Municipal Stormwater Permits

Urban areas that collect stormwater runoff in municipal separate storm sewers and discharge it to surface waters are required to have a permit under the federal Clean Water Act. The Environmental Protection Agency (EPA) stormwater regulations established two phases (Phase I and Phase II) for the municipal stormwater permit program. The Department of Ecology develops and administers National Pollution Discharge Elimination System (NPDES) municipal stormwater permits in Washington State.

Permits and Permittees

Phase I and Phase II permits; who's covered; petition criteria; appeals; and permit history.

Permittee Resources and Guidance

Resources and Guidance for permittees, including stormwater design manuals, information on emerging technologies, maps, annual reports, and stormwater education and outreach resources.

Trainings and Workshops

Information on Ecology's and Ecology-approved trainings and materials from previous workshops.

Contacts and Listserv

How to contact your permit manager and sign up for the listserv.