Guthrie Leads Members of Congress in Submitting Amicus Brief in Support of Kentucky Lawsuit Against the EPA

WASHINGTON, D.C. – On Friday, Congressman Brett Guthrie (KY-02), Chairman of the House Committee on Energy and Commerce, led in filing an amicus brief on behalf of 12 Members of Congress in support of the Commonwealth of Kentucky and other states’ request that the Supreme Court of the United States hear an appeal in a significant Clean Air Act case, Commonwealth of Kentucky, et al. v. U.S. Environmental Protection Agency, et al . Petitioning states argue that the Biden-Harris Administration’s Environmental Protection Agency (EPA) revised the National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5) in 2024 without conducting the “thorough review” required by the Clean Air Act . These revised standards, imposed by the Biden-Harris EPA, will restrict the construction of new American manufacturing plants and energy projects, as well as improvements at existing sites, in many parts of the country. “For four years, the Biden-Harris Administration imposed countless burdensome environmental regulations that handcuffed American industries and made everyday life more expensive,” said Congressman Guthrie. “I am proud to lead my colleagues in filing this amicus brief in support of the Commonwealth of Kentucky’s lawsuit to vacate the Biden-Harris Administration’s PM2.5 NAAQS finalized rule, arguing that the revised NAAQS was adopted on an incomplete scientific record and without the required thorough review. If implemented, this rule would devastate American manufacturing and energy and stifle American innovation. I am hopeful the Supreme Court will grant the petitioning states a Writ of Certiorari and that the petitioning states will ultimately prevail in court.” The full text of the amicus brief can be viewed HERE . The amicus brief is supported by Reps. Brett Guthrie (KY-02), Rick Allen (GA-12), Troy Balderson (OH-12), Andy Barr (KY-06), Julie Fedorchak (ND-AL), Craig Goldman (TX-12), Morgan Griffith (VA-09), Diana Harshbarger (TN-01), Erin Houchin (IN-09), Nick Langworthy (NY-22),  August Pfluger (TX-11), Hal Rogers (KY-05), and Randy Weber (TX-14). Background: In 2020, the Trump Administration EPA finalized a rule for the PM2.5 NAAQS under the Clean Air Act , which was conducted as part of the standard 5-year review required under the Act and kept the standard at 12 micrograms/cubic meter. In 2024, the Biden-Harris EPA revised the Trump Administration’s EPA ruling, lowering the PM2.5 standard to 9 micrograms/cubic meter. Throughout the 119th Congress, the House Committee on Energy and Commerce has held multiple hearings and taken action on legislation to ensure the Clean Air Act continues protecting human health and the environment and without stopping economic development and growth. During this work, the Committee has found that the Biden Administration’s new NAAQS standards are very close to background levels and will make it very difficult to build and permit new facilities. While the Clean Air Act allows the EPA to reconsider a NAAQS outside of the normal 5-year review cycle, the Biden-Harris Administration EPA did not follow the required process of conducting a “thorough review” of the science before establishing a new NAAQS under the Clean Air Act . Kentucky, and other petitioning states, sued the EPA, along with several industry groups, in 2024. The Trump Administration EPA tried to have the Biden-Harris NAAQS vacated, but in a June 2026 decision, the D.C. Circuit Court of Appeals denied EPA’s motion to vacate the 2024 NAAQS and upheld the Biden-Harris Administration’s burdensome mandates. Petitioning states are requesting that the Supreme Court rule on the following questions: Whether the Clean Air Act gives EPA the authority to revise NAAQS without conducting a thorough review merely because the revision occurs before the normal, five-year review. Whether the Clean Air Act bars EPA from considering the costs and feasibility of revising NAAQS when deciding whether to exercise its discretion to undertake a revision before the normal, five-year review.