Environmental Protection Agency Administrator Lee Zeldin on Sept. 14 signed a final rule partially repealing the 2024 Carbon Pollution Standards for Fossil Fuel-Fired Electric Generating Units.
EPA issued the final action alongside a supplemental proposal that would rescind the greenhouse gas findings for fossil fuel-fired power plants and repeal the remaining power plant greenhouse gas regulations under Clean Air Act section 111.
Final Rule Partial Repeal of the Carbon Pollution Standard
EPA has finalized its alternative approach to repeal of the 2024 CPS rule. The final rule rescinds the CAA section 111(d) emission guidelines for existing coal-fired EGUs and repeals the carbon capture and storage (CCS) based standards in the 2024 rule, including those applicable to coal units undertaking large modifications and new baseload natural gas combustion turbines.
EPA states that the final rule repeals most provisions of the 2024 CPS based on its reevaluation of the best system of emission reduction for the relevant source subcategories.
However, EPA is not revising or repealing the 2024 efficiency-based Phase 1 standards for new combustion turbines in this final action.
While the agency acknowledges concerns raised by commenters including APPA regarding the achievability of these standards, it notes that a separate supplemental proposal is being issued concurrently that would repeal all greenhouse gas standards for fossil fuel-fired electric generating units under CAA section 111. If finalized, that broader action would address those concerns and effectively replace the remaining requirements.
Supplemental Proposal to Repeal the Carbon Pollution Standard
EPA has issued a supplemental proposal that would eliminate the remaining greenhouse gas (GHG) standards for fossil fuel-fired power plants under section 111. The proposal is separate from EPA's concurrent final rule repealing major portions of the 2024 CPS and instead focuses on whether EPA has statutory authority to regulate power plant GHG emissions at all. EPA proposes that CAA section 111 does not authorize regulation of EGUs based on global climate change concerns and seeks comment on rescinding the legal findings that supported both the 2015 new source performance standard and the 2024 CPS.
The supplemental proposal builds on EPA’s June 2025 proposal to repeal the power plant greenhouse gas standards. In that proposal, EPA asserted that it lacks authority under section 111 to regulate GHG emissions from fossil fuel-fired EGUs because those sources do not “contribute significantly” to air pollution that endangers public health or welfare. EPA now offers additional legal rationales in light of its intervening final action rescinding the 2009 motor vehicle GHG Endangerment Finding.
The proposal seeks comment on whether global climate change concerns can satisfy section 111’s threshold requirement that emissions from a source category contribute significantly to air pollution reasonably anticipated to endanger public health or welfare.
EPA’s proposal rests on three principal arguments.
First, EPA contends that CAA section 111 is best read to authorize regulation only of air pollution that affects public health or welfare through local or regional exposure, not global climate change. EPA argues that its 2015 interpretation exceeded congressional intent by regulating emissions based on worldwide climate impacts rather than direct local or regional effects, and that the agency further erred by listing a new source category and relying on the 2009 Endangerment Finding.
Second, EPA argues that power plant GHG regulation presents a "major question" of significant economic and political importance, requiring clear congressional authorization under recent U.S. Supreme Court precedent, particularly West Virginia v. EPA and Loper Bright. EPA contends Congress has never clearly authorized the agency to establish a national climate policy through section 111 regulation of power plants.
Third, EPA advances a "futility" rationale, asserting that even complete elimination of all U.S. power-sector carbon dioxide (CO₂) emissions would have only a minimal effect on global climate indicators. EPA's modeling estimates that eliminating all U.S. power plant CO₂ emissions would reduce projected global temperature increases by approximately 0.035°C by 2100 and reduce projected global sea level rise by approximately 1.37 centimeters by 2100. EPA argues these impacts are de minimis and therefore insufficient to support regulation under section 111.
EPA states that, if finalized, the proposal would repeal the remaining GHG standards in 40 CFR Part 60, Subparts TTTT and TTTTa and rescind the findings supporting regulation of GHG emissions from fossil fuel-fired EGUs. EPA emphasizes that repeal would not affect existing requirements for criteria pollutants, Regional Haze, National Ambient Air Quality Standards implementation, or other CAA programs applicable to power plants.
Upon publication of the supplemental proposal in the Federal Register there will be a 45-day public comment period and EPA anticipates holding one virtual public hearing.
APPA said it will provide further analysis of the final rule and supplemental proposal soon.
