[Federal Register Volume 87, Number 35 (Tuesday, February 22, 2022)]
[Proposed Rules]
[Pages 9838-9878]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-02953]
[[Page 9837]]
Vol. 87
Tuesday,
No. 35
February 22, 2022
Part III
Environmental Protection Agency
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40 CFR Part 52
Air Plan Disapproval; Illinois, Indiana, Michigan, Minnesota, Ohio,
Wisconsin; Air Plan Disapproval; Region 5 Interstate Transport of Air
Pollution for the 2015 8-Hour Ozone National Ambient Air Quality
Standards; Proposed Rule
Federal Register / Vol. 87, No. 35 / Tuesday, February 22, 2022 /
Proposed Rules
[[Page 9838]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2022-0006; EPA-HQ-OAR-2021-0663; FRL-9431-01-R5]
Air Plan Disapproval; Illinois, Indiana, Michigan, Minnesota,
Ohio, Wisconsin; Air Plan Disapproval; Region 5 Interstate Transport of
Air Pollution for the 2015 8-Hour Ozone National Ambient Air Quality
Standards
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 disapprove State
Implementation Plan (SIP) submittals from Illinois, Indiana, Michigan,
Minnesota, Ohio, and Wisconsin regarding interstate transport for the
2015 ozone national ambient air quality standards (NAAQS). 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. This disapproval,
if finalized, will establish a 2-year deadline for EPA to promulgate a
Federal Implementation Plan (FIP) to address the relevant interstate
transport requirements, unless EPA approves a subsequent SIP submittal
that meets these requirements. Disapproval does not start a mandatory
sanctions clock.
DATES: Comments: Written comments must be received on or before April
25, 2022.
ADDRESSES: You may send comments, identified as Docket No. EPA-R05-OAR-
2022-0006, by any of the following methods: Federal Rulemaking Portal
at https://www.regulations.gov following the online instructions for
submitting comments or via email to [email protected]. Include Docket
ID No. EPA-R05-OAR-2022-0006 in the subject line of the message.
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to https://www.regulations.gov/, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document. Out
of an abundance of caution for members of the public and our staff, the
EPA Docket Center and Reading Room are open to the public by
appointment only to reduce the risk of transmitting COVID-19. Our
Docket Center staff also continues to provide remote customer service
via email, phone, and webform. For further information on EPA Docket
Center services and the current status, please visit us online at
https://www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT: Olivia Davidson, Environmental
Scientist, Attainment Planning and Maintenance Section, Air Programs
Branch (AR-18J), Environmental Protection Agency, Region 5, 77 West
Jackson Boulevard, Chicago, Illinois 60604, (312) 886-0266,
[email protected]. The EPA Region 5 office is open from 8:30 a.m.
to 4:30 p.m., Monday through Friday, excluding Federal holidays and
facility closures due to COVID-19.
SUPPLEMENTARY INFORMATION:
Public Participation: Submit your comments, identified by Docket ID
No. EPA-R05-OAR-2022-0006, at https://www.regulations.gov (our
preferred method), or the other methods identified in the ADDRESSES
section. Once submitted, comments cannot be edited or removed from the
docket. EPA may publish any comment received to its public docket. Do
not submit to EPA's docket at https://www.regulations.gov 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. 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).
There are two dockets supporting this action, EPA-R05-OAR-2022-0006
and EPA-HQ-OAR-2021-0663. Docket No. EPA-R05-OAR-2022-0006 contains
information specific to Illinois, Indiana, Michigan, Minnesota, Ohio,
and Wisconsin, 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 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-R05-OAR-2022-0006. For additional submission
methods, please contact Olivia Davidson, (312) 886-0266,
[email protected]. For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets. Due to public health concerns related to COVID-
19, the EPA Docket Center and Reading Room are open to the public by
appointment only. Our Docket Center staff also continues to provide
remote customer service via email, phone, and webform. For further
information and updates on EPA Docket Center services, please visit us
online at https://www.epa.gov/dockets.
EPA continues to carefully and continuously monitor information
from the Centers for Disease Control and Prevention (CDC), local area
health departments, and our Federal partners so that we can respond
rapidly as conditions change regarding COVID-19. The index to the
docket for this action, Docket No. EPA-R05-OAR-2022-0006, is available
electronically at www.regulations.gov. 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).
Throughout this document, ``we,'' ``us,'' and ``our'' means EPA.
I. Background
A. Description of Statutory Background
On October 1, 2015, EPA promulgated a revision to the ozone NAAQS
(2015 ozone NAAQS), lowering the level of both the primary and
secondary standards to 0.070 parts per million (ppm).\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
[[Page 9839]]
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 Four Step Interstate Transport Regulatory
Process
EPA is using the 4-step interstate transport framework (or 4-step
framework) to evaluate the states' SIP submittals addressing the
interstate transport provision 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 ozone NAAQS in several
regional 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\ and the Cross-State Air Pollution Rule Update (CSAPR
Update) \5\ and the Revised CSAPR Update, both of which addressed the
2008 ozone NAAQS.\6\
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\4\ See 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\ 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).
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Through the development and implementation of the CSAPR rulemakings
and prior regional rulemakings pursuant to the interstate transport
provision,\7\ EPA, working in partnership with states, developed 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 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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\7\ In addition to the 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. To quantify
the contribution of emissions from specific upwind states on 2023 ozone
design values for the identified downwind nonattainment and maintenance
receptors, EPA performed nationwide, state-level ozone source
apportionment modeling for 2023. The source apportionment modeling
provided 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 evaluating
interstate transport with respect to the 2015 ozone NAAQS. First, on
January 6, 2017, EPA published a notice of data availability (NODA) in
which we requested comment on preliminary interstate ozone transport
data including projected ozone design values and interstate
contributions for 2023 using a 2011 base year platform.\8\ In the NODA,
EPA used the year 2023 as the analytic year for this preliminary
modeling because that year aligns with the expected attainment year for
Moderate ozone nonattainment areas for the 2015 ozone NAAQS.\9\ On
October 27, 2017, we released a memorandum (October 2017 memorandum)
containing updated 2011 platform-based modeling data for 2023, which
incorporated changes made in response to comments on the NODA, and
noted that the modeling may be useful for states developing SIPs to
address interstate transport obligations for the 2008 ozone NAAQS.\10\
On March 27, 2018, we 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.\11\ 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 ozone NAAQS under Step 2 of the 4-
step interstate transport framework.\12\ 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,
[[Page 9840]]
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.\13\
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\8\ See Notice of Availability of the Environmental Protection
Agency's Preliminary Interstate Ozone Transport Modeling Data for
the 2015 ozone National Ambient Air Quality Standard (NAAQS), 82 FR
1733 (January 6, 2017).
\9\ 82 FR at 1735.
\10\ 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 EPA-HQ-
OAR-2021-0663 or at https://www.epa.gov/interstate-air-pollution-transport/interstate-air-pollution-transport-memos-and-notices.
\11\ 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, available in docket EPA-HQ-OAR-
2021-0663 or at https://www.epa.gov/interstate-air-pollution-transport/interstate-air-pollution-transport-memos-and-notices.
\12\ 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.''
\13\ 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 EPA-HQ-
OAR-2021-0663 or at https://www.epa.gov/airmarkets/memo-and-supplemental-information-regarding-interstate-transport-sips-2015-ozone-naaqs.
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Since the release of the modeling data shared in the March 2018
memorandum, EPA has performed 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.\14\ 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.\15\ See 85 FR 68964, 68981. Although the
Revised CSAPR Update addressed transport for the 2008 ozone NAAQS, the
projected design values and contributions from the 2016v1 platform are
also useful for identifying downwind ozone problems and linkages with
respect to the 2015 ozone NAAQS.\16\
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\14\ The results of this modeling, as well as the underlying
modeling files, are included in docket ID No. EPA-HQ-OAR-2021-0663.
\15\ See 85 FR 68964, 68981.
\16\ 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 emissions platform to include mobile emissions from EPA's
Motor Vehicle Emission Simulator MOVES3 model \17\ and updated
emissions projections for electric generating units (EGUs) that reflect
the emissions reductions from the Revised CSAPR Update, recent
information on plant closures, and other sector trends. The construct
of the updated emissions platform, 2016v2, is described in the
emissions modeling technical support document (TSD) for this proposed
rule.\18\
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\17\ 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.
\18\ See Technical Support Document (TSD) Preparation of
Emissions Inventories for the 2016v2 North American Emissions
Modeling Platform included in the Headquarters docket ID No. EPA-HQ-
OAR-2021-0663.
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EPA's latest projections of the baseline EGU emissions uses the
version 6--Summer 2021 Reference Case of the Integrated Planning Model
(IPM).\19\ IPM is a multi-regional, dynamic, and deterministic linear
programming model of the U.S. electric power sector. The model provides
forecasts of least cost capacity expansion, electricity dispatch, and
emission control strategies, while meeting energy demand,
environmental, transmission, dispatch, and reliability constraints.
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\19\ Detailed information and documentation of EPA's Base Case,
including all the underlying assumptions, data sources, and
architecture parameters can be found on EPA's website at: https://www.epa.gov/airmarkets/epas-power-sector-modeling-platform-v6-using-ipm-summer-2021-reference-case.
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The IPM version 6--Summer 2021 Reference Case incorporated recent
updates through the Summer of 2021 to account for updated Federal and
State environmental regulations for EGUs. This projected base case
accounts for the effects of the finalized Mercury and Air Toxics
Standards rule (MATS), CSAPR, the CSAPR Update, the Revised CSAPR
Update, New Source Review settlements, the final Effluent Limitation
Guidelines (ELG) Rule, the Coal Combustion Residual (CCR) Rule, and
other on-the-books Federal and State rules (including renewable energy
tax credit extensions from the Consolidated Appropriations Act of 2021)
through early 2021 impacting sulfur dioxide (SO2),
NOX, directly emitted particulate matter, carbon dioxide,
and power plant operations. It also includes final actions EPA has
taken to implement the Regional Haze Rule and Best Available Retrofit
Technology (BART) requirements. Further, the EPA Platform v6 uses
demand projections from the Energy Information Agency's (EIA) Annual
Energy Outlook (AEO) 2020.
The IPM version 6--Summer 2021 Reference Case uses the National
Electric Energy Data System (NEEDS) v6 database as its source for data
on all existing and planned-committed units. Units are removed from the
NEEDS inventory only if a high degree of certainty could be assigned to
future implementation of the announced future closure or retirement.
The available retirement-related information was reviewed for each
unit, and the following rules are applied to remove:
(i) Units that are listed as retired in the December 2020 EIA
Form 860M
(ii) Units that have a planned retirement year prior to June 30,
2023 in the December 2020 EIA Form 860M
(iii) Units that have been cleared by a regional transmission
operator (RTO) or independent system operator (ISO) to retire before
2023, or whose RTO/ISO clearance to retire is contingent on actions
that can be completed before 2023
(iv) Units that have committed specifically to retire before
2023 under Federal or state enforcement actions or regulatory
requirements
(v) And finally, units for which a retirement announcement can
be corroborated by other available information. Units required to
retire pursuant to enforcement actions or state rules on July 1,
2023 or later are retained in NEEDS v6.
Retirements or closures taking place on or after July 1, 2023 are
captured as constraints on those units in the IPM modeling, and the
units are retired in future year projections per the terms of the
related requirements. Any retirements excluded from the NEEDS v6
inventory can be viewed in the NEEDS spreadsheet.\20\
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\20\ The ``Capacity Dropped'' and the ``Retired Through 2023''
worksheets in NEEDS lists all units that are removed from the NEEDS
v6 inventory--NEEDS v6 Summer 2021 Reference Case. This data can be
found on EPA's website at: https://www.epa.gov/airmarkets/national-electric-energy-data-system-needs-v6.
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As highlighted in previous rulemakings, the IPM documentation, and
EPA's Power Sector Modeling website, EPA's goal is to explain and
document the use of IPM in a transparent and publicly accessible
manner, while also providing for concurrent channels for improving the
model's assumptions and representation by soliciting constructive
feedback to improve the model. This includes making all inputs and
assumptions to the model, output files from the model, and IPM feedback
form publicly available on EPA's website.
EPA performed air quality modeling of the 2016v2 emissions using
the most recent public release version of the Comprehensive Air-quality
Model with extensions (CAMx) photochemical modeling, version 7.10.\21\
EPA now proposes to primarily rely on modeling
[[Page 9841]]
based on the updated and newly available 2016v2 emissions platform in
evaluating these submissions with respect to Steps 1 and 2 of the 4-
step interstate transport framework and generally referenced within
this action as 2016v2 modeling for 2023. By using the updated modeling
results, EPA is using the most current and technically appropriate
information for this proposed rulemaking. Section III of this action
and the Air Quality Modeling TSD for 2015 Ozone NAAQS Transport SIP
Proposed Actions, included in Docket ID No. EPA-HQ-OAR-2021-0663 for
this proposal, contain additional detail on EPA's 2016v2 modeling. In
this action, EPA is accepting public comment on this updated 2023
modeling, which uses a 2016v2 emissions platform. Comments on EPA's air
quality modeling should be submitted in the Regional docket for this
action, docket ID No. EPA-R05-OAR-2022-0006. Comments are not being
accepted in docket ID No. EPA-HQ-OAR-2021-0663.
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\21\ Ramboll Environment and Health, January 2021, www.camx.com.
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States may have chosen to rely on the results of EPA modeling and/
or alternative modeling performed by states or MJOs to evaluate
downwind air quality problems and contributions as part of their
submissions. As most Region 5 states have done so, in Sections III.A,
III.B, III.C, III.D, and III.E, we evaluate how Region 5 states used
air quality modeling information in their submissions.
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 submittals for the
2015 ozone NAAQS. These policy judgments reflect consistency with
relevant case law and past agency practice as reflected in the CSAPR
and related rulemakings. Nationwide consistency in 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 to ensure an
``efficient and equitable'' approach. See EME Homer City, 572 U.S. 489,
519 (2014).
In the March, August, and October 2018 memoranda, EPA recognized
that states may be able to establish alternative approaches to
addressing their interstate transport obligations for the 2015 ozone
NAAQS that vary from a nationally uniform framework. EPA emphasized in
these memoranda, however, that such alternative approaches must be
technically justified and appropriate in light of the facts and
circumstances of each particular state's submittal. In general, EPA
continues to believe that deviation from a nationally consistent
approach to ozone transport must be substantially justified and have a
well-documented technical basis that is consistent with relevant case
law. Where states submitted SIPs that rely on any potential
``flexibilities'' as may have been identified or suggested in the past,
EPA will evaluate whether the state adequately justified the technical
and legal basis for doing so.
EPA notes that certain concepts included in an attachment to the
March 2018 memorandum require unique consideration, and these ideas do
not constitute agency guidance with respect to transport obligations
for the 2015 ozone NAAQS. Attachment A to the March 2018 memorandum
identified a ``Preliminary List of Potential Flexibilities'' that could
potentially inform SIP development.\22\ However, EPA made clear in that
Attachment that the list of ideas were not suggestions endorsed by the
Agency but rather ``comments provided in various forums'' on which EPA
sought ``feedback from interested stakeholders.'' \23\ Further,
Attachment A stated, ``EPA is not at this time making any determination
that the ideas discussed below are consistent with the requirements of
the CAA, nor are we specifically recommending that states use these
approaches.'' \24\ Attachment A to the March 2018 memorandum,
therefore, does not constitute agency guidance, but was intended to
generate further discussion around potential approaches to addressing
ozone transport among interested stakeholders. To the extent states
sought to develop or rely on these ideas in support of their SIP
submittals, EPA will thoroughly review the technical and legal
justifications for doing so.
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\22\ March 2018 memorandum, Attachment A.
\23\ Id. at A-1.
\24\ Id.
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The remainder of this section describes EPA's proposed 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.]'' 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).\25\ 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 v. EPA, 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). 938 F.3d at 313.
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\25\ For attainment dates for the 2015 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). 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,\26\ which is
[[Page 9842]]
now the Moderate area attainment date under CAA section 181 for ozone
nonattainment. The Moderate area attainment date for the 2015 ozone
NAAQS is August 3, 2024.\27\ EPA believes that 2023 is now 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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\26\ 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.
\27\ 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
upon EPA 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 submittals 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 at 23074; see also Wisconsin, 938 F.3d at 322. Consequently, in
this proposal EPA will use the analytical year of 2023 to evaluate each
state's CAA section 110(a)(2)(D)(i)(I) SIP submission with respect to
the 2015 ozone NAAQS.
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, we proceed to the next step of our 4-
step interstate transport framework by identifying the upwind state's
contribution to those receptors.
EPA's approach to identifying ozone nonattainment and maintenance
receptors in this action is consistent with the approach used in
previous transport rulemakings. EPA's approach 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 v. EPA.\28\
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\28\ See North Carolina v. EPA, 531 F.3d at 910-11 (D.C. Cir.
2008) (holding that EPA must give ``independent significance'' to
each prong of CAA section 110(a)(2)(D)(i)(I)).
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For the purpose of this proposal, 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 future 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 the 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).\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, 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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Recognizing that nonattainment receptors are also, by definition,
maintenance receptors, 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
above, 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. 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.
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 significantly contribute to nonattainment or
interfere with maintenance of the NAAQS in the
[[Page 9843]]
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 under CAA section
110(a)(2)(D)(i)(I). EPA is proposing to rely in the first instance on
the 1 percent threshold for the purpose of evaluating a state's
contribution to nonattainment or maintenance of the 2015 ozone NAAQS
(i.e., 0.70 ppb) 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 when evaluating
interstate transport obligations for the 2008 ozone NAAQS. EPA
continues to find 1 percent to be an appropriate threshold. For ozone,
as EPA found in the Clean Air Interstate Rule (CAIR), CSAPR, and the
CSAPR Update, a portion of the nonattainment problems from
anthropogenic sources in the U.S. result from the combined impact of
relatively small contributions from many upwind states, along with
contributions from in-state sources and, in some cases, substantially
larger contributions from a subset of particular upwind states. EPA's
analysis shows that much of the ozone transport problem being analyzed
in this proposed rule is still the result of the collective impacts of
contributions from many 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 at
74518. See also 86 FR at 23085 (reviewing and explaining rationale from
CSAPR, 76 FR at 48237-38, for selection of 1 percent threshold).
i. EPA's Experience With Alternative Step 2 Thresholds
EPA's August 2018 memorandum recognized that in certain
circumstances, a state may be able to establish that an alternative
contribution threshold of 1 ppb is justifiable. Where a state relies on
this alternative threshold, and where that state determined that it was
not linked at Step 2 using the alternative threshold, EPA will evaluate
whether the state provided a technically sound assessment of the
appropriateness of using this alternative threshold based on the facts
and circumstances underlying its application in the particular SIP
submission.
EPA here shares further evaluation of its experience since the
issuance of the August 2018 memorandum regarding use of alternative
thresholds at Step 2. This experience leads the Agency to now believe
it may not be appropriate to continue to attempt to recognize
alternative contribution thresholds at Step 2. The August 2018
memorandum stated that ``it may be reasonable and appropriate'' for
states to rely on an alternative threshold of 1 ppb threshold at Step
2.\31\ (The memorandum also indicated that any higher alternative
threshold, such as 2 ppb, would likely not be appropriate.) However,
EPA also provided that ``air agencies should consider whether the
recommendations in this guidance are appropriate for each situation.''
Following receipt and review of 49 good neighbor SIP submittals for the
2015 ozone NAAQS, EPA's experience has been that nearly every state
that attempted to rely on a 1 ppb threshold did not provide sufficient
information and analysis to support a determination that an alternative
threshold was reasonable or appropriate for that state.
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\31\ August 2018 memorandum at 4.
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For instance, in nearly all submittals, the states did not provide
EPA with analysis specific to their state or the receptors to which its
emissions are potentially linked. In one case, the proposed approval of
Iowa's SIP submittal, EPA expended its own resources to attempt to
supplement the information submitted by the state, in order to more
thoroughly evaluate the state-specific circumstances that could support
approval.\32\ It was at EPA's sole discretion to perform this analysis
in support of the state's submittal, and the Agency is not obligated to
conduct supplemental analysis to fill the gaps whenever it believes a
state's analysis is insufficient. The Agency no longer intends to
undertake supplemental analysis of SIP submittals with respect to
alternative thresholds at Step 2 for purposes of the 2015 ozone NAAQS.
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\32\ Air Plan Approval; Iowa; Infrastructure State
Implementation Plan Requirements for the 2015 Ozone National Ambient
Air Quality Standard, 85 FR 12232 (March 2, 2020). The Agency
received adverse comment on this proposed approval and has not taken
final action with respect to this proposal.
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Furthermore, EPA's experience since 2018 is that allowing for
alternative Step 2 thresholds may be impractical or otherwise
inadvisable for a number of additional policy reasons. For a regional
air pollutant such as ozone, consistency in requirements and
expectations across all states is essential. Based on its review of
submittals to-date and after further consideration of the policy
implications of attempting to recognize an alternative Step 2 threshold
for certain states, the Agency now believes the attempted use of
different thresholds at Step 2 with respect to the 2015 ozone NAAQS
raises substantial policy consistency and practical implementation
concerns.\33\ The availability of different thresholds at Step 2 has
the potential to result in inconsistent application of good neighbor
obligations based solely on the strength of a state's implementation
plan submittal at Step 2 of the 4-Step interstate transport framework.
From the perspective of ensuring effective regional implementation of
good neighbor obligations, the more important analysis is the
evaluation of the emissions reductions needed, if any, to address a
state's significant contribution after consideration of a multifactor
analysis at Step 3, including a detailed evaluation that considers air
quality factors and cost. Where alternative thresholds for purposes of
Step 2 may be ``similar'' in terms of capturing the relative amount of
upwind contribution (as described in the August 2018 memorandum),
nonetheless, use of an alternative threshold would allow certain states
to avoid further evaluation of potential emission controls while other
states must proceed to a Step 3 analysis. This can create significant
equity and consistency problems among states.
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\33\ EPA notes that Congress has placed on EPA a general
obligation to ensure the requirements of the CAA are implemented
consistently across states and regions. See CAA section 301(a)(2).
Where the management and regulation of interstate pollution levels
spanning many states is at stake, consistency in application of CAA
requirements is paramount.
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Further, it is not clear that national ozone transport policy is
best served by allowing for less stringent thresholds at Step 2. EPA
recognized in the August 2018 memorandum that there was some similarity
in the amount of total upwind contribution captured (on a nationwide
basis) between 1 percent and 1 ppb. However, EPA notes that while this
may be true in some sense, that is hardly a compelling basis to move to
a 1 ppb threshold. Indeed, the 1 ppb threshold has the disadvantage of
losing a certain
[[Page 9844]]
amount of total upwind contribution for further evaluation at Step 3
(e.g., roughly seven percent of total upwind state contribution was
lost according to the modeling underlying the August 2018 memorandum;
\34\ in EPA's updated modeling, the amount lost is five percent).
Considering the core statutory objective of ensuring elimination of all
significant contribution to nonattainment or interference of the NAAQS
in other states and the broad, regional nature of the collective
contribution problem with respect to ozone, there does not appear to be
a compelling policy imperative in allowing some states to use a 1 ppb
threshold while others rely on a 1 percent of the NAAQS threshold.
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\34\ See August 2018 memorandum at 4.
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Consistency with past interstate transport actions such as CSAPR,
and the CSAPR Update and Revised CSAPR Update rulemakings (which used a
Step 2 threshold of 1 percent of the NAAQS for two less stringent ozone
NAAQS), is also important. Continuing to use a 1 percent of NAAQS
approach ensures that as the NAAQS are revised and made more stringent,
an appropriate increase in stringency at Step 2 occurs, so as to ensure
an appropriately larger amount of total upwind-state contribution is
captured for purposes of fully addressing interstate transport. See 76
FR 48208, 48237-38.
Therefore, notwithstanding the August 2018 memorandum's recognition
of the potential viability of alternative step 2 thresholds, and in
particular, a potentially applicable 1 ppb threshold, EPA's experience
since the issuance of that memorandum has revealed substantial
programmatic and policy difficulties in attempting to implement this
approach. Nonetheless, EPA is not at this time rescinding the August
2018 memorandum. EPA invites comment on this broader discussion of
issues associated with alternative thresholds at Step 2. Depending on
comment and further evaluation of this issue, EPA may determine to
rescind the August 2018 memorandum in the future.
4. Step 3 of the 4-Step Interstate Transport Framework
Consistent with EPA's longstanding approach to eliminating
significant contribution or interference with maintenance at Step 3,
states linked at Steps 1 and 2 are generally expected to prepare a
multifactor assessment of potential emissions controls. EPA's analysis
at Step 3 in prior Federal actions addressing interstate transport
requirements has primarily focused on an evaluation of the 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 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 approval. In general,
the emissions-reducing effects of all existing emissions control
requirements are already reflected in the air quality results of the
modeling for Steps 1 and 2. If the state is shown still to be linked to
one or more downwind receptor(s), the state must provide a well-
documented evaluation determining whether their emissions constitute
significant contribution or interference with maintenance by evaluating
additional available control opportunities by preparing a multifactor
assessment. 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.\35\
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\35\ 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, 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 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 110(a)(2)(A); Committee for a Better Arvin v. U.S. E.P.A.,
786 F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on
by state to meet CAA requirements must be included in the SIP).
II. SIP Submissions Addressing Interstate Transport of Air Pollution
for the 2015 Ozone NAAQS
Five of the six states within EPA Region 5 that are included in
this multi-state proposed disapproval have chosen to use air quality
modeling performed by the Lake Michigan Air Directors Consortium
(LADCO) \36\ as an alternative to or in addition to EPA's modeling for
the purpose of identifying downwind receptors and upwind state
contributions to these receptors relevant to their submissions. The
LADCO modeling consisted of ozone season (May 1-September 30, 2011)
model simulations using the Comprehensive Air Quality Model with
Extensions, CAMx version 6.4 for a 2011 base year and 2023 as the
future analytic year. In their modeling, LADCO used EPA's 2011-based
``EN'' emissions modeling platform, except for emissions from EGU's in
2023. In their modeling, LADCO used the Eastern Regional Technical
Advisory Committee (ERTAC) EGU Tool version 2.7 \37\ to provide EGU
emissions for 2023, whereas EPA used projected EGU emissions based on
engineering analytics.\38\
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\36\ LADCO works collaboratively with state governments, tribal
governments, and various Federal agencies in Illinois, Indiana,
Michigan, Minnesota, Ohio, and Wisconsin.
\37\ https://www.marama.org/2013-ertac-egu-forecasting-tool-documentation.
\38\ Technical Support Document (TSD) Additional Updates to
Emissions Inventories for the Version 6.3, 2011 Emissions Modeling
Platform for the Year 2023 https://www.epa.gov/air-emissions-modeling/additional-updates-2011-and-2023-emissions-version-63-platform-technical.
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LADCO provided projected 2023 future year average and maximum
design values using the methodology in EPA's 2014 modeling
guidance.\39\ Although projected design values were presented based on
the 3x3 approach and the ``no water cell'' approach, described in the
March 2018 memorandum, LADCO relied upon design values from the 3x3
approach for
[[Page 9845]]
calculating contribution metric values at each receptor.
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\39\ See EPA's 2014 Draft Guidance Document, ``Draft Modeling
Guidance for Demonstrating Attainment of Air Quality Goals for
Ozone, PM2s, and Regional Haze'', https://www.epa.gov/sites/default/files/2020-10/documents/draft-o3-pm-rh-modeling_guidance-2014.pdf.
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Source apportionment modeling was performed by LADCO using the CAMx
Anthropogenic Precursor Culpability Assessment (APCA) tool to calculate
contributions from individual states to ozone at downwind monitoring
sites. In their modeling, LADCO tracked ozone contributions from only
those states that contributed at or above a 1 percent of the NAAQS
threshold to nonattainment and maintenance monitors in the EPA 2023
modeling provided in the March 2018 memorandum.
A. Illinois
Illinois Environmental Protection Agency (IEPA) submitted a SIP
revision to address CAA Section 110(a)(2)(D)(i)(I) on May 21, 2019. The
submission utilized LADCO modeling results previously mentioned. IEPA
followed the 4-step interstate transport framework using an analytic
year of 2023 to identify receptors, Illinois' linkages to receptors,
and assess some emission reduction considerations. The following
sections will discuss IEPA's submission and the information provided
for each step in the process.
1. Information Provided by Illinois Regarding Step 1
For Step 1 in the 4-step framework, the IEPA relied on LADCO
modeling to identify monitoring sites that are projected to have
problems attaining or maintaining the 2015 ozone NAAQS in 2023. As
previously mentioned, the LADCO modeling used the same technique as EPA
to calculate future year design values which were used to identify
maintenance and nonattainment receptors but used the ERTAC EGU Tool for
EGU emissions. IEPA noted they believed that the ERTAC EGU tool
provides better estimates of growth and forecasts than EPA's EGU
emission projections. IEPA identified two maintenance receptors in the
Great Lakes area (Sheboygan, Wisconsin and Allegan County, Michigan) as
well as and three nonattainment receptors and five additional
maintenance receptors in the Northeast. Across the continental U.S.,
IEPA identified a total of twelve nonattainment or maintenance
receptors: seven nonattainment receptors and five maintenance
receptors.\40\
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\40\ IEPA's SIP submission, Table CC, page 15.
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2. Information Provided by Illinois Regarding Step 2
IEPA's submittal at Step 2 presented Illinois' projected 2023
contribution of ozone emissions to the downwind maintenance and
nonattainment receptors and based on LADCO's ``with water'' modeling
\41\ IEPA used a contribution threshold of 1 ppb to define linkage as
opposed to one percent of the 2015 ozone NAAQS standard (0.70 ppb).
Illinois, relying on the August 2018 memorandum, argued that the
state's reliance on the 1 ppb threshold to identify linkages was
justified. First, IEPA asserted that the one percent of the NAAQS
contribution threshold is arbitrary because it is not in the CAA.
Second, IEPA claimed that a one percent of the NAAQS contribution
threshold is inappropriate for the 2015 ozone NAAQS because 0.70 ppb is
an order of magnitude smaller than the biases and errors typically
documented for regional photochemical modeling. IEPA noted that 1 ppb
is very small compared to the allowable error in peak performance and
bias and in IEPA's view is a conservative Step 2 contribution
threshold.
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\41\ Id.
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IEPA identified that Illinois is projected to contribute 14.93 ppb
and 19.25 ppb, respectively, in 2023 to two maintenance receptors:
Sheboygan, Wisconsin (Site ID: 55-117-0006), and Allegan, Michigan
(Site ID: 26-005-0003). IEPA concluded that Illinois is linked above a
contribution threshold of 1 ppb to these receptors.
3. Information Provided by Illinois Regarding Step 3
IEPA provided several arguments to justify their conclusion that no
additional emission reductions are necessary to satisfy Illinois' ozone
transport obligations. The submittal stated that Illinois is developing
new NOX RACT standards for the Chicago area that, in
conjunction with existing NOX reductions, are estimated to
reduce NOX emissions by up to 20,000 tons/year relative to
existing state and Federal regulations impacting non-EGUs since 2014.
IEPA claims that these reductions were not included in any 2023
modeling. Illinois claims these expected emissions reductions,
alongside future Federal rules, will be enough to meet Illinois' good
neighbor obligations.
IEPA asserted that Illinois' contributions to the Sheboygan,
Wisconsin and Allegan County maintenance monitors, which are both in
the LADCO domain, can be addressed in a manner that is fair and
equitable for all involved states through Illinois' participation in
LADCO. Illinois has been a member of LADCO since 1991. IEPA says that
since the inception of LADCO in 1991, ambient ozone concentrations have
drastically decreased in the Lake Michigan region. IEPA stated that it
is working through LADCO to refine ozone forecasting for air quality
and ozone receptors in the Midwest through various means including
updating emissions inventories and a base case for the modeling that
LADCO is preparing. IEPA stated that it expects field data from the
2017 Lake Michigan Ozone Study will inform the LADCO states to better
simulate the meteorology and chemistry of ozone in the Lake Michigan
area.
IEPA also attempted to rely on a concept related to international
emissions, which was developed by outside parties and listed in
Attachment A to the March 2018 memorandum. IEPA noted that if
international emissions and offshore contributions to receptors from
LADCO's modeling, 1.40 ppb to the Sheboygan, Wisconsin receptor and
0.98 ppb at the Allegan County receptor, were subtracted off the top of
the receptors' maximum design values, Allegan, Michigan receptor's
maximum design value would be below 71 ppb and the Sheboygan, Wisconsin
receptor's maximum design value would drop down to 71.4 ppb. IEPA noted
that subtracting international and offshore contributions would result
in Allegan County no longer qualifying as a maintenance receptor.
4. Information Provided by Illinois Regarding Step 4
IEPA did not consider any new permanent and enforceable measures to
reduce emissions in the SIP submission. IEPA instead noted they would
continue to assist LADCO with future modeling and analysis and would
work with EPA to identify additional ``flexibilities'' to define
maintenance, quantify transport, and demonstrate attainment.\42\
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\42\ Illinois' SIP submission at 16.
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B. Indiana
On November 2, 2018 the Indiana Department of Environmental
Management (IDEM) submitted a revision to the Indiana SIP addressing
interstate transport of air pollution for the 2015 ozone NAAQS. The
submission contained what the state characterized as a weight of
evidence analysis of Indiana's ozone transport receptors utilizing
LADCO modeling results previously mentioned. Indiana did not explicitly
follow the 4-Step interstate transport framework but did examine
downwind air quality and Indiana's contributions using an analytic year
of 2023 to describe
[[Page 9846]]
Indiana's linkages to receptors. The following sections will describe
IDEM's submission, and the information provided for each step in the
process.
1. Information Provided by Indiana Regarding Step 1
For Step 1 of the 4-Step framework, IDEM identified monitoring
sites that are projected to have problems attaining and/or maintaining
the 2015 ozone NAAQS in 2023. As previously mentioned, the LADCO
modeling used the same technique as EPA to calculate future year design
values which were used to identify maintenance and nonattainment
receptors but used the ERTAC EGU Tool for EGU emissions. IDEM noted
they believed that the ERTAC EGU tool provides better estimates of
growth and forecasts than EPA's EGU emission projections. IDEM
presented the LADCO results, based on the ``3x3'' approach, which
identified ten receptors: Seven monitors with 2023 maximum design
values above the NAAQS, or maintenance receptors, and three monitors
with 2023 average design values greater than the 2015 ozone standard,
or nonattainment receptors.\43\
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\43\ Indiana's SIP submission Attachment 1, Table 7, page 30.
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2. Information Provided by Indiana Regarding Step 2
IDEM's submittal presented Indiana's projected 2023 ozone
contributions to maintenance and nonattainment receptors projected by
the LADCO modeling. IDEM relied primarily on the August 2018 memorandum
to justify the State's reliance on a 1 ppb contribution threshold to
identify linkages, as opposed to the 1 percent of the 2015 ozone NAAQS
standard (0.70 ppb) contribution threshold. IDEM noted that (1) the
tolerance level of ozone monitors is 1 ppb and (2) model run results
may contain biases larger than 1 percent of the NAAQS (0.70 ppb). Using
a 1 ppb threshold, IDEM identified that Indiana is linked to three
maintenance receptors: Sheboygan, Wisconsin (Monitor ID: 551170006),
Allegan, Michigan (Monitor ID: 260050003), and Richmond, New York
(Monitor ID: 360850067), and one nonattainment receptor: Harford,
Maryland (Monitor ID: 240251001).\44\ \45\ However, IDEM concluded on
the basis of its weight of evidence analysis, summarized in the
following subsection, that the monitors at Sheboygan, Wisconsin and
Allegan, Michigan would be in attainment in 2023.\46\
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\44\ Indiana's SIP submission Attachment 1, Table 1, page 12.
\45\ IDEM acknowledged that both the Harford, Maryland and
Richmond, New York receptors are nonattainment receptors in EPA's
modeling. Indiana's SIP submission Attachment 1, page 12.
\46\ Indiana's SIP submission Attachment 1, page 38, 53.
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3. Information Provided by Indiana Regarding Step 3
IDEM cited Indiana's rule amendments under CSAPR to conclude the
State was already satisfying its good neighbor obligations for the
ozone NAAQS.\47\ In support, IDEM provided a weight-of-evidence
analysis to justify their conclusion that no additional emission
reductions as necessary to satisfy Indiana's ozone transport
obligations. The evidence consisted of an ozone monitoring data
analysis, emissions analysis, and photochemical modeling analyses,
including a back trajectory analysis.
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\47\ Indiana's SIP submission, page 6.
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IDEM provided information ozone and emissions trends. They cited a
general decline in monitored ozone concentrations across Indiana from
2007 through 2017, a decrease in Indiana's overall statewide
NOX emissions and VOC emissions from 2005 to 2014, a
decrease in Indiana EGU NOX emissions from 2011 to 2016, and
projected decreases in Region 5 EGU NOX and VOC emissions
through 2023 relative to a 2011 base year (based on both the ERTAC EGU
Tool and EPA's EGU projections using the Integrated Planning Model
(IPM)). IDEM credited the downward emissions trends to permanent and
enforceable control measures. IDEM made the argument that overall
decreasing ozone concentration and emissions trends in the State, and
in the LADCO states, correlate with reduced contributions to
nonattainment and maintenance receptors outside of Indiana. IDEM also
identified air quality trends at the four downwind receptors to which
IDEM determined Indiana was linked. IDEM asserted that a declining
trend in three-year design values at the receptors in Harford, Maryland
and Richmond, New York in combination with national emission reduction
regulations in place for EGUs, tighter mobile source emission controls
and other transport related emission reduction measures, would result
in those two receptors reaching attainment over time. For the
Sheboygan, Wisconsin and Allegan, Michigan receptors, IDEM concluded
that if ozone design value trends continued as expected then those two
receptors would reach attainment before 2023. IDEM also asserted they
believed that the receptors in the Northeast (Harford, Maryland and
Richmond, New York) received a greater contribution from local sources.
IDEM represented EPA had reached the same conclusion, citing a May 14,
2018 presentation.
Next, IDEM presented an analysis of NOx controls for EGUs and non-
EGUs in the state from 2008 to 2017. IDEM considered current NOx
control measures, consent decree requirements, and future fuel switches
and retirements for large EGUs and non-EGUs. IDEM reported that the
State has seen a downward trend in annual NOX emissions from
both EGUs and non-EGUs due a combination of state and Federal rules
targeting fossil fueled EGUs and other large sources of NOX.
IDEM argued that it would not be cost-effective for non-EGUs to
implement further NOX controls because in 2017 there were
more than 93% fewer NOX emissions from non-EGUs when
compared to EGUs. IDEM stated they expect to see continued future
NOX emission reductions through 2028 from implementation of
Federal rules, the expected shutdown of nine EGUs, planned fuel
switches to natural gas for three EGUs, and enforceable consent decree
caps on NOX emissions at eleven EGUs. IDEM noted that future
retirements or retrofits to coal fired EGUs in Indiana were expected to
reduce NOX emissions by several thousand tons beyond those
projected by either LADCO or EPA. IDEM argued that the non-modeled
emission reductions would further assure future year attainment of the
ozone NAAQS at downwind receptors.
For their photochemical analyses, IDEM presented LADCO modeling
results to show contributions from individual states to 12
monitors,\48\ as well as contributions from individual sectors to the
same 12 monitors.\49\ IDEM noted that Indiana contributed above 1 ppb
to monitors that would be receptors based on EPA's definitions. IDEM
used these data as the backdrop to several arguments related to
potential flexibilities identified in Attachment A to the March 2018
memorandum.\50\ IDEM stated that additional emissions reductions from
EGU and non-EGU sources in Indiana are becoming more difficult to
require because of reduced effectiveness of controls to make
significant decreases in ozone values, operational concerns, and
increased
[[Page 9847]]
costs for customers. IDEM asserted that emission reductions from local
mobile and nonroad sources would be more beneficial to the receptors
than additional reductions from EGUs and non-EGUs in Indiana because
EGUs and non-EGUs contribute less to the receptors than either the
mobile or nonroad sectors. IDEM also argued that EPA should address
contributions from Canada and Mexico as well as contributions from
offshore commercial marine vessels. In addition, IDEM compared 2012-
2017 monitoring data to LADCO's and EPA's modeling and concluded that
all four linked receptors were already below the projected 2023 design
values. IDEM also calculated Indiana's portion of contribution to the
Harford, Maryland receptor as 0.077 ppb (based on a contribution
threshold of 1 ppb) and determined that Indiana would need to reduce
its contribution by 0.0077 ppb to bring the Harford, Maryland receptor
into attainment. IDEM argued that 0.0077 ppb is well within the error
of the model and it would be ``difficult'' to translate into an
emission reduction requirement.\51\
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\48\ Indiana's SIP submission, Attachment 1, Table 9.
\49\ Indiana's SIP submission, Attachment 1, Table 11.
\50\ Based on the reference to the potential flexibilities in
Attachment A to the March 2018 memorandum on page 2 of Attachment 1
to Indiana's SIP submission, EPA assumes the reference to
``flexibilities'' on page 38 of Attachment 1 likewise references
Attachment A to the March 2018 memorandum.
\51\ Indiana's SIP submission, Attachment 1 at 42.
---------------------------------------------------------------------------
Finally, IDEM provided a back trajectory analysis to evaluate
contributions from Indiana to the Harford, Maryland and Richmond, New
York receptors on exceedance days from 2015 to 2017. These back
trajectories were conducted at 10 meters and 750 meters and initialized
at 18Z Greenwich Mean Time over a three-year period from 2015-2017. The
trajectories were run backwards over a 72-hour period from the
exceedance day measured at each of the monitors. Considering the
Harford, Maryland receptor, Indiana measured one back trajectory at 10
meters and six back trajectories at 750 meters that passed through
Indiana. For the Richmond, New York receptor, out of 27 exceedance
days, Indiana measured three back trajectories at 10 meters and eight
trajectories at 750 meters that passed through Indiana. Indiana argues
that only a fraction of the exceedance days at the Harford and Richmond
receptors has back trajectories that pass-through Indiana. Based on
this analysis, IDEM concluded that those receptors are more likely to
be impacted by local emissions and suggested that emission reductions
should come first from the surrounding areas in the Northeast before
from Indiana.
4. Information Provided by Indiana Regarding Step 4
IDEM did not provide a Step 4 analysis.
C. Michigan
Environment, Great Lakes and Energy (EGLE) (formerly Michigan
Department of Environmental Quality) submitted a SIP revision to
address CAA Section 110(a)(2)(D)(i)(I) on March 5, 2019. EGLE utilized
EPA modeling released with the March 2018 memorandum and LADCO modeling
and followed the 4-step interstate transport framework using an
analytic year of 2023 to describe Michigan's linkages to receptors in
other states. The submission also contained a weight-of-evidence
analysis to support EGLE's conclusions. The following sections will
discuss EGLE's submission and the information provided for each step in
the process.
1. Information Provided by Michigan Regarding Step 1
For Step 1 in the 4-step framework, EGLE identified monitoring
sites that are projected to have problems attaining and/or maintaining
the 2015 ozone NAAQS in 2023. EGLE presented the results from both the
EPA modeling from the March 2018 memorandum and LADCO (using both the
with- and without-water approaches). EGLE noted that they believe the
ERTAC EGU Tool uses a more transparent and state-driven data gathering
mechanism for EGU emissions and control projects. EPA's modeling
projected 16 receptors to which Michigan is projected to contribute in
2023. LADCO modeling (with and without water) identified 15 receptors
to which Michigan is projected to contribute in 2023.
2. Information Provided by Michigan Regarding Step 2
The first part of EGLE's submittal's step 2 analysis presented
Michigan's projected contributions to maintenance and nonattainment
receptors in 2023 from both the LADCO modeling (with and without water)
and the EPA modeling released with the March 2018 memorandum. The
submittal noted similar contribution concentrations between the two,
but found that the LADCO results often yielded slightly lower
contribution from Michigan sources than the EPA modeling for some
receptors. The state claimed this is attributed to LADCO's use of the
ERTAC EGU tool which they stated includes information on EGU shutdowns
and facility-specific information not included in the EPA modeling.
EGLE stated they had more confidence in the LADCO modeling.
Further, EGLE attempted to rely on the 1 ppb Significant Impact
Level (SIL) threshold from Guidance on Significant Impact Levels for
Ozone and Fine Particles in the Prevention of Significant Deterioration
Permitting Program (April 17, 2018) \52\ for the Prevention of
Significant Deterioration (PSD) permitting program as an appropriate
contribution threshold to determine whether Michigan was linked to any
receptors at step 2. Michigan argued that if a stationary source's
contributions are insignificant below 1 ppb, then a state's interstate
transport contributions below 1 ppb are likewise insignificant. EGLE
performed an analysis on contribution thresholds to analyze whether a 1
ppb threshold is appropriate for identifying Michigan's linkages. The
analysis looked at all 15 receptors to which Michigan contributes,
based on the LADCO with water modeling, and plotted potential
contribution thresholds ranging from 0.5 to 1.4 ppb against collective
upwind contributions from all source categories and states with
contribution above 0.5 ppb. EGLE plotted the collective contribution as
a function of contribution threshold and concluded the first inflection
point occurred in a majority of the collective contribution at a
contribution threshold between 0.9 and 1 ppb, correlating with the PSD
permitting SIL of 1 ppb. Based on this analysis, EGLE concluded that a
1 ppb contribution threshold was appropriate for use in the good
neighbor context. EGLE also mentioned the August 2018 memorandum,
described in Section I of this proposal, as additional support for the
use of a 1 ppb contribution threshold.\53\
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\52\ https://www.epa.gov/sites/default/files/2018-04/documents/sils_policy_guidance_document_final_signed_4-17-18.pdf.
---------------------------------------------------------------------------
EGLE's Step 2 conclusion was that, based on LADCO with water
modeling, Michigan was projected to be linked above a 1 ppb
contribution threshold in 2023 to three maintenance receptors; 1.85 ppb
to Sheboygan, Wisconsin (Site ID: 36-081-0124), 1.22 ppb to Queens, New
York (Site ID: 36-085-0067), and 1.03 ppb to Richmond, New York (Site
ID: 55-117-0006).
3. Information Provided by Michigan Regarding Step 3
EGLE provided what it characterized as a ``weight-of-evidence
analysis'' in step 3 to justify their conclusion that no additional
emissions reductions are necessary to satisfy Michigan's ozone
transport obligations for the ozone NAAQS. The evidence presented in
EGLE's submittal consisted primarily of an argument that upwind states
should have a lower responsibility to other states when the upwind
state is only linked to maintenance-only receptors.
[[Page 9848]]
EGLE's analysis focused in large part on the Sheboygan, Wisconsin
maintenance receptor (Site ID: 36-081-0124), as EGLE concluded it was
the receptor to which Michigan was projected to contribute the most in
2023 at 1.85 ppb.
On the issue of maintenance receptors, the state referenced a
concept identified by outside parties and listed in Attachment A to the
March 2018 memorandum, which was to consider whether the remedy for
upwind states linked to maintenance receptors could be less stringent
than those linked to nonattainment receptors. EGLE reasoned that
because the CAA incudes different SIP development requirements for
nonattainment and maintenance areas, that likewise nonattainment and
maintenance areas should be treated differently in good neighbor SIPs.
EGLE argued that because the CAA does not require emission reductions
from maintenance areas, then upwind states can potentially make a
sufficient showing they have no obligation to reduce emissions to
monitors in other states projected to be maintaining the NAAQS. EGLE
said they believe the reduction of projected contributions to projected
maintenance receptors is not required in certain circumstances, such as
when: (1) The projected maintenance exceedance is very small in
magnitude, (2) the projected contribution is very small, especially
compared to other states' contributions, (3) sector contributions
demonstrate the majority of contribution is from either sources already
federally regulated or sources without the possibility of additional
regulation, (4) there are large impacts of international emissions, and
(5) there are downward emission trends.
Applying this logic to the Sheboygan, Wisconsin receptor, EGLE
argued that because the projected maximum design value at that receptor
is 72.8 ppb, the projected exceedance above the 2015 ozone NAAQS of 1.9
ppb is very small (values are truncated to ppb, thus 70.9 ppb would be
considered in attainment of the NAAQS). Based on this number, EGLE
argued that further emissions reductions from Michigan would be overly
burdensome. Secondly, citing a potential flexibility in Attachment A to
the March 2018 memorandum related to sector contribution, EGLE claimed
that 77% of contribution to the Sheboygan receptor is from federally
regulated sources or sources that cannot be regulated by Michigan. EGLE
noted that the other sectors of contribution it identified--oil and
gas, EGUs, and non-EGUs--are already controlled by Michigan. EGLE
argued Michigan sources should not be required to implement additional
contribution reductions in light of the relative size of their
contribution.
Citing Attachment A to the March 2018 memorandum, again, EGLE
argued that the three receptors to which Michigan is linked are heavily
influenced by international emissions and other states. EGLE shared
that LADCO modeling projects Michigan's contribution to the Sheboygan
receptor (1.85 ppb) is less than projected contributions from
international contributions and boundary conditions (16.61 ppb),
Illinois (14.93 ppb), Wisconsin (9.1 ppb), biogenic sources (7.19 ppb),
and Indiana (6.19 ppb). EGLE used these numbers and an apportionment of
contributions from states and other sources to the amount the Sheboygan
monitor exceeds the 2015 ozone NAAQS to conclude that additional
emissions reductions from Michigan should not be required.
Additionally, EGLE argued that international contributions to the
Sheboygan receptor, which is geographically close to Canada, should be
eliminated from the projected DV, in which case the Sheboygan monitor
would be in attainment.
EGLE also cited Attachment A to the March 2018 memorandum along
with an interpretation of EME Homer City to argue that EPA cannot
require reductions that would result in a reduction greater than an
upwind state's portion of the difference between the NAAQS and a
maintenance receptor's projected maximum design value. EGLE claimed
that Michigan's apportioned contribution to three linked receptors,
when distributed proportionally among other states that also contribute
more than 1 ppb to those receptors, is less than 0.12 ppb, but that
Michigan's responsibility to the exceedance is actually substantially
less than that amount when the home state's responsibility is
considered. EGLE also stated Michigan's apportioned contribution is at
less than 0.05 ppb of the projected maintenance exceedance at the
Sheboygan receptor, which is less than the variation among the modeled
maximum design values by both LADCO and EPA. EGLE concluded that
because of built-in modeling noise it would be ``difficult'' to either
verify that Michigan contributed 0.05 ppb to the Sheboygan, Wisconsin
receptor or for Michigan to require any additional reduction from
sources in the state.\54\ EGLE speculated it was quite likely that the
three linked receptors would maintain the NAAQS without any emissions
reductions from Michigan at all because the projected exceedances were
small.
---------------------------------------------------------------------------
\54\ Michigan's SIP submission at 27.
---------------------------------------------------------------------------
The state also stated that Michigan has downward emissions trends
(44% and 18% reduction in industrial point source NOX and
VOC emissions from 2008 through 2016, respectively) that are expected
to continue to decline or stay consistent over time due to projected
reductions in emissions from point sources of NOX and VOCs
EGUs, mobile sources and through other Federal measures. For EGUs, EGLE
pointed out that the shutdown of the Marquette Board of Light & Power
Shiras Steam Plant shut down was not included in either EPA or LADCO
modeling and that the U.S. Energy Information Agency's Annual Energy
Outlook anticipates growth in renewable energy in Michigan in 2019 and
a decline in coal beginning in 2022. EGLE also provided a list of
additional coal-fired EGUs that they stated were expected to retire by
2023. To support the conclusion that emissions will further be reduced
from mobile sources and through other Federal action, EGLE listed
several on the books and on the way Federal regulations. Finally, EGLE
noted existing controls on the oil and gas sector (applicable Federal
standards), non-EGUs (subject to the NOX SIP Call), and EGUs
(subject to CSAPR Update).
4. Information Provided by Michigan Regarding Step 4
EGLE concluded it would be unreasonable for Michigan to take
further actions to address its obligations under the good neighbor
provisions for the ozone NAAQS, and so at Step 4 EGLE determined that
no permanent and enforceable measures to reduce emissions were
necessary.
D. Minnesota
Minnesota Pollution Control Agency (MPCA) submitted a SIP revision
to address CAA Section 110(a)(2)(D)(i)(I) on October 1, 2018. The
submission utilized both EPA modeling released with the March 2018
memorandum and LADCO modeling results previously mentioned. Minnesota
followed the 4-step interstate transport framework and used an analytic
year of 2023 to describe Minnesota's lack of contributions to out of
state receptors and assess emission reduction considerations. The
following sections will summarize MPCA's submission and the information
provided for each step in the process.
[[Page 9849]]
1. Information Provided by Minnesota Regarding Step 1
For Step 1 in the 4-step framework, MPCA identified monitoring
sites that are projected to have problems attaining and/or maintaining
the 2015 ozone NAAQS in 2023 according to LADCO modeling and EPA
modeling released in the March 2018 memorandum.\55\ As previously
mentioned, the LADCO modeling efforts used the same technique as EPA to
calculate future year design values which are used to identify
maintenance and nonattainment receptors. The submittal expressed MPCA's
opinion that the ERTAC EGU tool used in LADCO's modeling is superior to
EPA's 2023en modeling platform because the ERTAC EGU tool addresses
economic factors, preserves system reliability, and includes controls
or emissions reductions measure justified through some legal framework.
---------------------------------------------------------------------------
\55\ MPCA's SIP submittal at Tables 2 and 3, pages 8-9.
---------------------------------------------------------------------------
2. Information Provided by Minnesota Regarding Step 2
MPCA's submittal at Step 2 presented Minnesota's projected 2023
ozone contributions to maintenance and nonattainment receptors
identified by both LADCO modeling and EPA modeling released in the
March 2018 memorandum.\55\ The submittal noted there were differences
in identified receptors between the two modeling results, and that the
LADCO results overall yielded slightly lower projected contributions to
downwind receptors from Minnesota sources than EPA modeling.
Minnesota relied on a contribution threshold of 1 percent of the
ozone NAAQS (0.70 ppb) to define linkages for a state's contribution to
downwind air quality problems. Both the LADCO modeling and the EPA
modeling released in the March 2018 memorandum projected that Minnesota
contributes less than 1 percent of the NAAQS to all downwind receptors.
MPCA showed in Table 2 of its submission that the highest projected
contribution to a receptor in 2023 was 0.40 ppb, based on EPA modeling
released in the March 2018 memorandum, or 0.45 ppb, based on LADCO ``no
water'' modeling, to the Milwaukee, Wisconsin receptor (Site ID: 55-
079-0085). Based on this analysis, MPCA concluded that Minnesota was
not linked above 1 percent of the NAAQS to any downwind receptor, and
therefore would not contribute to nonattainment or interference with
maintenance in other state with respect to the ozone NAAQS.
3. Information Provided by Minnesota Regarding Step 3
Despite concluding Minnesota was not linked at Step 2, MPCA
proceeded with a Step 3 analysis. MPCA provided air quality data in
Step 3 to justify that no additional emissions reductions are necessary
to satisfy their transport obligations. MPCA provided evidence of
decreasing ambient ozone concentrations in Minnesota from the mid-1990s
through 2017 as well as decreasing NOX and VOC emissions
from the state from 2002 through 2015 to further support their
conclusion.\56\
---------------------------------------------------------------------------
\56\ See Minnesota's SIP submittal Figures 1-3, pages 10-11.
---------------------------------------------------------------------------
The state concluded that decreasing ambient ozone concentrations in
the state point to Minnesota contributing less to ozone in downwind
states as time goes on. Minnesota provided an analysis of
NOX and VOC emissions levels in the state from 2002 through
2015 to further support this point. According to MPCA, NOX
emissions have been steadily declining in the state from all sectors
and especially from EGUs due to emission limits and reductions required
in that category. MPCA also asserted that VOCs emissions have also seen
a similar decline in Minnesota in the years reported. MPCA concluded
that decreasing emissions in the state would make it unlikely for the
state to contribute significantly to nonattainment or interference with
maintenance in downwind states.
4. Information Provided by Minnesota Regarding Step 4
Citing declining emissions and their conclusion that Minnesota was
not projected to contribute above 1 percent of the NAAQS to any
receptor, MPCA concluded that no additional permanent or enforceable
measures would be needed to address ozone transport contribution from
Minnesota sources. MPCA determined the existing emission controls would
be sufficient to maintain Minnesota's continued contribution of less
than 1 percent of the NAAQS to downwind receptors. In support of this
argument, Minnesota provided a list of several Federal and State
emissions regulations applicable to sources in Minnesota, including
Part 70 permits, the CSAPR NOX trading programs, Mercury and
Air Toxics Standards, and various state standards for SO2,
particulate matter, NOX, NO2, and VOC. Hence,
Minnesota declined to consider any new permanent and enforceable
measures to reduce emissions as part of the Step 4 analysis.
E. Ohio
On September 28, 2018 the Ohio Environmental Protection Agency
(OEPA) submitted a revision to the Ohio SIP addressing interstate
transport of air pollution for the 2015 ozone NAAQS. OEPA stated that
its submittal, which relied on an analytic year of 2023, conforms with
EPA's four-step framework. The following sections will describe what
OEPA provided for each step.
1. Information Provided by Ohio Regarding Step 1
For Step 1 in the 4-step framework, OEPA first identified 10
monitoring sites in the Northeast and Midwest that are projected to be
nonattainment, nonattainment/maintenance, or maintenance-only receptors
for the 2015 ozone NAAQS in 2023 based on LADCO's modeling and EPA's
method for defining nonattainment and maintenance receptors (See Table
1 below, reproduced from OEPA's submission).
Table 1--Ohio's Projected 2023 Nonattainment and Maintenance Monitors
--------------------------------------------------------------------------------------------------------------------------------------------------------
2023
2015-2017 2023 OH Maintenance Status (TX
Site ID County State DV Average DV 2023 Max DV contribution Status DV (TX approach)
approach)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-103-0002........ Suffolk............ NY 76 71.6 73.1 1.75 Nonattainment/ 69.7 Nonattainment.
Maintenance.
09-001-9003........ Fairfield.......... CT 83 71.4 74.2 1.58 Nonattainment/ 73.7 Nonattainment/
Maintenance. Maintenance.
[[Page 9850]]
24-035-1001........ Harford............ MD 75 71.0 73.3 2.83 Nonattainment/ 67.0 Nonattainment.
Maintenance.
36-085-0067........ Richmond........... NY 76 70.9 72.4 2.24 Maintenance..... 68.0 Attainment.
55-117-0006........ Sheyboygan......... WI 80 70.5 72.8 1.17 Maintenance..... 71.1 Maintenance.
09-009-9002........ New Haven.......... CT 82 69.9 72.6 1.12 Maintenance..... 72.6 Maintenance.
09-001-3007........ Fairfield.......... CT 83 69.8 73.7 1.84 Maintenance..... 73.7 Maintenance.
36-081-0124........ Queens............. NY 74 69.2 71.0 1.88 Maintenance..... 70.1 Attainment.
09-001-0017........ Fairfield.......... CT 79 68.9 71.2 1.05 Maintenance..... 71.2 Maintenance.
26-005-0003........ Allegan............ MI 73 68.8 71.5 0.19 Maintenance--Not 71.5 Maintenance--No
Linked. t Linked.
--------------------------------------------------------------------------------------------------------------------------------------------------------
OEPA then claimed that EPA's methodology for determining
maintenance-only receptors is inappropriate because it is more
stringent than EPA's methodology for identifying nonattainment monitors
and is inconsistent with the CAA. In OEPA's view, EPA's methodology
results in greater emissions reduction requirements to address
maintenance receptors than nonattainment receptors. Citing stakeholder-
identified potential flexibilities that were listed in an attachment to
EPA's March 2018 memorandum, OEPA used an alternative method developed
by the Texas Commission for Environmental Quality (TCEQ) to identify
maintenance receptors. This method determines a future year design
value (DV) for purposes of identifying maintenance-only receptors by
applying the model-predicted relative response factor (RRF) to the most
recent 3-year design value (i.e., 2011-2013 design value) within the
five-year base period (i.e., 2009-2013), rather than the highest 3-year
DV in the same 5-year base period, which is used in EPA's approach.
OEPA stated that using the TCEQ approach accounts for emissions
reductions over the five-year period, while also accounting for
meteorological variability, since the design value is calculated based
on monitoring data from a three-year period. By using the TCEQ
approach, Ohio concluded that four monitors which would be either
nonattainment/maintenance receptors under EPA's method would, under the
TCEQ method, actually be nonattainment-only receptors (i.e., sites
261030002 in Suffolk, New York, 240251001 in Harford, Maryland) or
monitors in attainment (i.e., sites 360850067 in Richmond, New York,
and 360810124 in Queens, New York) in 2023.\57\
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\57\ Ohio's SIP submission, Table 1.
---------------------------------------------------------------------------
OEPA's submittal provided information on inter-annual
meteorological variability, ozone design value trends at the four
monitoring sites that the state eliminated as receptors, as well as
recent and projected trends in NOX and VOC emissions to
support the use of an alternative definition of maintenance receptors.
The meteorological information provided in OEPA's submission included
nationwide maps showing the maximum temperature anomaly (i.e.,
departure from the long-term average or ``normal'') for the period May
through October in the years 2011, 2012, and 2013. OEPA concluded from
these maps that temperatures in the Northeast and Midwest were above or
much above average during May through October in each of the years
2011, 2012, and 2013. OEPA examined trends in ozone design values at
each of the four monitoring sites in question and concluded that design
values at these sites have declined substantially from 2000 through
2017 and that although there has been a slight leveling off or increase
in recent years, this is no greater than the normal year to year
variability. In addition, based on the emissions trends data, OEPA
stated that NOX emissions have declined in concert with
these trends in design values and are projected to continue to decline
through 2028 for the continental U.S. as well as those states that were
projected to be linked to the four monitors eliminated under the TCEQ
approach. Based on their analysis of the meteorological and ozone and
emissions trends data, OEPA concluded that the four monitoring sites
identified previously are not reasonably expected to have difficulty
maintaining the standards in 2023.
2. Information Provided by Ohio Regarding Step 2
OEPA's submittal presented the projected 2023 ozone contributions
from Ohio to ten maintenance and nonattainment receptors in the
Northeast and Midwest using data from the LADCO source apportionment
modeling. LADCO's contribution data identified a total of nine
receptors in 2023 (3 nonattainment and 6 maintenance-only) with modeled
contributions from emissions in Ohio that exceed both a one percent of
the 2015 NAAQS threshold (i.e., 0.70 ppb) and a 1 ppb contribution
threshold (Table 1). Despite acknowledging Ohio was linked to the same
number of receptors under either a 1 percent of the NAAQS or 1 ppb,
OEPA maintained they had concerns about both thresholds being too
stringent, noting that Ohio would have two linkages if the threshold
were 3 percent and zero linkages if the threshold were 4 percent.
As noted above, OEPA applied the TCEQ method for identifying
maintenance-only receptors, and concluded that four of the receptors to
which Ohio was linked would not have difficulty maintaining the NAAQS
in 2023. However, after eliminating these four monitoring sites as
having maintenance issues, OEPA acknowledged that Ohio would still be
linked to seven receptors in 2023.
3. Information Provided by Ohio Regarding Step 3
OEPA provided what they characterize as a weight of evidence
analysis in Step 3 to justify their conclusion that no additional
emissions reductions are necessary to satisfy Ohio's interstate
transport obligations under the 2015 ozone NAAQS. OEPA argued that
their analysis demonstrated that any additional controls beyond those
on the books or already planned would result in overcontrol of sources
in Ohio, likely at cost-prohibitive levels.
First, OEPA attempted to show that NOX and VOC 2023
emissions from EGU, nonEGU, and onroad sectors had been overestimated
by 21,761 tons of NOX and 3,240 tons of VOC annually, and
7,040 tons of NOX and 878 tons of VOC per ozone season. The
submittal performed an evaluation of the ERTAC EGU Tool, emphasizing
that projected 2023 EGU emissions from eight facilities
[[Page 9851]]
were overestimated, analyzed through a comparison of actual emissions
data obtained from EPA's Clean Air Markets Database (CAMD) and CSAPR/
CSAPR Update allocations obtained from EPA's CSAPR website with
projected emissions in 2023 obtained from ERTAC EGU tool. OEPA also
based its conclusions on an expected increase of natural gas sources
projected by the U.S. Energy Information's Annual Energy Outlook 2018
and recently permitted natural gas facilities not reflected in the
ERTAC EGU tool. Further, OEPA evaluated emissions from nine non-EGU
sources to claim EPA's 2023 projected emissions were overestimated. For
this analysis, OEPA compared actual emissions data trends from Ohio's
Emissions Inventory System18 with projected emissions from EPA's Air
Emissions Modeling Platform 2011v6.319 to conclude EPA's projections
overestimated non-EGU emissions. OEPA also asserted that EPA's
projections of vehicle miles traveled (VMT) were higher than the local
projections.
OEPA's submittal also looked at NOX and VOC emissions
trends, and asserted that from 2011 to 2016, NOX emissions
declined while VOC emissions remained steady. Additionally, based on
state-specific data, OEPA posited that Ohio's VOC emissions will
decrease even more rapidly than predicted by EPA because the large
growth in the State's oil and gas sector had begun to level off. OEPA
attributed the trends it identified to several Federal and State
programs, including SIP approved state programs, non-SIP approved
programs such as NOX RACT, Architectural and Industrial
Maintenance (AIM) Coatings rules, Ohio's Beneficiary Mitigation Plan
for the Volkswagen settlement, and Federal programs such as CAIR and
CSAPR, NOX SIP Call, the National Emission Standards for
Hazardous Air Pollutants (NESHAP), the Regional Haze Rule, BART,
SO2 Data Requirements Rule, and MATS.
In addition to emissions trends data, OEPA noted LADCO modeling
projected downwind trends in design values at the ten receptors from
2000 through 2017 and included a reference to ``a May 14, 2018
presentation, U.S. EPA Office of Air Quality Planning and Standards
(OAQPS)''.\58\ OEPA also stated that LADCO sector-based source
apportionment modeling indicates a significant contribution from onroad
sources at nine receptors. OEPA argued that local onroad emissions
should be addressed by EPA before EPA requires additional reductions
from upwind states. OEPA also suggested EPA should take into account
the impact on ozone of the proposed Safer Affordable Fuel-Efficient
(SAFE) Vehicles Rule before taking final action on SAFE. Further, OEPA
asserted that Ohio's contribution to nine monitors is in the 1 or 2 ppb
range while the home state and initial and boundary contributions are
each up to 19 ppb, and the contribution from Canada/Mexico is in the
same range as Ohio's. OEPA argued that ignoring international emissions
sources and placing all responsibility for addressing receptors on
upwind states would result in overcontrol.
---------------------------------------------------------------------------
\58\ Ohio's SIP submission at 43.
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OEPA concluded that there were no cost-effective measures to be
taken for EGU or non-EGU sources in Ohio. To support this claim, OEPA
pointed to the cost effectiveness threshold of $1400/ton from the CSAPR
Update (81 FR 74508, October 26, 2016), and while OEPA recognized that
it was developed for the 2008 ozone standard, OEPA stated they believed
it is a reasonable cost-effectiveness level for the 2015 ozone NAAQS.
As for non-EGUs, OEPA asserted that those sectors were adequately
controlled by the Boiler MACT and numerous other MACT categories, BART,
SO2 Data Requirements Rule and other Federal regulations.
4. Information Provided by Ohio Regarding Step 4
OEPA concluded, based on its weight of evidence analysis, that no
additional emissions reduction measures beyond existing and planned
controls are necessary to address ozone transport contribution from
Ohio sources for the 2015 ozone NAAQS.
F. Wisconsin
Wisconsin Department of Natural Resources (WDNR) submitted a SIP
revision to address CAA Section 110(a)(2)(D)(i)(I) on September 14,
2018. The submittal notes state and Federal rules applicable to sources
in Wisconsin that are relevant to interstate transport, as well as
Wisconsin's participation in LADCO. WDNR identified CAIR, CSAPR, CSAPR
Update, Wisconsin's regional haze SIP applicable for the 2008-2018
planning period, and state PSD programs. Further, WDNR cited continued
consultation with LADCO, three Wisconsin Administrative Code statutes
that could be relied on ``[i]f needed'' to address disagreements for
SIP development in other states' nonattainment areas, and an adequate
PSD program.\59\ The statues mentioned include Wisconsin Administrative
Code, Natural Resources (Wis. Admin. Code, NR), subsections 285.11,
285.13 and 285.15. The first two address air pollution control
department duties and powers. The third, Wisconsin Statute 285.15,
entitled Interstate Agreement, gives the governor the authority to
enter an agreement to solve interstate pollution transport with
Illinois, Indiana and Michigan if the area includes portions of both
Wisconsin and Illinois.\60\ WDNR does not explicitly reach the
conclusion that Wisconsin has satisfied the good neighbor provision for
the 2015 ozone NAAQS, but it is implied. WDNR did not reference the 4-
step framework. WDNR did not rely on any modeling, identify any
receptors, or determine whether Wisconsin contributes any amount of
ozone precursor emissions to downwind states. The submittal does not
include an analysis of potential NOX controls. WDNR did not
rely on any EPA memoranda. No supporting documentation was provided.
Apart from the cited rules and LADCO membership, WDNR provided no
discussion or analysis to determine whether they have any obligations
under the 2015 ozone NAAQS.
---------------------------------------------------------------------------
\59\ Wisconsin's SIP submission at 4.
\60\ See Wis. Admin. Code NR 285.15 (2021), available at https://docs.legis.wisconsin.gov/statutes/statutes/285/ii/11.
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III. EPA Evaluation
EPA is proposing to find that the Illinois, Indiana, Michigan,
Minnesota, Ohio, and Wisconsin's SIP submissions do not meet the
states' obligations with respect to prohibiting emissions that
contribute significantly to nonattainment or interfere with maintenance
of the 2015 ozone NAAQS in any other state based on EPA's evaluation of
the SIP submissions using the 4-step interstate transport framework,
and EPA is therefore proposing to disapprove Illinois, Indiana,
Michigan, Minnesota, Ohio, and Wisconsin's SIP submissions.
A. Illinois
1. Evaluation of Information Provided by Illinois Regarding Step 1
For Step 1 in the 4-step framework, IEPA identified monitoring
sites that are projected to have problems attaining or maintaining the
2015 ozone NAAQS in 2023. As previously mentioned, the LADCO modeling
efforts used the same technique as EPA to calculate future year design
values used to identify maintenance and nonattainment receptors. IEPA
presented the LADCO results with water cells, which identified five
monitors with 2023 maximum design values greater than the
[[Page 9852]]
2015 ozone standard, or maintenance receptors, and seven monitors with
2023 average design values greater than the 2015 ozone standard, or
nonattainment receptors. Since new modeling has been performed by EPA
with updated emission data, EPA proposes to rely on the most recent
modeling to identify nonattainment and maintenance receptors with
linkage to Wisconsin in 2023. Nonetheless, the alternative modeling
relied on by IEPA also identified a number of nonattainment and
maintenance receptor sites in 2023. See Table CC on page 15 of IEPA's
submittal. Thus, even under the alternative modeling of 2023, IEPA
acknowledges in its submittal the existence of several nonattainment
and maintenance receptors.
2. Evaluation of Information Provided by the State Regarding Step 2
Although Illinois relied on alternative modeling to EPA's modeling,
Illinois acknowledged in their SIP submission that it is linked to one
or more downwind receptors above either a 1 percent of the NAAQS or a 1
ppb contribution threshold in 2023. Because the alternative modeling
relied on by the state also demonstrates that a linkage exists between
the state and downwind receptors at step 2, EPA need not conduct a
comparative assessment of the alternative modeling; the state concedes
that it is linked. IEPA's analysis corroborates the conclusion in EPA's
most recent modeling in that the modeling demonstrates the State to be
linked above 1 percent of the NAAQS to a downwind receptor, as
described in the next section.
IEPA, relying on a concept listed in Attachment A to the March 2018
memorandum, attempted to justify the use of a 1 ppb threshold at step 2
to identify whether the state was ``linked'' to a projected downwind
nonattainment or maintenance receptor. As explained in Section I above,
the concepts presented in Attachment A to the March 2018 memorandum
were developed by outside parties; they are neither guidance nor
determined by EPA to be consistent with the CAA. However, EPA's August
2018 memorandum also addressed possible alternative thresholds and
suggested that, with appropriate additional analysis, it may be
reasonable for states to use a 1 ppb contribution threshold, as an
alternative to a 1 percent of the NAAQS threshold, at Step 2 of the 4-
Step interstate transport framework for the purposes of identifying
linkages to downwind receptors.
As an initial matter, EPA does not accept Illinois' argument that a
1 percent of the NAAQS contribution threshold at Step 2 is
``inappropriate'' for the 2015 ozone NAAQS due to modeling biases and
errors.\61\ The explanation for how the 1 percent contribution
threshold was originally derived is available in the 2011 CSAPR
rulemaking. See 76 FR 48208, 48237-38. Further, in the CSAPR Update,
EPA re-analyzed the threshold for purposes of the 2008 ozone NAAQS and
determined it was appropriate to continue to apply this threshold. EPA
compared the 1 percent threshold to a 0.5 percent of NAAQS threshold
and a 5 percent of NAAQS threshold. EPA found that the lower threshold
did not capture appreciably more upwind state contribution compared to
the 1 percent threshold, while the 5 percent threshold allowed too much
upwind state contribution to drop out from further analysis. See Final
CSAPR Update Air Quality Modeling TSD, at 27-30 (EPA-HQ-OAR-2015-0596-
0144). If EPA were to apply this analysis to the 2015 ozone NAAQS using
the updated modeling based on the 2016v2 emissions platform, a 5
percent of the NAAQS contribution threshold (i.e., 3.5 ppb) only
captures approximately 50 percent of the total upwind contribution.
Compared to a 1 percent threshold, a 5 percent threshold would, on
average, forgo 27 percent of the total upwind contribution. As EPA
noted in the August 2018 memorandum, the use of even a 2 ppb
contribution threshold under the modeling released with the March 2018
memorandum would only capture about 55 percent of all upwind
contributions, and therefore ``emission reductions from states linked
at that higher threshold may be insufficient to address collective
upwind state contribution to downwind air quality problems.'' \31\
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\61\ Illinois' SIP submission at 8, 14.
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With these figures in mind, IEPA's claims that the contribution
threshold should be substantially higher than 1 or even 2 ppb solely on
the basis of modeling uncertainty cannot be accepted. First, both
LADCO's and EPA's modeling techniques are sufficiently reliable and fit
for the purpose to measure upwind contribution levels down to at least
one percent of the NAAQS. EPA's recommended model attainment test is
based on application of the model in a relative sense rather than
relying upon absolute model predictions.\62\ All models have
limitations resulting from uncertainties in inputs and scientific
formulation. To minimize the effects of these uncertainties, the
modeling is anchored to base period measured data in EPA's guidance
approach for projecting design values. Notably, EPA also uses our
source apportionment modeling in a relative sense when calculating the
average contribution metric (used to identify linkages). In this method
the magnitude of the contribution metric is tied to the magnitude of
the projected average design value which is tied to the base period
average measured design value. EPA's guidance has not established a
bright line criteria for judging whether or not statistical measures of
model performance constitute acceptable or unacceptable model
performance. So, contrary to what Illinois appears to be claiming with
regards to modeling biases, there are no EPA recommended measures of
allowable error. Although EPA does not typically focus on using
particular benchmarks as the sole criteria for model performance, EPA
notes that the model performance for the updated modeling based on the
2016v2 emissions platform is generally within the benchmarks
recommended by Emery.\63\
---------------------------------------------------------------------------
\62\ See Section 4.1' ``Overview of Modeled Attainment Test in
EPA Modeling Guidance for Demonstrating Air Quality Goals for Ozone,
PM2.5, and Regional Haze. November 2018. EPA 454-R-18-
009. https://www.epa.gov/scram/sip-modeling-guidance-documents.
\63\ Christopher Emery, Zhen Liu, Armistead G. Russel, M. Talat
Odman, Greg Yarwood and Naresh Kumar (2017). Recommendations on
statistics and benchmarks to assess photochemical model performance,
Journal of the Air & Waste Management Association, 67:5,582-598,
DOI: 10.1080/10962247.2016.1265027.
---------------------------------------------------------------------------
EPA has successfully applied a 1 percent of NAAQS threshold to
identify linked upwind states in three prior rulemakings. And the D.C.
Circuit has declined to establish bright line criteria for model
performance. In upholding EPA's approach to evaluating interstate
transport in CSAPR, the D.C. Circuit held that they would not
``invalidate EPA's predictions solely because there might be
discrepancies between those predictions and the real world. That
possibility is inherent in the enterprise of prediction.'' EME Homer
City Generation, L.P. v. EPA, 795 F.3d 118, 135 (2015). The court
continued to note that ``the fact that a `model does not fit every
application perfectly is no criticism; a model is meant to simplify
reality in order to make it tractable.''' Id. at 135-36 (quoting
Chemical Manufacturers Association v. EPA, 28 F.3d 1259, 1264 (D.C.
Cir. 1994).
Finally, EPA's August 2018 memorandum provided that whether use of
a 1 ppb threshold is appropriate must be based on an evaluation of
state-specific circumstances, and no such evaluation was included in
the
[[Page 9853]]
submission. IEPA did not conduct such an analysis. EPA's experience
with the alternative Step 2 thresholds is further discussed in Section
I.D.3.i. As discussed there, EPA is considering withdrawing the August
2018 memorandum.
However, based on both the state's alternative modeling and EPA's
updated modeling, the state is projected to contribute greater than
both the 1 percent and alternative 1 ppb thresholds. While EPA does
not, in this action, approve of the IEPA's application of the 1 ppb
threshold, based on Illinois' linkages greater than 1 ppb to projected
downwind nonattainment or maintenance receptors, the state's use of
this alternative threshold at step 2 of the 4-step interstate framework
would not alter our review and proposed disapproval this SIP submittal.
3. Results of EPA's Step 1 and Step 2 Modeling and Findings for
Illinois
As described in Section I, EPA performed air quality modeling using
the 2016v2 emissions platform to project design values and
contributions for 2023. These data were examined to determine if
Illinois contributes at or above the threshold of 1 percent of the 2015
ozone NAAQS (0.70 ppb) to any downwind nonattainment or maintenance
receptor. As shown in Table 2, the data \64\ indicate that in 2023,
emissions from Illinois contribute greater than 1 percent of the
standard to nonattainment or maintenance-only receptors in
Wisconsin.\65\
---------------------------------------------------------------------------
\64\ Design values and contributions at individual monitoring
sites nationwide are provide in the file:''
2016v2_DVs_state_contributions.xlsx'' which is included in docket ID
No. EPA-HQ-OAR-2021-0663.
\65\ These modeling results are consistent with the results of a
prior round of 2023 modeling using the 2016v1 emissions platform
which became available to the public in the fall of 2020 in the
Revised CSAPR Update, as noted in Section I. That modeling showed
that Illinois had a maximum contribution greater than 0.70 ppb to at
least one nonattainment or maintenance-only receptor in 2023. These
modeling results are included in the file ``Ozone Design Values And
Contributions Revised CSAPR Update.xlsx'' in docket ID No. EPA-HQ-
OAR-2021-0663.
Table 2--Illinois Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Illinois
Receptor ID Location Nonattainment/ design value design value contribution
maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
550590025.................... Kenosha, WI..... Maintenance.... 69.2 72.3 18.55
550590019.................... Kenosha, WI..... Nonattainment.. 72.8 73.7 18.13
551010020.................... Racine, WI...... Nonattainment.. 71.3 73.2 13.86
----------------------------------------------------------------------------------------------------------------
Therefore, based on EPA's evaluation of the information submitted
by IEPA, and based on EPA's most recent modeling results for 2023, EPA
proposes to find that Illinois is linked at Steps 1 and 2 and has an
obligation to assess potential emissions reductions from sources or
other emissions activity at Step 3 of the 4-step framework. EPA will
proceed to Step 3 of the 4-step interstate transport framework to
assess the arguments the state presented as to why, despite this
linkage, the state should not be considered to significantly contribute
to nonattainment or interfere with maintenance of the NAAQS in any
other state.
4. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I).
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the obligations in CAA section 110(a)(2)(D)(i)(I) must
prohibit ``any source or other type of emissions activity within the
state'' from emitting air pollutants which will contribute
significantly to downwind air quality problems. Thus, states must
complete something similar to EPA's analysis (or an alternative
approach to defining ``significance'' that comports with the statute's
objectives) to determine whether and to what degree emissions from a
state should be ``prohibited'' to eliminate emissions that will
``contribute significantly to nonattainment in or interfere with
maintenance of'' the NAAQS in any other state. IEPA did not conduct
such an analysis in Illinois' SIP submission.
IEPA argued that Illinois' contributions to the nonattainment
monitors in the LADCO domain, namely the Allegan and Sheboygan
receptors, EPA can be fairly and adequately addressed through Illinois'
participation in LADCO. Though IEPA suggested that LADCO may be
partially responsible for decreases in ambient ozone concentrations in
the Lake Michigan area, LADCO is not a regulatory agency responsible
for implementing emissions controls. Furthermore, Illinois did not
provide any information on any planned emission reductions, or
evaluation of control strategies that the LADCO states intend to
implement within their domain, that would reduce either the ozone
concentrations or Illinois' contributions at the nonattainment or
maintenance monitors to which IEPA identified Illinois as linked.
IEPA's basis for concluding that LADCO participation may relieve
Illinois of any good neighbor obligations to downwind receptors is
entirely unsubstantiated and does not present any basis on which EPA
can approve IEPA's SIP submittal. As such, EPA proposes to find
Illinois' LADCO participation as inadequate to resolve Illinois' good
neighbor obligations for the 2015 ozone NAAQS.
[[Page 9854]]
The submittal also stated that Illinois is developing new
NOX RACT standards for the Chicago area that, in conjunction
with existing regulations and future Federal reductions, are estimated
to reduce NOX emissions by up to 20,000 tons/year which had
not yet been reflected in modeling to 2023. However, Illinois failed to
provide any information on the control measures or implementation
schedule that would achieve the estimated 20,000 tons/year in
reductions. IEPA did not quantify how the emissions reductions they
estimated would impact air quality at downwind receptors or Illinois'
contributions. In fact, Illinois has not yet finalized the
NOX RACT rule for Chicago. In general, any changes in the
emissions inventory and on-the-books controls relevant to emissions in
2023 have now been incorporated into EPA's modeling using the 2016v2
emissions platform, which projects a continuing contribution from
Illinois to out of state receptors above a threshold of 1 percent of
the NAAQS (at Steps 1 and 2) despite these measures. Therefore, IEPA's
SIP submission should have evaluated the availability of additional air
quality controls to improve downwind air quality at nonattainment and
maintenance receptors at Step 3.
Additionally, states may not rely on non-SIP measures to meet SIP
requirements. 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. U.S. E.P.A., 786 F.3d
1169, 1175-76 (9th Cir. 2015) (holding that measures relied on by state
to meet CAA requirements must be included in the SIP). IEPA did not
attempt to revise Illinois' SIP to include these measures in order to
implement its good neighbor obligations. Further, the listing of
existing or on-the-way control measures, whether approved into the
State's SIP or not, does not substitute for a complete Step 3 analysis
under EPA's 4-step framework to define ``significant contribution.''
IEPA did not identify the control measures, provide an assessment of
the overall effects of these measures, note when the reductions would
be achieved, or explain what the overall resulting air quality effects
would be at identified out of state receptors. IEPA did not evaluate
additional, potential emissions control opportunities, or their costs
or impacts, or attempt to analyze whether, if applied more broadly
across linked states, the emissions reductions would constitute the
elimination of significant contribution on a regional scale. IEPA did
not offer an explanation as to whether any faster or more stringent
emissions reductions that may be available were prohibitively costly or
infeasible. Although EPA acknowledges states are not necessarily bound
to follow its own analytical framework at Step 3, IEPA did not attempt
to determine or justify an appropriate uniform cost-effectiveness
threshold for the more stringent 2015 ozone NAAQS. This would have been
similar to the approach to defining significant contribution that EPA
has applied in prior rulemakings such as CSAPR and or the CSAPR Update,
even if such an analysis is not technically mandatory.
Finally, under the Wisconsin decision, states and EPA may not delay
implementation of measures necessary to address good neighbor
requirements beyond the next applicable attainment date without a
showing of impossibility or necessity. See 938 F.3d at 320. The IEPA's
submittal is insufficient to the extent the implementation timeframes
for identified control measures were left unidentified, unexplained, or
too uncertain to permit EPA to form a judgment as to whether the timing
requirements for good neighbor obligations have been met.
IEPA also attempted to rely on a concept related to international
emissions identified in Attachment A to the March 2018 memorandum--a
concept that apparently had its origins outside EPA and was not
endorsed or recommend by EPA at the time or since. IEPA noted that
Illinois would be linked to only one receptor if international and
offshore emissions were simply subtracted from the receptor's maximum
design values. As explained in Section I.D above, the concepts
presented in Attachment A to the March 2018 memorandum were neither
guidance nor determined by EPA to be consistent with the CAA. EPA made
clear at the time that it would thoroughly review the technical and
legal justifications states put forward in relying on any concepts from
Attachment A to the March 2018 memorandum. In this case, what IEPA
proposes is clearly unacceptable.
The state's reasoning related to international and offshore
emissions is inapplicable to the requirements of CAA section
110(a)(2)(D)(i)(I). The good neighbor provision requires states and EPA
to address interstate transport of air pollution that contributes to
downwind states' ability to attain and maintain NAAQS. Whether
emissions from other states or other countries also contribute to the
same downwind air quality issue is irrelevant in assessing whether a
downwind state has an air quality problem, or whether an upwind state
is significantly contributing to that problem. States are not obligated
under CAA section 110(a)(2)(D)(i)(I) to reduce emissions sufficient on
their own to resolve downwind receptors' nonattainment or maintenance
problems. Rather, states are obligated to eliminate their own
``significant contribution'' or ``interference'' with the ability of
other states to attain or maintain the NAAQS.
Indeed, the D.C. Circuit in Wisconsin specifically rejected
petitioner arguments suggesting that upwind states should be excused
from good neighbor obligations on the basis that some other source of
emissions (whether international or another upwind state) could be
considered the ``but-for'' cause of downwind air quality problem. See
938 F.3d at 323-324. The court viewed petitioners' arguments as
essentially an argument ``that an upwind state `contributes
significantly' to downwind nonattainment only when its emissions are
the sole cause of downwind nonattainment.'' Id. at 324. The court
explained that ``an upwind state can `contribute' to downwind
nonattainment even if its emissions are not the but-for cause.'' Id. at
324-325. See also Catawba County v. EPA, 571 F.3d 20, 39 (D.C. Cir.
2009) (rejecting the argument ``that `significantly contribute'
unambiguously means `strictly cause' '' because there is ``no reason
why the statute precludes EPA from determining that [an] addition of
[pollutant] into the atmosphere is significant even though a nearby
county's nonattainment problem would still persist in its absence'');
Miss. Comm'n on Envtl. Quality v. EPA, 790 F.3d 138, 163 n.12 (D.C.
Cir. 2015) (observing that the argument that ``there likely would have
been no violation at all . . . if it were not for the emissions
resulting from [another source]'' is ``merely a rephrasing of the but-
for causation rule that we rejected in Catawba County''). Therefore, a
state is not excused from eliminating its significant contribution on
the basis that international emissions also contribute some amount of
pollution to the same receptors to which the state is linked. Illinois'
argument related to international and offshore emissions fails to
change the status of any receptor at Step 1, to eliminate Illinois'
linkages at Step 2, or to provide sufficient evidence that Illinois
does not contribute significantly to receptors at Step 3.
We therefore propose that Illinois was required to analyze
emissions from the sources and other emissions activity from within the
state to determine whether its contributions were
[[Page 9855]]
significant, and we propose to disapprove its submission because
Illinois failed to do so.
5. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-step interstate transport framework calls for
development of 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. IEPA identified future
NOX RACT standards for the Chicago area and unnamed Federal
rules were sufficient to resolve Illinois' good neighbor obligations
for the 2015 ozone NAAQS. However, Illinois did not revise its SIP to
include these emission reductions in a revision to its SIP to ensure
the reductions were permanent and enforceable. As a result, EPA
proposes to disapprove Illinois' submittal on the separate,\66\
additional basis that the Illinois has not included permanent and
enforceable emissions reductions in its SIP as necessary to meet the
obligations of CAA section 110(a)(2)(d)(i)(I).
---------------------------------------------------------------------------
\66\ Pointing to anticipated upcoming emission reductions is not
sufficient as a step 3 analysis, for the reasons discussed in
Section 4. In this section, we explain that to the extent such
anticipated reductions are not included in the SIP and rendered
permanent and enforceable, reliance on such anticipated reductions
is also insufficient at step 4.
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6. Conclusion
Based on EPA's evaluation of Illinois SIP submission, EPA is
proposing to find that the portion of Illinois' May 21, 2018 SIP
submission addressing CAA section 110(a)(2)(D)(i)(I) does not meet the
state's interstate transport obligations, because it fails to contain
the necessary provisions to eliminate emissions that will contribute
significantly to nonattainment or interfere with maintenance of the
2015 ozone NAAQS in any other state.
B. Indiana
1. Evaluation of Information Provided by Indiana Regarding Step 1
IDEM relied on LADCO modeling released in 2018 to identify
nonattainment and maintenance receptors in 2023. As described
previously in this action, LADCO performed a modeling demonstration
like that of EPA's 2018 transport modeling efforts, except with use of
the ERTAC EGU Tool for EGU emissions. LADCO identified nonattainment
and maintenance receptors using EPA methodology identified in Section
I. IDEM elected to rely on LADCO's modeling results, which identified
similar receptors to EPA's modeling included in the March 2018 memo.
Since new modeling has been performed by EPA which includes updated
emission data using the 2016v2 platform, EPA proposes to primarily rely
on the most recent modeling to identify nonattainment and maintenance
receptors in 2023 (see Table 3 further in this action).
Nonetheless, the LADCO modeling relied on by IDEM also identified a
number of nonattainment and maintenance receptor sites in 2023. See
Table 7 on page 30 of Attachment 1 to Indiana's submittal. Thus, even
under the LADCO modeling for 2023, IDEM acknowledges in its submittal
the existence of several nonattainment and maintenance receptors.
IDEM essentially argues that two of the receptors to which Indiana
was linked would not actually be receptors in 2023. Based on updated
modeling of EPA's 2016v2 emissions platform, EPA agrees with IDEM that
that the Allegan, Michigan monitor is not expected to be a receptor in
2023, but not the receptor in Sheboygan, Wisconsin. Regardless, EPA
disagrees with the line of reasoning IDEM put forward to argue that
those two monitors would not be receptors to the extent such reasoning
could be applied to Indiana's linkages in EPA's modeling using the
2016v2 emissions platform. First, IDEM concluded that if ozone design
value trends continued as expected then those two receptors would reach
attainment before 2023. In addition, IDEM compared 2012-2017 monitoring
data with LADCO's and EPA's modeling and concluded that the Sheboygan,
Wisconsin and Allegan, Michigan receptor monitors were already below
the 2023 projections. Additionally, EPA's updated modeling, which
considers more recent design values and emissions, continues to find
that Indiana is linked to downwind nonattainment and maintenance
receptors, despite downward trends in emissions and design values
2. Evaluation of Information Provided by the State Regarding Step 2
Although Indiana relied on alternative modeling to EPA's modeling,
Indiana acknowledged in its SIP submission that it is linked to one or
more downwind receptors above either a 1 percent of the NAAQS or 1 ppb
contribution threshold in 2023. Because the alternative modeling relied
on by IDEM also demonstrates that a linkage exists between the state
and one or more downwind receptors at Step 2, EPA need not conduct a
comparative assessment of the alternative modeling; the State concedes
that it is linked. IDEM's analysis corroborates the conclusion in EPA's
most recent modeling, described in the next section.
IDEM additionally utilized a 1 ppb threshold at Step 2 to identify
whether it was linked to a projected downwind nonattainment or
maintenance receptor. As discussed in EPA's August 2018 memorandum,
with appropriate additional analysis it may be reasonable for states to
use a 1 ppb contribution threshold, as an alternative to a 1 percent
threshold, at Step 2 of the 4-Step interstate transport framework, for
the purposes of identifying linkages to downwind receptors. However,
IDEM's submission did not contain any additional analysis of
contributions at the receptors to which they were linked to support
their claim that a 1 ppb threshold was an appropriate Step 2 screening
threshold. Rather, IDEM claimed that a threshold of 1 percent was too
low because it is less than the ozone monitoring ``tolerance level'' of
1 ppb (i.e., precision) used for reporting measured ozone
concentrations. In its submittal IDEM failed to provide any basis for
asserting that the precision of an ozone monitor is applicable to the
precision of ozone contributions which are not a directly measured
quantity. Regardless, total upwind contributions are well above 1 ppb
at all receptors to which Indiana is linked based on modeling by LADCO
and by EPA. In addition, Indiana alone contributes above 1 ppb to
several downwind receptors. Because contributions are not directly
measured, modeling is used to apportion projected ozone design values
into contributions from individual states and other sources of ozone
precursors (e.g., fires and biogenic sources). The projected ozone
design values are calculated using the method recommended in EPA's
modeling guidance.\67\ As part of this method, projected design values
are reported with a precision of a tenth of a ppb. Consistent with our
modeling guidance, ozone contributions are evaluated with a precision
of a tenth of a ppb. For example, a contribution of 0.6999 . . . ppb is
reported as 0.69 ppb and evaluated as 0.6 ppb which is below the 1
percent threshold.
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\67\ Modeling Guidance for Demonstrating Air Quality Goals for
Ozone, PM2.5, and Regional Haze. November 2018. EPA 454-
R-18-009. https://www.epa.gov/scram/sip-modeling-guidance-documents.
---------------------------------------------------------------------------
Indiana seemingly conflates the contribution threshold at Step 2
with a Step 3 determination of ``significance'' (which is reached only
after the application of a multi-factor analysis), regardless EPA does
not accept
[[Page 9856]]
Indiana's argument that a 1 percent of the NAAQS contribution threshold
at Step 2 is ``not appropriate'' for the 2015 ozone NAAQS on the basis
of unwarranted modeling reliability concerns.\68\ The explanation for
how the 1 percent contribution threshold was originally derived is
available in the 2011 CSAPR rulemaking. See 76 FR 48208, 48237-38.
Further, in the CSAPR Update, EPA re-analyzed the threshold for
purposes of the 2008 ozone NAAQS and determined it was appropriate to
continue to apply this threshold. EPA compared the 1 percent threshold
to a 0.5 percent of NAAQS threshold and a 5 percent of NAAQS threshold.
EPA found that the lower threshold did not capture appreciably more
upwind state contribution compared to the 1 percent threshold, while
the 5 percent threshold allowed too much upwind state contribution to
drop out from further analysis. See Final CSAPR Update Air Quality
Modeling TSD, at 27-30 (EPA-HQ-OAR-2015-0596-0144). If EPA were to
apply this analysis to the 2015 ozone NAAQS using the updated modeling
based on the 2016v2 emissions platform, a 5 percent of the NAAQS
contribution threshold would forgo nearly 30 percent of the total
upwind contribution, on average, for those receptors to which Indiana
is linked using a 1 percent threshold. As EPA noted in the August 2018
memorandum, the use of even a 2 ppb contribution threshold under the
modeling released with the March 2018 memorandum would only capture
about 55 percent of all upwind contributions, and therefore ``emission
reductions from states linked at that higher threshold may be
insufficient to address collective upwind state contribution to
downwind air quality problems.'' \69\
---------------------------------------------------------------------------
\68\ Indiana's SIP submission, Attachment 1 at 4.
\69\ August 2018 memorandum at 4.
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With these figures in mind, IDEM's claims that the contribution
threshold should be substantially higher than 1 or even 2 ppb solely on
the basis of modeling uncertainty cannot be accepted. First, both
IDEM's and EPA's modeling techniques are sufficiently reliable and fit
for the purpose to measure upwind contribution levels down to at least
one percent of the NAAQS. EPA's recommended model attainment test is
based on application of the model in a relative sense rather than
relying upon absolute model predictions.\70\ All models have
limitations resulting from uncertainties in inputs and scientific
formulation. To minimize the effects of these uncertainties, the
modeling is anchored to base period measured data in EPA's guidance
approach for projecting design values. Notably, EPA also uses our
source apportionment modeling in a relative sense when calculating the
average contribution metric (used to identify linkages). In this method
the magnitude of the contribution metric is tied to the magnitude of
the projected average design value which is tied to the base period
average measured design value. EPA's guidance has not established a
bright-line criteria for judging whether or not statistical measures of
model performance constitute acceptable or unacceptable model
performance. So, contrary to what Indiana appears to be claiming with
regards to modeling biases, there are no EPA recommended measures of
allowable error. Although EPA does not typically focus on using
particular benchmarks as the sole criteria for model performance, EPA
notes that the model performance for the updated modeling based on the
2016v2 emissions platform is generally within the benchmarks
recommended by Emery, et al., (2017).\71\
---------------------------------------------------------------------------
\70\ See Section 4.1' ``Overview of Modeled Attainment Test in
EPA Modeling Guidance for Demonstrating Air Quality Goals for Ozone,
PM2.5, and Regional Haze. November 2018. EPA 454-R-18-
009. https://www.epa.gov/scram/sip-modeling-guidance-documents.
\71\ Christopher Emery, Zhen Liu, Armistead G. Russel, M. Talat
Odman, Greg Yarwood and Naresh Kumar (2017). Recommendations on
statistics and benchmarks to assess photochemical model performance,
Journal of the Air & Waste Management Association, 67:5,582-598,
DOI: 10.1080/10962247.2016.1265027.
---------------------------------------------------------------------------
EPA has successfully applied a 1 percent of NAAQS threshold to
identify linked upwind states in three prior rulemakings. And the D.C.
Circuit has declined to establish bright line criteria for model
performance. In upholding EPA's approach to evaluating interstate
transport in CSAPR, the Supreme Court held that they would not
``invalidate EPA's predictions solely because there might be
discrepancies between those predictions and the real world. That
possibility is inherent in the enterprise of prediction.'' EME Homer
City Generation, L.P. v. EPA, 795 F.3d 118, 135 (2015). The court
continued to note that ``the fact that a `model does not fit every
application perfectly is no criticism; a model is meant to simplify
reality in order to make it tractable.' '' Id. at 135-36 (quoting
Chemical Manufacturers Association v. EPA, 28 F.3d 1259, 1264 (D.C.
Cir. 1994).
EPA's August 2018 memorandum provided that whether use of a 1 ppb
threshold is appropriate must be based on an evaluation of state-
specific circumstances, and no such evaluation was included in the
submission. EPA's experience with the alternative Step 2 thresholds is
further discussed in Section I.D.3.i. As discussed there, EPA is
considering withdrawing the August 2018 memorandum.
3. Results of EPA's Step 1 and Step 2 Modeling and Findings for Indiana
As described in Section I, EPA performed air quality modeling using
the 2016v2 emissions platform to project design values and
contributions for 2023. These data were examined to determine if
Indiana contributes at or above the threshold of 1 percent of the 2015
ozone NAAQS (0.70 ppb) to any downwind nonattainment or maintenance
receptor. As shown in Table 3, the data \72\ indicate that in 2023,
emissions from Indiana contribute greater than 1 percent of the
standard to nonattainment or maintenance-only receptors in Wisconsin,
Illinois, Connecticut, and Pennsylvania.\73\
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\72\ Design values and contributions at individual monitoring
sites nationwide are provide in the file:
2016v2_DVs_state_contributions.xlsx which is included in docket ID
No. EPA-HQ-OAR-2021-0663.
\73\ These modeling results are consistent with the results of a
prior round of 2023 modeling using the 2016v1 emissions platform
which became available to the public in the fall of 2020 in the
Revised CSAPR Update, as noted in Section I. That modeling showed
that Indiana had a maximum contribution greater than 0.70 ppb to at
least one nonattainment or maintenance-only receptor in 2023. These
modeling results are included in the file ``Ozone Design Values And
Contributions Revised CSAPR Update.xlsx'' in docket ID No. EPA-HQ-
OAR-2021-0663.
Table 3--Indiana Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Indiana
Receptor ID Location Nonattainment/ design value design value contribution
maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
550590025.................... Kenosha, WI..... Maintenance.... 69.2 72.3 7.10
170310032.................... Cook, IL........ Maintenance.... 69.8 72.4 7.03
[[Page 9857]]
550590019.................... Kenosha, WI..... Nonattainment.. 72.8 73.7 6.60
551010020.................... Racine, WI...... Nonattainment.. 71.3 73.2 6.60
170317002.................... Cook, IL........ Maintenance.... 70.1 73.0 6.33
170310076.................... Cook, IL........ Maintenance.... 69.3 72.1 6.21
170310001.................... Cook, IL........ Maintenance.... 69.6 73.4 5.44
170314201.................... Cook, IL........ Maintenance.... 69.9 73.4 4.65
90099002..................... New Haven, CT... Nonattainment.. 71.8 73.9 0.87
90019003..................... Fairfield, CT... Nonattainment.. 76.1 76.4 0.76
90013007..................... Fairfield, CT... Nonattainment.. 74.2 75.1 0.75
420170012.................... Bucks, PA....... Maintenance.... 70.7 72.2 0.73
----------------------------------------------------------------------------------------------------------------
Therefore, based on EPA's evaluation of the information submitted
by IDEM, and based on EPA's most recent modeling results for 2023, EPA
proposes to find that Indiana is linked at Steps 1 and 2 and has an
obligation to assess potential emissions reductions from sources or
other emissions activity at Step 3 of the 4-Step framework. EPA
therefore will proceed to Step 3 of the 4-Step interstate transport
framework to assess the arguments the State presented as to why,
despite this linkage, the state should not be considered to
significantly contribute to nonattainment or interfere with maintenance
of the NAAQS in any other state.
4. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-Step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I).
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-Step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the obligations in CAA section 110(a)(2)(D)(i)(I) must
prohibit ``any source or other type of emissions activity within the
state'' from emitting air pollutants which will contribute
significantly to downwind air quality problems. Thus, states must
complete something similar to EPA's analysis (or an alternative
approach to defining ``significance'' that comports with the statute's
objectives) to determine whether and to what degree emissions from a
state should be ``prohibited'' to eliminate emissions that will
``contribute significantly to nonattainment in, or interfere with
maintenance of'' the NAAQS in any other state. IDEM did not conduct
such an analysis in their SIP submission.
IDEM first asserted that Indiana's rule amendments under CSAPR
meant that Indiana was already meeting the good neighbor requirements
for the 2015 ozone NAAQS. The submittal, however, did not contain a
demonstration at Step 3 that the State was adequately controlling its
emissions for purposes of the good neighbor provision, particularly
because the State conceded in its submission that it was potentially
significantly contributing to one or more receptors in 2023 at Steps 1
and 2. The SIP submittal pointed to the state's existing NOX
control measures, consent decree requirements, and future fuel switches
and retirements for large EGUs and non-EGUs for the years 2008 through
2017 to conclude Indiana is already meeting its good neighbor
obligations for the 2015 ozone NAAQS.
However, the state's submittal does not include a sufficient
examination or a technical justification that could support the
conclusion that the state has no further good neighbor obligations for
the 2015 ozone NAAQS. In particular, the state did not conduct in its
submittal an analysis of potential additional emissions reductions
measures to further reduce its impact on the identified downwind
receptors. For example, although Indiana did include in its submission
a list of controls at individual emissions units at facilities in the
state, IDEM did not analyze additional potential NOX
emissions control technologies, their associated costs, estimated
emissions reductions, and downwind air quality improvements. Nor does
the submittal include an analysis of whether such potential, additional
control technologies or measures could reduce the impact of Indiana's
emissions on out of state receptors. Though there is not a prescribed
method for a Step 3 analysis, EPA has consistently applied Step 3 of
the good neighbor framework through a more rigorous evaluation of
potential additional control technologies or measures than what Indiana
provided in its submission. Identifying a range of various emissions
control measures that have been or may be enacted at the state level,
without analysis of the impact of those measures on the out of state
receptors, is not analytically sufficient. In general, the air quality
modeling that EPA has conducted (as well the modeling relied on by
Indiana in its submittal) already accounts for ``on-the-books''
emissions control measures. Both sets of modeling clearly establish
continued linkage from Indiana to downwind receptors in 2023 at Steps 1
and 2, despite those emissions control efforts.
IDEM provided what they characterized as a weight of evidence
analysis consisting of monitoring data, emissions data, and
photochemical modeling to justify their conclusion that no additional
emission reductions would be necessary to satisfy Indiana's ozone
transport obligations. First, IDEM
[[Page 9858]]
presented evidence of downward trends of statewide ozone concentrations
and emissions, as well as a decrease in projected EGU emissions in 2023
relative to 2011. Despite these trends, however, the LADCO modeling
that Indiana depended on for its submittal still identified that
Indiana would contribute over 1 ppb to one or more receptors in 2023.
As for downwind design value trends, EPA disagrees that IDEM's
reliance on trends data to conclude that the Harford, Maryland and
Richmond, New York monitors would reach attainment ``over time'' is
sufficient to support a conclusion that Indiana has no good neighbor
obligations. The states and EPA are to address interstate transport
obligations ``as expeditiously as practicable'' and no later than the
attainment schedule set in accordance with CAA section 181(a). See
North Carolina, 531 F.3d at 911-13; Wisconsin, 938 F.3d at 313-20;
Maryland, 958 F.3d at 1204; New York v. EPA, 964 F.3d 1214, 1226 (D.C.
Cir. 2020); New York v. EPA, 781 Fed. App'x 4, 6-7 (D.C. Cir. 2019).
IDEM asserted that EGUs are well controlled in Indiana and cited
several state and Federal regulations that EGUs may be subject to in
Indiana. In general, however, the listing of existing or on-the-way
control measures, whether approved into the state's SIP or not, does
not substitute for a complete Step 3 analysis under EPA's 4-Step
framework to define ``significant contribution.'' IDEM did not provide
an assessment of the overall effects of the identified control measures
or explain what the overall resulting air quality effects would be at
identified out of State receptors. IDEM did not perform an analysis of
all large NOX emitting EGU for factors that may affect the
facilities' emissions, including but not limited to allowance prices,
fuel prices, and enforceable limits. IDEM did not evaluate additional,
potential emissions control opportunities, or their costs or impacts,
or attempt to analyze whether, if applied more broadly across linked
states, the emissions reductions would constitute the elimination of
significant contribution on a regional scale. IDEM did not offer an
explanation as to whether any faster or more stringent emissions
reductions that may be available were prohibitively costly or
infeasible. Although EPA acknowledges states are not necessarily bound
to follow its own analytical framework at Step 3, IDEM did not attempt
to determine or justify an appropriate uniform cost-effectiveness
threshold. This would have been similar to the approach to defining
significant contribution that EPA has applied in prior rulemakings such
as CSAPR and or the CSAPR Update, even if such an analysis is not
technically mandatory. As discussed previously, both the LADCO modeling
relied on by the state and EPA's updated modeling indicates sources in
Indiana are linked to downwind air quality problems for the 2015 ozone
standard. However, Indiana's SIP submittal did not include an analysis
of potential NOX emissions control technologies, associated
costs, estimated emissions reductions, and downwind air quality in
order to determine whether the State had eliminated the State's
downwind contribution in amounts which will significantly contribute to
nonattainment or interfere with maintenance. Thus, EPA proposes to
disapprove Indiana's SIP submission on the separate, additional basis
that the SIP submittal did not assess additional emission control
opportunities.
IDEM concluded it is not cost-effective to evaluate and implement
controls on non-EGUs in the state on the sole basis that the majority
of NOX emissions in the state come from EGUs. EPA cannot
accept the assertion as it is insufficiently supported. Cost-
effectiveness must be assessed in the context of the specific CAA
program; assessing cost-effectiveness in the context of ozone transport
should reflect a more comprehensive evaluation of the nature of the
interstate transport problem, the total emissions reductions available
at several cost thresholds, and the air quality impacts of the
reductions at downwind receptors. EPA notes that there are as many as
two dozen non-EGU facilities in Indiana with more than 300 tons per
year of NOX emissions each, but IDEM did not analyze control
opportunities at these sources at all in the SIP submission.
IDEM also argued that additional emissions reductions from EGU and
non-EGU sources in Indiana ``are getting more difficult to mandate''
because of reduced effectiveness of controls to make significant
decreases in ozone values, operational concerns, and increased costs
for customers.\74\ Again, the SIP submission does not contain
sufficient evidence to support that conclusion. IDEM did not identify
controls that had reduced effectiveness or explain why they believed
they had reduced effectiveness. IDEM did not describe what any
operational concerns were for any controls, nor did IDEM provide any
information to support their claim that controls would increase costs
for consumers. While Indiana's existing control measures have
undoubtedly reduced the amount of transported ozone pollution to other
states and have contributed to the downward emissions trends and
improving air quality in the State as shown in the state's SIP
submittal, in the Revised CSAPR Update, EPA's analysis found that
despite Indiana's existing control programs, additional emissions
reductions were achievable from EGUs in the state, even under the level
of control stringency EPA determined appropriate to eliminate
significant contribution for the 2008 ozone NAAQS. In any case, EPA has
not established a benchmark cost-effectiveness threshold for good
neighbor obligations for the 2015 ozone NAAQS, and IDEM in its
submittal has not conducted an analysis to establish one for EPA to
evaluate.
---------------------------------------------------------------------------
\74\ Indiana's SIP submission, Attachment 1 at 37.
---------------------------------------------------------------------------
IDEM also identified several planned retirements or retrofits to
coal fired EGUs in Indiana that were not included in any modeling
available at the time of Indiana's submission and stated they would
reduce emissions several thousand tons beyond the modeling. Further,
EPA's assessment of future air quality conditions generally accounts
for on-the-books emission reductions and the most up-to-date forecast
of future emissions in the absence of the transport policy being
evaluated (i.e., base case conditions).\75\ As described in more detail
in Section I, EPA's latest projections of the baseline EGU emissions
uses the version 6--Summer 2021 Reference Case of the IPM. The IPM
version 6--Summer 2021 Reference Case uses the NEEDS v6 database as its
source for data on all existing and planned-committed units. Units are
removed from the NEEDS inventory only if a high degree of certainty
could be assigned to future implementation of the announced future
closure or retirement. Any retirements excluded from the NEEDS v6
inventory can be viewed in the NEEDS spreadsheet.\76\ EPA looked into
the upcoming retirements cited by IDEM and following the guidelines
regarding retirements for the IPM version--6 Summer 2021 Reference Case
certain units are not excluded from the NEEDS v6 inventory. There are
other retirements that were not included in the SIP submission that
were excluded
[[Page 9859]]
from the NEEDS v6 inventory for the 2023 projections. This includes
retirements at AES Petersburg, Merom, and RM Schahfer. In other words,
in general, any changes in the emissions inventory and on-the-books
controls relevant to emissions in 2023 have now been incorporated into
the EPA's modeling using the 2016v2 emissions platform, which projects
a continuing contribution from Indiana to out of state receptors above
a threshold of 1 percent of the NAAQS (at Steps 1 and 2) despite these
measures. Therefore, in light of continuing contribution to out of
state receptors from Indiana notwithstanding these identified
retirements, IDEM's SIP submission should have evaluated the
availability of additional air quality controls to improve downwind air
quality at nonattainment and maintenance receptors at Step 3
Furthermore, under the Wisconsin decision, states and EPA may not delay
implementation of measures necessary to address good neighbor
requirements beyond the next applicable attainment date without a
showing of impossibility or necessity. See 938 F.3d at 320. The IDEM's
submittal is insufficient to the extent the implementation timeframes
for several claimed expected shutdowns were left unidentified,
unexplained, or too uncertain to permit EPA to form a judgment as to
whether the timing requirements for good neighbor obligations have been
met.
---------------------------------------------------------------------------
\75\ See 81 FR 74504 at 74517; 85 FR 68964 at 68979.
\76\ The ``Capacity Dropped'' and the ``Retired Through 2023''
worksheets in NEEDS lists all units that are removed from the NEEDS
v6 inventory--NEEDS v6 Summer 2021 Reference Case. This data can be
found on EPA's website at: https://www.epa.gov/airmarkets/national-electric-energy-data-system-needs-v6.
---------------------------------------------------------------------------
Additionally, IDEM explained in only the most general terms how the
unaccounted emissions reductions would influence downwind air quality
or Indiana's contributions to other state. IDEM also did not quantify
how the emissions reductions they estimated would impact air quality at
downwind receptors or Indiana's contributions. IDEM did not demonstrate
that the downwind improvements from these regulations and programs
would be sufficient to eliminate Indiana's linkages or prohibit the
State's emissions in amounts that will contribute significantly to
nonattainment or interfere with maintenance of the NAAQS in any other
state.
IDEM also made several arguments related to potential flexibilities
identified in Attachment A to the March 2018 memorandum.\77\ As
explained previously in Section I, the concepts presented in Attachment
A to the March 2018 memorandum were neither guidance nor determined by
EPA to be consistent with the CAA. EPA will thoroughly review the
technical and legal justifications IDEM put forward in their attempt to
use a potential flexibility from Attachment A to the March 2018
memorandum.
---------------------------------------------------------------------------
\77\ Based on the reference to the potential flexibilities in
Attachment A to the March 2018 memorandum on page 2 of Attachment 1
to Indiana's SIP submission, EPA assumes the reference to
``flexibilities'' on page 38 of Attachment 1 likewise references
Attachment A to the March 2018 memorandum.
---------------------------------------------------------------------------
IDEM suggested that local emissions reductions from the
jurisdiction where downwind receptors are located should first be
implemented and accounted for before imposing obligations on upwind
states under the interstate transport provision. IDEM represented that
EPA had concluded that monitors in the Northeast ``are impacted from
more local emissions'' by citing a May 14, 2018 presentation. The
purpose of that presentation was to share a technical, exploratory
analysis of ozone trends. IDEM misrepresented the contents of the
presentation, which labeled the results as ``preliminary'' and
indicated that ``[f]urther exploration of the relative contribution
from various source sectors within the NE Corridor and in nearby upwind
states might also be informative.'' \78\ These preliminary results of
that analysis are generally consistent with EPA's updated modeling
using the 2016v2 emissions platform. Although EPA's modeling shows that
a large portion of the transport problem affecting the receptors in
Coastal Connecticut is indeed from sources within the Ozone Transport
Region (OTR), a substantial portion of the transport problem at these
receptors, on the order of 25 percent, is the result of transport from
states outside the OTR. However, the relevance of that presentation to
the evaluation of Indiana's good neighbor obligations is not clear. As
already discussed, the statute and the case law (particularly the
holdings in Wisconsin and Maryland) make clear that good neighbor
obligations are not merely supplementary to or deferable until after
local emission reductions are achieved. Further, based on EPA's
modeling released with the March 2018 memorandum, nearly all of the
receptors to which Indiana is linked are also heavily impacted by
distant upwind state emissions in addition to local sources and sources
in neighboring states. The Wisconsin decision's holding in regard to
international contribution (discussed in more detail later) is equally
applicable to an upwind state's claims that some other state's
emissions, or local emissions, are more to blame than its own
emissions. See 938 F.3d 303 at 323-25 (``an upwind state can
`contribute' to downwind nonattainment even if its emissions are not
the but-for cause'').
---------------------------------------------------------------------------
\78\ Indiana's SIP submission, Appendix E at 4, 17.
---------------------------------------------------------------------------
There is nothing in the CAA that supports Indiana's position on
local sources, and Indiana does not provide grounds on which to approve
its SIP submission. The D.C. Circuit has held on five different
occasions that the timing framework for addressing interstate transport
obligations must be consistent with the downwind areas' attainment
schedule. In particular, for the ozone NAAQS, the states and EPA are to
address interstate transport obligations ``as expeditiously as
practicable'' and no later than the attainment schedule set in
accordance with CAA section 181(a). See North Carolina, 531 F.3d at
911-13; Wisconsin, 938 F.3d at 313-20; Maryland, 958 F.3d at 1204; New
York v. EPA, 964 F.3d 1214, 1226 (D.C. Cir. 2020); New York v. EPA, 781
Fed. App'x 4, 6-7 (D.C. Cir. 2019). The court in Wisconsin explained
its reasoning in part by noting that downwind jurisdictions often may
need to heavily rely on emissions reductions from upwind states in
order to achieve attainment of the NAAQS, 938 F.3d at 316-17; such
states would face increased regulatory burdens including the risk of
bumping up to a higher nonattainment classification if attainment is
not reached by the relevant deadline, Maryland, 958 F.3d at 1204. The
statutory framework of the CAA and these cases establish clearly that
states and EPA must address interstate transport obligations in line
with the attainment schedule provided in the CAA in order to timely
assist downwind states in attaining and maintain the NAAQS, and this
schedule is ``central to the regulatory scheme.'' Wisconsin, 938 F.3d
at 316 (quoting Sierra Club v. EPA, 294 F.3d 155, 161 (D.C. Cir.
2002)).
IDEM similarly suggested that international and offshore emissions
contributions should be part of the good neighbor calculus. IDEM's
reasoning related to international and offshore emissions is
inapplicable to the requirements of CAA section 110(a)(2)(D)(i)(I). The
good neighbor provision requires states and EPA to address interstate
transport of air pollution that contributes to downwind states' ability
to attain and maintain NAAQS. Whether emissions from other states or
other countries also contribute to the same downwind air quality issue
is irrelevant in assessing whether a downwind state has an air quality
problem, or whether an upwind state is significantly contributing to
that problem. States are not obligated under CAA section
110(a)(2)(D)(i)(I) to reduce
[[Page 9860]]
emissions sufficient on their own to resolve downwind receptors'
nonattainment or maintenance problems. Rather, states are obligated to
eliminate their own ``significant contribution'' or ``interference''
with the ability of other states to attain or maintain the NAAQS.
Indeed, the D.C. Circuit in Wisconsin specifically rejected
petitioner arguments suggesting that upwind states should be excused
from good neighbor obligations on the basis that some other source of
emissions (whether international or another upwind state) could be
considered the ``but-for'' cause of downwind air quality problem. See
938 F.3d at 323-324. The court viewed petitioners' arguments as
essentially an argument ``that an upwind state `contributes
significantly' to downwind nonattainment only when its emissions are
the sole cause of downwind nonattainment.'' Id. at 324. The court
explained that ``an upwind state can `contribute' to downwind
nonattainment even if its emissions are not the but-for cause.'' Id. at
324-325. See also Catawba County v. EPA, 571 F.3d 20, 39 (D.C. Cir.
2009) (rejecting the argument ``that `significantly contribute'
unambiguously means `strictly cause''' because there is ``no reason why
the statute precludes EPA from determining that [an] addition of
[pollutant] into the atmosphere is significant even though a nearby
county's nonattainment problem would still persist in its absence'');
Miss. Comm'n on Envtl. Quality v. EPA, 790 F.3d 138, 163 n.12 (D.C.
Cir. 2015) (observing that the argument that ``there likely would have
been no violation at all . . . if it were not for the emissions
resulting from [another source]'' is ``merely a rephrasing of the but-
for causation rule that we rejected in Catawba County''). Therefore, a
state is not excused from eliminating its significant contribution on
the basis that international emissions also contribute some amount of
pollution to the same receptors to which the state is linked.
IDEM also calculated Indiana's portion of contribution to the
Harford, Maryland receptor was 0.077 ppb, and determined that Indiana
would need to reduce its contribution by 0.0077 ppb (based on a
contribution threshold of 1 ppb) to bring the Maryland receptor into
attainment. IDEM argued that 0.0077 ppb is well within the error of the
model and would be ``difficult'' to translate into an emission
reduction requirement.\79\ We first note that this approach is a
deviation from EPA's traditional approach of apportioning upwind-state
responsibility at Step 3 using a uniform cost of control metric set at
a level that maximizes cost-effectiveness of emissions reductions in
relation to downwind state impacts across all linked states. Thus, this
is not how EPA has interpreted the statutory term ``significant'' in
the past, and EPA does not reach a conclusion whether this approach
would be approvable, had IDEM had imposed emissions reductions in line
with this logic.
---------------------------------------------------------------------------
\79\ Indiana's SIP submission, Attachment 1 at 42.
---------------------------------------------------------------------------
We do not need to reach that point in the analysis, however,
because, having selected that approach to defining its obligations,
IDEM proceeded to ignore the result. IDEM's submission identified
Indiana's proportional contribution as 0.077 ppb to the Harford,
Maryland receptor. Having acknowledged Indiana was responsible for
eliminating up to 0.0077 ppb of contribution, IDEM claimed that because
that amount was within the ``error of the model'' that it would be
``difficult'' to require that amount of reductions from Indiana
sources.
This argument does not rise to the level of acceptable proof. EPA
has routinely been capable of successfully implementing good neighbor
obligations through the CSAPR framework, and achieving significant
downwind air quality improvements through upwind-state reductions, at
levels of ``significant contribution'' comparable or even less than
those found in Indiana's submission, irrespective of alleged modeling
errors. See Wisconsin, 938 F.3d at 322-23 (rejecting Wisconsin's
argument that it should not face good neighbor obligations on the basis
that its emission reductions would only improve a downwind receptor by
two ten-thousandths of a part per billion).
After measuring Indiana's significant contribution, IDEM suggested
that modeling uncertainty was too great to either require emissions
reductions. But IDEM had measured the state's significant contribution
and was therefore identifying the measurable amount of significant
contribution the state was legally responsible for eliminating. See
Michigan v. EPA, 213 F.3d 663, 683-84 (D.C. Cir. 2000) (significant
contribution must be ``measurable''). Further, scientific uncertainty
may only be invoked to avoid comporting with the requirements of the
CAA when ``the scientific uncertainty is so profound that it precludes
. . . reasoned judgment'' Massachusetts v. EPA, 127 S.Ct. 1438 (2007).
See Wisconsin, 938 F.3d at 318-19 (``Scientific uncertainty, however,
does not excuse EPA's failure to align the deadline for eliminating
upwind States' significant contributions with the deadline for downwind
attainment of the NAAQS.''). See also EME Homer City, 795 F.3d 118,
135-36 (``We will not invalidate EPA's predictions solely because there
might be discrepancies between those predictions and the real world.
That possibility is inherent in the enterprise of prediction.'').
IDEM's arguments related to modeling uncertainty do not establish a
level of uncertainty so high as to preclude reasoned judgement.
IDEM provided an analysis of back trajectories from the Harford and
Richmond receptors to support its contention that Indiana does not
contribute significantly to nonattainment or maintenance at those
monitors, and that the receptors are more impacted by local emissions
anyway. IDEM also relied on an EPA presentation from 2018 to support
this conclusion.
As already discussed, the statute and the case law (particularly
the holdings in Wisconsin and Maryland) make clear that good neighbor
obligations are not merely supplementary to or deferable until after
local emission reductions are achieved. Further, all of the receptors
to which Indiana is linked are heavily impacted by upwind state
emissions in addition to local sources and conditions. The Wisconsin
decision's holding in regard to international contribution (discussed
previously) is equally applicable to an upwind state's claims that some
other state's emissions, or local emissions, are more to blame than its
own emissions. See 938 F.3d 303 at 323-25 (``an upwind state can
`contribute' to downwind nonattainment even if its emissions are not
the but-for cause'').
Further, EPA finds Indiana's back trajectory analysis to be
deficient in proving that Indiana does not contribute significantly to
nonattainment or maintenance at the Harford and Richmond monitors that
the State was linked to in the LADCO modeling. Indiana's back
trajectory analysis shows a linkage between Indiana and the monitors
when evaluating two altitudes, 10 meters and 750 meters, on several of
the exceedance days at these monitoring sites. By only evaluating two
altitudes, Indiana neglects to consider the wide range of heights that
might show back trajectories leading back to Indiana, potentially
further tying the state to more exceedance events. Furthermore, 10
meters is too low of an altitude to measure long range transport and it
would have been appropriate for Indiana to analyze several higher
altitudes to bolster its back trajectory analysis.
[[Page 9861]]
Back trajectories alone are not sufficient to disconnect upwind
States from downwind receptors. Relying solely on back trajectories for
establishing linkages neglects the myriad of factors, most importantly
photochemical reactions, that are important for determining the
magnitude of ozone and precursor transport from upwind states to
downwind receptors. In this regard, EPA and LADCO modeling which
accounts for 3 dimensional meteorological conditions, regional
emissions, and photochemical reactions is the most complete, and
technically sound method to establish linkages between upwind states
and downwind nonattainment and maintenance receptors.
The information and claims presented by IDEM did not provide
sufficient evidence to support alternative conclusions that EPA is
proposing to make in this action: Namely, that several receptors exist,
Indiana contributes to those receptors above a 1 percent of the NAAQS
contribution threshold, and that Indiana continues to have good
neighbor obligations that need to be addressed for the 2015 ozone
NAAQS. We therefore propose that Indiana was required to analyze
emissions from the sources and other emissions activity from within the
state to determine whether its contributions were significant, and we
propose to disapprove its submission because Indiana failed to do so.
5. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-Step interstate transport framework calls for
development of 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. IDEM identified the State's
existing NOX control measures, consent decree requirements,
and future fuel switches and retirements for large EGUs and non-EGUs
for the years 2008 through 2017 \80\ States may not rely on non-SIP
measures to meet SIP requirements. 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. U.S. E.P.A.,
786 F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on
by state to meet CAA requirements must be included in the SIP).
However, the state did not revise its SIP to include these emission
reductions in a revision to its SIP to ensure the reductions were
permanent and enforceable. As a result, EPA proposes to disapprove
Indiana's submittal on the separate, additional basis that Indiana has
not included permanent and enforceable emissions reductions in its SIP
as necessary to meet the obligations of CAA section
110(a)(2)(d)(i)(I).6.
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\80\ Pointing to anticipated upcoming emission reductions, even
if they were not included in the analysis at Steps 1 and 2, is not
sufficient as a Step 3 analysis, for the reasons discussed in
Section II.B.4. In this section, we explain that to the extent such
anticipated reductions are not included in the SIP and rendered
permanent and enforceable, reliance on such anticipated reductions
is also insufficient at Step 4.
---------------------------------------------------------------------------
6. Conclusion
Based on EPA's evaluation of Indiana's SIP submission, EPA is
proposing to find that the portion of Indiana's November 12, 2018 SIP
submission addressing CAA section 110(a)(2)(D)(i)(I) does not meet the
state's interstate transport obligations, because it fails to contain
the necessary provisions to eliminate emissions that will contribute
significantly to nonattainment or interfere with maintenance of the
2015 ozone NAAQS in any other state.
C. Michigan
1. Evaluation of Information Provided by Michigan Regarding Step 1
At Step 1 of the 4-step interstate transport framework, Michigan
relied primarily on the LADCO modeling released in 2018 to identify
nonattainment and maintenance receptors in 2023. As described
previously in this action, LADCO performed a modeling demonstration
like that of EPA modeling released with the March 2018 memorandum,
except with use of the ERTAC EGU Tool to replace specific EGU
information. LADCO identified nonattainment and maintenance receptors
using EPA methodology. EGLE elected to rely on LADCO's ``water only''
modeling results, but also presented results from EPA's modeling
released with the March 2018 memorandum. EGLE noted that in general,
design values in the LADCO modeling were lower. However, since new
modeling has been performed by EPA which includes updated emission data
using the 2016v2 platform, EPA proposes to primarily rely on the most
recent modeling to identify nonattainment and maintenance receptors in
2023. Nonetheless, the alternative modeling relied on by EGLE also
identified a number of nonattainment and maintenance receptor sites in
2023. See Table 2 on page 14 of EGLE's submittal. Thus, even under its
alternative modeling of 2023, EGLE acknowledges in its submittal the
existence of several nonattainment and maintenance receptors.
2. Evaluation of Information Provided by the State Regarding Step 2
Although Michigan relied on alternative modeling to EPA's modeling,
EGLE acknowledged in their SIP submission that Michigan is linked above
either a 1 percent of the NAAQS or 1 ppb or threshold to one or more
downwind receptors in 2023 (1.85 ppb to Sheboygan, Wisconsin (Site ID:
36-081-0124), 1.22 ppb to Queens, New York (Site ID: 36-085-0067), and
1.03 ppb to Richmond, New York (Site ID: 55-117-0006)). Because the
alternative modeling relied on by the state also demonstrates that a
linkage exists between the state and downwind receptors at Step 2, EPA
need not conduct a comparative assessment of the alternative modeling;
the state concedes that it is linked. EGLE's analysis corroborates the
conclusion in EPA's most recent modeling, described in the next
section.
EGLE, relying on a concept from outside parties listed in
Attachment A to the March 2018 memorandum, attempted to justify the use
of a 1 ppb threshold at Step 2 to identify whether the state was
``linked'' to a projected downwind nonattainment or maintenance
receptor. In part, EGLE attempted to justify the use of a 1 ppb
contribution threshold based on the 2018 PSD SIL guidance document.
EGLE also referenced EPA's August 2018 memorandum, which said that with
appropriate additional analysis it may be reasonable for states to use
a 1 ppb contribution threshold, as an alternative to a one percent
threshold, at Step 2 of the 4-Step interstate transport framework for
the purposes of identifying linkages to downwind receptors. As
explained in Section I above, the concepts presented in Attachment A to
the March 2018 memorandum were neither guidance nor determined by EPA
to be consistent with the CAA. Further, EGLE did not explain the
relevance of the SILs Guidance to which it referred. This guidance
relates to a different provision of the Clean Air Act regarding
implementation of the prevention of significant deterioration (PSD)
permitting program, i.e., a program that applies in areas that have
been designated attainment of the NAAQS, and it is not applicable to
the good neighbor provision, which requires
[[Page 9862]]
states to eliminate significant contribution or interference with
maintenance of the NAAQS at known and ongoing air quality problem areas
in other states. Further, it is not correct to conflate the use of the
term ``significance'' as used in the SIL guidance, with the term
``contribution,'' which is the appliable statutory term that EPA
applies at Step 2 of the 4-step interstate transport framework.
(``Significance'' within the 4-step framework is evaluated at Step 3
through a multifactor analysis, for those states that are determined to
``contribute'' to downwind receptors at Steps 1 and 2. See Section
I.D.4 above.) Given the fundamentally different statutory objectives
and context, EPA disagrees with EGLE's contention that the SIL guidance
is applicable in the good neighbor context.
EGLE's attempt to show ``inflection points'' through collectively
presenting contribution data at each linked receptor and its claim that
1 ppb reflects the most meaningful inflection point are likewise not
compelling. The presented data show a range of upwind contribution
levels captured by different contribution thresholds depending on which
receptor is analyzed. Certain receptors show a substantial downward
trend in captured total upwind contribution well before a threshold of
1 ppb. Therefore, EPA does not find this evidence supportive of a 1 ppb
threshold.
EPA does not accept Michigan's position that a 1 percent of the
NAAQS contribution threshold at Step 2 ``may not be appropriate'' for
the 2015 ozone NAAQS due to modeling biases and errors.\81\ The
explanation for how the 1 percent contribution threshold was originally
derived is available in the 2011 CSAPR rulemaking. See 76 FR 48208,
48237-38. Further, in the CSAPR Update, EPA re-analyzed the threshold
for purposes of the 2008 ozone NAAQS and determined it was appropriate
to continue to apply this threshold. EPA compared the 1 percent
threshold to a 0.5 percent of NAAQS threshold and a 5 percent of NAAQS
threshold. EPA found that the lower threshold did not capture
appreciably more upwind state contribution compared to the 1 percent
threshold, while the 5 percent threshold allowed too much upwind state
contribution to drop out from further analysis. See Final CSAPR Update
Air Quality Modeling TSD, at 27-30 (EPA-HQ-OAR-2015-0596-0144). If EPA
were to apply this analysis to the 2015 ozone NAAQS using the updated
modeling based on the 2016v2 emissions platform, a 5 percent of the
NAAQS contribution threshold (i.e., 3.5 ppb) only captures
approximately 50 percent of the total upwind contribution. Compared to
a 1 percent threshold, a 5 percent threshold would, on average, forgo
27 percent) of the total upwind contribution. As EPA noted in the
August 2018 memorandum, the use of a 2 ppb contribution threshold under
the modeling released with the March 2018 memorandum would only capture
about 55 percent of all upwind contributions, and therefore ``emission
reductions from states linked at that higher threshold may be
insufficient to address collective upwind state contribution to
downwind air quality problems.''\31\
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\81\ Michigan's SIP submission at 16.
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With these figures in mind, EGLE's claim based on unwarranted
concerns over modeling uncertainty cannot be accepted. Both LADCO's and
EPA's modeling techniques are sufficiently reliable and fit for the
purpose to measure upwind contribution levels down to at least one 1
percent of the NAAQS. EPA's recommended model attainment test is based
on application of the model in a relative sense rather than relying
upon absolute model predictions.\82\ All models have limitations
resulting from uncertainties in inputs and scientific formulation. To
minimize the effects of these uncertainties, the modeling is anchored
to base period measured data in EPA's guidance approach for projecting
design values. Notably, EPA also uses our source apportionment modeling
in a relative sense when calculating the average contribution metric
(used to identify linkages). In this method the magnitude of the
contribution metric is tied to the magnitude of the projected average
design value which is tied to the base period average measured design
value. EPA's guidance has not established a bright-line criteria for
judging whether or not statistical measures of model performance
constitute acceptable or unacceptable model performance. So, contrary
to what Michigan appears to be claiming with regards to modeling
biases, there are no EPA recommended measures of allowable error.
Although EPA does not typically focus on using particular benchmarks as
the sole criteria for model performance, EPA notes that the model
performance for the updated modeling based on the 2016v2 emissions
platform is generally within the benchmarks recommended by Emery.\83\
---------------------------------------------------------------------------
\82\ See Section 4.1' ``Overview of Modeled Attainment Test in
EPA Modeling Guidance for Demonstrating Air Quality Goals for Ozone,
PM2.5, and Regional Haze. November 2018. EPA 454-R-18-
009. https://www.epa.gov/scram/sip-modeling-guidance-documents.
\83\ Christopher Emery, Zhen Liu, Armistead G. Russel, M. Talat
Odman, Greg Yarwood and Naresh Kumar (2017). Recommendations on
statistics and benchmarks to assess photochemical model performance,
Journal of the Air & Waste Management Association, 67:5,582-598,
DOI: 10.1080/10962247.2016.1265027.
---------------------------------------------------------------------------
EPA has successfully applied a 1 percent of the NAAQS threshold to
identify linked upwind states in three prior rulemakings. And the D.C.
Circuit has also declined to establish bright line criteria for model
performance. In upholding EPA's approach to evaluating interstate
transport in CSAPR, the D.C. Circuit held that they would not
``invalidate EPA's predictions solely because there might be
discrepancies between those predictions and the real world. That
possibility is inherent in the enterprise of prediction.'' EME Homer
City Generation, L.P. v. EPA, 795 F.3d 118, 135 (2015). The court
continued to note that ``the fact that a `model does not fit every
application perfectly is no criticism; a model is meant to simplify
reality in order to make it tractable.' '' Id. at 135-36 (quoting
Chemical Manufacturers Association v. EPA, 28 F.3d 1259, 1264 (D.C.
Cir. 1994).
EPA's August 2018 memorandum provided that whether use of a 1 ppb
threshold is appropriate must be based on an evaluation of state-
specific circumstances, and no such evaluation was included in the
submission. EPA's experience with the alternative Step 2 thresholds is
further discussed in Section I.D.3.i. As discussed there, EPA is
considering withdrawing the August 2018 memorandum.
Based on EPA's updated modeling (as well as the LADCO's 2018
modeling (with water) the state elected to rely on in its SIP
submission), the state is projected to contribute greater than both the
1 percent and alternative 1 ppb thresholds. While EPA does not, in this
action, approve of the state's application of the 1 ppb threshold,
based on its linkages greater than 1 ppb to projected downwind
nonattainment or maintenance receptors, the state's use of this
alternative threshold at Step 2 of the 4-Step interstate framework is
inconsequential to our action on this SIP submission.
3. Results of EPA's Step 1 and Step 2 Modeling and Findings for
Michigan
As described in Section I, EPA performed air quality modeling using
the 2016v2 emissions platform to project design values and
contributions for 2023. These data were examined to determine if
Michigan contributes at or above the threshold of 1 percent of the
[[Page 9863]]
2015 ozone NAAQS (0.70 ppb) to any downwind nonattainment or
maintenance receptor. As shown in Table 4, the data \84\ indicate that
in 2023, emissions from Michigan contribute greater than one percent of
the standard to nonattainment or maintenance-only receptors in
Illinois, Connecticut, Wisconsin, and Pennsylvania.\85\
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\84\ Design values and contributions at individual monitoring
sites nationwide are provide in the file
``2016v2_DVs_state_contributions.xlsx'' which is included in docket
ID No. EPA-HQ-OAR-2021-0663.
\85\ These modeling results are consistent with the results of a
prior round of 2023 modeling using the 2016v1 emissions platform
which became available to the public in the fall of 2020 in the
Revised CSAPR Update, as noted in Section I. That modeling showed
that Illinois had a maximum contribution greater than 0.70 ppb to at
least one nonattainment or maintenance-only receptor in 2023. These
modeling results are included in the file ``Ozone Design Values &
Contributions Revised CSAPR Update.xlsx'' in docket ID No. EPA-HQ-
OAR-2021-0663.
Table 4--Michigan Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Michigan
Receptor ID Location Nonattainment/ design value design value contribution
(county, state) maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
170314201.................... Cook, IL........ Maintenance.... 69.9 73.4 1.67
170310076.................... Cook, IL........ Maintenance.... 69.3 72.1 1.54
90099002..................... New Haven, CT... Nonattainment.. 71.8 73.9 1.27
170317002.................... Cook, IL........ Maintenance.... 70.1 73.0 1.26
170310032.................... Cook, IL........ Maintenance.... 69.8 72.4 1.21
550590025.................... Kenosha, WI..... Maintenance.... 69.2 72.3 1.17
550590019.................... Kenosha, WI..... Nonattainment.. 72.8 73.7 1.07
90010017..................... Fairfield, CT... Nonattainment.. 73.0 73.7 1.07
551010020.................... Racine, CT...... Nonattainment.. 71.3 73.2 1.02
90013007..................... Fairfield, CT... Nonattainment.. 74.2 75.1 0.94
170310001.................... Cook, IL........ Maintenance.... 69.6 73.4 0.93
90019003..................... Fairfield, CT... Nonattainment.. 76.1 76.4 0.92
420170012.................... Bucks, PA....... Nonattainment.. 70.7 72.2 0.75
----------------------------------------------------------------------------------------------------------------
Therefore, based on EPA's evaluation of the information submitted
by EGLE, and based on EPA's most recent modeling results for 2023, EPA
proposes to find that Michigan is linked at Steps 1 and 2 and has an
obligation to assess potential emissions reductions from sources or
other emissions activity at Step 3 of the 4-step framework. EPA
therefore will proceed to Step 3 of the 4-step interstate transport
framework to assess the arguments the state presented as to why,
despite this linkage, the state should not be considered to
significantly contribute to nonattainment or interfere with maintenance
of the NAAQS in any other state.
4. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I).
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the obligations in CAA section 110(a)(2)(D)(i)(I) must
prohibit ``any source or other type of emissions activity within the
State'' from emitting air pollutants which will contribute
significantly to downwind air quality problems. Thus, states must
complete something similar to EPA's analysis (or an alternative
approach to defining ``significance'' that comports with the statute's
objectives) to determine whether and to what degree emissions from a
state should be ``prohibited'' to eliminate emissions that will
``contribute significantly to nonattainment in, or interfere with
maintenance of'' the NAAQS in any other state.
EGLE did not conduct a sufficient step 3 analysis in Michigan's SIP
submission. As explained previously, at Step 3 EGLE instead applied a
weight of evidence analysis to argue that the state needed no
additional emission reductions despite concluding Michigan was linked
to three receptors at Step 2. The evidence presented in EGLE's
submittal consisted primarily of support for the argument that upwind
states should have a lower responsibility to other states when the
upwind state is only linked to maintenance receptors. EGLE's analysis
focused on the Sheboygan, Wisconsin maintenance receptor (Site ID: 36-
081-0124), as EGLE concluded it was the receptor to which Michigan was
projected to contribute the most in 2023 at 1.85 ppb. EGLE also relied
on several ideas in Attachment A to the March 2018 memorandum to
further discount the importance of its own emissions. As noted in
Section I, the ideas listed in Attachment A to the March 2018
memorandum were not agency guidance nor had EPA determined them to be
consistent with the requirements of the CAA. EPA will thoroughly review
the technical and legal justifications ELGE made put forward in their
attempt to use them as flexibilities.
In its submittal, EGLE cited a concept in Attachment A to the March
2018 memorandum to ``[c]onsider whether the remedy for upwind states
linked to maintenance receptors could be less
[[Page 9864]]
stringent than those linked to nonattainment receptors'' and argued
that because the CAA incudes different SIP development requirements for
nonattainment and maintenance areas, that likewise nonattainment and
maintenance areas should be treated differently in good neighbor SIPs.
EGLE posited that because the CAA does not require emission reductions
from maintenance areas, then upwind states can potentially make a
sufficient showing they have no obligation to reduce emissions to
monitors in other states projected to be maintaining the NAAQS. EGLE
specifically noted that (1) the projected exceedance at the Sheboygan,
Wisconsin receptor is very small, (2) the majority of the projected
contribution to the Sheboygan, Wisconsin receptor is from federally
regulated sources or sources Michigan cannot otherwise regulate, (3)
Michigan's projected contribution to all three linked receptors is
small compared to the projected contribution from other states and
sources, (4) there are large projected contributions to the Sheboygan,
Wisconsin receptor from international emissions, (5) Michigan's
contributions to projected exceedance at the three maintenance
receptors are small relative to other sources that also contribute more
than 1 ppb to those receptors, (6) the modeling variability is greater
than Michigan's contributions to the amount of the projected exceedance
at each linked receptor and (7) there is a downward emissions trend in
Michigan.
As a general matter, EPA disagrees with EGLE's premise that if no
emission reductions are needed for the receptor to which Michigan
contributes the most, that automatically no emission reductions are
needed for the other receptors to which Michigan is linked. EGLE
unreasonably failed to analyze receptor-specific circumstances present
at other receptors to which it was linked, and this is particularly the
case because EGLE chose to rely so heavily on receptor-specific
information to support their conclusions with respect to the Sheboygan
receptor. Further, while the set of receptors to which Michigan is
linked has changed in the most recent modeling (and now includes
nonattainment receptors), EPA disagrees with Michigan's arguments to
the extent such reasoning could be applied to Michigan's linkages
identified in EPA's 2016v2 emissions platform modeling.
EGLE argued that because the Sheboygan, Wisconsin receptor, had a
small projected exceedance over the NAAQS, requiring additional
emission reductions in Michigan would be ``premature'' and
``burdensome.'' \86\ EGLE's premise goes beyond the concept in
Attachment A to the 2018 memorandum that emission-reduction obligations
as to maintenance receptors may be different; rather, EGLE argues that
not only should Michigan have lower obligations with respect to
maintenance receptors, but no obligations at all. Under the D.C.
Circuit's decision in North Carolina, states and EPA are required to
give independent significance to the ``interference with maintenance''
prong of section 110(a)(2)(D)(i)(I). 531 F.3d at 910. Since CSAPR,
EPA's nationally consistent policy framework for addressing interstate
ozone transport has given meaning to this prong through a separate
definition of maintenance receptors at step 1 of the 4-step interstate
transport framework. For states linked only to those receptors, EPA has
found it appropriate to apply an emissions control solution that is
uniform with the strategy applied for states that are linked to
nonattainment receptors. See 76 FR at 48271. EPA's approach to
addressing interference with maintenance under prong 2 for ozone NAAQS
has been upheld twice, including on remand from the Supreme Court
decision EGLE cited. See EME Homer City Generation, L.P., 795 F.3d at
136; Wisconsin, 938 F.3d at 325-27. See also 86 FR at 23074.
Particularly given this context, Michigan's SIP does not provide
sufficient evidence to support less stringent or even no standards of
emissions reductions relative to what would result from EPA's
historical approach of addressing emissions activities from upwind
states that are linked to maintenance-only receptors.
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\86\ See Michigan SIP submission p. 20.
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Further, EPA believes it would be inconsistent with the CAA for EPA
to identify receptors that are at risk of NAAQS violations given
certain conditions due to transported upwind emissions and then not
prohibit the emissions that place the receptor at risk. The Supreme
Court held that it was a permissible interpretation of the statute to
apportion responsibility for states linked to nonattainment receptors
considering ``both the magnitude of upwind states' contributions and
the cost associated with eliminating them.'' EME Homer City, 572 U.S.
at 518-19. It is equally reasonable and permissible to use these
factors to apportion responsibility among upwind states linked to
maintenance receptors because the goal in both instances is to prohibit
the ``amounts'' of pollution that will either significantly contribute
to nonattainment or interfere with maintenance of the NAAQS downwind.
See Id. 515 n.18 (finding EPA's uniform-cost approach reasonable as to
both prongs of the good neighbor provision). EPA's updated modeling
indicates that Michigan will remain linked to downwind nonattainment
and maintenance receptors for the 2015 ozone standard at least through
2023. Consequently, EPA believes EGLE's assertion that upwind states
linked to maintenance-only receptors should be held to less stringent
standards of emissions reductions (as compared to states linked to a
nonattainment receptor) is inappropriate, whether applied to its
downwind linkages in either the modeling EGLE relied on or in EPA's
more recent modeling.
EGLE also claimed that Attachment A to the March 2018 memorandum
suggested states linked only to maintenance receptors should consider
whether emissions reduction factors should be influenced by high
international contributions and high contributions from other states
and sources. As a concept presented by outside parties, Attachment A to
the March 2018 memorandum listed an idea that states may consider
whether air quality, cost, or emission reduction factors should be
weighted differently in areas where international contributions are
relatively high. EPA did not at the time endorse this concept, nor does
it do so now. However, EGLE did not present an approach or explain how
international contributions to the linked receptors should influence
the weighting of air quality, cost, or emission reductions at Step 3.
Rather, EGLE suggested that if a receptor is near an international
border, then international contribution could simply be removed from
that monitor's projected design value. This is neither appropriate nor
acceptable under the good neighbor provision or any other provision of
the Clean Air Act. Michigan's approach effectively takes the position
that no air quality problem should be deemed to exist at a downwind
receptor location under the false assumption that the international
portion of emissions affecting that area simply do not exist. EPA
categorically rejects this approach as an entirely unacceptable form of
air quality planning.
EGLE further cited contributions from other states and sources to
the linkages it identified to conclude it would be ``unreasonable'' for
linked states with relatively low contributions to reduce their
contributions.\87\ The Step 2 threshold (whether at 1 percent or 1
[[Page 9865]]
ppb) is intended to reflect the ``collective contribution'' nature of
the interstate ozone transport problem and the complexity of the
various linkages among states. Cf. EME Homer City, 572 U.S. at 515-16.
The threshold functions as a screening step toward a more detailed
analysis of emission-reduction opportunities across all of the states
that contribute to some extent (i.e., above the threshold) to a
downwind air quality problem. To simply conclude that nothing need be
done regarding emissions that exceed the step 2 threshold because those
emissions can be characterized as ``small'' compared to others'
emissions (by the upwind state's lights at least) is an attempt to
simply move the ``contribution'' threshold at Step 2 and is clearly
insufficient at Step 3.
---------------------------------------------------------------------------
\87\ See Michigan SIP submission p. 32.
---------------------------------------------------------------------------
Whether emissions from other states or other countries also
contribute to the same downwind air quality issue is irrelevant in
assessing whether a downwind state has an air quality problem, or
whether an upwind state is significantly contributing to that problem.
States are not obligated under CAA section 110(a)(2)(D)(i)(I) to reduce
emissions sufficient on their own to resolve downwind receptors'
nonattainment or maintenance problems. Rather, states are obligated to
eliminate their own ``significant contribution'' or ``interference''
with the ability of other states to attain or maintain the NAAQS.
Further, the court in Wisconsin explained that downwind
jurisdictions often may need to heavily rely on emissions reductions
from upwind states in order to achieve attainment of the NAAQS, 938
F.3d at 316-17; such states would face increased regulatory burdens
including the risk of bumping up to a higher nonattainment
classification if attainment is not reached by the relevant deadline,
Maryland, 958 F.3d at 1204. Indeed, the D.C. Circuit in Wisconsin
specifically rejected petitioner arguments suggesting that upwind
states should be excused from good neighbor obligations on the basis
that some other source of emissions (whether international or another
upwind state) could be considered the ``but-for'' cause of downwind air
quality problem. 938 F.3d at 323-324. The court viewed petitioners'
arguments as essentially an argument ``that an upwind state
`contributes significantly' to downwind nonattainment only when its
emissions are the sole cause of downwind nonattainment.'' 938 F.3d at
324. The court explained that ``an upwind state can `contribute' to
downwind nonattainment even if its emissions are not the but-for
cause.'' Id. at 324-325. See also Catawba County v. EPA, 571 F.3d 20,
39 (D.C. Cir. 2009) (rejecting the argument ``that `significantly
contribute' unambiguously means `strictly cause' '' because there is
``no reason why the statute precludes EPA from determining that [an]
addition of [pollutant] into the atmosphere is significant even though
a nearby county's nonattainment problem would still persist in its
absence''); Miss. Comm'n on Envtl. Quality v. EPA, 790 F.3d 138, 163
n.12 (D.C. Cir. 2015) (observing that the argument that ``there likely
would have been no violation at all . . . if it were not for the
emissions resulting from [another source]'' is ``merely a rephrasing of
the but-for causation rule that we rejected in Catawba County.'').
Therefore, a state is not excused from eliminating its significant
contribution on the basis that emissions from other sources also
contribute some amount of pollution to the same receptors to which the
state is linked. Thus, the state's arguments related to contributions
from other sources, including removing international emissions from
projected design values at the Sheboygan, Wisconsin monitor, are
insufficient at Step 3 of the analysis.
EGLE's submission included an apportionment analysis to quantify
individual states' relative responsibility of the projected exceedances
at the three linked receptors. EGLE cited Attachment A to the March
2018 memorandum as well as EME Homer City Generation to suggest
Michigan could be found to be only responsible for eliminating its
share of the projected exceedances relative to other states that also
contribute more than 1 ppb to the same receptors. We first note that
this approach is a deviation from EPA's traditional approach of
apportioning upwind-state responsibility at Step 3 using a uniform cost
of control metric set at a level that maximizes cost-effectiveness of
emissions reductions in relation to downwind state impacts across all
linked states. Thus, this is not how EPA has interpreted the statutory
term ``significant'' in the past, and EPA does not reach a conclusion
whether this approach would be approvable, had EGLE had imposed
emissions reductions in line with this logic. We do not need to reach
that point in the analysis, however, because, having selected that
approach to defining its obligations, EGLE proceeded to ignore the
result.
EGLE's submission identified Michigan's proportional contribution
as less than 0.12 ppb to the three linked receptors and .05 ppb to the
Sheboygan, Wisconsin receptor. Having acknowledged Michigan was
responsible for eliminating up to 0.12 ppb of contribution to the
downwind receptors, EGLE claimed that modeling ``noise'' made it
``difficult'' to require that amount of reductions from Michigan
sources. EGLE further opined that the downwind jurisdiction's share of
responsibilities likely made Michigan's contributions even lower and
the projected exceedances were so small that those three receptors were
likely to not have difficulty attaining the NAAQS anyway. EPA has
routinely been capable of successfully implementing good neighbor
obligations through the CSAPR framework, and achieving significant
downwind air quality improvements through upwind-state reductions, at
levels of ``significant contribution'' comparable or even less than
those found in Michigan's submittal, irrespective of alleged ``modeling
noise.'' See Wisconsin, 938 F.3d at 322-23 (rejecting Wisconsin's
argument that it should not face good neighbor obligations on the basis
that its emission reductions would only improve a downwind receptor by
two ten-thousandths of a part per billion).
After measuring Michigan's significant contribution, EGLE suggested
that modeling uncertainty was too great to either require emissions
reductions or demonstrate that EGLE had any linkages to maintenance
receptors at all. But EGLE had measured the state's significant
contribution and was therefore identifying the measurable amount of
significant contribution the state was legally responsible for
eliminating. See Michigan v. EPA, 213 F.3d 663, 683-84 (D.C. Cir. 2000)
(significant contribution must be ``measurable''). Further, scientific
uncertainty may only be invoked to avoid comporting with the
requirements of the CAA when ``the scientific uncertainty is so
profound that it precludes . . . reasoned judgment'' Massachusetts v.
EPA, 127 S.Ct. 1438 (2007). See Wisconsin, 938 F.3d at 318-19
(``Scientific uncertainty, however, does not excuse EPA's failure to
align the deadline for eliminating upwind States' significant
contributions with the deadline for downwind attainment of the
NAAQS.''). See also EME Homer City, 795 F.3d 118, 135-36 (``We will not
invalidate EPA's predictions solely because there might be
discrepancies between those predictions and the real world. That
possibility is inherent in the enterprise of prediction.''). EGLE's
arguments related to modeling uncertainty or ``noise'' do not establish
a level of uncertainty so high as to
[[Page 9866]]
preclude reasoned judgement. EGLE argued that the three maintenance
receptors at issue could maintain the NAAQS without further emissions
reductions from any linked upwind state. In support, EGLE's submission
provided a list of on-the-way and on-the-books emission reductions
measures to argue that Michigan's good neighbor obligations were
already satisfied. EGLE provided references to certain facility
retirements in Michigan, Federal mobile source rules, Federal rules
reducing NOX and VOCs such as MATS and the Oil and Natural
Gas Industry Standards, the NOX SIP Call, and CSAPR Update.
EPA's assessment of future air quality conditions generally already
accounts for on-the-books emission reductions and the most up-to-date
forecast of future emissions in the absence of the transport policy
being evaluated (i.e., base case conditions).\88\ As described in more
detail in Section I, EPA's latest projections of the baseline EGU
emissions uses the version 6--Summer 2021 Reference Case of the
IPM.\89\ The IPM version 6--Summer 2021 Reference Case uses the NEEDS
v6 database as its source for data on all existing and planned-
committed units. Units are removed from the NEEDS inventory only if a
high degree of certainty could be assigned to future implementation of
the announced future closure or retirement. Any retirements excluded
from the NEEDS v6 inventory can be viewed in the NEEDS spreadsheet.\90\
The inventory for these projections takes account of the retirement of
the Marquette Board of Light & Power Shiras Steam Plant, Lansing Board
of Water and Light, Eckert Station, Units 1 and 3-6; DTE, River Rouge,
Unit 3; We Energies, Presque Isle Power Plant, Units 5-9; DTE St.
Clair, Units 1-4 and 6-7; DTE Trenton Channel, Unit 9; Wyandotte, Unit
5; Consumers Energy Karn, Units 1-2.
---------------------------------------------------------------------------
\88\ See 81 FR 74504 at 74517; 85 FR 68964 at 68979.
\89\ Detailed information and documentation of EPA's Base Case,
including all the underlying assumptions, data sources, and
architecture parameters can be found on EPA's website at: https://www.epa.gov/airmarkets/epas-power-sector-modeling-platform-v6-using-ipm-summer-2021-reference-case.
\90\ We note that for one of the units EGLE listed as projected
to retire, Wyandotte--Unit 5, this facility was still included in
the NEEDS as operating. Additionally, the unit IDs listed by EGLE in
the SIP submittal may be different from those listed in EPA's NEEDS
v6 inventory--NEEDS v6 Summer 2021 Reference Case, however we have
verified that these emissions decreases have been accounted for in
our most recent modeling.
---------------------------------------------------------------------------
Additionally, EPA's modeling using the 2016v2 emissions platform
accounts for the onroad and nonroad rules that Michigan identified,
such as the Tier 3 Motor Vehicle Emission and Fuel Standards, to the
extent still on the books and projected to have ozone-precursor
emissions consequences.\91\
---------------------------------------------------------------------------
\91\ See Technical Support Document (TSD) Preparation of
Emissions Inventories for the 2016v2 North American Emissions
Modeling Platform included in the Headquarters docket ID No. EPA-HQ-
OAR-2021-0663.
---------------------------------------------------------------------------
In other words, changes in the emissions inventory and on-the-books
controls relevant to emissions in 2023 that EGLE claims EPA missed in
its prior modeling have now been incorporated into EPA's most recent
modeling of 2023 using the 2016v2 emissions platform. This modeling
projects a continuing contribution from Michigan to thirteen out-of-
state receptors above a threshold of 1 percent of the NAAQS (at Steps 1
and 2) despite these measures--nine of which have contribution from
Michigan above 1 ppb and seven of which are nonattainment receptors
(see Table 4).\92\ Therefore, in light of continuing contribution to
out of state receptors from Michigan notwithstanding these identified
on-the-books control measures, EGLE's SIP submission should have
evaluated the availability of additional air quality controls to
improve downwind air quality at nonattainment and maintenance receptors
at Step 3.
---------------------------------------------------------------------------
\92\ Notably, in focusing its Step 3 analysis only on a single
receptor, EGLE gave no weight to the scope of its contribution to
downwind air quality problems. Linkages to thirteen receptor sites
in EPA's most recent modeling indicate that Michigan's emissions
have widespread effects in other states--effects that the State's
SIP submittal would do nothing to address.
---------------------------------------------------------------------------
Nor does EGLE's listing of existing control measures or overall
emission trends serve as an adequate substitute for a Step 3 analysis
of additional potential emission reductions. In general, the listing of
existing or on-the-way control measures, whether approved into the
State's SIP or not, does not substitute for a complete step 3 analysis
under EPA's 4-step framework to define ``significant contribution.''
ELGE did not provide an assessment of the overall effects of these
measures, when the emissions reductions would be achieved, and what the
overall resulting air quality effects would be at identified out of
state receptors. EGLE did not identify which portion of ongoing
emissions trends were not already accounted for in steps 1 and 2 of the
analysis (EPA addresses specific identified changes in emissions
inventory in the discussion above). EGLE did not evaluate additional,
potential emissions control opportunities, or their costs or impacts,
or attempt to analyze whether, if applied more broadly across linked
states, the emissions reductions would constitute the elimination of
significant contribution on a regional scale. The state did not offer
an explanation as to whether any faster or more stringent emissions
reductions that may be available were prohibitively costly or
infeasible. Although EPA acknowledges states are not necessarily bound
to follow its own analytical framework at step 3, we note that the
state did not attempt to determine or justify an appropriate uniform
cost-effectiveness threshold for the more stringent 2015 ozone NAAQS.
This would have been similar to the approach to defining significant
contribution that EPA has applied in prior rulemakings such as CSAPR
and or the CSAPR Update, even if such an analysis is not technically
mandatory.
Further, the state's attempt to categorize certain sectors of
emissions as beyond its regulatory control is unpersuasive. Clearly the
state possesses regulatory authority over its EGU and non-EGU large
stationary sources as well as authority over other types of ``emissions
activity within the state,'' see CAA section 110(a)(2)(D)(i). And while
mobile sources are generally regulated at the Federal level under title
II of the Clean Air Act, the state also has the authority to undertake
any number of measures to reduce emissions from mobile sources through
means and techniques that are not preempted by title II. See, e.g., CAA
sections 182(b)(3), 182(b)(4), 182(c)(3), 182(c)(4), 182(c)(5),
182(d)(1), 182(e)(3), and 182(e)(4) (identifying programs to control
mobile source emissions that states are required to implement depending
on the degree of ozone nonattainment). Specifically with respect to
EGUs, EPA notes that no EGU NOX control program has yet been
established to implement good neighbor requirements for the 2015 ozone
NAAQS. Thus reliance on prior programs, such as the CSAPR Update or
Revised CSAPR Update, is misplaced, since those programs only addressed
good neighbor obligations under the less stringent 2008 ozone NAAQS.
Finally, under the Wisconsin decision, states and EPA may not delay
implementation of measures necessary to address good neighbor
requirements beyond the next applicable attainment date without a
showing of impossibility or necessity. See 938 F.3d at 320. In those
cases where the measures identified by Michigan had implementation
timeframes beyond the next relevant attainment dates, the submission
did not offer a demonstration of impossibility of earlier
implementation of those control measures that would go into effect
after
[[Page 9867]]
2024. Similarly, the State's submittal is insufficient to the extent
the implementation timeframes for identified control measures were left
unidentified, unexplained, or too uncertain to permit EPA to form a
judgment as to whether the timing requirements for good neighbor
obligations have been met.
For the reasons listed above, EPA proposes to find that Michigan
has not satisfied its obligations of the good neighbor SIP provisions
at Step 3 of the 4-step transport framework. We propose that Michigan
was required to analyze emissions more fully from the sources and other
emissions activity from within the state to determine whether its
contributions were significant, and we propose to disapprove its
submission because Michigan failed to do so.
5. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-step interstate transport framework calls for
development of 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. EGLE provided references to
on the books and on the way Federal mobile source rules, MATS and the
Oil and Natural Gas Industry Standards, the NOX SIP Call,
and CSAPR Update. As an initial matter, pointing to or listing existing
state or Federal control measures is not what is called for at Step 4.
Rather Step 4 requires the development of permanent and enforceable
measures to implement those measures determined to be required at Step
3. EGLE claimed that nothing was required of Michigan at Step 3 and
thus EGLE stated that it did not believe anything was required at Step
4. Therefore, we do not interpret the list of existing state or Federal
measures to be EGLE's attempt at implementation at Step 4.
Because Michigan's SIP submission did not contain an evaluation of
additional emission control opportunities (or establish that no
additional controls are required), no information was provided at Step
4. As a result, EPA proposes to disapprove Michigan's submittal on the
separate, additional basis that the state has not developed permanent
and enforceable emissions reductions necessary to meet the obligations
of CAA section 110(a)(2)(d)(i)(I).
6. Conclusion
Based on EPA's evaluation of EGLE's SIP submission, EPA is
proposing to find that the portion of Michigan's March 5, 2019 SIP
submission addressing CAA section 110(a)(2)(D)(i)(I) does not meet the
state's interstate transport obligations, because it fails to contain
the necessary provisions to eliminate emissions that will contribute
significantly to nonattainment or interfere with maintenance of the
2015 ozone NAAQS in any other state.
D. Minnesota
1. Evaluation of Information Provided by Minnesota Regarding Steps 1
and 2
At Step 1 of the 4-step interstate transport framework, Minnesota
relied on both LADCO modeling and EPA modeling released in the March
2018 memorandum and to identify nonattainment and maintenance receptors
in 2023. As described previously, LADCO performed a modeling
demonstration like that of EPA's 2018 transport modeling, except with
use of the ERTAC EGU Tool to supplement state specific EGU information.
LADCO identified nonattainment and maintenance receptors using EPA
methodology. MPCA presented several nonattainment and maintenance
receptors identified by both LADCO modeling, showing ``no water'' and
``with water'' results and EPA modeling released with the March 2018
memorandum. Since new modeling has been performed by EPA with updated
emission data, EPA proposes to primarily rely on the most recent
modeling to identify nonattainment and maintenance receptors in 2023.
MPCA made several criticisms of EPA's method for projecting EGU
emissions in EPA's modeling released with the March 2018 memorandum.
Although EPA does not agree with those criticisms, we note that EPA is
relying on a different method for projecting emissions from EGUs in the
updated modeling using the 2016v2 emissions platform as explained in
more detail in Section I.
Nonetheless, the alternative modeling relied on by MPCA also
identified a number of nonattainment and maintenance receptor sites in
2023. See Tables 2 and 3 on pages 8 and 9 of MPCA's submittal. Thus,
even under the alternative modeling of 2023, MPCA acknowledges in its
submittal the existence of several nonattainment and maintenance
receptors.
At Step 2 of the 4-Step interstate transport framework, MPCA relied
on both LADCO modeling and EPA modeling released in the March 2018
memorandum to identify upwind state linkages to nonattainment and
maintenance receptors in 2023. Based on both modeling results, MPCA
concluded that Minnesota would contribute below 1 percent of the NAAQS
to receptors in 2023. However, in this proposal, EPA relies on the
Agency's most recently available modeling, which uses a more recent
base year and more up-to-date emissions inventories, to identify upwind
contributions and ``linkages'' to downwind air quality problems in 2023
using a threshold of 1 percent of the NAAQS. As shown in Table 5
(explained in the next section), the updated EPA modeling identifies
Minnesota's maximum contribution to a downwind nonattainment or
maintenance receptor is greater than 1 percent of the standard (i.e.,
0.70 ppb). Although the state did not rely on a 1 ppb contribution
threshold in its SIP submittal, EPA recognizes that the modeling the
MPCA used relied on the most recently available EPA modeling at the
time the state submitted its SIP submittal (EPA modeling released in
the March 2018 memorandum as well as the LADCO modeling). The 2018
modeling indicated the state was not projected to contribute above one
1 percent of the NAAQS to a projected downwind nonattainment or
maintenance receptor. Therefore, the state may not have considered
analyzing the reasonableness and appropriateness of a 1 ppb threshold
at Step 2 of the 4-step Step interstate transport framework per the
August 2018 memorandum. EPA's August 2018 memorandum provided that
whether use of a 1 ppb threshold is appropriate must be based on an
evaluation of state-specific circumstances, and no such evaluation was
included in the submission. EPA's experience with the alternative Step
2 thresholds is further discussed in Section I.D.3.i. As discussed
there, EPA is considering withdrawing the August 2018 memorandum.
2. Results of EPA's Step 1 and Step 2 Modeling and Findings for
Minnesota
As described in Section I, EPA performed air quality modeling using
the 2016v2 emissions platform to project design values and
contributions for 2023. These data were examined to determine if
Minnesota contributes at or above the threshold of 1 percent of the
2015 ozone NAAQS (0.70 ppb) to any downwind nonattainment or
maintenance receptor. As shown in
[[Page 9868]]
Table 5, the data \93\ indicate that in 2023, emissions from Minnesota
contribute greater than 1 percent of the standards to two maintenance-
only receptors in Illinois. These modeling results are consistent with
the results of a prior round of 2023 modeling using the 2016v1
emissions platform that became available to the public in the fall of
2020 in the Revised CSAPR Update, as noted in Section I, which showed
that Minnesota had a maximum contribution of 0.86 ppb to a
nonattainment or maintenance receptor in 2023.\94\
---------------------------------------------------------------------------
\93\ Design values and contributions at individual monitoring
sites nationwide are provide in the file:
2016v2_DVs_state_contributions.xlsx which is included in docket ID
No. EPA-HQ-OAR-2021-0663.
\94\ These modeling results are consistent with the results of a
prior round of 2023 modeling using the 2016v1 emissions platform
which became available to the public in the fall of 2020 in the
Revised CSAPR Update, as noted in Section I. That modeling showed
that Minnesota had a maximum contribution greater than 0.70 ppb to
at least one nonattainment or maintenance-only receptor in 2023.
These modeling results are included in the file ``Ozone Design
Values And Contributions Revised CSAPR Update.xlsx'' in docket EPA-
HQ-OAR-2021-0663.
Table 5--Minnesota Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Minnesota
Receptor ID Location Nonattainment/ design value design value contribution
maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
170310001.................... Cook............ Maintenance.... 69.6 73.4 0.97
170310076.................... Cook............ Maintenance.... 69.3 72.1 0.79
----------------------------------------------------------------------------------------------------------------
Based on EPA's evaluation of the information submitted by MPCA, and
based on EPA's most recent modeling results for 2023 using the 2016v2
emissions platform, EPA proposes to find that Minnesota is linked at
Steps 1 and 2 and has an obligation to assess potential emissions
reductions from sources or other emissions activity at Step 3 of the 4-
Step framework. Despite the linkage EPA determines exists at Step 2,
the state concluded in its submission based on other factors that it
should not be considered to significantly contribute to nonattainment
or interfere with maintenance of the NAAQS in other states. Therefore,
EPA will proceed to evaluate MPCA's additional analyses at Step 3 of
the 4-Step interstate transport framework.
4. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-Step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I).
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the obligations in CAA section 110(a)(2)(D)(i)(I) must
prohibit ``any source or other type of emissions activity within the
state'' from emitting air pollutants which will contribute
significantly to downwind air quality problems. Thus, states must
complete something similar to EPA's analysis (or an alternative
approach to defining ``significance'' that comports with the statute's
objectives) to determine whether and to what degree emissions from a
state should be ``prohibited'' to eliminate emissions that will
``contribute significantly to nonattainment in or interfere with
maintenance of'' the NAAQS in any other state. MPCA did not conduct
such an analysis in their SIP submission.
Neither the LADCO modeling nor EPA modeling released with the March
2018 memorandum indicated that Minnesota would contribute over 1
percent of the NAAQS to any nonattainment or maintenance receptor in
2023. Therefore, MPCA stated they did not consider it necessary to
consider further emission reductions because Minnesota was not
projected to contribute to downwind air quality issues above the
contribution threshold. Despite this, Minnesota provided supporting
analysis to strengthen the conclusions of the modeling results. MPCA
presented evidence that ambient ozone concentrations in Minnesota had
been at or below the NAAQS from the late 1990s to 2017, and that
NOX and VOCs emissions had been steadily decreasing from
2002 through 2015. MPCA asserted that these trends would translate to
continued reductions in ozone being transported from the state to
nonattainment or maintenance receptors. Additionally, MPCA listed
several state and Federal regulatory programs that control or
incentivize NOX and VOC limits, including the CSAPR
NOX trading program.
EPA does not dispute the evidence about ambient ozone
concentrations and NOX and VOC emissions trends or existence
of the NOX and VOC controls presented by Minnesota.\95\
However, as explained in Section I.C, the most recent EPA modeling
captures numerous updates to the 2016 emissions platform, including all
existing CSAPR trading programs, in the baseline,\96\ and that modeling
confirms that most these control programs were not sufficient to
eliminate Minnesota's linkage at Steps 1 and 2 under the 2015 ozone
NAAQS. The state therefore has good neighbor obligations under the 2015
8-hour NAAQS and is obligated at Step 3 to assess additional control
measures using a multifactor analysis.
---------------------------------------------------------------------------
\95\ See Minnesota's SIP submittal Figures 1-3, pages 10-11.
\96\ For a complete explanation of air quality modeling of the
2016v2 emissions platform modeling, please see ``AQ Modeling
TSD_2016v2 Platform.pdf'' included in docket ID No. EPA-HQ-OAR-2021-
0663.
---------------------------------------------------------------------------
MPCA identified state permitting programs, rules, voluntary
programs, and the CSAPR NOX trading program,
[[Page 9869]]
among others, as NOX and VOC control measures which satisfy
Minnesota's good neighbor obligations under the 2015 ozone NAAQs. In
general, however, the listing of existing or on-the-way control
measures, whether approved into the state's SIP or not, does not
substitute for a complete Step 3 analysis under EPA's 4-step framework
to define ``significant contribution.'' Minnesota's submission does not
include an assessment of the overall effects of these measures, when
the reductions would be achieved, and what the overall resulting air
quality effects would be observed at identified out-of-state receptors.
Minnesota's submission does not include an evaluation of additional
potential emissions control opportunities, or their costs or impacts,
or attempt to analyze whether, if applied more broadly across linked
states, the emissions reductions would constitute the elimination of
significant contribution on a regional scale. The state's submission
did not contain an explanation as to whether any faster or more
stringent emissions reductions that may be available were prohibitively
costly or infeasible. Furthermore, states may not rely on non-SIP
measures to meet SIP requirements, and Minnesota has not revised its
SIP to contain the CSAPR NOX trading program or the non-SIP
approved rules MPCA identified. 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. U.S. E.P.A.,
786 F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on
by state to meet CAA requirements must be included in the SIP).
As mentioned above, EPA has newly available information that
indicates sources in Minnesota are linked to downwind air quality
problems for the 2015 ozone standard. Therefore, EPA proposes to
disapprove Minnesota's August 20, 2018 interstate transport SIP
submission on the separate, additional basis that the SIP submittal did
not assess additional emissions control opportunities.
5. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-Step interstate transport frameworks calls for
development of 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. MPCA identified state
permitting programs, rules, voluntary programs, and the CSAPR
NOX trading program, among others, as NOX and VOC
control measures which are not all part of Minnesota's SIP. Although
the state has since incorporated some of these control measures into
their SIP, Minnesota did not revise its SIP to include all these
emission reductions in a revision to its SIP to ensure the reductions
were permanent and enforceable and eliminate their significant
contribution to nonattainment or interference with maintenance of the
NAAQS. As a result, EPA proposes to disapprove Minnesota's submittal on
the separate, additional basis that the Minnesota has not developed
permanent and enforceable emissions reductions necessary to meet the
obligations of CAA section 110(a)(2)(d)(i)(I).
6. Conclusion
Based on EPA's evaluation of Minnesota's SIP submission and after
consideration of updated EPA modeling using the 2016-based emissions
modeling platform, EPA is proposing to find that the portion of
Minnesota's October 1, 2018 SIP submission addressing CAA section
110(a)(2)(D)(i)(I) does not meet the state's interstate transport
obligations for 2015 ozone NAAQS, because it fails to contain the
necessary provisions to eliminate emissions that will contribute
significantly to nonattainment or interfere with maintenance of the
NAAQS in any other state.
E. Ohio
1. Evaluation of Information Provided by Ohio Regarding Steps 1
At Step 1 of the 4-step interstate transport framework, OEPA relied
on LADCO modeling released in 2018 to identify nonattainment and
maintenance receptors in 2023. As described previously in this action,
LADCO performed modeling similar to EPA's modeling released in the
March 2018 memorandum, except with use of ERTAC for projecting future
year EGU emissions. LADCO identified nonattainment and maintenance
receptors using EPA methodology. OEPA elected to rely on LADCO's
``3x3'' modeling results, which identified similar receptors to EPA's
modeling included in the March 2018 memorandum.
However, OEPA elected to use an alternative method developed by
TCEQ for identifying maintenance receptors at Step 1 of the 4-step
framework. Using the TCEQ method to identify maintenance receptors OEPA
claimed that four maintenance receptors based on EPA's approach would
not have difficulty maintaining the NAAQS in 2023. OEPA relied on the
potential flexibilities in Attachment A to the March 2018 in support of
its use of the TCEQ method. As explained in Section I.C above, the
concepts presented in Attachment A to the March 2018 memorandum were
neither guidance nor determined by EPA to be consistent with the CAA.
OEPA submitted Ohio's SIP submission before EPA released its October
2018 memorandum discussing maintenance receptors. Regardless, EPA will
examine the legal and technical merits of OEPA's arguments related to
the use of an alternative maintenance-only definition in light of the
October 2018 memorandum. OEPA has not adequately explained or justified
how TCEQ's method for identifying maintenance receptors reasonably
identifies areas that will have difficulty maintaining the NAAQS. That
is, EPA proposes to find that OEPA has provided no sound technical
basis for how TCEQ's methodology gives meaning to the CAA's instruction
that states submit good neighbor SIPs that prohibit their states'
emissions from interfering with the maintenance of the NAAQS in another
state.
In North Carolina v. EPA, 531 F.3d 896, 909-11 (D.C. Cir. 2008),
the D.C. Circuit rejected EPA's CAIR on the basis that EPA had not
adequately given meaning to the phrase ``interfere with maintenance''
in the good neighbor provision. Specifically, North Carolina argued
that it had counties that were projected to attain the NAAQS in the
future analytic year, but were at risk of falling back into
nonattainment due to interference from upwind sources, particularly
given year-to-year variability in ozone levels. The court agreed,
holding that EPA's rule did not adequately protect ``[a]reas that find
themselves barely meeting attainment.'' Id. at 910. Consequently, EPA
has developed a methodology, used in its 2011 CSAPR and its 2016 CSAPR
Update and Revised CSAPR Update, for identifying areas that may
struggle to maintain the NAAQS. See 76 FR at 48227-28. EPA's approach
to addressing maintenance receptors was upheld in the EME Homer City
litigation. See 795 F.3d 118, 136-37. It was also upheld in Wisconsin.
938 F.3d at 325-26. In Wisconsin, the court noted that four upwind
states were linked only to maintenance receptors and rejected the
argument that application of the same control level as EPA imposes for
those states linked to nonattainment receptors was unreasonable or
unlawful absent a
[[Page 9870]]
particularized showing of overcontrol. Id. at 327.
In order to explain the differences between TCEQ's and EPA's
methodology for identifying maintenance receptors, it is helpful to
provide some additional context for how EPA projects future air
quality. EPA's air quality modeling guidance has long recommended
developing a base design value (i.e., the design value that will be
used as a starting point to model and analyze for purposes of
projecting future air quality concentrations) that is the average of
three design values spanning a five-year period, centered around one
year for which an emissions inventory will be submitted (e.g., if 2011
was the base emissions inventory year, a state would use monitored
values from 2009-2011, 2010-2012, 2011-2013 as the starting point for
projecting air quality concentrations in future years). The average of
these three design values is then multiplied by a relative response
factor to generate an average design value for the future year. If a
receptor's average future year design value is greater than or equal to
the level of the NAAQS, and the receptor has recent monitored data that
violates the NAAQS, that receptor is considered a ``nonattainment''
receptor at step 1. To identify maintenance receptors, EPA's
methodology looks to the highest design value of the three DVs used to
calculate the 5-year weighted average design value (e.g., in the 2011
example, if 2009-2011 had the highest design value of 2009-2011, 2010-
2012, and 2011-2013). EPA then applies the same relative response
factor to that highest design value to generate a projected future
maximum design value. Where a receptor's maximum design value exceeds
the level of the NAAQS, EPA has deemed those receptors to be
``maintenance'' receptors. This methodology was designed to address the
D.C. Circuit's holding that the CAA's ``interference with maintenance''
prong requires states and EPA to protect areas that may struggle with
maintaining the standard in the face of variable conditions.
For its maintenance receptors, TCEQ elected not to use the highest
design value of the three DVs making up the base period average design
value. Instead, Texas (and by extension, Ohio), used the most recent
design value of the three DVs, regardless of whether the most recent
design value was highest or lowest. OEPA's proffered explanation for
using the most recent design value to identify maintenance receptors
was that the latest design value ``takes into consideration . . . any
emissions reductions that might have occurred.'' \97\ OEPA in its
submission did not explain why or how this methodology identifies those
areas that may be meeting the NAAQS or that may be projected to meet
the NAAQS but may nevertheless struggle to maintain the NAAQS, given
interannual variability in ozone conducive meteorology. In fact,
because the TCEQ's methodology adopted by OEPA uses the most recent
design value to capture more recent emissions reductions rather than
capture variable conditions, the methodology appears to be aimed at
limiting receptors which could be identified as maintenance receptors,
compared to EPA's methodology, which was designed to identify those
areas that might struggle to maintain the NAAQS in ozone conducive
conditions.
---------------------------------------------------------------------------
\97\ TCEQ submission at 3-39 to 3-40.
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EPA disagrees that the use of latest three years for calculating a
DV properly accounts for the effects of meteorological variability for
the purpose of identifying projected maintenance receptors. Rather, the
use of a three-year average is intended to average out, not account
for, the effects of inter-annual variability in ozone conducive
meteorology. EPA reviewed the information provided by OEPA and proposes
to find that the information is insufficient to support the use of an
alternative approach. OEPA analysis of meteorological information did
not discuss or consider how other meteorological factors that are
typically associated with high ozone episodes such as humidity, solar
radiation, vertical mixing, and/or other meteorological indicators such
as cooling-degree days to confirm whether conditions affecting these
monitors may have been conducive to ozone formation during the 2009
through 2013 base period. In addition, the ozone trends data provided
in OEPA submittal indicate that several of the receptors in Coastal
Connecticut to which Ohio is linked by more than 1 ppb continue to
measure ozone design values close to or exceeding 80 ppb with no
overall downward trend in the most recent data in the submittal.\98\ In
any event, OEPA's use of an alternative approach to identifying
maintenance receptors does not result in a dispositive change in
receptor status for purposes of EPA's evaluation of OEPA's SIP
submittal at Step 1 because OEPA did not reach the conclusion that
there were no receptors in 2023 or claim at Step 2 that Ohio was not
linked to any receptor on the basis of the use of an alternative
definition of maintenance receptor.
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\98\ See ``2010 Thru 2020 Ozone Design Values.xlsx'' in docket
ID No. EPA-HQ-OAR-2021-0663.
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In conclusion, the modeling relied on by OEPA identified a number
of nonattainment and maintenance receptor sites in the Midwest and
Northeast in 2023. See Table 1 on page 8 of OEPA's submittal. Under
EPA's approach to defining nonattainment and maintenance receptors,
Ohio was shown to be linked to three ``nonattainment/maintenance''
receptors and six ``maintenance'' receptors. Under an alternative
approach to defining receptors (discussed below), OEPA concluded that
Ohio was shown to be linked to two ``nonattainment'' receptors, one
``nonattainment/maintenance'' receptor, and four ``maintenance''
receptors. Thus, based on using the LADCO's 2023 modeling and even
under an alternative approach to defining ``maintenance'' receptors,
OEPA acknowledges in its submittal the existence of several
nonattainment and maintenance receptors in the Midwest and Northeast.
EPA further evaluates Ohio's linkage to these receptors in the
following section.
2. Evaluation of Information Provided by the State Regarding Step 2
Although OEPA relied on alternative modeling to EPA's modeling,
OEPA acknowledged in their SIP submission that Ohio is linked above
either a 1 percent of the NAAQS or a 1 ppb contribution threshold to
one or more downwind receptors in 2023. Because the LADCO modeling
relied on by the state also demonstrates that a linkage exists between
the state and downwind receptors at Step 2, EPA need not conduct a
comparative assessment of the alternative modeling; the state concedes
that it is linked above either 1 percent of the NAAQS or 1 ppb.
The state additionally evaluated the use of an alternative
threshold exceeding 1 ppb at Step 2 to identify whether the state was
``linked'' to a projected downwind nonattainment or maintenance
receptor. EPA's August 2018 memorandum provided that whether use of a 1
ppb threshold is appropriate must be based on an evaluation of state-
specific circumstances, but that the use of a threshold greater than 1
ppb at Step 2 would likely not be appropriate because higher thresholds
would not capture a sufficient amount of total upwind state
contribution to allow for the development of effective remedies at Step
3.\31\ In particular, EPA found that a 2 ppb threshold would cause 45%
of total upwind contribution to be removed from further analysis across
all
[[Page 9871]]
receptors as compared to a 1 percent of NAAQS threshold.
EPA does not accept Ohio's position that a 1 percent of the NAAQS
contribution threshold at Step 2 is ``impractical and infeasible'' for
the 2015 ozone NAAQS because ``it results in very small contributions
having substantial consequences.'' \99\ This argument conflates the
contribution threshold at Step 2 with a determination of
``significance'' reached at Step 3 after a multi-factor analysis. In
its submittal, OEPA justified a higher threshold than either 1 percent
or 1 ppb by noting that, if applied, these alternative thresholds (3 or
4 percent of the NAAQS) would progressively de-link the State from an
increasing number of identified downwind receptors. EPA likewise
disagrees with this reasoning; selecting progressively higher
contribution thresholds simply on the basis that they would excuse an
ever greater number of upwind states from having any good neighbor
obligations lacks any persuasive technical justification and is
inconsistent with the purposes of the Act.
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\99\ Michigan's SIP submission at 16.
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The explanation for how the 1 percent contribution threshold was
originally derived is available in the 2011 CSAPR rulemaking. See 76 FR
48208, 48237-38. Further, in the CSAPR Update, EPA re-analyzed the
threshold for purposes of the 2008 ozone NAAQS and determined it was
appropriate to continue to apply this threshold. EPA compared the 1
percent threshold to a 0.5 percent of NAAQS threshold and a 5 percent
of NAAQS threshold. EPA found that the lower threshold did not capture
appreciably more upwind state contribution compared to the 1 percent
threshold, while the 5 percent threshold allowed too much upwind state
contribution to drop out from further analysis. See Final CSAPR Update
Air Quality Modeling TSD, at 27-30 (EPA-HQ-OAR-2015-0596-0144). If EPA
were to apply this analysis to the 2015 ozone NAAQS using the updated
modeling based on the 2016v2 emissions platform, a 5 percent of the
NAAQS contribution threshold (i.e., 3.5 ppb) only captures
approximately 50 percent of the total upwind contribution. Compared to
a 1 percent threshold, a 5 percent threshold would, on average, forgo
27 nearly 30 percent) of the total upwind contribution. As EPA noted in
the August 2018 memorandum, the use of a 2 ppb contribution threshold
under the modeling released with the March 2018 memorandum would only
capture about 55 percent of all upwind contributions, and therefore
``emission reductions from states linked at that higher threshold may
be insufficient to address collective upwind state contribution to
downwind air quality problems.''\31\
Based on EPA's updated modeling and the LADCO modeling, the state
is projected to contribute greater than both the 1 percent and
alternative 1 ppb thresholds. While EPA does not, in this action,
approve of the state's application of the 1 ppb threshold, based on its
linkages greater than 1 ppb to projected downwind nonattainment or
maintenance receptors, the state's use of this alternative threshold at
Step 2 of the 4-Step interstate framework would not alter our review
and proposed disapproval of this SIP submittal.
Table 6--Ohio Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Ohio
Receptor ID Location Nonattainment/ design value design value Contribution
(county, state) maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
90099002..................... New Haven, CT... Nonattainment.. 71.8 73.9 1.94
90019003..................... Fairfield, CT... Nonattainment.. 76.1 76.4 1.90
420170012.................... Bucks, PA....... Maintenance.... 70.7 72.2 1.88
90013007..................... Fairfield, CT... Nonattainment.. 74.2 75.1 1.87
170317002.................... Cook, IL........ Maintenance.... 70.1 73.0 1.69
550590019.................... Kenosha, WI..... Nonattainment.. 72.8 73.7 1.67
550590025.................... Kenosha, WI..... Maintenance.... 69.2 72.3 1.33
170310032.................... Cook, IL........ Maintenance.... 69.8 72.4 1.26
170314201.................... Cook, IL........ Maintenance.... 69.9 73.4 1.23
170310076.................... Cook, IL........ Maintenance.... 69.3 72.1 1.23
90010017..................... Fairfield, CT... Nonattainment.. 73.0 73.7 1.18
551010020.................... Racine, WI...... Nonattainment.. 71.3 73.2 1.00
170310001.................... Cook, IL........ Maintenance.... 69.6 73.4 0.82
----------------------------------------------------------------------------------------------------------------
4. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I). As explained in Section II.E, Ohio relied on a
combination of both cost and air quality factors to determine that
there were no further reductions necessary for Ohio to meet its
obligations under the interstate transport provision. In this
subsection, we have evaluated the information provided by the state at
Step 3 to support this conclusion.
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the
[[Page 9872]]
obligations in CAA section 110(a)(2)(D)(i)(I) must prohibit ``any
source or other type of emissions activity within the State'' from
emitting air pollutants which will contribute significantly to downwind
air quality problems. Thus, states must complete something similar to
EPA's analysis (or an alternative approach to defining ``significance''
that comports with the statute's objectives) to determine whether and
to what degree emissions from a state should be ``prohibited'' to
eliminate emissions that will ``contribute significantly to
nonattainment in, or interfere with maintenance of'' the NAAQS in any
other state. OEPA did not conduct such an analysis in their SIP
submission.
OEPA's submission concluded that projected emissions were
overestimated for the EGU, non-EGU, and onroad sectors. OEPA claimed
that the ERTAC EGU tool's emissions inventories were overestimated for
eight specific sources for various reasons, including adoption of rules
in late 2016 and early 2017, CSAPR and CSAPR Update allocations, and
substantive changes in plant operation. The submission also asserted
that ERTAC EGU tool version 2.7 does not consider that future energy
generation sources will likely be a steady level of coal with
increasing natural gas and renewable fuels, citing an un-enumerated
number of natural gas source permits issued by Ohio and projected
trends identified in the US Energy Information Administration's Annual
Energy Outlook (AEO) 2018.\100\ Similarly, the submission claimed
projected emissions from EPA's Air Emissions Modeling Platform 2011v6.3
were overestimated for nine non-EGU point sources, primarily based on
actual emissions trends from 2010 to 2017. OEPA also claimed that EPA
over projected onroad emissions using 2023 vehicle miles traveled
(VMT). However, OEPA did not explain how accounting for changed
projected emissions from those 17 sources or the onroad sector would
have resulted in different outcomes with regards to the identification
of downwind receptors or Ohio's contributions or linkages in the 2023
analytic year. Furthermore, nationwide trends and an unspecified number
of state permits are insufficient by themselves to support a conclusion
that EGUs in Ohio would not be affected by generation shifting. EPA
notes the information presented from the AEO is related to nationwide
trends and OEPA did not explain what the nationwide trends revealed
about Ohio's level of contribution or good neighbor obligations to
downwind receptors. Merely claiming that the modeling used to project
receptors and contributions relies on overestimated emissions
projections without an explanation of how the inputs would affect the
outcome is not enough to draw a conclusion at Step 2 that Ohio is not
linked to any downwind receptor or a conclusion at Step 3 that Ohio
does not contribute significantly or interfere with maintenance in any
other state. Considered individually or in the context of the other
information and arguments put forward by OEPA, select EGU, non-EGU, and
onroad emissions evaluations and nation-wide projections of fuel types
fail to show that additional emissions reductions are either not cost-
effective or permanent and federally enforceable. OEPA did not
demonstrate that the downwind improvements from these regulations and
programs would be sufficient to eliminate the state's significant
contribution or interference with maintenance.
---------------------------------------------------------------------------
\100\ See https://www.eia.gov/outlooks/archive/aeo18/, last
accessed 1/18/2022.
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Further, EPA's assessment of future air quality conditions
generally accounts for on-the-books emission reductions and the most
up-to-date forecast of future emissions in the absence of the transport
policy being evaluated (i.e., base case conditions).\101\ As described
in more detail in Section I, EPA's latest projections of the baseline
EGU emissions uses the version 6--Summer 2021 Reference Case of the
IPM.\102\ The IPM version 6--Summer 2021 Reference Case uses the NEEDS
v6 database as its source for data on all existing and planned-
committed units. Units are removed from the NEEDS inventory only if a
high degree of certainty could be assigned to future implementation of
the announced future closure or retirement. Any retirements excluded
from the NEEDS v6 inventory can be viewed in the NEEDS
spreadsheet.\103\ The inventory for these projections contains various
Ohio EGUs including the Avon Lake Power Plant in Lorain County
(Facility ID 0247030013), Painesville Municipal Electric Plant in Lake
County (Facility ID 0243110008), and the Department of Public
Utilities, City of Orrville in Wayne County (Facility ID 0285010188).
Mingo Junction Energy Center in Jefferson County (Facility ID
0641090234) and the Conesville Power Plant (Facility ID 0616000000)
retired in 2020.
---------------------------------------------------------------------------
\101\ See 81 FR 74504 at 74517; 85 FR 68964 at 68979.
\102\ Detailed information and documentation of EPA's Base Case,
including all the underlying assumptions, data sources, and
architecture parameters can be found on EPA's website at: https://www.epa.gov/airmarkets/epas-power-sector-modeling-platform-v6-using-ipm-summer-2021-reference-case.
\103\ The ``Capacity Dropped'' and the ``Retired Through 2023''
worksheets in NEEDS lists all units that are removed from the NEEDS
v6 inventory--NEEDS v6 Summer 2021 Reference Case. This data can be
found on EPA's website at: https://www.epa.gov/airmarkets/national-electric-energy-data-system-needs-v6.
---------------------------------------------------------------------------
Also, EPA's non-EGU emissions inventory in the updated modeling
using the 2016v2 emissions platform does not include either Carmeuse
Lime Inc Millersville Operations (Facility ID 0372000081) or RockTenn
CP, LLC (Facility ID 0616010001). EPA's latest modeling also uses
emissions inventories that incorporate Ohio's submitted 2023 VMT
data.\104\ In other words, in general, any changes in the emissions
inventory and on-the-books controls relevant to emissions in 2023 have
now been incorporated into EPA's modeling using the 2016v2 emissions
platform, which projects a continuing contribution from Ohio to out of
state receptors above a threshold of 1 percent of the NAAQS (at Steps 1
and 2) despite these measures. Therefore, in light of continuing
contribution to out of state receptors from Indiana notwithstanding
these identified retirements, OEPA's SIP submission should have
evaluated the availability of additional air quality controls to
improve downwind air quality at nonattainment and maintenance receptors
at Step 3.
---------------------------------------------------------------------------
\104\ Technical Support Document (TSD) Preparation of Emissions
Inventories for the 2016v2 North American Emissions Modeling
Platform, section 4.3.2. Available in the Headquarters docket ID No.
EPA-HQ-OAR-2021-0663.
---------------------------------------------------------------------------
Ohio's projected contribution to downwind receptors in EPA's
updated modeling is lower relative to the LADCO modeling results
presented in OEPA's submission; it could be assumed that these
decreases are due to overestimation of sources that were corrected in
the updated modeling. These results could also be attributed to Federal
programs in place (NOX RACT, AIM Coatings Rules, CSAPR, NOx
SIP Call, NESHAPs, RHR, BART, SO2 Data Requirements rule,
and MATS) as OEPA suggests. Regardless, despite the lessened projected
contributions, Ohio's contributions continue to be projected to be
above 1 percent of the NAAQS to one or more receptors in 2023 as shown
in Table 6.
OEPA's assessment of actual and projected NOX and VOC
emissions trends and listing of various regulations likewise do not
support a conclusion that existing controls in Ohio adequately address
the state's good neighbor obligations for the 2015 ozone NAAQS. For
one, OEPA listed numerous non-SIP measures and states may not rely on
non-SIP measures to
[[Page 9873]]
meet SIP requirements. 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. U.S. E.P.A., 786
F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on by
state to meet CAA requirements must be included in the SIP). OEPA did
not attempt to revise Ohio's SIP to include all these measures.\105\ In
general, the listing of existing or on-the-way control measures,
whether approved into the state's SIP or not, does not substitute for a
complete Step 3 analysis under EPA's 4-step framework to define
``significant contribution.'' OEPA's submittal does not include an
assessment of the overall effects of these measures, when the
reductions would be achieved, and what the overall resulting air
quality effects would be observed at identified out-of-state receptors.
The state's submission does not include an evaluation of additional
potential emissions control opportunities, or their costs or impacts,
or attempt to analyze whether, if applied more broadly across linked
states, the emissions reductions would constitute the elimination of
significant contribution on a regional scale. The state's submission
did not contain an explanation as to whether any faster or more
stringent emissions reductions that may be available were prohibitively
costly or infeasible. Second, the information and claims presented by
OEPA did not provide sufficient evidence to support alternative
conclusions that EPA is proposing to make in this action: Namely, that
several receptors exist, Ohio contributes to those receptors above a 1
percent of the NAAQS contribution threshold, and that Ohio continues to
have good neighbor obligations that need to be addressed for the 2015
ozone NAAQS.
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\105\ EPA notes that OEPA submitted a source specific
NOX emission limit contained in the Ohio NOX
RACT Rules for approval into the Ohio SIP, approved by EPA on
September 8, 2017 (82 FR 42451).
---------------------------------------------------------------------------
OEPA also pointed to declining design values at the ten receptors
identified by LADCO to support their conclusion that no further
emissions reductions were required from Ohio to meet their interstate
transport obligations. They additionally reference a May 14, 2018 EPA
presentation, stating that EPA indicated remaining ozone air quality
problems were becoming more local and less regional in nature. While it
is true that since 2011, design values have generally declined, air
quality problems at some locations are projected to continue out to
2023 and beyond, based on EPA's 2018 modeling provided in the March
2018 memorandum, LADCO's modeling completed in 2018, EPA's modeling
results used in the Revised CSAPR Update, and EPA's updated modeling
results. In addition, each of these modeling analyses show that Ohio
will contribute to the air quality problems in excess of 1 percent of
the 2015 ozone standards in 2023. Regarding the May 14, 2018
presentation, EPA assumes the state is referencing a presentation given
by an EPA air quality modeler, which Indiana attached to their SIP
submission. The purpose of that presentation was to share a technical,
exploratory analysis of ozone trends. The results of that presentation,
which were labeled as ``preliminary'' indicated that ``[f]urther
exploration of the relative contribution from various source sectors
within the NE Corridor and in nearby upwind states might also be
informative.'' \106\ The preliminary results of that analysis are
generally consistent with EPA's updated modeling using the 2016v2
emissions platform. Although EPA's modeling shows that a large portion
of the transport problem affecting the receptors in Coastal Connecticut
is indeed from sources within the Ozone Transport Region (OTR), a
substantial portion of the transport problem at these receptors, on the
order of 25 percent, is the result of transport from states outside the
OTR. However, the relevance of that presentation to the evaluation of
Ohio's good neighbor obligations is not clear. As already discussed,
the statute and the case law (particularly the holdings in Wisconsin
and Maryland) make clear that good neighbor obligations are not merely
supplementary to or deferable until after local emission reductions are
achieved. Further, based on EPA's modeling released with the March 2018
memorandum, nearly all of the receptors to which Ohio is linked are
also heavily impacted by distant upwind state emissions in addition to
local sources and sources in neighboring states. The Wisconsin
decision's holding in regard to international contribution (discussed
in more detail later) is equally applicable to an upwind state's claims
that some other state's emissions, or local emissions, are more to
blame than its own emissions. See 938 F.3d 303 at 323-25 (``an upwind
state can `contribute' to downwind nonattainment even if its emissions
are not the but-for cause'').
---------------------------------------------------------------------------
\106\ Indiana's SIP submission, Appendix E at 4, 17.
---------------------------------------------------------------------------
OEPA also put forward an argument that onroad mobile sources in
downwind states should be more stringently controlled before any
additional sources in upwind states. This is equivalent to the claim
that local emissions reductions from the jurisdiction where the
downwind receptor is located must first be implemented and accounted
for before imposing obligations on upwind states under the interstate
transport provision. However, there is nothing in the CAA that supports
that position, and it does not provide grounds on which to approve
OEPA's SIP submission. The D.C. Circuit has held on five different
occasions that the timing framework for addressing interstate transport
obligations must be consistent with the downwind areas' attainment
schedule. In particular, for the ozone NAAQS, the states and EPA are to
address interstate transport obligations ``as expeditiously as
practicable'' and no later than the attainment schedule set in
accordance with CAA section 181(a). See North Carolina, 531 F.3d at
911-13; Wisconsin, 938 F.3d at 313-20; Maryland, 958 F.3d at 1204; New
York v. EPA, 964 F.3d 1214, 1226 (DC Cir. 2020); New York v. EPA, 781
Fed. App'x 4, 6-7 (DC Cir. 2019). The court in Wisconsin explained that
downwind jurisdictions often may need to heavily rely on emissions
reductions from upwind states in order to achieve attainment of the
NAAQS, 938 F.3d at 316-17; such states would face increased regulatory
burdens including the risk of bumping up to a higher nonattainment
classification if attainment is not reached by the relevant deadline,
Maryland, 958 F.3d at 1204. The statutory framework of the CAA and
these cases establish clearly that states and EPA must address
interstate transport obligations in line with the attainment schedule
provided in the Act in order to timely assist downwind states in
attaining and maintain the NAAQS, and this schedule is ``central to the
regulatory scheme.'' Wisconsin, 938 F.3d at 316 (quoting Sierra Club v.
EPA, 294 F.3d 155, 161 (D.C. Cir. 2002)).
As for the suggestion that EPA should assess the SAFE Vehicles
Rule's impact on ozone before finalizing, EPA and the National Highway
Traffic Safety Administration finalized the revisions to the greenhouse
gas (GHG) and CAFE standards for light duty vehicles in 2020.\107\
However, that final action is not expected to have a meaningful impact
on ozone-precursor emissions. Because the vehicles affected by the
[[Page 9874]]
2017-2025 GHG standards would still need to meet applicable criteria
pollutant emissions standards (e.g., the Tier 3 emissions standards;
see 79 FR 23414), the SAFE Vehicles Rule anticipated that any impacts
of the SAFE Vehicles Rule on ozone precursor emissions ``would most
likely be far too small to observe.'' See 85 FR 25041. On December 30,
2021, EPA revised the GHG light duty standards for model years 2023 and
later to make them more stringent.\108\ The impacts of the SAFE
Vehicles Rule are included in the 2016v2 onroad emissions as described
in the emissions modeling TSD in Section 4.3.2.\109\
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\107\ The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule
for Model Years 2021-2026 Passenger Cars and Light Trucks, 85 FR
24174 (April 30, 2020) (SAFE Vehicles Rule).
\108\ Revised 2023 and Later Model Year Light-Duty Vehicle
Greenhouse Gas Emissions Standards, 86 FR 74434 (December 30, 2021).
\109\ See Technical Support Document (TSD) Preparation of
Emissions Inventories for the 2016v2 North American Emissions
Modeling Platform included in the Headquarters docket ID No. EPA-HQ-
OAR-2021-0663.
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Further, OEPA makes the argument that assigning all responsibility
to Ohio and other upwind states for downwind air quality problems
despite home state and international contributions would result in
overcontrol of Ohio sources. OEPA's reasoning related to emissions in
downwind states and international emissions is inapplicable to the
requirements of CAA section 110(a)(2)(D)(i)(I). As an initial matter,
CAA section 110(a)(2)(D)(i)(I) only requires that upwind states
prohibit those emissions that ``contribute significantly to
nonattainment'' or ``interfere with maintenance of the NAAQS.'' It does
not require that the upwind states bear the full burden of bringing
downwind states into attainment or that a threshold ppb improvement
from upwind states emission reductions be met in order for them to be
required (once the 1 percent threshold has been satisfied). However,
the good neighbor provision does require states and EPA to address
interstate transport of air pollution that contributes to downwind
states' ability to attain and maintain NAAQS. Whether emissions from
other states or other countries also contribute to the same downwind
air quality issue is irrelevant in assessing whether a downwind state
has an air quality problem, or whether an upwind state is significantly
contributing to that problem. States are not obligated under CAA
section 110(a)(2)(D)(i)(I) to reduce emissions sufficient on their own
to resolve downwind receptors' nonattainment or maintenance problems.
Rather, states are obligated to eliminate their own ``significant
contribution'' or ``interference'' with the ability of other states to
attain or maintain the NAAQS.
Indeed, after OEPA submitted Ohio's SIP submission, the D.C.
Circuit in Wisconsin specifically rejected petitioner arguments
suggesting that upwind states should be excused from good neighbor
obligations on the basis that some other source of emissions (whether
international or another upwind state) could be considered the ``but-
for'' cause of downwind air quality problem. 938 F.3d 303 at 323-324.
The court viewed petitioners' arguments as essentially an argument
``that an upwind state `contributes significantly' to downwind
nonattainment only when its emissions are the sole cause of downwind
nonattainment.'' 938 F.3d 303 at 324. The court explained that ``an
upwind state can `contribute' to downwind nonattainment even if its
emissions are not the but-for cause.'' Id. at 324-325. See also Catawba
County v. EPA, 571 F.3d 20, 39 (D.C. Cir. 2009) (rejecting the argument
``that `significantly contribute' unambiguously means `strictly
cause''' because there is ``no reason why the statute precludes EPA
from determining that [an] addition of [pollutant] into the atmosphere
is significant even though a nearby county's nonattainment problem
would still persist in its absence''); Miss. Comm'n on Envtl. Quality
v. EPA, 790 F.3d 138, 163 n.12 (D.C. Cir. 2015) (observing that the
argument that ``there likely would have been no violation at all . . .
if it were not for the emissions resulting from [another source]'' is
``merely a rephrasing of the but-for causation rule that we rejected in
Catawba County.''). Therefore, a state is not excused from eliminating
its significant contribution on the basis that international emissions,
or emissions from other sources, also contribute some amount of
pollution to the same receptors to which the state is linked.
Finally, as part of its cost-effectiveness evaluation, OEPA relied
on its EGUs being subject to the CSAPR Update (which reflected a
stringency at the nominal marginal cost threshold of $1400/ton (2011$)
for the 2008 8-hour ozone NAAQS) to argue that it has already
implemented all cost-effective emissions reductions. For non-EGUs, OEPA
did not identify a cost-effectiveness threshold, but rather listed a
few regulations (the Boiler MACT and other MACT categories, BART,
SO2 Data Requirements Rule and other unidentified Federal
regulations) to draw the conclusion that emissions reductions had been
achieved from non-EGUs in Ohio. First, the CSAPR Update did not
regulate non-electric generating units, and thus this analysis is
incomplete. See Wisconsin, 938 F.3d at 318-20. Second, relying on the
CSAPR Update's (or any other CAA program's) determination of cost-
effectiveness without further Step 3 analysis is not approvable. Cost-
effectiveness must be assessed in the context of the specific CAA
program; assessing cost-effectiveness in the context of ozone transport
should reflect a more comprehensive evaluation of the nature of the
interstate transport problem, the total emissions reductions available
at several cost thresholds, and the air quality impacts of the
reductions at downwind receptors. While EPA has not established a
benchmark cost-effectiveness value for 2015 ozone NAAQS interstate
transport obligations, because the 2015 ozone NAAQS is a more stringent
and more protective air quality standard, it is reasonable to expect
control measures or strategies to address interstate transport under
this NAAQS to reflect higher marginal control costs. As such, the
marginal cost threshold of $1,400/ton for the CSAPR Update (which
addresses the 2008 ozone NAAQS and is in 2011$) is not an appropriate
cost threshold and cannot be approved as a benchmark to use for
interstate transport SIP submissions for the 2015 ozone NAAQS. The lack
of a sufficient cost-effectiveness evaluation also means that Ohio's
claims that requiring additional emissions reductions would result in
overcontrol is premature. Ohio's submission does present sufficient
evidence to support that conclusion.
In addition, the updated EPA modeling captures all existing CSAPR
trading programs in the baseline, and that modeling confirms that these
control programs were not sufficient to eliminate Ohio's linkage at
Steps 1 and 2 under the 2015 ozone NAAQS. The state was therefore
obligated at Step 3 to assess additional control measures using a
multifactor analysis.
Finally, relying on a FIP at Step 3 is per se not approvable if the
state has not adopted that program into its SIP and instead continues
to rely on the FIP. States may not rely on non-SIP measures to meet SIP
requirements. 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. U.S. E.P.A., 786 F.3d
1169, 1175-76 (9th Cir. 2015) (holding that measures relied on by state
to meet CAA requirements must be included in the SIP). We therefore
propose that Ohio was required to analyze emissions from the sources
and other emissions activity from within the state to determine whether
its contributions were
[[Page 9875]]
significant, and we propose to disapprove its submission because Ohio
failed to do so.
5. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-step interstate transport framework calls for
development of 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. OEPA identified
NOX RACT rules limiting NOX emissions from new
and existing sources, VOC reduction measures through control of
architectural and industrial maintenance coatings, and reallocation of
funds received through a settlement with Volkswagen to be applied to
on-road and off-road mobile emissions reductions through replacements
and infrastructure updates.\110\ However, OEPA did not revise Ohio's
SIP to include these emission reductions in a revision to its SIP to
ensure the reductions were permanent and enforceable.\105\ As a result,
EPA proposes to disapprove OEPA submittal on the separate, additional
basis that the Ohio has not included permanent and enforceable
emissions reductions in its SIP as necessary to meet the obligations of
CAA section 110(a)(2)(d)(i)(I).
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\110\ Pointing to anticipated upcoming emission reductions, even
if they were not included in the analysis at Steps 1 and 2, is not
sufficient as a Step 3 analysis, for the reasons discussed in
Section [Ohio step 3 analysis section]. In this section, we explain
that to the extent such anticipated reductions are not included in
the SIP and rendered permanent and enforceable, reliance on such
anticipated reductions is also insufficient at Step 4.
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6. Conclusion
Based on EPA's evaluation of Ohio's SIP submission, EPA is
proposing to find that the portion of Ohio's September 28, 2018 SIP
submission addressing CAA section 110(a)(2)(D)(i)(I) does not meet the
state's interstate transport obligations for the 2015 ozone NAAQS,
because it fails to contain the necessary provisions to eliminate
emissions that will contribute significantly to nonattainment or
interfere with maintenance of the 2015 ozone NAAQS in any other state.
F. Wisconsin
1. Evaluation of Information Provided by Wisconsin Regarding Steps 1
and 2
WDNR did not perform an analysis under the 4-step framework to
assess Wisconsin's good neighbor obligations. The submission did not
identify areas in other states that may have trouble attaining or
maintaining the 2015 ozone NAAQS. Nor did WDNR perform a Step 2
analysis to identify Wisconsin's contribution to areas that are
projected to have difficulty attaining or maintaining the NAAQS or
reach a conclusion about whether Wisconsin is linked to any receptors.
2. Results of EPA's Step 1 and Step 2 Modeling and Findings for
Wisconsin
As described in Section I, EPA performed air quality modeling using
the 2016v2 emissions platform to project design values and
contributions for 2023. These data were examined to determine if
Wisconsin contributes at or above the threshold of one percent of the
2015 ozone NAAQS (0.70 ppb) to any downwind nonattainment or
maintenance receptor. As shown in Table 7, the data \111\ indicate that
in 2023, emissions from Wisconsin contribute greater than one percent
of the standard to nonattainment or maintenance-only receptors in
Illinois.\112\ Therefore, based on EPA's evaluation of the information
submitted by WDNR, and based on EPA's most recent modeling results for
2023, EPA proposes to find that Wisconsin is linked at Steps 1 and 2
and has an obligation to assess potential emissions reductions from
sources or other emissions activity at Step 3 of the 4-step framework.
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\111\ Design values and contributions at individual monitoring
sites nationwide are provide in the file
``2016v2_DVs_state_contributions.xlsx'' which is included in docket
ID No. EPA-HQ-OAR-2021-0663.
\112\ These modeling results are consistent with the results of
a prior round of 2023 modeling using the 2016v1 emissions platform
which became available to the public in the fall of 2020 in the
Revised CSAPR Update, as noted in Section I. That modeling showed
that Wisconsin had a maximum contribution greater than 0.70 ppb to
at least one nonattainment or maintenance-only receptor in 2023.
These modeling results are included in the file ``Ozone Design
Values And Contributions Revised CSAPR Update.xlsx'' in docket ID
No. EPA-HQ-OAR-2021-0663.
Table 7--Wisconsin Linkage Results Based on EPA Updated 2023 Modeling
----------------------------------------------------------------------------------------------------------------
2023 Average 2023 Maximum Wisconsin
Receptor ID Location Nonattainment/ design value design value contribution
(county, state) maintenance (ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
170310032.................... Cook, IL........ Maintenance.... 69.8 72.4 2.61
170314201.................... Cook, IL........ Maintenance.... 69.9 73.4 2.55
170310076.................... Cook, IL........ Maintenance.... 69.3 72.1 2.47
170310001.................... Cook, IL........ Maintenance.... 69.6 73.4 2.41
170317002.................... Cook, IL........ Maintenance.... 70.1 73.0 1.47
----------------------------------------------------------------------------------------------------------------
As shown in Table 7, the updated EPA modeling identifies
Wisconsin's maximum contribution Because the entire technical basis for
the state's submittal is that the state has satisfied good neighbor
obligations through implementation of various rules, including CSAPR
Update, EPA proposes to disapprove the SIP submission based on EPA's
finding that WDNR has not provided adequate information to allow EPA to
assess whether Wisconsin has adequate provisions to prohibit emissions
in amounts which will contribute significantly to nonattainment or
interfere with maintenance in any other state. Though this deficiency
would be sufficient on its own to disapprove Wisconsin's good neighbor
submission, EPA will proceed to evaluate the additional points raised
by WDNR at Step 3 of the 4-step interstate transport framework.
3. Evaluation of Information Provided Regarding Step 3
At Step 3 of the 4-step interstate transport framework, a state's
emissions are further evaluated, in light of multiple factors,
including air quality and cost considerations, to determine what, if
any, emissions significantly contribute to nonattainment or interfere
with maintenance and, thus, must be eliminated under CAA section
110(a)(2)(D)(i)(I).
[[Page 9876]]
To effectively evaluate which emissions in the state should be
deemed ``significant'' and therefore prohibited, states generally
should prepare an accounting of sources and other emissions activity
for relevant pollutants and assess potential, additional emissions
reduction opportunities and resulting downwind air quality
improvements. EPA has consistently applied this general approach (i.e.,
Step 3 of the 4-step interstate transport framework) when identifying
emissions contributions that the Agency has determined to be
``significant'' (or interfere with maintenance) in each of its prior
Federal, regional ozone transport rulemakings, and this interpretation
of the statute has been upheld by the Supreme Court. See EME Homer
City, 572 U.S. 489, 519 (2014). While EPA has not directed states that
they must conduct a Step 3 analysis in precisely the manner EPA has
done in its prior regional transport rulemakings, state implementation
plans addressing the obligations in CAA section 110(a)(2)(D)(i)(I) must
prohibit ``any source or other type of emissions activity within the
state'' from emitting air pollutants which will contribute
significantly to downwind air quality problems. Thus, states must
complete something similar to EPA's analysis (or an alternative
approach to defining ``significance'' that comports with the statute's
objectives) to determine whether and to what degree emissions from a
state should be ``prohibited'' to eliminate emissions that will
``contribute significantly to nonattainment in, or interfere with
maintenance of'' the NAAQS in any other state. The state did not
conduct such an analysis in their SIP submission.
WDNR listed several rules relevant to interstate transport and
seemingly relied on its participation in LADCO to suggest sources in
Wisconsin are adequately controlled for purposes of the good neighbor
provision for the 2015 ozone NAAQS. WDNR mentioned Wisconsin's FIPs
under CSAPR and CSAPR Update. EPA disagrees that this is a sufficient
approach for assessing good neighbor obligations.
First, the CSAPR Update did not regulate non-electric generating
units, and thus this analysis is incomplete. See Wisconsin, 938 F.3d at
318-20. Second, relying on the CSAPR Update (or any other CAA program)
without further Step 3 analysis is not approvable. While EPA has not
established a benchmark cost-effectiveness value for 2015 ozone NAAQS
interstate transport obligations, because the 2015 ozone NAAQS is a
more stringent and more protective air quality standard, it is
reasonable to expect control measures or strategies to address
interstate transport under this NAAQS to reflect higher marginal
control costs. As such, the CSAPR Update Rule is not an appropriate
analysis and cannot be approved to satisfy interstate transport
obligations for the 2015 ozone NAAQS.
In addition, the updated EPA modeling captures all existing CSAPR
trading programs in the baseline, and that modeling confirms that these
control programs were not sufficient to eliminate the Wisconsin's
linkage at Steps 1 and 2 under the 2015 ozone NAAQS. The state was
therefore obligated at Step 3 to assess additional control measures
using a multifactor analysis.
Finally, relying on a FIP at Step 3 is per se not approvable if the
state has not adopted that program into its SIP and instead continues
to rely on the FIP. States may not rely on non-SIP measures to meet SIP
requirements. 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. U.S. E.P.A., 786 F.3d
1169, 1175-76 (9th Cir. 2015) (holding that measures relied on by state
to meet CAA requirements must be included in the SIP).
WDNR cited continued consultation with LADCO, three Wis. Admin.
Code subsections that could be relied on ``if needed'' to address
disagreements for SIP development in other states' nonattainment areas,
and an adequate PSD program. WDNR did not attempt to revise Wisconsin's
SIP to include to include all these measures. In general, the listing
of existing or on-the-way control measures, including potential future
emissions reductions obtained through participation in LADCO, whether
approved into the state's SIP or not, does not substitute for a
complete Step 3 analysis under EPA's 4-step framework to define
``significant contribution.'' WDNR did not identify control measures,
provide an assessment of the overall effects of these measures, note
when the reductions would be achieved, or explain what the overall
resulting air quality effects would be at identified out of state
receptors. WDNR did not evaluate additional, potential emissions
control opportunities, or their costs or impacts, or attempt to analyze
whether, if applied more broadly across linked states, the emissions
reductions would constitute the elimination of significant contribution
on a regional scale. WDNR did not offer an explanation as to whether
any faster or more stringent emissions reductions that may be available
were prohibitively costly or infeasible. Although EPA acknowledges
states are not necessarily bound to follow its own analytical framework
at Step 3, WDNR did not attempt to determine or justify an appropriate
uniform cost-effectiveness threshold. This would have been similar to
the approach to defining significant contribution that EPA has applied
in prior rulemakings such as CSAPR and or the CSAPR Update, even if
such an analysis is not technically mandatory.
As mentioned previously, Wis. Admin. Code NR 285.15, entitled
Interstate Agreement, gives the governor the authority to enter an
agreement to solve interstate pollution transport with Illinois,
Indiana, and Michigan if the area includes portions of both Wisconsin
and Illinois. Furthermore, Wis. Admin. Code, NR 285.1560 does not
provide for emission reductions toward resolving good neighbor
obligations, as while the statute allows for consultation, there is no
indication this rule has been exercised to resolve good neighbor
obligations or explain how the rule would impact areas in Illinois to
which Wisconsin is linked. Under the Wisconsin decision, states and EPA
may not delay implementation of measures necessary to address good
neighbor requirements beyond the next applicable attainment date
without a showing of impossibility or necessity. See 938 F.3d at 320.
Wisconsin's submittal is insufficient to the extent the implementation
timeframes for the cited control measures were left unidentified,
unexplained, or too uncertain to permit EPA to form a judgment as to
whether the timing requirements for good neighbor obligations have been
met.
We therefore propose that Wisconsin was required to analyze
emissions from the sources and other emissions activity from within the
state to determine whether its contributions were significant, and we
propose to disapprove its submission because Wisconsin failed to do so.
4. Evaluation of Information Provided Regarding Step 4
Step 4 of the 4-step interstate transport framework calls for
development of 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. As mentioned previously,
Wisconsin's SIP submission did not contain an evaluation of additional
emission
[[Page 9877]]
control opportunities (or establish that no additional controls are
required), thus, no information was provided at Step 4. As a result,
EPA proposes to disapprove Wisconsin' submittal on the separate,
additional basis that the state has not developed permanent and
enforceable emissions reductions necessary to meet the obligations of
CAA section 110(a)(2)(d)(i)(I).
5. Conclusion
Based on EPA's evaluation of Wisconsin's SIP submission, EPA is
proposing to find that the portion of Wisconsin's September 14, 2018
SIP submission addressing CAA section 110(a)(2)(D)(i)(I) does not meet
Wisconsin's interstate transport obligations, because it fails to
contain the necessary provisions to eliminate emissions that will
contribute significantly to nonattainment or interfere with maintenance
of the 2015 ozone NAAQS in any other state.
IV. Proposed Action
We are proposing to disapprove the portions of Illinois, Indiana,
Michigan, Minnesota, Ohio, and Wisconsin's SIP submissions pertaining
to interstate transport of air pollution which will significantly
contribute to nonattainment or interfere with maintenance of the 2015
ozone NAAQS in other states. Under CAA section 110(c)(1), disapproval
would establish a 2-year deadline for EPA to promulgate a FIP for
states to address the CAA section 110(a)(2)(D)(i)(I) interstate
transport requirements pertaining to significant contribution to
nonattainment and interference with maintenance of the 2015 ozone NAAQS
in other states, unless EPA approves a SIP that meets these
requirements. Disapproval does not start a mandatory sanctions clock
for Illinois, Indiana, Michigan, Minnesota, Ohio, or Wisconsin. The
remaining elements of the states' submissions are not addressed in this
action and either have been or will be acted on in a separate
rulemaking.
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 action does not have tribal implications as specified in
Executive Order 13175. This action does not apply on any Indian
reservation land, any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction, or non-reservation areas of
Indian country. Thus, Executive Order 13175 does not apply to 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 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.
K. CAA Section 307(b)(1)
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 whether to invoke
the exception in (ii).\113\
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\113\ 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.
---------------------------------------------------------------------------
EPA anticipates that this proposed rulemaking, if finalized, would
be ``nationally applicable'' within the meaning of CAA section
307(b)(1) because it would take final action on SIP submittals for the
2015 ozone NAAQS for six states, which are located in three different
Federal judicial circuits. It would apply uniform, nationwide
analytical methods, policy judgments, and interpretation with respect
to the same CAA obligations, i.e., implementation of good neighbor
requirements under CAA section 110(a)(2)(D)(i)(I) for the 2015 ozone
NAAQS for states across the country, and final action would be based on
this common core of determinations, described in further detail below.
If EPA takes final action on this proposed rulemaking, in the
alternative,
[[Page 9878]]
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 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 a nationally uniform analytic year (2023) for this analysis
and is applying a nationally uniform approach to nonattainment and
maintenance receptors and a nationally uniform approach to contribution
threshold analysis.\114\ 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 one or more determinations of nationwide
scope or effect for purposes of CAA section 307(b)(1).\115\
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\114\ 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.
\115\ EPA may take a consolidated, single final action on all of
the proposed SIP disapproval actions with respect to obligations
under CAA section 110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS.
Should EPA take a single final action on all such disapprovals, this
action would be nationally applicable, and EPA would also
anticipate, in the alternative, making and publishing 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: January 31, 2022.
Debra Shore,
Regional Administrator, Region 5.
[FR Doc. 2022-02953 Filed 2-18-22; 8:45 am]
BILLING CODE 6560-50-P