EPA repeals most 2024 Carbon Pollution Standards for fossil fuel-fired power plants

On September 17, 2026, the Environmental Protection Agency (EPA) finalized a rule repealing a majority of the greenhouse gas (GHG) emission requirements established by the 2024 Carbon Pollution Standards (CPS) for fossil fuel-fired power plants. The agency also issued a supplemental proposed rule to rescind all other GHG emission standards for fossil fuel-fired power plants.

Who’s impacted?

EPA’s final rule applies to the fossil fuel-fired electric generating unit (EGU) category, including:

• Fossil fuel-fired electric utility steam generating units, and
• Stationary combustion turbine EGUs.

The final rule specifically impacts:

• Existing fossil fuel-fired steam generating EGUs (subject to 40 CFR Part 60 Subpart UUUUb),
• Coal-fired steam generating units conducting a large modification (subject to Part 60 Subpart TTTTa), and
• New base load stationary combustion turbines (subject to Part 60 Subpart TTTTa).

Final rule: Repeal 2024 CPS regulations

The agency finalized the alternative option from its June 2025 proposed rule, repealing parts of the 2024 CPS and revising the associated best system of emission reduction (BSER) determinations.

EPA’s final rule removes most of the 2024 CPS regulations, including:

• The emission guidelines for existing coal-, oil-, and natural gas-fired steam generating units (Part 60 Subpart UUUUb in its entirety);
• The carbon capture and sequestration/storage (CCS)-based standards for coal-fired EGUs conducting a large modification; and
• The CCS-based standards for new base load stationary combustion turbines (the Phase 2 standards).

The final rule doesn’t repeal or revise the 2024 CPS efficiency-based standards for new stationary combustion turbines (the Phase 1 standards). However, EPA addresses them in the supplemental proposed rule.

Proposed rule: Repeal remaining GHG emission requirements

EPA also issued a supplemental proposed rule to rescind all remaining GHG emissions requirements for fossil fuel-fired power plants, including the Phase 1 standards for new stationary combustion turbines. It would require the same regulatory changes as the June 2025 proposed rule but for different reasons.

The supplemental proposed rule would repeal all GHG emission standards in 60 Subparts TTTT and TTTTa for the fossil fuel-fired EGU source category, including the 2015 New Source Performance Standards (NSPS) and the 2024 CPS.

Specifically, EPA would repeal the:

• Partial CCS-based standards for new and efficiency-based standards for reconstructed or modified steam generating units and integrated gasification combined cycle facilities, and
• Efficiency-based standards for new or reconstructed stationary combustion turbines.

If the rule is finalized as proposed, new fossil fuel-fired EGUs would no longer be required to comply with the GHG emission standards established under the 2015 NSPS or the 2024 CPS regulations.

Key to remember: EPA’s final rule repeals a majority of the greenhouse gas (GHG) emission standards established by the 2024 Carbon Pollution Standards for fossil fuel-fired power plants. The agency also proposes to remove the remaining GHG emission requirements for fossil fuel-fired power plants.