[Federal Register Volume 86, Number 156 (Tuesday, August 17, 2021)]
[Proposed Rules]
[Pages 45947-45950]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-17546]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2020-0385; FRL-8826-01-R5]
Air Plan Approval; Michigan; Sulfur Dioxide Clean Data
Determination for St. Clair
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to make
a determination that the St. Clair sulfur dioxide (SO2)
nonattainment area has attained the 2010 primary SO2
National Ambient Air Quality Standard (2010 SO2 NAAQS). If
finalized, this determination would suspend certain requirements for
the nonattainment area for as long as the area continues to attain the
2010 SO2 NAAQS.
DATES: Comments must be received on or before September 16, 2021.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2020-0385 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: Mary Portanova, Environmental
Engineer, Control Strategies Section, Air Programs Branch (AR18J),
Environmental Protection Agency, Region 5, 77 West Jackson Boulevard,
Chicago, Illinois 60604, (312) 353-5954 [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. Background
The St. Clair area was designated nonattainment for the 2010
SO2 NAAQS on July 12, 2016 (81 FR 45039), based on air
quality modeling showing violations of the standard. The two
SO2-emitting facilities in the St. Clair area are DTE
Energy-Belle River (Belle River plant) and DTE Energy-St. Clair (St.
Clair plant), which are both coal-fired power plants. The nonattainment
area consists of a portion of southeastern St. Clair County, Michigan,
located northeast of Detroit. The nonattainment area shares a border
with Ontario, Canada along the St. Clair River. (See the area's
complete boundary description at 40 CFR 81.323).
The Michigan Department of Environment, Great Lakes, and Energy
(EGLE) was required to prepare a nonattainment State Implementation
Plan (NA SIP) by March 12, 2018 to bring the St. Clair area into
attainment by the attainment date of September 12, 2021, but EGLE did
not submit a complete NA SIP for the St. Clair area by the March 12,
2018 deadline. On September 20, 2019 (84 FR 49462), EPA issued a
finding of failure to submit (FFS) a SIP required for attainment of the
2010 SO2 NAAQS.
EGLE has informed EPA that DTE intends to close the St. Clair plant
in 2022, and use a new natural gas power plant, already under
construction, to generate electric power in its place. This plant
closure and replacement is expected to result in a large SO2
emission reduction for the area, but the expected SO2
reductions would not occur in time to be a timely element of the
required 2018 NA SIP for the St. Clair area. Nevertheless, the
September 20, 2019 FFS resulted in the initiation of an 18-month clock
toward imposition of sanctions for the state under CAA section 179,
unless an approvable SO2 SIP is submitted and deemed
complete by EPA. (See 40 CFR 52.31(d)(5)). In addition, the FFS started
a two-year clock by which EPA is required under CAA section 110(c) to
promulgate a Federal Implementation Plan (FIP) for the area, unless the
state submits and
[[Page 45948]]
EPA approves a SIP for the area before that date.
In the meantime, EGLE obtained air quality monitoring data in the
St. Clair area which had not been available before the St. Clair area
was designated nonattainment. On July 24, 2020, EGLE submitted a
request that EPA make a determination under the Clean Air Act (CAA) and
EPA's Clean Data Policy, based on both local monitored air quality data
and a new dispersion modeling analysis, that the St. Clair
nonattainment area has attained the 2010 SO2 NAAQS (Clean
Data Determination). Approval of EGLE's request would suspend the
requirement for the state to submit certain planning elements otherwise
required under CAA section 172(c) for a NA SIP for the St. Clair area,
and suspend the sanctions and FIP clocks, for so long as the area
continues to attain the 2010 SO2 NAAQS. EGLE would still be
required to submit an emissions inventory (EI) required by CAA section
172(c)(3) and a nonattainment new source review (NNSR) program required
by CAA section 172(c)(5), in order to avoid sanctions. EGLE submitted
the St. Clair area's EI and NNSR verification to EPA on June 30, 2021.
II. Clean Data Determinations
Following enactment of the CAA Amendments of 1990, EPA discussed
its interpretation of the requirements for implementing the NAAQS in
the General Preamble for the Implementation of title I of the CAA
Amendments of 1990 (General Preamble), 57 FR 13498, 13564 (April 16,
1992). In 1995, based on the interpretation of CAA sections 171, 172,
and 182 in the General Preamble, EPA set forth what has become known as
its ``Clean Data Policy'' for the 1-hour ozone NAAQS. Under the Clean
Data Policy, for a nonattainment area that can demonstrate attainment
of the standard before implementing CAA nonattainment measures, EPA
interprets the requirements of the CAA that are specifically designed
to help an area achieve attainment, such as attainment demonstrations,
implementation of reasonably available control measures, including
reasonably available control technology (RACM/RACT), reasonable further
progress (RFP) demonstrations, emissions limitations and control
measures as necessary to provide for attainment, and contingency
measures, to be suspended for so long as air quality continues to meet
the standard. See the May 10, 1995 memorandum from John S. Seitz,
Director, Office of Air Quality Planning and Standards, entitled,
``Reasonable Further Progress, Attainment Demonstration, and Related
Requirements for Ozone Nonattainment areas Meeting the Ozone National
Ambient Air Quality Standard.'' In an April 23, 2014 memorandum from
Steve Page, Director of the EPA's Office of Air Quality Planning and
Standards, to the EPA Air Division Directors entitled, ``Guidance for
1-hr SO2 Nonattainment Area SIP Submissions'' (2014
SO2 Nonattainment Area Guidance), EPA provides guidance and
a rationale for the application of the Clean Data Policy to the 2010 1-
hour primary SO2 NAAQS.
A state may notify EPA that it believes a nonattainment area is
attaining the 2010 SO2 NAAQS and request a clean data
determination under EPA's Clean Data Policy. EPA will determine whether
the area has attained the 2010 SO2 NAAQS based on available
information, including available air quality monitoring data and air
quality dispersion modeling information for the affected area. If the
determination of attainment is granted, then requirements for the area
such as a nonattainment SIP submittal or reasonable further progress
measures are suspended for so long as the area continues to attain the
NAAQS. Provided the area has submitted a complete EI and NNSR program,
sanctions for failing to timely submit a SIP are also suspended for so
long as the area remains in attainment.
However, the suspension of the obligations to submit attainment
planning related SIPs is only appropriate where the area remains in
attainment of the NAAQS. EPA is proposing to require EGLE to submit
annual statements by July 1 to EPA, to address whether the St Clair
area has continued to attain the 2010 SO2 NAAQS. EPA expects
that these statements could include such information as available air
quality monitoring data or an assessment of changes in facility
emissions or operations and whether these changes warrant updated
modeling. If EPA does not receive credible information indicating that
the area continues to attain the SO2 NAAQS, EPA will propose
to rescind the St. Clair area's clean data determination, the
finalization of which would lift the suspension of its attainment
planning requirements and would reinstate the sanctions and FIP clocks
with their original deadlines.
The determination of attainment under the Clean Data Policy does
not serve to alter the area's nonattainment designation. Clean data
determinations are not redesignations to attainment. For EPA to
redesignate an area to attainment, the area must meet the requirements
of CAA section 107(d)(3) and demonstrate maintenance as required by CAA
section 175A.
III. Analysis of EGLE's Request
EGLE's July 24, 2020 request for a clean data determination
included local monitoring data and a dispersion modeling analysis for
the St. Clair nonattainment area. The 2014 SO2 Nonattainment
Area Guidance states that when air agencies provide monitoring and/or
modeling to support clean data determinations, the monitoring data
provided by the state should follow EPA's ''SO2 NAAQS
Designations Source-Oriented Monitoring Technical Assistance Document''
(SO2 Monitoring TAD) and the modeling provided by the state
should follow EPA's ``SO2 NAAQS Designations Modeling
Technical Assistance Document'' (SO2 Modeling TAD).
The Monitoring TAD was provided by EPA to assist states in siting
monitors to characterize ambient air quality impacted by significant
SO2 sources, with the goal to identify peak SO2
concentrations attributable to those sources. Collaboration with other
stakeholders such as affected industry was encouraged in the Monitoring
TAD. The Monitoring TAD suggests that existing industry monitoring
operations could be found to meet the necessary requirements to produce
data of appropriate quality for comparison to the NAAQS. Industrial
monitors should be appropriately sited and operated in a manner largely
equivalent to those monitors operated elsewhere in the State and Local
Air Monitoring Stations (SLAMS) network, meeting applicable criteria in
40 CFR part 58, appendices A, C, and E and reporting their data to the
Air Quality Subsystem (AQS).
EGLE's July 24, 2020 submittal included three years of monitoring
data from two industrial monitors located in the St. Clair
nonattainment area, near the power plants. DTE installed the two
SO2 monitors in the St. Clair nonattainment area in 2016 to
evaluate SO2 impacts from the two facilities. The monitors
were sited using dispersion modeling to help identify the locations of
predicted maximum SO2 concentrations. Considering the
monitor siting guidance in the Monitoring TAD, EPA believes that these
monitors' locations adequately represent the locations of potential
maximum SO2 impacts from the two power plants. One monitor,
known as the Remer monitor, is sited near the St. Clair River, between
and slightly north of the two power plants, about one kilometer (km)
from each plant. Previously modeled
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maximum SO2 concentrations have been predicted at or near
this location. The other monitor, known as the Mills monitor, is sited
3 km west of the Belle River plant, so that it can capture the worst-
case combined impacts when winds are blowing from the St. Clair plant
toward the Belle River plant.
EPA reviewed the ambient air monitoring data for the 2017-2019
period, which were the three most recent full calendar years of data
available. Ambient and quality assurance data for these two monitoring
sites are recorded in EPA's AQS database. EGLE and EPA have reviewed
the data and have determined that this data meets completeness and data
quality indicators confirm that the data is suitable to be used in
support of a clean data determination for the St. Clair area.
The data cited by EGLE in its request show attainment of the 2010
SO2 NAAQS at both monitors for the 2017-2019 time period,
with three-year average 99th percentile daily maximum 1-hour
concentrations (design values) of 54 and 45 parts per billion (ppb),
which are below the 2010 SO2 NAAQS of 75 ppb. Data for 2020
indicate that the monitors have continued to show attainment. Table 1
shows the 2017-2020 SO2 monitoring results for the St. Clair
area monitors.
Table 1--2017-2020 Monitored SO2 Values in the St. Clair Area
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Annual 99th percentile (ppb) 2017-2019 2018-2020
Monitor ---------------------------------------------------------------- design value design value
2017 2018 2019 2020 (ppb) (ppb)
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Mills Monitor........................................... 46 50 40 29 45 40
Remer Monitor........................................... 51 65 45 25 54 45
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EPA also reviewed the dispersion modeling analysis for the St.
Clair area which EGLE submitted on July 24, 2020. The SO2
Modeling TAD outlines modeling approaches for SO2 NAAQS
attainment status designations and states that, for the purposes of
modeling to characterize air quality for use in SO2
designations, EPA recommends using a minimum of the most recent three
years of actual emissions data and concurrent meteorological data to
allow the modeling to simulate what a monitor would observe.
EGLE's analysis followed the Modeling TAD and modeled the impacts
of the Belle River and St. Clair plants in the St. Clair nonattainment
area. EGLE used the actual 2017-2019 hourly SO2 emissions
for the Belle River and St. Clair plants as measured by continuous
emissions monitor (CEM) data. EGLE also characterized the buildings at
the two plants using the AERMOD component BPIPPRM, to address building
downwash. There were no additional nearby sources that were expected to
produce a significant SO2 concentration gradient in the
nonattainment area.
To model the St. Clair nonattainment area, EGLE used EPA's AERMOD
model, version 19191, with meteorological data for 2017-2019 from the
Oakland County International Airport (Pontiac), located 75 km to the
west of the St. Clair plants. This meteorological data set is
considered to be representative of the St. Clair area. The area was
modeled as rural, based on local land use characteristics. Terrain
information was included in the modeling analysis. The nonattainment
area is flat and mostly residential or agricultural. The river valley
is not deep, although some wind channeling could occur. The
geographical and topographical features of the area are not considered
to significantly impact air pollution transport. The St. Clair modeling
analysis used a nested receptor grid with resolution from 50 meters
near the facilities to 100 meters in the central portion, and then 250
meters to the edge of the modeling domain, 10 km from the power plants.
For a background concentration for the modeling analysis, EGLE used
monitored SO2 data from Michigan's SO2 monitor in
Port Huron, located 21 km to the north of the St. Clair plants. The
Port Huron monitor has an SO2 design value of 67 ppb for
2017-2019. EGLE determined its background concentration using a
temporally varying approach to characterize background SO2
emissions, based on the 99th percentile monitored concentrations by
season and hour of day. In this analysis, EGLE used data measured when
winds were blowing from wind direction sectors which were chosen to
avoid double-counting emissions from the St. Clair and Belle River
plants and to avoid overestimating impacts from sources which are
located in Canada, 3-5 km east of Port Huron but 15-20 km from the St.
Clair area. The Modeling TAD provides for this approach. At such
distances, the Canadian sources are not expected to provide a
significant concentration gradient in the St. Clair area. The modeling
analysis' results match well with the monitored values near the St.
Clair plants, which suggests that the modeling analysis is not missing
significant additional ambient contributions at those locations.
Therefore, EPA concurs with the background values EGLE used in its
analysis. The background concentrations for the St. Clair modeling
analysis were determined to vary from 1.3 to 6.5 ppb, with an average
value of 2.4 ppb.
The state's modeling resulted in a three-year maximum predicted
99th percentile daily maximum 1-hour concentration of 64.4 ppb,
including background. This design value was predicted at a receptor
located very near the St. Clair plant. As the predicted design value is
below the 2010 SO2 NAAQS of 75 ppb, the state's modeling
demonstrates attainment of the 2010 SO2 NAAQS.
EGLE's modeling results for receptors placed at the two
SO2 monitors' locations matched well with the actual
monitored design values. The model's predicted design value at the
Remer monitor location was 47.7 ppb, compared to the monitored design
value of 45 ppb, and the model's predicted design value at the Mills
monitor location was 52.7 ppb, compared to the monitored design value
of 54 ppb. The location of the maximum modeled 99th percentile
concentration was less than half a kilometer from the Remer monitor,
which lends support to EPA's expectation that the Remer monitor is
located in the area of expected maximum concentrations. Other areas of
predicted high concentrations were at approximately the same distance
to the northwest and west of the power plants as the Mills monitor,
again lending support to EPA's expectation that the Mills monitor
location is also representative of areas of high expected
concentrations.
After reviewing EGLE's July 24, 2020 submittal, EPA proposes to
find that the St. Clair area has attained the 2010 SO2 NAAQS
and satisfies the requirements of the Clean Data Policy.
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IV. What action is EPA taking?
EPA is proposing to approve EGLE's request for a Clean Data
Determination for the St. Clair nonattainment area in St. Clair County,
Michigan. Finalizing this determination would suspend the requirements
for EGLE to submit an attainment demonstration and other associated
nonattainment planning requirements for so long as the St. Clair
nonattainment area continues to attain the 2010 SO2 NAAQS.
This proposed action is consistent with EPA's long-held interpretation
of CAA requirements.
Finalizing this action would not constitute a redesignation of the
St. Clair area to attainment of the 2010 SO2 NAAQS under
section 107(d)(3) of the CAA. The St. Clair area will remain designated
nonattainment for the 2010 SO2 NAAQS until such time as EPA
determines that the area meets the CAA requirements for redesignation
to attainment and takes action to redesignate the area.
V. Statutory and Executive Order Reviews
This action proposes to make a clean data determination for the St.
Clair area for the 2010 SO2 NAAQS based on air quality data
which would result in the suspension of certain Federal requirements
and does not impose any additional requirements. 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, November 9, 2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Sulfur oxides.
Dated: August 9, 2021.
Cheryl Newton,
Acting Regional Administrator, Region 5.
[FR Doc. 2021-17546 Filed 8-16-21; 8:45 am]
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