Municipal stormwater general permits

Municipal stormwater general permits regulate discharges from municipal stormwater systems. These drainage systems are separated from sanitary sewer systems and are owned or operated by cities, counties, and other public entities.

Stormwater is rain and snow melt that runs off surfaces such as rooftops, paved streets, highways, and parking lots. As water runs off these surfaces, it can pick up pollutants that contaminate local water bodies.

There are four municipal stormwater general permits in Washington.

Municipal Stormwater Permits

The Phase I Municipal Stormwater Permit regulates discharges from municipal separate storm sewer systems (MS4s) owned or operated by the state's largest cities and counties.
 

The Phase II Municipal Stormwater Permits regulate discharges from certain "small" MS4s in Washington.

We issue two Phase II permits:

Secondary permittees

  • The permits also apply to public separate storm sewer systems operated by other types of public entities located in a Phase I or II city or county. Examples include ports, prison complexes, park districts, universities, or diking and drainage districts.
  • See Secondary Permittee guidance to determine whoe should apply for permit coverage. 

Washington State Department of Transportation (WSDOT) Municipal Stormwater Permit

The WSDOT municipal stormwater permit regulates discharges from state highways, rest areas, park-and-ride lots, ferry terminals, and maintenance facilities within the urbanized areas of the state.

Who's covered under the municipal stormwater permits?

View a map of Phase I and Phase II Municipal Stormwater Permit area boundaries

The 1990 Phase I regulation requires medium and large cities or certain counties with populations of 100,000 or more to obtain NPDES permit coverage for their stormwater discharges.

The 1999 Phase II regulation requires small MS4s in U.S. Census Bureau defined urbanized areas, as well as MS4s designated by the permitting authority, to obtain NPDES permit coverage for their stormwater discharges. 

List of Phase I Permittees
Cities Counties Secondaries

Seattle
Tacoma

Snohomish 
King 
Pierce 
Clark 

UW Seattle
Seattle School District #1
Tacoma Community College
Camp Murray
Tacoma Metro Parks
Port of Seattle
Port of Tacoma
Washington State Military Department
Washington State Dept. of Corrections

 

List of Western Washington Phase II Municipal Stormwater Permittees
Cities Counties Secondaries
Aberdeen
Algona
Anacortes
Arlington
Auburn
Bainbridge Island
Battleground
Bellevue
Bellingham
Black Diamond
Bonney Lake
Bothell
Bremerton
Brier
Buckley
Burien
Burlington
Camas
Centralia
Clyde Hill
Covington          
Des Moines
DuPont
Duvall
Edgewood
Edmonds
Enumclaw
Everett
Federal Way
Ferndale
Fife
Fircrest
Gig Harbor
Granite Falls
Issaquah
Kelso
Kenmore
Kent
Kirkland
Lacey
Lake Forest Park
Lake Stevens      
Lakewood
Longview
Lynden
Lynnwood
Maple Valley
Marysville
Medina
Mercer Island
Mill Creek
Milton
Monroe
Mountlake Terrace
Mount Vernon
Mukilteo
Newcastle
Normandy Park
Oak Harbor
Olympia
Orting
Pacific  
Port Angeles
Port Orchard
Poulsbo
Puyallup
Redmond
Renton
Sammamish
SeaTac
Sedro-Woolley
Shelton
Shoreline     
Snohomish
Snoqualmie
Steilacoom
Sumner
Tukwila
Tumwater
University Place
Vancouver
Washougal
Woodinville
Cowlitz 
Kitsap 
Skagit 
Thurston 
Whatcom 

Bainbridge Island School District #303
Bellingham School District
Bellingham Technical College
Cascadia College
Central Kitsap School District
Centralia College
Clark College
Clark College
Consolidated Diking Improvement District #1
Edmonds Community College
Evergreen State College
Highline Community College
Kelso School District
Kent School District
Longview School District
Lower Columbia College
Port of Anacortes
Port of Bellingham
Port of Edmonds
Port of Olympia
Port of Skagit County
Port of Vancouver
Skagit Co Drainage District #19
Skagit Valley College
UW Bothell 
WA General Administration (Capitol Campus)
Washington Dept of Corrections
Washington State University
Western Washington University
Whatcom Community College

 

 

 

List of Eastern Washington Phase II Municipal Stormwater Permittees
Cities Counties Secondaries
Asotin
Clarkston
College Place
East Wenatchee
Ellensburg
Kennewick
Moses Lake        
Pasco
Pullman
Richland
Selah
Spokane
Spokane Valley  
Sunnyside
Union Gap
Walla Walla
Wenatchee
West Richland
Yakima
Asotin 
Chelan 
Douglas 
Spokane 
Walla Walla 
Yakima 
Eastmont Metropolitan Park District
Port of Benton 
Central Washington University
Sunnyside Valley Irrigation District
Yakima Valley Community College
Washington State University Tri-Cities
Washington State University Pullman
Washington State University Spokane
Selah School District #19

 

Apply for permit coverage

Apply through SecureAccess Washington and use the WQWebPortal to submit your NOI (Notice of Intent).

Guidance

For guidance about applying, changing, or implementing and complying with your municipal stormwater permit see the municipal stormwater guidance page. Stormwater manuals provide stormwater permit implementation and management guidance. For more general stormwater permit guidance, see the stormwater guidance page.

Frequently asked questions

Have a question? Check out our frequently asked questions page.

Stormwater monitoring

Are our permits successful at preventing or reducing pollution from stormwater runoff? Check out the Stormwater Action Monitoring program and our other results on the stormwater monitoring page.

Keep in touch with us

Join our municipal stormwater permit listserv to receive updates about our permits.