The full scope of the Trump Administration’s deregulatory efforts in the environmental space was recently made clear with a series of announcements from US Environmental Protection Agency (EPA) Administrator Lee Zeldin.

On March 12, in what the Trump Administration touts as “the greatest deregulation action in US history,” Administrator Zeldin announced a slate of 31 different actions to scale back federal environmental regulations. The announcement continues the Administration’s efforts to downsize the role of the federal government in energy and environmental spaces. The Administration foreshadowed many of the newly announced policies in its first-day Executive Order, “Unleashing American Energy” (see our coverage here) and EPA’s “Powering the Great American Comeback Initiative” released last month. (See our discussion here.)

Many of the Trump Administration’s early actions primarily targeted Biden-era executive actions — and as a result could take immediate effect. This next wave of action puts the crosshairs on formally promulgated administrative rules and policies, meaning most changes will also need to pass through the full rulemaking process (including public comments) and inevitable litigation. As a result, most actions involve “reconsidering” existing rules rather than immediately imposing a new framework.

Below, we break down some of EPA’s most significant planned actions and provide context.

Reversing Federal GHG Policy

EPA’s announcement is a full-scale reversal of the federal government’s policy toward greenhouse gases. EPA announced that it will:

• Reconsider EPA’s 2009 Greenhouse Gas (GHG) Endangerment Finding and Regulations Based on It
  In 2009, EPA found that GHGs “threaten the public health and welfare” and that motor vehicle emissions contribute to GHG pollution. This finding created EPA’s legal authority to regulate GHG emissions from motor vehicles. By reconsidering this finding, EPA questions whether GHG emissions endanger public welfare. Administrator Zeldin announced that he was “driving a dagger straight into the heart of the climate change religion.” This action is likely to reinvigorate debate about the US Supreme Court’s decision in Massachusetts v. EPA.
• Reconsider GHG Regulations on Power Plants
  In 2024, the Biden Administration finalized a rule to reduce GHG emissions from the power sector by requiring many power plants to install 90 percent carbon capture equipment by 2032. EPA will reconsider this rule, which it calls “Clean Power Plan 2.0.” This is a reference to the Supreme Court’s 2017 decision in West Virginia v. EPA, which struck down the Obama-era Clean Power Plan.
• Reconsider GHG Regulations on Fossil Fuel Extraction
  EPA will reconsider regulations limiting methane from new and existing oil and gas drilling. The existing regulations were finalized in 2024.
• Reconsider Emission Standards for Vehicles
  In 2024, the Biden Administration announced new emission standards to reduce GHG, nitrogen oxide, and particulate matter emissions from passenger cars and trucks beginning in model year 2027.
• Reconsider the Social Cost of Carbon
  This action follows one of President Trump’s executive orders that instructed EPA to consider eliminating the social cost of GHG emissions from federal consideration. (Background on this issue is available here.)

Rolling Back Regulations on Coal, Oil, and Natural Gas

In addition to the broader focus on GHGs, EPA may scale back several other major Biden-era regulations impacting fossil-fuel powered energy generation:

• Reconsider MATS for Coal-Fired Power Plants
  EPA will again reconsider whether to ease or do away with its limitations on mercury and other metals emitted from coal-fired power plants. The rules withdrawn during the first Trump Administration and reinstated by the Biden Administration last year. While it prepares a new final rule, EPA may temporarily pause enforcement of the Mercury and Air Toxics Standards (MATS) rule for two years.
• Changing Clean Air Act State Implementation Plan Policy
  EPA is reconsidering the 2023 “Good Neighbor Plan,” which is currently stayed pending litigation, that required states to reduce smog forming emissions from power plants and other industries that could drift to downwind states. EPA states that it also plans to work to approve nearly two-dozen state air regulations that had been denied for failure to comply with the “Good Neighbor Plan.”
• Revise CCR Rule
  EPA announced plans to work with states to quickly approve state-level regulations governing the disposal of coal-ash generated by coal-fired power plants, including a promise to propose a determination on North Dakota’s Coal Combustion Residual (CCR) permit program within 60 days. EPA is also “evaluating whether to grant short- and long-term relief such as extending compliance deadlines” for the Legacy CCR Rule. (Ways CCR issues play out can be seen here.)
• Revise Wastewater Regulations for Oil and Gas Extraction and for Steam-Powered Electric Generation
  EPA announced it will reconsider wastewater pollution standards impacting coal-fired power plants and oil and gas extraction. In 2024, EPA updated its rules for four types of coal plant wastewater: flue gas desulfurization wastewater, bottom ash transport water, combustion residual leachate, and legacy wastewater. EPA’s reconsideration may attempt to ease costs for coal-fired power plants.

Redefining the Scope of Clean Water Act

The Clean Water Act has been in the news lately because the Supreme Court recently decided San Francisco v. EPA. (For more, see here.)

In a separate announcement, EPA said it would revise its definition of “waters of the United States,” (WOTUS) the key jurisdictional term that defines which waters and wetlands the Clean Water Act applies to. The federal government and courts have generally accepted that WOTUS includes interstate or traditionally navigable waters and their tributaries, as well as wetlands “adjacent” to those waters. Where the Supreme Court and past Administrations have disagreed is what counts as an “adjacent” wetland.

As we have explained, past Administrations have alternated between two tests for adjacent wetlands: a permanent surface connection test and an ecologically “significant nexus” test. In 2023, the Biden Administration adopted its version of the significant nexus test. Then, the Supreme Court’s decision in Sackett v. EPA held that WOTUS includes only oceans, rivers, streams, lakes, and waters with a continuous surface connection to those waters.

EPA recently announced it will revise the 2023 rule and align its definition with Sackett. EPA stated its new rule will prioritize “empowering American farmers [and] landowners.”

Terminating EPA’s Environmental Justice Staff

EPA announced that it would “terminate” EPA’s environmental justice (EJ) arm. This is no surprise, given the Trump Administration’s reversal of the Biden Administration’s EJ policies. As we explained, Trump’s first-week executive orders revoked several Biden-era policies and announced an effort to terminate all EJ and diversity, equity, and inclusion (DEI) offices and positions. While this rollback will remove EPA from EJ issues, the focus on EJ by many states is expected to continue.