Proposed Rule2026-17499
Air Plan Approval; Oklahoma; Regional Haze Plan for the First Implementation Revision; Revision to State Implementation Plan and Requirements
Primary source
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Published
August 27, 2026
Issuing agencies
Environmental Protection Agency
Abstract
Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is proposing to approve the State implementation plan (SIP) revision submitted by the State of Oklahoma on March 12, 2026, (Oklahoma's 2026 SIP submission) for the regional haze program's first implementation (planning) period. Oklahoma's 2026 SIP submission revises previously approved source-specific requirements for the American Electric Power/Public Service of Oklahoma (AEP/PSO) Northeastern Power Station as part of the State's long-term strategy for the first planning period. The EPA is proposing to find that this SIP revision meets the requirements of the CAA and the Regional Haze Rule.
Full Text
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<title>Federal Register, Volume 91 Issue 165 (Thursday, August 27, 2026)</title>
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[Federal Register Volume 91, Number 165 (Thursday, August 27, 2026)]
[Proposed Rules]
[Pages 55287-55294]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-17499]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R06-OAR-2026-2080; FRL-13425-01-R6]
Air Plan Approval; Oklahoma; Regional Haze Plan for the First
Implementation Revision; Revision to State Implementation Plan and
Requirements
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the
Environmental Protection Agency (EPA) is proposing to approve the State
implementation plan (SIP) revision submitted by the State of Oklahoma
on March 12, 2026, (Oklahoma's 2026 SIP submission) for the regional
haze program's first implementation (planning) period. Oklahoma's 2026
SIP submission revises previously approved source-specific requirements
for the American Electric Power/Public Service of Oklahoma (AEP/PSO)
Northeastern Power Station as part of the State's long-term strategy
for the first planning period. The EPA is proposing to find that this
SIP revision meets the requirements of the CAA and the Regional Haze
Rule.
DATES: Written comments must be received on or before September 28,
2026.
ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2026-2080, at <a href="https://www.regulations.gov">https://www.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>. 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 persons 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>.
Docket: The index to the docket for this action is available
electronically at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. While all documents in
the docket are listed in the index, some information may not be
publicly available due to docket file size restrictions or content
(e.g., CBI).
FOR FURTHER INFORMATION CONTACT: Karolina Ruan Lei, EPA Region 6
Office, Air and Radiation Division, Regional Haze and SO<INF>2</INF>
Section, telephone number: 214-665-7346; email address: <a href="/cdn-cgi/l/email-protection#aedcdbcfc083c2cbc780c5cfdcc1c2c7c0cfeecbdecf80c9c1d8"><span class="__cf_email__" data-cfemail="6a181f0b0447060f0344010b18050603040b2a0f1a0b440d051c">[email protected]</span></a>. We encourage the public to submit comments via
<a href="https://www.regulations.gov">https://www.regulations.gov</a>. Please call or email the contacts listed
above if you need alternative access to material indexed but not
provided in the docket.
SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,''
``us,'' or ``our'' is used, we mean the EPA.
I. What action is the EPA proposing?
The EPA is proposing to approve a revision to the Oklahoma SIP for
the regional haze first implementation period that revises source-
specific requirements for the American Electric Power/Public Service of
Oklahoma (AEP/PSO) \1\ Northeastern Power Station that are part of the
State's long-term strategy. Specifically, this action proposes to
remove the requirement that PSO Northeastern Unit 3 cease operations by
December 31, 2026, and allow the unit to continue operations as a
natural gas-fired unit. In addition, consistent with the requirements
of Clean Air Act Section 110(l) this action proposes to approve
reductions in nitrogen oxides (NO<INF>X</INF>) emissions at Unit 2. The
EPA is proposing to find that Oklahoma's 2026 SIP submission, with the
accompanying revised regional haze agreement for PSO Northeastern,
satisfies the long-term strategy regulatory requirements from the first
planning period under the regional haze program.\2\
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\1\ Public Service Company (PSO) is a subsidiary of American
Electric Power (AEP). Throughout this document, AEP/PSO Northeastern
Power Station may be used interchangeably with PSO Northeastern.
\2\ 40 CFR 51.308(d)(3).
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II. Background and Requirements for Regional Haze First Planning Period
Plans
In the 1977 CAA amendments, Congress created a program for
protecting visibility in the nation's mandatory Class I Federal areas,
which include certain national parks and wilderness areas. The CAA
under section 169A establishes as a national goal the ``prevention of
any future, and the remedying of any existing, impairment of visibility
in mandatory class I Federal areas which impairment results from
manmade air pollution.'' \3\
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\3\ CAA section 169A(a)(1).
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Regional haze is visibility impairment that is produced by a
multitude of anthropogenic sources and activities that are located
across a broad geographic area and that emit pollutants that impair
visibility. Visibility impairing pollutants include fine and coarse
particulate matter (PM) (e.g., sulfates, nitrates, organic carbon,
elemental carbon, and soil dust) and their precursors (e.g., sulfur
dioxide (SO<INF>2</INF>), nitrogen oxides (NO<INF>X</INF>), and, in
some cases, volatile organic compounds (VOC) and ammonia
(NH<INF>3</INF>)). Fine particle precursors react in the atmosphere to
form fine particulate matter (PM<INF>2.5</INF>), which impairs
visibility by scattering and absorbing light. Visibility impairment
reduces the
[[Page 55288]]
perception of clarity and color, as well as visible distance.\4\
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\4\ There are several ways to measure the amount of visibility
impairment, i.e., haze. One such measurement is the deciview, which
is the principal metric used by the RHR. Under many circumstances, a
change in one deciview will be perceived by the human eye to be the
same on both clear and hazy days. The deciview is unitless. It is
proportional to the logarithm of the atmospheric extinction of
light, which is the perceived dimming of light due to its being
scattered and absorbed as it passes through the atmosphere.
Atmospheric light extinction (b\ext\) is a metric used for
expressing visibility and is measured in inverse megameters
(Mm<SUP>-1</SUP>). The formula for the deciview is 10 ln (b\ext\)/10
Mm<SUP>-1</SUP>). 40 CFR 51.301.
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To address regional haze visibility impairment, the 1999 Regional
Haze Rule (RHR) established an iterative planning process that requires
both States in which Class I areas are located and States ``the
emissions from which may reasonably be anticipated to cause or
contribute to any impairment of visibility'' in a Class I area to
periodically submit SIP revisions to address such impairment (CAA
section 169A(b)(2); \5\ see also 40 CFR 51.308(b) and (f) (establishing
submission dates for iterative regional haze SIP revisions); 64 FR
35714 at 64 FR 35768 (July 1, 1999)).
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\5\ The RHR expresses the statutory requirement for States to
submit plans addressing out-of-state Class I areas by providing that
States must address visibility impairment ``in each mandatory Class
I Federal area located outside the State that may be affected by
emissions from within the State.'' 40 CFR 51.308(d), (f).
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Much of the focus in the first implementation period of the
regional haze program, which ran from 2007 through 2018, was on
satisfying States' Best Available Retrofit Technology (BART)
obligations.\6\ First implementation period SIPs were additionally
required to contain long-term strategies for making reasonable progress
toward the national visibility goal, of which BART is one component.
The long-term strategy is the compilation of ``enforceable emissions
limitations, compliance schedules, and other measures as necessary to
achieve the [reasonable progress goals (RPGs)],'' \7\ and is the means
through which the State ensures that its RPG will be met. The core
required elements for the first implementation period SIPs (other than
BART) are laid out in 40 CFR 51.308(d). The RHR gives States wide
latitude to determine the set of source categories and control measures
for the long-term strategy and the related reasonable progress goals
(RPGs). Those provisions required that States containing Class I areas
establish RPGs that are measured in deciviews and reflect the
anticipated visibility conditions at the end of the implementation
period including from implementation of States' long-term strategies.
The first planning period RPGs were required to provide for an
improvement in visibility for the most impaired days over the period of
the implementation plan and ensure no degradation in visibility for the
least impaired days over the same period. In establishing the RPGs for
any Class I area in a State, the State was required to consider four
statutory factors: the costs of compliance, the time necessary for
compliance, the energy and nonair quality environmental impacts of
compliance, and the remaining useful life of any potentially affected
sources.\8\
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\6\ 40 CFR 51.308(e).
\7\ 40 CFR 51.308(d)(3).
\8\ CAA 169A(g)(1); 40 CFR 51.308(d)(1).
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States were also required to calculate baseline (using the five
year period of 2000 through 2004) and natural visibility conditions
(i.e., visibility conditions without anthropogenic visibility
impairment) for each Class I area, and to calculate the linear rate of
progress needed to attain natural visibility conditions, assuming a
starting point of baseline visibility conditions in 2004 and ending
with natural conditions in 2064. This linear interpolation is known as
the uniform rate of progress (URP) and is used as a tracking metric to
help States assess the amount of progress they are making towards the
national visibility goal over time in each Class I area.\9\ The 1999
RHR also provided that States' long-term strategies must include the
``enforceable emissions limitations, compliance, schedules, and other
measures as necessary to achieve the reasonable progress goals.'' \10\
In establishing their long-term strategies, States are required to
consult with other States that also contribute to visibility impairment
in a given Class I area and include all measures necessary to obtain
their shares of the emission reductions needed to meet the RPGs.\11\
Section 51.308(d) also contains seven additional factors States must
consider in formulating their long-term strategies, 40 CFR
51.308(d)(3)(v), as well as provisions governing monitoring and other
implementation plan requirements.\12\
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\9\ The EPA established the URP framework in the 1999 RHR to
provide ``an equitable analytical approach'' to assessing the rate
of visibility improvement at Class I areas across the country. The
starting point for the URP analysis is 2004 and the endpoint was
calculated based on the amount of visibility improvement that was
anticipated to result from implementation of existing CAA programs
over the period from the mid-1990s to approximately 2005. Assuming
this rate of progress would continue into the future, the EPA
determined that natural visibility conditions would be reached in 60
years, or 2064 (60 years from the baseline starting point of 2004).
However, the EPA did not establish 2064 as the year by which the
national goal must be reached (64 FR 35714 at 64 FR 35731 through
35732, July 1, 1999). That is, the URP and the 2064 date are not
enforceable targets but are rather tools that ``allow for analytical
comparisons between the rate of progress that would be achieved by
the State's chosen set of control measures and the URP.'' (82 FR
3078 at 82 FR 3084, January 10, 2017).
\10\ 40 CFR 51.308(d)(3).
\11\ 40 CFR 51.308(d)(3)(i), (ii).
\12\ 40 CFR 51.308(d)(4).
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Finally, the 1999 RHR required States to consult with the Federal
Land Manager(s) \13\ (FLMs) responsible for each Class I area according
to the requirements in CAA section 169A(d) and 40 CFR 51.308(i).
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\13\ The EPA's regulations define ``Federal Land Manager'' as
``the Secretary of the department with authority over the Federal
Class I area (or the Secretary's designee) or, with respect to
Roosevelt-Campobello International Park, the Chairman of the
Roosevelt-Campobello International Park Commission.'' 40 CFR 51.301.
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III. Rulemaking History on Oklahoma's Regional Haze Plans for the AEP
PSO Northeastern Facility
A. Oklahoma's Regional Haze Plan for the First Implementation Period
Oklahoma submitted its regional haze SIP for the first
implementation period to the EPA on February 19, 2010. On December 28,
2011 (76 FR 81728), the EPA partially approved certain requirements for
the PSO Northeastern facility as provided in the 2010 Oklahoma regional
haze SIP. As part of that action, we approved Oklahoma's
SO<INF>2</INF>, NO<INF>X</INF>, and PM BART determinations for PSO
Northeastern Unit 2, and the NO<INF>X</INF> and PM BART determinations
for PSO Northeastern Units 3 and 4. Specifically, we approved
Oklahoma's determination that for Unit 2, the NO<INF>X</INF> BART
emission limit is 0.28 pounds per million British thermal units (lbs/
MMBtu) on a 30-day rolling average. As Unit 2 is gas fired, the
Oklahoma Department of Environmental Quality (ODEQ) determined that no
additional controls were necessary for SO<INF>2</INF> and PM BART. For
Units 3 and 4, we approved Oklahoma's determination that the
NO<INF>X</INF> BART emission limit is 0.15 lbs/MMBtu on a 30-day
rolling average. In that same 2011 action, we disapproved Oklahoma's
SO<INF>2</INF> BART determination for PSO Northeastern Units 3 and 4
and promulgated a Federal implementation plan (FIP) that imposed
SO<INF>2</INF> BART emission limits for these units.
The State of Oklahoma and AEP/PSO filed Petitions for Review \14\
of the FIP,
[[Page 55289]]
and both parties separately entered into a settlement agreement with
the EPA and Sierra Club (``2013 PSO Settlement Agreement,'' formalized
February 8, 2013), which included a timeline for preparing and
processing a SIP that would implement a comprehensive strategy for PSO
and Oklahoma to comply with its obligations with respect to visibility
and interstate transport provisions of the CAA.\15\ On March 7, 2014
(79 FR 12944), the EPA approved the 2013 Oklahoma regional haze SIP
\16\ that replaced and approved SO<INF>2</INF> BART requirements for
the PSO Northeastern Units 3 and 4 and concurrently withdrew the FIP's
applicability to these two units. In that same 2014 action (79 FR
12944, March 7, 2014), the EPA approved revised NO<INF>X</INF> BART
compliance schedules for these two units as well as requirements
providing for further reductions for NO<INF>X</INF> and SO<INF>2</INF>
through reductions in maximum utilization. Specifically, the approved
Oklahoma revised SO<INF>2</INF> BART determination included interim
SO<INF>2</INF> emission limits for Units 3 and 4 of 0.60 lbs/MMBtu
(with additional caps on combined annual SO<INF>2</INF> emissions)
until 2016 when AEP/PSO would retire one of the two units. The unit
remaining in operation had an SO<INF>2</INF> emission limit of 0.40
lbs/MMBtu on a 30-day rolling average basis through December 31, 2026,
when the remaining unit would cease operation. Currently, Oklahoma has
SIP-approved regional haze first planning period requirements that
provide for emission controls and compliance schedules for PSO
Northeastern Units 2, 3, and 4.
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\14\ Public Service Company of Oklahoma v. U.S. Environmental
Protection Agency, et al., No. 12-9525 (10th Cir, filed February 24,
2012). Sierra Club filed a Motion to Intervene on March 26, 2012,
which was granted on March 27, 2012.
\15\ A copy of the settlement agreement may be found in Appendix
I of the 2013 Oklahoma regional haze SIP. As stated in our August
21, 2013, proposal (78 FR 51686), the settlement agreement did not
dictate the EPA's final determination with respect to the submitted
SIP revision; that approval is based on our statutorily prescribed
role of reviewing the submitted SIP revision for consistency with
the requirements of the CAA.
\16\ The 2013 Oklahoma regional haze SIP was Oklahoma's first
revision to its first planning period regional haze SIP (the 2010
Oklahoma regional haze SIP).
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As part of the approval of Oklahoma's regional haze SIP
submissions, the EPA approved Oklahoma's BART determinations for PSO
Northeastern facility, which included provisions contained in the ``PSO
Regional Haze Agreement, DEQ Case No. 10-025 (February 10, 2010)''
(``2010 PSO Regional Haze Agreement''), as amended by the ``First
Amended Regional Haze Agreement, DEQ Case No. 10-025 (March 26, 2013)''
(``2013 PSO Regional Haze Agreement'').\17\
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\17\ See the docket for this action for the ``PSO Regional Haze
Agreement, DEQ Case No. 10-025 (February 10, 2010)'' (``2010 PSO
Regional Haze Agreement''), and the ``First Amended Regional Haze
Agreement, DEQ Case No. 10-025 (March 26, 2013)'' (``2013 PSO
Regional Haze Agreement'').
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In sum, the NO<INF>X</INF> requirements for PSO Northeastern Unit 2
and initial NO<INF>X</INF> requirements for Units 3 and 4 are contained
in the 2010 PSO Regional Haze Agreement. The SO<INF>2</INF>
requirements and revised NO<INF>X</INF> compliance schedules for Units
3 and 4, including requirements for reduced utilization and cessation
of operation of these units, are contained in the 2013 PSO Regional
Haze Agreement.\18\
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\18\ Although the PM determination and requirements for PSO
Northeastern Units 2, 3, and 4 as provided in the 2010 Oklahoma
regional haze SIP and 2010 PSO Regional Haze Agreement were also
approved by the EPA, it is not discussed in detail in this proposal
as part of the EPA's evaluation as the proposed changes in
Oklahoma's 2026 SIP submission only discusses revisions in
NO<INF>X</INF> and SO<INF>2</INF> requirements for these units.
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B. Oklahoma's 2026 SIP Submission for the Regional Haze First
Implementation Period
On March 12, 2026, the Oklahoma Department of Environmental Quality
(ODEQ) \19\ submitted a SIP revision to amend certain source-specific
requirements for the PSO Northeastern facility and included a revised
agreement as the enforceable mechanism. Our evaluation of this SIP
submission is provided in the following section.
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\19\ In this document, ODEQ and Oklahoma are used
interchangeably.
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IV. The EPA's Evaluation of Oklahoma's 2026 SIP Submission
A. Background for the Revised PSO Northeastern Facility's Source-
Specific Requirements
AEP/PSO Northeastern Power Station is an electric utility located
in Rogers County, Oklahoma. PSO Northeastern Units 2, 3, and 4 were
BART-eligible sources under the regional haze program first planning
period.\20\ Unit 2 is a gas-fired boiler with a gross output of 495 MW.
Units 3 and 4 are or were coal-fired boilers, permitted to fire coal
and/or natural gas, with gross outputs of 490 MW each. Consistent with
Oklahoma regional haze SIP requirements for the first planning period,
AEP/PSO elected to retire Unit 4 on April 16, 2016, and only Units 2
and 3 are currently in operation.
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\20\ In our review and action on the 2010 Oklahoma regional haze
SIP, we agreed with Oklahoma's identification of sources that are
BART-eligible and subject to BART, including Units 2, 3 and 4 of the
PSO Northeastern facility (76 FR 81728, December 28, 2011).
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More information and our evaluation of the proposed changes to the
regional haze SIP requirements for PSO Northeastern Units 2 and 3 are
provided in sections IV.A.1 and IV.A.2. of this document.
1. Oklahoma's Revisions to Requirements for AEP/PSO Northeastern Units
2 and 3
In 2024, AEP/PSO notified ODEQ that they would not be able to
comply with the Southwest Power Pool's (SPP) increasing electric
generation demands if Northeastern Unit 3 is required to cease
operation on December 31, 2026, as stipulated in the 2013 settlement
agreement and SIP. Therefore, to ensure reliable power in Oklahoma,
AEP/PSO requested that Unit 3 be allowed to continue operating past
this deadline as a natural gas-fired unit. Operating on natural gas
will limit Unit 3's SO<INF>2</INF> emissions to a negligible 2.34 tons
per year (TPY). In addition, AEP/PSO committed to an annual
NO<INF>X</INF> emission limit of 300 TPY on Unit 3 and lowering the
allowable NO<INF>X</INF> emissions of Unit 2 by 300 TPY to address CAA
section 110(l) requirements with respect to the NO<INF>X</INF>
emissions from the continued operation of Unit 3.
On August 2, 2024, the Sierra Club and PSO executed a new
settlement agreement based on these terms. The agreement provides for
Northeastern Unit 3 continuing to operate as a natural gas-fired power
plant, contingent upon ODEQ developing and EPA approving a SIP
revision.\21\ On May 14, 2025, ODEQ and PSO executed the ``Second
Amended Regional Haze Agreement, DEQ Case No. 10-025'' (``2025 PSO
Regional Haze Agreement''), which amends portions of the 2010 and 2013
PSO Regional Haze Agreements from Case No. 10-025 and allows for the
continued operation of Northeastern Unit 3 as a natural gas-fired unit,
while also limiting the NO<INF>X</INF> emissions at Unit 2, contingent
upon an EPA-approved SIP revision.
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\21\ See Settlement Agreement between Public Service Company of
Oklahoma (PSO) and Sierra Club, dated August 2, 2024, included in
the docket for this action.
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The revised NO<INF>X</INF> and SO<INF>2</INF> emission limits for
PSO Northeastern Units 2 and 3 are provided as follows in table 1 of
this document.\22\
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\22\ There are no revisions to the requirements for PSO
Northeastern Unit 4 as that unit retired on April 16, 2016.
[[Page 55290]]
Table 1--NOX and SO2 Emission Limits for PSO Northeastern Units 2 and 3
Under the 2025 Oklahoma Regional Haze SIP and the 2025 PSO Regional Haze
Agreement \23\
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PSO Northeastern Unit 3
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Compliance date NOX limit SO2 limit
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January 1, 2025 (50% 1,569 TPY............. 4,183 TPY.
Utilization).
January 1, 2026, or upon 300 TPY............... No Coal
approval of the [2025 PSO Combustion;
Regional Haze Agreement] if 2.34 TPY using
after January 1, 2026 (20% pipeline grade
Utilization). natural gas.
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PSO Northeastern Unit 2--By January 1, 2027
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NOX control [LNB with OFA] \24\
------------------------------------------------------------------------
Emission Rate (lbs/MMBtu)..... 0.22 lbs/MMBtu (30-day rolling average).
Emissions (TPY)............... 5,530 TPY.
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Certain requirements for PSO Northeastern Units 2 and 3 remain
unchanged from the previous PSO regional haze agreements. Unit 2 will
still be subject to the NO<INF>X</INF> emission limits from the 2010
PSO Regional Haze Agreement. For Unit 3, until January 1, 2026, or the
EPA's approval of the 2026 SIP submission, PSO will continue to meet
the utilization and emission limits that were required under the 2013
PSO Regional Haze Agreement as approved by the EPA.
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\23\ See paragraphs 12 and 26 of the 2025 PSO Regional Haze
Agreement.
\24\ As provided under the 2010 PSO Regional Haze Agreement.
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The 2025 PSO Regional Haze Agreement provides new and revised
requirements for PSO Northeastern Units 2 and 3, by providing (1) new,
lower NO<INF>X</INF> emission limits for Unit 2 by January 1, 2027 to
offset the increase in NO<INF>X</INF> emissions at Unit 3; and (2)
revised requirements for Unit 3, including annual emission limits and a
utilization rate of no more than 20% in addition to limiting operation
to burning only pipeline-grade natural gas by the date of the EPA's
approval of the agreement. In addition, and as discussed further in
section IV.C of this document, the 2025 PSO Regional Haze Agreement
also contains testing, monitoring, recordkeeping and reporting
requirements for PSO Northeastern Units 2 and 3 to ensure compliance
with the revised emission limits. Applicable requirements for Units 2
and 3 will also be incorporated into their corresponding Oklahoma air
quality permits upon final EPA approval of Oklahoma's 2026 SIP
submission incorporating the requirements of the 2025 PSO Regional Haze
Agreement.
2. Evaluation of PSO Northeastern Facility's Source-Specific
Requirements in Oklahoma's 2026 SIP Submission
Oklahoma's 2026 SIP submission revises or adds to those portions of
Oklahoma's regional haze SIP that relate to the SO<INF>2</INF> and
NO<INF>X</INF> regional haze requirements for AEP/PSO's Northeastern
Units 2 and 3. Oklahoma's SIP revision does not revise the previously
approved BART determinations for the PSO Northeastern facility. As
discussed further in section III.A of this document, the NO<INF>X</INF>
limits approved in 2011 for Units 2 and 3 are 0.28 and 0.15 lbs/MMBtu
respectively. The NO<INF>X</INF> emission limit for Unit 3 will
continue to be 0.15 lbs/MMBtu, and as discussed further in sections
IV.A.1 and IV.F of this document, the NO<INF>X</INF> limit for Unit 2
will be reduced to 0.22 lbs/MMBtu and lowered by 300 tons annually.
Unit 3 will continue to meet an SO<INF>2</INF> emission limit of 0.4
lbs/MMBtu, as required by the 2013 PSO Regional Haze agreement, until
the unit only burns pipeline-grade natural gas. After January 1, 2026,
or upon EPA approval of the 2026 SIP submission, the SO<INF>2</INF>
emission limit will be a nominal 2.34 TPY based on an SO<INF>2</INF>
emission rate of 0.0006 lbs/MMBtu from burning pipeline-grade natural
gas.\25\ Gas-fired EGUs have inherently low SO<INF>2</INF> emissions
\26\ and there are no known SO<INF>2</INF> controls that can be
evaluated. Oklahoma states in the SIP submission that these emission
limitations effectively equal the SO<INF>2</INF> and NO<INF>X</INF>
emission reductions in the approved Oklahoma SIP as part of the long-
term strategy.
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\25\ See Oklahoma's 2026 SIP submission, section II.B, and the
2025 PSO Regional Haze Agreement.
\26\ AP-42, Fifth Edition, Volume 1, Chapter 1: External
Sources, Section 1.4, Natural Gas Combustion, available here:
<a href="https://www.epa.gov/sites/default/files/2020-09/documents/1.4_natural_gas_combustion.pdf">https://www.epa.gov/sites/default/files/2020-09/documents/1.4_natural_gas_combustion.pdf</a> (accessed from <a href="https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-fifth-edition-volume-i-chapter-1-external-0">https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-fifth-edition-volume-i-chapter-1-external-0</a>).
\27\ See paragraphs 12 and 26 of the 2010, 2013, and 2025 PSO
Regional Haze Agreements.
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A comparison of the requirements for PSO Northeastern Units 2 and 3
between the 2010, 2013, and 2025 PSO Regional Haze Agreements are
provided in table 2 of this document.
Table 2--Comparison of the Existing and Proposed NOX and SO2 Controls for PSO Northeastern Units 2 and 3 Under
the PSO Regional Haze Agreements \27\
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Existing requirements under the 2010/2013 Proposed requirements under the 2025 PSO
PSO Regional Haze Agreements Regional Haze Agreement
Unit --------------------------------------------------------------------------------------
Unit 2 Unit 3 Unit 2 Unit 3
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Fuel Usage............... Natural Gas......... Previously Utilized Natural Gas......... Limited to Only
Coal--Unit Burn Natural Gas
Retirement by and Utilization
December 31, 2026. Limited to 20%.
NOX Limit................ 5,830 TPY, 0.28 lbs/ 1,569 TPY, 0.15 lbs/ 5,530 TPY, m0.22 lbs/ 300 TPY, 0.15 lbs/
MMBtu. MMBtu (through MMBtu. MMBtu.
December 31, 2026).
SO2 Limit................ .................... 8,366 TPY, 0.40 lbs/ .................... 2.34 TPY.
MMBtu (through
December 31, 2026).
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[[Page 55291]]
When comparing the current and proposed NO<INF>X</INF> requirements
for Units 2 and 3, the total amount of annual NO<INF>X</INF> emissions
between the two units is equivalent to the previous requirement to
retire Unit 3 because the 300 TPY NO<INF>X</INF> emissions from the
burning of natural gas at Unit 3 is offset by a commensurate reduction
of 300 TPY NO<INF>X</INF> at Unit 2. Oklahoma's 2026 SIP submission
revises, and we propose to approve, the NO<INF>X</INF> annual limit for
Unit 2 to decrease by 300 tons and limit Unit 3 to 300 tons annually;
the NO<INF>X</INF> annual emissions would continue to be limited to
5,830 TPY combined for these units. In addition, we propose to approve
the revised requirement that Unit 2 will be subject to a NO<INF>X</INF>
emission rate limit of 0.22 lbs/MMBtu on a 30-day rolling average,
compared to the 0.28 lbs/MMBtu under the current requirements, which
represents a 20 percent reduction in the permitted emission rate.
SO<INF>2</INF> emissions under the existing and revised
requirements are anticipated to provide for the same visibility
benefits. The combustion of natural gas results in minimal
SO<INF>2</INF> emissions, typically at a rate of 0.6 pounds per million
standard cubic feet (MMscf).\28\ Consistent with the 2010 approval of
Oklahoma's regional haze SIP, Unit 2 continues to operate as a natural
gas-fired unit. For Unit 3, the requirement to retire by December 31,
2026, is revised to allow for continued operation using only natural
gas with a nominal limit of 2.34 TPY for SO<INF>2</INF>. As discussed
in Oklahoma's 2026 SIP submission, Unit 3 is limited to burning
pipeline-grade natural gas as defined in 40 CFR 72.2, with an
equivalent SO<INF>2</INF> emission rate of 0.0006 lbs/MMBtu.\29\
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\28\ SO<INF>2</INF> emissions from natural gas-fired boilers are
low because pipeline-quality natural gas typically has sulfur levels
of 2,000 grains per million cubic feet. However, sulfur-containing
odorants are added to natural gas for detecting leaks, leading to
small amounts of SO<INF>2</INF> emissions (0.6 lb/MMscf). In
comparison, NO<INF>X</INF> emission factors range from 32 to 280 lb/
MMscf. See US EPA's AP-42: Compilation of Air Emissions Factors from
Stationary Sources, Chapter 1: External Combustion Sources, Section
1.4: Natural Gas Combustion, at <a href="https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilation-air-emissions-factors-stationary-sources">https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilation-air-emissions-factors-stationary-sources</a>.
\29\ As defined under 40 CFR 72.2, pipeline natural gas contains
0.5 grains or less of total sulfur per 100 standard cubic feet,
which is equivalent to an SO<INF>2</INF> emission rate of 0.0006
lbs/MMBtu.
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The EPA is proposing to find that the revised requirements for PSO
Northeastern Units 2 and 3 provide for equivalent emission reductions
compared to the existing EPA-approved requirements for the PSO
Northeastern facility.
B. Amended Long-Term Strategy
Under 40 CFR 308(d)(3), a State's ``long-term strategy must include
enforceable emissions limitations, compliance schedules, and other
measures as necessary to achieve the reasonable progress goals
established by States having mandatory Class I Federal areas.''
Oklahoma submitted its 2026 SIP submission to revise the currently
approved source-specific requirements for PSO Northeastern Unit 3 under
its long-term strategy with equivalent emission reductions and
reasonable progress. As described in more detail in section IV.A of
this document, we are proposing to find that limiting Unit 3 operations
to only pipeline-grade natural gas in combination with a new
NO<INF>X</INF> limit for Unit 2 results in equivalent NO<INF>X</INF>
and SO<INF>2</INF> emissions reductions that would be achieved through
the shutdown of PSO Northeastern Unit 3.
Since reasonable progress is a subset of the requirements for the
long-term strategy, adoption of the emission reductions under
reasonable progress for Oklahoma PSO Northeastern Unit 3 will also
ensure that the long-term strategy requirements will continue to be
met. Because Oklahoma has demonstrated that the proposed control
measures and emissions reductions for PSO Northeastern Units 2 and 3
are equivalent to the current SIP-approved control measures, we are
proposing to approve Oklahoma's amended long-term strategy as provided
in its 2026 SIP submission. This includes Oklahoma's revised
NO<INF>X</INF> and SO<INF>2</INF> requirements for PSO Northeastern
Units 2 and 3 as provided in Oklahoma's 2026 SIP submission and
accompanying 2025 PSO Regional Haze Agreement.
C. Testing, Monitoring, Recordkeeping, and Reporting Requirements
We are proposing to approve the testing, monitoring, recordkeeping,
and reporting requirements as provided Oklahoma's 2026 SIP submission,
and as detailed in the 2025 PSO Regional Haze Agreement, paragraphs
26.E and 26.F, for the PSO Northeastern facility Units 2 and 3 that are
associated with Unit 3 burning only natural gas and the revised
emission limits for these two units. Specifically, the 2025 PSO
Regional Haze Agreement contains provisions for testing and continuous
monitoring requirements in accordance with 40 CFR 60.8, 60.13(e)
through (h), appendix B of 40 CFR part 60, as well 40 CFR part 75, with
further requirements detailed in paragraph 26.E of the agreement. The
2025 PSO Regional Haze Agreement also includes reporting and
recordkeeping requirements for continuous monitoring compliance in
accordance with 40 CFR 60.7(c) and (d) and 40 CFR part 75, as well as
compliance with the Unit 2 SO<INF>2</INF> emission rate through fuel
records. These testing, monitoring, recordkeeping, and reporting would
provide for enforceability of the new emission limits for PSO
Northeastern Units 2 and 3.
D. Consultation With States
States must meet the additional requirements when developing their
long-term strategies. 40 CFR 51.308(d)(3)(i) requires States to consult
with other States that have emissions that are reasonably anticipated
to contribute to visibility impairment in Class I areas to develop
coordinated emission management strategies. In section V.C of its 2026
SIP submission, Oklahoma describes how it consulted with other States
on its draft SIP in accordance with 40 CFR 51.308(d)(3)(i). Oklahoma
stated that it consulted with States that have Class I areas whose
visibility is potentially affected by Oklahoma emissions during its
original first planning period regional haze SIP development. On
December 18, 2025, Oklahoma notified electronically the appropriate
clean air agency staff for bordering and potentially affected States
that were previously consulted on its proposed 2026 SIP submission and
provided them with electronic access to the revision and related
documents. These States include Arkansas, Iowa, Kansas, Louisiana,
Minnesota, Missouri, Nebraska, New Mexico, and Texas, and the
appropriate agency staff for each State is included in appendix VII of
its SIP submission. Oklahoma also notified the State agency staff of
the public hearing scheduled for January 22, 2026. Oklahoma did not
receive any comments from other States on its draft SIP.
We are proposing to find that Oklahoma met applicable State to
State consultation requirements under 40 CFR 51.308(d)(3)(i) in its
2026 SIP submission.
E. Consultation With Federal Land Managers
Oklahoma has one mandatory Class I Federal area within its borders,
the Wichita Mountains Wilderness, located in the Wichita Mountains
National Wildlife Refuge in Comanche County, in the southwest part of
Oklahoma. Wichita Mountains Wilderness is managed by the US Fish and
Wildlife Service (FWS). As provided in this section and in section II.D
of this document, the RHR grants the FLMs,
[[Page 55292]]
regardless of whether an FLM manages a Class I area within the State, a
special role in the review of regional haze implementation plans.
Section 169A(d) of the CAA requires States to consult with FLMs
before holding the public hearing on a proposed regional haze SIP, and
to include a summary of the FLMs' conclusions and recommendations in
the notice to the public. Under the RHR, 40 CFR 51.308(i)(2)'s FLM
consultation provision requires a State to provide FLMs with an
opportunity for consultation at least sixty days before a public
hearing or public comment period at the State level. 40 CFR
51.308(i)(3) requires States, in developing their implementation plans,
to include a description of how they addressed FLMs' comments.
In section V.B of its 2026 SIP submission, Oklahoma describes how
it consulted with FLMs on its draft SIP in accordance with 40 CFR
51.308(i)(2). Oklahoma provided the FLMs a draft copy of its proposed
2026 SIP submission via email on November 13, 2025, and a consultation
meeting was held virtually on December 16, 2025, between ODEQ and the
U.S. Department of Agriculture Forest Service (FS) and the National
Park Service (NPS). Oklahoma held a separate consultation phone call
with the FWS on December 16, 2025. Oklahoma stated in it SIP that none
of the agencies had any comments on the revision or requested further
consultation. Oklahoma provided documentation of the virtual meeting
and phone record in appendix II of its 2026 SIP submission. Oklahoma
also provided the FLMs with notice of the opening of the public comment
period on December 18, 2025, and the public hearing scheduled for
January 22, 2026. FLMs did not provide any comments during the public
comment period or during the public hearing. Oklahoma provided FLMs an
opportunity for consultation in accordance with 40 CFR 51.308(i)(2). No
comments were provided by FLMs, and thus no comments needed to be
addressed in accordance with 40 CFR 51.308(i)(3).
We are proposing to find that Oklahoma met applicable FLM
consultation requirements under CAA section 169A(d) and 40 CFR
51.308(i) in its 2026 SIP submission.
F. CAA Section 110(l)
Under CAA section 110(l), the EPA cannot approve a plan revision
``if the revision would interfere with any applicable requirement
concerning attainment and reasonable further progress (as defined in
section 7501 of this title), or any other applicable requirement of
this chapter.'' \30\
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\30\ Note that ``reasonable further progress'' as used in CAA
section 110(l) is a reference to that term as defined in CAA section
171(1) (i.e., 42 U.S.C. 7501(1)), and as such means reductions
required to attain the NAAQS set for criteria pollutants under CAA
section 109. This term as used in CAA section 110(l) (and defined in
CAA section 171(1)) is not synonymous with ``reasonable progress''
as that term is used in the regional haze program under CAA section
169A(g). Instead, section 110(l) provides that the EPA cannot
approve plan revisions that interfere with regional haze
requirements (including reasonable progress requirements) insofar as
they are ``other applicable requirement[s]'' of the CAA.
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The previous sections of this rulemaking explain how Oklahoma's
2026 SIP submission will comply with applicable regional haze
requirements and general implementation plan requirements, such as
compliance and enforceability through testing, monitoring,
recordkeeping, and reporting requirements, and that annual
NO<INF>X</INF> and SO<INF>2</INF> emissions are not greater than what
is currently allowed in the SIP. Additionally, there are no National
Ambient Air Quality Standard (NAAQS) nonattainment areas in Oklahoma
for nitrogen dioxide (NO<INF>2</INF>), SO<INF>2</INF>, ozone, or PM.
ODEQ provided a CAA section 110(l) demonstration to show that the
substitute measures provided in this SIP revision are quantifiable and
represent a surplus from current allowable emission levels.\31\ As
discussed in section IV.C of this document, testing, monitoring,
recordkeeping, and reporting requirements in Oklahoma's 2026 SIP
submission provide for enforceability of the new requirements.
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\31\ See Oklahoma's 2026 SIP submission, section IV, pages 7
through 8. See also, EPA Green Book, ``Current Nonattainment
Counties for All Criteria Pollutants'', at <a href="https://www3.epa.gov/airquality/greenbook/ancl.html">https://www3.epa.gov/airquality/greenbook/ancl.html</a>.
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In Oklahoma's 2026 SIP submission, allowing for the continued
operation of Unit 3 will result in an increase in NO<INF>X</INF>
emissions of 300 TPY, as compared to the existing requirement to retire
Unit 3. To demonstrate that this change in emissions will not interfere
with any applicable requirements, specifically the regional haze
requirements, ODEQ's 2026 SIP submission includes a commensurate 300
TPY reduction in NO<INF>X</INF> emissions from Unit 2. Therefore,
emission limits for the PSO Northeastern Units 2 and 3 will provide for
equivalent emissions reductions when compared to the existing
requirements for Unit 3.\32\ Under these existing requirements, PSO
Northeastern Unit 3 is required to cease operation by December 31,
2026. Under Oklahoma's 2026 SIP submission and accompanying 2025 PSO
Regional Haze Agreement requirements, PSO Northeastern Unit 3 will burn
only natural gas, and Units 2 and 3 will be subject to additional
emission limits.
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\32\ The EPA approved Oklahoma's 2013 regional haze SIP
submission on March 7, 2014 (79 FR 12944).
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In the 2025 PSO Regional Haze Agreement, PSO committed to only use
natural gas as fuel in Northeastern Unit 3 no later than the EPA's
approval of Oklahoma's 2026 SIP submission. The use of pipeline-grade
natural gas at Unit 3 will provide for negligible annual SO<INF>2</INF>
emissions (2.34 TPY). Under the agreement, Unit 3 will also be subject
to a 300 TPY NO<INF>X</INF> limit. As stated in the SIP, effective
January 1, 2027, PSO Northeastern Unit 2 will be subject to a
NO<INF>X</INF> emission rate limit of 0.22 lbs/MMBtu (compared to the
current limit of 0.28 lbs/MMBtu), which is included in the agreement
and will also be incorporated into and made enforceable through the
facility's New Source Review (NSR) construction permit.\33\ This
emission rate limit represents a 20 percent reduction in allowable
NO<INF>X</INF> emissions at full load and will result in a reduction in
allowable NO<INF>X</INF> emissions of at least 300 tons per 12-month
period to offset the continuing NO<INF>X</INF> emissions from Unit 3.
The 2025 PSO Regional Haze Agreement includes an annual limit for Unit
2 of 5,530 TPY of NO<INF>X</INF> on a 12-month rolling basis, which is
a 300 TPY decrease from PSO Northeastern's current permit limit of
5,830 TPY of NO<INF>X</INF> as provided in the original February 17,
2010, Regional Haze Agreement between PSO and ODEQ.
---------------------------------------------------------------------------
\33\ ODEQ NSR Permit No. 2019-0607-C (M-1).
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Because the proposed emission limits for the PSO Northeastern Units
2 and 3 will provide for quantifiable and enforceable emission limits
that provide for equivalent emissions when compared to the existing SIP
requirements for the PSO Northeastern facility, we propose to find that
Oklahoma's 2026 SIP submission is not anticipated to interfere with
applicable requirements of the CAA, including requirements concerning
attainment and reasonable further progress.
G. Summary of the EPA's Evaluation
We are proposing to approve Oklahoma's 2026 SIP submission as it
meets the following requirements as provided under sections IV.A
through F of this document:
(1) Long-term strategy requirements under 40 CFR 51.308(d)(3) as
applied to the revision of the PSO Northeastern facility control
measures as well as enforceability of those controls through testing,
monitoring, recordkeeping, and reporting requirements;
[[Page 55293]]
(2) FLM consultation requirements under CAA section 169A(d) and 40
CFR 51.308(i); and,
(3) CAA section 110(l) requirements.
V. Proposed Action
The EPA is proposing to approve Oklahoma's SIP submission submitted
on March 12, 2026, that revises source-specific requirements for the
PSO Northeastern facility and amends the State's long-term strategy for
the first implementation period of the regional haze program as meeting
applicable Federal requirements under CAA section 110(l), section 169A,
and 40 CFR 51.308. The EPA is proposing to find that Oklahoma's 2026
SIP submission satisfies the long-term strategy regulatory requirements
from the first planning period under the regional haze program.\34\
---------------------------------------------------------------------------
\34\ 40 CFR 51.308(d)(3).
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The EPA is proposing to approve as part of Oklahoma's 2026 SIP
submission source-specific requirements for the AEP/PSO Northeastern
Power Station as described in the accompanying Seconded Amended
Regional Haze Agreement between PSO and ODEQ, Case No. 10-025, dated
May 14, 2025 (``2025 PSO Regional Haze Agreement''), which amends
portions of the 2010 and 2013 PSO Regional Haze Agreements from Case
No. 10-025. The 2025 PSO Regional Haze Agreement is the enforceable
mechanism for the revised control measures for the PSO Northeastern
facility. The EPA is proposing to approve all requirements set forth in
the 2025 PSO Regional Haze Agreement as source-specific revisions to be
incorporated into the Oklahoma SIP.
VI. Impact on Areas of Indian Country
Following the U.S. Supreme Court decision in McGirt v. Oklahoma,
140 S. Ct. 2452 (2020), the Governor of the State of Oklahoma requested
approval under Section 10211(a) of the Safe, Accountable, Flexible,
Efficient Transportation Equity Act of 2005: A Legacy for Users, Public
Law 109-59, 119 Stat. 1144, 1937 (August 10, 2005) (``SAFETEA''), to
administer in certain areas of Indian country (as defined at 18 U.S.C.
1151) the State's environmental regulatory programs that were
previously approved by the EPA outside of Indian country. The State's
request excluded certain areas of Indian country further described
below. In addition, the State only sought approval to the extent that
such approval was necessary for the State to administer a program in
light of Oklahoma Dept. of Environmental Quality v. EPA, 740 F.3d 185
(D.C. Cir. 2014).\35\
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\35\ In ODEQ v. EPA, the D.C. Circuit held that under the CAA,
States have the authority to implement a SIP in non-reservation
areas of Indian country in the State, unless there has been a
demonstration of Tribal jurisdiction. Under the D.C. Circuit's
decision, the CAA does not provide authority to States to implement
SIPs in Indian reservations.
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The EPA has approved Oklahoma's SAFETEA request to administer all
of the State's EPA-approved environmental regulatory programs in the
requested areas of Indian country. As requested by Oklahoma, the EPA's
approval under SAFETEA does not include Indian country lands, including
rights-of-way running through the same, that: (1) qualify as Indian
allotments, the Indian titles to which have not been extinguished,
under 18 U.S.C. 1151(c); (2) are held in trust by the United States on
behalf of an individual Indian or Tribe; or (3) are owned in fee by a
Tribe, if the Tribe (a) acquired that fee title to such land, or an
area that included such land, in accordance with a treaty with the
United States to which such Tribe was a party, and (b) never allotted
the land to a member or citizen of the Tribe (collectively ``excluded
Indian country lands'').
The EPA's approval under SAFETEA expressly provided that to the
extent the EPA's prior approvals of Oklahoma's environmental programs
excluded Indian country, any such exclusions are superseded for the
geographic areas of Indian country covered by the EPA's approval of
Oklahoma's SAFETEA request.\36\ The approval also provided that future
revisions or amendments to Oklahoma's approved environmental regulatory
programs would extend to the covered areas of Indian country (without
any further need for additional requests under SAFETEA).
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\36\ The EPA's prior approvals relating to Oklahoma's SIP
frequently noted that the SIP was not approved to apply in areas of
Indian country (except as explained in the D.C. Circuit's decision
in ODEQ v. EPA) located in the State (see, e.g., 79 FR 12944, March
7, 2014). Such prior expressed limitations are superseded by the
EPA's approval of Oklahoma's SAFETEA request.
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As explained above, the EPA is proposing to approve Oklahoma's 2026
Regional Haze SIP for meeting applicable CAA requirements. This SIP
submission revises a portion of Oklahoma's previously approved regional
haze SIP for the first planning period for the PSO Northeastern
facility located in Rogers County. If this proposed approval is
finalized, this revision will become a part of the overall approved
Oklahoma regional haze SIP, which applies statewide. Consistent with
the D.C. Circuit's decision in ODEQ v. EPA and with the EPA's SAFETEA
approval, these SIP revisions will apply to areas of Indian country as
follows: (1) pursuant to the SAFETEA approval, the SIP revisions will
apply to all Indian country in the State of Oklahoma other than the
excluded Indian country lands as described above; and (2) pursuant to
the D.C. Circuit's decision in ODEQ v. EPA, the SIP revisions will also
apply to any Indian allotments or dependent Indian communities that are
located outside of any Indian reservation over which there has been no
demonstration of Tribal authority.
VII. Incorporation by Reference
In this proposed action, we are proposing to include in a final
rule regulatory text that includes incorporation by reference. In
accordance with the requirements of 1 CFR 51.5, we are proposing to
incorporate by reference revisions to the Oklahoma source specific
requirements as described in section V of this preamble. We have made,
and will continue to make, these documents generally available
electronically through <a href="https://www.regulations.gov">https://www.regulations.gov</a> (please contact the
persons identified in the FOR FURTHER INFORMATION CONTACT section of
this preamble for more information).
VIII. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act 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 proposes to approve 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
[[Page 55294]]
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.
This proposed approval of Oklahoma's 2026 Regional Haze SIP that
contains revisions to Oklahoma's first planning period regional haze
source-specific requirements will apply, if finalized as proposed, to
certain areas of Indian country throughout Oklahoma as discussed in the
preamble, and therefore has Tribal implications as specified in E.O.
13175 (65 FR 67249, November 9, 2000). However, this action will
neither impose substantial direct compliance costs on federally
recognized Tribal governments, nor preempt Tribal law. This action will
not impose substantial direct compliance costs on federally recognized
Tribal governments because no actions will be required of Tribal
governments. This action will also not preempt Tribal law as no
Oklahoma Tribe implements a regulatory program under the CAA, and thus
does not have applicable or related Tribal laws. Consistent with the
EPA Policy on Consultation and Coordination with Indian Tribes
(December 7, 2023), the EPA has offered consultation to Tribal
governments that may be affected by this action and provided
information about this action.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Ozone,
Particulate matter, Reporting and recordkeeping requirements, Sulfur
oxides.
Authority: 42 U.S.C. 7401 et seq.
Dated: August 19, 2026.
Walter Mason,
Regional Administrator, Region 6.
[FR Doc. 2026-17499 Filed 8-26-26; 8:45 am]
BILLING CODE 6560-50-P
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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.