EPA Partially Disapproves Hawaii’s Regional Haze Plan and Ensures the State’s Energy Needs Continue to Be Met
SAN FRANCISCO – Today, U.S. Environmental Protection Agency (EPA) announced the partial approval and partial disapproval of Hawaii’s 2024 Regional Haze State Implementation Plan (SIP) revision, thus not approving the premature closure of several units at critical power plants vital to delivering reliable and affordable energy to families and businesses in Hawaii. EPA has determined that Hawaii’s plan to shut down these fuel oil-fired units, without consent from the units’ owner, does not comply with the Clean Air Act (CAA) and is not necessary to meet Regional Haze Requirements.
Today’s final action reflects EPA’s commitment to fulfilling all statutory obligations and ensuring Hawaiians have affordable power. EPA Administrator Lee Zeldin’s Powering the Great American Comeback initiative prioritizes cooperative federalism, and the agency actively looks for ways to work with states to achieve results. EPA stands ready to assist Hawaii in creating a regional haze plan that fulfills all statutory requirements, while balancing the needs of Hawaiians for future electric grid reliability.
“We remain committed to ensuring American families – here in the Pacific Southwest and across the U.S. -- have continued access to stable and affordable energy,” said EPA Acting Pacific Southwest Regional Administrator Michael Martucci. “EPA’s partial disapproval of the Hawaii SIP revision delivers on this promise in a way that is fully compliant with the Clean Air Act, while responding to the unique energy needs of the Hawaiian Islands.”
Section 110 of the CAA requires states to provide necessary assurances that provisions within SIPs, such as the inclusion of an enforceable closure deadline, are not prohibited under federal or state law. However, Hawaii did not provide the required necessary assurances when submitting its SIP revision. Specifically, the state did not properly consider and explain whether EPA’s approval of the unconsented closures of units at the Kanoelehua-Hill and Kahului Generating Stations would violate the Takings Clause of the U.S. Constitution for the taking of private property without just compensation. The Trump EPA is unequivocally committed to following the law and the agency legally cannot fully approve Hawaii’s SIP revision.
Additionally, EPA has concerns that, if approved, Hawaii’s long-term strategy would harm grid reliability. After Hawaii submitted its SIP revision, Hawaiian Electric Company noted that these unconsented closures could have negative impacts to grid reliability on the islands of Maui and Hawaii, due to actual and potential cancellations and delays in replacement generation projects planned by independent power producers. However, EPA is approving the portions of Hawaii’s submission that meet several requirements of the Regional Haze Program, including calculations of baseline, current, and natural visibility conditions, the uniform rate of progress, and requirements related to reasonably attributable visibility impairment.
Ensuring affordable and reliable energy supply is a top priority of the Trump Administration. Under Administrator Zeldin’s leadership, EPA has worked tirelessly to fulfill President Trump’s executive orders that promote energy dominance. As EPA delivers on the president’s agenda, finding a path forward that provides reliable energy for Hawaii families and businesses remains a priority.
Hawaii will be required to submit a revised SIP for EPA approval, or the agency will need to promulgate a federal implementation plan (FIP) within two years. The FIP or SIP will need to fully address statutory requirements, including revisions to Hawaii’s long-term strategy. The line of communication between Hawaii and the EPA is open, and the agency welcomes the opportunity to work hand in hand with Hawaii to accomplish a revised SIP.
To read the EPA’s full final action partially disapproving Hawaii’s SIP revision, please click here.
Background
The CAA and Regional Haze Rule (RHR) require states, in coordination with the EPA and other federal partners, to develop and implement plans to improve visibility impairment in certain national parks and wilderness areas. Historically, the implementation of this program has imposed significant costs on power plants and other sectors, calling into question the supply of affordable and reliable energy for American families. After years of implementation and feedback from stakeholders, it is clear that the Regional Haze program is broken and needs significant revisions to clarify requirements and alleviate the unnecessary burdens on states and the regulated community, and more closely align with Congressional intent.
On December 31, 2025, Administrator Zeldin signed a final rule revising the current RHR to extend the due date from July 31, 2028, to July 31, 2031, for the third planning period of SIPs. EPA extended this deadline to ensure that states and regional planning organizations have adequate time to adapt third planning period SIPs to any changes the agency makes to the RHR as part of the ongoing effort to restructure existing regulations. This action was first announced through an Advanced Notice of Proposed Rulemaking. The SIP due date extension final rule does not impact the EPA’s decision on Hawaii’s SIP revision for the second planning period, as the second period required SIP revisions by 2021.