Puget Sound Olympia

Municipal Stormwater

Water Quality > Stormwater > Municipal Stormwater General Permit

Municipal Stormwater General Permit Information


Phase I | Phase II Eastern | Phase II Western | WSDOT permits

Permit Components

Help and guidance, organized by the sections of the permits.

Permittee Resources

Additional resources for permittees, such as training and grants.

Stormwater Manuals

Western | Eastern | Technical Assistance

Keeping pollutants out of municipal water systems

Many urban areas that collect stormwater runoff in municipal separate storm sewer systems (MS4s) are required to have a permit under the federal Clean Water Act.

The Environmental Protection Agency (EPA) stormwater regulations established two phases — Phase I (for medium and large MS4s) and Phase II (for smaller MS4s) — for the municipal stormwater permit program. (See our Municipal Stormwater Permittee Lists for a listing of the permittees covered by the Municipal Stormwater Permits.)

In Washington State, the Department of Ecology develops and administers National Pollutant Discharge Elimination System (NPDES - a section of the Clean Water Act) municipal stormwater permits.


New item Catch Basin Maintenance

New item 2012 Permit Appeals

Regional Stormwater Monitoring Program (RSMP)

Ecology's LID Resources webpage