Rule2025-15440
Air Plan Approval; Missouri; Removal of Obsolete Rules on Control of NOX Emissions
Primary source
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Published
August 14, 2025
Effective
September 15, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is taking final action to approve a revision to the State Implementation Plan (SIP) submitted by the Missouri Department of Natural Resources (MoDNR) on November 14, 2018. MoDNR requested that the EPA remove from its SIP two rules related to control of emissions of nitrogen oxides (NO<INF>X</INF>). One of the rules previously applied to electricity generating units (EGUs) and certain non-EGUs in a portion of the state and the other rule previously applied to EGUs throughout the entire state. The EPA has already approved a SIP revision that included provisions to sunset the two rules, and removal of the now-sunsetted rules from the SIP would not have an adverse effect on air quality. The EPA's 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 90 Issue 155 (Thursday, August 14, 2025)</title>
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[Federal Register Volume 90, Number 155 (Thursday, August 14, 2025)]
[Rules and Regulations]
[Pages 39128-39130]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-15440]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R07-OAR-2025-0138; FRL-12693-02-R7]
Air Plan Approval; Missouri; Removal of Obsolete Rules on Control
of NOX Emissions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency (EPA) is taking final
action to approve a revision to the State Implementation Plan (SIP)
submitted by the Missouri Department of Natural Resources (MoDNR) on
November 14, 2018. MoDNR requested that the EPA remove from its SIP two
rules related to control of emissions of nitrogen oxides
(NO<INF>X</INF>). One of the rules previously applied to electricity
generating units (EGUs) and certain non-EGUs in a portion of the state
and the other rule previously applied to EGUs throughout the entire
state. The EPA has already approved a SIP revision that included
provisions to sunset the two rules, and removal of the now-sunsetted
rules from the SIP would not have an adverse effect on air quality. The
EPA's approval of this rule revision is being done in accordance with
the requirements of the Clean Air Act (CAA).
DATES: This final rule is effective on September 15, 2025.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-R07-OAR-2025-0138. 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 Permitting and Planning Branch,
11201 Renner Boulevard, Lenexa, Kansas 66219; telephone number: (913)
551-7714; email address: <a href="/cdn-cgi/l/email-protection#77040318191259001e1b1b1e161a3712071659101801"><span class="__cf_email__" data-cfemail="acdfd8c3c2c982dbc5c0c0c5cdc1ecc9dccd82cbc3da">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and
``our'' refer to EPA.
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 the removal of 10 Code of State Regulations
(CSR) 10-6.360, Control of NOX Emissions From Electric Generating Units
and Non-Electric Generating Boilers (referred to here as the Missouri
NBTP Rule), and 10 CSR 10-6.350, Emission Limitations and Emissions
Trading of Oxides of Nitrogen (referred to here as the Missouri EGU
Emission Rate Rule), from the Missouri SIP.
II. Have the requirements for approval of a SIP revision been met?
The State 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 February 28,
2018, to April 5, 2018 and received one comment from the EPA.
Missouri's official submission addressed the EPA's comment. In
addition, as explained above the revision meets the substantive SIP
requirements of the CAA, including section 110 and implementing
regulations.
III. The EPA's Response to Comments
The public comment period on the EPA's proposed rule opened April
28, 2025, the date of its publication in the Federal Register and
closed on May 29, 2025. During this period, EPA received comments from
four commenters.
Comment 1: One comment did not identify a specific issue that was
relevant to the proposed rule and
[[Page 39129]]
therefore does not require a response. The comment can be found in the
docket for this action.
Comment 2: Two commenters were concerned that the removal of these
rules could lead to an increase in ``greenhouse gases (GHG) like Nox''
emissions.
Response: As stated in the proposal, the rules were sunsetted in
2009 and have not been in effect since that time. This action has no
effect on ozone-precursor emissions and thus, no direct or indirect
effects with respect to GHGs or climate change.
Comment 3: The commenter stated that EPA should require an analysis
of the air quality or public health impacts from removing these
NO<INF>X</INF> control rules, especially vulnerable and low-income
groups.
Response: Please see response to Comment 2. Because the rules were
sunsetted in 2009 and no substantive provisions of the Missouri NBTP
Rule and the Missouri EGU Emission Rate Rule remain operative, this
action has no effect on emissions or air quality.
Comment 4: The commenter stated that EPA should require Missouri to
correct a compliance gap for large non-EGUs in eastern Missouri with a
deadline.
Response: This action only removes obsolete provisions from the
Missouri SIP. As noted in the NPRM, while the EPA has identified the
existence of this compliance gap for NO<INF>X</INF> SIP Call-affected
large non-EGUs in eastern Missouri, the removal of the already-
sunsetted rules from the state's SIP would not have any effect on the
compliance gap. See 90 FR at 17754. As EPA further states in the NPRM,
the EPA remains ready to assist Missouri in remedying the gap, but that
remedy is beyond the scope of this action.
Comment 5: The commenter stated that EPA and Missouri should
perform environmental justice reviews to prevent disproportionate
impacts on marginalized, low-income, or Black communities for SIP
revisions.
Response: Please see response to Comment 3. Because no substantive
provisions of the Missouri NBTP Rule and the Missouri EGU Emission Rate
Rule remain operative, the rules currently have no effect on emissions
or air quality.
Comment 6: The commenter stated that NO<INF>X</INF> emissions,
seasonal trends and ozone readings should be publicly posted.
Response: The state of Missouri \1\ and the EPA publicly post ozone
levels from each monitor \2\ and annual NO<INF>X</INF> emissions are
publicly available from the EPA's National Emissions Inventory
(NEI).\3\ More detailed emissions data is available for sources
regulated by the EPA's Clean Air Markets Program Data (CAMPD).\4\
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\1\ Air Quality Analysis Ozone--Weekly Monitor Data [verbar]
Missouri Department of Natural Resources.
\2\ Air Quality Design Values [verbar] US EPA.
\3\ Get Air Emissions Data [verbar] US EPA.
\4\ Clean Air Markets Program Data (CAMPD) [verbar] US EPA.
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Comment 7: The commenter stated that the rule should be reinstated
if air quality deteriorates or the ozone non-attainment areas expand.
Response: As stated in the proposal, this rulemaking only removes
obsolete provisions of the Missouri SIP. Further, these rules are no
longer in effect and have not been since 2009. There are ongoing ozone
season requirements for EGU sources. Missouri's large EGUs continue to
participate in the interstate Cross-State Air Pollution Rule (CSAPR)
Ozone Season Group 2 Trading Program (the CSAPR OS G2 trading program),
as required by the Missouri CSAPR OS G2 Rule. See 90 FR at 17753. In
addition, for the state's NO<INF>X</INF> SIP Call-affected large non-
EGUs, the Missouri Clean Air Interstate Rule (CAIR) OS Rule's
requirements to monitor seasonal NO<INF>X</INF> emissions in accordance
with 40 CFR part 75 remain federally enforceable SIP requirements,
notwithstanding the fact that the EPA has stopped carrying out its
functions administering the trading program elements of that rule and
the fact that the state has removed the rule from the state's
regulations. Those monitoring requirements remain codified federal law.
See id. 17753-54.
Comment 8: The commenter stated that EPA should track GHG emission
co-benefits from EGU controls for NO<INF>X</INF>.
Response: As stated in the proposal, this rulemaking only removes
obsolete provisions of the Missouri SIP. GHG tracking is beyond the
scope of the rulemaking.
Comment 9: The commenter stated that Missouri should do meaningful
community engagement for SIP revisions and provide information in
multiple languages.
Response: The State submission has met the public notice
requirements for SIP submissions in accordance with 40 CFR 51.102.
Comment 10: The commenter stated that EPA should clarify how this
action will be impacted by pending litigation on interstate transport.
Response: Since the rules being removed are no longer in effect and
have not been since 2009, this action is not affected by or relevant to
more recent interstate transport litigation, which generally concerns
interstate transport obligations for the 2015 ozone NAAQS.
Comment 11: The commenter stated that EPA should require Missouri
to assess and mitigate any negative impacts on workers in the EGU and
non-EGU sectors, including air quality monitoring professionals during
regulatory transitions.
Response: As stated above, this rulemaking is limited to the
removal of obsolete SIP provisions for a program that EPA no longer
implements. This comment is outside the scope of the rulemaking.
Comment 12: The commenter stated that the SIP should mandate
periodic, data-driven reviews of NO<INF>X</INF> and ozone trends, with
automatic triggers for rule reassessment if air quality indicators
worsen or if EPA adopts new ozone standards.
Response: See response to Comment 10.
IV. What action is the EPA taking?
The EPA is taking final action to approve Missouri's request to
remove 10 CSR 10-6.350 and 10 CSR 10-6.360 from the SIP because the
rules are no longer operative.
V. Incorporation by Reference
In this document, the EPA is removing rules that were previously
incorporated by reference from the applicable Missouri SIP. In
accordance with requirements of 1 CFR 51.5, the EPA is removing 10 CSR
10-6.350 and 10 CSR 10-6.360 as discussed in section II. of this
preamble and as set forth below in the proposed revision to 40 CFR part
52.
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, 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 Orders 12866 (58
FR 51735, October 4, 1993);
<bullet> Is not subject to Executive Order 14192 (90 FR 9065,
February 6, 2025)
[[Page 39130]]
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 October 14, 2025. 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, and Ozone.
Dated: July 31, 2025.
James Macy,
Regional Administrator, Region 7.
For the reasons stated in the preamble, the EPA amends 40 CFR part
52 as set forth below:
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
Sec. 52.1320 [Amended]
0
2. In Sec. 52.1320, the table in paragraph (c) is amended by removing
the entries ``10-6.350'' and ``10-6.360'' under the heading ``Chapter
6--Air Quality Standards, Definitions, Sampling and Reference Methods,
and Air Pollution Control Regulations for the State of Missouri''.
[FR Doc. 2025-15440 Filed 8-13-25; 8:45 am]
BILLING CODE 6560-50-P
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