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The 303(d) List of Impaired Waterbodies and The 305(b) Water Quality Assessment

The 303(d) List of Impaired Waterbodies

Section 303(d) of the federal Clean Water Act and 40 CFR §130.7 require states to identify waterbodies that do not meet water quality standards and are not supporting their beneficial uses. These waters are placed on the Section 303(d) List of Impaired Waterbodies. The List identifies the pollutant or stressor causing impairment and establishes a schedule for developing a control plan to address the impairment.

Placement on this list generally triggers development of a pollution control plan called a Total Maximum Daily Load (TMDL) for each waterbody and associated pollutant/stressor on the list. The TMDL serves as the means to attain and maintain water quality standards for the impaired waterbody.

The current 303(d) List is commonly known as the 2006 List since that was the year of the last major update. Since that time, several water bodies have been added to the list. The most recent addition is for the reach of the mainstem Klamath River from the Copco 1 Reservoir to Iron Gate Dam for microcystin toxins, which was added May 29, 2008, by the US EPA.

The 305(b) Water Quality Assessment Report

Section 305(b) of the federal Clean Water Act requires states to report biennially to the US EPA on the water quality conditions of their surface waters. The US EPA then compiles these assessments into their biennial “National Water Quality Inventory Report” to Congress.

2008 305(b) and 303(d) Integrated Report

For 2008, California is integrating the 303(d) List of Impaired Waters and the 305(b) Water Quality Assessment Report into a single report.  This report is called the 2008 Integrated Report, and it will satisfy the requirements of both CWA Sections 303(d) and 305(b).

North Coast Regional Water Board staff developed 2008 Integrated Report for waters within the North Coast Region of California.  Staff analyzed available monitoring data, including data submitted by interested parties (data submitted after February 28, 2007, will be considered during the next listing cycle).

Public Hearing on June 3, 2009

Based on public comments, Regional Water Board staff have revised the 2008 Integrated Report in the final “Staff Report for the 2008 Integrated Report for the Clean Water Act Section 305(b) Surface Water Quality Assessment and the 303(d) List of Impaired Waters.” 
The Regional Water Board will hold a public hearing on the final Clean Water Act (CWA) Section 303(d) List of Impaired Waters section of the 2008 Integrated Report for the North Coast Region as follows:

June 3, 2009
Hearing Room, Regional Water Board Office
5550 Skylane Blvd, Ste A
Santa Rosa, CA

At the Public Hearing, the Regional Water Board will consider for approval each proposed listing change to the CWA Section 303(d) List of Impaired Waters, and will consider adoption of a Resolution in support of its recommendations to the State Water Resources Control Board.

Following Regional Water Board adoption, the CWA Section 303(d) List of Impaired Waters section of the 2008 Integrated Report will be considered by the State Water Resources Control Board.  Following State Water Board approval, it will be considered by the US EPA.

Other 303(d) List Links

Contact Information

Acting Unit Manager:
Matt St. John, Water Resources Control Engineer
707-570-3762
mstjohn@waterboards.ca.gov


Page Updated: May 21, 2009