The Washington state department of ecology (ecology) is reissuing the Construction Stormwater National Pollutant Discharge Elimination System and state waste discharge general permit on November 19, 2025. The permit becomes effective on January 1, 2026, and expires on December 31, 2030.

Purpose of the Permit: Ecology's construction stormwater general permit regulates stormwater, and conditionally approved nonstormwater, runoff from more than 2,500 construction sites across Washington1. The coverage we issue helps support the industry in ways that protect the environment and are practical for Washington businesses. By following the requirements in the permit, construction sites help protect water quality in Washington state from pollution that could occur when rainfall and stormwater come into contact with disturbed soil, building materials, and any preexisting contamination that may be present at these sites.

The 2026 permit maintains ecology's compliance with the United States Environmental Protection Agency requirements, provides clarification on the construction activities that require a permit, and adds new requirements to parts of the permit. We also made changes and updates to improve readability and clarity. Those changes can be found on the permit's web page2.

Applying for Coverage Under the Permit: New or unpermitted construction activities/facilities may obtain coverage under the permit by submitting a complete permit application to ecology3 and satisfying all applicable public notice and State Environmental Policy Act requirements in WAC 173-226-200.

Public Process: The previous permit was issued November 18, 2020, and is scheduled to expire December 31, 2025. The draft general permit, fact sheet, economic impact analysis, and the proposed application for coverage were shared on the permit's web page2. Ecology provided public notice and accepted public comments on the draft permit from March 19 through May 9, 2025. Two public meetings and hearings were held during this comment period on April 21 and 24, 2025. Ecology received written comments via our comments online, by mail, by email, and spoken comments provided during the public hearings. The comments and ecology's responses are included as an appendix of the fact sheet for the draft general permit.

Right to Appeal: An appeal of the general permit conditions, the content of the permit, is a formal challenge to the decisions made by ecology during the permit's development, specifically regarding the regulation of discharges into state waters. This appeal process is governed by chapters 43.21B RCW and 371-08 WAC. Appeals must be submitted within 30 days of the permit's issuance. For further details, refer to the Appeal of the General Permit4.

Copies of the Permit: The permit, fact sheet, an official response to comments, and related documents are available on the construction stormwater general permit web page2. You may also request hard copies from Jackie Lince, jackie.lince@ecy.wa.gov, 360-407-6600.

Americans with Disabilities Act (ADA) Accessibility: To request an ADA accommodation, email kendra.henderson@ecy.wa.gov, call 360-870-6757, or dial 711 to call through the Washington telecommunications relay for services like text telephone (TTY). Visit https://ecology.wa.gov/ADA for more accessibility information.

Translation: To request this document in another language, please contact Kendra Henderson at 360-870-6757 and ask for an interpreter, or email kendra.henderson@ecy.wa.gov.

Ecology Contact: Kendra Henderson, Washington State Department of Ecology, Water Quality Program, P.O. Box 47696, Olympia, WA 98504-7696, phone 360-870-6757, email kendra.henderson@ecy.wa.gov.

1	Public Permitting and Reporting Information System (PARIS) database: https://apps.ecology.wa.gov/paris/
2	https://ecology.wa.gov/ConstructionStormwaterPermit
3	https://secureaccess.wa.gov
4	https://apps.ecology.wa.gov/publications/SummaryPages/1710009.html