[Federal Register Volume 86, Number 135 (Monday, July 19, 2021)]
[Proposed Rules]
[Pages 37942-37948]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-15097]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2019-0156; FRL-8697-01-R4]


Air Plan Approval; FL, GA, NC, SC; Interstate Transport (Prongs 1 
and 2) for the 2015 8-Hour Ozone Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: Through this supplemental notice of proposed rulemaking 
(``supplemental proposal'' or ``SNPRM''), the Environmental Protection 
Agency (EPA) is supplementing its proposed approval of state 
implementation plan (SIP) submissions from Florida, Georgia, North 
Carolina, and South Carolina (four Southeastern States), addressing the 
Clean Air Act (CAA or Act) interstate transport requirements for the 
2015 8-hour ozone National Ambient Air Quality Standard (NAAQS or 
standard). Specifically, EPA is proposing to rely on updated analysis 
using a 2021 analytic year to support the proposed finding that each 
state's implementation plan 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 August 18, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2019-0156, at www.regulations.gov. Follow the online instructions 
for submitting comments. Once submitted, comments cannot be edited or 
removed from 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 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

[[Page 37943]]

making effective comments, please visit www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Evan Adams of the Air Regulatory 
Management Section, Air Planning and Implementation Branch, Air and 
Radiation Division, U.S. Environmental Protection Agency, Region 4, 61 
Forsyth Street SW, Atlanta, Georgia 30303-8960. Mr. Adams can be 
reached by telephone at (404) 562-9009, or via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION:

I. Background for This Supplemental Proposal

    On December 30, 2019, EPA proposed to approve SIP submissions from 
six Southeast States (i.e., Alabama, Florida, Georgia, North Carolina, 
South Carolina, and Tennessee) \1\ as meeting the interstate transport 
requirements of CAA section 110(a)(2)(D)(i)(I), or the Good Neighbor 
provision, for the 2015 8-hour ozone NAAQS. See 84 FR 71854. Refer to 
the December 30, 2019, notice of proposed rulemaking (NPRM) for an 
explanation of the CAA requirements, the four-step framework that EPA 
applies under the Good Neighbor provision for ozone NAAQS, a detailed 
summary of the state submissions, and EPA's proposed rationale for 
approval. See 84 FR 71854. The public comment period for the December 
30, 2019, NPRM closed on January 29, 2020.\2\
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    \1\ The submittals from these six southeastern states were 
submitted separately under the following cover letters: Alabama 
Department of Environmental Management dated August 20, 2018 
(received by EPA on August 27, 2018); Florida Department of 
Environmental Protection dated September 18, 2018 (received by EPA 
on September 26, 2018); Georgia Environmental Protection Division 
dated September 19, 2018 (received by EPA on September 24, 2018); 
North Carolina Department of Environmental Quality dated September 
27, 2018 (received by EPA October 10, 2018); South Carolina 
Department of Health and Environmental Control dated and received by 
EPA on September 7, 2018; and Tennessee Department of Environment 
and Conservation dated September 13, 2018 (received by EPA on 
September 17, 2018).
    \2\ On March 24, 2020, former EPA Region 4 Administrator Mary 
Walker signed a document (hereinafter referred to as the March 24, 
2020 document) that EPA intended to become a final rule upon 
publication in the Federal Register. However, the March 24, 2020 
document was never published in the Federal Register. Further, on 
January 19, 2021, former EPA Region 4 Administrator Mary Walker 
signed a document (hereinafter referred to as the January 19, 2021 
document), which EPA posted to its website at https://www.epa.gov/air-quality-implementation-plans/epas-approval-2015-8-hour-ozone-interstate-transport-requirements. EPA noted in that posting 
``Notwithstanding the fact that the EPA is posting a pre-publication 
version, the final rule will not be promulgated until published in 
the Federal Register.'' EPA will not publish either the March 24, 
2020 document or the January 19, 2021 document in the Federal 
Register; therefore, neither document will result in a final rule.
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    Subsequent to the December 30, 2019, proposal, two events occurred 
which have caused EPA to adjust its analysis of the aforementioned SIP 
submissions, and consequently, to issue this supplemental proposal. 
First, on May 19, 2020, the United States Court of Appeals for the 
District of Columbia Circuit (D.C. Circuit) issued its ruling in 
Maryland v. EPA, 958 F.3d 1185 (D.C. Cir. 2020) (Maryland). That case 
involved EPA's denial of administrative petitions filed by the states 
of Maryland and Delaware under CAA section 126(b), seeking to have EPA 
impose emissions limits on sources in upwind states alleged to be 
emitting in violation of the Good Neighbor Provision. The court held 
that EPA must address Good Neighbor obligations consistent with the 
2021 attainment date for downwind areas classified as being in Marginal 
nonattainment under the 2015 8-hour ozone NAAQS, ``not at some later 
date.'' 958 F.3d at 1203-04 (citing Wisconsin v. EPA, 938 F.3d 303, 314 
(D.C. Cir. 2019) (Wisconsin)). The court disagreed with EPA that use of 
a 2023 analytic year, consistent with the 2024 attainment date for 
areas classified as being in Moderate nonattainment, was a proper 
reading of the court's earlier decision in Wisconsin. Id. at 1204. In 
light of the Maryland decision, EPA is evaluating these states' Good 
Neighbor obligations using a 2021 analytic year, corresponding to the 
2021 Marginal area attainment date under the 2015 8-hour ozone NAAQS.
    Second, on October 30, 2020, EPA released and accepted public 
comment on updated 2023 modeling that used the 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.\3\ On April 30, 2021, EPA published the 
final Revised Cross-State Air Pollution Rule (CSAPR) Update using the 
same modeling that was made publicly available in the proposed 
rulemaking for the Revised CSAPR Update.\4\ Although that modeling 
focused on the year 2023, EPA conducted an ``interpolation'' analysis 
of these modeling results to generate air quality and contribution 
values for the 2021 analytic year, consistent with the Maryland 
holding, as the relevant analytic year for the 2015 8-hour ozone NAAQS.
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    \3\ See Revised CSAPR Update, 86 FR 23054; see also Emissions 
Modeling TSD titled ``Preparation of Emissions Inventories for the 
2016v1 North American Emissions Modeling Platform.'' This TSD is 
available in the docket for this proposed action and at https://www.epa.gov/air-emissionsmodeling/2016v1-platform. The underlying 
modeling files are available on data drives in the Docket office for 
public review. See the docket for the Revised CSAPR Update (EPA-HQ-
OAR-2020-0272). See also in the docket for this supplemental 
proposal the document titled Air Quality Modeling Data Drives_Final 
RCU.pdf for a file inventory and instructions on how to access the 
modeling files.
    \4\ See 86 FR 23054.
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    This new modeling and analysis now provides the primary basis for 
EPA's proposed approval of the Good Neighbor SIP submissions for 
Florida, Georgia, North Carolina, and South Carolina. By relying on the 
updated modeling results, EPA is using the most current and technically 
appropriate information as the primary basis for this proposed 
rulemaking. As explained in greater detail in this supplemental 
proposal, this new analysis indicates that in 2021, these four states 
are not projected to impact any downwind states at or above a 
contribution threshold of one percent of the 2015 8-hour ozone NAAQS, 
which is equivalent to 0.70 parts per billion (ppb). Thus, EPA is 
proposing to approve these four states' submissions.
    Additionally, EPA previously proposed to approve infrastructure SIP 
elements submitted to fulfill the interstate transport requirements of 
CAA section 110(a)(2)(D)(i)(I) by the states of Alabama and Tennessee 
for the 2015 8-hour ozone NAAQS in the December 30, 2019, NPRM 
referenced above. This supplemental proposal does not address these 
submissions, and EPA is deferring action on the referenced SIP 
submissions from Alabama and Tennessee at this time.

II. EPA's Analysis

    On May 19, 2020, the D.C. Circuit issued the Maryland decision 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). See 958 F.3d 
1185, 1203-04. The court noted that ``section 126(b) incorporates the 
Good Neighbor Provision,'' and therefore ``the 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, EPA 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 address Good Neighbor obligations 
by the next applicable attainment date for downwind areas, including a 
Marginal

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area attainment date under CAA section 181 for ozone nonattainment.\5\
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    \5\ EPA notes 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 four-step 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 a certain degree of flexibility in 
effectuating the implementation of the Good Neighbor provision. Such 
circumstances are not at issue in this proposed action.
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    The Marginal area attainment date for the 2015 8-hour ozone NAAQS 
is August 3, 2021.\6\ See CAA section 181(a); 40 CFR 51.1303; 83 FR 
25776 (June 4, 2018, effective August 3, 2018). Historically, EPA has 
considered the last full ozone season prior to the attainment date as 
supplying an appropriate analytic year for assessing Good Neighbor 
obligations. See, e.g., 81 FR 74540. 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 analytic year that is wholly in the past because EPA 
interprets the Good Neighbor provision as forward looking. See 85 FR 
68964, 68981; see also Wisconsin, 938 F.3d at 322. Consequently, as 
discussed further below, EPA is using the analytic year of 2021 in this 
supplemental proposal to evaluate Good Neighbor obligations for 
Florida, Georgia, North Carolina, and South Carolina with respect to 
the 2015 8-hour ozone NAAQS.
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    \6\ The December 30, 2019, NPRM incorrectly referred to the 2015 
8-hour ozone NAAQS Marginal attainment date as August 2, 2021, and 
the Moderate attainment date as August 2, 2024. See 84 FR 71857.
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    The December 30, 2019, NPRM proposing approval of the 2015 8-hour 
ozone Good Neighbor SIPs for Florida, Georgia, North Carolina, and 
South Carolina predates the D.C. Circuit's decision in Maryland. This 
decision also came after the close of the public comment period on the 
December 30, 2019, NPRM. However, this decision bears directly on EPA's 
action and its consideration of the comments received on the December 
30, 2019, NPRM. As discussed above and in accordance with the Wisconsin 
and Maryland decisions, the Agency considers 2021 to be the relevant 
analytic year for the purpose of determining whether sources in 
Florida, Georgia, North Carolina, and South Carolina will significantly 
contribute to nonattainment or interfere with maintenance of the 2015 
8-hour ozone NAAQS in any other states.
    EPA is proposing to determine that the Florida, Georgia, North 
Carolina, and South Carolina Good Neighbor SIP submissions for the 2015 
8-hour ozone NAAQS are approvable using a 2021 analytic year. The SIP 
submissions from Florida, Georgia, North Carolina, and South Carolina 
rely on analysis of the year 2023 to show that they do not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2015 8-hour ozone NAAQS in any other state. However, given the 
holdings in Wisconsin and Maryland, analysis of that year is no longer 
sufficient where the next attainment date for the 2015 8-hour ozone 
NAAQS is in 2021.\7\ Nonetheless, the analysis EPA has conducted for 
the 2021 analytic year corroborates the conclusion reached in each 
state's submission and in the December 30, 2019, NPRM. In accordance 
with the holdings in Wisconsin and Maryland, EPA's supplemental 
analysis relies on 2021 as the relevant attainment year for evaluating 
Good Neighbor obligations for Florida, Georgia, North Carolina, and 
South Carolina with respect to the 2015 8-hour ozone NAAQS using the 
same four-step interstate transport framework described in the proposal 
of this action. See 84 FR 71855.
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    \7\ EPA recognizes that Florida, Georgia, North Carolina, and 
South Carolina as well as other states may have been influenced by 
EPA's 2018 guidance memoranda (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 Florida, Georgia, North Carolina, and South 
Carolina have not done this, as explained in this section, EPA's 
proposed independent analysis concludes that the states' submissions 
in this instance are approvable.
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    In step 1, EPA identifies locations where the Agency expects there 
to be nonattainment or maintenance receptors for the 2015 8-hour ozone 
NAAQS based on analysis of ozone concentrations at individual 
monitoring sites in the appropriate analytic year. Where EPA's analysis 
shows that a monitoring site does not fall under the definition of a 
nonattainment or maintenance receptor in the analytic year, that site 
is excluded from further analysis under EPA's four-step interstate 
transport framework.\8\ For monitoring sites that are identified as 
nonattainment or maintenance receptors in the appropriate analytic 
year, EPA proceeds to step 2 of the four-step interstate transport 
framework by identifying whether emissions in upwind states contribute 
to those receptors in amounts that exceed a contribution threshold.
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    \8\ While EPA has focused its analysis in this notice on the 
year 2021, the Revised CSAPR Update modeling data in years 2023 and 
2028 confirm that no new linkages to downwind receptors are 
projected for these states in later years. EPA notes this is 
consistent with an overall, long-term downward trend in emissions 
from these states. See Revised CSAPR Update, 86 FR 23054; see also 
Air Quality Modeling Technical Support Document for the final 
Revised Cross-State Air Pollution Rule Update,'' available in the 
docket for this proposed action and at https://www.epa.gov/csapr/revised-cross-state-air-pollution-rule-update. The results of this 
modeling are included in a spreadsheet in the docket for this 
proposed action titled ``Ozone Design Values and Contributions for 
the Revised CSAPR Update.xlsx''.
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    EPA's approach to identifying ozone nonattainment and maintenance 
receptors in this supplemental proposal is consistent with the approach 
described in the December 30, 2019, NPRM, and is the same 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, 531 F.3d 896, 910-911 (2008) (holding that EPA 
must give ``independent significance'' to each prong of CAA section 
110(a)(2)(D)(i)(I)).
    For the purpose of this supplemental 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 compliance year.\9\
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    \9\ See 81 FR 74504 (October 26, 2016). The 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 supplemental proposal, EPA identifies a 
receptor to be a ``maintenance'' receptor for purposes of defining 
interference with maintenance, consistent with the method used in CSAPR 
and upheld by the D.C. Circuit in EME Homer City

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Generation, L.P. v. EPA, 795 F.3d 118, 136 (DC Cir. 2015).\10\ 
Specifically, monitoring sites with a maximum projected design value in 
2021 that exceeds the NAAQS are identified as maintenance receptors in 
2021. EPA's method of defining these receptors takes into account both 
measured data and reasonable projections based on modeling 
analysis.\11\
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    \10\ See 76 FR 48208 (August 8, 2011). The CSAPR Update and 
Revised CSAPR Update also used this approach. See 81 FR 74504 
(October 26, 2016) and 86 FR 23054 (April 30, 2021).
    \11\ Further, as recognized by the court in Wisconsin, 938 F.3d 
at 320, nonattainment areas that do not measure an exceedance of the 
level of the standard in a given year, even if not sufficient to be 
redesignated to attainment based on the three-year design value, may 
qualify for up to two one-year extensions of their attainment dates, 
as provided at CAA section 181(a)(5). Thus, simply providing the 
value that would be needed in 2020 in order for an area to be 
designated to attainment using the three-year average does not 
present a complete picture of the likelihood that an area will be 
``reclassified'' or ``bumped-up.''
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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.
    Florida, Georgia, North Carolina, and South Carolina relied on the 
modeling included in an EPA memorandum dated March 2018 (``March 2018 
memorandum''),\12\ as well as state specific ozone precursor emission 
trends, design values, and regulations, to develop their SIPs as EPA 
had suggested. In the December 30, 2019, NPRM, EPA also relied on the 
modeling results included in the March 2018 memorandum. See 84 FR 
71855-71856, 71859-71861. However, EPA is now supplementing the 
December 30, 2019, NPRM with newly available, updated modeling that was 
developed using a 2016-based modeling platform prepared under the EPA/
Multi-Jurisdictional Organization/state collaborative) project.\13\ The 
results of this updated modeling were released with the NPRM for the 
Revised CSAPR Update on October 30, 2020, and finalized in the final 
Revised CSAPR Update without changes. See 86 FR 23054 (April 30, 2021). 
The updated modeling includes 2016 base year and 2023 projection year 
model simulations that were analyzed to identify receptors and 
determine interstate ozone contributions to these receptors in 2021. 
Specifically, EPA developed an interpolation technique based on 
modeling for 2023 and measured ozone data to determine ozone design 
values for 2021. To estimate average and maximum design values for 
2021, EPA first performed air quality modeling for 2016 and 2023 to 
project measured 2016 design values to 2023. The 2023 design values 
were then coupled with the corresponding 2016 measured design values to 
estimate design values in 2021. The Air Quality Modeling technical 
support document (TSD) developed in connection with the Revised CSAPR 
Update, which is included in the docket for this supplemental proposal, 
describes the modeling and interpolation for estimating design values 
in 2021.\14\
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    \12\ ``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 at https://www.epa.gov/sites/production/files/2018-03/documents/transport_memo_03_27_18_1.pdf and available in the docket for this 
SNPRM.
    \13\ See 86 FR 23054. The results of this modeling are included 
in a spreadsheet in the docket for this proposed action titled Ozone 
Design Values and Contributions Revised CSAPR Update.xlsx. The 
underlying modeling files are available on data drives in the Docket 
office for public review under the docket for the Revised CSAPR 
Update (EPA-HQ-OAR-2020-0272). See also in the docket for this 
proposed action the document titled Air Quality Modeling Data 
Drives_Final RCU.pdf for a file inventory and instructions on how to 
access the modeling files.
    \14\ See ``Air Quality Modeling Technical Support Document for 
the Revised Cross-State Air Pollution Rule Update,'' available in 
the docket for this supplemental proposal and at https://www.epa.gov/csapr/revised-cross-state-air-pollution-rule-update. 
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 8-hour 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 8-hour ozone NAAQS and used in support of this 
supplemental proposed action.
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    EPA's analysis for this supplemental proposal, supported by the 
modeling analysis completed in the Revised CSAPR Update, further 
substantiates EPA's proposed approval in the December 30, 2019, NPRM. 
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 (NOX) and volatile organic 
compounds (VOCs) in each state, individually. The modeled 2023 
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 Florida, Georgia, North Carolina, and South Carolina contribute at 
or above the threshold of one percent of the 2015 8-hour ozone NAAQS 
(0.70 ppb) to any downwind nonattainment or maintenance receptor.\15\ 
Table 1 presents the highest contribution in 2021 from Florida, 
Georgia, North Carolina, and South Carolina to a downwind nonattainment 
or maintenance receptor.
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    \15\ This supplemental proposal relies on the same contribution 
threshold of one percent of the NAAQS proposed in the December 30, 
2019, NPRM. See 85 FR 68964.

  Table 1--Maximum Contribution From Each State to Downwind Nonattainment or Maintenance-Only Receptors in 2021
                                                      \16\
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                                         Maximum                          Downwind receptor
               State                  contribution  ------------------------------------------------------------
                                          (ppb)              County                 State             AQS ID
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Florida............................            0.34  Galveston.............  TX                        481671034
Georgia............................            0.39  Fairfield.............  CT                         90011123
North Carolina.....................            0.69  Fairfield.............  CT                         90011123

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South Carolina.....................            0.25  Fairfield.............  CT                         90011123
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    Based on the analysis of the updated modeling as described above, 
EPA proposes to find that it is reasonable to conclude that Florida, 
Georgia, North Carolina, and South Carolina, individually, will not 
contribute greater than one percent of the 2015 8-hour ozone NAAQS to 
any potential nonattainment or maintenance receptors in 2021.
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    \16\ See data file titled Ozone Design Values and Contributions 
Revised CSAPR Update.xlsx in the docket for this SNPRM.
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    EPA also analyzed ozone precursor emissions trends in Florida, 
Georgia, North Carolina, and South Carolina to support the findings 
from the air quality analysis. In evaluating emissions trends, EPA 
first reviewed the information submitted by Florida, Georgia, North 
Carolina, and South Carolina and then reviewed additional information 
derived from EPA's National Emissions Inventory. EPA focused on state-
wide emissions of NOX and VOCs in Florida, Georgia, North 
Carolina, and South Carolina.\17\ Combined, emissions from mobile 
sources, electric generating units (EGUs), industrial facilities, 
gasoline vapors, and chemical solvents are a large percentage of 
anthropogenic emissions of ozone precursors. This evaluation looks at 
both past emissions trends, as well as projected trends.
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    \17\ See 81 FR 74504, 74513-14.
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    As shown in Table 2, from 2011 to 2023 annual total NOX 
and VOC emissions are projected to decline in the following amounts, 
respectively: By 56 percent and 35 percent in Florida; by 57 percent 
and 27 percent in Georgia; by 53 percent and 18 percent in North 
Carolina; and by 47 percent and 24 percent in South Carolina. The 
projected reductions are a result of the implementation of existing 
control programs that will continue to decrease NOX and VOC 
emissions in Florida, Georgia, North Carolina, and South Carolina, as 
indicated by EPA's most recent 2021 and 2023 projected emissions used 
in the updated 2023 modeling.

               Table 2--Annual Emissions of NOX and VOC From Anthropogenic Sources in Florida, Georgia, North Carolina, and South Carolina
                                                                  [Tons per year]18, 19
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                                                                                                                                    Projected  Projected
                                            2011      2012      2013      2014      2015      2016      2017      2018      2019       2021       2023
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FL NOX..................................   585,605   569,789   553,974   538,158   487,946   411,085   398,245   346,680   312,677    276,138    249,391
FL VOC..................................   637,315   598,992   560,669   522,345   506,276   473,769   454,694   442,470   430,246    419,961    411,321
GA NOX..................................   412,070   385,178   358,287   331,395   314,900   288,421   274,956   255,975   232,538    202,406    177,951
GA VOC..................................   338,259   325,680   313,101   300,523   306,404   290,702   286,047   276,886   267,724    244,549    240,387
NC NOX..................................   365,550   345,513   325,477   305,441   281,599   242,797   229,047   214,574   198,442    181,669    169,258
NC VOC \20\.............................   328,942   321,229   313,516   305,803   294,299   272,534   265,404   262,394   259,385    269,915    267,208
SC NOX..................................   205,952   194,924   183,896   172,868   160,064   157,222   148,786   139,694   128,656    114,238    107,420
SC VOC..................................   183,937   178,844   173,750   168,656   164,822   160,869   158,476   153,877   149,279    143,119    140,107
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\18\ The annual emissions data for the years 2011 through 2019 in Tables 2 and 3 were obtained from EPA's National Emissions Inventory website: https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data. Emissions from miscellaneous sources are not included in the state totals
  presented in Table 2. The emissions for 2021 and 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 proposed action.
\19\ Note that the methods used for calculating emissions for certain tier 1 categories in the NEI changed over time between 2005 and 2019 and certain
  methods used for the NEI differ from the methods used for the 2016 Emissions Platform. These methodological differences may result in some year-to-
  year inconsistencies in the emissions trends and the projected emissions trends.
\20\ EPA notes that for North Carolina, 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 North Carolina, NOx
  emissions are projected to continue to decline. As a result of these NOx emissions reductions, North Carolina is projected to contribute below the one
  percent threshold in 2021 to projected nonattainment and maintenance receptors and is projected to continue to contribute below one percent in 2023
  and 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.

    As presented below in Table 3, onroad and nonroad mobile source 
emissions collectively (i.e., mobile source emissions) comprise a large 
portion of these states' total anthropogenic NOX and VOC 
(i.e., 67 percent of the state total NOX and 36 percent to 
state total VOC for Florida; 61 percent of the state total 
NOX and 30 percent to state total VOC for Georgia; 57 
percent of the state total NOX and 31 percent to state total 
VOC for North Carolina; and 57 percent of the state total 
NOX and 31 percent to state total VOC for South Carolina).

         Table 3--Annual Emissions of NOX and VOC From Onroad and Nonroad Mobile Sources in Florida, Georgia, North Carolina, and South Carolina
                                                                     [Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    Projected  Projected
                                            2011      2012      2013      2014      2015      2016      2017      2018      2019       2021       2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
FL NOX..................................   468,496   451,186   433,876   416,565   373,961   304,708   299,476   271,122   242,768    184,676    165,897

[[Page 37947]]

 
FL VOC..................................   351,631   325,059   298,486   271,914   255,262   222,173   202,502   190,278   178,054    155,760    145,133
GA NOX..................................   297,838   276,697   255,555   234,413   225,072   205,747   199,437   180,291   161,144    122,097    108,363
GA VOC..................................   171,049   157,722   144,394   131,067   134,296   115,940   108,633    99,471    90,309     72,285     67,187
NC NOX..................................   272,542   253,619   234,697   215,775   197,948   165,162   157,428   145,004   132,580    107,114     95,139
NC VOC..................................   176,370   162,257   148,144   134,032   124,615   104,938    99,959    96,950    93,940     88,486     81,551
SC NOX..................................   144,953   137,401   129,850   122,298   111,751   111,167   104,989    95,687    86,385     68,365     61,243
SC VOC..................................    86,955    82,634    78,312    73,991    70,288    66,464    64,202    59,603    55,005     46,372     42,789
--------------------------------------------------------------------------------------------------------------------------------------------------------
\21\ Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards (79 FR 23414, April 28, 2014); Control of Hazardous
  Air Pollutants From Mobile Sources (72 FR 8428, February 26, 2007); Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle
  Standards and Highway Diesel Fuel Sulfur Control Requirements (66 FR 5002, January 18, 2001); Control of Emissions of Air Pollution From Nonroad
  Diesel Engines and Fuel (69 FR 38957, June 29, 2004); Control of Emissions of Air Pollution From Locomotive Engines and Marine Compression-Ignition
  Engines Less Than 30 Liters per Cylinder (73 FR 25098, May 6, 2008); Control of Emissions From Nonroad Spark-Ignition Engines and Equipment (73 FR
  59034, October 8, 2008); Control of Emissions From New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (75 FR 22895, April 30,
  2010); Control of Air Pollution From Aircraft and Aircraft Engines, Emission Standards and Test Procedures (77 FR 36342, June 18, 2012).

    The large decrease in NOX emissions between 2016 
emissions and projected 2023 emissions in Florida, Georgia, North 
Carolina, and South Carolina are primarily driven by reductions in 
emissions from onroad and nonroad mobile sources. As shown by the 
mobile source emissions trends in Table 3, EPA projects that both VOC 
and NOX 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.\21\
    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 2021would not continue to show a decline in 
emissions.\22\
---------------------------------------------------------------------------

    \22\ EPA's normal practice is to only include changes in 
emissions from final regulatory actions in its modeling because, 
until such rules are finalized, any potential changes in 
NOX or VOC emissions are speculative.
---------------------------------------------------------------------------

    This downward trend in emissions in Florida, Georgia, North 
Carolina, and South Carolina adds support to the air quality analysis 
presented above and indicates that the contributions from emissions 
from sources in Florida, Georgia, North Carolina, and South Carolina to 
ozone receptors in downwind states will continue to decline and remain 
below one percent of the 2015 8-hour ozone NAAQS. Thus, based on this 
supplemental analysis, EPA continues to propose to conclude that the 
air quality and emissions analyses indicate that emissions from 
Florida, Georgia, North Carolina, and South Carolina will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2015 8-hour ozone NAAQS in any other state.

III. Supplemental Proposed Actions

    In its December 30, 2019, NPRM, EPA originally proposed to find 
that emissions from sources in Florida, Georgia, North Carolina, and 
South Carolina will not significantly contribute to nonattainment or 
interfere with maintenance of the 2015 8-hour ozone NAAQS in any other 
state based on information for the analytic year 2023, consistent with 
the 2024 Moderate area attainment date. Thus, EPA proposed to approve 
the interstate transport portions of the infrastructure SIP submissions 
from Florida, Georgia, North Carolina, and South Carolina as meeting 
CAA section 110(a)(2)(D)(i)(I) requirements for the 2015 8-hour ozone 
NAAQS.\23\ See 84 FR 71854.
---------------------------------------------------------------------------

    \23\ As mentioned in Section I above, EPA is deferring action on 
Alabama's and Tennessee's Good Neighbor infrastructure SIP 
submittals at this time.
---------------------------------------------------------------------------

    The analysis presented in this notice provides a new primary basis 
for approval to supplement EPA's proposed finding in the December 30, 
2019, NPRM. EPA continues to propose to find that emissions from 
sources in Florida, Georgia, North Carolina, and South Carolina will 
not significantly contribute to nonattainment or interfere with 
maintenance of the 2015 8-hour ozone NAAQS in any other state. Thus, 
EPA continues to propose to approve the interstate transport portions 
of the infrastructure SIP submissions from Florida, Georgia, North 
Carolina, and South Carolina as meeting CAA section 110(a)(2)(D)(i)(I) 
requirements for the 2015 8-hour ozone NAAQS.

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations. See 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. These actions merely 
propose to approve state law as meeting Federal requirements and do not 
impose additional requirements beyond those imposed by state law. For 
that reason, these proposed actions:
     Are not significant regulatory actions 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);
     Do not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are 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.);
     Do 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);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are not subject to requirements of Section 12(d) of the 
National

[[Page 37948]]

Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) 
because application of those requirements would be inconsistent with 
the CAA; and
     Do 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).
    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 as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000), nor will it impose substantial direct 
costs on tribal governments or preempt tribal law.
    For South Carolina, because this proposed action merely proposes to 
approve state law as meeting Federal requirements and does not impose 
additional requirements beyond those imposed by state law, this action 
for the state of South Carolina does not have Tribal implications as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000). 
Therefore, this proposed action will not impose substantial direct 
costs on Tribal governments or preempt Tribal law. The Catawba Indian 
Nation Reservation is located within the boundary of York County, South 
Carolina. Pursuant to the Catawba Indian Claims Settlement Act, S.C. 
Code Ann. 27-16-120 (Settlement Act), ``all state and local 
environmental laws and regulations apply to the Catawba Indian Nation 
and Reservation and are fully enforceable by all relevant state and 
local agencies and authorities.'' The Catawba Indian Nation also 
retains authority to impose regulations applying higher environmental 
standards to the Reservation than those imposed by state law or local 
governing bodies, in accordance with the Settlement Act.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Reporting and recordkeeping 
requirements, Volatile organic compounds.

    Authority: 42 U.S.C. 7401 et seq

    Dated: July 12, 2021.
John Blevins,
Acting Regional Administrator, Region 4.
[FR Doc. 2021-15097 Filed 7-16-21; 8:45 am]
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