Ocean Standards - CWA §316(b) Regulation


On May 4, 2010, the State Water Resources Control Board (State Water Board) adopted the statewide Water Quality Control Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling (Once-Through Cooling or OTC Policy) under Resolution Number 2010-0020. The OTC Policy became effective on October 1, 2010, and was amended in 2012, 2014, 2016, and 2017. The OTC Policy establishes uniform, technology-based standards to implement federal Clean Water Act (CWA) Section 316(b) and reduce the harmful effects associated with cooling water intake structures on marine and estuarine life.

Once-Through Cooling Policy – CURRENT VERSION Effective December 23, 2021

Policy Amendments

2021 – Amendment to Revise the Compliance Schedule for Redondo Beach Generating Station

  • OAL Approval 2021
    • This amendment’s administrative record was reviewed and approved by the Office of Administrative Law on December 23, 2021

2020 – Amendment to Revise Compliance Schedules for Alamitos, Huntington Beach, Ormond Beach, and Redondo Beach Generating Stations and Diablo Canyon Nuclear Power Plant

2017 - Encina Power Station Compliance Date Extension Amendment

2016 - Moss Landing Power Station Compliance Date Extension Amendment

2014 - Reassignment of NPDES Permitting Responsibility to Regional Boards Amendment

2012 - LADWP Power Stations Compliance Dates Extension and Additional Entrainment Measures Amendment

2010 Policy Adoption

Quarterly Reports from the California Public Utilities Commission (CPUC)

On September 1, 2020, the State Water Board adopted Resolution No. 2020-0029, in part to address short-term, system-wide grid reliability concerns while 3,300 Megawatts (MW) of procurement associated with CPUC Decision 19-11-016 comes online. Finding 19 of this resolution identified that the state’s energy agencies will provide quarterly reports to the State Water Board providing the status of all associated projects anticipated to be online by August 1, 2021, which comprise half of the 3,300 MW of capacity ordered by Decision 19-11-016.

To obtain copies of these quarterly reports, please submit a request to Katherine Walsh or Jonathan Dolan using the contact information listed below.

Questions or Comments about Power Plant Once-Through Cooling Regulation?

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