Chapter 173-201A WAC (Aquatic Life Toxics Criteria)

Ecology is considering revising chapter 173-201A WAC, Water Quality Standards for Surface Waters of the State of Washington. We are considering the following revisions in this rulemaking:

  • Amending WAC 173-201A-240, Toxic substances, specifically aquatic life criteria, including, but not limited to, Table 240 and footnotes
  • Minor, non-substantive edits to rule language in WAC 173-201A-240 to correct typographical, calculation, and formatting errors

We may amend other sections of Chapter 173-201A WAC as necessary to support any revisions to the sections noted above.

We are considering revisions to aquatic life toxics criteria to provide additional water quality protection for organisms that live in water. We will:

  • Review all of Washington’s current aquatic life toxics criteria to ensure they are consistent with nationally recommended water quality criteria issued by the Environmental Protection Agency (EPA)
  • Evaluate pollutant protection levels for endangered species in Washington waters
  • Evaluate new scientific data, methods, and modeling tools to update protection levels necessary for aquatic life in Washington’s surface waters
  • Consider adding new toxic substances to the water quality standards that EPA has recommended or that the state of Washington designates as high priority for the protection of aquatic life

Rulemaking timeline


Announcement phase (CR-101)

Filing date:
June 22, 2022

Announcement documents

Rule development phase

June 22, 2022 - Fall 2023

Public input & involvement

Oct. 27, 2022 - Informational webinar

We invite you to attend an informational webinar for the rulemaking. During this webinar, we’ll provide an overview of:

  • Aquatic life toxics criteria – what they are and what they protect
  • History of the criteria in Washington
  • Strategy and scope of the rulemaking
  • Timeline and opportunities for public participation

View the presentation slides (pdf)

Oct. 27, 2022 - 1:30 p.m.
Register for the webinar*
Join by phone only - 1-253-215-8782 
Meeting ID - 816 6361 7294 

*Workshops offered via webinar allow individuals to view the presentation and ask questions via computer or mobile device.

Additional languages

Español (Spanish) 中文 (Chinese) Tiếng Việt (Vietnamese) 한국어 (Korean)


To request ADA accommodation for disabilities, or printed materials in a format for the visually impaired, contact Ecology's ADA Coordinator by email at, or call 360-407-6831. People with impaired hearing may call Washington Relay Service at 711. People with speech disability may call TTY at 877-833-6341.