Comments due November 13, 2023
On September 27, 2023, the EPA introduced a proposed rule known as the Reclassification of Major Sources as Area Sources Under Section 112 of the Clean Air Act (MM2A), which sets new requirements for major sources of hazardous air pollutants (HAPs) that opt to reclassify themselves as area sources under the National Emissions Standards for Hazardous Air Pollutants (NESHAP) program. Major sources are defined as those emitting 10 tons per year (tpy) or more of a single HAP or 25 tpy or more of a combination of HAP, while area sources emit HAP below these specified thresholds. Historically, a policy known as “once in always in” required facilities that were major sources of HAP to comply permanently with that standard and this was a disincentive for major sources to reduce emissions.
Who this affects: This proposed rule would apply to any source that chooses to reclassify, including those that have reclassified since January 25th, 2018.
When does this go into effect: Reclassification will become effective once a permit with federally enforceable conditions has been issued and the EPA has been notified. This rule also clarifies reporting requirements and submitting confidential business information.
Federally enforceable permit conditions: A key point of this change is that sources changing from major to area sources will need to establish federally enforceable emission limits. This will aid in preventing sources increasing emissions above the limits allowed by the major source NESHAP that the sources were subject to before reclassification.
Small business impacts: Small businesses should note that while the proposed rule is intended to clarify regulatory requirements, there may be additional costs associated with establishing federally enforceable permit conditions.