On June 17, 2025, the U.S. Environmental Protection Agency (EPA) proposed a rule that repeals greenhouse gas (GHG) emissions standards for fossil fuel-fired power plants. Current GHG emission standards for fossil fuel-fired power plants have a goal of controlling 90 percent of carbon emissions by 2032; facilities that will shut down by 2032 are exempt from the existing regulation.
The EPA’s proposal would roll back regulations that were promulgated during both the Biden and Obama administrations. According to the Trump administration, the proposed rule would save the industry approximately $19 billion in regulatory compliance costs over the next two decades.
Simultaneously, the EPA proposed amendments to the National Standards for Hazardous Air Pollutants for Coal- and Oil-fired Electric Utility Steam Generating Units, a rule commonly referred to as the Mercury and Air Toxics Standards (MATS), which were most recently updated in 2024. Under the proposed rule, the standards would revert back to those of 2012.
Both proposals include alternatives to the aggressive rollback of current regulations, allowing regulators to rescind portions of the rules rather than the rules entirely.
These proposed changes bring uncertainty for operators of fossil fuel-fired power plants who may have already begun compliance activities or who planned to change to renewable generation, such as wind or solar. Power plant operators should monitor this rulemaking and consider providing input. Early preparation for potential stakeholder engagement and collaboration with industry associations can help mitigate the impact of potential changes during this transition period.
In relation to the repeal of GHG emissions standards for fossil fuel-fired power plants, the EPA announced that it will hold a virtual public hearing on July 8, 2025 and invited the public to comment on the proposed rule and alternatives by Aug. 7, 2025. The EPA also announced that it will host a virtual public hearing on the proposed amendments to MATS on July 10, 2025 and requested public comment by Aug. 11, 2025.
Attorneys at Haynes Boone will continue to track this rulemaking process and stand ready to assist clients with drafting public comments and navigating these evolving regulatory issues. For assistance or more information about how this change could affect you, please contact one of the attorneys listed below or a member of the Environmental Practice Group.
