The federal Clean Water Act (CWA) sets limitations for discharges of pollutants. The Department of Ecology (Ecology) is the delegated CWA authority by the U.S. Environmental Protection Agency. Ecology is also 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 discernible, discrete, and confined conveyances from which pollutant discharges can or do occur. NPDES permits are required for anyone who discharges wastewater to surface waters or who has a significant potential to impact surface water quality.
The Puget Sound Nutrient General Permit (Permit) is administered by Ecology and limits the excess of nutrients from entering Puget Sound from domestic wastewater treatment plants (WWTPs). Excess nutrients can cause low oxygen levels, expand dead zones, increase seawater acidification, and increase harmful algal blooms. The Permit applies to 58 domestic WWTPs discharging into marine and estuary waters of Puget Sound and the Salish Sea. The Permit focuses only on controlling nutrients and works in conjunction with the WWTPs other existing individual permits. The Permit became effective January 1, 2022, and expires December 31, 2026.
Ecology must revise and strengthen the requirements of the Permit to limit pollution from WWTPs into Puget Sound and the Salish Sea. The components of the Permit that must be strengthened include:
By December 1, 2022, Ecology must submit a report to the Legislature with intended revisions to the Permit requirements.