Nooksack River photo.  Photographer unknown.

Ecology Revised the State Standards Following EPA Ruling

In August 2006 Ecology held hearings on proposed revisions to the surface water quality standards (Chapter 173-201A WAC). Ecology developed this supplemental revision to the 2003-adopted water quality standards in response to the U.S. Environmental Protection Agency’s (EPA) disapproval of the state’s standards in March 2006. This revision sets colder temperature standards for specific streams, and increases the amounts of dissolved oxygen that will be required in those streams.

After carefully considering the written and oral testimony provided, Ecology's director signed the final rule on November 20, 2006. The revised rule went into effect on December 21, 2006. It replaced the version of the rule adopted in 2003.

A Focus Sheet on the revisions can be found at:

December, 2006 - Ecology Began Transitioning to Using the New State Standards

See Implementation Plan for more information. (Ecology publication)


If you have questions about the water quality standards please go to our Contacts page. You can also subscribe to the Water Quality mailing list.


Back to top of page

Last updated April 2009