Dissolved Oxygen Amendment

The Regional Water Quality Control Board (Regional Board) directed staff in its 2007 Triennial Review of the Water Quality Control Plan for the North Coast Region (Basin Plan) to develop a proposal for the revision of the water quality objectives (objective) for dissolved oxygen (DO) as contained in the Basin Plan. Two California Environmental Quality Act (CEQA) Scoping Meetings were held in the fall of 2008, one in Santa Rosa and one in Weaverville. A Scoping Document was presented and public comments solicited. The proposed revision of the existing DO objectives is intended to apply throughout the North Coast Region.

In the spring of 2009, a draft staff report was written, based in part on scoping comments received. It was submitted to 2 peer reviewers for their scientific review and comment. The Regional Water Board received peer review comments later in the spring of 2009 and began revision of the document for public review.

In the mean time, the schedule for the Klamath River Total Maximum Daily Load (TMDL) for DO (and other parameters) required the immediate review of the Site Specific Objectives (SSO) for DO in the Klamath mainstem. Staff turned its attention to the Klamath SSOs for DO, determined its need for revision and issued during the summer of 2009 for public review a proposal to amend them. The proposal for the revision of the Klamath SSOs for DO adheres to the recommendations as provided by the peer reviewers of the regionwide proposal. The SSO for DO in the Klamath River was adopted by the Regional Water Board in March 2010, adopted by the State Water Resources Control Board in September 2010, and approved by USEPA Region 9 in December 2010.

Staff is continuing to work on the development of a proposed revision of the region wide DO objectives, including consideration of appropriate DO requirements in flowing waters, ephemeral waters, lakes, reservoirs, wetlands, and estuaries.

Available Documents

• CEQA Scoping Document for Regionwide DO Amendment
• Peer Review Draft Staff Report for Regionwide DO Amendment
• Peer Review Comments submitted by Michael Brett, University of Washington
• Peer Review Comments submitted by Dr. Daniel Schindler, University of Washington
• Staff Response to Peer Review Comments
• Staff Report for the Proposed Site Specific DO Objectives for the Klamath River in California (Appendix 1 of the Final Staff Report for the Klamath River TMDL)

Contact Information

For information, comments, or questions concerning the DO Amendment please contact Alydda Mangelsdorf at 707-576-6735 or amangelsdorf@waterboards.ca.gov.

Mailing Lists

We encourage users interested in the DO Amendment and other basin planning issues to subscribe to the Basin Planning email list here.

If you would like to be added to the hard-copy mailing list, please contact Alydda Mangelsdorf at 707-576-6735 or 5550 Skylane Blvd, Suite A, Santa Rosa, CA 95403.

( Updated November 22, 2011 )