On January 5, 2022, the United States Environmental Protection Agency (US EPA) added a new Hazardous Air Pollutant (HAP), 1-bromopropane (1-BP) for the first time since the list was established by the Clean Air Act (CAA). As a result, many sources of 1-BP emissions who were previously considered minor sources of emissions now exceeded the major source thresholds. Additionally, many existing major sources of emissions who were already subject to various National Emission Standards for Hazardous Air Pollutants (NESHAP) rules had to evaluate their compliance program to determine the impact of this change.
In response to widespread feedback from industry, the EPA on September 13, 2023, issued a proposed rule to modify the NESHAP general provisions to address applicability and compliance issues resulting from the addition of 1-BP to the CAA HAP list. The proposed rule clarifies the regulatory requirements of facilities when listing a new HAP, when facilities need to include new HAP when calculating projection of future HAP emissions, and when facilities can trigger new requirements from being regulated under CAA “minor” source to a “major” source of hazardous air pollutants. In addition to the impacts that require no rule change, the proposed rule addresses three (3) issues that may require changes:
1. Newly Listed HAPS and Previously Promulgated NESHAPs
Newly listed HAPs are not regulated by any NESHAP promulgated before the HAP was added to the list. NESHAP standards are set by collecting HAP emissions data from existing facilities, establishing a baseline for standards based on the best performing sources for those HAP emissions, then evaluating whether more stringent options are justified. As a newly listed HAP was not included in the original review, the existing HAP standard cannot be used to regulate its emissions. Therefore, the EPA must conduct a new review for any new HAP, evaluating emissions data from existing sources and setting new/updated standards accordingly. For example, 1-BP will not be regulated under any existing Hazardous Organic NESHAP (HON, 40 CFR 63 Subparts F,G, and H) standards for organic HAP until the EPA evaluates 1-BP emissions for existing sources and either confirms existing standard are sufficient for 1-BP control or issues new/revised standard to include impacts from 1-BP
2. Permitting Implications for Major Sources due to a New HAP Listing
On and after the effective date of the listing of a new HAP, a source’s PTE must include the new HAP. In the case of 1-BP, sources need to include 1-BP in their PTE as of February 4, 2022.
Some area sources of HAP may become a major source after including the newly listed HAP in their PTE. The EPA refers to such sources as “MSDL”, or “major source due to listing.” MSDL facilities must comply with 40 CFR 70.5(a)(1)(i) by applying apply for a Part 70 permit within 12 months after the new HAP is designated. Therefore, The Part 70 application due date for MSDL facilities due to 1-BP was February 5, 2023. (It should be noted that individual states, tribes, and other permitting authorities may have different deadlines; please contact your local Trinity office for more information.) MSDL facilities wanting to continue operating as an area source must obtain federally enforceable PTE restrictions below major source levels; typically, such restrictions come in the form of a minor source operating permit from the appropriate permitting agency.
3. NESHAP Compliance Timeline for MSDL Facilities
In addition to triggering Part 70 permitting requirements, MSDL facilities are also subject to existing major-source NESHAPs covering source categories at their facility. While this applicability is triggered upon the rule effective date, February 4, 2023, EPA provided specific guidance on compliance dates for MSDL sources, proposing two key changes. First, the EPA is proposing to treat affected sources at MSDL facilities, i.e., sources that become major solely by adding 1-BP to their PTE, as existing sources under all NESHAP subparts. This allows facilities to avoid new source requirements that may be difficult to meet for already constructed emission units. Second, the EPA is proposing to provide compliance deadlines for MSDL facilities based on the types of emission limitations or requirements in individual NESHAP subparts. Specifically, EPA is proposing a 2-year compliance deadline for facilities that must install add-on controls and a 1-year deadline for all other standards. These timelines would supersede timelines promulgated in individual NESHAPs. Note no compliance extension will be provided for NESHAPs that have identical requirements for area and major sources.
MSDL facilities must also submit notification upon becoming a major source, as required by two existing NESHAP requirements. No new notifications are required, but the proposed rule does require sources to identify if they are a MSDL when submitting their Title V operating permit application or any initial notification submitted for an individual NESHAP (which would be due 180 days after the new HAP designation is finalized). No new notification requirements are proposed for sources that emit the new HAP but are already subject to major source NESHAPs, but EPA is requesting comments on whether such notice should be required and what it should include (e.g., information on HAP usage, emissions, potential controls, etc.)
Trinity has a range of expertise to support the chemical sector. For more information about the impacts of this new HAP, you can contact Inaas Darrat and visit our website.
