Document ID: EPA-R04-OAR-2022-0265-0003
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: North Carolina; Charlotte-Gastonia-Rock Hill Area Limited Maintenance Plan for the 1997 8-Hour Ozone NAAQS
Posted Date: 2022-11-21T05:00Z

[Federal Register Volume 87, Number 223 (Monday, November 21, 2022)]
[Proposed Rules]
[Pages 70758-70765]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-25078]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2022-0265; FRL-9781-01-R4]

Air Plan Approval; North Carolina; 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 North Carolina, through the North Carolina Division of Air 
Quality (NCDAQ), via a letter dated December 9, 2021. The SIP revision 
includes the 1997 8-hour ozone national ambient air quality standards 
(NAAQS) Limited Maintenance Plan (LMP) for the North Carolina portion 
(hereinafter referred to as the Metrolina

[[Page 70759]]

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, and Union 
Counties and a portion of Iredell County (i.e., Coddle Creek and 
Davidson Townships) in North Carolina; and the Rock Hill Metropolitan 
Planning Organization boundary in York County, South Carolina. EPA is 
proposing to approve the Metrolina Area LMP because it provides for the 
maintenance of the 1997 8-hour ozone NAAQS within the Metrolina Area 
through the end of the second 10-year portion of the maintenance period 
in 2034. The effect of this action would be to make certain commitments 
related to maintenance of the 1997 8-hour ozone NAAQS in the Metrolina 
Area federally enforceable as part of the North Carolina SIP.

DATES: Comments must be received on or before December 21, 2022.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2022-0265 at http://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 http://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. North Carolina's SIP Submittal
IV. EPA's Evaluation of North Carolina's SIP Submittal
    A. Attainment Emissions Inventory
    B. Maintenance Demonstration
    C. Monitoring Network and Verification of Continued Attainment
    D. Contingency Plan
    E. 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 Metrolina Area LMP for the 1997 8-hour ozone NAAQS that 
was submitted by NCDAQ as a revision to the North Carolina SIP on 
December 9, 2021. In 2004, the Charlotte NC-SC 1997 8-hour NAAQS Area, 
which includes the Metrolina Area, was designated as nonattainment for 
the 1997 8-hour ozone NAAQS. Subsequently, in 2013, after a clean data 
determination and EPA's approval of a maintenance plan, the Metrolina 
Area was redesignated to attainment for the 1997 8-hour ozone NAAQS. 
See 76 FR 70656 (November 15, 2011) and 78 FR 72036 (December 2, 2013
    The Metrolina Area LMP is designed to maintain the 1997 8-hour 
ozone NAAQS within the Metrolina 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 Metrolina Area LMP relies on the same 
control measures and 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 NCDAQ 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.\1\
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    \1\ See ``Fact Sheet, Proposal to Revise the National Ambient 
Air Quality Standards for Ozone,'' January 6, 2010, available at 
https://www.epa.gov/sites/default/files/2020-12/documents/decision_to_retain_ozone_standards_fact_sheet_final2.pdf, and 27 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), or 120 parts 
per billion (ppb), 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).\2\ 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 NAAQS would be more protective of human 
health, especially for children and adults who are active outdoors, and 
individuals with a pre-existing respiratory disease, such as asthma.
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    \2\ 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 and Union Counties and a portion of Iredell 
County (i.e., Coddle Creek and Davidson Townships) in North Carolina; 
and the Rock Hill Metropolitan Planning Organization boundary in York 
County,

[[Page 70760]]

South Carolina, 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. The 
Charlotte-Gastonia-Rock Hill NC-SC Area \3\ (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. 
See 77 FR 30088.
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    \3\ 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.
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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 were designated attainment/unclassifiable for the 2015 8-hour 
ozone NAAQS, with an effective date of January 16, 2018. See 82 FR 
54232.
    A state may submit a request that EPA 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.\4\ 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 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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    \4\ 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, beginning with a 1992 memo referred to as the 
Calcagni memo.\5\ The Calcagni memo provides that states may generally 
demonstrate maintenance in one of two ways: 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 generated 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 can meet the CAA section 175A requirement to provide for 
maintenance by showing that the area is unlikely to violate the NAAQS 
in the future, using information such as the area's design value \6\ 
being well below the standard and the area having a historically stable 
design value.\7\ EPA refers to a maintenance plan containing this 
streamlined demonstration as an LMP.
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    \5\ 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, available at https://www.epa.gov/ground-level-ozone-pollution/procedures-processing-requests-redesignate-areas-attainment).
    \6\ 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.
    \7\ 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 LMPs 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,\8\ EPA has extended the LMP interpretation of section 175A to 
other NAAQS and pollutants not specifically covered by the previous 
guidance memos.\9\
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    \8\ 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.
    \9\ 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 Metrolina 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. NCDAQ submitted this LMP for the Metrolina Area to 
fulfill the second maintenance plan requirement in the Act. EPA's 
evaluation of the Metrolina Area LMP is presented below.
    In November of 2011 and in March of 2013, NCDAQ submitted to EPA a 
request to redesignate the Metrolina Area of the Charlotte NC-SC 1997 
8-hour NAAQS 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 Metrolina Area through 2024 as a revision to the 
North Carolina SIP. EPA approved North Carolina's Metrolina Area 
maintenance plan and the State's request to redesignate the North 
Carolina portion of the Charlotte NC-SC 1997 NAAQS Area to attainment 
for the 1997 8-hour ozone NAAQS effective January 2, 2014.\10\
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    \10\ See 78 FR 72036 (December 2, 2013).
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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

[[Page 70761]]

plans under CAA section 175A(b). See 80 FR 12264, 12315 (March 6, 
2015).
    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 the 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 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, on 
December 9, 2021, North Carolina submitted a second 10-year maintenance 
plan covering the Metrolina Area that provides for attainment of the 
1997 8-hour ozone NAAQS through 2034.
    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, NCDAQ 
chose the LMP option for the development of its second 1997 8-hour 
ozone NAAQS maintenance plan covering the Metrolina Area.

III. North Carolina's SIP Submittal

    As mentioned above, on December 9, 2021, NCDAQ submitted the 
Metrolina Area LMP as a revision to the North Carolina SIP. The 
submittal includes the LMP, air quality data, emissions inventory 
information, and appendices. Appendices to the plan include average 
2017 summer day anthropogenic emissions by county and sector and 
documentation of notice, hearing, and public participation prior to 
adoption of the plan by NCDAQ on December 9, 2021. The Metrolina Area 
LMP does not include any additional emission reduction measures but 
relies on the same emission reduction strategy as the first 10-year 
maintenance plan that provides for the maintenance of the 1997 8-hour 
ozone NAAQS through 2024. Specifically, the measures upon which the 
second 10-year LMP for the Metrolina Area relies include the foundation 
control program, which consists of federal and state control measures 
that ensure continued maintenance of the NAAQS, as well as supporting 
programs such as the Air Awareness Program, Advance Program, Grant 
Program, Volkswagen Settlement, and EPA Consent Decree with Duke Energy 
Corporation. It also relies on continued implementation of federal 
measures (e.g., Tier 2 and 3 Motor Vehicle Emission and Fuel 
Standards,\11\ Utility New Source Performance Standards (NSPS),\12\ 
NOX SIP Call,\13\ and interstate transport rules such as the 
Cross-State Air Pollution Rule (CSAPR) \14\ and CSAPR Update).\15\
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    \11\ See 79 FR 23414 (April 28, 2014).
    \12\ See 77 FR 9304 (February 16, 2012).
    \13\ See 63 FR 57355 (October 27, 1998).
    \14\ See 76 FR 48208 (August 8, 2011).
    \15\ See 81 FR 74504 (October 26, 2016).
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IV. EPA's Evaluation of North Carolina's SIP Submittal

    EPA has reviewed the Metrolina Area's LMP, which is designed to 
maintain the 1997 8-hour ozone NAAQS within the Metrolina Area through 
the end of the 20-year period beyond redesignation, as required under 
CAA Section 175A(b). The following is a summary of EPA's interpretation 
of the section 175A requirements \16\ and EPA's evaluation of how each 
requirement is met.
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    \16\ See Calcagni memo at pages 7-13.
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A. 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 VOCs and 
NOX, as these pollutants are precursors to ozone formation. 
The Metrolina LMP includes an ozone attainment emissions inventory for 
the Metrolina Area that reflects typical summer day emissions in 2017. 
Table 1 presents a summary of the inventory for 2017 contained in this 
LMP.

 Table 1--Average Summer Day 2017 Anthropogenic NOX and VOC Emissions by
                      Sector for the Metrolina Area
                            [Tons/summer day]
------------------------------------------------------------------------
                 Sector                         NOX             VOC
------------------------------------------------------------------------
Fire....................................           0.028           0.269
Nonpoint................................           0.267           2.266
Nonroad.................................           0.436           0.451
Onroad..................................           2.184           1.376
Point...................................           0.072           0.912
                                         -------------------------------
    Total...............................           2.987           5.274
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    The Attainment Emissions Inventory section of the Metrolina Area's 
LMP describes the methods, models, and assumptions used to develop the 
attainment inventory. As described in the Emissions Inventory section 
(Section 3.1) of the LMP, NCDAQ generally relied on the 2017 National 
Emissions Inventory (NEI).\17\ The Metrolina Area's maintenance 
inventory is comprised of anthropogenic sources. Naturally occurring, 
or biogenic, emissions are not included in the inventory, as these 
emissions are outside the State's purview. Because much of the EPA's 
2017 NEI is compiled at the county level, but the Metrolina Area 
includes only a subset of the townships in relevant counties, the NCDAQ 
developed methodologies to estimate the proportion of county emissions 
occurring in the maintenance area. When available, these methodologies 
utilize locational information; otherwise, they assume population as a 
surrogate indicator of emissions activity.
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    \17\ U.S. EPA, 2017 Emissions Modeling Data downloaded from 
ftp://newftp.epa.gov/air/emismod/2017/reports, accessed August 2021.
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    Based on our review of the methods, models, and assumptions used by 
NCDAQ to develop the inventory, as well as our review of the 2017 
summer emissions data, EPA proposes to find that the Metrolina Area's 
LMP includes

[[Page 70762]]

a comprehensive, reasonably accurate inventory of actual ozone 
precursor emissions in attainment year 2017 and proposes to conclude 
that this is acceptable for the purposes of a subsequent maintenance 
plan under CAA section 175A(b).

B. Maintenance Demonstration

    The maintenance demonstration requirement is considered satisfied 
in an 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.\18\ These criteria are 
evaluated below with regard to the Charlotte NC-SC 1997 8-hour NAAQS 
Area as a whole.
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    \18\ See Footnote 7.
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1. Evaluation of Ozone Concentration Levels
    To attain the 1997 8-hour ozone NAAQS, the three-year average of 
the fourth-highest daily maximum 8-hour average ozone concentrations 
(i.e., the 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 2018-2020 monitoring data \19\ and determined that the design 
value for the Charlotte NC-SC 1997 8-hour NAAQS Area was 0.067 ppm, or 
80 percent of the level of the 1997 8-hour ozone NAAQS (measured at the 
Garinger High School Monitor (AQS ID: 37-119-0041) and the University 
Meadows monitor (AQS ID: 37-119-0046) in Mecklenburg County, NC). 
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 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.
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    \19\ See https://www.epa.gov/air-trends/air-quality-design-values#report (follow the ``Ozone Design Values 2020 (xlsx)'' 
hyperlink, then open ``Table4. County Status'' in the spreadsheet 
and scroll down to North Carolina).
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    Tables 2a and 2b present the 2003-2021 design values for each 
monitor in the Charlotte NC-SC 1997 8-hour NAAQS Area. As shown in 
these tables, all sites have been below the level of the 1997 8-hour 
ozone NAAQS since the area was redesignated to attainment, and the most 
recent design value is below the level of 85 percent of the NAAQS, 
consistent with prior LMP guidance. The 2019-2021 design value is 0.066 
ppm or 79 percent of the level of the 1997 8-hour ozone NAAQS (measured 
at the Garinger High School Monitor (AQS ID: 37-119-0041) and the 
University Meadows monitor (AQS ID: 37-119-0046) in Mecklenburg County, 
NC).

               Table 2a--1997 8-Hour Ozone NAAQS 2003-2011 Design Values (ppm) at Monitoring Sites in the Charlotte NC-SC 1997 NAAQS Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          2001-    2002-    2003-    2004-    2005-    2006-    2007-    2008-    2009-
          AQS site ID                 Site name          County name     2003 DV  2004 DV  2005 DV  2006 DV  2007 DV  2008 DV  2009 DV  2010 DV  2011 DV
--------------------------------------------------------------------------------------------------------------------------------------------------------
37-109-0004....................  Crouse............  Lincoln...........    0.092    0.086    0.081    0.079    0.083    0.082    0.076    0.072    0.071
37-119-0041....................  Garinger..........  Mecklenburg.......    0.096    0.091    0.086    0.088    0.090    0.089    0.082    0.078    0.079
37-119-0046....................  University Meadows  Mecklenburg.......  .......  .......  .......  .......  .......  .......  .......  .......  .......
37-119-1005....................  Arrowood..........  Mecklenburg.......    0.084    0.081    0.078    0.080    0.083    0.079    0.076    0.073    0.076
37-119-1009....................  County Line.......  Cabarrus..........    0.098    0.092    0.087    0.088    0.093    0.094    0.086    0.082    0.078
37-159-0021....................  Rockwell CSS......  Rowan.............    0.100    0.094    0.088    0.083    0.089    0.088    0.083    0.077    0.075
37-159-0022....................  Enochville........  Rowan.............    0.099    0.091    0.085    0.085    0.090    0.088    0.083    0.077    0.076
37-179-0003....................  Monroe............  Union.............    0.088    0.085    0.079    0.078    0.081    (\e\)    0.076    0.072    0.070
45-091-8801....................  Catawba Longhouse.  Catawba Indian      .......  .......  .......  .......  .......  .......  .......  .......  .......
                                                      Nation.
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               Table 2b--1997 8-Hour Ozone NAAQS 2012-2021 Design Values (ppm) at Monitoring Sites in the Charlotte NC-SC 1997 NAAQS Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 2010-    2011-    2012-    2013-    2014-    2015-    2016-    2017-    2018-    2019-
         AQS site ID             Site name       County name    2012 DV  2013 DV  2014 DV  2015 DV  2016 DV  2017 DV  2018 DV  2019 DV  2020 DV  2021 DV
--------------------------------------------------------------------------------------------------------------------------------------------------------
37-109-0004.................  Crouse.........  Lincoln (NC)...    0.075    0.072    0.068    0.065    0.067    0.067    0.065    0.064    0.060    0.061
37-119-0041.................  Garinger.......  Mecklenburg        0.083    0.078    0.070    0.068    0.069    0.069    0.068    0.070    0.067    0.066
                                                (NC).
37-119-0046.................  University       Mecklenburg      .......  .......  .......  .......      \a\      \a\    0.070    0.069    0.067    0.066
                               Meadows.         (NC).                                                 0.070    0.070
37-119-1005.................  Arrowood.......  Mecklenburg        0.077    0.072      \b\  .......  .......  .......  .......  .......  .......  .......
                                                (NC).                               0.066
37-119-1009.................  County Line....  Cabarrus (NC)..    0.083    0.078    0.073      \c\  .......  .......  .......  .......  .......  .......
                                                                                             0.067
37-159-0021.................  Rockwell CSS...  Rowan (NC).....    0.078    0.073    0.068    0.064    0.065    0.064    0.062    0.062    0.061    0.062
37-159-0022.................  Enochville.....  Rowan (NC).....    0.077      \d\  .......  .......  .......  .......  .......  .......  .......  .......
                                                                           0.072
37-179-0003.................  Monroe.........  Union (NC).....    0.073    0.070    0.068    0.067  .......  .......    (\e\)    (\e\)    0.063    0.062

[[Page 70763]]

 
45-091-8801.................  Catawba          Catawba Indian   .......  .......  .......  .......  .......  .......    0.063    0.064    0.062    0.062
                               Longhouse.       Nation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Monitor started in 2016 to replace 37-119-1009; EPA approved combining data for the two sites to calculate a design value; value reported is a
  combined design value.
\b\ Monitor was shut down at the end of the 2014 ozone season.
\c\ Monitor was shut down at the end of the 2015 ozone season and replaced by 37-119-0046 in 2016. EPA approved combining data from the two monitors to
  calculate design values.
\d\ Monitor was shut down at the end of the 2013 ozone season.
\e\ Monitor did not meet the 3-year completeness requirement of 90 percent.

    Therefore, the Metrolina 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, adequately 
provide for the maintenance of the 1997 8-hour ozone NAAQS in the 
Metrolina Area through the second 10-year maintenance period and 
beyond.
    Additional supporting information that the Metrolina 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.\20\ 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 parts per billion (ppb). EPA 
is not proposing to make any finding in this action regarding 
interstate transport obligations for any state.
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    \20\ 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 Charlotte SC-NC maintenance area. See the 
spreadsheet titled ``Data File with Ozone Design Values and Ozone 
Contributions (xlsx)'' at https://www.epa.gov/csapr/revised-cross-state-air-pollution-rule-update.
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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 
twelve design values. Additionally, the design value data shown in 
Tables 2a and 2b illustrate that ozone levels have been relatively 
stable over the 2001-2021 timeframe, with an overall downward trend. 
For example, data in Tables 2a and 2b indicate that the largest year 
over year change in design values at any one monitor during these 
seventeen years was 0.008 ppm, which occurred between the 2003 and 2004 
design values and between the 2013 and the 2014 design values, 
representing approximately an 8 percent and 10 percent decrease at 
monitors 37-159-0022 (Enochville) and 37-119-0041 (Garinger), 
respectively. Furthermore, the overall trend in design values for the 
Charlotte NC-SC 1997 8-hour NAAQS Area between the 2003-2021 design 
values, shows a decrease of 38 percent at the highest monitor, Rockwell 
CSS monitor 37-159-002. 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 Charlotte NC-SC 1997 
8-hour NAAQS Area will not exceed the 1997 8-hour ozone NAAQS during 
the second 10-year maintenance period.

C. 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 are submitted annually to EPA, and network assessments are 
submitted every five years. NCDAQ operates a network plan with multiple 
monitors within the boundary of the Charlotte NC-SC 1997 8-hour NAAQS 
Area.\21\ The annual network plan developed by NCDAQ follows a public 
notification and review process. EPA has reviewed and approved the 
North Carolina 2021 Ambient Air Monitoring Network Plan (``2021 Annual 
Network Plan'').\22\ Mecklenburg County Air Quality and NCDAQ also 
submitted 2020 Ambient Air Monitoring Network Assessments as required 
by 40 CFR 58.10(d).
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    \21\ 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. The Catawba Longhouse monitor 
referenced in Tables 2a and 2b is a monitor maintained by the 
Catawba Indian Nation (CIN), and the CIN land was included in the 
Charlotte NC-SC 1997 8-hour NAAQS Area boundary.
    \22\ See October 27, 2021, 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.
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    To verify the attainment status of the Metrolina 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 part 58. In the LMP, North Carolina commits to 
continue to monitoring ozone in the Metrolina Area. North Carolina 
states that any monitoring changes will only be made if they are 
consistent with 40 CFR part 58 and that any monitor shutdowns or 
relocations will only be made with EPA's approval.

D. Contingency Plan

    Section 175A(d) of the Act 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. The 
state should identify specific triggers which will be used to determine 
when the contingency measures need to be implemented.
    The LMP has three triggers. The primary trigger will be a violating 
design value of the 1997 8-hour ozone NAAQS within the Charlotte NC-SC 
1997 8-hour NAAQS Area. The trigger date will be 60 days from the date 
on which an ozone monitor in the Area records a fourth highest value 
that, when averaged with the two previous ozone seasons' fourth highest 
values, results in a three year average equal to

[[Page 70764]]

or greater than 85 ppb. If this trigger or the secondary trigger is 
activated, the LMP requires North 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 plan outlines 
the steps that North Carolina must conduct to determine control 
measures, including verification and analysis of data related to the 
exceedance, and possible causes. North Carolina will adopt and 
implement as expeditiously as practicable, but no later than 24 months 
after the trigger event, at least one control measure that is 
determined to be most appropriate for reducing NOx emissions.\23\
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    \23\ See Contingency Plan section of the LMP for further 
information regarding the contingency plan, including measures that 
North Carolina will consider for adoption if the trigger is 
activated. The LMP is available in the docket for this proposed 
action.
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    The secondary trigger will apply if the state finds monitored ozone 
levels indicating that an actual ozone NAAQS violation may be imminent, 
i.e., when there are two consecutive ozone seasons in which the fourth 
highest values are 85 ppb or greater at a single monitor within the 
maintenance area. The tertiary trigger will be a first alert as to a 
potential future violation and will be activated when a monitor in the 
Area has a fourth highest value of 85 ppb or greater, starting the 
first year after the maintenance plan has been approved. Like the 
primary trigger, the trigger date for the secondary and tertiary 
triggers will be 60 days from the date on which an ozone monitor in the 
Area records the pertinent fourth highest value. Tertiary trigger 
activation will result in the analyses described in the LMP to 
understand why a fourth high exceedance has occurred and in the 
development of an outreach plan identifying any additional voluntary 
measures that can be implemented.
    EPA proposes to find that the contingency provisions in North 
Carolina's second maintenance plan for the 1997 8-hour Ozone NAAQS meet 
the requirements of the CAA section 175A(d).

E. Conclusion

    EPA proposes to find that the Metrolina 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 Metrolina 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 well below the NAAQS and historically 
stable design values. EPA believes the Metrolina 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 Metrolina Area 
over the second maintenance period (i.e., through 2034) and thereby 
satisfies the requirements for such a plan under CAA section 175A(b). 
EPA is therefore proposing to approve North Carolina's December 9, 
2021, submission of the Metrolina Area LMP as a revision to the North 
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 that it 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 vehicle 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 August 
13, 2013, EPA made a finding that the MVEBs for the first 10 years of 
the 1997 8-hour ozone maintenance plan for the North Carolina portion 
of the Charlotte NC-SC 1997 8-hour NAAQS Area were adequate for 
transportation conformity purposes. In a Federal Register notice dated 
August 13, 2013, EPA notified the public of that finding. See 78 FR 
49265. This adequacy determination became effective on August 28, 2013.
    After approval of this LMP or an adequacy finding for this LMP, 
there is no requirement to meet the ``budget test'' for motor vehicle 
emissions pursuant to the transportation conformity rule for the 
Metrolina Area. All actions that would require a transportation 
conformity determination for the Metrolina 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).\24\ 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 applicable requirements of the 
general conformity regulations.
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    \24\ 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 Metrolina Area LMP for the 
1997 8-hour ozone NAAQS, submitted by NCDAQ on December 9, 2021, as a 
revision to the North Carolina SIP. EPA is proposing to approve the 
Metrolina 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 (including emissions inventory, 
assurance of adequate monitoring and verification of

[[Page 70765]]

continued attainment, and contingency provisions), and retains the 
relevant provisions of the SIP.
    EPA also finds that the Metrolina Area qualifies for the LMP option 
and that, therefore, the Metrolina Area's 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 that 
the Metrolina Area's 1997 8-Hour Ozone LMP is sufficient to provide for 
maintenance of the 1997 8-hour ozone NAAQS in the Metrolina Area over 
the second 10-year maintenance period, through 2034, and thereby 
satisfies 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 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).
    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.

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 10, 2022.
Daniel Blackman,
Regional Administrator, Region 4.
[FR Doc. 2022-25078 Filed 11-18-22; 8:45 am]
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