[Federal Register Volume 86, Number 204 (Tuesday, October 26, 2021)]
[Proposed Rules]
[Pages 59073-59075]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-23116]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R05-OAR-2021-0441; FRL-9160-01-R5]


Air Plan Approval; Michigan; Base Year Emissions Inventory for 
the 2010 Sulfur Dioxide Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve, under the Clean Air Act (CAA), revisions to the State 
Implementation Plan (SIP) submitted by the Michigan department of 
Environment, Great Lakes, and Energy (EGLE) on June 30, 2021. The 
revisions address the emission inventory requirements for the St. Clair 
County nonattainment area under the 2010 sulfur dioxide 
(SO2) National Ambient Air Quality Standard (NAAQS or 
standard). The CAA requires states to develop and submit, as SIP 
revisions, emission inventories for all areas designated as 
nonattainment for any NAAQS.

DATES: Comments must be received on or before November 26, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2021-0441 at http://www.regulations.gov or via email to 
[email protected]. For comments submitted at Regulations.gov, 
follow the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, EPA may publish any comment received to its 
public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Emily Crispell, Environmental 
Scientist, Control Strategies Section, Air Programs Branch (AR-18J), 
Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, 
Chicago, Illinois 60604, (312) 353-8512, [email protected]. The 
EPA Region 5 office is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding Federal holidays and facility closures due to COVID-
19.

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

I. The 2010 SO2 NAAQS Emissions Inventory Requirements

    On June 22, 2010, EPA promulgated a revised 1-hour SO2 
NAAQS of 75 parts per billion (ppb) (75 FR 35520). On September 12, 
2016 the partial St. Clair County area was designated as nonattainment 
(St. Clair nonattainment area) for the 2010 1-hour SO2 
NAAQS. The St. Clair nonattainment area is defined by the St. Clair 
River for the eastern boundary, an extension from the St. Clair River 
directly west to the intersection of State Highway M-29 and St. Clair 
River Drive, continuing west on State Highway M-29 to Church Road to 
Arnold Road to County Line Road for the southern boundary, County Line 
Road and the Macomb/St. Clair County boundary to Stoddard Road to Wales 
Ridge Road for the western boundary, and Alpine Road to Fitz Road to 
Smith Creek Road to Range Road to Huron Avenue, extending directly east 
from the intersection of Huron Road and River Road to the St. Clair 
River for the northern boundary (83 FR 1098, January 9, 2018).
    CAA section 172(c)(3), 42 U.S.C. 7502(c)(3), requires states to 
develop and submit, as SIP revisions, emission inventories for all 
areas designated as nonattainment for any NAAQS. An emission inventory 
for SO2 is an estimation of actual emissions of sulfur 
oxides (SOX) in an area. SO2 is the component of 
greatest concern and is used as the indicator for the larger group of 
gaseous SOX. SO2 is a gas that is formed by the 
burning of fossil fuels by

[[Page 59074]]

power plants and other industrial facilities such as extracting metal 
from ore; natural sources such as volcanoes; and locomotives, ships and 
other vehicles and heavy equipment that burn fuel with a high sulfur 
content. Control measures that reduce SO2 can generally be 
expected to reduce people's exposures to all gaseous SOX. 
Therefore, an emission inventory for SOX focuses on the 
emissions of SO2.
    Emission inventories provide emissions data for a variety of air 
quality planning tasks, including establishing baseline emission levels 
(anthropogenic [manmade] emissions associated with SO2 
standard violations), calculating emission reduction targets needed to 
attain the NAAQS, determining emission inputs for SO2 air 
quality modeling analyses, and tracking emissions over time to 
determine progress toward achieving air quality and emission reduction 
goals. As stated above, the CAA requires the states to submit emission 
inventories for areas designated as nonattainment for SO2. 
For the 2010 1-hour SO2 NAAQS, EPA specifies that states 
submit SO2 emission estimates for an inventory calendar year 
preceding the year of the area's effective date of designation as a 
nonattainment area (75 FR 35520). States are required to submit 
estimates of SO2 emissions for four general classes of 
anthropogenic sources: stationary point sources; area sources; on-road 
mobile sources; and off-road mobile sources.

II. EGLE's Emissions Inventory

    On June 30, 2021, EGLE submitted a SIP revision addressing the 
emissions inventory requirement of CAA section 172(c)(3). EGLE also 
clarified that Michigan has a fully approved Nonattainment New Source 
Review (NSR) program, which is set forth in Part 19 of Michigan's rules 
(R 336.2901 through R 336.2908). EPA confirms that this NSR program was 
approved by the EPA into the SIP on December 16, 2013 (78 FR 76064). 
EGLE provided documentation for the 2014 SO2 base year 
emissions inventory for the St. Clair County nonattainment area. EGLE 
selected 2014 because this was one of the three years of SO2 
data indicating a violation of the SO2 standard that were 
used to designate the areas as nonattainment for the 2010 
SO2 NAAQS (83 FR 1098). In addition, the 2014 emissions 
inventory was the most recent comprehensive, accurate, and quality 
assured (QA) triennial emissions inventory in the National Emissions 
Inventory (NEI) database, available at the time the state began 
preparing the emissions inventory submittal for the partial St. Clair 
County area. Table 1 summarizes the 2014 SO2 emissions for 
the partial St. Clair County area in tons of emissions per year.

                                           Table 1--2014 SO2 Emissions
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                                                              2014 SO2 Emissions (tons/year)
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               County/NAA                               Non-EGU                                        Total SO2
                                            EGU \1\      point       Area      Non-road     On-road
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Partial St. Clair.......................      51,920       1,632        74.4        0.59        12.2   53,639.19
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\1\ Electric Generating Units (EGU).

A. Base Year Inventory

    EGLE estimated SO2 emissions for all source categories 
in the St. Clair County SO2 nonattainment area. Emissions 
for the St. Clair County SO2 nonattainment area were totaled 
by source category.
a. Point Sources
    To develop the SO2 point source emissions inventory, 
EGLE used the annual emissions data contained in EPA's Clean Air 
Markets Division database for emissions from EGU point sources and 
annual emissions data reported by facility operators to EGLE's air 
emissions inventory database for non-EGU point sources.
b. Area Sources
    To develop the SO2 area source emissions inventories, 
EGLE used the annual emissions data contained in EPA's 2014 NEI to 
estimate 2014 emissions.
c. On-Road and Non-Road Sources
    To develop the SO2 non-road and on-road source emissions 
inventories, EGLE used the annual emissions data contained in EPA's 
2014 NEI to estimate 2014 emissions.

III. EPA's Evaluation

A. Emissions Inventory

    EPA has reviewed EGLE's June 30, 2021, requested SIP revision for 
consistency with section 172(c)(3) CAA and with EPA's emission 
inventory requirements. In particular, EPA has reviewed the techniques 
used by EGLE to quantify and quality assure the emission estimates. EPA 
has also considered whether EGLE has provided the public with the 
opportunity to review and comment on the development of the emission 
estimates, and whether the State has addressed all public comments. 
EGLE received no comments during the comment period but did receive a 
comment from EPA Region 5. The comment asked that the emission 
inventory include the 2014 NEI emissions for 3 other categories of 
sources: on-road, non-road, and area. EGLE addressed this comment by 
adding on-road, non-road, and area SO2 emissions estimates 
for the St. Clair County nonattainment area to their emissions 
inventory submittal. EGLE documented the procedures used to estimate 
the emissions for each of the major source types. Our review finds that 
EGLE followed acceptable procedures to estimate the emissions.
    Accordingly, we propose to conclude that EGLE has developed an 
inventory of SO2 sources that is comprehensive and complete. 
EGLE's submittal of a complete emission inventory and certification of 
an approved NSR program in addition to a Clean Data Determination, 
proposed in a separate action on August 17, 2021 (86 FR 45947), 
addresses deficiencies identified in the September 20, 2019 (84 FR 
49463) finding of failure to submit a nonattainment plan for the St. 
Clair area, and will stop the sanctions clocks applicable to those 
deficiencies.

IV. EPA Action

    EPA is proposing to approve EGLE's SIP revision submitted to 
address the SO2-related emission inventory and NSR 
certification requirements for the partial St. Clair County 
SO2 nonattainment area for the 2010 SO2 NAAQS. 
The emission inventory we are approving into the SIP is specified in 
Table 1. We are also proposing to approve the emission inventory 
because it contains comprehensive, accurate, and current inventories of 
actual emissions for all relevant sources in

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accordance with CAA section 172(c)(3), and because EGLE adopted the 
emission inventories after providing for reasonable public notice. EPA 
also proposes to approve the certification of Michigan's fully approved 
NSR program, which was approved by the EPA into the SIP on December 16, 
2013 (78 FR 76064) and meets the requirements of CAA section 172(c)(5).

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves state law as meeting Federal requirements and 
does not impose additional requirements beyond those imposed by state 
law. For that reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rule does not have tribal implications and will not impose 
substantial direct costs on tribal governments or preempt tribal law as 
specified by Executive Order 13175 (65 FR 67249).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, sulfur oxides.

    Dated: October 19, 2021.
Cheryl Newton,
Acting Regional Administrator, Region 5.
[FR Doc. 2021-23116 Filed 10-25-21; 8:45 am]
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