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Santa Ana Region - Total Maximum Daily Load

Santa Ana Region - 303(d) List of Water Quality Limited Segments

The 303(d) list of water quality limited segments

The Federal Clean Water Act Section 303(d) requires that States assess the quality of their waters every two years and publish a list of those waters not meeting the water quality standards established for them.  Water quality standards include beneficial uses, water quality objectives necessary to protect these uses and the antidegradation policy, and are found in the Basin Plan. For water bodies placed on the 303(d) List of Water Quality Limited Segments, states are required to develop Total Maximum Daily Loads (TMDLs) for the pollutant(s) that are causing standards impairment.

Water bodies are included on the 303(d) List of Water Quality Limited Segments after evaluation of existing water quality data using the methodology for determining impairment identified in the Water Quality Control Policy for Developing California's Clean Water Act Section 303(d) List and the Functional Equivalent Document, both adopted by the Sate Water Resources Control Board in September 2004.

Once a water body is placed on the 303(d) List of Water Quality Limited Segments, it remains on the list until a TMDL is adopted and the water quality standards are attained or there are sufficient data to demonstrate that water quality standards have been met and delisting should take place.

On April 28, 2017, the Santa Ana Regional Water Board adopted Order No. R8-2017-0013, Approval of Recommendations for the Federal Clean Water Act Section 303(d) List, with two Errata sheets. Order No. R8-2017-0013

Order No. R8-2017-0013

Errata Sheet #1
Errata Sheet #2

Approved Staff Report (April 28, 2017)

Upon approving the 2016 303(d) List, the Regional Water Board is required to submit the water body fact sheets, responses to comments, and all other information it considered during the hearing, to the State Water Resources Control Board (State Water Board).

If any person or entity seeks to have the State Water Board review a listing recommendation made by the Regional Water Board with respect to one or more waterbodies, the individual or entity must submit a request to the State Water Board to review of the specific listing recommendation no later than 30 days after the date of the Regional Water Board’s approval. Send requests for specific review by emailing the specific listing recommendations and the concerns related to those recommendations to WQAssessment@waterboards.ca.gov (must be no more than 15 megabytes); or mail or hand delivery at:

Surface Water Quality Assessment Unit
State Water Resources Control Board, Division of Water Quality
P.O. Box 100, Sacramento, CA 95812‐2000 (mail)
1001 I Street, 15th Floor, Sacramento, CA 95814 (hand delivery)

Please also indicate in the subject line, “Request for Review of specific Regional Board listing recommendation – 303(d) List portion of the 2016 California Integrated Report.”

Before the State Water Board approves the 2016 303(d) List, the State Water Board shall provide advance notice and an opportunity for public comment. The public comment will be limited to the listing recommendations that are timely requested for review unless the State Water Board elects to consider recommendations on other waters.

Upon approval by the State Water Board, the statewide 2016 List shall be submitted to U.S. EPA for approval as required by the Clean Water Act.

Preapproval Documents


Santa Ana Region's Approved 303(d) Lists of Water Quality Limited Segments

Additional Information on the 2006 303(d) List of Water Quality Limited Segments

Contact persons regarding the 303(d) List of Water Quality Limited Segments

If you have any questions or comments regarding the 303(d) List please contact Mark Smythe at (951) 782-4998.

To receive notifications by e-mail, subscribe on-line to our Impaired Waters 303(d) List, electronic mailing list.