Proposed Rule2026-18290
Air Plan Approval; Reconsideration and Repeal of Air Plan Partial Approval and Partial Disapproval of North Dakota's Regional Haze State Implementation Plan for the Second Implementation Period
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
September 9, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA or Agency) is proposing to repeal a final rule published in the Federal Register on December 2, 2024, partially approving and partially disapproving North Dakota's 2022 regional haze State Implementation Plan (SIP) submission for the second implementation period. As a result, the EPA is proposing to approve the portions of North Dakota's 2022 SIP submission for the second implementation period that were disapproved in the EPA's 2024 partial approval/partial disapproval. In the December 2024 final rule, the EPA determined that North Dakota submitted a regional haze SIP that did not meet all the statutory and regulatory requirements for the regional haze second implementation period. On January 31, 2025, and February 6, 2025, EPA received petitions for reconsideration from the State of North Dakota, Basin Electric Power Cooperative, Lignite Energy Council (LEC), Rainbow Energy Center, and the Coyote Station Co-Owners. On January 31, 2025, the State of North Dakota, Montana-Dakota Utilities Company, NACCO Natural Resources Corporation, Basin Electric Power Cooperative, Rainbow Energy Center, and Lignite Energy Center filed petitions for review in the Eighth Circuit Court of Appeals. EPA granted reconsideration on April 30, 2025, sending letters to the State of North Dakota, Basin Electric, LEC, Rainbow Energy Center, and Coyote Station Co-Owners. The petitions for review were held in abeyance by the Eighth Circuit on June 4, 2025 pending the administrative reconsideration process.
Full Text
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<title>Federal Register, Volume 91 Issue 173 (Wednesday, September 9, 2026)</title>
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[Federal Register Volume 91, Number 173 (Wednesday, September 9, 2026)]
[Proposed Rules]
[Pages 57302-57312]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-18290]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2023-0495; FRL-13512-01-R8]
Air Plan Approval; Reconsideration and Repeal of Air Plan Partial
Approval and Partial Disapproval of North Dakota's Regional Haze State
Implementation Plan for the Second Implementation Period
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule; reconsideration of final rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA or Agency) is
proposing to repeal a final rule published in the Federal Register on
December 2, 2024, partially approving and partially disapproving North
Dakota's 2022 regional haze State Implementation Plan (SIP) submission
for the second implementation period. As a result, the EPA is proposing
to approve the portions of North Dakota's 2022 SIP submission for the
second implementation period that were disapproved in the EPA's 2024
partial approval/partial disapproval. In the December 2024 final rule,
the EPA determined that North Dakota submitted a regional haze SIP that
did not meet all the statutory and regulatory requirements for the
regional haze second implementation period. On January 31, 2025, and
February 6, 2025, EPA received petitions for reconsideration from the
State of North Dakota, Basin Electric Power Cooperative, Lignite Energy
Council (LEC), Rainbow Energy Center, and the Coyote Station Co-Owners.
On January 31, 2025, the State of North Dakota, Montana-Dakota
Utilities Company, NACCO Natural Resources Corporation, Basin Electric
Power Cooperative, Rainbow Energy Center, and Lignite Energy Center
filed petitions for review in the Eighth Circuit Court of Appeals. EPA
granted reconsideration on April 30, 2025, sending letters to the State
of North Dakota, Basin Electric, LEC, Rainbow Energy Center, and Coyote
[[Page 57303]]
Station Co-Owners. The petitions for review were held in abeyance by
the Eighth Circuit on June 4, 2025 pending the administrative
reconsideration process.
DATES: Comments must be received on or before October 9, 2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2024-0001 to the Federal Rulemaking Portal: <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://www.regulations.gov">www.regulations.gov</a>. The EPA may publish any comment received to the
Agency's public docket. Do not submit electronically any information
you consider to be Confidential Business Information (CBI) or other
information the disclosure of which 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. 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, 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: All documents in the docket are listed in the <a href="https://www.regulations.gov">https://www.regulations.gov</a> index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
the disclosure of which is restricted by statute. Certain other
material, such as copyrighted material, will be publicly available only
in hard copy. Publicly available docket materials are available
electronically in <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Please email or call the
person listed in the FOR FURTHER INFORMATION CONTACT section if you
need to make alternative arrangements for access to the docket.
FOR FURTHER INFORMATION CONTACT: For information about this proposed
rule, contact Chelsea Cancino, Air and Radiation Division, EPA, Region
8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, Colorado, 80202-1129,
telephone number: (303) 312-6276, email address:
<a href="/cdn-cgi/l/email-protection#5231333c313b3c3d7c313a373e213733123722337c353d24"><span class="__cf_email__" data-cfemail="f390929d909a9d9cdd909b969f809692b3968392dd949c85">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, the use of ``we,''
``us,'' or ``our'' is intended to refer to the EPA. We use multiple
acronyms and terms in this preamble. While this list may not be
exhaustive, to ease the reading of this preamble and for reference
purposes, the EPA defines the following terms and acronyms here:
NH<INF>3</INF> Ammonia
BART Best Available Retrofit Technology
BLM Bureau of Land Management
CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
CSU Colorado State University
EPA U.S. Environmental Protection Agency
FIP Federal Implementation Plan
FLM Federal Land Manager
FR Federal Register
IMPROVE Interagency Monitoring of Protected Visual Environments
LB Pound
LEC Lignite Energy Council
LNC3+ Combination of closed coupled overfired air, separated
overfired air, and low NO<INF>X</INF> burners in conjunction with
DryFining and expanded overfire air registers.
MACT Maximum Achievable Control Technology
MMBtu Million British Thermal Units
NAAQS National Ambient Air Quality Standards
NO<INF>X</INF> Nitrogen Oxides
NPS National Park Service
OMB Office of Management and Budget
PM Particulate Matter
PM<INF>2.5</INF> Fine Particulate Matter
PRA Paperwork Reduction Act
RFA Regulatory Flexibility Act
RHR Regional Haze Rule
RPGs Reasonable Progress Goals
RPOs Regional Planning Organizations
SIP State Implementation Plan
SO2 Sulfur Dioxide
TSS Technical Support System
UMRA Unfunded Mandates Reform Act
URP Uniform Rate of Progress
USFS United States Forest Service
USFWS United States Fish and Wildlife Service
VOC Volatile Organic Compounds
WRAP Western Regional Air Partnership
Table of Contents
I. What action is EPA proposing?
II. Background
A. History of the Regional Haze Program
B. Roles of Agencies in Addressing Regional Haze
C. Status of North Dakota's Regional Haze Plan for First
Implementation Period
D. North Dakota's Regional Haze Plan for the Second
Implementation Period
III. Requirements of Regional Haze Plans for the Second
Implementation Period
IV. EPA's Evaluation of North Dakota's Regional Haze Submission for
the Second Implementation Period
A. North Dakota's Long-Term Strategy Under CAA 169A and 40 CFR
51.308(f)(2)
1. North Dakota's Long-Term Strategy Four-Factor Analysis
a. Summary of North Dakota's Long-Term Strategy Four-Factor
Analysis
b. EPA's Evaluation of North Dakota's Long-Term Strategy Four-
Factor Analysis
2. Other Long-Term Strategy Requirements
B. Reasonable Progress Goals
C. Requirements for State and Federal Land Manager Coordination
V. Statutory and Executive Order Reviews
I. What action is the EPA proposing?
In this action, after granting reconsideration of the prior action,
the EPA is proposing full approval of North Dakota's 2022 SIP
submission, including the requirements relating to 40 CFR 51.308(f)(1):
calculations of baseline, current, and natural visibility conditions,
progress to date, and the uniform rate of progress (URP); 40 CFR
51.308(f)(2): long-term strategy; 40 CFR 51.308(f)(3): reasonable
progress goals; 40 CFR 51.308(f)(4): reasonably attributable visibility
impairment; 40 CFR 51.308(f)(5) and 40 CFR 51.308(g): progress report
requirements; 40 CFR 51.308(f)(6): monitoring strategy and other
implementation plan requirements; and 40 CFR 51.308(i): Federal Land
Manager (FLM) consultation.
On August 11, 2022, the North Dakota Department of Environmental
Quality submitted a revision to its SIP to address regional haze for
the second implementation period. North Dakota made this SIP submission
to satisfy the requirements of the Clean Air Act's (CAA's) regional
haze program under CAA sections 169A and 169B and 40 Code of Federal
Register (CFR) 51.308(f). In 2024, the EPA proposed and finalized
partial approval and partial disapproval of North Dakota's 2022
submission.
In the 2024 final action, the EPA disapproved 40 CFR 51.308(f)(2):
long-term strategy; 40 CFR 51.308(f)(3): reasonable progress goals; and
40 CFR 51.308(i): Federal Land Manager (FLM) consultation.
The EPA seeks comments on all of the proposed actions described in
this preamble, including with respect to the EPA's statutory authority
to reconsider and repeal the December 2, 2024 final rule and any
changes in interpretation and policy relevant thereto. Because this
action would, if finalized, relieve certain obligations for the State
of North Dakota, the EPA does not believe there are reasonable and
cognizable reliance interests that would be adversely impacted by
finalizing this action as proposed. Nevertheless, the EPA seeks comment
on whether such reliance interests exist, and if so, how the EPA should
consider them in taking any final action on this preamble.
II. Background
A detailed history and background of the regional haze program is
provided in
[[Page 57304]]
the EPA's prior proposed action for Idaho.\1\ For additional background
on the 2017 Regional Haze Rule (RHR) revisions, refer to section III.
Overview of Visibility Protection Statutory Authority, Regulation, and
Implementation of ``Protection of Visibility: Amendments to
Requirements for State Plans'' of the 2017 RHR.\2\ The following is an
abbreviated history and background of the regional haze program and
2017 Regional Haze Rule as it applies to the current action.
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\1\ See 90 Federal Register (FR) 13516 (Mar. 24, 2025).
\2\ See 82 FR 3078 (Jan. 10, 2017, located at <a href="https://www.federalregister.gov/documents/2017/01/10/2017-00268/protection-of-visibility-amendments-to-requirements-for-State-plans#h-16">https://www.federalregister.gov/documents/2017/01/10/2017-00268/protection-of-visibility-amendments-to-requirements-for-State-plans#h-16</a>).
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A. History of the Regional Haze Program
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.\3\ \4\ The
CAA 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.'' \5\
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\3\ Areas statutorily designated as mandatory Class I Federal
areas consist of national parks exceeding 6,000 acres, wilderness
areas and national memorial parks exceeding 5,000 acres, and all
international parks that were in existence on August 7, 1977. See
CAA section 162(a). There are 156 mandatory Class I areas. The list
of areas to which the requirements of the visibility protection
program apply is in 40 CFR part 81, subpart D.
\4\ See CAA section 169A.
\5\ Id. at (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 perception of clarity and color, as well as visible
distance.\6\
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\6\ 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>). See 40 CFR 51.301.
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To address regional haze visibility impairment, the 1999 RHR
established an iterative planning process that requires States
containing Class I areas and States containing sources whose emissions
``may reasonably be anticipated to cause or contribute to any
impairment of visibility'' in a Class I area in another State to
periodically submit SIP revisions to address such impairment.\7\
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\7\ See CAA section 169A(b)(2); see also 40 CFR 51.308(b), (f)
(establishing submission dates for iterative regional haze SIP
revisions); (64 FR 35714, at 35768 (July 1, 1999)).
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On January 10, 2017, the EPA promulgated revisions to the RHR (82
FR 3078, January 10, 2017) that apply for the second and subsequent
implementation periods. The reasonable progress requirements as revised
by the 2017 rule (referred to here as the 2017 RHR Revisions) are
codified at 40 CFR 51.308(f).
B. Roles of Agencies in Addressing Regional Haze
Because the air pollutants and pollution affecting visibility in
Class I areas can be transported over long distances, successful
implementation of the regional haze program requires long-term,
regional coordination among multiple jurisdictions and agencies that
have responsibility for Class I areas and the emissions that impact
visibility in those areas. To address regional haze, States need to
develop strategies in coordination with one another, considering the
effect of emissions from one jurisdiction on the air quality in
another. Five regional planning organizations (RPOs), which include
representation from State and Tribal governments, EPA, and FLMs, were
developed in the lead-up to the first implementation period to address
regional haze. RPOs evaluate technical information to better understand
how emissions from State and Tribal land impact Class I areas across
the country, pursue the development of regional strategies to reduce
emissions of particulate matter and other pollutants leading to
regional haze, and help States meet the consultation requirements of
the RHR.
The Western Regional Air Partnership (WRAP), one of the five
regional planning organizations described in the previous paragraph, is
a collaborative effort of State governments, local air agencies, Tribal
governments, and various federal agencies established to initiate and
coordinate activities associated with the management of regional haze,
visibility, and other air quality issues in the Western United States.
Members include the States of Alaska, Arizona, California, Colorado,
Hawaii, Idaho, Montana, Nevada, New Mexico, North Dakota, Oregon, South
Dakota, Utah, Washington, Wyoming, and 28 Tribal governments.\8\ The
federal partner members of WRAP are EPA, U.S. National Parks Service
(NPS), U.S. Fish and Wildlife Service (USFWS), U.S. Forest Service
(USFS), and the Bureau of Land Management (BLM).
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\8\ A full list of WRAP membership agencies is available at
<a href="https://www.westar.org/wrap-council-members/">https://www.westar.org/wrap-council-members/</a>.
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The WRAP formed a workgroup to develop a planning framework for
State regional haze second implementation period SIPs. The WRAP
produced a technical system to support regional modeling of visibility
impacts at Class I areas across the West that was based on emissions
and monitoring data supplied by its membership. The WRAP Technical
Support System (TSS) consolidated air quality monitoring data,
meteorological and receptor modeling data analyses, emissions
inventories and projections, and gridded air quality/visibility
regional modeling results. The TSS is accessible by member States and
allows for the creation of maps, figures, and tables to export and use
in State plan development. It also maintains the original source data
for verification and further analysis. North Dakota collaborated with
the WRAP on various aspects of the State's 2022 SIP submission which
informed the development of its long-term strategy. This included the
identification of Class I areas outside of North Dakota that may be
affected by sources in the State, source selection, analysis of air
quality monitoring data, preparation of emission inventories,
development of reasonable progress goals, and air quality modeling.
C. Status of North Dakota's Regional Haze Plan for the First
Implementation Period
The CAA requires that regional haze plans for the first
implementation period (2008 through 2018) include, among other things,
a long-term strategy for making reasonable progress and best available
retrofit technology (BART)
[[Page 57305]]
requirements for certain older stationary sources, where applicable.\9\
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\9\ Requirements for regional haze SIPs for the first
implementation period are also contained in CAA section 169A(b)(2).
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The governor of North Dakota submitted North Dakota's Regional Haze
SIP for the first implementation period to the EPA on March 3, 2010,
followed by SIP Supplement No. 1 submitted on July 27, 2010, and SIP
Amendment No. 1 submitted on July 28, 2011 (collectively, the ``2010
Regional Haze SIP''). On April 6, 2012, the EPA promulgated a final
rule titled ``Approval and Promulgation of Implementation Plans; North
Dakota; Regional Haze State Implementation Plan; Federal Implementation
Plan for Interstate Transport of Pollution Affecting Visibility and
Regional Haze; Final Rule'' (2012 Final Rule).\10\ The 2012 Final Rule
approved in part and disapproved in part the State's 2010 Regional Haze
SIP. The EPA's disapproval included portions of the plan that addressed
reasonable progress requirements and North Dakota's BART determinations
for Coal Creek Station (Coal Creek) Units 1 and 2 and Antelope Valley
Station (Antelope Valley) Units 1 and 2. In the same rulemaking, the
EPA promulgated a federal implementation plan (FIP) that imposed, among
other things, a NO<INF>X</INF> emission limit for Antelope Valley Units
1 and 2, and a NO<INF>X</INF> BART determination and emission limit for
Coal Creek Units 1 and 2.
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\10\ 77 FR 20894 (Apr. 6, 2012).
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Subsequently, North Dakota and other petitioners challenged the
2012 Final Rule in the United States Court of Appeals for the Eighth
Circuit, resulting in a September 23, 2013, vacatur and remand. On
January 2, 2013, North Dakota submitted a SIP revision to the EPA to
provide additional information supporting its original NO<INF>X</INF>
BART determination for Coal Creek.\11\ On September 23, 2013, the
Eighth Circuit concluded in North Dakota v. EPA that the EPA properly
disapproved portions of the 2010 Regional Haze SIP, including the
reasonable progress determination for Antelope Valley Units 1 and
2.\12\ The Eighth Circuit also upheld the EPA's FIP promulgating an
emission limit of 0.17 pounds per million British thermal units (lb/
MMBtu) NO<INF>X</INF> (30-day rolling average) for Antelope Valley
Units 1 and 2.\13\ However, the Eighth Circuit vacated and remanded the
EPA's FIP promulgating an emission limit of 0.13 lb/MMBtu
NO<INF>X</INF> (30-day rolling average) for Coal Creek.\14\
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\11\ North Dakota referred to the January 2, 2013 SIP submission
as ``Supplement No. 2.'' EPA herein refers to North Dakota's January
2, 2013 submission as a SIP submission.
\12\ North Dakota v. EPA, 730 F.3d 750, 766 (8th Cir. 2013).
\13\ Id.
\14\ Id. at 764.
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Several SIP submissions from North Dakota and subsequent EPA
actions for the first implementation period followed the Eighth
Circuit's decision. On January 12, 2015, North Dakota submitted a SIP
revision for a regional haze five-year progress report, pursuant to 40
CFR 51.308(g). On April 26, 2018, the EPA proposed to approve the Coal
Creek NO<INF>X</INF> BART determination submitted in North Dakota's
January 2013 SIP submission.\15\ The EPA did not finalize that action
and North Dakota subsequently withdrew the Coal Creek Station
NO<INF>X</INF> BART portion of the 2013 submission as is further
explained in Section D below.<SUP>16 17</SUP> On August 3, 2020, North
Dakota submitted a SIP revision to incorporate the 2012 FIP
requirements for Antelope Valley, which the EPA approved on April 5,
2022.\18\ In the same action, the EPA withdrew from the CFR the FIP
requirements for Coal Creek that the Eighth Circuit vacated in North
Dakota v. EPA.
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\15\ 83 FR 18248 (Apr. 26, 2018).
\16\ North Dakota's 2022 SIP submission, Letter from North
Dakota Governor Doug Burgum to EPA Administrator Michael Regan.
\17\ As explained in this document in section II.D., North
Dakota subsequently withdrew the Coal Creek Station NO<INF>X</INF>
BART portion of its 2013 SIP submission in its 2022 SIP submission
to the EPA that included a revised NO<INF>X</INF> BART determination
for Coal Creek. On March 10, 2026, the EPA approved the Coal Creek
Station NO<INF>X</INF> BART portion of the 2022 SIP submission as
well as North Dakota's 5-year progress report.
\18\ 87 FR 19635 (Apr. 5, 2022).
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D. North Dakota's Regional Haze Plan for the Second Implementation
Period
In accordance with CAA section 169A and the RHR at 40 CFR
51.308(f), on August 11, 2022, the governor of North Dakota submitted
North Dakota's 2022 SIP submission to address the State's regional haze
obligations for the second implementation period, which continues
through 2028. Concurrently, North Dakota also withdrew its 2013 SIP
submission that addressed NO<INF>X</INF> BART for Coal Creek.\19\ North
Dakota's 2022 SIP submission provided an updated submission addressing
the first implementation period NO<INF>X</INF> BART determination for
Coal Creek that was remanded in North Dakota v. EPA. The EPA approved
the Coal Creek NO<INF>X</INF> BART portion of North Dakota's 2022 SIP
submission on March 10, 2026.\20\ The remaining portion of the 2022 SIP
submission, addressing North Dakota's second implementation period
obligations, is addressed below.
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\19\ North Dakota refers to its January 2, 2013, SIP submission
as SIP Supplement No. 2.
\20\ 91 FR 11474 (Mar. 10, 2026).
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III. Requirements of Regional Haze Plans for the Second Implementation
Period
Under the CAA and EPA's regulations, all 50 States, the District of
Columbia, and the U.S. Virgin Islands were required to submit regional
haze SIPs satisfying the applicable requirements for the second
implementation period of the regional haze program by July 31, 2021.
Each SIP must contain a long-term strategy for making reasonable
progress toward meeting the national goal of remedying any existing and
preventing any future anthropogenic visibility impairment in Class I
areas.\21\ To this end, 40 CFR 51.308(f) lays out the process by which
States determine what constitutes their long-term strategies, with the
order of the requirements in 40 CFR 51.308(f)(1) through (3) generally
mirroring the order of the steps in the reasonable progress analysis
and (f)(4) through (6) containing additional, related requirements.\22\
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\21\ See CAA section 169A(b)(2)(B).
\22\ The EPA explained in the 2017 RHR revisions that the EPA
was adopting new regulatory language in 40 CFR 51.308(f) that,
unlike the structure in 51.308(d), ``tracked the actual planning
sequence.'' (82 FR 3078, at 3091 (Jan. 10, 2017)).
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Broadly speaking, a State first must identify the Class I areas
within the State and determine the Class I areas outside the State in
which visibility may be affected by emissions from the State. These are
the Class I areas that must be addressed in the State's long-term
strategy.\23\ For each Class I area within its borders, a State must
then calculate the baseline (five-year average period of 2000-2004),
current, and natural visibility conditions (i.e., visibility conditions
without anthropogenic visibility impairment) for that area, as well as
the visibility improvement made to date and the ``uniform rate of
progress'' (URP). The URP is 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 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.\24\
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\23\ See 40 CFR 51.308(f), (f)(2).
\24\ See 40 CFR 51.308(f)(1).
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Each State having a Class I area and/or emissions that may affect
visibility in a Class I area must then develop a long-term strategy
that includes the
[[Page 57306]]
enforceable emission limitations, compliance schedules, and other
measures that are necessary to make reasonable progress in such areas.
A reasonable progress determination is based on applying the four
statutory factors in CAA section 169A(g)(1) to sources of visibility
impairing pollutants that the State has selected to assess for controls
for the second implementation period. Additionally, as further
explained below, the RHR at 40 CFR 51.3108(f)(2)(iv) separately
provides five ``additional factors'' \25\ that States must consider in
developing their long-term strategies.\26\ A State evaluates potential
emission reduction measures for those selected sources and determines
which are necessary to make reasonable progress. Those measures are
then incorporated into the State's long-term strategy.
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\25\ The five ``additional factors'' for consideration in 40 CFR
51.308(f)(2)(iv) are distinct from the four statutory factors listed
in CAA section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that States
must consider and apply to sources in determining reasonable
progress.
\26\ See 40 CFR 51.308(f)(2).
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After a State has developed its long-term strategy, it then
establishes reasonable progress goals (RPGs) for each Class I area
within its borders by modeling the visibility impacts of all reasonable
progress controls at the end of the second implementation period, i.e.,
in 2028, as well as the impacts of other requirements of the CAA. The
RPGs include reasonable progress controls not only for sources in the
State in which the Class I area is located, but also for sources in
other States that contribute to visibility impairment in that area. The
RPGs are then compared to the baseline visibility conditions and the
URP to ensure that progress is being made towards the statutory goal of
preventing any future and remedying any existing anthropogenic
visibility impairment in Class I areas.\27\ There are additional
requirements in the rule, including FLM consultation, that apply to all
visibility protection SIPs and SIP revisions.\28\
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\27\ See 40 CFR 51.308(f)(2)-(3).
\28\ See e.g., 40 CFR 51.308(i).
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While States have discretion to choose any source selection
methodology that is reasonable, whatever choices they make should be
reasonably explained. To this end, 40 CFR 51.308(f)(2)(i) requires that
a State's SIP submission include ``a description of the criteria it
used to determine which sources or groups of sources it evaluated.''
The technical basis for source selection, which may include methods for
quantifying potential visibility impacts such as emissions divided by
distance metrics, trajectory analyses, residence time analyses, and/or
photochemical modeling, must also be appropriately documented, as
required by 40 CFR 51.308(f)(2)(iii).
Once a State has selected the set of sources, the next step is to
determine the emissions reduction measures for those sources that are
necessary to make reasonable progress for the second implementation
period.\29\ This is accomplished by considering the four statutory
factors--``the costs of compliance, the time necessary for compliance,
the energy and non-air quality environmental impacts of compliance, and
the remaining useful life of any existing source subject to such
requirements.'' \30\
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\29\ The CAA provides that, ``[i]n determining reasonable
progress there shall be taken into consideration'' the four
statutory factors. CAA section 169A(g)(1). However, in addition to
four-factor analyses for selected sources, groups of sources, or
source categories, a State may also consider additional emission
reduction measures for inclusion in its long-term strategy, e.g.,
from other newly adopted, on-the-books, or on-the-way rules and
measures for sources not selected for four-factor analysis for the
second implementation period.
\30\ See CAA section 169A(g)(1).
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The EPA has also explained that, in addition to the four statutory
factors, States have flexibility under the CAA and RHR to reasonably
consider visibility benefits as an additional factor alongside the four
statutory factors.\31\ Ultimately, while States have discretion to
reasonably weigh the factors and to determine what level of control is
needed, 40 CFR 51.308(f)(2)(i) provides that a State ``must include in
its implementation plan a description of . . . how the four statutory
factors were taken into consideration in selecting the measures for
inclusion in its long-term strategy.''
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\31\ See, e.g., Responses to Comments on Protection of
Visibility: Amendments to Requirements for State Plans; Proposed
Rule (81 FR 26942 (May 4, 2016)), Docket ID No. EPA-HQ-OAR-2015-
0531, U.S. Environmental Protection Agency at 186.
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As explained above, 40 CFR 51.308(f)(2)(i) requires States to
determine the emission reduction measures for sources that are
necessary to make reasonable progress by considering the four statutory
factors. Pursuant to 40 CFR 51.308(f)(2), measures that are necessary
to make reasonable progress towards the national visibility goal must
be included in a State's long-term strategy and in its SIP. If the
outcome of a four-factor analysis is that an emissions reduction
measure is necessary to make reasonable progress towards remedying
existing or preventing future anthropogenic visibility impairment, that
measure must be included in the SIP.
The characterization of information on each of the factors is also
subject to the documentation requirement in 40 CFR 51.308(f)(2)(iii).
The reasonable progress analysis is a technically complex exercise, and
also a flexible one that provides States with bounded discretion to
design and implement approaches appropriate to their circumstances.
Given this flexibility, 40 CFR 51.308(f)(2)(iii) plays an important
function in requiring a State to document the technical basis for its
decision making so that the public and the EPA can comprehend and
evaluate the information and analysis the State relied upon to
determine what emission reduction measures must be in place to make
reasonable progress. The technical documentation must include the
modeling, monitoring, cost, engineering, and emissions information on
which the State relied to determine the measures necessary to make
reasonable progress.
Additionally, the RHR at 40 CFR 51.3108(f)(2)(iv) separately
provides five ``additional factors'' that States must consider in
developing their long-term strategies: (1) Emission reductions due to
ongoing air pollution control programs, including measures to address
reasonably attributable visibility impairment; (2) measures to reduce
the impacts of construction activities; (3) source retirement and
replacement schedules; (4) basic smoke management practices for
prescribed fire used for agricultural and wildland vegetation
management purposes and smoke management programs; and (5) the
anticipated net effect on visibility due to projected changes in point,
area, and mobile source emissions over the period addressed by the
long-term strategy.
Because the air pollution that causes regional haze crosses State
boundaries, 40 CFR 51.308(f)(2)(ii) requires a State to consult with
other States that also have emissions that are reasonably anticipated
to contribute to visibility impairment in a given Class I area. If a
State, pursuant to consultation, agrees that certain measures (e.g., a
certain emission limitation) are necessary to make reasonable progress
at a Class I area, it must include those measures in its SIP.\32\
Additionally, the RHR requires that States that contribute to
visibility impairment at the same Class I area consider the emission
reduction measures the other contributing States have identified as
being necessary to make reasonable progress for their own sources.\33\
If a State has been asked by another State(s) to consider or adopt
certain emission reduction measures,
[[Page 57307]]
but ultimately determines those measures are not necessary to make
reasonable progress, that State must document in its SIP the actions
taken to resolve the disagreement.\34\ Under all circumstances, a State
must document in its SIP submission all substantive consultations with
other contributing States.\35\
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\32\ See 40 CFR 51.308(f)(2)(ii)(A).
\33\ See 40 CFR 51.308(f)(2)(ii)(B).
\34\ See 40 CFR 51.308(f)(2)(ii)(C).
\35\ Id.
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RPGs ``measure the progress that is projected to be achieved by the
control measures States have determined are necessary to make
reasonable progress based on a four-factor analysis.'' \36\ For the
second implementation period, the RPGs are set for 2028. Reasonable
progress goals are not enforceable targets.\37\ While States are not
legally obligated to achieve the visibility conditions described in
their RPGs, 40 CFR 51.308(f)(3)(i) requires that ``[t]he long-term
strategy and the reasonable progress goals must provide for an
improvement in visibility for the most impaired days since the baseline
period and ensure no degradation in visibility for the clearest days
since the baseline period.''
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\36\ See 82 FR 3078, at 3091 (Jan. 10, 2017).
\37\ See 40 CFR 51.308(f)(3)(iii).
---------------------------------------------------------------------------
RPGs may also serve as a metric for assessing the amount of
progress a State is making towards the national visibility goal. To
support this approach, the RHR requires States with Class I areas to
compare the 2028 RPG for the most impaired days to the corresponding
point on the URP line (representing visibility conditions in 2028 if
visibility were to improve at a linear rate from conditions in the
baseline period of 2000-2004 to natural visibility conditions in 2064).
If the most impaired days RPG in 2028 is above the URP (i.e., if
visibility conditions are improving more slowly than the rate described
by the URP), each State that contributes to visibility impairment in
the Class I area must demonstrate, based on the four-factor analysis
required under 40 CFR 51.308(f)(2)(i), that no additional emission
reduction measures would be reasonable to include in its long-term
strategy.\38\ To this end, 40 CFR 51.308(f)(3)(ii) requires that each
State contributing to visibility impairment in a Class I area that is
projected to improve more slowly than the URP provide ``a robust
demonstration, including documenting the criteria used to determine
which sources or groups [of] sources were evaluated and how the four
statutory factors required by paragraph (f)(2)(i) were taken into
consideration in selecting the measures for inclusion in its long-term
strategy.''
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\38\ See 40 CFR 51.308(f)(3)(ii).
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Section 51.308(f)(6) requires States to have certain strategies and
elements in place for assessing and reporting on visibility. Individual
requirements under this section apply either to States with Class I
areas within their borders, States with no Class I areas but that are
reasonably anticipated to cause or contribute to visibility impairment
in any Class I area, or both. Compliance with the monitoring strategy
requirement may be met through a State's participation in the
Interagency Monitoring of Protected Visual Environments (IMPROVE)
monitoring network, which is used to measure visibility impairment
caused by air pollution at the 156 Class I areas covered by the
visibility program.\39\
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\39\ See 40 CFR 51.308(f)(6), (f)(6)(i), (f)(6)(iv).
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All States' SIPs must provide for procedures by which monitoring
data and other information are used to determine the contribution of
emissions from within the State to regional haze visibility impairment
in affected Class I areas, as well as a statewide inventory documenting
such emissions.\40\ All States' SIPs must also provide for any other
elements, including reporting, recordkeeping, and other measures, that
are necessary for States to assess and report on visibility.\41\
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\40\ See 40 CFR 51.308(f)(6)(ii), (iii), (v).
\41\ See 40 CFR 51.308(f)(6)(vi).
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Section 51.308(f)(5) requires a State's regional haze SIP revision
to address the requirements of paragraphs 40 CFR 51.308(g)(1) through
(5) so that the plan revision due in 2021 will serve also as a progress
report addressing the period since submission of the progress report
for the first implementation period. The regional haze progress report
requirement is designed to inform the public and the EPA about a
State's implementation of its existing long-term strategy and whether
such implementation is in fact resulting in the expected visibility
improvement.\42\ To this end, every State's SIP revision for the second
implementation period is required to assess changes in visibility
conditions and describe the status of implementation of all measures
included in the State's long-term strategy, including BART and
reasonable progress emission reduction measures from the first
implementation period, and the resulting emissions reductions.\43\
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\42\ See 81 FR 26942, at 26950 (May 4, 2016), (82 FR 3078, at
3119 (Jan. 10, 2017)).
\43\ See 40 CFR 51.308(g)(1) and (2).
---------------------------------------------------------------------------
CAA section 169A(d) requires that before a State holds a public
hearing on a proposed regional haze SIP revision, it must consult with
the appropriate FLM or FLMs; pursuant to that consultation, the State
must include a summary of the FLMs' conclusions and recommendations in
the notice to the public. Consistent with this statutory requirement,
the RHR also requires that States ``provide the [FLM] with an
opportunity for consultation, in person and at a point early enough in
the State's policy analyses of its long-term strategy emission
reduction obligation so that information and recommendations provided
by the [FLM] can meaningfully inform the State's decisions on the long-
term strategy.'' \44\ For the EPA to evaluate whether FLM consultation
meeting the requirements of the RHR has occurred, the SIP submission
should include documentation of the timing and content of such
consultation. The SIP revision submitted to the EPA must also describe
how the State addressed any comments provided by the FLMs.\45\ Finally,
a SIP revision must provide procedures for continuing consultation
between the State and FLMs regarding the State's visibility protection
program, including development and review of SIP revisions, five-year
progress reports, and the implementation of other programs having the
potential to contribute to impairment of visibility in Class I
areas.\46\
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\44\ See 40 CFR 51.308(i)(2).
\45\ See 40 CFR 51.308(i)(3).
\46\ See 40 CFR 51.308(i)(4).
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Finally, the SIP must meet the approval requirements in CAA section
110(a)(2) for plans ``submitted by a State under this chapter'' to the
extent not already addressed in the regulations described previously.
As relevant here, the State must provide ``necessary assurances'' that
the State has adequate personnel, funding, and authority to carry out
the implementation plan, that the State ``is not prohibited by any
provision of Federal or State law from carrying out such implementation
plan or portion thereof,'' and that the State can lawfully rely on
regional and local instrumentalities to implement the SIP, as
applicable.\47\
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\47\ See CAA section 110(a)(2)(E)(i)-(iii).
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IV. EPA's Evaluation of North Dakota's Regional Haze Submission for the
Second Implementation Period
In this section of the document, the EPA describes North Dakota's
2022 SIP submission and evaluates it against the requirements of the
CAA and RHR for the second implementation period of the regional haze
program. This preamble will focus only on the
[[Page 57308]]
portions of North Dakota's 2022 SIP submission that were disapproved in
the EPA's 2024 partial approval/partial disapproval: 40 CFR
51.308(f)(2): long-term strategy; 40 CFR 51.308(f)(3): reasonable
progress goals; and 40 CFR 51.308(i): Federal Land Manager (FLM)
consultation.\48\ Because the EPA, in its 2024 partial approval/partial
disapproval, approved the portions of North Dakota's 2022 SIP
submission relating to 40 CFR 51.308(f)(1): calculations of baseline,
current, and natural visibility conditions, progress to date, and the
uniform rate of progress (URP); 40 CFR 51.308(f)(4): reasonably
attributable visibility impairment; 40 CFR 51.308(f)(5) and 40 CFR
51.308(g): progress report requirements; and 40 CFR 51.308(f)(6):
monitoring strategy and other implementation plan requirements,\49\
these elements will not be addressed in this action.
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\48\ 89 FR 95126 (Dec. 2, 2024).
\49\ 89 FR 56693 (July 10, 2024); finalized at 89 FR 95126 (Dec.
2, 2024).
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A. North Dakota's Long-Term Strategy Under CAA 169A and 40 CFR
51.308(f)(2)
The EPA is proposing to approve North Dakota's long-term strategy
for the second implementation period. As explained in other recent
actions \50\ and in subsection (1)(b) below, the EPA's URP policy is
that so long as the Class I areas impacted by a State are below the URP
and the State considers the four statutory factors, the State will have
presumptively demonstrated it has made reasonable progress for the
second implementation period for that area. This policy was not in
place at the time of the EPA's partial approval/partial disapproval in
2024. As detailed in this preamble, the EPA finds that North Dakota has
met the requirements of CAA 169A(b)(2) and 40 CFR 51.308(f)(2). Within
its SIP, North Dakota evaluated and determined the emission reduction
measures that are necessary to make reasonable progress by considering
the four statutory factors. They also projected that 2028 visibility
conditions are all below the 2028 URP for Class I areas in North Dakota
and for areas affected by emissions from North Dakota sources.
Therefore, the EPA is proposing to conclude that North Dakota's long-
term strategy contains the enforceable emission limitations, compliance
schedules, and other measures that are necessary to make reasonable
progress.
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\50\ See 90 FR 20425, at 20434 (May 14, 2025), 90 FR 22033, at
22043 (May 23, 2025); 90 FR 22166, at 22185; (May 23, 2025); 90 FR
25944, at 25952 (June 18, 2025); 90 FR 25975, at 25980 (June 18,
2025); 90 FR 29737, at 29738 (July 7, 2025); 90 FR 34792, at 34796
(July 24, 2025); 90 FR 36005, at 36017 (July 31, 2025); 90 FR 40272,
at 40287 (Aug. 19, 2025); 90 FR 43030, at 43038 (Sept. 5, 2025); 90
FR 42833, at 42834 (Sept. 5, 2025); 90 FR 43958, at 43966 (Sept. 11,
2025); 90 FR 46070 (Sept. 25, 2025); 90 FR 48481, at 48496 (Oct. 23,
2025); 90 FR 48855, at 48859 (Oct. 30, 2025); 90 FR 54586 (Nov. 28,
2025); 90 FR 57636, at 57637 (Dec. 11, 2025); 91 FR 5321, at 5322
(Feb. 6, 2026); 91 FR 6581, at 6590 (Feb. 12, 2026).
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Each State having a Class I area within its borders, or emissions
that may affect visibility in any Class I area outside the State must
develop a long-term strategy for making reasonable progress towards the
national visibility goal for each impacted Class I area.\51\ As
explained in the II. Background section of this document, reasonable
progress is achieved when all States contributing to visibility
impairment in a Class I area are implementing the measures that have
been determined necessary to make reasonable progress through
consideration of the four statutory factors.\52\ Each State's long-term
strategy must include the enforceable emission limitations, compliance
schedules, and other measures that are necessary to make reasonable
progress.\53\ After considering the four statutory factors, all
measures that are determined to be necessary to make reasonable
progress must be incorporated into the long-term strategy. In
developing its long-term strategy, a State must also consider the five
additional factors in 40 CFR 51.308(f)(2)(iv). As part of its
reasonable progress determinations, the State must describe the
criteria used to determine which sources, or group of sources, were
evaluated (i.e., subject to four-factor analysis) for the second
implementation period and how the four statutory factors were taken
into consideration in selecting the emission reduction measures for
inclusion in the long-term strategy.\54\
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\51\ See CAA section 169A(b)(2)(B).
\52\ See 40 CFR 51.308(f)(2)(i).
\53\ See 40 CFR 51.308(f)(2).
\54\ See 40 CFR 51.308(f)(2)(iii).
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1. North Dakota's Long-Term Strategy Four-Factor Analysis
a. Summary of North Dakota's Long-Term Strategy Four-Factor Analysis
As detailed below, the EPA is proposing to approve North Dakota's
long-term strategy because North Dakota's 2022 SIP submission meets CAA
and RHR requirements. As detailed in North Dakota's 2022 SIP
submission, North Dakota determined that existing measures for Otter
Tail Power Company--Coyote Station, Basin Electric Power Cooperative--
Antelope Valley Station, Basin Electric Power Cooperative--Leland Olds
Station, Coal Creek Station, Minnkota--Milton R. Young Station, Montana
Dakota Utilities--Heskett Station, Petro-Hunt, L.L.C.--Little Knife Gas
Plant, Hess Tioga Gas Plant, LLC--Tioga Gas Plant, Northern Border
Compressor Station No. 4, and Dakota Gasification Company--Great Plains
Synfuels Plant comprise what is necessary to make reasonable progress
based on an analysis of the four statutory factors.\55\ As a result of
the evaluation, North Dakota did not find it reasonable to require
additional emission limitations, compliance schedules, or control
measures at the selected sources.
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\55\ North Dakota's 2022 SIP submission, section 5.2.
---------------------------------------------------------------------------
Under 40 CFR 51.308(f)(2)(i), SIP submittals must include a
description of the criteria a State used to determine which sources, or
groups of sources, to evaluate through four-factor analysis. In its
2022 SIP submission, North Dakota focused its control strategy analysis
for the second implementation period on emissions of NO<INF>X</INF> and
SO<INF>2</INF>.\56\ NO<INF>X</INF> and SO<INF>2</INF> are the two
primary pollutants that react to form ammonium nitrates and ammonium
sulfates, the primary visibility impairing pollutants that affect
visibility at Class I areas in North Dakota on the most impaired
days.\57\ In North Dakota, point sources are the largest contributors
to SO<INF>2</INF> and NO<INF>X</INF>.\58\ Thus, North Dakota focused
primarily on existing point sources in this implementation period.
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\56\ North Dakota's 2022 SIP submission, section 5.1.
\57\ Id.
\58\ Id.
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For purposes of source selection, North Dakota utilized a Q/d
metric. The Q/d screening metric uses a source's annual emissions in
tons (Q) divided by the distance in kilometers (d) between the source
and the nearest Class I area, along with a reasonably selected
threshold for this metric. The larger the Q/d value, the greater the
source's expected effect on visibility in each associated Class I area.
Using a Q/d threshold of 10,\59\ North Dakota selected ten facilities
for four-factor analysis: Coyote Station, Antelope Valley, Milton R.
Young Station, Coal Creek Station, Leland Olds Station, Heskett
Station, Little Knife Gas Plant, Tioga Gas Plant, Northern Border
Compressor Station #4,
[[Page 57309]]
and Great Plains Synfuels Plant.\60\ North Dakota required each of
these facilities to submit a report detailing available emission
control measures. Section 5.2 of North Dakota's 2022 SIP submission
contains North Dakota's evaluation of the four statutory factors for
each source and North Dakota's determinations of the source-specific
emission reduction measures necessary to make reasonable progress.
---------------------------------------------------------------------------
\59\ The Q/d threshold of ``10'' is based on the Federal Land
Managers' Air Quality Related Values Work Group (FLAG) report that
was issued in October 2010 that adopts similar criteria derived from
EPA's 2005 Best Available Retrofit Technology (BART) guidelines for
the Regional Haze Rule. See Federal Land Managers' Air Quality
Related Values Work Group (FLAG) Phase I Report--Revised (2010),
Background Information on Thresholds: <a href="https://irma.nps.gov/DataStore/DownloadFile/420352">https://irma.nps.gov/DataStore/DownloadFile/420352</a>.
\60\ North Dakota's 2022 SIP submission, section 5.1.2.
---------------------------------------------------------------------------
b. EPA's Evaluation of North Dakota's Long-Term Strategy Four-Factor
Analysis
Based on the EPA's review, the EPA finds that North Dakota's 2022
SIP submission satisfies the requirements under 51.308(f)(2)(i) because
North Dakota selected 10 point sources, evaluated the four statutory
factors, and determined the emission reductions necessary to make
reasonable progress as described in section IV.A.1.a. of this document.
As discussed earlier in this preamble, CAA section 169A(b)(2)
requires each State to have a plan for making reasonable progress
toward the national visibility goal. CAA section 169A(g)(1) specifies:
``[I]n determining reasonable progress there shall be taken into
consideration the costs of compliance, the time necessary for
compliance, and the energy and non-air quality environmental impacts of
compliance, and the remaining useful life of any existing source
subject to such requirements.'' \61\ The RHR implements this statutory
requirement in 40 CFR 51.308(f) for the second and subsequent
implementation periods for regional haze. 40 CFR 51.308(f) requires
States to submit a long-term strategy that addresses regional haze
visibility impairment for each mandatory Class I area within the State
and for each mandatory Class I area located outside the State that may
be affected by emissions from the State. 40 CFR 51.308(f)(2)(i) lays
out the CAA 169A four statutory factor criteria for the evaluation and
development of the long-term strategy.
---------------------------------------------------------------------------
\61\ The EPA refers to the CAA section 169A(g)(1) requirements
as the four statutory factors.
---------------------------------------------------------------------------
With respect to source selection, North Dakota used the 2012-2016
average annual emissions of NO<INF>X</INF> and SO<INF>2</INF> in tons
divided by distance in kilometers between a source and the nearest
Class I area as a surrogate for baseline visibility impact (Q/d).
Applying this protocol, North Dakota selected the 10 point sources
identified above for analysis. As stated in section IV.A.1.a., 40 CFR
51.308(f)(2)(i) requires that a State's SIP submission include a
``description of the criteria it used to determine which sources or
groups of sources it evaluated,'' and 40 CFR 51.308(f)(2)(iii) requires
that it must be appropriately documented. Because North Dakota provided
a detailed description of the technical information \62\ used to select
a reasonable set of sources for a four-factor analysis, the EPA finds
that North Dakota's source selection was reasonable and consistent with
the requirements of 40 CFR 51.308(f)(2).\63\ Based upon the analysis,
North Dakota's 2022 SIP submission does not require additional emission
control measures to make reasonable progress.
---------------------------------------------------------------------------
\62\ Technical information provided included facilities' recent
average annual emissions of SO<INF>2</INF> and NO<INF>X</INF> and
distance to the nearest Class I area. This is known as Q/d, where
the ``Q'' represents emissions in tons, and ``d'' represents
distance in kilometers. See Chapter 5 and table 35 in the 2022 SIP
submission.
\63\ North Dakota's 2022 SIP submission, section 5.1.2.
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In the EPA's 2024 partial approval/partial disapproval action, the
EPA concluded that North Dakota had improperly relied on the visibility
impact of controls to reject controls at Coyote Station and Antelope
Valley, that North Dakota rejected controls without providing adequate
justification at Coal Creek and Leland Olds, and that North Dakota had
not adequately considered the time necessary for compliance factor in
its evaluation of additional NO<INF>X</INF> controls at Coal Creek.\64\
As explained below, based on the EPA's updated policy, the EPA proposes
to reconsider and reverse the 2024 disapproval of North Dakota's long-
term strategy in this action.
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\64\ 89 FR 56693, at 56705 (July 10, 2024); Finalized at 89 FR
95126 (Dec. 2, 2024).
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As explained in other recent actions \65\ and more specifically in
this section below, the EPA's recently implemented policy is that so
long as the Class I areas impacted by a State are below the URP and the
State considers the four statutory factors, the State will have
presumptively demonstrated it has made reasonable progress for the
second implementation period for that area. The EPA believes this
policy recognizes the considerable improvements in visibility
impairment that have been made by a wide variety of State and Federal
programs in recent decades. When the 2028 URP is adjusted for wildland
prescribed fire and international anthropogenic impacts, all of the
Class I areas impacted by North Dakota are below the 2028 URP.\66\
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\65\ See 90 FR 20425, at 20434 (May 14, 2025), 90 FR 22033, at
22043 (May 23, 2025); 90 FR 22166, at 22185; (May 23, 2025); 90 FR
25944, at 25952 (June 18, 2025); 90 FR 25975, at 25980 (June 18,
2025); 90 FR 29737, at 29738 (July 7, 2025); 90 FR 34792, at 34796
(July 24, 2025); 90 FR 36005, at 36017 (July 31, 2025); 90 FR 40272,
at 40287 (Aug. 19, 2025); 90 FR 43030, at 43038 (Sept. 5, 2025); 90
FR 42833, at 42834 (Sept. 5, 2025); 90 FR 43958, at 43966 (Sept. 11,
2025); 90 FR 46070 (Sept. 25, 2025); 90 FR 48481, at 48496 (Oct. 23,
2025); 90 FR 48855, at 48859 (Oct. 30, 2025); 90 FR 54586 (Nov. 28,
2025); 90 FR 57636, at 57637 (Dec. 11, 2025); 91 FR 5321, at 5322
(Feb. 6, 2026); 91 FR 6581, at 6590 (Feb. 12, 2026).
\66\ WRAP TSS; Colorado State University (CSU) and the
Cooperative Institute for Research in the Atmosphere (CIRA), 25 Mar
2026, <a href="https://views.cira.colostate.edu/tssv2">https://views.cira.colostate.edu/tssv2</a>.
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Based on a reevaluation of the 2022 SIP submission under the new
URP policy, the EPA finds that North Dakota's four-factor analyses and
control determinations at Coyote Station, Antelope Valley, Coal Creek,
and Leland Olds are reasonable and the EPA agrees with North Dakota's
conclusion that no additional emission control measures are necessary
to include in North Dakota's long-term strategy. Additionally, within
this preamble the EPA finds that North Dakota properly evaluated the
time necessary for compliance factor in its analysis of potential
NO<INF>X</INF> controls for reasonable progress at Coal Creek because
their analysis included compliance schedules, such as the installation
schedule, for the selected controls. The selected LNC3+ control was
installed at Unit 2 in 2007 and at Unit 1 in 2020.\67\ Thus, the EPA
finds that North Dakota adequately considered the time necessary for
the compliance factor in its analysis of potential controls at Coal
Creek since the control measures were installed in prior years.
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\67\ North Dakota's 2022 SIP submission, Appendix F.1-2. The EPA
also notes a statement from the 2019 Guidance that discusses how the
time necessary for compliance factor should be used in decision
making: ``We recommend that states consider the time necessary for
compliance as part of their determination of what compliance
deadlines for selected control measures are reasonable, rather than
as part of their determination whether to adopt the control measures
in the first instance'' (2019 Guidance at 41).
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With respect to the EPA's application of the URP policy, the EPA
has the discretion and authority to change policy. In FCC v. Fox
Television Stations, Inc., the U.S. Supreme Court plainly stated that
an agency is free to change a prior policy and ``need not demonstrate .
. . that the reasons for the new policy are better than the reasons for
the old one; it suffices that the new policy is permissible under the
statute, that there are good reasons for it, and that the agency
believes it to be
[[Page 57310]]
better.'' \68\ The EPA believes that its recently adopted policy aligns
with the purpose of the statute and RHR, which is achieving
``reasonable'' progress, not maximal progress, toward Congress' natural
visibility goal.
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\68\ See 556 U.S. 502, 515 (2009) (referencing Motor Vehicle
Mfrs. Ass'n of United States, Inc. v. State Farm Mut. Auto. Ins.
Co., 463 U.S. 29 (1983)). See also Perez v. Mortgage Bankers Assn.,
135 S. Ct. 1199 (2015).
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In the 2017 RHR Revisions, the EPA addressed the role of the URP as
it relates to a State's development of its second implementation period
SIP.\69\ Specifically, in response to comments suggesting that the URP
should be considered a ``safe harbor'' that relieve States of any
obligation to consider the four statutory factors, the EPA explained
that the URP was not intended to be such a safe harbor.\70\ ``Some
commenters stated a desire for corresponding rule text dealing with
situations where RPGs are equal to (``on'') or better than (``below'')
the URP or glidepath. Several commenters stated that the URP or
glidepath should be a `safe harbor,' opining that States should be
permitted to analyze whether projected visibility conditions for the
end of the implementation period will be on or below the glidepath
based on on-the-books or on-the-way control measures, and that in such
cases a four-factor analysis should not be required.'' \71\
---------------------------------------------------------------------------
\69\ See 82 FR 3078 (Jan. 10, 2017).
\70\ Id. at 3099.
\71\ Id.
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Other 2017 RHR comments indicated a similar approach, such as ``a
somewhat narrower entrance to a `safe harbor,' '' by suggesting that if
current visibility conditions are already below the end-of-planning-
period point on the URP line, a four-factor analysis should not be
required.'' \72\ The EPA stated in its response that the EPA did not
agree with either of these recommendations. ``The CAA requires that
each SIP revision contain long-term strategies for making reasonable
progress, and that in determining reasonable progress States must
consider the four statutory factors. Treating the URP as a safe harbor
would be inconsistent with the statutory requirement that States assess
the potential to make further reasonable progress towards natural
visibility goal in every implementation period.'' \73\
---------------------------------------------------------------------------
\72\ Id.
\73\ Id.
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However, so long as a State considers the four statutory factors,
the presumption that a Class I area below the URP is achieving
reasonable progress is consistent with the CAA and RHR. The EPA
believes this policy also recognizes the considerable improvements in
visibility impairment that have been made by a wide variety of State
and Federal programs in recent decades. In sum, North Dakota selected a
number of sources, evaluated emissions control measures, and considered
the four statutory factors. In addition, visibility conditions at all
Class I areas to which North Dakota contributes are below the URP. In
light of these facts, the EPA agrees with North Dakota's conclusion
that no additional measures are necessary to make reasonable progress
during the second implementation period and is proposing to approve the
State's SIP submittal.
2. Other Long-Term Strategy Requirements
When developing long-term strategies, States must meet the
additional requirements specified in 40 CFR 51.308(f)(2)(ii)-(iv).
After reviewing North Dakota's 2022 SIP elements, the EPA finds that
North Dakota has satisfied these additional long-term strategy
requirements of 40 CFR 51.308(f)(2)(ii)-(iv).
40 CFR 51.308(f)(2)(ii) requires States to consult with other
States to develop coordinated emission management strategies when they
have emissions that are reasonably anticipated to contribute to
visibility impairment in Class I areas across State boundaries.
Specifically, 40 CFR 51.308(f)(2)(ii)(A) requires a State to
demonstrate that its SIP includes all measures agreed upon during the
State-to-State consultations. North Dakota considered additional
controls for facilities affecting out of State Class I areas through a
four-factor analysis and determined that no additional controls on
North Dakota sources are required. 40 CFR 51.308(f)(ii)(B) requires a
State to consider emission reduction measures, identified by other
States, as being necessary to make reasonable progress in a Class I
area. North Dakota did not receive recommendations for any of the
sources within the State from other States. Section 2.1 of North
Dakota's 2022 SIP submission describes North Dakota's consultation with
other States throughout the development of its regional haze plan.\74\
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\74\ North Dakota's 2022 SIP submission, section 2.1.
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40 CFR 51.308(f)(2)(iii) requires States to document the technical
basis on which it is relying to determine the emission reduction
measures that are necessary to make reasonable progress in each
impacted mandatory Class I area. This includes modeling, monitoring,
costs, engineering, and emissions information. North Dakota relied on
WRAP technical information, modeling, and analysis to support
development of its long-term strategy. Section 4.1 of North Dakota's
2022 SIP submission describes the emissions inventories and projections
North Dakota used in its analysis, including its ``on-the-books'' and
``potential additional controls'' modeling scenarios.
40 CFR 51.308(f)(2)(iv) specifies five additional factors States
must consider in developing their long-term strategies. The five
additional factors are: emission reductions due to ongoing air
pollution control programs, including measures to address reasonably
attributable visibility impairment; measures to mitigate the impacts of
construction activities; source retirement and replacement schedules;
basic smoke management practices for prescribed fire used for
agricultural and wildland vegetation management purposes and smoke
management programs; and the anticipated net effect on visibility due
to projected changes in point, area, and mobile source emissions over
the period addressed by the long-term strategy. North Dakota described
each of the five additional factors and how it considered those factors
in section 5.3.1. to 5.3.5. of its 2022 SIP submission.
North Dakota's emission reductions due to ongoing air pollution
programs are through State regulations contained in the North Dakota
Administrative Code, federal programs such as the Volkswagen
Environmental Mitigation Trust, EPA's Diesel Emissions Reductions Act,
Acid Rain Program, Tier 3 Motor Vehicle Emission and Fuel Standards,
Tier 4 Emission Standards for Nonroad Diesel Engines, Emission
Standards for New Nonroad Engines, Heavy Duty Highway Engine and
Vehicle Standards, the NO<INF>X</INF> SIP Call, National Emission
Standards for Industrial, Commercial, and Institutional Boilers and
Process Heaters, National Emission Standards for Hazardous Air
Pollutants, and maximum achievable control technology (MACT)
Standards.\75\ North Dakota also listed measures to mitigate the
impacts of construction activities, source retirements and replacement
schedules, smoke management practices, and the anticipated net impact
on visibility due to emissions changes over the long-term strategy
period.\76\
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\75\ North Dakota's 2022 SIP submission, section 5.3.1.
\76\ North Dakota's 2022 SIP submission, sections 5.3.2-5.3.5.
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[[Page 57311]]
B. Reasonable Progress Goals
The EPA proposes to find that North Dakota's 2022 SIP submission
meets the reasonable progress goal requirements under 40 CFR
51.308(f)(3). Section 51.308(f)(3)(i) requires a State in which a Class
I area is located to establish RPGs, one for the most impaired days and
one for the clearest days. These RPGs reflect the visibility conditions
that will be achieved at the end of the implementation period as a
result of the emission limitations, compliance schedules and other
measures required under paragraph (f)(2) in States' long-term
strategies, as well as implementation of other CAA requirements.
After establishing its long-term strategy, North Dakota developed
reasonable progress goals for each Class I area for the 20 percent most
impaired days and 20 percent clearest days based on the results of 2028
WRAP modeling.\77\ The reasonable progress goals are based on North
Dakota's long-term strategy, the long-term strategy of other States
that may affect Class I areas in North Dakota, and other CAA
requirements. Per 40 CFR 51.308(f)(3)(iv), the EPA must evaluate the
demonstrations the State developed pursuant to 40 CFR 51.308(f)(2) to
determine whether the State's reasonable progress goals for visibility
improvement provide for reasonable progress towards natural visibility
conditions.
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\77\ North Dakota's 2022 SIP Submission, section 6.
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Compliance with the reasonable progress goals requirements under 40
CFR 51.308(f)(3) is in part dependent on compliance with the long-term
strategy provisions under 40 CFR 51.308(f)(2). Since reasonable
progress goals must reflect conditions that are projected to be
achieved as a result of the long-term strategy (40 CFR
51.308(f)(3)(i)), it is not possible to approve the reasonable progress
goals if the long-term strategy is not approvable. Therefore, in the
EPA's 2024 partial approval/partial disapproval of North Dakota's 2022
SIP submission, the EPA disapproved North Dakota's long-term strategy
under 51.308(f)(2) and disapproved North Dakota's reasonable progress
goals under 51.308(f)(3).\78\ However, as described above, based on the
URP policy, the EPA is now proposing to conclude that North Dakota's
long-term strategy contains the enforceable emission limitations,
compliance schedules, and other measures that are necessary to make
reasonable progress. North Dakota projected reasonable progress goals
that reflect the visibility conditions that are projected to be
achieved by the end of 2028 as a result of those enforceable emissions
limitations, compliance schedules, and other measures required under
51.308 (f)(2).\79\ North Dakota projected its reasonable progress goal
for Lostwood Wilderness Area at 15.78 deciview impairment in 2028,
which is under the adjusted uniform rate of progress of 16.00 deciview
impairment.\80\ North Dakota projected its reasonable progress goal for
Theodore Roosevelt National Park at 13.56 deciview impairment in 2028,
which is under the adjusted uniform rate of progress of 14.43
deciview.\81\ North Dakota showed its reasonable progress goals achieve
a faster rate of improvement in visibility than the URP, addressing the
requirements of paragraph (f)(3)(ii).\82\ Therefore, since the EPA has
determined that North Dakota's long-term strategy and the associated
RPGs meet CAA and RHR requirements, the EPA is proposing to approve the
RPG component of North Dakota's 2022 SIP submission in this preamble.
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\78\ 89 FR 95127 (Dec. 2, 2024).
\79\ North Dakota's 2022 SIP submission, section 6.
\80\ North Dakota's 2022 SIP submission, section 6.1.1.
\81\ Id.
\82\ North Dakota's 2022 SIP submission, section 6.2 and 6.3.
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C. Requirements for State and Federal Land Manager Coordination
The EPA has determined that North Dakota's long-term strategy meets
CAA and RHR requirements, and the SIP meets all of the FLM consultation
requirements. Therefore, the EPA is proposing to approve the FLM
consultation component of North Dakota's 2022 SIP submission in this
action.
CAA section 169A(d) 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. In addition, the 40 CFR 51.308(i)(2) FLM
consultation provision requires a State to provide FLMs with an
opportunity for consultation that is early enough in the State's policy
analysis of its emission reduction obligation so that information and
recommendations provided by the FLMs can meaningfully inform the
State's decisions on its long-term strategy. The opportunity for
consultation will be deemed to have been early enough if the
consultation has taken place at least 120 days prior to holding any
public hearing or other public comment opportunity on the
implementation plan.\83\ Regardless, the opportunity for consultation
must be provided at least sixty days before a public hearing or public
comment period at the State level.\84\ Section 51.308(i)(2) lists two
substantive topics on which FLMs must be provided an opportunity to
discuss with States: assessment of visibility impairment in any Class I
area and recommendations on the development and implementation of
strategies to address visibility impairment. Section 51.308(i)(3)
requires States, in developing their SIPs, to include a description of
how they addressed FLM comments.
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\83\ 40 CFR 51.308(i)(ii)(2) and August 20, 2019, Memorandum
``Guidance on Regional Haze State Implementation Plans for the
Second Implementation Period,'' from Peter Tsirigotis, Director, to
Regional Air Division Directors, Regions 1-10.
\84\ Id.
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North Dakota's 2022 SIP submission summarizes the State's
consultation and coordination with the FLMs. North Dakota met via video
conference with the NPS on November 6, 2020, and December 15, 2020, and
with the USFS on November 23, 2020. Upon completing its draft 2022 SIP
submission, North Dakota provided it to FLMs for a review and
consultation period from September 20, 2021, through November 19, 2021.
Additionally, North Dakota held a video conference with the NPS, USFS,
and EPA Region 8 staff on November 10, 2021, to discuss the draft and
receive feedback from the FLMs. North Dakota received comments from
USFS on November 17, 2021, and from the NPS on November 19, 2021.\85\
North Dakota responded to the FLM comments and included the responses
in appendix D of its 2022 SIP submission.
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\85\ The USFWS did not comment on North Dakota's 2022 SIP
submission.
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Because the EPA disapproved North Dakota's long-term strategy under
51.308(f)(2) and the reasonable progress goals under 51.308(f)(3), the
EPA also disapproved North Dakota's FLM consultation under
51.308(i).\86\ While North Dakota did take administrative steps to
provide the FLMs the opportunity to review and provide feedback on the
State's draft regional haze plan, the EPA could not approve the
consultation in that plan because the EPA determined that the plan did
not meet the statutory and regulatory requirements of the CAA and the
RHR. Therefore, compliance with 40 CFR 51.308(i) is dependent on
satisfying the 40 CFR 51.308(f)(2)'s long-term strategy provisions and
(f)(3)'s reasonable
[[Page 57312]]
progress goals provisions. However, as described in section IV.A. of
this document and in other recent actions, based on the EPA's URP
policy, the EPA is proposing to approve North Dakota's long-term
strategy and reasonable progress goals. Because North Dakota evaluated
and determined the emission reduction measures that are necessary to
make reasonable progress by considering the four statutory factors, and
the projected 2028 visibility conditions for Class I areas both in
North Dakota and those areas influenced by emissions from North Dakota
sources, are all below the 2028 URP, the EPA finds that North Dakota's
long-term strategy contains the enforceable emission limitations,
compliance schedules, and other measures that are necessary to make
reasonable progress. Therefore, since the EPA has determined that North
Dakota's long-term strategy meets CAA and RHR requirements, and the SIP
meets all of the FLM consultation requirements, the EPA is proposing to
approve the FLM consultation component of North Dakota's 2022 SIP
submission in this action.
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\86\ 89 FR 95127 (Dec. 2, 2024).
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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.\87\ 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:
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\87\ 42 U.S.C. 7410(k); 40 CFR 52.02(a).
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<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 Clean Air Act.
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).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Carbon monoxide,
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen
dioxide, Ozone, Particulate matter, Reporting and recordkeeping
requirements, Sulfur oxides, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: August 25, 2026.
Cyrus M. Western,
Regional Administrator, Region 8.
[FR Doc. 2026-18290 Filed 9-8-26; 8:45 am]
BILLING CODE 6560-50-P
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</html>Indexed from Federal Register on September 9, 2026.
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.