in effect
This is a final EPA rule, published January 15, 2026, that updates the emission performance standards that new, modified, or reconstructed stationary combustion turbines and gas turbines must meet. It carries out a mandatory Clean Air Act review of existing standards and replaces the prior ruleset with a new regulatory subpart (40 CFR Part 60, Subpart KKKKa).
The rule divides turbines into subcategories based on size, how often they run, fuel type, and design efficiency, then sets nitrogen oxide (NOx) emission limits tailored to each group — for most subcategories the required control method is combustion controls alone, but for one subcategory those controls must be supplemented by selective catalytic reduction (SCR), an additional treatment system. The sulfur dioxide (SO2) standards remain unchanged from the prior review. A new subcategory is created for turbines used only in temporary applications, and certain turbines are exempted from Title V operating permit requirements. The new standards apply to any turbine that began construction, modification, or reconstruction after December 13, 2024, and the rule took effect on January 15, 2026. Anyone wishing to challenge the rule in court must file a petition with the U.S. Court of Appeals for the D.C. Circuit by March 16, 2026.
Companies and government entities that own or operate stationary combustion turbines in industries such as oil and gas extraction, electric power generation, natural gas distribution, pipeline transportation, chemical manufacturing, and data centers are directly subject to the new standards. Any such facility that builds, significantly modifies, or reconstructs a qualifying turbine after December 13, 2024 must comply with the updated NOx emission limits and associated monitoring, testing, and reporting requirements.