[Federal Register Volume 87, Number 9 (Thursday, January 13, 2022)]
[Proposed Rules]
[Pages 2095-2101]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-00028]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2021-0428; FRL-9374-01-R4]


Finding of Failure To Attain the 2010 Sulfur Dioxide Standard; 
Tennessee; Sullivan County Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
determine that the Sullivan County, Tennessee sulfur dioxide 
(SO2) nonattainment area failed to attain the 2010 1-hour 
SO2 primary National Ambient Air Quality Standard (NAAQS or 
standard) by the applicable attainment date of October 4, 2018, based 
upon a weight of evidence analysis of available quality-assured and 
certified SO2 ambient air monitoring data and SO2 
emissions data from January 2015 through December 2017. If EPA 
finalizes this determination as proposed, the State of Tennessee will 
be required to submit revisions to the Tennessee State Implementation 
Plan (SIP) that, among other elements, provide for expeditious 
attainment of the 2010 SO2 standard.

DATES: Comments must be received on or before February 14, 2022.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2021-0428 at https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. 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, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Evan Adams, Air Regulatory

[[Page 2096]]

Management Section, Air Planning and Implementation Branch, Air and 
Radiation Division, U.S. Environmental Protection Agency, Region 4, 61 
Forsyth Street SW, Atlanta, Georgia 30303-8960. Mr. Adams can be 
reached by telephone at (404) 562-9009 or via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
    A. The 2010 SO2 NAAQS
    B. Designations, Classifications, and Attainment Dates for the 
2010 SO2 NAAQS
II. Proposed Determinations and Consequences
    A. Applicable Statutory and Regulatory Provisions
    B. Monitoring Network Considerations
    C. Sullivan County SO2 Monitoring Network
    D. SO2 Data Considerations and Proposed Determination
    E. Consequences for SO2 Nonattainment Areas Failing 
To Attain Standards by Attainment Dates
III. Proposed Action and Request for Public Comment
IV. Statutory and Executive Order Reviews

I. Background

A. The 2010 SO2 NAAQS

    Under section 109 of the Clean Air Act (CAA or ``Act''), EPA has 
established primary and secondary NAAQS for certain pervasive air 
pollutants (referred to as ``criteria pollutants'') and conducts 
periodic reviews of the NAAQS to determine whether they should be 
revised or whether new NAAQS should be established. The primary NAAQS 
represent ambient air quality standards the attainment and maintenance 
of which EPA has determined, including a margin of safety, are 
requisite to protect the public health. The secondary NAAQS represent 
ambient air quality standards the attainment and maintenance of which 
EPA has determined are requisite to protect the public welfare from any 
known or anticipated adverse effects associated with the presence of 
such air pollutant in the ambient air.
    Under the CAA, EPA must establish a NAAQS for SO2, which 
is primarily released to the atmosphere through the burning of fossil 
fuels by power plants and other industrial facilities. Short-term 
exposure to SO2 can damage the human respiratory system and 
increase breathing difficulties. Small children and people with 
respiratory conditions, such as asthma, are more sensitive to the 
effects of SO2. Sulfur oxides at high concentrations can 
also react with compounds to form small particulates that can penetrate 
deeply into the lungs and cause health problems.
    EPA first established primary SO2 standards in 1971 at 
0.14 parts per million (ppm) over a 24-hour averaging period and 0.3 
ppm over an annual averaging period.\1\ In June 2010, EPA revised the 
primary NAAQS for SO2 to provide increased protection of 
public health, providing for revocation of the 1971 primary annual and 
24-hour SO2 standards for most areas of the country 
following area designations under the new NAAQS.\2\ The 2010 NAAQS is 
75 parts per billion (ppb) (equivalent to 0.075 ppm) over a 1-hour 
averaging period.\3\ A violation of the 2010 1-hour SO2 
NAAQS occurs when the annual 99th percentile of ambient daily maximum 
1-hour average SO2 concentrations, averaged over a 3-year 
period, exceeds 75 ppb.\4\
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    \1\ See 36 FR 8186 (April 30, 1971).
    \2\ 40 CFR 50.4(e).
    \3\ See 75 FR 35520 (June 22, 2010).
    \4\ 40 CFR 50.17.
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B. Designations, Classifications, and Attainment Dates for the 2010 SO2 
NAAQS

    Following promulgation of any new or revised NAAQS, EPA is required 
by CAA section 107(d) to designate areas throughout the nation as 
attaining or not attaining the NAAQS. On August 5, 2013, EPA finalized 
its first round (round 1) of designations for the 2010 primary 
SO2 NAAQS.\5\ Specifically, in the 2013 action, EPA 
designated 29 areas in 16 states as nonattainment for the 2010 
SO2 NAAQS, including a portion of Sullivan County 
(hereinafter referred to as ``the Sullivan County Area'' or Area) in 
Tennessee. The Sullivan County Area lies within a 3-kilometer (km) 
radius circle centered around the B-253 powerhouse at the Eastman 
Chemical Company facility in Kingsport, Tennessee (Eastman), which 
encompasses an SO2 monitor operating at the time of 
designation (Air Quality System (AQS) Site ID: 47-163-0007).\6\ EPA's 
round 1 designations for the 2010 SO2 NAAQS, including the 
Sullivan County Area, became effective on October 4, 2013. Pursuant to 
CAA section 192(a), the attainment date for the Area was no later than 
October 4, 2018, which is five years after the effective date of the 
final action designating each round 1 area as nonattainment for the 
2010 SO2 NAAQS.
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    \5\ See 78 FR 47191 (August 5, 2013).
    \6\ For exact descriptions of the Sullivan County Area, refer to 
40 CFR 81.343.
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    Under CAA section 179(c) of the CAA, within six months of the 
attainment date, the EPA is required to make a determination, based on 
the area's air quality as of the attainment date, whether an area 
attained by that date. If the EPA determines that an area failed to 
attain by the attainment date, EPA is required to publish that 
determination in the Federal Register. CAA section 179(c)(2). On June 
25, 2021, EPA entered into a consent decree with the Center for 
Biological Diversity in the U.S. District Court for the Northern 
District of California.\7\ The consent decree requires EPA to finalize, 
by January 31, 2022, or March 31, 2022, depending on the nonattainment 
area, a determination whether certain round 1 SO2 
nonattainment areas (including the Sullivan County Area) attained the 
1-hour SO2 standard by the October 4, 2018 attainment date. 
For the Sullivan County Area, the consent decree deadline is March 31, 
2022.
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    \7\ See Center for Biological Diversity et al v. EPA; Case No. 
3:20-cv-05436-EMC in the docket for this proposed action.
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II. Proposed Determination and Consequences

A. Applicable Statutory and Regulatory Provisions

    Section 179(c)(1) of the CAA requires EPA to determine whether a 
nonattainment area attained an applicable standard by the applicable 
attainment date based on the area's air quality as of the applicable 
attainment date. A determination of whether an area's air quality meets 
applicable standards is generally based upon the most recent three 
years of complete, quality-assured data gathered at established state 
and local air monitoring stations (SLAMS) in a nonattainment area and 
entered into the EPA's Air Quality System (AQS) database.\8\ Data from 
ambient air monitors operated by state and local agencies in compliance 
with EPA's monitoring requirements must be submitted to AQS.\9\ 
Monitoring agencies annually certify that these data are accurate to 
the best of their knowledge.\10\ EPA uses the certified air monitoring 
data to calculate design values that are used to determine the area's 
air quality status in accordance with 40 CFR part 50 Appendix T (for 
SO2).
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    \8\ AQS is EPA's repository of ambient air quality data.
    \9\ 40 CFR 58.16.
    \10\ 40 CFR 58.15.
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    Specifically, under EPA regulations in 40 CFR 50.17 and in 
accordance with 40 CFR part 50 Appendix T, the 2010 1-hour annual 
SO2 standard is met when the design value is less than or 
equal to 75 ppb. Design values are calculated by

[[Page 2097]]

computing the three-year average of the annual 99th percentile daily 
maximum 1-hour average concentrations.\11\ When calculating 1-hour 
primary standard design values, the calculated design values are 
rounded to the nearest whole number (i.e., 1 ppb) by convention. An 
SO2 1-hour primary standard design value is valid if it 
encompasses three consecutive calendar years of complete data. A year 
is considered complete when all four quarters are complete, and a 
quarter is complete when at least 75 percent of the sampling days are 
complete. A sampling day is considered complete if 75 percent of the 
hourly concentration values are reported; this includes data affected 
by exceptional events that have been approved for exclusion by the EPA 
Administrator.\12\
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    \11\ As defined in 40 CFR part 50, Appendix T, section 1(c), 
daily maximum 1-hour values refer to the maximum 1-hour 
SO2 concentration values measured from midnight to 
midnight that are used in the NAAQS computations.
    \12\ See 40 CFR part 50, Appendix T, sections 1(c), 3(b), 4(c), 
and 5(a).
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    EPA notes that when determining the attainment status of 
SO2 nonattainment areas, including when making 
determinations of attainment by the attainment date, in addition to 
ambient monitoring data, the Agency may also consider air quality 
dispersion modeling and/or a demonstration that the control strategy in 
the SIP has been fully implemented.\13\ With regard to the use of 
monitoring data for such determinations, EPA's 2014 Nonattainment 
SO2 Guidance \14\ specifically notes that ``[i]f the EPA 
determines that the air quality monitors located in the affected area 
are located in the area of maximum concentration, the EPA may be able 
to use the data from these monitors to make the determination of 
attainment without the use of air quality modeling data.'' \15\ The 
modeling analysis of whether monitors are located in the area of 
maximum concentration is necessary where EPA is making a determination 
that an area attained by its attainment date based solely on that 
monitoring information. In the case of the Sullivan County Area, the 
SLAMS monitors did not start collecting data until the middle of 2016; 
therefore, a valid 2015-2017 design value based on three consecutive 
calendar years cannot be calculated.\16\ EPA's proposed determination 
that the area did not attain by its attainment date is, therefore, 
based on a technical analysis of the weight of available evidence -- 
including monitoring data and emissions data from the relevant time 
period, as described in section II.C and II.D of this notice. As noted, 
the determination of whether the monitors are located in the area of 
maximum concentration is not needed in this situation, because a 
demonstration is not being made that the Area has attained the 2010 
SO2 NAAQS by the October 4, 2018, attainment date.
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    \13\ For the Sullivan County Area, EPA has not yet approved an 
attainment demonstration with accompanying emission limits into the 
SIP. Thus, EPA cannot analyze compliance with an approved SIP 
control strategy.
    \14\ EPA, Guidance for 1-Hour SO2 Nonattainment Area 
SIP Submissions (April 2014) (``2014 SO2 Guidance''), 
p.49, available at: https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
    \15\ Id., p.50.
    \16\ The current SO2 monitoring network in the Area, 
which is comprised of four SLAMS monitors and represented in 
Tennessee's ambient air monitoring network plan, is designed to 
measure SO2 air quality in the areas of expected maximum 
1-hour SO2 concentration.
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B. Monitoring Network Considerations

    Section 110(a)(2)(B)(i) of the CAA requires states to establish and 
operate air monitoring networks to compile data on ambient air quality 
for all criteria pollutants. EPA's monitoring requirements are 
specified by regulation in 40 CFR part 58. These requirements are 
applicable to the state, and where delegated, to local air monitoring 
agencies that operate criteria pollutant monitors. The regulations in 
40 CFR part 58 establish specific requirements for operating air 
quality surveillance networks to measure ambient concentrations of 
SO2, including requirements for measurement methods, network 
design, quality assurance procedures, and the minimum number of 
monitoring sites designated as SLAMS. In sections 4.4 and 4.5 of 
Appendix D to 40 CFR part 58, EPA specifies minimum SLAMS monitoring 
requirements for SO2. SLAMS produce data that are eligible 
for comparison with the NAAQS, and therefore, the monitor must be an 
approved federal reference method (FRM), federal equivalent method 
(FEM), or approved regional method (ARM) monitor. Appendix A to 40 CFR 
part 58 specifies quality assurance requirements for SLAMS monitors. 
The minimum number of required SO2 SLAMS is described in 
sections 4.4.2 and 4.4.3 of Appendix D to 40 CFR part 58. According to 
section 4.4.2, the minimum number of required SO2 monitoring 
sites is determined by the population weighted emissions index for each 
state's core based statistical area. Section 4.4.3 describes additional 
monitors that may be required by an EPA regional administrator.
    Under 40 CFR 58.10, states are required to submit annual monitoring 
network plans (AMNP) for ambient air monitoring networks for approval 
by EPA. Each AMNP discusses the status of the air monitoring network as 
required under 40 CFR 58.10 and addresses the operation and maintenance 
of the air monitoring network, including any proposed modifications to 
the network. EPA reviews these AMNPs for compliance with the applicable 
monitoring network design requirements in 40 CFR part 58.\17\ EPA also 
conducts regular technical systems audits (TSAs) during which EPA 
reviews and inspects ambient air monitoring programs to assess 
compliance with applicable regulations concerning the collection, 
analysis, validation, and reporting of ambient air quality data.\18\
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    \17\ See, e.g., letter dated September 14, 2020, from Caroline 
Y. Freeman, Director, Air and Radiation Division, EPA Region IV, to 
Michelle Owenby, Director, Division of Air Pollution Control, TDEC. 
Copies of EPA letters responding to Tennessee's AMNPs for 2016-2020 
are included in the docket for this proposed action.
    \18\ See 40 CFR part 58, appendix A, section 2.5.
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    For the Sullivan County Area, the Tennessee Department of 
Environment and Conservation (TDEC) is responsible for assuring that 
the Area meets air quality monitoring requirements. TDEC submitted an 
annual monitoring network plan to EPA that describes the various 
monitoring sites operated by TDEC.\19\ EPA approved TDEC's most recent 
AMNP on September 30, 2021, and concluded that the air agency's ambient 
air monitoring network meets or exceeds the requirements for the 
minimum number of SLAMS for all criteria pollutants, including 
SO2, in the Sullivan County Area.\20\ For additional 
information related to Sullivan County Area's SO2 monitoring 
network, including EPA's TSAs and the State's response and air 
monitoring data, please refer to EPA's technical support document (TSD) 
located in the docket for this proposed action (Sullivan County 
TSD).\21\
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    \19\ See, e.g., Tennessee's current AMNP ``2021 Tennessee Annual 
Monitoring Network Plan.'' EPA Region 4 approved the 2021 AMNP on 
September 30, 2021. Copies of Tennessee's AMNPs for 2015-2021 are 
included in the docket for this proposed action.
    \20\ See letter dated September 30, 2021, from Caroline Y. 
Freeman, Director, Air and Radiation Division, EPA Region IV, to 
Michelle Owenby, Director, Division of Air Pollution Control, TDEC 
in the docket for this proposed action.
    \21\ See Technical Support Document Finding of Failure to Attain 
the 2010 1-Hour SO2 NAAQS For the Sullivan County, 
Tennessee Nonattainment Area in the docket for this proposed action.
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C. Sullivan County SO2 Monitoring Network

    During the round 1 SO2 designations in 2013, Eastman 
operated an industrial

[[Page 2098]]

SO2 monitor near the facility at the Ross N. Robinson site 
(AQS ID: 47-163-0007). From 2010 to 2012, Tennessee certified to EPA 
that all industry-operated monitoring data in Tennessee, including the 
Eastman SO2 monitor, met EPA regulatory requirements, 
including quality assurance requirements. EPA used this data as the 
basis for an SO2 nonattainment determination on August 13, 
2013, based on a 2009-2011 design value of 196 ppb at the Ross N. 
Robinson industrial monitor.
    In September 2013 (and subsequently in 2016), after an EPA TSA, EPA 
found that Tennessee was unable to provide the required quality 
assurance records and documentation for the industry-operated air 
monitoring sites in Sullivan County. EPA determined that the Eastman 
industrial monitors were not meeting the quality assurance requirements 
in 40 CFR part 58 Appendix A and therefore not comparable to the NAAQS. 
As a result of EPA's TSA findings, TDEC assigned a NAAQS exclusion flag 
to the Ross N. Robinson industrial monitor's data in AQS beginning in 
September 2013 to indicate the data did not meet regulatory 
requirements. For the 2015-2017 period, no valid SO2 
monitoring data were collected in the Area from January 1, 2015, to 
July 20, 2016. Consequently, the Area did not have a valid 
SO2 design value for the 2015-2017 period. See Sullivan 
County TSD for more details on EPA's TSAs.
    To characterize SO2 concentrations in the Sullivan 
County Area, Tennessee began operating a SLAMS SO2 monitor 
(AQS ID: 47-163-6001) on July 21, 2016, adjacent to the Ross N. 
Robinson industrial monitoring site under an EPA-approved quality 
assurance project plan, and in accordance with EPA's regulatory 
requirements at Appendix D to 40 CFR part 58. The Ross N. Robinson 
SLAMS site is located adjacent to Eastman's industrial monitor of the 
same name on Wilburn Drive in Kingsport. On September 1, 2016, TDEC 
also installed a second monitor (AQS ID: 47-163-6002) at the Skyland 
Drive industrial monitoring site to further characterize high elevation 
SO2 concentrations in the complex terrain around the 
Sullivan County Area. This monitor was sited in accordance with the 
normalized air modeling conducted by Tennessee in accordance with 40 
CFR part 58 and EPA's SO2 Monitoring Technical Assistance 
Document (TAD).\22\ The Skyland Drive SLAMS monitor site is located 
with Eastman's industrial SO2 monitor of the same name on 
Skyland Drive at Bagwell St. in Kingsport. The primary monitors \23\ at 
each of these sites are FEM monitors. Valid hourly SO2 data 
for the Area became available for the remainder of the design value 
period (i.e., from July 21, 2016, to December 31, 2017) once the Ross 
N. Robinson SLAMS site started operating. These monitoring data have 
been reported to AQS and certified by TDEC. Eastman stopped reporting 
data to AQS in 2016 for their industrial monitors and ceased operating 
these monitors in 2019. During the 2015-2017 design value period, the 
TDEC SLAMS monitors did not collect data in 2015 or the first half of 
2016. Therefore, a valid 2015-2017 design value cannot be calculated 
for the nonattainment area.
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    \22\ See SO2 NAAQS Designations Source-Oriented 
Monitoring Technical Assistance Document (TADs), Draft February 2016 
in the docket for this proposed action.
    \23\ A primary monitor is a term defined in 40 CFR part 58 that 
means the monitor identified by the monitoring organization that 
provides concentration data used for comparison to the NAAQS. For 
any specific site, only one monitor for each pollutant can be 
designated in AQS as primary monitor for a given period of time. The 
primary monitor identifies the default data source for creating a 
combined site record for purposes of NAAQS comparisons.
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    In 2017, Tennessee committed to expanding its existing 
SO2 ambient air monitoring network within the nonattainment 
area.\24\ In 2018, EPA approved the portion of TDEC's AMNP that added 
two SLAMS monitors within the Sullivan County Area to characterize the 
expected areas of maximum 1-hour SO2 concentrations near the 
Eastman facility.\25\ TDEC subsequently began operating the two 
additional SLAMS sites at Happy Hill (AQS ID: 47-163-6004) in October 
2018 and Andrew Johnson Elementary School (AQS ID: 47-163-6003) in 
January 2019 to characterize the areas of expected maximum 1-hour 
SO2 concentrations around the facility. These monitors were 
sited in accordance with the normalized air modeling conducted by 
Tennessee in accordance with 40 CFR part 58 and EPA's SO2 
TAD. EPA approved the SO2 portion of TDEC's AMNP in 2016, 
2018, 2019, and 2020.\26\
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    \24\ In 2017, EPA commented on TDEC's SO2 draft 
attainment SIP for the Sullivan County Area and recommended that the 
State expand the monitoring network within the nonattainment area to 
verify that the SO2 emission reduction measures proposed 
in the attainment SIP at the time would ensure attainment of the 1-
hour standard. See EPA 2017 comment letter found in the docket for 
this proposed action. Tennessee submitted an attainment SIP for the 
Sullivan County Area on May 11, 2017. EPA proposed approval of the 
attainment SIP on June 29, 2018 (83 FR 30609) but has not finalized 
approval as of this action.
    \25\ See letter dated July 24, 2018, from Beverly Banister, 
Director, Air, Pesticides and Toxic Management Division, EPA Region 
IV, to Michelle Owenby, Director, Division of Air Pollution Control, 
TDEC included in the docket for this proposed action.
    \26\ The most recent TDEC AMNP, submitted and approved in 2020, 
includes four SO2 SLAMS in the nonattainment area which 
will provide NAAQS-comparable monitoring data moving forward.
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D. SO2 Data Considerations and Proposed Determination

    As discussed in section II.C above, air monitoring data in the area 
from January 1, 2015, to July 20, 2016, did not meet the quality 
assurance requirements in 40 CFR part 58 Appendix A and therefore are 
not comparable to the NAAQS. Therefore, a valid 2015-2017 design value 
could not be determined for the nonattainment area. In lieu of a 2015-
2017, 3-year design value, EPA has developed a weight of evidence 
assessment based on available air quality monitoring data and source-
specific SO2 emissions in the Area from January 2015 through 
December 2017 to support the determination that the Sullivan County 
Area did not attain the 1-hour SO2 standard by the October 
4, 2018, attainment date based on the area's air quality as of the 
attainment date. This section summarizes EPA's weight of evidence 
approach and data considerations for the nonattainment area. More 
detailed discussions on the air monitoring and SO2 emission 
data are provided in EPA's Sullivan County TSD located in the docket 
for this proposed action.
1. Sullivan County SO2 Monitoring Data
    As discussed in section I.B above, the applicable attainment date 
for the Sullivan County Area, is October 4, 2018. In accordance with 
Appendix T to 40 CFR part 50, determinations of SO2 NAAQS 
compliance are based on three consecutive calendar years of data. To 
determine the air quality as of the attainment date in the 
nonattainment area, EPA reviewed the available data collected during 
the three calendar years immediately preceding the attainment date for 
the Sullivan County Area (i.e., January 1, 2015, through December 31, 
2017), as well as SO2 emissions data at Eastman.
    As discussed above, no NAAQS-comparable SO2 monitoring 
data is available for the Area for January 1, 2015, to July 20, 2016. 
The available SLAMS SO2 data for the Sullivan County Area 
from July 21, 2016, through December 31, 2017, have been certified by 
TDEC. EPA has also evaluated the completeness of these data in 
accordance with the requirements of 40 CFR part 50, Appendix T. The 
data collected by TDEC in the three calendar years preceding the 
attainment date meet the quarterly completeness criteria

[[Page 2099]]

for only 6 out of 12 quarters at the Ross N. Robinson SO2 
monitor since the monitor began operation on July 21, 2016, and 5 out 
of 12 quarters at the Skyland Drive SO2 monitor since the 
monitor began operation on September 1, 2016. The available annual 99th 
percentile daily maximum 1-hour average SO2 data at each 
monitoring site within the Sullivan County Area for the 2015-2017 
period are presented in Table 1.

                       Table 1--2015-2017 SO2 Monitoring Data for the Sullivan County Area
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                                   Annual 99th percentile daily maximum 1-hour
                                                  average (ppb)
         Site (AQS ID)          ------------------------------------------------       Design value valid?
                                      2015            2016            2017
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Ross N. Robinson (47-163-6001).         \a\ N/A         \b\ 152              92  No.
Skyland Dr. (47-163-6002)......         \a\ N/A          \b\ 91              78  No.
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Notes:
\a\ The SLAMS monitors did not collect data in 2015.
\b\ The Ross N. Robinson monitor had only two quarters of complete data in 2016 due to the monitor beginning
  operation on July 21, 2016. The Skyland Drive monitor had only one quarter of complete data in 2016 due to the
  monitor beginning operation on September 1, 2016.
Source: EPA AQS Design Value Report, retrieved September 14, 2021.

    The data in Table 1 indicates that although the two sites in the 
Sullivan County Area did not have complete data in 2015 and 2016 to 
determine a 3-year design value, both monitors consistently measured 
99th percentile daily maximum 1-hour SO2 concentrations 
above the 75 ppb level of the 1-hour NAAQS in 2016 and 2017, after 
beginning operation in mid-2016. Both monitors have complete 2017 
datasets.
    For an area to attain the 2010 SO2 NAAQS by the October 
4, 2018, attainment date, the design value based upon monitored air 
quality data from 2015-2017 at each eligible monitoring sites must be 
equal to or less than 75 ppb for the 1-hour standard. Table 1 above 
shows that the annual 99th percentile daily maximum 1-hour average at 
each monitoring site exceeds 75 ppb in 2016 and 2017. See also Table 1 
in the Sullivan County TSD.
2. Eastman SO2 Emissions Data
    As mentioned above, in round 1 SO2 designations, EPA 
designated as nonattainment the portion of Sullivan County within a 3-
km radius circle centered at Eastman's B-253 powerhouse, which at the 
time of designations encompassed the one monitor that was violating the 
2010 1-hour SO2 NAAQS based on 2009-2011 air quality data. 
Table 2 shows that the SO2 emissions, expressed in tons per 
year (tpy), from Eastman account for more than 99 percent of the total 
SO2 emissions in Sullivan County during the 2015-2017 period 
relevant for this proposed determination that the Area failed to attain 
the SO2 NAAQS by the applicable attainment date. Prior to 
the Sullivan County Area being designated as nonattainment for the 2010 
1-hour SO2 NAAQS in 2013, Eastman operated 15 coal-fired 
boilers at their facility to generate steam and electricity. As 
discussed in more detail in the Sullivan County TSD for this proposed 
action, Eastman's annual SO2 emissions have been steadily 
decreasing since 2013 due primarily to the changes in operations of the 
coal-fired boilers.

    Table 2--2015-2017 SO2 Emission Data for the Sullivan County SO2
                           Nonattainment Area
------------------------------------------------------------------------
                                         Total Sullivan
                                           County SO2       Eastman SO2
             Calendar year               emissions from      emissions
                                           all sources         (tpy)
                                              (tpy)
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2015..................................            17,980          17,978
2016..................................            14,325          14,324
2017..................................            10,792          10,746
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    As shown in Table 2, the total annual SO2 emissions from 
Eastman decreased over 7,000 tpy from 17,978 tpy in 2015 to 10,746 tpy 
in 2017. During 2015-2017, the annual emissions were highest in 2015, 
when no air monitoring data is available, and emissions decreased 
significantly in 2016 and 2017. The decrease was primarily because of 
the conversion of two large coal-fired boilers, Boilers 27 and 28 in 
the B-253 powerhouse, from burning coal to natural gas fuel that was 
completed in 2016. These two boiler conversions were part of a larger 
SO2 emissions control project beginning in 2014 and ending 
in 2018, which converted all five boilers in the B-253 powerhouse from 
burning coal to burn natural gas fuel. These conversions had a 
significant impact on SO2 emissions: Emissions from the B-
253 powerhouse decreased from 14,171 tpy in 2012 to less than 10 tpy in 
2019.\27\ The total annual SO2 emissions from the entire 
Eastman facility decreased from 21,246 tpy in 2012 to 4,510 tpy in 
2019. See Sullivan County TSD for complete details of the boiler 
conversions and resulting emissions changes.
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    \27\ The conversion of the B-253 boilers from burning coal to 
natural gas was completed in October 2018. Thus, the SO2 
emissions from the B-253 powerhouse dropped significantly to 10 tpy 
in 2019.
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    It is important to also consider trends in hourly SO2 
emissions since the 2010 SO2 NAAQS is a short-term standard 
that is evaluated using hourly measurements of ambient SO2 
concentrations. EPA's evaluation of Eastman's hourly emissions data 
found that their emissions were over 33 percent higher during the 
period from January 1, 2015, to June 30, 2016, (when no valid ambient 
monitoring data was available), than the July 1, 2016, through December 
31, 2017, period (when valid

[[Page 2100]]

ambient monitoring data show exceedances of the NAAQS).\28\
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    \28\ See Figure 5 and Table 3 of the Sullivan County TSD in the 
docket for this proposed action.
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3. Weight of Evidence Analysis Conclusions and Proposed Determination
    To determine the air quality in the Sullivan County Area as of the 
applicable attainment date, EPA reviewed the available ambient 
monitoring data and annual and hourly SO2 emissions data at 
Eastman from January 1, 2015, to December 31, 2017. As shown in Table 
1, the available SO2 ambient monitoring data in the Sullivan 
County Area indicates that the 99th percentile maximum daily 1-hour 
SO2 concentration in both 2016 and 2017 exceeded the 1-hour 
SO2 NAAQS level of 75 ppb. The primary SO2 
emissions sources in the nonattainment area are the coal-fired boilers 
at Eastman. Both the annual SO2 emissions and the hourly 
SO2 emissions from the Eastman boilers were significantly 
higher from January 1, 2015, to June 30, 2016, when air monitoring data 
are not available, than from July 1, 2016, through December 31, 2017, 
when air monitoring data are available. Ambient SO2 
concentrations are very source-oriented, and in this case, the Eastman 
boilers make up virtually the entire emissions inventory for the Area. 
Considering that the ambient measured concentrations exceeded the level 
of the NAAQS in 2016 and 2017, when emissions from the primary source 
of SO2 were lower than they were in 2015, EPA believes it is 
reasonable to expect that the 99th percentile maximum daily 1-hour 
SO2 concentration in 2015 likely also exceeded the level of 
75 ppb. Consequently, the three-year average of: The 99th percentile 
value for 2015 (likely exceeded the level of the NAAQS), 2016 (exceeded 
the level of the NAAQS), and 2017 (exceeded the level of the NAAQS) 
almost certainly would have resulted in a design value that violated 
the NAAQS. EPA therefore proposes to find that this analysis of 
available ambient concentration data and SO2 emissions data 
demonstrates by a weight of evidence that the Sullivan County Area 
failed to attain the 1-hour SO2 NAAQS by the required 
attainment date of October 4, 2018.

E. Consequences for SO2 Nonattainment Areas Failing To Attain Standards 
by Attainment Dates

    The consequences for SO2 nonattainment areas for failing 
to attain the standard by the applicable attainment date are set forth 
in CAA section 179(d). Under section 179(d), a state must submit a SIP 
revision for the area meeting the requirements of CAA sections 110 and 
172, the latter of which requires, among other elements, a 
demonstration of attainment and reasonable further progress, and 
contingency measures. In addition, under CAA section 179(d)(2), the SIP 
revision must include such additional measures as EPA may reasonably 
prescribe, including all measures that can be feasibly implemented in 
the area in light of technological achievability, costs, and any non-
air quality and other air quality-related health and environmental 
impacts.
    In this case, the dominant source of SO2 emissions in 
the Sullivan County Area is the Eastman facility. EPA expects that 
information concerning potential additional control measures would be 
collected by TDEC as part of its development of the SIP revision to 
address the requirements that would be triggered by a final finding of 
failure to attain for the Area. The State is required to submit the SIP 
revision within one year after EPA publishes a final action in the 
Federal Register determining that the nonattainment area failed to 
attain the applicable SO2 standard by the applicable 
attainment date. In addition to triggering requirements for a new SIP 
submittal, a final determination that a nonattainment area failed to 
attain the NAAQS by the applicable attainment date would trigger the 
implementation of contingency measures adopted into the SIP under 
172(c)(9).
    Under CAA sections 179(d)(3) and 172(a)(2), the new attainment date 
for each nonattainment area is the date by which attainment can be 
achieved as expeditiously as practicable, but no later than five years 
after EPA publishes a final action in the Federal Register determining 
that the nonattainment area failed to attain the applicable 
SO2 standard by the applicable attainment date.\29\
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    \29\ Pursuant to CAA sections 172(a)(2)(D) and 192(a), the 
attainment date extension provision under section 172(a)(2)(A) does 
not apply to the SO2 NAAQS.
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III. Proposed Action and Request for Public Comment

    Under CAA section 179(c)(1), EPA proposes to determine that the 
Sullivan County Area failed to attain the 2010 1-hour SO2 
standard by the applicable attainment date of October 4, 2018. This 
determination is based upon a weight of evidence analysis of available 
quality assured and certified SO2 monitored air quality data 
and emissions data from January 2015 through December 2017 in lieu of a 
valid 2015-2017 design value. If finalized as proposed, the State of 
Tennessee would be required under CAA section 179(d) to submit a 
revision to the SIP for the Sullivan County Area. The required SIP 
revision for the area must, among other elements, demonstrate 
expeditious attainment of the standards within the period prescribed by 
CAA section 179(d). If finalized as proposed, the SIP revision required 
under CAA section 179(d) would be due for submittal to EPA no later 
than one year after the publication date of the final action.
    EPA is soliciting public comments on the issues discussed in this 
notice.\30\ The Agency will accept comments from the public on this 
proposal for the next 30 days. The deadline and instruction on how to 
submit comment can be found in the DATES and ADDRESSES sections of this 
notice. EPA will consider these comments before taking final action.
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    \30\ The scope of this proposed action is limited to whether the 
Sullivan County Area attained the 1-hour SO2 standard by 
the applicable October 4, 2018, attainment date. Therefore, EPA is 
not soliciting further comment on the approvability of the State's 
2017 SO2 attainment SIP that the Agency previously 
proposed to approve on June 29, 2018. See 83 FR 30609. The comment 
period for that proposal closed on July 30, 2018. EPA has not yet 
taken final action on that SIP submission.
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IV. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at https://www2.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review, and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and therefore 
was not submitted to the Office of Management and Budget (OMB) for 
review.

B. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under 
the provisions of the PRA because it does not contain any information 
collection activities.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. This 
proposed action, if finalized, would require the state to adopt and 
submit a SIP revision to satisfy CAA requirements and would

[[Page 2101]]

not itself directly regulate any small entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate of $100 million 
or more, as described in UMRA (2 U.S.C. 1531-1538) and does not 
significantly or uniquely affect small governments. This action itself 
imposes no enforceable duty on any state, local, or tribal governments, 
or the private sector. This action proposes to determine that the 
Sullivan County Area failed to attain the NAAQS by the applicable 
attainment date. If finalized, this determination would trigger 
existing statutory timeframes for the State to submit SIP revisions. 
Such a determination in and of itself does not impose any federal 
intergovernmental mandate.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175, Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. The proposed finding of failure to attain 
SO2 NAAQS does not apply to tribal areas, and the proposed 
rule would not impose a burden on Indian reservation lands or other 
areas where EPA or an Indian tribe has demonstrated that a tribe has 
jurisdiction. Thus, this proposed 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.

G. Executive Order 13045, Protection of Children From Environmental 
Health Risks and Safety Risks

    EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that EPA has reason to believe may disproportionately affect children, 
per the definition of ``covered regulatory action'' in section 2-202 of 
the Executive Order. This proposed action is not subject to Executive 
Order 13045 because the effect of this proposed action, if finalized, 
would be to trigger additional planning requirements under the CAA. 
This proposed action does not establish an environmental standard 
intended to mitigate health or safety risks.

H. Executive Order 13211, Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This proposed rule is not subject to Executive Order 13211, because 
it is not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    EPA believes that this action does not have disproportionately high 
and adverse human health or environmental effects on minority 
populations, low-income populations and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The 
effect of this proposed action, if finalized, would be to trigger 
additional planning requirements under the CAA.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Lead, Pollution, Sulfur 
dioxide.

    Authority: 42 U.S.C. 7401 et seq.

    Dated: December 29, 2021.
Daniel Blackman,
Regional Administrator, Region 4.
[FR Doc. 2022-00028 Filed 1-12-22; 8:45 am]
BILLING CODE 6560-50-P