[Federal Register Volume 88, Number 155 (Monday, August 14, 2023)]
[Proposed Rules]
[Pages 54998-55006]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-16441]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2023-0375; EPA-HQ-OAR-2021-0663; FRL-11233-01-R8]
Air Plan Approval; Wyoming; Interstate Transport of Air Pollution
for the 2015 8-Hour Ozone National Ambient Air Quality Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule and withdrawal of 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 the
portion of a Wyoming State Implementation Plan (SIP) submission
addressing interstate transport for the 2015 8-hour ozone national
ambient air quality standards (NAAQS). EPA is also withdrawing our
prior May 24, 2022 proposed disapproval of the interstate transport
portion of the Wyoming SIP submission. The ``good neighbor'' or
``interstate transport'' provision requires that each state's SIP
contain adequate provisions to prohibit emissions from within the state
from significantly contributing to nonattainment or interfering with
maintenance of the NAAQS in other states. This requirement is part of
the broader set of ``infrastructure'' requirements, which are designed
to ensure that the structural components of each state's air quality
management program are adequate to meet the state's responsibilities
under the CAA.
DATES: Written comments must be received on or before September 13,
2023. As of August 14, 2023, the proposed rule published on May 24,
2022, at 87 FR 31495, is withdrawn.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2023-0375, to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
www.regulations.gov. 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
[[Page 54999]]
restricted by statute. Multimedia submissions (audio, video, etc.) must
be accompanied by a written comment. The written comment is considered
the official comment and should include discussion of all points you
wish to make. EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.
Docket: There are two dockets supporting this action, EPA-R08-OAR-
2023-0375 and EPA-HQ-OAR-2021-0663. Docket No. EPA-R08-OAR-2023-0375
contains information specific to Wyoming, including the notice of
proposed rulemaking. Docket No. EPA-HQ-OAR-2021-0663 contains
additional modeling files, emissions inventory files, technical support
documents, and other relevant supporting documentation regarding
interstate transport of emissions for the 2015 8-hour ozone NAAQS which
are being used to support this action. All comments regarding
information in either of these dockets are to be made in Docket No.
EPA-R08-OAR-2023-0375. All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available electronically in
www.regulations.gov.
FOR FURTHER INFORMATION CONTACT: Adam Clark, Air and Radiation
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver,
Colorado 80202-1129, telephone number: (303) 312-7104, email address:
[email protected].
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.
Table of Contents
I. Background
A. Description of Statutory Background
B. Description of EPA's 4-Step Interstate Transport Regulatory
Process
C. Background on EPA's Ozone Transport Modeling Information
D. EPA's Approach to Evaluating Interstate Transport SIPs for
the 2015 Ozone NAAQS
1. Selection of Analytic Year
2. Step 1 of the 4-Step Interstate Transport Framework
3. Step 2 of the 4-Step Interstate Transport Framework
4. Step 3 of the 4-Step Interstate Transport Framework
5. Step 4 of the 4-Step Interstate Transport Framework
II. Wyoming SIP Submission Addressing Interstate Transport of Air
Pollution for the 2015 8-Hour Ozone NAAQS
A. Summary of Wyoming's 2015 Ozone Interstate Transport SIP
Submission
B. Prior Notices Related to Wyoming's SIP Submission
III. EPA's Evaluation
IV. Proposed Action
V. Statutory and Executive Order Reviews
I. Background
A. Description of Statutory Background
On October 1, 2015, EPA promulgated a revision to the ozone NAAQS
(2015 8-hour ozone NAAQS), lowering the level of both the primary and
secondary standards to 0.070 parts per million (ppm) for the 8-hour
standard.\1\ Section 110(a)(1) of the CAA requires states to submit,
within 3 years after promulgation of a new or revised standard, SIP
submissions meeting the applicable requirements of section
110(a)(2).\2\ One of these applicable requirements is found in CAA
section 110(a)(2)(D)(i)(I), otherwise known as the ``interstate
transport'' or ``good neighbor'' provision, which generally requires
SIPs to contain adequate provisions to prohibit in-state emissions
activities from having certain adverse air quality effects on other
states due to interstate transport of pollution. There are two so-
called ``prongs'' within CAA section 110(a)(2)(D)(i)(I). A SIP for a
new or revised NAAQS must contain adequate provisions prohibiting any
source or other type of emissions activity within the state from
emitting air pollutants in amounts that will significantly contribute
to nonattainment of the NAAQS in another state (prong 1) or interfere
with maintenance of the NAAQS in another state (prong 2). EPA and
states must give independent significance to prong 1 and prong 2 when
evaluating downwind air quality problems under CAA section
110(a)(2)(D)(i)(I).\3\
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\1\ National Ambient Air Quality Standards for Ozone, Final
Rule, 80 FR 65292 (October 26, 2015). Although the level of the
standard is specified in the units of ppm, ozone concentrations are
also described in parts per billion (ppb). For example, 0.070 ppm is
equivalent to 70 ppb.
\2\ SIP revisions that are intended to meet the applicable
requirements of section 110(a)(1) and (2) of the CAA are often
referred to as infrastructure SIPs and the applicable elements under
section 110(a)(2) are referred to as infrastructure requirements.
\3\ See North Carolina v. EPA, 531 F.3d 896, 909-11 (D.C. Cir.
2008).
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B. Description of EPA's 4-Step Interstate Transport Regulatory Process
EPA is using the 4-step interstate transport framework (or 4-step
framework) to evaluate Wyoming's January 3, 2019 SIP submission
addressing interstate transport for the 2015 ozone NAAQS. EPA has
addressed the interstate transport requirements of CAA section
110(a)(2)(D)(i)(I) with respect to prior NAAQS in several regulatory
actions, including the Cross-State Air Pollution Rule (CSAPR), which
addressed interstate transport with respect to the 1997 ozone NAAQS as
well as the 1997 and 2006 fine particulate matter standards,\4\ the
Cross-State Air Pollution Rule Update (CSAPR Update) \5\ and the
Revised Cross-State Air Pollution Rule Update (Revised CSAPR
Update),\6\ both of which addressed the 2008 ozone NAAQS.\7\
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\4\ Federal Implementation Plans: Interstate Transport of Fine
Particulate Matter and Ozone and Correction of SIP Approvals, 76 FR
48208 (Aug. 8, 2011).
\5\ Cross-State Air Pollution Rule Update for the 2008 Ozone
NAAQS, 81 FR 74504 (Oct. 26, 2016).
\6\ Revised Cross-State Air Pollution Rule Update for the 2008
Ozone NAAQS, 86 FR 23054 (April 30, 2021).
\7\ In 2019, the D.C. Circuit Court of Appeals remanded the
CSAPR Update to the extent it failed to require upwind states to
eliminate their significant contribution by the next applicable
attainment date by which downwind states must come into compliance
with the NAAQS, as established under CAA section 181(a). Wisconsin
v. EPA, 938 F.3d 303, 313 (D.C. Cir. 2019). The Revised CSAPR Update
for the 2008 Ozone NAAQS, 86 FR 23054 (April 30, 2021), responded to
the remand of the CSAPR Update in Wisconsin and the vacatur of a
separate rule, the ``CSAPR Close-Out,'' 83 FR 65878 (December 21,
2018), in New York v. EPA, 781 F. App'x. 4 (D.C. Cir. 2019). The
Revised CSAPR Update was upheld in Midwest Ozone Group v. EPA, 61
F.4th 187 (D.C. Cir. 2023).
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Shaped through the years by input from state air agencies \8\ and
other stakeholders on EPA's prior interstate transport rulemakings and
SIP actions,\9\ as well as a number of court decisions, EPA has
developed and used the following 4-step interstate transport framework
to evaluate a state's obligations to eliminate interstate transport
emissions under the interstate transport provision for the ozone NAAQS:
(1) identify monitoring sites that are projected to have problems
attaining and/or maintaining the NAAQS (i.e., nonattainment and/or
maintenance receptors); (2) identify
[[Page 55000]]
states that impact those air quality problems in other (i.e., downwind)
states sufficiently such that the states are considered ``linked'' and
therefore warrant further review and analysis; (3) identify the
emissions reductions necessary (if any), applying a multifactor
analysis, to eliminate each linked upwind state's significant
contribution to nonattainment or interference with maintenance of the
NAAQS at the locations identified in Step 1; and (4) adopt permanent
and enforceable measures needed to achieve those emissions reductions.
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\8\ See 63 FR 57356, 57361 (October 27, 1998).
\9\ In addition to CSAPR rulemakings, other regional rulemakings
addressing ozone transport include the ``NOX SIP Call,''
63 FR 57356 (October 27, 1998), and the ``Clean Air Interstate
Rule'' (CAIR), 70 FR 25162 (May 12, 2005).
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C. Background on EPA's Ozone Transport Modeling Information
In general, EPA has performed nationwide air quality modeling to
project ozone design values which are used in combination with measured
data to identify nonattainment and maintenance receptors at Step 1. To
quantify the contribution of emissions from individual upwind states on
2023 ozone design values for the identified downwind nonattainment and
maintenance receptors at Step 2, EPA has performed multiple iterations
of nationwide, state-level ozone source apportionment modeling for
2023. The source apportionment modeling projected contributions to
ozone at receptors from precursor emissions of anthropogenic nitrogen
oxides (NOX) and volatile organic compounds (VOCs) in
individual upwind states.
EPA has released several documents containing projected ozone
design values, contributions, and information relevant to air agencies
for evaluation of interstate transport with respect to the 2015 ozone
NAAQS. First, on January 6, 2017, EPA published a notice of data
availability (NODA) in which the Agency requested comment on
preliminary interstate ozone transport data including projected ozone
design values and interstate contributions for 2023 using a 2011 base
year platform.\10\ In the NODA, EPA used the year 2023 as the analytic
year for this preliminary modeling because this year aligns with the
expected attainment year for Moderate ozone nonattainment areas for the
2015 8-hour ozone NAAQS.\11\ On October 27, 2017, EPA released a
memorandum (October 2017 memorandum) containing updated modeling data
for 2023, which incorporated changes made in response to comments on
the NODA, and was intended to provide information to assist states'
efforts to develop SIP submissions to address interstate transport
obligations for the 2008 ozone NAAQS.\12\ On March 27, 2018, EPA issued
a memorandum (March 2018 memorandum) noting that the same 2023 modeling
data released in the October 2017 memorandum could also be useful for
identifying potential downwind air quality problems with respect to the
2015 ozone NAAQS at Step 1 of the 4-step interstate transport
framework.\13\ The March 2018 memorandum also included the then newly
available contribution modeling data for 2023 to assist states in
evaluating their impact on potential downwind air quality problems for
the 2015 8-hour ozone NAAQS under Step 2 of the 4-step interstate
transport framework.\14\ EPA notes that the State of Wyoming relied
upon 2023 modeling contribution data released with the March 2018
memorandum in developing its 2019 SIP submission. EPA subsequently
issued two more memoranda in August and October 2018, providing
additional information to states developing interstate transport SIP
submissions for the 2015 ozone NAAQS concerning, respectively,
potential contribution thresholds that may be appropriate to apply in
Step 2 of the 4-step interstate transport framework, and considerations
for identifying downwind areas that may have problems maintaining the
standard at Step 1 of the 4-step interstate transport framework.\15\
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\10\ See Notice of Availability of the Environmental Protection
Agency's Preliminary Interstate Ozone Transport Modeling Data for
the 2015 8-hour Ozone National Ambient Air Quality Standard (NAAQS),
82 FR 1733 (January 6, 2017).
\11\ 82 FR 1735.
\12\ See Information on the Interstate Transport State
Implementation Plan Submissions for the 2008 Ozone National Ambient
Air Quality Standards under Clean Air Act Section
110(a)(2)(D)(i)(I), October 27, 2017, available in docket ID No.
EPA-HQ-OAR-2021-0663.
\13\ See Information on the Interstate Transport State
Implementation Plan Submissions for the 2015 Ozone National Ambient
Air Quality Standards under Clean Air Act Section
110(a)(2)(D)(i)(I), March 27, 2018 (``March 2018 memorandum''),
available in docket ID No. EPA-HQ-OAR-2021-0663.
\14\ The March 2018 memorandum, however, provided, ``While the
information in this memorandum and the associated air quality
analysis data could be used to inform the development of these SIPs,
the information is not a final determination regarding states'
obligations under the good neighbor provision. Any such
determination would be made through notice-and-comment rulemaking.''
\15\ See Analysis of Contribution Thresholds for Use in Clean
Air Act Section 110(a)(2)(D)(i)(I) Interstate Transport State
Implementation Plan Submissions for the 2015 Ozone National Ambient
Air Quality Standards, August 31, 2018 (``August 2018 memorandum''),
and Considerations for Identifying Maintenance Receptors for Use in
Clean Air Act Section 110(a)(2)(D)(i)(I) Interstate Transport State
Implementation Plan Submissions for the 2015 Ozone National Ambient
Air Quality Standards, October 19, 2018, available in docket ID No.
EPA-HQ-OAR-2021-0663.
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Following the release of the modeling data shared in the March 2018
memorandum, EPA performed updated modeling using a 2016-based emissions
modeling platform (i.e., 2016v1). This emissions platform was developed
under the EPA/Multi-Jurisdictional Organization (MJO)/state
collaborative project.\16\ This collaborative project was a multi-year
joint effort by EPA, MJOs, and states to develop a new, more recent
emissions platform for use by EPA and states in regulatory modeling as
an improvement over the dated 2011-based platform that EPA had used to
project ozone design values and contribution data provided in the 2017
and 2018 memoranda. EPA used the 2016v1 emissions to project ozone
design values and contributions for 2023. On October 30, 2020, in the
notice of proposed rulemaking for the Revised CSAPR Update, EPA
released and accepted public comment on 2023 modeling that used the
2016v1 emissions platform.\17\ Although the Revised CSAPR Update
addressed transport for the 2008 ozone NAAQS, the projected design
values and contributions from the 2016v1 platform were also useful for
identifying downwind ozone problems and linkages with respect to the
2015 ozone NAAQS.\18\
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\16\ The results of this modeling, as well as the underlying
modeling files, are included in docket ID No. EPA-HQ-OAR-2021-0663.
The 2016v1 emissions modeling technical support document is
available in Docket ID No. EPA-HQ-OAR-2020-0272-0187. Both dockets
are available at https://www.regulations.gov.
\17\ See 85 FR 68964, 68981.
\18\ See the Air Quality Modeling Technical Support Document for
the Final Revised Cross-State Air Pollution Rule Update, included in
the Headquarters docket ID No. EPA-HQ-OAR-2021-0663.
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Following the final Revised CSAPR Update, EPA made further updates
to the 2016-based emissions platform to include updated onroad mobile
emissions from Version 3 of EPA's Motor Vehicle Emission Simulator
(MOVES) model (MOVES3) \19\ and updated emissions projections for
electric generating units (EGUs) that reflected the emissions
reductions from the Revised CSAPR Update, recent information on plant
closures, and other inventory improvements. EPA published these
emissions inventories on its website in September of 2021 and invited
initial feedback from states and other interested stakeholders.\20\ The
construct of the updated emissions platform, 2016v2, is described in
the
[[Page 55001]]
``Technical Support Document (TSD): Preparation of Emissions
Inventories for the 2016v2 North American Emissions Modeling
Platform,'' hereafter known as the 2016v2 Emissions Modeling TSD, and
is included in Docket No. EPA-HQ-OAR-2021-0663. The EPA performed air
quality modeling using the 2016v2 emissions to provide projections of
ozone design values and contributions in 2023 and 2026 that reflect the
effects on air quality of the 2016v2 emissions platform. EPA used the
results of the 2016v2 modeling as part of our previous proposed
evaluation of the Wyoming 2019 SIP submission with respect to Steps 1
and 2 of the 4-step interstate transport framework. See 87 FR 31495
(May 24, 2022).
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\19\ Additional details and documentation related to the MOVES3
model can be found at https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves.
\20\ https://www.epa.gov/air-emissions-modeling/2016v2-platform.
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EPA invited and received comments on the 2016v2 emissions
inventories and modeling used to support proposals, including the
proposal on Wyoming, related to interstate transport under the 2015
ozone NAAQS. In response to these comments, EPA made a number of
updates to the 2016v2 inventories and model design to construct a
2016v3 emissions platform which was used to update the air quality
modeling. EPA used this updated modeling to inform a final rulemaking
taking final action on 21 interstate transport SIP submissions for the
2015 ozone NAAQS, which did not include Wyoming.\21\ Details on the
2016v3 air quality modeling and the methods for projecting design
values and determining contributions in 2023 and 2026 are described in
the TSD titled ``Air Quality Modeling Final Rule TSD--2015 Ozone NAAQS
Good Neighbor Plan,'' hereafter known as the Final Good Neighbor Plan
AQM TSD.\22\ Additional details related to the updated 2016v3 emissions
platform are located in the TSD titled ``Preparation of Emissions
Inventories for the 2016v3 North American Emissions Modeling
Platform,'' hereafter known as the 2016v3 Emissions Modeling TSD,
included in Docket ID No. EPA-HQ-OAR-2021-0663.\23\
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\21\ ``Air Plan Disapprovals; Interstate Transport of Air
Pollution for the 2015 8-Hour Ozone National Ambient Air Quality
Standards,'' 88 FR 9336 (February 13, 2023), and ``Federal ``Good
Neighbor Plan'' for the 2015 Ozone National Ambient Air Quality
Standards,'' 88 FR 36654 (June 5, 2023).
\22\ Air Quality Modeling Final Rule Technical Support
Document--2015 Ozone NAAQS Good Neighbor Plan in Docket ID No. EPA-
R08-OAR-2023-0375.
\23\ 2016v3 Emissions Modeling TSD in Docket ID No. EPA-HQ-OAR-
2021-0663.
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In this proposed action, EPA primarily relies on modeling based on
the updated 2016v3 emissions platform in evaluating Wyoming's 2019
submission with respect to Steps 1 and 2 of the 4-step interstate
transport framework, which will generally be referenced within this
action as the ``2016v3 modeling'' for 2023 and 2026. By using the
updated modeling results, EPA is using the most current and technically
appropriate information for this proposed rulemaking. In this proposed
action, EPA is accepting public comment on the 2016v3 modeling solely
as it relates to Wyoming's interstate transport obligations for the
2015 ozone NAAQS. EPA is not reopening the modeling in relation to any
other state or regulatory action. Any comments received on the modeling
that are not relevant to the evaluation of Wyoming's interstate-
transport obligations will be treated as beyond the scope of this
action.
D. EPA's Approach to Evaluating Interstate Transport SIPs for the 2015
Ozone NAAQS
EPA proposes to apply a consistent set of policy judgments across
all states for purposes of evaluating interstate transport obligations
and the approvability of interstate transport SIP submissions for the
2015 ozone NAAQS under CAA section 110(a)(2)(D)(i)(I). These policy
judgments conform with relevant case law and past agency practice as
reflected in CSAPR and related rulemakings. Employing a nationally
consistent approach is particularly important in the context of
interstate ozone transport, which is a regional-scale pollution problem
involving many smaller contributors. Effective policy solutions to the
problem of interstate ozone transport going back to the NOX
SIP Call have necessitated the application of a uniform framework of
policy judgments in order to ensure an ``efficient and equitable''
approach. See EME Homer City Generation, LP v. EPA, 572 U.S. 489, 519
(2014).
The remainder of this section describes EPA's analytic framework
with respect to analytic year, definition of nonattainment and
maintenance receptors, selection of contribution threshold, and
multifactor control strategy assessment.
1. Selection of Analytic Year
In general, the states and EPA must implement the interstate
transport provision in a manner ``consistent with the provisions of
[title I of the CAA.]'' See CAA section 110(a)(2)(D)(i). This requires,
among other things, that these obligations are addressed consistently
with the timeframes for downwind areas to meet their CAA obligations.
With respect to ozone NAAQS, under CAA section 181(a), this means
obligations must be addressed ``as expeditiously as practicable'' and
no later than the schedule of attainment dates provided in CAA section
181(a)(1).\24\ Several D.C. Circuit court decisions address the issue
of the relevant analytic year for the purposes of evaluating ozone
transport air-quality problems. On September 13, 2019, the D.C. Circuit
issued a decision in Wisconsin, remanding the CSAPR Update to the
extent that it failed to require upwind states to eliminate their
significant contribution by the next applicable attainment date by
which downwind states must come into compliance with the NAAQS, as
established under CAA section 181(a). See 938 F.3d 303, 313.
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\24\ For attainment dates for the 2015 8-hour ozone NAAQS, refer
to CAA section 181(a), 40 CFR 51.1303, and Additional Air Quality
Designations for the 2015 Ozone National Ambient Air Quality
Standards, 83 FR 25776 (June 4, 2018, effective Aug. 3, 2018).
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On May 19, 2020, the D.C. Circuit issued a decision in Maryland v.
EPA that cited the Wisconsin decision in holding that EPA must assess
the impact of interstate transport on air quality at the next downwind
attainment date, including Marginal area attainment dates, in
evaluating the basis for EPA's denial of a petition under CAA section
126(b) Maryland v. EPA, 958 F.3d 1185, 1203-04 (D.C. Cir. 2020)
(Maryland). The court noted that ``section 126(b) incorporates the Good
Neighbor Provision,'' and, therefore, ``EPA must find a violation [of
section 126] if an upwind source will significantly contribute to
downwind nonattainment at the next downwind attainment deadline.
Therefore, the agency must evaluate downwind air quality at that
deadline, not at some later date.'' Id. at 1204 (emphasis added). EPA
interprets the court's holding in Maryland as requiring the states and
the Agency, under the good neighbor provision, to assess downwind air
quality as expeditiously as practicable and no later than the next
applicable attainment date,\25\ which is currently the 2015 ozone NAAQS
Moderate area attainment date of August 3, 2024 under CAA section 181
for ozone nonattainment.\26\ Thus, 2023 remains
[[Page 55002]]
the appropriate year for analysis of interstate transport obligations
for the 2015 ozone NAAQS because the 2023 ozone season is the last
relevant ozone season during which achieved emissions reductions in
linked upwind states could assist downwind states with meeting the
August 3, 2024 Moderate area attainment date for the 2015 ozone NAAQS.
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\25\ We note that the court in Maryland did not have occasion to
evaluate circumstances in which EPA may determine that an upwind
linkage to a downwind air quality problem exists at steps 1 and 2 of
the interstate transport framework by a particular attainment date,
but for reasons of impossibility or profound uncertainty the Agency
is unable to mandate upwind pollution controls by that date. See
Wisconsin, 938 F.3d at 320. The D.C. Circuit noted in Wisconsin that
upon a sufficient showing, these circumstances may warrant
flexibility in effectuating the purpose of the interstate transport
provision.
\26\ See CAA section 181(a); 40 CFR 51.1303; Additional Air
Quality Designations for the 2015 Ozone National Ambient Air Quality
Standards, 83 FR 25776 (June 4, 2018, effective Aug. 3, 2018).
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EPA recognizes that the attainment date for nonattainment areas
classified as Marginal for the 2015 ozone NAAQS was August 3, 2021.
Under the Maryland holding, any necessary emissions reductions to
satisfy interstate transport obligations should have been implemented
by no later than this date. At the time of the statutory deadline to
submit interstate transport SIPs (October 1, 2018), many states relied
on EPA's modeling of the year 2023, and no state provided an
alternative analysis using a 2021 analytic year (or the prior 2020
ozone season). However, EPA must act on SIP submissions using the
information available at the time it takes such action. In this
circumstance, EPA does not believe it would be appropriate to evaluate
states' obligations under CAA section 110(a)(2)(D)(i)(I) as of an
attainment date that is wholly in the past, because the Agency
interprets the interstate transport provision as forward looking. See
86 FR 23074; see also Wisconsin, 938 F.3d at 322 (rejecting Delaware's
argument that EPA should have used an analytic year of 2011 instead of
2017). Consequently, in this proposal EPA will use the analytical year
of 2023 to evaluate Wyoming's CAA section 110(a)(2)(D)(i)(I) SIP
submission with respect to the 2015 ozone NAAQS.\27\
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\27\ EPA recognizes that by the time final action is taken with
respect to this SIP submission, the 2023 ozone season will likely be
wholly in the past. However, as discussed in section III., the
available modeling information indicates that our analysis would not
change as to Wyoming for any later year.
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2. Step 1 of the 4-Step Interstate Transport Framework
In Step 1, EPA identifies monitoring sites that are projected to
have problems attaining and/or maintaining the NAAQS in the 2023
analytic year. Where EPA's analysis shows that a site does not fall
under the definition of a nonattainment or maintenance receptor, that
site is excluded from further analysis under EPA's 4-step interstate
transport framework. For sites that are identified as a nonattainment
or maintenance receptor in 2023, EPA proceeds to the next step of the
4-step interstate transport framework by identifying which upwind
states contribute to those receptors above the contribution threshold.
EPA's approach to identifying ozone nonattainment and maintenance
receptors in this action gives independent consideration to both the
``contribute significantly to nonattainment'' and the ``interfere with
maintenance'' prongs of CAA section 110(a)(2)(D)(i)(I), consistent with
the D.C. Circuit's direction in North Carolina.\28\
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\28\ See North Carolina v. EPA, 531 F.3d at 910-11 (holding that
the EPA must give ``independent significance'' to each prong of CAA
section 110(a)(2)(D)(i)(I)).
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EPA identifies nonattainment receptors as those monitoring sites
that are projected to have average design values that exceed the NAAQS
and that are also measuring nonattainment based on the most recent
monitored design values. This approach is consistent with prior
transport rulemakings, such as the CSAPR Update, where EPA defined
nonattainment receptors as those areas that both currently measure
nonattainment and that EPA projects will be in nonattainment in the
analytic year (i.e., 2023).\29\
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\29\ See 81 FR 74504 (October 26, 2016). This same concept,
relying on both current monitoring data and modeling to define
nonattainment receptor, was also applied in CAIR. See 70 FR 25241,
25249 (January 14, 2005); see also North Carolina, 531 F.3d at 913-
14 (affirming as reasonable EPA's approach to defining nonattainment
in CAIR).
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In addition, in this proposal, EPA identifies a receptor to be a
``maintenance'' receptor for purposes of defining interference with
maintenance, consistent with the method used in CSAPR and upheld by the
D.C. Circuit in EME Homer City Generation, L.P. v. EPA, 795 F.3d 118,
136 (D.C. Cir. 2015) (EME Homer City II).\30\ Specifically, EPA
identified maintenance receptors as those receptors that would have
difficulty maintaining the relevant NAAQS in a scenario that takes into
account historical variability in air quality at that receptor. The
variability in air quality was determined by evaluating the ``maximum''
future design value at each receptor based on a projection of the
maximum measured design value over the relevant period. EPA interprets
the projected maximum future design value to be a potential future air
quality outcome consistent with the meteorology that yielded maximum
measured concentrations in the ambient data set analyzed for that
receptor (i.e., ozone conducive meteorology). EPA also recognizes that
previously experienced meteorological conditions (e.g., dominant wind
direction, temperatures, and air mass patterns) promoting ozone
formation that led to maximum concentrations in the measured data may
reoccur in the future. The maximum design value gives a reasonable
projection of future air quality at the receptor under a scenario in
which such conditions do, in fact, reoccur. The projected maximum
design value is used to identify upwind emissions that, under those
circumstances, could interfere with the downwind area's ability to
maintain the NAAQS.
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\30\ See 76 FR 48208 (August 8, 2011). CSAPR Update and Revised
CSAPR Update also used this approach. See 81 FR 74504 (October 26,
2016) and 86 FR 23054 (April 30, 2021).
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Nonattainment receptors are also, by definition, maintenance
receptors, and so EPA often uses the term ``maintenance-only'' to refer
to those receptors that are not nonattainment receptors. Consistent
with the concepts for maintenance receptors, as described earlier, EPA
identifies ``maintenance-only'' receptors as those monitoring sites
that have projected average design values above the level of the
applicable NAAQS, but that are not currently measuring nonattainment
based on the most recent official design values.\31\ In addition, those
monitoring sites with projected average design values below the NAAQS,
but with projected maximum design values above the NAAQS are also
identified as ``maintenance-only'' receptors, even if they are
currently measuring nonattainment based on the most recent official
design values.
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\31\ The Agency often uses the terms maintenance receptor and
maintenance-only receptor interchangeably when discussing
maintenance receptors that are not also nonattainment receptors.
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[[Page 55003]]
The Agency has also taken a closer look at measured ozone levels at
monitoring sites in 2021 and 2022 for the purposes of informing the
identification of additional receptors in 2023. As explained in more
detail in the February 13, 2022 final action disapproving 19 states'
good neighbor SIP submissions, and partially approving and partially
disapproving 2 states' good neighbor SIP submissions, see 88 FR 9349-
50, we find there is a basis to consider certain sites with elevated
ozone levels that are not otherwise identified as receptors to be an
additional type of maintenance-only receptor given the likelihood that
ozone levels above the NAAQS could persist at those locations through
at least 2023. We refer to these as violating-monitor maintenance-only
receptors (``violating monitors''). In this action, EPA proposes to use
certified monitoring data as an additional method to identify
maintenance-only receptors. In the case of Wyoming, this analysis
confirms that the state is not projected to be linked to any violating-
monitor receptors. EPA is not reopening this methodology, except to the
extent of its application to Wyoming, nor in relation to the evaluation
of any other state's good neighbor obligations for the 2015 ozone
NAAQS. Any such comments on those topics will be treated as beyond the
scope of this action.
3. Step 2 of the 4-Step Interstate Transport Framework
In Step 2 EPA quantifies the contribution of each upwind state to
each receptor in the 2023 analytic year. The contribution metric used
in Step 2 is defined as the average impact from each state to each
receptor on the days with the highest ozone concentrations at the
receptor based on the 2023 modeling. If a state's contribution value
does not equal or exceed the threshold of 1 percent of the NAAQS (i.e.,
0.70 ppb for the 2015 ozone NAAQS), the upwind state is not ``linked''
to a downwind air quality problem, and EPA therefore concludes that the
state does not contribute significantly to nonattainment or interfere
with maintenance of the NAAQS in the downwind states. However, if a
state's contribution equals or exceeds the 1 percent threshold, the
state's emissions are further evaluated in Step 3, considering both air
quality and cost as part of a multi-factor analysis, to determine what,
if any, emissions might be deemed ``significant'' and, thus, must be
eliminated pursuant to the requirements of CAA section
110(a)(2)(D)(i)(I).
In this proposed action, EPA relies in the first instance on the 1
percent of the NAAQS threshold for the purpose of evaluating a state's
contribution to nonattainment or maintenance of the 2015 ozone NAAQS at
downwind receptors. This is consistent with the Step 2 approach that
EPA applied in CSAPR for the 1997 ozone NAAQS, which has subsequently
been applied in the CSAPR Update and Revised CSAPR Update when
evaluating interstate transport obligations for the 2008 ozone NAAQS.
EPA continues to find 1 percent of the NAAQS to be an appropriate
threshold. For ozone, as EPA found in the CAIR, CSAPR, and CSAPR
Update, a portion of the nonattainment problems from anthropogenic
sources in the U.S. results from the combined impact of relatively
small contributions, typically from multiple upwind states and, in some
cases, substantially larger contributions from a subset of particular
upwind states, along with contributions from in-state sources. EPA's
analysis shows that much of the ozone transport problem in the United
States is still the result of the collective impacts of contributions
from upwind states. Therefore, application of a consistent contribution
threshold is necessary to identify those upwind states that should have
responsibility for addressing their contribution to the downwind
nonattainment and maintenance problems to which they collectively
contribute. Continuing to use 1 percent of the NAAQS as the screening
metric to evaluate collective contribution from many upwind states also
allows EPA (and states) to apply a consistent framework to evaluate
interstate emissions transport under the interstate transport provision
from one NAAQS to the next. See 81 FR 74518; see also 86 FR 23085
(reviewing and explaining rationale from CSAPR, 76 FR 48237-38, for
selection of 1 percent threshold).
4. Step 3 of the 4-Step Interstate Transport Framework
Consistent with EPA's longstanding approach to eliminating
significant contribution and interference with maintenance, at Step 3,
a multifactor assessment of potential emissions controls is conducted
for states linked at Steps 1 and 2. EPA's analysis at Step 3 in prior
Federal actions addressing interstate transport requirements has
primarily focused on an evaluation of cost-effectiveness of potential
emissions controls (on a marginal cost-per-ton basis), the total
emissions reductions that may be achieved by requiring such controls
(if applied across all linked upwind states), and an evaluation of the
air quality impacts such emissions reductions would have on the
downwind receptors to which a state is linked; other factors may
potentially be relevant if adequately supported. In general, where
EPA's or state-provided alternative air quality and contribution
modeling establishes that a state is linked at Steps 1 and 2, it will
be insufficient at Step 3 for a state merely to point to its existing
rules requiring control measures as a basis for SIP approval. In
general, the emissions-reducing effects of all existing emissions
control requirements are already reflected in the future year projected
air quality results of the modeling for Steps 1 and 2. If the state is
shown to still be linked to one or more downwind receptor(s) despite
these existing controls, but that state believes it has no outstanding
good neighbor obligations, EPA expects the state to provide sufficient
justification to support a conclusion by EPA that the state has
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 the
NAAQS. See CAA section 110(a)(2)(D)(i)(I). While EPA has not prescribed
a particular method for this assessment, EPA expects states at a
minimum to present a sufficient technical evaluation. This would
typically include information on emissions sources, applicable control
technologies, emissions reductions, costs, cost effectiveness, and
downwind air quality impacts of the estimated reductions, before
concluding that no additional emissions controls should be
required.\32\
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\32\ As examples of general approaches for how such an analysis
could be conducted for their sources, states could look to the CSAPR
Update, 81 FR 74504, 74539-51; CSAPR, 76 FR 48208, 48246-63; CAIR,
70 FR 25162, 25195-229; or the NOX SIP Call, 63 FR 57356,
57399-405. See also Revised CSAPR Update, 86 FR 23054, 23086-23116.
Consistently across these rulemakings, the EPA has developed
emissions inventories, analyzed different levels of control
stringency at different cost thresholds, and assessed resulting
downwind air quality improvements.
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5. Step 4 of the 4-Step Interstate Transport Framework
At Step 4, states (or EPA) develop permanent and federally-
enforceable control strategies to achieve the emissions reductions
determined to be necessary at Step 3 to eliminate significant
contribution to nonattainment or interference with maintenance of the
NAAQS. For a state linked at Steps 1 and 2 to rely on an
[[Page 55004]]
emissions control measure at Step 3 to address its interstate transport
obligations, that measure must be included in the state's SIP so that
it is permanent and federally enforceable. See CAA section 110(a)(2)(D)
(``Each such [SIP] shall . . . contain adequate provisions . . . .'').
See also CAA section 110(a)(2)(A); Committee for a Better Arvin v. EPA,
786 F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on
by a state to meet CAA requirements must be included in the SIP).
II. Wyoming SIP Submission Addressing Interstate Transport of Air
Pollution for the 2015 8-Hour Ozone NAAQS
A. Summary of Wyoming's 2015 Ozone Interstate Transport SIP Submission
On January 3, 2019, Wyoming submitted a SIP submission to EPA
addressing the infrastructure requirements of CAA section 110(a)(1) and
(2), including the CAA section 110(a)(2)(D)(i)(I) interstate transport
requirements, for the 2015 8-hour ozone NAAQS.\33\ The SIP submission
provided Wyoming's analysis of the State's impact to downwind states
and concluded that emissions from Wyoming will not significantly
contribute to nonattainment or interfere with maintenance of the 2015
ozone NAAQS in other states in 2023.\34\ The SIP submission cited EPA's
4-step framework, but also included a ``weight-of-evidence''
analysis.\35\ Based on the results of its ``weight-of-evidence''
analysis at Step 2, Wyoming's 2019 SIP submission concluded that
emissions from the State are not linked to a downwind projected
nonattainment or maintenance receptor and therefore do not contribute
to nonattainment or interfere with the maintenance of the 2015 ozone
NAAQS in any downwind state.\36\
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\33\ See Wyoming State Implementation Plan, Interstate
Transport, To Satisfy the Requirements of Clean Air Act
110(a)(2)(i)(I) for the 8-Hour Ozone NAAQS Promulgated in October
2015, December 2018, located in the docket for this rulemaking at
regulations.gov, Docket No. EPA-R08-OAR-2023-0375.
\34\ Wyoming State Implementation Plan, Attachment B at 10.
\35\ See generally id. at 3-10.
\36\ Id. at 9-10.
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B. Prior Notices Related to Wyoming's SIP Submission
On May 24, 2022, the EPA proposed disapproval of the portion of
Wyoming's January 3, 2019 SIP submission addressing CAA section
110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS. 87 FR 31495. In EPA's
proposed disapproval, as part of the evaluation of Wyoming's
submission, we considered the most recently updated modeling platform
available at the time, 2016v2, which established one linkage from
Wyoming to the Douglas County nonattainment receptor in Colorado (Site
ID 80350004), with a projected 2023 contribution from Wyoming of 0.81
ppb.\37\ When EPA completed updated modeling for 2023 and 2026 using
the 2016v3 platform, Wyoming was not projected to be linked to any
downwind nonattainment or maintenance-only receptors in 2023, with a
maximum projected contribution of 0.68 ppb at the Douglas County
nonattainment receptor in 2023.\38\ On January 31, 2023, EPA signed a
final rulemaking, finalizing disapproval of 19 SIP submissions, and
partially approved and partially disapproved two SIP submissions, for
inadequately addressing the good neighbor provision for the 2015 ozone
NAAQS and noted that EPA was not taking final action at that time on
two SIP submissions for which EPA had proposed disapproval, including
Wyoming's.\39\ Based on the updated modeling using the 2016v3 platform,
discussed in section I.C. above, as well as EPA's evaluation in section
III. below, EPA is now withdrawing our May 24, 2022 proposed
disapproval of the 110(a)(2)(D)(i)(I) portion of Wyoming's January 3,
2019 SIP submission, at 87 FR 31495.
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\37\ 87 FR 31505.
\38\ See Final Good Neighbor Plan AQM TSD in Docket ID No. EPA-
R08-OAR-2023-0375.
\39\ See Air Plan Disapprovals; Interstate Transport of Air
Pollution for the 2015 8-Hour Ozone National Ambient Air Quality
Standards, 88 FR 9336 (February 13, 2023).
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III. EPA's Evaluation
Wyoming's 2019 SIP submission addressing CAA section
110(a)(2)(D)(i)(I) for the 2015 Ozone NAAQS relies on the 4-step
framework and the analytic year 2023 contribution modeling results
released with the March 2018 memorandum to conclude that Wyoming does
not significantly contribute to nonattainment or interfere with
maintenance of the 2015 ozone NAAQS in any other state at Step 2 of the
4-step framework.
As described in section I.C. of this proposal, EPA performed air
quality modeling to project ozone design values and contributions for
2023 and 2026 using the 2016v3 emissions platform. EPA proposes to rely
primarily on this updated modeling in evaluating Wyoming's transport
SIP submission. The design values and contributions from the updated
modeling were examined to determine if Wyoming contributes at or above
the threshold of 1 percent of the 2015 ozone NAAQS (0.70 ppb) to any
downwind nonattainment or maintenance receptor.\40\ The data \41\
indicate that the highest contributions from Wyoming to downwind
nonattainment and maintenance-only receptors are 0.68 ppb and 0.67 ppb
in 2023, respectively, and 0.40 ppb and 0.59 ppb in 2026,
respectively.\42\ EPA's evaluation of Wyoming's contributions to
violating-monitor maintenance-only receptors indicate the State's
maximum contribution is 0.42 ppb in 2023.\43\
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\40\ EPA need not assess the data and analysis in Wyoming's
submission, as EPA's updated modeling corroborates Wyoming's
conclusion that the State will not significantly contribute to
nonattainment or interfere with maintenance of the 2015 ozone NAAQS
in any other state.
\41\ Design values and contributions at individual monitoring
sites nationwide are provided in the file Final GNP O3 DVs
Contributions, which is included in docket ID No. EPA-R08-OAR-2023-
0375.
\42\ EPA's analysis indicates that in 2023 Wyoming will have a
0.68 ppb impact at the projected nonattainment receptor in Douglas
County, Colorado (site ID 80350004), and a 0.67 ppb impact at the
projected maintenance-only receptor in Larimer County, Colorado
(site ID 80690011). EPA's analysis indicates maximum 2026 Wyoming
emission impacts of 0.40 ppb at projected nonattainment receptors in
Jefferson County, Colorado (sites 80590006 and 80590011), and 0.59
at a projected maintenance receptor in Larimer County, Colorado
(site 80690011).
\43\ EPA's analysis indicates that in 2023 Wyoming will have a
0.42 ppb impact at the violating-monitor maintenance-only receptor
in Arapahoe County, Colorado (site ID 80050002).
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EPA's evaluation of measured and monitored data and contribution
values in 2023 and 2026 indicates that the contribution to ozone
concentrations in other states from emissions in Wyoming will not equal
or exceed the contribution threshold of 0.70 ppb. Thus, EPA proposes to
find that the State does not impact downwind air quality problems such
that it should be considered ``linked'' at Step 2 of the 4-step
framework, and therefore does not warrant further review and analysis
at Steps 3 and 4. The results of EPA's evaluation are consistent with
the conclusion drawn by Wyoming in the 2019 SIP submission that
emissions from sources in Wyoming will not contribute to nonattainment
or interfere with maintenance of the 2015 ozone NAAQS in any other
state. For these reasons, EPA is proposing to approve Wyoming's 2019
SIP submission with regard to the interstate transport requirements of
CAA section 110(a)(2)(D)(i)(I).
IV. Proposed Action
Based on EPA's evaluation of the impact of air emissions from
Wyoming
[[Page 55005]]
to downwind states using 2023 analytic year modeling as described in
this document, EPA is proposing to approve Wyoming's January 3, 2019
SIP submission as meeting the interstate transport requirements of CAA
section 110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS. EPA is seeking
public comment on the issues discussed in this proposed rule. We will
accept comments from the public on this proposal for the next 30 days.
V. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, the EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely proposes to approve state law as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by state law. For that reason, this action:
Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Orders
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21,
2011);
Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the proposed rule does not have tribal implications and will
not impose substantial direct costs on tribal governments or preempt
tribal law as specified by Executive Order 13175 (65 FR 67249, November
9, 2000).
Executive Order 12898 (Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations, 59 FR 7629,
Feb. 16, 1994) directs Federal agencies to identify and address
``disproportionately high and adverse human health or environmental
effects'' of their actions on minority populations and low-income
populations to the greatest extent practicable and permitted by law.
EPA defines environmental justice (EJ) as ``the fair treatment and
meaningful involvement of all people regardless of race, color,
national origin, or income with respect to the development,
implementation, and enforcement of environmental laws, regulations, and
policies.'' EPA further defines the term fair treatment to mean that
``no group of people should bear a disproportionate burden of
environmental harms and risks, including those resulting from the
negative environmental consequences of industrial, governmental, and
commercial operations or programs and policies.'' Wyoming did not
evaluate environmental justice considerations as part of its SIP
submission; the CAA and applicable implementing regulations neither
prohibit nor require such an evaluation. EPA did not perform an EJ
analysis and did not consider EJ in this action. Consideration of EJ is
not required as part of this action, and there is no information in the
record inconsistent with the stated goal of E.O. 12898 of achieving
environmental justice for people of color, low-income populations, and
Indigenous peoples.
Section 307(b)(1) of the CAA governs judicial review of final
actions by EPA. This section provides, in part, that petitions for
review must be filed in the D.C. Circuit: (i) when the agency action
consists of ``nationally applicable regulations promulgated, or final
actions taken, by the Administrator,'' or (ii) when such action is
locally or regionally applicable, if ``such action is based on a
determination of nationwide scope or effect and if in taking such
action the Administrator finds and publishes that such action is based
on such a determination.'' For locally or regionally applicable final
actions, the CAA reserves to EPA complete discretion to decide whether
to invoke the exception in (ii).\44\
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\44\ In deciding whether to invoke the exception by making and
publishing a finding that an action is based on a determination of
nationwide scope or effect, the Administrator takes into account a
number of policy considerations, including his judgment balancing
the benefit of obtaining the D.C. Circuit's authoritative
centralized review versus allowing development of the issue in other
contexts and the best use of agency resources.
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If EPA takes final action on this proposed rulemaking, the
Administrator intends to exercise the complete discretion afforded to
him under the CAA to make and publish a finding that the final action
(to the extent a court finds the action to be locally or regionally
applicable) is based on a determination of ``nationwide scope or
effect'' within the meaning of CAA section 307(b)(1). Through this
rulemaking action (in conjunction with a series of related actions on
other SIP submissions for the same CAA obligations), EPA interprets and
applies section 110(a)(2)(D)(i)(I) of the CAA for the 2015 ozone NAAQS
based on a common core of nationwide policy judgments and technical
analysis concerning the interstate transport of pollutants throughout
the continental U.S. In particular, EPA is applying here (and in other
proposed and finalized actions related to the same obligations) the
same, nationally consistent 4-step framework for assessing good
neighbor obligations for the 2015 ozone NAAQS. EPA relies on a single
set of updated, 2016-base year photochemical grid modeling results of
the year 2023 as the primary basis for its assessment of air quality
conditions and contributions at steps 1 and 2 of that framework.
Further, EPA proposes to determine and apply a set of nationally
consistent policy judgments to apply the 4-step framework. EPA has
selected nationally uniform analytic years for this analysis and is
applying a nationally uniform approach to nonattainment and maintenance
receptors and a nationally uniform approach to contribution threshold
analysis.\45\ For these reasons, the Administrator intends, if this
proposed action is finalized, to exercise the complete discretion
afforded to him under the CAA to make and publish a finding that this
action is based on a determination of nationwide scope or
[[Page 55006]]
effect for purposes of CAA section 307(b)(1).\46\
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\45\ A finding of nationwide scope or effect is also appropriate
for actions that cover states in multiple judicial circuits. In the
report on the 1977 Amendments that revised section 307(b)(1) of the
CAA, Congress noted that the Administrator's determination that the
``nationwide scope or effect'' exception applies would be
appropriate for any action that has a scope or effect beyond a
single judicial circuit. See H.R. Rep. No. 95-294 at 323, 324,
reprinted in 1977 U.S.C.C.A.N. 1402-03.
\46\ If EPA takes a consolidated, single final action on this
and any other proposed SIP actions with respect to obligations under
CAA section 110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS, that action
may be nationally applicable, and EPA would also anticipate that in
that instance, in the alternative, the Administrator would make and
publish a finding that such final action is based on a determination
of nationwide scope or effect.
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List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Ozone.
Authority: 42 U.S.C. 7401 et seq.
Dated: July 27, 2023.
K.C. Becker,
Regional Administrator, Region 8.
[FR Doc. 2023-16441 Filed 8-11-23; 8:45 am]
BILLING CODE 6560-50-P