Air Plan Approval; Missouri; Control of NOX Emissions From Large Stationary Internal Combustion Engines

Issuing agencies

Abstract

The U.S. Environmental Protection Agency (EPA) is approving revisions to the Missouri State Implementation Plan (SIP) related to Control of Nitrogen Oxide (NO<INF>X</INF>) Emissions From Large Stationary Internal Combustion Engines. The revisions reformat and revise reporting, recordkeeping, and compliance requirements; incorporate other State rules by reference; add definitions specific to the rule; revise unnecessarily restrictive or duplicative language; and make administrative wording changes. The revisions also add an exemption for certain spark-ignited internal combustion engines. The EPA's final approval of this rule revision is being done in accordance with the requirements of the Clean Air Act (CAA).

Full Text

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<title>Federal Register, Volume 91 Issue 189 (Thursday, October 1, 2026)</title>
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[Federal Register Volume 91, Number 189 (Thursday, October 1, 2026)]
[Rules and Regulations]
[Pages 62320-62322]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-20096]



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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R07-OAR-2026-4819; FRL-13460-02-R7]


Air Plan Approval; Missouri; Control of NOX Emissions From Large 
Stationary Internal Combustion Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is approving 
revisions to the Missouri State Implementation Plan (SIP) related to 
Control of Nitrogen Oxide (NO<INF>X</INF>) Emissions From Large 
Stationary Internal Combustion Engines. The revisions reformat and 
revise reporting, recordkeeping, and compliance requirements; 
incorporate other State rules by reference; add definitions specific to 
the rule; revise unnecessarily restrictive or duplicative language; and 
make administrative wording changes. The revisions also add an 
exemption for certain spark-ignited internal combustion engines. The 
EPA's final approval of this rule revision is being done in accordance 
with the requirements of the Clean Air Act (CAA).

DATES: This rule is effective November 2, 2026.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-R07-OAR-2026-4819. 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, i.e., 
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 information.

FOR FURTHER INFORMATION CONTACT: William Stone, Environmental 
Protection Agency, Region 7 Office, Air Quality Planning Branch, 11201 
Renner Boulevard, Lenexa, Kansas 66219; telephone number: (913) 551-
7714; email address: <a href="/cdn-cgi/l/email-protection#26555249484308514f4a4a4f474b6643564708414950"><span class="__cf_email__" data-cfemail="deadaab1b0bbf0a9b7b2b2b7bfb39ebbaebff0b9b1a8">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' refer to the EPA. We use multiple abbreviations and terms in 
this rule. While this list may not be exhaustive, for ease of reading 
and for reference purposes, the EPA defines the following terms and 
acronyms here:

CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
CSR Missouri Code of State Regulations
EPA U.S. Environmental Protection Agency
FR Federal Register
IC Internal Combustion
NAAQS National Ambient Air Quality Standards
NO<INF>X</INF> Nitrogen Oxides
SIP State Implementation Plan
TSD Technical Support Document
U.S.C. United States Code

Table of Contents

I. What is being addressed in this document?
II. Have the requirements for approval of a SIP revision been met?
III. The EPA's Response to Comments
IV. What action is the EPA taking?
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews

I. What is being addressed in this document?

    The EPA is approving revisions to the Missouri SIP, Title 10 Code 
of State Regulations (CSR) 10-6.390 ``Control of NO<INF>X</INF> 
Emissions From Large Stationary Internal Combustion Engines,'' 
submitted to the EPA on March 7, 2019, and June 10, 2021. The purpose 
of the State regulation is to control NO<INF>X</INF> emissions from 
large stationary internal combustion (IC) engines and ensure compliance 
with the Federal NO<INF>X</INF> control plan to reduce the interstate 
transport of air pollutants. Missouri's rule revisions are detailed in 
the EPA's notice of proposed rulemaking, published on July 15, 2026.\1\ 
The EPA finds that these revisions meet the requirements of the CAA and 
do not impact the State's ability to attain or maintain the National 
Ambient Air Quality Standards (NAAQS). The full text of the rule 
revisions as well as the EPA's analysis of the revisions can be found 
in the technical support document (TSD) included in this docket.
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    \1\ 91 FR 43352 (July 15, 2026).
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II. Have the requirements for approval of a SIP revision been met?

    The State's submission has met the public notice requirements for 
SIP submissions in accordance with 40 CFR 51.102. The submission also 
satisfied the completeness criteria of 40 CFR part 51, appendix V. The 
State provided public notice on this SIP revision from August 4, 2018, 
to October 4, 2018, and from November 1, 2019, to December 10, 2019, 
and held public hearings on September 27, 2018, and December 3, 2019. 
The State received five comments during the first public comment period 
and none in the second comment period. Missouri's official submission 
adequately addressed the comments. In addition, as explained in the 
notice of proposed rulemaking and in more detail in the TSD, which is 
part of this docket, the revisions meet the substantive SIP 
requirements of the CAA, including section 110 and implementing 
regulations. The EPA concludes that in accordance with CAA section 
110(l), the revisions to 10 CSR 10-6.390 will not interfere with any 
applicable requirement concerning attainment, reasonable further 
progress, or any other applicable requirement of the CAA.

III. The EPA's Response to Comments

    The public comment period on the EPA's proposed rule opened July 
15, 2026, the date of its publication in the Federal Register, and 
closed on August 14, 2026. During this period, the EPA received one 
anonymous comment that was not supportive of the proposed action, 
available in the docket for this rulemaking, but did not raise a 
relevant, material objection with specificity that would constitute a 
significant comment requiring a response. See 5 U.S.C. 553(c); 42 
U.S.C. 7607(d)(6)(B).

IV. What action is the EPA taking?

    The EPA is taking final action to amend the Missouri SIP by 
approving the State's revisions to 10 CSR 10-6.390 ``Control of 
NO<INF>X</INF> Emissions From Large Stationary Internal Combustion 
Engines.'' This final action approves these amendments as part of the 
SIP.

V. Incorporation by Reference

    In this document, 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 
Missouri rule 10-6.390 discussed in section I. of this preamble and as 
set forth below in the amendments to 40 CFR part 52. The rule provides 
for control of NO<INF>X</INF> emissions from large stationary internal 
combustion engines and includes reporting, recordkeeping, and 
compliance requirements. The 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 7 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 the EPA for 
inclusion in the SIP, have been incorporated by

[[Page 62321]]

reference by the EPA into that plan, are fully federally enforceable 
under CAA sections 110 and 113 as of the effective date of the EPA's 
approval, and will be incorporated by reference in the next update to 
the SIP compilation.\2\
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    \2\ 62 FR 27968 (May 22, 1997).
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VI. 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, the 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:
    <bullet> Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Order 12866 (58 
FR 51735, Oct. 4, 1993);
    <bullet> Is not an Executive Order 14192 (90 FR 9065, Feb. 6, 2025) 
regulatory action because this action is not significant 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, Aug. 10, 1999);
    <bullet> Is not subject to Executive Order 13045 (62 FR 19885, Apr. 
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 the 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.\3\
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    \3\ 65 FR 67249 (Nov. 9, 2000)
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    This action is subject to the Congressional Review Act (CRA), and 
the 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 CAA section 307(b)(1), petitions for judicial review of this 
action must be filed in the United States Court of Appeals for the 
appropriate circuit by November 30, 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, Incorporation by 
reference, Intergovernmental relations, Nitrogen oxides, Ozone, 
Reporting and recordkeeping requirements.

    Dated: September 21, 2026.
James Macy,
Regional Administrator, Region 7.
    For the reasons stated in the preamble, the EPA amends 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 AA--Missouri

0
2. In Sec.  52.1320, the table in paragraph (c) is amended by revising 
the entry ``10-6.390'' to read as follows:


Sec.  52.1320  Identification of plan.

* * * * *
    (c) * * *

                                        EPA-Approved Missouri Regulations
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                                                              State
      Missouri citation                   Title             effective        EPA approval date       Explanation
                                                               date
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                                    Missouri Department of Natural Resources
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    Chapter 6--Air Quality Standards, Definitions, Sampling and Reference Methods, and Air Pollution Control
                                      Regulations for the State of Missouri
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                                                  * * * * * * *
10-6.390.....................  Control of NOX Emissions      5/30/2020  10/01/2026, 91 FR [insert
                                From Large Stationary                    Federal Register page
                                Internal Combustion                      where the document
                                Engines.                                 begins].
 
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[FR Doc. 2026-20096 Filed 9-30-26; 8:45 am]
BILLING CODE 6560-50-P


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