NPDES Phase II Municipal Stormwater Permit

Contact Information
Surface Water Engineering

The Western Washington Phase II Municipal Stormwater Permit, also known as the National Pollutant Discharge Elimination System (NPDES) Permit, was first issued on January 17, 2007, by the Washington State Department of Ecology under the provisions of the U.S. Environmental Protection Agency's Clean Water Act. The current five-year permit went into effect on August 1, 2019.  There are a total of 83 cities and five counties in Western Washington that must comply with the permit.

The permit has specific requirements and deadlines for implementation of programs to minimize the discharge of pollution from municipal stormwater systems into our streams, lakes, rivers and wetlands to protect their beneficial uses (swimming, boating, fishing, aesthetics) and other environmental resources.

The City of Renton is classified as a "small" municipal separate stormwater sewer system (MS4).

Stormwater Management Program Plan

The Stormwater Management Program Plan (Plan) describes the city’s planned actions and activities for the year to meet the requirements of the Western Washington Phase II Municipal Stormwater Permit issued by the Washington State Department of Ecology.

Review and Comment

The city encourages public comment and participation in the development and implementation of the Plan. Feedback on the current Stormwater Management Program Plan will be used to shape the next iteration of the plan.

Please provide your comments to Kristina Lowthian by December 31, 2022. Comments received after this date will be accepted for the following year's Stormwater Management Program Plan.

2022 Stormwater Management Program Plan - Translatable

2022 Stormwater Management Program Plan

City of Renton Municipal Stormwater Program

City of Renton
1055 S Grady Way
Renton, WA 98057

March 22, 2022

CONTENTS

Introduction and Background ... 1

Comprehensive Stormwater Planning ... 3

2019–2024 Phase II Permit Requirements ... 3
Planned Activities ... 4

Public Education and Outreach ... 5

2019–2024 Phase II Permit Requirements ... 5
Planned Activities ... 7
Recommended Activities ... 8

Public Involvement and Participation ... 9

2019-2024 Phase II Permit Requirements ... 9
Planned Activities ... 9

MS4 Mapping and Documentation ... 11

2019–2024 Phase II Permit Requirements ... 11
Planned Activities ... 12

Illicit Discharge Detection and Elimination ... 13

2019–2024 Phase II Permit Requirements ... 13
Planned Activities ... 14

Controlling Runoff from New Development, Redevelopment, and Construction Sites ... 15

2019–2024 Phase II Permit Requirements ... 15
Planned Activities ... 16

Operations and Maintenance ... 17

2019–2024 Phase II Permit Requirements ... 17
Planned Activities ... 18

Source Control Program for Existing Development ... 19

2019–2024 Phase II Permit Requirements ... 19
Planned Activities ... 20

Total Maximum Daily Load Requirements ... 21

2019-2024 Phase II Permit Requirements ... 21
Planned Activities ... 21

Monitoring ... 23

2019–2024 Phase II Permit Requirements ... 23
Planned Activities ... 23

Reporting ... 25

2019-2024 Phase II Permit Requirements ... 25
Planned Activities ... 25

APPENDICES

Appendix A Coordination Mechanisms
External Coordination Mechanisms ... A-1
Internal Coordination Mechanisms ... A-1

ACKNOWLEDGEMENTS

Funding for the SWMP Plan was provided by a Municipal Stormwater Capacity Grant from the Washington State Department of Ecology. Major content of this Plan was provided by Herrera.

INTRODUCTION AND BACKGROUND

In 1987, Congress amended the federal Clean Water Act to address municipal stormwater discharges through the National Pollution Discharge Elimination System (NPDES) permits. In Washington State, the Washington State Department of Ecology (Ecology) is responsible for issuing and renewing these permits. In 2007, NPDES Municipal Stormwater permits were issued in Washington for two groups of permittees: Phase I jurisdictions and Phase II jurisdictions.

Phase I permits were issued to large municipalities and county governments with populations over 100,000 (as of the 1990 census). Phase II Permits were issued to smaller governmental entities generally with populations between 10,000 and 100,000. The City of Renton (city) is covered under Western Washington’s Phase II Municipal Separate Stormwater Sewer System (MS4) NPDES permit (Phase II Permit).

Discharges from MS4s (systems designed to collect and convey stormwater runoff) are regulated by Ecology under the NPDES program. The municipal NPDES permit seeks to control or reduce pollutant discharge to the maximum extent practicable, primarily through programmatic efforts. The city is regulated by Ecology as a Phase II permittee. The first Phase II Permit became effective on February 16, 2007, was modified in 2009, and expired on February 15, 2012. Ecology extended the 2007–2012 Phase II Permit requirements until July 2013. The second Phase II Permit was issued on August 1, 2012 and became effective on August 1, 2013. Ecology extended the 2013-2018 Phase II Permit requirements until July 2019. The third Phase II Permit was issued on July 1, 2019 and became effective on August 1, 2019. For fiscal year 2022 (July 1, 2021 through June 30, 2022), the city was charged an annual permit fee of $68,695 by Ecology. This annual fee will likely increase with future Phase II Permit updates.

The Phase II Permit requires the city to develop a Stormwater Management Program (SWMP). The SWMP must include the following components:

  1. A stormwater planning program to inform and assist in the development of policies and strategies as water quality management tools to protect receiving waters.

  2. An education and outreach program designed to build general awareness about methods to address stormwater impacts, affect behavior change to reduce behaviors that lead to adverse stormwater impacts, and create stewardship opportunities that encourage the community to address stormwater impacts.

  3. A public involvement and participation program to provide opportunities for the public to get involved in the development, implementation, and update of the SWMP and SMAP.

  4. An ongoing program to map and document the MS4.

  5. An ongoing illicit discharge detection and elimination (IDDE) program to prevent, detect, characterize, trace, and eliminate illicit connections and illicit discharges into the MS4.

  6. A program to reduce pollutants in stormwater runoff to the MS4 from new development, redevelopment, and construction site activities

  7. An operation and maintenance (O&M) program to regulate and conduct maintenance activities to prevent or reduce pollutant runoff

  8. A program to prevent and reduce pollutant runoff from areas that discharge to the MS4

In addition, the Phase II Permit requires that the city prepare written documentation of the SWMP and update that documentation annually. This SWMP plan satisfies this requirement. In addition to the eight components listed above, this SWMP plan includes a discussion of the total maximum daily load, monitoring, and reporting requirements of the Phase II Permit.

This SWMP plan also includes a description of the city’s external and internal coordination mechanisms as required by permit sections S5.A.5.a and S5.A.5.b, respectively in Appendix A.

COMPREHENSIVE STORMWATER PLANNING

The city plans to implement the comprehensive stormwater planning requirements over the permit term, fulfilling the requirements of the permit by developing policies and strategies that protect receiving waters. The definition of receiving waters includes natural and constructed creeks, streams, rivers, lakes, wetlands, and groundwater to which Renton’s stormwater flows. This section describes the Phase II Permit requirements related to comprehensive stormwater planning, including planned activities.

2019–2024 Phase II Permit Requirements

Section S5.C.1 of the 2019–2024 Phase II Permit requires the city to implement a stormwater planning program to develop policies and strategies as water quality management tools to protect receiving waters. The specific Phase II Permit requirements are as follows:

  1. Convene an interdisciplinary team to inform in the development, progress, and influence of the program by August 1, 2020.

  2. Report on how stormwater management needs and receiving water protection/improvement inform the long-range planning update process and influence policies and implementation strategies. By March 31, 2021 respond to a series of questions in the annual report and by January 1, 2023, submit a report describing how water quality is addressed in long-range land use plans.

  3. Annually assess and report newly identified administrative or regulatory barriers to implementation of low impact development (LID) principles or low impact development best management practices (LID BMPs) since local codes were adopted in 2016. Describe mechanisms to encourage or require LID implementation.

  4. Implement stormwater management action planning:

  • Document and assess existing information related to local receiving water bodies and contributing area conditions. By March 31, 2022, submit a watershed inventory and assessment.

  • By June 30, 2022, develop a prioritization method and process to identify which receiving waters will most benefit from stormwater facility retrofits, tailored implementation of SWMP action and other land/development management actions. Document the prioritized and ranked list of receiving waters.

  • By March 31, 2023, develop a Stormwater Management Action Plan (SMAP) for at least one high priority area.

Planned Activities

  • Long Range Plan Update for 2019-2024 Permit: Community and Economic Development (CED) Department’s Long Range Planning and Planning Divisions, Surface Water Utility (SWU) Engineering and Transportation Planning Sections, and the Parks Planning & Natural Resources Division will respond to questions and submit a report describing how water quality is being addressed in the Comprehensive Plan during the 2019-2024 permit term by January 1, 2023.

  • Low Impact Development (LID) Implementation: Community and Economic Development (CED) Department’s Long Range Planning and Planning Divisions, Surface Water Utility (SWU) Engineering and Transportation Planning Sections, and the Parks Planning & Natural Resources Division will annually assess and document barriers and adopted mechanisms to encourage or require implementation of LID Principles or LID BMPs.

  • Receiving Water Basin Assessment: The Interdepartmental NPDES Stormwater Planning Team will document local receiving waters and contributing area conditions data and will submit a watershed inventory by March 31, 2022.

  • Receiving Water Basin Prioritization: The Interdepartmental NPDES Stormwater Planning Team will develop a prioritization method and use it to document a prioritized list of receiving waters by June 30, 2022.

  • Stormwater Management Action Plan: The Interdepartmental NPDES Stormwater Planning Team will develop a draft Stormwater Management Action Plan (SMAP).

PUBLIC EDUCATION AND OUTREACH

The city’s public education and outreach program currently includes a wide range of educational brochures for a variety of audiences. The city has partnered with the Environmental Coalition of South Seattle (ECOSS) to provide stormwater spill kits and spill response education training to small businesses since 2014. The city also has a drain marker volunteer program and participates in the Stormwater Outreach for Regional Municipalities (STORM) coalition. This section describes the Phase II Permit requirements related to Public Education and Outreach, including the city’s planned compliance activities.

2019–2024 Phase II Permit Requirements

Section S5.C.2 of the 2019–2024 Phase II Permit requires the city to implement an education and outreach program based on water quality information and target audience characteristics. Education and outreach efforts shall be prioritized in the following areas:

1. Build general awareness that annually selects at least one target audience and one subject area from A or B:

a. General public (including overburdened communities or school age children), or businesses (including home-based or mobile businesses)

Subject areas:

  • General impacts of stormwater on surface waters, including impacts from impervious surfaces

  • Low impact development (LID) principles and LID BMPs

b. Engineers, contractors, developers, or land-use planners

Subject areas:

  • Technical standards for stormwater site and erosion control plans

  • LID principles and BMPs

  • Stormwater treatment and flow control BMPs/facilities

2. Affect behavior change that selects at least one target audience and one BMP from the following:

a. Residents, landscapers, property managers/owners, developers, school age children, or businesses (including home-based or mobile businesses)

BMPs:

  • Use and storage of pesticides, fertilizers, and/or other household chemicals

  • Use and storage of automotive chemicals, hazardous cleaning supplies, carwash soaps, and/or other hazardous materials

  • Prevention of illicit discharges

  • Yard care techniques protective of water quality
    Carpet cleaning

  • Repair and maintenance BMPs for vehicles, equipment, and/or home buildings

  • Pet waste management and disposal

  • LID principles and LID BMPs

  • Stormwater facility maintenance, including LID facilities

  • Dumpster and trash compactor maintenance

  • Litter and debris prevention

  • Sediment and erosion control

  • (Audience specific) Source control BMPs

  • (Audience specific) Locally important, municipal stormwater-related subject area

b. By July 1, 2020, conduct a new evaluation of the effectiveness of an ongoing behavior change campaign with lessons learned and recommendations to inform a social marketing campaign.

c. Based on the recommendations, by February 1, 2021, use social marking methods to develop a campaign tailored to the community, including an evaluation plan, strategy, and schedule.

d. By April 1, 2021, begin to implement the developed strategy.

e. By March 31, 2024, evaluate and report on changes in understanding and adopted behaviors resulting from the implemented strategy and on planned or recommended changes to the program to improve efficacy.

f. Use the evaluation results to continue to direct effective methods and implementation of the ongoing behavior change program.

3. Provide and advertise stewardship opportunities and/or partner with existing organizations to encourage residents to participate in activities or events such as storm drain marking, volunteer monitoring, riparian plantings and education activities.

Planned Activities

General Awareness

  • Awareness Campaign: The SWU Engineering Section will promote Puget Sound Starts Here campaign messaging to build general awareness of the general impact of stormwater on surface water, including impacts from impervious surfaces through electronic and printed media.

  • Online Outreach Solid Waste Outreach: The Solid Waste Section will provide education on natural yard care, hazardous waste management, and waste prevention.

  • Natural Yard Care Funding: The Water Utility Section will coordinate and fund the Saving Water Partnership (SWP) to conduct natural yard care classes.

  • Nature Vision Classroom Programs: The Water Utility Section will provide the funding to conduct watershed science classes at elementary schools through the SWP.

  • Environmental Science Center Programs: The Parks & Recreation Department will partner with the Environmental Science Center to provide stormwater education and field study to school age children.

Behavior Change

  • Behavior Change Campaign: The SWU Engineering Section will implement a behavior change strategy to improve efficacy of the spill kit program by partnering with ECOSS to provide spill kits and spill response education/training to businesses.

  • Partner with Local Hazardous Waste Management: The Solid Waste Section will participate as a partner with local jurisdictions to provide outreach for proper handling and storage of hazardous materials and opportunities for their disposal.

  • Recycling Events: The Solid Waste Section will coordinate collection events for household wastes, including metals, Styrofoam, cardboard, and tires.

  • In-House Battery Collection: The Solid Waste Section will provide collection of batteries at city facilities.

  • Oil Recycling and Best Practices: The Solid Waste Section will support and partner with automotive businesses to increase access to motor oil recycling and provide education on safe handling practices.

  • Safe Cleaning: The Solid Waste Section will promote the safe use, storage, and disposal of household cleaning products as well as promoting safer alternatives.

Stewardship

  • Volunteer Storm Drain Marker Program: The SWU Engineering Section will coordinate civilian volunteer efforts to mark storm drains.

  • WRIA 8 and WRIA 9: The SWU Engineering Section will continue its partnership with WRIA 8 Salmon Recovery Council and WRIA 9 Watershed Ecosystem Forum.

  • Community Stewardship and Events: The Parks Planning and Natural Resources Division will coordinate community events to plant trees in public parks.

  • Volunteer Riparian Tree Planting: Parks & Trails will coordinate volunteer events to plant trees in riparian areas.

Recommended Activities

Implementation timelines for these activities are to be determined, and depend on available staff and funding, as well as COVID-19 Health Concerns.

  • Expand Education Materials: The City of Renton’s Surface Water Utility will expand education materials available through existing programs and streamline stormwater outreach messaging and public handouts.Stormwater education and outreach should be integrated into existing Public Works programs. Consistent stormwater outreach messaging should be developed between various city departments. Handouts should be combined based on target audiences and redundant information on handouts should be eliminated.

  • Car Wash Outreach: The Surface Water Utility will provide alternative options to groups holding charity car wash events.
    King Conservation District Classroom Programs: The City of Renton Surface Water Utility will partner with KCD to provide stormwater classes in elementary schools.

  • Multifamily Outreach: The Solid Waste Section will provide educational solid waste resources to multifamily residences.

  • Aquifer Protection Program: The Water Utility will provide education on water quality and conservation at public events and on proper chemical storage to businesses in aquifer protection zones.

  • Natural Yard Care Program: The Surface Water Utility will provide classes teaching yard care methods to eliminate use of pesticides, herbicides, and chemical fertilizers.
    Promote Community Stewardship: The Surface Water Utility will encourage community involvement with rain gardens, stream teams, volunteer monitoring, riparian planting, or education activities.

  • Expand the Adopt a Neighborhood Program: The Surface Water Utility will evaluate the addition of a stormwater BMP component to the city’s Adopt a Neighborhood Program.

  • New Public Education Materials: The City’s Surface Water Utility will develop an illicit discharge handout, and mailing handouts to single-family residences, and circulate these handouts. Relevant handouts will be distributed at pre-application meetings. This activity also can be used to meet S5.C.5.b – informing public employees, businesses, and the general public of hazards associated with illicit discharges and improper disposal of waste.

  • Street Tree Replacement: Parks Planning & Natural Resources will work to fill planting spots and replace trees and distribute tree care information.

  • Illicit Discharge Education and Outreach: An interdepartmental team will work to develop a handout for companies that respond to spills associated with automobile accidents.

PUBLIC INVOLVEMENT AND PARTICIPATION

Public input is important to the development and implementation of city plans. The city actively solicits public participation by making stormwater information available for review and providing opportunities for comment through its website. This section describes the Phase II Permit requirements related to public involvement, including planned compliance activities.

2019-2024 Phase II Permit Requirements

Section S5.C.3 of the 2019-2024 Phase II Permit require that the city create opportunities for the public to participate in the decision-making processes involving the development, implementation, and update of the SWMP and SMAP, and comply with applicable state and local public notice requirements. The two main components include:

  1. Providing opportunities for the public, including overburdened communities, to participate in the decision-making process of the development, implementation, and update of the city SMAP and SWMP.

  2. Posting the Annual Report and the SWMP Plan, on the city’s website no later than May 31 of each year.

Planned Activities

  • Revise SWMP Plan: The Surface Water Utility (SWU) Engineering Section will update the SWMP Plan with planned activities for 2022.

  • Prepare and post SWMP Plan and Annual Report: The SWU Engineering Section will prepare and post the SWMP Plan and Annual Report on the City’s website and other supplemental documentation as applicable by May 31, 2022.

  • Public involvement in the SWMP and SMAP: The SWU Engineering Section will solicit public feedback on the City’s website (www.rentonwa.gov/npdes) and social media channels.

MS4 MAPPING AND DOCUMENTATION

The city maintains a current electronic map of the Municipal Separate Storm Sewer System (MS4) in the City of Renton Map Viewer (CORMaps), which is available to the public. This section describes the MS4 Mapping and Documentation Phase II Permit requirements, as well as the city’s planned compliance activities for the 2019-2024 Phase II Permit cycle.

2019–2024 Phase II Permit Requirements

Section S5.C.4 of the 2019–2024 Phase II Permit requires the city include an ongoing program for mapping and documenting the MS4. The specific Phase II Permit requirements are as follows:

1. Maintain mapping data for these features:

a. Known MS4 outfalls and known MS4 discharge points

b. Receiving waters, other than groundwater

c. Stormwater treatment and flow control BMPs/facilities owned or operated by the city

d. Geographic areas served by the MS4 that do not discharge stormwater to surface waters

e. Tributary conveyances and associated features to known outfalls and discharge points with a 24” diameter or equivalent cross-sectional area

f. Connections between the city’s MS4 and other municipalities or public entities

g. All connections to the MS4 authorized or allowed by the city after February 16, 2007

2. Record mapping data for these features:

a. By January 1, 2020, collect size and material for all known MS4 outfalls during the normal course of business.

b. By August 1, 2023, all known connections from the MS4 to privately owned stormwater systems.

3. By August 1, 2021, record map electronically with fully described mapping standards.

4. Make maps available upon request to Ecology, federally recognized Tribes, municipalities, and other Permittees.

Planned Activities

  • Maintain Mapping Data: The Surface Water Utility (SWU) Engineering Section will maintain a map of existing required MS4 features.

  • Map Outfall Features: The SWU Engineering Section will continue to map size and material of known outfall features during the course of normal business operations.
    Map Connections: The SWU Engineering Section will map known connections from the MS4 to privately owned stormwater systems.

  • Electronic Map: The SWU Engineering Section will maintain an electronic map with fully described mapping standards.

  • Map Access: The City of Renton has mapping data available to the public via the online COR Maps GIS maps, and additional information will be provided to public entities upon request.

ILLICIT DISCHARGE DETECTION AND ELIMINATION

An illicit discharge is defined as any discharge into the stormwater system that is not composed entirely of stormwater, or of non-stormwater discharges allowed as specified in the Phase II Permit. Illicit discharges may be from a variety of sources and activities including illegal dumping, sanitary sewer overflow, swimming pool cleaning, and incidental spills (such as oil, gas, paints, or solvents). An Illicit Discharge Detection and Elimination Program is designed to protect surface water and ground water from being contaminated by illicit discharges by tracking, monitoring, and removing hazardous discharges in the stormwater drainage system. This section describes the Illicit Discharge Detection and Elimination (IDDE) Phase II Permit requirements, as well as the city’s planned compliance activities.

2019–2024 Phase II Permit Requirements

Section S5.C.5 of the 2019–2024 Phase II Permit requires the city to include an ongoing IDDE Program designed to prevent, detect, characterize, trace, and eliminate illicit connections and illicit discharges into the stormwater system. The specific Phase II Permit requirements are as follows:

  1. Implement a program with procedures to report and address illicit discharges including spills, and illicit connections, and procedures to address pollutants from an interconnected, adjoining MS4.

  2. Inform public employees, businesses, and the general public of the hazards associated with illicit discharges and improper disposal of waste.

  3. Implement an ordinance that effectively prohibits non-stormwater, illicit discharges into the MS4. Evaluate and update existing ordinances, as needed.

  4. Implement and document a field screening method for illicit discharges and connections, complete screening an average of 12 percent of the stormwater system per year, and track the total percentage of the MS4 screened between August 1, 2019 and December 31, 2023.

  5. Publicize a public hotline number for reporting of spills and other illicit discharges; and track all calls and follow-up actions taken.

  6. Implement an ongoing training program for municipal field staff on identification and reporting procedures.

  7. Implement an ongoing program designed to address illicit discharges, including spills and illicit connections, which includes procedures for characterizing the nature and potential threats of an illicit discharge, procedures for tracing the source of an illicit discharge, and procedures for eliminating the discharge within specific timeframes.

  8. Implement an ongoing training program for staff responsible for identification, investigation, termination, cleanup, and reporting.

  9. Track and maintain records of IDDE activities following the Permit-specified format.

Planned Activities

  • Coordination with Adjoining MS4s: The Surface Water Utility (SWU) Engineering and Surface Water (SW) Maintenance Sections will coordinate with adjacent jurisdictions to address pollutants from adjoining MS4s.

  • Illicit Discharge Program Implementation: The Public Works, Community and Economic Development (CED), and Parks & Recreation Departments will implement the City’s IDDE training and NPDES Spill Response Standard Operating Procedures to report, and correct or remove illicit connections and illicit discharges in the City.

  • Business Education and Outreach: The SWU Engineering Section will oversee Renton’s partnership with ECOSS to provide spill kits and spill response education and training for businesses.

  • Illicit Discharge Ordinance: SWU Engineering and SW Maintenance Sections, and Community and Economic Development (CED) Code Compliance will evaluate the effectiveness of the existing ordinance for prohibiting illicit discharges.

  • Illicit Discharge and Illicit Connection Field Screening: The SW Maintenance Section, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will use field screening methodologies from the Illicit Discharge Field Screening and Source Tracing Guidance Manual to screen for illicit connections in 12% of the storm system on average by December 31, 2022 and track the total percentage since August 1, 2019.

  • Spill Hotline: The SWU Engineering Section will publicize the spill hotline to report spills and other illicit discharges.

  • Staff Training: The Interdepartmental Team will train field staff on IDDE reporting and SW Maintenance will train staff on investigation, tracing, termination, and cleanup.

  • Record Keeping: The SWU Engineering and SW Maintenance Sections, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will utilize Cityworks or similar tracking software to record IDDE activities per Permit-specified format.

CONTROLLING RUNOFF FROM NEW DEVELOPMENT, REDEVELOPMENT, AND CONSTRUCTION SITES

New development can cause erosion and introduce sediment and polluted runoff into local waters. The City of Renton regulates and inspects construction sites to ensure best management practices are in use. The CED Development Services and Planning Divisions are responsible for permitting, inspection, and code enforcement actions for private construction-related activities in the city. City project managers are responsible for stormwater review of public capital projects. This section describes the Phase II Permit requirements related to controlling runoff from new development, redevelopment, and construction sites, including planned activities.

2019–2024 Phase II Permit Requirements

Section S5.C.6 of the 2019–2024 Phase II Permit requires that the city implement and enforce a program to reduce pollutants in stormwater runoff to the MS4 from new development, redevelopment, and construction activities. The specific Phase II Permit requirements are as follows:

  1. Implement an ordinance that addresses runoff from new development, redevelopment, and construction sites and adopt minimum requirements, thresholds and definitions in Appendix 1 of the Phase II Permit or approved program and amendments by June 30, 2022.

  2. Review all stormwater site plans for proposed development activities.

  3. Conduct inspections of construction sites prior to clearing and construction, during construction, and upon completion of construction.

  4. Conduct inspections of all stormwater treatment and flow control BMPs/facilities and catch basins in new residential developments every six months until 90% of the lots are constructed.

  5. Maintain records of inspections, maintenance activities, and enforcement activities.

  6. Implement an enforcement strategy to respond to non-compliance issues.

  7. Provide a link to state stormwater general permit NOI forms for construction and industrial sites.

  8. Conduct ongoing training for staff responsible for implementing the program to control stormwater runoff from new development, redevelopment, and construction sites.

Planned Activities

  • Implement and Adopt Program Amendments: The CED Department and SWU Engineering Section will implement the current ordinance, and review and adopt a new ordinance to meet the minimum requirements, thresholds and definitions in Appendix 1 of the Phase II Permit or an approved program and amendments no later than June 30, 2022.

  • Stormwater Site Plan Review: The Community and Economic Development (CED) Development Engineering Section and Capital Improvement Program (CIP) Leads will review all stormwater site plans for proposed development activities in accordance with the City of Renton Surface Water Design Manual.

  • Preconstruction Inspections: The CED Planning Division will inspect construction sites prior to construction if they exhibit high sediment transport potential.

  • Construction Inspections: The CED Construction Inspectors and CED Building Inspectors will inspect all sites during construction to verify proper installation and maintenance of required erosion and sediment controls.

  • Residential Construction Inspections: The Surface Water Utility (SWU) Engineering Section will inspect stormwater facilities and catch basins in new residential developments every six months until 90% of lots are constructed, and will identify maintenance needs and enforce maintenance standards.

  • Post-Construction Inspections: The CED Construction Inspectors and CED Building Inspectors will inspect all sites after construction to ensure proper installation of permanent stormwater facilities, verify that maintenance plan is complete and maintenance responsibility is assigned.

  • Development Site Enforcement: The CED Construction Inspectors, Building Inspectors and Code Enforcement will implement enforcement strategy for sites that are not in compliance.

  • Notice of Intent Availability: The Development Engineering Section will provide links to the Construction and Industrial Permits’ NOI forms on the City’s website.

  • Recordkeeping: The CED Planning Division, Building Inspectors and the SWU Engineering Section will maintain records of inspection, maintenance, and enforcement actions.

  • Staff Training: The CED Planning and Development Services Divisions will train staff in permitting, plan review, construction site inspections, and enforcement and maintain training records.

OPERATIONS AND MAINTENANCE

Maintenance of MS4 infrastructure is conducted to prevent or reduce stormwater impacts such as flooding and pollutant discharges into receiving waters. City staff from Public Works and Parks and Recreation are responsible for operations and maintenance of MS4 infrastructure. This section describes the Phase II Permit requirements related to operations and maintenance, including planned activities.

2019–2024 Phase II Permit Requirements

Section S5.C.7 of the 2019–2024 Phase II Permit requires the city to implement and document an O&M program to regulate and conduct maintenance activities to prevent or reduce stormwater impacts. The specific Phase II Permit requirements are as follows:

  1. Implement maintenance standards that are at least as protective as those specified in Ecology’s Stormwater Management Manual for Western Washington or approved program. No later than June 30, 2022, update maintenance standards as needed.

  2. Implement provisions to verify adequate long-term operation and maintenance (O&M) of stormwater treatment and flow control BMPs/facilities.

  3. Conduct annual inspections of all stormwater treatment and flow control BMPs/facilities that discharge to the stormwater system and were permitted by the city since 2010 (unless maintenance records justify a reduced inspection frequency).

  4. Perform annual inspections of all city-owned or operated permanent stormwater treatment and flow control BMPs/facilities, other than catch basins, and take appropriate maintenance actions (unless maintenance records justify a reduced inspection frequency).

  5. Spot check potentially damaged permanent treatment and flow control BMPs/facilities (other than catch basins) after major storm events; and conduct maintenance and repairs as needed.

  6. Perform routine catch basin and inlet inspections. Clean as needed based on maintenance standards. Elect to use an alternative approach to inspection if desired.

  7. Implement and document practices, policies, and procedures to reduce stormwater impacts associated with runoff from all lands owned or maintained by the city and road maintenance activities under the functional control of the city.

  8. Implement an ongoing training program for city staff whose primary construction, operations, or maintenance job functions may impact stormwater quality.

  9. Implement Stormwater Pollution Prevention Plans (SWPPPs) for all heavy equipment maintenance or storage yards and material storage facilities owned or operated by the city. Update SWPPPs by December 31, 2022.

  10. Maintain records of inspections, maintenance, repair, and enforcement activities.

Planned Activities

  • Implement Maintenance Standards: Surface Water (SW) Maintenance Section and Airport, Facilities, Parks & Trails, and Golf Course Divisions will implement maintenance standards and perform maintenance per the required schedule.

  • Update Maintenance Standards: The Surface Water Utility (SWU) Engineering and SW Maintenance Sections, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will review and update maintenance standards no later than June 30, 2022.

  • Private Stormwater Facility Inspections: The SWU Engineering Section will annually inspect private stormwater facilities constructed since February 2010, identify maintenance needs, and enforce maintenance standards.

  • Stormwater Treatment and Flow Control Facility/BMP Inspections: The SW Maintenance Section, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will conduct spot check after major storm events and annually inspect city-owned or operated stormwater facilities, identify maintenance needs and maintain and repair facilities in accordance with maintenance standards.

  • Catch Basin Inspection Program: The Facilities and Airport Divisions will implement the standard approach of inspecting catch basins and inlets every two years and cleaning per maintenance standards. The Parks & Trails and Golf Course Divisions will conduct inspections on a “circuit basis" every two years (i.e. 25% of catch basins and inlets in a circuit are inspected, and if needed to comply with maintenance standards, all catch basins and inlets in the circuit are cleaned). The Surface Water Maintenance Section will clean all pipes, ditches, catch basins, and inlets once during the permit term.

  • Maintenance Practices, Policies, and Procedures: The SW Maintenance Section, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will implement practices, policies, and procedures to reduce stormwater impacts associated with Permit-specified O&M activities.

  • Document Practices, Policies, and Procedures: The SW Maintenance Section, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will document practices, policies, and procedures for Permit-specified O&M activities by December 31, 2022.

  • Staff Training: The SW Maintenance Section, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will pursue training opportunities for maintenance staff.

  • Stormwater Pollution Prevention Plan (SWPPP): The Public Works Maintenance Division will implement the SWPPP for the Maintenance Shops Facility.

  • Update SWPPP: The Public Works Maintenance Division will update the SWPPP by December 31, 2022 to include a description of BMPs and schedule for implementation of additional BMPs, documented annual inspections, an inventory of materials and equipment and exposed activities, a site map, and a spill prevention plan.

  • Record Keeping: The SWU Engineering and SW Maintenance Sections, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will record O&M activities, including inspections, maintenance, and enforcement.

SOURCE CONTROL PROGRAM FOR EXISTING DEVELOPMENT

This section describes the Source Control Program for Existing Development Phase II Permit requirements, as well as the city’s planned compliance activities.

2019–2024 Phase II Permit Requirements

Section S5.C.8 of the 2019–2024 Phase II Permit requires the city to implement a program to prevent and reduce pollutants in runoff from areas that discharge to the MS4. The program includes applying operational and structural best management practices (BMPs), and treatment BMPs if needed, to existing sources, inspecting BMP implementation at commercial and industrial properties, applying and enforcing local ordinances at sites, and implementing practices to reduce polluted runoff from pesticide, herbicide, and fertilizer applications. The specific Phase II Permit requirements are as follows:

1. By August 1, 2022, adopt an ordinance to require source control BMPs for pollutant generating sources associated with existing land uses and activities

2. By August 1, 2022, establish an inventory of commercial, institutional, and industrial properties with pollutant generating potential.

3. By January 1, 2023, implement an inspection program for sites identified in the inventory.

  • Provide sites with information about pollutant generating activities.

  • Annually complete the number of inspections equal to 20% of the businesses and/or properties listed in the inventory, and inspect all sites identified through complaints.

4. By January 1, 2023, implement a progressive enforcement policy that includes documented follow-up actions.

5. Conduct training for staff responsible for implementing the source control program.

Planned Activities

  • Source Control Ordinance: The Surface Water Utility (SWU) Engineering Section will develop an ordinance by August 1, 2022 to require structural and/or operational source control BMPs for pollutant generating sources on existing development.

  • Inventory Development: The SWU Engineering and Surface Water (SW) Maintenance Sections, and Airport, Facilities, Parks & Trails, and Golf Course Divisions will identify pollutant generating businesses and/or sites to develop an inventory by August 1, 2022.

  • Educate Businesses: The SWU Engineering and SW Maintenance Sections, and Airport Division will inform businesses about activities that may generate pollutants and applicable source control requirements.

  • Inspect Businesses and/or Sites: The SWU Engineering and SW Maintenance Sections will annually inspect an equivalent number of 20% of businesses and/or sites in the inventory and all complaints starting no later than January 1, 2023.

  • Enforce Source Control Program: The SWU Engineering and SW Maintenance Sections, and Community and Economic Development (CED) Code Compliance will implement a progressive enforcement policy, documenting inspections and follow-up actions, no later than January 1, 2023.

  • Staff Training: The SWU Engineering and SW Maintenance Sections, and CED Code Compliance will pursue training opportunities for source control program staff.

TOTAL MAXIMUM DAILY LOAD REQUIREMENTS

This section provides a brief discussion of the Phase II Permit total maximum daily load (TMDL) requirements.

2019-2024 Phase II Permit Requirements

Section S7 of the NPDES Phase II Permit lists the following requirements:

  1. Implement the specific requirements identified in Appendix 2 of the Phase II Permit for applicable TMDLs listed in Appendix 2.

  2. Compliance with the permit constitutes compliance with applicable TMDLs not listed in Appendix 2 of the Phase II Permit.

  3. Comply with permit modifications and TMDL implementation plans prepared by Ecology for TMDLs that are approved by the US Environmental Protection Agency (EPA) after the Phase II Permit has been issued.

Planned Activities

The city is not required to implement actions for compliance with total maximum daily loads (TMDLs) pursuant to Section S7 and Appendix 2 of the Phase II Permit, since the city is currently not affected by any TMDLs listed in Appendix 2 of the NPDES Phase II Permit.

MONITORING

Monitoring and assessment are important to fully understand the impacts and effectiveness of stormwater management programs. This section provides a brief discussion of the Phase II Permit monitoring requirements including planned activities.

2019–2024 Phase II Permit Requirements

Section S8 of the 2019–2024 Phase II Permit requires the city to do the following:

1. For the previous permit cycle, pay into a collective fund to implement regional status and trends monitoring and effectiveness and source control identification studies by December 1, 2019.

2. For the current permit cycle, by December 1, 2019, notify Ecology of the city’s intent to pay into a collective fund to implement the following programs:

  • Regional status and trends monitoring

  • Stormwater management program effectiveness and source identification studies or conduct stormwater discharge monitoring.

3. Submit records of SWMP activities tracked and/or maintained in response to requests by the Stormwater Action Monitoring Coordinator.

Planned Activities

The city decided to opt to pay into the collective fund and started contributing to it beginning in August 2020. Annual payments into the collective fund, which began in December 2019, include the following:

  • Regional status and trends monitoring: $16,987

  • Stormwater management program effectiveness and source identification studies: $31,045

  • Annual Total: $48,032

  • 2019–2024 Phase II Permit Total: $240,160

REPORTING

This section provides a brief discussion of Phase II Permit reporting requirements, including planned activities.

2019-2024 Phase II Permit Requirements

Section S9 of the 2019-2024 Phase II Permit list the following requirements:

  1. Submit an annual report to Ecology no later than March 31 of each year (beginning in 2020).

  2. Keep all records related to the NPDES Phase II Permit and the SWMP for at least 5 years.

  3. Make records related to the NPDES Phase II Permit and the SWMP available to the public at reasonable times during business hours.

Planned Activities

The city plans to meet all the reporting requirements outlined in the 2019-2024 Phase II Permit.

APPENDIX A

Coordination Mechanisms

External Coordination Mechanisms

The city coordinates with adjacent jurisdictions as needed to control pollutants between physically interconnected MS4s and coordinates stormwater management activities to avoid conflicting plans, policies, and regulations.

The Surface Water Utility (SWU) Engineering and Surface Water (SW) Maintenance Sections implement procedures to coordinate with adjoining jurisdictions to address pollutants entering or leaving the city’s MS4.

The SWU Engineering Section coordinates stormwater management activities for shared watersheds through participation in the WRIA 8 Salmon Recovery Council, WRIA 9 Watershed Ecosystem Forum, and Our Green/Duwamish Watershed Stormwater Strategy.

Internal Coordination Mechanisms

The city formed a NPDES Interdepartmental Team composed of staff from select departments, divisions and sections in the fall of 2014. The Interdepartmental NPDES Stormwater Planning Team formed by August 1, 2020 and is indicated by an asterisk.

  • Public Works Department
  • Surface Water Utility (SWU) Engineering Section*

  • Public Works Maintenance Division

  • Surface Water (SW) Maintenance Section*

  • Renton Municipal Airport Division

  • Transportation Planning Section*

  • Solid Waste Section

  • Water Utility Engineering Section

  • Community and Economic Development (CED) Department
  • Development Engineering*

  • Planning*

  • Long Range Planning*

  • Construction Inspections

  • Building Inspections

  • Code Compliance

  • Parks & Recreation Department
  • Parks & Trails Division

  • Golf Course Division

  • Facilities Division

  • Parks Planning & Natural Resources Division*

The Interdepartmental Team developed a permit compliance matrix that lists Phase II Permit requirements, Ecology deliverables or documentation in the Annual Report, task leads, task support, and deadlines. The Interdepartmental Team will continue to coordinate Phase II Permit implementation activities during the duration of the permit, to ensure that the city meets the requirements of the Phase II Permit.

March 2022

2021 NPDES Report

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