The National Pollutant Discharge Elimination System (NPDES) Permit (Permit) is a federal permit that regulates stormwater and wastewater discharges to waters of the State. While it is a federal permit, the regulatory authority has been passed to the Washington State Department of Ecology (Ecology). The first Western Washington Phase II Municipal Stormwater Permit was issued by Ecology in January of 2007. The current permit term is five years, beginning August 1st 2013 and ending July 31st 2018. In 2017, Ecology announced an extension of the current permit term to July 31st 2019.
The Permit requires that all affected municipalities create and implement a Stormwater Management Program (SWMP) which addresses five required program elements:
Select cities, such as the City of Marysville, are required to provide additional actions applicable to Total Maximum Daily Load (TMDL) requirements.