Central Coast Region - Clean Water Act Section 303(d) List of Water Quality Limited Segments (the 303(d) List)

NEW – State Water Board’s Public Notice of opportunity to comment on the Staff Report for the 2020-2022 Integrated Report is from June 4, 2021 – July 16, 2021.
NEW – Central Coast Water Board Public Notice for public outreach workshop to discuss the 2020-2022 Integrated Report, June 29, 2021 from 1 p.m. to 3 p.m. via the Zoom platform. Presentation available upon request. Please email Shanta Keeling.

December 14, 2018 - Notice of Public Data Solicitation Period for the 2020 CA Integrated Report (closed June 14, 2019)

What is the 303(d) List?

Section 303(d) of the federal Clean Water Act requires states to develop, update, and submit to the United States Environmental Protection Agency (USEPA) for approval, a list of waterbodies that are polluted (the 303(d) List). Under Title 40 Code of Federal Regulations (40 CFR) Section 130.7(d)(1), states are required to submit the 303(d) List biennially to the USEPA. 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 pollution control plan (typically a Total Daily Maximum Load or TMDL) to address the impairment.

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

The State Water Resources Control Board (State Water Board) initiates the process to update the 303(d) List by soliciting data and information from the public. Staff at the Regional and State Water Boards considers these data, along with data available to the Water Boards, in preparing the updated 303(d) List. In California, the State and Regional Water Boards to follow the "Water Quality Control Policy for Developing California's Clean Water Act Section 303(d) List" when developing updates to the List. This policy describes the process by which the State and Regional Water Boards comply with the requirements of the Clean Water Act in developing the List. The policy requires that the Regional Water Boards adopt an updated 303(d) List for waters in each region and include public participation. Updates to the List are then submitted for subsequent approval by the State Water Board as part of the updated list for the state. Finally, the List is submitted to U.S. EPA for approval.

In addition, pursuant to CWA Section 305(b), states must prepare a report on the water quality and condition of waters (305(b) Report) to identify waters that are attaining water quality standards as well as those that are not. The 305(b) Report does not require approval. However, USEPA will compile the data from the state 305(b) Reports and transmit the summaries in their "National Water Quality Inventory Report" to Congress.

The State and Regional Water Quality Control Boards prepare a single Integrated Report that meets the reporting requirements of CWA sections 303(d) and 305(b). EPA approved the most current 303(d) List (the 2014 and 2016 303(d) List), and Integrated Report on April 6, 2018.

The 2014 and 2016 303(d) List contains updates for six of the nine Regional Water Quality Control Boards, including the Central Coast Region. The next opportunity for the Central Coast Region to approve updates to the 303(d) List is the 2020-2022 303(d) List. The process for updating the 2020-2022 303(d) List began in December 2018 with the public data solicitation notice. To receive notifications by email of the public data solicitation and other important updates, please subscribe to the Central Coast Water Board's email subscription list (see link at the bottom of this page).

Please also see the State Water Board’s website regarding the Integrated Report.

Current 303(d) List

303(d) List (the 2014 and 2016 303(d) List) and Integrated Report, USEPA approved April 6, 2018.

Past 303(d) Lists

EPA Approved 2012 303(d) List: On July 30, 2015 the USEPA approved California’s 2012 Clean Water Act section 303(d) List, replacing the 2010 Clean Water Act section 303(d) List. The 2012 303(d) List contains updates for three Regional Water Boards (North Coast, Lahontan, and Colorado River Basin) as well as the decisions from the previously approved 2010 303(d) List's for the other six Regional Water Boards (including the Central Coast).

EPA Approved 2010 303(d) List: On July 10, 2009, the Central Coast Water Board adopted changes to the 303(d) List and these changes were incorporated into the statewide 2010 Integrated Report. The 2010 303(d) List was approved by the State Water Board on August 4, 2010 and subsequently by USEPA on October 11, 2011.

You may access information on California's Final 2008-2010 Clean Water Act Section 303(d) List and related documents at http://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2010.html.


For questions on the California 303(d) List and/or Integrated Report contact Mary Hamilton of the Central Coast Water Board via email at: Mary.Hamilton@waterboards.ca.gov.

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