[Federal Register Volume 86, Number 156 (Tuesday, August 17, 2021)]
[Rules and Regulations]
[Pages 45871-45887]
[FR Doc No: 2021-17214]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2019-0618 and EPA-R04-OAR-2019-0619; FRL-8839-02-R4]

Air Plan Approval; TN; Removal of Vehicle I/M Program for the
Middle Tennessee and Hamilton County Areas

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is approving state
implementation plan (SIP) revisions submitted by the State of
Tennessee, through the Tennessee Department of Environment and
Conservation (TDEC), through letters dated February 26, 2020.
Specifically, EPA is approving the removal of Tennessee's motor vehicle
inspection and maintenance (I/M) program requirements for Davidson,
Sumner, Rutherford, Williamson and Wilson Counties in Tennessee (also
known as the Middle Tennessee Area) and Hamilton County (also known as
the Chattanooga Area), from the federally-approved SIP. EPA is
approving the February 26, 2020, SIP revisions to remove the I/M
program requirements for the aforementioned areas from the federally-
approved SIP because Tennessee's requests are consistent with the Clean
Air Act (CAA or Act) and applicable regulations.

DATES: This rule is effective on September 16, 2021.

ADDRESSES: EPA has established dockets for these actions under Docket
Identification No. EPA-R04-OAR-2019-0618 and EPA-R04-OAR-2019-0619 at
http://www.regulations.gov. All documents in the dockets are listed on
the www.regulations.gov website. Although listed in the index, some
information may not be publicly available, i.e., Confidential Business
Information or other information whose disclosure is restricted by
statute. Certain other material, such as copyrighted material, is not
placed on the internet and will be publicly available only in hard copy
form. Publicly available docket materials can either be retrieved
electronically via www.regulations.gov or in hard copy at the Air
Regulatory Management Section, Air Planning and Implementation Branch,
Air and Radiation Division, U.S. Environmental Protection Agency,
Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. EPA
requests that if at all possible, you contact the person listed in the
FOR FURTHER INFORMATION CONTACT section to schedule your inspection.
The Regional Office's official hours of business are Monday through
Friday 8:30 a.m. to 4:30 p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Lynorae Benjamin, Chief, Air Planning
and Implementation Branch, Air and Radiation Division, Region 4, U.S.
Environmental Protection Agency, 61 Forsyth Street SW, Atlanta, Georgia
30303-8960. The telephone number is<PHONE_NUMBER>. Ms. Benjamin can
also be reached via electronic mail at<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. This Action

    EPA is approving changes to the Tennessee SIP that were provided to
EPA under cover letters dated February 26, 2020.\1\ Specifically, the
State requested that Tennessee Air Pollution Control Regulations
(TAPCR) 1200-03-29 and Davidson County Regulation 8 be removed from the
Tennessee SIP.\2\ In addition, Tennessee requested that EPA remove the
requirements for the Middle Tennessee Area 3 4 and Hamilton
County to implement an I/M program as part of the Early Action Compact
(EAC) that was approved by EPA into the non-regulatory portion of the
Tennessee SIP on August 26, 2005. See 70 FR 50199. EPA is approving
these requests because the SIP revisions are consistent with the CAA,
including section 110(l).
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    \1\ EPA officially received Tennessee's I/M SIP revisions on
February 27, 2020.
    \2\ The State's I/M program at TAPCR 1200-03-29 covers Hamilton
County in addition to Sumner, Rutherford, Williamson and Wilson
Counties. Throughout this rule, where EPA uses the phrase ``I/M
program,'' the Agency is referring to the State's I/M program in
both the Middle Tennessee Area and Hamilton County, and the Davidson
County I/M program unless otherwise noted.
    \3\ In December 2002, the Middle Tennessee Area entered into
EPA's EAC program. As part of the EAC for the Middle Tennessee Area,
the I/M program was identified as an existing control strategy in
the SIP.
    \4\ Throughout this final rulemaking, unless otherwise noted,
where the Middle Tennessee Area is referenced EPA is intending for
this to mean the area covering Davidson, Sumner, Rutherford,
Williamson and Wilson Counties.
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II. Background

    On May 15, 2018, a Tennessee law was signed that states that ``no

inspection and maintenance program shall be employed in this state on
or after the effective date of this act.'' See Tenn. Code Ann. section
68-201-119. The Tennessee law states that it ``shall take effect [120]
calendar days following the date on which the [EPA] approves a revised
state implementation plan. . . .'' See Motor Vehicles--Inspection and
Inspectors--Air Pollution, 2018 Tennessee Laws Pub. Ch. 953 (H.B.
1782). Accordingly, Tennessee submitted the February 26, 2020, SIP
revisions requesting that EPA remove the provisions that implement an
I/M program for the Middle Tennessee Area and for Hamilton County from
the Tennessee SIP.\5\
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    \5\ Tenn. Code Ann. section 68-201-119(c) allows Tennessee
counties to retain local I/M programs under certain conditions. As
Tennessee is requesting removal of the I/M program from the SIP,
EPA's analysis in this final rule assumes that no I/M program will
be implemented in Hamilton County or the Middle Tennessee Area.
However, this final action does not preclude local I/M programs from
being retained at a local level outside of the SIP.
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    EPA published notices of proposed rulemaking (NPRMs) on June 8,
2020, and June 11, 2020, responding to Tennessee's February 26, 2020,
SIP revisions requesting that EPA approve removal of the I/M program
from the Tennessee SIP for the Middle Tennessee Area and for Hamilton
County, respectively. See 85 FR 35037 and 85 FR 35607. The June 8,
2020, and June 11, 2020, NPRMs (hereinafter referred to as the June
2020 NPRMs) were based on EPA's proposed findings that the removal of
the I/M program from the Tennessee SIP for the Middle Tennessee Area
and for Hamilton County will not interfere with attainment or
maintenance of any national ambient air quality standards (NAAQS or
standards) or with any applicable requirements of the CAA. See EPA's
June 2020 NPRMs. Comments were due on July 8, 2020, and July 13, 2020,
respectively. Adverse comments were received on the June 2020 NPRMs and
are addressed in Section IV of this final rulemaking.
    On April 22, 2021, EPA published a supplemental notice of proposed
rulemaking (hereinafter referred to as the April 2021 SNPRM) to seek
public comment on the Agency's additional and clarified technical
rationale related to the proposed approval of Tennessee's February 26,
2020, SIP revisions. See 86 FR 21248. The April 2021 SNPRM proposed to
affirm that the Hamilton County and Middle Tennessee areas would
continue to attain and maintain the NAAQS after removal of the I/M
program, and to rely on an emissions inventory comparison to inform its
determination that both areas would continue to attain and maintain the
ozone and carbon monoxide (CO) NAAQS. See 86 FR 21248. In the April
2021 SNPRM, EPA further proposed to conclude that the removal of the I/
M program will not interfere with the ability of other states to attain
and maintain the 2008 ozone NAAQS under the good neighbor provision of
the CAA and provided additional information related to that conclusion.
See 86 FR 21248. Comments on the April 2021 SNPRM were due May 24,
2021. Adverse comments were also received on the April 2021 SNPRM and
are addressed in Section IV of this final rulemaking.
    As mentioned above, in this action, EPA is responding to adverse
comments received of the June 2020 NPRMs. See Section IV of this final
rule. Further, as relevant, EPA is responding to additional comments
received on the April 2021 SNPRM and is finalizing the removal of the
I/M program from Tennessee's SIP for the Middle Tennessee Area and for
Hamilton County. EPA chose to issue one final rulemaking for all three
proposals. See Section IV of this final rule.

III. Summary of EPA's Analysis

    EPA's CAA section 110(l) non-interference demonstration supporting
approval of Tennessee's SIP revisions seeking removal of the I/M
program in Hamilton County and the Middle Tennessee Area focuses on
ozone (through its precursors nitrogen oxides (NOX) and
volatile organic compounds (VOC)) and carbon monoxide (CO), the
criteria pollutants addressed by I/M programs.\6\ I/M programs are not
designed to address lead and sulfur dioxide (SO2) emissions,
and nitrogen dioxide (NO2) is captured generally through
consideration of NOX impacts. While EPA considers
NOX, VOCs, ammonia, and SO2 as precursors for
particulate matter (PM), PM formation in Tennessee is dominated by
emissions of SO2, reacting in the atmosphere to form
sulfates, and not by emissions of NOX, VOCs, or ammonia.
However, NOX and VOC increases are considered through the
analysis for ozone. Although Tennessee is NOX-limited \7\
for ozone formation, EPA also evaluated VOC emissions to be
environmentally conservative in its action.
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    \6\ The total suite of CAA criteria pollutants are ozone
(through the precursors NOX and VOCs), CO, PM (and its
precursors--NOX, VOCs, ammonia, and SO2),
lead, SO2, and NO2.
    \7\ The term ``NOX limited'' means that changes in
anthropogenic VOC emissions have little effect on ozone formation.
Control of NOX and VOC are generally considered the most
important components of an ozone control strategy, and
NOX and VOC make up the largest controllable contribution
to ambient ozone formation. However, Tennessee has shown a greater
sensitivity of ground-level ozone to NOX controls rather
than VOC controls. This is due to high biogenic VOC emissions
compared to anthropogenic VOC emissions in Tennessee. Therefore,
implemented control measures have focused on the control of
NOX emissions.
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    EPA used an emissions inventory comparison to inform its
determination of whether Hamilton County and the Middle Tennessee Area
would continue to attain and maintain the ozone and CO NAAQS after
removal of the I/M program. As explained in the April 2021 SNPRM,
Tennessee chose 2022 as the future year for the State's non-
interference demonstrations.\8\ Tennessee's non-interference
demonstration utilized EPA's Motor Vehicle Emission Simulator (MOVES)
modeling system, specifically MOVES2014b, to estimate ozone precursor
emissions for mobile sources--both on-road and non-road. In general, an
emissions comparison approach is a reasonable and valid approach to
determining whether an area removing an I/M program can maintain the
NAAQS and is very similar to the maintenance demonstrations that
support the redesignations of areas from nonattainment to attainment
and 10-year maintenance plans that are required for redesignated areas.
EPA compared future year emissions (following the removal of the I/M
program) to emissions in a base year with an attaining design value.\9\
If the total future year emissions for the relevant pollutant(s)/
precursor(s) are less than the total base year emissions, EPA considers
that to be a sufficient and reasonable demonstration that the area will
maintain the NAAQS where the base year emissions are at a level
sufficient to achieve the NAAQS. EPA is concluding that these analyses,
as described greater in EPA's April 2021 SNPRM, provide adequate
support for the conclusion that the removal of the I/M program from
Hamilton County and the Middle Tennessee Area is consistent with CAA
section 110(l). CAA section 110(l) demonstrations are case-specific,
and modeling is not required to

demonstrate non-interference under these circumstances.
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    \8\ EPA notes that Tennessee did an analysis of emissions
between 2022 and 2030 without I/M to determine the potential impact
of mobile emissions. Tennessee's analysis shows that in the Middle
Tennessee Area emissions decrease by 35 percent for NOX,
24 percent for VOC, and 30 percent for CO; and that in Hamilton
County emissions decrease by 45 percent for NOX, 33
percent for VOC, and 40 percent for CO. This analysis is provided in
the dockets for this final rulemaking as weight of evidence.
    \9\ Design values are how EPA measures compliance with the
NAAQS.
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    In the April 2021 SNPRM, EPA clarified that although Tennessee
included photochemical modeling sensitivity analyses to provide
additional weight of evidence in its February 26, 2020, SIP revisions,
and EPA described those analyses in the June 2020 NPRMs, the
photochemical modeling sensitivity analyses were not required and were
not intended as the bases for EPA's proposed determinations that
removal of the I/M program from Hamilton County and the Middle
Tennessee Area would not interfere with attainment or maintenance of
the NAAQS or any other applicable CAA requirements. EPA's conclusion
that these removals satisfy CAA section 110(l) is based on the
technical analyses summarized above and provided in greater detail in
EPA's April 2021 SNPRM. See 86 FR 21248.

IV. Responses to Comments

    EPA received numerous comments on the June 2020 NPRMs and the April
2021 SNPRM.\10\ Two state representatives expressed objection to
removal of the I/M program while several state representatives
expressed strong support for removal of the I/M program and urged EPA
to take quick action. For this response to comments, the comments have
been grouped into the following categories: (1) Air quality
improvements/impacts; (2) non-interference demonstration; and (3)
comments outside the scope of this rulemaking. EPA's responses to
comments are provided below.
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    \10\ Comments are available on regulations.gov in dockets for
EPA-R04-OAR-2019-0619 (Hamilton County) and EPA-R04-OAR-2019-0618
(Middle Tennessee Area). A majority of the comments were received on
the June 2020 NPRMs.
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A. Responses to Comments Related to Air Quality Improvements/Impacts

    EPA received numerous comments related to air quality and the
potential impact of removing the I/M program on human health and the
environment. EPA's evaluation of these comments and responses is
provided below.
    Comment A1: Several commenters raise concerns regarding how the
removal of the ``carbon emissions testing program'' will affect the
health and wellbeing of the general population of Tennessee as well as
vulnerable populations, elderly, and children. Many of these commenters
are particularly concerned about those suffering from asthma or
allergies. Some commenters state that vehicle emissions could cause
shortness of breath, wheezing, coughing, pulmonary inflammation, and
lung disease. Other commenters identify vulnerable populations, such as
those with cardiovascular diseases, diabetes, or COVID-19, who could be
particularly affected by vehicle emissions.
    Response A1: Hamilton County and the Middle Tennessee Area are in
compliance with all of EPA's NAAQS. EPA has established NAAQS for six
of the most common air pollutants--CO, ozone, PM, NO2, lead,
and SO2--known as ``criteria pollutants.'' Primary NAAQS are
set to protect public health with an ``adequate margin of safety,''
including the health of at-risk groups; \11\ and secondary NAAQS are
set to protect the public welfare, which includes effects on trees,
plants, crops, and ecosystems. See CAA sections 108 and 109. Thus, EPA
evaluates air quality criteria and impacts to public health and welfare
as part of the comprehensive standard setting process. EPA's final rule
revising each of the NAAQS includes a thorough explanation of human
exposure and health risk assessments conducted in support of the
Agency's review of evidence of exposures on human health effects, as
well as detailed rationales for EPA's decisions on the relevant
standards. See, e.g., 80 FR 65291 (October 26, 2015) (containing an
analysis of the most recent ozone NAAQS).
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    \11\ For example, the rulemaking associated with the
establishment of the 2015 8-hour ozone NAAQS states that the action
provides increased protection for children, older adults, and people
with asthma or other lung diseases, and other at-risk populations
against an array of adverse health effects that include reduced lung
function, increased respiratory symptoms and pulmonary inflammation;
effects that contribute to emergency department visits or hospital
admissions; and mortality. See, e.g., 80 FR 65292 (October 26,
2015).
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    As discussed in the April 2021 SNPRM, EPA conducted a technical
analysis to comply with CAA section 110(l), which determined the
impacts of removal of the I/M program in Hamilton County and the Middle
Tennessee Area. EPA's technical analysis concludes that after removal
of the I/M program, Hamilton County and the Middle Tennessee Area will
continue to comply with all NAAQS, including the most stringent NAAQS.
As discussed above, since the NAAQS are set to protect the public
health and welfare and EPA's technical analysis shows that the areas
will continue to comply with all of the NAAQS, public health and
welfare will continue to be protected once the I/M program is removed
from the Tennessee SIP.
    Comment A2: Several commenters express concern that removing the I/
M program would harm the natural ecology and wildlife of Tennessee.
Another commenter wrote that removing the I/M program could negatively
affect food production. Both types of comments imply that removing the
I/M program would worsen air quality, resulting in problems for the
surrounding natural environment.
    Response A2: As mentioned in Response A1, EPA has established
primary and secondary NAAQS to protect human health and the
environment. Each NAAQS, with the exception of CO, has both a primary
and secondary NAAQS.\12\ In some cases, the primary and secondary NAAQS
are set at the same level. Secondary NAAQS provide public welfare
protection, including protection against decreased visibility and
damage to animals, crops, vegetation, and buildings.
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    \12\ See https://www.epa.gov/criteria-air-pollutants/naaqs-table.
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    Hamilton County and the Middle Tennessee Area are in compliance
with all secondary NAAQS. For reasons explained in EPA's June 2020
NPRMs and April 2021 SNPRM, EPA disagrees that removing the I/M program
from the Tennessee SIP will cause Hamilton County or the Middle
Tennessee Area to violate any NAAQS. Tennessee's technical
demonstrations support EPA's conclusion that the removal of the I/M
program for both Hamilton County and the Middle Tennessee Area will not
interfere with attainment or maintenance of the NAAQS or any other
applicable requirements of the CAA. Further information concerning
EPA's evaluation of Tennessee's technical demonstrations can be found
in Response B1. The commenters do not provide any technical information
to support their position or indicate that interference with
maintenance of the secondary NAAQS would result upon removal of the I/M
program in the Middle Tennessee Area or Hamilton County. EPA has
determined that upon removal of the I/M program, Hamilton County and
the Middle Tennessee Area will continue to be in compliance with all
secondary NAAQS, which are set to address the types of welfare concerns
raised by the commenters.
    Comment A3: A commenter asserts that air quality is getting worse
in the Middle Tennessee Area and showing a flat trend in ozone design
values in the Hamilton County region. With respect to the Middle
Tennessee Area, a commenter claims that while current ozone NAAQS-
related design values are below the standard, recent observations in
air quality in the Area have shown an upward trend in highest ozone
concentrations, indicating the reversal

of improvements resulting from ``existing control programs'' such as
Tennessee's I/M program. The commenter goes on to explain that
``[a]dditionally, when comparing monitor-level 4th high ozone [maximum
daily average (``MDA8'')]\13\ concentrations for receptors in the
Middle Tennessee region, values that are used by EPA in determining
ozone attainment and designations, not a single monitor has shown a
decrease between 2014 and 2018. In fact, of the five monitors in the
domain, . . . three show no change in 4th high MDA8 concentrations
between the two years while the other two monitors show an increase of
up to 3 parts per billion (ppb) in the MDA8 concentration observed.''
The commenter also points to an ``upward trend in highest
concentrations across all monitors, in particular the maximum
concentration exceeded 0.085 in 2018.'' The commenter also asserts that
ozone is increasing in the Middle Tennessee Area based on EPA's Air
Quality Index (AQI) and points to increases in the number of unhealthy
days for sensitive groups and the maximum AQI value per year.
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    \13\ In its comments regarding the Middle Tennessee Area, the
commenter appears to use the term ``MDA8'' to refer to the maximum
8-hour daily average ozone concentration in a given year at a
monitor.
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    With respect to Hamilton County, the commenter claims that while
current ozone NAAQS-related design values are below the standard in
Hamilton County, recent observations in air quality in the ``region''
have shown a flat trend in air quality. The commenter goes on to
explain that, ``[w]hen comparing monitor-level ozone MDA8 \14\
concentrations for receptors Hamilton County, Tennessee, values that
are used by EPA in determining ozone attainment and designations,
neither monitor has shown air quality improvement between 2015 and
2018. In fact, . . . both monitors in the domain . . . show no change
in MDA8 concentrations between the two years with increases in value
(poorer air quality) in the intermediate years.''
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    \14\ In its comments regarding Hamilton County, the commenter
appears to use the term ``MDA8'' to refer to the ozone design value
at a monitor. The design value at a monitor for the 8-hour ozone
NAAQS is the annual 4th highest daily maximum 8-hour ozone
concentration averaged over three years.
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    Response A3: As discussed above in Response A1, EPA sets the NAAQS
at levels protective of public health and welfare. With respect to
ozone, the most recent 2015 8-hour ozone NAAQS is met if the annual 4th
highest daily maximum 8-hour ozone concentration, averaged over three
years, is equal to or less than 70 ppb. See, e.g., 80 FR 65292 (October
26, 2015) (containing an analysis of the most recent ozone NAAQS). In
setting this standard, EPA considered all of the components of the
NAAQS (indicator, averaging time, level, and form) collectively, and
determined that the standard provided the requisite protection of
public health and welfare. See id.
    EPA agrees with the commenter that the Middle Tennessee Area and
Hamilton County are currently attaining all of the ozone NAAQS,
including the current 2015 8-hour ozone standard. EPA must evaluate
these SIP revisions for consistency with CAA section 110(l), which
prohibits the Agency from approving revisions that would interfere with
any applicable requirement regarding attainment or any other CAA
requirement. EPA reviews SIP revisions, like removal of the I/M program
from Tennessee's SIP, to determine whether they meet the applicable
requirements of the CAA, including section 110(a)(1), which requires
SIPs to provide for implementation, maintenance, and enforcement of the
NAAQS. See CAA section 110(k)(2), (3). EPA considers the status of an
area attaining the NAAQS when EPA evaluates whether a SIP revision will
interfere with attainment or maintenance of the NAAQS.\15\
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    \15\ Year to year changes in ozone levels result both from
changes in precursor pollutant emissions and from fluctuations in
meteorological conditions. This was taken into consideration in the
development of the NAAQS and resulted in a protective standard that
is based on a 3-year average of 4th maximums at an individual
monitor.
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    In response to concerns about increasing ozone concentrations
raised by the commenter, EPA evaluated the air quality trends in both
Hamilton County and the Middle Tennessee Area. The results of this
analysis, discussed in detail in the April 2021 SNPRM, show that while
both areas have observed yearly variability in measured ozone
concentrations, there is not a strong increasing or decreasing trend in
the ozone concentrations in either area since 2013. Both areas, along
with several other areas in the southeastern United States, measured
significantly higher ozone concentrations in 2012. These high
concentrations were primarily the result of meteorological conditions
that were very conducive to ozone formation (high temperature, low wind
speed, and moderate relative humidity). Both areas have continued to
attain the 2008 8-hour ozone NAAQS and the 2015 8-hour ozone NAAQS
after each standard became effective.\16\ EPA uses a three-year design
value to determine NAAQS compliance in order to account for the
inherent yearly variability in ozone concentrations due to variations
in meteorology, which can impact ozone levels during periods with
similar emissions levels.
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    \16\ As shown in Table 1, 2014 is one of the years associated
with attaining design values for the 2008 8-hour ozone NAAQS of
0.075 parts per million (ppm). The 2008 8-hour ozone NAAQS was the
applicable NAAQS for the 2015 ozone season. EPA notes that the 2015
8-hour ozone NAAQS of 0.070 ppm was not in effect until October 1,
2015, and all design values, beginning with the 2014-2016 design
value, attained the 2015 8-hour ozone NAAQS.
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    As shown in Table 1 below, the highest design value for the five
ozone monitors in the Middle Tennessee Area is 72 ppb in 2014 (using
2012-2014 data), 67 ppb in 2015 (using 2013-2015 data), 67 ppb in 2016
(using 2014-2016 data), 66 ppb in 2017 (using 2015-2017 data), 67 ppb
in 2018 (using 2016-2018 data), 66 ppb in 2019 (using 2017-2019 data),
and 65 ppb in 2020 (using 2018-2020 data). Starting with the 2013-2015
design values, the Area's design values do not indicate a strong
increasing or decreasing trend and have remained below the 2015 8-hour
ozone NAAQS.

                                             Table 1--Middle Tennessee Ozone Monitor Design Values,\***\ ppb
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                                                        Design value  Design value  Design value  Design value  Design value  Design value  Design value
           Monitor name                   County          2012-2014     2013-2015     2014-2016     2015-2017     2016-2018     2017-2019     2018-2020
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East Health/Trinity Lane.........  Davidson...........             *             *            66         ** 65            66            65            64
Percy Priest Dam.................  Davidson...........            70            65            67            64            67            65            65
Hendersonville...................  Sumner.............            72            67            67            66            66            66            65
Fairview Middle School...........  Williamson.........            66            62            61            60            60            60            60
Cedars of Lebanon................  Wilson.............            67            62            64            63             *             *            60
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* No valid design value due to incomplete data. The Cedars of Lebanon site had incomplete data in 2018 because there was an issue following the
  installation of a new monitoring shelter, and TDEC invalidated data collected before the issue was corrected. The East Health/Trinity Lane site had
  incomplete data in 2013.
** In the June 11, 2020, NPRM (85 FR 35607), EPA inadvertently stated that the 2015-2017 Design Value was 66 ppb. The correct value is 65 ppb.

*** The Middle Tennessee Area was in attainment with the most recent effective ozone NAAQS for the entire period. The 2012-2014 and 2013-2015 design
  values were attaining the 2008 8-hour ozone NAAQS of 75 ppb. EPA notes that the 2015 8-hour ozone NAAQS of 70 ppb was not in effect until October 1,
  2015, and all design values after this date attained the 2015 standard.
As shown in Table 2, the highest design value for the two ozone monitors in Hamilton County is 69 ppb in 2014 (using 2012-2014 data), 66 ppb in 2015
  (using 2013-2015 data), 68 ppb in 2016 (using 2014-2016 data), 67 ppb in 2017 (using 2015-2017 data), 66 ppb in 2018 (using 2016-2018 data), 64 ppb in
  2019 (using 2017-2019 data), and 62 ppb in 2020 (using 2018-2020 data). Since the 2013-2015 design values, the Area's design values do not indicate a
  strong increasing or decreasing trend and have remained below the 2015 8-hour ozone NAAQS.

                                                Table 2--Hamilton County Ozone Monitor Design Values, ppb
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                                           Design value    Design value    Design value    Design value    Design value    Design value    Design value
            Monitor Site Name                2012-2014       2013-2015       2014-2016       2015-2017       2016-2018       2017-2019       2018-2020
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Eastside Utility........................              69              66              68              67              66              64              62
Soddy Daisy High School.................              67              64              65              65              64              64              61
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    EPA also evaluated the annual 4th maximum daily maximum 8-hour
ozone concentrations for each site in both areas (shown in Table 3). As
discussed above, it is common for monitors to measure annual
variability in ozone concentrations due to several factors. These
annual values do not generally indicate a strong increasing or
decreasing trend at any of the monitors in the Middle Tennessee Area or
Hamilton County.

               Table 3--Middle Tennessee Area and Hamilton County: Annual 4th Highest Daily Maximum 8-Hour Ozone Concentrations, 2012-2020
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         Monitor Site name                  County            AQS ID       2012     2013     2014     2015     2016     2017     2018     2019     2020
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East Health.......................  Davidson (Middle        47-037-0011       76      (*)       65       67       66       64       68       65       60
                                     Tennessee Area).
Percy Priest Dam..................  Davidson (Middle        47-037-0026      (*)       60       71       64       68       62       71       63       61
                                     Tennessee Area).
Soddy-Daisy High School...........  Hamilton.............   47-065-1011       77       61       64       68       65       64       64       64       57
Eastside Utility..................  Hamilton.............   47-065-4003       77       64       67       68       69       65       64       65       58
Hendersonville....................  Sumner (Middle          47-165-0007       83       68       66       67       68       64       68       66       63
                                     Tennessee Area).
Fairview Middle School............  Williamson (Middle      47-187-0106       74       62       63       61       61       58       63       60       57
                                     Tennessee Area).
Cedars of Lebanon.................  Wilson (Middle          47-189-0103       77       62       64       61       67       61       64       60       58
                                     Tennessee Area).
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* Indicates that a monitor did not meet annual data completeness criteria for a given year

    Finally, for both areas, EPA evaluated the annual number of days
with monitored exceedances of the 2015 8-hour ozone NAAQS, where the
daily maximum 8-hour ozone concentration at any monitor in the area
exceeded 70 ppb. This is equivalent to the number of days with an ozone
AQI above 100 and the number of days with an AQI category of
``unhealthy for sensitive groups'' or worse. The results of this
analysis are shown in Table 4. Similar to the data presented above,
these values show year to year variability in the ozone concentrations
in both areas, but neither area shows a strong increasing nor
decreasing trend in the frequency of days above the 2015 8-hour ozone
NAAQS.

    Table 4--Middle Tennessee Area and Hamilton County: Annual Count of Days With Daily Maximum 8-Hour Ozone
                                     Concentrations Above 70 ppb, 2012-2020
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              Area                 2012     2013     2014     2015     2016     2017     2018     2019     2020
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Middle Tennessee...............       31        0        6        1        4        1        6        1        0
Hamilton County................        8        1        1        3        2        2        1        0        0
----------------------------------------------------------------------------------------------------------------
\*\ For consistency, EPA evaluated the number of days above 70 ppb (the level of the 2015 8-hour ozone NAAQS)
  for all years. Note that this standard was not effective until October 1, 2015. Some of the days counted in
  2012-2015 were not exceedances of the 2008 ozone NAAQS of 75 ppb, which was effective at the time this data
  was collected.

    Comment A4: Several commenters assert that air quality will worsen
by no longer requiring the monitoring of emissions, and therefore the
I/M program should not be removed. One commenter in reference to the
Middle Tennessee Area stated that ``[d]ropping the I/M program will
increase NOX by 478 tons per year and VOC by 593 tons per
year,'' and asserts that the analysis ``likely underestimates the
deterioration of air quality that will occur,'' concluding that the
emissions increases put ``Tennessee at risk of violating the standard
in the future.'' At least one commenter also implied that removal of
the I/M program would remove the ambient air monitoring requirements
for the areas.
    Response A4: There is no evidence that air quality will worsen to
the point of violating the NAAQS by no longer requiring periodic
testing of emissions from individual vehicles in Tennessee. It is
important to note that I/M programs require scheduled testing of a
vehicle's tailpipe and evaporative emissions to determine the
effectiveness of existing emission controls on that individual vehicle.
Emissions controls are not specifically required by I/M programs but
rather are required for all light-duty vehicles pursuant to EPA's
vehicle

emission standards, as discussed further below in this response. I/M
programs reduce the emissions of certain pollutants (primarily
NOX, VOC, and CO) by identifying individual vehicles with
malfunctioning or deteriorated emission control systems and requiring
the repair of these vehicles to bring them closer to their original
certification levels. As discussed in the April 2021 SNPRM, the
projected combined (point, non-point, on-road and non-road)
NOX, VOC, and CO emissions increases for the 2022 scenarios
with and without the I/M program will not impact the Areas' attainment
of the ozone NAAQS given that total emissions of these pollutants in
2022 without the I/M program will be well under the total emissions in
2014 and given the current design values for Hamilton County and the
Middle Tennessee area.
    Further, EPA has promulgated multiple Federal requirements for
engine and fuel standards to ensure that passenger vehicles are cleaner
since the 2000s. On February 10, 2000, EPA issued the Tier 2 passenger
(light duty) vehicle standards. See 65 FR 6698. The standards set
stringent emissions standards for passenger vehicles, as well as limits
on the amount of sulfur, a naturally occurring contaminant, in
gasoline. Limiting sulfur in gasoline allows emissions reduction
technologies like catalysts to be significantly more effective in
reducing NOX and other pollutants. Vehicles and their fuels
continue to be an important contributor to air pollution. EPA in 2014
issued standards commonly known as Tier 3, 79 FR 23414 (April 28,
2014), which considered the vehicle and its fuel as an integrated
system, setting new vehicle emissions standards and a new gasoline
sulfur standard beginning in 2017. The vehicle emissions standards
reduce both tailpipe and evaporative emissions from passenger cars,
light-duty trucks, medium-duty passenger vehicles, and some heavy-duty
vehicles. The gasoline sulfur standard enables more stringent vehicle
emissions standards and makes emissions control systems more effective.
These rules further cut the sulfur content of gasoline. Cleaner fuel
makes possible the use of new vehicle emission control technologies and
cuts harmful emissions in existing vehicles. These standards will
continue to reduce atmospheric levels of ozone (of which NOX
and VOC are the primary precursors), PM, NO2, and toxic
pollution. Also, cessation of the I/M program will not yield an
immediate change in vehicle emissions. The I/M program's benefits will
continue for a period of time after its cessation, as vehicles
inspected and/or repaired up until that time would continue to operate
in a manner that meets the emissions specification of the program.
    EPA also notes that the removal of the I/M program from Tennessee's
SIP does not remove the ambient air quality monitoring requirements
that the State must comply with pursuant to 40 CFR part 58. Ambient air
quality monitoring will continue in these areas without the I/M program
in Hamilton County and the Middle Tennessee Area.
    Comment A5: Some commenters mention that air quality is poor in
Hamilton County and the Middle Tennessee Area. Commenters refer to 2018
and 2019 reports from the American Lung Association (ALA).\17\ One
commenter states that in the 2019 ALA report, ``Hamilton County
received a `D' rating, ranking it among the worst counties in Tennessee
for air quality.'' Other commenters express concern with breathing
unhealthy air in Nashville, with one commenter stating that in 2019,
``Nashville plummeted to the bottom of the American Lung Association's
[ALA's] State of Air report with unhealthy levels of ozone that put
`citizens at risk for premature death and other health effects. . . .'
'' Commenters state that ``Tennessee achieved attainment status in
2017'' but also note that the ALA's ``annual State of Air Report
indicates air quality across the country is beginning to decline,'' and
that 4 in 10 Americans are living with unhealthy air. A commenter
further states that ``Emissions testing is important to ensure
Tennessee stays in attainment and continues to improve its air
quality.'' Additionally, a commenter cites to the ALA report to assert
that--while ozone levels are improving--PM2.5 levels are
becoming worse, in part due to climate change-driven wildfires. The
commenters also request that EPA ``allow local governments the ability
to opt-in to testing and use this tool to protect air quality.''
---------------------------------------------------------------------------

    \17\ Commenters did not provide either ALA report with their
comments. EPA has retrieved these reports and is providing them in
the dockets for this final rulemaking.
---------------------------------------------------------------------------

    Response A5: First, EPA notes that Tennessee is meeting all of the
NAAQS for all areas in the State with one exception, discussed below.
As further detailed in EPA's June 2020 NPRMs and EPA's April 2021
SNPRM, air monitoring data for EPA's most recent and stringent health-
based NAAQS demonstrate compliance with these NAAQS in most areas of
Tennessee, including Hamilton County and the Middle Tennessee Area.
State and local agencies submit air monitoring data annually, and EPA
evaluates this data for compliance with the NAAQS.\18\ See 40 CFR part
58. Tennessee's 2020 data for compliance with the NAAQS was certified
in April 2021. EPA has a robust process to establish the NAAQS and sets
the NAAQS at a level requisite to protect human health and the
environment. Tennessee's compliance with the NAAQS inherently means
that citizens in such areas are breathing air that is protective of
human health. Second, EPA notes that ALA uses a different methodology
in ``grading'' areas than EPA uses in evaluating areas for compliance
with the NAAQS. See 2019 ALA report pages 51-54 (discussing the
methodology used by ALA in grading areas). As discussed in Response A3,
EPA evaluates SIP revisions for compliance with the NAAQS. EPA notes
that the statement in the ALA report that 4 in 10 Americans are living
with unhealthy air is not a direct reference to areas in Tennessee.
With respect to the assertions regarding PM2.5, please see
response A6, below.
---------------------------------------------------------------------------

    \18\ The State of Tennessee submitted its 2020 data on April 7,
2021; EPA concurrence was sent on April 9, 2021. Nashville submitted
its 2020 data on April 19, 2021; EPA concurrence was sent on April
20, 2021. Chattanooga submitted its 2020 data on April 30, 2021; EPA
concurrence was sent on April 30, 2021.
---------------------------------------------------------------------------

    With respect to commenters' assertions that the I/M program should
be maintained to ensure continued compliance with the NAAQS and
requests that local areas be allowed to opt-in to I/M programs, EPA
disagrees in part. EPA notes that Tennessee currently implements the I/
M program as part of the State's discretionary measures to attain and
maintain the NAAQS. CAA section 110(l) provides that the Administrator
cannot approve a revision of a plan if the revision would interfere
with any applicable requirement concerning attainment, or any other
applicable requirement of the CAA. In addition, section 110(k) of the
CAA requires EPA to approve SIP revisions that meet all applicable CAA
requirements. As further discussed in the April 2021 SNPRM, EPA has
determined that section 110(l) requirements have been met because
removal of the I/M program will not interfere with attainment or
maintenance of any NAAQS or any other requirement of the CAA.
Therefore, because EPA has determined that the SIP revisions meet all
applicable requirements, EPA is approving Tennessee's request to remove
the I/M program from the SIP. EPA's action to remove the I/M program
does not preclude the state or local

government from maintaining an I/M program at the state or local level.
    The one exception where Tennessee's air quality does not meet the
NAAQS is a portion of Sullivan County, Tennessee, that encompasses the
Eastman Chemical Plant. In 2013, EPA designated a portion of Sullivan
County nonattainment for the 2010 1-hour SO2 NAAQS. CAA
section 191 requires Tennessee to develop a plan to bring the area back
in attainment with the SO2 NAAQS as expeditiously as
possible. As noted in the June 2020 NPRMs (85 FR 35037 and 85 FR 35607)
and the April SNPRM (86 FR 21248), the pollution control systems for
light-duty gasoline vehicles subject to the I/M program are not
designed to reduce emissions for SO2; therefore, removing
the I/M program requirements will not have any impact on ambient
concentrations of SO2.
    Comment A6: Some commenters assert that removal of Tennessee's I/M
program would cause greater increases or would exacerbate issues with
pollutants uninvolved in ozone formation (i.e., pollutants other than
NOX or VOC). Others worry that removing the I/M program as
Tennessee grows warmer would result in increased ozone formation. The
commenters also mention concerns about greater emissions in PM
pollution, CO, and greenhouse gases (GHGs) (i.e., methane and carbon
dioxide (CO2)). Some of the commenters that are worried
about an increase in GHGs have concerns stemming from a general worry
about climate change. Another commenter expresses concerns about
increases in emissions in general, but also acknowledges that ozone
formation in Tennessee appears to be limited by NOX.
    Response A6: With regard to PM emissions, EPA noted in the June
2020 NPRMs and the April 2021 SNPRM that I/M programs are not designed
to reduce direct PM emissions. In fact, EPA's state-of-the-science
Motor Vehicle Emission Simulator modeling system, MOVES, calculates no
benefit for direct PM emission reductions from an I/M program. In
addition, EPA notes that, separate and apart from I/M, there may be PM
emission benefits in future years due to expected fleet turnover and
continued implementation of EPA's engine and fuel standards.
Furthermore, PM formation in Tennessee is dominated by sulfates. As
noted in the June 2020 NPRMs and the April 2021 SNPRM, Hamilton County
and the Middle Tennessee Area are well in compliance with the PM
standards.
    As noted in the June 2020 NPRMs and the April 2021 SNPRM, Hamilton
County and the Middle Tennessee Area are well in compliance with the CO
standards. In support of its non-interference demonstration and as
discussed in EPA's June 2020 NPRMs and April SNPRM, Tennessee used the
MOVES2014b mobile emissions modeling to determine the change in
emissions for CO resulting from the removal the I/M program in Hamilton
County and the Middle Tennessee Area. The results show an increase in
CO emissions of 6.9 percent for Hamilton County, and of 6.1 percent for
the Middle Tennessee Area for scenarios in 2022 with and without the I/
M program. However, there is a decrease in total CO emissions from all
source categories from 2014 to 2022. For reasons described in the April
2021 SNPRM, EPA has concluded the removal of the I/M program from
Hamilton County and the Middle Tennessee Area is consistent with the
CAA.
    In terms of ozone, EPA agrees with the commenter that Tennessee is
NOX limited, making it the precursor of most consideration
related to potential impacts. As discussed in the April 2021 SNPRM,
there is a decrease in total NOX emissions from all source
categories from 2014 to 2022. EPA also notes that the I/M program does
not have a direct impact on GHGs and is not designed to reduce
emissions associated with climate change, such as GHGs.
    Comment A7: Some commenters assert that rural and urban areas face
different issues when it comes to pollution and air quality. In
particular, commenters are concerned that dropping the I/M program in
urban areas, which they claimed tend to have significantly more
emissions, would increase emissions not only for those areas, but also
for surrounding rural areas, and potentially cause future violations of
the standard.
    Response A7: EPA agrees that air quality is important. As discussed
in EPA's June 2020 NPRMs and April 2021 SNPRM, Hamilton County and the
Middle Tennessee Area are in attainment or maintenance for all criteria
pollutants. The Agency has provided detailed information showing that
the monitors in Hamilton County and the Middle Tennessee Area that
collect complete, quality assured and certified data for recent years
have design values that are less than the ozone, PM, and CO standards.
The design values and recently certified data, in combination with the
emissions inventory analysis, demonstrate that the areas will continue
to meet the NAAQS, even as population and vehicles increase not only in
Hamilton County and the Middle Tennessee Area, but statewide. While
commenters seem to make a distinction between emissions from urban
areas versus rural areas, the commenters do not provide information to
indicate that removal of the I/M program in Hamilton County and the
Middle Tennessee Area will cause a violation of the NAAQS in those
areas or any surrounding rural areas. As mentioned in Response A4, EPA
also notes that removal of the I/M program from the Tennessee SIP does
not impact Federal vehicle and fuel standards that EPA has promulgated
in separate rulemakings, and such standards will continue to result in
significant emission reductions from the operation of vehicles, whether
in rural or urban areas.
    Comment A8: A commenter implies that removal of the I/M program
will interfere with future visibility at the Great Smoky Mountains
National Park.
    Response A8: EPA disagrees with the commenter's assertion that
removal of the I/M program will interfere with visibility at the Great
Smoky Mountains National Park. Visibility impairment in the Southeast
is primarily dominated by sulfates. Sulfate particles form in the air
from SO2 gas. Most of this gas is released from coal-burning
power plants and other industrial sources, such as smelters, industrial
boilers, and oil refineries. As discussed in the June 2020 NPRMs and
the April 2021 SNPRM, the pollution control systems for light-duty
gasoline vehicles subject to the I/M program are not designed to reduce
emissions of SO2 or the broader group of sulfates. In
addition, as discussed in the April 2021 SNPRM, total NOX
emissions in 2022 without the I/M program are significantly less than
total NOX emissions in 2014 for the Middle Tennessee Area
and Hamilton County.\19\ EPA also notes that there are separate CAA
requirements related to visibility impairment, known as regional haze,
that all states must comply with. Removal of the I/M program will not
remove these requirements which are separate and apart from the I/M
requirements that individual areas may have.
---------------------------------------------------------------------------

    \19\ NOX emissions can convert to visibility
impairing nitrates in the atmosphere.
---------------------------------------------------------------------------

    Comment A9: Several commenters express concerns about population
and vehicle growth and the possible impacts on air quality.
    Response A9: As mentioned in more detail in this final rulemaking,
vehicles are, and continue to become, cleaner because of EPA's engine
and fuel standards. Although the population may grow and lead to more
vehicles, new vehicles will be covered by the most

recent vehicle emissions standards and be operated with gasoline that
complies with the most recent Federal requirements.
    Comment A10: A commenter states that ``In east Tennessee there is
no air emissions testing and the air quality is very poor. The
transportation sector is a major contributor of poor air quality,
therefore all vehicles must meet the original manufacturers
specification's and all aftermarket modifications to vehicle exhaust
and emissions equipment must be made illegal.''
    Response A10: EPA does not agree with the commenter that air
quality is very poor in east Tennessee. As mentioned in Response A1,
all areas in Tennessee are in compliance with the NAAQS with the
exception of a small portion of Sullivan County in the eastern part of
the State that is designated as nonattainment for the SO2
NAAQS. Also, EPA does not understand what the commenter means by ``. .
. no air emissions testing.'' As noted in Response A4, this action does
not remove the ambient air quality requirements that Tennessee is
subject to statewide. To the extent that the commenter is referring to
vehicle emissions testing, EPA notes that, with respect to SIPs, ``each
State is given wide discretion in formulating its plan,'' so long as
the revision is consistent with the CAA, including section 110(l). See
Union Elec. Co. v. EPA, 427 U.S. 246, 250 (1976); see also Alabama
Envtl. Council v. EPA, 711 F.3d 1277, 1280 (11th Cir. 2013), Sierra
Club v. EPA, 939 F.3d 649, 673 (5th Cir. 2019), and Alaska Dep't of
Envtl. Conservation v. EPA, 540 U.S. 461, 470 (2004).
    EPA agrees with the commenter that the transportation sector is an
important sector for maintaining air quality and, as discussed in
Response A4, EPA has taken steps to control emissions from the
transportation sector, such as the Federal vehicle and fuel standards
that will continue to provide benefits without the implementation of
the I/M program in Tennessee. EPA also notes that the commenter's
statements related to vehicle exhaust and emissions equipment are not
impacted by or within the scope of this rulemaking.
    Comment A11: One commenter suggests that the topography of
Chattanooga would exacerbate poor air quality if EPA removed the local
I/M program. Specifically, the Commenter explains that since
Chattanooga is surrounded by mountains, the city suffers from a ``well-
known inversion effect'' that traps pollutants in it during certain
times of the year. Another commenter explains that Nashville sits in a
depression called the ``Nashville or Central Basin,'' which tends to
cause air to stagnate over the entire area. Both commenters argue that
these unique geographical features would exacerbate poor air quality if
EPA removed the I/M program.
    Response A11: EPA disagrees that Hamilton County and the Middle
Tennessee Area have ``poor air quality,'' as both areas currently meet
all of the NAAQS, which is explained in more detail in Response A1. EPA
does not have evidence to indicate that the removal of the I/M program
from either Hamilton County or the Middle Tennessee Area will
exacerbate poor air quality because of the unique geographical features
in each area. While it is important to identify and mitigate vehicles
that are not properly functioning and as a result may increase
emissions, most vehicles are not producing increased emissions. Since
the 2000s, with EPA's promulgation of Federal requirements for engine
and fuel standards, passenger vehicles are cleaner. See Response A4 for
more information on the engine and fuel standards.
    Comment A12: A commenter asserts that COVID-19 pandemic has had an
anomalous impact on air quality improvements in 2020, and indicates
that removal of the Tennessee I/M program should not be considered
until after newer trends in air quality are available. The commenter
cites to three documents to assert that ``lockdown events have reduced
the population-weighted concentration of nitrogen dioxide
(NO2) and particulate matter levels by about 60% and 31%
across multiple countries, with mixed effects on ozone.''
    Response A12: EPA disagrees with the commenter's implication that
newer trends in air quality would be necessary to make the
determination on whether removal of the I/M program would interfere
with attainment or maintenance of the NAAQS in any area as a result of
removal of the program from the Tennessee SIP. As detailed in EPA's
April 2021 SNPRM and briefly described in Section III of this final
rule, EPA used an emissions inventory comparison approach in which
total emissions in 2014 were compared to total projected emissions in
2022. EPA's use of projected emissions in 2022 did not consider any
potential reduction of emissions or improvements in air quality that
might be sustained through changes in behavior that citizens in
Hamilton County and the Middle Tennessee Area might have made as a
result of the COVID-19 pandemic. Additionally, the commenter did not
provide any information or analysis indicating that consideration of
2020 air quality improvements would impact the non-interference
demonstration.
    In EPA's April 2021 SNPRM, for the Middle Tennessee Area, EPA
explained that the difference in NOX emissions in 2022, with
and without the I/M program, is 479 tons per year (tpy) for
NOX and 594 tpy for VOC. However, the total NOX
emissions in 2022 without the I/M program are 22,420 tpy less than the
total NOX emissions in 2014, and total VOC emissions in 2022
without the I/M program are 6,272 tpy less than the total VOC emissions
in 2014. For CO, the difference in emissions in 2022, with and without
the I/M program, is 10,368 tpy. However, the total CO emissions without
the I/M program are 56,466 tpy less than the total CO emissions in
2014. Even without the I/M program in 2022, emissions of
NOX, VOC, and CO are projected to decrease by 47.1 percent,
15.1 percent, and 23.9 percent, respectively, from 2014 levels.
    For Hamilton County, EPA explained in the April 20201 SNPRM that
the difference in emissions in 2022, with and without the I/M program,
is 100 tpy for NOX and 146 tpy for VOC. However, the total
NOX emissions in 2022 without the I/M program are 3,505 tpy
less than the total NOX emissions in 2014, and the total VOC
emissions in 2022 without the I/M program are 858 tpy less than the
total VOC emissions in 2014. For CO, the difference in emissions in
2022 with and without the I/M program is 2,979 tpy. However, the total
CO emissions without the I/M program are 10,061 tpy less than the total
CO emissions in 2014. Even without the I/M program in 2022, emissions
of NOX, VOC, and CO are expected to decrease by 27.0
percent, 8.1 percent and 18.7 percent, respectively from 2014 levels.
    In summary, because 2022 total emissions without the I/M program
are projected to be less than the total 2014 emissions, EPA is
concluding that removal of the I/M program in Hamilton County and the
Middle Tennessee Area will not interfere with attainment or maintenance
of the NAAQS, or any other applicable CAA requirements.\20\ As
mentioned above and in EPA's April 2021 SNPRM, while EPA considers
NOX, VOCs, ammonia, and SO2 as precursors for PM,
PM formation in Tennessee is dominated by emissions of SO2,
reacting in the atmosphere to form sulfates, and not by emissions of
NOX, VOCs, or ammonia. However, NOX and VOC
increases are considered through the analysis for ozone described in
great

detail in EPA's April 2021 SNPRM and summarized in this final rule. EPA
also notes that in the April 2021 SNPRM, the Agency explains that with
regard to the I/M program, NO2 is captured generally through
consideration of NOX impacts.
---------------------------------------------------------------------------

    \20\ Meteorology is not used directly for the emissions
inventory approach that EPA used as the basis of its technical
analysis.
---------------------------------------------------------------------------

B. Responses to Comments Related to the Non-Interference Demonstration

    EPA received technical comments asserting that the non-interference
demonstration is inadequate to approve the SIP revisions. EPA's
evaluation of these comments and responses is provided below.
    Comment B1: In response to EPA's June 2020 NPRMs, a commenter
asserts that the non-interference demonstrations cannot be considered
technically complete without air quality modeling to simulate the
impact of removing the I/M program. The commenter recommends ``a full
air quality simulation of the impact of removing the I/M program''--
specifically suggesting the use of a transport grid model--to ensure
that increases in air pollutant concentrations do not exceed NAAQS and
health-based recommendations. The commenter also recommends that the
``air quality simulation'' utilize the ``most current modeling platform
and associated emission projections,'' as well as meteorological and
base year inventories that meet EPA guidance. The commenter cites EPA
SIP modeling guidance in support of its recommendations. To further
support its modeling recommendation, the commenter expresses concerns
regarding the use of historical trends in air quality and emissions to
evaluate impacts of I/M program removal due to annual variations in
meteorology and actual emissions and the need for a solid conceptual
model of how ozone or PM2.5 is formed in the areas. Also, in
response to EPA's April 2021 SNPRM, the commenter reasserts its
position that the non-interference demonstration should be based on air
quality modeling, asserting that a case-by-case determination by EPA
that air quality modeling is warranted with respect to the removal of
the I/M program; the commenter further provides a number of comments
related to the ozone sensitivity analysis that Tennessee provided in
its SIP revisions. The commenter does not provide substantive comments
on EPA's technical non-interference demonstration as provided in the
April 2021 SNPRM.
    Response B1: EPA does not agree with the commenter that air quality
modeling is required in order for EPA or the State to assess, pursuant
to section 110(l) of the CAA, whether removal of the I/M program from
Tennessee's SIP will interfere with attainment or maintenance of the
NAAQS or any other requirement of the CAA. EPA acknowledges that air
quality modeling is an option that could be used to evaluate the impact
of removal of the I/M program. However, other technical analyses that
do not involve modeling may also be used for section 110(l)
demonstrations.
    EPA refers the commenter to EPA's April 2021 SNPRM for more detail
related to EPA's non-interference analysis. Also, as further explained
in EPA's June 2020 NPRMs and April 2021 SNPRM, the pollution control
systems for light-duty gasoline vehicles subject to the I/M program are
not designed to reduce (and do not reduce) emissions for PM, lead, and
SO2 in Tennessee.
    For CO and ozone, EPA reviewed Tennessee's MOVES2014b mobile
modeling which estimated emissions in 2022 with and without the I/M
program.\21\ Tennessee developed an inventory based on the best
available information to the State at the time of the submissions for
both Hamilton County and the Middle Tennessee Area. EPA reviewed the
inventory with and without the benefit of the I/M program for each
area. As EPA noted in the June 2020 NPRMs and the April 2021 SNPRM,
there was a slight increase in NOX and VOC on-road emissions
for each area for 2022 for the scenarios without the I/M program, as
compared to the scenarios with the I/M program. For ozone, EPA agrees
with a commenter's statement that ozone formation in Tennessee is
NOX-limited (i.e., ozone concentrations are most effectively
reduced by lowering NOX emissions rather than VOC
emissions).\22\ Nonetheless, as discussed in the April 2021 SNPRM, EPA
evaluated both the increases in on-road VOC and NOX to
determine whether the increase in total emissions in 2022 would
interfere with attainment or maintenance of the ozone NAAQS in either
area. EPA's analysis presented in the April 2021 SNPRM demonstrates
that total emissions in these areas are projected to decrease
significantly from the 2014 base year to the 2022 future year, even if
the I/M program is discontinued. The small increase in on-road
emissions resulting from removal of the I/M program in 2022 are
overcome by the continued decrease in total emissions, despite
increases in vehicle miles travelled, due to fleet turnover (i.e., old
vehicles being replaced with new vehicles that meet more stringent
engine standards).
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    \21\ Tennessee chose 2022 as the future year for the State's
non-interference demonstrations because it is the year when the
State anticipated that the Areas will cease implementation of the I/
M program due to the CAA's SIP processing timeframe and the language
of Tenn. Code Ann. section 68-201-119.
    \22\ As part of the Southeastern Modeling and Analysis Planning
(SEMAP) project, Georgia Institute of Technology performed an
analysis of the sensitivity of ozone concentrations in the Eastern
U.S. to reductions in emissions of both NOX and VOC and
determined that the Southeast is NOX limited. This
analysis was based off the 2007 and 2018 SEMAP modeling which used
the Community Multi-scale Air Quality model, version 5.01 with
updates to the vertical mixing coefficients and land-water
interface. May 1st through September 30th was modeled using a 12-km
modeling grid that covered the Eastern U.S.
---------------------------------------------------------------------------

    EPA disagrees with the commenter's concerns regarding the use of
historical trends in air quality and emissions to evaluate impacts of
I/M program removal due to annual variations in meteorology and actual
emissions and the need for a solid conceptual model of how ozone or
PM2.5 is formed in the areas. EPA acknowledges the
importance of understanding the factors affecting ozone and
PM2.5 formation in an area, and Response A6 provides
information about factors affecting ozone and PM2.5 in
Tennessee. Concerns about annual variations in meteorology are
addressed in Response A3. EPA believes that the large decreases in
emissions of NOX, VOC, and CO described in the April 2021
SNPRM overshadow the effects of annual variations in actual emissions.
    Although Tennessee included photochemical modeling sensitivity
analyses to provide additional weight of evidence in its submissions,
as described by EPA above and in the April 2021 SNPRM, such analyses
were not required and were not the basis for EPA's proposed
determinations that removal of the I/M program from Hamilton County and
the Middle Tennessee Area would not interfere with attainment or
maintenance of the NAAQS or any other applicable CAA requirements.
Specifically, in the April 2021 SNPRM, EPA clarified that it was not
the Agency's intention to rely on Tennessee's ozone sensitivity
analysis. Thus, any comments related to the sufficiency of that ozone
sensitivity analysis are not relevant to the actions that EPA are
finalizing in this document. EPA's conclusion that these removals
satisfy CAA section 110(l) is based on the technical analysis presented
in EPA's April 2021 SNPRM.
    Comment B2: With respect to the commenter's concerns on the June
2020 NPRMs and the April 2021 SNPRM regarding the nonlinearity of ozone
formation related to Tennessee's sensitivity analysis, the commenter

reviewed EPA modeling \23\ and ``developed ozone source apportionment
results and relationships between State-source category specific ozone
source apportionment modeling and the seasonal NOX emissions
used to develop the ozone concentrations,'' which, the commenter
states, ``provide indicators of relative contribution of source regions
(states) and categories (e.g., motor vehicle) NOX and VOC
emissions to downwind monitor ozone concentrations.'' The commenter
asserts that this analysis indicated that ``emissions from motor
vehicle sources contribute the greatest relative concentration from
U.S. anthropogenic emissions to the monitors,'' in the areas and
estimates that localized reductions (in the areas of analysis) would
have a larger relative impact on ozone concentrations (as compared to
statewide estimations). The commenter also developed regional ``impact
factors,'' and asserts that the commenter found (using updated
emissions, projections, and models) ``that the relative impact of
NOX emissions from mobile sources in Tennessee have factors
significantly higher than most other regional-category combinations,
leading us to conclude that motor vehicle and nonroad source emissions
have the greatest impact on ozone concentrations'' in the Areas. The
commenter did not provide the modeling files, just the summary of the
results in the comments.
---------------------------------------------------------------------------

    \23\ The commenter based their analysis on the Comprehensive Air
quality Model with eXtensions/Ozone Source Apportionment Technology
(CAMX/OSAT) modeling platform that EPA prepared for the
CSAPR Close-Out rule. See 83 FR 65878, 65887-88 (December 21, 2018).
---------------------------------------------------------------------------

    Response B2: As discussed in the April 2021 SNPRM, EPA's analysis
relies on an emissions inventory comparison to determine whether
Hamilton County and the Middle Tennessee Area would continue to attain
the ozone and CO NAAQS after removal of the I/M program. EPA is not
relying on an ozone sensitivity analysis to determine that removal of
the I/M program would not interfere with attainment or maintenance of
the NAAQS. Therefore, the alleged deficiencies related to nonlinearity
of ozone formation from NOX and VOC precursors in
Tennessee's sensitivity analyses are irrelevant. As noted in other
comment responses in this rule, the State has primacy over air quality
planning and has the authority to determine which source categories to
control to maintain the NAAQS. Under the CAA, the sole issue for EPA's
consideration in this rulemaking is whether removing the I/M program
from the SIP for these two areas would be consistent with CAA
provisions, including whether discontinuation is expected to interfere
with attainment and maintenance of air quality standards. As discussed
further in the April 2021 SNPRM, EPA is approving removal of the I/M
program from the SIP because removal is consistent with the
requirements of the CAA, including noninterference with attainment and
maintenance of the NAAQS.
    Comment B3: In response to EPA's June 2020 NPRMs, a commenter
asserts that Tennessee's MOVES modeling did not use appropriate
assumptions, pointing to changes in Federal Corporate Average Fuel
Economy (CAFE) standards, Reid Vapor Pressure (RVP) standards, and
biofuel blending requirements that were not included in the model. The
commenter asserts that EPA must either conduct the modeling itself
using the appropriate inputs to confirm that there will be no
interference with the NAAQS or disapprove the non-interference
demonstration and require the State to do the correct modeling.
Further, in response to EPA's April 2021 SNPRM, a commenter discusses
EPA's recent release of MOVES3 and asserts that TDEC should consider
the impact that the changes in this model have on the assumptions
included in the removal of the I/M program in the State. The commenter
further asserts that TDEC should consider this impact ``especially in
light of EPA's findings that NOX emissions estimates were
higher in future years in urban areas using MOVES3 compared to
MOVES2014b.''
    Response B3: EPA disagrees with the commenter. EPA reviewed the
MOVES2014b modeling that was submitted by Tennessee to support the non-
interference demonstration and concluded that the State used
appropriate assumptions for the model and performed the modeling in
accordance with EPA's MOVES Technical Guidance.\24\ Tennessee used the
MOVES2014b model which was the latest version of the model available at
the time that the State submitted its SIP revisions, and the State is
not required to redo its analysis based on the release of an updated
model after the State's submissions.\25\
---------------------------------------------------------------------------

    \24\ See EPA's July 2014 ``Policy Guidance on the Use of
MOVES2014 for State Implementation Plan Development, Transportation
Conformity, and Other Purposes'' (hereinafter MOVES 2014 Guidance).
This document is available at https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100K4EB.pdf.
    \25\ EPA released the latest mobile modeling platform, MOVES3,
on November 16, 2020, approximately nine months after Tennessee
submitted its SIP revisions, and EPA only recently announced MOVES
as EPA's official model for future SIP development outside of
California (January 7, 2021, 86 FR 1106). EPA's November 2020 Policy
Guidance on the Use of MOVES3 for State Implementation Plan
Development, Transportation Conformity, General Conformity, and
Other Purposes (EPA-420-B-20-044) (hereinafter MOVES3 Policy
Guidance) notes that ``[s]tates should use the latest version of
MOVES that is available at the time that a SIP is developed.'' This
document is available at https://www.epa.gov/sites/production/files/2020-11/documents/420b20044_0.pdf. Also, the Guidance states the
following: ``All states other than California should use MOVES3 for
SIPs that will be submitted in the future so that they are based on
the most accurate estimates of emissions possible. However, state
and local agencies that have already completed significant work on a
SIP with MOVES2014 (e.g., attainment modeling has already been
completed with MOVES2014) may continue to rely on the earlier
version of MOVES.''
---------------------------------------------------------------------------

    Regarding the changes to the CAFE standards, the National Highway
Traffic Safety Administration has finalized the revisions to the CAFE
standards for light duty vehicles.\26\ However, that final action does
not have any impact on Tennessee's demonstration related to removal of
the I/M program. The vehicles affected by the revised CAFE standards
would still need to meet applicable criteria pollutant emissions
standards (e.g., the Tier 3 emissions standards; see 79 FR 23414).
---------------------------------------------------------------------------

    \26\ See ``The Safer Affordable Fuel-Efficient (SAFE) Vehicles
Rule for Model Years 2021-2026 Passenger Cars and Light Trucks,'' 85
FR 24174 (April 30, 2020).
---------------------------------------------------------------------------

    Regarding RVP and biofuel blending requirements, EPA reviewed the
selected fuel formulations (including those for biofuels) for the
modeled mobile emissions and concurred that they accurately reflect the
Areas' profiles. The fuel formulation encompasses all the properties
for that particular fuel (i.e., sulfur levels, benzene, and RVP).
    While the commenter mentions that ``. . . NOX emissions
estimates were higher in future years in urban areas using MOVES3
compared to MOVES2014b[,]'' the commenter does not provide any
information to indicate that NOX emissions in either
Hamilton County or the Middle Tennessee Area would be higher or would
interfere with attainment or maintenance of any NAAQS. As detailed in
EPA's April 2021 SNPRM and summarized above, NOX emissions
in Hamilton County and the Middle Tennessee Area are estimated to be
3,505 tpy and 22,420 tpy lower than 2014 emissions, respectively. EPA
is concluding that it is reasonable to assume that a change to a more
recent version of MOVES would not result in an increase in emissions
over the significant decreases in emissions between 2014 and 2022.

    Comment B4: A commenter raises a number of concerns with regard to
the sensitivity analysis that was provided as part of the State's non-
interference demonstration. The commenter asserts that the wrong
inventory was used, stating that Tennessee used the ``outdated and
inappropriate 2014 National Emission Inventory (NEI) for base year and
future year emission assumptions,'' which the commenter claims is
contrary to EPA guidance. The commenter states that ``EPA and others
have concluded that 2014 is not useful for ozone sensitivity
simulations,'' specifically asserting that 2014 was not conducive to
ozone formation and did not contain high ozone periods adequate for an
assessment of the impact of control technologies and air quality
response. The commenter asserts that newer modeling platforms have been
released with vastly improved estimates (specifically citing to a 2016
NEI).\27\ The commenter specifically points to differences in
NOX and VOC estimates in the later-released platforms, and
provides a comparative analysis between the 2014 NEI and a 2016 NEI for
Hamilton County and the Middle Tennessee Area. The commenter
acknowledges that the 2014 NEI was the most current version at the time
that Tennessee conducted its analysis. The commenter recommends the
analysis be revised using the most current modeling platform and
associated emission projections, and specifically references the 2016
NEI. The commenter also recommends modeling be conducted using a
meteorological and associated base year inventory that meets the
requirements of EPA guidance for the determination of impact of control
strategies and air quality response.
---------------------------------------------------------------------------

    \27\ The commenter's phrase ``2016 NEI'' appears to refer to the
2016v1 emissions modeling platform produced by the National
Emissions Inventory Collaborative.
---------------------------------------------------------------------------

    The commenter also claims that old and inappropriate assumptions
were used, expressing concerns that the ozone sensitivity study was
based on the 2007 SEMAP data projected to 2018. The commenter asserts
that the non-interference analysis misuses the SEMAP study and points
toward language in the report stating that ``these factors should not
be used for anything other than identical conditions to those in the
SEMAP analysis.'' The commenter asserts that the demonstration assumes
a similar response in 2022, and that there is no basis for this
assumption. The commenter characterizes the information from the SEMAP
report as ``brute force factors'' that are not applicable because the
factors are not tailored to the I/M removals in Hamilton County and the
Middle Tennessee Area. The commenter points to differences between
SEMAP projections and actual emissions as reported in the 2016 NEI,
expressing concern about the ratios of NOX and VOC used in
the non-interference demonstration. The commenter further asserts that
the SEMAP data underestimates the ``contribution of vehicles to the
inventory'' as compared to the 2016 NEI. The commenter also asserts
that recent modeling indicates that on-road emission increases--and
specifically Tennessee's motor vehicle source category--have a greater
impact on regional air quality than what the demonstration calculates
(in part, due to the assumption that each ton of a precursor has an
equal impact on ozone formation). The commenter concludes that the
sensitivity factors used in the demonstration are ``not directly
applicable to today's ozone conditions and likely not representative of
the air quality change due to the removal of the I/M programs.'' The
commenter further states that Tennessee's ``recognition that its use of
the scaling analysis would yield erroneous results should be adequate
enough for the agency to reconsider using its analysis as a weight-of
evidence approach to removal of the I/M program.'' If the analysis does
not use air quality simulation, the commenter recommends an ```impact
factor'-like application to determine the impact of the removal of the
I/M program, [with] county and motor vehicle specific factors.''
    Response B4: As discussed above and in EPA's April 2021 SNPRM, EPA
is not relying on Tennessee's sensitivity analysis in its determination
that removal of the I/M program will not interfere with any applicable
requirement under the CAA. To the extent the commenter is asserting
that the emissions comparison analysis should be conducted with more
recent data, such as later versions of the NEI, EPA disagrees with the
commenter. The 2014 NEI was the latest available emissions data and
served as the baseline data for both Middle Tennessee Area and the
Chattanooga Area. In addition, the 2014 NEI matches the base year used,
which was the 2014 attainment year. While subsequent emissions data are
available since EPA received these SIP submissions, both areas continue
to attain the NAAQS. The 2014 NEI was developed consistent with EPA
guidance and sufficiently serves as the basis for this demonstration.
EPA's conclusion that removal satisfies CAA section 110(l) is based on
the technical analysis as described in detail in the April 2021 SNPRM
and summarized above.
    Comment B5: A commenter discusses and compares a Georgia analysis
to relax RVP requirements with the analysis to support removal of the
Tennessee I/M program. The commenter points to two aspects of the
Georgia analysis that differ from the Tennessee analysis: The
substitution of quantifiable, permanent, surplus, enforceable, and
contemporaneous measures to achieve equivalent emissions reductions to
offset potential emissions increases; and a demonstration that
emissions are well below (and will not exceed) motor vehicle emissions
budgets (MVEBs). The commenter asserts that Tennessee's analysis to
remove the I/M program does not include offsets nor does the analysis
calculate and provide additional support of meeting current and future
year MVEBs. The commenter further asserts that the MVEBs for Hamilton
County were never calculated, and that concern was expressed about the
Middle Tennessee Area meeting ``the old MVEBs'' at the Nashville Area
Interagency Consultation Group meetings. The commenter concludes that
the request to remove the I/M program does not have a supporting
analysis comparable to Georgia's and may fall short for EPA approval.
    Response B5: EPA disagrees with these comments. With respect to the
EPA-approved analysis to relax RVP requirements in Georgia, EPA notes
that section 110(l) analyses are case-specific, and in the case of
Georgia's request to relax RVP requirements for Atlanta, offsets were
needed given the facts in that situation. See 84 FR 49470 (September
20, 2019). Unlike Georgia, Tennessee has no areas designated as
nonattainment or maintenance for the ozone NAAQS and does not currently
have any violating ozone monitors. As discussed in the April 2021
SNPRM, EPA is concluding that removal of the I/M program from the
Tennessee SIP will not interfere with attainment or maintenance of the
NAAQS or any other applicable requirement of the CAA.
    In addition, motor vehicle emission budgets (sometimes referred to
in practice as ``MVEBs'') are a component of the regional emissions
analysis for implementing transportation conformity requirements. See
40 CFR 93.101 and 93.118. These comments are not relevant to this
rulemaking because neither Hamilton County nor the Middle Tennessee
Area are required to demonstrate transportation conformity for any
pollutant, and therefore, no such

budgets are required to be developed for either area.
    Comment B6: With respect to Hamilton County,\28\ a commenter states
``Tennessee appears to be taking credit for closures of three
[Tennessee Valley Authority (TVA)] power plants in its non-interference
demonstration.'' The commenter then goes on to assert that EPA cannot
allow offsets for Hamilton County from outside of the nonattainment
area because that would be a violation of the South Coast decision. The
commenter concludes that EPA must only consider offsets to the I/M
program that occur within the nonattainment area.
---------------------------------------------------------------------------

    \28\ This comment was received in docket EPA-R04-OAR-2019-0619
only.
---------------------------------------------------------------------------

    Response B6: EPA disagrees with this comment. While the commenter
does not provide a citation for the South Coast decision, EPA assumes
the commenter is referring to the decision of the United States Court
of Appeals for the District of Columbia Circuit (D.C. Circuit) in South
Coast Air Quality Management District v. EPA, 882 F.3d 1138, 1146 (D.C.
Cir. 2018), which addressed section 182 of the CAA and upheld EPA's
interpretation that states may not take credit for reductions outside a
nonattainment area for purposes of interim milestones towards
attainment. This decision is not relevant to this action, as it
addressed a different statutory provision not at issue here. Moreover,
as discussed above, Tennessee is not providing offsets for the removal
of the I/M program and, thus, no ``credits'' are being taken into
account for facility closures or any other actions.
    Comment B7: A commenter asserts that the trends in air quality in
the two areas are inconsistent with reductions in precursor emissions,
claiming that although emissions estimates for motor vehicles are
decreasing, air quality is stagnant in Hamilton County and
deteriorating in the Middle Tennessee Area. The commenter also
expresses concern about relying on the assumption that each ton of a
pollutant precursor emission has an equal impact on air quality as
compared to every other ton of the same pollutant precursor, regardless
of emission source and where in the state the emissions occur, citing
the uniqueness and nonlinearity of ozone precursors. The commenter
states that on-road emission increases would have a greater impact on
regional air quality than calculated and that an increase in emissions
due to the removal of the I/M program may have an accelerated
deterioration impact on the Areas' air quality.
    Response B7: The air quality data summarized in Response A3
demonstrates that ozone air quality in Hamilton County and the Middle
Tennessee Area is not worsening and is well below the 2015 8-hour ozone
NAAQS. As discussed in the April 2021 SNPRM, removal of the I/M program
from the Tennessee SIP will not interfere with attainment or
maintenance of the NAAQS or any other applicable requirement of the
CAA. In addition, as discussed in Response A4, I/M programs do not
mandate emission controls systems on motor vehicles, unlike Federal
motor vehicle emissions standards such as the Tier 3 rule. These
Federal vehicle emission standards will remain with or without the I/M
program in the Tennessee SIP for the Middle Tennessee Area and Hamilton
County.
    Comment B8: A commenter asserts that EPA must take into account
recent court decisions that will ``have a devastating impact on the
state's ability to ensure non-interference.'' The commenter
specifically points to the ``Wisconsin and New York decisions,'' which
``vacated and remanded these programs back to EPA, essentially wiping
them out entirely.'' The commenter claims that Tennessee cannot claim
credit for any reductions attributable to the programs. Further, the
commenter states EPA must check to make sure the state does not
interfere with any downwind states' ability to meet the NAAQS.
    Response B8: EPA has confirmed that the changes being approved by
EPA in this action do not interfere with other states' ability to meet
the 2008 ozone NAAQS. Although it is unclear from the comment, in
describing programs promulgated under the good neighbor provision, CAA
section 110(a)(2)(D)(i)(I), EPA assumes the commenter is referring to
the Cross-State Air Pollution Rule (CSAPR) Update. The CSAPR Update
addresses NOX pollution transported to other states that
significantly contributes to nonattainment or interferes with
maintenance of the 2008 ozone NAAQS.\29\ Among other things, the CSAPR
Update requires reductions of NOX from power plants during
the annual ozone season from May 1 to September 30 in 22 states,
including Tennessee. Although EPA found the CSAPR Update may only
partially address the good neighbor obligations for most covered
states, EPA found the rule fully addresses Tennessee's good neighbor
obligation for this NAAQS. See 81 FR 74504, 74540 (October 26, 2016).
That conclusion was based on an assessment of air quality in the
eastern U.S. with implementation of the CSAPR Update, and it accounted
for emissions from all source sectors, including mobile sources.
---------------------------------------------------------------------------

    \29\ The CSAPR Update is a rule that followed the original CSAPR
rulemaking in 2011. CSAPR requires certain states in the eastern
half of the U.S. to improve air quality by reducing power plant
emissions of NOX and SO2 that cross state
lines and contribute to smog and soot pollution in downwind states.
On September 7, 2016, EPA revised the CSAPR ozone season
NOX program by finalizing an update to CSAPR for the 2008
ozone National Ambient Air Quality Standards, known as the CSAPR
Update. The CSAPR Update ozone season NOX program was
designed to largely replace the original CSAPR ozone season
NOX program starting on May 1, 2017, and further reduce
summertime NOX emissions from power plants in the eastern
U.S.
---------------------------------------------------------------------------

    The CSAPR Update was reviewed and generally upheld in Wisconsin v.
EPA, 983 F.3d 303 (D.C. Cir. 2019). Contrary to the commenter's
assertion that the rule was vacated, the D.C. Circuit merely remanded
the rule without vacatur because, for states other than Tennessee, the
rule did not provide a full remedy by the next relevant attainment date
under CAA section 181. Thus, the CSAPR Update remains in effect. The
decision in New York v. EPA, 781 F. App'x 4 (D.C. Cir. 2019) vacated a
separate rule, the CSAPR Close-Out, but this rule did not impose
additional reductions and only purported to demonstrate, based on new
modeling analysis of the year 2023, that the CSAPR Update was a full
remedy for 20 states. In the New York case cited by commenter, the D.C.
Circuit found this conclusion incorrect as a matter of law in light of
its holding in Wisconsin because EPA analyzed a year beyond the next
attainment date without sufficient justification. Tennessee's
obligations were not at issue in the Close-Out rule. EPA notes that the
aspects of the CSAPR Update affecting Tennessee were not challenged in
the litigation over the rule and are not affected by the remand of the
rule in Wisconsin.
    EPA believes the projected increase in mobile source emissions from
the removal of Tennessee's I/M program does not affect EPA's prior
finding in the CSAPR Update that the State of Tennessee has no further
interstate transport obligations for the 2008 8-hour ozone NAAQS. In
the section 110(l) analysis for this action, EPA analyzed the impacts
of removing the I/M program in Hamilton County and the Middle Tennessee
Area from the subject final rule and found that the largest projected
increase in mobile source emissions in these areas would result in a
combined projected increase of 579 tons in 2022, or a 2 percent
increase in total anthropogenic NOX emissions in

these areas.\30\ Therefore, the net change in total anthropogenic
emissions across the entire State of Tennessee would be much less than
the projected 2 percent increase in NOX emissions.
---------------------------------------------------------------------------

    \30\ In 2022, emissions of VOC are projected to increase by 740
tons, or a 1.7 percent increase in total anthropogenic VOC
emissions. In the context of interstate ozone transport, EPA focuses
on NOX as the key ozone precursor pollutant.
---------------------------------------------------------------------------

    On October 30, 2020, in the NPRM for the Revised CSAPR Update, EPA
released and accepted public comment on updated 2023 modeling that used
a 2016 emissions platform developed under the EPA/Multi-Jurisdictional
Organization (MJO)/state collaborative project.\31\ On March 15, 2021,
EPA signed the final Revised CSAPR Update using the same modeling
released at proposal.\32\ In this modeling, EPA found that the highest
contribution in 2023 from the entire State of Tennessee to any downwind
receptor identified as having a nonattainment or maintenance problem
for the 2008 ozone standard is projected to be 0.32 ppb. This amount of
contribution is well below the 1 percent of the NAAQS threshold used in
EPA's good neighbor framework for determining whether an upwind state
contributes to a nonattainment or maintenance receptor under the 2008
ozone NAAQS (i.e., 0.75 ppb). The small amount of projected increase in
NOX emissions in Tennessee as a result of this action,
combined with the fact that the highest modeled contributions from this
state are well below the 1 percent threshold, support the conclusion
that the projected increase in mobile source emissions does not affect
EPA's prior decision that Tennessee has no remaining interstate
transport obligations under the 2008 ozone NAAQS.
---------------------------------------------------------------------------

    \31\ See 85 FR 68964, 68981 (October 30, 2020). The results of
this modeling are included in a spreadsheet in the dockets for this
action. The underlying modeling files are available for public
review in the docket for the Revised CSAPR Update (EPA-HQ-OAR-2020-
0272).
    \32\ See 86 FR 23054 at 23075, 23164 (April 30, 2021).
---------------------------------------------------------------------------

    This final action does not make any finding regarding Tennessee's
interstate transport obligations for the 2015 8-hour ozone NAAQS. EPA
has not yet taken final action on Tennessee's good neighbor SIP
submission for the 2015 8-hour ozone NAAQS.
    Comment B9: In response to EPA's April 2021 SNPRM, a commenter
asserts that EPA's proposed conclusion that ``removal of the I/M
program will not interfere with other states' ability to attain and
maintain the 2008 ozone NAAQS'' is based on ``an air quality modeling-
based technique'' performed for the Revised CSAPR Update that contains
``an error in the source apportionment model'' that was ``discovered in
December 2020.'' Specifically, the commenter asserts that EPA ``does
not know whether the specific beta version of the model used in their
analysis contained the bug and associated source apportionment error.''
The commenter further states that ``[n]o known quantification of the
error has been calculated and therefore it is unknown just how
significant a change might be seen in the upwind state contribution to
downwind receptors under the 2008 Ozone NAAQS or in potential
application for future consideration of significant contribution under
the 2015 Ozone NAAQS,'' and requests that EPA ``correct[] the source
apportionment results and significant contribution calculations with
the corrected version of the air quality model'' before making a final
decision on removal of the I/M program from the Tennessee SIP.
    Response B9: The commenter is correct that EPA relies on modeling
developed for the Revised CSAPR Update (RCU) to determine that removal
of the I/M program will not interfere with other states' ability to
attain and maintain the 2008 ozone NAAQS under the good neighbor
provision of the CAA. The modeling was made available to the public in
the proposed RCU on October 30, 2020. See 85 FR 68964. The comment
period for that rulemaking was open from October 30, 2020, through
December 14, 2020. Id. Petitions for review of the RCU were due by June
29, 2021 in the D.C. Circuit. See 86 FR 23054, 23164 (April 30, 2021);
see also CAA section 307(b). Additionally, EPA had previously
determined that the CSAPR Update Federal implementation plan for
Tennessee eliminated the State's significant contribution to downwind
ozone nonattainment or maintenance for the 2008 8-hour ozone NAAQS. See
81 FR 74504, 74508 (October 26, 2016).
    EPA disagrees that there was an error in the modeling that is
material to this action. EPA used CAMX version 7, beta6 for
the air quality modeling to support the RCU. This version of
CAMX was the most up-to-date version of the model available
at the time EPA performed air quality modeling for the RCU. The final
CAMX version 7.0 was released by the model developer,
Ramboll, in May of 2020. This version was a different version than the
beta6 version EPA used in its modeling.
    Following release of version 7.0, the commenter is correct that an
error was identified in the model code that affected model predicted
concentrations and, therefore, contributions when the model was run
using ozone or PM2.5 source apportionment tools (SAT) for
calculating source contributions to pollutant concentrations.
Specifically, when CAMX version 7.0 was run with SAT, the
pollutant species emissions in the input point source emissions file
did not match the species in the core model. For example, it is
possible that the model might have assigned point source emissions of
nitric oxide (NO) in the input emissions file to SO2 in the
model run. Thus, the effects on model predictions due to this type of
mismatch of pollutant emissions and concentrations would likely be
significant. Once this error was identified, it was quickly
corrected.\33\ Further, the code error in version 7.0 did not occur in
CAMX model runs when SAT were not invoked (i.e., model runs
without SA).
---------------------------------------------------------------------------

    \33\ From CAMXversion 7.10 release notes, January 5,
2021: ``Fixed bug that improperly mapped point source species to
model species when running SAT. Implications: Core model point
source species were improperly injected affecting core model
concentrations and by extension SAT concentrations.'' See https://camx-wp.azurewebsites.net/Files/Release_notes.v7.10.txt
---------------------------------------------------------------------------

    EPA contacted Ramboll to determine whether this coding error in the
final release of version 7.0 was also present in any of the pre-release
beta versions, particularly beta6, which EPA had used for the RCU.
Ramboll initially stated that they had no information to determine
whether or not the code error was in beta6 or any of the other version
7.0 beta codes. However, in consultation with Ramboll, EPA found that
this could be determined by comparing the model predictions from a run
without SAT to a companion model run with SAT invoked. If the
predictions are the same, then the code EPA used for the RCU did not
contain this coding error.
    For the RCU, EPA had performed two CAMX model runs for
2023, one without SAT and one with SAT. Thus, to respond to this
comment, EPA compared the ozone predictions from these two runs to
identify whether or not there are any notable differences between the
two. As an example, Table 5 provides the maximum daily 8-hour ozone
predictions for the 2023 emissions case for the month of July at the
RCU nonattainment receptor site in Stratford, Connecticut. In addition,
Figure 1, provided in the dockets for this final rulemaking, shows the
maximum daily 8-hour ozone concentrations in each model grid cell on
one of the days in June based on 2023 modeling without and with
SAT.\34\

In both the table and the figure, model predictions without and with SA
are essentially identical. Thus, based on EPA's analysis, the Agency
concludes that the error referenced by the commenter was not in the
CAMX model code that EPA used for the RCU modeling.
---------------------------------------------------------------------------

    \34\ Figure 1: Model-predicted 2023 maximum daily 8-hour ozone
concentrations (ppb) for June 20 from CAMX v7beta6 model
runs without SAT (top) and with STA (bottom); both maps use the same
0 to 80 ppb scale for depicting concentrations.
---------------------------------------------------------------------------

    For the reasons above, EPA disagrees with the commenter's
assertions regarding EPA's section 110(l) analysis for Tennessee's good
neighbor obligations for the 2008 ozone NAAQS, and EPA is confident
that the CAMX modeling used in the RCU and to support this
action is reliable.

  Table 5--Model-Predicted Maximum Daily 8-Hour Ozone Concentrations (ppb) Without and With SA for the Month of
                                July at the Stratford, Connecticut Receptor Site
----------------------------------------------------------------------------------------------------------------
                         Month                                  Day          2023 without SA      2023 with SA
----------------------------------------------------------------------------------------------------------------
7......................................................                  1             38.945             38.945
7......................................................                  2             33.380             33.380
7......................................................                  3             42.748             42.748
7......................................................                  4             58.685             58.685
7......................................................                  5             45.056             45.056
7......................................................                  6             75.488             75.488
7......................................................                  7             61.284             61.283
7......................................................                  8             50.325             50.325
7......................................................                  9             28.097             28.097
7......................................................                 10             34.460             34.460
7......................................................                 11             30.646             30.646
7......................................................                 12             64.362             64.362
7......................................................                 13             43.699             43.699
7......................................................                 14             49.537             49.537
7......................................................                 15             59.426             59.426
7......................................................                 16             58.222             58.222
7......................................................                 17             68.067             68.067
7......................................................                 18             77.420             77.421
7......................................................                 19             32.556             32.556
7......................................................                 20             36.040             36.040
7......................................................                 21             64.457             64.457
7......................................................                 22             72.682             72.682
7......................................................                 23             37.790             37.790
7......................................................                 24             47.433             47.433
7......................................................                 25             82.696             82.696
7......................................................                 26             40.812             40.812
7......................................................                 27             48.118             48.118
7......................................................                 28             62.982             62.982
7......................................................                 29             52.004             52.004
7......................................................                 30             60.485             60.485
7......................................................                 31             42.559             42.559
----------------------------------------------------------------------------------------------------------------

    Comment B10: A commenter identifies a number of regulations and
policies that have either been rolled back or are proposed to be rolled
back and expresses concern that the non-interference analysis did not
account for the status of these rollbacks. The commenter states that
air quality in the region has ``shown deterioration and movement
towards nonattainment of the various NAAQS'' due to the rollbacks.
Also, the commenter asserts that impacts from as far away as California
or New York could impact air in Tennessee. The commenter also concludes
that there are emissions increases attributable to the rollbacks and
that they should be taken into account to accurately assess air quality
prior to removal of the I/M programs from the SIP.
    Response B10: EPA does not agree with the commenter's assertion
that Tennessee should have or could have accounted for the final or
proposed rollbacks identified by the commenter. As described above,
Tennessee used the latest available information when the SIP revision
was developed with EPA's MOVES2014b model and associated technical and
policy guidance,\35\ and the SIP revision's new on-road mobile source
inventory was based on the EPA's vehicle and fuel standard rulemakings
that are relevant for criteria pollutants.
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    \35\ See EPA's July 2014 ``Policy Guidance on the Use of
MOVES2014 for State Implementation Plan Development, Transportation
Conformity, and Other Purposes'' (hereinafter MOVES 2014 Guidance).
This document is available at https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100K4EB.pdf.
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    With respect to a number of the rollbacks that the commenter
directly asserts ``could be considered to have an impact on the
Tennessee airshed,'' the commenter did not provide any documents or
citations, therefore, in some cases, it is not entirely clear what
changes the commenter is referring to. However, based on the changes
that EPA believes the commenter to be concerned with, EPA disagrees
that the changes will impact Tennessee air quality. For example, the
rule titled ``Oil and Natural Gas Sector: Emission Standards for New,
Reconstructed, and Modified Sources Review,'' 85 FR 57018 (September
14, 2020), was disapproved under the Congressional Review Act,\36\ and
the fuel volatility waivers under the rule titled ``Modifications to
Fuel Regulations To Provide Flexibility for E15; Modifications to RFS
RIN Market Regulations,'' 84 FR 26980 (June 10, 2019), were vacated by
the D.C. Circuit. See Am. Fuel & Petrochemical Manufacturers v. EPA,
No. 19-1124, 2021 WL 2755032, at *7 (D.C. Cir. July

2, 2021). The commenter also cites to a regulation that tracks--rather
than controls--emissions; \37\ denials of petitions that were before
the agency that did not alter any emissions controls in place, some of
which have been sent back to EPA; \38\ and guidance that, by its very
nature, does not impose binding requirements.\39\
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    \36\ See, e.g., White House signing statement at https://www.whitehouse.gov/briefing-room/statements-releases/2021/06/30/bills-signed-s-j-res-13-s-j-res-14-s-j-res-15/.
    \37\ National Performance Management Measures; Assessing
Performance of the National Highway System, Freight Movement on the
Interstate System, and Congestion Mitigation and Air Quality
Improvement Program, 83 FR 24920 (May 31, 2018).
    \38\ See, e.g., New York v. EPA, 964 F.3d 1214 (D.C. Cir. 2020);
Maryland v. EPA, 958 F.3d 1185 (D.C. Cir. 2020).
    \39\ See, e.g., August 31, 2018 Memo from Peter Tsirigotis
(OAQPS) re Analysis of Contribution Thresholds for Use in Clean Air
Act Section 110(a)(2)(D)(i)(I) Interstate transport State
Implementation Plan submissions for the 2015 Ozone National Ambient
Air Quality Standards, available at https://www.epa.gov/sites/default/files/2018-09/documents/contrib_thresholds_transport_sip_subm_2015_ozone_memo_08_31_18.pdf
(Memo ``does not impose binding, enforceable requirements on any
party''); October 9, 2020 Memo from Andrew Wheeler re Inclusion of
Provisions Governing Periods of Startup, Shutdown, and Malfunctions
in State Implementation Plans (``This memorandum does not alter in
any way the determinations made in the 2015 SSM SIP Action that
identified specific state SIP provisions that were substantially
inadequate to meet the requirements of the Act. In order to change
those determinations and alter or withdraw the 2015 SIP call,
subsequent actions will need to be taken.'').
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    With respect to any pending or proposed changes, per EPA's
Emissions Inventory Guidance, ``[i]mpacts of proposed [Federal] rules
are rarely included'' in EPA emissions projections ``as the changes in
emissions impacts can be very large between proposed and final rules.''
\40\ See ``Emissions Inventory Guidance for Implementation of Ozone and
Particulate Matter National Ambient Air Quality Standards (NAAQS) and
Regional Haze Regulations,'' May 2017, at 122.\41\
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    \40\ EPA notes that the commenter references ``withdrawal of a
proposed rule aimed at reducing pollutants, including air pollution,
at sewage treatment plants.'' However, the commenter cites to a
final rule ``National Emission Standards for Hazardous Air
Pollutants: Publicly Owned Treatment Works Residual Risk and
Technology Review,'' 82 FR 49513 (Oct. 26, 2017), within which EPA
did not take final action on several provisions that were proposed,
but did not withdraw proposal as to those provisions. To the extent
that the commenter refers to the provisions that were not acted
upon, those changes remain pending, and thus, EPA's emissions
projections will not take those into account.
    \41\ Available at https://www.epa.gov/sites/production/files/2017-07/documents/ei_guidance_may_2017_final_rev.pdf.
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    Furthermore, the commenter did not provide any technical
information or analysis to substantiate their claims that the final or
proposed rollbacks in combination with the removal of the I/M program
from the Tennessee SIP would cause either Hamilton County or the Middle
Tennessee Area to interfere with attainment or maintenance of the
NAAQS. In addition, any possible air quality impacts from many of the
rollbacks are speculative and hypothetical in nature. In contrast,
EPA's analysis projects that 2022 total emissions without the I/M
program are significantly less than 2014 total emissions for both the
Middle Tennessee and Hamilton County areas. See Section III, above, and
EPA's April 2021 SNPRM.\42\
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    \42\ See 86 FR 21248. With respect to the Middle Tennessee Area:
``Even without the I/M program in 2022, emissions of NOX,
VOC, and CO are projected to decrease by 47.1 percent, 15.1 percent,
and 23.9 percent, respectively, from 2014 levels.'' With respect to
Hamilton County: ``Even without the I/M program in 2022, emissions
of NOX, VOC, and CO are expected to decrease by 27.0
percent, 8.1 percent and 18.7 percent, respectively from 2014
levels.''
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C. Responses to Comments Outside the Scope of This Rulemaking

    EPA received numerous comments that are outside the scope of this
rulemaking. Even though EPA is not obligated to respond to these
comments, EPA nonetheless has provided responses below in order to
assist the public's understanding of EPA's final action.
    Comment C1: Many commenters opposed to the removal of the I/M
program acknowledge improved vehicle standards, but believe that the I/
M program is still needed as a check to ensure that citizens are
maintaining their vehicles (including for safety inspections).
    Response C1: To the extent commenters are concerned that removal of
the I/M program will result in citizens neglecting to maintain their
vehicles or affecting vehicle safety, those concerns are outside the
scope of this rulemaking. States have primary responsibility for
deciding how to attain and maintain the NAAQS. Tennessee has opted to
remove the I/M program from its SIP. Under the CAA, the sole issue for
EPA's consideration in this rulemaking is whether removing the I/M
program from the SIP would be consistent with CAA provisions, including
whether discontinuation is expected to interfere with attainment and
maintenance of air quality standards or any applicable requirement of
the CAA. EPA is approving removal of the I/M program from the SIP
because removal is consistent with the requirements of the CAA. The
option the commenter suggests to continue an I/M program to ensure
vehicles are maintained may be considered and implemented at the local
level without EPA's review or approval.
    EPA agrees that vehicles are cleaner now as a result of EPA rules
since the early 2000s that control emissions from on-road vehicles. EPA
refers commenters to Response A4 for more information concerning EPA
standards.
    Comment C2: A commenter opines that the I/M program is needed and
notes ``the testing procedures and equipment need updated badly.'' The
commenter goes on to state that ``A vehicle should not fail emissions
for a certain code that has nothing to do with emissions output. All
vehicles should be tested by their exhaust to see exactly what the air
to fuel ratio is. The software needs updates as well. Very old
equipment.'' Other commenters expressed concerns about whether the
testing procedures themselves met the intended purpose of the I/M
program. Some commenters questioned why the I/M program was only
required in six counties in Tennessee and wanted the program removed
for those counties, while others wanted the program expanded statewide
and even nationwide. Other commenters expressed concerns about I/M
program avoidance. They noted that citizens register their vehicles in
surrounding counties that do not have I/M requirements, yet commute
back and forth or even live in areas where I/M is required. Some of the
commenters expressed concern about program avoidance as support for the
removal of the I/M program. Commenters opined on whether or not the
cost of the program and related expenses were worth keeping the
program. Some commenters expressed concern related to the impact of the
test and repair costs on the elderly and low-income citizens. Others
asserted that this was a way to generate revenue and an unfair tax.
Those who did not support removal of the I/M program opined that the I/
M program was worth the benefit for air quality. Another commenter
expressed concerns with regard to ``replacements'' to the I/M program.
The commenter also stated that ``we . . . must be able to maintain the
progress that has been made.'' One commenter opined that there is a
``likelihood that current income limitations will impact future
replacement of aging vehicles.'' Another commenter said that ``[t]he
emissions program is doing more good than harm for the community.''
Some adverse comments indicated that removal of I/M could lead to
people not feeling the need to maintain their cars, which will lead to
even bigger problems.
    Response C2: These comments are all outside the scope of this
rulemaking. The design, technology, and implementation issues
associated with

an I/M program are outside this scope of this rulemaking. With regard
to the geographical coverage area of Tennessee's I/M program, EPA notes
that the I/M program is not currently mandated by the CAA or EPA
regulations in any part of Tennessee or throughout the entirety of the
United States.\43\ Additionally, the cost structure of individual I/M
programs is not a factor EPA evaluates when determining approvability
of a SIP revision to remove I/M requirements. A commenter's assertion
that the SIP revision is a ``repeal and replace'' is not clear.
Tennessee's February 2020 SIP revisions only addressed removal of the
I/M program, without a replacement program or offsets.
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    \43\ Except as required by CAA sections 182(a)(2)(B), 182(b)(4),
and 182(c)(3) for certain ozone nonattainment areas and sections
187(a)(4) and 187(a)(6) for certain CO nonattainment areas.
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    See Responses A5 and A10 regarding the scope of EPA's review and
the discretionary nature of Tennessee's program, and the April 2021
SNPRM regarding EPA's determination that section 110(l) requirements
have been met.
    Comment C3: Commenters suggest that EPA needs to monitor emissions
released from mobile sources outside of I/M programs, such as planes,
trains, trucks, and buses in order to either improve air quality or
prevent it from deteriorating.
    Response C3: These comments are outside the scope of this
rulemaking. As discussed in Response A5, CAA section 110(k) requires
EPA to approve SIP revisions that meet all applicable CAA requirements.
While monitoring and regulating emissions from planes, trains, trucks,
buses and any other ``mobile source'' that are not passenger vehicles
is out of scope of this action, EPA notes that the Agency's Office of
Transportation and Air Quality (OTAQ) addresses emissions from the
range of mobile sources. The commenters are encouraged to visit OTAQ's
website for more information at https://www.epa.gov/aboutepa/about-office-air-and-radiation-oar#otaq to learn more about these programs.
    Comment C4: A commenter opines that removing the I/M program is a
bad idea and recalls polluting cars and trucks before the I/M program
was enacted. The commenter goes on to say ``My only issue in
Chattanooga is the mayor has put in bike lanes everywhere that are used
very seldomly and reducing the auto lanes creates huge traffic
backups.'' The commenter goes on to say that bike lanes cause more
pollution and offsets what emissions benefits are achieved.
    Response C4: For reasons explained in the April 2021 SNPRM, EPA has
determined that section 110(l) requirements have been met. EPA also
notes that cars and trucks are cleaner, absent the I/M program, because
of Federal engine and fuel standards that all vehicles must comply
with. Thus, vehicles today are much cleaner than they were when the I/M
program was enacted in Hamilton County in the early 2000s, as vehicle
and fuel standards have become more stringent since then. To the extent
that the commenter expresses concerns about bike lanes and their impact
on traffic and emissions, these comments are outside the scope of this
rulemaking as I/M programs do not regulate bike lanes.
    Comment C5: A commenter in support of the emissions testing in
Hamilton County states that ``[i]t not only has helped clean up the air
in the county, it has also drawn other large businesses to our Area.
Volkswagen and Amazon both came here due in part to Hamilton County's
emission testing.'' Another commenter expresses concern for their
industry and stated: ``If Chattanooga and Nashville Ozone Standards are
changed in the future and the EPA is no longer able to effectively
regulate `on road' mobile source emissions, stationary sources and our
member's off-road fleets could, and likely would, be over regulated due
the inability to regulate the much more impactful on-road mobile
sources. This could create a severe adverse impact to our industry.''
    Response C5: These comments are outside the scope of this
rulemaking. In evaluating whether a SIP revision is approvable, EPA
must consider the relevant CAA provisions and does not consider what
impacts, if any, the SIP revision would have for attracting businesses
to an area. Nor does EPA try to anticipate what the State may do for
future air quality planning. As detailed in the April 2021 SNPRM, EPA
has determined that approval of these SIP revisions will not interfere
with attainment or maintenance of the NAAQS or any other requirement of
the CAA. EPA's action to remove the I/M program does not preclude the
state or local government from maintaining an I/M program at the state
or local level.
    Comment C6: One commenter asserted that during Tennessee's state
comment period it did not have access to inventory materials in
timeframes necessary to conduct an independent review and modeling of
the I/M program removal.
    Response C6: This comment is outside the scope of this rulemaking
because it relates to Tennessee's State comment period. In addition,
EPA notes that the inventories were available to the public during
EPA's public comment period on the June 2020 NPRMs and the April 2021
SNPRM. See regulations.gov document numbers EPA-R04-OAR-2019-0618-0002
(pdf pages 16 and 21) and EPA-R04-OAR-2019-0619-0002 (pdf pages 16, 17
and 22).

V. Incorporation by Reference

    In this document, EPA is finalizing regulatory text that includes
incorporation by reference. As described in the amendments to 40 CFR
part 52 set forth below, EPA is finalizing the removal of Tennessee
Regulation Chapter 1200-3-29--``Light Duty Vehicle Inspection and
Maintenance;'' and Nashville-Davidson County Regulation No. 8--
``Regulation of Emissions from Light-Duty Motor Vehicles through
Mandatory Vehicle Inspection and Maintenance Program,'' from the
Tennessee SIP, which is incorporated by reference in accordance with
the requirements of 1 CFR part 51.

VI. Final Action

    EPA is approving the SIP revisions and removing the I/M
requirements for the Middle Tennessee Area (i.e., Davidson, Sumner,
Rutherford, Williamson and Wilson Counties) and Hamilton County from
the Tennessee SIP. EPA is taking these actions because removing the
requirements is consistent with the CAA and applicable regulations.

VII. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve SIP
submissions that comply with the provisions of the Act and applicable
Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. These actions merely
approve state law as meeting Federal requirements and does not impose
additional requirements beyond those imposed by state law. For that
reason, these actions:
     Are not significant regulatory actions subject to review
by the Office of Management and Budget under Executive Orders 12866 (58
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Do not impose an information collection burden under the
provisions

of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
     Do not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Do not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Are not an economically significant regulatory action
based on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Are not a significant regulatory action 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 the 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.