686243831452818501221893072235122224151367550113955116936793523128224433281314320473274221128082308354831832352128338863674230035957820
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 37 of 41
/Lt
SM 7SM 7
2.860.630.35
1.4482.8431.0260.0233.1490.1753.5241.6840.0420.1330.4480.3060.6261.4280.0461.6969.7513.1471.1470.5050.3411.7911.4470.3191.5761.1540.0610.1941.5124.7136.3780.0630.3580.069
21.02597.38545.13991.94551.97723.09115.416
101.171107.101
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
1.925
6.98538.35061.06194.55480.601512.0882.68161.64510.71351.04993.20615.28162.07062.70054.52815.47263.27643.99232.85348.63750.63789.60487.04442.82471.20121.15121.25246.79157.50592.35793.95230.4881
10.799818.944115.530310.793346.5105
2,115.611,563.271,731.57
129.0922174.4522701.6123364.8191272.6737
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
8888868868868688866888886668888888868888
121810181018
ΛźƓΜ
5źğƒĻƷĻƩ
00
0.40.40.40.40.40.40.40.40.40.40.40.40.4
ΛіΜ
0.540.530.284.664.141.71
0.7912.2510.2690.1975.2094.1420.4440.5353.9980.4995.6220.6311.2621.2671.1990.3090.686
{ƌƚƦĻ
70.098
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
327330344343345348
326.3327.4326.6327.2329.3329.5330.2330.5330.1330.4330.2330.7330.9332.9335.7334.7335.1335.5513.3337.2338.7338.2339.6340.2340.2532.7343.1343.5343.6344.7344.1344.7344.3345.5345.7345.6345.9347.3346.4347.
4
\[ĻƓŭƷŷ
000
39.618.720.634.784.928.255.55.99
46.7699.5415.7683.9321.9590.9120.0381.38227.899.2220.7892.6111.8997.34
230.66199.74229.03127.77230.34116.83110.06234.93104.52144.45127.38116.09133.72164.16228.26249.08246.71215.84165.46136.04253.42
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
82
167720455179354698561641988875711363355291600531260595710193644348489487777398700955421829129980682716470151
12771195113311531101109310631109
MH-7780
5ƚǞƓƭƷƩĻğƒ bƚķĻ
000000000
22.635.936.57.37
48.0740.9216.6585.2592.2322.09145.882.76117.9241.485.8544.1974.8125.1396.7412.9698.72
233.24229.22207.11100.86129.09118.15123.85107.29128.73101.88135.09166.33232.63249.08150.42259.37
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
9782
166715732292616631995246229529261162632241488810603695969413972678469143
133412591194113411571396109413381104
MH-7816MH-7370MH-7817MH-7818MH-7819MH-7283MH-7820MH-7821MH-7268MH-7822MH-7823
ƦƭƷƩĻğƒ bƚķĻ
784952521814821961
1124281436772206629823343664326227953093359732483676236923432794120820402341267845374182190730754332202920552584347423043088405411033720307124372805241611554121
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 38 of 41
/Lt
2.590.360.56
9.8140.6940.8061.4830.0693.2991.3866.2130.1433.4283.0731.6841.3071.7360.1661.43755.081.6651.0320.1132.5289.4730.5030.415
15.92120.99921.45930.95417.87497.69688.51689.47488.18616.156249.3315.44613.831
110.704107.572190.252212.272111.847
1,013.87
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
6.0042.6886.066
4.588311.2535.25452.20740.55222.413711.2756.100525.5320.96947.23061.64434.91224.02614.911415.0880.80163.0815
15.6298117.22713.459410.304217.960311.355831.751910.318211.512430.4667622.663889.85213.522381.826810.829522.0289
4,751.29
253.4063656.4471194.2267131.0588659.5042880.2501876.9714246.1092
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos
Cement
6888886668888888888688888888868686668
101210301014141410
ΛźƓΜ
5źğƒĻƷĻƩ
0000000
0.40.40.40.40.40.40.40.4
ΛіΜ
1.061.530.420.170.170.170.29
1.4888.6139.6780.7620.8510.4340.5041.3390.0581.6350.3732.5310.4714.3457.8891.4382.6171.879
{ƌƚƦĻ
12.08315.289
Min. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
351354355366369369370
348.7348.8350.2349.2350.4350.1350.5394.6351.2351.4352.7353.3353.4352.8353.7354.9355.8356.8356.7357.1358.3359.9360.1360.7362.3364.3365.1366.5367.3369.7368.7369.6370.2372.3373.3372.5373.6372.9372.6
\[ĻƓŭƷŷ
00000000
45.585.12.351.092.9730.3
61.0925.11250.530.0922.7983.2317.1121.06204.223.4840.5139.4478.7976.98241.158.96
116.09181.73106.29227.39201.47192.87250.23219.47219.23235.01100.19146.25236.33215.17164.11145.79
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
934089
251489514365257849111675896555399456458753965727432735645525208787573495784383482755626221340213729899651300
136213231271
MH-7637MH-7270MH-7471MH-7263
5ƚǞƓƭƷƩĻğƒ bƚķĻ
00000000000
30.32.971.723.5937.3
62.48254.279.3832.7626.1586.5184.76206.217.3126.4942.99205.725.1896.3340.5184.1178.46165.660.46
146.25107.69229.17198.66251.55228.26116.09175.36242.59224.94147.28
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
43
2892
671300482226113556407442802953720510421301544594851209383582489786648468798290214722685224
13611058129410981234
MH-7824MH-7825MH-7806MH-7810MH-7404MH-7451MH-7827
ƦƭƷƩĻğƒ bƚķĻ
626621785332148280
2045135323187590232331563091114324281368243031442982361928151725230513521119245023251280217820642319205421772317298027403608391712091281224328165226136221652648
\[ğĬĻƌ
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 39 of 41
/Lt
SM 7
0.411.08
1.1140.5630.1291.0980.1984.1260.1572.4790.0840.6982.3733.5367.8468.5640.6231.5870.0710.1170.0894.61689.582.656
89.45988.15262.63547.68153.29777.31114.89173.03486.33320.60451.58814.829221.8390.09818.05315.918
103.718196.246157.774197.268103.872
1,184.83
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
3.7673.397
3.65825.62512.21864.32221.40613.650410.1183.03321.34224.19298.55683.94754.68223.31452.32918.51588.55512.52752.68451.56913.5421
10.643329.837451.076680.503510.698712.030812.128652.064857.424761.923554.602915.833530.0303
2,027.274,892.552,064.901,191.471,005.614,889.31
889.6515876.6694148.6481237.1231
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified Clay
Asbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos CementAsbestos Cement
888888888868868886888688888888688888888
14141230241030
ΛźƓΜ
5źğƒĻƷĻƩ
0000000000
0.40.40.40.40.40.40.40.40.4
ΛіΜ
0.170.1711.57.07
0.3670.5272.9810.1324.5030.1551.7540.3050.4381.4975.9451.5293.1860.0884.347
{ƌƚƦĻ
12.75753.526
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
449378382382341395400403
373.9373.7374.2373.6373.7373.7374.6375.5375.4375.5377.5380.1380.5381.7382.7384.1385.1388.6387.2388.9390.5391.1390.5392.5394.3396.2396.7398.5397.7399.8399.7400.3400.2402.3404.6408.3409.5410.4
\[ĻƓŭƷŷ
00000000000
2.9
193
1.723.592.455.199.343.274.881.93
90.91228.592.2551.2858.2162.8913.9422.8842.22124.825.6424.4115.16
143.74202.85167.93185.94175.36106.81225.36219.28254.78215.84177.84210.15
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
786291648298577474825527289493733134580328301866318297468788397222853821156176701666816186319815716199122
1230119210791078134610691298
MH-7700MH-7297MH-7296MH-7869
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000
2.354.233.9584.94.446.924.886.493.54
92.2893.7594.4714.4523.4143.4110.93231.315.52
230.47214.12111.58187.49192.87209.04113.67148.49225.36256.38190.85227.99
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
72
63
787345667268580475826521288487728518132298900746265458522789373247195836147821703653815287814717201123428
1232119110801079
MH-7828MH-7829MH-7681MH-7830
ƦƭƷƩĻğƒ bƚķĻ
769777947962944
2179392121763827476422722120304014723524215028191139453416884148381832801355413738282316247316533606399839993116308911172591224030353833303728061212114624782296
\[ğĬĻƌ
3092(1)
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 40 of 41
/Lt
SM 7SM 9
0.150.030.64
1.6020.9227.1510.5121.7531.7822.2830.2180.5242.8240.0540.8140.1657.3880.8160.1190.0220.95752.980.8130.6368.1338.3980.8622.8460.313
56.14210.47742.87992.34551.49847.79566.71119.43117.625
439.037131.329449.298109.695444.082129.905
5,066.391,392.32
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
2.47
2.7933.6187.758
7.12258.97641.07335.08183.75354.83135.94932.83917.64160.77232.32550.83482.04512.69960.76766.56941.94840.76764.31491.29531.01230.44110.4978
20.691123.810924.367416.687264.293326.743475.511812.017624.084511.766821.346830.9478
4,897.742,158.552,282.562,030.832,098.55
176.1808294.0686
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.01
30.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified
Clay
Asbestos CementAsbestos Cement
688818868686888688888866886866886668
30101812181812241812
ΛźƓΜ
5źğƒĻƷĻƩ
00000000000
0.40.40.40.40.40.40.40.4
ΛіΜ
0.120.22
0.2250.8361.8291.1970.3810.4280.2460.8520.1397.0613.2070.5060.1520.1989.465
{ƌƚƦĻ
10.21512.769
Min. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
ΛŅƷΜ
424423426468470510
59.1
414.4414.7415.3423.1431.3432.4435.4439.1440.9444.3444.1443.5443.9448.3451.5450.8460.1459.7461.4462.6464.3465.7466.1467.9469.4469.5471.7470.5481.7480.6485.7486.6488.3489.8493.7498.3500.6483.8214.2
\[ĻƓŭƷŷ
00000000000
7.5
35.943.524.931.79.540.26
13.6412.76165.968.0713.7420.8626.1510.8918.5642.99178.322.7991.4631.62
109.03162.38218.49107.93255.14229.99216.12222.88107.29195.31163.57168.73174.47140.67
bƚķĻ LƓǝĻƩƷ
5ƚǞƓƭƷƩĻğƒ 9ƌĻǝğƷźƚƓ ΛŅƷΜ
66
161317544133391877888724674663714229527964548362712961512910162253880510248429235245849679643264908595655664
1120110711201317127414101112
MH-7825MH-7348
5ƚǞƓƭƷƩĻğƒ bƚķĻ
0000000000000000000
37.89.3793.4
13.7171.7121.9930.0911.4519.2191.4658.2134.1322.8810.5163.8832.72
164.11226.52113.21256.92231.68217.93193.75165.52170.67176.51160.95
9ƌĻǝğƷźƚƓ ΛŅƷΜ
ƦƭƷƩĻğƒ LƓǝĻƩƷ
1083
153751546297120757882718659545647713230962564227257907254679493329662635909785684658
12711056105211111269
MH-7832MH-7833MH-7834MH-7835MH-7836MH-7837MH-7267MH-7838MH-7839MH-7869MH-7840
ƦƭƷƩĻğƒ bƚķĻ
43
141
1193134622754113411741121137210613703259178124422236197635962471362523593157279631583624236339271195313713591361633131202793176638132048246536693932167516064147136451962163
\[ğĬĻƌ
3092(2)
ЋЉΏĻğƩ ΛЋЉЍЌΜ ǞźƷŷ tƩƚƦƚƭĻķ LƒƦƩƚǝĻƒĻƓƷƭ Ώ tĻğƉ IƚǒƩ CƌƚǞ Ώ tźƦĻ /ğƦğĭźƷǤ ğĬƌĻ
/źƷǤ ƚŅ tƚƩƷ ƚǞƓƭĻƓķDĻƓĻƩğƌ {ĻǞĻƩ tƌğƓ{ĻǞĻƩD9a{ wĻƭǒƌƷƭ
1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
Page 41 of 41
/Lt
SM 9SM 9SM 9SM 9SM 9
0
3.93
0.6062.3710.1040.0569.0961.4111.0185.6031.4120.0212.0374.001
11.70692.63297.56690.53611.58712.669448.72
187.817107.699187.995193.433374.323235.385280.226
Λ5ĻƭźŭƓΜ ΛіΜ
CƌƚǞ Ή /ğƦğĭźƷǤ
0
2.594817.3830.88220.76761.62122.24885.90627.75956.3713
70.682113.742419.217882.506886.868695.027620.301224.336112.765915.1979
1,738.921,209.435,374.76
315.4645317.7134299.1288308.0774310.5501
CƌƚǞ ΛŭƦƒΜ
Ɠ
0.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.0130.013
ağƓƓźƓŭγƭ
PVCPVCPVCPVC
ağƷĻƩźğƌ
ConcreteConcreteConcreteConcreteConcreteConcrete
Vitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified ClayVitrified
Clay
668688866868868668888
10121524121212
ΛźƓΜ
5źğƒĻƷĻƩ
0000
0.40.40.40.40.40.40.40.4
ΛіΜ
0.150.220.22
2.8888.4750.6243.2231.2420.0792.288
{ƌƚƦĻ
24.69214.984
Min. SlopeMin. SlopeMin. SlopeMin. Slope
Λ/ğƌĭǒƌğƷĻķΜ
20
7.57.95.5
ΛŅƷΜ
557559627221
48.794.1
519.8519.9520.7529.3292.7293.5533.3542.4294.8553.3389.9550.7211.3122.2397.2166.4132.2222.7
\[ĻƓŭƷŷ
00000
7.690.775.951.310.85
12.6363.4562.2763.5891.3174.5174.1327.14
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1. Calculated slopes are based on invert elevations provided by the City. Where adverse slopes were present due to a lack of data a minimum slope was assumed.
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October 2022
Photo by Barney Burke
City of Port Townsend Sea Level Rise Risk Assessment
ACKNOWLEDGMENTS
The City of Port Townsend thanks the North Olympic Peninsula Resource Conservation & Development
Council for providing financial support for technical assistance.
Project Steering Committee
Steve King, Public Works Director, City of Port Townsend
Judy Surber, Planning Manager, City of Port Townsend
John Mauro, City ManagerCity of Port Townsend
Cindy Jayne, Chair, Climate Action Committee
Dave Wilkinson, Local 20/20
Consulting Team: Cascadia Consulting Group
Sebastian Espinosa
Mary Ann Rozance
Mike Chang
Suggested Citation
Flooding Risk Assessment. Prepared by the City of Port Townsend and Cascadia Consulting Group.
Cover Photo Credit: Barney Burke
October 2022 2
City of Port Townsend Sea Level Rise Risk Assessment
TABLE OF CONTENTS
ACKNOWLEDGMENTS............................................................................................................................................2
P ROJECT S TEERING C OMMITTEE........................................................................................................................................2
C ONSULTING T EAM:C ASCADIA C ONSULTING G ROUP............................................................................................................2
S UGGESTED C ITATION.....................................................................................................................................................2
INTRODUCTION.....................................................................................................................................................4
P ROJECT B ACKGROUND...................................................................................................................................................4
FLOOD EXPOSURE AND MAPPING APPROACH.......................................................................................................4
C OASTAL F LOODING P ROBABILITIES AND P ROJECTIONS..........................................................................................................5
Sea Level Rise Projections.....................................................................................................................................5
Current Coastal Flooding Processes......................................................................................................................6
Sea Level Rise and Coastal Flooding in Port Townsend.........................................................................................7
A PPROACH TO A SSESS F UTURE C OASTAL F LOODING L EVELS IN P ORT T OWNSEND.......................................................................8
Inundation Mapping for Future Water Levels.......................................................................................................8
PORT TOWNSEND ASSETS AND FLOOD RISK........................................................................................................11
A SSET R ISK A SSESSMENT M ETHODOLOGY.........................................................................................................................11
Assessing Exposure.............................................................................................................................................12
Assessing Sensitivity............................................................................................................................................13
Assessing Consequence.......................................................................................................................................14
RESULTS...............................................................................................................................................................14
S UMMARY OF C OASTAL F LOODING R ISK TO K EY A SSETS.......................................................................................................14
High Exposure.....................................................................................................................................................14
Highly Sensitive Assets .......................................................................................................................................15
High Consequence Assets....................................................................................................................................15
Asset Values at Risk............................................................................................................................................15
LIMITATIONS .......................................................................................................................................................17
REFERENCES.........................................................................................................................................................18
APPENDIX A: FLOODING AND INUNDATION MAPS..............................................................................................20
APPENDIX B. DETAILED ASSET TABLE...................................................................................................................28
D ETAILED A SSET T ABLE.................................................................................................................................................28
D ETAILED A SSET T ABLE,BY E XPOSURE .............................................................................................................................33
October 2022 3
City of Port Townsend Sea Level Rise Risk Assessment
INTRODUCTION
Project Background
The North Olympic Peninsula Resource
Conservation & Development Council
(NODC)securedtechnical assistance funding
to support fourlocal jurisdictions across the
North Olympic Peninsula to better prepare
for the future impacts of climate change.
Clallam County, the
Tribe, the City of Port Angeles,and the City
of Port Townsendreceivedfunding for
technical assistance to advance their climate
resilience and mitigationplanning. The City
of Port Townsend usedthe support to
identifyasset risks fromsea level rise and
other coastal floodingimpacts.
The City of Port Townsend is the county seat
of Jefferson County witha population of
10,148(U.S. Census Bureau, 2021). Located
on the Quimper Peninsula, the townis
surrounded by water and many areas of the
shoreline occurat low lying elevationsand
already experience coastal flooding from
Figure 1.Map of the Olympic Peninsula in Washington State
storm surge, wave run-up,and extreme high
with location of Port Townsend.
tides(Figure 1). This study examines sea
level rise and coastal flooding risks to
coastal assets in the City of Port Townsend, with the goalslisted below.
Model and map the extent of coastal flooding scenarios
Analyze City of PortTownsend coastal assetexposure to coastal flooding
Establish risk classifications toevaluate impacts of asset exposure to coastal flooding
Studies that share relatedgoals are currently being conducted, such as the Jefferson County Sea Level
Rise Study, which is currently underway in fall 2022. Both studies involve an analysisof sea level rise
models and other scientific information, identification of areas exposed to futuresea level rise, and an
assessment of at-riskcommunity assets and infrastructure. Additionally,the approach of the Port
Townsend analysis was similar to the sealevel rise matrix
Comprehensive Climate Adaptation Strategy.
FLOOD EXPOSURE AND MAPPING APPROACH
While much of the Port Townsendcoast occurs along bluffs at high elevation many coastal areas of the
citythat are at much lower elevationsare already susceptible to current coastal flooding.Rising sea
October 2022 4
City of Port Townsend Sea Level Rise Risk Assessment
levelsdue to climate changemeans that coastalinundationimpactswill extend and intensify across
many low-elevation areasof the City.
This study focuses on theimpactsofcoastalflooding that threatencity assets atlow elevations.
Mapping the relationship between assets and coastal inundation scenarios leads to a better
understanding of the risks and vulnerabilities of key assets and resources to current and future exposure
to coastal flooding, which will be exacerbated by sea levelrise.
Coastal Flooding Probabilities andProjections
Coastal flooding probabilities and projections were developed using sea level riseprojectionsand
current coastal flooding impacts, such asstorm surge, wave run-up, and 100-year floods.The
subsequent sections discuss each impact.
Sea Level Rise Projections
The Washington Coastal Resilience Project (WRCP) developed community-scale sea level rise projections
in 2018 across 171 locations aglobaland regional sea level rise
projections that account for vertical land movement(Miller et al. 2018). These projections are
accompanied by an interactive websitedeveloped by the University of
Group that includes sea level rise data visualizations for each of the 171locations. The sea level rise data
is presented based on two global greenhouse gas emissions scenarios, a high emissions scenario and a
1
low emissions scenario.The analysis in this report usessea level rise scenarios based on the RCP 8.5
scenario because it aligns with current the global emissions trajectory.
In addition to using different emissions scenarios, the 2018 sea level rise projections are based on
probabilistic projections of sea level rise exceedance. The WRCP produced a report with
recommendations for how to apply the projections, with guidance on applying the probabilistic
projections(Raymond et al. 2020). These projection scenarios are listed below.
High Probability Projections (>83%):This represents a lower rate of sealevel rise with a high
probability of occurring, meaning that it is very likely that the sea level will rise to the level
associated with this projection. It suggests that there is an 83% chance that the sea-level rise will
be greater than the identified rate with this threshold. The recommendation is to use this
projection for risk-tolerant situations where infrastructure can accommodate sea level rise
impacts or projects have flexibility or adaptabilityand where the consequences of flooding
would be minimal.
Low-Range Probability Projections (<17%):This represents a higher rate of sea level rise with a
lower probability of occurring. It suggests that there is a 17% chance that the sea-level rise will
be greater than the value identified for this probability, oramount of sea level rise. The
recommendation is to use this level for assets that are risk-averse and where sea level rise will
1
A high emissions scenario(RCP 8.5)assumes a global future in which we do not significantly reduce or limit emissions. It also
assumes high population and lower income growth with moderate technological change and energy improvement, resulting in
long-term to high energy demand and greenhouse gas emissions. A low emissions scenario (RCP 4.5)assumes a more
aggressive global response to emissions reduction actions based on the 2015 Paris Agreement and limits mean global warming
to less than 2C and achieves net-zero greenhouse gas emissions by2050. This scenario is considered politically challenging and
would require concerted action by all countries to shift to lower emissions.
October 2022 5
City of Port Townsend Sea Level Rise Risk Assessment
have substantial consequences. For example, using the estimated sea level rise associated with
this probabilityshould be used for critical infrastructure, such as sewage treatment plants or
emergency response infrastructure, or others that would be seriously compromised by flooding
and that the loss of that function would be a major disruption to the community.
Extreme Low Probability Projections (0.1%):This represents the highest rate of sea-level rise
with the lowest probability of occurring. Thisprojection represents the physical upper limit for
sea level rise and is a worst-casescenario for extremely conservative decisions. This level of sea-
level rise is unlikely to change with future scientific updates.
The National Oceanic and Atmospheric Administration (NOAA) also updated its sea level rise projections
in 2022, which arebased offextrapolated tide gauge record data, to reflect the most recent climate
change scenarios (Sweet et al. 2022). NOAAinclude5 scenariosthat generally
correspond to aglobal climate model scenario(Low,Intermediate-Low, Intermediate, Intermediate-
High, and High). The NOAA 2022 High Projection scenariowas used as a visual reference layerin this
spatial analysis,but the WRCP projections were used for the asset analysissince they are more locally
tailored.
Current Coastal Flooding Processes
Sea level rise can exacerbate existing coastal flooding, which is affected by a variety of processes,
events, and factors. This analysis usesstorm surge, wave runup,and the FEMA 100-year flood zone to
represent current drivers of coastal flooding, described below.
Storm surge:Storm surge creates water levels that are higher thanthe predicted astronomical
tides, due to a combination of high tide events, low atmospheric pressure, and wind-driven
waves. Because of the intensified impacts of these events, this study additively combines storm
surgewith WCRP sea level rise projections. Storm surge for Port Townsend was estimated by
examining the extreme water level historic data from the nearby Friday Harbor tide gauge and
comparing it to MHHW levels. There is 1% chance of a storm surge event for any given year in
Port Townsend that would raise
the tide levels by an additional
3.1 feet (Petersen et al. 2015).
For the purposes of this report,
the 3.1 feet of water level rise
attributable to storm surge was
used to represent current
flooding in Port Townsend.
Wave runup:Wave runup is the
height difference between the
elevation of still water and the
elevation that is reached by the
uprush of a wave on beaches and
shore barriers such as seawalls.
At a local monitoring site (Salmon
Figure 2. Wave runup at a city park and the Salmon Boat Club ramp.
Club Boat Ramp, Figure 2) with a
gently sloping shoreline, wave
October 2022 6
City of Port Townsend Sea Level Rise Risk Assessment
runup has been measured to increase tide levels by an additional 2.0 to 2.5 feet (Local 20/20
2018).For all inundation scenarios that were within 100 feet of the coast, an additional 2.5 feet
was added to the total elevation to represent wave runup.In the case of this report,the
purpose of evaluating wave runup was tobetter understand howpropertiesalong the shoreline
are directly impacted due to wave actionand serve as a planning tool for mitigation measures
against wave runup.
100-year flood: The National Flood Insurance Program provides geographic areas and
subdivisions atrisk of flooding and the associated base flood elevation. For this analysis, the
base elevations of the 1% annual flood eventor a 100-year floodfor designated high-risk
areas within Port Townsend were used. Depending on the subdivisions the base flood elevations
ranged from 7 feet to 17 feet (FEMA 2019). These flood maps were included in the asset
inundation analysisbecause it is representative of where historical flooding has occurred.
However, theFEMA flood map does notconsider future sea level rise.
Sea Level Rise and Coastal Flooding in Port Townsend
Sea level rise projections for the coastal area around the City of Port Townsendare summarized in Table
1. For the purposes of this analysis, we used WRCP17% and 1% probability of exceedance value with a
planning horizon of 2100(3-feetand 5-feetof sea level rise,respectively). We also mappedthe NOAA
2022 High Projectionscenariowith a planning horizon of 2100 (6.52-feet of sea level rise)to compare
across datasets.The sealevel rise projections and current coastal flooding levels selected for this
analysis are summarized on Table 2. To represent theimpacts of current coastal flooding impacts in Port
Townsend we used the FEMA 100-yearcoastal flood elevation, the observed tidal elevation from the 1%
storm surge event(3.1 feet), and 2.5 feet of wave run-up.
Table 1. Projected Sea Level Change forPort Townsend(in feet).
Time Greenhouse Central 17%Higher magnitude, but lower likelihood NOAA
periodGas Estimate probability possibilities2022 High
Scenario(50%)of projections
10% 1% 0.1%
exceedance
probability probability probability
of of of
exceedanceexceedanceexceedance
2050High 0.81.01.11.52.11.47
(2040-
2059)
2100 High 2.23.03.35.08.56.52
(2090-
2109)
2150High 3.75.25.910.218.816.2
(2140-
2159)
This table summarizes the 2018 assessment projections from the WCRP projections and NOAA 2022 High
Projection scenario for the City of Port Townsend. For the WCRP projections, projected changes are assessed
relative to contemporary sea level, which WCRP defines as the average sea level over the 19-year period 1991-
2009. For the NOAA 2022, projected changes are added on topof MHHWelevation. Projections highlighted in
orange were used for thisanalysis and the projections highlightedinyellow was usedas a reference.
October 2022 7
City of Port Townsend Sea Level Rise Risk Assessment
Table 2. Scenarios and their associated elevations (feet).
ProjectionInundation Scenario Feet of Sea-level Source
Rise
Washington State 2100 Low-Range Probability 3 feetMiller et al. 2018
Unified projections Projections (<17%)
Washington State 2100 Low Probability 5 feet Miller et al. 2018
Unified projectionsProjections (1%)
2022 NOAA Projection 2100 High projection6.52 feetSweet et al. 2022
Storm Surge 100 Year Storm event3.1 feet Petersen et al. 2015
FEMA Flood Hazards 100-year Flood Base elevations from FEMA 2019
7-15 feet
Wave Run-up Current observations2.5 feet,on top of Local 20/20 2018
storm surge
Approach to Assess Future Coastal Flooding Levels in Port Townsend
This section outlines how we assessed future coastal floodingbased on different sea level rise
projections and coastal flooding scenarios.
Inundation Mapping for Future Water Levels
źķğƌ 5ğƷǒƒƭ
The National Oceanic and Atmospheric Administration (NOAA) maintains a tide gauge along Water
Street near Point Hudson (Station ID: 9444900). Table 3 details the tidal datumsand their current
elevations(feet) that the gauge tracks.Forthis analysis,MHHW(8.52 feet)was used as a referencebase
elevation with all inundation projections added on top of the 8.52feet(in reference to Mean Lower Low
Water, or MLLW).
Table 3. Tidal datums and their current elevations (feet) relative to MLLW.
DatumCurrent Elevation
Mean higher high waterMHHW8.52
Mean high waterMHW7.84
Mean tide levelMTL5.17
Mean sea levelMSL5.00
Mean low waterMLW2.50
Mean lower low waterMLLW0.00
For instance, the1% annualstorm surge event was observed to increase the elevationof MHHW during
low atmospheric events by 3.1 feet. Cumulatively, this wouldmean that the water level during a 1%
storm surge event will be 11.62 feet (Table 4).
Table 4. Projected water level during 1% storm surge event (feet).
MHHW Elevation 1% Storm Surge Event IncreaseTotal Water Level During 1%
Storm Surge Event
8.523.111.62
October 2022 8
City of Port Townsend Sea Level Rise Risk Assessment
The totalwater level that accounts for sea level rise by 2100 wascalculated by totaling MHHW withthe
elevation ofWCRP sea level riseprojections and storm surge. This wouldmodelnot only thetotal water
level increase brought on bysea level rise, but also the additional elevation drivenby 1% storm surge
events(Table 5).
Table 5. 2100 Total water level (feet) according to WRCP Washington State projections.
Projection 2022 MHHW 1% Storm Surge Sea Level Rise2100 Projected
LevelsWater Level
17% Likelihood SLR 8.523.1 314.62
Event
1% Likelihood SLR 8.523.1516.62
Event
Because areas of the shorelinewithin proximityto thecurrent water level would be additionally
impacted by wave runup,the total water level for areas within100 feet of the shorelineincluded an
additional 2.5-feet of elevation that accounts for wave runup (Table 6).
Table 6. 2100 Projected (WRCP) total water level coupled with waverunup (feet).
Projection 2100 Projected Wave Runup 2100 Water Level
Water LevelwithWave Runup
17% Likelihood SLR 14.622.517.12
Event
1% Likelihood SLR 16.622.519.12
Event
As a comparison, the 2022 NOAA High Projection scenario was 6.52-feet of sea level rise by 2100, which
would place the total projected water level at 15.05 feet by 2100 (Table 7).
Table 7. Total water level (feet) in 2100 according to NOAA 2022 projections.
2022MHHW Level Sea Level Rise2100 Projected Water
Level
8.52 6.5215.05
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The DigitalElevation Model (DEM) for Jefferson County was obtained from the NOAA SeaLevel Rise
Viewertool and downloaded into ArcGIS.The DEM used was in meters and had a spatial reference
coordinate system of NAVD88. The DEM had a horizontal resolution of3-meters and a 0.328 RMSE of
vertical accuracy. Additionally,the elevation data source of the DEM metthestandards of theUSGS
Quality Level 2 as defined by the Lidar Base Specification of the national interagency 3D Elevation
Program. Using OnlineVDatum,the reference conversion from MLLWto NAVD88 for thePort Townsend
area was calculated to be -1.1 feet. By applying this offset,water levels could be converted to NAVD88.
For example, if MHHW of 8.52 feet was applied the conversion offset wouldhave an elevation of 7.42
feet in reference to NAVD88(Table 8).A visual representation of this offset illustrateshow the
conversion can be applied and can be seenin Figure 3.
October 2022 9
City of Port Townsend Sea Level Rise Risk Assessment
Table 8. Water level (feet) in reference to MLLW and NAVD88.
Inundation ScenarioElevation in reference to Elevation in reference to
MLLWNAVD88
MHHW8.527.42
Storm Surge11.6210.52
17% Likelihood SLR Event14.6213.52
NOAA High 2022 Event15.0413.94
1% Likelihood SLR event16.6215.52
Figure 3. Tidal datum elevationoffsetin reference to MLLW and NAVD88.
{Ļğ \[ĻǝĻƌ wźƭĻ ğƓķ {ƷƚƩƒ {ǒƩŭĻ ağƦƦźƓŭ
This section outlines a case study of how these various models and data were used to estimate the total
water level that accounts for sea level rise and storm surgewithin ArcGIS.Tocalculate storm surge,3.1-
feet was added on top ofthe MHHW (8.52 feet).This elevation of 12.62 feet was then offset by -1.1 feet
toensure total water elevation wasbased off the NAVD88 reference layer, leading to a total water level
of 10.52 feet (in reference to NAVD88). This elevation was then converted from feet to meters(3.21).
Finally, all areas of the DEMthat were under 3.21meters of elevation were selectedusing the Raster
Calculate tool(Figure 4).
October 2022 10
City of Port Townsend Sea Level Rise Risk Assessment
Figure 4.Example of how inundation layers were created using the Raster Calculate tool.In this scenario, the
graphic depicts all areas equal to or below 3.21 meters (pink), which is the 3.1-feet storm surge scenario.
The Reclassify tool was used to replace the raster values that were over the specified elevation (3.21
meters) with No Dataso that only the raster values representing sea level rise remained. The raster
was then converted to a polygon using the Raster to Polygon tool to smooth the layer into simpler
shapesand allow for further analysis.
Areasof the polygonthat were under the elevation of water level that were not hydrologically
connected tothe coast or . Theseareas were eventually
represented in a different color.
ğǝĻ wǒƓΏ
Ʀ ağƦƦźƓŭ
The wave runup mapswerecalculated by adding total water level observation(Salmon Club Boat Ramp,
Local 20/20 2018)and the NAVD88 offset and then subtracting the elevation from the tidal gauge
observation (Point Hudson).Wave run-up height was modeled by adding an additional 2.5-feet of
elevation for each inundation scenario.
The Erase tool was then used to delete all parts of the wave runup layer that overlapped witha
corresponding inundation layer, leaving a layer that represents areas 2.5-feet higher than the given
inundation scenario.Since waverunup only impacts shoreline areas, The Buffer tool was used to
establish a zone of Port Townsend that was within 100 feet of the shoreline. Areas 2.5-feet higher than
the given inundation scenariowere attached to this 100-footbuffer zone using the Clip tool.
PORT TOWNSEND ASSETSAND FLOODRISK
Asset Risk Assessment Methodology
Generally, climate vulnerability is defined as the climate risks and impacts moderated by the capacity to
adapt and cope to those impacts. For example, the extent of coastal flooding impacts on sewer
infrastructure is dependenton the location of sewerinfrastructure in relation to expected sea level rise
and whether the infrastructure can function with that inundation. A total of eighty-five(85)assets were
identified through city documents and city staff consultation with an emphasis on coastal assets. For this
October 2022 11
City of Port Townsend Sea Level Rise Risk Assessment
assessment we focused on climate risks to coastal assetsand categorized assets by various
characteristics(Table 9).
Table 9. Asset type and characteristics.
Asset TypeAsset Characteristics
Accommodations (Temporary Housing)Ownership (e.g., City owned, privately owned,
etc.)
Dock or Marina
Year Built
Education Facility
Expected Asset Lifespan
Fabrication or Working Boatyards
Estimated Cost (i.e., assessed parcel value or
Financial Facility
estimated replacement cost of public
Food, Restaurants, or Retail
infrastructure)
Fuel
Offices and Buildings
Open Outdoor Spaces and Parks
Parking Lots
Power Structures
Residences (Housing)
Safety Facilities
Stormwater Infrastructure
Transportation
Wastewater Infrastructure
Water Infrastructure
We then looked at three components of risks to assetsexposure, sensitivity, and consequenceto
assess sea level risk to these assets.These terms are furtherdefined in subsequent sections.
Assessing Exposure
Exposureincludes the physical factors that put assets in way from sealevel rise and coastal
flooding. includeselevation,
location, and whether it overlaps with anticipated futurecoastal flooding. We measured exposure by
identifying the spatial locationsof assets into ArcGIS Pro as points or polylinesand overlayed with
inundation layers. If an asset was within the boundary or intersected (partly within)with an inundation
layer,it was deemed to be exposed to that flooding scenario.
We categorized asset exposure level as high, medium, or low based on the likelihood of that asset
experiencing coastal flooding (Table 10). Ahigh exposure asset would intersect with one of the current
floodingrisks(i.e., an asset overlapped with current wave run-up, storm surge, or 100-year flood).A
medium exposure asset intersectswith the 17% sealevel rise threshold and a low exposure asset
intersects with the 1% sealevel rise threshold.We identified exposure for both private and public
assets, however, only provide results for the public assets in this document.
October 2022 12
City of Port Townsend Sea Level Rise Risk Assessment
Table 10.Exposure categories defined as high, medium, or low exposure levels
Exposure Short DescriptionCurrent Coastal Flooding Future Flooding Risk,
LevelRiskrelated to SLR Projections
HighAssets thatare already exposed Any asset exposed to any
to current floodingfrom storm current coastal flooding
surge+wave run-up or 100-year impact is considered to have
floods.high exposure.
MediumAssets that will be exposed to
future flooding due to SLR by
X
2100at the 17% probability of
exceedance.
LowAssets that will be exposed to
future flooding due to SLR by
2100at the 1% probability of X
exceedanceor will experience no
future flooding.
Assessing Sensitivity
Sensitivityis the degree to which the asset is affected by sealevel rise and coastal flooding. For example,
a new asset built with newer materials and built up to current designstandardswould be relatively less
affected by temporary inundation as compared to infrastructure or assets that are built with older
materials and to outdated designstandards.
Within this analysis, sensitivity is defined as the asset agerelative to expecteddesign life. We identified
less conservative and more conservative asset design life estimates using different sources related to
asset types(Table 11). High sensitivity assets were assets whose current ageexceeded less conservative
design life estimates. We only identified sensitivity for public assetsdue to data availability and
limitations.
Table 11. Design lifespan of key asset types.
Asset TypeDesign Life Design Life Source(s)
(Less (More
Conservative)Conservative)
Portland Cement Association(PCA),
Accommodations (Temporary
30100n.d.
Housing)
David and Sons, 2017
Dock / Marina4050Michigan Sea Grant, 2015
PCA, n.d.
Education30100
David and Sons, 2017
Fabrication / Working Boatyards30100Eurostat, 2003
PCA, n.d.
Financial30100
David and Sons, 2017
Food, Restaurants, Retail30100PCA, n.d.
October 2022 13
City of Port Townsend Sea Level Rise Risk Assessment
Asset TypeDesign Life Design Life Source(s)
(Less (More
Conservative)Conservative)
David and Sons, 2017
Fuel2030ServoPro, 2021
PCA, n.d.
Offices and Buildings30100
David and Sons, 2017
Open outdoor space and parks2050City of Hamilton, Public Works, 2009
CA Department of Transportation,
Parking lot2020
2017
Power5050Union of Concerned Scientists, 2017
PCA, n.d.
Residences (Housing)30100
David and Sons, 2017
No data found. Using lifespan of
Safety30100
concrete structures as proxy.
Stormwater50100ASCE, 2021a
Transportation10100Union of Concerned Scientists, 2017
Wastewater2550ASCE, 2021b
Water60100Union of Concerned Scientists, 2017
Assessing Consequence
High consequence assets represent assets that would affect key community functions if it failed due to
coastal flooding. For this project, we identified high consequence assets using
critical facilities which includes assets, systems, networks, or functions that would have a debilitating
effect on security or public health and safety if they were debilitated or incapacitated due to hazards
to identify critical infrastructure on the list of assets. Critical infrastructure wasidentifiedby the City
of Port Townsend project staff.These assets were subsequently categorized as high consequence assets.
RESULTS
Summary of Coastal Flooding Risk to Key Assets
The eighty-fiveassets assessed in this study are categorized based on asset type, ownership, exposure,
sensitivity, and whether it represents a high consequence asset (public assets are summarized on Table
12 with the detailedassetdescriptions for public and private assetsin Appendix B). Of these 85 assets,
forty (40) assetswere publicly owned or owned by NGOs.
High Exposure
Of the 40 publicassets, 32 wereidentified as having high exposure, meaning that those assets are
already located within the 1% chance ofstorm surge (3.1 feet)area, wave runup (2.5 feet)area, and/or
the FEMA 100-year flood zone.There highly exposed assets includeassets withinwastewater, water,
transportation, stormwater, safety, marinas,housing,and business categories. Out of the 29high
consequence assets representing critical infrastructure(which include private assets),23are highly
exposed to current coastal flooding.
These exposures represent current risk conditions and do not consider futuresea level rise. The high
exposure assets should be prioritized by the City for adapting to sealevel rise as theseare already
October 2022 14
City of Port Townsend Sea Level Rise Risk Assessment
known to experience coastal flooding during extreme high tide events and storm surgeevents and they
will be the first assets to be affected by future sea level rise.
Highly Sensitive Assets
Out of the 40public assets that were evaluated for sensitivity, six (6)are considered highly sensitive.
That means their current age exceeds their anticipateddesign life, or the estimated length of time that
asset is designed to function for. These assets aremore likely tofail after a single orrepeated flooding
eventsbecause of their agein relation to their design life.Assets with high sensitivity to sealevel rise
should also be considered as priorities for the City as they will be the assets least equipped to deal with
future coastal flooding worsened by sealevel rise.
High Consequence Assets
The highconsequence assets are assets that providecritical services such as food, gas, shelter, power,
and health services to Port Townsend that also have high exposure and high sensitivity. The City will
needto prioritize these assets inadapting to sealevel rise to avoid failure of these critical facilities. High
consequence assetsincludepublic and private assets. There are four(4) publicassets that have been
identified as high consequence assets.
Asset Valuesat Risk
Asset values wererepresented as orrepresented as
estimated replacement cost for public assets(included with detailed asset descriptions in Appendix B).
We identified total costs at risk by different exposure levels for both public and private assets.
For public assets, the total estimated replacement costs for assets with high exposurewhere assets are
already located within the 1% chance of storm surge, wave runup, or the FEMA 100-year flood zoneis
$179,200,000.The total estimated replacement cost for public assets with mediumexposure, orwhere
assets intersect with the 17% probability of exceedance,is $2,068,544.Finally, the total estimated
replacement costfor assets withlow exposure, or where assets intersect with the1% probability of
exceedance, is $12,771,167.
For private assets, the total assessed parcel value for assets with high exposure where assets are already
located within the 1% chance of storm surge, wave runup, or the FEMA 100-year flood zone is
$44,060,086.The total assessed parcel value for private assetswith medium exposure, orwhere assets
intersect with the 17% probability of exceedance,is $2,880,465.Finally, the total assessed parcel value
for private assets with low exposure, or where assets intersect with the 1% probability of exceedance, is
$1,231,924.
Table 12. Assets categorized by level of exposure and sensitivity and whether it represents a high consequence
asset.
IDAsset OwnershipExposureSensitivityHigh
Consequence
Wastewater
Monroe Street Lift
WW-1StationCityHighHighY
WW-2Gaines Street Lift StationCityHighLow
Kah Tai Nature Park
WW-3RestroomsCityHighMedium
October 2022 15
City of Port Townsend Sea Level Rise Risk Assessment
IDAsset OwnershipExposureSensitivityHigh
Consequence
Wastewater Treatment
WW-4PlantCityLowMedium
WW-5Port Lift StationCityMediumMedium
WW-6Point Hudson Lift StationCityHighMedium
WW-7Kearney SewerCityHighLow
WW-8Boat Haven SewerCityHighMedium
WW-9Downtown SewerCityHighHighY
Water
W-1Kearney WaterCityHighLow
W-2Boat Haven Water CityHighLow
W-3Downtown WaterCityHighLow
Transportation
Washington State Ferry Washington
TerminalStateHighMedium
U.2
Stormwater
SW-1Stormwater Lift StationCityHighLow
SW-2Kearney StormCityHighLow
SW-3Boat Haven Storm CityHighMedium
SW-4Downtown Storm CityHighHighY
Safety
S-1US Coast GuardFederalLowMedium
S-2Point Wilson LighthouseFederalHighHighY
Parking Lot
PL-1The Back AlleyCityLowHigh
Power
P-1Electric Sub-StationCityLowLow
Open Outdoor Space and Parks
OP-1Pope Marine ParkCityHighMedium
OP-2Adams Street ParkCityHighMedium
OP-3Tyler Street PlazaCityHighLow
OP-4Wave Viewing GalleryCityHighLow
Offices and Buildings
OB-1City HallCityLowLow
OB-2Cotton BuildingCityLowLow
OB-3Pope Marine BuildingCityHighLow
OB-4Port of Port TownsendPortHighLow
Education
E-1Marine Science Center-1NGOHighLow
Northwest Maritime
E-2CenterNGOHighLow
E-3Marine Science Center-2NGOHighLow
E-4Marine Science Center-3NGOMediumLow
Dock / Marina
October 2022 16
City of Port Townsend Sea Level Rise Risk Assessment
IDAsset OwnershipExposureSensitivityHigh
Consequence
Port of Port Townsend High
D-1MaintenancePort High
D-2Union WharfPublicHighLow
D-3City DockPublicHighLow
D-4Boat Haven MarinaPort HighLow
Point Hudson (Port
D-5Property)Port HighLow
Accommodations (Temporary Housing)
American Legion
A-9(Homeless Shelter)NGOHighHigh
LIMITATIONS
While this report attempts to assess the coastal flooding risk of key assets, there are some limitations of
this assessment, identified below.
The inundation modeling was based off elevationdata and does not account forthe effects of
seawallsor other fortification structures.Because of this,the hazard exposure analysismay have
resulted in more conservativehigh estimationsof flooding in certain areas.
The elevation of assets (i.e., building height) was not considered and therefore may
overrepresent flooding.
Site specific variables of wave runup were not assessed.
The effects of natural processes or human causes geomorphological changes that might lower or
raise the sea level elevation are not sufficiently understood and therefore the model does not
consider coastal geomorphological processes that might occur in the future.
Furthermore, we recommend expanding on this assessment in the future. These recommendations are
also listed below.
Assessing asset adaptive capacity or ability to cope with inundation is beyond the scope of this
project. We recommend reviewing the identified asset list and focusing on assets that are highly
exposed, highly sensitive,and would have a high consequence of failure to assess the ability of
those assets to copeor withstand impacts of coastal inundation, especially repeatedly. In
addition, identifying adaptive capacity of infrastructure and assets could result in policy and
planning recommendations for how to adapt key assets. This process is identified in the Climate
.
Erosion along bluffs may be impacted by sea level rise and storm surge but is outside the scope
of this study.
Port Townsenditshistoric and cultural resources. The Comprehensive
Plan encourages retention of significant buildings (Land Use Element Goal 17). We recommend
Buildings.
October 2022 17
City of Port Townsend Sea Level Rise Risk Assessment
This study did not account for the tsunami inundation zone. Future expansion of this could
include integration of assets exposed to tsunami-related flooding.
REFERENCES
American Society of Civil Engineers (ASCE). (2021a). Stormwater. In: 2021 Report Card
Infrastructure. https://infrastructurereportcard.org/cat-item/stormwater-infrastructure/.
https://infrastructurereportcard.org/cat-item/stormwater-infrastructure/.
California Department of Transportation. (2017). Chapter 610 Pavement Engineering Considerations. In:
, (610): 1-23.
City of Hamilton, Public Works. (2009). Chapter 8: Parks and Open Spaces.
http://www2.hamilton.ca/NR/rdonlyres/593520D0-7E19-4DF2-997C-
95C23D3235C1/0/SOTIParks_and_OpenSpaces.pdf. Accessed 31 October 2022.
David and Sons Concrete. (2017). The Average Lifespan of Concrete.
http://davisandsonsconcrete.com/2017/02/the-average-lifespan-of-
concrete/#:~:text=For%20larger%20projects%20such%20as%20buildings%20and%20homes%2C
,other%20materials%20such%20as%20wood%20begin%20to%20deteriorate.Accessed 31
October 2022.
Eurostat.(2003). The lifespan of main transport assets.
https://transportgeography.org/contents/chapter3/transportation-and-economic-
development/transport-assets-lifespan/. Accessed 31 October 2022.
Federal Emergency Management Agency (FEMA). (2019). FEMA Flood MapService Center: Search by
Address Tool.
https://msc.fema.gov/portal/search?AddressQuery=port%20townsend#searchresultsanchor.
Accessed 31 October 2022.
Local 20/20. (2018). King Tide Dec 20, 2018. https://l2020.org/king-tide-dec-20-2018/. Accessed 31
October 2022.
Michigan Sea Grant. (2015). Infrastructure Best Practices. https://www.michiganseagrant.org/wp-
content/blogs.dir/1/files/2012/05/15-703-Infrastructure-Best-Practices.pdf. Accessed 31
October 2022.
Miller, I.M., Morgan, H., Mauger, G., Newton, T., Weldon, R., Schmidt, D., Welch, M., Grossman, E.
(2018). Projected Sea Level Rise for Washington State A 2018 Assessment. A collaboration of
Washington Sea Grant, University of Washington Climate Impacts Group, University of Oregon,
University of Washington, and US Geological Survey. Prepared for the Washington Coastal
Resilience Project.
Petersen, S., Bell, J., Miller, I., Jayne, C., Dean, K., and Fougerat, M.(2015). Climate Change Preparedness
Plan for the North Olympic Peninsula. A Project of the North Olympic Peninsula Resource
October 2022 18
City of Port Townsend Sea Level Rise Risk Assessment
Conservation & Development Council and the Washington Department of Commerce, funded by
the Environmental Protection Agency. Available: www.noprcd.org.
Portland Cement Association (PCA). (No date). Durability. https://www.cement.org/learn/concrete-
technology/durability. Accessed 31 October 2022.
Raymond, C.L, Faghin, N., Morgan, H., and Roop, H. (2020). How to Choose: A Primerfor Selecting Sea
Level Rise Projections for Washington State. A collaboration of Washington Sea Grant and
University of Washington Climate Impacts Group. Prepared for the Washington Coastal
Resilience Project.
ServoPro. (2021). Knowing the lifespan of your underground fuel tanks.
https://servopro.com.au/knowing-the-lifespan-of-your-underground-fuel-tanks/. Accessed 31
October 2022.
Sweet, W.V., Hamlington, B.D., Kopp,R.E., Weaver, C.P., Barnard, P.L., Bekaert, D., Brooks, W., Craghan,
M., Dusek, G., Frederikse, T., Garner, G., Genz, A.S., Krasting, J.P., Larour, E., Marcy, D.,Marra,
J.J., Obeysekera, J., Osler, M., Pendleton, M., Roman, D.,Schmied,L., Veatch, W., White, K.D.,
and Zuzak, C. (2022).Global and Regional Sea Level Rise Scenarios for the United States: Up-
dated Mean Projections and Extreme Water Level Probabilities Along U.S. Coastlines. NOAA
Technical Report NOS 01. National Oceanic and Atmospheric Administration, National Ocean
Service, Silver Spring, MD, 111 pp. https://oceanservice.noaa.gov/hazards/sealevelrise/noaa-
nos-techrpt01-global-regional-SLR-scenarios-US.pdf.
Union of Concerned Scientists. (2017). Built to Last: Challenges and Opportunities for Climate-Smart
Infrastructure in California. Prepared by J.R. Gibson.
https://www.ucsusa.org/sites/default/files/attach/2017/11/gw-whitepaper-smart-
infrastructure.pdf.
U.S. Census Bureau. (2021). The City of Port Townsend, Washington:Quickfacts.
https://www.census.gov/quickfacts/fact/table/porttownsendcitywashington/PST045221.
Accessed 31 October 2022.
October 2022 19
City of Port Townsend Sea Level Rise Risk Assessment
APPENDIX A: FLOODING AND INUNDATION MAPS
This appendix section provides more detailed maps that depict coastal flooding and inundationof
assets.
Figure 5. Infrastructure along Kearney Street that are exposed to different inundation scenarios.Storm water
pipes are shown in pink, water systems are shown in orange, and sewer lines are shown in purple. Coastal flooding
is show in blue, wave runup in green, and areas unlikely to flood in a crosshatch blue pattern for each inundation
scenario.Coastal flooding from the 17% sea level rise event and the 1% sea level rise event also take into account
flooding brought on from 1% storm surge.
October 2022 20
City of Port Townsend Sea Level Rise Risk Assessment
Figure 6. BoatHaven infrastructure exposed to different inundation scenarios.Storm water pipes are shown in
pink, water systems are shown in orange, and sewer lines are shown in purple. Coastal flooding is show in blue,
wave runup in green, and areas unlikely to flood in a crosshatch blue pattern for each inundation scenario.Coastal
flooding from the 17% sea level rise event and the 1% sea level rise event also take into account flooding brought
on from 1% storm surge.
October 2022 21
City of Port Townsend Sea Level Rise Risk Assessment
Figure 7. Downtown infrastructure exposed to different inundation scenarios.Storm water pipes are shown in
pink, water systems are shown in orange, and sewer lines are shown in purple. Coastal flooding is show in blue,
wave runup in green, and areas unlikely to flood in a crosshatch blue pattern for each inundation scenario.Coastal
flooding from the 17% sea level rise event and the 1% sea level rise event also take into account flooding brought
on from 1% storm surge.
October 2022 22
City of Port Townsend Sea Level Rise Risk Assessment
Figure 8. Map of assets categorized by currentflood exposure inPort Townsend.Storm surge is depicted inblue
and wave runup in green. Areas that are below 1% storm surge event elevation but are hydrologically unconnected
are labeledas areas unlikely to floodand are depicted ina crosshatch blue pattern.Assets are classified by their
exposure types, high exposure assets are shown in red, medium exposure assets in yellow, and low exposure in
green.
October 2022 23
City of Port Townsend Sea Level Rise Risk Assessment
Figure 9. Map of assets categorized by futureflood exposure in Port Townsend by2100 underthe 17% likelihood
SLR event.Coastal flooding brought on by 17% SLRevent and the 1% storm surgeis depicted in blue, and wave
runup in green. Areas that are below the combined elevation of the 17% SLRevent and1% storm surgebut are
Assets are classified by their exposure types, high exposure assets are shown in red, medium exposure assets in
yellow, and low exposure in green.
October 2022 24
City of Port Townsend Sea Level Rise Risk Assessment
Figure 10.Map of assets categorized byflood exposure inPort Townsend by2100 underthe 1% likelihoodSLR
scenario.Coastal flooding brought on by 1% SLR event and the 1% storm surge is depicted in blue, and wave runup
in green. Areas that are below the combined elevation of the 1% SLR event and 1% storm surgebut are
Assets are classified by their exposure types, high exposure assets are shown in red, medium exposure assets in
yellow, and low exposure in green.
October 2022 25
City of Port Townsend Sea Level Rise Risk Assessment
Figure 11.Map of assets categorized by flood exposure in Port Townsendbased onFEMA 100-year flood areas,
which represent historic floodinginPort Townsend(Shown in blue). Assets are classified by their exposure types,
high-exposure assets are shown in red, medium-exposure assets in yellow, and low-exposureassets in green.
October 2022 26
City of Port Townsend Sea Level Rise Risk Assessment
Figure 12. Map of flooding impacts that would occur in 2100 under the 2022 NOAA High Projection scenario. This
was usedas a reference layer.
October 2022 27
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Chapter 13.21
SEWER SYSTEM - GENERAL PROVISIONS
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year term.
-
Up to 100% for Tribal Nations
ility loan.
o
.
development loan.
-
% interest rate.
.5
Typically up to $50,000 for feasibTypically up to $350,000 for preTypically a 151% loan fee. EDA investment $500,000 Cost sharing required from applicant Standard grant rate is total
project cost80%
Funding Available Grants:
7
-
for
-
profit organizations,
income rural
-
-
Eligible Applicants Nonpublic agencies, tribes, and lowcommunities with a 50,000 population or less, or 10,000 or less if proposed permanent financing is through USDA Rural Development.
Municipalities, counties, cities, towns, states, notprofit organizations, ports, tribal nations.
distribution
ribution.
-
Eligible Projects Water, wastewater, stormwater, or solid waste planning; environmental work; and other work to assist in developing an application for infrastructure improvements. Drinking
water infrastructure; including preconveyance, withdrawal/harvest (i.e. well extraction), storage facilities, treatment and distWaste water infrastructure; including conveyance, treatment
facilities, discharge infrastructure and water recycling.
&
evelopment
Program:
s
ic Adjustment
CONSTRUCTION
Development Loans
-
PREONLY ProgramRCAC Rural Community Assistance Corporation Feasibility and Pre Economic DAdministration (EDA) United States Department of Commerce EDA Public Works EconomAssistance Design
and/or Construction for distressed and disaster communities.
nd
v/DWSRF
Jocelyne Gray Jocelyne Gray
4893 4893
--
669669
--
How To Apply Online applications available aaccepted October 1 through November 30, 2024. Contact: 564Jocelyne.gray@doh.wa.gov For information and forms visit: http://www.doh.wa.goOnline
applications available and accepted October 1 through November 30, 2024. Contact: 564Jocelyne.gray@doh.wa.gov For information and forms visit: http://www.doh.wa.gov/DWSRF
idy are
year time of year time of
--
ving subsidy are
year repayment period
-
year time of performance, year time of performance,
--
Maximum $12 million per jurisdiction. 2.25% annual interest rate (Final rate is set September 1, 2024). 1.0% loan service fee (water systems receinot subject to loan fees). 4encouraged
2performance Loan repayment period: 20 years or life of the project, whichever is less. No local match required. Minimum $25,000 No maximum 2.25% annual interest rate (Final rate
is set September 1, 2024). 1% loan service fee (water systems receiving subsnot subject to loan fees) 4encouraged 2performance 20
Funding Available Loan Loan
--
--
--
forfor
aside aside
--
--
8
ms are eligible
community water community water
--
ystems are eligible
Eligible Applicants Group A (private and publiclyowned) community and notprofit nonsystems, but not federal or stateowned systems. Tribal systeprovided the project is not receiving other
national setfunding for the project. Group A (private and publiclyowned) community and notprofit nonsystems, but not federal or stateowned systems. Tribal sprovided the project is not
receiving other national setfunding for the project.
d
d ban, as
Eligible Projects Drinking water system infrastructure projects aimeat increasing public health protection. There is principal forgiveness for disadvantaged communities. Lead service
line replacement. Galvanized service lines to be replaced per Lead and Copper Rule. Service water meters older than 1986 leapart of LSL replacement. There is principal forgiveness for
disadvantaged communities.
s
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramDWSRF Drinking Water State Revolving Fund Construction Loan Program Department of Health DWSRF Drinking Water State Revolving Fund Lead Service Line (LSL)
Replacement Loan Department of Health
-
-
-
to
Board
to
loan/Water
-
Board
at
or
loans
or
-
-
Works
information
and
Works
-
grant
details
-
operate/Grants
-
a
latest
-
Public
Eliza Keeley
Sheila Richardson
1976
1927
periodically
we
-
-
grantsPublic
-
-
the
the
628999
--
program
How To Apply Applications due October 15, 2024. A cost effectiveness analysis must be complete at the time of application. Contact: 360Eliza.keeley@ecy.wa.gov https://ecology.wa.gov/Aboutus/Howloans/
FindQualityFY2025 cycle opens in Spring 2024 Contact: 564Sheila.richardson@commer ce.wa.gov Check website http://www.pwb.wa.gov obtain on contact staff.
until
construction
jurisdiction
-
for the
0,000, with a
20 year term: 1.2% 5 year term: 0.85%
--
per jurisdiction per
maximum award per
30 year loans: 1.6%
-
20 year loans: 1.2% 5 year loans: 0.6%
--
2161
construction awarded
-
Funding Available Loan: $200,000,000 available statewide. Interest rates (SFY 2025) Hardship assistance construction of wastewater treatment facilities may be available in the form of
a reduced interest rate, and up to $5,000,000 grant or loan forgiveness. SFAP grant jurisdiction: $10,00required 15% match, with match reduced to 5% for hardship. FY2024 Cycle: $235
million available. Interest rate: Projects with 5Projects with 1Maximum award per per biennium: $10 million Maximum project award: $10 million biennium. Construction and preare competitive
cycles. Two construction cycles per biennium. Prequarterly. Emergency open funds allocated.
school
d to
and
ricts, and
special
9
dist
cities,
districts,
port
per statute.
municipal
,
-
municipal corporations,
uasi
-
Counties, purpose qorganizations. Ineligible applicants: districts, tribes
Eligible Applicants Counties, cities, towns, conservation districts, or other political subdivision, municipal or quasiand federally recognized tribes. Stormwater Financial Assistance
Program (SFAP) is limitecities, counties, and public ports. Hardship Assistance Jurisdictions listed above with a service area population of 25,000 or less.
owned
-
repair
and
infrastructure
construction,
roads, streets and
existing
New replacement, of for bridges, domestic water, sanitary sewer, stormwater, and solid waste/recycling/organics.
ource pollution control
Eligible Projects Construction projects associated with publiclywastewater and stormwater facilities. The integrated program also funds planning and implementation of nonpoint sactivities.
Board
Program
Fund (SRF)
s
Works
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramECOLOGY: Water Quality Combined Funding Program State Water Pollution Control Revolving Centennial Clean Water Fund Stormwater Financial Assistance Program
(SFAP) PWB Public Construction
round round.
--
.
available basis
Marti Canatsey
-
Janea Stark
8570 0812
--
367252
--
How To Apply Applications accepted yearon a fund Contact: 509marlene.canatsey@usda.gov http://www.rd.usda.gov/wa Applications accepted yearThe Board meets six times a year. Contact:
360janea.stark@commerce.wa.gov
erest
.
.
term
unding
ases
3% Based on
-
partners: 50% (of
year loan term
-
rates change quarterly;
payment penalty
-
year maximum loan
million maximum per
-
Interest contact staff for latest intrates. Up to 40No preProjects without a committed private partner allowed for in rural areas. $5 project, per policy. Interest rates: 1Debt Service
Coverage Ratio (DSCR), Distressed County, and length of loan term. 20 Match for committed private partners: 20% (of total project cost). Match for prospective development total project
cost). Applicants must demonstrate gap in public project funding and need for CERB assistance. CERB is authority for fapprovals.
Funding Available Loans; Grants in some cases Loans; grants in unique c
-
ing rural
10
year).
-
profit
-
recognized tribes
-
.
2021 (5
-
ublic bodies, tribes and
Cities, towns, and other pprivate noncorporations servareas with populations under 10,000Population determined by U.S. Census 2020. Income determined by the American Community Survey
2017Counties, cities, towns, port districts, special districts FederallyMunicipal and quasimunicipal corporations with economic development purposes.
Eligible Applicants
truction,
Bridges, roads and railroad spurs, domestic and industrial water, sanitary and storm sewers. Electricity, natural gas and telecommunications General purpose industrial buildings, port
facilities. Acquisition, consrepair, reconstruction, replacement, rehabilitation
construction and
-
nificant private investment
Eligible Projects Preconstruction associated with building, repairing, or improving drinking water, wastewater, solid waste, and stormwater facilities. Public facility projects required
by private sector expansion and job creation. Projects must support significant job creation or sigin the state.
-
s
Loans and Grants
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramRD U.S. Dept. of Agriculture Rural Development Rural Utilities Service Water and Waste Disposal Direct CERB Community Economic Revitalization Board Construction
Program
round
-
.
w
ans/
loans/ lo
--
available basis
-
Jon Galo
Jessica Scott Jessica Scott
5021 5460 5460
---
: :
www.commerce.wa.gov/cdbg
847458458
---
How To Apply Applications accepted yearon a fundbeginning Spring 2024. Contact: 509Jon.galow@commerce.wa.gov Visit for more informationApplications accepted anytime. Contact 719jscott@rcac.org
Applications available online at http://www.rcac.org/lending/envi ronmentalApplications accepted anytime. Contact 719jscott@rcac.org Applications available online at http://www.rcac.org/lending/envi
ronmental
year term
eed
-
% loan fee
0,000 for construction % loan fee
cquisition projects.
1.125
0
% interest rate
,0
% .5.125
$2and a$500,000 for local housing rehabilitation programs. $250,000 for local microenterprise assistance programs. For smaller capital needs, normally not to exc$100,000. Typically up
to a 205% interest rate 1Typically up to $3 million with commitment letter for permanent financing Security in permanent loan letter of conditions Term matches construction period.
51
Funding Available Maximum grant amounts:
income income
--
state
by
come people
11
in
-
local
served
of
t.
map
entitlement cities and
-
program
to moderateprofit organizations, public profit organizations, public
--
and
-
Eligible Applicants Projects must principally benefit lowin noncounties. List governments CDBG Nonagencies, tribes, and lowrural communities with a 50,000 population or less. Nonagencies,
tribes, and lowrural communities with a 50,000 population or less, or 10,000 populations or less if using USDA Rural Development financing as the takeou
pport
and
olid waste
,
income income
--
design
affordable housing.
Planning, construction of wastewater, drinking water, side connections, stormwater, streets, and community facility projects. Infrastructure in suof
development costs.
-
ural communities. Can include
Eligible Projects Water, wastewater, sand stormwater facilities that primarily serve lowrural communities. Water, wastewater, solid waste and stormwater facilities that primarily serve
lowrpre
s
Purpose Grants
GP
-
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramCDBG Community Development Block Grant General RCAC Rural Community Assistance Corporation Intermediate Term Loan RCAC Rural Community Assistance Corporation
Construction Loans
for
-
grants/
-
solar
-
-
and
energy/energy
the
-
Kristen Kalbrener Kristen Kalbrener Kristen Kalbrener
-
8112 8112 8112
---
515515515
---
How To Apply Contact: 360energyretrofits@commerce.wa. gov Visit https://www.commerce.wa.gov /growingeconomy/efficiencymore information. Contact: 360energyretrofits@commerce.wa. gov Contact:
360energyretrofits@commerce.wa. gov
Maximum grant: $350,000 Minimum match requirements will apply. Other State funds cannot be used as match. Tentative: Applications due winter 2023.
23: $2,000,000
Funding Available 2023: $22,500,000 2023: $1,700,000 20
ome
-
nd state
12
Washington State public entities, such as cities, towns, local agencies, public higher education institutions, school districts, federally recognized tribal governments, aagencies. Some
percentage of funds are reserved for projects in small towns or cities with populations of 5,000 or fewer. Priority will be given to applicants who have not received funding previously,
certain priority communities, and school distrthrough lighting upgrades. Low to moderate inchomeowners, homeowners with little credit history Local governments (cities, counties, federallyrecognized
tribes) Priority for disadvantaged communities
Eligible Applicants
Retrofit projects that reduce energy consumption (electricity, gas, water, etc.) and operational costs on existing facilities and related projects owned by an eligible applicant. Projects
must utilize devices that do not require fossil fuels whenever possible. Energy audits, installation of energy saving equipment, conversion to electrification Energy audits and energy
conservation planning projects including financing, infrastructure, public education
Eligible Projects
Program:
s
gton State
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramEnergy Retrofits for Public Buildings Energy Efficiency Grant Washington State Department of Commerce Energy Efficiency Revolving Loan Fund Washington State
Department of Commerce Energy Efficiency and Conservation Block Grant WashinDepartment of Commerce
-
grants/
-
plus
-
-
-
the
-
the
-
rgyretrofits@commerce.wa.
How To Apply Contact: enegov Visit https://www.commerce.wa.gov /growingeconomy/energy/solarfor more information. Contact: solar@commerce.wa.gov Visit: https://www.commerce.wa.gov/g rowingeconomy/ener
gy/solarstorage/
2025.
-
Funding Available Approximately $21.8 million will be available in 2023Approximately $30 million will be available.
profit
-
13
blic higher education
governments, State
Washington State public entities, such as cities, towns, local agencies, puinstitutions, school districts, federally recognized tribal governments, and state agencies. See above.
Eligible Applicants Local governments, Tribal governments and their affiliates, Nonorganizations and Retail electric utilities.
,
.
stallation
up power so
-
tied solar
-
Purchase and inof gridphotovoltaic (electric) arrays net metered with existing facilities owned by public entities. Additional points for components.
Eligible Projects The Solar plus Storage program funds solar and battery backcommunity buildings can provide essential services when the power goes outincluding both planning and installation
grants
munities
s
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramEnergy Retrofits for Public Buildings: Solar Grants Washington State Department of Commerce Solar plus Storage for Resilient Com Washington State Department
of Commerce
w
1951 9287 Mischa Venables 3088
fund/
---
: Tracey Hunter
-
200462725
---
loan
-
How To Apply Information: EDA.gov Contact: Laura Ives 206lives@eda.gov Apply at: grants.gov Applications accepted anytime. Contact Evergreen Rural Water of WA 360thunter@erwow.org Download
application online: http://nrwa.org/initiatives/revolvi ngContact: 360Mischa.venables@commerce.a.gov Visit www.commerce.wa.gov/CHIP
.
given
loan.
RUS, with a
time of closing.
e lower of the
the facilities
2025 biennium.
-
Up to 100% for Tribal Nations
ul life of
ever is less. Applicants
o
s may not exceed $100,000 or
EDA investment share up to $5,000,000. Cost sharing required from applicant Standard grant rate is 50% of total project cost, and up to 80%. Loan75% of the total project cost, whichcredit
for documented project costs prior to receiving the Interest rates at thpoverty or market interest rate as published by USDA RD minimum of 3% at Maximum repayment period is 10 years.
Additional ranking points for a shorter repayment period. The repayment period cannot exceed the usef
r jurisdictions with a population
Funding Available Grants: $55.5 million in total funds available in 2023$19.4 million specifically reserved foof less than 150,000. $2,000,000 maximum award. Funds available as both
grants and deferred loans.
profit
-
urisdiction
14
for
-
, not
ith up to 10,000 population and
Eligible Applicants Municipalities, counties, cities, towns, statesorganizations, ports, tribal nations. Public entities, including municipalities, counties, special purpose districts,
Native American Tribes, and corporations not operated for profit, including cooperatives, wrural areas with no population limits. Cities, counties, and utility districts located in
a jwhich has a dedicated sales tax for affordable housing. The local jurisdiction will sponsor/ partner with a housing developer on the project.
regular
s
distribution
-withdrawal/
term costs incurred for
-
Eligible Projects Drinking water infrastructure; including preconveyance, harvest (i.e. well extraction), storage facilities, treatment and distribution. Waste water infrastructure;
including conveyance, treatment facilities, discharge infrastructure, water recycling. Shortreplacement equipment, small scale extension of services, or other small capital projects
that are not a part of operations and maintenance for drinking water and wastewater projects. Housing projects with at least 25% of units affordable for at least 25 years. Funding goetoward
water, sewer, and stormwater infrastructure improvements for eligible projects, as well as toward system development charges and impact fees, which are waived to encourage affordable
housing.
s
NSTRUCTION AND
CODESIGN/CONSTRUCTION ProgramEconomic Development Administration (EDA) United States Department of Commerce EDA Public Works & Economic Adjustment Assistance Program: Design and/or Construction
for distressed and disaster communities. RURAL WATER REVOLVING LOAN FUND Connecting Housing to Infrastructure Program (CHIP) Washington State Department of Commerce
round on
-
.
atsey
Marti Can
Jocelyne Gray
8570 4893
--
available basis
-
367669
--
How To Apply Applications accepted yeara fund Contact: 509marlene.canatsey@usda.gov http://www.rd.usda.gov/wa To be considered for an emergency loan, an applicant must submit a completed
emergency application package to the department. Contact: 564Jocelyne.gray@doh.wa.gov For information and forms visit: http://www.doh.wa.gov/DWSRF
.
n date
, no subsidy
ilability of funds
%
years
.
,000 for the
00,000 maximum award per
Water transmission line grants up to $150,000 to construct water line extensions, repair breaks or leaks in existing water distribution lines, and address related maintenance to replenish
the water supply Water source grants up to $1,000construction of new wells, reservoirs, transmission lines, treatment plants, and/or other sources of water (water source up to and including
the treatment plant)
Interest rate: 0available Loan fee: 1.5% Loan term: 10 $5jurisdiction. Time of performance: 2 years from contract execution to project completioRepayment commencing first October after
contract execution
Funding Available Grant; pending avaLoan
-
-
-
-
.
15
profit non
-
transient non
profit
-
-
year).
-
profit corporations
-
exempt
-
2021 (5
-
profit) Group A community
eiving other national set
-
Public bodies, tribes and private nonserving rural areas with populations under 10,000Population determined by U.S. Census 2020. Income determined by the American Community Survey 2017f
fewer than 10,000.
Publicly or privately owned (notforwater systems with a population oTransient or noncommunity public water systems owned by a nonorganization. Noncommunity water systems must submit
taxdocumentation. Tribal systems are eligible provided the project is not recaside funding for the project.
Eligible Applicants
n
.
Eligible Projects Domestic water projects needing emergency repairs due to an incident such as: a drought; earthquake; flood; chemical spill; fire; etc. A significant decline in quantity
or quality of potable water supply that was caused by aemergencyWill financially assist eligible communities experiencing the loss of critical drinking water services or facilities
due to an emergency.
unity
pment
s
ECWAG
EMERGENCY ProgramRD U.S. Dept. of Agriculture Rural DeveloEmergency CommWater Assistance Grants DWSRF Department of Health Drinking Water State Revolving Fund Emergency Loan Program
Department of Health
-
-
-
to obtain
loan/Water
-
loans
or
-
-
and
-
grant
-
operate/Grants
-
a
-
Sheila Richardson
1976
1927
we
-
-
grants
-
-
ct:
999628
latest information on program
--
How To Apply Conta 564Sheila.richardson@commerc e.wa.gov Check the Public Works Board website periodically at: http://www.pwb.wa.gov the details or to contact Public Works Board staff.
Available year round. Contact: Eliza Keeley 360Eliza.keeley@ecy.wa.gov https://ecology.wa.gov/Aboutus/Howloans/FindQuality
year loan,
-
ntinuously
year loan term or life of
-
Cycle open coduring the biennium until allocated funds exhausted. $7.5 million is available. Maximum loan amount $1 million per jurisdiction per biennium. 20the improvement, whichever
is less. Interest rates vary.
1.6%
-
Funding Available Loan: $5,000,000 maximum Interest rates (SFY25): 100.0
per
,
16
school
municipal
-
asi
municipal
-
i
Eligible Applicants Counties, cities, special purpose districts, and quorganizations. Ineligible applicants: districts, port districts, or tribesstatute. Only available to public bodies
serving a population of 10,000 or less. Counties, cities, and towns, federally recognized tribes, water and sewer districts, irrigation districts, conservation districts, local health
jurisdictions, port districts, quascorporations, Washington State institutions of higher education
issues
030(27)5
-
98
-
related projects
-
.
he public health
made necessary by a
Eligible Projects Roads, streets and bridges, domestic water, sanitary sewer, stormwater, and solid waste/recycling/organics projects natural disaster, or an immediate and emergent threat
to tand safety due to unforeseen or unavoidable circumstances. Projects that may result from a natural disaster or an immediate and emergent threat to public health due to water quality
resulting from unforeseen or unavoidable circumstances. Water qualityconsidered to be an environmental emergency that meets the WAC 173definition and has received a Declaration of Emergency
from the local Government
eligible
s
EMERGENCY ProgramPWB ECOLOGY Water Quality Emergency Clean Water State Revolving Funding Program
Public Works Board Emergency Loan Program: Repair, replace, rehabilitate, or reconstruct systems to current standards for existing users.
round
-or
bas
Gary UrNicole Patrick
9287 7072 7402 6997
----
: Tracey Hunter : Tim Cook
462512512713
----
How To Apply Applications accepted anytime. Contact Evergreen Rural Water of WA 360thunter@erwow.org Applications will be opened after a disaster declaration. Contact State Hazard Mitigation
Officer 253Tim.cook@mil.wa.gov Applications are opened after disaster declaration. Contact: Public Assistance Project Manager 253Gary.urbas@mil.wa.gov Applications accepted yearuntil
funding exhausted. Approximately $5 million available to award each year. Contact: 206Nicole.patrick@commerce.wa.gov For information and application visit: EmergencyRapidResponse https://deptofcomme
rce.box.com/ s/skmab4hq3l4z55jazzc7qlsmbrsger mv
share: 12.5%
-
on the level of
g/initiatives/revolvin
June
-
fund/
-
around.
-
day, no interest, disaster area
-
loan
p to $5,000,000
-
Funding Available 90emergency loans with immediate turnDownload application online: http://nrwa.orgVaries depending disaster, but projects only need to compete at the state level. Local
jurisdiction costVaries depending on the level of disaster and total damage caused. Grant; pending availability of funds UPeriod of performance state fiscal year July
-
17
up to 10,000
Eligible Applicants Public entities, including municipalities, counties, special purpose districts, Native American Tribes, and corporations not operated for profit, including cooperatives,
with population and rural areas with no population limits. Any state, tribe, county, or local jurisdiction (incl., special purpose districts) that has a current FEMAapproved hazard
mitigation plan. State, tribes, counties, and local jurisdictions directly affected by the disaster. Tribes and local governments
saving
-
es that
storation of
reduction
-
removal, life
-
Eligible Projects Contact staff for more information on emergency loans. Disaster riskprojects and planning after a disaster declaration in the state. Construction, repair to, and restoration
of publicly owned facilities damaged during a disaster. Debrismeasures, and republic infrastructure. Projects that provide continuity of essential community servicbecome diminished
during an emergency and recovery assistance after an emergency event. Projects that restore service for a limited duration or through a temporary measure.
Division
s
Emergency Rapid
-
aster area emergency
ASHINGTON STATE
EMERGENCY ProgramRURAL WATER REVOLVING LOAN FUND Disloans HAZARD MITIGATION GRANT PROGRAM FEMA/WA Emergency Management PUBLIC ASSISTANCE PROGRAM FEMA/WA Emergency Management Division
WDEPARTMENT OF COMMERCE ERR Response
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