Cost Reduction Underlies EPA Regulatory Rollback

This past week, EPA Administrator Lee Zeldin unveiled plans to revisit roughly two dozen environmental regulations, including significant climate change-related actions.[1] The proposed changes were framed in both environmental and economic terms. Announcing the plans, Mr. Zeldin said EPA is “committed to fulfilling President Trump’s promise to unleash American energy, lower cost of living for Americans, revitalize the American auto industry, restore the rule of law, and give power back to states to make their own decisions.” The historic mission of EPA is to “protect human health and the environment.”[2] Adding a heavier focus on the costs of regulation will be seen by some as necessary and bold. Others will object. One thing that that seems clear is that it will lead to a lot of litigation. 

Many of the announced moves focus on relaxing air and water quality requirements for energy production and electricity generation facilities. EPA also relayed its plans to revisit its definition of the Clean Water Act jurisdictional term “waters of the United States” (WOTUS).[3] The actions proposed, as noted, would also shift key environmental permitting and enforcement authorities to the States.

Nearly all of the actions EPA identified will trigger the Administrative Procedure Act’s (APA) notice-and-comment process; amending or rescinding existing federal rules requires the same process used to promulgate rules.[4] The agency has not yet published notices that would start that process. EPA’s amendment or rescission of rules also will be subject to judicial review.[5] At least two of the rule changes could be addressed through the Congressional Review Act—a separate, legislative process for overturning agency actions that are finalized in the waning months of the previous Congress.[6]

Below, we address each action identified in the announcements and provide context for the specific regulation(s) to be affected. The actions are divided into those: (1) broadly focused on climate change; (2) primarily affecting power plants; (3) focused on oil and gas production; (4) concerning air quality and cooperative federalism; (5) affecting specific air quality and climate issues; (6) affecting how EPA operates; and (7) concerning revision of the WOTUS rule. 

    I.    Climate Change 

Underpinning much of the regulatory regime that the Biden Administration implemented or expanded to combat climate change are EPA’s determination that greenhouse gases (GHGs) endanger public health and welfare and its methodology for estimating the benefits of climate-related rules. EPA now will reconsider or revise both actions. 

        a.    Endangerment Finding

In perhaps its most consequential announcement of the day, EPA indicated its plan to reconsider its 2009 action entitled, “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act” (Endangerment Finding).[7] In the Endangerment Finding, EPA determined that the current and projected concentrations of six key GHGs[8] in the atmosphere threatened the public health and welfare of current and future generations. EPA also concluded that the combined emissions of these GHGs from new motor vehicles and engines contribute to the GHG pollution that threatens public health and welfare.[9] The Endangerment Finding itself did not impose any requirements on industry or other entities, but it was a prerequisite for implementing GHG emission standards for vehicles and other sectors. As such, EPA now states that it “also intends to reconsider all of its prior regulations and actions that rely on the Endangerment Finding,” which would include standards regulating GHG emissions from vehicles and power plants.[10] EPA’s action follows the White House’s Day One directive to submit recommendations regarding the “legality and applicability” of the findings.^[11]

        b.    Social Cost of Carbon

EPA also states it will “overhaul” its use of estimates of the Social Cost of Greenhouse Gases (SC-GHG) (sometimes shortened to Social Cost of Carbon) in analyzing regulatory actions that affect GHG emissions.[12] The SC-GHG, in use since 2008, is the monetary value of future net damages associated with adding one ton of a given GHG to the atmosphere in a year. The metric includes the value of all climate change impacts (both negative and positive), such as changes in net agricultural productivity, human health effects, property damage from increased flood risk, changes in the frequency and severity of natural disasters, disruption of energy systems, and the value of ecosystem services. EPA most recently revised the values in 2023, resulting in estimates ranging from $140 (at a 2.5% discount rate) to $380 (at 1.5%) per ton for emissions in 2030 (in 2020 dollars).^[13] In his Unleashing American Energy Executive Order, President Trump disbanded the Interagency Working Group responsible for preparing the estimates and directed EPA to consider eliminating the metric from permitting and rulemaking decisions.^[14]

    II. Power Plants

Electricity-generating facilities, particularly those utilizing fossil fuels, are subject to a broad swath of climate, air quality, wastewater, and waste regulations. The Trump Administration views many of these regulations as overly burdensome and the cause of higher electricity prices for individuals and businesses. 

        a.    GHG Emissions from Power Plants

EPA plans to “[r]econsider[] regulations on power plants (Clean Power Plan 2.0),”[15] the rule finalized in April 2024 that sets GHG standards and guidelines for fossil fuel-fired power plants under the Clean Air Act.[16] The rule repealed the first Trump Administration's so-called “Affordable Clean Energy” rule,[17] which itself had repealed and replaced the Obama Administration's 2015 Clean Power Plan.[18] In reconsidering the 2024 rule, EPA may look to develop a rule similar to the first Trump rule, which was less stringent than both the original Clean Power Plan and the 2024 regulation and gave states flexibility regarding how they regulate GHG emissions. Coupled with EPA’s plan to reconsider the underlying Endangerment Finding, it is possible the agency will simply repeal the existing rule and leave GHG emission regulation to the states, perhaps subject to some guardrails.

        b.    Mercury and Air Toxics Standards 

EPA will reconsider[19] a 2024 Biden Administration rule that set new standards for the emission of mercury and air toxics from power plants with over 25 megawatts of capacity (the “MATS” rule).[20] When announcing the rule in 2024, EPA stated it would tighten emission standards for toxic metals by 67% and for mercury from certain existing sources by 70%.[21] The rule was challenged, but the Supreme Court declined to stay it.[22] EPA now states that the Administration will consider allowing a two-year compliance exemption via Section 112(i)(4) of the Clean Air Act—known as the Presidential Exemption[23]—for affected power plants while it initiates a rulemaking to repeal or modify the MATS rule.[24]

        c.    Mandatory Greenhouse Gas Reporting Program

EPA plans to reconsider major portions of its mandatory GHG reporting program contained in three sets of rules under the Clean Air Act.[25] Generally, these rules require fossil fuel suppliers, vehicle manufacturers, and a broad range of other industries to monitor and report their GHG emissions above certain thresholds.[26] In a fact sheet accompanying the announcement, EPA highlighted the May 2024 action entitled, “Greenhouse Gas Reporting Rule: Revisions and Confidentiality Determinations for Petroleum and Natural Gas Systems,”[27] which amended GHG reporting requirements for petroleum and natural gas systems, in particular those regarding methane emissions monitoring and reporting. EPA also notes that it may, among other things, streamline reporting requirements across the reporting program and revise the way GHGs are estimated in the landfill sector.[28]

        d.    Steam Electric Power Generation Discharge Standards

EPA will also consider changes to standards governing wastewater discharges from nuclear and fossil fuel-based steam-powered electric generation plants.[29] These technology-based effluent guidelines and standards (ELGs), promulgated under the Clean Water Act, are incorporated into national pollutant discharge elimination system (NPDES) permits for approximately 1,000 individual facilities. [30] The agency’s 2024 amendment to these ELGs tightened discharge limits for certain process water streams, including a zero-discharge limitation for pollutants in flue gas desulfurization wastewater and bottom ash transport water starting in 2025.[31]

        e.    Coal Ash Permitting and Standards

Finally, EPA announced that it will “work with state partners to place implementation of the coal ash regulations more fully into state hands,” including by assisting states in “preparing their regulations and applications” and “encourag[ing] state[s] to pursue oversight of coal ash management within their borders.”[32] EPA specifically committed to propose a determination on North Dakota’s coal combustion residuals (CCR) permit program, pending since 2020, within 60 days.[33] The agency is also reviewing the “Legacy-Coal Combustion Residuals Management Units” rule, promulgated in May 2024,[34] and may offer “short- and long-term relief such as extending compliance deadlines.”[35] That rule governs disposal of CCR in landfills and surface impoundments. 

    III.    Oil and Gas Production

Administrator Zeldin also announced two sets of oil and gas industry-specific pollution control regulations for reconsideration. These rules limit air emissions and control wastewater discharges associated with oil and natural gas production facilities.

        a.    Oil and Gas Performance Standards

First, EPA intends to reconsider two sets of air quality regulations, codified at 40 C.F.R. Part 60, Subparts OOOOb and OOOOc (referred to as “Quad O” regulations), that set performance standards for crude oil and natural gas facilities.[36] These March 2024 regulations focus on GHG (including methane) and volatile organic compound (VOC) emissions, including setting the first-ever methane emission standards for certain existing oil and gas industry sources.[37]

        b.    Oil and Gas Effluent Standards

EPA also plans to reconsider a set of Clean Water Act regulations that establish effluent standards and guidelines for wastewater discharges from oil and gas facilities including exploration, drilling, production, and well treatment.[38] Although many of the rules EPA plans to reconsider were promulgated during the Biden Administration, the oil and gas ELGs were last amended in June 2016.[39] EPA will evaluate strategies to promote the “beneficial reuse” of treated oil and gas wastewater, including for data center cooling, rangeland irrigation, fire control, power generation, critical minerals extraction, and for “ecological” purposes.[40] 

    IV.    Air Quality and Cooperative Federalism

        a.    National Ambient Air Quality Standards for Particulate Matter 

In enacting the Clean Air Act, Congress emphasized that “air pollution control at its source is the primary responsibility of States and local governments,” but federal leadership “is essential for the development of cooperative Federal, State, regional, and local programs to prevent and control air pollution.”[41] At the core of this framework are National Ambient Air Quality Standards (NAAQS) and State Implementation Plans (SIPs), as well as specific programs designed for states to address visibility and their contributions to air quality issues in neighboring states. 

First, EPA plans to revisit so-called soot standards.[42] Clean Air Act Sections 108 and 109 direct EPA to identify and list certain air pollutants, issue air quality criteria for those pollutants, then propose and promulgate “primary” and “secondary” NAAQS for those pollutants.[43] Revisions to NAAQS trigger a process under which States and Tribes make recommendations to EPA regarding identification of areas of the country that either meet or do not meet the new or revised standard. Areas in nonattainment then develop plans for how they will meet the standard.[44]

One such pollutant is particulate matter (PM), colloquially known as soot, which is emitted from vehicle tailpipes, industrial smokestacks, forest fires, and other sources. On March 6, 2024, EPA issued the “Reconsideration of the National Ambient Air Quality Standards for Particulate Matter” final rule. The rule revised the primary annual standard for fine particulate matter (PM)_2.5, lowering the level from 12.0 µg/m³ to 9.0 µg/m³.[45] EPA indicated in Zeldin’s announcement that “it will soon release guidance to increase flexibility on NAAQS implementation, reforms to New Source Review, and direction on permitting obligations.”[46]

        b.    Regional Haze Program

Sections 169A and 169B of the 1977 and 1990 Clean Air Act Amendments, respectively, lay the groundwork for a program for protecting visibility in national parks, federal wilderness areas, and other designated Class I areas due to their ‘‘great scenic importance.”[47] EPA’s 1999 “Regional Haze Regulations” call for States to submit periodic plans demonstrating how they have and will continue to make progress towards achieving their visibility improvement goals.[48] State plans covering the 2008-2018 first planning period were due in 2007, and plans covering the 2019-2028 period were due in 2021. The rule requires that certain aging facilities, such as power plants, adopt pollution controls that are determined to be the Best Available Retrofit Technology (BART). EPA now plans to “restructure” the Regional Haze Program but has not included details.[49]

        c.    Good Neighbor Plan

EPA will reconsider[50] the 2023 “Good Neighbor Plan” for the 2015 Ozone NAAQS.[51] The Good Neighbor Plan implements the “interstate transport” provision of the Clean Air Act,[52] which requires each State to prohibit air emissions that significantly contribute to nonattainment of a NAAQS. Prior to developing the Good Neighbor Plan, EPA rejected the SIPs of 23 States to address contribution to nonattainment of the 2015 ozone NAAQS and put in place a Federal Implementation Plan (FIP) to ensure those States comply with what EPA determined were their obligations under the interstate transport provision.[53] In Ohio v. EPA in 2024, the Supreme Court stayed the Good Neighbor Plan;[54] EPA later halted implementation of the plan pending ongoing litigation.[55] EPA has not specified what approach it will take in reconsidering the Good Neighbor Plan.

        d.    State Implementation Plan and Tribal Implementation Plan Backlog

Under the Clean Air Act, States and authorized Tribes are required to submit plans to achieve air quality standards to EPA for approval.[56] Though they are implemented primarily by States and Tribes, these plans (SIPs and TIPs) can be either approved, or rejected in part or in total, by EPA.[57] SIPs and TIPs focus on meeting national standards for the six “criteria pollutants” known to be harmful to human health (i.e., carbon monoxide, lead, nitrogen oxide, ozone, particulate matter, and sulfur dioxide).[58] EPA has struggled to keep up with timely review of SIPs[59] but plans to work with States and Tribes to “clear th[e] backlog [of SIPs and TIPs] as soon as possible.”[60]

        e.    National Emission Standards for Hazardous Air Pollutants (NESHAPs) 

Not all pollutants are covered by the NAAQS. Section 112 of the Clean Air Act directs EPA to regulate hazardous air pollutants, also known as air toxics, from categories of industrial facilities.[61] For major sources, Section 112 requires that EPA establish emission standards that require the maximum degree of reduction in emissions of hazardous air pollutants. Eight years after technology-based standards are issued for a source category, EPA must review those standards to determine whether any residual risk exists for that source category and, if necessary, revise the standards to address such risk. EPA has promulgated dozens of NESHAPs for various source categories, from asphalt processing and asphalt roof manufacturing to vinyl chloride production, codified at 40 C.F.R. Parts 61 and 63. 

EPA’s press release identifies eight sectors for which the agency is “initially reconsidering NESHAPs,” each of which were most recently revised in the last year of the Biden Administration: integrated iron and steel manufacturing,[62] rubber tire manufacturing,[63] synthetic organic chemical manufacturing,[64] ethylene oxide emission standards for sterilization facilities,[65] lime manufacturing,[66] coke ovens,[67] copper smelting,[68] and taconite ore processing.[69] The agency’s initial press release indicates EPA also will focus on the energy sector, which means later amendments could include source categories such as industrial, commercial, and institutional boilers and process heaters;[70] stationary combustion turbines;[71] oil and natural gas production facilities;[72] and gasoline distribution facilities.[73]

    V.    Other Air and Climate Actions

The Trump Administration is also focused on loosening regulations under other Clean Air Act programs, such as vehicle emissions, use of refrigerants (including their role in semiconductor manufacturing), chemical accident prevention, and how wildfires impact air quality monitoring results. 

        a.    Vehicle Emissions

Under President Biden, EPA promulgated three major rules concerning vehicle emissions. In January 2023, EPA issued the “Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicles Standards” rule,[74] which set emissions standards for heavy-duty vehicles and engines starting in model year (MY) 2027. In April 2024, EPA finalized two additional rules, the “Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles” rule[75] and the “Greenhouse Gas Emissions Standards for Heavy Duty Vehicles – Phase 3” rule.[76] The first addresses GHG and criteria pollutant emissions, including those that form smog and soot, for model year 2027 and later vehicles ranging from sedans and crossovers to larger pickup trucks and conversion vans. The second covers GHG emissions for model year 2027 and later heavy-duty vehicles. 

Manufacturers are not required to use particular technologies (such as electrification) to meet the standards. However, EPA stated in the preamble to the light-duty rule its expectation that manufacturers would choose to comply with the standards by substantially expanding their EV offerings, such that roughly two-thirds of new MY 2033 light-duty vehicles sold would be EVs or plug-in hybrids, which has caused opponents to describe the rules as EV mandates. 

Administrator Zeldin announced that EPA plans to reconsider each of these rules.[77] In April 2020, the first Trump Administration finalized “The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule for Model Years 2021–2026 Passenger Cars and Light Trucks,”[78] which increased GHG emissions standards by 1.5% per year from MY 2020 levels over MY 2021-2026—significantly smaller increases than the Obama-era standards they replaced. The SAFE Rule could foreshadow EPA’s approach to decreasing the stringency of the Biden-era mobile source rules.

        b.    Hydrofluorocarbons (HFCs)

The American Innovation and Manufacturing (AIM) Act, enacted by Congress in December 2020 as part of Division S of the Consolidated Appropriations Act, authorizes EPA to restrict the use of HFCs in a sector or subsector.[79] HFCs are GHGs with global warming potentials (GWPs) that can be hundreds to thousands of times more potent than carbon dioxide. HFCs are used in a wide variety of sectors, including refrigeration and air conditioning, foams, aerosols, fire suppression semiconductor manufacturing, and chemical manufacturing. 

In 2023, EPA finalized the “Phasedown of Hydrofluorocarbons: Restrictions on the Use of Certain Hydrofluorocarbons Under the American Innovation and Manufacturing Act of 2020” rule (colloquially known as the Technology Transitions Rule), which implements the AIM Act by restricting the use of HFCs in specific sectors or subsectors in which they are used, establishing a process for submitting technology transitions petitions, and establishing recordkeeping and reporting requirements.[80] Under the current rule, certain technologies must restrict use of higher-GWP HFCs or HFC blends beginning January 1, 2025 (extended to 2026 or 2027 in certain circumstances by subsequent rulemaking). Prohibitions apply to the manufacture, distribution, sale, installation, import, and export of products containing restricted HFCs, with compliance deadlines and GWP limits varying based on sector and subsector. EPA now intends to reconsider the Technology Transition Rule.[81]

        c.    Accidental Releases of Extremely Hazardous Substances

EPA plans to reconsider its Risk Management Program (RMP),[82] which implements Clean Air Act Section 112(r) to require certain stationary sources to implement risk management plans that identify the potential effects of chemical accidents and spell out steps and response procedures the facility will take regarding such accidents. Plans are required for facilities that hold more than a specified quantity of a certain regulated substance (there are over 200 listed substances under the program),[83] and must be revised every five years. In particular, the agency plans to reconsider the “Safer Communities by Chemical Accident Prevention” rule,[84] promulgated in February 2024, which revised numerous compliance requirements to be implemented by May 2027, including third-party audit provisions, safer technology requirements for certain industries, emergency response exercise requirements, and additional incident investigations. EPA estimates about 12,000 facilities are affected by the rule.[85]

        d.    Air Quality Monitoring and Wildfires

Clean Air Act Section 319(b) creates a pathway for air agencies to request that certain “exceptional event”-influenced air quality monitoring data be excluded from certain regulatory actions, including decisions as to the designation of an airshed as being in attainment or nonattainment of NAAQS.[86] EPA plans to reconsider[87] its 2016 regulation, “Treatment of Data Influenced by Exceptional Events,” which among other changes, required areas that commonly experience exceptional events to develop mitigation plans that describe steps agencies will take to mitigate their exposure to pollution from exceptional events.[88] Specifically, the agency will address the status of prescribed fire as an exceptional event within the exclusion carved out by the rule.[89] Current EPA regulations allow prescribed fires to be considered exceptional events in some circumstances but require states to demonstrate the use of adequate smoke management practices, as well as consistency with land management plans for the relevant area, and other requirements.

    VI.    Agency Operations

Administrator Zeldin also announced four key changes to how EPA plans to operate for the coming years, including with respect to how it focuses enforcement resources and the makeup of scientific advisory bodies that inform rulemakings and other actions. 

        a.    Enforcement Initiatives

First, EPA will revise its National Enforcement and Compliance Initiatives (NECIs)[90] to give priority to the most pressing health and safety issues while avoiding unnecessary impacts on domestic energy production.[91] The agency periodically revises its enforcement priorities; the latest set of initiatives[92] was issued in August 2023 and focused on mitigating climate change, addressing exposure to PFAS chemicals, and protecting communities from coal ash contamination. The anticipated realignment follows President Trump’s February executive order entitled “Ensuring Lawful Governance and Implementing the President’s ‘Department of Government Efficiency’ Deregulatory Initiative,”[93] which directs agencies to “preserve their limited enforcement resources by generally de-prioritizing actions to enforce regulations that are based on anything other than the best reading of a statute and de-prioritizing actions to enforce regulations that go beyond the powers vested in the Federal Government by the Constitution.”[94]

A March 12 memo from Jeffrey Hall, Acting Assistant Administrator for the EPA Office of Enforcement and Compliance Assurance, lays out specific “initial guidance” on realigning the agency’s 2023 NECIs with the Trump Administration’s stated goals.[95] The memo provides that “enforcement and compliance assurance actions shall not shut down any stage of energy production . . . or power generation absent an imminent and substantial threat to human health or an express statutory or regulatory requirement to the contrary.” Further, actions that “would unduly burden or significantly disrupt energy production or power generation,” among other consequences, must be approved by Mr. Hall. The memo also revises four existing NECIs—mitigating climate change, protecting communities from coal ash contamination, reducing air toxics in overburdened communities, and chemical accident risk reduction—to conform with the administration’s goals. Notably unchanged are the NECIs concerning PFAS exposure and drinking water standards. 

        b.    Environmental Justice and DEI

In another major policy departure, EPA announced it will terminate its Environmental Justice and Diversity, Equity, and Inclusion (DEI) arms.[96] Following President Trump’s Executive Order “Ending Radical and Wasteful Government DEI Programs and Preferencing,”[97] EPA employees in DEI and Environmental Justice roles were placed on administrative leave. President Trump also revoked[98] Executive Order 12898 of February 11, 1994,[99] which directed agencies over the last three decades in their efforts to develop strategies for achieving environmental justice. Because concerns about pollution’s cumulative impacts and distribution promise to remain, EPA’s move away from environmental justice will likely shift greater responsibility on these issues to the states. 

        c.    Scientific Advisory Bodies

Administrator Zeldin announced[100] the agency’s plans to formally seek nominations for the Science Advisory Board (SAB)[101] and Clean Air Scientific Advisory Committee (CASAC).[102] Nominations will be accepted for 30 days following publication of the Federal Register notice. Congress directed the establishment of both bodies in the late 1970s, and they provide independent scientific advice to the Administrator on science generally (SAB) or air quality specifically (CASAC) that underlies agency rulemaking. During the first Trump Administration, then-Administrator Wheeler dismissed CASAC members and dismantled panels tasked with reviewing air pollution science. In 2021, then-Administrator Regan replaced members from both panels. In January, the Trump Administration announced its decision to “reset” these committees to “reverse the politicization of SAB and CASAC under the Biden-Harris Administration.”[103]

        d.    Enforcement Discretion in Furtherance of Hurricane Helene Recovery

Finally, EPA also plans to grant an extension of the no-action assurance that North Carolina requested to allow use of large air curtain incinerators to clear debris without requiring permits under Title V of the Clean Air Act.[104] According to EPA, this method “will allow more efficient burning of debris with lower emissions than would occur through open burning or the use of smaller incinerators not subject to permitting requirements.” The agency first provided the no-action assurance in November 2024.[105]

    VII.    “Waters of the United States” Definition

EPA also announced on March 12 (through the Region 4 press office) that it plans to revise the regulatory definition of waterbodies that come within the jurisdiction of Clean Water Act regulations.[106]

Uncertainty regarding what waterbodies are encompassed within the Clean Water Act's jurisdictional definition of WOTUS has spanned decades and multiple presidential administrations. In 2023, the Supreme Court in Sackett v. EPA[107] significantly restricted federal jurisdiction over wetlands and other waterbodies under the CWA, leaving states to determine in many instances whether or not to regulate such waterbodies.[108] In response to the Sackett decision, in 2023 EPA and the U.S. Army Corps of Engineers (Corps) finalized a rule amending their regulatory definition of WOTUS to conform with the Sackett test.[109] This “conforming rule” has faced litigation, including from some states alleging the rule fails to fully heed the Sackett decision.[110]

EPA indicates it will work with the Corps to revise yet again the definition of WOTUS to ensure that it “follow[s] the law and implement[s] the Supreme Court’s clear holding in Sackett . . . with a focus on clarity, simplicity, and improvements that will stand the test of time.” While the rulemaking is underway, EPA plans to provide interim guidance to the states.[111] 

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For more information regarding these proposals or their potential impact, please contact Scott Fulton, Brad Marten, Jack Lyman, or Aidan Freeman.