[Regulatory Update] State and Local Coalition Files Petition for Review of EPA's Partial Repeal of Power Plant GHG Standards

On October 1, 2026, the New York Attorney General, leading a coalition with 25 other states, counties and cities, filed a petition for review in the U.S. Court of Appeals for the D.C. Circuit. The petition challenges the Environmental Protection Agency's (EPA) Partial Repeal of the Carbon Pollution Standards for Fossil Fuel-Fired Electric Generating Units, which the EPA carried out in September 2026, and asks the court to strike down the repeal. On the same day, the coalition also filed a notice of intent to sue in a separate proceeding, citing EPA's failure to regulate greenhouse gas emissions from many existing natural gas-fired power plants. According to the Federal Register (published September 17, 2026; 91 FR 58954; document number 2026-19071), the final rule takes effect on November 16, 2026. The rule repeals, from the 2024 standards, the entire set of emission guidelines for existing fossil fuel-fired steam generating units, the standards based on carbon capture and storage (CCS) for coal-fired units undertaking large modifications, and the second-phase CCS-based standards for new base-load combustion turbines. The efficiency-based standards for new combustion turbines (Phase 1) are not covered by the repeal. On the same day, EPA also published a supplemental proposal that would repeal all greenhouse gas emission standards for fossil fuel-fired power plants. That proposal is at the comment stage, and the petition targets the final rule.