The federal Clean Water Act (CWA) sets effluent limitations for discharges of pollutants. "Pollutant" is defined in the CWA to include a variety of materials that may be discharged into water through human activities, construction or industrial processes, or other methods.
The Department of Ecology (Ecology) is delegated federal CWA authority by the United States Environmental Protection Agency (EPA). Ecology also is the agency authorized by state law to implement state water quality programs.
The CWA establishes the National Pollutant Discharge Elimination System (NPDES) permit system to regulate wastewater discharges from point sources to surface waters. "Point sources" are defined generally as discernable, discrete, and confined conveyances from which pollutant discharges can or do occur. The NPDES permits are required for anyone who discharges wastewater to surface waters or who has a significant potential to impact surface waters.
A wastewater discharge permit places limits on the quantity and concentrations of contaminants that may be discharged. Permits may require wastewater treatment or impose operating or other conditions, including monitoring, reporting, and spill prevention planning. The NPDES permits are valid for five years but may be renewed.
In the NPDES permit programs, Ecology issues both individual permits (covering single, specific activities or facilities) and general permits (covering a category of similar dischargers). These permits include limits on the quantity and concentrations of contaminants that may be discharged. These permits also may require wastewater treatment or impose operating or other conditions.
One category of general NPDES permits issued by Ecology is municipal stormwater general permits, issued in connection with stormwater that drains into waterways from surfaces such as parking lots, streets, and highways. The municipal stormwater general permits are divided into different phases depending on the individual jurisdiction. The Phase 1 municipal stormwater general permit regulates systems owned or operated by:
The National Pollutant Discharge Elimination System municipal stormwater general permit issued by the Department of Ecology (Ecology) to a Phase 1 permittee must require the permittee to report certain information on an annual basis, including:
Annually, Ecology must issue the following awards to permittees whose work to address the urban heat island effect best demonstrates innovation and achievement in each of the following areas:
Beginning in 2025 and continuing every year thereafter, Ecology, in consultation with WDFW, may award one or more permittees with the designation of "salmon-safe community" for that year, based on the permittee's achievements within the following metrics: