Pursuant to provisions specified by the Clean Air Act (CAA), the Governors of Illinois, Iowa, Minnesota, Missouri, Nebraska, Ohio, South Dakota, and Wisconsin submitted petitions requesting that EPA remove the 1-pound per square inch (psi) Reid vapor pressure (RVP) waiver for summer gasoline-ethanol blended fuels containing 10 percent ethanol (E10). EPA is acting on those petitions by removing the 1-psi waiver in those States effective April 28, 2025. This action also finalizes regulatory amendments to implement the removal of the 1-psi waiver for E10 in those States, as well as a regulatory process by which a State may request to reinstate the 1-psi waiver. Finally, consistent with a decision issued by the United States Court of Appeals for the D.C. Circuit on July 2, 2021, this action removes regulations that extended the 1-psi waiver to gasoline-ethanol blends between 10 and 15 percent ethanol (E15).