[Federal Register Volume 84, Number 60 (Thursday, March 28, 2019)]
[Proposed Rules]
[Pages 11711-11723]
[FR Doc No: 2019-05860]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2016-0619; FRL-9990-53-Region 6]

Air Plan Approval; Oklahoma; Regional Haze Five-Year Progress
Report

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the
Environmental Protection Agency (EPA) is proposing to approve a
revision to a State Implementation Plan (SIP) submitted by the Governor
through the Oklahoma Department of Environmental Quality (ODEQ) on
September 28, 2016. The SIP revision addresses requirements of federal
regulations that direct the State to submit a periodic report
describing progress toward reasonable progress goals (RPGs) established
for regional haze and a determination of the adequacy of the existing
implementation plan.

DATES: Written comments must be received on or before April 29, 2019.

ADDRESSES: Submit comments, identified by Docket No. EPA-R06-OAR-2016-
0619, at https://www.regulations.gov or via email to
<EMAIL_ADDRESS>Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
Regulations.gov. The EPA may publish any comment received to its public
docket. Do not submit any information electronically that is considered
Confidential Business Information (CBI) or any other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include all
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e. on the web, cloud, or other file sharing systems). For
additional submission methods, please contact Bill Deese,<PHONE_NUMBER>,
<EMAIL_ADDRESS>For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
    Docket: The index to the docket for this action is available
electronically at www.regulations.gov and in hard copy at the EPA
Region 6, 1445 Ross Avenue, Suite 700, Dallas, Texas. While all
documents in the docket are listed in the index, some information may
be publicly available only at the hard copy location (e.g., copyrighted
material), and some may not be publicly available at either location
(e.g., CBI).

FOR FURTHER INFORMATION CONTACT: Clovis Steib,<PHONE_NUMBER>,
<EMAIL_ADDRESS>To inspect the hard copy materials, please
schedule an appointment with Mr. Bill Deese at<PHONE_NUMBER>.

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

I. Background

A. Oklahoma's Regional Haze SIP

    In section 169A of the 1977 CAA Amendments, 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,
visibility impairment in mandatory Class I Federal areas where
impairment results from manmade air pollution.\1\ Congress added
section 169B to the CAA in 1990 that added visibility protection
provisions, and the EPA promulgated final regulations addressing
regional haze as part of the 1999 Regional Haze Rule, which was most
recently updated

in 2017.\2\ The Regional Haze Rule revised the existing 1980 visibility
regulations and established a more 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 the EPA's broader visibility
protection regulations at 40 CFR 51.300 through 309. The regional haze
regulations require states to demonstrate reasonable progress toward
meeting the national goal of a return to natural visibility conditions
for mandatory Class I Federal areas both within and outside states by
2064. The requirement to submit a regional haze SIP revision at
periodic intervals applies to all 50 states, the District of Columbia,
and the Virgin Islands. Oklahoma submitted its initial regional haze
SIP on February 18, 2010.
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    \1\ 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. The EPA, in consultation with the
Department of Interior, promulgated a list of 156 areas where
visibility was identified as an important value. The extent of a
mandatory Class I area includes subsequent changes in boundaries,
such as park expansions. Although states and tribes may designate
additional areas as Class I, the requirements of the visibility
program set forth in the CAA applies only to ``mandatory Class I
Federal areas.'' Each mandatory Class I Federal area is the
responsibility of a ``Federal Land Manager.'' When the term ``Class
I area'' is used in this action, it means ``mandatory Class I
Federal areas.'' [See 44 FR 69122, November 30, 1979 and CAA
Sections 162(a), 169A, and 302(i)].
    \2\ See the July 1, 1999 Regional Haze Rule final action (64 FR
35714), as amended on July 6, 2005 (70 FR 39156), October 13, 2006
(71 FR 60631), June 7, 2012 (77 FR 33656) and on January 10, 2017
(84 FR 3079).
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    Oklahoma's 2010 Regional Haze SIP included calculations of baseline
and natural visibility conditions for the Wichita Mountains Wilderness
Area (``Wichita Mountains'' or WMWA),\3\ the only Class I area located
in Oklahoma (and potentially affected Class I areas located elsewhere),
a long-term strategy to address regional haze visibility impairment,
RPGs for the WMWA reflective of the visibility conditions projected to
be achieved by the end of the first implementation period, and a
monitoring and reporting strategy. The 2010 Regional Haze SIP also
included determinations of emission limitations and schedules for
compliance for a group of Oklahoma industrial air emissions sources
that are subject to best available retrofit technology (BART) \4\ under
national Regional Haze Program requirements. Oklahoma's Regional Haze
SIP purports that visibility improvement at the WMWA is limited by the
impact of out-of-state emission sources.
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    \3\ WMWA is contained within the Wichita Mountains National
Wildlife Refuge and is managed by the U.S. Fish and Wildlife
Service. The Refuge is located in Comanche County adjacent to Fort
Sill Military Reservation, a U.S. Army training base. The city of
Lawton is the closest population center and is located 22 miles
southeast of the Refuge.
    \4\ 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 by controlling emissions of pollutants that
contribute to visibility impairment, including a requirement that
certain categories of existing major stationary sources[thinsp]built
between 1962 and 1977 procure, install, and operate the ``Best
Available Retrofit Technology'' (BART).
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    The 2010 Regional Haze SIP evaluated numerous sources for
applicability of BART. Oklahoma relied on BART requirements for
emissions of sulfur dioxide (SO2) and nitrogen oxides
(NOX) from certain electric generating units (EGUs) in the
State in its regional haze plan to meet certain requirements of EPA's
Regional Haze Rule. This reliance was consistent with EPA's regulations
at the time that Oklahoma developed its regional haze plan. EPA
approved core elements of Oklahoma's Regional Haze SIP, including BART
determinations for the majority of emissions units that were subject to
BART. Those determinations became effective on January 27, 2012 (76 FR
81728, December 28, 2011). However, EPA disapproved ODEQ's BART
determinations for SO2 emissions from six-coal-fired EGUs
located at three facilities. As a result, EPA issued a federal
implementation plan (FIP), promulgating revised SO2 BART
emission limits on coal-fired EGUs at those three facilities.\5\ The
FIP affects two units at each of two facilities owned and operated by
Oklahoma Gas and Electric Company (OG&E): Muskogee Generating Station
in Muskogee County, and Sooner Generating Station in Noble County. The
FIP also initially applied to two units at American Electric Power/
Public Service Company of Oklahoma's (AEP/PSO's) Northeastern Power
Station in Rogers County, but those requirements have since been
removed from the FIP after EPA approval of a SIP revision addressing
these units.
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    \5\ See 76 FR 81728 (December 28, 2011), codified at 40 CFR
52.1923.
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    In the December 2011 action, EPA also disapproved the State's LTS
for regional haze because the LTS relied on the BART limits in the
disapproved determinations. EPA also disapproved portions of Oklahoma's
Interstate Transport SIP for the 1997 8-hour Ozone and 1997
PM2.5 National Ambient Air Quality Standards (submitted to
address the requirements of CAA section 110(a)(2)(D)(i)(II) as it
applies to visibility, also known as ``prong 4''). Specifically, this
disapproval found that the SIP submittal had not prevented
SO2 emissions from the above-mentioned units from
interfering with measures required to be included in the applicable
implementation plans of other states to protect visibility.
Subsequently, EPA promulgated the aforementioned FIP, to address these
deficiencies.\6\ EPA took no action on Oklahoma's RPGs for WMWA,
pending its evaluation of impacts of out-of-state emission sources.
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    \6\ The final rule noted in 40 CFR 52.1928(c) that the FIP
satisfied these deficiencies.
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    On March 7, 2014, EPA published a document \7\ in the Federal
Register approving Oklahoma's 2013 SIP revision \8\ submitted to
address certain disapproved portions of the Regional Haze SIP related
to the BART determination for two coal-fired units located at American
Electric Power/Public Service Company of Oklahoma's (AEP/PSO's)
Northeastern Power Station in Rogers County, Oklahoma. A separate
document, published simultaneously,\9\ withdrew the EPA-issued FIP as
it relates to the Northeastern Power Station facility. The approved
revision also satisfied the previously disapproved portions of
Oklahoma's Interstate Transport SIP and the Regional Haze SIP's LTS, as
those portions relate to the subject facility. The FIP still applies
(unaltered) to the four affected units at the Muskogee and Sooner
Generating Stations.
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    \7\ See 79 FR 12944.
    \8\ Oklahoma's Proposed Regional Haze Implementation Plan
Revision submitted on March 20, 2013; available in Docket No. EPA-
R06-OAR-2013-0227.
    \9\ See 79 FR 12954.
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    On December 16, 2014, EPA published a proposed action on the final
portion of Oklahoma's 2010 Regional Haze SIP and on regional haze
obligations for Texas.\10\ As mentioned previously, Oklahoma's 2010 SIP
concluded that visibility progress at the WMWA would be limited by the
impact of out-of-state emission sources; and documented that a
significant portion of the visibility impairment at the WMWA results
from emissions generated in Texas.
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    \10\ See 79 FR 74818.
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    Given the magnitude of these interstate impacts, EPA determined
that the Oklahoma and Texas regional haze SIPs were interconnected,
especially considering the relationship between upwind and downwind
states in the reasonable progress and long-term strategy provisions of
the Regional Haze Rule. On January 5, 2016, EPA issued a final action
\11\ for Texas and Oklahoma which:
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    \11\ See 81 FR 295 (January 5, 2016), codified at 40 CFR
52.2302.
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     Disapproved portions of Texas's implementation plan for
regional haze related to the effects of its emissions at the WMWA and
other Class I areas;
     Disapproved a portion of Oklahoma's regional haze SIP
revision, the reasonable progress goals at the

WMWA, and its reasonable progress consultation with Texas; \12\
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    \12\ See 81 FR 313: ``The Regional Haze Rule required that
Oklahoma use the consultation process under 40 CFR 51.308(d)(1)(iv)
in the development of reasonable progress goals in tandem with
Texas. Nevertheless, throughout the consultations, Oklahoma failed
to explicitly request that Texas further investigate whether
reasonable controls were available or that Texas reduce emissions
from these significantly impacting sources to ensure that all
reasonable measures to improve visibility were included in Texas'
long-term strategy and incorporated into Oklahoma's reasonable
progress goals for the Wichita Mountains. This failure resulted in
the development of improper reasonable progress goals for the
Wichita Mountains.''
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     Simultaneously promulgated a FIP for Texas, which required
additional reductions from eight coal-fired electric power plants; and
     Calculated new (numerical) reasonable progress goals at
the WMWA.

EPA's actions did not impose any additional requirements on emission
sources within Oklahoma.
    That rulemaking was challenged, however, and then stayed in its
entirety by the U.S. Court of Appeals for the Fifth Circuit pending
resolution of the litigation; in March 2017, following the submittal of
a request by the EPA for a voluntary remand of the parts of the rule
under challenge, the Fifth Circuit Court of Appeals remanded the rule
in its entirety.\13\
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    \13\ Texas, et al v. EPA, et al, No. 16-60118 (March 22, 2017).
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    EPA has not taken new action with respect to the RPGs for WMWA in
Oklahoma. Ultimately, as discussed elsewhere in this action, whether it
is the State's RPGs established in the 2010 RH SIP or the EPA's revised
RPGs in the January 2016 action that are evaluated, our review of the
State's 2016 progress report indicates that Oklahoma's emission
reductions and measured visibility conditions are on track to meet
those goals.
    As we state in the Regional Haze Rule, the RPGs set by the state
are not enforceable.\14\ The RPGs represent the State's best estimate
of the degree of visibility improvement that will result at the State's
Class I areas from changes in emissions--changes driven by the
particular set of control measures the state has adopted in its
regional haze SIP to address visibility, as well as all other
enforceable measures expected to reduce emissions over the period of
the SIP. Given the forward-looking nature of RPGs and the range of
assumptions that must be made as to emissions a decade or more in the
future, we expect there to be some uncertainty in a given State's
visibility projections.\15\
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    \14\ See 64 FR 35733: ``. . . the reasonable progress goal is a
goal and not a mandatory standard which must be achieved by a
particular date as is the case with the NAAQS. Once a State has
adopted a reasonable progress goal and determined what progress will
be made toward that goal over a 10-year period, the goal itself is
not enforceable. All that is `enforceable' is the set of control
measures which the State has adopted to meet that goal. If the
State's strategies have been implemented but the State has not met
its reasonable progress goal, the State could either: (1) revise its
strategies in the SIP for the next long-term strategy period to meet
its goal, or (2) revise the reasonable progress goals for the next
implementation period. In either case, the State would be required
to base its decisions on appropriate analyses of the statutory
factors included in 40 CFR 51.308(d)(1)(i)(A) and (B) of the final
rule.''
    \15\ See 40 CFR 51.308(d)(1)(v).
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B. Oklahoma's Regional Haze Progress Report

    Each state is required to submit a progress report that evaluates
progress towards the RPGs for each Class I area within the state and
for each Class I area outside the state which may be affected by
emissions from within the state. 40 CFR 51.308(g). In addition, the
provisions of 40 CFR 51.308(h) require states to submit, at the same
time as the progress report, a determination of the adequacy of the
state's existing regional haze implementation plan.\16\ The progress
report for the first planning period is due five years after submittal
of the initial regional haze SIP and must take the form of a SIP
revision. Oklahoma submitted its initial regional haze SIP on February
18, 2010.
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    \16\ The Regional Haze Rule requires states to provide in the
progress report an assessment of whether the current
``implementation plan'' is sufficient to enable the states to meet
all established RPGs under 40 CFR 51.308(g). The term
``implementation plan'' is defined for purposes of the Regional Haze
Rule to mean any SIP, FIP, or Tribal Implementation Plan. As such,
the Agency may consider measures in any issued FIP as well as those
in a state's regional haze plan in assessing the adequacy of the
``existing implementation plan'' under 40 CFR 51.308(g) and (h).
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    On September 28, 2016, Oklahoma submitted its progress report in
the form of a SIP revision under 40 CFR 51.308, which, among other
things, detailed the progress made in the first planning period toward
implementation of the long-term strategy (LTS) outlined in the State's
regional haze plan. The progress report also included the visibility
improvement measured at the WMWA, the only Class I area within
Oklahoma, an assessment of whether Class I areas outside of the State
are potentially impacted by emissions from Oklahoma, and a
determination of the adequacy of the existing implementation plan.

II. EPA's Evaluation of Oklahoma's Progress Report and Adequacy
Determination

A. Regional Haze Progress Report

    The progress report provides an opportunity for public input on the
State's (and the EPA's) assessment of whether the regional haze SIP is
being implemented appropriately and whether reasonable progress is
being achieved consistent with the projected visibility improvement in
the SIP. This section includes EPA's analysis of Oklahoma's 2016
progress report, and an explanation of the basis for the Agency's
proposed approval.
1. Control Measures
    In its progress report, Oklahoma summarizes the status of the
emissions reduction measures that were relied upon by Oklahoma in its
regional haze plan. The major control measures identified by the State
in the progress report are as follows:

 Best Available Retrofit Technology (BART) Controls
 Oklahoma Control Measures from:
    (1) Air Quality Permits
    (2) Prevention of Significant Deterioration
    (3) Compliance and Enforcement
    (4) Mobile Emissions
    (5) Cross-State Air Pollution Regulations
    (6) Other Measures
 Additional Air Pollution Emission Reductions
a. Best Available Retrofit Technology (BART) Controls
    On July 6, 2005, EPA published final amendments to its regional
haze rule, which requires emission sources that fit specific criteria
to install BART controls.\17\ The 2010 regional haze SIP originally
determined that there were twenty facilities \18\ in Oklahoma with
BART-eligible sources.\19\ Oklahoma determined six facilities with a
combined total of thirteen (now twelve \20\) units, were subject-to-
BART \21\

in the 2010 regional haze SIP.\22\ EPA approved Oklahoma's
identification of BART-eligible sources and determination of subject-
to-BART sources in our 2011 final action.\23\
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    \17\ See 70 FR 39103 through 39172 (July 6, 2005).
    \18\ See Table VI-1 of the 2010 regional haze SIP (page 71).
    \19\ BART-eligible sources are those sources that have the
potential to emit 250 tons or more of visibility-impairing
pollutants, were put in place between August 7, 1962 and August 7,
1977, and whose operations fall within one or more of 26
specifically listed source categories.
    \20\ AEP/PSO's Northeastern Power Station closed EGU#4 effective
April 2016.
    \21\ 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. Sources that are reasonably anticipated to cause
or contribute to any visibility impairment in a Class I area are
determined to be subject-to-BART. For each source subject to BART,
40 CFR 51.308(e)(1)(ii)(A) requires that states identify the level
of control representing BART after considering the factors set out
in CAA section 169A(g).
    \22\ See Table VI-4 of the 2010 regional haze SIP (page 73) and
Table 2.1 of the progress report.
    \23\ See 76 FR 81728 (December 28, 2011).
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    Section 2.4 of the progress report provides a discussion of BART
requirements and implementation status. The current BART determinations
for all subject-to-BART units in Oklahoma following the various,
aforementioned series of SIP revisions and FIPs along with their
implementation status, are listed in Table 1 below.

                                                          Table 1--Current BART Determinations
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                                                                          BART emission limits (in lb/MMBtu) \a\
              Facility                        Unit          -----------------------------------------------------------------       BART conditions
                                                                       SO2                  NOX                PM10
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OG&E Muskogee Generating Station...  Unit 4--coal-fired....  0.06 \b\...............            0.15  0.10..................  Meet low NOX emission
                                     Unit 5--coal-fired....                                                                    limits by 1/27/17 via
                                                                                installation of low-NOX
                                                                                burners (LNB) with over-
                                                                                fire air (OFA). Completed
                                                                                installation of LNB for
                                                                                Unit 4 in June 2015; Unit
                                                                                5 in December 2013.
                                                                                Meet lower PM emissions
                                                                                based on existing
                                                                                controls which included
                                                                                electro-static
                                                                                precipitators (ESP).\c\
                                                                                Units 4 and 5 are now
                                                                                planned to be converted
                                                                                over to natural gas in
                                                                                the Fall of 2018.\d\
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OG&E Seminole Generating Station     Unit 1--natural gas-    Natural Gas as primary            0.203  Natural Gas as primary  Meet low NOX emission
 \e\.                                 fired.                  fuel, no additional     ..............   fuel, no additional     limits by 1/27/17 via
                                     Unit 2--natural gas-     control required for             0.212   control required for    installation of LNB with
                                      fired.                  BART.                   ..............   BART.                   OFA and flue gas
                                     Unit 3--natural gas-    .......................           0.164  ......................   recirculation (FGR).
                                      fired.                 .......................                  ......................  Installation was completed
                                                                                on 2 of the 3 units at
                                                                                the time of the progress
                                                                                report SIP submission
                                                                                (approximately May 2016
                                                                                for Unit 1 and December
                                                                                2015 for Unit 2) and the
                                                                                3rd was completed in May
                                                                                2017.\f\
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OG&E Sooner Generating Station.....  Unit 1--coal-fired....  0.06 \b\...............            0.15  0.10..................  Meet low NOX emission
                                     Unit 2--coal-fired....                                                                    limits by 1/27/17 via
                                                                                installation of LNB with
                                                                                OFA Completed
                                                                                installation of the LNB
                                                                                for Unit 1 in March 2014;
                                                                                Unit 2 in April 2013.
                                                                                Meet lower PM emissions
                                                                                based on existing
                                                                                controls which included
                                                                                ESP.\g\
                                                                                Meet lower SO2 emissions
                                                                                via installation of dry
                                                                                gas desulfurization to be
                                                                                installed by 1/4/19 per
                                                                                the FIP.
                                                                                Construction of scrubber
                                                                                currently ongoing for
                                                                                Unit 1. Unit 2 is
                                                                                scheduled to commence in
                                                                                Fall 2018.\h\
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AEP/PSO Comanche Power Station \e\.  Unit 1--natural gas-    Natural Gas as primary             0.15  Natural Gas as primary  Meet low NOX emission
                                      fired.                  fuel, no additional                      fuel, no additional     limits by 1/27/17 via
                                     Unit 2--natural gas-     control required for                     control required for    installation of LNB.
                                      fired.                  BART.                                    BART.                   Installation completed
                                                                                (April 2016).\i\
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AEP/PSO Northeastern Power Station   Unit 2--natural gas-    Natural Gas as primary             0.28  Natural Gas as primary  Meet low NOX emission
 e j.                                 fired.                  fuel, no additional     ..............   fuel, no additional     limits by 1/27/17 via
                                     Unit 3--coal-fired....   control required for              0.15   control required for    installation of LNB with
                                     Unit 4--coal-fired       BART.                   ..............   BART.                   OFA Completed
                                      (Retired as of April   0.40...................  ..............  0.10..................   installation in March
                                      2016)..                                                                                2014.\k\
                                                                                Meet interim NOX and SO2
                                                                                emission limits until 4/
                                                                                16/16 when one of the two
                                                                                units would shut down
                                                                                (Unit 4 shut down on 4/16/
                                                                                16).
                                                                                Remaining unit (#3) must
                                                                                meet lower SO2 and NOX
                                                                                emission limits via
                                                                                installation of LNB with
                                                                                OFA, and further control
                                                                                system tuning.
                                                                                Installation of the LNB
                                                                                was completed in April
                                                                                2012; and modifications
                                                                                to install SO2 controls
                                                                                have not yet begun.\h\
                                                                                Remaining unit (#3) also
                                                                                must incrementally
                                                                                decrease capacity
                                                                                utilization during the
                                                                                period from 2021 to 2026;
                                                                                and completely shut down
                                                                                by 12/31/2026.\l\
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AEP/PSO Southwestern Power Station   Unit 3--natural gas-    Natural Gas as primary             0.45  Natural Gas as primary  Meet low NOX emission
 \e\.                                 fired.                  fuel, so no BART                         fuel, so no BART        limits by 1/27/17 via
                                                              requirement for SO2                      requirement for PM      installation of LNB with
                                                              control systems.                         control systems.        OFA Completed
                                                                                installation in May
                                                                                2014.\m\
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\a\ The facilities are currently operating under the federally-enforceable BART-subject emission limits set forth in 76 FR 81728, December 28, 2011,
  unless otherwise noted.
\b\ EPA disapproved Oklahoma's SO2 BART determinations and issued a FIP covering the BART-subject units at the facility (40 CFR 52.1923 (2015)). Under
  this FIP, each unit must meet lower SO2 emission limits (0.06 lbs/MMBtu Boiler Operation Day) based on installation of emission controls, including
  dry flue gas desulfurization. Due to litigation over EPA's decision, the deadline by which these units are required to meet their new SO2 emission
  limits contained in the FIP is January 4, 2019.
\c\ See page 12 of the progress report SIP.
\d\ See email response from ODEQ dated June 11, 2018 which has been included in docket for this proposed rulemaking: Units 4 and 5 were converted to
  natural gas in February 2017.
\e\ Natural gas units are considered ``grandfathered'' and currently do not have specific emission limits established in the current permit. The BART
  NOX and PM10 emission limits for each of the affected units are based on a 30-day rolling average in accordance with the federally-enforceable BART
  subject emission limits.
\f\ See page 10 of the progress report SIP; and Email response from ODEQ dated June 11, 2018 which has been included in docket for this proposed
  rulemaking.
\g\ See page 11 of the progress report SIP.
\h\ See email response from ODEQ dated June 11, 2018 which has been included in docket for this proposed rulemaking.
\i\ See page 10 of the progress report SIP.
\j\ EPA disapproved Oklahoma's SO2 BART determinations for Units 3 and 4 at the facility and issued a FIP covering these units. Subsequently, DEQ
  developed and submitted, and EPA approved, a revision to the Oklahoma regional haze SIP, which replaced the FIP as it related to EPA's SO2 BART
  requirements for Units 3 and 4, as well as revised Oklahoma's original NOX BART requirements for Units 3 and 4 (79 FR 12954, March 3,2014).
\k\ See page 12 of the progress report SIP.
\l\ See page 13 of the progress report SIP.
\m\ See pages 10-11 of the progress report SIP.

b. Other Oklahoma Control Measures
    In its original 2010 regional haze plan, ODEQ cited various air
quality rules and programs as part of its long-term strategy for
addressing the visibility impairment at WMWA. These efforts include
comprehensive permitting, compliance and enforcement programs, an
emissions inventory system, and a state-wide ambient air monitoring
network.
    The progress report states that ODEQ:
     Operates a robust permitting program that addresses both
major and minor source facilities. Regular inspections are performed so
as to ensure compliance with all permit requirements, applicable
statutes, rules and regulations. Additionally, ODEQ's permitting
program incorporates new source performance standards (NSPS) and
national emission standards for hazardous air pollutants (NESHAP) via
its permitting, compliance, and enforcement programs.
     Addresses visibility impairment for new or modified major
stationary sources via its Prevention of Significant Deterioration
(PSD) Requirements for Attainment Areas permitting process.\24\ The PSD
permitting rules limit the establishment of air pollution sources which
may contribute to visibility impairment and other air pollution
problems.
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    \24\ OAC 252:100, Subchapter 8, Part 7.

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     Addresses violations of its air-related environmental
rules by actively pursuing compliance and enforcement actions as
appropriate in its ongoing efforts to preserve air quality in the state
and surrounding areas. In doing so, these actions also have the added
effect of reducing emissions that contribute to visibility impairment
at WMWA (and other nearby mandatory Class I areas).
     Relies upon federal regulations on new motor vehicles to
limit air pollutant emissions from on-road mobile sources. These
federal standards result in emission reductions of PM, O3
precursors, and non-methane organic compounds. The State anticipates
that based on historical trends, the slow decline in motor-vehicle
emissions are likely to continue in the future.
     Intends to consider any future Cross-State Air Pollution
Rule (CSAPR)-related \25\ reductions and their effects in any
succeeding SIP revision for regional haze. EPA's ongoing updates to
CSAPR to address interstate transport for the 2008 ozone National
Ambient Air Quality Standard (NAAQS) may lead to additional reductions
in emissions that contribute to visibility impairment from sources in
Oklahoma, Texas, and various other upwind states.
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    \25\ CSAPR, as originally promulgated, required 28 eastern
states to reduce power plant emissions that contribute to pollution
from O3 and PM2.5 in other states. The rule
requires reductions in O3 season NOX emissions
that crossed state lines for states under the O3
requirements, and reductions in annual SO2 and
NOX emissions for states under the PM2.5
requirements. To assure emissions reductions, the EPA promulgated
FIPs for each of the states covered by the rule. The EPA set
pollution limits (emission budget) for each state covered by CSAPR.
Allowances are allocated to affected sources based on these state
emission budgets.
---------------------------------------------------------------------------

     Adopted efforts to address controlled and open-burning
practices within the state:
    [cir] In 2013, Oklahoma adopted a voluntary Smoke Management Plan
(SMP) \26\ to address agriculture and forestry smoke.\27\
---------------------------------------------------------------------------

    \26\ See the Oklahoma Smoke Management Plan (February 28, 2013).
Recognizing the benefits of prescribed and wildland fires to forest
management, wildlife management, and agriculture, the SMP was
developed by the Oklahoma Department of Agriculture, Food, and
Forestry (ODAFF) and ODEQ in cooperation with federal and private
stakeholders in an effort to mitigate smoke emissions from
prescribed and wildland fires.
    \27\ 40 CFR 51.308(d)(3)(v)(E) requires Oklahoma to consider
smoke management techniques for the purposes of agricultural and
forestry management.
---------------------------------------------------------------------------

    [cir] ODEQ also revised its open-burning rules,\28\ restricting its
use in certain land-clearing operations for several metropolitan
counties.
---------------------------------------------------------------------------

    \28\ See OAC 252:100-13.
---------------------------------------------------------------------------

    Additionally, the State has made various other updates and
modifications to its air quality rules and regulations, which it
contends will produce indirect benefits for visibility. These include:
     Incorporation by reference of the latest changes and
additions to the federal NSPSs and NESHAPs,
     Updates to minor-facility and major-source permitting
requirements, and
     Updates to OAC 252:100, Subchapter 31, Control of Emission
of Sulfur Compounds.
    Subsequently, since the aforementioned, additional existing control
measures also address some of the same emissions that contribute to
regional haze and visibility impairment at Class I areas, they are
anticipated to have a positive effect on the visibility at WMWA.
c. Additional Air Pollution Reductions
    Nationally, there have been several regulatory and economic
developments which resulted in reduced emissions of visibility
impairing pollutants since the preparation of the initial Oklahoma SIP
revision for regional haze. In the progress report SIP, ODEQ discusses
the anticipated benefit from efforts designed to meet new NAAQS
standards that have been established since the 2010 Regional Haze
submittal. Acknowledging the recent trend towards the use of cleaner
fuels for many industrial operations and particularly for EGUs, ODEQ's
progress report indicates that the resulting lower emissions,
particularly of SO2, would also equate to progress towards
the goal of natural visibility conditions at WMWA. Additionally, ODEQ
cited the potential impacts of ongoing emissions reductions in multiple
pollutants resulting from the EPA's 2013 mercury and air toxics
standards (a.k.a. the ``MATS'' rule), as further contributing to
visibility improvement. ODEQ did not perform any technical analyses to
quantify the visibility benefits of these developments in its progress
report, although it acknowledges that they likely contributed
considerably to observed visibility improvement for the state.
    EPA proposes to find that Oklahoma has adequately addressed the
applicable provisions under 40 CFR 51.308(g) regarding the
implementation status of control measures because the State adequately
described the status of the implementation of all measures included in
the implementation plan for achieving reasonable progress goals for
mandatory Class I Federal areas both within and outside the State.
2. Emissions Reductions
    In its progress report, ODEQ presents emissions data showing
emission trends and reductions due to controls. The State identified
Sulfureous Particulate (sulfate), Nitrate Particulate (nitrate), and
Organic Carbonaceous Particulate (organic carbon (OC)) as the three
largest contributors to visibility impairment at Oklahoma's WMWA Class
I area \29\ for the first implementation period for regional haze. Many
of the sources that produce these visibility-impairing pollutants in
Oklahoma are anthropogenic in nature and are controllable. In 2002,
point sources emitted 87.5 percent of Oklahoma SO2 emissions
and 31.6 percent of Oklahoma NOX emissions.\30\ Emissions
from Oklahoma sources contributed to 13.25 percent of the overall
visibility impairment \31\ in Oklahoma's WMWA Class I area. EGUs
accounted for 65 percent of the total Oklahoma SO2 emissions
\32\ and 17 percent of the total Oklahoma NOX emissions.\33\
---------------------------------------------------------------------------

    \29\ See Table 5-1 from the progress report SIP (September 2016)
and Table V-8 of the Regional Haze State Implementation Plan
(February 2010).
    \30\ See Table IV-1 of the Regional Haze State Implementation
Plan (February 2010).
    \31\ See Table V-7 of the Regional Haze State Implementation
Plan (February 2010).
    \32\ See Table IV-3 of the Regional Haze State Implementation
Plan (February 2010).
    \33\ See Table IV-5 of the Regional Haze State Implementation
Plan (February 2010).
---------------------------------------------------------------------------

    As part of the emission data submitted by the State, the State
reported point source emission data for NOX and
SO2 for the 2002 baseline year and 2011 (the latest official
National Emissions Inventory (NEI)-Oklahoma emissions inventory data
available at the time the progress report was submitted).\34\ The data
presented does not reflect any emission reductions from BART-eligible
sources due to BART limits, since the six required sources in question
had yet to install their respective BART control measures (see Table 1
above). Additionally, the State provided projected emissions data for
2018. Overall point source emissions of NOX increased
slightly from 2002 to 2011, while SO2 point source emissions
decreased by approximately 30,000 tons per year over the same period.
EPA reviewed additional, more recent EGU emissions data and, even
without emission reductions from all BART limits, the available EGU
emissions data through 2017 show large reductions from the 2002
baseline.
---------------------------------------------------------------------------

    \34\ See Table 5-2 in the Oklahoma progress report (page 20).
---------------------------------------------------------------------------

    Table 2 below, provided by the EPA to evaluate EGU emissions post-
2011, shows that NOX and SO2 EGU point source
emissions have decreased during the 2011 to 2017 time-period. In 2017,
the SO2 emissions were 50,270 tpy lower than the 2011 annual
levels while

NOX emissions were 56,786 tpy lower. These results represent
an additional 54 percent reduction in SO2 emissions and 73
percent reduction in NOX emissions from EGUs since 2011.
Overall, from the 2002 baseline year, EGU SO2 emissions have
reduced by 60 percent and EGU NOX emissions have reduced by
75 percent.

                   Table 2--Annual NOX and SO2 Emissions From EGU Point Sources in Oklahoma *
----------------------------------------------------------------------------------------------------------------
                                                                                NOX Emission    SO2 Emission
              Year                  NOX (tons)      SO2 (tons)      Heat input       rate (lb/       rate (lb/
                                                                      (MMBtu)         MMBtu)          MMBtu)
----------------------------------------------------------------------------------------------------------------
2002............................          85,999         106,318     553,566,474           0.311           0.384
2003............................          86,502         109,803     574,470,072           0.301           0.382
2004............................          78,217         100,098     558,112,281           0.280           0.359
2005............................          85,019         103,985     606,763,914           0.280           0.343
2006............................          82,810         106,091     620,400,705           0.267           0.342
2007............................          76,529         100,111     622,537,676           0.246           0.322
2008............................          79,989         101,320     647,315,009           0.247           0.313
2009............................          73,357          95,307     626,058,610           0.234           0.304
2010............................          71,439          85,135     603,295,697           0.237           0.282
2011............................          77,983          92,351     628,579,599           0.248           0.294
2012............................          64,338          77,128     619,284,535           0.208           0.249
2013............................          49,178          74,632     558,628,131           0.176           0.267
2014............................          37,562          72,855     519,423,413           0.145           0.281
2015............................          28,097          61,971     531,490,156           0.106           0.233
2016............................          24,895          49,485     502,603,800           0.099           0.197
2017............................          21,197          42,081     430,070,391           0.099           0.196
----------------------------------------------------------------------------------------------------------------
* Source: U.S. EPA Clean Air Market Division www.epa.gov/airmarkt/.

    A more-detailed breakdown of the distribution of emission trends
for each contributing pollutant species from all sources can be seen in
Section 4. Emission Tracking, of this proposed action.
    The EPA's NEI total point source data for Oklahoma in Table 3 shows
that reported PM emissions remained relatively consistent from their
NEI baseline totals for the first implementation period. Total 2014
NOX and SO2 point sources emissions are lower
than the 2002 baseline emission levels.

                  Table 3--NEI Total Point Source Emission Data for Oklahoma for 2002-2014 \a\
----------------------------------------------------------------------------------------------------------------
                                                                                PM2.5 (tpy)
                    Year \b\                         NOX (tpy)       SO2 (tpy)                      PM10 (tpy)
----------------------------------------------------------------------------------------------------------------
2002............................................         163,417         150,388           7,106          12,744
2005............................................         100,681         113,344           3,551           7,044
2008............................................         142,157         137,047           6,638          14,390
2011............................................         161,396         118,921           7,557          13,736
2014............................................         122,346         102,524           6,764          11,225
----------------------------------------------------------------------------------------------------------------
a As reported in the online EPA Emissions Inventory System (EIS) Gateway database for point sources only.
b Comprehensive NEI data is generated every three years.

    In addition to the above reductions, ODEQ's progress report
mentions that it anticipates some additional future reductions in
SO2 and NOX emissions due to more stringent CSAPR
budgets that apply to EGUs in Texas and most eastern states.\35\ These
emissions contribute to or are precursors for the formation of
sulfurous and nitrate PM, which together comprise the majority of haze
affecting the WMWA. Also, as mentioned earlier, BART controls at
Oklahoma-based EGUs (OG&E's Muskogee and Sooner plants had until
January 2019 to complete their installation of BART controls per the
recent FIP) are also expected to result in further haze-forming
emissions reductions from within the State.
---------------------------------------------------------------------------

    \35\ Since the submission of Oklahoma's Progress Report, the
CSAPR SO2 budget for Texas has been replaced by the Texas
Intrastate Regional Haze Bart-alternative SO2 trading
program--EPA finalized its determination that the intrastate trading
program is an appropriate SO2 BART alternative for EGUs
in Texas (see 82 FR 48324 October 17, 2017 and 83 FR 43586, August
27, 2018). Any additional future reductions in SO2
attributed to Texas would be the result of said trading program.
---------------------------------------------------------------------------

    The EPA proposes to conclude that the State adequately addressed
the requirements under 40 CFR 51.308(g) with its summary of emission
reductions of visibility-impairing pollutants. Overall, the State
demonstrated the emission reductions achieved for visibility-impairing
pollutants in the State for the first implementation period. Emissions
of SO2, NOX, and PM, the main contributors to
regional haze in Oklahoma, have all been decreasing. Even before
additional BART limits and lower CSAPR budgets have been fully
implemented, the SO2 and NOX haze pollutant
precursors from EGU point sources in the State have decreased from the
baseline levels in 2002. In addition, with the promulgation of the
CSAPR Update in September of 2016, which included Oklahoma and Texas
EGUs within the ozone-season NOX budget trading program and
applied in 20 other eastern states, reduced NOX emissions
were required beginning in the 2017 ozone season.\36\
---------------------------------------------------------------------------

    \36\ See 81 FR 74506 (October 26, 2016).
---------------------------------------------------------------------------

3. Visibility Conditions
    In their progress report, ODEQ provides information on visibility
conditions for the Class I area within Oklahoma's borders. The progress
report addressed current visibility conditions,

the difference between current visibility conditions and baseline
visibility conditions (expressed in terms of five-year averaged of
these annual values, with values for the haziest (i.e., most impaired),
and clearest (i.e., least impaired) days), and the change in visibility
impairment.
    Oklahoma's progress report provides figures with visibility
monitoring data for WMWA. Additionally, EPA has obtained and examined
visibility data for more recent five-year time periods from the IMPROVE
network's monitoring data. Table 4, below, shows the visibility
conditions from 2002-16, compared to the natural/baseline visibility
conditions in deciviews (dv).

                  Table 4--IMPROVE Visibility Trends for the Wichita Mountains WIMO1 Monitor *
----------------------------------------------------------------------------------------------------------------
                                                                                Natural
                                                  Annual average      Natural     Annual average  condition haze
                      Year                          haze index,   condition haze    haze index,       index,
                                                   haziest days   index, haziest   clearest days   clearest days
                                                       (dv)          days (dv)         (dv)            (dv)
----------------------------------------------------------------------------------------------------------------
2002............................................            23.6  ..............             9.8  ..............
2003............................................            23.6  ..............              10  ..............
2004............................................            24.2  ..............             9.6  ..............
2005............................................            25.7             7.5            10.6               3
2006............................................            21.8  ..............             9.7  ..............
2007............................................            22.8  ..............             9.3  ..............
2008............................................            21.6  ..............             9.8  ..............
2010............................................            21.8  ..............             9.2  ..............
2011............................................            22.9  ..............            10.3  ..............
2012............................................            20.2  ..............             8.9  ..............
2013............................................            20.3  ..............             8.4  ..............
2014............................................            21.2  ..............             9.3  ..............
2015............................................            18.8  ..............             8.5  ..............
2016............................................            17.2  ..............             8.1  ..............
----------------------------------------------------------------------------------------------------------------
* See the IMPROVE Visibility Trend Charts for the Wichita Mountains WIMO1 monitor: http://vista.cira.colostate.edu/Improve/aqrv-summaries/.

    Although visibility conditions have varied from year to year, Table
6-8 of the progress report shows that WMWA has displayed an overall
improvement in visibility since 2001. At the time the progress report
was produced, WMWA showed improved visibility when comparing the 2000
to 2004 baseline period to the 2009 to 2013 visibility period (the most
recent five-year average presented in ODEQ's progress report) during
the most impaired days of the first implementation period. The progress
report's most recent five-year average of 21.25 dv \37\ shows that as
of 2013, WMWA met the 2010 regional haze SIP RPGs for the twenty
percent most impaired days.\38\ The WMWA Class I area also showed
improvement from the 2000 to 2004 baseline on the twenty percent least
impaired days for the first implementation period. Visibility
conditions at WMWA had improved nearly enough to meet the RPG for 2018
for the best quintile of days,\39\ with a five-year average of 9.25
dv.\40\
---------------------------------------------------------------------------

    \37\ See Table 6-8 on pages 27-28 of the progress report.
    \38\ In the 2010 Regional Haze SIP, WMWA had a visibility
impairment reduction goal of 2.33 dv (See Table IX-3, pg. 107) to
reach a RPG of 21.47 dv by 2018 for ``worst days'' (See Table IX-4,
pg. 109).
    \39\ In the 2010 Regional Haze SIP, WMWA had a RPG of 9.23 dv by
2018 for ``best days'' (page 104). See Table 6-8 (pages 27-28) and
the chart on page 29 of the progress report.
    \40\ See Table 6-8 on pages 27-28 of the progress report.
---------------------------------------------------------------------------

    That being said, the 2010 Regional Haze SIP RPGs for the twenty
percent least impaired and most impaired days for WMWA were disapproved
as part of the previously mentioned, EPA FIP of January 2016 and
replaced with revised RPGs developed by EPA. Though the FIP was stayed
at the time the State submitted the progress report SIP, the State
included these revised RPGs (for 2018 standards) of 9.22 dv and 21.33
dv for best and worst quintiles, respectively, in its progress report.
When comparing the 2018 RPGs calculated by EPA in its final action with
the observed five-year visibility trends reported in the State's
progress report, WMWA has exceeded the visibility improvements needed
to meet the goal for the worst quintile days; and was close to meeting
the goal for the best quintile days (9.25 versus 9.22 dv) as of 2013.
    IMPROVE's data from 2001-16 demonstrates that visibility for the
haziest/worst days at the Wichita Mountains monitoring site has been
improving at a rate of 0.41 dv/year.\41\ The average visibility for
WMWA on the worst days has been below the 2018 RPGs calculated by EPA
since the 2009-14 five-year period, as seen in Table 5. Most recently,
the 2012-16 period showed the visibility at the Wichita Mountains to be
19.54 dv, 1.79 dv below the EPA calculated 2018 RPGs. We note that the
visibility conditions needed to meet the uniform rate of progress for
2018 is 20.01 dv for the twenty percent most impaired days.
---------------------------------------------------------------------------

    \41\ Source: IMPROVE Visibility Trend monitoring data for
Wichita Mountains: http://vista.cira.colostate.edu/Improve/aqrv-summaries/.

                                                      Table 5--Visibility Conditions at WMWA Class I Area for the Twenty Percent Worst Days
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Most recently
                                                  Baseline (2000-   (2007-2011)     (2008-2012)     (2009-2013)     (2010-2014)     (2011-2015)     (2012-2016)      2018 FIP-    available data
                  Class I area                      2004) (dv)       \a\ (dv)        \a\ (dv)        \a\ (dv)        \b\ (dv)        \b\ (dv)        \b\ (dv)      revised RPGs     v. baseline
                                                                                (dv)          data (dv)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Wichita Mountains Wilderness Area...............           23.83           22.26           21.61           21.25           21.28           20.68           19.54           21.33            -2.5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
a 4-yr average b/c there was no available data for 2009.
b Source: IMPROVE Visibility Trend monitoring data for Wichita Mountains.

    IMPROVE's clearest/best days monitoring data from 2001 to 2016
indicates that the haze index values at the WMWA monitor has been
declining at a rate of 0.12 dv/year.\42\ The average visibility for
WMWA on the clearest of days has been below the 2018 RPGs calculated by
EPA since the 2010 to 2015 five-year period as seen in Table 6. Most
recently, the 2012 to 2016 period showed the best days' visibility at
the Wichita Mountains to be 0.58 dv below the 2018 RPGs.
---------------------------------------------------------------------------

    \42\ Source: IMPROVE Visibility Trend monitoring data for
Wichita Mountains: http://vista.cira.colostate.edu/Improve/aqrv-summaries/.

                                                      Table 6--Visibility Conditions at WMWA Class I Area for the Twenty Percent Best Days
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Most recently
                                                  Baseline (2000-   (2007-2011)     (2008-2012)     (2009-2013)     (2010-2014)     (2011-2015)     (2012-2016)      2018 FIP-    available data
                  Class I area                      2004) (dv)       \a\ (dv)        \a\ (dv)        \a\ (dv)        \b\ (dv)        \b\ (dv)        \b\ (dv)      revised RPGs     v. baseline
                                                                                (dv)          data (dv)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Wichita Mountains Wilderness Area...............            9.92            9.80            9.65            9.25            9.22            9.08            8.64            9.22           -1.28
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
a 4-yr average b/c there was no available data for 2009.
b Source: IMPROVE Visibility Trend monitoring data for Wichita Mountains.

    EPA proposes to conclude that Oklahoma has adequately addressed the
applicable provisions under 40 CFR 51.308(g) regarding assessment of
visibility conditions because the State provided baseline visibility
conditions (2000 to 2004), current conditions based on the most
recently available visibility monitoring data available at the time of
progress report development, the difference between these current sets
of visibility conditions and baseline visibility conditions, and the
change in visibility impairment from 2009-13. The WMWA has shown
improved visibility for the most impaired and least impaired days since
2001 and is projected to continue to improve with additional future
emission reductions due to BART and other measures.
4. Emissions Tracking
    In its progress report SIP, the State presents NEI emission
inventories for the 2002 baseline year and 2011, as well as projected
inventories for 2018.\43\ The pollutants inventoried include
SO2, NOX, NH3, VOC, PM2.5
(i.e., fine particulates), and PM10-PM2.5 (i.e.,
coarse particulates). The inventories were categorized for all major
visibility-impairing pollutants under biogenic and major anthropogenic
source groupings. The anthropogenic source categorization included on
and non-road mobile sources; point sources; and area sources. The 2011
NEI inventory was the latest comprehensive inventory available at the
time the State prepared its progress report SIP revision in 2016.
---------------------------------------------------------------------------

    \43\ Emission development and air quality modeling were
performed by the Central Regional Air Planning Association (CENRAP)
in support of SIP development in the central states region for 2002
and projected 2018 emissions.
---------------------------------------------------------------------------

    Reductions in emissions from the baseline year to 2011 occurred in
every pollutant with the exception of VOCs and coarse particulates,
which increased by 16 percent and 79 percent respectively. The dramatic
increase in coarse particulates can be attributed to drought conditions
which developed in late 2010 and intensified in 2011 for the WMWA. The
three-month period of June through August of 2011 ranked as the
``hottest [summer] ever recorded in any state.'' \44\ ODEQ asserts that
the dry conditions and intense heat resulted in an increase in coarse
PM from the resulting dust storms.\45\ Total NOX and
SO2 emissions were reduced by 54,211 and 46,372 tpy, with
the largest reductions of NOX being realized from the on-
road and non-road mobile sources categories; and two thirds of the
SO2 reductions attributed to point sources. \46\
---------------------------------------------------------------------------

    \44\ See page 18, Section 4.4 of the progress report.
    \45\ Ibid.
    \46\ See Table 5-2 (page 20) of the progress report.
---------------------------------------------------------------------------

    For comparison purposes, EPA provides additional 2008 and 2014 NEI
data.\47\ A breakdown of the total emissions for the state can be seen
below in Table 7.
---------------------------------------------------------------------------

    \47\ As reported in the online EPA Emissions Inventory System
(EIS) Gateway database for total state emissions.

                     Table 7--Comparison of Total State Emissions to CENRAP 2018 Projections
----------------------------------------------------------------------------------------------------------------
                                    2002 State
                                     reported     2008 NEI total  2011 NEI total  2014 NEI total    CENRAP 2018
        Pollutant species            baseline        emissions       emissions       emissions      projections
                                     emissions        (tpy) *          (tpy)          (tpy) *          (tpy)
                                       (tpy)
----------------------------------------------------------------------------------------------------------------
SO2.............................         170,021         148,710         123,649         109,210         119,776
NOX.............................         502,122         463,951         447,911         385,782         369,248
NH3.............................         143,179         112,650         112,230         112,863         182,605
VOCs............................       1,375,653       1,356,355       1,600,734       1,505,886       1,581,788
PM2.5...........................         124,954         168,554         103,638         133,381         142,252
PM10............................         438,852         809,223         666,672         488,258         429,945
----------------------------------------------------------------------------------------------------------------
* Provided by the EPA from the EIS gateway database

    In its 2010 Regional Haze SIP, ODEQ determined that the primary
visibility-impairing pollutants in Oklahoma include SO2,
NOX, and PM (both PM10 and 2.5).
Oklahoma provides in its progress report SIP a comparison of the
inventories for all potential visibility-impairing pollutants for 2002
(the baseline year), recent NEI data for 2011, and CENRAP-projected
data for 2018.\48\ This span is sufficiently representative of emission
levels for the purpose of EPA's review of the progress report. A
comparison of the data for these years shows that total state emissions
have decreased for all of the visibility-impairing pollutants except
for VOCs and PM10, which had slight to modest increases (14%
and 34%) over 2008, respectively. VOC emissions increased by 225,081
tpy since 2002, but CENRAP

modeling has demonstrated that anthropogenic VOCs do not significantly
impair visibility at WMWA. Total PM10 levels appear to have
spiked briefly after 2002 and then began to steadily decline. More
recently available 2014 NEI data shows that, other than PM10
levels, the emissions inventory for all pollutants is currently below
the CENRAP 2018 Projections. Despite not already having met the 2018
projections, Oklahoma's PM10 emissions declined nearly 40
percent from 2008 levels.
---------------------------------------------------------------------------

    \48\ Page 20 of the progress report.
---------------------------------------------------------------------------

    The projected 2018 CENRAP data also showed that there is an
anticipated overall downward trend in SO2, and
NOX. The decrease in SO2 is especially noteworthy
as sulfurous emissions contribute the most to visibility impairment at
WMWA. (Nitrate particulate matter forms from NOX emissions
but occurs predominantly during the winter months; whereas sulfurous
aerosol comprises the plurality during the rest of the year.) \49\
---------------------------------------------------------------------------

    \49\ Page 66 of the 2010 Regional Haze SIP.
---------------------------------------------------------------------------

    Because of the limiting role of NOX and SO2
on PM2.5-formation, and the uncertainties in assessing the
effect of NH3 emission reductions on visibility, Oklahoma
does not consider ammonia among the visibility-impairing
pollutants.\50\
---------------------------------------------------------------------------

    \50\ Page 69 of the 2010 Regional Haze SIP. EPA agreed with
Oklahoma's decision to exclude ammonia in our December 2011 final
rile. 76 FR 81727, 81754 (December 28, 2011).
---------------------------------------------------------------------------

    When considered as a whole, the above indicates that the main
precursors that cause the formation of haze and visibility impairment
in Oklahoma are being reduced.
    Table 8 below shows the inventoried categories that were the
driving factors behind the total emission trends. Nearly every category
across the inventory showed emission decreases for each pollutant. The
total emissions change for each pollutant, except NH3 and
VOCs, showed a reduction from 2008 to 2014. The trends were consistent
with the emission trends shown in section II, A, 2 of this proposed
action, which also showed the latest updates for EGUs.

                                 Table 8--2014 Emission Data (tpy) and the Category Changes Since 2008 for Oklahoma \*\
--------------------------------------------------------------------------------------------------------------------------------------------------------
           Category                   NOX                SO2                PM10              PM2.5               NH3                     VOC
--------------------------------------------------------------------------------------------------------------------------------------------------------
Agricultural/Biogenic........  37,854...........  0................  199,471..........  38,845...........  95,232...........  1,041,372
                               (-5,637).........                     (+32,530)........  (+5,457).........  (-2,142).........  (+180,237)
Area/Non-point...............  138,795..........  1,759............  421,375..........  79,251...........  100,409..........  1,283,217
                               (-8,375).........  (-2,976).........  (-305,703).......  (-23,170)........  (+2,166).........  (+173,338)
Fires........................  9,707............  4,362............  56,858...........  47,146...........  11,798...........  111,238
                               (-1,661).........  (-901)...........  (-4,145).........  (-4,819).........  (+2,633).........  (-21,782)
Fugitive Dust................  0................  0................  20,292...........  2,029............  0................  0
                                                                     (-11,924)........  (-1,193).........
Road Dust....................  0................  0................  175,729..........  19,815...........  0................  0
                                                                     (-329,400).......  (-33,262)........
Non-road Mobile..............  20,462...........  44...............  2,004............  1,912............  31...............  20,885
                               (-7,180).........  (-472)...........  (-703)...........  (-677)...........  (+2).............  (-10,011)
On-road Mobile...............  92,071...........  450..............  4,986............  2,834............  1,600............  42,735
                               (-43,267)........  (-757)...........  (-661)...........  (-1,519).........  (-555)...........  (-14,225)
Point Sources................  126,000..........  102,846..........  11,486...........  8,361............  3,292............  50,777
                               (-17,071)........  (-34,270)........  (-3,056).........  (-619)...........  (+233)...........  (+23,871)
                              --------------------------------------------------------------------------------------------------------------------------
    Total Emission Change....  -83,191..........  -39,376..........  -623,062.........  -59,802..........  +2,337...........  +331,428
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The numbers in parentheses indicate an increase (+) or decrease (-) in emissions from 2008.
* As reported in the online EPA Emissions Inventory System (EIS) Gateway database.

    EPA is proposing to find that the State adequately addressed the
provisions of 40 CFR 51.308(g) regarding emissions tracking because the
State compared the most recent updated emission inventory data for the
key visibility impairing pollutants across Oklahoma available at the
time of progress report development with the baseline emissions used in
the modeling for the regional haze plan. The results showed that the
emissions from SO2, NOX, and PM, the main
contributors of regional haze in Oklahoma, have all been decreasing
since 2008. The State's analysis relied on the latest emissions data
available to them at the time (2002 to 2011); \51\ and the EPA provided
additional updates for 2008 and 2014.
---------------------------------------------------------------------------

    \51\ While ideally the five-year period to be analyzed for
emission inventory changes is defined as the time period since the
current regional haze SIP was submitted, there is an inevitable time
lag in developing and reporting complete emissions inventories once
quality-assured emissions data becomes available.
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5. Assessment of Changes Impeding Visibility Progress
    Oklahoma also provided an assessment of any significant changes in
anthropogenic emissions within or outside the State that could limit or
impede reasonable progress. Data presented in the State's progress
report \52\ indicates that there were no significant changes in
anthropogenic emissions that have limited or impeded progress in
reducing pollutant emissions and improving visibility. Visibility
Conditions as the WMWA Class I area demonstrated overall downward
trends in Haze Index values for both its best (i.e., ``clearest'') and
worst (i.e., ``haziest'') days. EPA proposes to agree with Oklahoma's
conclusion that there have been no significant changes in emissions of
visibility-impairing pollutants which have limited or impeded progress
in reducing emissions and improving visibility in Class I areas
impacted by the State's sources. Although Oklahoma continues to
experience visibility impacts from sources outside the State that
affect the WMWA Class I area,\53\ this progress report demonstrates
that, the State remains on track to meet both its original and the EPA-
determined 2018 RPGs for the Class I area in Oklahoma. EPA is not
evaluating at this time whether existing trends in emissions are
sufficient, or could impede or limit progress, with respect to any
future RPGs for subsequent planning periods for Class I areas in
Oklahoma.
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    \52\ See page 20 of the progress report.
    \53\ Oklahoma's initial SIP Revision for Regional Haze
documented that the majority of visibility impairment at the Wichita
Mountains results from emissions generated in Texas. EPA's
examination and review of Oklahoma's reasonable progress
consultation with Texas determined that additional emissions
reductions from Texas were necessary to address visibility
impairment at WMWA for the first implementation period ending in
2018, and issued a FIP for Texas to that effect, requiring
additional emissions reductions from eight coal-fired electric power
plants (See 81 FR 295). This action was subsequently stayed and
later remanded.

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6. Assessment of Current Strategy
    The State concludes that it is on track to meet the 2018 RPGs for
the WMWA based on the trends in visibility and emissions presented in
its progress report. In its progress report SIP submittal, the State
assesses the 2010 SIP elements and strategies and determines that,
based upon emission trends and monitor data, they were sufficient to
enable Oklahoma to meet all the originally established RPGs.\54\ The
state notes that the visibility at the WMWA has improved sufficiently
to meet the originally established RPGs for 2018 during 2009-2013 for
the 20% worst days and they anticipate further improvement in
visibility as additional emission reductions occur due to
implementation of BART controls.
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    \54\ Note that states don't necessarily need to refer to
specific RPGs to meet the requirements of 51.308(g)(6). If they're
currently achieving more reductions than they anticipated when they
developed their SIP, this demonstrates that they're on track to
ensure RP in class I areas.
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    The evaluation set forth by the State also shows that it is meeting
the revised RPGs that EPA calculated in its currently stayed January
2016 FIP action for Texas and Oklahoma.\55\ In its progress report,
Oklahoma shows it was achieving greater visibility improvements than
the EPA-calculated RPGs at WMWA for the worst quintile of days.\56\
Based on more recently available monitored data, the State has also
reached its 2018 goals for the best quintile days as well. We note that
the recent monitored data showing visibility improvements at WMWA also
meet the uniform rate of progress for 2018 of 20.01 dv for the twenty
percent most impaired days.
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    \55\ On March 18, 2016, Texas filed a request for a stay of the
FIP. On July 15, 2016, the court issued a stay of the FIP, including
the emission control requirements. ODEQ notes that the RPG at WMWA
presumably depends on the outcome of this litigation.
    \56\ See Table 6-8 on pages 27 to 28 of the progress report SIP.
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    EPA proposes to find that Oklahoma has adequately addressed the
provisions of 40 CFR 51.308(g) regarding the strategy assessment. In
its progress report SIP, Oklahoma describes the improving visibility
trends using data from the IMPROVE network and the downward emissions
trends in NOX and SO2 emissions in the State.
These trends support the State's determination that its regional haze
plan is sufficient to meet the 2018 RPGs for Class I areas within the
State. Oklahoma also notes that additional improvement in visibility
conditions are anticipated in the future after installation of all
controls required to meet BART (see Table 1).
    EPA's modeling data used to develop the previously mentioned FIP
and SIP revisions for Oklahoma's subject-to-BART EGU sources, also
demonstrated that the potential visibility impacts for Class I areas
outside the state would be significantly reduced by implementation of
the associated revised BART controls/limits.\57\
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    \57\ See Comments on Modeling section, 76 FR 81738-81739
(December 28, 2011).
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    With regards to the effect of Oklahoma's emissions on other states
with Class I areas, Oklahoma acknowledges the possible impact of its
sources on Arkansas' Class I areas, Caney Creek and Upper Buffalo
Wilderness Areas, but concludes that the impact on visibility
conditions in those areas is negligible.\58\ ODEQ could not identify
any emissions from within the State that either prevented or inhibited
reasonable progress at Class I areas outside the State, nor had they
(ODEQ) been contacted any other state to assert such an interstate-
transport impact.
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    \58\ ODEQ noted in its progress report SIP revision (on page 30)
that, ``Although it is rare that emissions from Oklahoma impact the
Caney Creek and Upper Buffalo Wilderness Areas in Arkansas due to
the location of large pollutant emitting sources in Oklahoma
combined with the prevailing wind direction and topographical setup
along the Oklahoma/Arkansas border, DEQ will continue to surveil
these and other necessary Class I areas in other states.''
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    In support of this assertion, we submit that Arkansas' Class I
areas have seen marked improvement in visibility since the start of
regional haze monitoring. Based on Arkansas' respective IMPROVE data,
the haze index for the 20 percent worst days of visibility at both the
Caney Creek and Upper Buffalo Wilderness Areas have been steadily
improving as a result of reduced emissions within Arkansas and because
of broader industrial and energy trends in other states. EPA's review
of recent monitoring data \59\ from Arkansas' Class I areas indicates
that both Caney Creek and Upper Buffalo are well on track for
demonstrating improved visibility for the most impaired and least
impaired days since 2001.\60\ Based on the five-year rolling averages,
both wilderness areas are not only on schedule but have also
outperformed their stricter revised 2018 RPGs for the twenty percent
worst days \61\ (22.47 and 22.51 dv; See Table 9).
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    \59\ See RPG Calculation Data Sheets, sip-rev-rpg-calcs.xlsx and
visibility-progress.xlsx provided at https://www.adeq.state.ar.us/air/planning/sip/regional-haze.aspx.
    \60\ See figures 2 to 9 and tables 5 to 8 (pages 28 to 39) of
the Arkansas Regional Haze SO2 and PM SIP revision.
    \61\ See page 54 of the Arkansas Regional Haze SO2
and PM SIP revision.

                                 Table 9--Visibility Conditions at Arkansas Class I Areas for Twenty Percent Worst Days
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Baseline (2000-
                      Class I area                          2004) (dv)      (2007-2011)     (2008-2012)     (2009-2013)     (2010-2014)    2018 Revised
                                                                               (dv)            (dv)            (dv)            (dv)          RPGs (dv)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Caney Creek Wilderness..................................           26.36           22.99           22.69           22.23           21.83           22.47
Upper Buffalo Wilderness................................           26.27           24.15           22.99           22.16           21.63           22.51
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on the above, the State's assertion that sources in Oklahoma
are not interfering with the achievement of any other neighboring
state's RPGs for their respective Class I areas for the first planning
period appears valid.\62\
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    \62\ In its 2011 SIP submittal, see 76 FR 64186 at 64196
(October 17, 2011), Arkansas concluded that the impact from Oklahoma
sources (among other states) was non-impactful: ``ADEQ determined
that additional emissions reductions from other States are not
necessary to address visibility impairment at Caney Creek and the
Upper Buffalo for the first implementation period ending in 2018,
and all states participating in its consultations agreed with
this.''
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    EPA is proposing to approve Oklahoma's finding that the elements
and strategies in its implementation plan are sufficient to achieve the
RPGs for the WMWA Class I area in the State and for any Class I areas
in nearby states potentially impacted by sources in the State.
7. Review of Current Monitoring Strategy
    The monitoring strategy for regional haze in Oklahoma relies upon
participation in the Interagency Monitoring of Protected Visual
Environments (IMPROVE) regional haze monitoring network. IMPROVE
provides

a long-term record for tracking visibility improvement or degradation.
Oklahoma currently relies on data collected through the IMPROVE network
to satisfy the regional haze monitoring requirement as specified in 40
CFR 51.308(d)(4) of the Regional Haze Rule. In its progress report SIP,
Oklahoma summarizes the existing IMPROVE monitoring network and its
intended continued reliance on it for future visibility planning.
Measurements at the Wichita Mountains monitoring site began in March
2001 and were compiled via the IMPROVE ``WIMO1'' monitor.\63\ The
IMPROVE program makes data available on the internet and submits it to
EPA's air quality system. For the progress report, Oklahoma evaluates
its use of the IMPROVE monitoring network and found it to be
satisfactory.
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    \63\ Wichita Mountains Wildlife Refuge personnel operate and
maintain the IMPROVE particulate sampler and are responsible for
disseminating and submitting the collected data (See Oklahoma's
initial regional haze SIP revision, pg. 8.).
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    Oklahoma reaffirmed its continued reliance upon the IMPROVE
monitoring network. Oklahoma also explained the importance of the
IMPROVE monitoring network for tracking visibility trends at its Class
I area and identified that it did not anticipate any changes to its
reliance on the network for visibility assessments. EPA proposes to
find that Oklahoma has adequately addressed the applicable provisions
of 40 CFR 51.308(g) regarding monitoring strategy because the State
reviewed its visibility monitoring strategy and determined that no
further modifications to the strategy are necessary.

B. Determination of Adequacy of the Existing Implementation Plan

    In its progress report SIP, Oklahoma submits a negative declaration
to EPA regarding the need for additional actions or emissions
reductions in Oklahoma beyond those already in place and those to be
implemented by 2018 according to Oklahoma's regional haze plan.
Oklahoma determined that the current version of its regional haze plan
requires no further substantive revision at this time to achieve the
2018 RPGs for Class I areas affected by the State's sources. The basis
for the State's declaration is the findings from the progress report
SIP which conclude that the control measures in Oklahoma's regional
haze plan are on track to meet their implementation schedules and the
reduction of SO2, NOX and PM emissions from
subject to BART EGUs in Oklahoma continues to be the appropriate
strategy for improvement of visibility in Oklahoma's WMWA Class I area.
Additional improvements in visibility are expected to continue, as at
the time of submission for the progress report, the major emitting
facilities in Oklahoma had not yet installed their respective BART
controls.
    Review of more recent emissions and visibility data shows that EGU
SO2 and NOX emissions dropped from 2002 to 2017
by 64,802 and 64,237 tons, respectively; and the actual change in
visibility observed/reported via its IMPROVE monitor through 2016 for
the WMWA Class I area is better \64\ than what the State predicted for
2016 and is currently exceeding the uniform rate of progress.\65\ EPA
proposes to conclude that Oklahoma has adequately addressed 40 CFR
51.308(h) because the visibility trends at the WMWA Class I area and at
Class I areas outside the State potentially impacted by sources within
Oklahoma and the emissions trends of the largest emitters of
visibility-impairing pollutants in the State indicate that the relevant
RPGs will be met; and support the State's determination of the adequacy
of its SIP.
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    \64\ AQRV Summary data for the WIMO 1 monitor at WMWA indicates
that the 2017 observed visibility was 17.23 dv--4.1 dv lower than
the FIP-revised 2018 RPG for the haziest of days.
    \65\ See the Visibility Impairment Projections graph on page 29
of the progress report SIP.
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C. Consultation With Federal Land Managers

    In accordance with 40 CFR 51.308(i), the state must provide the
FLMs with an opportunity for consultation, at least 60 days prior to
holding any public hearings on an implementation plan (or plan
revision). The state must also include a description of how it
addressed any comments provided by the FLMs. ODEQ shared its draft
progress report with the FLMs on April 11, 2016; and notified them of
the associated public review comment period on August 2, 2016 and of
the opportunity to request a public hearing (for September 6, 2016).
The FLM comments and Oklahoma's responses are presented in Appendix II
of the progress report.
    The EPA proposes to find that Oklahoma has addressed the
requirements in 40 CFR 51.308(i). Oklahoma provided a 60-day period for
the FLMs to comment on the progress report, which was at least 60 days
before seeking public comments, and provides a summary of these
comments and responses to these comments in the progress report.

III. Proposed Action

    EPA is proposing to approve the State of Oklahoma regional haze
five-year progress report SIP revision (submitted September 28, 2016)
as meeting the applicable regional haze requirements under the CAA and
set forth in 40 CFR 51.308(g), (h) and (i). Because the SIP and FIP
will ensure the control of SO2 and NOX emissions
reductions relied upon by Oklahoma and other states in setting their
reasonable progress goals, EPA is proposing to approve Oklahoma's
finding that there is no need for revision of the existing
implementation plan to achieve the reasonable progress goals for the
Class I areas in Oklahoma and in nearby states impacted by Oklahoma
sources.

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
proposed action proposes to approve a State's determination that their
current regional haze plan is meeting federal requirements and does not
impose additional requirements beyond those imposed by state law. This
proposed 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 expected to be an Executive Order 13771 regulatory
action because this action is not significant 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, as 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
proposed rule does not have tribal implications and will not impose
substantial direct costs on tribal governments or preempt tribal law as
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Best Available
Retrofit Technology, Incorporation by reference, Intergovernmental
relations, Nitrogen dioxide, Ozone, Particulate matter, Reporting and
recordkeeping requirements, Regional haze, Sulfur dioxide, Visibility,
Volatile organic compounds.

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

    Dated: March 21, 2019.
Anne Idsal,
Regional Administrator, Region 6.
[FR Doc. 2019-05860 Filed 3-27-19; 8:45 am]
 BILLING CODE 6560-50-P