Rule2026-09612
Air Plan Approval; Indiana; Indiana NOX Emissions Monitoring
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
May 14, 2026
Effective
June 15, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is approving under the Clean Air Act (CAA) a request from the Indiana Department of Environmental Management (IDEM) to revise the Indiana State Implementation Plan (SIP) to incorporate revisions to nitrogen oxides (NO<INF>X</INF>) emissions monitoring, reporting, and recordkeeping requirements for new and existing large non-Electric Generating Units (non-EGUs) affected by the NO<INF>X</INF> SIP Call. This SIP revision would approve monitoring, reporting, and recordkeeping requirements that are permissible as alternatives under Federal rules for these sources for purposes of the NO<INF>X</INF> SIP Call.
Full Text
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<title>Federal Register, Volume 91 Issue 93 (Thursday, May 14, 2026)</title>
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[Federal Register Volume 91, Number 93 (Thursday, May 14, 2026)]
[Rules and Regulations]
[Pages 27214-27217]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-09612]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2021-0761; FRL-12258-02-R5]
Air Plan Approval; Indiana; Indiana NOX Emissions Monitoring
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency (EPA) is approving under
the Clean Air Act (CAA) a request from the Indiana Department of
Environmental Management (IDEM) to revise the Indiana State
Implementation Plan (SIP) to incorporate revisions to nitrogen oxides
(NO<INF>X</INF>) emissions monitoring, reporting, and recordkeeping
requirements for new and existing large non-Electric Generating Units
(non-EGUs) affected by the NO<INF>X</INF> SIP Call. This SIP revision
would approve monitoring, reporting, and recordkeeping requirements
that are permissible as alternatives under Federal rules for these
sources for purposes of the NO<INF>X</INF> SIP Call.
DATES: This final rule is effective on June 15, 2026.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-R05-OAR-2021-0761. 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), Proprietary Business
Information (PBI), 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 either
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: Cecilia Magos, Air and Radiation
Division (AR-18J), Environmental Protection Agency, Region 5, 77 West
Jackson Boulevard, Chicago, Illinois 60604, telephone number: (312)
886-7336, email address: <a href="/cdn-cgi/l/email-protection#147975737b673a7771777d787d75547164753a737b62"><span class="__cf_email__" data-cfemail="d6bbb7b1b9a5f8b5b3b5bfbabfb796b3a6b7f8b1b9a0">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean the EPA.
I. Background
Under the ``good neighbor provision'' of the CAA section
110(a)(2)(D)(i)(I), States are required to prohibit emissions within
their State that contribute significantly to nonattainment in, or
interfere with the maintenance of, the National Ambient Air Quality
Standards (NAAQS) in a downwind State. The EPA published a series of
regulations requiring eastern States, including Indiana, to comply with
statewide budgets limiting ozone season emissions of NO<INF>X</INF>, a
precursor to ozone, as well as annual emissions of NO<INF>X</INF> and
sulfur dioxide (SO<INF>2</INF>), precursors to fine particulate matter
(PM<INF>2.5</INF>). On October 27, 1998 (63 FR 57356), the EPA
published the NO<INF>X</INF> SIP Call pursuant to the good neighbor
provision for the 1979 ozone NAAQS. The NO<INF>X</INF> SIP Call
required eastern States to submit SIPs that prohibit excessive
emissions of ozone season NO<INF>X</INF> by complying with statewide
NO<INF>X</INF> emissions budgets. The NO<INF>X</INF> SIP Call also
established the NO<INF>X</INF> Budget Trading Program (NBTP), a
regional allowance trading program that States could adopt to meet most
of their obligations under the NO<INF>X</INF> SIP Call.
On August 8, 2011 (76 FR 48208), the EPA published the Cross-State
Air Pollution Rule (CSAPR), pursuant to the good neighbor provision of
the 1997 ozone NAAQS, 1997 PM<INF>2.5</INF> NAAQS, and the 2006
PM<INF>2.5</INF> NAAQS, establishing new statewide budgets for eastern
States for ozone season NO<INF>X</INF> emissions and annual
NO<INF>X</INF> and SO<INF>2</INF> emissions. State EGUs participating
in the CSAPR trading program for ozone season NO<INF>X</INF> emissions
generally addressed their NO<INF>X</INF> SIP Call obligations for EGUs
through the CSAPR trading program.
Indiana is meeting its obligation under the NO<INF>X</INF> SIP Call
for EGUs by participating in the CSAPR trading program for ozone season
NO<INF>X</INF> emissions. For large non-EGUs, Indiana is meeting its
NO<INF>X</INF> SIP Call obligations through the implementation of
emissions cap and monitoring requirements under the SIP-approved (85 FR
44738, July 24, 2020) State rule at 326 Indiana Administrative Code
(IAC) 10-2. Under 326 IAC 10-2, the affected large non-EGUs in the
State are required to monitor, report, and keep records of their mass
emissions of ozone season NO<INF>X</INF> in accordance with 40 CFR part
75.
On March 8, 2019 (84 FR 8422), the EPA published final amendments
to the
[[Page 27215]]
NO<INF>X</INF> SIP Call regulations giving States flexibility to
authorize other monitoring, recordkeeping and reporting requirements as
alternatives to the requirements of 40 CFR part 75 for large non-EGUs
for purposes of the NO<INF>X</INF> SIP Call. Ultimately, such
alternative monitoring requirements could be made available to sources
through the EPA approval of their State SIP revisions. On October 21,
2021, IDEM submitted a request to revise the Indiana SIP at 326 IAC 10-
2 to allow for alternative NO<INF>X</INF> monitoring, recordkeeping and
reporting requirements permitted under the newly published
NO<INF>X</INF> SIP Call amendments.
On April 21, 2025 (90 FR 16658), the EPA published a rulemaking
proposing to approve IDEM's October 21, 2021, request addressing
ongoing NO<INF>X</INF> SIP Call requirements with respect to most of
the State's affected large non-EGUs, specifically approve monitoring,
reporting, and recordkeeping requirements that are permissible as
alternatives to the part 75 monitoring requirements for purposes of the
NO<INF>X</INF> SIP Call. Public comments on the proposal were due by
May 21, 2025.
II. The EPA's Response to Comments
The EPA received one supportive comment recommending the EPA
finalize the proposed action and two adverse comments. Summaries of the
adverse comments and the EPA's responses are provided below. The
comments submitted during the public comment period are available in
the docket of this action.
Comment: A commenter recommends Indiana be prohibited from revising
its NO<INF>X</INF> emissions monitoring, noting such revisions will
lead to increased pollution.
Response: The EPA disagrees with this comment. An owner or operator
of a large non-EGU is required to apply for an operating permit or a
modification to an existing operating permit with an indication of the
alternative monitoring to be used and procedures being requested. The
request should demonstrate compliance sufficiently with existing ozone
season NO<INF>X</INF> emissions budgets established upon approval. The
request does not modify the established ozone season NO<INF>X</INF>
emissions budgets; it only modifies the monitoring procedures utilized.
As discussed in more detail in the proposed rule and below, the EPA
does not expect alternative monitoring procedures either to be
systematically biased toward understatement of emissions or to create
any incentive leading to increased emissions, as the commenter states.
IDEM must report all NO<INF>X</INF> emissions under this rule annually
to the EPA.
Comment: A commenter requests information on provisions that
prioritize air quality monitoring and target emissions reductions of
NO<INF>X</INF> and ozone pollution in communities of color and low-
income neighborhoods, citing an EPA 2021 environmental justice web
page.
Response: This rule does not establish new monitoring locations. It
applies to all sources affected by the NO<INF>X</INF> SIP Call and does
not involve targeted monitoring in certain communities.
Comment: A commenter questions how IDEM and the EPA will ``verify
that alternative monitoring and reporting methods do not systematically
underestimate NO<INF>X</INF> emissions, especially when emission
factors are used instead of continuous emissions monitoring systems
(CEMS).'' The commenter also references a journal article on
occupational air pollution exposure in urban workers.
Response: As stated in the proposal, the EPA acknowledges
alternative monitoring requirements may provide less detailed
monitoring data and require less rigorous quality assurance with a
consequently greater possibility that the total NO<INF>X</INF>
emissions amount reported by a source for a given ozone season might
understate or overstate the source's actual total emissions for that
ozone season to some degree. However, there is no reason to expect any
approved alternative monitoring methodology, including the use of
emission factors, either to be systematically biased toward
understatement of emissions or to create any incentive leading to
increased emissions. In the proposed rule, the EPA stated that no
changes to air emissions or air quality are expected because no changes
are being made to the NO<INF>X</INF> SIP Call's emissions requirements.
Additionally, the EPA does not find the cited journal article on
occupational air pollution exposure in urban workers to be relevant to
the concerns raised by the commenter. The cited article compares the
differences in air pollution exposure across a range of occupations in
urban workers, which the EPA does not find applicable for this action.
Comment: A commenter raised concerns on stack testing frequency and
the availability of stack testing data, requesting IDEM's commitment to
more frequent stack tests and public reporting. The commenter cited a
U.S. Government Accountability Office (GAO) report that recommends
identifying a federal entity to lead efforts to update methodologies
used to develop the social cost of carbon.
Response: This rulemaking is specific to the EPA's authority under
CAA section 110, to approve amendments to the Indiana SIP. The EPA
defers to States' choices regarding additional stack testing and
reporting, as such additional testing and reporting are not required by
Federal regulations. The cited report originates from the GAO, an
office within the legislative branch, and does not apply to the
authority of the EPA under the executive branch of the United States.
Comment: A commenter inquired about additional measures to prevent
gaps in NO<INF>X</INF> emissions data ``during transitions between
monitoring methods or when equipment malfunctions,'' and the
accessibility of such information to the public.
Response: IDEM's rule changes include revisions to monitoring
procedures that describe how NO<INF>X</INF> emissions will be accounted
for during periods of missing data, such as maintenance and
malfunctions, as inquired by the commenter. Additionally, if
alternative monitoring and reporting is requested within an ozone
control period, IDEM will require adequate description of the
transition process to ensure there will be no gaps in data collection
and reporting of ozone control period NO<INF>X</INF> emissions. As
stated, all alternative monitoring and reporting shall meet the
conditions of recording and reporting data in accordance with the terms
and conditions in the operating permit. These records must be made
available upon request. The EPA finds the requirements for the use of
approaches other than part 75 monitoring requests satisfactory. The
commenter cites an online web page that is not available, so the EPA
was unable to review that source.
Comment: A commenter questioned how the EPA and IDEM will ensure
alternative monitoring options do not weaken enforcement of ozone
season NO<INF>X</INF> caps or attainment of the NAAQS.
Response: The original purpose of the emission monitoring
requirements under the NO<INF>X</INF> SIP Call was to ensure compliance
with the control measures adopted to achieve the rule's emissions
reduction requirements. This action does not change NO<INF>X</INF>
emission budgets or the emissions from the impacted facilities. The
rule amendments to the NO<INF>X</INF> SIP Call published on March 8,
2019 (84 FR 8422), expanded the options available to States for
addressing the ongoing general requirements by allowing alternative
monitoring methods other than methods
[[Page 27216]]
in 40 CFR part 75 monitoring. Alternative monitoring requirements are
intended to potentially reduce monitoring costs. As stated previously,
alternative monitoring requirements are not meant to impact emissions
or air quality. Sources must submit an application for an operating
permit or a modification to an existing one to implement alternative
monitoring methods. And IDEM's rules require compliance with ozone
season emissions budget to implement an alternative monitoring method.
Alternative monitoring methods will provide adequate data to support
enforcement of ozone season NO<INF>X</INF> budgets as required under
the NO<INF>X</INF> SIP Call. Further, the commenter cites an online web
page that is not available.
Comment: A commenter questioned whether IDEM conducted cumulative
impact assessments ensuring alternative monitoring methods do not
exacerbate local NO<INF>X</INF> ``hotspots'' and asked about the public
availability of these assessments.
Response: The commenter cited a United States White House web page
that is no longer applicable nor available. This action is meant to
support monitoring and enforcement of ozone season NO<INF>X</INF>
budgets as required under the NO<INF>X</INF> SIP Call and does not
change any emission limits for sources that might be contributing to
local NO<INF>X</INF> hotspots.
Comment: A commentor requested information pertaining to the
reporting of worker safety and training associated with the
installation, maintenance, and operation of new monitoring systems.
Response: The EPA notes these comments are outside the scope of
this action and are not discussed further in this document. This
rulemaking addresses compliance with NO<INF>X</INF> SIP Call
regulations, which do not contain provisions related to worker safety
and training.
Comment: A commenter inquired whether the EPA or IDEM will track
possible co-benefits for greenhouse gas reductions and climate
resilience as a result of NO<INF>X</INF> emission reductions in
vulnerable communities.
Response: The commenter includes an online web page that is not
available, and these concerns are outside the scope of this action. As
previously stated, this rule does not change existing emission limits,
rather it allows for the use of alternative monitoring requirements in
compliance with NO<INF>X</INF> SIP Call emissions reductions.
Comment: A commenter inquired about the availability of all
monitoring and compliance data in a ``centralized, accessible, and
multilingual online database to promote transparency and community
engagement.''
Response: The commenter cites an online web page that is no longer
available. The EPA notes the changes in this rule pertain to the use of
non-part 75 monitoring requirements for reporting NO<INF>X</INF> ozone
season emissions. These alternative monitoring approaches require data
collection and reporting systems, in accordance with the terms and
conditions of the approved operating permit.
Comment: A commenter inquired about the EPA and IDEM's commitment
to re-evaluating ``the effectiveness and equity of these alternative
monitoring provisions every three years and updating the SIP
accordingly,'' citing an invalid web page presumably on the evolution
of the CAA.
Response: The comments fall outside the scope of this action and
the commenter cites an invalid online web page. There is no Federal
requirement for States to re-evaluate alternative monitoring provisions
or update a SIP every three years.
III. What Action Is the EPA Taking?
The EPA is approving IDEM's request to modify its SIP to revise
rule 326 IAC 10-2. Specifically, this includes revisions to 326 IAC 10-
2-3, 326 IAC 10-2-4, and 326 IAC 10-2-8 and the addition of 326 IAC 10-
2-8.5 to include alternative monitoring, recordkeeping and reporting
requirements.
IV. 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
Indiana Regulations described in section III of this preamble and set
forth in the amendments to 40 CFR part 52 below. 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 5 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 reference by the 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 the EPA's approval, and will
be incorporated by reference in the next update to the SIP
compilation.\1\
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\1\ 62 FR 27968 (May 22, 1997).
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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, 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, October 4, 1993);
<bullet> Is not an Executive Order 14192 (90 FR 9065, February 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, 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 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 (65 FR 67249, November 9,
2000).
This action is subject to the Congressional Review Act, and the EPA
[[Page 27217]]
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 July 13, 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,
Particulate matter, Reporting and recordkeeping requirements, Sulfur
oxides.
Dated: May 4, 2026.
Anne Vogel,
Regional Administrator, Region 5.
For the reasons stated in the preamble, 40 CFR part 52 is amended
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.
0
2. In Sec. 52.770, the table in paragraph (c) is amended by revising
the entry for ``10-2'' under the section titled ``Article 10. Nitrogen
Oxides'' to read as follows:
Sec. 52.770 Identification of plan.
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(c) * * *
EPA-Approved Indiana Regulations
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Indiana
Indiana citation Subject effective EPA approval date Notes
date
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Article 10. Nitrogen Oxides
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* * * * * * *
10-2.................... NOX Emissions from 10/21/2021 5/14/2026, 91 FR ....................
Large Affected Units. [INSERT FEDERAL
REGISTER PAGE WHERE
THE DOCUMENT BEGINS].
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[FR Doc. 2026-09612 Filed 5-13-26; 8:45 am]
BILLING CODE 6560-50-P
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