[Federal Register Volume 89, Number 72 (Friday, April 12, 2024)]
[Proposed Rules]
[Pages 25849-25856]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-07701]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2023-0057; FRL-11847-01-R4]


Air Plan Approval; North Carolina; Revision to Approved Motor 
Vehicle Emissions Budgets

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a revision to the North Carolina State Implementation Plan 
(SIP), submitted by the North Carolina Department of Environmental 
Quality (NCDEQ), Division of Air Quality, on December 19, 2022. The 
revision seeks to update the 2026 on-road and nonroad emissions 
inventories and safety margins, allocate a portion of the newly 
available 2026 safety margins in the 2008 8-hour Ozone Maintenance Plan 
to the 2026 nitrogen oxides (NOX) and volatile organic 
compounds (VOC) motor vehicle emissions budgets (``budgets'') for the 
North Carolina portion of the Charlotte-Rock Hill, NC-SC bi-state Area 
(hereinafter referred to as the ``North Carolina portion of the 
Charlotte Maintenance Area'') to accommodate updates from the EPA Motor 
Vehicle Emissions Simulator (MOVES3) model. The SIP revision also 
revises the current 2026 budgets based on the MOVES3 updates and 
recalculates new available safety margins. NCDEQ's December 19, 2022, 
submission supplements the revised 2008 8-hour Ozone Maintenance Plan 
submitted by NCDEQ on July 16, 2020, and approved by EPA on August 25, 
2021. EPA is proposing to approve North Carolina's December 19, 2022, 
SIP revision and deem the budgets adequate for transportation 
conformity purposes because they meet the applicable statutory and 
regulatory requirements.

DATES: Comments must be received on or before May 13, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2023-0057 at www.regulations.gov. Follow the online instructions 
for submitting comments. Once submitted, comments cannot be edited or 
removed from Regulations.gov. EPA may publish any comment received to 
its public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Dianna Myers, 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) 562-9207. Ms. Myers can also be reached via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION: 

I. Introduction

    EPA is proposing to approve NCDEQ's December 19, 2022, SIP revision 
which updates the 2026 on-road and nonroad emissions inventories with 
the latest (at the time of NCDEQ's submission) approved EPA mobile 
emissions model, MOVES3, allocates a portion of the newly available 
safety margin, revises the 2026 NOX and VOC budgets, and 
recalculates the available safety margins for the North Carolina 
portion of Charlotte 2008 8-hour Ozone Maintenance Area \1\ for 
transportation conformity purposes.
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    \1\ The North Carolina portion of the Charlotte Maintenance Area 
for the 2008 8-hour ozone national ambient air quality standards 
(NAAQS or standards) is comprised of the following counties: 
Mecklenburg County in its entirety and portions of Cabarrus, Gaston, 
Iredell, Lincoln, Rowan, and Union Counties. See section II.B. for 
more detail.
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    If EPA finalizes this proposed approval, the revised 2026 
NOX and VOC budgets from NCDEQ's December 19, 2022, SIP 
revision will replace the existing budgets in the State's 2008 8-hour 
Ozone Maintenance Plan approved on August 25, 2021. See 86 FR 47387. If 
approved, these newly revised 2026 budgets must be used in future

[[Page 25850]]

transportation conformity analyses for the Area according to the 
Transportation Conformity Rule. See 40 CFR 93.118. Therefore, the 
August 25, 2021, approved budgets would no longer be applicable for 
transportation conformity purposes.
    In the State's submission, the emissions inventories for point and 
area sources from NCDEQ's July 16, 2020, SIP revision remain the same. 
This submission revises the 2026 on-road and nonroad emissions 
inventories and the NOX and VOC safety margins using MOVES3. 
The revision also allocates a portion of the revised available safety 
margins to the 2026 NOX and VOC budgets and recalculates new 
available safety margins. As explained below, EPA is proposing to 
conclude that North Carolina's December 19, 2022, SIP revision 
continues to demonstrate maintenance for the Charlotte Maintenance 
Area.

II. Background

A. SIP Budgets and Transportation Conformity

    Under the Clean Air Act (CAA or Act), states are required to 
submit, at various times, control strategy SIP revisions and 
maintenance plans for nonattainment and maintenance areas for a given 
NAAQS. These emission control strategy SIP revisions (e.g., reasonable 
further progress and attainment demonstration SIP revisions) and 
maintenance plans include budgets of on-road mobile source emissions 
for criteria pollutants and/or their precursors to address pollution 
from cars, trucks, and other on-road vehicles. The budgets are the 
portion of the total allowable emissions that are allocated to on-road-
vehicle use that, together with emissions from other sources in the 
area, will provide for attainment or maintenance. The budgets serve as 
a ceiling on emissions from an area's planned transportation system.
    Under section 176(c) of the CAA, transportation plans, 
transportation improvement programs (TIPs), and transportation projects 
must ``conform'' to (i.e., be consistent with) the SIP before they can 
be adopted or approved. Conformity to the SIP means that transportation 
activities will not cause new air quality violations, worsen existing 
air quality violations, or delay timely attainment of the NAAQS or an 
interim milestone. The transportation conformity regulations can be 
found at 40 CFR parts 51 and 93.
    Before budgets may be used in conformity determinations, EPA must 
affirmatively find the budgets adequate. However, adequate budgets do 
not supersede approved budgets for the same CAA purpose. If the 
submitted SIP budgets are meant to replace budgets for the same CAA 
purpose and year(s) addressed by a previously approved SIP revision, as 
is the case with this SIP revision, EPA may approve the revised SIP and 
budgets and also affirm that the budgets are adequate at the same time. 
Once EPA approves the submitted budgets, the revised budgets must be 
used by State and Federal agencies in determining whether 
transportation activities conform to the SIP as required by section 
176(c) of the CAA. EPA's substantive criteria for determining the 
adequacy of budgets are set out in 40 CFR 93.118(e)(4).

B. Prior Approval of Budgets

    Effective July 20, 2012, EPA designated the Charlotte-Rock Hill, 
NC-SC Area as Marginal nonattainment for the 2008 8-hour ozone NAAQS. 
The North Carolina portion of the Charlotte 2008 Maintenance Area 
includes Mecklenburg County in its entirety and portions of Cabarrus, 
Gaston, Iredell, Lincoln, Rowan, and Union Counties. The Charlotte 
Maintenance Area also includes a portion of York County located in Rock 
Hill, South Carolina. See 77 FR 30088 (May 21, 2012). The North 
Carolina portion of the Charlotte Maintenance Area is comprised of 
three metropolitan planning organizations (MPOs): the Charlotte 
Regional Transportation Planning Organization (CRTPO) which covers 
Iredell, Mecklenburg, and Union Counties; the Cabarrus-Rowan 
Metropolitan Planning Organization (CRMPO) which covers Cabarrus and 
Rowan Counties; and the Gaston-Cleveland-Lincoln Metropolitan Planning 
Organization (GCLMPO) which covers Gaston, Cleveland, and Lincoln 
Counties. Although Cleveland County is included in the GCLMPO planning 
boundary, it was not included in the North Carolina portion of the 
Charlotte Maintenance Area. Each MPO has its own budget, which is 
referred to as a ``sub-area budget.'' The York County, South Carolina, 
portion of this maintenance area has a separate MPO and budgets. The 
South Carolina portion of the maintenance area implements 
transportation conformity independent of the North Carolina portion.
    EPA approved the redesignation request and maintenance plan for 
North Carolina's portion of the Charlotte 2008 8-hour ozone Area on 
July 28, 2015 (80 FR 44873) with 2014 and 2026 NOX and VOC 
sub-area budgets. On August 17, 2015 (80 FR 49164), EPA approved North 
Carolina's requested relaxation of the Federal Reid Vapor Pressure 
(RVP) requirement from 7.8 pounds per square inch (psi) to 9.0 psi. See 
80 FR 44868 (approving the CAA section 110(l) non-interference 
demonstration that relaxing the Federal RVP requirement from 7.8 psi to 
9.0 psi in Mecklenburg and Gaston Counties would not interfere with 
maintenance of the NAAQS in the Area and approving a revision to the 
2026 NOX and VOC sub-area budgets for Mecklenburg and Gaston 
Counties only).
    On July 25, 2018, NCDEQ submitted a revision to the Charlotte 2008 
8-hour ozone maintenance plan to update the emissions forecast and 
budgets for 2026 to account for the small increase in NOX 
and VOC emissions associated with the change in vehicle model year 
coverage due to changes in the State of North Carolina's inspection and 
maintenance (I/M) program. On September 11, 2019 (84 FR 47889), EPA 
approved NCDEQ's July 25, 2018, SIP revision related to North 
Carolina's I/M Program. The September 11, 2019, SIP approval updated 
the on-road mobile source inventory and revised the 2026 sub-area VOC 
and NOX budgets for Cabarrus and Rowan Counties. The revised 
2026 budgets became effective on October 11, 2019.
    Subsequently, on August 25, 2021, EPA approved NCDEQ's July 16, 
2020, SIP revision which allocated a portion of the available safety 
margin to the 2026 sub-area NOX and VOC budgets to 
accommodate updates to the travel demand model used to calculate 
vehicle miles traveled in the Area. See 86 FR 47387. The revision to 
the 2026 sub-area budgets became effective on September 24, 2021.

C. MOVES Emissions Model

    The MOVES model is designed by EPA to estimate air pollution 
emissions from mobile sources. MOVES can be used to estimate exhaust 
and evaporative emissions as well as brake and tire wear emissions from 
all types of on-road vehicles for any part of the country, except 
California.\2\ On January 7, 2021 (86 FR 1106), EPA announced the 
availability of MOVES3 for official purposes outside of California. At 
that time, MOVES3 was the latest state of-the art upgrade to EPA's 
modeling tools for estimating emissions from cars, trucks, buses, and 
motorcycles based on the latest data and regulations and was available 
for use in SIPs and transportation conformity analyses outside of 
California. The notice of availability started a two-year grace

[[Page 25851]]

period \3\ after which MOVES3 was required to be used in new regional-
emissions and hot-spot analyses for transportation conformity 
determinations outside of California.
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    \2\ In California, a different on-road emissions model, EMFAC, 
is used for regulatory purposes instead of MOVES.
    \3\ The two-year grace period ended on January 9, 2023.
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    On September 12, 2023 (88 FR 62567), EPA announced the availability 
of MOVES4 for official purposes outside of California. MOVES4 is the 
latest state-of-the art upgrade to EPA's modeling tools for estimating 
emissions from cars, trucks, buses, and motorcycles based on the latest 
data and regulations. MOVES4 is available for use in SIPs and 
transportation conformity analyses outside of California. The notice of 
availability started a two-year grace period \4\ after which MOVES4 is 
required to be used in new regional-emissions and hot-spot analyses for 
transportation conformity determinations outside of California. States 
should use the latest version of MOVES that is available at the time 
that a SIP is developed. However, state and local agencies that have 
already completed significant work on a SIP with a version of MOVES3 
(e.g., attainment modeling has already been completed with MOVES3) may 
continue to rely on this earlier version of MOVES. It would be 
unreasonable to require states to revise such SIPs using MOVES4 since 
significant work has already occurred based on the latest information 
available at the time the SIP was developed, and EPA intends to act on 
these SIPs in a timely manner. North Carolina developed and submitted 
the SIP revision that is the subject of this proposed rulemaking before 
the MOVES3 grace period ended and before MOVES4 was available. 
Therefore, use of MOVES3 is appropriate here.
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    \4\ The two-year grace period will end on September 12, 2025.
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III. EPA's Analysis of North Carolina's Submittal

    EPA's analysis involves an emissions comparison between the current 
SIP-approved on-road and nonroad emissions inventory and budgets and 
the revised inventories and budgets that North Carolina has requested 
that EPA approve in the December 19, 2022, SIP submittal. Section 
III.A. provides information regarding the current SIP-approved and 
revised inventories and safety margins, while sections III.B. and 
III.C. contain information and analysis regarding the proposed 
percentages and revisions to the 2026 budgets and new safety margins, 
respectively. Section III.D. contains EPA's analysis of the adequacy of 
North Carolina's revised budgets pursuant to 40 CFR 93.118(e)(4).
    As discussed further below, EPA's analysis of North Carolina's 
December 19, 2022, SIP submittal indicates that maintenance will 
continue to be demonstrated after allocation of a portion of the safety 
margin to the budgets because the total level of emissions from all 
source categories remains equal to or less than the attainment level of 
emissions. Thus, EPA is proposing to approve North Carolina's December 
19, 2022, SIP submittal.

A. Maintenance Demonstration and Emissions Inventory

    This section contains information regarding the previous and 
current SIP-approved budgets and inventories. The point and area source 
inventories are provided for illustrative purposes only since, in this 
action, EPA is not proposing any changes to the September 11, 2019, SIP 
point and area source inventories.\5\ The 2026 on-road and nonroad \6\ 
emissions inventories were modeled using MOVES3, which, as discussed in 
section II.C. above, is based on the latest modeling assumptions and 
input data available at the time it was released. The on-road mobile 
source emissions for all other years were unchanged as compared to the 
currently approved version of the maintenance plan.
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    \5\ As discussed above, if EPA approves NCDEQ's December 19, 
2022, SIP submittal, emissions inventories for the point and area 
sources from NCDEQ's September 11, 2019, SIP revision will remain 
the same.
    \6\ Information on the changes to the revised nonroad emissions 
inventory for 2026 can be found on pages 39-40 and in tables 3.9 and 
3.10 of the December 19, 2022, submittal. The nonroad mobile 
sources, referred to as off-road mobile sources, are pieces of 
equipment that can move but do not use the roadways (i.e., lawn 
mowers, construction equipment, railroad locomotives, etc.). The 
nonroad emissions inventory is separate from the on-road emissions 
inventory and does not impact the budgets but does impact the amount 
of the available safety margins. The MOVES3 nonroad modeling data 
for the nonroad emissions can be found in Appendix B of the 
submittal.
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    As discussed above, EPA originally approved NCDEQ's 2008 8-hour 
ozone maintenance SIP for the North Carolina portion of the Charlotte 
Maintenance Area on July 28, 2015, with the following inventories for 
NOX and VOC emissions: base year actual emissions 
inventories for 2014; projected, future, and interim year inventories 
for 2015, 2018, and 2022; and projected final year emission inventory 
for 2026. On September 11, 2019 (84 FR 47889), EPA approved NCDEQ's 
July 25, 2018, SIP, which revised the budgets and the inventories. EPA 
subsequently approved NCDEQ's July 16, 2020, SIP revision (86 FR 
47387), which revised the sub-area budgets. These remain the current 
SIP-approved budgets and inventories. See tables 1 through 3, below.
    Maintenance for the Charlotte Maintenance Area is demonstrated when 
the emissions in the final year of the maintenance plan (``maintenance 
year'') are less than the emissions in the baseline attainment year. In 
the current SIP-approved inventories, the baseline year is 2014 and the 
maintenance year is 2026. See 80 FR 29250.

   Table 1--Current Total Man-Made NOX Emissions for North Carolina Portion of the Charlotte Maintenance Area
                                                   [Tons/day]
----------------------------------------------------------------------------------------------------------------
             County                    2014            2015            2018            2022            2026
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Cabarrus *......................           11.49           10.73            6.78            5.44            4.44
Gaston *........................           27.89           27.62           12.03            6.41            7.87
Iredell *.......................            6.86            6.49            5.41            4.68            4.16
Lincoln *.......................            4.36            4.71            6.41            4.29            2.34
Mecklenburg.....................           56.71           52.97           39.16           33.52           31.33
Rowan *.........................           11.74           11.31            8.28            7.01            6.10
Union *.........................           11.13           10.36            6.63            5.09            4.05
                                 -------------------------------------------------------------------------------
    Total.......................          130.18          124.19           84.69           66.44           60.28
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* Emissions for the portion of the county included in the maintenance area.


[[Page 25852]]


   Table 2--Current Total Man-Made VOC Emissions for North Carolina Portion of the Charlotte Maintenance Area
                                                   [Tons/day]
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             County                    2014            2015            2018            2022            2026
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Cabarrus *......................           11.50           11.27            9.51            9.23            9.02
Gaston *........................           12.96           12.74           11.53           10.94           10.74
Iredell *.......................            6.33            6.22            5.29            5.11            4.97
Lincoln *.......................            6.55            6.47            4.81            4.66            4.51
Mecklenburg.....................           50.10           49.16           45.31           44.47           43.99
Rowan *.........................           12.59           12.38           12.47           12.19           12.32
Union *.........................           13.09           12.85           10.91           10.68           10.45
                                 -------------------------------------------------------------------------------
    Total.......................          113.12          111.09           99.82           97.28           95.99
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* Emissions for the portion of the county included in the maintenance area.


Table 3--Current Maintenance Demonstration for North Carolina Portion of
                     the Charlotte Maintenance Area
------------------------------------------------------------------------
                                            NOX  (tons/     VOC  (tons/
                  Year                      summer day)     summer day)
------------------------------------------------------------------------
2014....................................          130.18          113.12
2015....................................          124.19          111.09
2018....................................           84.69           99.82
2022....................................           66.44           97.28
2026....................................           60.28           95.99
Reduction in emissions from 2014 to 2026           69.90           17.13
------------------------------------------------------------------------

    As shown in table 4, the revised NOX emissions for all 
years (interim years and maintenance year) are under the baseline of 
130.18 tons per summer day (tons/day); in the maintenance year of 2026, 
emissions are now projected to be 64.75 tons/day. Additionally, as 
shown in table 5, the revised VOC emissions for all years (interim 
years and maintenance year) are under the baseline of 113.12 tons/day; 
in the maintenance year of 2026, emissions are projected to be 94.57 
tons/day. The downward trend in revised NOX and VOC 
emissions based on the updated MOVES3 2026 NOX and VOC on-
road emissions inventory continues to show maintenance of the NAAQS. 
See table 6, below.

   Table 4--Revised Total Man-Made NOX Emissions for North Carolina Portion of the Charlotte Maintenance Area
                                                   [Tons/day]
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             County                    2014            2015            2018            2022            2026
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Cabarrus *......................           11.49           10.73            6.78            5.44            4.61
Gaston *........................           27.89           27.62           12.03            6.41            7.87
Iredell *.......................            6.86            6.49            5.41            4.68            4.42
Lincoln *.......................            4.36            4.71            6.41            4.29            2.48
Mecklenburg.....................           56.71           52.97           39.16           33.52           34.95
Rowan *.........................           11.74           11.31            8.28            7.01            6.02
Union *.........................           11.13           10.36            6.63            5.09            4.40
                                 -------------------------------------------------------------------------------
    Total.......................          130.18          124.19           84.69           66.44           64.75
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* Emissions for the portion of the county included in the maintenance area.


   Table 5--Revised Total Man-Made VOC Emissions for North Carolina Portion of the Charlotte Maintenance Area
                                                   [Tons/day]
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             County                    2014            2015            2018            2022            2026
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Cabarrus *......................           11.50           11.27            9.51            9.23            8.57
Gaston *........................           12.96           12.74           11.53           10.94           10.42
Iredell *.......................            6.33            6.22            5.29            5.11            4.88
Lincoln *.......................            6.55            6.47            4.81            4.66            4.63
Mecklenburg.....................           50.10           49.16           45.31           44.47           43.72
Rowan *.........................           12.59           12.38           12.47           12.19           11.96
Union *.........................           13.09           12.85           10.91           10.68           10.39
                                 -------------------------------------------------------------------------------

[[Page 25853]]

 
    Total.......................          113.12          111.09           99.82           97.28           94.57
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* Emissions for the portion of the county included in the maintenance area.


Table 6--Revised Maintenance Demonstration for North Carolina Portion of
                     the Charlotte Maintenance Area
------------------------------------------------------------------------
                                            NOX  (tons/     VOC  (tons/
                  Year                         day)            day)
------------------------------------------------------------------------
2014....................................          130.18          113.12
2015....................................          124.19          111.09
2018....................................           84.69           99.82
2022....................................           66.44           97.28
2026....................................           64.75           94.57
Reduction in emissions from 2014 to 2026           65.43           18.55
------------------------------------------------------------------------

    Table 7 provides the revised NOX and VOC on-road mobile 
emissions inventory for 2014 (base year) and 2026 (maintenance year) 
for the 2008 8-hour ozone NAAQS for the North Carolina portion of the 
Charlotte Maintenance Area. The emissions are expressed in tons/day and 
in kg/day because the budgets are expressed in kilograms per day (kg/
day). The MOVES3 output emissions values were rounded to the nearest 
kg/day and were divided by 907.1847 to convert them to units of tons/
day. The resulting values in tons/day were rounded to two decimal 
places.

  Table 7--Revised On-Road Mobile Source NOX and VOC Summer Day Emissions in 2014 and 2026 for the North Carolina Portion of the Charlotte Maintenance
                                                                          Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 2014 NOX                2014 VOC                2026 NOX                2026 VOC
                         County                          -----------------------------------------------------------------------------------------------
                                                           tons/day     kg/day     tons/day     kg/day     tons/day     kg/day     tons/day     kg/day
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cabarrus *..............................................        6.60       5,989        4.15       3,765        2.43       2,208        1.76       1,600
Gaston *................................................        8.11       7,357        4.61       4,179        2.45       2,224        1.68       1,524
Iredell *...............................................        3.36       3,045        1.95       1,768        1.29       1,171        0.86         782
Lincoln *...............................................        3.00       2,723        1.91       1,737        1.06         963        0.76         688
Mecklenburg *...........................................       26.99      24,488       14.40      13,060       12.08      10,957        7.14       6,476
Rowan *.................................................        6.42       5,825        3.76       3,408        1.94       1,757        1.37       1,246
Union *.................................................        5.67       5,146        3.54       3,210        2.29       2,074        1.62       1,471
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................       60.15      54,572       34.32      31,127       23.54      21,354       15.19      13,787
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Emissions for the portion of the county included in the maintenance area.

    A safety margin is the difference between the attainment level of 
emissions from all source categories (i.e., point, area, on-road, and 
nonroad) (2014 in this case) and the projected level of emissions from 
all source categories in the maintenance year (2026 in this case). The 
State may choose to allocate some of the safety margin to the budgets, 
for transportation conformity purposes, so long as the total level of 
emissions from all source categories remains equal to or less than the 
attainment level of emissions. As noted above, North Carolina 
previously chose to allocate a portion of its NOX and VOC 
safety margin to the budgets for the entire North Carolina portion of 
the Charlotte Maintenance Area for the year 2026. See 86 FR 32850 (June 
23, 2021) and 86 FR 47387 (August 25, 2021). Tables 8 and 9, below, 
show the revised MOVES3 safety margins and percentages North Carolina 
is proposing to allocate to the 2026 NOX and VOC budgets 
from the newly calculated safety margins, respectively, in the North 
Carolina portion of the Charlotte Maintenance Area.

  Table 8--Revised Safety Margins for the North Carolina Portion of the
                       Charlotte Maintenance Area
------------------------------------------------------------------------
                                            NOX  (tons/     VOC  (tons/
                  Year                         day)            day)
------------------------------------------------------------------------
2014....................................             N/A             N/A
2015....................................           -5.99           -2.03
2018....................................          -45.49          -13.30
2022....................................          -63.74          -15.84
2026....................................          -65.43          -18.55
------------------------------------------------------------------------


[[Page 25854]]

B. Revised Budgets

    In the December 19, 2022, SIP revision, North Carolina requested 
that EPA approve revisions to the budgets for the North Carolina 
portion of the Charlotte 2008 Ozone Maintenance Area by allocating a 
portion of the remaining safety margin to the budgets.\7\ The budget 
revisions are proposed to accommodate updates from the mobile emissions 
model MOVES3. The proposed percentages of the on-road emissions 
allocated to the 2026 budgets for the North Carolina counties in the 
Charlotte 2008 Ozone Maintenance Area are listed in the table 9, below.
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    \7\ As with the original SIP revision approved on July 15, 2015, 
and the last revision approved on August 25, 2021, NCDEQ utilized a 
five-step approach for determining a factor to use to calculate the 
amount of safety margin to apply to the budgets for 2026. See 
Appendix A of the submittal for more detailed information.
    \8\ These VOC percentages were not clearly delineated in NCDEQ's 
December 19, 2022, submittal (at table 4.1 in the narrative portion 
of the submittal and table 4.4-1 in Appendix A). NCDEQ submitted a 
correction to the December 19, 2022, submittal via a letter dated 
March 15, 2024, which is in the docket for this proposed rulemaking.

 Table 9--Proposed Percentage of On-Road Emissions Allocated to the 2026
                     Motor Vehicle Emissions Budget
------------------------------------------------------------------------
                                          NOX  (percent)      VOC \8\
                 County                                      (percent)
------------------------------------------------------------------------
Cabarrus................................              65              67
Gaston..................................              60              62
Iredell.................................              62              62
Lincoln.................................              62              62
Mecklenburg.............................              57              57
Rowan...................................              65              67
Union...................................              60              62
------------------------------------------------------------------------

    Based on the on-road emissions inventory revisions in table 7, the 
following tables provide the proposed NOX and VOC sub-area 
budgets with the proposed safety margin allocations in kg/day for 
transportation conformity purposes for 2026 (2014 is only shown for 
illustration because no changes are being made to the budgets for that 
year).

      Table 10--Proposed Cabarrus-Rowan Metropolitan Planning Organization (CRMPO) Budgets in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          11,814           7,173           3,965           2,846
Safety margin allocated to budget...............                                           2,578           1,907
Conformity budget...............................          11,814           7,173           6,543           4,753
----------------------------------------------------------------------------------------------------------------
* Includes the portions of Cabarrus and Rowan Counties in the maintenance area.


Table 11--Proposed Gaston-Cleveland-Lincoln Metropolitan Planning Organization (GCLMPO) Budgets in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          10,079           5,916           3,187           2,212
Safety margin allocated to budget...............                                           1,930           1,371
Conformity budget...............................          10,079           5,916           5,117           3,583
----------------------------------------------------------------------------------------------------------------
* Includes the portions of Gaston and Lincoln Counties in the maintenance area. Although Cleveland County is
  included in the MPO, it is not included in the Charlotte ozone maintenance area.


 Table 12--Proposed Charlotte Regional Transportation Planning Organization (CRTPO)--Rocky River Rural Planning
                                  Organization (RRRPO) Budgets in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          32,679          18,038          14,202           8,729
Safety margin allocated to budget...............                                           8,215           5,089
Conformity budget...............................          32,679          18,038          22,417          13,818
----------------------------------------------------------------------------------------------------------------
* Includes all of Mecklenburg County and a portion of Iredell and Union Counties in the maintenance area.


[[Page 25855]]

C. Revised Safety Margin

    As mentioned above, a safety margin is the difference between the 
attainment level of emissions from all source categories (i.e., point, 
area, on-road, and nonroad) and the projected level of emissions from 
all source categories. NCDEQ has requested that EPA approve the 
proposed allocation of some of the available safety margin to the 2026 
NOX and VOC budgets for transportation conformity purposes. 
The total level of emissions from all source categories remains equal 
to or less than the attainment level of emissions.
    EPA is proposing to approve changes to the budgets that include a 
proposed allocation of 2,577 and 1,907 kg/day of NOX and 
VOC, respectively, for the Cabarrus-Rowan MPO; 1,931 and 1,371 kg/day 
of NOX and VOC, respectively, for the Gaston-Cleveland MPO; 
and 8,215 and 5,089 kg/day of NOX and VOC, respectively, for 
the Charlotte Regional TPO. Thus, if EPA's action is finalized as 
proposed, the amount of the safety margin allocated to the 2026 budgets 
will be 12,723 kg/day (14.02 tons/day) of NOX and 8,367 kg/
day (9.22 tons/day) of VOC. The proposed new safety margins available 
for the North Carolina portion of the Charlotte Maintenance Area are 
listed below.

   Table 15--New Safety Margins for the North Carolina Portion of the
                       Charlotte Maintenance Area
------------------------------------------------------------------------
                                            NOX  (tons/     VOC  (tons/
                  Year                         day)            day)
------------------------------------------------------------------------
2014....................................           * N/A             N/A
2015....................................           -5.99           -2.03
2018....................................          -45.49          -13.30
2022....................................          -63.74          -15.84
2026....................................          -51.41           -9.33
------------------------------------------------------------------------

D. Adequacy of the Budgets

    EPA evaluated NCDEQ's December 19, 2022, SIP revision allocating a 
portion of the available safety margin to the 2026 MOVES3 based budgets 
in the revised 2008 8-hour ozone Charlotte maintenance plan for use in 
determining transportation conformity in the North Carolina portion of 
the Charlotte Maintenance Area. EPA is proposing this action based on 
its evaluation of these budgets using the adequacy criteria found in 40 
CFR 93.118(e)(4) and its evaluation of NCDEQ's submittal and SIP 
requirements. EPA is proposing to approve this SIP revision because the 
SIP continues to serve its intended purpose of maintenance of the 2008 
8-hour ozone standard with the newly revised MOVES3 based budgets. EPA 
is also proposing to deem the budgets adequate for transportation 
conformity purposes because they meet the adequacy criteria in the 
conformity rule at 40 CFR 93.118(e)(4). Specifically:
     NCDEQ's SIP was endorsed by the Governor's designee and 
was subject to a State public hearing ((e)(4)(i));
     Before NCDEQ submitted the SIP revision to EPA, 
consultation among Federal, State, and local agencies occurred and full 
documentation was provided to EPA and EPA had no concerns ((e)(4)(ii));
     The budgets are clearly identified and precisely 
quantified ((e)(4)(iii));
     The budgets, when considered together with all other 
emissions sources, are consistent with applicable requirements for 
reasonable further progress, attainment, or maintenance ((e)(4)(iv));
     The budgets are consistent with and clearly related to the 
emissions inventory and control measures in the SIP revision 
((e)(4)(v); and
     The December 19, 2022, SIP revision explains and documents 
changes to the previous budgets, impacts on point, area, nonroad and 
on-road source emissions, and changes to established safety margins, 
and reasons for the changes (including the basis for any changes 
related to emission factors or vehicle miles traveled) ((e)(4)(vi)).

IV. Proposed Action

    EPA is proposing to approve NCDEQ's December 19, 2022, SIP 
revision, requesting approval of a revision to the Charlotte 2008 8-hr 
Ozone Maintenance Plan that updates the 2026 on-road and nonroad 
emissions inventories and safety margins with MOVES3, allocates a 
portion of the newly available 2026 safety margins. The SIP revision 
also updates the current 2026 budgets with MOVES3 and recalculates new 
available safety margins. The revised budgets ensure continued 
attainment of the 2008 8-hour ozone NAAQS through the maintenance year 
2026. In addition, EPA is proposing to deem the budgets adequate for 
transportation conformity purposes because the budgets meet the 
adequacy criteria in the conformity rule at 40 CFR 93.118(e)(4). If 
approved, the newly revised MOVES3 2026 budgets for NOX and 
VOC identified in tables 10 through 12 will be used by the MPOs in 
future transportation conformity determinations. The remaining safety 
margins are 51.41 tons/day and 9.33 tons/day for NOX and 
VOC, respectively. EPA has evaluated North Carolina's submittal and has 
determined that it meets the applicable requirements of the CAA and EPA 
regulations and is consistent with EPA policy.

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve State choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
proposed action merely 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 14094 (88 FR 21879, April 11, 2023);
     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);

[[Page 25856]]

     Is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it approves a State program;
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
     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.
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rulemaking does not have Tribal implications and will not 
impose substantial direct costs on Tribal governments or preempt Tribal 
law as specified by Executive Order 13175 (65 FR 67249, November 9, 
2000).
    Executive Order 12898 (Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
Feb. 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. 
EPA defines environmental justice (EJ) as ``the fair treatment and 
meaningful involvement of all people regardless of race, color, 
national origin, or income with respect to the development, 
implementation, and enforcement of environmental laws, regulations, and 
policies.'' EPA further defines the term fair treatment to mean that 
``no group of people should bear a disproportionate burden of 
environmental harms and risks, including those resulting from the 
negative environmental consequences of industrial, governmental, and 
commercial operations or programs and policies.''
    NCDEQ did not evaluate EJ considerations as part of its SIP 
submittal; the CAA and applicable implementing regulations neither 
prohibit nor require such an evaluation. EPA did not perform an EJ 
analysis and did not consider EJ in this proposed action. Due to the 
nature of the action being proposed here, this proposed action is 
expected to have a neutral to positive impact on the air quality of the 
affected area. Consideration of EJ is not required as part of this 
proposed action, and there is no information in the record inconsistent 
with the stated goal of E.O. 12898 of achieving EJ for people of color, 
low-income populations, and Indigenous peoples.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Carbon monoxide, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements, Volatile organic compounds.

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

    Dated: April 5, 2024.
Jeaneanne Gettle,
Acting Regional Administrator, Region 4.
[FR Doc. 2024-07701 Filed 4-11-24; 8:45 am]
BILLING CODE 6560-50-P