Phase I Equivalent Stormwater Manuals for Western Washington

This webpage provides information for Western Washington Phase II Permittees and other interested parties regarding Phase I Municipal Stormwater Permittee programs for Runoff Controls for New and Redevelopment. Ecology will post additional information on this webpage as it becomes available.

Historical information, current status, and links to the Phase I programs (including codes, ordinances, Directors’ Rules, public rules and manuals) are described below.

King County

Ecology subsequently reviewed King County’s Phase I submittal against the February comments. Ecology also clarified the adoption deadline in Adoption Timeline Clarification Letter. King County described its local adoption process and timeline in a letter submitted in accordance with the Phase I permit, King County G20. King County has now adopted and put their program into effect. King County’s program consists of:

City of Tacoma

Ecology reviewed the City of Tacoma’s Phase I submittal for controlling runoff from new development, redevelopment and construction sites. The City of Tacoma has now adopted and put their approved program into effect with these components and the associated Response to Comments agreements below. Tacoma’s program consists of:

• City of Tacoma Surface Water Management Manual (2008)
• Tacoma Municipal Code Chapter 12.08 Wastewater and Surface Water Management

Ecology reviewed the City of Tacoma’s Phase I submittal and provided the following comments and adoption deadline clarification:

The material the city submitted is available online on the City of Tacoma’s webpage for NPDES Municipal Stormwater Permit Submittals.

City of Seattle

Ecology reviewed the City of Seattle Phase I submittal. Seattle is currently conducting their local adoption process. Seattle’s program consists of:

Seattle Municipal Code chapters 22.800 - 22.808 titled "Stormwater and Drainage Control Code" as adopted in 2009.
Seattle Municipal Code chapter 22.170 titled “Grading Code” as adopted in 2009.
Joint SPU/DPD Director's Rule titled "Source Control Technical Requirements Manual" as approved by the Director of Seattle Public Utilities (SPU) and the Director of the Department of Planning and Development (DPD) in 2009.
Joint SPU/DPD Director's Rule titled "Construction Stormwater Control Technical Requirements Manual" as approved by the Director of SPU and the Director of DPD in 2009.
Joint SPU/DPD Director's Rule titled "Stormwater Flow Control and Water Quality Treatment Technical Requirements Manual" as approved by the Director of SPU and the Director of DPD in 2009.
Joint SPU/DPD Director's Rule titled "Stormwater Code Enforcement Manual" as approved by the Director of SPU and the Director of DPD in 2009.

Ecology reviewed Seattle’s Phase I submittal and provided the following comments and adoption deadline clarification:

Seattle has made changes to their Stormwater Code and associated Directors' Rules to address Ecology’s comments. The draft code and manual information is available online on the City of Seattle’s webpage at City of Seattle Proposed Revisions to Stormwater Code.

Documentation regarding the final resolution of Ecology’s initial comments is reflected in Seattle Program Comment Resolution 031709 and Second Round Ecology-Seattle Annotated Responses 031709.

Pierce County

Ecology reviewed Pierce County’s Phase I submittal for controlling runoff from new development, redevelopment, and construction sites. Pierce County has now adopted and put their approved program into effect with these components and the associated Response to Comments agreements below. Pierce County’s program consists of:

Pierce County Stormwater Management and Site Development Manual (2008), as amended in agreement with “Pierce County’s letter to DOE, date March 6, 2009” concluding the Ecology review process.
Pierce County Code Title 11”Storm Drainage and Surface Water Management” and Title 17A“Construction and Infrastructure Regulations – Site Development and Stormwater Drainage,” as amended by Ordinance No. 2008-59s.
Pierce County Code Title 18E “Development Regulations-Critical Areas”

Ecology reviewed Pierce County’s Phase I submittal and provided the following comments and adoption deadline clarification:

The material the County submitted is available online on the Pierce County website at Proposed Changes to the SWM Manual.

Snohomish County

Ecology reviewed Snohomish County’s February 2008 Phase I submittal and provided the following comments and adoption deadline clarification:

The material the County submitted in February 2008 is available online on the Snohomish County website at Snohomish County NPDES Draft Stormwater Regulations.

Snohomish County has prepared a revised submittal for Ecology’s review that can be found at Snohomish County Revised Draft Stormwater Regulations.

Ecology and Snohomish County entered into Agreed Order #6688 to establish a compliance schedule for the revision and adoption of Ecology-approved stormwater regulations to control runoff from new development and redevelopment.

Clark County

Ecology has reviewed Clark County’s Phase I submittal. Clark County’s program consists of:

Clark County Stormwater Manual (2008)
Clark County Code Chapter 40.35 Stormwater and Erosion Control
Clark County Code Chapter13.26A Water Quality
Clark County Code Chapter 40.450 Wetland Permits

Upon review, Ecology has determined that these documents do not meet the criteria contained in the Permit. Specifically, the following conditions are not approved as equivalent:

Adopting a flow control policy that the Ecology has determined does not provide equal or similar protection of receiving waters and equal or similar levels of pollutant control as compared to Appendix I; and,

Failing to adopt as part of their flow control policy a threshold that would require Appendix I flow control standards for projects that through a combination of effective impervious surfaces and converted pervious surfaces cause a 0.1 cubic feet per second increase in the 100-year flow frequency from a threshold discharge area as estimated using the Western Washington Hydrology Model or other approved model.

Correspondence regarding Clark County’s late Phase I submittal are included below:

Ecology subsequently reviewed Clark County’s Phase I submittal and on August 14, 2008 provided the following Comments on the July 2008 Ordinance and Manual Submittal.

The material the County submitted is available online on Clark County’s website: Clark County Ordinance Update

WSDOT Highway Runoff Manual - Approved for use for WSDOT projects and by local governments for public road projects.