Proposed Rule2021-15467
Air Plan Approval; Oklahoma; Interstate Visibility Transport
Primary source
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Published
July 22, 2021
Issuing agencies
Environmental Protection Agency
Abstract
Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is proposing to approve elements of a State Implementation Plan (SIP) submission from the State of Oklahoma for the 2015 Ozone National Ambient Air Quality Standard (NAAQS), and proposing to disapprove elements of two SIP submissions for the 2010 sulfur dioxide (SO<INF>2</INF>) and the 2012 fine particulate matter (PM<INF>2.5</INF>) NAAQS. These infrastructure SIP (i-SIP) submissions address how the existing SIP provides for implementation, maintenance, and enforcement of these NAAQS. The i-SIP requirements are to ensure that the Oklahoma SIP is adequate to meet the state's responsibilities under the CAA for these NAAQS. Specifically, this proposed rule addresses the interstate visibility transport requirements of the i-SIP for the 2010 SO<INF>2</INF>, 2012 PM<INF>2.5</INF>, and 2015 Ozone NAAQS under CAA section 110(a)(2)(D)(i)(II). We are also proposing to find that the deficiencies in the Oklahoma SIP that form the basis of our proposed disapproval of the interstate visibility transport portions of the Oklahoma i-SIP submissions for the 2010 SO<INF>2</INF> and 2012 PM<INF>2.5</INF> NAAQS are remedied by the existing Federal Implementation Plan (FIP) in place for the Oklahoma Regional Haze program, and that no further federal action is required to address the proposed disapproval.
Full Text
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<title>Federal Register, Volume 86 Issue 138 (Thursday, July 22, 2021)</title>
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[Federal Register Volume 86, Number 138 (Thursday, July 22, 2021)]
[Proposed Rules]
[Pages 38630-38643]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-15467]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R06-OAR-2021-0032; FRL-8688-01-R6]
Air Plan Approval; Oklahoma; Interstate Visibility Transport
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 elements
of a State Implementation Plan (SIP) submission from the State of
Oklahoma for the 2015 Ozone National Ambient Air Quality Standard
(NAAQS), and proposing to disapprove elements of two SIP submissions
for the 2010 sulfur dioxide (SO<INF>2</INF>) and the 2012 fine
particulate matter (PM<INF>2.5</INF>) NAAQS. These infrastructure SIP
(i-SIP) submissions address how the existing SIP provides for
implementation, maintenance, and enforcement of these NAAQS. The i-SIP
requirements are to ensure that the Oklahoma SIP is adequate to meet
the state's responsibilities under the CAA for these NAAQS.
Specifically, this proposed rule addresses the interstate visibility
transport requirements of the i-SIP for the 2010 SO<INF>2</INF>, 2012
PM<INF>2.5</INF>, and 2015 Ozone NAAQS under CAA section
110(a)(2)(D)(i)(II). We are also proposing to find that the
deficiencies in the Oklahoma SIP that form the basis of our proposed
disapproval of the interstate visibility transport portions of the
Oklahoma i-SIP submissions for the 2010 SO<INF>2</INF> and 2012
PM<INF>2.5</INF> NAAQS are
[[Page 38631]]
remedied by the existing Federal Implementation Plan (FIP) in place for
the Oklahoma Regional Haze program, and that no further federal action
is required to address the proposed disapproval.
DATES: Comments must be received on or before August 23, 2021.
ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2021-0032, at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or via email to
<a href="/cdn-cgi/l/email-protection#543931303d3a357a30352d353a35143124357a333b22"><span class="__cf_email__" data-cfemail="09646c6d606768276d6870686768496c7968276e667f">[email protected]</span></a>. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://Regulations.gov">Regulations.gov</a>. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, please contact Dayana Medina, 214-665-
7341, <a href="/cdn-cgi/l/email-protection#7e131b1a17101f501a1f071f101f3e1b0e1f50191108"><span class="__cf_email__" data-cfemail="7d10181914131c53191c041c131c3d180d1c531a120b">[email protected]</span></a>. For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
Docket: The index to the docket for this action is available
electronically at <a href="http://www.regulations.gov">www.regulations.gov</a>. While all documents in the
docket are listed in the index, some information may not be publicly
available due to docket file size restrictions or content (e.g., CBI).
FOR FURTHER INFORMATION CONTACT: Dayana Medina, EPA Region 6 Office,
Regional Haze and SO<INF>2</INF> Section, 214-665-7341,
<a href="/cdn-cgi/l/email-protection#acc1c9c8c5c2cd82c8cdd5cdc2cdecc9dccd82cbc3da"><span class="__cf_email__" data-cfemail="acc1c9c8c5c2cd82c8cdd5cdc2cdecc9dccd82cbc3da">[email protected]</span></a>. Out of an abundance of caution for members of
the public and our staff, the EPA Region 6 office will be closed to the
public to reduce the risk of transmitting COVID-19. We encourage the
public to submit comments via <a href="https://www.regulations.gov">https://www.regulations.gov</a>, as there
will be a delay in processing mail and no courier or hand deliveries
will be accepted. Please call or email the contact listed above if you
need alternative access to material indexed but not provided in the
docket.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' means the EPA.
I. Background
Whenever a new or revised NAAQS is promulgated, the Clean Air Act
(CAA) requires states to submit a plan for the implementation,
maintenance, and enforcement of the standard, commonly referred to as
infrastructure requirements. Section 110(a)(2) lists specific
requirements that infrastructure SIPs, or i-SIPs, must include to
adequately address such new or revised NAAQS, as applicable. Section
110(a)(2)(D)(i) includes four distinct elements related to interstate
transport of air pollution, commonly referred to as prongs, that must
be addressed in i-SIP submissions. The first two prongs are codified in
section 110(a)(2)(D)(i)(I) and the third and fourth prongs are codified
in section 110(a)(2)(D)(i)(II). These four prongs prohibit any source
or type of emission activities in one state from:
<bullet> Contributing significantly to nonattainment of the NAAQS
in another state (prong 1);
<bullet> Interfering with maintenance of the NAAQS in another state
(prong 2);
<bullet> Interfering with measures that prevent significant
deterioration of air quality in another state (prong 3); and
<bullet> Interfering with measures that protect visibility in
another state (prong 4 or ``visibility transport'').
We are only addressing the prong 4 element in this proposal. In an
effort to assist states in complying with the i-SIP requirements, EPA
issued guidance in 2013.\1\ In the 2013 i-SIP guidance, EPA discussed
its interpretation of prong 4 and its relationship to the Regional Haze
program under CAA sections 169A and 169B, which require each state to
address its share of emission reductions needed to meet reasonable
progress goals (RPGs) for surrounding Class I areas. EPA suggested two
options states may have to demonstrate that the requirements of prong 4
are met. One way in which prong 4 may be satisfied for any relevant
NAAQS is through confirmation in the state's i-SIP submission that it
has an approved regional haze SIP that fully meets the requirements of
40 CFR 51.308 or 51.309. Alternatively, a state may demonstrate in its
i-SIP submission that emissions within its jurisdiction do not
interfere with other states' plans to protect visibility. The
demonstration should show that the state has sufficient measures that
have been approved into its SIP to prevent emissions within its
jurisdiction from interfering with the visibility protection plans of
other states.
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\1\ Stephen D. Page, Director, Office of Air Quality Planning
and Standards. ``Guidance on Infrastructure State Implementation
Plan (SIP) Elements under Clean Air Act Section 110(a)(1) and
110(a)(2).'' Memorandum to EPA Air Division Directors, Regions 1
through 10, September 13, 2013 (hereinafter ``2013 i-SIP
Guidance'').
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A. Oklahoma's Infrastructure SIP Submittals for 2010 SO2, 2012 PM2.5,
and 2015 Ozone NAAQS
EPA has regulated particulate matter (PM) since the first NAAQS for
PM were published in 1971. (36 FR 8186 (April 30, 1971)). Most
recently, by notice dated January 15, 2013, following a periodic review
of the NAAQS for PM<INF>2.5</INF>, EPA revised the primary annual
PM<INF>2.5</INF> NAAQS to 12.0 [mu]g/m\3\ and retained the secondary
annual PM<INF>2.5</INF> standard of 15 [mu]g/m\3\ as well as the
primary and secondary 24-hour PM<INF>2.5</INF> standards of 35 [mu]g/
m\3\ (2012 PM<INF>2.5</INF> NAAQS).\2\ The primary NAAQS is designed to
protect human health, and the secondary NAAQS is designed to protect
the public welfare. On June 16, 2016, the Oklahoma Secretary of Energy
and Environment submitted a SIP revision to address most of the i-SIP
elements for this revised 2012 PM<INF>2.5</INF> NAAQS. On November 21,
2016, we proposed to approve all elements included in the 2012
PM<INF>2.5</INF> i-SIP submission except for the 110(a)(2)(D)(i)(II)
prong 4 portion, which we proposed to disapprove.\3\ On June 14, 2017,
we took final action to approve all elements included in this i-SIP
submission, but deferred taking final action on the 110(a)(2)(D)(i)(II)
prong 4 portion.\4\ In this notice, we are once again proposing to
disapprove the prong 4 visibility transport portion of the June 16,
2016 i-SIP submission for the 2012 PM<INF>2.5</INF> NAAQS.
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\2\ 78 FR 3085 (Jan. 15, 2013).
\3\ 81 FR 83184 (November 21, 2016).
\4\ 82 FR 27121 (June 14, 2017).
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On June 22, 2010, we revised the primary NAAQS for SO<INF>2</INF>
to establish a new 1-hour standard at a level of 75 parts per billion
(ppb), based on the 3-year average of the annual 99th percentile of 1-
hour daily maximum concentrations.\5\ On January 28, 2015, the Oklahoma
Secretary of Energy and Environment submitted a SIP revision to address
i-SIP elements for this revised NAAQS. On November 21, 2016, we
proposed to disapprove the 110(a)(2)(D)(i)(II) prong 4 portion of the
2010 SO<INF>2</INF> i-SIP submission, but we did not finalize this
disapproval.\6\ In this notice, we are once again proposing to
disapprove the prong 4 visibility
[[Page 38632]]
transport portion of the January 28, 2015 i-SIP submission for the 2010
SO<INF>2</INF> NAAQS.
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\5\ 75 FR 35520 (June 22, 2010).
\6\ 81 FR 83184.
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EPA has regulated ozone since 1971, when we published the first
NAAQS for Photochemical Oxidants (36 FR 8186 (April 30, 1971)). Most
recently, following a periodic review of the 2008 NAAQS for ozone, the
EPA promulgated a revision to the ozone NAAQS in 2015 lowering the
level of both the primary and secondary standards to 0.070 parts per
million.\7\ On October 25, 2018, the Oklahoma Secretary of Energy and
Environment submitted a SIP revision to address i-SIP elements for this
revised NAAQS. On March 30, 2020, we approved most infrastructure
elements of the 2015 ozone i-SIP submission but deferred taking final
action on the 110(a)(2)(D)(i)(II) prong 4 portion.\8\
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\7\ 82 FR 65291 (Oct. 26, 2015). Additional information on the
history of the NAAQS for ozone is available at <a href="https://www.epa.gov/ozone-pollution/table-historical-ozone-national-ambient-air-quality-standards-naaqs">https://www.epa.gov/ozone-pollution/table-historical-ozone-national-ambient-air-quality-standards-naaqs</a>.
\8\ See 85 FR 17502 (March 30, 2020).
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In this notice, we refer to each of these NAAQS by the year
promulgated, e.g., ``the 2008 ozone standard.'' For more information on
these standards, please visit <a href="https://www.epa.gov/criteria-air-pollutants">https://www.epa.gov/criteria-air-pollutants</a>.
B. Regional Haze and Visibility Transport in Oklahoma
On February 17, 2010, Oklahoma submitted a regional haze SIP (the
2010 Regional Haze SIP) to the EPA that included best available
retrofit technology (BART) requirements for SO<INF>2</INF>,
NO<INF>X</INF>, and PM for Oklahoma sources. On December 28, 2011, we
took final action to partially approve and partially disapprove the
2010 Regional Haze SIP.\9\ In this final action, we disapproved
Oklahoma's SO<INF>2</INF> BART determinations for the Oklahoma Gas and
Electric (OG&E) Sooner Units 1 and 2, the OG&E Muskogee Units 4 and 5,
and the American Electric Power/Public Service Company of Oklahoma
(AEP/PSO) Northeastern Units 3 and 4 because they do not comply with
our regional haze regulations under 40 CFR 51.308(e). We approved
Oklahoma's remaining SO<INF>2</INF> BART determinations as well as all
nitrogen oxide (NO<INF>X</INF>) and PM BART determinations.
Additionally, we approved all remaining portions of the 2010 Regional
Haze SIP, with the exception of (1) the long-term strategy to the
extent it relied on the BART emission limits that we disapproved and
(2) Oklahoma's 2018 RPGs on the 20% least impaired and 20% most
impaired days for the Wichita Mountains Class I area.\10\
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\9\ 76 FR 81728 (December 28, 2011).
\10\ In a final rule published in the Federal Register on
January 5, 2016, we disapproved Oklahoma's 2018 RPGs on the 20%
least impaired and 20% most impaired days for the Wichita Mountains
Class I area because Oklahoma did not adequately demonstrate that
its RPGs provide for reasonable progress towards meeting the
national visibility goal. Specifically, Oklahoma did not satisfy
several of the requirements at section 51.308(d)(1) with regard to
setting RPGs, including the requirement to adequately consult with
other states that may reasonably be anticipated to cause or
contribute to visibility impairment at the Wichita Mountains and the
requirement to adequately justify RPGs that are less stringent than
the uniform rate of progress (URP). However, that final rulemaking
was challenged, and in December 2016, 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 without vacatur. Texas v. EPA, 829 F.3d 405
(5th Cir. 2016).
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In the December 28, 2011 final rule, we also evaluated whether
Oklahoma's SIP ensures that emissions from sources within Oklahoma do
not interfere with the visibility programs of other states with respect
to the 1997 8-hour Ozone NAAQS and the 1997 PM<INF>2.5</INF> NAAQS. In
developing their respective regional haze SIPs and reasonable progress
goals (RPGs), the Central Regional Air Planning Association (CENRAP)
states consulted with each other through CENRAP's work groups. As a
result of this process, the understanding was that each CENRAP state
would take action to achieve the emissions reductions relied upon by
other states in their reasonable progress demonstrations. CENRAP states
consulted in the development of RPGs, using the products of the
technical consultation process to co-develop their RPGs. In developing
their visibility projections using photochemical grid modeling, CENRAP
states assumed a certain level of emissions from sources within
Oklahoma. The CENRAP modeling assumed SO<INF>2</INF> reductions from
the OG&E Sooner Units 1 and 2, the OG&E Muskogee Units 4 and 5, and the
AEP/PSO Northeastern Units 3 and 4, which Oklahoma did not secure when
making its BART determinations for these sources and were thus not
required by the 2010 Oklahoma Regional Haze SIP. Since this modeling
was used by other states and Oklahoma in establishing their RPGs, we
made the finding that the Oklahoma SIP does not ensure that emissions
from sources within Oklahoma do not interfere with measures required in
the SIP of any other state under Part C of the CAA to protect
visibility.\11\ In the December 28, 2011 final rule, we finalized a FIP
(Oklahoma SO<INF>2</INF> BART FIP) that controls SO<INF>2</INF>
emissions from the six units to address the deficiencies identified in
our disapproval of these SO<INF>2</INF> BART determinations and the
disapproval of the SIP submission addressing its prong 4 visibility
transport obligations for the 1997 8-hour Ozone NAAQS and the 1997
PM<INF>2.5</INF> NAAQS.\12\
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\11\ 76 FR 81728.
\12\ Id.
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On June 20, 2013, Oklahoma submitted a regional haze SIP revision
to replace the FIP's SO<INF>2</INF> BART requirements for the AEP/PSO
Northeastern Units 3 and 4 and a related revision to the SIP addressing
interstate visibility transport requirements (the 2013 Oklahoma
Regional Haze SIP Revision). On March 7, 2014, we approved this SIP
revision and concurrently withdrew the FIP's applicability to these two
units.\13\ In addition to approving the SO<INF>2</INF> BART
determinations for the AEP/PSO Northeastern Units 3 and 4 in that final
rule, we also approved revised NO<INF>X</INF> BART requirements for
these two units,\14\ and approved the portion of the 2013 Oklahoma
Regional Haze SIP Revision concerning Oklahoma's interstate visibility
transport obligations of CAA section 110(a)(2)(D)(i)(II) with respect
to the 1997 8-hour ozone and 1997 PM<INF>2.5</INF> NAAQS as applied to
this source and its associated impacts on other states' programs to
protect visibility in Class I Areas.\15\ The FIP provisions applicable
to the OG&E Muskogee and Sooner plants remain in place.
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\13\ 79 FR 12944, 12954 (March 7, 2014).
\14\ EPA approved the NO<INF>X</INF> BART determinations for the
AEP/PSO Northeastern Units 3 and 4 and all other subject-to-BART
sources in Oklahoma in the December 28, 2011 final rule, but
Oklahoma revised the EPA-approved NO<INF>X</INF> BART determinations
for Northeastern Units 3 and 4 in the 2013 Oklahoma Regional Haze
SIP Revision to require earlier installation and compliance with
reduced NO<INF>X</INF> emission limits prior to the original SIP-
imposed deadline. This is discussed in more detail in section III.C
of this notice.
\15\ 79 FR at 12945.
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II. Oklahoma Infrastructure SIP Submittals
On January 28, 2015, Oklahoma submitted a SIP revision to address
the infrastructure requirements for the 2010 1-hour SO<INF>2</INF>
NAAQS, including the interstate visibility transport requirements. In
its evaluation, Oklahoma stated that the 2010 Regional Haze SIP
describes Oklahoma's measures to protect visibility and ensure that
emissions do not interfere with any other state's measures to protect
visibility. Oklahoma stated that these measures include provisions in
the Oklahoma Administrative Code 252:100-8, Part 11. Oklahoma noted
that EPA partially approved and
[[Page 38633]]
partially disapproved Oklahoma's Regional Haze SIP and partially
approved and partially disapproved Oklahoma's SIP submission addressing
its prong 4 visibility transport requirements for the 1997 8-hour Ozone
NAAQS and the 1997 PM<INF>2.5</INF> NAAQS on December 28, 2011.
Oklahoma noted that in the same action, EPA promulgated a FIP
addressing the disapproved portions of Oklahoma's 2010 Regional Haze
SIP and the interstate visibility transport SIP revisions for the 1997
8-hour Ozone NAAQS and the 1997 PM<INF>2.5</INF> NAAQS, and that EPA
found that the controls under this FIP, in combination with the
controls required by the portion of the Oklahoma Regional Haze SIP
submittal approved by EPA, will serve to prevent sources in Oklahoma
from emitting pollutants in amounts that will interfere with efforts to
protect visibility in other states. Oklahoma also noted that it
submitted a revision to its regional haze and interstate visibility
transport SIPs (2013 Oklahoma Regional Haze SIP Revision) on June 14,
2013, to replace the FIP as it relates to the AEP/PSO Northeastern
Units 3 and 4, and that EPA approved this revision effective April 7,
2014. Oklahoma asserted that any contribution to visibility impairment
or interference with any other state's measures to protect visibility
attributable to SO<INF>2</INF> emissions are addressed through
Oklahoma's 2010 Regional Haze SIP as revised in the 2013 Oklahoma
Regional Haze SIP Revision and through EPA's related regional haze
actions in Oklahoma. This includes EPA's FIP action that currently
addresses the OG&E Sooner Units 1 and 2 and the OG&E Muskogee Units 4
and 5. Oklahoma also noted that although no additional visibility
protection obligations are anticipated on Oklahoma's part as a result
of the revised 2010 1-hour SO<INF>2</INF> NAAQ, other program actions
taken to ensure maintenance of the revised SO<INF>2</INF> NAAQS will
indirectly assist in avoiding interference with any other state's
measures to protect visibility.
On June 16, 2016, Oklahoma submitted a SIP revision to address the
infrastructure requirements for the 2012 PM<INF>2.5</INF> NAAQS,
including the transport requirements. In its evaluation, Oklahoma
stated that the 2010 Regional Haze SIP describes Oklahoma's measures to
protect visibility and ensure that emissions do not interfere with any
other state's measures to protect visibility. Oklahoma stated that
these measures include provisions in the Oklahoma Administrative Code
252:100-8, Part 11. Oklahoma noted that EPA partially approved and
partially disapproved Oklahoma's Regional Haze SIP and partially
approved and partially disapproved Oklahoma's SIP submission addressing
the visibility prong of interstate transport for the 1997 8-hour Ozone
NAAQS and the 1997 PM<INF>2.5</INF> NAAQS on December 28, 2011.
Oklahoma noted that in the same action, EPA promulgated a FIP
addressing the disapproved portions of Oklahoma's 2010 Regional Haze
SIP and the interstate visibility transport SIP submittals for the 1997
8-hour Ozone NAAQS and the 1997 PM<INF>2.5</INF> NAAQS, and that EPA
found that the controls under this FIP, in combination with the
controls required by the portion of the Oklahoma Regional Haze SIP
submittal approved by EPA, will serve to prevent sources in Oklahoma
from emitting pollutants in amounts that will interfere with efforts to
protect visibility in other states. Oklahoma also noted that it
submitted a revision to its regional haze and interstate visibility
transport SIPs on June 14, 2013, to replace the FIP as it relates to
the AEP/PSO Northeastern Units 3 and 4, and that EPA approved this
revision effective April 7, 2014. In its evaluation, Oklahoma asserted
that any contribution to visibility impairment or interference with any
other state's measures to protect visibility attributable to emission
of PM<INF>2.5</INF> or its precursors (e.g., SO<INF>2</INF>) are
addressed through Oklahoma's 2010 Regional Haze SIP as revised in the
2013 Oklahoma Regional Haze SIP Revision and through EPA's related
regional haze actions in Oklahoma. This includes EPA's FIP action that
currently addresses the OG&E Sooner Units 1 and 2 and the OG&E Muskogee
Units 4 and 5. Oklahoma also noted that although no additional
visibility protection obligations are anticipated on Oklahoma's part as
a result of the revised 2012 PM<INF>2.5</INF> NAAQS, other program
actions taken to assure maintenance of the revised PM<INF>2.5</INF>
NAAQS will indirectly assist in avoiding interference with any other
state's measures to protect visibility.
On October 25, 2018, Oklahoma submitted a SIP revision to address
the CAA section 110(a)(1) and 110(a)(2) infrastructure and transport
requirements for the 2015 Ozone NAAQS. In its evaluation, Oklahoma
stated that the 2010 Regional Haze SIP describes Oklahoma's measures to
protect visibility and ensure that emissions do not interfere with any
other state's measures to protect visibility. Oklahoma stated that
these measures include provisions in the Oklahoma Administrative Code
252:100-8, Part 11. Oklahoma noted that EPA partially approved and
partially disapproved Oklahoma's Regional Haze SIP and partially
approved and partially disapproved Oklahoma's SIP submission addressing
the visibility prong of interstate transport for the 1997 8-hour Ozone
NAAQS and the 1997 PM<INF>2.5</INF> NAAQS on December 28, 2011.
Oklahoma noted that in the same action, EPA promulgated a FIP
addressing the disapproved portions of Oklahoma's 2010 Regional Haze
SIP and the interstate visibility transport SIP submittals for the 1997
8-hour Ozone NAAQS and the 1997 PM<INF>2.5</INF> NAAQS, and that EPA
found that the controls under this FIP, in combination with the
controls required by the portion of the Oklahoma Regional Haze SIP
submittal approved by EPA, will serve to prevent sources in Oklahoma
from emitting pollutants in amounts that will interfere with efforts to
protect visibility in other states. Oklahoma also noted that it
submitted a revision to its regional haze and interstate visibility
transport SIPs on June 14, 2013, to replace the FIP as it relates to
the AEP/PSO Northeastern Units 3 and 4, and that EPA approved this
revision effective April 7, 2014. In its evaluation, Oklahoma asserted
that ozone from ozone precursor emissions are not believed to
contribute significantly to visibility impairment and that Oklahoma's
2010 Regional Haze SIP demonstrates that Oklahoma's PM<INF>2.5</INF>
emissions do not interfere with any other state's measures to protect
visibility. Oklahoma noted that this portion of the 2010 Regional Haze
SIP was approved by EPA on December 28, 2011. Additionally, the
submission includes a technical support document (TSD) \16\ intended to
address the requirements of CAA section 110(a)(2)(D)(i)(I), which
requires a state's SIP to contain adequate provisions prohibiting any
source or other type of emissions activity within the state from
emitting any air pollutant in amounts which will contribute
significantly to nonattainment in, or interfere with maintenance by,
any other state with respect to any such national primary or secondary
ambient air quality standard (i.e., prongs 1 and 2). In that document,
Oklahoma asserted that the Oklahoma Department of Environmental Quality
(ODEQ) has determined that Oklahoma meets the
[[Page 38634]]
prong 4 visibility transport provisions for the 2015 Ozone NAAQS, as
the state is not contributing significantly to nonattainment or
maintenance issues in any other state.
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\16\ See ``Oklahoma Demonstration of Compliance with the Good
Neighbor Requirements of Clean Air Act Section 110(a)(2)(D)(i)(I)
for the 2015 Ozone National Ambient Air Quality Standard,'' which is
part of Oklahoma's October 25, 2018 Infrastructure SIP submittal for
the 2015 Ozone NAAQS.
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In summary, Oklahoma relied on the following points to support its
conclusion that Oklahoma meets the prong 4 visibility transport
provision for the 2015 Ozone NAAQS: (1) The modeling and technical
analysis in the State's interstate transport SIP revision (as to
``prongs 1 and 2'' under section 110(a)(2)(D)(i)(I)) purportedly
demonstrating that Oklahoma does not significantly contribute to
nonattainment or maintenance in another state for the 2015 Ozone NAAQS;
(2) the fact that ozone formed from ozone precursor emissions is not
believed to contribute significantly to visibility impairment; and (3)
Oklahoma's 2010 Regional Haze SIP, which Oklahoma says demonstrates
that PM<INF>2.5</INF> emissions from Oklahoma do not interfere with any
other state's measures to protect visibility.
On December 1, 2020, EPA sent a letter to ODEQ requesting
clarification on how the Oklahoma SIP satisfies the prong 4 interstate
visibility transport requirement with respect to the 2015 Ozone
NAAQS.\17\ In a letter dated January 5, 2021, ODEQ pointed out that EPA
approved the NO<INF>X</INF> BART determinations in the 2010 Oklahoma
Regional Haze SIP and also clarified that the SIP addressed
NO<INF>X</INF> and VOC emissions, which are ozone precursors, using an
approach that is consistent with what was anticipated under the CENRAP
process for the first regional haze planning period.\18\ In the letter,
ODEQ noted that Sections VII and IX of the 2010 Oklahoma Regional Haze
SIP explain that the SIP requires NO<INF>X</INF> reductions resulting
from BART and other program requirements, as well as other factors,
that are consistent with what was anticipated under the CENRAP
consultation process for regional haze SIP development for the first
planning period. In the letter, ODEQ further noted that Section VIII of
the 2010 Oklahoma Regional Haze SIP explains that the CENRAP modeling
used to project the visibility impacts in 2018 as a result of growth
and control of emissions from the baseline for Class I areas in CENRAP
states included emission adjustments made by ODEQ to reflect
presumptive BART controls for the OG&E Sooner Plant, the OG&E Muskogee
Plant, and the AEP/PSO Northeastern Plant. For NO<INF>X</INF>
emissions, this presumptive control level is equivalent to 0.15 lb/
MMBtu for NO<INF>X</INF> BART and is consistent with the NO<INF>X</INF>
emission limits required by the 2010 Oklahoma Regional Haze SIP for
subject-to-BART units at these three power plants.
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\17\ Letter from Michael Feldman, Chief, SO<INF>2</INF> and
Regional Haze Section, U.S. Environmental Protection Agency, Region
6, to Melanie Foster, Manager, Rules & Planning Section, Air Quality
Division, Oklahoma Department of Environmental Quality, (December 1,
2020). A copy of this letter is included in the docket associated
with this proposed rulemaking.
\18\ Letter from Kendal Stegmann, Director, Air Quality
Division, Oklahoma Department of Environmental Quality, to Michael
Feldman, Chief, SO<INF>2</INF> and Regional Haze Section, U.S.
Environmental Protection Agency, Region 6 (January 5, 2021). A copy
of this letter is included in the docket associated with this
proposed rulemaking.
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In the January 5, 2021 letter, ODEQ also explains that the 2010
Oklahoma Regional Haze SIP did not include additional control
requirements to address VOC emissions under regional haze for the first
planning period. In the letter, ODEQ points to Section VI(A) of the
2010 Oklahoma Regional Haze SIP, which explains that ODEQ determined
that the visibility impairing pollutants in Oklahoma include
SO<INF>2</INF>, NO<INF>X</INF>, PM<INF>10</INF>, and PM<INF>2.5</INF>,
while CENRAP modeling showed that anthropogenic VOCs do not
significantly impair visibility at the Wichita Mountains. ODEQ also
notes that Section IX(E)(4) of the 2010 Oklahoma Regional Haze SIP
explains that the emissions inventory associated with the SIP assigns
most emissions of VOCs to biogenic sources, which ODEQ considers to be
natural and therefore uncontrollable. ODEQ explains that Section
IX(E)(4) of the 2010 Oklahoma Regional Haze SIP noted that a minority
of VOC emissions in Oklahoma originate from area, industrial, point,
and mobile sources, and that most of these sources already employ
controls under various federal mandates. The 2010 Oklahoma Regional
Haze SIP explained that considering the small and uncertain
contribution of anthropogenic sources of VOC to visibility impairment
at the Wichita Mountains, ODEQ did not find further VOC controls
reasonable. In the letter, ODEQ explains that these determinations
similarly apply to the approach taken in the 2010 Oklahoma Regional
Haze SIP regarding potential VOC-related impacts of and remedies for
visibility impairment at other states' Class I areas, and that this
approach is consistent with what was anticipated under the CERNAP
process for the first regional haze planning period. Further, ODEQ
notes that Section VIII of the 2010 Oklahoma Regional Haze SIP
presented model output data that demonstrates that Oklahoma emissions
are projected to impair visibility only insignificantly at all Class I
areas in other states, and ODEQ therefore concluded that additional
emission reduction action was not needed to protect other Class I
areas, including for NO<INF>X</INF> and VOC as ozone precursors.
Thus, ODEQ clarifies in the letter that the EPA-approved portion of
the 2010 Oklahoma Regional Haze SIP addressed NO<INF>X</INF> and VOC
emissions using an approach that is consistent with what was
anticipated in the CENRAP process for the first regional haze planning
period and ODEQ states that it believes that, considering the
clarifications in the January 5, 2021 letter, and as certified in the
October 25, 2018 submittal, the Oklahoma SIP satisfies the interstate
visibility transport CAA requirement of section 110(a)(2)(D)(i)(II)
with respect to the 2015 Ozone NAAQS.
III. The EPA's Evaluation
Our 2013 i-SIP guidance addresses the requirements for prong 4 and
lays out two ways in which a state's infrastructure SIP submittal may
satisfy these requirements.\19\ The first method is through a state's
confirmation in its infrastructure SIP submittal that it has a fully
approved regional haze SIP in place. As previously discussed, EPA
promulgated a partial approval and partial disapproval of the 2010
Oklahoma Regional Haze SIP in 2011 because the SO<INF>2</INF> BART
determinations for the OG&E Sooner Units 1 and 2, the OG&E Muskogee
Units 4 and 5, and the AEP/PSO Northeastern Units 3 and 4 did not
comply with our regional haze regulations under 40 CFR 51.308(e), and
EPA concurrently promulgated a FIP to address these deficiencies.\20\
On June 20, 2013, Oklahoma submitted a SIP revision to address this
deficiency with respect to the AEP/PSO Northeastern Units 3 and 4, and
the FIP with respect to these two units was withdrawn on March 7,
2014.\21\ However, the FIP remains in place with SO<INF>2</INF> BART
requirements for the OG&E Sooner Units 1 and 2 and the OG&E Muskogee
Units 4 and 5. Therefore, Oklahoma cannot rely on a fully approved
Regional Haze SIP as the basis for meeting its prong 4 visibility
transport obligations for the 2010 SO<INF>2</INF>, 2012
PM<INF>2.5</INF>, and the 2015 Ozone NAAQS.
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\19\ See 2013 i-SIP Guidance at 32-35.
\20\ 76 FR 81728.
\21\ 79 FR 12954.
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In the absence of a fully approved Regional Haze SIP, the second
method provided by the 2013 i-SIP guidance to meet prong 4 requirements
is a demonstration that emissions within a state's jurisdiction do not
interfere with
[[Page 38635]]
other states' plans to protect visibility.\22\ EPA interprets prong 4
to be pollutant-specific such that the state need only address the
potential for interference with visibility protection caused by the
pollutant (including precursors) to which the new or revised NAAQS
applies.\23\ According to the guidance, such a demonstration for the
first planning period should establish or identify the measures in the
approved SIP that limit visibility-impairing pollutants and ensure that
the resulting reductions conform with any mutually agreed emission
reductions under the relevant regional haze regional planning
organization (RPO) process.\24\ As explained below, Oklahoma did not
make such a demonstration in the i-SIP submittals for the 2010
SO<INF>2</INF> and 2012 PM<INF>2.5</INF> NAAQS. The i-SIP submittal for
the 2015 Ozone NAAQS as clarified by Oklahoma's January 5, 2021 letter,
provides a demonstration identifying the measures in the approved SIP
that limit visibility-impairing ozone precursor emissions and clarifies
that the resulting reductions conform with mutually agreed emission
reductions under the relevant regional haze RPO process with respect to
the 2015 Ozone NAAQS. We discuss this in the subsections that follow.
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\22\ See 2013 i-SIP Guidance at 34.
\23\ See 2013 i-SIP Guidance at 33.
\24\ See 2013 i-SIP Guidance at 34. See also 76 FR 22036 (April
20, 2011) (containing EPA's approval of the visibility requirement
of 110(a)(2)(D)(i)(II) based on a demonstration by Colorado that did
not rely on the Colorado Regional Haze SIP).
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A. Analysis of Oklahoma's January 28, 2015 Prong 4 Submittal for the
2010 SO2 NAAQS
The portion of the 2015 infrastructure SIP submittal for the 2010
1-hour SO<INF>2</INF> NAAQS that addresses interstate visibility
transport relied on both Oklahoma's 2010 Regional Haze SIP submittal,
as revised in the 2013 Regional Haze SIP revision that addresses the
AEP/PSO facility, and EPA's FIP that currently applies to the OG&E
Sooner Units 1 and 2 and the OG&E Muskogee Units 4 and 5. As explained
above, the prong 4 requirements are pollutant specific. Some portions
of the 2010 Oklahoma Regional Haze SIP that address SO<INF>2</INF>
emissions have been disapproved and thus cannot be relied upon by
Oklahoma to satisfy the prong 4 requirements. Further, the EPA's 2013
i-SIP guidance states, ``Under section 110(a)(2)(D(i)(II), an i-SIP
submission cannot be approved with respect to prong 4 (visibility
transport) until the EPA has issued final approval of SIP provisions
that the EPA has found to adequately address any contribution of that
state's sources to impacts on visibility program requirements in other
states.'' \25\ Thus, Oklahoma cannot rely on the existing
SO<INF>2</INF> BART FIP to satisfy the prong 4 requirements for the
2010 1-hour SO<INF>2</INF> NAAQS. Moreover, the 2015 i-SIP submittal
does not provide any additional information to demonstrate that the
measures in the SIP are sufficient to prohibit emissions from sources
within Oklahoma from interfering with measures that have been developed
by other states to protect visibility with respect to the 2010 1-hour
SO<INF>2</INF> NAAQS. Therefore, while the FIP provides an appropriate
level of SO<INF>2</INF> control to prohibit emissions from sources
within Oklahoma from interfering with measures that have been developed
by other states to protect visibility (as discussed in Section III.E.),
the SIP submittal does not; Thus, we are proposing to disapprove the
110(a)(2)(D)(i)(II) prong 4 portion of Oklahoma's 2015 i-SIP submittal
for the 2010 1-hour SO<INF>2</INF> NAAQS.
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\25\ See 2013 i-SIP Guidance at 32-33.
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B. Analysis of Oklahoma's June 16, 2016 Prong 4 Submittal for the 2012
PM2.5 NAAQS
The portion of the 2016 infrastructure SIP submittal for the 2012
PM<INF>2.5</INF> NAAQS that addresses interstate visibility transport
relied on both Oklahoma's 2010 Regional Haze SIP submittal, as revised
in the June 20, 2013 SIP revision with respect to the AEP/PSO facility,
and EPA's FIP that currently applies to the OG&E Sooner Units 1 and 2
and the OG&E Muskogee Units 4 and 5. The portions of Oklahoma's 2010
Regional Haze SIP that address PM BART have been approved, but portions
of the SIP that address PM precursor emissions (i.e., SO<INF>2</INF>)
have not, and thus cannot be relied upon to satisfy the prong 4
requirements. PM emissions can be emitted directly from sources and can
also form in the atmosphere as a result of complex reactions of other
pollutants (i.e., precursors) such as SO<INF>2</INF> and
NO<INF>X</INF>, which are visibility impairing pollutants themselves
and are required to be addressed under regional haze.\26\ As discussed
above, EPA disapproved the SO<INF>2</INF> BART determinations for the
OG&E Sooner Units 1 and 2, the OG&E Muskogee Units 4 and 5, and the
AEP/PSO Northeastern Units 3 and 4, and promulgated a FIP to address
these deficiencies.\27\ EPA approved the 2013 Oklahoma Regional Haze
SIP Revision that addressed SO<INF>2</INF> BART for the AEP/PSO
Northeastern Units 3 and 4, and EPA withdrew the FIP with respect to
these two units on March 7, 2014.\28\ However, the FIP remains in place
with SO<INF>2</INF> BART requirements for the OG&E Sooner Units 1 and 2
and the OG&E Muskogee Units 4 and 5. As explained above, Oklahoma
cannot rely upon the portions of the 2010 Oklahoma Regional Haze SIP
that address SO<INF>2</INF> emissions that have been disapproved or on
the existing SO<INF>2</INF> BART FIP to satisfy the prong 4
requirements for the 2012 PM<INF>2.5</INF> NAAQS. The 2016 i-SIP
submittal does not provide any additional information to demonstrate
that the measures in the SIP are sufficient to prohibit emissions from
sources within Oklahoma from interfering with measures that have been
developed by other states to protect visibility with respect to the
2012 PM<INF>2.5</INF> NAAQS. We are therefore proposing to disapprove
the 110(a)(D)(2)(i)(II) prong 4 portion of Oklahoma's 2016
infrastructure SIP submittal for the 2012 PM<INF>2.5</INF> NAAQS.
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\26\ The BART Guidelines direct states to address
SO<INF>2</INF>, NO<INF>X</INF> and direct PM (including both
PM<INF>10</INF> and PM<INF>2.5</INF>) emissions as visibility-
impairment pollutants, and states must exercise their ``best
judgment to determine whether VOC or ammonia emissions from a source
are likely to have an impact on visibility in an area.'' See 70 FR
39162.
\27\ 76 FR 81728.
\28\ 79 FR 12954.
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C. Analysis of Oklahoma's 2018 Prong 4 Submittal for the 2015 Ozone
NAAQS
In Oklahoma's 2018 infrastructure SIP submittal for the 2015 Ozone
NAAQS, Oklahoma asserted that it meets the visibility transport
provisions under section 110(a)(2)(D)(i)(II) for the 2015 Ozone NAAQS
given that it has determined the state is not contributing
significantly to nonattainment or maintenance issues in any other state
under section 110(a)(2)(D)(i)(I). The analysis in the SIP submittal
that purports to find that Oklahoma emissions do not significantly
contribute to nonattainment or interfere with maintenance in another
state under section 110(a)(2)(D)(i)(I) focuses on the potential impact
of ozone-precursor emissions at certain ozone monitor locations in
other states as related to the attainment and maintenance of the ozone
NAAQS (i.e., prongs 1 and 2), but does not provide an analysis of
visibility impacts at Class I areas due to emissions of ozone
precursors as visibility pollutants (prong 4).\29\ This basis is
[[Page 38636]]
inadequate for approval of the visibility transport requirements.
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\29\ See 2013 i-SIP Guidance at 33 (``The EPA interprets [prong
4] to be pollutant-specific, such that the infrastructure SIP
submission need only address the potential for interference with
protection of visibility caused by the pollutant (including
precursors) to which the new or revised NAAQS applies.'')
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In the 2018 submittal, Oklahoma also stated that ozone formed from
ozone precursor emissions is not believed to contribute significantly
to visibility impairment. Oklahoma asserted that the 2010 Regional Haze
SIP demonstrates that PM<INF>2.5</INF> emissions from Oklahoma do not
interfere with any other state's measures to protect visibility, and
that this portion of the SIP was approved by EPA on December 28, 2011.
Here, Oklahoma is referring to EPA's approval of all the PM BART
determinations in Oklahoma's 2010 Regional Haze SIP. However, it is
unclear in the submittal how the SIP fulfills the prong 4 requirements
for the 2015 Ozone NAAQS.\30\
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\30\ Id.
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The EPA has not established a separate visibility transport
standard for ozone because it does not directly impair visibility or
substantially produce or contribute to the production of the secondary
air contaminants that cause visibility impairment or regional haze. As
stated above, section 110(a)(2)(D)(i)(II) prong 4 requirements apply to
all pollutants (including precursors) for which EPA has promulgated a
NAAQS. As such, Oklahoma is required to demonstrate to EPA that it has
approved measures in its SIP that ensure that ozone-precursor emissions
within its jurisdiction do not interfere with other states' visibility
protection plans. While ozone itself does not directly impair
visibility, ozone precursors (i.e., NO<INF>X</INF> and in some cases
volatile organic compounds) can react to generate visibility impairing
pollutants. Thus, the pertinent question is whether Oklahoma's SIP
adequately controls emissions of ozone precursors that may contribute
to visibility impairment in other states and whether the level of
control of these emissions is consistent with mutually-agreed emissions
reductions under the CENRAP regional haze planning process for the
first planning period.
As explained in Oklahoma's January 5, 2021 clarification letter,
EPA approved all NO<INF>X</INF> BART determinations in Oklahoma's 2010
Regional Haze SIP and these EPA-approved NO<INF>X</INF> BART
determinations conform with the mutually-agreed emission reductions
\31\ under the CENRAP regional haze planning process that Oklahoma and
other Midwestern states participated in for regional haze SIP
development for the first regional haze planning period.\32\ In the
2013 Oklahoma Regional Haze SIP Revision, Oklahoma revised the
NO<INF>X</INF> BART requirements for the Northeastern Units 3 and 4
that EPA approved in the December 28, 2011 final rule.\33\ The
revisions require earlier installation and compliance with reduced
NO<INF>X</INF> emission limits prior to the original SIP-imposed
deadline.\34\ Our December 2011 approval of NO<INF>X</INF> BART for
Units 3 and 4 required that these units meet a NO<INF>X</INF> emission
limit of 0.15 lb/MMBtu (based on a 30-day rolling average) within five
years from the effective date of EPA's approval, or by January 27,
2017.\35\ However, under the 2013 Oklahoma Regional Haze SIP Revision,
which EPA approved on March 7, 2014, both units are required to meet an
initial NO<INF>X</INF> emission limit of 0.23 lb/MMBtu (based on a 30-
day rolling average) by December 31, 2013, with additional limits of
1,098 lb/hr per unit on a 30-day rolling average basis and a 9,620 tpy
combined cap for both units.\36\ By April 16, 2016, one unit is
required to be permanently shut down, while the remaining unit is
required to meet a NO<INF>X</INF> emission limit of 0.15 lb/MMBtu
(based on a 30-day rolling average), with an additional limit of 716
lb/hr on a 30-day rolling average basis and a cap of 3,137 tpy on a 12-
month rolling basis. Finally, this second unit is required to shut down
by December 31, 2026. Thus, these revised NO<INF>X</INF> BART
determination for the Northeastern Units 3 and 4 are more stringent
than the determinations that we previously approved given that they
require compliance with the 0.15 lb/MMBtu limit on a more expeditious
schedule. The Oklahoma SIP contains NO<INF>X</INF> BART determinations
for all subject-to-BART sources in Oklahoma, which have been approved
by EPA in previous actions and conform with the mutually-agreed
emission reductions under the CENRAP regional haze planning process
that Oklahoma and other Midwestern states participated in for regional
haze SIP development for the first regional haze planning period.
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\31\ During consultation ODEQ indicated that Sooner Units 1 and
2, Muskogee Units 4 and 5, and Northeastern Units 3 and 4 would have
emission limits based on 0.15 lb of NO<INF>X</INF> per MMBtu. ODEQ's
January 5, 2021 letter noted that Section VIII of the 2010 Oklahoma
Regional Haze SIP explained that these emissions reductions for
these six units were included in the CENRAP 2018 modeling
projections that other CENRAP states relied on in developing their
regional haze SIPs.
\32\ 76 FR 81728.
\33\ 76 FR at 81729.
\34\ 78 FR 51686, 51690 (August 21, 2013).
\35\ 76 FR 16168, 16181, 16182 (March 22, 2011).
\36\ 79 FR at 12944.
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In the January 5, 2021 letter, ODEQ also explained that VOC
emissions, which are an ozone precursor, were addressed in the 2010
Oklahoma Regional Haze SIP in a manner consistent with what was
anticipated under the CENRAP process for the first regional haze
planning period. Specifically, in the 2010 Oklahoma Regional Haze SIP,
ODEQ asserted that the emissions inventory associated with that SIP
submittal assigns most VOC emissions to biogenic sources, which ODEQ
considers to be uncontrollable; \37\ The CENRAP modeling shows that
anthropogenic VOC emissions do not significantly impair visibility at
the Wichita Mountains; \38\ And, only a minority of VOC emissions in
Oklahoma originate from area, industrial, point, and mobile sources,
which ODEQ asserted are sources that are already controlled under
various federal mandates.\39\ ODEQ stated in the 2010 Oklahoma Regional
Haze SIP that considering the small and uncertain contribution of
anthropogenic sources of VOC to visibility impairment at the Wichita
Mountains, ODEQ did not find further controls for VOC sources to be
reasonable.\40\ The CENRAP modeling used to project the visibility
impacts in 2018 for Class I areas in CENRAP states, which reflects the
mutually-agreed emissions reductions in CENRAP states, did not assume
additional control of VOC emissions in Oklahoma. In the December 28,
2011 final rule on the 2010 Oklahoma Regional Haze SIP, EPA agreed with
ODEQ's decision to not further evaluate or require additional controls
for VOC emissions in Oklahoma.\41\ Thus, Oklahoma's approach for VOC
emissions in the 2010 Oklahoma Regional Haze SIP has been approved by
EPA and conforms with the mutually-agreed emission reductions under the
CENRAP regional haze planning process that Oklahoma and other
Midwestern states participated in for regional haze SIP development for
the first regional haze planning period.
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\37\ See 2010 Oklahoma Regional Haze SIP, Section IX.E.4, page
113. A copy of the submittal is included in the docket associated
with this proposed rulemaking.
\38\ Id at Section VI.A, page 69.
\39\ Id.
\40\ Id.
\41\ See 76 FR at 81729 77 FR (proposed rule) and 76 FR 81728
(final rule).
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Therefore, we are proposing to find that the Oklahoma SIP includes
the necessary emission reductions to satisfy the 110(a)(2)(D)(i)(II)
prong 4 requirements for the 2015 Ozone NAAQS and are proposing to
approve the portion of the 2018 infrastructure SIP submittal that
addresses interstate visibility transport for the 2015 Ozone NAAQS.
[[Page 38637]]
D. AEP/PSO Northeastern SO2 Emission Reductions Assumed in the CENRAP
Modeling
As discussed earlier in this notice, Oklahoma engaged in a regional
planning process with other CENRAP states to develop their regional
haze SIP for the first planning period. This regional planning process
included a forum in which state representatives built emission
inventories that assumed that specific pollution sources would be
controlled to specific levels. This included adjustments to projected
emissions by ODEQ to reflect the assumption that the OG&E Sooner Units
1 and 2, the OG&E Muskogee Units 4 and 5, and the AEP/PSO Northeastern
Units 3 and 4 would each be controlled to presumptive BART emission
levels for SO<INF>2</INF>,\42\ which is equivalent to 0.15 lb/
MMBtu.\43\ Visibility modeling projections conducted by CENRAP
subsequently included those emission reductions, and other states
relied on them as part of their reasonable progress demonstrations.
However, Oklahoma, in its subsequent 2010 Regional Haze SIP, did not
include these promised reductions on which the other states relied on
in developing their own RPGs and regional haze SIPs. Instead, Oklahoma
determined that SO<INF>2</INF> BART for these units was no additional
control and specified an SO<INF>2</INF> limit of 0.65 lbs/MMBtu on a
30-day rolling average. In a final rule published on December 28, 2011,
we disapproved the SIP's SO<INF>2</INF> BART determinations for these
six units because they do not comply with our regulations under 40 CFR
51.308(e).\44\ In the same final rule, we promulgated a FIP
establishing an emission limit of 0.06 lb/MMBtu for each of the six
units for purposes of complying with SO<INF>2</INF> BART.\45\
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\42\ 76 FR at 16189 and 76 FR at 81735.
\43\ 70 FR 39104, 39131 (July 6, 2005).
\44\ 76 FR at 81730.
\45\ 76 FR 81728.
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On June 20, 2013, Oklahoma submitted a regional haze SIP revision
to replace the FIP's SO<INF>2</INF> BART requirements for the AEP/PSO
Northeastern Units 3 and 4. On March 7, 2014, we approved this SIP
revision and concurrently withdrew the sections of the FIP that applied
to those two units.\46\ The 2013 Oklahoma Regional Haze SIP Revision
requires one of the two Northeastern units to shut down no later than
April 16, 2016, while the remaining unit is required to install dry
sorbent injection (DSI) to meet an SO<INF>2</INF> emission limit of 0.4
lb/MMBtu.\47\ However, the SO<INF>2</INF> emission reductions for the
AEP/PSO Northeastern facility contained in the 2013 Oklahoma Regional
Haze SIP Revision fall short of the levels assumed in other states'
regional haze plans through the CENRAP RPO process. In order to achieve
emission levels equivalent to the levels assumed in other states'
regional haze plans through the CENRAP RPO process, the remaining
Northeastern unit would have to meet an emission limit of 0.3 lb/MMBtu
(0.15 + 0.15).\48\ To address this, the 2013 Oklahoma Regional Haze SIP
Revision also requires the source operators to optimize the performance
of DSI on the remaining unit to ensure that the best possible
performance is achieved and adjust the limit accordingly. The ``AEP/PSO
Settlement Agreement'' included in the 2013 Oklahoma Regional Haze SIP
Revision requires the company to develop and propose a monitoring
program to test various operating profiles and other measures in order
to determine whether increased SO<INF>2</INF> removal efficiencies can
be achieved during normal operations.\49\ AEP/PSO was required to
implement this monitoring program and to evaluate and report the
results to EPA and ODEQ. If the evaluation demonstrated that the
technology is capable of sustainably achieving an emission rate of less
than 0.37 lbs/MMBtu on a 30-day rolling average basis without (i)
altering the unit's fuel supply, (ii) incurring additional capital
costs, (iii) increasing operating expenses by more than a negligible
amount, and/or (iv) adversely impacting overall unit operations, ODEQ
would have to propose to revise the emission rate for the remaining
Northeastern unit by 60 percent of the difference between 0.40 and the
demonstrated emission rate.\50\
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\46\ 79 FR 12954.
\47\ 79 FR at 12945.
\48\ Northeastern Units 3 and 4 are similar design capacity so
comparing them as the same is a reasonable approximation for this
contextual assessment. Specific assessment is included later in this
notice and in docket materials.
\49\ See Attachment A, paragraph 1(f) of the ``AEP/PSO
Settlement Agreement,'' which is presented in Appendix I of the June
20, 2013 Oklahoma Regional Haze SIP revision. A copy of the
submittal is found in the docket for this proposed rulemaking.
\50\ Id.
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If it is determined that the remaining operating unit still cannot
meet the emission limit of 0.3 lb/MMBtu, then the 2013 Oklahoma
Regional Haze SIP Revision contains an enforceable commitment
obligating ODEQ to ``obtain and/or identify additional SO<INF>2</INF>
reductions within the State of Oklahoma to the extent necessary to
achieve the anticipated visibility benefits estimated'' by CENRAP.\51\
As explained in our March 7, 2014 final rule approving the 2013
Oklahoma Regional Haze SIP Revision, any additional SO<INF>2</INF>
emissions reductions that can be obtained or identified from the
northeast quadrant of the State will be presumed to count toward the
emission reductions necessary to achieve the anticipated visibility
benefits associated with a 0.30 lb/MMBtu emission limit at Northeastern
Power Station.\52\ Emissions reductions obtained outside the northeast
quadrant that are technically justified will also be counted.\53\ We
explained in our March 7, 2014 final rule that if necessary, additional
emissions reductions are to be obtained via enforceable emission limits
or control equipment requirements where necessary and submitted to EPA
as a SIP revision as expeditiously as practicable, but in no event
later than the end of the first full Oklahoma legislative session
occurring subsequent to AEP/PSO's submission of the evaluation and
report for the monitoring program required under the AEP/PSO Settlement
Agreement.\54\
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\51\ 79 FR at 12945.
\52\ 79 FR at 12945
\53\ 79 FR at 12945.
\54\ 79 FR at 12945.
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On June 25, 2019, AEP/PSO submitted to ODEQ the ``BART
SO<INF>2</INF> Monitoring Program for Northeastern Power Station Unit
3'' (SO<INF>2</INF> Monitoring Program), pursuant to one of the
requirements in the AEP/PSO Settlement Agreement.\55\ Based on the
results of the SO<INF>2</INF> Monitoring Program, AEP/PSO concluded
that the lowest target emission rate sustainably achieved consistent
with the conditions in the AEP/PSO Agreement is 0.35 lb/MMBTU on a 30-
day rolling average basis, and that the resulting federally enforceable
emission rate should be 0.37 lb/MMBtu on a 30-day rolling average
basis.\56\ However, an emission limit of 0.37 lb/MMBtu for AEP/PSO
Northeastern Unit 3 would still fall short of the 0.3 lb/MMBtu emission
limit necessary to achieve emission levels equivalent to the levels
assumed in other states' regional haze plans through the CENRAP RPO
process.
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\55\ A copy of the June 25, 2019 ``BART SO<INF>2</INF>
Monitoring Program for Northeastern Power Station Unit 3'' can be
found in the docket for this proposed rulemaking.
\56\ The 0.37 lb/MMBtu emission rate is 60 percent of the
difference between 0.40 and the demonstrated emission rate (0.35 lb/
MMBtu), per the terms of the AEP/PSO Settlement Agreement.
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Following final disapproval of a SIP revision in whole or in part,
EPA has an obligation under section 110(c) of the Act to either approve
a SIP revision and/or promulgate a FIP to address the disapproval
within 24 months. We believe EPA's FIP obligation under
[[Page 38638]]
section 110(c) could be addressed through a demonstration that the
deficiencies in the Oklahoma SIP that form the basis of our proposed
disapproval of the interstate visibility transport portions of the
Oklahoma i-SIP submissions for the 2010 SO<INF>2</INF> and 2012
PM<INF>2.5</INF> NAAQS are already addressed by the existing FIP in
place for the Oklahoma Regional Haze program. As discussed in the next
section, we have assessed whether the emissions reductions secured by
the existing SO<INF>2</INF> BART emission limits for the OG&E Sooner
Units 1 and 2 and the OG&E Muskogee Units 4 and 5, required under the
existing FIP, are sufficient to make up for any shortfall to achieve
the necessary anticipated visibility benefits associated with a 0.30
lb/MMBtu emission limit at Northeastern Power Station that CENRAP
states agreed on and relied upon in their regional haze plans. We
discuss our technical analysis in the subsection that follows.
E. Proposed Finding That EPA's Prong 4 FIP Obligations Are Satisfied
for the 2010 SO2 and 2012 PM2.5 NAAQS
For the reasons explained above, Oklahoma's reliance on both its
2010 Regional Haze SIP submittal as revised in its 2013 Regional Haze
SIP revision and EPA's FIP that applies to the OG&E Sooner Units 1 and
2 and OG&E Muskogee Units 4 and 5 is insufficient to satisfy its prong
4 requirements in accordance with EPA's 2013 i-SIP guidance. EPA is
thus proposing to disapprove the submissions with regard to CAA section
110(a)(2)(D)(i)(II). EPA's disapproval triggers its obligation to
promulgate a FIP under CAA section 111(c)(1) to address the
deficiencies in the state's SIP. However, as discussed below, EPA finds
that its FIP obligation with respect to prong 4 for these two NAAQS is
already satisfied, and no further action is required.
The FIP we published on December 28, 2011,\57\ included
SO<INF>2</INF> emission limitations for the OG&E Sooner Units 1 and 2,
the OG&E Muskogee Units 4 and 5, and the AEP/PSO Northeastern Units 3
and 4 based on EPA's analysis of the five BART statutory factors, and
these emission limitations reflected a level of control more stringent
than what was assumed in the CENRAP modeling.\58\ On June 20, 2013,
Oklahoma submitted a regional haze SIP revision to replace the FIP's
SO<INF>2</INF> BART requirements for the AEP/PSO Northeastern Units 3
and 4. On March 7, 2014, we approved this SIP revision and concurrently
withdrew the FIP's applicability to these two units.\59\ The FIP
provisions applicable to the OG&E Sooner Units 1 and 2 and the OG&E
Muskogee Units 4 and 5 remain in place.
---------------------------------------------------------------------------
\57\ 76 FR 81728.
\58\ 76 FR 16193.
\59\ 79 FR 12954 (March 7, 2014).
---------------------------------------------------------------------------
As discussed in the previous subsection, based on the results of
the SO<INF>2</INF> Monitoring Program that was required under the AEP/
PSO Settlement Agreement and part of the 2013 Regional Haze SIP
Revision, AEP/PSO concluded that the federally enforceable emission
rate for AEP/PSO Northeastern Unit 3 should be 0.37 lb/MMBtu on a 30-
day rolling average basis. However, this level of control falls short
of the 0.3 lb/MMBtu emission limit necessary to achieve emission levels
equivalent to the levels assumed in other states' regional haze plans
through the CENRAP RPO process. To address this issue, EPA assessed
whether the SO<INF>2</INF> emissions reductions secured from other
facilities under the existing FIP promulgated on December 28, 2011,
would be sufficient to make up for the shortfall in emissions
reductions and associated visibility benefit from the AEP/PSO
Northeastern facility compared to what was assumed in the CENRAP
modeling. Under the CENRAP regional haze planning process, CENRAP
included emissions for these sources based upon Oklahoma's indications
that the OG&E Sooner Units 1 and 2, the OG&E Muskogee Units 4 and 5,
and the AEP/PSO Northeastern Units 3 and 4 would each be controlled to
presumptive BART emission levels for SO<INF>2</INF>, which is 0.15 lb/
MMBtu.\60\ Further, the FIP EPA promulgated on December 28, 2011, which
continues to apply to the OG&E Sooner Units 1 and 2 and the OG&E
Muskogee Units 4 and 5, requires each of these four units to comply
with an emission limit of 0.06 lb/MMBtu for purposes of complying with
the SO<INF>2</INF> BART requirements.\61\
---------------------------------------------------------------------------
\60\ 76 FR at 16189 and 76 FR at 81735.
\61\ Although the FIP requires an SO<INF>2</INF> emission limit
of 0.06 lb/MMBtu for the OG&E Muskogee Units 4 and 5, the company
elected to convert the units to natural gas in 2019 to comply with
this emission limit. Therefore, these two units have actual
SO<INF>2</INF> emissions near zero.
---------------------------------------------------------------------------
In Table 1 below, we present the controlled SO<INF>2</INF> annual
emission levels included in the CENRAP chemical transport modeling
using the Comprehensive Air Quality Model with Extensions (CAMx) for
the six units and the controlled SO<INF>2</INF> annual emission levels
required by both the FIP for 4 units and the 2013 Oklahoma Regional
Haze SIP Revision for the AEP/PSO Northeastern facility's 2 units.\62\
These SO<INF>2</INF> annual emissions were based on annual firing rate
information for the base period (2002) and the appropriate lb/MMBtu
emission limit. The CENRAP CAMx modeling assumed that AEP/PSO
Northeastern Units 3 and 4 would have combined controlled
SO<INF>2</INF> emissions of 5,921 tpy, while the 2013 Oklahoma Regional
Haze SIP revision includes control requirements that result in combined
controlled SO<INF>2</INF> emissions of 7,895 tpy using the same annual
firing rate information used in CENRAP's CAMx modeling. This results in
a shortfall of 1,974 tpy between the controlled emission level assumed
in the CENRAP CAMx modeling and the level of control required by the
2013 SIP Revision. The CENRAP CAMx modeling also assumed that the OG&E
Muskogee Units 4 and 5 would have combined controlled SO<INF>2</INF>
emissions of 5,249 tpy, while the FIP requires SO<INF>2</INF> controls
that result in combined controlled SO<INF>2</INF> emissions of 2,100
tpy using the same annual firing rate information used in CENRAP's CAMx
modeling. The FIP results in SO<INF>2</INF> controlled emissions on
Muskogee units that are 3,150 SO<INF>2</INF> tpy lower than the level
assumed in the CENRAP modeling, which is greater than the 1,974 tpy
shortfall from the AEP/PSO Northeastern facility. Focusing on the OG&E
Muskogee Units 4 and 5 alone, the level of SO<INF>2</INF> control
required by the FIP at these two units is sufficient to make up for the
shortfall in emission reductions from the AEP/PSO Northeastern
facility. This is significant because the OG&E Muskogee facility is
located in the northeast quadrant of Oklahoma, which is where the AEP/
PSO Northeastern facility is located. In our final rule approving the
2013 Oklahoma Regional Haze SIP revision, we explained that any
additional SO<INF>2</INF> emissions reductions that can be obtained or
identified from the northeast quadrant of the State will be presumed to
count toward the emission reductions necessary to achieve the
anticipated visibility benefits associated with a 0.30 lb/MMBtu
emission limit at Northeastern Power Station.\63\ The OG&E Sooner Units
1 & 2 also provide additional surplus emissions (3,304 tpy of
SO<INF>2</INF>) that provide benefit beyond the net surplus of 1,176
tpy of SO<INF>2</INF> from the net of Muskogee units surplus and
Northeastern units shortfall (3,150 tpy - 1,974 tpy). The level of
SO<INF>2</INF> controls within EPA's FIP is therefore sufficient
[[Page 38639]]
to make up for the shortfall from the AEP/PSO Northeastern facility.
---------------------------------------------------------------------------
\62\ See the Excel spreadsheet ``NE SIP vs FIP visibility review
calcs.xlsx'' which can be found in the docket for this proposed
rulemaking.
\63\ 79 FR 12945.
Table 1--Comparison of Controlled SO2 Emissions Reductions in SIP/FIP vs. CENRAP CAMx Modeling
--------------------------------------------------------------------------------------------------------------------------------------------------------
CENRAP Modeling
Annual avg. CENRAP modeling Controlled SO2 SIP/FIP
heat input rate SO2 emission emissions SIP/FIP SO2 controlled SO2
Facility/unit used in CAMx limit assumption emission limit emissions (tpy)
modeling for assumption (lb/ (tpy) * (lb/MMBtu) *
SIP (MMBtu/hr) MMBtu)
--------------------------------------------------------------------------------------------------------------------------------------------------------
OG&E Sooner Unit 1................................................. 4,548 0.15 2,988.2 0.06 1,195.3
OG&E Sooner Unit 2................................................. 3,835 0.15 2,519.4 0.06 1,007.7
OG&E Muskogee Unit 4............................................... 4,112 0.15 2,701.7 0.06 ** 1,440.1
OG&E Muskogee Unit 5............................................... 3,877 0.15 2,547.5 0.06 ** 1,080.7
AEP/PSO Northeastern Unit 3........................................ 4,506 0.15 2,960.6 0.40 7,895.0
AEP/PSO Northeastern Unit 4........................................ 4,506 0.15 2,960.6 0 0
------------------------------------------------------------------------------------
Total Controlled SO2 Emissions................................. ............... ............... 16,678 ............... 12,198
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Controlled SO2 emissions calculated based on the 2002 annual heat input rate (MMBtu/yr) of the unit used in CENRAP's CAMx modeling that was included
in CENRAP states SIPs.
** The controlled SO2 emissions we have calculated in this table for the OG&E Muskogee Units 4 and 5 are based on the FIP emission limits and the actual
annual heat input rate (MMBtu/yr). However, OG&E Muskogee Units 4 and 5 converted to natural gas to comply with their SO2 BART emission limits in the
FIP. Therefore, even though the FIP requires SO2 emission limits of 0.06 lb/MMBtu, these two units are actually emitting SO2 at much lower (near
negligible) levels.
Since hourly emission estimates for these six units were also used
in CALPUFF modeling that was part of the BART analyses in the 2010
Oklahoma Regional Haze SIP, the FIP and the 2013 SIP revision, we also
evaluated the difference in modeled emission rates and emissions used
in the CALPUFF modeling to compare the estimated hourly emission rates
between the 0.15 lb/MMBtu presumptive rate utilized in the CENRAP RPO
process and the rates required by the FIP and 2013 SIP revision. The
CALPUFF modeling provides visibility impact information for each of the
three facilities to further support that the net changes in emissions
at these three facilities result in a net surplus of emission
reductions and visibility benefits that supports EPA's proposed
conclusion that visibility transport is adequately addressed for
SO<INF>2</INF>. Below we discuss the difference in emissions followed
by a discussion of the modeled visibility impacts.
Single source modeling with the CALPUFF model was conducted for
each of these facilities using maximum firing rates (instead of the
actual annual firing rate used in CAMx analysis). The use of maximum
firing rate rather than the actual annual rate that was utilized in the
CENRAP CAMx modeling results in a higher estimate of hourly emission
rates and also annual emission rates. Since these maximum hourly
emission rates used for CALPUFF modeling give a larger difference
(larger potential shortfall) for the Northeastern Units 3 & 4 and also
are the emission rates evaluated for individual visibility assessments,
we perform our evaluation on these rates as well as the annual CAMx
modeled rates discussed above and in Table 1. In Table 2, these
controlled SO<INF>2</INF> maximum hourly emission levels were
calculated assuming the maximum heat input rate (MMBtu/hr) of each
unit, which is also the heat input rate used in EPA's CALPUFF BART
modeling for the FIP, multiplied by the applicable emission rate (lb/
MMBtu). A comparison of these numbers shows that even though the AEP/
PSO Northeastern Unit 3 is required to comply with an emission limit of
0.40 lb/MMBtu under the 2013 Oklahoma Regional Haze SIP Revision, which
is higher (less stringent) than the 0.30 lb/MMBtu level (0.15 + 0.15
for Northeastern Units 3 and 4) needed in order to achieve hourly
emission levels equivalent to the levels relied upon in other states'
regional haze plans through the CENRAP RPO process, the total maximum
hourly controlled SO<INF>2</INF> emissions levels for the six units
under the FIP and the 2013 Oklahoma Regional Haze SIP Revision are
lower than the total controlled maximum hourly SO<INF>2</INF> emissions
levels based on the presumptive control level included in the CENRAP
RPO consultation and modeling. In other words, the FIP and the 2013
Oklahoma Regional Haze SIP Revision result in greater SO<INF>2</INF>
emission reductions for these three facilities for the maximum hourly
emissions compared to the maximum hourly emissions based on the 0.15
lb/MMBtu emission limit used in the CENRAP RPO consultation process.
Specifically, the combination of the FIP and the 2013 Oklahoma Regional
Haze SIP Revision result in combined maximum hourly controlled
SO<INF>2</INF> emissions of 3,596.3 lb/hr from the six units, which is
1,293.4 lb/hr less than the levels estimated from the rate (4,889.7 lb/
hr) based on the 0.15 lb of SO<INF>2</INF>/MMBtu controlled emission
rate that Oklahoma shared in consultation and was used in the CENRAP
RPO process, including the CENRAP CAMx modeling. This is because the
FIP requires a greater level of SO<INF>2</INF> control for the OG&E
Sooner Units 1 and 2 and the OG&E Muskogee Units 4 and 5 than the
presumptive rate included in consultation and in the CENRAP CAMx
modeling. The more stringent level of SO<INF>2</INF> controls required
by EPA's FIP is therefore sufficient to make up for the shortfall from
the AEP/PSO Northeastern facility. Using the 0.15 lb/MMBtu controlled
emission rate from the CENRAP CAMx modeling, the maximum hourly
emission rate using the higher firing rate (maximum firing rate)
calculated that AEP/PSO Northeastern Units 3 and 4 would have combined
controlled SO<INF>2</INF> emissions of 1710.9 lb/hr, while the 2013
Oklahoma Regional Haze SIP revision includes control requirements that
result in combined controlled SO<INF>2</INF> maximum hourly emissions
of 2324.8 lb/hr, resulting in a shortfall of 613.9 lb/hr. Using the
0.15 lb/MMBtu from the CENRAP CAMx modeling, the OG&E Muskogee Units 4
and 5 would have combined maximum hourly controlled SO<INF>2</INF>
emissions of 1644 lb/hr, while the FIP requires SO<INF>2</INF> controls
that result in combined maximum hourly controlled SO<INF>2</INF>
emissions of 657.6 lb/hr, a difference of 986.4 lb/hr. This surplus of
986.4 lb/hr of SO<INF>2</INF> is greater than the 613.9 lb/hr shortfall
from the AEP/PSO Northeastern facility. Focusing on the OG&E Muskogee
Units 4 and 5 alone, the level of SO<INF>2</INF> control required by
the FIP at these two units is sufficient to make up for the shortfall
from the AEP/PSO Northeastern facility. This is significant because the
OG&E Muskogee facility is located in the northeast quadrant of
Oklahoma, which is where
[[Page 38640]]
the AEP/PSO Northeastern facility is located. In our final rule
approving the 2013 Oklahoma Regional Haze SIP revision, we explained
that any additional SO<INF>2</INF> emissions reductions that can be
obtained or identified from the northeast quadrant of the State will be
presumed to count toward the emission reductions necessary to achieve
the anticipated visibility benefits associated with a 0.30 lb/MMBtu
emission limit at Northeastern Power Station.\64\ The OG&E Sooner Units
1 & 2 also provide an additional surplus of maximum hourly emission
reductions (920.9 lb/hr of SO<INF>2</INF>) that provide benefit beyond
the net surplus of 372.5 lb/hr of SO<INF>2</INF> from Muskogee units
surplus and Northeastern units shortfall (986.4 lb/hr-613.9 lb/hr). The
level of SO<INF>2</INF> controls within EPA's FIP is therefore
sufficient to make up for the shortfall from the AEP/PSO Northeastern
facility when comparing maximum hourly emissions. In the spreadsheet in
the docket we also evaluated using these maximum hourly emission
estimates on an annual basis (tpy) for general comparison and it also
indicated that EPA's FIP requirements result in a net surplus of annual
emissions.\65\
---------------------------------------------------------------------------
\64\ 79 FR 12945.
\65\ See ``CALPUFF tpy'' tab of the Excel spreadsheet ``NE SIP
vs FIP visibility review calcs.xlsx,'' which can be found in the
docket for this proposed rulemaking.
Table 2--Comparison of Controlled SO2 Emissions Reductions in SIP/FIP vs. CENRAP CALPUFF Modeling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum heat CENRAP modeling CENRAP modeling
input rate SO2 emission controlled SO2 SIP/FIP SO2 SIP/FIP
Facility/unit used in BART limit emissions emission limit controlled SO2
modeling for assumption (lb/ assumption (lb/ (lb/MMBtu) emissions (lb/
FIP (MMBtu/hr) MMBtu) hr) * hr) *
--------------------------------------------------------------------------------------------------------------------------------------------------------
OG&E Sooner Unit 1................................................. 5,116 0.15 767.40 0.06 306.96
OG&E Sooner Unit 2................................................. 5,116 0.15 767.40 0.06 306.96
OG&E Muskogee Unit 4............................................... 5,480 0.15 822.0 0.06 ** 328.8
OG&E Muskogee Unit 5............................................... 5,480 0.15 822.0 0.06 ** 328.8
AEP/PSO Northeastern Unit.......................................... 5,812 0.15 871.8 0.40 2,324.8
AEP/PSO Northeastern Unit.......................................... 5,594 0.15 839.1 0 0
------------------------------------------------------------------------------------
Total Controlled SO2 Emissions................................. ............... ............... 4,889.7 ............... 3,596.3
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Controlled SO2 emissions calculated based on the maximum heat input rate (MMBtu/hr) of the unit used in EPA's BART modeling for the FIP.
** The controlled SO2 emissions we have calculated in this table for the OG&E Muskogee Units 4 and 5 are based on the FIP emission limits. However, OG&E
Muskogee Units 4 and 5 converted to natural gas to comply with their SO2 BART emission limits in the FIP. Therefore, even though the FIP requires SO2
emission limits of 0.06 lb/MMBtu, these two units are actually emitting SO2 at much lower (near negligible) levels.
We also assessed whether the visibility benefits resulting from the
SO<INF>2</INF> controls for the OG&E Sooner Units 1 and 2 and the OG&E
Muskogee Units 4 and 5 under the FIP are estimated to make up for any
visibility benefit shortfall from the AEP/PSO Northeastern Units 3 and
4 by scaling modeled visibility improvements from the CALPUFF modeling
that was performed as part of the 2011 Oklahoma SO<INF>2</INF> BART
FIP.\66\ Based on previous modeling performed for these sources and
other sources in other Region 6 FIPs and SIPs linear scaling within the
ranges performed is a reasonable approach to estimate impacts. We
scaled modeled visibility improvements for Wichita Mountains as well as
Class I areas in other states affected by Oklahoma: Caney Creek
Wilderness Area and Upper Buffalo Wilderness Area in Arkansas and
Hercules-Glades Wilderness Area in Missouri. We used the 2001-2003
average of the 98th percentile of daily maximum dv as the visibility
impact values for our calculations and assumed linear concentration and
linear visibility impairment calculations. Based on our calculations,
the SO<INF>2</INF> emission reduction shortfall in the 2013 Oklahoma
Regional Haze SIP Revision for the AEP/PSO Northeastern Units 3 and 4
(difference between visibility impacts under the 2013 SIP requirements
and the CENRAP consultation and modeling assumptions of 0.15 lb/MMBtu
for each unit) is estimated to result in a visibility benefit shortfall
of 0.096 dv for the four affected Class I areas combined (See Table 3
below).\67\ On the other hand, the FIP's estimated visibility benefits
in excess of the assumptions in the CENRAP consultation and modeling
(i.e., comparing 0.15 lb/MMBtu emission limit from the CENRAP
consultation and CAMx modeling with 0.06 lb/MMBtu emission limit
required under the FIP) with respect to the OG&E Muskogee Units 4 and 5
are 0.332 dv and the OG&E Sooner Units 1 and 2 are 0.190 dv for the
four affected Class I areas combined.\68\ The excess benefit from OG&E
Muskogee Units 4 and 5 alone is enough to more than offset the
Northeastern shortfall at each Class I area, including the nearby areas
in other states. In addition, the cumulative benefit at all four Class
I areas is greater than the cumulative shortfall, resulting in an
overall benefit of 0.236 dv (0.332 dv excess-0.096 dv shortfall = 0.236
dv). Including the benefits from the four OG&E Muskogee and Sooner
units results in t a net estimated excess visibility benefit of 0.425
dv at the four affected Class I areas combined. These results are
summarized in the Table 3 below.
---------------------------------------------------------------------------
\66\ Our calculations are found in the Excel spreadsheet ``NE
SIP vs FIP visibility review calcs.xlsx,'' which can be found in the
docket for this proposed rulemaking.
\67\ See ``Summary Visibility'' tab of the Excel spreadsheet
``NE SIP vs FIP visibility review calcs.xlsx,'' which can be found
in the docket for this proposed rulemaking.
\68\ See ``Summary Visibility'' tab of the Excel spreadsheet
``NE SIP vs FIP visibility review calcs.xlsx,'' which can be found
in the docket for this proposed rulemaking.
[[Page 38641]]
Table 3--Estimated Shortfall and Excess Visibility Benefits at Affected Class I Areas Due to SO2 Controls
--------------------------------------------------------------------------------------------------------------------------------------------------------
2001-2003 Average 98th percentile value ([Delta]dv)
------------------------------------------------------------------------------------
AEP/PSO Sum of OG&E
Northeastern OG&E Sooner OG&E Muskogee Sooner and Estimated net
Class I Area estimated estimated estimated Muskogee excess
visibility visibility visibility estimated visibility
benefit benefit excess benefit excess visibility benefit \3\
shortfall \1\ \2\ ([Delta]dv) \2\ ([Delta]dv) benefit excess ([Delta]dv)
([Delta]dv) \2\ ([Delta]dv)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Wichita Mountains.................................................. 0.033 0.097 0.091 0.187 0.154
Caney Creek........................................................ 0.025 0.035 0.072 0.107 0.082
Upper Buffalo...................................................... 0.017 0.033 0.094 0.127 0.110
Hercules-Glades.................................................... 0.022 0.026 0.076 0.102 0.081
------------------------------------------------------------------------------------
Total.......................................................... 0.096 0.190 0.332 0.522 0.425
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Based on a comparison of SO2 control requirements for the AEP/PSO Northeastern facility in the 2013 Regional Haze SIP (i.e., zero emissions for one
unit and 0.4 lb/MMBtu for the remaining unit) against the CENRAP consultation and modeling assumptions (0.15 lb/MMBtu for each unit).
\2\ Based on a comparison of SO2 control requirements in the FIP (0.06 lb/MMBtu for each unit) against the CENRAP consultation and modeling assumptions
(0.15 lb/MMBtu for each unit).
\3\ Based on a comparison of the ``Sum of OG&E Sooner and Muskogee Estimated Visibility Benefit Excess'' column against the ``AEP/PSO Northeastern
Estimated Visibility Benefit Shortfall'' column.
The FIP SO<INF>2</INF> emission limits for the OG&E Sooner Units 1
and 2 and the OG&E Muskogee Units 4 and 5 are permanent and federally
enforceable.\69\ Therefore, we are proposing to find that the existing
SO<INF>2</INF> emission limits for the OG&E Sooner Units 1 and 2 and
the OG&E Muskogee Units 4 and 5, required under the FIP, are sufficient
to make up for the shortfall in the 2013 Oklahoma Regional Haze SIP
Revision to secure the emission reductions necessary to achieve the
anticipated visibility benefits associated with a 0.30 lb/MMBtu
emission limit at Northeastern Power Station.
---------------------------------------------------------------------------
\69\ Due to litigation over the FIP, the deadline by which these
units were required to meet their SO<INF>2</INF> emission limits
contained in the FIP is January 4, 2019. The necessary control
equipment was installed by the compliance deadline and these units
are currently meeting their SO<INF>2</INF> emission limits.
---------------------------------------------------------------------------
The CENRAP modeling did not assume there would be any PM emission
reductions from sources in Oklahoma for the first planning period.
Therefore, the PM BART determinations in Oklahoma's 2010 Regional Haze
SIP, which EPA approved on December 28, 2011,\70\ conform with the
mutually agreed emission reductions under the CENRAP regional haze
planning process. Based on our assessment presented in the preceding
paragraphs, we believe that the SO<INF>2</INF> controls required by the
existing FIP, in combination with the SO<INF>2</INF> controls required
by the EPA-approved 2013 Oklahoma Regional Haze SIP Revision,
constitute an assemblage of SO<INF>2</INF> controls that conform with
the mutually agreed emission reductions under the CENRAP regional haze
planning process. This ensures that the existing FIP, together with the
approved SIP, prevents sources in Oklahoma from emitting pollutants in
amounts that will interfere with efforts to protect visibility in other
states with respect to the 2010 1-hour SO<INF>2</INF> and the 2012
PM<INF>2.5</INF> NAAQS. Under EPA's 2013 i-SIP guidance, this is
sufficient to satisfy prong 4 requirements for the first planning
period.\71\ Thus, there are no additional practical consequences from
this disapproval for the state, the sources within its jurisdiction, or
the EPA.\72\ EPA is proposing to find that its prong 4 obligations in
Oklahoma for the 2010 1-hour SO<INF>2</INF> and 2012 PM<INF>2.5</INF>
NAAQS are satisfied.
---------------------------------------------------------------------------
\70\ 76 FR 81728.
\71\ See 2013 i-SIP Guidance at 33.
\72\ Id at 34-35.
---------------------------------------------------------------------------
F. Impact on Areas of Indian Country
Following the U.S. Supreme Court decision in McGirt v. Oklahoma,
140 S.Ct. 2452 (2020), the Governor of the State of Oklahoma requested
approval under Section 10211(a) of the Safe, Accountable, Flexible,
Efficient Transportation Equity Act of 2005: A Legacy for Users, Public
Law 109-59, 119 Stat. 1144, 1937 (August 10, 2005) (``SAFETEA''), to
administer in certain areas of Indian country (as defined at 18 U.S.C.
1151) the State's environmental regulatory programs that were
previously approved by the EPA outside of Indian country.\73\ The
State's request excluded certain areas of Indian country further
described below. In addition, the State only sought approval to the
extent that such approval is necessary for the State to administer a
program in light of Oklahoma Dept. of Environmental Quality v. EPA, 740
F.3d 185 (D.C. Cir. 2014).\74\
---------------------------------------------------------------------------
\73\ A copy of the Governor's July 22, 2020 request can be found
in the docket for this proposed rulemaking.
\74\ In ODEQ v. EPA, the D.C. Circuit held that under the CAA, a
state has the authority to implement a SIP in non-reservation areas
of Indian country in the state, where there has been no
demonstration of tribal jurisdiction. Under the D.C. Circuit's
decision, the CAA does not provide authority to states to implement
SIPs in Indian reservations. ODEQ did not, however, substantively
address the separate authority in Indian country provided
specifically to Oklahoma under SAFETEA. That separate authority was
not invoked until the State submitted its request under SAFETEA, and
was not approved until EPA's decision, described in this section, on
October 1, 2020.
---------------------------------------------------------------------------
On October 1, 2020, the EPA approved Oklahoma's SAFETEA request to
administer all of the State's EPA-approved environmental regulatory
programs, including the Oklahoma SIP, in the requested areas of Indian
country.\75\ As requested by Oklahoma, the EPA's approval under SAFETEA
does not include Indian country lands, including rights-of-way running
through the same, that: (1) Qualify as Indian allotments, the Indian
titles to which have not been extinguished, under 18 U.S.C. 1151(c);
(2) are held in trust by the United States on behalf of an individual
Indian or Tribe; or (3) are owned in fee by a Tribe, if the Tribe (a)
acquired that fee title to such land, or an area that included such
land, in accordance with a treaty with the United States to which such
Tribe was a party, and (b) never allotted the land to a member or
citizen of the Tribe (collectively ``excluded Indian country lands'').
---------------------------------------------------------------------------
\75\ A copy of EPA's October 1, 2020 approval can be found in
the docket for this proposed rulemaking.
---------------------------------------------------------------------------
EPA's approval under SAFETEA expressly provided that to the extent
EPA's prior approvals of Oklahoma's environmental programs excluded
[[Page 38642]]
Indian country, any such exclusions are superseded for the geographic
areas of Indian country covered by the EPA's approval of Oklahoma's
SAFETEA request.\76\ The approval also provided that future revisions
or amendments to Oklahoma's approved environmental regulatory programs
would extend to the covered areas of Indian country (without any
further need for additional requests under SAFETEA).
---------------------------------------------------------------------------
\76\ EPA's prior approvals relating to Oklahoma's SIP frequently
noted that the SIP was not approved to apply in areas of Indian
country (consistent with the D.C. Circuit's decision in ODEQ v. EPA)
located in the state. See, e.g., 85 FR 20178, 20180 (April 10,
2020). Such prior expressed limitations are superseded by the EPA's
approval of Oklahoma's SAFETEA request.
---------------------------------------------------------------------------
As explained above, the EPA is proposing to disapprove the
interstate visibility transport portions of the Oklahoma i-SIP
submittals for the 2010 SO<INF>2</INF> and the 2012 PM<INF>2.5</INF>
NAAQS because they do not meet the interstate visibility transport
requirements of CAA Section 110(a)(2)(D)(i)(II) with respect to these
NAAQS; however, the EPA is also proposing to make the determination
that the deficiencies forming the basis of the proposed disapproval of
these SIPs are met through the existing Federal Implementation Plan
(FIP) in place for the Oklahoma Regional Haze program. The FIP applies
to all lands within the State regardless of land status. In practice,
the FIP requirements, as discussed previously, only apply to the OG&E
facilities, Sooner Station Units 1 and 2, and Muskogee, Units 4 and 5.
Additionally, EPA is proposing to approve the interstate visibility
transport element of the Oklahoma i-SIP for the 2015 Ozone NAAQS.
Consistent with the D.C. Circuit's decision in ODEQ v. EPA and with
EPA's October 1, 2020, SAFETEA approval, if this approval is finalized
as proposed, this portion of the SIP will apply in certain areas of
Indian country. Under EPA's October 1, 2020 SAFETEA approval, the SIP
will apply to all Indian country within the State of Oklahoma, other
than the excluded Indian country lands. Because--per the State's
request under SAFETEA--EPA's October 1, 2020 approval does not displace
any SIP authority previously exercised by the State under the CAA as
interpreted in ODEQ v. EPA, the SIP will also apply to any Indian
allotments or dependent Indian communities located outside of an Indian
reservation over which there has been no demonstration of tribal
authority. \77\
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\77\ In accordance with Executive Order 13990, EPA is currently
reviewing our October 1, 2020 SAFETEA approval and is engaging in
further consultation with tribal governments and discussions with
the state of Oklahoma as part of this review. EPA also notes that
the October 1, 2020 approval is the subject of a pending challenge
in federal court. (Pawnee v. Regan, No. 20-9635 (10th Cir.)).
Pending completion of EPA's review, EPA is proceeding with this
proposed action in accordance with the October 1, 2020 approval.
EPA's final action on the approved interstate visibility transport
portion of the Oklahoma i-SIP for the 2015 Ozone NAAQS will address
the scope of the state's program with respect to Indian country, and
may make any appropriate adjustments, based on the status of our
review at that time. If EPA's final action on Oklahoma's SIP is
taken before our review of the SAFETEA approval is complete, EPA may
make further changes to the approval of Oklahoma's program to
reflect the outcome of the SAFETEA review.
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This action will not result in the imposition of new requirements
for the affected sources. Rather, it proposes to approve Oklahoma's
determination that the regional haze measures that have already been
approved and are currently being implemented satisfy the visibility
transport requirements for the 2015 Ozone NAAQS and also proposes to
make the determination that the regional haze measures promulgated by
EPA in the Oklahoma FIP that are currently being implemented address
the deficiencies in the Oklahoma SIP with respect to visibility
transport requirements for the 2010 SO<INF>2</INF> and 2012
PM<INF>2.5</INF> NAAQS.
IV. Proposed Action
We are proposing to approve the interstate visibility transport
element of Oklahoma's infrastructure SIP submission for the 2015 Ozone
NAAQS. We are also proposing to disapprove the interstate visibility
transport elements of two SIP submissions from Oklahoma: One for the
2010 1-hour SO<INF>2</INF> NAAQS and the other for the 2012
PM<INF>2.5</INF> NAAQS. In order to address EPA's FIP obligation under
section 110(c) of the Act, we are proposing to find that the
deficiencies in the Oklahoma SIP that form the basis of our proposed
disapproval of the interstate visibility transport portions of the
Oklahoma i-SIP submissions for the 2010 SO<INF>2</INF> and 2012
PM<INF>2.5</INF> NAAQS are already addressed by the existing FIP in
place for the Oklahoma Regional Haze program, and no further federal
action is required.
V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review
This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget for
review.
B. Paperwork Reduction Act (PRA)
This proposed action does not impose an information collection
burden under the PRA because it does not contain any information
collection activities.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. This
action merely proposes to disapprove a SIP submission as not meeting
the CAA.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. The action imposes no enforceable duty on any state,
local or tribal governments or the private sector.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This proposal to approve the interstate visibility transport
element of the Oklahoma i-SIP submission for the 2015 Ozone NAAQS and
to disapprove the interstate visibility transport elements of the
Oklahoma i-SIP submissions for the 2010 1-hour SO<INF>2</INF> NAAQS and
the 2012 PM<INF>2.5</INF> NAAQS (and to propose a determination that no
further action is required to address the deficiencies identified in
the proposed disapproval) will apply, if finalized as proposed, to
certain areas of Indian country as discussed in the preamble, and
therefore has tribal implications as specified in E.O. 13175 (65 FR
67249, November 9, 2000). However, this action will neither impose
substantial direct compliance costs on federally recognized tribal
governments, nor preempt tribal law. This action will not impose
substantial direct compliance costs on federally recognized tribal
governments because no actions will be required of tribal governments.
This action will also not preempt tribal law as no Oklahoma tribe
implements a regulatory program under the CAA, and thus does not have
applicable or related tribal laws. Consistent with the EPA Policy on
Consultation and Coordination with Indian Tribes (May 4,
[[Page 38643]]
2011), the EPA has offered consultation to tribal governments that may
be affected by this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the EPA has reason to believe may disproportionately affect
children, per the definition of ``covered regulatory action'' in
section 2-202 of the Executive Order. This action is not subject to
Executive Order 13045 because it merely proposes to disapprove a SIP
submission as not meeting the CAA.
H. Executive Order 13211, Actions That Significantly Affect Energy
Supply, Distribution or Use
This action is not subject to Executive Order 13211, because it is
not a significant regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act
This rulemaking does not involve technical standards.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
EPA believes the human health or environmental risk addressed by
this action will not have potential disproportionately high and adverse
human health or environmental effects on minority, low-income or
indigenous populations. This action merely proposes to disapprove a SIP
submission as not meeting the CAA.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Ozone,
Particulate matter, Sulfur oxides, Visibility transport.
Authority: 42 U.S.C. 7401 et seq.
Dated: July 15, 2021.
David Gray,
Acting Regional Administrator, Region 6.
[FR Doc. 2021-15467 Filed 7-21-21; 8:45 am]
BILLING CODE 6560-50-P
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</html>Indexed from Federal Register on July 22, 2021.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.