SUPPLEMENTARY INFORMATION:

Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA.

Table of Contents

I. Background and Purpose

II. Final Action

III. Incorporation by Reference

IV. Statutory and Executive Order Reviews

I. Background and Purpose

On November 28, 2025 (90 FR 54609), EPA published a Notice of Proposed Rulemaking (NPRM) for the State of Connecticut. The NPRM proposed approval of revisions to Connecticut's New Source Review (NSR) permit program, primarily to clarify applicability for stationary sources in nonattainment areas.

The formal SIP revision was submitted by The Connecticut Department of Energy and Environmental Protection (CT DEEP) on October 3, 2024.^[1] CT DEEP submitted a SIP revision containing changes to Regulations of Connecticut State Agencies (RCSA) sections 22a-174-3a(a)(2)(C)(ii), 22a-174-3a(l)(1)(B) and 22a-174-3a(l)(1)(C). These revisions to RCSA became effective, as a matter of state enforceability, on March 14, 2024.

The first revision made by CT DEEP is to RCSA section 22a-174-3a(a)(2)(C)(ii), which references the federal definition of a “non-road engine.” The citation to 40 CFR part 89 in this clause was amended to 40 CFR 1068.30 in order reflect the correct citation after EPA renumbering. The two other revisions relate to subsection (l) of RCSA section 22a-174-3a, which addresses permit requirements for nonattainment areas. Subparagraph (B) of subdivision (1) of subsection (l) is amended to clarify how the subsection applies to modifications. The revised text provides more detail on how changes to an existing unit may be considered a major modification. The amended text also includes references to the states' significant emission rate thresholds at Table 3a(k)-1. In subparagraph (C) of the same subdivision, the text is revised to add the phrase “for such pollutant” after “nonattainment area” for clarity.

The rationale for EPA's proposed action is explained in the NPRM and will not be restated here. No public comments were received on the NPRM. ( printed page 16557)

II. Final Action

EPA is approving the changes to RCSA sections 22a-174-3a(a)(2)(C)(ii), 22a-174-3a(l)(1)(B) and 22a-174-3a(l)(1)(C) as a revision to the Connecticut SIP.

III. Incorporation by Reference

In this rule, the EPA is finalizing regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, the EPA is finalizing the incorporation by reference of the RCSA section 22a-174-3a described in the amendments to 40 CFR part 52 set forth below. The EPA has made, and will continue to make, these documents generally available through https://www.regulations.gov and at the EPA Region 1 Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information). Therefore, these materials have been approved by EPA for inclusion in the State implementation plan, have been incorporated by reference by EPA into that plan, are fully federally enforceable under sections 110 and 113 of the CAA as of the effective date of the final rulemaking of EPA's approval, and will be incorporated by reference in the next update to the SIP compilation.^[2]

IV. Statutory and Executive Order Reviews

Under the Clean Air Act, the Administrator is required to approve a SIP submission that complies with the provisions of the Clean Air Act and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP 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 (58 FR 51735, October 4, 1993);
• Is not subject toExecutive Order 14192 (90 FR 9065, February 6, 2025) because SIP actions are exempt from review under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified inExecutive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject toExecutive Order 13045 (62 FR 19885, April 23, 1997) because it approves a state program;
• Is not a significant regulatory action subject toExecutive Order 13211 (66 FR 28355, May 22, 2001); and
• Is not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the Clean Air Act.

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the rule does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this action and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of the rule in the Federal Register . A major rule cannot take effect until 60 days after it is published in the Federal Register . This action is not a “major rule” as defined by 5 U.S.C. 804(2).

Under section 307(b)(1) of the Clean Air Act, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by June 1, 2026. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2).)

Authority: 42 U.S.C. 7401 et seq.

For the reasons stated in the preamble the Environmental Protection Agency amends part 52 of chapter I, title 40 of the Code of Federal Regulations, to read as follows:

91 FR 16556