[Federal Register Volume 87, Number 49 (Monday, March 14, 2022)]
[Proposed Rules]
[Pages 14210-14224]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[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 (NO<INF>X</INF>) 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 <a href="/cdn-cgi/l/email-protection#bfdecdcdde91ccdecdded7ffdacfde91d8d0c9"><span class="__cf_email__" data-cfemail="1e7f6c6c7f306d7f6c7f765e7b6e7f30797168">[email protected]</span></a>. 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, (312) 353-4489, 
<a href="/cdn-cgi/l/email-protection#85f6f3ecebe2e0ebabe0f7ece6c5e0f5e4abe2eaf3"><span class="__cf_email__" data-cfemail="0477726d6a63616a2a61766d67446174652a636b72">[email protected]</span></a>. 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

[[Page 14211]]

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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[[Page 14212]]

    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., NO<INF>X</INF> 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

[[Page 14213]]

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 
NO<INF>X</INF> 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

[[Page 14214]]

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 
NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> budgets and annual sulfur dioxide 
(SO<INF>2</INF>) budgets (70 FR 25152). CAIR addressed the good 
neighbor provision for the 1997 ozone NAAQS and 1997 fine particulate 
matter (PM<INF>2.5</INF>) NAAQS and was designed to mitigate the impact 
of transported NO<INF>X</INF> emissions, a precursor of both ozone and 
PM<INF>2.5</INF>, as well as transported SO<INF>2</INF> emissions, 
another precursor of PM<INF>2.5</INF>. 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

[[Page 14215]]

developing a replacement rule, implementation of the CAIR program 
continued as planned with the NO<INF>X</INF> annual and ozone season 
programs beginning in 2009 and the SO<INF>2</INF> 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 PM<INF>2.5</INF> 
NAAQS, and the 2006 PM<INF>2.5</INF> NAAQS.\5\ Through Federal 
Implementation Plans, CSAPR required electric generating units (EGUs) 
in eastern states, including Michigan, to meet annual and ozone season 
NO<INF>X</INF> budgets and annual SO<INF>2</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 
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 NO<INF>X</INF> emissions from EGUs by 
17,000 tons beginning in 2021, compared to emissions without the rule. 
The reduction in NO<INF>X</INF> 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 NO<INF>X</INF> program, addressing the 1997 ozone 
NAAQS (76 FR 80760).
---------------------------------------------------------------------------

b. Federal Emission Control Measures
    Reductions in VOC and NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> and 
VOC emissions from light-duty vehicles and light-duty trucks by 
approximately 76% and 28%, respectively. NO<INF>X</INF> 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 
NO<INF>X</INF>, presented as NMOG+NO<INF>X</INF>, and for particulate 
matter. The VOC and NO<INF>X</INF> tailpipe standards for light-duty 
vehicles represent approximately an 80% reduction in fleet average 
NMOG+NO<INF>X</INF> 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+NO<INF>X</INF> 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 NO<INF>X</INF>, 
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 NO<INF>X</INF> and VOC emissions. EPA has estimated future 
year emission reductions due to implementation of this rule. EPA 
estimated that by 2015 NO<INF>X</INF> and VOC emissions would decrease 
nationally by 1,260,000 tons and 54,000 tons, respectively, and that by 
2030 NO<INF>X</INF> 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 
NO<INF>X</INF> 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

[[Page 14216]]

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 NO<INF>X</INF> 
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 NO<INF>X</INF> emissions from these engines. Final Tier 3 
emission standards apply beginning in 2016 and are expected to result 
in approximately an 80% reduction in NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> and 
VOC emissions from 2014 to 2019

[[Page 14217]]

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 
NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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.

[[Page 14218]]

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 NO<INF>X</INF>. 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 
NO<INF>X</INF> 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

[[Page 14219]]

 
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, NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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.

[[Page 14220]]

    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 NO<INF>X</INF> 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 NO<INF>X</INF> control on sources emitting less than 100 tons 
per year
5. Increased VOC or NO<INF>X</INF> 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 NO<INF>X</INF>) 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 
NO<INF>X</INF> 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 NO<INF>X</INF> 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

[[Page 14221]]

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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> 
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 NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> and VOC emissions for four general classes of 
anthropogenic sources, point, nonpoint, on-road mobile, and nonroad 
mobile; biogenic

[[Page 14222]]

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.
    NO<INF>X</INF> 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 NO<INF>X</INF> 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 
NO<INF>X</INF> 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

[[Page 14223]]

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 NO<INF>X</INF> or VOC to 
provide the state with an annual statement documenting the actual 
emissions of NO<INF>X</INF> 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 NO<INF>X</INF> 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 NO<INF>X</INF> and 
VOC. At AQD-013, Michigan requires annual reports from sources with VOC 
emissions of 10 tpy or greater statewide, and NO<INF>X</INF> 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

[[Page 14224]]

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:
    <bullet> 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);
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> 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.);
    <bullet> 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);
    <bullet> Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
    <bullet> 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
    <bullet> 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


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