U.S. EPA Proposes to Repeal GHG Standards for Fossil Fuel-Fired Power Plants

On June 11, 2025, in response to President Trump’s energy-related Executive Orders, the United States Environmental Protection Agency (U.S. EPA) signed a proposal to repeal all greenhouse gas (GHG) emissions standards for fossil fuel-fired power plants. U.S. EPA also proposes to find that Clean Air Act (CAA) Section 111 requires the Agency to make a finding that GHG emissions from fossil fuel-fired power plants contribute significantly to dangerous air pollution before regulating GHG emissions from the source category. U.S. EPA states in this proposal that GHG emissions from this sector do not contribute significantly to dangerous air pollution within the meaning of the CAA. As an alternative, U.S. EPA is proposing to repeal a narrower set of requirements as discussed below. 

What rules are included in the proposal? 

The proposal seeks to repeal all GHG components of the following rules, based on a legal and technical reassessment of the underpinnings of U.S. EPA’s efforts to regulate GHG emissions from fossil fuel-fired power plants: 

• 40 CFR Part 60, Subpart TTTT: Standards of Performance (NSPS) for GHG Emissions from Electric Generating Units (fossil fuel-fired power plants, or EGUs), promulgated on October 23, 2015 

• 40 CFR Part 60, Subpart TTTTa: NSPS for GHG Emissions from Modified Coal-Fired EGUs and New and Reconstructed Stationary Combustion Turbine EGUs promulgated in the Carbon Pollution Standards (CPS) on May 9, 2024 

• 40 CFR Part 60, Subpart UUUUb: Emission Guidelines for GHG Emissions from Existing EGUs, also promulgated in the CPS on May 9, 2024. 

U.S. EPA is proposing to eliminate these standards, claiming the regulation of GHG emissions from U.S. fossil fuel-fired power plants would not have a significant effect on GHG air pollution and GHG emissions. They believe the current regulations are overburdensome because U.S. fossil fuel-fired power plants are a small and decreasing part of global GHG emissions and the control measures required under the rules are not reasonably available. U.S. EPA’s goal for this regulation is driven by this Administration’s priority of energy dominance and independence.  

Alternatively, U.S. EPA proposes to repeal only the following elements of the above subparts: 

• Emissions guidelines for existing fossil fuel-fired EGUs, 

• Carbon capture and storage (CCS)-based standards for coal-fired steam generating units undertaking a large modification, and 

• CCS-based standards for new base load stationary combustion turbines. 

This alternate proposal is based on a review of the Best System of Emission Reduction (BSER) for the source category. U.S. EPA proposes that 90% CCS is not BSER for existing long-term coal-fired EGUs or for new base load combustion turbines because it is neither adequately demonstrated or cost-reasonable, and that 40% gas co-firing is not BSER for existing medium-term coal-fired EGUs because it is an inefficient use of natural gas and is impermissible generation shifting.  

Does this mean fossil fuel-fired power plants’ GHG emissions will no longer be regulated? 

If the proposal is finalized and survives legal action, fossil fuel-fired power plants will have no or very limited carbon dioxide (CO2) or other GHG emissions standards.  

There are GHG emissions reporting requirements other than the standards in 40 CFR Part 60 that will remain in place for now. Unless and until U.S. EPA repeals its Mandatory GHG Reporting Rule, power plants will still need to comply with 40 CFR Part 98 and any state-level GHG emissions standards, reporting programs, or reduction programs, such as those in place in New York, Oregon, Washington, and California that remain in effect.  

What does this mean for power plants and carbon reduction strategies? 

The proposal, if finalized, will ease short-term federal regulatory burdens such as the following: 

• GHG emissions standards for fossil fuel-fired combustion turbines 

• CCS requirements for coal-fired electricity generating units (EGU)  

• Periodic GHG performance reports under NSPS 

Although the current U.S. EPA seems determined to roll back GHG emissions-related requirements, owners of fossil fuel-fired power plants should not necessarily interpret this as a signal to pause or slow down GHG planning, especially given the unknowns around whether a final rule would be stayed or survive litigation, what GHG emissions standards a future administration may establish, the economic implications of continuing to operate certain fossil fuel-fired resources, the evolving state of energy technology, and the fact that many energy companies have already committed to carbon reduction plans. Instead, this is a strategic moment to reassess, adapt, and future-proof energy generation and carbon reduction approaches. 

What is next? 

Because energy is a priority for this administration, we expect that U.S. EPA will finalize their determinations fairly quickly after reviewing comments received on the proposal. However, it is certain that U.S. EPA’s final action will be litigated, and it is possible that a court would stay any final action that eliminates the GHG emissions standards, pending the outcome of such litigation. Companies submitting permit applications for energy projects will have to watch the regulatory and legal developments closely.  

U.S. EPA is currently accepting comments on the proposed action until August 7, 2025. Comments can be submitted at https://www.regulations.gov/ or via email (a-and-r-docket@epa.gov with the docket number EPA-HQ-OAR-2025-0124 in the subject line). There will also be a public hearing held on July 8, 2025 starting at 11 am ET and the public hearing registration link will be posted on U.S. EPA’s website. 

Need help understanding how this affects you? 

If you are wondering how this proposal will affect your facility or ongoing projects directly, please reach out to your ALL4 project manager or contact me at lshaffer@all4inc.com.