[Federal Register Volume 83, Number 29 (Monday, February 12, 2018)]
[Rules and Regulations]
[Pages 5927-5940]
[FR Doc No: 2018-02147]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2015-0189; FRL-9973-30-Region 6]

Approval and Promulgation of Implementation Plans; Arkansas;
Approval of Regional Haze State Implementation Plan Revision for NOX
for Electric Generating Units in Arkansas

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the
Environmental Protection Agency (EPA) is finalizing an approval of a
revision to the Arkansas State Implementation Plan (SIP) submitted by
the State of Arkansas through the Arkansas Department of Environmental
Quality (ADEQ) that addresses regional haze for the first planning
period. ADEQ submitted this revision to address certain requirements of
the Clean Air Act (CAA) and the EPA's regional haze rules for the
protection of visibility. The EPA is taking final action to approve the
State's SIP revision, which addresses nitrogen oxide (NOX)
best available retrofit technology (BART) requirements for the Arkansas
Electric Cooperative Corporation (AECC) Bailey Plant Unit 1; AECC
McClellan Plant Unit 1; the American Electric Power/Southwestern
Electric Power Company (AEP/SWEPCO) Flint Creek Plant Boiler No. 1;
Entergy Arkansas, Inc. (Entergy) Lake Catherine Plant Unit 4; Entergy
White Bluff Plant Units 1 and 2 and the Auxiliary Boiler. The SIP
revision also addresses reasonable progress requirements for
NOX for the Entergy Independence Plant Units 1 and 2. In
conjunction with this final approval, we are finalizing in a separate
rulemaking, which is also being published in this Federal Register, our
withdrawal of federal implementation plan (FIP) emission limits for
NOX that would otherwise apply to these nine units.

DATES: This rule is effective on March 14, 2018.

ADDRESSES: The EPA has established a docket for this action under
Docket No. EPA-R06-OAR-2015-0189. All documents in the dockets are
listed on the http://www.regulations.gov 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 and will be publicly available only in
hard copy form. Publicly available docket materials are available
either electronically through http://www.regulations.gov or in hard
copy at the EPA Region 6, 1445 Ross Avenue, Suite 700, Dallas, Texas
75202-2733.

FOR FURTHER INFORMATION CONTACT: Dayana Medina,<PHONE_NUMBER>.

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

Table of Contents

I. Background
    A. The Regional Haze Program
    B. Our Previous Actions
    C. CSAPR as an Alternative to Source-Specific NOX
BART
II. Summary of Final Action
III. Response to Comments
    A. Reliance on CSAPR-Better-Than BART Rule
    B. Reasonable Progress
    C. Clean Air Act Section 110(l)
    D. Legal
    E. General
IV. Final Action
V. Statutory and Executive Order Reviews

I. Background

A. The Regional Haze Program

    Regional haze is visibility impairment that is produced by a
multitude of sources and activities that are located across a broad
geographic area and emit fine particulates (PM2.5) (e.g.,
sulfates, nitrates, organic carbon (OC), elemental carbon (EC), and
soil dust), and their precursors (e.g., sulfur dioxide
(SO2), nitrogen oxides (NOX), and in some cases,
ammonia (NH3) and volatile organic compounds (VOCs)). Fine
particle precursors react in the atmosphere to form PM2.5,
which impairs visibility by scattering and absorbing light. Visibility
impairment reduces the clarity, color, and visible distance that can be
seen. PM2.5 can also cause serious adverse health effects
and mortality in humans; it also contributes to environmental effects
such as acid deposition and eutrophication.
    Data from the existing visibility monitoring network, ``Interagency
Monitoring of Protected Visual Environments'' (IMPROVE), shows that
visibility impairment caused by air pollution occurs virtually all of
the time at most national parks and wilderness areas. In 1999, the
average visual range \1\ in many Class I areas (i.e., national parks
and memorial parks, wilderness areas, and international parks meeting
certain size criteria) in the western United States was 100-150
kilometers, or about one-half to two-thirds of the visual range that
would exist under estimated natural conditions.\2\ In most of the
eastern Class I areas of the United States, the average visual range
was less than 30 kilometers, or about one-fifth of the visual range
that would exist under estimated natural conditions. CAA programs have
reduced emissions of some haze-causing pollution, lessening some
visibility impairment and resulting in partially improved average
visual ranges.\3\
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    \1\ Visual range is the greatest distance, in kilometers or
miles, at which a dark object can be viewed against the sky.
    \2\ 64 FR 35715 (July 1, 1999).
    \3\ An interactive ``story map'' depicting efforts and recent
progress by EPA and states to improve visibility at national parks
and wilderness areas may be visited at: http://arcg.is/29tAbS3.
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    CAA requirements to address the problem of visibility impairment
continue to be implemented. In Section 169A of the 1977 Amendments to
the CAA, Congress created a program for protecting visibility in the
nation's national parks and wilderness areas. This section of the CAA
establishes as a national goal the prevention of any future, and the
remedying of any existing, man-made impairment of visibility in 156
national parks and wilderness areas designated as mandatory Class I
Federal areas.\4\ Congress added section 169B to the CAA in 1990 to
address regional haze issues, and the EPA promulgated regulations
addressing regional haze in 1999. The Regional Haze Rule \5\ revised
the existing visibility regulations to add provisions addressing
regional haze impairment and established a comprehensive visibility
protection program for Class I areas. The requirements for regional
haze, found at 40 CFR 51.308 and 51.309, are included in our visibility
protection regulations at 40 CFR 51.300-51.309. The requirement to
submit a regional haze SIP applies to all 50 states, the District of
Columbia, and the Virgin Islands. States were required to submit the
first implementation plan addressing regional haze visibility
impairment no later than December 17, 2007.\6\
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    \4\ Areas 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. 42 U.S.C. 7472(a).
In accordance with section 169A of the CAA, EPA, in consultation
with the Department of Interior, promulgated a list of 156 areas
where visibility is identified as an important value. 44 FR 69122
(November 30, 1979). The extent of a mandatory Class I area includes
subsequent changes in boundaries, such as park expansions. 42 U.S.C.
7472(a). Although states and tribes may designate as Class I
additional areas which they consider to have visibility as an
important value, the requirements of the visibility program set
forth in section 169A of the CAA apply only to ``mandatory Class I
Federal areas.'' Each mandatory Class I Federal area is the
responsibility of a ``Federal Land Manager.'' 42 U.S.C. 7602(i).
When we use the term ``Class I area'' in this action, we mean a
``mandatory Class I Federal area.''
    \5\ Here and elsewhere in this document, the term ``Regional
Haze Rule,'' refers to the 1999 final rule (64 FR 35714), as amended
in 2005 (70 FR 39156, July 6, 2005), 2006 (71 FR 60631, October 13,
2006), 2012 (77 FR 33656, June 7, 2012), and January 10, 2017 (82 FR
3078).
    \6\ See 40 CFR 51.308(b). EPA's regional haze regulations
require subsequent updates to the regional haze SIPs. 40 CFR
51.308(g)-(i).
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    Section 169A of the CAA directs states to evaluate the use of
retrofit controls at certain larger, often under-controlled, older
stationary sources in order to address visibility impacts from these
sources. Specifically, section 169A(b)(2)(A) of the CAA requires states
to revise their SIPs to contain such measures as may be necessary to
make reasonable progress toward the natural visibility goal, including
a requirement that certain categories of existing major stationary
sources \7\ built between 1962 and 1977 procure, install and operate
BART controls. Larger ``fossil-fuel fired steam electric plants'' are
one of these source categories. Under the Regional Haze Rule, states
are directed to conduct BART determinations for ``BART-eligible''
sources that may be anticipated to cause or contribute to any
visibility impairment in a Class I area. The evaluation of BART for
electric generating units (EGUs) that are located at fossil-fuel fired
power plants having a generating capacity in excess of 750 megawatts
must follow the ``Guidelines for BART Determinations Under the Regional
Haze Rule'' at appendix Y to 40 CFR part 51 (hereinafter referred to as
the ``BART Guidelines''). Rather than requiring source-specific BART
controls, states also have the flexibility to adopt an emissions
trading program or other alternative program as long as the alternative
provides for greater progress towards improving visibility than BART.
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    \7\ See 42 U.S.C. 7491(g)(7) (listing the set of ``major
stationary sources'' potentially subject-to-BART).
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B. Our Previous Actions

    Arkansas submitted a SIP revision on September 9, 2008, to address
the requirements of the first regional haze implementation period. On
August 3, 2010, Arkansas submitted a SIP revision with non-substantive
revisions to the Arkansas Pollution Control and Ecology Commission
(APCEC) Regulation 19, Chapter 15; this Chapter identified the BART-
eligible and subject-to-BART sources in Arkansas and established BART
emission limits for subject-to-BART sources. On September 27, 2011, the
State submitted supplemental information to address the regional haze

requirements. We are hereafter referring to these regional haze
submittals collectively as the ``2008 Arkansas Regional Haze SIP.'' On
March 12, 2012, we partially approved and partially disapproved the
2008 Arkansas Regional Haze SIP.\8\ On September 27, 2016, we published
a FIP addressing the disapproved portions of the 2008 Arkansas Regional
Haze SIP (the Arkansas Regional Haze FIP).\9\ Among other things, the
FIP established NOX emission limits under the BART
requirements for Bailey Unit 1; McClellan Unit 1; Flint Creek Boiler
No. 1; Lake Catherine Unit 4; and White Bluff Units 1 and 2 and the
Auxiliary Boiler. The FIP also established NOX emission
limits under the reasonable progress requirements for Independence
Units 1 and 2.
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    \8\ 77 FR 14604.
    \9\ 81 FR 66332; see also 81 FR 68319 (October 4, 2016)
(correction).
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    Following the issuance of the Arkansas Regional Haze FIP, the State
of Arkansas and several industry parties filed petitions for
reconsideration and an administrative stay of the final rule.\10\ We
announced in April 2017 our decision to convene a proceeding to
reconsider several elements of the FIP, including the appropriate
compliance dates for the NOX emission limits for Flint Creek
Unit 1, White Bluff Units 1 and 2, and Independence Units 1 and 2.\11\
EPA also published a document in the Federal Register on April 25,
2017, administratively staying the effectiveness of the 18-month
NOX compliance dates in the FIP for these units for a period
of 90 days.\12\ On July 13, 2017, the EPA published a proposed rule to
extend the NOX compliance dates for Flint Creek Unit 1,
White Bluff Units 1 and 2, and Independence Units 1 and 2, by 21 months
to January 27, 2020.\13\ \14\
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    \10\ See the docket associated with this proposed rulemaking for
a copy of the petitions for reconsideration and administrative stay
submitted by the State of Arkansas; Entergy Arkansas Inc., Entergy
Mississippi Inc., and Entergy Power LLC (collectively ``Entergy'');
AECC; and the Energy and Environmental Alliance of Arkansas (EEAA).
    \11\ Letter from E. Scott Pruitt, Administrator, EPA, to
Nicholas Jacob Bronni and Jamie Leigh Ewing, Arkansas Attorney
General's Office (April 14, 2017). A copy of this letter is included
in the docket, https://www.regulations.gov/document?D=EPA-R06-OAR-2015-0189-0240.
    \12\ 82 FR 18994.
    \13\ 82 FR 32284.
    \14\ EPA has not taken final action on the July 13, 2017
proposed rule. This final action approving the Arkansas Regional
Haze NOX SIP revision together with the separate final
action that EPA is taking to withdraw the source-specific
NOX emission limits for the nine EGUs in the Arkansas
Regional Haze FIP, make it unnecessary to finalize our July 13, 2017
proposed rule to revise the NOX compliance dates in the
Arkansas Regional Haze FIP.
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    On July 12, 2017, Arkansas submitted a proposed SIP revision with a
request for parallel processing, addressing the NOX
requirements for Bailey Unit 1, McClellan Unit 1, Flint Creek Boiler
No. 1, Lake Catherine Unit 4, White Bluff Units 1 and 2 and the
Auxiliary Boiler, and Independence Units 1 and 2 (Arkansas Regional
Haze NOX SIP revision or Arkansas NOX SIP
revision). In our March 12, 2012 final action on the 2008 Arkansas
Regional Haze SIP, we disapproved the State's source-specific
NOX BART determinations for Bailey Unit 1; McClellan Unit 1;
Flint Creek Boiler No. 1; Lake Catherine Unit 4; White Bluff Units 1
and 2 and its auxiliary boiler.\15\ In that same action, we also made
the determination that the State did not satisfy the statutory and
regulatory requirements for the reasonable progress analysis. We
promulgated a FIP on September 27, 2016, that established source-
specific NOX BART emission limits for these seven EGUs and
NOX emission limits under reasonable progress for
Independence Units 1 and 2 to address the disapproved portions of the
2008 Arkansas Regional Haze SIP submittal.
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    \15\ 77 FR 14604.
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    Arkansas' proposed July 2017 Regional Haze NOX SIP
revision addressed the NOX BART requirements for Arkansas'
EGUs by relying on participation in the Cross State Air Pollution Rule
(CSAPR) ozone season NOX trading program as an alternative
to BART. The July 2017 Regional Haze NOX SIP revision
proposal also made the determination that no additional NOX
emission controls for Arkansas sources, beyond participation in CSAPR's
ozone season NOX trading program, are required for ensuring
reasonable progress in Arkansas. As noted above, the July 2017 Regional
Haze SIP revision addresses NOX requirements for the same
EGUs for which we established source-specific NOX emission
limits in our September 27, 2016 FIP. In a document published in the
Federal Register on September 11, 2017, we proposed to approve the
Arkansas Regional Haze NOX SIP revision.\16\ On October 31,
2017, we received ADEQ's final NOX SIP revision addressing
BART and reasonable progress requirements for NOX for EGUs
in Arkansas for the first implementation period. The final Arkansas
Regional Haze NOX SIP revision we received on October 31,
2017, did not contain significant changes from the state's proposed SIP
revision. Therefore, it is appropriate for us to take final action, as
proposed, on the final SIP revision.
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    \16\ 82 FR 42627.
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C. CSAPR as an Alternative to Source-Specific NOX BART

    In 2005, the EPA published the Clean Air Interstate Rule (CAIR),
which required 27 states and the District of Columbia to reduce
emissions of SO2 and NOX from affected electric
generating units (EGUs) that significantly contribute to or interfere
with maintenance of the 1997 national ambient air quality standards
(NAAQS) for fine particulates and/or 8-hour ozone in any downwind
state.\17\ EPA demonstrated that CAIR would achieve greater reasonable
progress toward the national visibility goal than would BART;
therefore, states could rely on CAIR as an alternative to BART for
SO2 and NOX at EGUs.\18\ Although Arkansas was
subject to certain NOX requirements of CAIR, including the
state-wide ozone season NOX budget but not the annual
NOX budget, and although this would have been sufficient for
Arkansas to rely on CAIR to satisfy NOX BART, it elected not
to rely on CAIR in its 2008 Regional Haze SIP to satisfy the
NOX BART requirement for its EGUs.
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    \17\ 70 FR 25161 (May 12, 2005).
    \18\ 70 FR 39104, 39139 (July 6, 2005).
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    On July 11, 2008, the D.C. Circuit found CAIR was fatally flawed
and on December 23, 2008, the Court remanded CAIR to EPA without
vacatur to ``preserve the environmental benefits provided by CAIR.''
\19\ In 2011, acting on the D.C. Circuit's remand, we promulgated the
Cross-State Air Pollution Rule (CSAPR) to replace CAIR and issued FIPs
to implement the rule in CSAPR-subject states.\20\ Arkansas EGUs are
covered under CSAPR for ozone season NOX.\21\
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    \19\ North Carolina v. EPA, 531 F.3d 896, 901 (D.C. Cir. 2008),
modified, 550 F.3d 1176, 1178 (D.C. Cir. 2008).
    \20\ 76 FR 48207 (August 8, 2011).
    \21\ 76 FR 82219 (December 30, 2011).
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    In 2012, we issued a limited disapproval of several states'
regional haze SIPs because of reliance on CAIR as an alternative to EGU
BART for SO2 and/or NOX.\22\ We also determined
that CSAPR would provide for greater reasonable progress than BART and
amended the Regional Haze Rule to allow for CSAPR participation as an
alternative to source-specific SO2 and/or NOX
BART for EGUs, on a pollutant-specific basis.\23\ As Arkansas did not

rely on CAIR to satisfy the NOX BART requirements in the
2008 Regional Haze SIP, Arkansas was not included in the EPA's limited
disapproval of regional haze SIPs that relied on CAIR to satisfy
certain regional haze requirements.\24\ As noted above, in the 2012
rulemaking in which we promulgated those limited disapprovals, the EPA
also promulgated FIPs to replace reliance on CAIR with reliance on
CSAPR in many of those regional haze SIPs; however, Arkansas was
likewise not included in that FIP action.
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    \22\ The limited disapproval triggered the EPA's obligation to
issue a FIP or approve a SIP revision to correct the relevant
deficiencies within 2 years of the final limited disapproval action.
CAA section 110(c)(1); 77 FR 33642, at 33654 (June 7, 2012).
    \23\ See 40 CFR 51.308(e)(4).
    \24\ See 77 FR 33642, at 33654.
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    CSAPR has been subject to extensive litigation, and on July 28,
2015, the DC Circuit issued a decision generally upholding CSAPR but
remanding without vacating the CSAPR emissions budgets for a number of
states.\25\ On October 26, 2016, we finalized an update to CSAPR that
addresses the 1997 ozone NAAQS portion of the remand as well as the CAA
requirements addressing interstate transport for the 2008 ozone
NAAQS.\26\ Additionally, three states, Alabama, Georgia, and South
Carolina, have adopted or committed to adopt SIPs to continue their
participation in the CSAPR program, including adoption on a voluntary
basis of state SO2 emission budgets equal to those state's
remanded SO2 emission budgets. On November 10, 2016, we
proposed a rule intended to address the remainder of the court's remand
as it relates to Texas.\27\ This separate proposed rule included an
assessment of the impacts of the set of actions that the EPA had taken
or expected to take in response to the D.C. Circuit's remand on our
2012 demonstration that participation in CSAPR provides for greater
reasonable progress than BART. Based on that assessment, the EPA
proposed that states may continue to rely on CSAPR as an alternative to
BART on a pollutant-specific basis. On September 29, 2017, we finalized
our proposed finding that the EPA's 2012 analytical demonstration
remains valid and that participation in CSAPR, as it now exists, meets
the Regional Haze Rule's criteria for an alternative to BART.\28\ In
the October 2017 Arkansas Regional Haze NOX SIP revision,
the state relies on CSAPR as an alternative to BART for control of
NOX from EGUs.
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    \25\ Arkansas' ozone season NOX budgets were not
included in the remand. EME Homer City Generation v. EPA, 795 F.3d
118, 138 (D.C. Cir. 2015).
    \26\ 81 FR74504 (October 26, 2016).
    \27\ 81 FR 78954 (November 10, 2016).
    \28\ 82 FR 45481 (September 29, 2017).
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II. Summary of Final Action

    This action finalizes our proposed approval of the Arkansas
Regional Haze NOX SIP revision, which relies on EPA's
determination that CSAPR provides for greater reasonable progress than
BART to address the NOX BART requirements for Arkansas EGUs.
Consistent with 40 CFR 51.308(e)(4), Arkansas makes the determination
that since the Arkansas EGUs are currently subject to the CSAPR
requirements for ozone-season NOX, the State need not have
source specific requirements for subject-to-BART EGUs to install,
operate, and maintain BART for NOX. We find that it is
appropriate for Arkansas to rely on participation in the CSAPR ozone
season NOX trading program to satisfy the NOX
BART requirements for Arkansas EGUs. EPA's 2012 determination and our
September 29, 2017 final rulemaking make the finding that the EPA's
2012 analytical demonstration remains valid and that participation in
CSAPR, as it now exists, meets the Regional Haze Rule's criteria for an
alternative to BART.\29\ Arkansas' reliance on CSAPR addresses the
NOX BART requirements for Bailey Unit 1; McClellan Unit 1;
Flint Creek Boiler No. 1; Lake Catherine Unit 4; White Bluff Units 1
and 2 and the Auxiliary Boiler.
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    \29\ 82 FR 45481 (September 29, 2017).
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    We also find that Arkansas reasonably determined that additional
NOX control measures are not needed to ensure reasonable
progress for the first implementation period. Given the level of
visibility impairment due to NOX emissions from Arkansas
point sources at the state's two Class I areas, Caney Creek and Upper
Buffalo, on the 20% worst days, additional NOX controls for
Arkansas point sources are not anticipated to yield meaningful
visibility improvements at Arkansas Class I areas on the 20% worst
days.\30\ In light of this, and considering that Arkansas EGUs are
participating in CSAPR for ozone season NOX, we are
finalizing our determination that Arkansas' decision to screen out
Arkansas point sources from further evaluation of additional
NOX controls is reasonable and we are finalizing our
approval of Arkansas' determination that no additional NOX
controls, beyond Arkansas EGU participation in CSAPR for ozone season
NOX, are necessary to satisfy the reasonable progress
requirements for NOX in Arkansas for the first
implementation period.
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    \30\ Arkansas also recognized that sources in Arkansas impact
the two Class I areas in Missouri: Hercules Glade Wilderness Area
and Mingo Wilderness Area. Arkansas provided the Missouri Department
of Natural Resources with an opportunity for consultation on the
proposed Arkansas NOX SIP revision, including an
opportunity to discuss Missouri's assessment of the impact of the
proposed SIP revision on reasonable progress at Missouri Class I
areas. The Missouri Department of Natural Resources did not have
comments on the proposed SIP revision and did not pursue
consultation. Additionally, Arkansas looked at the most recent five-
year rolling average of observed visibility impairment on the 20%
haziest days for Missouri's Class I areas and concluded that the
visibility progress observed at the IMPROVE monitors indicates that
sources in Arkansas are not interfering with the achievement of
Missouri's 2018 RPGs for Hercules Glades and Mingo. Taking these
things into consideration, Arkansas made the determination that no
additional NOX reductions from Arkansas sources are
required to improve visibility in Missouri Class I areas for the
first implementation period.
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    We are finalizing our approval of the Arkansas Regional Haze
NOX SIP revision as we have found it to meet the applicable
provisions of the Act and EPA regulations and it is consistent with EPA
guidance. We received comments from three commenters on our proposed
approval. Our response to the substantive comments we received are
summarized in Section III. We have fully considered all significant
comments on our proposed action on the SIP revision submittal, and have
concluded that no changes to our final determination are warranted.
    We are approving the October 2017 Arkansas Regional Haze
NOX SIP revision submitted by ADEQ as we have determined
that it meets the regional haze SIP requirements, including the
reasonable progress requirements in Sec.  51.308(d) and the BART
requirements in Sec.  51.308(e). In conjunction with this final
approval, we are finalizing in a separate rulemaking, which is also
being published in this Federal Register, our withdrawal of FIP
emission limits for NOX that would otherwise apply to the
nine affected units.

III. Response to Comments

    The public comments received on our proposed rule are included in
the publicly posted docket associated with this action at
www.regulations.gov. We reviewed all public comments that we received
on the proposed action. Below, we provide a summary of certain comments
and our responses. The comments and our responses thereto are contained
in a separate document titled the Arkansas Regional Haze NOX
SIP Revision Response to Comments.

A. Reliance on CSAPR-Better-Than-BART Rule

    Comment: ADEQ proposes to rely on ozone-season NOX
reductions under the updated CSAPR in lieu of the source-specific BART
emission limits that EPA finalized as part of its 2016 regional

haze FIP. ADEQ relies on a ``back-of-the-envelope'' calculation of
anticipated emission reductions, and asserts that EPA's updated 2018
Arkansas ozone season NOX emission budgets under the CSAPR
update achieve a greater reduction in NOX emissions than do
implementation of NOX BART controls included in the Arkansas
Regional Haze FIP. Without any further analysis, ADEQ suggests that
compliance with the 2018 CSAPR ozone season allocations for Arkansas
EGUs satisfies the BART requirements of the Regional Haze Rule.
    Response: This comment is in relation to ADEQ's comparison of
anticipated NOX emissions reductions based on the CSAPR
emission budgets versus the anticipated NOX emissions
reductions from the Arkansas Regional Haze FIP. We did not base our
proposed approval of the Arkansas NOX SIP revision on the
state's comparison of the anticipated NOX reductions in
Arkansas from CSAPR against those anticipated from the FIP.
Furthermore, in response to comments that the state received during its
state rulemaking process, ADEQ proceeded to remove from its final SIP
revision the comparison of anticipated NOX emissions
reductions under the FIP versus CSAPR because such information is not
necessary for EPA approval of the SIP.\31\ With regard to the comment
that ADEQ did not adequately support its determination that compliance
with the 2018 CSAPR ozone season allocations for Arkansas EGUs
satisfies the BART requirements, we disagree that ADEQ was required to
undertake a state-specific analysis of whether reliance on CSAPR
provides for greater reasonable progress than BART; as allowed under 40
CFR 51.308(e)(4), Arkansas is relying on EPA's determination that CSAPR
provides for greater reasonable progress than BART to address the
NOX BART requirements for its EGUs. Arkansas' EGUs are
currently subject to the CSAPR requirements for ozone-season
NOX, the State need not require subject-to-BART EGUs to
install, operate, and maintain BART for NOX. As explained
above, although the D.C. Circuit remanded the CSAPR emissions budgets
of certain states in 2015, we recently reaffirmed our determination
that participation in CSAPR, as it now exists, continues to meet the
Regional Haze Rule's criteria for an alternative to BART.\32\
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    \31\ See final Arkansas NOX SIP revision, Tab E
(Public Comment Period Documentation, Responsive Summary for State
Implementation Plan Revision, p. 20).
    \32\ 82 FR 45481 (September 29, 2017).
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    Comment: Arkansas' proposal unlawfully exempts sources from
installing BART controls without going through the exemption process
Congress prescribed. The visibility protection provisions of the Clean
Air Act include a ``requirement'' that certain sources ``install, and
operate'' BART controls. Congress specified the standard by which
sources could be exempted from the BART requirements, which is that the
source is not ``reasonably anticipated to cause or contribute to a
significant impairment of visibility'' in any Class I area. Appropriate
federal land managers must concur with any proposed exemption. Neither
EPA nor Arkansas has demonstrated that the Arkansas EGUs subject to
BART meet the standards for an exemption. Nor has EPA or the state
obtained the concurrence of federal land managers. Therefore, Arkansas
must require source-specific BART for each power plant subject to BART.
    Response: To the extent the comment is directed to prior final
agency actions allowing states to rely on alternatives to BART
generally or on CSAPR specifically to meet the BART requirements, this
comment falls outside of the scope of our action here. Objections that
the use of BART alternatives does not comply with 42 U.S.C.
7491(b)(2)(A) do not properly pertain to this action, but instead to
our past regulatory actions that provided for BART alternatives.\33\ We
do note that the Arkansas SIP does not exempt the EGUs from BART but
rather relies on EPA's determination that states may rely on CSAPR as
an alternative means of meeting the BART requirements.
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    \33\ See the June 7, 2012 final rulemaking where we made the
determination that CSAPR provides for greater reasonable progress
than BART (77 FR 33642). See also our September 29, 2017 final
rulemaking where we made the finding that the EPA's 2012 analytical
demonstration remains valid and that participation in CSAPR, as it
now exists, meets the Regional Haze Rule's criteria for an
alternative to BART (82 FR 45481).
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    Comment: Even if Arkansas could meet a BART statutory exemption
test, the state cannot rely on CSAPR because of flaws in the rule that
purport to show that CSAPR makes more reasonable progress than BART
(the ``Better than BART'' rule). EPA's regulations purport to allow the
use of an alternative program in lieu of source-specific BART only if
the alternative makes ``greater reasonable progress'' than would BART.
To demonstrate greater reasonable progress, a state or EPA must show
that the alternative program does not cause visibility to decline in
any Class I area and results in an overall improvement in visibility
relative to BART at all affected Class I areas. Here, EPA claims that
its 2012 ``Better than BART'' rule demonstrated that CSAPR achieves
greater reasonable progress than BART.
    EPA compared CSAPR to BART in the Better than BART rule by using
CSAPR allocations that are more stringent than now required as well as
by using presumptive BART limits that are less stringent than required
under the statute. These assumptions tilted the scales in favor of
CSAPR. It would be arbitrary and capricious for EPA to rely on such an
inaccurate, faulty comparison to conclude that CSAPR will achieve
greater reasonable progress than will BART. Even under EPA's skewed
comparison, CSAPR achieves barely more visibility improvement than BART
at the Breton and Caney Creek National Wilderness Areas. If EPA had
modeled accurate BART limits and up-to-date CSAPR allocations, then EPA
would likely find that CSAPR would lead to less visibility improvement
than BART.
    EPA cannot lawfully rely on the Better than BART rule because the
rule is based on a version of CSAPR that no longer exists. Accordingly,
any conclusion that EPA made in the 2012 Better than BART rule
regarding whether CSAPR achieves greater reasonable progress than BART
is no longer valid. Since 2012, EPA has significantly changed the
allocations and the compliance deadlines for CSAPR. Of particular
relevance here, after 2012, EPA increased the total ozone season CSAPR
allocations for every covered EGU in Arkansas. EPA also extended the
compliance deadlines by three years, such that the phase 1 emissions
budgets take effect in 2015-2016 and the phase 2 emissions budgets take
effect in 2017 and beyond.
    In addition to EPA's increased emissions budgets and extended
compliance timeline, the D.C. Circuit's decision in EME Homer City
Generation v. EPA, 795 F.3d 118, 130-32 (D.C. Cir. 2015), which
invalidated the SO2 or NOX emission budgets for
thirteen states, has fundamentally undermined the rationale underlying
EPA's Better than BART rule. Specifically, the Court invalidated the
2014 SO2 emission budgets for Alabama, Georgia, South
Carolina, and Texas, and the 2014 NOX emission budgets for
Florida, Maryland, New Jersey, New York, North Carolina, Ohio,
Pennsylvania, South Carolina, Texas, Virginia, and West Virginia. As
explained in our initial brief in the still-pending challenge to the
CSAPR Better than BART rule, the effect of Homer City is to pull the
rug out from under EPA's BART exemption rule. EPA's finding that CSAPR
would produce better

visibility improvement than BART was premised on the existence of all
the state-specific emission budgets adopted in the Transport Rule.
Because the D.C. Circuit has now invalidated many of those budgets, the
BART exemption rule is left without the factual basis on which it
relied.
    Response: As we had proposed, our finalized determination that
CSAPR participation will resolve the NOX BART requirements
for Arkansas EGUs is based on a separately proposed and recently
finalized action that affirms that participation in CSAPR, as it now
exists, continues to meet the Regional Haze Rule's criteria for an
alternative to BART.\34\ This comment is directed to the separately
proposed action that was finalized on September 29, 2017, and
therefore, falls outside of the scope of our action here.
---------------------------------------------------------------------------

    \34\ 82 FR 45481 (September 29, 2017).
---------------------------------------------------------------------------

    Comment: Arkansas's reliance on CSAPR as an alternative to BART is
unlawful because the emissions reductions achieved by CSAPR in Arkansas
are limited to five months of the year--the ozone season. Under the
Regional Haze Rule, BART represents a year-round limit on emissions.
Given that CSAPR does not limit annual NOX emissions from
Arkansas sources, but instead only applies to Arkansas sources for five
months out of the year, CSAPR cannot satisfy the Regional Haze Rule's
requirement that sources meet the ``best system of continuous emission
reduction'' for NOX. In fact, as noted in EPA's Technical
Support Document for the proposed disapproval of Arkansas's 2008 SIP,
the adverse impacts of Arkansas NOX emissions on visibility
``tend to be a large component of visibility impairment during the
winter months''--i.e., outside of the ozone season. Thus,
NOX emissions reductions that are effective only during the
ozone season will not address the visibility impact due to wintertime
ammonium nitrate at Breton Island or other Class I areas in neighboring
states.
    Even within the five-month ozone season, CSAPR allows for temporal
variability such that a facility could emit at high levels within a
shorter time period, creating higher than anticipated visibility
impacts. Because of the high degree of variability and flexibility,
power plants may exercise options that would lead to little or no
emission reductions. For example, a facility in Arkansas might purchase
emission credits from a source beyond the air shed of the Class I area
the Arkansas source impairs. Because CSAPR requirements only pertain to
the Arkansas source for a fraction of the year, that source may be even
more incentivized to purchase emission credits from elsewhere than a
source in a fully covered CSAPR state. Thus, without knowing which
Arkansas EGUs will reduce pollutants by what amounts under CSAPR, or
when they will do so, and because these emissions reductions are
applicable for less than half the year, Arkansas simply cannot know the
impact of CSAPR upon Breton and other affected Class I areas.
    For these reasons, reliance on CSAPR to satisfy the NOX
BART requirements is unlawful. EPA should disapprove Arkansas' reliance
on CSAPR to satisfy the NOX requirements.
    Response: These comments fall outside the scope of this rulemaking.
In 2012, when we finalized our determination that CSAPR provides for
greater reasonable progress than BART, we considered comments that the
imposition of BART would require year-round operation of NOX
controls but that under CSAPR there would be no assurance that controls
would operate outside of the ozone season. The basis for our decision
to allow Arkansas and other states covered by CSAPR for ozone season
only to rely on participation in that program to satisfy NOX
BART is explained in that rulemaking.\35\
---------------------------------------------------------------------------

    \35\ 77 FR at 33650.
---------------------------------------------------------------------------

    Comment: Arkansas purports to satisfy the regulatory requirements
for a BART alternative by relying on ozone-season budgets for
NOX that no longer exist. To rely on CSAPR as an alternative
to BART, Arkansas must demonstrate that the version of CSAPR that is
now in effect, and will be in effect at the time of the final rule,
makes greater reasonable progress than BART. Having failed to make that
demonstration, Arkansas has not met its burden to show that CSAPR will
achieve greater reasonable progress than source-specific BART. More
troubling, Arkansas' reliance on the CSAPR ``Better than BART'' rule
fails to account for, or even mention, the possibility that CSAPR or
the ``Better than BART'' rule will not exist in any form when the SIP
is finalized.
    Response: As we had proposed, our finalized determination that
CSAPR participation will resolve NOX BART requirements for
Arkansas EGUs is based on a separately proposed and finalized action
taken in 2012. On September 29, 2017, we affirmed our proposed finding
that the EPA's 2012 analytical demonstration remains valid and that
participation in CSAPR, as it now exists, meets the Regional Haze
Rule's criteria for an alternative to BART.\36\ This comment falls
outside of the scope of our action here.
---------------------------------------------------------------------------

    \36\ 82 FR 45481 (September 29, 2017).
---------------------------------------------------------------------------

    Comment: When evaluating a state's BART determination, the EPA
looks at existing requirements and cannot rely on potential future
actions in its decision to approve or disapprove a state SIP. As EPA
recognizes in the proposed approval, the agency cannot finalize
Arkansas' proposed SIP until EPA finalizes its finding that CSAPR
continues to be better than BART as an alternative to source-specific
EGU BART for NOX. Although EPA, on September 29, 2017,
finalized a rule purporting to conclude that ozone-season
NOX limitations under CSAPR continue to be ``better than
BART'' for eligible EGUs in Arkansas, EPA failed to include any of the
documentation or analyses supporting that finding in this docket. As
such, EPA cannot approve Arkansas's SIP proposal unless and until those
analyses are included in the docket and the public has a meaningful
opportunity to comment on those materials.
    Response: We included the notice of proposed rulemaking addressing
whether CSAPR continues to be better than BART following changes to the
budgets of certain states in our docket for this action because of its
relevance to Arkansas' proposed SIP revision.\37\ As explained in our
proposed approval of Arkansas' SIP revision, EPA would be able to
approve regional haze SIP submissions that rely on participation in
CSAPR as an alternative to BART only if it were to finalize its
proposed rule or to otherwise determine that participation in CSPAR
remains a viable BART alternative.\38\ We accordingly made clear that a
final determination that CSAPR participation will resolve the
NOX BART requirements for Arkansas' EGUs is based on a
separately proposed and finalized action. The supporting materials and
analyses underlying that action are contained in the docket for that
action, and the public has had a meaningful opportunity to comment on
that determination.
---------------------------------------------------------------------------

    \37\ See the document in the docket titled ``AR020.0250 CSAPR
Better than BART Proposed Rulemaking, dated November 10, 2016.''
    \38\ 82 FR at 42629.
---------------------------------------------------------------------------

    Comment: EPA should approve the Arkansas Regional Haze
NOX SIP revision because it satisfies the criteria of the
Regional Haze program. The states, not EPA, play the lead role in
designing and implementing [the] regional haze programs. EPA may
disapprove a SIP only if it does not satisfy the minimum criteria of
Section

110 of the Clean Air Act. Accordingly, EPA has no authority to question
the wisdom of a State's choices of emission limitations if they are
part of a plan which satisfies the standards of Section 110(a)(2), and
has no authority to disapprove of a SIP ``simply on a preference for a
particular control measure. The SIP revision meets the requirements of
the Regional Haze Program and must be approved. ADEQ's determination
that compliance with the CSAPR ozone season NOX trading
program requirements satisfies NOX BART and any reasonable
progress obligations for the state's EGUs is consistent with the
Regional Haze Rule, is appropriate considering the minimal role that
NOX emissions play in visibility impairment in Arkansas'
Class I areas, and would eliminate the unnecessary and duplicative
requirements currently imposed by the Arkansas Regional Haze FIP.
    Response: We appreciate the commenter's support of our proposed
approval of the Arkansas Regional Haze NOX SIP revision. As
we had proposed, we are finalizing our approval of the Arkansas
Regional Haze NOX SIP revision.

B. Reasonable Progress

    Comment: The State attempts to justify the elimination of
reasonable progress controls on Independence by claiming that the CSAPR
allocations for NOX will result in greater reductions in
NOX emissions than the FIP would. The State's rationale has
no basis in law or in fact. To begin, there is no statutory or
regulatory provision which allows states to rely on CSAPR in lieu of
conducting a four-factor analysis of reasonable progress. While EPA has
issued a rule that purports to allow states to rely on CSAPR in lieu of
imposing source-specific controls on BART sources, EPA has not issued a
comparable rule for reasonable progress.
    Moreover, the State's comparison of NOX reductions under
CSAPR versus the FIP is flawed. The State compares CSAPR allocations to
binding reductions which must occur under the FIP, based on legally
enforceable emissions limits. This compares apples to oranges. As the
name suggest, CSAPR allocations are not emissions limits, they are
initial entitlements to emit certain amounts of pollution. Sources can
emit more than their initial allocations, because CSAPR allows both
intra- and inter-state trading of allowances. Thus, it is highly
misleading to treat CSAPR allocations as binding emission limits which
can be compared directly to the emission limits and reductions under
the Arkansas Regional Haze FIP.
    ADEQ further claims in its SIP that it ``anticipates that some EGUs
will choose to install combustion controls to comply with CSAPR that
would reduce emissions year-round, not just in the ozone season.'' ADEQ
provides no evidence for this assumption. More importantly, ADEQ
wrongly conflates installation of controls with operation and optimized
operation of controls. Even if it were true that some EGUs will install
controls to comply with CSAPR, ADEQ provides no reason to assume that
EGUs will operate those controls when they are not legally required to
do so. ADEQ has advanced no basis for assuming that Arkansas EGUs will
spend additional money to run NOX controls or optimize them
to reduce NOX when they are not required to do so, i.e.,
outside of the CSAPR ozone season. Thus, there is no record basis for
assuming that CSAPR will reduce NOX emissions in Arkansas
outside of the ozone season.
    Response: We disagree with the commenter that Arkansas is relying
on CSAPR in lieu of conducting an appropriate reasonable progress
analysis. In assessing the need for additional NOX controls
to address reasonable progress, Arkansas focused its reasonable
progress assessment on the Central Regional Air Planning (CENRAP) \39\
Comprehensive Air Quality Model with extensions (CAMx) source
apportionment modeling,\40\ and observed that a small portion of total
light extinction is due to nitrate (NO3) from Arkansas
sources and that this portion is driven by on-road sources and not
point sources. Arkansas notes that the source apportionment data show
that NO3 from Arkansas point sources contributes less than
0.5% of the total light extinction at Caney Creek and Upper Buffalo on
the 20% worst days in 2002, and that, for the first implementation
period, NOX is not a key pollutant contributing to
visibility impairment at Arkansas' Class I areas on those days. Based
on the above observations, Arkansas reached the conclusion that, for
the first implementation period, additional NOX controls for
Arkansas point sources are not anticipated to yield meaningful
visibility improvements at Arkansas Class I areas on the 20% worst days
in view of the amount of visibility impairment attributed to these
sources. Given the level of visibility impairment due to NOX
from Arkansas point sources at Caney Creek and Upper Buffalo on the 20%
worst days and considering that Arkansas EGUs are participating in
CSAPR for ozone season NOX, Arkansas decided to screen out
Arkansas point sources from further evaluation of additional
NOX controls, thereby not evaluating the four reasonable
progress factors for point sources with respect to NOX in
the first implementation period.
---------------------------------------------------------------------------

    \39\ In developing their Regional Haze SIP and RPGs, Arkansas
and potentially impacted States collaborated through CENRAP. Each
State developed its Regional Haze Plans and RPGs based on the CENRAP
modeling. The CENRAP modeling was based in part on the emissions
reductions each state intended to achieve by 2018.
    \40\ CENRAP utilized CAMx with its Particulate Source
Apportionment Technology (PSAT) tool to provide estimated
contributions to visibility impairment at Class I areas by source
region (e.g., states) and major source category for both the
baseline and future case (i.e., 2018) visibility modeling.
---------------------------------------------------------------------------

    With regard to the comment that ``the State's comparison of
NOX reductions under CSAPR versus the FIP is flawed,'' we
note that we did not base our proposed approval of the Arkansas
NOX SIP revision on the state's comparison of these
NOX reductions. In its draft SIP revision, ADEQ compared
anticipated NOX emission reductions under CSAPR as compared
to the source-specific BART determinations required by EPA's FIP in
assessing the need for additional reductions in NOX to
ensure reasonable progress. However, in its final SIP, ADEQ did not
include this information as part of its rationale. We note that our
proposed approval of Arkansas' SIP revision did not rely on this
comparison of emissions. As a result, the adequacy of ADEQ's assessment
is irrelevant to their final action or to our review of the final SIP.
The commenter's statements questioning ADEQ's assumptions that Arkansas
EGUs will install and operate NOX combustion controls to
comply with CSAPR for ozone-season NOX and operate those
controls year-round appear to be in the context of the commenter's
contention that ADEQ's comparison of NOX reductions under
CSARP versus the Arkansas FIP is flawed. As noted above, the adequacy
of ADEQ's comparison of NOX emissions reductions in the
proposed SIP revision is irrelevant to their final action or to our
review of the final SIP.
    Comment: The State failed to consider any of the four statutory
factors for reasonable progress and the reasonable progress analysis is
therefore unlawful and not approvable. Arkansas recognizes that ``the
RHR requires states to consider four factors: (1) Cost of compliance,
(2) the time necessary for compliance, (3) the energy and non-air
quality environmental impacts of compliance, and (4) the remaining
useful life of potentially affected sources,'' but then the State
proceeds to ignore all four reasonable progress

factors for point sources in its reasonable progress analysis for
NOX. The Clean Air Act provides that in determining
reasonable progress there shall be taken into consideration the costs
of compliance, the time necessary for compliance, and the energy and
nonair quality environmental impacts of compliance, and the remaining
useful life of any existing source subject to such requirements. The
Act contains no exception to this requirement. The SIP fails to
consider these four statutory factors, and therefore violates the Clean
Air Act. In particular, for NOX emissions, the SIP contains
no analysis of the four factors. For emissions of other pollutants, the
SIP contains only a single sentence claiming that the cost
effectiveness for control of POA and CM species from many individual
small sources is difficult to quantify.
    The SIP's failure to consider any of the four factors for
NOX controls is particularly egregious given that the State
acknowledges that EPA has already issued a final rule containing a
four-factor analysis for the Independence plant, which resulted in a
requirement that Independence install and operate low-NOX
burners. The State has produced no evidence that EPA's four-factor
analysis was incorrect in any way, because the State does not analyze
any of the four factors which EPA considered.
    Response: We agree that the CAA and the Regional Haze Rule provide
that in determining reasonable progress, states ``shall take into
consideration 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.'' \41\ However, in cases where it has
been demonstrated that a particular pollutant or source category does
not contribute significantly to visibility impairment at affected Class
I areas, it may be appropriate to end the analysis at that point,
without the need to evaluate the four statutory factors for potential
controls to address that pollutant and/or source category. For example,
EPA's ``Guidance for Setting Reasonable Progress Goals Under the
Regional Haze Program'' provides that the reasonable progress analysis
involves identification of key pollutants and source categories that
contribute to visibility impairment at the Class I area; the guidance
provides that once the key pollutants contributing to visibility
impairment at each Class I area have been identified, the sources or
source categories responsible for emitting these pollutants or
pollutant precursors can also be determined.\42\ The reasonable
progress factors are then to be applied to the key pollutants and
sources or source categories contributing to visibility impairment at
each affected Class I area. As we discussed on our proposed action on
the Arkansas Regional Haze NOX SIP revision, taking into
consideration that states have significant discretion in determining
what sources to analyze for controls under reasonable progress, we
proposed to agree with the state that it is reasonable for Arkansas to
reach the conclusion that, for the first implementation period,
additional NOX controls for Arkansas point sources are not
anticipated to yield meaningful visibility improvements at Arkansas
Class I areas in view of the amount of visibility impairment attributed
to these sources.\43\ Given the level of visibility impairment due to
NOX from Arkansas point sources at Caney Creek and Upper
Buffalo on the 20% worst days and considering that Arkansas EGUs are
participating in CSAPR for ozone season NOX, we find that it
is reasonable for Arkansas to screen out Arkansas point sources from
further evaluation of additional NOX controls and therefore
not have to evaluate the four reasonable progress factors for point
sources with respect to NOX in the first implementation
period.
---------------------------------------------------------------------------

    \41\ 42 U.S.C. 7491(g)(1). See also 40 CFR 51.308(d)(1)(i)(A).
    \42\ EPA's ``Guidance for Setting Reasonable Progress Goals
Under the Regional Haze Program,'' p. 3-1 (June 1, 2007).
    \43\ 82 FR 42633.
---------------------------------------------------------------------------

    Arkansas' conclusions with regard to the percentage contribution to
light extinction from NO3 on the 20% worst days is generally
consistent with the findings we made in the Arkansas Regional Haze
FIP.\44\ In the FIP, we made the finding that NO3 due to
NOX emissions from point sources is not considered a driver
of regional haze at Caney Creek and Upper Buffalo on the 20% worst
days, contributing only approximately 3% of the total light extinction,
as projected by CENRAP's CAMx source apportionment modeling.\45\ We
also stated in the FIP proposal that because of the small contribution
of NO3 from point sources to the total light extinction at
Caney Creek and Upper Buffalo on the 20% worst days, we did not expect
that NOX controls under the reasonable progress requirements
would offer as much improvement on these days compared to
SO2 controls.\46\ However, in the FIP, we decided to look at
2011 National Emissions Inventory (NEI) data for NOX for
Arkansas point sources to determine if there are any large point
sources that are reasonable candidates for evaluation under the four
reasonable progress factors. Based on this assessment, we proceeded
with an analysis of the four reasonable progress factors for
NOX controls for the Independence facility as we reasoned
that it is the second largest point source of NOX emissions
in the state and potentially one of the largest single contributors to
visibility impairment at Class I areas in Arkansas.\47\ We also
conducted CALPUFF modeling to determine the maximum 98th percentile
visibility impacts from the Independence facility and the predicted
visibility improvement due to NOX controls at the facility.
That analysis revealed that low NOX burner controls would be
cost-effective and would result in an improvement of the 98th
percentile visibility impacts from the Independence facility at Caney
Creek and Upper Buffalo, and we finalized NOX controls for
the Independence facility under the reasonable progress
requirements.\48\ In the Arkansas NOX SIP revision, the
state takes a different approach in arriving at its decision that no
additional NOX controls for Arkansas point sources are
necessary under reasonable progress for the first implementation
period. In its evaluation, Arkansas places greater emphasis on its
assessment of the relative contributions to light extinction of sources
within the State than it does on its assessment of the relative
contributions of all sources (i.e., sources both in and outside
Arkansas). Arkansas focused its assessment on the CENRAP's CAMx source
apportionment modeling and reaches the conclusion that, for the first
implementation period, additional NOX controls for Arkansas
point sources are not anticipated to yield meaningful visibility
improvements at Arkansas Class I areas on the 20% worst days in view of
the amount of visibility impairment attributed to these sources.
Therefore, Arkansas determined that no additional NOX
controls beyond EGU participation in CSAPR for ozone season
NOX are necessary to satisfy the reasonable progress
requirements for Arkansas sources in the first planning period. In
future planning periods, Arkansas will have to reevaluate the benefit
of NOX reductions, which will likely become more important
as other pollutants are reduced. We believe Arkansas is within its
discretion to take

a different approach than we did in the Arkansas FIP, and that the
approach Arkansas has taken to determine whether additional
NOX controls are necessary under reasonable progress is
reasonable and therefore, approvable. The Clean Air Act gave EPA the
power to identify pollutants and set air quality standards. Congress
gave states ``the primary responsibility for implementing those
standards.'' Luminant Generation Co. v. EPA, 675 F.3d 917, 921 (5th
Cir. 2012). (internal quotation marks omitted); see 42 U.S.C. 7407(a)
(``Each State shall have the primary responsibility for assuring air
quality within [its] entire geographic area.''); id. section 7401(a)(3)
(``[A]ir pollution prevention . . . is the primary responsibility of
States and local governments.''). The states have ``wide discretion''
in formulating SIPs. Union Elec. Co. v. EPA, 427 U.S. 246, 250 (1976).
---------------------------------------------------------------------------

    \44\ 81 FR 66332; see also 81 FR 68319 (October 4, 2016)
(correction).
    \45\ 80 FR 18996.
    \46\ 80 FR 18996.
    \47\ 80 FR 18995.
    \48\ 81 FR 66332.
---------------------------------------------------------------------------

    We are finalizing our approval of Arkansas' determination that
Arkansas EGU participation in CSAPR for ozone season NOX is
sufficient to satisfy the reasonable progress requirements for
NOX in Arkansas for the first implementation period.
    Comment: The State's reasonable progress analysis unlawfully fails
to consider whether measures are needed to make reasonable progress at
Class I areas outside Arkansas. The State's analysis is unlawful,
regardless of whether the old or new version of the Regional Haze rule
applies here. The prior version of the Regional Haze rule required each
state to make an independent determination of the measures needed to
make reasonable progress at out-of-state Class I areas. After noting
the statutory goal to eliminate all human-caused visibility impairment,
EPA observed that ``it would be impossible to achieve this goal if
upwind states did not have the same responsibility to address their
visibility impairing emissions and achieve reasonable progress in
downwind Class I areas as the downwind states themselves.''
    The current version of the regional haze rule clarifies, but does
not alter, this obligation. As EPA noted in the 2017 revisions to the
regional haze rule, states have an ``independent obligation to include
in their SIPs enforceable emission limits and other measures that are
necessary to make reasonable progress at all affected Class I areas, as
determined by considering the four factors.'' Despite the requirement
to consider whether measures are needed to make reasonable progress at
out of state Class I areas, the State's analysis focuses exclusively on
the two Class I areas within Arkansas. Yet the State acknowledges that
emissions from Arkansas sources impact visibility at Class I areas in
Missouri. EPA's analysis of the SIP revision commits the same mistake
as the SIP revision itself. EPA fails to analyze whether the State has
complied with Clean Air Act requirements to determine whether measures
are needed to make reasonable progress at out-of-state Class I areas.
By failing to consider whether measures are necessary to make
reasonable progress at Missouri Class I areas, the draft SIP violates
the Regional Haze Rule, and is unapprovable.
    Response: We disagree with the commenter that Arkansas failed to
consider whether additional controls are necessary to make reasonable
progress in Class I areas outside the state. The Arkansas
NOX SIP revision recognizes that sources in Arkansas impact
the two Class I areas in Missouri: Hercules Glade Wilderness Area and
Mingo Wilderness Area. Arkansas also explains that ``[t]he most recent
five-year rolling average of observed visibility impairment on the
twenty percent haziest days at Hercules Glades Wilderness Area beat
Missouri's 2018 RPG for that Class I area and the most recent five
year-rolling average of observed visibility impairment on the twenty
percent haziest days at Mingo Wilderness Area is on track to beat
Missouri's RPG for that Class I area.'' \49\ Arkansas concludes that
the visibility progress observed at the IMPROVE monitors indicates that
sources in Arkansas are not interfering with the achievement of
Missouri's 2018 RPGs for Hercules Glades and Mingo Wilderness Areas,
and that no additional controls are therefore needed on Arkansas
sources to ensure reasonable progress at Missouri's Class I areas.\50\
Furthermore, Arkansas provided Missouri with an opportunity for
consultation on the Arkansas NOX SIP revision.\51\ Arkansas
sent a letter dated June 14, 2017, to the Missouri Department of
Natural Resources (DNR) providing notification and electronic access to
the proposed SIP revision, and providing an opportunity to discuss
Missouri's assessment of the impact of the proposed SIP revision on
reasonable progress at Missouri Class I areas.\52\ Missouri DNR did not
have comments on Arkansas' proposed SIP revision.
---------------------------------------------------------------------------

    \49\ See final Arkansas NOX SIP revision, Section
IV.C, p. 23.
    \50\ See final Arkansas NOX SIP revision, Section
IV.C, p. 23.
    \51\ See final Arkansas NOX SIP revision, Section
V.C, p. 25.
    \52\ See final Arkansas NOX SIP revision, Tab E.
---------------------------------------------------------------------------

    Comment: The Arkansas Regional Haze NOX SIP revision
determines that controls for reasonable progress are not necessary for
the first planning period. The Clean Air Act requires that regional
haze implementation plans contain measures ``necessary to make
reasonable progress toward meeting the national goal'' of no manmade
visibility impairment. In its regulations implementing the Regional
Haze program, EPA established that, in setting a reasonable progress
goal, the State must consider the uniform rate of improvement in
visibility and the emission reduction measures needed to achieve it for
the period covered by the implementation plan. EPA has further
explained in its guidance for setting reasonable progress goals that
states should take into account the fact that the long-term goal of no
manmade impairment encompasses several planning periods and that it is
reasonable for the state to defer reductions to later planning periods
in order to maintain a consistent glidepath toward the long-term goal.
Mandating emissions controls that are not necessary to make reasonable
progress during the planning period contradicts this statutory and
regulatory scheme.
    Reasonable progress controls during the first planning period
clearly are not necessary for Arkansas sources. Interagency Monitoring
of Protected Visual Environments (IMPROVE) monitoring data show that
the haze index has been consistently below the glidepath in Arkansas'
Class I areas--Caney Creek and Upper Buffalo--and Entergy's analysis
demonstrates that it is projected to remain so through the end of the
second planning period.
    Even if controls were required for reasonable progress during the
first planning period, NOX controls on Arkansas EGUs are not
necessary, as they will provide minimal visibility improvement in
Arkansas' Class I areas. As EPA's own analysis indicates, the
contribution of Arkansas point sources' nitrate emissions to visibility
impairment in Arkansas' Class I areas is insignificant. According to
EPA's analysis, nitrate from all point sources included in the regional
modeling is projected to account for only 3% of the total light
extinction at the Caney Creek and Upper Buffalo Class I areas, with
nitrate from Arkansas point sources being responsible for only 0.27% of
the total light extinction at Caney Creek and 0.14% at Upper Buffalo.
As a result, NOX controls on Arkansas EGUs during the first
planning period are not necessary to make reasonable progress towards
natural visibility conditions.

    Response: We appreciate the commenter's support of our proposed
approval of Arkansas' reasonable progress determination for
NOX. As we had proposed, given the level of visibility
impairment due to NOX from Arkansas point sources at Caney
Creek and Upper Buffalo on the 20% worst days and considering that
Arkansas EGUs are participating in CSAPR for ozone season
NOX, we are finalizing our determination that Arkansas'
decision to screen out Arkansas point sources from further evaluation
of additional NOX controls is reasonable and we are
finalizing our approval of Arkansas' determination that Arkansas EGU
participation in CSAPR for ozone season NOX is sufficient to
satisfy the reasonable progress requirements for NOX in
Arkansas for the first implementation period.

C. Clean Air Act Section 110(l)

    Comment: EPA asserts that in the SIP revision, Arkansas takes a
different, but nonetheless equally reasonable, approach to determine
whether additional controls are necessary under reasonable progress.
But EPA ignores that the State's ``different'' approach would result in
more air pollution and worse air quality relative to the existing FIP.
As a result, the State's reasonable progress determination violates the
Clean Air Act's ``anti-backsliding'' requirement under 42 U.S.C.
7410(l), and is therefore unapprovable.
    In the 2016 FIP, EPA determined that reasonable progress requires
that Independence Units 1 and 2 meet NOX emission limits
based on the use of low-NOX burners and separated over-fire
air controls. Now, the State proposes a SIP that would replace those
NOX emission limits with nothing. Eliminating the
requirement that a source meet an emission limit necessarily would
result in greater air pollution and worse visibility impairment at
affected Class I areas. Section 110(l) of the Clean Air Act prevents a
plan revision that would weaken the existing FIP requirements in this
manner.
    Section 110(l) states that the Administrator shall not approve a
revision of a plan if the revision would interfere with any applicable
requirement concerning attainment and reasonable further progress or
any other applicable requirement of this chapter. Section 110(l) is the
Act's ``anti-backsliding'' provision. The anti-backsliding provision
prohibits plan revisions that would interfere with attainment of the
NAAQS or other ``applicable requirements'' of the Act. Section 110(l)
prohibits plan revisions that would interfere with an existing
requirement to make reasonable further progress, including a BART
determination, as the Act's ``applicable requirement[s]'' include the
regional haze program's BART requirements. When determining whether a
plan revision interferes with NAAQS attainment, EPA has interpreted
section 110(l) as preventing plan revisions that would increase overall
air pollution or worsen air quality. For example, the Eleventh Circuit
has upheld EPA's section 110(l) interpretation as prohibiting plan
revisions that would increase emissions or worsen air quality. In
Kentucky Resources Council, Inc. v. EPA, 467 F.3d 986 (6th Cir. 2006),
EPA interpreted section 110(l) as allowing the agency to approve a plan
revision that weakened some existing control measures while
strengthening others, but only ``[a]s long as actual emissions in the
air are not increased.'' The court upheld EPA's interpretation, which
``allow[ed] the agency to approve a [state implementation plan] SIP
revision unless the agency finds it will make the air quality worse.''
The Seventh Circuit has also upheld EPA's interpretation in Indiana v.
EPA, 796 F.3d 803, 812 (7th Cir. 2015). Moreover, in a short discussion
regarding a challenge to the Nevada regional haze plan in WildEarth
Guardians v. EPA, 759 F.3d 1064, 1074 (9th Cir. 2014), the Ninth
Circuit suggested that a haze plan that ``weakens or removes any
pollution controls'' would violate section 110(l).
    The existing reasonable progress determination in the FIP requires
Independence Units 1 and 2 to meet emission limits based on the use of
low-NOX burners and separated over-fire air. These pollution
reductions must occur by April 27, 2018. EPA has proposed to extend the
compliance deadline for this requirement, but has not proposed to alter
the emission limits themselves. Even if the deadline extension is
finalized, the final FIP for Arkansas requires Independence Units 1 and
2 to reduce NOX emissions. The draft SIP would eliminate the
FIP requirements for Independence without imposing any other
requirement that would achieve equal or greater reductions in
NOX emissions from Independence.
    Response: We disagree that the Arkansas NOX SIP revision
violates the CAA's requirements under section 110(l). As discussed in
our proposed approval of the Arkansas NOX SIP revision, we
believe an approval of the SIP revision and concurrent withdrawal of
the corresponding parts of the FIP, as proposed, will meet the Clean
Air Act's 110(1) provisions. Generally, a SIP revision may be approved
under section 110(l) if EPA finds that it will at least preserve status
quo air quality, particularly where the pollutants at issue are those
for which an area has not been designated nonattainment.\53\ Approval
of the Arkansas NOX SIP revision is not expected to
interfere with attainment and maintenance of any of the NAAQS within
the state of Arkansas. No areas in Arkansas are currently designated
nonattainment for any NAAQS pollutants. The SIP revision we are
approving would allow Arkansas to rely on compliance with CSAPR for
ozone-season NOX to satisfy the NOX BART
requirement for Arkansas EGUs and makes the determination that no
additional NOX controls beyond EGU participation in CSAPR
for ozone season NOX are necessary to satisfy the reasonable
progress requirements for NOX for Arkansas sources. While
the commenter is correct that the Arkansas NOX SIP revision
we are approving does not require source-specific NOX
controls under reasonable progress for Independence Units 1 and 2, as
was required by the FIP, we note that those units are subject to CSAPR
for ozone season NOX and their NOX emissions will
thus be addressed through participation in the CSAPR ozone season
NOX program. Further, the CSAPR 2018 NOX ozone
season allocations for Arkansas sources are more stringent than the
2017 allocations. As all areas in Arkansas are attaining all the NAAQS
even with current emissions levels, compliance with the CSAPR 2018
NOX ozone season more stringent allocations will not
interfere with any applicable requirement concerning attainment or
reasonable further progress toward attainment of the NAAQS. We are not
aware of any basis for concluding or demonstrating that the Arkansas
NOX SIP revision, when implemented, would interfere with the
continued attainment of all the NAAQS in Arkansas.
---------------------------------------------------------------------------

    \53\ 78 FR 51686 at 51694 (August 21, 2013).
---------------------------------------------------------------------------

    We also do not find that our approval of the Arkansas
NOX SIP revision, as proposed, will interfere with the
applicable CAA regional haze requirements for BART or reasonable
progress because our action is supported by an evaluation that those
CAA regional haze requirements for BART and reasonable progress are
met. Specifically, EPA has made the determination that Arkansas EGU
participation in CSAPR for ozone-season NOX satisfies the
NOX BART requirements for Arkansas EGUs, consistent with 40
CFR 51.308(e)(4). On September 29, 2017, we affirmed our proposed
finding that the EPA's 2012

analytical demonstration remains valid and that participation in CSAPR,
as it now exists, meets the Regional Haze Rule's criteria for an
alternative to BART. With regard to reasonable progress for regional
haze, the Arkansas NOX SIP revision includes an assessment
of anthropogenic sources of visibility impairment and arrives at the
determination that given the level of contribution to light extinction
from NOX due to Arkansas point sources, Arkansas EGU
participation in CSAPR for ozone season NOX is sufficient to
satisfy the reasonable progress requirements for NOX in
Arkansas for the first implementation period. The Independence
facility, on which the FIP imposed source specific NOX
controls under the reasonable progress requirements, is subject to
CSAPR for ozone season NOX. Even though we are approving the
Arkansas NOX SIP revision and concurrently withdrawing the
source-specific NOX controls in the FIP for the Independence
facility, the NOX emissions from the Independence facility
will still be addressed under the regional haze reasonable progress
requirements through participation in the CSAPR ozone season
NOX emissions trading program. In addition, all Arkansas
EGUs with a nameplate capacity of 25 megawatts or greater participate
in the CSAPR ozone season NOX emissions trading program.
This means that many EGUs that were not subject to control requirements
under the FIP are required under the CSAPR trading program to comply
with specific NOX emissions allocations during the ozone
season.

D. Legal

    Comment: To be approvable, any SIP must include enforceable
emissions limitations, compliance schedules, and other measures as
necessary to achieve the reasonable progress goals. The agency
recognized in disapproving Arkansas's 2011 SIP package, that when
evaluating a state's BART determination, the EPA looks at existing
requirements and cannot rely on potential future actions in its
decision to approve or disapprove a state SIP. Here, EPA's proposed
approval is impermissibly based on future contingencies that have not
occurred. Indeed, the agency recognized in the proposal that it cannot
take a final action until the state completes its rulemaking process,
adopts its final regulations, and submits these final adopted
regulations as a revision to the Arkansas SIP. Because EPA's proposed
action relies on potential future state actions, it cannot be approved.
    Response: We disagree with comments that we are relying on
potential future state actions in taking final action. CSAPR is an
existing program that the state of Arkansas is participating in for
NOX. The Arkansas SIP revision relies on participation in
CSAPR to meet the requirements of NOX BART, as well as the
fact that NOX is not the driver of visibility impairment on
the 20% worst days, in their determination under reasonable progress,
that no other NOX controls are needed. Future decisions on
trading as part of its current participation in CSAPR are not
considered future state actions. Current participation in CSAPR is the
state action that EPA's proposed action is based upon.
    Further, our proposed approval was based on a proposed SIP revision
submitted by ADEQ on July 12, 2017, with a request for parallel
processing. As we explained in our September 11, 2017 proposal, we
proposed action on the SIP revision at the same time that ADEQ was
completing the corresponding public comment and rulemaking process at
the state level.\54\ We explained that the July 2017 SIP revision
request would not be complete and would not meet all the SIP
approvability criteria until the state completes the public process and
submits the final, adopted SIP revision with a letter from the Governor
or Governor's designee to EPA.\55\ In our September 11, 2017 proposal,
we proposed to approve the SIP revision request after completion of the
state public process and final submittal of the SIP revision. On
October 31, 2017, we received ADEQ's final SIP revision addressing BART
and reasonable progress requirements for NOX for EGUs in
Arkansas for the first implementation period. The final Arkansas
Regional Haze NOX SIP revision we received on October 31,
2017 did not contain significant changes from the state's proposed SIP
revision. Therefore, it is appropriate for us to take final action, as
proposed, on the final SIP revision.
---------------------------------------------------------------------------

    \54\ 82 FR at 42629.
    \55\ Id.
---------------------------------------------------------------------------

E. General

    Comment: The proposed rule contains certain calculation errors,
which, although sufficiently minor that they do not affect EPA's
conclusions, should be corrected. EPA states that total light
extinction on the 20% worst days in 2002 was 115.87 Mm-1 for
Caney Creek and 115 Mm-1 for Upper Buffalo. These values are
inconsistent with CENRAP PSAT results, which are 133.93 Mm-1
and 131.79 Mm-1, respectively. EPA's values appear to
exclude certain source categories, namely Initial Conditions, Boundary
Conditions, Secondary Organic Aerosols--Anthropogenic, and Secondary
Organic Aerosols--Biogenic. EPA does not explain why these categories
are or should be excluded when calculating light extinction on the 20%
worst days in 2002. Further, EPA does include these categories in its
calculation of other values, such as the 87.05 Mm-1 value
for the SO4 contribution at Caney Creek, which accounts for
3.32 Mm-1 from the Boundary Conditions source category.
Because the total light extinction values form the basis for many other
values in EPA's analysis, errors in the total light extinction values
carry over into the derivative values.
    The proposed rule also contains a number of miscalculations
unrelated to the total light extinction error. These miscalculations
relate to EPA's characterization of the CENRAP PSAT results. While
sufficiently minor that they do not affect the outcome of EPA's
determination, Entergy lists these errors here in the interest of
correcting the record:
     EPA states that the remaining source categories each
contribute between 2% and 6% of total light extinction at Arkansas'
Class I areas. The high-end rounded value should be changed from 6% to
7%, as the true range is 1.83% to 6.72%, pursuant to the CENRAP PSAT
results.
     EPA states that the PSAT results show that natural, on-
road, and non-road sources are projected to continue to contribute a
very small portion of total light extinction at Arkansas' Class I areas
on the 20% worst days in 2018. According to the CENRAP PSAT results,
the contribution of natural, on-road, and non-road sources is 8.5% to
9.4% of the total light extinction. This amount should not be
characterized as ``a very small portion.''
     EPA states that the other species (i.e., NO3,
POA, EC, soil, and CM) are also projected to have reductions in their
contribution to total light extinction at Caney Creek and Upper Buffalo
in 2018. This statement is true for all the species except soil, which
actually increases in 2018 for both Class I areas according to the
CENRAP PSAT results.
     EPA states that the other source categories in Arkansas
each contribute between 7% and 14% to light extinction attributed to
Arkansas sources at Caney Creek and Upper Buffalo. According to the
CENRAP PSAT results, the correct range is 7% to 8%.
     EPA states that CM from Arkansas sources, primarily area
sources,

contribute approximately 1 and 2% of total light extinction at Caney
Creek and Upper Buffalo, respectively. According to the CENRAP PSAT
results, the value for Upper Buffalo is 2.68% (which would round to
3%).
    Response: We appreciate the commenter pointing out errors and other
mischaracterizations of light extinction values presented in our
proposed action. We acknowledge these errors. As pointed out by the
commenter, these errors are minor in nature and do not affect our
proposed and final determinations on the Arkansas Regional Haze
NOX SIP revision.
     The commenter is correct that our proposed action stated
that total light extinction on the 20% worst days in 2002 was 115.87 Mm
-1 for Caney Creek and 115 Mm -1 for Upper
Buffalo.\56\ However, as pointed out by the commenter, these cited
values did not include initial conditions, boundary conditions, and
secondary organic matter. As we noted in our proposed action on the
2008 Arkansas Regional Haze SIP,\57\ the correct total visibility
extinction on the 20% worst days in 2002, including contributions from
initial conditions, boundary conditions, and secondary organic matter,
is 133.93 Mm -1 at Caney Creek \58\ and 131.79 Mm
-1 at Upper Buffalo.\59\
---------------------------------------------------------------------------

    \56\ 82 FR at 42630.
    \57\ 76 FR at 64186 (October 17, 2011).
    \58\ 76 FR at 64214.
    \59\ 76 FR at 64215.
---------------------------------------------------------------------------

     The commenter pointed out that we stated in our proposal
that the PSAT results show that natural, on-road, and non-road sources
are projected to contribute a very small portion of total light
extinction at Arkansas' Class I areas on the 20% worst days in
2018.\60\ The commenter further points out that the combined
contribution of these three source categories is 8.5% and 9.4% at Caney
Creek and Upper Buffalo, which the commenter says should not be
characterized as ``a very small portion.'' While we agree with the
commenter that the combined contribution of the three source categories
is not ``very small,'' we would like to clarify that the statement made
in our proposal referred to the contribution of each individual source
category at each Class I area. For example, the natural source category
contributes approximately 2.47% of the total light extinction at Caney
Creek and 2.6% at Upper Buffalo on the 20% worst days in 2018; the on-
road source category contributes approximately 1.68% of the total light
extinction at Caney Creek and 1.82% at Upper Buffalo; and the on-road
source category contributes approximately 4.38% of the total light
extinction at Caney Creek and 4.93% at Upper Buffalo.
---------------------------------------------------------------------------

    \60\ 82 FR 42631.
---------------------------------------------------------------------------

     The commenter pointed out that our statement that the
light extinction due to species other than SO4 is projected
to decrease in 2018 on the 20% worst days at Caney Creek and Upper
Buffalo is correct for all species except soil. The commenter is
correct, as the light extinction due to soil is projected to increase
slightly in 2018 on the 20% worst days at both Class I areas.\61\ The
commenter points out that according to the CENRAP PSAT results, CM from
Arkansas sources contribute approximately 2.68% of the total light
extinction at Upper Buffalo, not 2%, as stated in our proposal.\62\ The
commenter is correct. The CM contribution from all Arkansas source
categories is 3.53 Mm -1, out of a total light extinction of
131.79 Mm -1, which is a contribution of approximately
2.68%.
---------------------------------------------------------------------------

    \61\ 76 FR at 64214-64215; see Tables 8 and 10.
    \62\ 82 FR at 42631.
---------------------------------------------------------------------------

IV. Final Action

    We are approving a revision to the Arkansas SIP submitted on
October 31, 2017, as meeting the regional haze requirements for the
first implementation period. This action includes the finding that the
submittal meets the applicable regional haze requirements as set forth
in sections 169A and 169B of the CAA and 40 CFR 51.300-51.308. The EPA
is approving the SIP revision submittal as meeting the following: the
core requirements for regional haze SIPs found in 40 CFR 51.308(d) such
as the reasonable progress requirement for NOX; the
NOX BART requirements for regional haze visibility
impairment with respect to emissions of visibility impairing pollutants
from EGUs in 40 CFR 51.308(e); and the requirement for coordination
with state and Federal Land Managers in Sec.  51.308(i). We are
approving ADEQ's reliance on CSAPR participation for ozone season
NOX to meet the NOX BART requirement for EGUs.
Arkansas' reliance on CSAPR addresses the NOX BART
requirements for Bailey Unit 1; McClellan Unit 1; Flint Creek Boiler
No. 1; Lake Catherine Unit 4; White Bluff Units 1 and 2 and the
Auxiliary Boiler.
    We also agree that Arkansas' conclusion that given the relatively
small level of visibility impairment due to NOX from
Arkansas point sources at Caney Creek and Upper Buffalo on the 20%
worst days, for the first implementation period, additional
NOX controls for Arkansas point sources are not anticipated
to yield meaningful visibility improvements at Arkansas Class I areas
on the 20% worst days is reasonable. In light of the level of
visibility impairment due to NOX from Arkansas point sources
at Caney Creek and Upper Buffalo and considering that Arkansas EGUs are
participating in CSAPR for ozone season NOX, we are
finalizing our determination that Arkansas' decision to screen out
Arkansas point sources from further evaluation of additional
NOX controls is reasonable and we are finalizing our
approval of Arkansas' determination that no additional NOX
controls, beyond Arkansas EGU participation in CSAPR for ozone season
NOX, are necessary to satisfy the reasonable progress
requirements for NOX in Arkansas for the first
implementation period.
    Concurrent with our final approval of the Arkansas Regional Haze
NOX SIP revision, we are finalizing in a separate rulemaking
our final action to withdraw those portions of the Arkansas Regional
Haze FIP at 40 CFR 52.173 that impose NOX requirements on
Bailey Unit 1; McClellan Unit 1; Flint Creek Boiler No. 1; Lake
Catherine Unit 4; White Bluff Units 1 and 2 and the Auxiliary Boiler;
and Independence Units 1 and 2.\63\
---------------------------------------------------------------------------

    \63\ Our final action withdrawing part of the Arkansas Regional
Haze FIP is also being published in this Federal Register.
---------------------------------------------------------------------------

    We find that an approval of the SIP revision meets the Clean Air
Act's 110(1) provisions. No areas in Arkansas are currently designated
nonattainment for any NAAQS pollutants. Approval of the Arkansas
NOX SIP revision will not interfere with continued
attainment of all the NAAQS within the state of Arkansas. The SIP
revision we are approving would allow Arkansas to rely on compliance
with CSAPR for ozone-season NOX to satisfy the
NOX BART requirement for Arkansas EGUs and makes the
determination that no additional NOX controls beyond EGU
participation in CSAPR for ozone season NOX are necessary to
satisfy the reasonable progress requirements for NOX for
Arkansas sources. We also find that our approval of the Arkansas
NOX SIP revision will not interfere with the applicable CAA
regional haze requirements for BART because our action is supported by
an evaluation EPA made in a separate rulemaking \64\ that the CAA
requirement for BART can be satisfied through participation in

CSAPR. We also find that our approval of the Arkansas NOX
SIP revision will not interfere with the applicable CAA regional haze
requirements for reasonable progress because the Arkansas
NOX SIP revision includes an assessment of anthropogenic
sources of visibility impairment and arrives at the determination that
given the level of contribution to light extinction from NOX
due to Arkansas point sources, Arkansas EGU participation in CSAPR for
ozone season NOX is sufficient to satisfy the reasonable
progress requirements for NOX in Arkansas for the first
implementation period. The Independence facility, on which the FIP
imposed source specific NOX controls under the reasonable
progress requirements, is subject to CSAPR for ozone season
NOX. Even though we are approving the Arkansas
NOX SIP revision and concurrently withdrawing the source-
specific NOX controls in the FIP for the Independence
facility, the NOX emissions from the Independence facility
will still be addressed under the regional haze reasonable progress
requirements through participation in the CSAPR ozone season
NOX emissions trading program.
---------------------------------------------------------------------------

    \64\ On September 29, 2017, we finalized our proposed finding
that the EPA's 2012 analytical demonstration remains valid and that
participation in CSAPR, as it now exists, meets the Regional Haze
Rule's criteria for an alternative to BART.
---------------------------------------------------------------------------

V. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a
SIP submission that complies with the provisions of the Act and
applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a).
Thus, in reviewing SIP submissions, the EPA's role is to approve state
choices, provided that they meet the criteria of the Clean Air Act.
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:
     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) and 13563 (76 FR 3821, January 21,
2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2,
2017) regulatory action because SIP approvals are exempted under
Executive Order 12866;
     Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     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.);
     Does not contain any unfunded mandate or significantly or
uniquely affect small governments, described in the Unfunded Mandates
Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
     Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using practicable and legally permissible methods, under
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the rule does not have tribal implications and will not impose
substantial direct costs on tribal governments or preempt tribal law as
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this action and
other required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by April 13, 2018. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this action for the purposes of
judicial review nor does it extend the time within which a petition for
judicial review may be filed, and shall not postpone the effectiveness
of such rule or action. This action may not be challenged later in
proceedings to enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Air pollution control, Best available retrofit technology,
Environmental protection, Incorporation by reference, Intergovernmental
relations, Nitrogen dioxide, Ozone, Regional haze, Reporting and
recordkeeping requirements, Visibility.

    Dated: January 24, 2018.
Anne Idsal,
Regional Administrator, Region 6.

    Title 40, chapter I, of the Code of Federal Regulations is amended
as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

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

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

Subpart E--Arkansas

0
2. In Sec.  52.170, paragraph (e) is amended by adding the entry
``Arkansas Regional Haze NOX SIP Revision'' at the end of
the third table titled ``EPA-Approved Non-Regulatory Provisions and
Quasi-Regulatory Measures in the Arkansas SIP'' to read as follows:

Sec.  52.170  Identification of plan.

* * * * *
    (e) * * *

            EPA-Approved Non-Regulatory Provisions and Quasi-Regulatory Measures in the Arkansas SIP
----------------------------------------------------------------------------------------------------------------
                                                                 State
     Name of SIP provision        Applicable geographic or    submittal/    EPA approval date     Explanation
                                     nonattainment area     effective date
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Arkansas Regional Haze NOX SIP   Statewide................      10/31/2017  2/12/2018,         Regional Haze SIP
 Revision.                                                                   [Insert Federal    submittal
                                                                             Register           addressing NOX
                                                                             citation].         BART
                                                                                requirements for
                                                                                Arkansas EGUs
                                                                                and reasonable
                                                                                progress
                                                                                requirements for
                                                                                NOX for the
                                                                                first
                                                                                implementation
                                                                                period.
----------------------------------------------------------------------------------------------------------------

0
3. In Sec.  52.173, paragraphs (e) and (f) are added to read as
follows:

Sec.  52.173  Visibility protection.

* * * * *
    (e) Measures addressing best available retrofit technology (BART)
for electric generating unit (EGU) emissions of nitrogen oxides (NOX).
The BART requirements for EGU NOX emissions are satisfied by
Sec.  52.184 and the Arkansas Regional Haze NOX SIP Revision
approved February 12, 2018, [Insert Federal Register citation].
    (f) Other measures addressing reasonable progress. The reasonable
progress requirements for NOX emissions are satisfied by the
Arkansas Regional Haze NOX SIP Revision approved February
12, 2018, [Insert Federal Register citation].

[FR Doc. 2018-02147 Filed 2-9-18; 8:45 am]
 BILLING CODE 6560-50-P