Document ID: EPA-R04-OAR-2020-0677-0004
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: South Carolina; Catawba Indian Nation Portion of the Charlotte-Gastonia-Rock Hill Area Limited Maintenance Plan for the 1997 8-Hour Ozone National Ambient Air Quality Standards
Posted Date: 2021-11-26T05:00Z

[Federal Register Volume 86, Number 225 (Friday, November 26, 2021)]
[Proposed Rules]
[Pages 67402-67408]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-25527]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2020-0677; FRL-9276-01-R4]

Air Plan Approval; South Carolina; Catawba Indian Nation Portion 
of the Charlotte-Gastonia-Rock Hill Area Limited Maintenance Plan for 
the 1997 8-Hour Ozone NAAQS

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a state implementation plan (SIP) revision submitted by the 
State of South Carolina, through the Department of Health and 
Environmental Control (DHEC), via a letter dated July 7, 2020. The SIP 
revision includes the 1997 8-hour ozone national ambient air quality 
standards (NAAQS) Limited Maintenance Plan (LMP) for the Catawba Indian 
Nation portion (hereinafter referred to as the Catawba Area) of the 
Charlotte-Gastonia-Rock Hill NC-SC 1997 8-hour ozone maintenance area 
(hereinafter referred to as the Charlotte NC-SC 1997 8-hour NAAQS 
Area). The Charlotte NC-SC 1997 8-hour NAAQS Area is comprised of 
Cabarrus, Gaston, Lincoln, Mecklenburg, Rowan, Union and a portion of 
Iredell County (i.e., Davidson and Coddle Creek Townships) in North 
Carolina and a portion of York County, South Carolina which includes 
the Catawba Area. EPA is proposing to approve the Catawba Area LMP 
because it provides for the maintenance of the 1997 8-hour ozone NAAQS 
within the Catawba Area through the end of the second 10-year portion 
of the maintenance period. The effect of this action would be to make 
certain commitments related to maintenance of the 1997 8-hour ozone 
NAAQS in the Catawba Area federally enforceable as part of the South 
Carolina SIP.

DATES: Written comments must be received at the address below on or 
before December 27, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2020-0677 at https://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 making effective comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Jane Spann, 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. The telephone number is (404) 
562-9029. Ms. Spann can also be reached via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Summary of EPA's Proposed Action
II. Background
III. South Carolina's SIP Submittal
IV. EPA's Evaluation of South Carolina's SIP Submittal
    A. Area Characteristics
    B. Attainment Emissions Inventory
    C. Maintenance Demonstration
    D. Monitoring Network and Verification of Continued Attainment

[[Page 67403]]

    E. Contingency Plan
    F. Conclusion
V. Transportation Conformity and General Conformity
VI. Proposed Action
VII. Statutory and Executive Order Reviews

I. Summary of EPA's Proposed Action

    In accordance with the Clean Air Act (CAA or Act), EPA is proposing 
to approve the Catawba Area LMP for the 1997 8-hour ozone NAAQS, 
adopted by DHEC on July 7, 2020, and submitted by DHEC as a revision to 
the South Carolina SIP under a letter dated July 7, 2020.\1\ In 2004, 
the Charlotte NC-SC 1997 8-hour NAAQS Area, which includes the Catawba 
Area, was designated as nonattainment for the 1997 8-hour ozone NAAQS. 
Subsequently, in 2012, after a clean data determination \2\ and EPA's 
approval of a maintenance plan, the South Carolina portion of the 
Charlotte NC-SC 1997 8-hour NAAQS Area, which includes the Catawba 
Area, was redesignated to attainment for the 1997 8-hour ozone NAAQS.
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    \1\ EPA received the SIP submission on July 10, 2020.
    \2\ See 77 FR 13493 (March 7, 2012).
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    The Catawba Area LMP is designed to maintain the 1997 8-hour ozone 
NAAQS within the Catawba Area through the end of the second 10-year 
portion of the maintenance period beyond redesignation. EPA is 
proposing to approve the plan because it meets all applicable 
requirements under CAA sections 110 and 175A.
    As a general matter, the Catawba Area LMP relies on the same 
control measures and relevant contingency provisions to maintain the 
1997 8-hour ozone NAAQS during the second 10-year portion of the 
maintenance period as the maintenance plan submitted by DHEC for the 
first 10-year period.

II. Background

    Ground-level ozone is formed when oxides of nitrogen 
(NOX) and volatile organic compounds (VOC) react in the 
presence of sunlight. These two pollutants, referred to as ozone 
precursors, are emitted by many types of pollution sources, including 
on- and off-road motor vehicles and engines, power plants and 
industrial facilities, and smaller area sources such as lawn and garden 
equipment and paints. Scientific evidence indicates that adverse public 
health effects occur following exposure to ozone, particularly in 
children and in adults with lung disease. Breathing air containing 
ozone can reduce lung function and inflame airways, which can increase 
respiratory symptoms and aggravate asthma and other lung diseases.
    Ozone exposure also has been associated with increased 
susceptibility to respiratory infections, medication use, doctor 
visits, and emergency department visits and hospital admissions for 
individuals with lung disease. Children are at increased risk from 
exposure to ozone because their lungs are still developing and they are 
more likely to be active outdoors, which increases their exposure.\3\
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    \3\ See ``Fact Sheet, Proposal to Revise the National Ambient 
Air Quality Standards for Ozone,'' January 6, 2010, and 75 FR 2938 
(January 19, 2010).
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    In 1979, under section 109 of the CAA, EPA established primary and 
secondary NAAQS for ozone at 0.12 parts per million (ppm), averaged 
over a 1-hour period. See 44 FR 8202 (February 8, 1979). On July 18, 
1997, EPA revised the primary and secondary NAAQS for ozone to set the 
acceptable level of ozone in the ambient air at 0.08 ppm, averaged over 
an 8-hour period. See 62 FR 38856 (July 18, 1997).\4\ EPA set the 8-
hour ozone NAAQS based on scientific evidence demonstrating that ozone 
causes adverse health effects at lower concentrations and over longer 
periods of time than was understood when the pre-existing 1-hour ozone 
NAAQS was set. EPA determined that the 8-hour ozone NAAQS would be more 
protective of human health, especially children and adults who are 
active outdoors, and individuals with a pre-existing respiratory 
disease, such as asthma.
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    \4\ In March 2008, EPA completed another review of the primary 
and secondary ozone NAAQS and tightened them further by lowering the 
level for both to 0.075 ppm. See 73 FR 16436 (March 27, 2008). 
Additionally, in October 2015, EPA completed a review of the primary 
and secondary ozone NAAQS and tightened them by lowering the level 
for both to 0.070 ppm. See 80 FR 65292 (October 26, 2015).
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    Following promulgation of a new or revised NAAQS, EPA is required 
by the CAA to designate areas throughout the nation as attaining or not 
attaining the NAAQS. On April 15, 2004, EPA designated the Charlotte 
NC-SC 1997 8-hour NAAQS Area which consists of Cabarrus, Gaston, 
Lincoln, Mecklenburg, Rowan, Union and a portion of Iredell County 
(i.e., Davidson and Coddle Creek Townships) in North Carolina and a 
portion of York County, South Carolina, including the Catawba Area, as 
nonattainment for the 1997 8-hour ozone NAAQS. The designation became 
effective on June 15, 2004. See 69 FR 23858 (April 30, 2004).
    Similarly, on May 21, 2012, EPA designated areas as unclassifiable/
attainment or nonattainment for the 2008 8-hour ozone NAAQS.\5\ The 
Catawba Area was designated unclassifiable/attainment although the 
surrounding Charlotte--Gastonia-Rock Hill NC-SC Area \6\ (hereinafter 
referred to as the Charlotte NC-SC 2008 NAAQS Area) was designated as 
nonattainment for the 2008 8-hour ozone NAAQS and classified as a 
marginal nonattainment area. This designation became effective on July 
20, 2012.\7\ In summary, the Catawba Area was included in the Charlotte 
NC-SC 1997 8-hour NAAQS boundary designation in 2004 but was not 
included in the Charlotte NC-SC 2008 NAAQS boundary designation in 
2012.
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    \5\ In 2011, EPA established the ``Guidance to Regions for 
Working with Tribes during the National Ambient Air Quality 
Standards (NAAQS) Designations Process'' memorandum providing 
guidance to EPA Regional Offices for working with federally-
recognized Indian tribes regarding the CAA section 107(d) NAAQS 
boundary designations process for Indian country. See https://www.epa.gov/sites/production/files/2017-02/documents/12-20-11_guidance_to_regions_for_working_with_tribes_naaqs_designations.pdf
. This guidance was then applied to the 2012 designation process for 
the 2008 ozone NAAQS.
    \6\ The Charlotte--Gastonia-Rock Hill NC-SC Area for the 2008 8-
hour ozone NAAQS consists of portions of Cabarrus, Gaston, Iredell, 
Lincoln, Rowan and Union Counties and the entirety of Mecklenburg 
County in North Carolina, and a portion of York County, South 
Carolina which excludes the Catawba Area.
    \7\ See 77 FR 30088.
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    In addition, on November 16, 2017, areas were designated for the 
2015 8-hour ozone NAAQS. The entire states of North Carolina and South 
Carolina--including the Catawba Indian Nation--were designated 
attainment/unclassifiable for the 2015 8-hour ozone NAAQS, with an 
effective date on January 16, 2018.\8\
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    \8\ See 82 FR 54232.
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    A state may submit a request to redesignate a nonattainment area 
that is attaining a NAAQS to attainment, and, if the area has met other 
required criteria described in section 107(d)(3)(E) of the CAA, EPA may 
approve the redesignation request.\9\ One of the criteria for 
redesignation is to have an approved maintenance plan under CAA section 
175A. The maintenance plan must demonstrate that the area will continue 
to maintain the NAAQS for the period extending ten years after 
redesignation, and it must contain such additional measures as 
necessary to

[[Page 67404]]

ensure maintenance and such contingency provisions as necessary to 
assure that violations of the NAAQS will be promptly corrected. Eight 
years after the effective date of redesignation, the state must also 
submit a second maintenance plan to ensure ongoing maintenance of the 
NAAQS for an additional ten years pursuant to CAA section 175A(b) 
(i.e., ensuring maintenance for 20 years after redesignation).
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    \9\ Section 107(d)(3)(E) of the CAA sets out the requirements 
for redesignating a nonattainment area to attainment. They include 
attainment of the NAAQS, full approval of the applicable SIP 
pursuant to CAA section 110(k), determination that improvement in 
air quality is a result of permanent and enforceable reductions in 
emissions, demonstration that the state has met all applicable 
section 110 and part D requirements, and a fully approved 
maintenance plan under CAA section 175A.
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    EPA has published long-standing guidance for states on developing 
maintenance plans.\10\ The Calcagni memo provides that states may 
generally demonstrate maintenance by either performing air quality 
modeling to show that the future mix of sources and emission rates will 
not cause a violation of the NAAQS or by showing that projected future 
emissions of a pollutant and its precursors will not exceed the level 
of emissions during a year when the area was attaining the NAAQS (i.e., 
attainment year inventory). See Calcagni memo at page 9. EPA clarified 
in three subsequent guidance memos that certain areas could meet the 
CAA section 175A requirement to provide for maintenance by showing that 
the area was unlikely to violate the NAAQS in the future, using 
information such as the area's design value \11\ being significantly 
below the standard and the area having a historically stable design 
value.\12\ EPA refers to a maintenance plan containing this streamlined 
demonstration as an LMP.
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    \10\ John Calcagni, Director, Air Quality Management Division, 
EPA Office of Air Quality Planning and Standards (OAQPS), 
``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' September 4, 1992 (Calcagni memo).
    \11\ The ozone design value for a monitoring site is the 3-year 
average of the annual fourth-highest daily maximum 8-hour average 
ozone concentrations. The design value for an ozone area is the 
highest design value of any monitoring site in the area.
    \12\ See ``Limited Maintenance Plan Option for Nonclassifiable 
Ozone Nonattainment Areas'' from Sally L. Shaver, OAQPS, dated 
November 16, 1994; ``Limited Maintenance Plan Option for 
Nonclassifiable CO Nonattainment Areas'' from Joseph Paisie, OAQPS, 
dated October 6, 1995; and ``Limited Maintenance Plan Option for 
Moderate PM10 Nonattainment Areas'' from Lydia Wegman, 
OAQPS, dated August 9, 2001. Copies of these guidance memoranda can 
be found in the docket for this proposed rulemaking.
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    EPA has interpreted CAA section 175A as permitting the LMP option 
because section 175A of the Act does not define how areas may 
demonstrate maintenance, and in EPA's experience implementing the 
various NAAQS, areas that qualify for an LMP and have approved LMPs 
have rarely, if ever, experienced subsequent violations of the NAAQS. 
As noted in the LMP guidance memoranda, states seeking an LMP must 
still submit the other maintenance plan elements outlined in the 
Calcagni memo, including: An attainment emissions inventory, provisions 
for the continued operation of the ambient air quality monitoring 
network, verification of continued attainment, and a contingency plan 
in the event of a future violation of the NAAQS. Moreover, a state 
seeking an LMP must still submit its section 175A maintenance plan as a 
revision to its SIP, with all attendant notice and comment procedures. 
While the LMP guidance memoranda were originally written with respect 
to certain NAAQS,\13\ EPA has extended the LMP interpretation of 
section 175A to other NAAQS and pollutants not specifically covered by 
the previous guidance memos.\14\
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    \13\ The prior memos addressed: Unclassifiable areas under the 
1-hour ozone NAAQS, nonattainment areas for the PM10 
(particulate matter with an aerodynamic diameter less than 10 
microns) NAAQS, and nonattainment areas for the carbon monoxide (CO) 
NAAQS.
    \14\ See, e.g., 79 FR 41900 (July 18, 2014) (Approval of the 
second ten-year LMP for the Grant County 1971 SO2 
maintenance area).
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    In this case, EPA is proposing to approve the Catawba Area LMP 
because the State has made a showing, consistent with EPA's prior LMP 
guidance, that the Charlotte NC-SC 1997 8-hour NAAQS Area's ozone 
concentrations are well below the 1997 8-hour ozone NAAQS and have been 
historically stable, and that it has met the other maintenance plan 
requirements. DHEC submitted this LMP for the Catawba Area to fulfill 
the second maintenance plan requirement in the Act. EPA's evaluation of 
the Catawba Area LMP is presented below.
    In June of 2011, DHEC submitted to EPA a request to redesignate the 
York County, South Carolina portion of the Charlotte NC-SC 1997 8-hour 
NAAQS Area (which includes the Catawba Area), to attainment for the 
1997 8-hour ozone NAAQS. This submittal included a plan to provide for 
maintenance of the 1997 8-hour ozone NAAQS in the Charlotte NC-SC 1997 
8-hour NAAQS Area through 2022 as a revision to the South Carolina SIP. 
EPA approved South Carolina's Charlotte NC-SC 1997 8-hour NAAQS Area 
Maintenance Plan and the State's request to redesignate the South 
Carolina portion of the Charlotte NC-SC 1997 NAAQS Area to attainment 
for the 1997 8-hour ozone NAAQS effective December 26, 2012.\15\
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    \15\ See 77 FR 75862 (December 26, 2012).
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    Under CAA section 175A(b), states must submit a revision to the 
first maintenance plan eight years after redesignation to provide for 
maintenance of the NAAQS for ten additional years following the end of 
the first 10-year period. EPA's final implementation rule for the 2008 
8-hour ozone NAAQS revoked the 1997 8-hour ozone NAAQS and stated that 
one consequence of revocation was that areas that had been redesignated 
to attainment (i.e., maintenance areas) for the 1997 NAAQS no longer 
needed to submit second 10-year maintenance plans under CAA section 
175A(b).\16\ On December 11, 2015, EPA redesignated the South Carolina 
portion of the Charlotte NC-SC 2008 NAAQS Area (which does not include 
the Catawba Area) as attainment for the 2008 8-hour ozone NAAQS, and 
the designation became effective on January 11, 2016. See 80 FR 76865.
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    \16\ See 80 FR 12264, 12315 (March 6, 2015).
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    In South Coast Air Quality Management District v. EPA, the United 
States Court of Appeals for the District of Columbia Circuit (D.C. 
Circuit) vacated EPA's interpretation that, because of the revocation 
of the 1997 8-hour ozone NAAQS, second maintenance plans were not 
required for ``orphan maintenance areas,'' i.e., areas that had been 
redesignated to attainment for the 1997 8-hour ozone NAAQS (maintenance 
areas) and were designated attainment for the 2008 ozone NAAQS. South 
Coast, 882 F.3d 1138 (D.C. Cir. 2018). Thus, states with these ``orphan 
maintenance areas'' under the 1997 8-hour ozone NAAQS must submit 
maintenance plans for the second maintenance period. Accordingly, 
through a letter dated July 7, 2020, South Carolina submitted a second 
maintenance plan covering the Catawba Area that provides for attainment 
of the 1997 8-hour ozone NAAQS through 2032.\17\
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    \17\ In an email dated October 18, 2021, DHEC clarified that the 
end of the maintenance plan submitted on June 7, 2020, is 2032.
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    In recognition of the continuing record of air quality monitoring 
data showing ambient 8-hour ozone concentrations in the Charlotte NC-SC 
1997 8-hour NAAQS Area well below the 1997 8-hour ozone NAAQS, DHEC 
chose the LMP option for the development of its second 1997 8-hour 
ozone NAAQS maintenance plan covering the Catawba Area. On July 7, 
2020, DHEC adopted this second 10-year 1997 8-hour ozone maintenance 
plan, and subsequently submitted the Catawba Area LMP to EPA as a 
revision to the South Carolina SIP.

III. South Carolina's SIP Submittal

    As mentioned above, on July 7, 2020, DHEC submitted the Catawba 
Area LMP

[[Page 67405]]

to EPA as a revision to the South Carolina SIP. The submittal includes 
the LMP, air quality data, a summary of the previous emissions 
inventory and a conclusion regarding future emission levels, and 
attachments, as well as certification of adoption of the plan by DHEC. 
Attachments to the plan include documentation of notice, opportunity 
for hearing and public participation prior to adoption of the plan by 
DHEC on July 7, 2020, and state legal authority. The LMP notes that 
South Carolina's LMP submittal for the remainder of the 20-year 
maintenance period for the Catawba Area is in response to the D.C. 
Circuit's decision overturning aspects of EPA's Implementation Plan 
rule. The Catawba Area LMP does not include any additional emissions 
reduction measures but relies on the same emissions reduction strategy 
as the first 10-year Maintenance Plan that provides for the maintenance 
of the 1997 8-hour ozone NAAQS through 2022. Prevention of significant 
deterioration (PSD) requirements and control measures contained in the 
SIP will continue to apply, and federal measures (e.g., Federal motor 
vehicle control program) will continue to be implemented in the Catawba 
Area.

IV. EPA's Evaluation of South Carolina's SIP Submittal

    EPA has reviewed the Catawba Area LMP which is designed to maintain 
the 1997 8-hour ozone NAAQS within the Catawba Area through the end of 
the 20-year period beyond redesignation, as required under CAA section 
175A(b).
    As discussed below, the Catawba Area's impact on the larger 
Charlotte NC-SC 1997 8-hour NAAQS Area is very limited due to its size, 
population, and emissions profile. In addition, the monitoring values 
in the Charlotte NC-SC 1997 8-hour NAAQS Area, including the Catawba 
Area, are well below the NAAQS. As a result, EPA is proposing to 
approve the Catawba Area LMP as meeting the 175A requirements. The 
following is a more detailed summary of EPA's interpretation of the 
section 175A requirements \18\ and EPA's evaluation of how each 
requirement is met.
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    \18\ See Calcagni memo.
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A. Area Characteristics

    The Catawba Indian Nation tribal lands are comprised of a total of 
approximately 1,000 acres, in two sections along the Catawba River in 
the eastern portion of York County, South Carolina.\19\ The total 
Catawba Indian Nation population is 3,370 (2010 Census), however, based 
on recent census estimates, the population of the Reservation is only 
1,288 with 517 housing units within the Reservation.\20\ According to 
the 2019 census estimates, the total York County population is 280,979, 
and the Reservation is home to 0.46 percent of York County's 
population.\21\ The Reservation is a residential area which contains no 
industry, no limited access highways or transportation facilities, and 
only a few miles of secondary roads. There is a boat ramp but there are 
no airports, helipads, railroad tracks, or associated facilities. The 
Reservation has no shopping centers or industrial sites. The only 
community facilities, which are of modest size, are the Tribal offices 
and the Senior Center.
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    \19\ As described in the July 7, 2020 Submittal, the Catawba 
Area consists of two tracts of land along the Catawba River with a 
total land base of approximately 1,000 acres, which comprises only 
0.002 percent of the land area of York County. See Technical Support 
Document for Charlotte-Rock Hill, NC-SC Area Designations for the 
2008 Ozone National Ambient Air Quality Standards, available at 
https://www.regulations.gov/search?filter=EPA-HQ-OAR-2008-0476-0642.
    \20\ See Catawba Reservation, U.S. Census Bureau, 2015-2019 
American Community Survey 5-Year Estimates, available at https://www.census.gov/tribal/index.html?aianihh=0525.
    \21\ Id., see also https://www.census.gov/quickfacts/yorkcountysouthcarolina (showing York County, South Carolina with a 
2019 estimated population of 280,979 and a 2020 census population of 
282,090).
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B. Attainment Emissions Inventory

    For maintenance plans, a state should develop a comprehensive, 
accurate inventory of actual emissions for an attainment year to 
identify the level of emissions which is sufficient to maintain the 
NAAQS. A state should develop this inventory consistent with EPA's most 
recent guidance on emissions inventory development. For ozone, the 
inventory should be based on typical summer day emissions of VOC and 
NOX, as these pollutants are precursors to ozone formation.
    The 175A maintenance plan approved by EPA included an attainment 
inventory for the South Carolina portion of the Charlotte NC-SC 1997 8-
hour NAAQS Area that reflects typical summer day VOC and NOX 
emissions in 2010.\22\ As previously mentioned, the Catawba Area is 
included in the South Carolina portion of the Charlotte NC-SC 1997 8-
hour NAAQS Area.
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    \22\ See 77 FR 68087 (November 15, 2012) and 77 FR 75862 
(December 26, 2012).
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    Because the Catawba Nation Reservation is a small residential area, 
both geographically and in population, with no industrial sites, no 
limited access highways, no transportation facilities, and no point 
sources of ozone precursors, there are no estimates of VOC and 
NOX emissions from the Catawba Area. Given the unique nature 
of the Catawba Area and the air quality analysis in section IV.C, 
below, EPA does not believe that a detailed accounting of attainment 
level emissions is necessary in this instance.

C. Maintenance Demonstration

    The maintenance demonstration requirement is considered to be 
satisfied in a LMP if the state can provide sufficient weight of 
evidence indicating that air quality in the area is well below the 
level of the NAAQS, that past air quality trends have been shown to be 
stable, and that the probability of the area experiencing a violation 
over the second 10-year maintenance period is low.\23\ These criteria 
are evaluated below with regard to the Catawba Area.
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    \23\ See Calcagni memo.
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1. Evaluation of Ozone Air Quality Levels
    To attain the 1997 8-hour ozone NAAQS, the three-year average of 
the fourth-highest daily maximum 8-hour average ozone concentrations 
(design value) at each monitor within an area must not exceed 0.08 ppm. 
Based on the rounding convention described in 40 CFR part 50, Appendix 
I, the NAAQS is attained if the design value is 0.084 ppm or below. At 
the time of submission, EPA evaluated quality assured and certified 
2016-2018 monitoring data and determined that the highest design value 
for the Charlotte NC-SC 1997 8-hour NAAQS Area was 0.070 ppm, or 83 
percent of the level of the 1997 8-hour ozone NAAQS (measured at the 
University Meadows monitor in Mecklenburg, North Carolina (AQS ID: 37-
119-0046)), and the design value for the Catawba Area monitor (AQS ID: 
45-091-8801) was 0.064 ppm, or 76 percent of the level of the 1997 8-
hour ozone NAAQS. Based on quality assured and certified monitoring 
data for 2018-2020, the current, highest design value for the Charlotte 
NC-SC 1997 8-hour NAAQS Area is 0.067 ppm, or 80 percent of the level 
of the 1997 8-hour ozone NAAQS (measured at the University Meadows 
monitor and the Garinger High School Monitor in Mecklenburg, NC (AQS 
ID: 37-119-0041)), and the current design value for the Catawba Area 
monitor is 0.062 ppm, or 74 percent of the level of the 1997 8-hour 
ozone NAAQS. Consistent with prior guidance, EPA believes that if the 
most recent air quality design value for the area is at a level that is 
well below the NAAQS (e.g., below 85 percent of the NAAQS, or in this 
case below 0.071 ppm), then

[[Page 67406]]

EPA considers the state to have met the section 175A requirement for a 
demonstration that the area will maintain the NAAQS for the requisite 
period. Such a demonstration assumes continued applicability of 
prevention of significant deterioration requirements and any control 
measures already in the SIP and that Federal measures will remain in 
place through the end of the second 10-year maintenance period, absent 
a showing consistent with section 110(l) that such measures are not 
necessary to assure maintenance.
    Table 3 presents the design values for each monitor in the 
Charlotte NC-SC 1997 8-hour NAAQS Area over the 2008-2020 period. As 
shown in Table 3, all sites have been below the level of the 1997 8-
hour ozone NAAQS since the area was redesignated to attainment, and the 
most current design value is below the level of 85 percent of the 
NAAQS, consistent with prior LMP guidance.

   Table 3--1997 8-Hour Ozone NAAQS Design Values (DV) (ppm) at Monitoring Sites in the Charlotte NC-SC 1997 NAAQS Area for the 2008-2020 Time Period
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                                                                   2008-   2009-   2010-   2011-   2012-   2013-   2014-   2015-   2016-   2017-   2018-
            Location              County (state)/    AQS site ID   2010    2011    2012    2013    2014    2015    2016    2017    2018    2019    2020
                                    tribal land                     DV      DV      DV      DV      DV      DV      DV      DV      DV      DV      DV
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Catawba Area Monitor...........  Catawba Indian      45-091-8801     (*)     (*)     (*)     (*)     (*)     (*)     (*)     (*)   0.064   0.064   0.062
                                  Nation.
Arrowood.......................  Mecklenburg (NC).   37-119-1005   0.073   0.076   0.077   0.072   0.066    (**)    (**)    (**)    (**)    (**)    (**)
Crouse.........................  Lincoln (NC).....   37-109-0004   0.072   0.071   0.075   0.072   0.068   0.065   0.067   0.067   0.065   0.064   0.060
Enochville.....................  Rowan (NC).......   37-159-0022   0.077   0.076   0.077   0.072   (***)   (***)   (***)   (***)   (***)   (***)   (***)
Garinger High School...........  Mecklenburg (NC).   37-119-0041   0.078   0.079   0.083   0.078   0.070   0.068   0.069   0.069   0.068   0.070   0.067
County Line....................  Mecklenburg (NC).   37-117-1009   0.082   0.078   0.083   0.078   0.073   0.067  (****)  (****)  (****)  (****)  (****)
University Meadows.............  Mecklenburg (NC).   37-119-0046  (****)  (****)  (****)  (****)  (****)  (****)   0.070   0.070   0.070   0.069   0.067
Rockwell.......................  Rowan (NC).......   37-159-0021   0.077   0.075   0.078   0.073   0.068   0.064   0.065   0.064   0.062   0.062   0.061
Monroe School..................  Union (NC).......   37-179-0003   0.072   0.070   0.073   0.070   0.068   0.065   0.068   0.067   0.068   0.068   0.063
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* The ozone monitor in the Catawba Indian Nation (AQS Site ID 45-091-8801) began operation for the 2016 ozone season.
** The Arrowood monitor in Mecklenburg County (AQS Site ID 37-119-1005) was shut down in 2014.
*** The Enochville School monitor in Rowan County (AQS Site ID 37-159-0022) was shut down in 2013.
**** In 2014, the ozone monitor at Mecklenburg County Line (AQS Site ID 37-117-1009) changed locations to University Meadows (AQS ID 37-119-0046).

    Therefore, the Catawba Area is eligible for the LMP option, and EPA 
proposes to find that the long record of monitored ozone concentrations 
that attain the NAAQS, together with the continuation of existing VOC 
and NOX emissions control programs in the Charlotte NC-SC 
1997 8-hour NAAQS Area, adequately provide for the maintenance of the 
1997 8-hour ozone NAAQS in the Catawba Area through the second 10-year 
maintenance period and beyond.
    Additional supporting information that the Area is expected to 
continue to maintain the NAAQS can be found in projections of future 
year design values that EPA recently completed for the Revised Cross-
State Air Pollution Rule Update for the 2008 Ozone NAAQS that EPA 
finalized on April 30, 2021.\24\ Those projections, made for the year 
2023, show that the maximum design value for the Charlotte NC-SC 1997 
Ozone Area is expected to be 60.3 ppb and the maximum design value of 
the Catawba Area monitor is expected to be 53.3 ppb. EPA is not 
proposing to make any finding in this action regarding interstate 
transport obligations for any state.
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    \24\ On April 30, 2021, EPA published the final Revised Cross-
State Air Pollution Rule (CSAPR) Update (RCU) using updated modeling 
that focused on analytic years 2023 and 2028 and an 
``interpolation'' analysis of these modeling results to generate air 
quality and contribution values for the 2021 analytic year. See 86 
FR 23054. https://www.govinfo.gov/content/pkg/FR-2021-04-30/pdf/2021-05705.pdf. This modeling included projected ozone design values 
for ozone monitors in the Catawba Area and Charlotte SC-NC 
maintenance areas.
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2. Stability of Ozone Levels
    As discussed above, the Charlotte NC-SC 1997 8-hour NAAQS Area has 
maintained air quality below the 1997 8-hour ozone NAAQS over the past 
eleven design values. Additionally, the design value data shown in 
Table 3 illustrates that ozone levels have been relatively stable over 
this timeframe, with a modest downward trend. For example, the data in 
Table 3 indicates that the largest, year over year change in design 
value at any one monitor during these eleven years was 0.008 ppm which 
occurred between the 2013 design value and the 2014 design value, 
representing approximately a 10 percent decrease at monitor 37-119-0041 
(Garinger High School). Furthermore, there is an overall downward trend 
in design values for the Charlotte NC-SC 1997 8-hour NAAQS Area. See, 
e.g., Table 1, above, data for monitor 37-159-0021 (Rockwell)0.016 ppm, 
or 20.8 percent). This downward trend in ozone levels, coupled with the 
relatively small, year-over-year variation in ozone design values, 
makes it reasonable to conclude that the Catawba Area will not exceed 
the 1997 8-hour ozone NAAQS during the second 10-year maintenance 
period.

D. Monitoring Network and Verification of Continued Attainment

    EPA periodically reviews the ozone monitoring networks operated and 
maintained by the states in accordance with 40 CFR part 58. The network 
plans, which are submitted annually to EPA, are consistent with the 
ambient air quality monitoring network assessment. It is important to 
note that the Charlotte NC-SC 1997 8-hour NAAQS Area was designated 
nonattainment due to violating monitors in the North Carolina portion 
of that area and that South Carolina has never operated any part 58 
monitors in the Charlotte NC-SC 1997 8-hour NAAQS Area.\25\ \26\ North 
Carolina operates a network plan with multiple monitors within the 
boundary of the Charlotte NC-SC 1997 8-hour NAAQS Area. The annual 
network plan developed by North Carolina follows a public notification 
and review process. EPA has reviewed and approved the North Carolina's 
2020 Ambient Air Monitoring Network Plan (``2020 Annual Network Plan'') 
which addresses the relevant monitors used to determine attainment for 
the Charlotte NC-SC 1997 8-hour NAAQS Area.\27\

[[Page 67407]]

Separately, North Carolina has committed to maintain the monitoring 
network that is used to monitor ozone for compliance with the 1997 8-
hour ozone NAAQS, which includes the monitors within the North Carolina 
portion of the Charlotte NC-SC 1997 8-hour NAAQS Area.\28\
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    \25\ See 69 FR 23858 (April 30, 2004) for the final designation 
action for the 1997 8-hour ozone NAAQS and https://www.epa.gov/ground-level-ozone-pollution/1997-ozone-national-ambient-air-quality-standards-naaqs-nonattainment for the monitoring data 
associated with the designation for the 1997 8-hour ozone NAAQS.
    \26\ South Carolina maintains one monitor in York County. 
Although that monitor is near the maintenance boundary, it is not 
used to determine compliance of the Charlotte NC-SC 1997 8-hour 
NAAQS Area with the 1997 8-hour ozone NAAQS because it is not 
located within the maintenance area.
    \27\ See October 30, 2020, letter and approval from Caroline 
Freeman, Director, Air and Radiation Division, EPA Region 4 to Mike 
Abraczinskas, Director, Division of Air Quality, North Carolina 
Department of Environmental Quality, available in the docket for 
this proposed action.
    \28\ See 78 FR 72036 (December 2, 2013), 78 FR 45152 (July 26, 
2013).
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    Subsequent to the nonattainment designation for the 1997 8-hour 
ozone NAAQS, the Catawba Indian Nation, under a CAA section 103 grant 
agreement with EPA, erected and operates a monitor in the Catawba Area. 
EPA provides oversight of the Catawba Indian Nation's operation of this 
monitor through normal grant monitoring activities on annual basis.
    To verify the attainment status of the Area over the maintenance 
period, the maintenance plan should contain provisions for continued 
operation of an appropriate, EPA-approved monitoring network in 
accordance with 40 CFR part 58. As noted above, North Carolina's 2020 
Annual Network Plan, which covers the monitors within the Charlotte NC-
SC 1997 8-hour NAAQS Area, has been approved by EPA in accordance with 
40 CFR part 58, and North Carolina has committed to continue to 
maintain a network in accordance with EPA requirements. Although South 
Carolina does not operate any part 58 monitors in the Charlotte NC-SC 
1997 8-hour NAAQS Area, the State commits to continue operating an 
approved ozone monitoring network near the South Carolina portion of 
that area; commits to consult with the EPA prior to making changes to 
the existing monitoring network should changes become necessary in the 
future; and acknowledges the obligation to meet monitoring requirements 
in compliance with 40 CFR part 58.\29\ EPA proposes to find that there 
is an adequate ambient air quality monitoring network in the Charlotte 
NC-SC 1997 8-hour NAAQS Area to verify continued attainment of the 1997 
8-hour ozone NAAQS.
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    \29\ See South Carolina's July 7, 2020, SIP submittal at page 7.
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E. Contingency Plan

    Section 175A(d) of the CAA requires that a maintenance plan include 
contingency provisions. The purpose of such contingency provisions is 
to prevent future violations of the NAAQS or to promptly remedy any 
NAAQS violations that might occur during the maintenance period. These 
contingency measures are required to be implemented expeditiously once 
they are triggered by a future violation of the NAAQS or some other 
trigger. The state should identify specific triggers which will be used 
to determine when the contingency measures need to be implemented.
    The trigger identified in the Catawba Area LMP is a Quality 
Assured/Quality Controlled (QA/QC) violating design value of the 1997 
8-hour ozone NAAQS within or near the Charlotte NC-SC 1997 8-hour NAAQS 
Area.\30\ If this trigger is activated, the maintenance plan requires 
South Carolina to conduct analyses to determine the emission control 
measures that will be necessary for attaining or maintaining the 1997 
8-hour ozone NAAQS. The maintenance plan outlines the steps that South 
Carolina must conduct to determine control measures, including 
verification and analysis of data related to the exceedance, and 
possible causes. South Carolina will adopt and implement appropriate 
contingency measures tailored to the specific circumstances of the 
violation (or increased concentrations) within 24 months after a 
triggering event.\31\ \32\
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    \30\ If QA/QC data indicates a violating design value for the 8-
hour ozone NAAQS, then the triggering event will be the date of the 
design value violation, and not the final QA/QC date. However, if 
initial monitoring data indicates a possible design value violation 
but later QA/QC indicates that a NAAQS violation did not occur, then 
a triggering event will not have occurred, and contingency measures 
will not need to be implemented.
    \31\ As stated above, the Catawba Area LMP contains the same 
contingency measures that were included in the first 10-year 
maintenance plan, as tailored to the Catawba Area. For example, some 
contingency measures included only in the first 10-year LMP would 
have limited emissions reductions or were not applicable based on 
the characteristics of the Catawba Area (for example, alternative 
fuel programs for fleet vehicle operations, as there are no vehicle 
fleets in the Catawba Area). In addition, South Carolina added a 
provision to work closely with the York County Air Coalition for 
outreach and stakeholder input, contingency measure support, and 
community emission reduction efforts, which is a logical extension 
in recognition that this LMP is for a subset of the larger South 
Carolina portion of the Charlotte NC-SC 1997 8-hour NAAQS Area.
    \32\ See the Contingency Plan section of the Catawba Area LMP 
for further information regarding the contingency plan, including 
measures that South Carolina will consider for adoption if the 
trigger is activated, as well as additional steps and notification 
to EPA if DHEC determines additional time than 24 months is 
necessary to implement specific contingency measures.
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    EPA proposes to find that the contingency provisions in South 
Carolina's second maintenance plan for the 1997 8-hour ozone NAAQS meet 
the requirements of the CAA section 175A(d).

F. Conclusion

    EPA proposes to find that the Catawba Area LMP for the 1997 8-hour 
ozone NAAQS includes an approvable update of various elements of the 
initial EPA-approved Maintenance Plan for the 1997 8-hour ozone NAAQS. 
EPA also proposes to find that the Catawba Area qualifies for the LMP 
option and adequately demonstrates maintenance of the 1997 8-hour ozone 
NAAQS through the documentation of monitoring data showing maximum 1997 
8-hour ozone levels below the NAAQS and historically stable design 
values. EPA believes the Catawba Area LMP, which retains existing 
control measures in the SIP, is sufficient to provide for maintenance 
of the 1997 8-hour ozone NAAQS in the Catawba Area over the second 
maintenance period (i.e., through 2032) and thereby satisfies the 
requirements for such a plan under CAA section 175A(b). EPA is 
therefore proposing to approve South Carolina's July 7, 2020, 
submission of the Catawba Area LMP as a revision to the South Carolina 
SIP.

V. Transportation Conformity and General Conformity

    Transportation conformity is required by section 176(c) of the CAA. 
Conformity to a SIP means that transportation activities will not 
produce new air quality violations, worsen existing violations, or 
delay timely attainment of the NAAQS. See CAA 176(c)(1)(A) and (B). 
EPA's transportation conformity rule at 40 CFR part 93 subpart A 
requires that transportation plans, programs, and projects conform to 
SIPs and establishes the criteria and procedures for determining 
whether they conform. The conformity rule generally requires a 
demonstration that emissions from the Regional Transportation Plan 
(RTP) and the Transportation Improvement Program (TIP) are consistent 
with the motor vehicles emissions budget (MVEB) contained in the 
control strategy SIP revision or maintenance plan. See 40 CFR 93.101, 
93.118, and 93.124. A MVEB is defined as ``the portion of the total 
allowable emissions defined in the submitted or approved control 
strategy implementation plan revision or maintenance plan for a certain 
date for the purpose of meeting reasonable further progress milestones 
or demonstrating attainment or maintenance of the NAAQS, for any 
criteria pollutant or its precursors, allocated to highway and transit 
vehicle use and emissions.'' See 40 CFR 93.101.
    Under the conformity rule, LMP areas may demonstrate conformity 
without a regional emissions analysis. See 40 CFR 93.109(e). On October 
9, 2012, EPA made a finding that the MVEBs for the first 10 years of 
the 1997 8-hour ozone

[[Page 67408]]

maintenance plan for the South Carolina portion of the Charlotte NC-SC 
1997 8-hour NAAQS Area were adequate for transportation conformity 
purposes. In a Federal Register notice dated September 24, 2012, EPA 
notified the public of that finding. See 77 FR 58829. This adequacy 
determination became effective on October 9, 2012. After approval of 
this LMP or an adequacy finding for this LMP, there is no requirement 
to meet the budget test pursuant to the transportation conformity rule 
for the Catawba Area. All actions that would require a transportation 
conformity determination for the Catawba Area under EPA's 
transportation conformity rule provisions are considered to have 
already satisfied the regional emissions analysis and ``budget test'' 
requirements in 40 CFR 93.118 as a result of EPA's adequacy finding for 
this LMP. See 69 FR 40004 (July 1, 2004).
    However, because LMP areas are still maintenance areas, certain 
aspects of transportation conformity determinations still will be 
required for transportation plans, programs, and projects. 
Specifically, for such determinations, RTPs, TIPs, and transportation 
projects still will have to demonstrate that they are fiscally 
constrained (40 CFR 93.108) and meet the criteria for consultation (40 
CFR 93.105) and Transportation Control Measure implementation in the 
conformity rule provisions (40 CFR 93.113) as well as meet the hot-spot 
requirements for projects (40 CFR 93.116).\33\ Additionally, conformity 
determinations for RTPs and TIPs must be determined no less frequently 
than every four years, and conformity of plan and TIP amendments and 
transportation projects is demonstrated in accordance with the timing 
requirements specified in 40 CFR 93.104. In addition, in order for 
projects to be approved they must come from a currently conforming RTP 
and TIP. See 40 CFR 93.114 and 40 CFR 93.115. The Charlotte NC-SC 2008 
NAAQS Area must continue to meet all of the applicable requirements of 
the general conformity regulations.
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    \33\ A conformity determination that meets other applicable 
criteria in Table 1 of paragraph (b) of this section (93.109(e)) is 
still required, including the hot-spot requirements for projects in 
CO, PM10, and fine particulate matter (PM2.5) 
areas.
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VI. Proposed Action

    Under sections 110(k) and 175A of the CAA and for the reasons set 
forth above, EPA is proposing to approve the Catawba Area LMP for the 
1997 8-hour ozone NAAQS, submitted by DHEC on July 7, 2020, as a 
revision to the South Carolina SIP. EPA is proposing to approve the 
Catawba Area LMP because it includes an acceptable update of various 
elements of the 1997 8-hour ozone NAAQS Maintenance Plan approved by 
EPA for the first 10-year period and retains the relevant provisions of 
the SIP.
    EPA also finds that the Catawba Area qualifies for the LMP option 
and that therefore the Catawba Area LMP adequately demonstrates 
maintenance of the 1997 8-hour ozone NAAQS through documentation of 
monitoring data showing maximum 1997 8-hour ozone levels well below the 
NAAQS and continuation of existing control measures. EPA believes the 
Catawba Area's 1997 8-Hour Ozone LMP to be sufficient to provide for 
maintenance of the 1997 8-hour ozone NAAQS in the Catawba Area over the 
second 10-year maintenance period, through 2032, and thereby satisfy 
the requirements for such a plan under CAA section 175A(b).

VII. 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. 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. 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 CAA; 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).
    Because this Catawba Area LMP merely proposes to approve state law 
as meeting Federal requirements and does not impose additional 
requirements beyond those imposed by state law, this Catawba Area LMP 
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 action will not impose substantial direct costs on 
Tribal governments or preempt Tribal law. The Catawba Indian Nation 
(CIN) 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 CIN 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, Incorporation by 
reference, Intergovernmental Relations, Nitrogen oxides, Ozone, 
Reporting and recordkeeping requirements, Volatile Organic Compounds.

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

    Dated: November 17, 2021.
John Blevins,
Acting Regional Administrator,Region 4.
[FR Doc. 2021-25527 Filed 11-24-21; 8:45 am]
BILLING CODE 6560-50-P