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Comment Period

Irrigation System Aquatic Weed Control General Permit

Draft Permit

Jan. 18, 2023 - March 6, 2023, 11:59 p.m.

We invite you to comment on the draft Irrigation System Aquatic Weed Control general permit. Submit your feedback on the draft permit documents by March 6, 2023.

We will accept comments on the draft permit documents. We ask that comments reference specific permit text when possible. We propose updates to the requirements, including: 

  • Updating the permit to match current standards for aquatic pesticide permits.
  • Updating and clarifying reporting requirements.
  • New guidance on how to qualify for and maintain a reduced monitoring plan.
  • Allowing permittees to use new adjuvants (products added to pesticides to improve their effectiveness or performance) and active ingredients, consistent with other aquatic pesticide permits.
  • Adding a new chemical-tracking option to avoid the requirement to hold water back from closed side channels after a main canal treatment.
  • Adding requirements that improve permittees’ communication with the public.
  • New draft Environmental Impact Statement (DEIS) to analyze effects of permit activities and alternatives.

General permit documents

Documents are available for review online. To request a hard copy document, please contact Jackie Lince at (360) 407-6600 or by email at jackie.lince@ecy.wa.gov.

We are also accepting comments for the related draft Environmental Impact Statement (DEIS). Visit the draft EIS public comment page.


We issue the Irrigation System Aquatic Weed Control permit to irrigation districts, reclamation districts, water companies, and similar entities that discharge wastewater either directly or indirectly to waters of the state.

This permit allows the regulated use of aquatic pesticides, marker dyes, and nutrient inactivation products to control the growth of aquatic plants and algae within irrigation systems, helping them maintain the capacity to convey water.

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Comment by mail

Danielle Edelman
WA State Department of Ecology - Water Quality Program
P.O. Box 47696
Olympia, WA 98504-7696
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Danielle Edelman
General Permit Writer

To request ADA accommodation, contact Ecology's ADA Coordinator by email at ecyadacoordinator@ecy.wa.gov, or call 360-407-6831, 711 (relay service), or 877-833-6341 (TTY). More about our accessibility services.