Ocean Standards - CWA §316(b) Regulation

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Cooling Water Intake Structures
Once-Through Cooling

On May 4, 2010, the State Water Resources Control Board (State Water Board) adopted a Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling (Once-Through Cooling or OTC Policy). The OTC Policy became effective on October 1, 2010.

The OTC Policy establishes technology-based standards to implement federal Clean Water Act section 316(b) and reduce the harmful effects associated with cooling water intake structures for power generating facilities on marine and estuarine life. The OTC Policy applied to 19 existing power plants (including two nuclear plants) with the combined ability to withdraw almost 16 billion gallons of water per day from the state’s coastal and estuarine waters using a single-pass system, also known as once-through cooling (OTC). Closed-cycle wet cooling has been selected as Best Technology Available (BTA). Permittees must either reduce intake flow and velocity (Track 1) or reduce impacts to aquatic life comparably by other means (Track 2).

Ten plants have ceased their once-through cooling operations. Eight of the remaining plants have informed the State Water Board that they are planning to comply by retiring their existing OTC plants’ equipment. In some cases, plants will repower their locations with modern non-water-cooled systems. Dynegy’s Moss Landing Power Plant is the only OTC plant that is complying with the OTC Policy through Track 2.

OTC Policy – Current Version

 » Go to the Official Policy Documentation


News!

NEW! NOTICE OF OPPORTUNITY FOR PUBLIC COMMENT
2018-2019 DRAFT DETERMINATIONS TO
APPROVE MITIGATION MEASURES FOR THE
WATER QUALITY CONTROL POLICY ON THE USE OF
COASTAL AND ESTUARINE WATERS FOR POWER PLANT COOLING
ALAMITOS GENERATING STATION
DIABLO CANYON NUCLEAR POWER PLANT
HARBOR GENERATING STATION
HAYNES GENERATING STATION
HUNTINGTON BEACH GENERATING STATION
ORMOND BEACH GENERATING STATION
REDONDO BEACH GENERATING STATION
SCATTERGOOD GENERATING STATION

The State Water Resources Control Board (State Water Board) will receive public comments on the 2018-2019 draft determinations to approve mitigation measures for the Water Quality Control Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling (Once-Through Cooling or OTC Policy) for the eight power plants listed above. A separate draft determination is available for each power plant.

The draft determinations are available on the Interim Mitigation Measures webpage. Please see the notice on the Documents for Public Comment webpage for more information on how to submit written comments. All comments are due to the Clerk of the Board by noon on July 20, 2020.

Public Meetings

PUBLIC HEARING AND CONSIDERATION OF ADOPTION MEETING

The State Water Board will hold a public hearing to receive oral public input and comments on the Draft OTC Policy Amendment and Draft Staff Report. Following the public hearing, the State Water Board will consider adoption of the OTC Policy Amendment and Staff Report. The public hearing and consideration of adoption meeting will be held as follows:

Public Hearing and Consideration of Adoption Meeting
Tuesday, September 1, 2020 at 9:30 a.m.
Joe Serna Jr. - CalEPA Headquarters Bldg.
Coastal Hearing Room
1001 I Street, Second Floor
Sacramento, CA 95814

Please see the third revised notice posted on the Board calendar for more information on attending the Board meeting for the public hearing and consideration of adoption of the proposed amendment to the OTC Policy.

Other Relevant Documents

Committees

The two committees listed below, were convened by the Executive Director of the State Water Board, as required by the OTC Policy. The committees are subject to the Bagley-Keene Open Meeting Act.

Statewide Advisory Committee on Cooling Water Intake Structures (SACCWIS)
SACCWIS was established to advise the State Water Board on the implementation of the OTC Policy to ensure that implementation plans and schedules established by the OTC Policy are realistic and will not cause disruption to the State’s electrical power supply.  SACCWIS includes representatives from the California Energy Commission, California Public Utilities Commission, California Coastal Commission, California State Lands Commission, California Air Resources Board, California Independent System Operator, and the State Water Board. 

Review Committee for Nuclear Fueled Power Plants
This Review Committee was established to oversee special studies, which investigated ability, alternatives, and cost, for the two nuclear-fueled power plants to meet OTC Policy requirements.  The special studies were conducted by an independent third party with engineering experience with nuclear power plants, selected by the Executive Director of the State Water Board, and paid for by the two nuclear-fueled power plants subject to the OTC Policy.  The Review Committee included representatives from the SACCWIS agencies, the nuclear power companies, the environmental community, and staffs of the State Water Board and appropriate Regional Water Boards.

Permitting of Affected Power Plants

The OTC Policy is implemented through National Pollutant Discharge Elimination System (NPDES) permits. The applicable Regional Water Boards are responsible for implementing the OTC Policy requirements in NPDES permits for existing coastal and estuarine power plants. The Water Boards determine requirements to implement best technology available for cooling water intake structures to be included in the permits. State Water Board staff provides technical support to the Regional Water Boards to ensure a high level of statewide consistency in implementing the OTC Policy.

»»   For more information on each power plant required to comply with the OTC Policy, visit the Power Plants That Are Affected page.

Questions or Comments

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