Proposed Rule2021-18516
Air Plan Approval; Connecticut; 2015 Ozone NAAQS Interstate Transport Requirements
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
August 30, 2021
Issuing agencies
Environmental Protection Agency
Abstract
The Clean Air Act (CAA) requires each State Implementation Plan (SIP) to contain adequate provisions prohibiting emissions that will have certain adverse air quality effects in other states. The State of Connecticut made a submission to the Environmental Protection Agency (EPA) to address these requirements for the 2015 ozone National Ambient Air Quality Standards (NAAQS). EPA is proposing to approve the submission as meeting the requirement that each SIP contain adequate provisions to prohibit emissions that will significantly contribute to nonattainment or interfere with maintenance of the 2015 ozone NAAQS in any other state.
Full Text
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<title>Federal Register, Volume 86 Issue 165 (Monday, August 30, 2021)</title>
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[Federal Register Volume 86, Number 165 (Monday, August 30, 2021)]
[Proposed Rules]
[Pages 48357-48363]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-18516]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R01-OAR-2021-0353; FRL-8916-01-R1]
Air Plan Approval; Connecticut; 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 have certain adverse air quality effects in other states. The
State of Connecticut made a submission to the Environmental Protection
Agency (EPA) to address these requirements for the 2015 ozone National
Ambient Air Quality Standards (NAAQS). EPA is proposing to approve the
submission as meeting the requirement that each SIP contain 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 September 29,
2021.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R01-
OAR-2021-0353 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>, or via email to
<a href="/cdn-cgi/l/email-protection#d1a2b8bcb2bea9ffb0bdb8a2bebf91b4a1b0ffb6bea7"><span class="__cf_email__" data-cfemail="66150f0b05091e48070a0f1509082603160748010910">[email protected]</span></a>. For comments submitted at <a href="http://Regulations.gov">Regulations.gov</a>,
follow the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. For either
manner of submission, EPA may publish any comment received to its
public docket. Do not submit electronically any information you
consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia
submissions (audio, video, etc.) must be
[[Page 48358]]
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, please
contact the person identified in the FOR FURTHER INFORMATION CONTACT
section. For the full EPA public comment policy, information about CBI
or multimedia submissions, and general guidance on making effective
comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>. Publicly available docket materials are available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or at the U.S. Environmental Protection Agency, EPA
Region 1 Regional Office, Air and Radiation Division, 5 Post Office
Square--Suite 100, Boston, MA. EPA requests that if at all possible,
you contact the contact listed in the FOR FURTHER INFORMATION CONTACT
section to schedule your inspection. The Regional Office's official
hours of business are Monday through Friday, 8:30 a.m. to 4:30 p.m.,
excluding legal holidays and facility closures due to COVID-19.
FOR FURTHER INFORMATION CONTACT: Alison C. Simcox, Air Quality Branch,
U.S. Environmental Protection Agency, EPA Region 1, 5 Post Office
Square--Suite 100, (Mail code 05-2), Boston, MA 02109--3912, telephone
number: (617) 918-1684, email address: <a href="/cdn-cgi/l/email-protection#6b180206080413450a07021804052b0e1b0a450c041d"><span class="__cf_email__" data-cfemail="91e2f8fcf2fee9bff0fdf8e2feffd1f4e1f0bff6fee7">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.
Table of Contents
I. Background
II. Connecticut Submittal
III. EPA Evaluation of Connecticut's Submittal
IV. Proposed Action
V. Statutory and Executive Order Reviews
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 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, 909-911 (D.C. Cir.
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), and, most recently, the Revised
CSAPR Update for the 2008 ozone NAAQS.<SUP>5 6</SUP>
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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), applying a multi-
factor analysis, 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 NO<INF>X</INF>
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 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 memo) 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 memo) noting that the same 2023 modeling data released in
the 2017 memo could also be useful for identifying potential downwind
air quality problems with respect to the 2015 ozone NAAQS at step 1 of
the
[[Page 48359]]
four-step interstate transport framework. The March 2018 memo 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.\11\
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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 or at <a href="https://www.epa.gov/interstate-air-pollution-transport/interstate-air-pollution-transport-memos-and-notices">https://www.epa.gov/interstate-air-pollution-transport/interstate-air-pollution-transport-memos-and-notices</a>.
\11\ 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 memo''), 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 or at <a href="https://www.epa.gov/airmarkets/memo-and-supplemental-information-regarding-interstate-transport-sips-2015-ozone-naaqs">https://www.epa.gov/airmarkets/memo-and-supplemental-information-regarding-interstate-transport-sips-2015-ozone-naaqs</a>.
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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.\12\ On March 15, 2021, EPA signed the final
Revised CSAPR Update using the same modeling released at proposal.\13\
Although Connecticut relied on the modeling included in the March 2018
memo to develop its 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 updated
modeling results, EPA is using the most current and technically
appropriate information as the primary basis for this proposed
rulemaking. EPA's independent analysis, which also evaluated historical
monitoring data, recent DVs, and emissions trends, found that such
information provides additional support and further substantiates the
results of the 2016 base year modeling as the basis for this proposed
rulemaking. 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 this modeling.\14\
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\12\ See 85 FR 68964, 68981. The results of this modeling are
included in a spreadsheet in the docket for this action. The
underlying modeling files are available for public review in the
docket for the Revised CSAPR Update (EPA-HQ-OAR-2020-0272).
\13\ See 86 FR 23054 at 23075, 23164 (April 30, 2021).
\14\ See ``Air Quality Modeling Technical Support Document for
the 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 proposing to
rely on the one percent threshold (which is 0.70 ppb) for the purpose
of evaluating Connecticut'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). 938 F.3d 303, 313.
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 Agency, under the good neighbor
provision, to assess downwind air quality by the next applicable
attainment date, including a Marginal area attainment date under CAA
section 181 for ozone nonattainment.\15\ The Marginal area attainment
date for the 2015 ozone NAAQS is August 3, 2021.\16\ Historically, EPA
has considered the full ozone season prior to the attainment date as
supplying an appropriate analytic year for assessing good neighbor
obligations. While this would be 2020 for an August 2021 attainment
date (which falls within the 2021 ozone season running from May 1 to
September 30), in this circumstance, when the 2020 ozone season is
wholly in the past, it is appropriate to focus on 2021 to address good
neighbor obligations to the extent possible by the 2021 attainment
date. EPA does not believe it would be appropriate to select an
analytical year 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, in
this proposal EPA will use the analytical year of 2021 to evaluate
Connecticut's good neighbor
[[Page 48360]]
obligation with respect to the 2015 ozone NAAQS.\17\
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\15\ 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.
\16\ 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).
\17\ EPA recognizes that by the time final action is taken with
respect to this SIP submission, the 2021 ozone season will be wholly
in the past. As discussed below, the available modeling information
indicates that our analysis would not change even using 2023 as the
analytic year. The 2023 modeling results are included in the ``Ozone
Design Values and Contributions Revised CSAPR Update.xlsx'',
included in the docket for this action.
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II. Connecticut Submittal
On December 6, 2018, Connecticut submitted a SIP revision
addressing the CAA section 110(a)(2)(D)(i)(I) interstate transport
requirements for the 2015 ozone NAAQS. Connecticut relied on the
results of EPA's modeling for the 2015 ozone NAAQS contained in the
March 2018 memo to identify downwind nonattainment and maintenance
receptors that may be impacted by emissions from sources in Connecticut
in the year 2023. These results indicate Connecticut's greatest impact
on any potential downwind nonattainment or maintenance receptor would
be 0.83 ppb in Suffolk County, New York.\18\ Based on the March 2018
memo, this was the only nonattainment or maintenance receptor for which
Connecticut was projected in 2023 to contribute above the screening
threshold of 0.70 ppb (one percent of the 2015 ozone NAAQS).
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\18\ EPA notes that the monitoring site ID for Suffolk County,
New York is 361030002.
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Connecticut noted in its December 2018 good neighbor submittal that
``EPA had considered cost-effective only reductions that are available
at a cost of less than $1,400 per ton of emissions reduced.
Connecticut's emitters are currently required to adopt control measures
at costs exceeding $13,000 per ton (of NO<INF>X</INF>).'' \19\
Connecticut states that as it requires this high level of control of
ozone precursor emissions, it has exhausted lower-cost emission
reduction measures.
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\19\ EPA notes that the $1,400 ton per year threshold stated by
Connecticut is in reference to the cost per ton threshold used in
the CSAPR Update, which was used to evaluate available cost-
effective EGU controls under the 2008 ozone NAAQS of 0.075 ppm. See
81 FR 74504 (October 26, 2016).
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As evidence of this, Connecticut points to Regulations of
Connecticut Agencies section 22a-174-22e(g) and its ozone attainment
plan technical support document for the 2008 ozone NAAQS, which was
submitted to EPA in August 2017 and documents the State's ozone
precursor emission reduction measures.
Connecticut concludes that it has met its good neighbor obligations
for the 2015 ozone NAAQS because of the existing control measures that
are in place.
III. EPA Evaluation of Connecticut's Submittal
Connecticut's SIP submission relies on analysis of the year 2023 to
show whether it contributes to nonattainment or interferes with
maintenance of the 2015 ozone NAAQS in any other state.\20\ As
explained in Section I of this proposal, EPA has conducted an updated
analysis for the 2021 analytical year that is being used to evaluate
Connecticut's transport SIP submittal. Significantly, this new analysis
shows that, in 2021, Connecticut is not projected to contribute to any
potential downwind nonattainment or maintenance receptor, including the
monitor in Suffolk County, New York, above the screening threshold of
0.70 ppb (one percent of the 2015 ozone NAAQS). While EPA has focused
its analysis in this document on the year 2021, modeling data in the
record for years 2023 and 2028 confirm that no new linkages to downwind
receptors are projected for Connecticut in later years. This is not
surprising as it is consistent with an overall, long-term downward
trend in emissions from this state.
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\20\ We recognize that Connecticut and other states may have
been influenced by EPA's 2018 guidance memos (issued prior to the
Wisconsin and Maryland decisions) in making good neighbor
submissions that relied on EPA's modeling of 2023. When there are
intervening changes in relevant law or legal interpretation of CAA
requirements, states are generally free to withdraw, supplement,
and/or re-submit their SIP submissions with new analysis (in
compliance with CAA procedures for SIP submissions). While
Connecticut has not done this, as explained in this section, the
independent analysis EPA has conducted at its discretion confirms
that the state's submission in this instance is ultimately
approvable.
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As explained in Section I of this document, in consideration of the
holdings in Wisconsin and Maryland, EPA's analysis relies on 2021 as
the relevant attainment year for evaluating Connecticut's good neighbor
obligations with respect to the 2015 ozone NAAQS using the four-step
interstate transport framework. In step 1, we identify locations where
the Agency expects there to be nonattainment or maintenance receptors
for the 2015 8-hour ozone NAAQS in the 2021 analytic year. Where EPA's
analysis shows that an area or site does not fall under the definition
of a nonattainment or maintenance receptor, 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 2021, 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 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.\21\
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\21\ See North Carolina v. EPA, 531 F.3d 896, 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 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.\22\
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\22\ 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-
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).\23\ Specifically, monitoring sites with a
projected maximum design value in 2021 that exceeds the NAAQS are
considered maintenance receptors. EPA's method of defining these
receptors takes into account both measured data and reasonable
projections based on modeling analysis.
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\23\ 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 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,
[[Page 48361]]
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.
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.\24\ Because this platform does
not include emissions for 2021, EPA developed an interpolation
technique based on modeling for 2023 and measured ozone data to
determine ozone concentrations for 2021. To estimate average and
maximum design values for 2021, EPA first performed air quality
modeling for 2016 and 2023 to obtain design values in 2023. The 2023
design values were then coupled with the corresponding 2016 measured
design values to estimate design values in 2021. Details on the
modeling, including the interpolation methodology, can be found in the
Air Quality Modeling TSD, found in the docket for this proposal.
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\24\ 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 2021 8-hour design values for the identified downwind
nonattainment and maintenance receptors, EPA first performed
nationwide, state-level ozone source apportionment modeling for 2023.
The source apportionment modeling provided contributions to ozone from
precursor emissions of anthropogenic nitrogen oxides (NO<INF>X</INF>)
and volatile organic compounds (VOCs) in each state, individually. The
modeled contributions were then applied in a relative sense to the 2021
average design value to estimate the contributions in 2021 from each
state to each receptor. Details on the source apportionment modeling
and the methods for determining contributions in 2021 are in the Air
Quality Modeling TSD in the docket.
The 2021 design values and contributions were examined to determine
if Connecticut 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 \25\ indicate that the highest
contribution in 2021 from Connecticut to a downwind nonattainment or
maintenance receptor is 0.44 ppb to a nonattainment receptor in
Richmond County, New York (monitoring site 360850067). The data also
show modeled ozone contributions from Connecticut to the design values
of a larger set of monitoring sites (independent of attainment status)
and indicate that the highest projected contribution in 2021 from
Connecticut to any of these sites is 3.51 ppb to Kent County in Rhode
Island (monitoring site 440030002; #378 on the Design Values and
Contributions spreadsheet). While Connecticut's modeled contribution to
the Kent County monitor exceeds one percent of the 2015 ozone NAAQS,
EPA's analysis at step 1 does not identify the Kent County monitor as a
downwind area that may have problems maintaining the 2015 ozone NAAQS.
The Kent County monitor's projected average design value in 2021 is
65.5 ppb. The updated modeling for 2021 also shows that Connecticut is
no longer projected to be linked to the Suffolk County monitoring site,
since this monitor is no longer projected to be a nonattainment or
maintenance receptor.
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\25\ 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 ozone precursor emissions trends in Connecticut
to support the findings from the air quality analysis. In evaluating
emissions trends, we first reviewed the information submitted by the
state and then reviewed additional information available to the Agency.
We focused on state-wide emissions of NO<INF>X</INF> and VOCs.\26\
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.
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\26\ This is because ground-level ozone is not emitted directly
into the air but is formed by chemical reactions between ozone
precursors, chiefly NO<INF>X</INF> and VOCs, in the presence of
sunlight. See 86 FR 23054, 23063.
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As shown in Table 1, for Connecticut, annual total NO<INF>X</INF>
and VOC emissions are projected to decline between 2016 and 2023 by 31
percent and 2 percent, respectively. The projected reductions are a
result of the implementation of existing control programs that will
continue to decrease NO<INF>X</INF> and VOC emissions in Connecticut,
as indicated by EPA's most recent 2021 and 2023 projected emissions.
As shown in Table 2, on-road and nonroad mobile source emissions
collectively comprise a large portion of Connecticut's total
anthropogenic NO<INF>X</INF> and VOCs. For example, in 2019,
NO<INF>X</INF> emissions from mobile sources in Connecticut comprised
62 percent of total NO<INF>X</INF> emissions and 38 percent of total
VOC emissions.
The large decrease in NO<INF>X</INF> emissions between 2016
emissions and projected 2023 emissions in Connecticut is primarily
driven by reductions in emissions from on-road and nonroad mobile
sources. EPA projects that both VOC and NO<INF>X</INF> emissions will
continue declining to 2023 as newer vehicles and engines that are
subject to the most recent, stringent mobile source standards replace
older vehicles and engines.\27\
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\27\ 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, based on the projected downward trend in projected
future emissions trends, in combination with the historical decline in
actual emissions, there is no evidence to suggest that the overall
emissions trend demonstrated in Table 2 would suddenly reverse or spike
in 2021 compared to historical emissions levels or those projected for
2023. Further, there is no evidence that the projected ozone precursor
emissions trends beyond 2021 would not continue to show a decline in
emissions. In addition, EPA followed its normal practice of including
in our modeling only changes in NO<INF>X</INF> or VOC emissions that
result from final regulatory actions. Any potential changes in
NO<INF>X</INF> or VOC emissions that may result from possible future or
proposed regulatory actions are speculative.
This downward trend in emissions in Connecticut adds support to the
air quality analyses presented above for the state and indicates that
the contributions from emissions from sources in Connecticut to ozone
receptors in downwind states will
[[Page 48362]]
continue to decline and remain below one percent of the NAAQS.
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\28\ The annual emissions data for the years 2011 through 2019
were obtained from EPA's National Emissions Inventory website:
<a href="https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data">https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data</a>. Note that emissions from miscellaneous
sources are not included in the state totals. The emissions for 2021
and 2023 are based on the 2016 emissions modeling platform. See
``2005 thru 2019 + 2021_2023_2028 Annual State Tier 1 Emissions_v3''
and the Emissions Modeling TSD in the docket for this action.
Table 1--Annual Emissions of NOX and VOCs From Anthropogenic Sources in Connecticut
[Tons per year] 28
--------------------------------------------------------------------------------------------------------------------------------------------------------
Projected Projected
2011 2012 2013 2014 2015 2016 2017 2018 2019 2021 2023
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CT NOX.............................. 72,815 69,540 66,264 62,989 57,791 48,729 46,285 43,751 40,219 35,033 33,412
CT VOCs............................. 79,806 80,621 81,435 82,250 74,313 62,658 57,777 56,137 54,498 63,354 61,110
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Table 2--Annual Emissions of NOX and VOCs From On-Road and Nonroad Vehicles in Connecticut
[Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Projected Projected
2011 2012 2013 2014 2015 2016 2017 2018 2019 2021 2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
CT NOX.............................. 54,371 50,956 47,540 44,124 40,040 32,090 30,760 27,878 24,995 19,128 16,935
CT VOCs............................. 38,749 37,166 35,583 33,999 30,837 23,957 23,851 22,212 20,573 17,398 16,229
--------------------------------------------------------------------------------------------------------------------------------------------------------
Thus, EPA's air quality and emissions analyses indicate that
emissions from Connecticut will not significantly contribute to
nonattainment or interfere with maintenance of the 2015 ozone NAAQS in
any other state in 2021.
IV. Proposed Action
As discussed in Section II, Connecticut concluded that it has met
its good neighbor obligations for the 2015 ozone NAAQS based on
existing control measures that are in place. EPA conducted an
independent analysis for the analytic year 2021 based on more recent
data and updated modeling. EPA's evaluation of measured and monitored
data, including interpolating values to generate a reasonable
expectation of air quality and contribution values in 2021, is
discussed in Section III. Based on the updated modeling and analysis,
EPA concluded that emissions from sources in the state will not
contribute significantly to nonattainment or interfere with maintenance
of the 2015 ozone NAAQS in any other state. This conclusion remains
true for later modeled years 2023 and 2028 in the updated modeling EPA
is relying on. Therefore, we propose to approve the Connecticut
submission as meeting the requirements of CAA section
110(a)(2)(D)(i)(I).
EPA is soliciting public comments on this document. These 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 document.
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 Clean Air Act.
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:
<bullet> 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);
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> 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.);
<bullet> 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);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
<bullet> 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
<bullet> 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 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, Carbon monoxide,
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen
dioxide, Ozone, Particulate matter, Reporting and recordkeeping
[[Page 48363]]
requirements, Sulfur oxides, Volatile organic compounds.
Dated: August 24, 2021.
Deborah Szaro,
Acting Regional Administrator, EPA Region 1.
[FR Doc. 2021-18516 Filed 8-27-21; 8:45 am]
BILLING CODE 6560-50-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.