WSR 26-04-132
DEPARTMENT OF ECOLOGY
[Filed February 4, 2026, 10:28 a.m.]
Public Notice: Announcing the Reissuance of the Aquatic Plant
and Algae Management General Permit
The Washington state department of ecology (ecology) is reissuing the aquatic plant and algae management National Pollutant Discharge Elimination System and state waste discharge general permit on February 18, 2026. The permit becomes effective on March 20, 2026 and expires on March 19, 2031.
Purpose of the Permit: The aquatic plant and algae management general permit provides coverage for the chemical treatments of aquatic noxious weeds, native nuisance plants, algae, and phosphorus. This permit protects Washington's waters and aquatic life by controlling the discharge of pollutants into fresh water (lakes, streams, and rivers) or along shorelines, roadsides, dikes/levees, and ditch banks. Under the authority of the Federal Water Pollution Control Act and the state Water Pollution Control Act, a permit is required for the discharge of pesticides and other products either directly or indirectly to waters of the state. When the permitted activities are similar, ecology issues a general permit to cover all of them, rather than issuing a series of individual permits.
Ecology has made a few important changes to this permit, including:
| |
| • | Revised the monitoring requirements for some types of phosphorous control treatments. |
| • | Updated dissolved oxygen monitoring. Although fish kills are rare after aquatic herbicide or algaecide treatments, low dissolved oxygen can contribute to these events. To further reduce this risk, we have added monitoring requirements during situations when very low levels of dissolved oxygen are more likely. |
| • | Added another formulation of the aquatic herbicide triclopyr, and a new formulation of phosphorous control product based on iron coated lanthanum. These changes required an addendum to the existing 2017 supplemental environmental impact statement, which went through a State Environmental Policy Act (SEPA) review process. |
| • | Revised requirements to protect known rare plants or habitat. |
| • | Removed the list of approved adjuvants from the permit. The adjuvant list is now linked on the permit web page so the list can be kept up-to-date. |
Applying for Coverage Under the Permit: Permittees covered under the existing permit that have renewed are covered under the new permit. New or unpermitted activities may obtain coverage under the permit by submitting a complete permit application to ecology and satisfying all applicable public notice and SEPA requirements (WAC 173-226-200). Access to the application is available at https://ecology.wa.gov/AquaticPlants.
Public Notice Process and Comments: The previous permit was last issued March 17, 2021, and is scheduled to expire [March] 21, 2026. The draft general permit, fact sheet explaining the legal and technical basis for the permit, economic impact analysis, and a copy of the proposed application for coverage were shared on the permit's web page. Ecology provided public notice of the draft general permit determinations and accepted public comments on the draft permit from September 10, 2025, through October 24, 2025. Two public meetings and hearings were held during this comment period via online statewide webinars on October 14 and 16, 2025. Ecology received written comments via our comments web application, by email, and spoken comments provided during the public hearings. The comments and ecology's responses are included as an appendix to the fact sheet for the draft general permit.
Your Right to Appeal: You have a right to appeal the final general permit to the pollution control hearings board (
https://eluho.wa.gov/boards/pollution-control-hearings-board) within 30 days of issuance of the general permit. The appeal process is governed by chapters
43.21B RCW and 371-08 WAC. See the
appeal of the general permit (
https://apps.ecology.wa.gov/publications/SummaryPages/1710009.html) for more information.
Copies of the Permit: The permit, fact sheet with responses to public comments, and related documents are available online at https://ecology.wa.gov/AquaticPlants. You may request hard copies from the water quality program by contacting Jackie Lince at jackie.lince@ecy.wa.gov or 360-407-6600.
Americans with Disabilities Act (ADA) Accessibility: To request an ADA accommodation, email shawn.ultican@ecy.wa.gov, call 360-870-3492, or dial 711 to call through the Washington telecommunications relay for services like text telephone (TTY). Visit https://ecology.wa.gov/accessibility for more accessibility information.
Translation: Ecology is committed to providing language services, including translation and interpretation, for people whose primary language is not English. To request these services, email Shawn Ultican at shawn.ultican@ecy.wa.gov or call 360-870-3492. If you call, ask for an interpreter to be connected with one.
En Español: Para información en español, por favor comuníquese con Shawn Ultican al 360-870-3492.
Ecology Contact: Shawn Ultican, Washington State Department of Ecology, Water Quality Program, P.O. Box 47696, Olympia, WA 98504-7696, phone 360-870-3492, email shawn.ultican@ecy.wa.gov.