Board adopts amendment extending once-through-cooling operations at four coastal plants

SACRAMENTO – Following its evaluation of recommendations by the state’s energy and utility operators for managing climate change impacts to grid reliability, as well as substantial public comment, the State Water Resources Control Board on Tuesday adopted an amendment to its Once-Through-Cooling Policy that extends final compliance dates for phasing out the use of ocean water for cooling operations at the Alamitos, Huntington Beach, Ormond Beach and Scattergood coastal power generating stations.

The policy is designed to protect marine life when large amounts of water from the ocean or estuaries are used for cooling at power plants. The extensions the board granted yesterday follow recommendations made by the Statewide Advisory Committee on Cooling Water Intake Structures (SACCWIS) in 2022.

The committee recommended additional resource capacity as the state transitions to renewable energy sources and moves to address a projected shortfall as much as 10,000 megawatts in summer 2025, according to an electricity demand forecast and reliability analysis conducted by the California Public Utilities Commission, the California Independent System Operator and the California Energy Commission, all members of the SACCWIS.

“The State Water Board appreciates the passionate testimony it heard yesterday about the impacts of once-through-cooling operations, including harm to marine life and the plants’ air quality impacts on nearby communities,” said Joaquin Esquivel, chair of the board. “We established the SACCWIS to help us evaluate grid reliability concerns, which the policy requires us to consider alongside water quality and environmental issues. We accept the SACCWIS’ recommendations that the extensions are necessary to meet projected energy needs, and we are including conditions with the extensions that are designed to limit further operations.”

The board’s amendment will allow once-through-cooling operations to continue for three years at the Alamitos, Huntington Beach and Ormond Beach plants beyond their current phase-out dates, from Dec. 31, 2023 to Dec. 31, 2026, specifically to support grid reliability and the Electricity Supply Strategic Reliability Reserve Program (Strategic Reserve). The board’s extension of the final compliance date for the three plants is contingent on their participation in the Strategic Reserve, which was established through Assembly Bill 205 in 2022 to harden critical grid assets and bring new clean resources online. By participating in the reserve, the power plants would only be called upon to support grid operations during extreme events, which would limit the use of once through cooling and air emissions.

The amendment also extends the compliance date for the Scattergood Generating Station in Playa Del Rey for five years, from Dec. 31, 2024 to Dec. 31, 2029, to support local energy stability as the Los Angeles Department of Water and Power (LADWP) moves toward a zero-carbon grid. As a condition of the extension, the board is requiring LADWP to establish clear, semi-annual milestones necessary to attain final compliance with the policy.

The amendment also revises the final compliance date for the Diablo Canyon Nuclear Power Plant to Oct. 31, 2030 to comport with the extension already provided through Senate Bill 846 last year.

Since the policy became effective in 2010, 11 of 19 plants in California have ceased once-through-cooling operations. Seven of the remaining plants have informed the board that they plan to comply by retiring their existing once-through-cooling equipment.

Please see the OTC Policy's Official Policy Documentation for additional information.

The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health, and all beneficial uses, and to ensure proper resource allocation and efficient use for present and future generations.