Air Plan Approval; Arkansas; Regional Haze State Implementation Plan for the Second Implementation Period

Issuing agencies

Abstract

Pursuant to the Clean Air Act (CAA or the Act), the U.S. Environmental Protection Agency (EPA) is finalizing approval of a State Implementation Plan (SIP) revision submitted by the State of Arkansas through the Division of Environmental Quality (DEQ) on August 8, 2022, clarified by DEQ on July 29, 2025, and further supplemented on May 4, 2026, to satisfy the requirements of the Act and the EPA's Regional Haze Rule (RHR) for visibility protection in mandatory Class I Federal areas (Class I areas) for the program's second implementation period. Arkansas' SIP submission addresses the requirement that States must revise their long-term strategies for making reasonable progress to prevent any future and remedy any existing man-made visibility impairment in the Class I areas. The EPA is taking this action pursuant to CAA sections 110 and 169A.

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)]
[Rules and Regulations]
[Pages 55268-55272]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-17494]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2022-0735; FRL-9405-02-R6]


Air Plan Approval; Arkansas; Regional Haze State Implementation 
Plan for the Second Implementation Period

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Pursuant to the Clean Air Act (CAA or the Act), the U.S. 
Environmental Protection Agency (EPA) is finalizing approval of a State 
Implementation Plan (SIP) revision

[[Page 55269]]

submitted by the State of Arkansas through the Division of 
Environmental Quality (DEQ) on August 8, 2022, clarified by DEQ on July 
29, 2025, and further supplemented on May 4, 2026, to satisfy the 
requirements of the Act and the EPA's Regional Haze Rule (RHR) for 
visibility protection in mandatory Class I Federal areas (Class I 
areas) for the program's second implementation period. Arkansas' SIP 
submission addresses the requirement that States must revise their 
long-term strategies for making reasonable progress to prevent any 
future and remedy any existing man-made visibility impairment in the 
Class I areas. The EPA is taking this action pursuant to CAA sections 
110 and 169A.

DATES: This rule is effective on September 28, 2026.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-R06-OAR-2022-0735. All documents in the docket are 
listed on the <a href="https://www.regulations.gov">https://www.regulations.gov</a> website. Although listed in 
the index, some information is not publicly available, e.g., 
Confidential Business Information or other information whose disclosure 
is restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the internet. Publicly available docket 
materials are available electronically through <a href="https://www.regulations.gov">https://www.regulations.gov</a>.

FOR FURTHER INFORMATION CONTACT: James E. Grady, EPA Region 6 Office, 
Regional Haze and SO<INF>2</INF> Section; telephone number: (214) 665-
6745; email address: <a href="/cdn-cgi/l/email-protection#97f0e5f6f3eeb9fdf6faf2e4d7f2e7f6b9f0f8e1"><span class="__cf_email__" data-cfemail="84e3f6e5e0fdaaeee5e9e1f7c4e1f4e5aae3ebf2">[email&#160;protected]</span></a>. Please call or email Mr. 
Grady above or call Mr. Bill Deese via telephone at (214) 665-7253 if 
you need alternative access to material indexed but not provided in the 
docket.

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' mean ``the EPA.''

Table of Contents

I. Background
II. Rationale for This Final Action
III. Public Comments and EPA Responses
IV. Final Action
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews

I. Background

    The background for this action is discussed in detail in our 
September 5, 2025, proposed action (90 FR 43030). In that document, we 
proposed approval of the 2022 Arkansas Regional Haze Planning Period II 
SIP revision (2022 Planning Period II SIP), submitted August 8, 2022, 
and clarified on July 29, 2025, as meeting the applicable regional haze 
program requirements for the second implementation period contained in 
40 CFR 51.308(f), (g)(1) through (5), and (i).
    On May 4, 2026, DEQ submitted a supplemental package to the EPA to 
finalize the 2022 Planning Period II SIP and address any concerns with 
Arkansas' SIP revision and its July 29, 2025, clarification letter 
regarding opportunity for public comment and FLM consultation. The 
supplemental package contained the July 2025 letter, as well as 
required documentation of FLM consultation and public notice with 
opportunity to comment. The State did not receive any public comments 
nor comments from FLMs or State agencies through this process.
    We find that the 2022 Planning Period II SIP revision meets the 
statutory and specific regulatory requirements of the regional haze 
second planning period as discussed in the preamble of this final 
action (see sections II and III), the accompanying response-to-comments 
document (RTC Document), and in our September 2025 proposed action.\1\
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    \1\ See 90 FR 43030 (Sept. 5, 2025).
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II. Rationale for This Final Action

    In this final action, we are approving the 2022 Planning Period II 
SIP and affirming that it is now the Agency's policy that, where 
visibility conditions for a Class I Federal area impacted by a State 
are below the uniform rate of progress (URP) and that State has 
considered the four statutory factors, then that State will have 
presumptively demonstrated reasonable progress for the second planning 
period for that area. We acknowledge that this final action reflects a 
change in policy as to how the URP should be used in the evaluation of 
regional haze second planning period SIPs but believe that this policy 
better aligns with the purpose of the statute and the RHR for achieving 
``reasonable'' progress toward natural visibility. As described in the 
September 2025 proposed action,\2\ we have discretion and authority to 
change our policy.\3\
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    \2\ Id.
    \3\ 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 better.'' 566 
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 developing the regulations required by CAA section 169A(b), we 
established the concept of the URP for each Class I area. The URP is 
determined by drawing a straight line from the measured 2000 through 
2004 baseline conditions (in deciviews) for the 20 percent most 
impaired days at each Class I area to the estimated natural conditions 
(in deciviews) for the 20 percent most impaired days in 2064. From this 
calculation, a URP value can be calculated for each year between 2004 
and 2064. We developed the URP to address the diverse concerns of 
Eastern and Western States and account for the varying levels of 
visibility impairment in Class I areas around the Country while 
ensuring an equitable approach nationwide. For each Class I area, 
States must calculate the URP for the end of each planning period 
(e.g., in 2028 for the second planning period).\4\ See 40 CFR 
51.308(f)(1)(vi)(A). States may also adjust the URP to account for 
impacts from anthropogenic sources outside the United States and/or 
impacts from certain wildland prescribed fires. See 40 CFR 
51.308(f)(1)(vi)(B). Then, for each Class I area, States must compare 
the RPG for the 20 percent most impaired days to the URP for the end of 
the planning period. If the RPG is above the URP, then an additional 
``robust demonstration'' requirement is triggered for each State that 
contributes to that Class I area. See 40 CFR 51.308(f)(3)(ii)(B).
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    \4\ We note that reasonable progress goals (RPGs) are a 
regulatory construct that we developed to address the statutory 
mandate in CAA section 169B(e)(1), which required our regulations to 
include ``criteria for measuring `reasonable progress' toward the 
national goal.'' Under 40 CFR 51.308(f)(3)(ii), RPGs measure the 
progress that is projected to be achieved by the control measures a 
State has determined are necessary to make reasonable progress. 
Consistent with the 1999 RHR, the RPGs are not enforceable, though 
they create a benchmark that allows for analytical comparisons to 
the URP and mid-implementation-period course corrections if 
necessary. 82 FR 3078 at 3091 through 3092 (Jan. 10, 2017).
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    In the 2017 RHR revisions,\5\ we addressed the role of the URP as 
it relates to the development of a State's second planning period SIP. 
Specifically, in response to comments suggesting that the URP should be 
considered a ``safe harbor'' that relieves States of any obligation to 
consider the four statutory factors, we explained that the URP was not 
intended to be such a safe harbor.\6\ ``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

[[Page 55270]]

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.'' \7\ 
Other 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.\8\ We stated in our response that we did not agree with 
either of these recommendations. ``The CAA requires that each SIP 
revision contains 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 toward natural visibility 
goal in every implementation period.'' \9\
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    \5\ See 82 FR 3078 (Jan. 10, 2017).
    \6\ See 82 FR 3078 at 3099 (Jan. 10, 2017).
    \7\ Id.
    \8\ Id.
    \9\ Id.
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    Importantly, our recently adopted policy does not make the URP a 
safe harbor. The policy merely creates a presumption that a State's 
second planning period SIP is making reasonable progress for a Class I 
area if a State has taken into consideration the four statutory factors 
of CAA section 169A(g)(1) and that area is below the URP. This is 
consistent with the CAA and RHR.
    The Class I areas impacted by emissions from Arkansas are all below 
their 2028 URP values, and Arkansas' SIP submittal demonstrated that 
the State took into consideration the four reasonable progress factors 
\10\ listed in CAA section 169A(g)(1) with respect to an adequate 
number of emissions sources selected for analysis. Thus, we have 
determined that 2022 Planning Period II SIP revision is fully 
approvable under the Agency's new policy. Indeed, we think this policy 
better aligns with the statutory goal because it recognizes the 
considerable improvements in visibility impairment made by a wide 
variety of State and Federal programs in recent decades.
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    \10\ The four statutory factors required to be taken into 
consideration in determining reasonable progress are: 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.
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III. Public Comments and EPA Responses

    The public comment period for our proposed approval \11\ of the 
2022 Planning Period II SIP revision expired on October 6, 2025. We 
received four total sets of comments. We received two adverse comment 
letters submitted on October 6, 2025--one collectively from 
Conservation Organizations (Sierra Club, National Parks Conservation 
Association (NPCA), and the Coalition to Protect America's National 
Parks), and another from the Mid-Atlantic/Northeast Visibility Union 
(MANEVU). Both adverse commenters asserted that the new URP policy 
violates the plain language of the CAA and RHR; that it violates the 
procedural requirements of the CAA when announcing and applying it in 
State-specific regional actions; that it is inconsistent with different 
aspects of the RHR; and that the 2022 Planning Period II SIP does not 
meet the new URP policy for presumptive approval. The Conservation 
Groups also specifically asserted that removal of the Independence 
retirement order was arbitrary, capricious, and contrary to law; that 
DEQ's cost effectiveness thresholds were based on incomplete data; that 
Flint Creek's reasonable progress determination was arbitrary, 
capricious, and contrary to law; and that the EPA should have analyzed 
impacts of Arkansas pollution on local communities.
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    \11\ See 90 FR 43030 (Sept. 5, 2025).
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    We also acknowledge two other comment letters received on October 
6, 2025, from Entergy Services LLS on behalf of Entergy Arkansas, LLC; 
and Hunton Andrews Kurth LLP on behalf of Ameren Missouri, American 
Electric Power, Inc. and its operating companies, and Nebraska Public 
Power District (collectively referred to as ``the utilities'') that 
were largely in support of our proposed action. Specifically, Entergy 
supported the determinations that Arkansas made in its second 
implementation period regional haze SIP and that EPA proposed to 
approve. The utilities specifically supported EPA's new URP policy 
stating that the policy implements EPA's original understanding of the 
regional haze program and its fundamental purpose; that it implements 
the Congressional design of cooperative federalism; and that it 
implements the plain text of the CAA and the RHR.
    We evaluated the 2022 Planning Period II SIP submission against the 
statutory and regulatory regional haze requirements and determined that 
it satisfies those requirements. As detailed at length in the RTC 
document associated with this rulemaking, we explained that our new 
policy is consistent with the CAA and RHR, and the 2022 Planning Period 
II SIP met the applicable statutory and regulatory requirements in 
accordance with the new policy. In addition, we detailed that the 2022 
Planning Period II SIP without the Independence Administrative Order 
(LIS No. 22-085) demonstrates reasonable progress under the RHR and the 
CAA and addresses all required elements of 40 CFR 51.308(f). We 
explained that the May 4, 2026, supplement addressed any concerns with 
the 2022 Planning Period II SIP regarding opportunity for public 
comment and FLM consultation. We further explained in the RTC document 
that the State reasonably considered the cost effectiveness for the 
different equipment types and analyzed the four factors based on 
complete cost data that was appropriate for the second planning period. 
We also detailed that DEQ adequately considered the four statutory 
factors in its assessment of potential additional controls for the 
Flint Creek Power Plant and demonstrated reasonable progress toward the 
national visibility goal for the second planning period. We clarified 
that the State reasonably documented all cost calculations and provided 
appropriate assumptions and parameters in its analyses for Flint Creek. 
Lastly, regarding analyzing impacts to local communities, we explained 
that neither the CAA nor the RHR requires States or the EPA to consider 
the impact of pollution on communities near potentially affected 
facilities when developing or reviewing a regional haze SIP.
    We provide the complete comments with our detailed responses to the 
full range of significant issues raised in the associated RTC document 
included in the docket of this action. After careful consideration of 
the public comments received, we are finalizing our action as proposed.

IV. Final Action

    We are finalizing approval of the Arkansas 2022 Regional Haze 
Planning Period II SIP revision submitted August 8, 2022, clarified on 
July 29, 2025, and further supplemented on May 4, 2026, as meeting the 
applicable regional haze program requirements for the second 
implementation period contained in 40 CFR 51.308(f), (g)(1) through 
(5), and (i).
    We are finalizing approval of the State's determination for 
FutureFuel Chemical Company to require a fuel switch from coal with 3 
percent sulfur

[[Page 55271]]

content by weight to a low sulfur coal that has 1.5 percent sulfur 
content (equating to 2.93 lb/MMBtu SO<INF>2</INF>) for its three coal-
fired boilers (SN:6M01-01). This requirement has been made enforceable 
by the State through an Administrative Order (LIS No. 22-085) dated 
August 3, 2022, and is included as part of the 2022 Planning Period II 
SIP submittal. We are finalizing approval of all requirements set forth 
in this Administrative Order for FutureFuel Chemical Company included 
as part of the 2022 Planning Period II SIP submittal as a source 
specific revision to be incorporated into the Arkansas SIP.

V. Incorporation by Reference

    In this rule, we are finalizing regulatory text that includes 
incorporation by reference. In accordance with requirements of 1 CFR 
51.5, we are finalizing the incorporation by reference of the revisions 
to the Arkansas source specific requirements described in section IV of 
the preamble of this final action. We have made, and will continue to 
make, these materials generally available through <a href="https://www.regulations.gov">https://www.regulations.gov</a> (please contact the person identified in the FOR 
FURTHER INFORMATION CONTACT section of this preamble for more 
information). Therefore, these materials are approved by the EPA for 
inclusion in the SIP, and have been incorporated by reference by the 
EPA into the plan, are fully federally enforceable under CAA sections 
110 and 113 as of the effective date of our approval of this final 
rulemaking, and will be incorporated by reference into the next update 
to the SIP compilation.

VI. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve State choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely 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 Orders 
12866 (58 FR 51735, October 4, 1993);
    <bullet> Is not subject to Executive Order 14192 (90 FR 9065, 
February 6, 2025) because State Implementation Plan approvals under the 
CAA are exempt from review under Executive Order 12866;
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
    <bullet> Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
    <bullet> Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
    <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 proposed 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, Incorporation by 
reference, Intergovernmental relations, Nitrogen dioxide, Ozone, 
Particulate matter, Reporting and recordkeeping requirements, Sulfur 
oxides, Volatile organic compounds.

    Dated: August 19, 2026.
Walter Mason,
Regional Administrator, Region 6.

    For the reasons stated in the preamble, the EPA amends 40 CFR part 
52 as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for part 52 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

Subpart E--Arkansas

0
2. In Sec.  52.170:
0
a. In paragraph (d), amend the table titled ``EPA-Approved Arkansas 
Source-Specific Requirements'' by adding the entry ``FutureFuel 
Chemical Company'' at the end of the table.
0
b. In paragraph (e), amend the third table titled ``EPA-Approved Non-
Regulatory Provisions and Quasi-Regulatory Measures in the Arkansas 
SIP'' by adding the entry ``Arkansas Regional Haze Planning Period II 
SIP Revision'' at the end of the table.
    The additions read as follows:


Sec.  52.170  Identification of plan.

* * * * *
    (d) * * *
* * * * *

                               EPA-Approved Arkansas Source-Specific Requirements
 
                                                  * * * * * * *
FutureFuel Chemical Company.....  Administrative                8/3/2022  8/27/2026, 91 FR    Three boiler
                                   Order LIS No. 22-                       [INSERT FEDERAL     system (SN:6M01-
                                   085.                                    REGISTER PAGE       01).
                                                                           WHERE THE
                                                                           DOCUMENT BEGINS].
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    (e) * * *
* * * * *

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            EPA-Approved Non-Regulatory Provisions and Quasi-Regulatory Measures in the Arkansas SIP
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                                    Applicable
                                  geographic or     State submittal/
     Name of SIP provision        nonattainment      effective date    EPA approval date        Explanation
                                       area
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                                                  * * * * * * *
Arkansas Regional Haze          Statewide........            8/8/2022  8/27/2026, 91 FR   Approval of regional
 Planning Period II SIP                                                 [INSERT FEDERAL    haze SIP revision
 Revision.                                                              REGISTER PAGE      addressing program
                                                                        WHERE THE          requirements for the
                                                                        DOCUMENT BEGINS].  second implementation
                                                                                           period contained in
                                                                                           40 CFR 51.308(f),
                                                                                           (g)(1) through (5),
                                                                                           and (i).
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0
3. In Sec.  52.173, add paragraph (k) to read as follows:


Sec.  52.173  Visibility protection.

* * * * *
    (k) Arkansas Regional Haze Planning Period II SIP Revision. The 
Arkansas Regional Haze Planning Period II SIP Revision submitted on 
August 8, 2022, is approved as meeting all program requirements for the 
second implementation period contained in 40 CFR 51.308(f), (g)(1) 
through (5), and (i).

[FR Doc. 2026-17494 Filed 8-26-26; 8:45 am]
BILLING CODE 6560-50-P


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