303(d) LIST

What is the 303(d) list?

Section 303(d) of the 1972 Federal Clean Water Act requires states to identify waterbodies that do not meet water quality objectives and are not supporting their beneficial uses. Each state must submit an updated list, called the 303(d) list, to the U.S. EPA every two years. In addition to identifying the waterbodies that are not supporting beneficial uses, the list also identifies the pollutant or stressor causing impairment, and establishes a priority for developing a control plan to address the impairment. The list also identifies waterbodies where 1) a TMDL has been approved by U.S. EPA and an implementation is available, but water quality standards are not yet met, and 2) waterbodies where the water quality problem is being addressed by an action other than a TMDL and water quality standards are not yet met. 

On November 30, 2006, U.S. EPA gave partial approval to California's 2006 Section 303(d) List of Water Quality Limited Segments.  On June 28, 2007, U.S. EPA gave final approval to the list with modifications.  You may access information on California’s Final 2006 Clean Water Act Section 303(d) List and related documents at
http://www.waterboards.ca.gov/water_issues/programs/tmdl/303d_lists2006_epa.shtml

How and when does the 303(d) list get updated? And how can I participate?

Pursuant to Section 303(d) of the 1972 Federal Clean Water Act, the state must submit an updated list to the U.S. EPA every two years. The State Water Resources Control Board (State Water Board) initiates the process to update the list by soliciting data and information from the public. Staff at the Regional and State Water Boards consider this data, along with data available to the Water Boards, in preparing the updated list. Once received, the data and information is evaluated consistent with the Policy for Developing California's Clean Water Act Section 303(d) List. You may access this policy at http://www.waterboards.ca.gov/water_issues/programs/tmdl/303d_listing.shtml
The policy requires that the Regional Water Boards approve an updated list for waters in each region and submit this list for subsequent approval by the State Water Board as part of the updated list for the state. The U.S. EPA then must approve the state list. The Regional Water Boards typically consider a recommendation for updating the list seven to ten months after the data and information is received. The State Water Board usually considers the state-wide list two to four months after all the Regional Water Boards approve updated regional lists. The U.S. EPA usually approves the updated state list two to four months after the State Board approves an updated state list.

The State and Regional Boards have initiated the process to update the list for 2008 by distributing letters to interested parties. You can access information on this process and the State Board letter at http://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2008.shtml and you can access the Central Coast Water Board’s letter by clicking here.

The schedule for completing the 2008 list update will be accessible at the State Water Board link immediately above or on this page in the near future. If you have specific questions about the schedule or the process, you may contact Mary Adams at madams@waterboards.ca.gov or 805-542-4768 or Lisa Horowitz McCann at lmccann@waterboards.ca.gov or 805-549-3132.

What happens when a water body is placed on the 303(d) list?

Once a waterbody is placed on the 303(d) list, Regional Board staff evaluates the nature of the impairment and begins developing a Total Maximum Daily Load (TMDL), if appropriate and necessary.   For each TMDL developed, staff will also develop an implementation or water quality control plan for each water body and associated pollutant/stressor on the list. The TMDL and the implementation plan serve as the means to attain and maintain water quality standards for the impaired water body. During each 303(d) listing cycle the water bodies on the list are prioritized in order to facilitate scheduling and budgeting to develop TMDLs and implementation plans.

This page last updated April 25, 2008.