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Surface Water Management

What is the NPDES permit?

The NPDES permit program, created in 1972 by the Clean Water Act, helps address water pollution by regulating the release of pollutants into our streams, lakes, rivers, and wetlands.  In order to meet the requirements of the permit, the city is asked to annually update the Storm Water Management Plan to achieve the long term goal of clean water in our streams, lakes, and Puget Sound.


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What is an MS4?

The city of Federal Way is classified as a "small" MS4.  MS4 stands for municipal separate storm sewer systems.  It is a conveyance system or set of storm drains, ditches, or pipes that collect and move stormwater, and are:

  • Owned by a state, city, town, or other public entity that discharges to waters of the United States.
  • Not a combined sewer, meaning stormwater and sewer are not within the same conveyance system.
  • Not part of a sewage treatment plant or publicly-owned treatment works.


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What is the difference between a Phase I and a Phase II Municipal Stormwater Permit?

The Phase I Municipal Stormwater Permit regulates releases 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.  The Department of Ecology issues two Phase II permits:

The Western Washington Phase II permit requires local governments to manage and control stormwater runoff so that it does not pollute downstream waters.  The Stormwater Management Program Plan (Plan) describes the city’s planned actions and activities for the year to meet the requirements of the permit.


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