Proposed Rule2025-21413
Air Plan Approval; Connecticut; New Source Review Permit Program State Plan Revision
Primary source
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Published
November 28, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Connecticut. This action consists of revisions to Connecticut's New Source Review (NSR) permit program, primarily to clarify applicability for stationary sources in nonattainment areas. This action is being taken under the Clean Air Act (CAA).
Full Text
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<title>Federal Register, Volume 90 Issue 227 (Friday, November 28, 2025)</title>
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[Federal Register Volume 90, Number 227 (Friday, November 28, 2025)]
[Proposed Rules]
[Pages 54609-54611]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-21413]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R01-OAR-2025-0653; FRL-13092-01-R1]
Air Plan Approval; Connecticut; New Source Review Permit Program
State Plan Revision
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve a State Implementation Plan (SIP) revision submitted by the
State of Connecticut. This action consists of revisions to
Connecticut's New Source Review (NSR) permit program, primarily to
clarify applicability for stationary sources in nonattainment areas.
This action is being taken under the Clean Air Act (CAA).
DATES: Written comments must be received on or before December 29,
2025.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R01-
OAR-2025-0653 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>, or via email to
<a href="/cdn-cgi/l/email-protection#99edecebf7fcebb7f8f7fdebfcd9fce9f8b7fef6ef"><span class="__cf_email__" data-cfemail="90e4e5e2fef5e2bef1fef4e2f5d0f5e0f1bef7ffe6">[email protected]</span></a>. For comments submitted at <a href="http://Regulations.gov">Regulations.gov</a>, follow
the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. For either
manner of submission, the EPA may publish any comment received to its
public docket. Do not submit electronically any information you
consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia
submissions (audio, video, etc.) must be accompanied by a written
comment. The written comment is considered the official comment and
should include discussion of all points you wish to make. The EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the web, cloud, or other file sharing
system). For additional submission methods, please contact the person
identified in the FOR FURTHER INFORMATION CONTACT section. For the full
EPA public comment policy, information about CBI or multimedia
submissions, and general guidance on making effective comments, please
visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>. Publicly
available docket materials are available at <a href="https://www.regulations.gov">https://www.regulations.gov</a>
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 FOR FURTHER INFORMATION CONTACT section to
schedule your inspection.
FOR FURTHER INFORMATION CONTACT: Andre Turner, U.S. Environmental
Protection Agency, Region 1 Office of Air and Radiation Division, 5
Post Office Square, Suite 100, Boston, MA 02109, Phone number: (617)
918-1216, Email: <a href="/cdn-cgi/l/email-protection#146061667a71663a757a706671547164753a737b62"><span class="__cf_email__" data-cfemail="a2d6d7d0ccc7d08cc3ccc6d0c7e2c7d2c38cc5cdd4">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.
Table of Contents
I. Background
II. Description and Review of Submittal
III. EPA's Evaluation of CT DEEP's Submittal
1. RCSA Section 22a-174-3a(a)(2)(C)(ii)
[[Page 54610]]
2. RCSA Section 22a-174-3a(l)(1)(B)
3. RCSA Section 22a-174-3a(l)(1)(C)
IV. Proposed Action
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews
I. Background
The Connecticut Department of Energy and Environmental Protection
(CT DEEP) established its SIP, including its NSR permit program, in
1972 in accordance with CAA section 110 and 40 CFR part 51. Since then,
there have been numerous revisions to the SIP in accordance with state
and federal air permitting regulations. The most recent federally
enforceable revision to Connecticut's NSR permit program was approved
into the SIP by EPA on September 5, 2023, and included changes to
sections 22a-174-2a and 22a-174-3a of the Regulations of Connecticut
State Agencies (RCSA).
II. Description and Review of Submittal
On October 3, 2024,\1\ CT DEEP submitted a SIP revision containing
changes to RCSA section 22a-174-3a, primarily to clarify the
applicability of Connecticut's permit requirements for stationary
sources in nonattainment areas. These revisions to RCSA became
effective, as a matter of state enforceability, on March 14, 2024.
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\1\ The Connecticut SIP cover letter lists a submittal date of
June 27, 2024, however EPA received this through the online
submittal system State Planning Electronic Collaboration System
(SPeCS) on October 3, 2024.
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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 Table 3a(k)-1, which lists the significant
emission rate threshold values for pollutants and their precursors. In
subparagraph (C) of the same subdivision, the text is revised to add
the phrase ``for such pollutant'' after ``nonattainment area'' for
clarity.
III. EPA's Evaluation of CT DEEP's Submittal
EPA has reviewed the following revisions to RCSA section 22a-174-3a
submitted by CT DEEP.
1. RCSA Section 22a-174-3a(a)(2)(C)(ii)
CT DEEP revised this provision to replace the outdated reference to
40 CFR part 89 with the current federal definition of ``nonroad
engine'' at 40 CFR 1068.30. EPA has determined that this correction
does not change the applicability of the exemption for nonroad engines
but ensures that the state regulation references the appropriate
federal definition.
2. RCSA Section 22a-174-3a(l)(1)(B)
CT DEEP revised this provision to clarify the applicability of
nonattainment new source review (NNSR) requirements to modifications at
major stationary sources. The revised regulations clarify that the NNSR
program applies to two categories of modifications:
(i) modifications to an emission unit that is itself a major
stationary source that triggers NNSR when the modification results in a
significant emissions increase equal to or greater than the significant
emission rate thresholds of a pollutant (or their precursors) for which
the area is designated as nonattainment; or
(ii) modifications to a premises that is a major stationary source
that triggers NNSR when the modification results in a net emissions
increase equal to or greater than the significant emission rate
threshold of a pollutant (or their precursors) for which the area is
designated as nonattainment.
The revisions to 22a-174-3a(l)(1)(B) do not change NNSR
applicability thresholds, offset obligations, or control technology
requirements, but rather clarify the circumstances that a modification
may be considered major and trigger NNSR to either a unit itself or to
a premises that is considered a major stationary source. EPA has
determined that this revision appropriately clarifies NNSR
applicability for major modifications and is consistent with EPA's 40
CFR 51.165 requirements for state NNSR programs.
3. RCSA Section 22a-174-3a(l)(1)(C)
CT DEEP revised this provision by adding the phrase ``for such a
pollutant'' after ``nonattainment area.'' This revision clarifies that
NNSR requirements apply only to nonattainment pollutants (and their
precursors) at new major stationary sources and modifications at
existing major stationary sources located in nonattainment areas. The
revisions to 22a-174-3a(l)(1)(C) do not change NNSR applicability
thresholds, offset obligations, or control technology requirements. EPA
has determined that this revision clarifies NNSR applicability and is
consistent with EPA's 40 CFR 51.165 requirements for state NNSR
programs.
IV. Proposed Action
EPA is proposing to approve Connecticut's October 3, 2024, SIP
submittal that addresses revisions to RCSA section 22a-174-3a. EPA is
soliciting public comments on the issues discussed in this notice or on
other relevant matters. These comments will be considered before taking
final action. Interested parties may participate in the Federal
rulemaking procedure by submitting written comments to this proposed
rule by following the instructions listed in the ADDRESSES section of
this Federal Register.
V. Incorporation by Reference
In this rule, the EPA is proposing to include in a final EPA rule
regulatory text that includes incorporation by reference. In accordance
with requirements of 1 CFR 51.5, the EPA is proposing to incorporate by
reference the changes to RCSA section 22a-174-3a as adopted on March
14, 2024, and discussed in Section II of this preamble. The EPA has
made, and will continue to make, these documents generally available
through <a href="https://www.regulations.gov">https://www.regulations.gov</a> 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).
VI. 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. See 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 proposed 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
proposed action:
<bullet> Is not a significant regulatory action subject to review
by the Office of Management and Budget under
[[Page 54611]]
Executive Orders 12866 (58 FR 51735, October 4, 1993);
<bullet> Is not subject to Executive Order 14192 (90 FR 9065,
February 6, 2025) because SIP actions are exempt from review under
Executive Order 12866;
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> 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.);
<bullet> 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);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it approves a state program;
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
<bullet> 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).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.
Dated: November 20, 2025.
Mark Sanborn,
Regional Administrator, EPA Region 1.
[FR Doc. 2025-21413 Filed 11-26-25; 8:45 am]
BILLING CODE 6560-50-P
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