[Federal Register Volume 87, Number 49 (Monday, March 14, 2022)]
[Proposed Rules]
[Pages 14210-14224]
[FR Doc No: 2022-05253]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2020-0730; EPA-R05-OAR-2020-0731; EPA-R05-OAR-2022-0004;
FRL-9629-01-R5]

Air Plan Approval; Michigan; Redesignation of the Detroit, MI
Area to Attainment of the 2015 Ozone Standards

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to find
that the Detroit, Michigan area is attaining the 2015 primary and
secondary ozone National Ambient Air Quality Standards (NAAQS), and to
act in accordance with a request from the Michigan Department of
Environment, Great Lakes, and Energy (EGLE) to redesignate the area to
attainment for the 2015 ozone NAAQS because the request meets the
statutory requirements for redesignation under the Clean Air Act (CAA).
The Detroit area includes Livingston, Macomb, Monroe, Oakland, St.
Clair, Washtenaw, and Wayne Counties. EGLE submitted this request on
January 3, 2022. EPA is proposing to approve, as a revision to the
Michigan State Implementation Plan (SIP), the State's plan for
maintaining the 2015 ozone NAAQS through 2035 in the Detroit area. EPA
is also proposing to approve Michigan's 2025 and 2035 volatile organic
compound (VOC) and oxides of nitrogen (NOX) motor vehicle
emissions budgets (budgets) for the Detroit area and initiating the
adequacy review process for these budgets. Finally, EPA is proposing to
approve portions of separate December 18, 2020, submittals as meeting
the applicable requirements for a base year emissions inventory and
emissions statement program.

DATES: Comments must be received on or before April 13, 2022.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2020-0730, EPA-R05-OAR-2020-0731, or EPA-R05-OAR-2022-0004 at
http://www.regulations.gov, or via email to [email protected]. For
comments submitted at Regulations.gov, follow the online instructions
for submitting comments. Once submitted, comments cannot be edited or
removed from Regulations.gov. For either manner of submission, EPA may
publish any comment received to its public docket. Do not submit
electronically any information you consider to be Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Multimedia submissions (audio, video, etc.) must be
accompanied by a written comment. The written comment is considered the
official comment and should include discussion of all points you wish
to make. EPA will generally not consider comments or comment contents
located outside of the primary submission (i.e., on the web, cloud, or
other file sharing system). For additional submission methods, please
contact the person identified in the FOR FURTHER INFORMATION CONTACT
section. For the full EPA public comment policy, information about CBI
or multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Eric Svingen, Environmental Engineer,
Attainment Planning and Maintenance Section, Air Programs Branch (AR-
18J), Environmental Protection Agency, Region 5, 77 West Jackson
Boulevard, Chicago, Illinois 60604,<PHONE_NUMBER>,
[email protected]. The EPA Region 5 office is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding Federal holidays and
facility closures due to COVID-19.

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.

I. What is EPA proposing?

    EPA is proposing to take several related actions. EPA is proposing
to determine that the Detroit nonattainment area is attaining the 2015
ozone NAAQS, based on quality-assured and certified monitoring data for
2019-2021, and that the Detroit area has met the requirements for
redesignation under section 107(d)(3)(E) of the CAA. EPA is thus
proposing to change the legal designation of the Detroit area

from nonattainment to attainment for the 2015 ozone NAAQS. EPA is also
proposing to approve, as a revision to the Michigan SIP, the State's
maintenance plan for the area. The maintenance plan is designed to keep
the Detroit area in attainment of the 2015 ozone NAAQS through 2035.
EPA is proposing to approve the newly established 2025 and 2035 motor
vehicle emissions budgets for the Detroit area and is initiating the
adequacy process for these budgets. Finally, EPA is proposing to
approve portions of Michigan's separate December 18, 2020, submittals,
because they satisfy the applicable CAA requirements for a base year
emissions inventory and emissions statement program for the Detroit
area.

II. What is the background for these actions?

    EPA has determined that ground-level ozone is detrimental to human
health. On October 1, 2015, EPA promulgated a revised 8-hour ozone
NAAQS of 0.070 parts per million (ppm). See 80 FR 65292 (October 26,
2015). Under EPA's regulations at 40 CFR part 50, the 2015 ozone NAAQS
is attained in an area when the 3-year average of the annual fourth
highest daily maximum 8-hour average concentration is equal to or less
than 0.070 ppm, when truncated after the thousandth decimal place, at
all of the ozone monitoring sites in the area. See 40 CFR 50.19 and
appendix U to 40 CFR part 50.
    Upon promulgation of a new or revised NAAQS, section 107(d)(1)(B)
of the CAA requires EPA to designate as nonattainment any areas that
are violating the NAAQS, based on the most recent three years of
quality assured ozone monitoring data. The Detroit area was designated
as a Marginal nonattainment area for the 2015 ozone NAAQS on June 4,
2018 (83 FR 25776) (effective August 3, 2018).

III. What are the criteria for redesignation?

    Section 107(d)(3)(E) of the CAA allows redesignation of an area to
attainment of the NAAQS provided that: (1) The Administrator (EPA)
determines that the area has attained the NAAQS; (2) the Administrator
has fully approved the applicable implementation plan for the area
under section 110(k) of the CAA; (3) the Administrator determines that
the improvement in air quality is due to permanent and enforceable
reductions in emissions resulting from implementation of the applicable
SIP, applicable Federal air pollutant control regulations, and other
permanent and enforceable emission reductions; (4) the Administrator
has fully approved a maintenance plan for the area as meeting the
requirements of section 175A of the CAA; and (5) the state containing
the area has met all requirements applicable to the area for the
purposes of redesignation under section 110 and part D of the CAA.
    On April 16, 1992, EPA provided guidance on redesignations in the
General Preamble for the Implementation of Title I of the CAA
Amendments of 1990 (57 FR 13498) and supplemented this guidance on
April 28, 1992 (57 FR 18070). EPA has provided further guidance on
processing redesignation requests in policy memoranda.

IV. What is EPA's analysis of Michigan's redesignation request?

A. Has the Detroit area attained the 2015 ozone NAAQS?

    For redesignation of a nonattainment area to attainment, the CAA
requires EPA to determine that the area has attained the applicable
NAAQS (CAA section 107(d)(3)(E)(i)). An area is attaining the 2015
ozone NAAQS if it meets the 2015 ozone NAAQS, as determined in
accordance with 40 CFR 50.19 and appendix U of part 50, based on three
complete, consecutive calendar years of quality-assured air quality
data for all monitoring sites in the area. To attain the 2015 ozone
NAAQS, the 3-year average of the annual fourth-highest daily maximum 8-
hour average ozone concentrations (ozone design values) at each monitor
must not exceed 0.070 ppm. The air quality data must be collected and
quality-assured in accordance with 40 CFR part 58 and recorded in EPA's
Air Quality System (AQS). Ambient air quality monitoring data for the
3-year period must also meet data completeness requirements. An ozone
design value is valid if daily maximum 8-hour average concentrations
are available for at least 90% of the days within the ozone monitoring
seasons,\1\ on average, for the 3-year period, with a minimum data
completeness of 75% during the ozone monitoring season of any year
during the 3-year period. See section 4 of appendix U to 40 CFR part
50.
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    \1\ The ozone season is defined by state in 40 CFR 58, appendix
D. The ozone season for Michigan is March-October. See 80 FR 65292,
65466-67 (October 26, 2015).
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    EPA has reviewed the available ozone monitoring data from EGLE's
monitoring sites in the Detroit area for the 2019-2021 period. These
data have been quality assured, are recorded in the AQS, and were
certified in advance of EPA's publication of this proposal. These data
demonstrate that the Detroit area is attaining the 2015 ozone NAAQS.
The annual fourth-highest 8-hour ozone concentrations and the 3-year
average of these concentrations (monitoring site ozone design values)
for all monitoring sites are summarized in Table 1.

   Table 1--Annual Fourth-Highest Daily Maximum 8-Hour Ozone Concentrations and 3-Year Average of the Fourth-
                     Highest Daily Maximum 8-Hour Ozone Concentrations for the Detroit Area
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                                                   2019 4th high   2020 4th high   2021 4th high     2019-2021
             County                   Monitor          (ppm)           (ppm)           (ppm)       average (ppm)
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Macomb..........................     26-099-0009           0.063           0.074           0.068           0.068
                                     26-099-1003           0.062           0.070           0.067           0.066
Oakland.........................     26-125-0001           0.066           0.074           0.068           0.069
St. Clair.......................     26-147-0005           0.070           0.069           0.072           0.070
Washtenaw.......................     26-161-0008           0.060           0.072           0.066           0.066
                                     26-161-9991           0.058           0.067           0.063           0.062
Wayne...........................     26-163-0001           0.062           0.070           0.069           0.067
                                     26-163-0019           0.068           0.073           0.069           0.070
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    The Detroit area's 3-year ozone design value for 2019-2021 is 0.070
ppm,\2\ which meets the 2015 ozone NAAQS. Therefore, in today's action,
EPA proposes to determine that the Detroit area is attaining the 2015
ozone NAAQS.
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    \2\ The monitor ozone design value for the monitor with the
highest 3-year averaged concentration.
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    EPA will not take final action to determine that the Detroit area
is attaining the NAAQS nor to approve the redesignation of this area if
the design value of a monitoring site in the area violates the NAAQS
prior to final approval of the redesignation. As discussed in section
IV.D.3. below, EGLE has committed to continue monitoring ozone in this
area to verify maintenance of the 2015 ozone NAAQS.

B. Has Michigan met all applicable requirements of section 110 and part
D of the CAA for the Detroit area, and does Michigan have a fully
approved SIP for the area under section 110(k) of the CAA?

    For redesignation of an area from nonattainment to attainment of a
NAAQS, the CAA requires EPA to determine that the state has met all
applicable requirements under section 110 and part D of title I of the
CAA (see section 107(d)(3)(E)(v) of the CAA) and that the state has a
fully approved SIP under section 110(k) of the CAA (see section
107(d)(3)(E)(ii) of the CAA). EPA proposes to find that Michigan has
met all applicable SIP requirements for purposes of redesignation under
section 119 and part D of title I of the CAA (requirements specific to
nonattainment areas for the 2015 ozone NAAQA). Additionally, with the
exception of the base year emissions inventory requirement of section
182(a)(1) of the CAA and the emissions statement requirement of section
182(a)(3)(B) of the CAA, EPA proposes to find that Michigan has a fully
approved SIP under section 110(k) of the CAA. As discussed in sections
VI. and VII. below, EPA is proposing to approve Michigan's base year
emissions inventory and emissions statement program as meeting the
requirements of sections 182(a)(1) and 182(a)(3), respectively, for the
2015 ozone NAAQS. Upon final approval of these SIP elements, all
applicable requirements of the Michigan SIP for the area will have been
fully approved under section 110(k) of the CAA. In making these
proposed determinations, EPA ascertained which requirements are
applicable for purposes of redesignation, and whether the required
Michigan SIP elements are fully approved under section 110(k) and part
D of the CAA. As discussed more fully below, SIPs must be fully
approved only with respect to these applicable requirements of the CAA.
    The September 4, 1992, memorandum from John Calcagni, Director, Air
Quality Management Division, entitled ``Procedures for Processing
Requests to Redesignate Areas to Attainment,'' describes EPA's
interpretation of which requirements are ``applicable'' for purposes of
redesignation under section 107(d)(3)(E) of the CAA. Under this
interpretation, a requirement is not ``applicable'' unless it was due
prior to the state's submittal of a complete redesignation request for
the area. See also the September 17, 1993, memorandum from Michael H.
Shapiro, entitled ``State Implementation Plan (SIP) Requirements for
Areas Submitting Requests for Redesignation to Attainment of the Ozone
and Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS)
On or After November 15, 1992,'' and 60 FR 12459, 12465-66 (March 7,
1995) (redesignation of Detroit-Ann Arbor, Michigan to attainment of
the 1hour ozone NAAQS). Applicable requirements of the CAA that come
due subsequent to the state's submittal of a complete request remain
applicable until a redesignation to attainment is approved but are not
required as a prerequisite to redesignation.\3\ See section 175A(c) of
the CAA. Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004). See also 68
FR 25424, 25427 (May 12, 2003) (redesignation of the St. Louis/East St.
Louis area to attainment of the 1hour ozone NAAQS).
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    \3\ EPA is, in a separate action, proposing to find that the
Detroit area failed to attain the 2015 ozone NAAQS by its attainment
date. If that determination were finalized, the area would be
reclassified to Moderate by operation of law. However, because of
EPA's interpretation and the date by which Michigan submitted its
request, those Moderate area requirements are not considered
applicable requirements for purposes of redesignating the Detroit
area. Specifically, at the time Michigan submitted its request, EPA
had not yet determined that the area failed to attain and had not
yet reclassified the area. Per CAA section 182(i) and consistent
with CAA section 179(d), EPA typically adjusts the deadlines for SIP
submissions that are required for newly reclassified areas.
Therefore, even if EPA were to finalize today the determination that
the area failed to attain and reclassify the area, the deadline for
the requirements associated with the reclassification would be set
at some point in the future. Michigan submitted its request to
redesignate well in advance of any hypothetical due date associated
with Moderate area requirements.
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    1. Michigan has met all applicable requirements of section 110 and
part D of the CAA applicable to the Detroit area for purposes of
redesignation.
a. Section 110 General Requirements for Implementation Plans
    Section 110(a)(2) of the CAA delineates the general requirements
for a SIP. Section 110(a)(2) provides that the SIP must have been
adopted by the state after reasonable public notice and hearing, and
that, among other things, it must: (1) Include enforceable emission
limitations and other control measures, means or techniques necessary
to meet the requirements of the CAA; (2) provide for establishment and
operation of appropriate devices, methods, systems and procedures
necessary to monitor ambient air quality; (3) provide for
implementation of a source permit program to regulate the modification
and construction of stationary sources within the areas covered by the
plan; (4) include provisions for the implementation of part C
prevention of significant deterioration (PSD) and part D new source
review (NSR) permit programs; (5) include provisions for stationary
source emission control measures, monitoring, and reporting; (6)
include provisions for air quality modeling; and, (7) provide for
public and local agency participation in planning and emission control
rule development.
    Section 110(a)(2)(D) of the CAA requires SIPs to contain measures
to prevent sources in a state from significantly contributing to air
quality problems in another state. To implement this provision, EPA has
required certain states to establish programs to address transport of
certain air pollutants, e.g., NOX SIP call, the Clean Air
Interstate Rule (CAIR), and the Cross State Air Pollution Rule (CSAPR).
However, like many of the 110(a)(2) requirements, the section
110(a)(2)(D) SIP requirements are not linked with a particular area's
ozone designation and classification. EPA concludes that the SIP
requirements linked with the area's ozone designation and
classification are the relevant measures to evaluate when reviewing a
redesignation request for the area. The section 110(a)(2)(D)
requirements, where applicable, continue to apply to a state regardless
of the designation of any one particular area within the state. Thus,
we believe these requirements are not applicable requirements for
purposes of redesignation. See 65 FR 37890 (June 15, 2000), 66 FR 50399
(October 19, 2001), 68 FR 25418, 25426-27 (May 13, 2003).
    In addition, EPA believes that other section 110 elements that are
neither connected with nonattainment plan submissions nor linked with
an area's ozone attainment status are not

applicable requirements for purposes of redesignation. The area will
still be subject to these requirements after the area is redesignated
to attainment of the 2015 ozone NAAQS. The section 110 and part D
requirements which are linked with a particular area's designation and
classification are the relevant measures to evaluate in reviewing a
redesignation request. This approach is consistent with EPA's existing
policy on applicability (i.e., for redesignations) of conformity
requirements, as well as with section 184 ozone transport requirements.
See Reading, Pennsylvania proposed and final rulemakings, 61 FR 53174-
53176 (October 10, 1996) and 62 FR 24826 (May 7, 1997); Cleveland-
Akron-Loraine, Ohio final rulemaking, 61 FR 20458 (May 7, 1996); and
Tampa, Florida final rulemaking, 60 FR 62748 (December 7, 1995). See
also the discussion of this issue in the Cincinnati, Ohio ozone
redesignation (65 FR 37890, June 19, 2000), and the Pittsburgh,
Pennsylvania ozone redesignation (66 FR 50399, October 19, 2001).
    We have reviewed Michigan's SIP and propose to find that it meets
the general SIP requirements under section 110 of the CAA, to the
extent those requirements are applicable for purposes of redesignation.
In any case, on September 28, 2021 (86 FR 53550), EPA approved elements
of the SIP submitted by Michigan to meet the requirements of section
110 for the 2015 ozone standard.
b. Part D Requirements
    Section 172(c) of the CAA sets forth the basic requirements of air
quality plans for states with nonattainment areas that are required to
submit them pursuant to section 172(b). Subpart 2 of part D, which
includes section 182 of the CAA, establishes specific requirements for
ozone nonattainment areas depending on the areas' nonattainment
classifications.
    The Detroit area was classified as Marginal under subpart 2 for the
2015 ozone NAAQS. As such, the area is subject to the subpart 1
requirements contained in section 172(c) and section 176. Similarly,
the area is subject to the subpart 2 requirements contained in section
182(a) (Marginal nonattainment area requirements). A thorough
discussion of the requirements contained in section 172(c) and 182 can
be found in the General Preamble for Implementation of Title I (57 FR
13498).
i. Subpart 1 Section 172 Requirements
    As provided in subpart 2, for Marginal ozone nonattainment areas
such as the Detroit area, the specific requirements of section 182(a)
apply in lieu of the attainment planning requirements that would
otherwise apply under section 172(c), including the attainment
demonstration and reasonably available control measures (RACM) under
section 172(c)(1), reasonable further progress (RFP) under section
172(c)(2), and contingency measures under section 172(c)(9). 42 U.S.C.
7511a(a).
    Section 172(c)(3) requires submission and approval of a
comprehensive, accurate and current inventory of actual emissions. This
requirement is superseded by the inventory requirement in section
182(a)(1) discussed below.
    Section 172(c)(4) requires the identification and quantification of
allowable emissions for major new and modified stationary sources in an
area, and section 172(c)(5) requires source permits for the
construction and operation of new and modified major stationary sources
anywhere in the nonattainment area. EPA approved Michigan's NSR program
on December 16, 2013 (78 FR 76064), and most recently approved
revisions to Michigan's NSR program on May 12, 2021 (86 FR 25954).
Nonetheless, EPA has determined that, since PSD requirements will apply
after redesignation, areas being redesignated need not comply with the
requirement that a NSR program be approved prior to redesignation,
provided that the area demonstrates maintenance of the NAAQS without
part D NSR. A more detailed rationale for this view is described in the
October 14, 1994, memorandum from Mary Nichols, Assistant Administrator
for Air and Radiation, entitled, ``Part D New Source Review
Requirements for Areas Requesting Redesignation to Attainment.'' See
rulemakings for Detroit, Michigan (60 FR 12467-12468, March 7, 1995);
Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996);
Louisville, Kentucky (66 FR 53665, October 23, 2001); and Grand Rapids,
Michigan (61 FR 31834-31837, June 21, 1996). Michigan's PSD program
will become effective in the Detroit area upon redesignation to
attainment. EPA conditionally approved Michigan's PSD program on
September 16, 2008 (73 FR 53366), fully approved Michigan's PSD program
on March 25, 2010 (75 FR 14352), and most recently approved revisions
to Michigan's PSD program on May 12, 2021 (86 FR 25954).
    Section 172(c)(6) requires the SIP to contain control measures
necessary to provide for attainment of the NAAQS. Because attainment
has been reached, no additional measures are needed to provide for
attainment.
    Section 172(c)(7) requires the SIP to meet the applicable
provisions of section 110(a)(2). As noted above, we believe the
Michigan SIP meets the requirements of section 110(a)(2) for purposes
of redesignation.
ii. Section 176 Conformity Requirements
    Section 176(c) of the CAA requires that federally supported or
funded projects conform to the applicable SIP. The requirement to
determine conformity applies to transportation plans, programs and
projects that are developed, funded or approved under title 23 of the
United States Code (U.S.C.) and the Federal Transit Act (transportation
conformity) as well as to all other federally supported or funded
projects (general conformity). State transportation conformity SIP
revisions must be consistent with Federal conformity regulations
relating to consultation, enforcement and enforceability that EPA
promulgated pursuant to its authority under the CAA.
    EPA interprets the conformity SIP requirements \4\ as not applying
for purposes of evaluating a redesignation request under section 107(d)
because state conformity rules are still required after redesignation
and Federal conformity rules apply where state conformity rules have
not been approved. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001)
(upholding this interpretation); see also 60 FR 62748 (December 7,
1995) (redesignation of Tampa, Florida). Nonetheless, Michigan has an
approved conformity SIP for the Detroit area. See 61 FR 66609 (December
18, 1996) and 82 FR 17134 (April 10, 2017).
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    \4\ CAA section 176(c)(4)(E) requires states to submit revisions
to their SIPs to reflect certain Federal criteria and procedures for
determining transportation conformity. Transportation conformity
SIPs are different from SIPs requiring the development of motor
vehicle emissions budgets, such as control strategy SIPs and
maintenance plans.
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iii. Section 182(a) Requirements
    Section 182(a)(1) requires states to submit a comprehensive,
accurate, and current inventory of actual emissions from sources of
NOX and VOC emitted within the boundaries of the ozone
nonattainment area within two years of designation. On December 18,
2020, Michigan submitted emissions inventories for the Detroit area for
the 2017 base year. As described in section VI. below, EPA is proposing
to approve Michigan's base year emissions inventory as meeting the
requirements

of section 182(a)(1) for the 2015 ozone NAAQS.
    Under section 182(a)(2)(A), states with ozone nonattainment areas
that were designated prior to the enactment of the 1990 CAA amendments
were required to submit, within six months of classification, all rules
and corrections to existing VOC reasonably available control technology
(RACT) rules that were required under section 172(b)(3) prior to the
1990 CAA amendments. The Detroit area is not subject to the section
182(a)(2) RACT ``fix up'' requirement for the 2015 ozone NAAQS because
it was designated as nonattainment for this standard after the
enactment of the 1990 CAA amendments and, in any case, Michigan
complied with this requirement for the Detroit area under the prior 1-
hour ozone NAAQS. See 60 FR 46182 (September 7, 1994).
    Section 182(a)(2)(B) requires each state with a Marginal ozone
nonattainment area that implemented or was required to implement a
vehicle inspection and maintenance (I/M) program prior to the 1990 CAA
amendments to submit a SIP revision for an I/M program no less
stringent than that required prior to the 1990 CAA amendments or
already in the SIP at the time of the CAA amendments, whichever is more
stringent. For the purposes of the 2015 ozone NAAQS and the
consideration of Michigan's redesignation request for this standard,
the Detroit area is not subject to the section 182(a)(2)(B) requirement
because the Detroit area was designated as nonattainment for the 2015
ozone NAAQS after the enactment of the 1990 CAA amendments and because
Michigan complied with this requirement for the Detroit area under the
prior 1-hour ozone NAAQS.
    Regarding the source permitting and offset requirements of section
182(a)(2)(C) and section 182(a)(4), Michigan currently has a fully
approved part D NSR program in place. EPA approved Michigan's NSR
program on December 16, 2013 (78 FR 76064), and most recently approved
revisions to Michigan's NSR program on May 12, 2021 (86 FR 25954). In
addition, EPA conditionally approved Michigan's PSD program on
September 16, 2008 (73 FR 53366), fully approved Michigan's PSD program
on March 25, 2010 (75 FR 14352), and most recently approved revisions
to Michigan's PSD program on May 12, 2021 (86 FR 25954). The state's
PSD program will become effective in the Detroit area upon
redesignation to attainment.
    Section 182(a)(3)(A) requires states to submit periodic emission
inventories and section 182(a)(3)(B) requires states to submit a
revision to the SIP to require the owners or operators of stationary
sources to annually submit emissions statements documenting actual
NOX and VOC emissions. As discussed below in section IV.D.4.
of this proposed rule, Michigan will continue to update its emissions
inventory at least once every three years. With regard to stationary
source emissions statements, EPA approved Michigan's emissions
statement program on March 8, 1994 (49 FR 10752). On December 18, 2020,
Michigan submitted a separate request to strengthen its SIP-approved
emissions statement program by adding, removing, and updating certain
statutes and reporting forms. As described in section VII. below, EPA
is proposing to approve most portions of Michigan's emissions statement
submittal as meeting the requirements of section 182(a)(3)(B) for the
2015 ozone NAAQS.
    Upon approval of Michigan's emissions inventory and emissions
statements rules, the Detroit area will have satisfied all applicable
requirements for purposes of redesignation under section 110 and part D
of title I of the CAA.
    2. The Detroit area has a fully approved SIP for purposes of
redesignation under section 110(k) of the CAA.
    At various times, Michigan has adopted and submitted, and EPA has
approved, provisions addressing the various SIP elements applicable for
the ozone NAAQS. As discussed above, if EPA finalizes approval of
Michigan's section 182(a)(1) base year inventory requirements and
section 182(a)(3)(B) emission statement requirements, EPA will have
fully approved the Michigan SIP for the Detroit area under section
110(k) for all requirements applicable for purposes of redesignation
under the 2015 ozone NAAQS. EPA may rely on prior SIP approvals in
approving a redesignation request (see the Calcagni memorandum at page
3; Southwestern Pennsylvania Growth Alliance v. Browner, 144 F.3d 984,
989-990 (6th Cir. 1998); Wall v. EPA, 265 F.3d 426). Additional
measures may also be approved in conjunction with a redesignation
action (see 68 FR 25426 (May 12, 2003) and citations therein).

C. Are the air quality improvements in the Detroit area due to
permanent and enforceable emission reductions?

    To redesignate an area from nonattainment to attainment, section
107(d)(3)(E)(iii) of the CAA requires EPA to determine that the air
quality improvement in the area is due to permanent and enforceable
reductions in emissions resulting from the implementation of the SIP
and applicable Federal air pollution control regulations and other
permanent and enforceable emission reductions. EPA proposes to
determine that Michigan has demonstrated that that the observed ozone
air quality improvement in the Detroit area is due to permanent and
enforceable reductions in VOC and NOX emissions resulting
from state measures adopted into the SIP and Federal measures.
    In making this demonstration, the State has calculated the change
in emissions between 2014 and 2019. The reduction in emissions and the
corresponding improvement in air quality over this time period can be
attributed to several regulatory control measures that the Detroit area
and upwind areas have implemented in recent years. In addition,
Michigan provided an analysis to demonstrate the improvement in air
quality was not due to unusually favorable meteorology. Based on the
information summarized below, EPA proposes to find that Michigan has
adequately demonstrated that the improvement in air quality is due to
permanent and enforceable emissions reductions.
1. Permanent and Enforceable Emission Controls Implemented
a. Regional NOX Controls
    CAIR/CSAPR. Under the ``good neighbor provision'' of CAA section
110(a)(2)(D)(i)(I), states are required to address interstate transport
of air pollution. Specifically, the good neighbor provision provides
that each state's SIP must contain provisions prohibiting emissions
from within that state which will contribute significantly to
nonattainment of the NAAQS, or interfere with maintenance of the NAAQS,
in any other state.
    On May 12, 2005, EPA published CAIR, which required eastern states,
including Michigan, to prohibit emissions consistent with annual and
ozone season NOX budgets and annual sulfur dioxide
(SO2) budgets (70 FR 25152). CAIR addressed the good
neighbor provision for the 1997 ozone NAAQS and 1997 fine particulate
matter (PM2.5) NAAQS and was designed to mitigate the impact
of transported NOX emissions, a precursor of both ozone and
PM2.5, as well as transported SO2 emissions,
another precursor of PM2.5. The United States Court of
Appeals for the District of Columbia Circuit (D.C. Circuit) remanded
CAIR to EPA for replacement in 2008. North Carolina v. EPA, 531 F.3d
896, modified, 550 F.3d 1176 (2008). While EPA worked on

developing a replacement rule, implementation of the CAIR program
continued as planned with the NOX annual and ozone season
programs beginning in 2009 and the SO2 annual program
beginning in 2010.
    On August 8, 2011 (76 FR 48208), acting on the D.C. Circuit's
remand, EPA published CSAPR to replace CAIR and to address the good
neighbor provision for the 1997 ozone NAAQS, the 1997 PM2.5
NAAQS, and the 2006 PM2.5 NAAQS.\5\ Through Federal
Implementation Plans, CSAPR required electric generating units (EGUs)
in eastern states, including Michigan, to meet annual and ozone season
NOX budgets and annual SO2 budgets implemented
through new trading programs. After delays caused by litigation, EPA
started implementing the CSAPR trading programs in 2015, simultaneously
discontinuing administration of the CAIR trading programs. On October
26, 2016, EPA published the CSAPR Update, which established, starting
in 2017, a new ozone season NOX trading program for EGUs in
eastern states, including Michigan, to address the good neighbor
provision for the 2008 ozone NAAQS (81 FR 74504). The CSAPR Update was
estimated to result in a 20% reduction in ozone season NOX
emissions from EGUs in the eastern United States, a reduction of 80,000
tons in 2017 compared to 2015 levels. On April 30, 2021, EPA published
the Revised CSAPR Update, which fully resolved the obligations of
eastern states, including Michigan, under the good neighbor provision
for the 2008 ozone NAAQS (82 FR 23054). The Revised CSAPR Update is
estimated to reduce ozone season NOX emissions from EGUs by
17,000 tons beginning in 2021, compared to emissions without the rule.
The reduction in NOX emissions from the implementation of
CAIR and then CSAPR occurred by the attainment years and additional
emission reductions will occur throughout the maintenance period.
---------------------------------------------------------------------------

    \5\ In a December 27, 2011 rulemaking, EPA included Michigan in
the ozone season NOX program, addressing the 1997 ozone
NAAQS (76 FR 80760).
---------------------------------------------------------------------------

b. Federal Emission Control Measures
    Reductions in VOC and NOX emissions have occurred
statewide and in upwind areas as a result of Federal emission control
measures, with additional emission reductions expected to occur in the
future. Federal emission control measures include the following:
    Tier 2 Emission Standards for Vehicles and Gasoline Sulfur
Standards. On February 10, 2000 (65 FR 6698), EPA promulgated Tier 2
motor vehicle emission standards and gasoline sulfur control
requirements. These emission control requirements result in lower VOC
and NOX emissions from new cars and light duty trucks,
including sport utility vehicles. With respect to fuels, this rule
required refiners and importers of gasoline to meet lower standards for
sulfur, which were phased in between 2004 and 2006. By 2006, refiners
and importers were required to meet a 30 ppm average sulfur level, with
a maximum cap of 80 ppm. This reduction in fuel sulfur content ensures
the effectiveness of low emission-control technologies. The Tier 2
tailpipe standards established in this rule were phased in for new
vehicles between 2004 and 2009. At the time of promulgation of Tier 2
standards, EPA estimated that this rule would cut NOX and
VOC emissions from light-duty vehicles and light-duty trucks by
approximately 76% and 28%, respectively. NOX and VOC
reductions from medium-duty passenger vehicles included as part of the
Tier 2 vehicle program were estimated to be approximately 37,000 and
9,500 tons per year, respectively, when fully implemented. As projected
by these estimates and demonstrated in the on-road emission modeling
for the Detroit area, a portion of these emission reductions occurred
during the period 2014 through 2016, i.e., after the area was
designated nonattainment for the 2015 ozone NAAQS. As discussed below,
the Tier 2 vehicle and gasoline sulfur standards were replaced by the
Tier 3 emission standards for vehicles and gasoline sulfur standards
beginning on January 1, 2017.
    Tier 3 Emission Standards for Vehicles and Gasoline Sulfur
Standards. On April 28, 2014 (79 FR 23414), EPA promulgated Tier 3
motor vehicle emission and fuel standards to reduce both tailpipe and
evaporative emissions and to further reduce the sulfur content in
fuels. The rule is being phased in between 2017 and 2025. Tier 3 sets
new tailpipe standards for non-methane organic gases (NMOG) and
NOX, presented as NMOG+NOX, and for particulate
matter. The VOC and NOX tailpipe standards for light-duty
vehicles represent approximately an 80% reduction in fleet average
NMOG+NOX and a 70% reduction in per-vehicle particulate
matter (PM) standards, relative to the fleet average at the time of
phase-in. Heavy-duty tailpipe standards represent about a 60% reduction
in both fleet average NMOG+NOX and per-vehicle PM standards.
The evaporative emissions requirements in the rule will result in
approximately a 50% reduction from previous standards and apply to all
light-duty and on-road gasoline-powered heavy-duty vehicles. Finally,
the rule lowered the sulfur content of gasoline to an annual average of
10 ppm starting in January 2017. As projected by these estimates and
demonstrated in the on-road emission modeling for the Detroit area,
some of these emission reductions occurred by the attainment years and
additional emission reductions will occur throughout the maintenance
period, as older vehicles are replaced with newer, compliant model
years.
    Heavy-Duty Diesel Engine Rules. In July 2000, EPA issued a rule for
on-road heavy-duty diesel engines that includes standards limiting the
sulfur content of diesel fuel. Emissions standards for NOX,
VOC and PM were phased in between model years 2007 and 2010. In
addition, the rule reduced the highway diesel fuel sulfur content to 15
parts per million by 2007, leading to additional reductions in
combustion NOX and VOC emissions. EPA has estimated future
year emission reductions due to implementation of this rule. EPA
estimated that by 2015 NOX and VOC emissions would decrease
nationally by 1,260,000 tons and 54,000 tons, respectively, and that by
2030 NOX and VOC emissions will decrease nationally by
2,570,000 tons and 115,000 tons, respectively. As projected by these
estimates and demonstrated in the on-road emission modeling for the
Detroit area, some of these emission reductions occurred by the
attainment years and additional emission reductions will occur
throughout the maintenance period, as older vehicles are replaced with
newer, compliant model years.
    Nonroad Diesel Rule. On June 29, 2004 (69 FR 38958), EPA issued a
rule adopting emissions standards for nonroad diesel engines and sulfur
reductions in nonroad diesel fuel. This rule applies to diesel engines
used primarily in construction, agricultural, and industrial
applications. Emission standards were phased in for the 2008 through
2015 model years based on engine size. The sulfur limits for nonroad
diesel fuels were phased in from 2007 through 2012. EPA estimates that
when fully implemented, compliance with this rule will cut
NOX emissions from these nonroad diesel engines by
approximately 90%. As projected by these estimates and demonstrated in
the nonroad emission modeling for the Detroit area, some of these
emission reductions occurred by the attainment years and additional

emission reductions will occur throughout the maintenance period.
    Nonroad Spark-Ignition Engines and Recreational Engine Standards.
On November 8, 2002 (67 FR 68242), EPA adopted emission standards for
large spark-ignition engines such as those used in forklifts and
airport ground-service equipment; recreational vehicles such as off-
highway motorcycles, all-terrain vehicles, and snowmobiles; and
recreational marine diesel engines. These emission standards were
phased in from model years 2004 through 2012. When fully implemented,
EPA estimates an overall 72% reduction in national VOC emissions from
these engines and an 80% reduction in national NOX
emissions. As projected by these estimates and demonstrated in the
nonroad emission modeling for the Detroit area, some of these emission
reductions occurred by the attainment years and additional emission
reductions will occur throughout the maintenance period.
    Category 3 Marine Diesel Engine Standards. On April 30, 2010 (75 FR
22896), EPA issued emission standards for marine compression-ignition
engines at or above 30 liters per cylinder. Tier 2 emission standards
apply beginning in 2011 and are expected to result in a 15 to 25%
reduction in NOX emissions from these engines. Final Tier 3
emission standards apply beginning in 2016 and are expected to result
in approximately an 80% reduction in NOX from these engines.
As projected by these estimates and demonstrated in the nonroad
emission modeling for the Detroit area, some of these emission
reductions occurred by the attainment years and additional emission
reductions will occur throughout the maintenance period.
c. Detroit Point Source NOX Reductions.
    The DTE Energy River Rouge power plant ceased operations in May
2021. In its submittal, EGLE estimated this shutdown would reduce
annual point source NOX emissions by 2,716 tons.
d. Detroit Low Reid Vapor Pressure (RVP) Program.
    RVP is a measure of a fuel's volatility and thereby affects the
rate at which gasoline evaporates and emits VOCs. The lower a fuel's
RVP, the lower the rate of evaporation of the fuel. Lowering RVP in the
summer months can offset the effect of summer temperature upon the
evaporation of gasoline, which in turn lowers emissions of VOCs.
Michigan's Low RVP program requires the sale of 7.0 psi RVP gasoline in
the Detroit area during the summer months, as compared to the 9.0 psi
RVP originally required under Federal RVP controls. EPA approved
Michigan's Low RVP program for the Detroit area on January 31, 2007 (72
FR 4432).
2. Emission Reductions
    Michigan is using a 2014 emissions inventory to represent
nonattainment level emissions (nonattainment year inventory or
nonattainment inventory), which is appropriate because it was one of
the years used to designate the area as nonattainment due to an
exceedance of the NAAQS. Michigan is using a 2019 emissions inventory
to represent attainment level emissions (attainment year inventory or
attainment inventory), which is appropriate because it is one of the
years in the 2019-2021 period used to demonstrate monitored attainment
with the NAAQS.
    For both 2014 and 2019, Michigan has provided inventories for
point, nonpoint, on-road, and nonroad sources. The point source
category includes facilities that report their emissions directly to
EGLE, as well as sources such as airports and rail yards. Nonpoint
sources, sometimes called area sources, include emissions from sources
that are more ubiquitous, such as consumer products or architectural
coatings. On-road sources are vehicles that are primarily used on
public roadways, such as cars, trucks, and motorcycles. Nonroad sources
include engine-based emissions that do not occur on roads, such as
trains or boats.
    For its on-road emissions inventory, Michigan submitted an analysis
by the Southeast Michigan Council of Governments (SEMCOG). This
analysis used EPA's MOVES3 model to generate July weekday on-road
emissions for both 2014 and 2019. SEMCOG's analysis relied on local
travel inputs including demographic data, travel demand forecasting,
road types, Vehicle Miles of Travel (VMT), Vehicle Hours of Travel,
vehicle population, and vehicle age, as well as meteorological data. In
Attachment B of its submittal, Michigan has included a detailed
narrative of SEMCOG's methods.
    For its point, nonpoint, and nonroad emissions inventories,
Michigan's primary data sources were EPA's 2014 National Emissions
Inventory (NEI)--Version 2 dataset and EPA's 2016v2 modeling platform.
The 2014 NEI includes emissions data only for the year 2014, and the
2016v2 modeling platform includes emissions data for the years 2016,
2023, 2026 and 2032. EGLE used the 2014 NEI as the basis of its point,
nonpoint, and nonroad inventories for 2014. To derive point, nonpoint,
and nonroad inventories for 2019, EGLE interpolated between 2016 and
2023 data from the 2016v2 modeling platform. The 2016v2 modeling
platform and 2014 NEI have been quality-assured, and documentation
regarding these datasets and their methods is available on EPA's
website.\6\ In Attachment B of its submittal, Michigan has included a
detailed listing of the facilities used to create the point source
inventory for 2014.
---------------------------------------------------------------------------

    \6\ https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-technical-support-document-tsd and https://www.epa.gov/air-emissions-modeling/2016-version-2-technical-support-document.
---------------------------------------------------------------------------

    To obtain the inventories for source categories other than on-road,
EGLE summed the annual totals of NOX and VOC emissions for
each county and each source category. Then, to convert the annual
totals to a value of tons per ozone season day, EGLE calculated a
conversion factor for each county and each source category, using
outputs from the 2016v2 modeling platform. This conversion factor was
generated by taking the July category emissions and dividing them by
the annual category emissions, and then dividing by 31 to represent the
number of days in July. It was not necessary to determine a conversion
factor for on-road emissions because SEMCOG provided results for a July
weekday. EGLE selected July as the standard ozone season month, due to
an analysis showing that July had the most days with high ozone values
in recent years.
    Because Michigan's inventory for 2019 relies on data from the
2016v2 modeling platform, EPA compared EGLE's inventory of point source
emissions against records of actual point source emissions available to
EPA through the Emissions Inventory System (EIS). To ensure that the
two agencies' calculations for point source emissions for 2019 would be
comparable, EPA converted annual totals of NOX and VOC
emissions to a value of tons per ozone season day using the same
conversion factors calculated by EGLE. Both EGLE's analysis and EPA's
analysis show a decrease in point source emissions from 2014 to
2019.\7\
---------------------------------------------------------------------------

    \7\ For both NOX and VOC, EGLE's 2019 inventory shows
emissions levels that are lower than the levels of actual emissions
derived by EPA from EIS. By relying on the lower level of point
source emissions from the 2016v2 modeling platform in setting the
level of its attainment inventory, Michigan's inventories for the
maintenance period, described in section IV.D.2. below, are more
cautious than necessary in setting levels of emissions that are
sufficient to attain the standard.
---------------------------------------------------------------------------

    Using the inventories described above for all categories of
sources, Michigan's submittal documents changes in NOX and
VOC emissions from 2014 to 2019

for the Detroit area. Emissions data are shown in Table 2. Data are
expressed in terms of tons per ozone season day.

   Table 2--NOX and VOC Emissions in the Detroit Area for the 2014 Nonattainment Year and 2019 Attainment Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                                       NOX                                   VOC
                                     ---------------------------------------------------------------------------
                                                              Net change                            Net change
                                         2014       2019      (2014-2019)      2014       2019      (2014-2019)
----------------------------------------------------------------------------------------------------------------
Point...............................     166.86      97.01          -69.85      32.24      13.74          -18.50
Nonpoint............................      36.69      27.98           -8.71     149.93     134.77          -15.16
On-road.............................     192.70     105.80          -86.90      83.20      51.70          -31.50
Nonroad.............................      60.26      22.51          -37.75      69.63      30.46          -39.17
                                     ---------------------------------------------------------------------------
    Total...........................     456.51     253.30         -203.21     335.00     230.67         -104.33
----------------------------------------------------------------------------------------------------------------

    As shown in Table 2, Michigan's inventories demonstrate that
NOX and VOC emissions in the Detroit area declined by 203.21
tons per ozone season day and 104.33 tons per ozone season day,
respectively, between 2014 and 2019.
3. Meteorology and Temporary Adverse Economic Conditions
    Michigan performed several analyses to further support its
demonstration that the improvement in air quality is due to permanent
and enforceable emission reductions, and not unusually favorable
meteorology or temporary adverse economic conditions.
    EGLE conducted a meteorological analysis based on 22 years of data
collected at the three monitors that have historically monitored the
highest ozone concentrations in the Detroit area. Michigan analyzed
ozone values for May, June, July, August, and September, for years 2000
to 2021. First, the maximum 8-hour ozone concentration at each monitor
was compared to the number of days where the maximum temperature was
greater than or equal to 80 [deg]F. Second, EGLE examined the
relationship between the average summer temperature for each year of
the 2000-2021 period and the fourth-highest 8-hour ozone concentration.
Third, the number of days with an 8-hour average greater than 70 ppb
was compared to the number of days where the maximum temperature was
greater than or equal to 80 [deg]F. These analyses show that over the
last 22 years, ozone concentrations at the Detroit monitors have
decreased substantially. In contrast, temperatures have increased, with
the area showing an overall warming trend. Because the correlation
between temperature and ozone formation is well established, these data
suggest that reductions in precursors are responsible for the
reductions in ozone concentrations in the area, and not unusually
favorable summer temperatures.
    To further support EGLE's demonstration that the improvement in air
quality is not due to unusually favorable meteorology, an analysis was
performed by the Lake Michigan Air Directors Consortium (LADCO). A
classification and regression tree (CART) analysis was conducted with
2005 through 2019 data from Detroit area ozone sites. The goal of the
analysis was to determine the meteorological and air quality conditions
associated with ozone episodes, and construct trends for the days
identified as sharing similar meteorological conditions. Regression
trees were developed for the Detroit area ozone data to classify each
summer day by its ozone concentration and associated meteorological
conditions. By grouping days with similar meteorology, the influence of
meteorological variability on the underlying trend in ozone
concentrations is partially removed and the remaining trend is presumed
to be due to trends in precursor emissions or other non-meteorological
influences. The CART analysis showed the resulting trends in ozone
concentrations declining over the period examined, supporting the
conclusion that the improvement in air quality was not due to unusually
favorable meteorology.
    Michigan conducted an additional analysis to assess whether the
improvement in air quality was caused by temporary adverse economic
conditions, especially the economic conditions associated with the
COVID-19 pandemic which first impacted Michigan in 2020. First, EGLE
charted point source VOC emissions in the Detroit area from 2012 to
2020. Second, EGLE charted point source NOX emissions in the
Detroit area for the same period. These two charts show the overall
downward trend in point source emissions from 2012 to 2020. Third, for
2014 to 2021, EGLE compared the maximum 8-hour ozone concentration
against VMT and employment. This chart shows that VMT and employment
had a direct correlation to one another, but these economic indicators
had no correlation to ozone values. The impacts of the COVID-19
pandemic are apparent in data showing a decrease in point source
emissions, VMT, and employment between 2019 and 2020. But these
decreases were not associated with a corresponding decline in ozone
values from 2019 to 2020. Instead, there was an increase in the fourth-
highest 8-hour ozone concentration from 2019 to 2020. Together, these
analyses show that economic conditions associated with the COVID-19
pandemic were not correlated with the improved air quality and
strengthen Michigan's demonstration that the improved air quality is
due to permanent and enforceable emissions reductions.
    As discussed above, Michigan identified numerous Federal rules that
resulted in the reduction of VOC and NOX emissions from 2014
to 2019. In addition, Michigan's analyses of meteorological variables
associated with ozone formation demonstrate that the improvement in air
quality in the area between the year violations occurred and the year
attainment was achieved is not due to unusually favorable meteorology.
Michigan also showed that emissions reductions were not due to
temporary adverse economic conditions, but rather were consistent with
a longer-term trend. Therefore, EPA proposes to find that Michigan has
shown that the air quality improvements in the Detroit area are due to
permanent and enforceable emissions reductions.

D. Does Michigan have a fully approvable ozone maintenance plan for the
Detroit area?

    To redesignate an area from nonattainment to attainment, section
107(d)(3)(E)(iv) of the CAA requires EPA to determine that the area has
a fully approved maintenance plan pursuant to section 175A of the CAA.
Section 175A of the CAA sets forth the elements of a maintenance plan
for areas seeking redesignation from nonattainment to attainment. Under
section 175A, the maintenance plan must demonstrate continued
attainment of the NAAQS for at least 10 years after the Administrator
approves a redesignation to attainment. Eight years after the
redesignation, the state must submit a revised maintenance plan which
demonstrates that attainment of the NAAQS will continue for an
additional 10 years beyond the initial 10-year maintenance period. To
address the possibility of future NAAQS violations, the maintenance
plan must contain contingency measures, as EPA deems necessary, to
assure prompt correction of the future NAAQS violation.
    The Calcagni Memorandum provides further guidance on the content of
a maintenance plan, explaining that a maintenance plan should address
five elements: (1) An attainment emission inventory; (2) a maintenance
demonstration; (3) a commitment for continued air quality monitoring;
(4) a process for verification of continued attainment; and (5) a
contingency plan. In conjunction with its request to redesignate the
Detroit area to attainment for the 2015 ozone NAAQS, Michigan submitted
a SIP revision to provide for maintenance of the 2015 ozone NAAQS
through 2035, more than 10 years after the expected effective date of
the redesignation to attainment. As discussed below, EPA proposes to
find that Michigan's ozone maintenance plan includes the necessary
components and to approve the maintenance plan as a revision of the
Michigan SIP.
1. Attainment Inventory
    EPA is proposing to determine that the Detroit area has attained
the 2015 ozone NAAQS based on monitoring data for the period of 2019-
2021. Michigan selected 2019 as the attainment emissions inventory year
to establish attainment emission levels for VOC and NOX. The
attainment emissions inventory identifies the levels of emissions in
the Detroit area that are sufficient to attain the 2015 ozone NAAQS.
The derivation of the attainment year emissions is discussed above in
section IV.C.2. of this proposed rule. The emissions for the 2019
attainment year, by source category, are summarized in Table 2 above.
2. Has the state demonstrated maintenance of the ozone standard in the
Detroit area?
    Michigan has demonstrated maintenance of the 2015 ozone NAAQS
through 2035 by projecting that current and future emissions of VOC and
NOX for the Detroit area remain at or below attainment year
emission levels. A maintenance demonstration need not be based on
modeling. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), Sierra Club v.
EPA, 375 F. 3d 537 (7th Cir. 2004). See also 66 FR 53094, 53099-53100
(October 19, 2001), 68 FR 25413, 25430-25432 (May 12, 2003).
    Michigan is using emissions inventories for the years 2025 and 2035
to demonstrate maintenance. 2035 was selected because it is more than
10 years after the expected effective date of the redesignation to
attainment, and 2025 was selected to demonstrate that emissions are not
expected to spike in the interim between the 2019 attainment year and
the 2035 final maintenance year.
    To develop emissions inventories for the years 2025 and 2035,
Michigan used the same data sources discussed above in section IV.C.2.
of this proposed rule.
    For its on-road emissions inventory, Michigan again relied upon the
SEMCOG analysis, which used EPA's MOVES3 model to generate July weekday
on-road emissions for 2025 and 2035. SEMCOG's analysis relied on local
travel inputs including demographic data, travel demand forecasting,
road types, VMT, Vehicle Hours of Travel, vehicle population, and
vehicle age, as well as meteorological data. In Attachment B of its
submittal, Michigan has included a detailed narrative of SEMCOG's
methods.
    For its point, nonpoint, and nonroad emissions inventories,
Michigan again used EPA's 2016v2 modeling platform. To derive
inventories for 2025, EGLE interpolated between 2023 and 2026 data from
the 2016v2 modeling platform. To derive inventories for 2035, EGLE
extrapolated forward from the 2016v2 modeling platform data using the
2026 and 2032 years. For both the 2025 and 2035 inventories, to convert
annual emissions totals into a value of tons per ozone season day, EGLE
calculated conversion factors using the same methodology described in
section IV.C.2. of this proposed rule.
    By calculating its inventories through interpolation and
extrapolation, EGLE projects that changes within a source category and
county are linearly constant. For point sources, actual reductions may
not align with inventories derived from linear interpolation, because
shutdowns and the operation of new control equipment may be staggered
across several years. However, given the magnitude of the reductions in
other categories of sources, any uncertainty caused by linear
interpolation would be outweighed by the emissions reductions in other
sectors. Similarly, inventories derived from extrapolation may not
align with actual reductions for some types of sources. However, even
if Michigan as a cautious measure had projected that emissions from the
2016v2 modeling platform for the year 2032 would remain constant
through 2035, this level of emissions would still have been sufficient
to show that the area would maintain the standard through 2035.
Although the 2016v2 modeling platform does not project emissions beyond
2032, some amount of additional reductions into future years is likely.
    Emissions data for the 2014 nonattainment year, 2019 attainment
year, 2025 interim year, and 2035 maintenance year are shown in Tables
3 and 4 below. Data are expressed in terms of tons per ozone season
day.

 Table 3--NOX Emissions in the Detroit Area for the 2014 Nonattainment Year, 2019 Attainment Year, 2025 Interim
                                         Year, and 2035 Maintenance Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                                                         2014       2019       2025       2035      (2019-2035)
----------------------------------------------------------------------------------------------------------------
Point...............................................     166.86      97.01      80.83      76.44          -20.57
Nonpoint............................................      36.69      27.98      27.39      25.84           -2.14
On-road.............................................     192.70     105.80      61.20      40.30          -65.50

Nonroad.............................................      60.26      22.51      17.49      15.17           -7.34
                                                     -----------------------------------------------------------
    Total...........................................     456.51     253.30     186.91     157.75          -95.55
----------------------------------------------------------------------------------------------------------------

 Table 4--VOC Emissions in the Detroit Area for the 2014 Nonattainment Year, 2019 Attainment Year, 2025 Interim
                                         Year, and 2035 Maintenance Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                                                         2014       2019       2025       2035      (2019-2035)
----------------------------------------------------------------------------------------------------------------
Point...............................................      32.24      13.74      14.06      14.12           +0.38
Nonpoint............................................     149.93     134.77     134.12     133.11           -1.66
On-road.............................................      83.20      51.70      34.40      22.00          -29.70
Nonroad.............................................      69.63      30.46      27.39      26.56           -3.90
                                                     -----------------------------------------------------------
    Total...........................................     335.00     230.67     209.97     195.79          -34.88
----------------------------------------------------------------------------------------------------------------

    As shown in Tables 3 and 4, NOX and VOC emissions in the
Detroit area are projected to decrease by 95.55 tons per ozone season
day and 34.88 tons per ozone season day, respectively, between the 2019
attainment year and 2035 maintenance year. Michigan's maintenance
demonstration for the Detroit area shows maintenance of the 2015 ozone
NAAQS by providing emissions information to support the demonstration
that future emissions of NOX and VOC will remain at or below
2019 emission levels when considering both future source growth and
implementation of future controls.
    In addition, EPA's 2016v2 modeling platform includes updated air
quality modeling of the contiguous United States, projecting ozone
concentrations at all air quality monitors in 2023, 2026, and 2032.\8\
That modeling incorporates the most recent updates to emissions
inventories, including on-the-books emissions reductions, and
meteorology. This modeling indicates that EPA does not project the
Detroit area to be in nonattainment of the 2015 ozone NAAQS, nor does
EPA expect the area to struggle with maintenance, in those modeled
future years. We propose to find that EPA's ozone transport air quality
modeling further supports Michigan's demonstration that the Detroit
area will continue to maintain the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \8\ https://www.epa.gov/air-emissions-modeling/2016v2-platform.
---------------------------------------------------------------------------

3. Continued Air Quality Monitoring
    Michigan has committed to continue to operate its ozone monitors in
the Detroit area for the duration of the maintenance period. Michigan
remains obligated to meet monitoring requirements, to continue to
quality assure monitoring data in accordance with 40 CFR part 58, and
to enter all data into the AQS in accordance with Federal guidelines.
4. Verification of Continued Attainment
    Michigan has confirmed that it has the legal authority to enforce
and implement the requirements of its SIP. Michigan has further
committed that it has the authority to implement the requested SIP
revision, which would include the maintenance plan for the Detroit
area. This includes the authority to adopt, implement, and enforce any
subsequent emission control measures determined to be necessary to
correct future ozone attainment problems.
    Verification of continued attainment is accomplished through
operation of the ambient ozone monitoring network and the periodic
update of the area's emissions inventory. Michigan will continue to
operate the ozone monitors located in the Detroit area. There are no
plans to discontinue operation, relocate, or otherwise change the
existing ozone monitoring network other than through revisions in the
network approved by EPA.
    In addition, to track future levels of emissions, Michigan will
continue to develop and submit to EPA updated emission inventories for
all source categories at least once every three years, consistent with
the requirements of 40 CFR part 51, subpart A, and in 40 CFR 51.122.
The Consolidated Emissions Reporting Rule (CERR) was promulgated by EPA
on June 10, 2002 (67 FR 39602). The CERR was replaced by the Annual
Emissions Reporting Requirements on December 17, 2008 (73 FR 76539).
The most recent triennial inventory for Michigan was compiled for 2017,
and 2020 is in progress. Point source facilities covered by Michigan's
emission statement program, described below in section VII., will
continue to submit VOC and NOX emissions on an annual basis.
5. What is the contingency plan for the Detroit area?
    Section 175A of the CAA requires that the state adopt a maintenance
plan as a SIP revision that includes such contingency measures as EPA
deems necessary to assure that the state will promptly correct a
violation of the NAAQS that occurs after redesignation of the area to
attainment of the NAAQS. The maintenance plan must identify: The
contingency measures to be considered and, if needed for maintenance,
adopted and implemented; a schedule and procedure for adoption and
implementation; and a time limit for action by the state. The state
should also identify specific indicators to be used to determine when
the contingency measures need to be considered, adopted, and
implemented. The maintenance plan must include a commitment that the
state will implement all measures with respect to the control of the
pollutant that were contained in the SIP before redesignation of the
area to attainment in accordance with section 175A(d) of the CAA.

    As required by section 175A of the CAA, Michigan has adopted a
contingency plan for the Detroit area to address possible future ozone
air quality problems. The contingency plan adopted by Detroit has two
levels of response, a warning level response and an action level
response.
    In Michigan's plan, a warning level response will be triggered when
an annual fourth-highest monitored value of 0.074 ppm or higher is
monitored within the maintenance area. A warning level response will
require Michigan to conduct a study. The study would assess whether the
ozone value indicates a trend toward a higher ozone value and whether
emissions appear to be increasing. The study will evaluate whether the
trend, if any, is likely to continue and, if so, the control measures
necessary to reverse the trend, taking into account ease and timing of
implementation. Any implementation of necessary controls in response to
a warning level response trigger will occur within 18 months of the
conclusion of the ozone season.
    In Michigan's plan, an action level response would be triggered
when the fourth-highest monitored value, averaged over two years, of
0.071 ppm or higher is monitored within the maintenance area. The
action level response will also be triggered if a three-year design
value exceeds the level of the 2015 ozone NAAQS (0.070 ppm). When an
action level response is triggered and not found to be due to an
exceptional event, malfunction, or noncompliance with a permit
condition or rule requirement, Michigan will determine what additional
control measures are needed to assure future attainment of the 2015
ozone NAAQS. Control measures selected will be adopted and implemented
within 18 months from the close of the ozone season that prompted the
action level. Michigan may also consider if significant new regulations
not currently included as part of the maintenance provisions will be
implemented in a timely manner and would thus constitute an adequate
contingency measure response.
    Michigan included the following list of potential contingency
measures in its maintenance plan. However, Michigan is not limited to
the measures on this list:

1. VOC or NOX RACT rules for existing sources covered by
Control Technique Guidelines, Alternative Control Guidelines, or other
appropriate guidance
2. Application of VOC RACT on existing smaller sources
3. Alternative fuel and diesel retrofit programs for fleet vehicle
operations
4. VOC or NOX control on sources emitting less than 100 tons
per year
5. Increased VOC or NOX emission offsets for new and
modified major sources
6. Reduced idling programs
7. Trip reduction programs
8. Traffic flow and transit improvements
9. Increased turnover of legacy natural gas distribution pipelines
10. Stationary engine controls
11. Rules under the American Innovation and Manufacturing Act
12. Rules for consumer products
13. Additional measures identified by EGLE

    To qualify as a contingency measure, emissions reductions from that
measure must not be factored into the emissions projections used in the
maintenance plan.
    EPA has concluded that Michigan's maintenance plan adequately
addresses the five basic components of a maintenance plan: Attainment
inventory, maintenance demonstration, monitoring network, verification
of continued attainment, and a contingency plan. In addition, as
required by section 175A(b) of the CAA, Michigan has committed to
submit to EPA an updated ozone maintenance plan eight years after
redesignation of the Detroit area to cover an additional ten years
beyond the initial 10-year maintenance period. Thus, EPA finds that the
maintenance plan SIP revision submitted by Michigan for the Detroit
area meets the requirements of section 175A of the CAA, and EPA
proposes to approve it as a revision to the Michigan SIP.

V. Has the state adopted approvable motor vehicle emission budgets?

A. Motor Vehicle Emission Budgets

    Under section 176(c) of the CAA, new transportation plans,
programs, or projects that receive Federal funding or support, such as
the construction of new highways, must ``conform'' to (i.e., be
consistent with) the SIP. Conformity to the SIP means that
transportation activities will not cause or contribute to any new air
quality violations, increase the frequency or severity of any existing
air quality problems, or delay timely attainment or any required
interim emissions reductions or any other milestones. Regulations at 40
CFR part 93 set forth EPA policy, criteria, and procedures for
demonstrating and ensuring conformity of transportation activities to a
SIP.
    Transportation conformity is a requirement for nonattainment and
maintenance areas. Maintenance areas are areas that were previously
nonattainment for a particular NAAQS, but that have been redesignated
to attainment with an approved CAA section 175A maintenance plan for
the NAAQS.
    Under the CAA, states are required to submit, at various times,
control strategy SIPs for nonattainment areas and maintenance plans for
areas seeking redesignations to attainment of the ozone standard and
maintenance areas. See the SIP requirements for the 2015 ozone standard
in EPA's December 6, 2018, implementation rule (83 FR 62998). These
control strategy SIPs (including reasonable further progress plans and
attainment plans) and maintenance plans must include motor vehicle
emissions budgets for criteria pollutants, including ozone, and their
precursor pollutants (VOC and NOX) to address pollution from
on-road transportation sources. The budgets are the portion of the
total allowable emissions that are allocated to highway and transit
vehicle use that, together with emissions from other sources in the
area, will provide for attainment or maintenance. See 40 CFR 93.101.
    Under 40 CFR part 93, a budget for an area seeking a redesignation
to attainment must be established, at minimum, for the last year of the
maintenance plan. A state may adopt budgets for other years as well.
The budget serves as a ceiling on emissions from an area's planned
transportation system. The budget concept is further explained in the
preamble to the November 24, 1993, Transportation Conformity Rule (58
FR 62188). The preamble also describes how to establish the budget(s)
in the SIP and how to revise the budget(s), if needed, after initially
establishing a budget in the SIP.
    As discussed earlier, Michigan's maintenance plan includes
NOX and VOC budgets for the Detroit area for 2025, which is
an interim year, as well as 2035, which is the last year of the
maintenance period. EPA has reviewed Michigan's NOX and VOC
budgets for the area and, in this action, is proposing to approve
them.\9\ We are also starting the adequacy review process for these
budgets to determine if they meet the adequacy criteria in the
transportation conformity regulations (40 CFR 93.118(e)(4)). Michigan's
January 3, 2022, maintenance plan submission, including the budgets for
this area, is available for public comment via this

proposed rulemaking. The submission was endorsed by the Governor's
designee and Michigan provided opportunity for a public hearing. The
budgets were developed as part of an interagency consultation process
which includes Federal, state, and local agencies. The budgets were
clearly identified and precisely quantified. These budgets, when
considered together with all other emissions sources, are consistent
with maintenance of the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \9\ See 40 CFR 93.118(f)(2) for requirements associated with
making adequacy findings through rulemaking on a submitted SIP.

  Table 5--Motor Vehicle Emissions Budgets for the Detroit Area for the 2025 Interim Year and 2035 Maintenance
                                                      Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                              2025 Interim year                    2035 Maintenance year
                                   -----------------------------------------------------------------------------
                                     Projected      Safety                  Projected      Safety
                                      on-road       margin       Total       on-road       margin       Total
                                     emissions    allocation     budget     emissions    allocation     budget
----------------------------------------------------------------------------------------------------------------
NOX...............................        61.20        43.15       104.35        40.30        62.11       102.41
VOCs..............................        34.40        13.46        47.86        22.00        22.67        44.67
----------------------------------------------------------------------------------------------------------------

    As shown in Table 5, the 2025 and 2035 budgets exceed the estimated
2025 and 2035 on-road sector emissions. To accommodate future
variations in VMT in the area, EGLE allocated to the mobile sector a
portion of the safety margin, as described further below.\10\ Michigan
has demonstrated that the Detroit area can maintain the 2015 ozone
NAAQS in the 2035 maintenance year with mobile source emissions of
102.41 tons per ozone season day of NOX and 44.67 tons per
ozone season day of VOCs. Similarly, the Detroit area can maintain the
2015 ozone NAAQS in the 2025 interim year with mobile source emissions
of 104.35 tons per ozone season day of NOX and 47.86 tons
per ozone season day of VOCs. Despite partial allocation of the safety
margin, emissions will remain under emission levels in the 2019
attainment year.
---------------------------------------------------------------------------

    \10\ Allocation of a safety margin to an area's motor vehicle
emissions budgets is provided for by the transportation conformity
rule. See 40 CFR 93.124(a).
---------------------------------------------------------------------------

    EPA is proposing to approve the budgets for use to determine
transportation conformity in the Detroit area, because EPA has
determined that the area can maintain attainment of the 2015 ozone
NAAQS for the relevant maintenance period with mobile source emissions
at the levels of the budgets.

B. What is a safety margin?

    A ``safety margin'' is the amount by which the total projected
emissions from all sources of a given pollutant are less than the total
emissions that would satisfy the applicable requirement for
maintenance. 40 CFR 93.101. As noted in Tables 3 and 4, the emissions
in the Detroit area are projected to have safety margins of 95.55 tons
per ozone season day for NOX and 34.88 tons per ozone season
day for VOC in 2035 (the difference between emissions in the 2019
attainment year, and projected emissions in the 2035 maintenance year,
for all sources in the Detroit area). Similarly, there is a safety
margin of 66.39 tons per ozone season day for NOX and 20.69
tons per ozone season day for VOC in 2025. Even if emissions exceeded
projected levels by the full amount of the safety margin, the counties
would still demonstrate maintenance since emission levels would equal
those in the attainment year.
    As shown in Table 5 above, Michigan is allocating a portion of that
safety margin to the mobile source sector. Specifically, in 2025,
Michigan is allocating 43.15 tons per ozone season day and 13.46 tons
per ozone season day of the NOX and VOC safety margins,
respectively. In 2035, Michigan is allocating 62.11 tons per ozone
season day and 22.67 tons per ozone season day of the NOX
and VOC safety margins, respectively. Michigan is not requesting
allocation to the budgets of the entire available safety margins
reflected in the demonstration of maintenance. In fact, the amount
allocated to the budgets represents only a portion of the 2025 and 2035
safety margins. Therefore, even though the State is requesting budgets
that exceed the projected on-road mobile source emissions for 2025 and
2035 contained in the demonstration of maintenance, the increase in on-
road mobile source emissions that can be considered for transportation
conformity purposes is within the safety margins of the ozone
maintenance demonstration. Further, once allocated to mobile sources,
these safety margins will not be available for use by other sources.

VI. Base Year Emissions Inventory

    As discussed above, sections 172(c)(3) and 182(a)(1) of the CAA
require states to submit a comprehensive, accurate, and current
inventory of actual emissions from sources of NOX and VOC
emitted within the boundaries of the ozone nonattainment area. For the
2015 ozone NAAQS, EPA specifies that states submit ozone season day
emissions estimates for an inventory calendar year to be consistent
with the base year for RFP plans as required by 40 CFR 51.1310(b). For
the RFP base year for the 2015 ozone NAAQS under 40 CFR 51.1310(b),
states may use a calendar year for the most recently available complete
triennial emissions inventory (40 CFR 51, subpart A) preceding the year
of the area's effective date of designation as a nonattainment area (83
FR 62998).\11\ See the SIP requirements for the 2015 ozone standard in
EPA's December 6, 2018, implementation rule (83 FR 62998), and EPA's
2017 document ``Emissions Inventory Guidance for Implementation of
Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations.'' \12\
---------------------------------------------------------------------------

    \11\ The RFP requirements specified in CAA section 182(b)(1)
applies to all ozone nonattainment areas classified Moderate or
higher.
    \12\ https://www.epa.gov/sites/default/files/2016-12/documents/2016_ei_guidance_for_naaqs.pdf.
---------------------------------------------------------------------------

    In its December 18, 2020, submittal, Michigan requested that EPA
approve into its SIP an inventory addressing the emissions inventory
requirement of CAA section 182(a)(1). Michigan's SIP revision included
inventories of NOX and VOC emissions for several
nonattainment areas, including the Detroit area, for the year 2017. At
the time of its submittal, data for 2017 was the most recent
comprehensive, accurate, and quality assured triennial emissions
inventory in the NEI database. Michigan's submittal included estimates
of NOX and VOC emissions for four general classes of
anthropogenic sources, point, nonpoint, on-road mobile, and nonroad
mobile; biogenic

emissions; and event emissions, which are discrete and short-lived
sources such as wildfires.
    To develop emissions inventories for the year 2017, Michigan began
with annual emissions data contained in the 2017 NEI for the point,
nonpoint, on-road, nonroad, biogenic, and event categories. In
developing ozone season day emissions, Michigan again used July as the
representative ozone season month. EGLE also analyzed the prevalence of
weekend days with ozone values exceeding the 2015 ozone NAAQS and
determined that including weekend days in the typical ozone season day
emission derivation is appropriate. To convert annual emissions data to
ozone season day values, EGLE extracted data from EPA's 2016v1 modeling
platform and calculated a conversion factor for the point, nonpoint,
on-road, nonroad, and biogenic data categories.\13\ EGLE determined the
event category emissions were too low and too variable from year to
year to benefit from applying a conversion factor.
---------------------------------------------------------------------------

    \13\ https://www.epa.gov/air-emissions-modeling/2016v1-platform.
---------------------------------------------------------------------------

    Under CAA section 182(a)(1) and 40 CFR 51.1115, states must submit
a base year emissions inventory within two years of the effective date
of designation of each nonattainment area for the 2015 ozone NAAQS. For
the Detroit area, this requirement became due on August 3, 2020. At the
time that EGLE prepared its inventory of 2017 emissions to address the
requirements of section 182(a)(1), several improvements in data sources
were not yet available. Specifically, EGLE relied upon a version of the
2017 NEI that did not include a revised point source inventory to
correct airport emissions. Additionally, EGLE relied upon the 2016v1
modeling platform, which did not yet include improvements from the
2016v2 modeling platform including updated information from the 2017
NEI, MOVES3, and revised inventory methodologies. EPA is not evaluating
Michigan's 2017 emissions inventory against platforms or data sources
that were not available at the time of submission.
    NOX and VOC emissions data for the year 2017 are shown
in Tables 6 and 7 below. Data are expressed in terms of tons per ozone
season day.

                 Table 6--NOX Emissions for Counties in the Detroit Area for the 2017 Base Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                       Point     Nonpoint   On-road    Nonroad    Biogenic    Event      Total
----------------------------------------------------------------------------------------------------------------
Livingston.........................       1.53       0.72       5.78       1.13       1.32       0.04      10.52
Macomb.............................       2.55       3.78      16.19       3.83       1.21       0.02      27.58
Monroe.............................      16.05       1.43       5.22       1.31       2.29       0.01      26.31
Oakland............................       2.83       5.22      29.68       7.54       1.37       0.08      46.72
St. Clair..........................      55.62       3.04       3.98       1.42       1.99       0.03      66.08
Washtenaw..........................       2.56       1.45       9.35       1.64       1.73       0.05      16.78
Wayne..............................      41.35       7.77      36.79       2.71       1.00       0.05      89.67
                                    ----------------------------------------------------------------------------
    Total..........................     122.49      23.41     106.99      19.58      10.91       0.28     283.66
----------------------------------------------------------------------------------------------------------------

                 Table 7--VOC Emissions for Counties in the Detroit Area for the 2017 Base Year
                                           [Tons per ozone season day]
----------------------------------------------------------------------------------------------------------------
                                       Point     Nonpoint   On-road    Nonroad    Biogenic    Event      Total
----------------------------------------------------------------------------------------------------------------
Livingston.........................       0.42       6.10       3.14       1.77      22.11       0.65      34.19
Macomb.............................       8.22      28.46      11.50       4.77      13.64       0.47      67.06
Monroe.............................       0.97       5.79       2.66       2.02      13.17       0.18      24.79
Oakland............................       2.61      36.72      18.55      10.62      33.00       1.48     102.98
St. Clair..........................       3.16       5.68       2.45       2.41      28.77       0.59      43.06
Washtenaw..........................       0.61      15.56       5.12       2.59      22.67       0.77      47.32
Wayne..............................      15.19      57.45      21.74       8.50      24.51       1.05     128.44
                                    ----------------------------------------------------------------------------
    Total..........................      31.18     155.76      65.16      32.68     157.87       5.19     447.84
----------------------------------------------------------------------------------------------------------------

    As shown in Table 6, total NOX emissions in the Detroit
area for the 2017 base year are 283.66 tons per summer day. As shown in
Table 7, total VOC emissions in the Detroit area for the 2017 base year
are 447.84 tons per summer day.
    Michigan's December 18, 2020, emissions inventory submission
includes a demonstration showing that approval of this SIP revision is
consistent with CAA section 110(l). Section 110(l) provides that EPA
cannot approve a SIP revision if the revision would interfere with
attainment and maintenance of the NAAQS, reasonable further progress,
or any other applicable requirement of the CAA. EGLE is making this
submission as required by CAA sections 172(c)(3) and 182(a)(1), and
approval of the 2017 base year inventories would strengthen the
Michigan SIP and would not interfere with any applicable CAA
requirement.
    EPA reviewed Michigan's December 18, 2020, submittal for
consistency with sections 172(c)(3) and 182(a)(1) of the CAA, and with
EPA's emissions inventory requirements. In particular, EPA reviewed the
techniques used by EGLE to derive and quality assure the emissions
estimates. The documentation of the emissions estimation procedures is
thorough and is adequate for EPA to determine that Michigan followed
acceptable procedures to estimate the emissions. Accordingly, we
propose to conclude that Michigan has developed inventories of
NOX and VOC emissions that are comprehensive and complete.
EPA therefore proposes to approve the emissions inventory for the
Detroit area in Michigan's December 18, 2020, submittal and shown above
in Tables 6 and 7 as meeting the emissions

inventory requirements of sections 172(c)(3) and 182(a)(1) of the CAA.
    In this rulemaking, EPA is only evaluating the portions of
Michigan's December 18, 2020, emissions inventory submittal relating to
the Detroit area. EPA is not evaluating inventories relating to other
nonattainment areas. Instead, EPA will evaluate these inventories in a
separate rulemaking.

VII. Emissions Statement

    Section 182(a)(3)(B) of the CAA requires states with ozone
nonattainment areas to submit revisions to their SIP to require the
owner or operator of each stationary source of NOX or VOC to
provide the state with an annual statement documenting the actual
emissions of NOX and VOC from their source. Under section
182(a)(3)(B)(ii), a state may waive the emissions statement requirement
for any class or category of stationary sources which emits less than
25 tons per year of VOC or NOX if the state, in its base
year emissions inventory, provides an inventory of emissions from such
class or category of sources based on the EPA's emission factors, or
other method acceptable to the EPA.
    On March 8, 1994, EPA approved Michigan's emission statement
program as a revision to the SIP (59 FR 10752). Specifically, EPA
approved into the SIP the following: Section 5 of the 1965 Air
Pollution Act 348 (1965 PA 348), Section 14a of 1965 PA 348, Air
Pollution Control Rule 336.202 (Rule 2), and the 1993 Michigan Air
Pollution Reporting Forms, Reference Tables, and General Instructions.
    In a separate SIP submittal also dated December 18, 2020, Michigan
requested that EPA revise the emissions statement program in its SIP by
adding, removing, and updating certain statutes and reporting forms.
    First, Michigan requests that EPA remove from the SIP Section 5 of
1965 PA 348 and approve into the SIP Michigan Complied Laws (MCL)
324.5503, Section 5503 of 1994 PA 451. At the time that EPA approved
Section 5 of 1965 PA 348 in 1994, this measure conferred several
authorities onto the Michigan Commission on the Environment, including
the authority to require sources to report their emissions. In 1995,
1965 PA 348 was repealed by the Michigan Legislature and replaced with
1994 PA 451, and all Commission powers were transferred to the
department. EGLE's current authority to require emissions reports,
which Michigan is now requesting EPA approve into the SIP, is provided
at MCL 324.5503, Section 5503 of 1994 PA 451.
    Second, Michigan requests that EPA remove from the SIP Section 14a
of 1965 PA 348, which relates to surveillance fees. In its submittal,
Michigan states its belief that Section 14a was incorrectly submitted
to and approved into the SIP as part of the emissions statement
program, and that this measure is not required as part of an emissions
statement program. In this rulemaking, EPA is not evaluating the
portion of Michigan's submittal requesting the removal of Section 14a
of 1965 PA 348 from its SIP. Instead, EPA will evaluate this request in
a separate rulemaking.
    Third, Michigan requests that EPA retain in its SIP Rule 2 and
strengthen this rule by approving into the SIP AQD-013, Last Revision
Date: July 22, 2020, entitled ``Criteria Pollutant Threshold Levels for
Point Sources'' (AQD-013), of EGLE's AQD Policy and Procedure.
Michigan's remaining authority to require emissions reports from
certain sources is provided at Rule 2; since EPA approved Rule 2 into
its SIP, Michigan has developed specific policies and procedures to
determine which stationary sources must comply with Rule 2. These
policies and procedures, including specific thresholds of emissions
that trigger Rule 2 applicability, are provided at AQD-013.
Additionally, AQD-013 is applicable to the emissions reporting
requirements of Air Pollution Control Rule 336.1212 (Rule 212), which
EPA approved into the SIP on August 31, 2018 (83 FR 44485). Michigan
first developed AQD-013 in 1996 and most recently updated AQD-013 in
2020.
    Fourth, Michigan requests that EPA remove from the SIP its 1993
Michigan Air Pollution Reporting forms and reference tables and
strengthen its SIP by replacing them with the 2019 version of certain
Michigan Air Emissions Reporting System (MAERS) forms. Specifically,
Michigan is requesting that EPA approve into the SIP the 2019 version
of five forms: MAERS form SB-101 Submit, MAERS form S-101 Source, MAERS
form A-101 Activity, MAERS form EU-101 Emission Unit, and MAERS form E-
101 Emissions. These forms satisfy requirements under EPA's 1992
Guidance on the Implementation of an Emission Statement Program
relating to certification of data accuracy, source identification
information, operating schedule, emissions information, control
equipment information, and process data.
    Fifth, Michigan requests that EPA remove from its SIP the 1993
general instructions and strengthen its SIP by replacing them with the
January 2020 MAERS User Guide. EGLE no longer uses the 1993 general
instructions that are currently in the SIP, and instead provides
sources with its 2020 user guide, which clearly defines terms used in
the MAERS forms and aids the sources in completing their MAERS
submittal via the electronic format for all required pollutants.
    Michigan's December 18, 2020, emissions statement submission also
includes a demonstration showing that approval of this SIP revision is
consistent with CAA section 110(l). The revisions EPA is proposing to
approve would strengthen Michigan's SIP-approved emissions statement
program by removing from the SIP outdated reporting forms and a statute
that has been repealed by the state legislature and replacing those
measures with the statute containing the state's current authority to
require the reporting of emissions, as well as updated program forms,
policies and procedures, and user information. These revisions would
not interfere with any applicable CAA requirement.
    EPA reviewed Michigan's December 18, 2020, submittal for
consistency with 182(a)(3)(B) of the CAA and EPA's Guidance on the
Implementation of an Emission Statement Program. Section 182(a)(3)(B)
requires annual submission emissions from stationary sources with
emissions greater than 25 tons per year (tpy) of NOX and
VOC. At AQD-013, Michigan requires annual reports from sources with VOC
emissions of 10 tpy or greater statewide, and NOX emissions
of 25 tpy or greater in ozone nonattainment areas and 40 tpy in all
other areas of the state. As described above, EPA will address the
portion of Michigan's submittal requesting the removal of Section 14a
of 1965 PA 348 from its SIP in a separate action. The remaining
portions of Michigan's submittal are consistent with 182(a)(3)(B) of
the CAA and relevant guidance and would strengthen Michigan's SIP-
approved emissions statement program. EPA therefore proposes to approve
the remaining portions of Michigan's December 18, 2020, emissions
statement submittal as meeting the emissions statement requirements of
section 182(a)(3)(B) of the CAA.

VIII. What action is EPA taking?

    EPA is proposing to determine that the Detroit nonattainment area
is attaining the 2015 ozone NAAQS, based on quality-assured and
certified monitoring data for 2019-2021. EPA is proposing to approve
portions of Michigan's December 18, 2020, submittals as meeting the
base year emissions inventory and emissions

statement requirements of sections 182(a)(1) and 182(a)(3),
respectively. EPA is also proposing to approve, as a revision to the
Michigan SIP, the state's maintenance plan for the area. The
maintenance plan is designed to keep the Detroit area in attainment of
the 2015 ozone NAAQS through 2035. EPA is proposing to determine that
upon final approval of Michigan's 2017 base year emissions inventory,
emission statement SIP, and maintenance plan SIP, the area will have
met the requirements for redesignation under section 107(d)(3)(E) of
the CAA. EPA is thus proposing to change the legal designation of the
Detroit area from nonattainment to attainment for the 2015 ozone NAAQS.
Finally, EPA is proposing to approve the newly established 2025 and
2035 motor vehicle emissions budgets for the Detroit area and
initiating the adequacy process for these budgets.

IX. Incorporation by Reference

    In this rule, EPA is proposing to include in a final EPA rule
regulatory text that includes incorporation by reference. In accordance
with requirements of 1 CFR 51.5, EPA is proposing to incorporate by
reference Michigan Act 451, Section 5503, effective March 30, 1995. EPA
has made, and will continue to make, these documents generally
available through www.regulations.gov and at the EPA Region 5 Office
(please contact the person identified in the FOR FURTHER INFORMATION
CONTACT section of this preamble for more information).

X. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment and the
accompanying approval of a maintenance plan under section 107(d)(3)(E)
are actions that affect the status of a geographical area and do not
impose any additional regulatory requirements on sources beyond those
imposed by state law. A redesignation to attainment does not in and of
itself create any new requirements, but rather results in the
applicability of requirements contained in the CAA for areas that have
been redesignated to attainment. Moreover, the Administrator is
required to approve a SIP submission that complies with the provisions
of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40
CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to
approve state choices, provided that they meet the criteria of the CAA.
Accordingly, the proposed actions to approve Michigan's SIP submissions
merely approve state law as meeting Federal requirements and do not
impose additional requirements beyond those imposed by state law. For
these reasons, this action:
     Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Orders 12866 (58
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
     Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using practicable and legally permissible methods, under
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the rule does not have tribal implications as specified by
Executive Order 13175 (65 FR 67249, November 9, 2000), because
redesignation is an action that affects the status of a geographical
area and does not impose any new regulatory requirements on tribes,
impact any existing sources of air pollution on tribal lands, nor
impair the maintenance of ozone national ambient air quality standards
in tribal lands.

List of Subjects

40 CFR Part 52

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

40 CFR Part 81

    Environmental protection, Air pollution control, National parks,
Wilderness areas.

    Dated: March 7, 2022.
Debra Shore,
Regional Administrator, Region 5.
[FR Doc. 2022-05253 Filed 3-11-22; 8:45 am]
BILLING CODE 6560-50-P