HONOLULU - Attorney General Anne Lopez has filed a petition on behalf of the Hawaiʻi Department of Health (DOH) challenging the U.S. Environmental Protection Agency's (EPA) partial disapproval of Hawaiʻi's Regional Haze State Implementation Plan (RHSIP).

Under the Clean Air Act, states must develop RHSIPs to improve visibility and protect air quality around national parks. Haze-forming pollutants have been linked to serious health problems and environmental damage.

Hawaiian Electric Company, Inc.'s Kanoelehua Hill, Kahului, Māʻalaea and Puna generating stations were identified as the top contributors of human-caused, haze-causing pollution affecting visibility in Hawaiʻi Volcanoes National Park and Haleakalā National Park.

Following extensive consultation, Hawaiian Electric voluntarily agreed to retire older and inefficient oil-burning units on Maui and Hawaiʻi Island currently operating with minimal pollution controls. While cost analyses found air pollution controls to be economically feasible, Hawaiian Electric proposed to retire the units instead of installing air pollution controls.

But when the EPA changed administrations in 2025, Hawaiian Electric abruptly reversed course on its commitment and notified the EPA that it no longer agreed to the retirements. On May 29, EPA issued a final rule partially disapproving Hawaiʻi's RHSIP.

"Hawaiʻi will fight to protect our people and our environment," said Deputy Director for Environmental Health Kathleen Ho. "Our regional haze plan was tailored to Hawaiʻi's unique circumstances and developed through years of collaboration to improve air quality in and around our state's national parks. EPA's partial disapproval undermines the goals of the Clean Air Act and weakens important environmental protections designed to reduce harmful air pollution."

"Congress enacted the Regional Haze Program to decrease haze and improve visibility in all national parks," said Attorney General Anne Lopez. "Hawaiʻi's national parks are culturally and environmentally significant places. Haleakalā National Park and Hawaiʻi Volcanoes National Park are home to unique landscapes and many species of plants and wildlife found nowhere else on Earth. Residents and visitors deserve to experience these parks with the natural air quality and visibility the RHSIP was intended to protect. We challenge EPA's action because it is inconsistent with the goals of the RHSIP and is based on an unlawful interpretation of the Clean Air Act."

In the disapproval, Hawaiian Electric's voluntary retirements were characterized by EPA as "unconsented" closures. Characterizing the closures as unconsented disregards years of negotiations that resulted in the voluntary commitments incorporated into the RHSIP. Further, in disapproving Hawaiʻi's implementation plan, EPA creates uncertainty in the retirements and other pollution remediation measures.

https://health.hawaii.gov/cab/regional-haze/

The petition was filed in the U.S. Court of Appeals for the Ninth Circuit. The state is asking the court to declare EPA's partial disapproval unlawful and vacate the agency's action.

The state of Hawaiʻi is represented in this litigation by Lyle T. Leonard, deputy attorney general with the Department of the Attorney General's Health Division.

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