Revised Classification of Significant Emission Sites under Section 112 of the Clean Air Act
The Major MACT (Maximum Achievable Control Technology) to Area Source rule, which allows major sources of hazardous air pollutants (HAP) to reclassify as area sources, continues to be a topic of interest in the environmental sector.
The rule, published as a final rule on November 19, 2020, was a significant amendment to the Clean Air Act. It was followed by a proposed MM2A Rule on June 26, 2019, and another on September 21, 2023. A technical correction to the 2020 MM2A Rule was also made on December 28, 2020.
However, the current status of the Major MACT to Area Source rule post-congressional disapproval of the 2024 amendments to the 2020 MM2A Rule is not explicitly detailed in the documents available as of mid-2025.
The Environmental Protection Agency (EPA) and states are maintaining and updating control technology requirements under the Clean Air Act, applying Best Available Control Technology (BACT) and related controls for major sources impacting air quality. This is evident in recent EPA reviews of state submissions for serious PM2.5 area plans, which confirm that BACT or Lowest Achievable Emission Rate provisions remain central to compliance strategy.
The mention of SIP (State Implementation Plan) processes and associated updates in various states, including reviews of control technology standards and public comment periods extending into 2024 and 2025, indicates ongoing active management and revisions to state-level air quality control plans consistent with Clean Air Act requirements.
While there is a reference to the 2024 period in relation to Congressional disapproval of amendments to the 2020 MM2A Rule, the search results do not explicitly address the outcome or the operational impact of this disapproval on the MACT to Area Source rule itself. There is no clear statement that the disapproval has reversed or nullified the amendments or how EPA is responding administratively or regulatory in consequence.
On June 20, 2025, a joint Congressional resolution (S.J. Res. 31) under the Congressional Review Act disapproving the 2024 amendments to the 2020 MM2A Rule was signed into law by President Donald J. Trump, effectively nullifying the 2024 MM2A Rule. The exact implications of this action on the MACT to Area Source rule are not yet clear and may require further updates from the EPA or official Congressional reports.
For inquiries related to 508 compliance, contact Elineth Torres at torres.elineth@our website.
[1] EPA. (2025). State Implementation Plan (SIP) Submissions for Serious PM2.5 Area Plans. Retrieved from https://www.epa.gov/air-quality-planning/state-implementation-plan-sip-submissions-serious-pm25-area-plans
[2] EPA. (2025). Best Available Control Technology (BACT) and Related Controls for Major Sources Impacting Air Quality. Retrieved from https://www.epa.gov/air-quality-planning/best-available-control-technology-bact-and-related-controls-major-sources-impacting
[3] EPA. (2025). Control Technology Standards Reviews and Public Comment Periods. Retrieved from https://www.epa.gov/air-quality-planning/control-technology-standards-reviews-and-public-comment-periods
- The ongoing management and revisions to state-level air quality control plans suggest that industry may need to comply with stricter environmental-science standards due to ongoing efforts to reduce air pollution and combat climate-change.
- Although the 2024 amendments to the 2020 MM2A Rule were nullified in June 2025, the exact implications of this action on the Major MACT to Area Source rule are not yet clear, requiring further updates from the Environmental Protection Agency (EPA) or official Congressional reports.
- In the realm of environmental-science and finance, the EPA is actively updating control technology requirements under the Clean Air Act, which could significantly impact various industries that contribute to air pollution.
- The important links between science, technology, finance, and the environment are highlighted in the ongoing efforts to address climate-change and air pollution, as the energy sector is increasingly held accountable for its role in these issues.
