Approval of the Clean Air Act, Section 112(l), Authority for Hazardous Air Pollutants; State of Connecticut Department of Energy and Environmental Protection; Approval of the Clean Air Act Section 502, State Operating Permit Programs, State of Connecticut Department of Energy and Environmental Protection

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 70</CFR> <DEPDOC>[EPA-R01-OAR-2025-0655; FRL-12924-02-R1]</DEPDOC> <SUBJECT>Approval of the Clean Air Act, Section 112(l), Authority for Hazardous Air Pollutants; State of Connecticut Department of Energy and Environmental Protection; Approval of the Clean Air Act Section 502, State Operating Permit Programs, State of Connecticut Department of Energy and Environmental Protection</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is approving regulatory amendments that revise two previous program approvals from the Connecticut Department of Energy and Environmental Protection (CT DEEP). The revisions include amendments to the Regulations of Connecticut State Agencies (RCSA) that revise the Connecticut State Operating Permit Program and amendments to RCSA that revise limitations on potential to emit Clean Air Act (CAA) pollutants. A significant aspect of this action involves revising the definition of “hazardous air pollutant” in the RCSA in response to EPA adding 1-bromopropane to the list of hazardous air pollutants (HAPs). This action is being taken under the Clean Air Act. </SUM> <EFFDATE> <HD SOURCE="HED">DATES: </HD> This rule is effective on December 22, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket Identification No. EPA-R01-OAR-2025-0655. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">i.e.,</E> CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available at <E T="03">https://www.regulations.gov</E> or at the U.S. Environmental Protection Agency, EPA Region 1 Regional Office, Air and Radiation Division, 5 Post Office Square—Suite 100, Boston, MA. EPA requests that, if at all possible, you contact the contact listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section to schedule your inspection. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Liam Numrich, Air Permits, Toxics, and Indoor Programs Branch, U.S. Environmental Protection Agency, EPA New England Regional Office, 5 Post Office Square—Suite 100, (Mail code 5-MI), Boston, MA 02109-3912, telephone number 617-918-1307, <E T="03">numrich.liam@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. Background and Purpose</FP> <FP SOURCE="FP-2">II. Response to Comments</FP> <FP SOURCE="FP-2">III. Final Action</FP> <FP SOURCE="FP-2">IV. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Background and Purpose</HD> On August 28, 2025, the EPA published a Notice of Proposed Rulemaking (NPRM) that proposed approval of revisions to Connecticut's State Operating Permit Program and to its Approved Limitations on Potential to Emit CAA section 112 pollutants. The Administrator may, under the authority of section 112(l) and 40 CFR 63.91, approve a State program designed to establish limits on the potential to emit HAPs listed pursuant to section 112 of the CAA. Any request for approval under this subpart shall meet all section 112(l) approval criteria specified by the otherwise applicable Federal section 112 rule, emission standard, or requirement. Approval of the rule delegates to the State the authority to implement and enforce the approved rule in lieu of the otherwise applicable Federal section 112 rule. CT DEEP's 112(l) program was approved on April 11, 2022 (87 FR 13936). The Connecticut State Operating Permit Program's initial approval became effective on May 31, 2002. (67 FR 31966.) On June 14, 2024, CT DEEP submitted revisions to its State Operating Permit Program and to its Approved Limitations on Potential to Emit CAA section 112 pollutants to EPA. These amendments revise two previous program approvals for EPA's approval. They consist of (1) amendments to sections 22a-174-1 (Definitions) and 22a-174-33 (Title V sources) of the RCSA that revise the Connecticut State Operating Permit Program; and (2) amendments to RCSA sections 22a-174-1, 22a-174-33a (Limit on Premises-Wide Actual Emissions Below 50% of Title V Source Thresholds), and 22a-174-33b (Limit on Premises-Wide Actual Emissions Below 80% of Title V Source Thresholds) that revise limitations on potential to emit CAA section 112 pollutants for the state's CAA section 112(l) state program to limit the potential to emit HAPs pollutants below Title V source thresholds. In accordance with Title V program revisions required at 40 CFR 70.4(i)(2) and CAA 112(l) state program revision requirements at 40 CFR 63.91, the primary change in CT DEEP's June 14, 2024, submittal is a new definition of “hazardous air pollutant” in RCSA section 22a-174-1. The current definition of “hazardous air pollutant” is deleted and replaced with the following: `Hazardous air pollutant,' `Federal hazardous air pollutant' or `HAP,' except as otherwise provided in section 22a-174-29 of the Regulations of Connecticut State Agencies, means any air pollutant listed in section 112(b)(1) of the Act, inclusive of deletions and additions set out in 40 CFR part 63, subpart C, as may be amended from time to time.” This new definition is consistent with EPA's most recent change to the federal definition of HAP to include 1-bromopropane in the list of HAPs established under the CAA Section 112. The new definition also incorporates future changes to the federal definition resulting from EPA's listing or delisting of a chemical compound. CT DEEP submitted companion changes to RCSA section 22a-174-33a and RCSA section 22a-174-33b to effectuate the change in the definition of “hazardous air pollutant” at RCSA section 22a-174-1 into those two regulations as they regulate HAP emissions as a CAA section 112(l) state program. In addition to this change, there are a number of revisions to CT DEEP's Title V operating permit program at RCSA section 22a-174-33 to correct citations to another Connecticut air quality regulation. The corrections will better ensure that Title V applications, notifications, reports, and records are properly certified by a responsible official, and are as follows: • RCSA section 22a-174-33(g)(1)(G). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). • RCSA section 22a-174-33(h)(2). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). • RCSA section 22a-174-33(o)(4). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). • RCSA section 22a-174-33(p)(3). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). • RCSA section 22a-174-33(q)(1). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). • RCSA section 22a-174-33(q)(2). The internal citation to section 22a-174-2a(a)(5) is corrected to 22a-174-2a(a)(4). EPA's analysis of Connecticut's 112(l) state program revisions finds the revisions necessary for maintaining consistency between state regulations and federal regulations. <HD SOURCE="HD1">II. Response to Comments</HD> We received four comments expressing support of EPA approving this action. The comments do not suggest that EPA approval of this action would be erroneous or otherwise inconsistent with the CAA, applicable regulations, or other authorities. None of the comments propose changes to the draft rule. Therefore, these comments do not necessitate specific responses. <HD SOURCE="HD1">III. Final Action</HD> EPA is approving Connecticut's revisions to its Title V Operating Permit program and CAA section 112(l) state program revision. In addition to changes to Connecticut's definitions, a number of revisions to CT DEEP's Title V operating permit at RSCA 22a-174-33 to correct citations to another Connecticut air quality regulation are being made. Specifically, EPA is approving section 1 and 33 as Title V program revisions and sections 1, 33a and 33b as CAA section 112(l) state program revision. In summary, the following changes are being approved under Sections 112(l) and 502 of the Clean Air Act: • RCSA section 22a-174-1(51). The new definition of “hazardous air pollutant” is added, as this definition will now apply to RCSA sections 22a-174-33a and -33b. • RCSA section 22a-174-33a(a)(4). The currently approved definition of “hazardous air pollutant” is deleted with the result that the newly revised definition in RCSA section 22a-174-1 will apply. • RCSA section 22a-174-33b(a)(10). The currently approved definition of “hazardous air pollutant” is deleted with the result that the newly revised definition in RCSA section 22a-174-1 will apply. <HD SOURCE="HD1">IV. Statutory and Executive Order Reviews</HD> Under the Clean Air Act, the Administrator is required to approve CAA Section 112(l) and Title V submissions that comply with the provisions of the Clean Air Act and applicable Federal regulations. Thus, in reviewing submissions, EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. Accordingly, this action merely approves state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this action: • Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Orders 12866 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 13k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━