Current Status
In Sept. 2024, the Biden EPA finalized requirements for sources that reclassify from “major source status” to “area source status” under the National Emission Standards for Hazardous Air Pollutants (NESHAP) program. It requires sources subject to certain CAA major source standards for seven specific persistent and bioaccumulative pollutants to remain subject to those standards even if the source reclassifies to “area source status.” The case petitioning for review of the rule, Environmental Defense Fund, et al v. EPA, No. 24-01354 (D.C. Cir. Nov 12, 2024), is currently being held in abeyance while the Trump Administration reviews the government’s position.
Why It Matters
As part of the Clean Air Act (CAA), EPA regulates HAPs (Hazardous Air Pollutants). HAPs include benzene, metals, and other pollutants that are known to cause cancer and other serious health effects. A facility is considered a major source if it has the potential to emit 10 tons per year of any one HAP or 25 tons per year of any combination of HAPs. All other facilities are considered area sources. Major sources (such as power plants and petroleum refineries) are subject to Maximum Achievable Control Technology (MACT) standards, which are stringent pollution control requirements based on the technology used in the best-controlled sources in the industry.
MACT standards significantly limit hazardous air pollutants, often reducing emissions to below the major source thresholds of 10 and 25 tons per year. For many years EPA’s policy has been that a major source remains a major source even after MACT is applied and it reduces its emissions. Sources must continue to operate under the more stringent requirements and maintain MACT-level low emissions.
A different approach – allowing the source to reclassify as an area source after it reduces its emissions below the threshold – would replace the source’s initial MACT requirements with less stringent requirements but could result in a large increase in pollution. After first applying the MACT, the source could switch to less effective pollution controls, or operate its controls less frequently or at lower removal efficiencies and release more HAPs up to the major source threshold amounts. This increase could have significant health effects on local communities, especially those that are located near major sources of toxic air pollutants.
Allowing a major source to stop operating with stringent controls would be counter to the primary goal of the Clean Air Act of protecting public health and the environment by minimizing emissions consistent with standards such as MACT-based ones.
Timeline
Feb. 6, 2025 EPA filed an unopposed motion for abeyance in Environmental Defense Fund, et al v. EPA, No. 24-01354 (D.C. Cir. Nov 12, 2024) with a status report due in 90 days. The court granted the motion and requested a status report for May 7, 2025.
Nov. 12, 2024 EDF and other environmental NGOs petitioned for review of the final rule in the D.C. Circuit. Environmental Defense Fund, et al v. EPA, No. 24-01354 (D.C. Cir. Nov 12, 2024).
Sept. 10, 2024 EPA published the final rule in the Federal Register. The rule requires major sources subject to NESHAP for the seven “specific persistent and bioaccumulative pollutants” listed in section 112(c)(6) of the Clean Air Act to remain subject to their NESHAP even if they are reclassified as area sources. According to EPA’s final rule, requiring reclassified major sources of certain persistent and bioaccumulative pollutants to remain subject to the mandated NESHAP will make sure that the CAA regulations still apply to sources accounting for 90 percent or more of aggregate emissions of each of these pollutants.
It requires sources subject to certain CAA major source standards for seven specific persistent and bioaccumulative pollutants to remain subject to those standards even if the source reclassifies to “area source status.” The case petitioning for review of the rule, Environmental Defense Fund, et al v. EPA, No. 24-01354 (D.C. Cir. Nov 12, 2024), is currently being held in abeyance while the Trump Administration to review the agency’s position.
June 4, 2024 OMB began official review of EPA’s final rule on reclassification of major sources as area sources under section 112 of the CAA.
Sept. 21, 2023 EPA proposed a rule to refine “major source” review under the NESHAP program, proposing to allow major sources that limit emissions to reclassify as “area sources” but to also impose emission limitation safeguards on those sources.
Feb. 18, 2022 EPA filed an uncontested motion in State of California, et al. v. EPA, No. 21-01034 (DC Cir.), requesting the D.C. Circuit to hold the case in abeyance until September 19, 2022. EPA explained that it was reviewing the Reclassification Rule and needed additional time to determine whether it would revise or rescind the rule, obviating the need for judicial resolution. The court granted EPA’s motion on Feb. 28, 2022.
Jan. 20, 2021 President Biden issued an Executive Order requiring EPA to review the final rule replacing the “Once In, Always In” policy.
Jan. 19, 2021 A coalition of states filed suit against EPA over the final rule. State of California, et al. v. EPA, No. 21-1034 (DC Cir.).
Jan. 18, 2021 A coalition of environmental groups filed a petition for reconsideration with EPA, arguing the final rule was arbitrary and capricious and that EPA acted unlawfully by removing existing regulatory requirements without public comment. The groups asked EPA to stay the rule for 90 days, withdraw the rule, and immediately withdraw associated guidance.
Jan. 15, 2021 Environmental groups filed suit challenging the final rule. California Communities Against Toxics, et al. v. EPA, No. 20-1024 (DC Cir.).
Oct. 1, 2020 EPA released the final rule replacing the “Once In, Always In” policy. The final rule allowed major sources of HAPs to reclassify area sources, making them subject to less stringent emissions control and compliance requirements. According to EPA’s emissions impact analysis, the rule would have increased HAP emissions between 919 to 1,258 tons per year. EPA published the final rule replacing the “Once In, Always In” policy in the Federal Register on Nov. 19, 2020; it became effective 60 days later.
July 26, 2019 EPA published a proposed rule to replace the “Once In, Always In” policy it withdrew in January 2018. This proposal formalized the Jan. 2018 memo that allows a major source that falls below HAP emissions thresholds to reclassify and no longer use MACT.
Jan. 25, 2018 EPA issued a guidance memorandum withdrawing the “Once In, Always In” policy. The new guidance established that, at any time, “a major source which takes an enforceable limit on its potential to emit and takes measures to bring its HAP emissions below the applicable threshold” may be reclassified and no longer be required to use MACT. The guidance was published in the Federal Register on Feb. 8, 2018.
Jan 2007 EPA proposed a rule to replace the “Once In, Always In” guidance. EPA did not finalize this rule.
May 1995 The Environmental Protection Agency (EPA) issued “once in, always in” guidance for major sources under the Clean Air Act (CAA). This guidance declared that, after the first Maximum Achievable Control Technology (MACT) standard compliance date, a major source could not be reclassified and would always be required to limit its Hazardous Air Pollutants (HAPs) emissions through MACT.