U.S. EPA Publishes New Regulations Governing State Plans for Existing Sources of Emissions
On November 9, 2023, the U.S. Environmental Protection Agency (EPA) published implementing regulations that set timelines and other requirements for state plans to limit pollution from existing sources under Clean Air Act (CAA) Section 111. The amended provisions apply to all emissions guidelines published after July 8, 2019, and will affect the scope and pace of development of updated performance standards for existing facilities.
EPA Proposes Stricter Air Pollution Limits on Reclassified Area Sources
On September 21, 2023, the U.S. Environmental Protection Agency (EPA) published a notice of a proposed rule, “Review of Final Rule Reclassification of Major Sources as Area Sources Under Section 112.” The proposal adds requirements for regulated sources of hazardous air pollutants (HAPs) to reclassify from major source status to area source status under the National Emission Standards for Hazardous Air Pollutants (NESHAPs) program. Stakeholders who qualified under the revised policy adopted by the Trump administration should particularly take note of this further change by the Biden administration’s EPA. Comments are due by November 13, 2023.
California Air Resources Board Revisits Advanced Clean Fleets Rule Through Formation of Truck Regulation Advisory Committee
In April 2023, the California Air Resources Board (CARB) passed its Advanced Clean Fleets (ACF) rule, which will require California medium- and heavy-duty truck and bus fleet owners with over $50 million in annual revenue to transition to zero emission vehicles through a phaseout of their existing internal combustion engine–powered vehicles by 2045. On July 26, 2023, while the ACF rule was pending with the California Office of Administrative Law for a final determination prior to release, CARB withdrew the regulatory package with the intention of resubmitting it “at a subsequent date.” CARB is now forming a Truck Regulation Advisory Committee and, on August 22, 2023, will host a public meeting to discuss and solicit feedback on future efforts to implement the ACF rule. Instructions for participation in this public meeting can be found here.
Spring 2023 Agenda Previews Continued U.S. Significant Environmental Regulatory Action
On June 13, 2023, the Biden administration released the 2023 Spring Unified Agenda of Regulatory and Deregulatory Actions (Agenda). The Agenda lists federal agencies’ planned “short-term” regulatory actions to be taken over the next 12 months and “long-term” actions under development. The dates listed in the Agenda are based on publication dates in the Federal Register. Stakeholders should take note, as the Agenda provides a window into the administration’s priorities and strategies:
D.C. Circuit Upholds U.S. EPA’s 2021 Interstate Ozone Transport Rule
On March 3, 2023, the D.C. Circuit Court of Appeals rejected an industry challenge to the April 2021 Revised Cross-State Air Pollution Rule (CSAPR) Update Rule from the Environmental Protection Agency (EPA or Agency), which required power plants in 12 “upwind” states to reduce nitrogen oxide (NOx), an ozone precursor, emissions such that those states did not inhibit downwind states’ ability to comply with the 2008 Ozone National Ambient Air Quality Standard (NAAQS).

EPA Acts on Interstate Transport Requirements for Ozone Under State Implementation Plans
On Tuesday, January 31, EPA Administrator Michael Regan finalized EPA’s disapproval of State Implementation Plan (SIP) submissions for 19 states regarding the interstate transport of ozone under the 2015 eight-hour ozone national ambient air quality standards (NAAQS) of 70 parts per billion. Under the Clean Air Act, states were required to submit SIPs for the 2015 eight-hour ozone standard by October 1, 2018. The Clean Air Act required the SIPs to include “good neighbor” provisions, which prohibit emissions that either significantly contribute to nonattainment in a neighboring state or interfere with maintenance of the NAAQS in a neighboring state.
EPA Proposes Change to Treatment of Fugitive Emissions in New Source Review
On October 13, 2022, the U.S. Environmental Protection Agency (EPA) released a proposed rule changing the treatment of fugitive emissions in determining whether a modification is major under the New Source Review (NSR) provisions of the Clean Air Act. The proposed rule — which modifies NSR regulations that have been stayed since 2009 — would require all major sources to consider fugitive emissions when determining whether a proposed change would constitute a major modification. Regulated entities considering changes to their existing facilities should monitor the progress of this rule and consider commenting.
U.S. EPA Proposes New Risk Management Program Standards for Stationary Sources
On August 19, 2022, the U.S. Environmental Protection Agency (EPA) issued a proposed rule to revise Risk Management Program (RMP) standards for stationary sources using certain regulated substances under the Clean Air Act (CAA). EPA’s proposal marks the latest reconsideration of a rule issued under the prior administration, as directed by Executive Order 13990. The proposed changes include more stringent requirements for accident prevention, emergency preparedness, and public availability of information as well as regulatory clarifications, with climate change and environmental justice featured prominently as a basis for many proposed changes. Interested parties will have 60 days to comment on the proposed rule following publication in the Federal Register.

EPA Conducts Flyovers in New Mexico and Texas
On August 1, 2022, the U.S. Environmental Protection Agency (EPA) announced that it is conducting helicopter flyovers of the Permian Basin region in New Mexico and Texas. EPA asserted that the purpose of the flyovers was to “survey oil and gas operations to identify large emitters” of methane and volatile organic compounds. This follows recent flyovers conducted in other regions for the same purpose.
Supreme Court Upends EPA’s Broad Claims of Climate Regulatory Authority
On Thursday, June 30, the U.S. Supreme Court released its decision in West Virginia v. EPA, holding that the Environmental Protection Agency (EPA) exceeded its statutory authority in adopting the Obama-era Clean Power Plan (CPP). The 6–3 decision may limit EPA’s ability to address greenhouse gas (GHG) emissions comprehensively. A summary of the Court’s reasoning is set out below, followed by four “key takeaways.” (more…)