On September 27, 2023, US EPA issued a proposed rule to strengthen emission standards for facilities that choose to switch from major to area source status for Hazardous Air Pollutants (HAP) to avoid standards under 40 CFR Part 63. To better understand the reasons for this change and how it could impact your facility, this article presents a brief history of past EPA guidance and a summary of the proposed rule’s impact for facilities attempting to transition to HAP areas source status.
Since the initial issuance of the hazardous air pollutant (HAP) emission standards under 40 CFR Part 63 standards, facilities have been subjected to varying guidance on how to demonstrate that they are not a major source and, therefore, not subject the Part 63 requirements. A major source is a source that emits 10 tons per year (TPY) or more of any single HAP, or 25 TPY or more of any combination of HAPs; conversely, an area source is any non-major source. If a facility has the potential to emit (PTE) above major source levels of HAP, then area source status must be demonstrated obtaining a permit with synthetic minor limits that restrict PTE below major source levels.
History of OIAI
On May 16, 1995, U.S. EPA released its “once in always in” (OIAI) policy memorandum. This policy stated that all synthetic minor limits must be in place by the compliance date of an applicable Part 63 rule; otherwise, the facility is considered a major source under the applicable Part 63 rule and will always be subject to that Part 63 standard, even if steps were taken to reduce emissions below major source thresholds at a later date.
On January 25, 2018, the EPA issued a memorandum that was titled “Reclassification of Major Sources as Area Sources Under Section 112 of the Clean Air Act”, also known as the MM2A Rule. This memo discussed that the OIAI policy was contrary to section 112 (a) of the CAA, in which Congress placed no temporal limitations on determination of major source status. Therefore, the policy was withdrawn, and major sources could now reclassify as an area source after any Part 63 rule applicability date and no longer be subject to that Part 63 standard. On November 19, 2020, the final version of the MM2A rule was published, and it became effective January 19, 2021. The final action provides sources that reduce emissions and potentials to levels below major source thresholds (MST) the ability to reclassify as an area source. Conditions for compliance dates, emissions standards, and notification requirements were added under 40 CFR Part 63 Subpart A (1)(c)(6). As summarized below, the following conditions should be noted when reclassifying:
- Under 40 CFR 63.1(c)(6)(i)(A), any major sources that have decided to reclassify as an area source should follow any applicable major source requirements until the reclassification goes into effect (i.e., receipt of the permit that restricts site PTE to below major source levels). When the reclassification is completed, the site becomes applicable to all area source regulations immediately. The owner or operator of a reclassified area source should comply with all notification requirements under 40 CFR 63.9 (b).
- Under 40 CFR 63.1(c)(6)(i)(B), if a major source that reclassified as an area source becomes a major source again, the site immediately becomes subject to all applicable major source requirements. Initial notification of changes should be made as required under 40 CFR 63.9 (b).
- Under 40 CFR 63.1(c)(6)(ii), if a site that was major source reclassifies as an area source, this does not keep the site from being under enforcement action or investigation from any violations that occurred while the site was major source. Additionally, if an area source becomes a major source again, any violations committed while under area source status do not keep a site from enforcement action or investigation.
Further Reclassification Ramifications
Further changes regarding the MM2A rule are on the horizon. On September 21, 2023, U.S. EPA published proposed amendments and additions to 40 CFR Part 63 Subpart A for sources that reclassified from major to area source since January 25, 2018, or for sources that wish to reclassify in the future. A summary of the topics brought up in the proposal and proposed amendments are found below.
- Clarify that major sources that reclassify as area sources will be required to have their potential emission limits be federally enforceable. What this effectively means is that sites will be required to keep records of historic reductions in emissions. Additionally, by adding federal enforcement for reclassified sites, it ensures that the EPA and equivalent groups can enforce and regulate emission reductions. [40 CFR 63.1(c)(6)(iii)].
- The EPA added a measure to ensure that permit limitations contain safeguards that prevent any increases in emissions once reclassification occurs, i.e., the source would, at a minimum, continue to meet the HAP emissions standards, control requirements, and work practices of the applicable Part 63 NESHAP after reclassification. Option proposed in include the following: [40 CFR 63.1(c)(6)(iv)]
- Continue to use emission control methods that were used and required while a site was major source, following NESHAP requirements. This could include control devices and practices to reduce emissions.
- Follow control methods that are outlined in the applicable NESHAP subpart that are meant for reclassified sources.
- Utilize equivalent emission controls. This method must be reviewed and approved by a permitting authority to ensure that these methods will not increase emissions or potential limits.
- Clarify that reclassifications (after this rule is federally active) will be effective upon electronically submitting reclassification notice to the EPA through the Compliance and Emissions Data Reporting Interface (CEDRI).
- Under the proposed rule updates, U.S. EPA also included procedures for submitting Confidential Business Information (CBI) outside of CEDRI, with a preference for electronic submittals.
- The U.S. EPA is requesting comment on whether every permit used to reclassify a source from major to area source status should undergo an individual public notice and comment period.
For any questions regarding these rule changes, or if you think your site qualifies for reclassification, reach out to Trinity Consultants‘ CSS director, Inaas Darrat for more information or for assistance.
