Document ID: EPA-R04-OAR-2020-0515-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: North Carolina; Revision to Approved Motor Vehicle Emissions Budgets
Posted Date: 2021-06-23T04:00Z

[Federal Register Volume 86, Number 118 (Wednesday, June 23, 2021)]
[Proposed Rules]
[Pages 32850-32856]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13081]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2020-0515; FRL-10024-72-Region 4]

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 to EPA on July 16, 2020, by the State of North 
Carolina, through the North Carolina Department of Environment and 
Natural Resources, Division of Air Quality (NCDAQ) for the purpose of 
allocating a portion of the available 2026 safety margin in the 2008 8-
hour Ozone Maintenance Plan to the 2026 nitrogen oxides 
(NOX) and volatile organic compounds (VOC) motor vehicle 
emissions budgets (``MVEBs'' or ``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 account for uncertainty associated with the 
mobile emissions model and unanticipated growth in vehicle miles 
traveled for the North Carolina portion of the Charlotte Maintenance 
Area. This SIP revision also revises the 2026 MVEBs which are used for 
transportation conformity. NCDAQ's July 16, 2020 submission supplements 
the revised 2008 8-hour Ozone Maintenance Plan submitted by NCDAQ on 
July 25, 2018, and approved by EPA on September 11, 2019. EPA is 
proposing to approve North Carolina's July 16, 2020 SIP revision and 
deem the MVEBs adequate for transportation conformity purposes because 
they meet all the statutory and regulatory requirements.

DATES: Comments must be received on or before July 23, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2020-0515 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 www2.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 
myers.dianna@epa.gov.

SUPPLEMENTARY INFORMATION:

I. What action is EPA proposing?

    EPA is proposing to approve NCDAQ's July 16, 2020, SIP revision to 
allocate a portion of the available safety margin to revise the 2026 
NOX and VOC budgets for the North Carolina portion of 
Charlotte 2008 8-hour Ozone Maintenance Area \1\ for transportation 
conformity purposes. NCDAQ requested approval of the July 16, 2020 SIP 
revision in order to account for unanticipated changes in the travel 
demand model, such as unanticipated growth in vehicle miles traveled, 
changes and uncertainty in vehicle mix assumptions, and uncertainty 
associated with mobile emissions modeling.
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    \1\ The North Carolina portion of the Charlotte Maintenance Area 
for the 2008 ozone NAAQS is comprised of the following counties: 
Mecklenburg 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 budgets 
from NCDAQ's July 16, 2020, SIP revision will replace the existing 
budgets in the State's 2008 8-hour Ozone Maintenance Plan revision 
approved on September 11, 2019. See 84 FR 47889. If approved, these 
newly revised 2026 budgets must be used in future transportation 
conformity analyses for the Area according to the transportation 
conformity rule. See 40 CFR 93.118. Therefore, the September 11, 2019, 
approved budgets would no longer be applicable for transportation 
conformity purposes.
    In the State's submission, all emissions inventories (on-road, 
point, area, and nonroad) from NCDAQ's September 11, 2019, SIP revision 
remain the same. The submission only allocates a portion of the 
available safety margin to the 2026 NOX and VOC MVEBs. 
Therefore, EPA is proposing to conclude that North Carolina's July 16, 
2020, SIP revision continues to demonstrate

[[Page 32851]]

maintenance for the Charlotte Maintenance Area.

II. What is the background for this action?

A. SIP Budgets and Transportation Conformity

    Under the CAA, 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 MVEBs 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 MVEBs 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 can 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, EPA can approve the revised SIP and budgets 
and also affirm that the budgets are adequate at the same time. Once 
EPA approves the SIP with 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 national 
ambient air quality standard (hereinafter referred to as NAAQS or 
standard). The North Carolina portion of the Charlotte 2008 Maintenance 
Area includes Mecklenburg 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. 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 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 MVEBs.\2\ On August 17, 2015 (80 FR 49164), EPA approved North 
Carolina's section 110(l) noninterference demonstration requesting 
relaxation of the Federal Reid Vapor Pressure from 7.8 pounds per 
square inch (psi) to 9.0 psi and a revision to the 2026 NOX 
and VOC sub-area MVEBs for Mecklenburg and Gaston Counties only. See 80 
FR 44868.
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    \2\ There are currently six ozone monitors located throughout 
the North Carolina portion of the Charlotte Maintenance Area and one 
monitor located in York County, South Carolina. The current design 
value for the Charlotte Maintenance Area is 70 parts per billion.
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    Subsequently, on July 25, 2018, NCDAQ submitted a revision to the 
Charlotte 2008 8-hour ozone maintenance plan to update the emissions 
forecast and MVEBs 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 NCDAQ'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 MVEBs became effective on October 11, 2019.

C. MOVES Emissions Model

    The Motor Vehicle Emissions Simulator (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.\3\ MOVES2014 and its subsequent 
minor updates, MOVES2014a and MOVES2014b, added the capability to 
estimate exhaust and evaporative emissions from most types of nonroad 
equipment. North Carolina's July 16, 2020 SIP submittal contains mobile 
source emissions estimates using MOVES2014 with local inputs data to 
more accurately represent local vehicle fleets and emissions 
characteristics.\4\ See MOVES2014, MOVES2014a, and MOVES2014b Technical 
Guidance: Using MOVES to Prepare Emission Inventories for State 
Implementation Plans and Transportation Conformity, EPA-420-B-18-039, 
August 2018, available at https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100V7EY.txt.
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    \3\ In California, a different on-road emissions model, EMFAC, 
is used for regulatory purposes instead of MOVES.
    \4\ On January 7, 2021 (86 FR 1106), EPA announced the 
availability of the MOVES3 for official purposes outside of 
California. MOVES3 is the state of the science emission modeling 
system that incorporates the latest emissions data and estimates 
emissions from mobile sources at the national, county, and project 
level for criteria air pollutants, greenhouse gases, and air toxics. 
While MOVES3 is available for use in SIPs and transportation 
conformity analyses outside of California, states and local agencies 
that had completed a SIP revision with MOVES2014 at the time of the 
release of MOVES3 could continue to rely on MOVES2014 for that SIP 
submittal. NCDAQ completed and submitted the SIP revision that is 
the subject of this proposed action on July 16, 2020, before MOVES3 
was released.
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III. What is EPA's analysis of North Carolina's submittal?

    EPA's analysis involves an emissions comparison between the current 
SIP-approved MVEBs and the MVEBs that North Carolina has requested EPA 
approve in the July 16, 2020 SIP submittal. Section III.A. provides 
information regarding the current SIP-

[[Page 32852]]

approved MVEBs and inventories, while sections III.B. and III.C. 
contain information and analysis regarding the proposed revisions to 
the MVEBs and safety margin, respectively. Section III.D. contains 
EPA's proposed analysis of the adequacy of North Carolina's revised 
MVEBs pursuant to 40 CFR 93.118(e)(4).
    As discussed further below, EPA's analysis of North Carolina's July 
16, 2020 SIP submittal indicates that maintenance will continue to be 
demonstrated after allocation of a portion of the safety margin to the 
MVEBs 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 July 16, 2020 SIP 
submittal.

A. Maintenance Demonstration and Emissions Inventory

    This section contains information regarding the previous and 
current SIP-approved MVEBs and inventories. The inventories are 
provided for illustrative purposes only, as in this action, EPA is not 
proposing any changes the inventories.\5\
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    \5\ As discussed above, if EPA approves NCDAQ's July 16, 2020 
SIP submittal, all emissions inventories (on-road, point, area, and 
nonroad) from NCDAQ's September 11, 2019, SIP revision remain the 
same, while a portion of the safety margin will be allocated to the 
MVEBs.
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    As discussed above, EPA originally approved NCDAQ'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, 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 NCDAQ's July 
25, 2018 SIP, which revised the MVEBs and the inventories; these remain 
the current SIP-approved MVEBs and inventories.
    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 baseline attainment year. In the current SIP-
approved inventories, the baseline year is 2014 and the maintenance 
year is 2026. See 80 FR 29250. As shown in Table 1, for 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 projected to be 60.28 tons/day. 
Additionally, as shown in Table 2, for 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 95.99 tons/day. The downward trend in NOX and VOC 
emissions is shown in Table 3 below.

       Table 1--Total Man-Made NOX Emissions for North Carolina Portion of the Charlotte Maintenance Area
                                                   [tons/day]
----------------------------------------------------------------------------------------------------------------
             County                    2014            2015            2018            2022            2026
----------------------------------------------------------------------------------------------------------------
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.

       Table 2--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--Maintenance Demonstration for North Carolina Portion of the
                       Charlotte Maintenance Area
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                                            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

[[Page 32853]]

 
2026....................................           60.28           95.99
Reduction in emissions from 2014 to 2026           69.90           17.13
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    The following table provides the NOX and VOC on-road 
mobile emissions inventory for the 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 MVEBs are expressed in 
kilograms per day kg/day. The MOVES2014 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 4--On-Road Mobile Source NOX and VOC Summer Day Emissions in 2014 and 2026 for the North Carolina Portion of the Charlotte Maintenance Area
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                                                          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         2.00        1,810         2.19        1,982
Gaston **.......................................         8.11        7,357         4.61        4,179         2.12        1,924         1.86        1,689
Iredell *.......................................         3.36        3,045         1.95        1,768         1.00          903         0.88          801
Lincoln *.......................................         3.00        2,723         1.91        1,737         0.83          757         0.86          779
Mecklenburg **..................................        26.99       24,488        14.40       13,060         7.17        6,501         6.98        6,334
Rowan *.........................................         6.42        5,825         3.76        3,408         1.73        1,571         1.53        1,389
Union *.........................................         5.67        5,146         3.54        3,210         1.62        1,466         1.68        1,520
                                                 -------------------------------------------------------------------------------------------------------
    Total.......................................        60.15       54,572        34.32       31,127        16.47       14,932        15.98       14,494
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* Emissions for the portion of the county included in the maintenance area.
** The 2014 base year NOX and VOC emissions for Gaston and Mecklenburg counties have been revised slightly to correct a transcription error in the
  original maintenance plan.

    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 MVEBs, 
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. North Carolina previously chose to 
allocate a portion of its NOX and VOC safety margin to the 
MVEBs for the entire North Carolina portion of the Charlotte 
Maintenance Area for the year 2026. See 84 FR 22774 (May 20, 2019) and 
84 FR 47889 (Sept. 11, 2019). The current SIP-approved safety margins, 
percent increase allocated to the 2026 NOX and VOC MVEBs 
from the safety margin for each county, and resulting subarea MVEBs in 
the North Carolina portion of the Charlotte Maintenance Area are listed 
in Tables 5 through 9 below.

    Table 5--Current Safety Margins for North Carolina Portion of the
                       Charlotte Maintenance Area
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                                            NOX  (tons/     VOC  (tons/
                  Year                      summer day)     summer day)
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2014....................................             N/A             N/A
2015....................................           -5.99           -2.03
2018....................................          -45.49          -13.30
2022....................................          -63.74          -15.84
2026....................................          -66.60          -13.92
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 Table 6--Current Percent Increase to the 2026 Mobile Vehicle Emissions
                                 Budget
------------------------------------------------------------------------
                         County                                2026
------------------------------------------------------------------------
Cabarrus................................................              25
Gaston..................................................              20
Iredell.................................................              22
Lincoln.................................................              22
Mecklenburg.............................................              17
Rowan...................................................              25

[[Page 32854]]

 
Union...................................................              20
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            Table 7--Cabarrus Rowan Metropolitan Planning Organization (CRMPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
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                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
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Base On-road Emissions..........................          11,814           7,173           3,381           3,371
Safety margin allocated to MVEB.................  ..............  ..............             846             843
Conformity MVEB.................................          11,814           7,173           4,227           4,214
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* Includes the portion of Cabarrus and Rowan Counties in the maintenance area.

      Table 8--Gaston-Cleveland-Lincoln Metropolitan Planning Organization (GCLMPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
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                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
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Base On-road Emissions..........................          10,079           5,916           2,681           2,468
Safety margin allocated to MVEB.................  ..............  ..............             551             510
Conformity MVEB.................................          10,079           5,916           3,232           2,978
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* Includes the portion 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 9--Charlotte Regional Transportation Planning Organization (CRTPO)--Rocky River Rural Planning
                                   Organization (RRRPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
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                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          32,679          18,038           8,870           8,655
Safety margin allocated to MVEB.................  ..............  ..............           1,596           1,557
Conformity MVEB.................................          32,679          18,038          10,466          10,212
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 *Includes all of Mecklenburg County and a portion of Iredell and Union Counties in the maintenance area.

B. Revised MVEBs

    In the July 16, 2020 SIP revision, North Carolina requested that 
EPA approve revisions to the MVEBs for the North Carolina portion of 
the Charlotte 2008 Ozone Maintenance Area by allocating a portion of 
the remaining safety margin to the MVEBs.6 7 The MVEB 
revisions are proposed to accommodate recent updates to the travel 
demand model impacting vehicle miles traveled, changes and uncertainty 
in vehicle mix assumptions, and uncertainty associated with mobile 
modeling in the North Carolina portion of the Charlotte Maintenance 
Area. The cumulative percent increases--including both the current SIP-
approved percent increases as shown in Table 6, above, as well as the 
proposed 20 percent increase applied to all counties--to the MVEBs for 
the North Carolina counties in the Charlotte 2008 Ozone Maintenance 
Area are listed in the Table 10 below.
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    \6\ As with the original SIP approved on July 15, 2015, and the 
last revision approved on September 11, 2019, NCDAQ utilized a five-
step approach for determining a factor to use to calculate the 
amount of safety margin to apply to the MVEBs for 2026. See Appendix 
A of the submittal for more detailed information.
    \7\ The proposed changes to the safety margins are discussed in 
section III.C., below.

Table 10--Proposed Percent Increase to the 2026 Mobile Vehicle Emissions
                                 Budget
------------------------------------------------------------------------
                         County                                2026
------------------------------------------------------------------------
Cabarrus................................................              45
Gaston..................................................              40
Iredell.................................................              42
Lincoln.................................................              42
Mecklenburg.............................................              37
Rowan...................................................              45
Union...................................................              40
------------------------------------------------------------------------

[[Page 32855]]

    The following tables provide the proposed updated NOX 
and VOC sub-area MVEBs 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 MVEBs 
for that year). The amount of the proposed safety margin allocation 
includes the current SIP-approved safety margin allocations referenced 
in the tables above as well as the proposed percentages in values.

           Table 11--Cabarrus Rowan Metropolitan Planning Organization (CRMPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          11,814           7,173           3,381           3,371
Safety margin allocated to MVEB.................  ..............  ..............           1,522           1,517
Conformity MVEB.................................          11,814           7,173           4,903           4,888
----------------------------------------------------------------------------------------------------------------
* Includes the portion of Cabarrus and Rowan Counties in the maintenance area. The allocation proposed in this
  action to the NOX MVEB is 676 kg/day and VOC is 674 kg/day.

      Table 12--Gaston-Cleveland-Lincoln Metropolitan Planning Organization (GCLMPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          10,079           5,916           2,681           2,468
Safety margin allocated to MVEB.................               -               -           1,087           1,004
Conformity MVEB.................................          10,079           5,916           3,768           3,472
----------------------------------------------------------------------------------------------------------------
* Includes the portion 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. The allocation proposed in
  this action to the NOX MVEB is 536 kg/day and VOC is 494 kg/day.

      Table 13--Charlotte Regional Transportation Planning Organization (CRTPO)--Rocky River Rural Planning
                                   Organization (RRRPO) MVEBs in 2014 and 2026
                                                   [kg/day] *
----------------------------------------------------------------------------------------------------------------
                                                     2014 NOX        2014 VOC        2026 NOX        2026 VOC
----------------------------------------------------------------------------------------------------------------
Base On-road Emissions..........................          32,679          18,038           8,870           8,655
Safety margin allocated to MVEB.................  ..............  ..............           3,371           3,288
Conformity MVEB.................................          32,679          18,038          12,241          11,943
----------------------------------------------------------------------------------------------------------------
* Includes all of Mecklenburg County and a portion of Iredell and Union Counties in the maintenance area. The
  allocation proposed in this action to the NOX MVEB is 1,775 kg/day and VOC is 1,731 kg/day.

C. Revised Safety Margin

    As mentioned before, 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 in the 
maintenance year from all source categories. NCDAQ has requested EPA 
approve allocation of some of the available safety margin to the 2026 
MVEBs 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 MVEBs that result in 
additional safety margin allocations to the 2026 MVEBs of 2,987 kg/day 
(3.29 tons/day) of NOX and 2,899 kg/day (3.19 tons/day) of 
VOC. This includes a proposed allocation of 676 and 674 kg/day of 
NOX and VOC, respectively for the Cabarrus-Rowan MPO; 536 
and 494 kg/day of NOX and VOC, respectively for the Gaston-
Cleveland MPO; and 1,775 and 1,731 kg/day, respectively for the 
Charlotte Regional TPO. Thus, if EPA's action is finalized as proposed, 
the cumulative safety margin emissions allocated to the 2026 MVEBs will 
be 5,980 kg/day (6.59 tons/day) of NOX and 5,809 kg/day 
(6.40 tons/day) of VOC.\8\ The proposed new safety margins available 
for the North Carolina portion of the Charlotte Maintenance Area are 
listed below.
---------------------------------------------------------------------------

    \8\ The amount of the safety margin is a cumulative total of the 
current safety margin allocations (shown in Tables 5 through 7) and 
the proposed safety margin allocations (shown in Tables 11 through 
13).

   Table 14--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....................................          -63.31          -10.73
------------------------------------------------------------------------

[[Page 32856]]

D. Adequacy of the Budgets

    EPA evaluated NCDAQ's July 16, 2020 SIP revision allocating a 
portion of the available safety margin to the 2026 MOVES2014 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 our evaluation of these budgets using the adequacy criteria 
found in 40 CFR 93.118(e)(4) and evaluation of NCDAQ'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 MOVES2014 based 
budgets and 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:
     NCDAQ's SIP was endorsed by the Governor's designee and 
was subject to a state public hearing ((e)(4)(i));
     Before NCDAQ 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 submitted 
July 16, 2020 ((e)(4)(v)); and
     The July 16, 2020 SIP revision explains and documents 
changes to the previous budgets, impacts on point and area 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 NCDAQ's July 16, 2020 SIP revision, 
requesting approval of a revision to the Charlotte 2008 8-hr Ozone 
Maintenance Plan in order to allocate a portion of the available safety 
margin to revise the 2026 NOX and VOC MVEBs. The revised 
MVEBs ensure continued attainment of the 2008 8-hour ozone NAAQS 
through the maintenance year 2026. In addition, EPA is proposing to 
deem the MVEBs 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 2026 budgets for 
NOX and VOC identified in Tables 11 through 13 will be used 
by the MPOs in future transportation conformity determinations. The 
remaining safety margin is 63.31 tons/day and 13.73 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 
submittal 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. Accordingly, this 
proposed action merely proposes to approve state law as meeting Federal 
requirements and does not propose to impose additional requirements 
beyond those imposed by state law. For that reason, these proposed 
actions:
     Are not significant regulatory actions subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Do not impose information collection burdens under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are certified as not having significant economic impacts 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Do not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, October 7, 1999);
     Are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Do not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    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 proposed 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, Carbon monoxide, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements and Volatile organic compounds.

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

    Dated: June 10, 2021.
John Blevins,
Acting Regional Administrator, Region 4.
[FR Doc. 2021-13081 Filed 6-22-21; 8:45 am]
BILLING CODE 6560-50-P