U.S. EPA Announces “Biggest Deregulatory Action in U.S. History”

On March 12, 2025, U.S. Environmental Protection Agency (“U.S. EPA”) Administrator Lee Zeldin announced that the agency will undertake 31 deregulatory actions to advance President Donald Trump’s Day One executive orders and U.S. EPA’s “Powering the Great American Comeback” Initiative.

As described in the announcement, U.S. EPA’s initiative aims to “roll back” regulatory costs and burdens to promote domestic energy production and manufacturing. To this end, the agency is reconsidering certain existing environmental regulations and programs impacting water, air, and climate rules related to power plants, the oil and gas industry, electric vehicles, and manufacturing sectors. The announcement is divided into three categories: (1) unleashing American energy; (2) lowering the cost of living for American facilities; and (3) advancing cooperative federalism.    

The majority of U.S. EPA’s announced actions involve the “reconsideration” of existing regulations, including, for example, the Mandatory Reporting of Greenhouse Gases rule, Mercury and Air Toxics Standards, and the Model Year 2027 and Later Light-Duty and Medium-Duty Vehicles regulation as well as the Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles, which provided the foundation for the Biden Administration’s electric vehicle mandate. Notably, U.S. EPA also announced its intention to reconsider the 2009 Greenhouse Gas Endangerment Finding issued under Section 202(a) of the Clean Air Act. The Greenhouse Gas Endangerment Finding is the agency’s landmark determination that six key greenhouse gases endanger public health and welfare and provides the basis for many of the climate regulations that the agency plans to revoke or amend.

To revoke or amend these rules, the agency will need to follow the formal rulemaking process set forth under the Administrative Procedure Act, including the opportunity for public notice and comment. This process may take many months, if not years, to complete. Once a final rule is issued, it is likely to be subject to litigation and challenged in court by the regulated community. U.S. EPA also no longer has the benefit of Chevron deference when it comes to advancing new interpretations of an ambiguous environmental statute. The U.S. Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo overturned this deference by holding that courts are required to exercise their independent judgment in deciding whether an agency has acted within its statutory authority. As a result, U.S. EPA’s ability to revoke or amend rules could be restricted. 

In U.S. EPA’s announcement, there are also several actions that will not involve the rulemaking process and will therefore be effective relatively quickly. For example, U.S. EPA is revising its National Enforcement and Compliance Initiatives to ensure enforcement does not discriminate based on race and socioeconomic status or shut down energy production and that it focuses on the most pressing health and safety issues. In addition, U.S. EPA terminated the Biden Administration’s Environmental Justice and Diversity, Equity, and Inclusion (“EJ/DEI”) initiatives and closed all EJ/DEI offices.

In all of the announced actions, U.S. EPA has indicated that while its core mission is to protect the environment, the agency is committed to fulfilling the President’s promise to “unleash American energy, lower costs for Americans, revitalize the American auto industry, restore the rule of law, and give power back to states to make their own decisions.” The below list identifies the specific actions that the agency plans to take:

Unleashing American Energy: 

• Reconsideration of regulations on power plants (Clean Power Plan 2.0)
• Reconsideration of regulations throttling the oil and gas industry (OOOO b/c)
• Reconsideration of Mercury and Air Toxics Standards that improperly targeted coal-fired power plants (MATS)
• Reconsideration of mandatory Greenhouse Gas Reporting Program that imposed significant costs on the American energy supply (GHG Reporting Program)
• Reconsideration of limitations, guidelines and standards (ELG) for the Steam Electric Power Generating Industry to ensure low-cost electricity while protecting water resources (Steam Electric ELG)
• Reconsideration of wastewater regulations for oil and gas development to help unleash American energy (Oil and Gas ELG)
• Reconsideration of Biden-Harris Administration Risk Management Program rule that made America’s oil and natural gas refineries and chemical facilities less safe (Risk Management Program Rule)

Lowering the Cost of Living for American Families:

• Reconsideration of light-duty, medium-duty, and heavy-duty vehicle regulations that provided the foundation for the Biden-Harris electric vehicle mandate (Car GHG Rules)
• Reconsideration of the 2009 Endangerment Finding and regulations and actions that rely on that Finding (Endangerment Finding)
• Reconsideration of technology transition rule that forces companies to use certain technologies that increased costs on food at grocery stores and semiconductor manufacturing (Technology Transition Rule)
• Reconsideration of Particulate Matter National Ambient Air Quality Standards that shut down opportunities for American manufacturing and small businesses (PM 2.5 NAAQS)
• Reconsideration of multiple National Emission Standards for Hazardous Air Pollutants for American energy and manufacturing sectors (NESHAPs)
• Restructuring the Regional Haze Program that threatened the supply of affordable energy for American families (Regional Haze)
• Overhauling Biden-Harris Administration’s “Social Cost of Carbon”
• Redirecting enforcement resources to EPA’s core mission to relieve the economy of unnecessary bureaucratic burdens that drive up costs for American consumers (Enforcement Discretion)
• Terminating Biden’s Environmental Justice and DEI arms of the agency (EJ/DEI)

Advancing Cooperative Federalism: 

• Ending so-called “Good Neighbor Plan” which the Biden-Harris Administration used to expand federal rules to more states and sectors beyond the program’s traditional focus and led to the rejection of nearly all State Implementation Plans
• Working with states and tribes to resolve massive backlog with State Implementation Plans and Tribal Implementation Plans that the Biden-Harris Administration refused to resolve (SIPs/TIPs)
• Reconsideration of exceptional events rulemaking to work with states to prioritize the allowance of prescribed fires within State and Tribal Implementation Plans (Exceptional Events)
• Reconstituting Science Advisory Board and Clean Air Scientific Advisory Committee (SAB/CASAC)
• Prioritizing coal ash program to expedite state permit reviews and update coal ash regulations (CCR Rule)
• Utilizing enforcement discretion to further North Carolina’s recovery from Hurricane Helene

U.S. EPA’s March 12, 2025 announcement can be viewed here.