[Federal Register Volume 87, Number 23 (Thursday, February 3, 2022)]
[Proposed Rules]
[Pages 6095-6100]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-02111]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2021-0678; FRL-9299-01-R8]
Air Plan Approval; Montana; 2015 Ozone NAAQS Interstate Transport
Requirements
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Clean Air Act (CAA) requires each State Implementation
Plan (SIP) to contain adequate provisions prohibiting emissions that
will significantly contribute to nonattainment or interfere with
maintenance of air quality in other states. The State of Montana made a
submission to the Environmental Protection Agency (EPA or Agency) to
address these requirements for the 2015 ozone National Ambient Air
Quality Standards (NAAQS). EPA is proposing to approve the submission
for Montana as meeting the requirement that the SIP contains adequate
provisions to prohibit emissions that will significantly contribute to
nonattainment or interfere with maintenance of the 2015 ozone NAAQS in
any other state.
DATES: Written comments must be received on or before March 7, 2022.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2021-0678, to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
www.regulations.gov. EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is
[[Page 6096]]
restricted by statute. Multimedia submissions (audio, video, etc.) must
be accompanied by a written comment. The written comment is considered
the official comment and should include discussion of all points you
wish to make. EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available electronically in
www.regulations.gov. To reduce the risk of COVID-19 transmission, for
this action we do not plan to offer hard copy review of the docket.
Please email or call the person listed in the FOR FURTHER INFORMATION
CONTACT section if you need to make alternative arrangements for access
to the docket.
FOR FURTHER INFORMATION CONTACT: Ellen Schmitt, Air and Radiation
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver,
Colorado 80202-1129, telephone number: (303) 312-6728, email address:
[email protected].
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.
I. 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 requirements is found in section 110(a)(2)(D)(i)(I),
otherwise known as the 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 four
so-called ``prongs'' within CAA section 110(a)(2)(D)(i); section
110(a)(2)(D)(i)(I) contains prongs 1 and 2. Under prongs 1 and 2 of the
good neighbor provision, 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, 909-911 (2008).
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We note that 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\ the Cross-State Air
Pollution Rule Update (CSAPR Update) with respect to the 2008 ozone
NAAQS, and, most recently, the Revised CSAPR Update for the 2008 ozone
NAAQS.\5\ \6\
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\4\ See 76 FR 48208 (August 8, 2011).
\5\ 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).
\6\ The Revised Cross-State Air Pollution Rule Update for the
2008 ozone NAAQS (86 FR 23054 (April 30, 2021)) was signed by the
EPA Administrator on March 15, 2021 and responded to the remand of
the CSAPR Update (81 FR 74504 October 26, 2016)) and the vacatur of
a separate rule, the CSAPR Close-Out (83 FR 65878 (December 21,
2018)) by the D.C. Circuit. Wisconsin v. EPA, 938 F.3d 303 (D.C.
Cir. 2019); New York v. EPA, 781 F. App'x. 4 (D.C. Cir. 2019).
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Through the development and implementation of CSAPR and other
regional rulemakings pursuant to the good neighbor provision,\7\ EPA,
working in partnership with states, developed the following four-step
interstate transport framework to address the requirements of the good
neighbor provision for the ozone NAAQS: (1) Identify downwind air
quality problems; (2) identify upwind states that impact those downwind
air quality problems sufficiently such that they are considered
``linked'' and therefore warrant further review and analysis; (3)
identify the emissions reductions necessary (if any), considering air-
quality and cost factors, to prevent linked upwind states identified in
step 2 from contributing significantly to nonattainment or interfering
with maintenance of the NAAQS at the locations of the downwind air
quality problems; 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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EPA has released several documents containing 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) with preliminary interstate ozone transport
modeling with projected ozone design values (DVs) for 2023 using a 2011
base year modeling platform, on which we requested public comment.\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 (2017
memorandum) containing updated 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 good neighbor 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 2017 memorandum could
also be useful for identifying potential downwind air
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quality problems with respect to the 2015 ozone NAAQS at step 1 of the
four-step interstate transport framework.\11\ The March 2018 memorandum
also included the then newly available contribution modeling results to
assist states in evaluating their impact on potential downwind air
quality problems for the 2015 ozone NAAQS under step 2 of the
interstate transport framework. EPA subsequently issued two more
memoranda in August and October 2018, providing additional information
to states developing good neighbor SIP submissions for the 2015 ozone
NAAQS concerning, respectively, potential contribution thresholds that
may be appropriate to apply in step 2 of the framework, and
considerations for identifying downwind areas that may have problems
maintaining the standard at step 1 of the framework.\12\
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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 1733, 1735 (January 6, 2017).
\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 the docket for
this action as ``October 2017 Memorandum'' 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 the docket for this
action as ``March 2018 Memorandum.''
\12\ 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 the docket for this action as ``Maintenance Receptors
Memo_Oct2018'' or at https://www.epa.gov/airmarkets/memo-and-supplemental-information-regarding-interstate-transport-sips-2015-ozone-naaqs.
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On October 30, 2020, in the notice of proposed rulemaking for the
Revised CSAPR Update, EPA released and accepted public comment on
updated 2023 modeling that used a 2016 emissions platform developed
under the EPA/Multi-Jurisdictional Organization (MJO)/state
collaborative project as the primary source for the base year and
future year emissions data.\13\ On March 15, 2021, EPA signed the final
Revised CSAPR Update using the same modeling released at proposal.\14\
Although Montana relied on the modeling included in the March 2018 memo
to develop their SIP submission as EPA had suggested, EPA now proposes
to primarily rely on the updated and newly available 2016 base year
modeling in evaluating these submissions. By using the Revised CSAPR
Update modeling results, EPA is using the most current and technically
appropriate information as the primary basis for this proposed
rulemaking.\15\ EPA's independent analysis, which evaluated historical
monitoring data, recent DVs, and emissions trends, in addition to the
Revised CSAPR Update modeling, provides support and further
substantiates the results of the 2011 platform modeling relied on my
Montana. Section III of this document and the Air Quality Modeling
technical support document (TSD) included in the docket for this
proposal contain additional detail on Revised CSAPR Update
modeling.\16\
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\13\ See 85 FR 68964, 68981. The underlying modeling files are
available for public review in the docket for the Revised CSAPR
Update (EPA-HQ-OAR-2020-0272).
\14\ See 86 FR 23054 at 23075, 23164 (April 30, 2021).
\15\ EPA recently made available updated modeling results on its
website but was not able to incorporate those results into this
proposal prior to signature. See https://www.epa.gov/air-emissions-modeling/2016v2-platform. In any case, these results corroborate the
prior EPA modeling on which this proposal relies with respect to
Montana.
\16\ See ``Air Quality Modeling Technical Support Document for
the Final Revised Cross-State Air Pollution Rule Update,'' 86 FR
23054 (April 30, 2021), available in the docket for this action.
This TSD was originally developed to support EPA's action in the
Revised CSAPR Update, as relating to outstanding good neighbor
obligations under the 2008 ozone NAAQS. While developed in this
separate context, the data and modeling outputs, including
interpolated design values for 2021, may be evaluated with respect
to the 2015 ozone NAAQS and used in support of this proposal.
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In the CSAPR, CSAPR Update, and the Revised CSAPR Update, EPA used
a threshold of one percent of the NAAQS to determine whether a given
upwind state was ``linked'' at step 2 of the interstate transport
framework and would, therefore, contribute to downwind nonattainment
and maintenance sites identified in step 1. If a state's impact did not
equal or exceed the one percent threshold, the upwind state was not
``linked'' to a downwind air quality problem, and EPA, therefore,
concluded the state would not significantly contribute to nonattainment
or interfere with maintenance of the NAAQS in the downwind states.
However, if a state's impact equaled or exceeded the one percent
threshold, the state's emissions were further evaluated in step 3,
considering both air quality and cost considerations, to determine
what, if any, emissions might be deemed ``significant'' and, thus, must
be eliminated under the good neighbor provision. EPA is relying on the
one percent threshold for the purpose of evaluating Montana's
contribution to nonattainment or maintenance of the 2015 ozone NAAQS in
downwind areas.
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).\17\
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\17\ 938 F.3d 303, 313.
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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).\18\ 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 Agency,
under the good neighbor provision, to assess downwind air quality by no
later than the next applicable attainment date, including a Marginal
area attainment date under CAA section 181 for ozone nonattainment.\19\
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\18\ Maryland v. EPA, 958 F.3d 1185, 1203-04 (D.C. Cir. 2020).
\19\ 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 good neighbor
provision. Such circumstances are not at issue in the present
proposal.
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However, the Marginal area attainment date for the 2015 ozone NAAQS
was August 3, 2021.\20\ EPA does not believe it would be appropriate to
focus its analysis on an attainment date that is wholly in the past
because the Agency interprets the good neighbor provision as forward
looking. See 86 FR 23054 at 23074; see also Wisconsin, 938 F.3d at 322.
Consequently, as this action is being proposed after the 2021
attainment date (as well as after the end of the 2021 ozone season),
EPA proposes to use 2023 as an appropriate
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analytic year in this action. The year 2023 contains the last full
ozone season before the next downwind attainment date, which is the
August 3, 2024, Moderate area attainment date. (Historically, EPA has
considered the full ozone season prior to the attainment date as
supplying an appropriate analytic year for assessing Montana's good
neighbor obligations.) EPA acknowledges that the first order directive
for the timing of good neighbor compliance is ``as expeditiously as
practicable.'' See CAA section 181(a)(1); 938 F.3d at 313. EPA believes
that an assessment of future air quality in the 2023 analytic year is
as expeditiously as practicable. Should any emission reductions be
required under the four-step interstate transport framework (though, to
be clear, none are found to be necessary for Montana in this proposal),
EPA believes 2023 is the earliest ozone season by which such reductions
would be possible. Therefore, EPA has analyzed projected ozone air
quality and Montana's emissions for purposes of the good neighbor
provision using the 2023 analytic year.
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\20\ 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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II. Montana Submission
On October 1, 2018, EPA received a SIP revision from the State of
Montana addressing the CAA section 110(a)(2)(D)(i)(I) interstate
transport requirements for the 2015 ozone NAAQS. Montana relied on the
results of EPA's modeling for the 2015 ozone NAAQS contained in the
March 2018 memorandum to identify downwind nonattainment and
maintenance receptors that may be impacted by emissions from sources in
Montana in the year 2023. These results indicated the State's greatest
impact on any potential downwind nonattainment or maintenance receptor
would be 0.10 ppb. Referencing the March 2018 memorandum modeling, this
level of impact from Montana was found in Brazoria, Texas (monitoring
site 480391004), Tarrant, Texas (monitoring site 484392003), and
Milwaukee, Wisconsin (monitoring site 550790085). Montana compared this
value to a screening threshold of 0.70 ppb, representing one percent of
the 2015 ozone NAAQS. Because Montana's impacts to receptors in
downwind states are projected to be less than 0.70 ppb in 2023, the
State concluded that emissions from sources within Montana will not
significantly contribute to nonattainment or interfere with maintenance
of the 2015 ozone NAAQS in any other state.
Montana's October 2018 good neighbor SIP submission also lists the
State's regulations for controlling ozone precursors. These rules and
regulations are included in ARM Title 17, Chapter 8, subchapters 7, 8,
9, 10, 16, and 17.
III. EPA Evaluation of Montana's Submission
Montana's SIP submission relies on analysis of the year 2023 (using
a 2011 base year platform) to show that the State does not
significantly contribute to nonattainment or interfere with maintenance
of the 2015 ozone NAAQS in any other state. As explained in Section I
of this proposal, EPA has conducted an updated analysis for the 2023
analytical year (using a 2016 base year platform) and proposed to rely
primarily on this updated modeling to evaluate Montana's transport SIP
submission. This updated modeling corroborates Montana's conclusion
that the State will not significantly contribute to nonattainment or
interfere with maintenance of the 2015 ozone NAAQS in any other
state.\21\ While EPA has focused its analysis in this document on the
year 2023, modeling data in the record for a future analytic year,
2028, confirm that no new linkages to downwind receptors are projected
in later years. This is consistent with an overall, long-term downward
trend in emissions from the State.
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\21\ See 86 FR 23054 (April 30, 2021). The results of this
modeling are included in a spreadsheet in the docket for this
action. The underlying modeling files are available for public
access in the docket for the Revised CSAPR Update (EPA-HQ-OAR-2020-
0272).
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In step 1 of the four-step interstate framework, we identify
locations where the Agency expects there to be nonattainment or
maintenance receptors for the 2015 8-hour ozone NAAQS in the 2023
analytic future year, using the 2016 base year modeling platform. Where
EPA's analysis shows that an area or site does not fall under the
definition of a nonattainment or maintenance receptor in 2023, that
site is excluded from further analysis under EPA's four step interstate
transport framework. For areas that are identified as a nonattainment
or maintenance receptor in 2023, we proceed to the next step of our
four-step framework by identifying the upwind state's contribution to
those receptors.
EPA's approach to identifying ozone nonattainment and maintenance
receptors in this proposal is consistent with the approach used in
previous transport rulemakings and is consistent with the D.C.
Circuit's direction in North Carolina to give independent consideration
to both the ``contribute significantly to nonattainment'' and the
``interfere with maintenance'' prongs of CAA section
110(a)(2)(D)(i)(I).\22\
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\22\ 531 F.3d at 910-911 (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 monitor nonattainment and that EPA projects will be
in nonattainment in the future analytic year.\23\
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\23\ See 81 FR 74504 (October 26, 2016). Revised CSAPR Update
also used this approach. See 86 FR 23054 (April 30, 2021). This same
concept, relying on both current monitoring data and modeling to
define nonattainment receptor, was also applied in CAIR. See 70 FR
25241 (January 14, 2005). See also North Carolina, 531 F.3d at 913-
914 (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).\24\ Specifically, monitoring sites with a
projected maximum design value in 2023 that exceeds the NAAQS are
considered maintenance receptors. EPA's method of defining these
receptors takes into account both measured data and projections based
on modeling analysis.
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\24\ 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 See 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 receptors that are not also nonattainment receptors.
Consistent with the methodology described above, monitoring sites with
a projected maximum design value that exceeds the NAAQS, but with a
projected average design value that is below the NAAQS, are identified
as maintenance-only receptors. In addition, those sites that are
currently measuring ozone concentrations below the level of the
applicable NAAQS, but are projected to be nonattainment based on the
average design value and that, by definition, are projected to have a
maximum design value above the standard are also identified as
maintenance-only receptors.
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To evaluate future air quality in steps 1 and 2 of the interstate
transport framework, EPA is using the 2016 and 2023 base case emissions
developed under the EPA/MJO/state collaborative emissions modeling
platform project as the primary source for base year and 2023 future
year emissions data for this proposal.\25\
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\25\ See 86 FR 23054 (April 30, 2021). The results of this
modeling are included in a spreadsheet in the docket for this
action. The underlying modeling files are available for public
access in the docket for the Revised CSAPR Update (EPA-HQ-OAR-2020-
0272).
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To quantify the contribution of emissions from specific upwind
states on 2023 8-hour design values for the identified downwind
nonattainment and maintenance receptors, EPA first performed
nationwide, state-level ozone source apportionment modeling. The source
apportionment modeling provided contributions to ozone from precursor
emissions of anthropogenic nitrogen oxides (NOX) and
volatile organic compounds (VOCs) in each state, individually. Details
on the source apportionment modeling and the methods for determining
contributions are in the Air Quality Modeling TSD in the docket.
The design values and contributions were examined to determine if
Montana contributes at or above the threshold of one percent of the
2015 ozone NAAQS (0.70 ppb) to any downwind nonattainment or
maintenance receptor. The data \26\ indicate that the highest
contribution in 2023 from Montana to downwind nonattainment or
maintenance receptors is 0.08 ppb, well below the one percent of the
NAAQS screening threshold. Montana contributes 0.08 ppb to two
nonattainment receptors in Connecticut (monitoring site 90013007 in
Fairfield County and monitoring site 90099002 in New Haven County) and
to one maintenance receptor in Illinois (monitoring site 170314201 in
Cook County).
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\26\ The data are given in the ``Air Quality Modeling Technical
Support Document for the Revised Cross-State Air Pollution Rule
Update'' and ``Ozone Design Values and Contributions Revised CSAPR
Update.xlsx,'' which are included in the docket for this action.
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EPA also analyzed emissions trends for ozone precursors in Montana
to support the findings from the air quality analysis. We focused on
state-wide emissions of NOX and VOC.\27\ Emissions from
mobile sources, electric generating units (``EGUs''), industrial
facilities, gasoline vapors, and chemical solvents are some of the
major anthropogenic sources of ozone precursors. This evaluation looks
at both past emissions trends, as well as projected trends. EPA notes
that the projected VOC emissions are greater than historical emissions
in recent years according to NEI data. However, EPA also notes that
NOX emissions are the primary contributor to regional ozone
formation in ozone transport, and for Montana, NOX emissions
are projected to continue to decline. As a result of these
NOX emissions reductions, Montana is projected to contribute
below the one percent threshold in 2023 to projected nonattainment and
maintenance receptors and is projected to continue to contribute below
one percent in 2028, despite the greater projected VOC emissions.
Projected ozone design values and contributions data for 2021, 2023,
and 2028 can be found in the file ``Ozone Design Values and
Contributions Revised CSAPR Update.xlsx'' in the docket for this
action.
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\27\ This is because ground-level ozone is not emitted directly
into the air but is formed by chemical reactions between ozone
precursors, chiefly NOX and VOC, in the presence of
sunlight. See 86 FR 23054, 23063.
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As shown in Table 1, for Montana, between 2015 and 2019, annual
total NOX and VOC emissions have declined by 19 percent and
21 percent, respectively. Between 2016 and 2023, annual NOX
emissions are projected to decline by 30 percent as a result of the
implementation of existing control programs that will continue to
decrease NOX in Montana as indicated by EPA's most recent
2023 projected emissions.
As shown in Table 2, onroad and nonroad mobile source emissions
collectively comprise a large portion of the State's total
anthropogenic NOX and VOC. For example, in 2019,
NOX emissions from mobile sources in Montana comprised 63
percent of total NOX emissions and 25 percent of total VOC
emissions.
The large decrease in NOX emissions between 2016
emissions and projected 2023 emissions in Montana is primarily driven
by reductions in emissions from onroad and nonroad mobile sources. EPA
projects that the total anthropogenic NOX emissions and the
highway and off highway VOC emissions will continue declining out to
2023 as newer vehicles and engines that are subject to the most recent,
stringent mobile source standards replace older vehicles and
engines.\28\
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\28\ Tier 3 Motor Vehicle Emission and Fuel Standards (79 FR
23414, April 28, 2014); Mobile Source Air Toxics Rule (MSAT2) (72 FR
8428, February 26, 2007), Heavy-Duty Engine and Vehicle Standards
and Highway Diesel Fuel Sulfur Control Requirements (66 FR 5002,
January 18, 2001); Clean Air Nonroad Diesel Rule (69 FR 38957, June
29, 2004); Locomotive and Marine Rule (73 FR 25098, May 6, 2008);
Marine Spark-Ignition and Small Spark-Ignition Engine Rule (73 FR
59034, October 8, 2008); New Marine Compression-Ignition Engines at
or Above 30 Liters per Cylinder Rule (75 FR 22895, April 30, 2010);
and Aircraft and Aircraft Engine Emissions Standards (77 FR 36342,
June 18, 2012).
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In summary, there is no evidence to suggest that the overall
emissions trend for Montana demonstrated in Table 1 will suddenly
reverse or spike in 2021 or 2022 compared to historical emissions
levels or those projected for 2023. Further, there is no evidence that
the projected NOX emissions trend out to 2023 and beyond
would not continue to show a decline in emissions from Montana. In
addition, EPA's normal practice is to include in our modeling only
changes in NOX or VOC emissions that result from final
regulatory actions. Any potential changes in NOX or VOC
emissions that may result from possible future or proposed regulatory
actions are speculative.
This general downward trend in emissions in Montana adds support to
the air quality analyses presented above and indicates that the
contributions from emissions from sources in the State to ozone
receptors in downwind states will generally continue to decline and
remain below one percent of the NAAQS.
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\29\ The annual emissions data for the years 2011 through 2019
were obtained from EPA's National Emissions Inventory website:
https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data. Note that emissions from miscellaneous
sources are not included in the State totals presented in Table 1.
The emissions for 2023 are based on the 2016 emissions modeling
platform. See ``2005 thru 2019_2021_2023_2028 Annual State Tier1
Emissions_v3'' and the Emissions Modeling TSD in the docket for this
action.
Table 1--Annual Emissions of NOX and VOC From Anthropogenic Sources in Montana
[tons per year] \29\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Projected
2011 2012 2013 2014 2015 2016 2017 2018 2019 2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX...................................... 108,605 108,895 109,184 109,474 103,417 92,623 88,663 85,882 84,040 64,567
[[Page 6100]]
VOC...................................... 100,778 104,768 108,759 112,750 103,312 91,612 83,660 82,432 81,204 92,076
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 2--Annual Emissions of NOX and VOC From Onroad and Nonroad Vehicles in Montana
[tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Projected
2011 2012 2013 2014 2015 2016 2017 2018 2019 2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX...................................... 75,883 75,352 74,821 74,289 69,640 60,254 57,701 55,182 52,662 41,261
VOC...................................... 31,108 30,865 30,622 30,379 28,059 23,477 22,644 21,416 20,188 16,631
--------------------------------------------------------------------------------------------------------------------------------------------------------
Thus, EPA's evaluation of measured and monitored data, and
contribution values in 2023, as discussed in this section, is
consistent with conclusions made by Montana that emissions from sources
in the State will not contribute to nonattainment or interfere with
maintenance of the 2015 ozone NAAQS in any other state.
IV. Proposed Action
EPA is proposing to approve the October 1, 2018 SIP submittal as
meeting the interstate transport requirements of CAA section
110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS. At this time, EPA is not
proposing action on the remaining infrastructure elements included in
Montana's submittal and will act on those elements in a future action.
The Agency is soliciting public comments on its proposed approval
of the CAA section 110(a)(2)(D)(i)(I) element of Montana's
infrastructure SIP submittal for the 2015 ozone NAAQS. Significant
comments will be considered before taking final action. Interested
parties may participate in the Federal rulemaking procedure by
submitting written comments to this proposed rule by following the
instructions listed in the ADDRESSES section of this Federal Register.
V. Statutory and Executive Order Reviews
Under the Clean Air Act, the Administrator is required to approve a
SIP submission that complies with the provisions of the Act and
applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a).
Thus, in reviewing SIP submissions, EPA's role is to approve state
choices, provided that they meet the criteria of the CAA. Accordingly,
this proposed action merely approves state law as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by state law. For that reason, this proposed action:
Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Orders 12866 (58
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the Clean Air Act; and
Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using practicable and legally permissible methods, under
Executive Order 12898 (59 FR 7629, February 16, 1994).
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the proposed rule does not have tribal implications and will
not impose substantial direct costs on tribal governments or preempt
tribal law as specified by Executive Order 13175 (65 FR 67249, November
9, 2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: January 27, 2022.
KC Becker,
Regional Administrator, Region 8.
[FR Doc. 2022-02111 Filed 2-2-22; 8:45 am]
BILLING CODE 6560-50-P