Puget Sound Nutrient General Permit

Discharges of excess nutrients — particularly nitrogen — to the Puget Sound from public domestic wastewater treatment plants (WWTPs) are contributing to low oxygen levels in the Puget Sound and the rest of the Salish Sea. The Clean Water Act and federal rules require WWTPs that contribute to water quality impairments, by discharging excess nutrients, take action to prevent this pollution. The Puget Sound Nutrient General Permit is designed to address excess nutrients from the identified 58 domestic wastewater facilities discharging to the Washington Salish Sea.

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Learn about the 2025 permit updates
Read the Financial Capability Assessment Guide
Read the 2022 permit

2025 permit reissuance

In February 2025, the Pollution Control Hearings Board (PCHB) invalidated the Puget Sound Nutrient General Permit "insofar as it is mandatory" and remanded the permit back to Ecology for further action. In April 2025, we sent a letter to permittees terminating their coverage and providing an overview of possible next steps.

We consider the general permit to be an appropriate tool for our long-term strategy to reduce nitrogen discharges and improve water quality in the Sound. So, we are proposing to reissue the permit with changes to allow facilities to opt in and apply for permit coverage. If a facility does not opt in to the general permit, Ecology will incorporate nutrient reduction requirements into the facility's individual permit, which will have a separate formal public process.

Draft permit documents

Public involvement

We provided a public notice of the draft general permit, issued a news release, and accepted public comments from June 18, 2025, through Aug. 27, 2025. In early July we hosted a public meeting with an informational presentation and question and answer session to help explain the draft permit's proposed changes. A second public informational meeting paired with a formal hearing was held on July 22, 2025, providing opportunity for formal spoken testimony on the draft permit. We received comments online, by mail, and during our public hearing.

Next steps

We will review and consider all comments recieved. We will make appropriate revisions and publish a Response to Comments as an appendix to the fact sheet and make a final decision on permit issuance in 2026.

Timeline

June 18 to Aug. 27, 2025: Formal public comment period on the draft general permit
Fall/Winter 2025: Reviewing comments, make revisions, and issue final permit
Early 2026: Final permit will be effective 30 days after issuance, which will start the permit application period for facilities to opt in or out of the permit.

map of puget sound with all WWTP marked as small or dominant loader. Contact Ecology for more info — The Permit covers 58 wastewater facilities that discharge to Puget Sound. Seven of those facilities are dominant loaders contributing over 80% of the nutrients.

Brief history of the general permit

We held a public process to decide if we should use a general permit or individual permits to control nutrients. In January 2020, with support, we announced our decision to move forward with developing a draft Nutrient General Permit. During 2020, we worked with the General Permit Advisory Committee to develop recommendations for permit conditions. We held public reviews of a preliminary draft, then in Summer 2021 we developed a formal draft, held another comment period, and finalized the permit in December 2021. Several parties appealed the permit (see "Appeals of the general permit" below).

More permit information

General permit appeals:

Several municipalities, two environmental groups, and the Suquamish Tribe appealed the general permit. On Feb. 28, 2025, the Pollution Control Hearings Board invalidated the Puget Sound Nutrient General Permit “insofar as it is mandatory for already-permitted dischargers” and remanded the permit to Ecology for further action. We sent a letter to permittees with additional information about possible next steps.

You can visit the Pollution Control Hearings Board and use the Case Search Tool.

Legal challenges to the process:

City of Tacoma et al., filed legal challenges to the general permit in both Pierce County and Thurston County Superior Courts. The Pierce County case was dismissed, and the Thurston County case resulted in an adverse decision (January 2023), essentially stating that a letter Ecology wrote denying a petition for rulemaking was a rule. We appealed that decision to the Court of Appeals.

The Court of Appeals issued a decision (September 2023) acknowledging wastewater treatment plants are contributing to low dissolved oxygen in Puget Sound. However, the court concluded that a letter we wrote denying a petition for rulemaking is a rule and nutrient limits referenced in that letter are unlawful. We disagreed and filed a Petition for Review with the State Supreme Court (October 2023).

The State Supreme Court issued a unanimous decision (September 2024) supporting the process we're using for regulating excess nutrients. Specifically, the court concluded that the letter we wrote was not a rule and we followed proper process.

We developed a Financial Capability Assessment Guide. This guide helps permittees look at the financial impact to their communities and identify economically reasonable levels of wastewater treatment in the context of AKART (all known, available and reasonable methods of prevention, control, and treatment). We also provided an Excel worksheet tool and a focus sheet that covers common questions.

In March 2020, we convened a General Permit Advisory Committee to advise us in drafting general permit requirements for domestic wastewater treatment plants discharging to Puget Sound. This Advisory Committee was comprised of regional treatment-plant representatives, state agencies, the EPA, and the environmental community. Committee members met throughout 2020 to develop recommendations for permit conditions, and they brought a diverse array of ideas and concerns to the table. View the list of members and previous meeting materials.

Help applying for coverage, finding or completing forms, or drafting public notices

Northwest Region
Southwest Region

Tricia Miller
tricia.miller@ecy.wa.gov
206-594-0167

Mail forms to:

Washington State Department of Ecology
Attn: WQ Puget Sound Nutrient Permit Coordinator
Northwest Region Office
PO Box 330316
Shoreline, WA 98133-9716

Carey Cholski
carey.cholski@ecy.wa.gov
360-407-6279

Mail forms to:

Washington State Department of Ecology
Attn: WQ Puget Sound Nutrient Permit Coordinator
Southwest Regional Office
P.O. Box 47775
Olympia WA 98504-7775

Contact information

William Weaver, Ph.D., P.E.
Senior Environmental Engineer
william.weaver@ecy.wa.gov
360-870-7424

Puget Sound Nutrient General Permit

I want to...

2025 permit reissuance

Draft permit documents

Public involvement

Next steps

Timeline

Brief history of the general permit

More permit information

2022 permit documents

General permit appeals:

Legal challenges to the process:

Help applying for coverage, finding or completing forms, or drafting public notices

Mail forms to:

Mail forms to:

Related links

Contact information