Rule2025-20203
Air Plan Approval; Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
November 18, 2025
Effective
December 18, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is approving elements of a state implementation plan (SIP) submission from Montana regarding the infrastructure requirements of the Clean Air Act (CAA) for the 2015 8-hour ozone National Ambient Air Quality Standards (NAAQS). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. Additionally, EPA is finalizing approval of Montana's request to update their SIP to incorporate the most recent version of EPA's "Guidelines on Air Quality Models." EPA is taking this action pursuant to the CAA.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 220 (Tuesday, November 18, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 220 (Tuesday, November 18, 2025)]
[Rules and Regulations]
[Pages 51512-51515]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-20203]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2019-0418; FRL-12875-02-R8]
Air Plan Approval; Montana: Infrastructure Requirements for the
2015 Ozone National Ambient Air Quality Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The Environmental Protection Agency (EPA) is approving
elements of a state implementation plan (SIP) submission from Montana
regarding the infrastructure requirements of the Clean Air Act (CAA)
for the 2015 8-hour ozone National Ambient Air Quality Standards
(NAAQS). The infrastructure requirements are designed to ensure that
the structural components of each state's air quality management
program are adequate to meet the state's responsibilities under the
CAA. Additionally, EPA is finalizing approval of Montana's request to
update their SIP to incorporate the most recent version of EPA's
``Guidelines on Air Quality Models.'' EPA is taking this action
pursuant to the CAA.
DATES: This rule is effective on December 18, 2025.
ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-R08-OAR-2019-0418. All documents in the docket are listed on
the <a href="https://www.regulations.gov">https://www.regulations.gov</a> website. Although listed in the index,
some information is not publicly available, e.g., Confidential Business
Information (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 through
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, or please contact the person identified in
the FOR FURTHER INFORMATION CONTACT section for additional availability
information.
FOR FURTHER INFORMATION CONTACT: Amrita Singh, Air and Radiation
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver,
Colorado 80202-1129, telephone number: (303) 312-6103, email address:
<a href="/cdn-cgi/l/email-protection#fa8993949d92d49b9788938e9bba9f8a9bd49d958c"><span class="__cf_email__" data-cfemail="c7b4aea9a0afe9a6aab5aeb3a687a2b7a6e9a0a8b1">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and
``our'' means EPA.
I. Background
Under sections 110(a)(1) and (2) of the CAA, each state is required
to submit a SIP that provides for the implementation, maintenance, and
enforcement of a revised primary or secondary NAAQS or standard. CAA
sections 110(a)(1) and (2) requires each state to make a new SIP
submission within three years after EPA promulgates a new or revised
NAAQS
[[Page 51513]]
for approval into the existing federally approved SIP to assure that
the SIP meets the applicable requirements for new and revised NAAQS.
On July 16, 2025 EPA proposed to approve all elements of a SIP
submission from the Montana Department of Environmental Quality (MDEQ)
submitted on October 1, 2018 except for those previously approved in 87
FR 21578. We proposed approval for the following CAA section 110(a)(2)
infrastructure elements for the 2015 ozone NAAQS: (A), (B), (C),
(D)(i)(II), (D)(ii), (E), (F), (G), (H), (J), (K), (L) and (M).
Concurrently, EPA also proposed to approve revisions to appendix W
submitted on December 28, 2022. An explanation of the CAA requirements,
detailed analysis of the revisions, and EPA's reasons for proposing
approval were provided in the proposed rulemaking (90 FR 31911).
II. Response to Comments
During the public comment period of EPA's July 16, 2025, proposed
rulemaking, EPA received one anonymous comment in support of our action
and one anonymous adverse comment. A summary of the comments and EPA's
response are provided below.
Comment: The commentor urged EPA to consider the role of
CO<INF>2</INF> emissions and climate change in ozone formation when
reviewing the Montana infrastructure SIP for the 2015 ozone NAAQS. The
commentor stated that climate-change driven factors such as increased
temperatures, biogenic emissions, and wildfire activity is projected to
influence both the frequency and severity of ozone exceedances and
suggested that infrastructure SIPs should acknowledge the long-term
planning risks associated with climate-driven ozone trends.
Response: EPA appreciates the commenter's concern regarding the
influence of CO<INF>2</INF> emissions and climate change on ozone
formation and air quality. However, the scope of this action is limited
to determining whether Montana's SIP meets the infrastructure
requirements of CAA section 110(a)(1) and (2) for the 2015 ozone NAAQS.
These requirements address the basic structural elements of a state's
air quality management program. EPA's review of Montana's SIP
submission is limited to the applicable statutory and regulatory
requirements for infrastructure SIPs related to the 2015 ozone NAAQS,
which the submission satisfies. Therefore, the considerations raised by
the commentor are outside the scope of this rulemaking.
Comment: The commentor supported EPA's proposal to approve
Montana's infrastructure SIP submission for the 2015 ozone NAAQS,
noting that Montana has met the CAA's structural requirements. The
commentor encouraged EPA and the Montana Department of Environmental
Quality to ensure strong public education, transparency, and community
outreach efforts.
Response: EPA appreciates the commentor's support for this action.
The scope of this action is limited to evaluating whether Montana's SIP
submission meets the infrastructure requirements of the CAA section
110(a)(1) and (2) for the 2015 Ozone NAAQS. EPA has determined that
Montana's SIP submission satisfies the applicable statutory and
regulatory requirements for this action.
III. Final Action
EPA is approving the infrastructure SIP elements listed in table 1
below. These elements were included in a SIP submission from Montana
certifying that its current SIP is sufficient to meet the required
elements under section 110(a)(1) and (2) for the 2015 ozone NAAQS.
Additionally, EPA is approving the revisions to appendix W submitted by
the State of Montana on December 28, 2022.
Table 1--2015 Ozone NAAQS Infrastructure SIP Elements
----------------------------------------------------------------------------------------------------------------
Elements Approval status
----------------------------------------------------------------------------------------------------------------
(A): Emission Limitations and Other Control Approve.
Measures.
(B): Ambient Air Quality Monitoring/Data Approve.
System.
(C): Program for Enforcement of Control Approve.
Measures; minor NSR; PSD.
(D)(i)(I): Prong 1 Interstate Transport-- Previously approved in 87 FR 21578.
significant contribution.
(D)(i)(I): Prong 2 Interstate Transport-- Previously approved in 87 FR 21578.
interference with maintenance.
(D)(i)(II): Prong 3 Interstate Transport-- Approve.
PSD.
(D)(i)(II): Prong 4 Interstate Transport-- Previously approved in 87 FR 21578.
visibility.
(D)(ii): Interstate and International Approve.
Pollution Abatement.
(E): Adequate Personnel. Funding, and Approve.
Authority; State Boards; Local
Implementation.
(F): Stationary Source Monitoring........... Approve.
(G): Emergency Authority; Emergency Episode Approve.
Plans.
(H): Future SIP Revisions................... Approve.
(J): Consultation with Government Officials, Approve.
Public Notification, PSD and Visibility
Protection.
(K): Air Quality Modeling/Data.............. Approve.
(L): Permitting Fees........................ Approve.
(M): Consultation/Participation by Affected Approve.
Local Entities.
----------------------------------------------------------------------------------------------------------------
IV. Incorporation by Reference
In this document, EPA is finalizing regulatory text that includes
incorporation by reference. In accordance with requirements of 1 CFR
51.5, EPA is finalizing the incorporation by reference of appendix W
revisions submitted by the State of Montana as discussed in the
previously mentioned proposed rulemaking that can be found in the
Federal Register at 90 FR 31911. EPA has made, and will continue to
make, these materials generally available through <a href="https://www.regulations.gov">https://www.regulations.gov</a> and at the EPA Region 8 Office (please contact the
person identified in the FOR FURTHER INFORMATION CONTACT section of
this preamble for more information).
V. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the CAA 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 CAA. 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:
[[Page 51514]]
<bullet> Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Order 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 CAA.
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).
This action is subject to the Congressional Review Act (CRA), and
EPA will submit a rule report to each House of the Congress and to the
Comptroller General of the United States. This action is not a ``major
rule'' as defined by 5 U.S.C. 804(2).
Under section 307(b)(1) of the CAA, petitions for judicial review
of this action must be filed in the United States Court of Appeals for
the appropriate circuit by January 20, 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)).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Carbon monoxide,
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen
dioxide, Ozone, Particulate matter, Reporting and recordkeeping
requirements, Sulfur oxides, Volatile organic compounds.
Dated: October 29, 2025.
Cyrus M. Western,
Regional Administrator, Region 8.
For the reasons set forth in the preamble, the Environmental
Protection Agency is amending 40 CFR part 52 as follows:
PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
0
1. The authority citation for part 52 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
Subpart BB--Montana
0
2. In Sec. 52.1370:
0
a. The table in paragraph (c) is amended by revising the entry
``17.8.802''.
0
b. The table in paragraph (e) is amended by adding the entry
``Infrastructure Requirements for the 2015 8-hour Ozone National
Ambient Air Quality Standards'' under the heading entitled ``(1)
Statewide'' at the end of the section.
The revision and addition read as follows:
Sec. 52.1370 Identification of plan.
* * * * *
(c) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
State EPA final rule
State citation Rule title effective date date Final rule citation Comments
--------------------------------------------------------------------------------------------------------------------------------------------------------
(VI) Administrative Rules of Montana, Subchapter 08, Prevention of Significant Deterioration of Air Quality
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
17.8.802.......................... Incorporation By 5/13/2022 11/18/2025 90 FR [insert Federal Excluding (1)(c)-(d).
Reference Register page where
the document begins]
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * *
(e) * * *
----------------------------------------------------------------------------------------------------------------
Notice of
Title/subject State effective date final rule NFR citation
date
----------------------------------------------------------------------------------------------------------------
(1) Statewide
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Infrastructure Requirements for the 2015 N/A 11/18/2025 90 FR [insert Federal
8-hour Ozone National Ambient Air Register page where the
Quality Standards. document begins].
* * * * * * *
----------------------------------------------------------------------------------------------------------------
[[Page 51515]]
0
3. In Sec. 52.1394, add paragraph (c) to read as follows:
Sec. 52.1394 Section 110(a)(2) infrastructure requirements.
* * * * *
(c) On September 26, 2018, Steve Bullock, Governor, State of
Montana, submitted a certification letter which provides the State of
Montana's SIP provisions which meet the requirements of CAA section
110(a)(1) and (2) relevant to the 2015 8-hour Ozone NAAQS.
[FR Doc. 2025-20203 Filed 11-17-25; 8:45 am]
BILLING CODE 6560-50-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on November 18, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.