The city was designed as a National Pollutant Discharge Elimination System (NPDES) II city in January, 2007. The City was reissued a NPDES Permit on August 1, 2012. To comply with the permit, effective December 31, 2016, the City has revised development codes to:
make Low Impact Development (LID) the preferred and commonly-used approach to site development
adopt the Department of Ecology 2014 Stormwater Management Manual of Western Washington
reduce thresholds triggering stormwater controls to 2000 square feet of hard surface area of 7000 square feet of land disturbance.
The purpose of these standards and requirements is to improve water quality in all of the streams and local water bodies, and to control connections to the city's stormwater system.
The revised site development related ordinances were approved by the City Council on December 20, 2016, and have been incorporated into the January 2017 edition of Urban Service Standards and Guidelines.