Enviro group challenges California nuclear power plant water permit

By Noah Baustin | 03/27/2026 04:05 PM EDT

The California Coastkeeper Alliance wants regulators to require new technology at the plant to protect marine life.

The Diablo Canyon nuclear power plant.

The Diablo Canyon power plant is in San Luis Obispo County. Mark Ralston/AFP via Getty Images

Ocean advocates on Thursday asked California regulators to toss out a permit that a Central Coast board recently issued to the state’s only in-service nuclear power plant, threatening the facility’s efforts to extend its operations to 2030 and beyond.

What happened: The California Coastkeeper Alliance, a nonprofit advocate for the state’s oceans, rivers and drinking water, filed a petition asking the California State Water Resources Control Board to toss out a permit issued for Diablo Canyon in February.

Why it matters: The February permit was the final state-level certification that Pacific Gas & Electric, which operates Diablo Canyon, needed before the federal Nuclear Regulatory Commission could decide whether to extend the plant’s permissions through 2045, as PG&E requested. If the environmental group’s challenge is successful, it could disrupt the utility’s progress.

Advertisement

Context: The Coastkeeper Alliance is challenging Diablo Canyon’s new National Pollutant Discharge Elimination System permit. The group alleges in its petition that the regional water regulator “abused its discretion” and failed to properly enforce a federal Clean Water Act rule that power plant cooling systems must use the best technology available to protect aquatic life.

GET FULL ACCESS