Regulatory Tracker Regulating Greenhouse Gases for New and Existing Fossil Fuel-Fired Power Plants In June 2025 EPA proposed a rule rolling back the 2024 EPA standards for GHG emissions from existing coal-fired power plants and new gas-fired power plants. August 26, 2026
Regulatory Tracker Regional Haze Rule Through two state plan approvals, EPA finalized a new policy that eases all states’ Regional Haze planning obligations. Environmental groups are challenging the approvals. August 21, 2026
Regulatory Tracker PFAS and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) The Trump administration decided to keep in place a Biden administration rule designating two common PFAS chemical sub-types as hazardous substances under CERCLA. August 18, 2026
Regulatory Tracker Once In Always In Guidance for Major Sources under the Clean Air Act Congress used the Congressional Review Act to repeal the 2024 rule and reinstated the 2020 rule, which allows a major source to reclassify as an area source if the source reduces HAP emissions. August 18, 2026
Regulatory Tracker Mercury and Air Toxics Standards EPA rescinded the 2024 mercury and air toxics standards (MATS) for power plants and reinstated the 2012 MATS. August 13, 2026
Regulatory Tracker New Source Review EPA establishes the baseline requirements for new source review (NSR) permits, which are then issued by state and local air pollution agencies. In 2025 and 2026, EPA made changes to the NSR program easing permitting requirements. August 6, 2026
Regulatory Tracker National Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM) The CAA requires EPA to review and set primary and secondary standards for PM NAAQS every 5 years. The Biden EPA strengthened the standard in March 2024. July 17, 2026
Environmental Justice Tracker EPA Released Guidance Exempting “Islanded” Power Generation from Acid Rain Program July 16, 2026
