On Feb. 22, 2022, the U.S. Environmental Protection Agency (EPA) published final rule amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Miscellaneous Coating Manufacturing (MCM) facilities. EPA’s amendments establish inorganic HAP standards for process vessels, following the mandated technology review conducted under the Clean Air Act (CAA), originally promulgated in August 2020. Prior to adoption of these amendments, the MCM NESHAP hadn’t regulated metal HAP from process vessels.
Specifically, EPA’s final amendments revise Table 1 of 40 CFR part 63 subpart HHHHH to include the emission limits that apply to process vessels based on the following:
- Existing sources must demonstrate initial compliance with the particulate matter (PM) emissions limit of 0.014 gr/dscf (grains per dry standard cubic foot); and
- New sources must demonstrate initial compliance with the PM emissions limit of 0.0079 gr/dscf..
During the manufacturing process, with the addition of raw materials in powder form to paint mixing vessels, emissions of metal HAP in the form of PM emissions may occur and are typically collected and routed to a PM control device (i.e., baghouse, fabric filters, cartridge filters, or scrubbers). EPA’s final rule addresses the previously unregulated metal HAP emissions from this category and promulgates Maximum Achievable Control Technology (MACT) for emission sources of metal HAP.
Facilities will be required to comply continuously with the standards during all operations that emit metal HAP; but it does not apply to pigments and other solids that are in paste, slurry, or liquid form. The agency also provided a mechanism for owners and operators to demonstrate that materials containing inorganic HAP metals below certain levels are not subject to the standards, as well as a definition for “material containing metal HAP.”
EPA is allowing one year to comply with the final rule amendments, with an effective compliance date of February 22, 2024. The agency maintains that one year is an adequate amount of time for facilities to conduct performance tests on existing inorganic HAP control devices. Notably, 40 CFR 63.6(i)(4)(ii) provides an opportunity to request an additional two (2) years to comply if necessary for the installation of controls.
In August 2022, ACA, through its MCM Workgroup, submitted extensive comments to EPA on its proposed amendments, including suggesting a 3-year compliance date. The agency was somewhat receptive to ACA’s comments. While the agency’s final rule did not add design evaluations of PM control devices as an alternative to Method 5 performance testing, EPA recognizes that there may be instances where inorganic HAP materials are processed for very limited periods of time. As such, EPA’s final rule clarifies that the performance test may be conducted during any solids addition or processing steps, and not just during the addition of inorganic HAP-containing materials. The final rule amends the regulatory text at 40 CFR 63.8005(i)(1)(i) to specify that EPA Method 5 may be conducted during the addition of any dry materials.
EPA’s final rule also addresses the applicability of Subpart SS, in section III.A.1. In its August 2022 comments, ACA had sought official clarification from EPA that Subpart SS, which is referenced by the existing MCM rule, does not apply to PM control devices. To avoid any potential confusion, ACA asked EPA to specify in the rule’s subsection language that Subpart SS does not apply to the proposed requirements for metal HAP by adding qualifiers and proposed explicit clarifying verbiage.
Contact ACA’s Rhett Cash for more information.