[Federal Register Volume 89, Number 111 (Friday, June 7, 2024)]
[Proposed Rules]
[Pages 48523-48532]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-11175]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R03-OAR-2024-0024; FRL-11529-01-R3]
Air Plan Approval; Pennsylvania; Attainment Plan for the Indiana
Nonattainment Area for the 2010 1-Hour Sulfur Dioxide National Ambient
Air Quality Standard
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve a state implementation plan (SIP) revision submitted by the
Commonwealth of Pennsylvania (Pennsylvania). This revision pertains to
the attainment plan for the Indiana, Pennsylvania (PA) nonattainment
area for the 2010 1-Hour Sulfur Dioxide (SO2) national
ambient air quality standard (NAAQS). This action is being taken under
the Clean Air Act (CAA).
DATES: Written comments must be received on or before July 8, 2024.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R03-
OAR-2024-0024 at 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, the 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. The 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 www.epa.gov/dockets/commenting-epa-dockets.
[[Page 48524]]
FOR FURTHER INFORMATION CONTACT: Megan Goold, Planning & Implementation
Branch (3AD30), Air & Radiation Division, U.S. Environmental Protection
Agency, Region III, 1600 John F Kennedy Boulevard, Philadelphia,
Pennsylvania 19103. The telephone number is (215) 814-2027. Ms. Goold
can also be reached via electronic mail at [email protected].
SUPPLEMENTARY INFORMATION: On October 5, 2023, the Pennsylvania
Department of Environmental Protection (PADEP) submitted a revision to
its SIP to demonstrate attainment of the 2010 SO2 NAAQS in
the Indiana, PA nonattainment area. This plan includes Pennsylvania's
attainment demonstration and other attainment plan elements required
under the CAA, including the requirement for meeting reasonable further
progress (RFP) toward attainment of the NAAQS, reasonably available
control measures and reasonably available control technology (RACM/
RACT), enforceable emission limitations and control measures, and
contingency measures. Notably, the submission does not contain
information regarding the required emissions inventory or the state's
Nonattainment New Source Review (NNSR) program, as these were
previously approved by the EPA (87 FR 50778, August 18, 2022).
I. Background
On June 22, 2010, the EPA published a new 1-hour primary
SO2 NAAQS of 75 parts per billion (ppb) at 40 CFR 50.17(a),
which is met at an ambient air quality monitoring site when the 3-year
average of the annual 99th percentile of daily maximum 1-hour average
concentrations does not exceed 75 ppb, as determined in accordance with
40 Code of Federal Regulations (CFR) part 50 appendix T (75 FR 35520,
June 22, 2010). Under CAA section 107(d)(1), the EPA is required to
designate areas as ``nonattainment,'' ``attainment,'' or
``unclassifiable'' within two years of establishing a new or revising
an existing standard. As part of this process, states must submit
recommendations for area designations and boundaries to the EPA within
one year of the effective date of the standard. Effective on October 4,
2013,\1\ the Indiana Area (which encompasses Indiana County, and
Plumcreek Township, South Bend Township and Eldertown Borough of
Armstrong County) was designated as nonattainment for the 2010
SO2 NAAQS for an area that encompasses the primary
SO2 emitting sources: the Keystone Generating Station
(Keystone), Conemaugh Generating Station (Conemaugh), Homer City
Generating Station (Homer City), and Seward Generating Station (Seward)
(hereafter referred to as ``the Indiana, PA NAA''). The October 4,
2013, final designation triggered a requirement for Pennsylvania to
submit by April 4, 2015 (within 18 months per CAA section 191(a)), a
SIP revision with an attainment plan for how the Indiana, PA NAA would
attain the 2010 SO2 NAAQS as expeditiously as practicable,
but no later than October 4, 2018, (five years from the designation per
CAA section 192(a)) in accordance with CAA sections 110(a), 172(c) and
191-192.
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\1\ 78 FR 47191 (August 5, 2013).
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For a number of areas, including the Indiana, PA NAA, the EPA
published a March 18, 2016 Finding of Failure to Submit, with an
effective date of April 18, 2016, finding that Pennsylvania and other
pertinent states had failed to submit the required SO2
attainment plan by this submittal deadline. (see 81 FR 14736, March 18,
2016). This finding initiated a deadline under CAA section 179(a) for
the potential imposition of new source review and highway funding
sanctions. However, as a result of Pennsylvania's October 11, 2017
submittal (hereafter referred to as ``the 2017 SIP submittal''), and
the EPA's subsequent October 13, 2017 letter to Pennsylvania finding
the submittal complete, the CAA section 179(a) sanctions were not
imposed. Additionally, under CAA section 110(c), the March 18, 2016,
finding triggered a requirement that the EPA promulgate a Federal
implementation plan (FIP) within two years of the effective date of the
finding unless, by that time, the state has made the necessary complete
submittal and the EPA has approved the submittal as meeting applicable
requirements. The EPA took final action approving this attainment plan
on October 19, 2020 (85 FR 66240, October 19, 2020), which removed the
FIP obligation.
On December 18, 2020, the Sierra Club, Clean Air Council, and
Citizens for Pennsylvania's Future filed a petition for judicial review
with the U.S. Court of Appeals for the Third Circuit, challenging that
final approval.\2\ On April 5, 2021, the EPA filed a motion for
voluntary remand without vacatur of its approval of the Indiana, PA
SO2 attainment plan.
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\2\ Sierra Club, et al. v. EPA, Case No. 20-3568 (3d Cir.).
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On August 17, 2021, the U.S. Court of Appeals for the Third Circuit
granted the EPA's request for remand without vacatur of the final
approval of Pennsylvania's SO2 attainment plan for the
Indiana, PA NAA, and required that the EPA take final action in
response to the remand no later than one year from the date of the
court's order.
On August 18, 2022, the EPA revised and corrected its prior full
approval action (85 FR 66240, October 19, 2020) without further
submission from Pennsylvania (effective September 19, 2022) (87 FR
50778, August 18, 2022). Specifically, the EPA retained the approval of
the emissions inventory and NNSR program requirements, and disapproved
the attainment demonstration, RACM/RACT requirements, RFP requirements,
and contingency measures (hereafter referred to as the ``2022 Partial
Approval/Partial Disapproval'') (87 FR 50778, August 18, 2022). The
partial disapproval action initiated a sanctions clock under CAA
section 179, providing for emission offset sanctions for new sources if
EPA has not fully approved a revised attainment plan within 18 months
(March 19, 2024) after final partial disapproval, and providing for
highway funding sanctions if the EPA has not fully approved a revised
plan within 6 months thereafter (September 19, 2024). The sanctions
clock can be stopped only if the conditions of the EPA's regulations at
40 CFR 52.31 are met. Also, under CAA section 110(c), the partial
disapproval action initiated an obligation for EPA to promulgate a FIP
within two years unless Pennsylvania has submitted, and EPA has fully
approved, a plan addressing the disapproved attainment planning
requirements.
On October 5, 2023, Pennsylvania submitted a 2023 SO2
Attainment Plan SIP Revision for the Indiana, PA NAA (hereafter
referred to as the ``2023 SIP submittal''). The 2023 SIP submittal
addresses the requirements of CAA sections 172(c), 191 and 192 and the
disapproved attainment planning requirements in the EPA's 2022 Partial
Approval/Partial Disapproval. Specifically, this SIP revision contains
a modified attainment demonstration using dispersion modeling,
evaluates sources for RACT/RACM purposes, gives an RFP explanation, and
provides for contingency measures, and includes revised emissions
limitations and control measures.
Nonattainment area SO2 SIPs must meet the applicable
requirements of the CAA, specifically CAA sections 110, 172, 191 and
192. The EPA's regulations governing nonattainment area SIPs are set
forth at 40 CFR part 51, with specific procedural requirements and
control strategy requirements residing at subparts F and G,
respectively. Soon
[[Page 48525]]
after Congress enacted the 1990 amendments to the CAA, the EPA issued
comprehensive guidance on SIPs in a document entitled the ``General
Preamble for the Implementation of Title I of the Clean Air Act
Amendments of 1990,'' published in the Federal Register at 57 FR 13498
(April 16, 1992) (General Preamble). Among other things, the General
Preamble addressed SO2 SIPs and fundamental principles for
SIP control strategies. Id. at 13545-49, 13567-68. On April 23, 2014,
the EPA issued guidance and recommendations for meeting the statutory
requirements in SO2 SIPs addressing the 2010 primary NAAQS,
in a document entitled, ``Guidance for 1-Hour SO2
Nonattainment Area SIP Submissions'' (hereafter referred to as ``2014
SO2 Nonattainment Guidance'').\3\ In the 2014 SO2
Nonattainment Guidance, the EPA described the statutory requirements
for a complete nonattainment area SIP, which include an accurate
emissions inventory of current emissions for all sources of
SO2 within the nonattainment area; an attainment
demonstration; enforceable emissions limitations and control measures;
demonstration of RFP; implementation of RACM (including RACT);
nonattainment new source review; and adequate contingency measures for
the affected area.
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\3\ www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
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For the EPA to fully approve a SIP as meeting the requirements of
CAA sections 110, 172, 191, and 192 and the EPA's regulations at 40 CFR
part 51, the SIP for the affected area needs to demonstrate to the
EPA's satisfaction that each of the aforementioned requirements have
been met. Under CAA sections 110(l) and 193, the EPA may not approve a
SIP that would interfere with any applicable requirement concerning
NAAQS attainment and RFP, or any other applicable requirement, and no
requirement in effect before November 15, 1990 (or required to be
adopted by an order, settlement, agreement, or plan in effect before
November 15, 1990), in any area which is a nonattainment area for any
air pollutant, may be modified in any manner unless it ensures
equivalent or greater emission reductions of such air pollutant.
CAA section 172(c)(1) directs states with areas designated as
nonattainment to demonstrate that the submitted plan provides for
attainment of the NAAQS. 40 CFR part 51, subpart G further delineates
the control strategy requirements that SIPs must meet, and the EPA has
long required that all SIPs and control strategies reflect the four
fundamental principles of quantification, enforceability,
replicability, and accountability. See General Preamble, at 13567-68.
SO2 attainment plans must consist of two components: (1)
emission limits and other control; measures that assure implementation
of permanent, enforceable and necessary emission controls, and (2) a
modeling analysis which meets the requirements of 40 CFR part 51,
appendix W and demonstrates that these emission limits and control
measures provide for timely attainment of the primary SO2
NAAQS as expeditiously as practicable, but by no later than the
attainment date for the affected area. In all cases, the emission
limits and control measures must be accompanied by appropriate methods
and conditions to determine compliance with the respective emission
limits and control measures, and must be quantifiable (i.e., a specific
amount of emission reduction can be ascribed to the measures), fully
enforceable (specifying clear, unambiguous and measurable requirements
for which compliance can be practicably determined), replicable (the
procedures for determining compliance are sufficiently specific and
non-subjective so that two independent entities applying the procedures
would obtain the same result), and accountable (source-specific limits
must be permanent and must reflect the assumptions used in the SIP
demonstrations).
The EPA's 2014 SO2 Nonattainment Guidance recommends
that the emission limits established for the attainment demonstration
be expressed as short-term average limits (e.g., addressing emissions
averaged over one or three hours), but also describes the option to
utilize emission limits with longer averaging times of up to 30 days so
long as the state meets various suggested criteria. See 2014
SO2 Nonattainment Guidance, pp. 22 to 39. The guidance
recommends that--should states and sources utilize longer averaging
times--the longer-term average limit should be set at an adjusted level
that reflects a stringency comparable to the 1-hour average limit at
the critical emission value (CEV) shown to provide for attainment that
the plan otherwise would have set.
The 2014 SO2 Nonattainment Guidance provides an
extensive discussion of the EPA's rationale for concluding that
appropriately set, comparably stringent limitations based on averaging
times as long as 30 days can be found to provide for attainment of the
2010 SO2 NAAQS. In evaluating this option, the EPA
considered the nature of the standard, conducted detailed analyses of
the impact of 30-day average limits on the prospects for attaining the
standard, and carefully reviewed how best to achieve an appropriate
balance among the various factors that warrant consideration in judging
whether a state's plan provides for attainment. Id. at pp. 22-39, and
Appendices B, C, and D.
As specified in 40 CFR 50.17(b), the 1-hour primary SO2
NAAQS is met at an ambient air quality monitoring site when the 3-year
average of the annual 99th percentile of daily maximum 1-hour average
concentrations is less than or equal to 75 ppb. In a year with 365 days
of valid monitoring data, the 99th percentile would be the fourth
highest daily maximum 1-hour value. The 2010 SO2 NAAQS,
including this form of determining compliance with the standard, was
upheld by the U.S. Court of Appeals for the District of Columbia
Circuit in Nat'l Envt'l Dev. Ass'n's Clean Air Project v. EPA, 686 F.3d
803 (D.C. Cir. 2012). Because the standard has this form, a single
hourly exceedance of the 75 ppb NAAQS level does not by itself result
in a violation of the standard. Instead, at issue is whether a source
operating in compliance with a properly set longer-term average could
cause multiple hourly exceedances over multiple days in a year, and if
so, the resulting frequency and magnitude of such exceedances, and in
particular, whether the EPA can have reasonable confidence that a
properly set longer-term average limit will provide that the 3-year
average of annual fourth highest daily maximum hourly values will be at
or below 75 ppb. A synopsis of how the EPA evaluates whether such plans
``provide for attainment,'' based on modeling of projected allowable
emissions and in light of the SO2 NAAQS' form for
determining attainment at monitoring sites, follows.
For SO2 attainment plans based on 1-hour emission
limits, the standard approach is to conduct modeling using fixed 1-hour
emission rates. The maximum modeled emission rate that results in
attainment is labeled the ``critical emissions value'' (CEV). The
modeling process for identifying this CEV inherently considers the
numerous variables that affect ambient concentrations of
SO2, such as meteorological data, background concentrations,
and topography. In the standard approach, the state would then provide
for attainment by setting a continuously applicable 1-hour emission
limit for each stationary SO2 source at this CEV.
[[Page 48526]]
The EPA recognizes that some sources have highly variable
emissions, for example due to variations in fuel sulfur content and
operating rate, that can make it extremely difficult, even with a well-
designed control strategy, to ensure in practice that emissions for any
given hour do not exceed the CEV. The EPA also acknowledges the concern
that longer-term emission limits can allow short periods with emissions
above the CEV, which, if coincident with meteorological conditions
conducive to high SO2 concentrations, could in turn create
the possibility of an hourly NAAQS exceedance occurring on a day when
an exceedance would not have occurred if emissions were continuously
controlled at the level corresponding to the CEV. However, for several
reasons, EPA believes that the approach recommended in its guidance
document suitably addresses this concern.
First, from a practical perspective, the EPA expects the actual
emission profile of a source subject to an appropriately set longer-
term average limit to be similar to the emission profile of a source
subject to an analogous 1-hour average limit. The EPA expects this
similarity because it has recommended that the longer-term average
limit be set at a level that is comparably stringent to the otherwise
applicable 1-hour limit (reflecting a downward adjustment from the CEV)
and that takes the source's emissions profile (and inherent level of
emissions variability) into account. As a result, the EPA expects
either form of emission limit to yield comparable air quality.
Second, from a more theoretical perspective, the EPA has compared
the likely air quality with a source having maximum allowable emissions
under an appropriately set longer-term limit, to the likely air quality
with the source having maximum allowable emissions under the comparable
1-hour limit. In this comparison, in the 1-hour average limit scenario,
the source is presumed at all times to emit at the CEV, and in the
longer-term average limit scenario, the source is presumed occasionally
to emit more than the CEV, but on average, and presumably at most
times, to emit well below the CEV. In an ``average year,'' \4\
compliance with the 1-hour limit is expected to result in three
exceedance days (i.e., three days with maximum hourly values above 75
ppb) and a fourth day with a maximum hourly value at 75 ppb. By
comparison, with the source complying with a longer-term limit, it is
possible that additional hourly exceedances would occur that would not
occur in the 1-hour limit scenario (if emissions exceed the CEV at
times when meteorology is conducive to poor air quality). However, this
comparison must also factor in the likelihood that exceedances that
would be expected in the 1-hour limit scenario would not occur in the
longer-term limit scenario. This result arises because the longer-term
limit requires lower emissions most of the time (because the limit is
set below the CEV), so a source complying with an appropriately set
longer-term limit is likely to have lower emissions at critical times
than would be the case if the source were emitting as allowed with a 1-
hour limit.
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\4\ An ``average year'' is used to mean a year with average air
quality. While 40 CFR part 50, appendix T, provides for averaging
three years of annual 99th percentile daily maximum hourly values
(e.g., the fourth highest maximum daily hourly concentration in a
year with 365 days with valid data), this discussion and an example
below uses a single ``average year'' in order to simplify the
illustration of relevant principles.
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To illustrate this point, the EPA conducted a statistical analysis
using a range of scenarios using actual plant data. The analysis is
described in appendix B of EPA's 2014 SO2 Nonattainment
Guidance. Based on the analysis described in the 2014 SO2
Nonattainment Guidance, the EPA expects that an emission profile with
maximum allowable emissions under an appropriately set, comparably
stringent 30-day average limit is likely to have the net effect of
having a lower number of hourly exceedances and better air quality than
an emission profile with maximum allowable emissions under a 1-hour
emission limit at the CEV. This result provides a compelling policy
rationale for allowing the use of a longer averaging period, in
appropriate circumstances where the facts indicate this result can be
expected to occur.
The 2014 SO2 Nonattainment Guidance offers specific
recommendations for determining an appropriate longer-term average
limit. The recommended method starts with determination of the 1-hour
emission limit that would provide for attainment (i.e., the CEV), and
applies an adjustment factor to determine the (lower) level of the
longer-term average emission limit that would be estimated to have a
stringency comparable to the otherwise necessary 1-hour emission limit.
This method uses a database of continuous emission data reflecting the
type of control that the source will be using to comply with the SIP
emission limits, which (if compliance requires new controls) may
require use of an emission database from another source. The
recommended method involves using these data to compute a complete set
of emission averages, computed according to the averaging time and
averaging procedures of the prospective emission limitation (i.e.,
using 1-hour historical emission values from the emissions database to
calculate 30-day average emission values). In this recommended method,
the ratio of the 99th percentile among these long-term averages to the
99th percentile of the 1-hour values represents an adjustment factor
that may be multiplied to the candidate 1-hour emission limit (CEV) to
determine a longer-term average emission limit that may be considered
comparably stringent.\5\
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\5\ For example, if the CEV is 1,000 pounds of SO2
per hour, and a suitable adjustment factor is determined to be 70
percent, the recommended longer-term average limit would be 700
pounds per hour.
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The 2014 SO2 Nonattainment Guidance also addresses a
variety of related topics, including the potential utility of setting
supplemental emission limits, such as mass-based limits or work
practice requirements for the operation of SO2 control
equipment, to reduce the likelihood and/or magnitude of elevated
emission levels that might occur under the longer-term emission rate
limit.
Preferred air quality models for use in regulatory applications are
described in appendix A of the EPA's Guideline on Air Quality Models
(40 CFR part 51, appendix W). In 2005, the EPA promulgated AERMOD as
the Agency's preferred near-field dispersion modeling for a wide range
of regulatory applications addressing stationary sources (for example
in estimating SO2 concentrations) in all types of terrain
based on extensive developmental and performance evaluation.
Supplemental guidance on modeling for purposes of demonstrating
attainment of the SO2 standard is provided in appendix A to
the 2014 SO2 Nonattainment Guidance. Appendix A provides
extensive guidance on the modeling domain, the source inputs, assorted
types of meteorological data, and background concentrations.
Consistency with the recommendations in this guidance is generally
necessary for the attainment demonstration to offer adequately reliable
assurance that the plan provides for attainment.
Attainment demonstrations for the 2010 1-hour primary
SO2 NAAQS must demonstrate future attainment and maintenance
of the NAAQS in the entire area designated as nonattainment (i.e., not
just at the violating monitor) by using air quality dispersion modeling
(see appendix W to 40 CFR part 51) to show that the mix of sources and
enforceable control measures and emission rates in an identified area
will not lead to a violation of the SO2
[[Page 48527]]
NAAQS. For a short-term (i.e., 1-hour) standard, the EPA believes that
dispersion modeling, using allowable emissions and addressing
stationary sources in the affected area (and in some cases those
sources located outside the nonattainment area which may affect
attainment in the area) is technically appropriate, efficient, and
effective in demonstrating attainment in nonattainment areas because it
takes into consideration combinations of meteorological and emission
source operating conditions that may contribute to peak ground-level
concentrations of SO2.
The meteorological data used in the analysis should generally be
processed with the most recent version of AERMET. AERMET is a
meteorological data preprocessor that incorporates air dispersion based
on planetary boundary layer turbulence structure and scaling concepts.
Estimated concentrations should include ambient background
concentrations, should follow the form of the standard, and should be
calculated as described in section 2.6.1.2 of the August 23, 2010,
clarification memo on ``Applicability of Appendix W Modeling Guidance
for the 1-hour SO2 National Ambient Air Quality Standard''
(U.S. EPA, 2010).
II. Summary of SIP Revision and EPA Analysis
Pennsylvania's 2023 SIP submittal contained an attainment
demonstration that located, identified, and quantified sources of
emissions contributing to violations of the 2010 SO2 NAAQS
in the Indiana, PA NAA; a determination that the control strategy for
the primary SO2 sources (Keystone, Conemaugh, Homer City,
and Seward) constitutes RACM/RACT; requirements for RFP toward
attaining the SO2 NAAQS in the Indiana, PA NAA; contingency
measures; and the request that emission limitations and compliance
parameters for Keystone, Conemaugh, and Seward be incorporated into the
SIP.\6\ The EPA disapproved these elements of PADEP's 2017 SIP
submittal because they were based on longer-term averaging
SO2 limits for Keystone and Seward that EPA could not
approve. Those particular longer-term averaging limits were
unsupportable because PADEP's modeling and analysis fell short of
demonstrating that the longer-term limits were comparably stringent to
the 1-hour CEV and that such limits would provide for attainment under
worst-case emission scenarios, unlike the approach set forth in the
2014 SO2 Nonattainment Guidance. But PADEP's 2023 SIP
submittal includes appropriate modeling and revised longer-term
averaging emission limits for Keystone, Conemaugh, and Seward that are
comparably stringent to the 1-hour CEV for each facility. Therefore,
the 2023 SIP submittal's attainment plan elements, the effectiveness of
which are dependent upon correct longer-term averaging emission limits,
are similarly approvable. The EPA already determined that Pennsylvania
satisfied the emissions inventory and NNSR requirements and approved
those elements of the attainment plan into Pennsylvania's SIP as stated
in the 2022 Partial Approval/Partial Disapproval of Pennsylvania's 2017
submittal (87 FR 50778, August 18, 2022).
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\6\ SO2 emission limits for Homer City that were used
in the attainment modeling were already approved into the SIP. (87
FR 50778, August 18, 2022).
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A. Attainment Demonstration-Air Quality Modeling
The SO2 attainment demonstration provides air quality
dispersion modeling analyses to demonstrate that control strategies
chosen to reduce SO2 source emissions will bring the
Indiana, PA NAA into attainment. The modeling analyses, conducted
pursuant to recommendations outlined in appendix W to 40 CFR part 51
(EPA's Modeling Guidance), are used to assess the control strategy for
a nonattainment area and establish emission limits that will provide
for attainment. The analysis requires five years of meteorological data
to simulate the dispersion of pollutant plumes from multiple point,
area, or volume sources across the averaging times of interest.\7\ The
modeling demonstration typically also relies on maximum allowable
emissions from sources in the nonattainment area. Though the actual
emissions are likely to be below the allowable emissions, sources have
the ability to run at higher production rates or optimize controls such
that emissions approach the allowable emissions limits. A modeling
analysis that provides for attainment under all scenarios of operation
for each source must therefore consider the worst-case scenario of both
the meteorology (e.g., predominant wind directions, stagnation, etc.)
and the maximum allowable emissions.
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\7\ The period of meteorological data needed for an air-quality
analysis is described in section 8.4.2(e) of Appendix W: ``The use
of 5 years of adequately representative [National Weather Service]
or comparable meteorological data, at least 1 year of site-specific,
or at least 3 years of prognostic meteorological data, are
required.''
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Air dispersion modeling served as the basis for developing
SO2 emission limits that provide for attainment of the 2010
SO2 NAAQS throughout the Indiana, PA NAA. PADEP's air
dispersion modeling methodology is fully described in appendix A of the
state submittal, the Air Dispersion Modeling Technical Support
Document.
PADEP's air dispersion modeling utilized the AERMOD v22112 and its
associated preprocessors, the building downwash preprocessor (BPIPPRM)
v04274, the AERMOD terrain preprocessor (AERMAP) v18081, and the AERMOD
meteorological preprocessor (AERMET) v22112.
The modeling analysis included the following SO2 sources
in the NAA: (1) Keystone's SO2 emission sources include two
coal-fired boilers (Unit 1 & Unit 2 or Source ID 031 & 032). The
SO2 emissions vent from each source to the atmosphere
through separate flues within a common stack, which was characterized
in AERMOD as a point source; (2) Homer City's SO2 emission
sources include three coal-fired boilers (Unit 1, Unit 2 & Unit 3 or
Source ID 031, 032 & 033). The SO2 emissions vent from each
source to the atmosphere through separate stacks, which were each
characterized in AERMOD as a point source; (3) Conemaugh's
SO2 emission sources include two coal-fired boilers (Unit 1
& Unit 2 or Source ID 031 & 032). The SO2 emissions vent
from each source to the atmosphere through separate flues within a
common stack, which was characterized in AERMOD as a point source; and
(4) Seward's SO2 emission sources include two refuse coal-
fired boilers (Unit 1 & Unit 2 or Source ID 034 & 035). The
SO2 emissions vent from each source to the atmosphere
through a common stack, which was characterized in AERMOD as a point
source.
PADEP modeled three domains with three meteorological data sets.
Domain 1, the Armstrong County portion of the Indiana, PA NAA, included
SO2 emissions data from Keystone and Homer City in AERMOD.
Domain 2, the Indiana County portion of the Indiana, PA NAA, included
SO2 emissions data from all four power plant facilities in
AERMOD. The air dispersion modeling in Domains 1 and 2 utilized
representative meteorological datasets from the Johnstown--Cambria
County Airport (KJST) meteorological site. The KJST meteorological
dataset consists of a 5-year period of hourly records from January 1,
2011, through December 31, 2015, consistent with the meteorological
data period that was utilized in the air dispersion modeling for
PADEP's 2017 SIP submittal for the Indiana, PA NAA. Additionally, a
second KJST meteorological dataset was utilized, which consists of a
more recent 5-year
[[Page 48528]]
period of hourly records from January 1, 2017, through December 31,
2021.
Domain 3, the portion of Indiana County near Conemaugh and Seward,
included SO2 emissions data from those two plants. PADEP
used data from the Conemaugh-Seward meteorological site to represent
atmospheric conditions in the vicinity of Conemaugh and Seward. A 1-
year (September 1, 2015-August 31, 2016) Conemaugh-Seward
meteorological dataset was utilized with AERMOD.
Background SO2 was represented in AERMOD by temporally
varying (by season and hour-of-day), 99th-percentile concentrations
that were derived from data measured at the Allegheny County Health
Department's South Fayette monitor (Site ID: 42-003-0067) for the 3-
year period, 2019-2021.
AERMOD was used to determine the CEVs for Conemaugh, Keystone, and
Seward where the modeled 1-hour emission rates demonstrate attainment
of the 2010 1-hour SO2 NAAQS. The SO2 emission
rates for Homer City were based on the unit 1, unit 2, and unit 3
combined mass-based SO2 emission limits established in Plan
Approval 32-00055H,\8\ which authorized the installation of Novel
Integrated Desulfurization (NID) systems, often referred to as Dry Flue
Gas Desulphurization (FGD) systems on unit 1 and unit 2. This 1-hour
SO2 limit was based on air dispersion modeling that
demonstrated attainment of the 2010 1-hour SO2 NAAQS. The
CEV rates used in the demonstration analysis for each of the four
sources are summarized in Table 1, in this document. The modeled
emission rate in grams per second (g/s) was converted to pounds per
hour (lbs/hr), which is the CEV.\9\
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\8\ Plan Approval 32-00055H was issued on April 2, 2012, and
modified on April 4, 2013, by the DEP.
\9\ Based on the National Institute of Standards and Technology
conversion: 1 pound = 453.59237 grams.
Table 1--Critical Emission Values (CEV) From Indiana, PA SIP Modeling
Demonstration
------------------------------------------------------------------------
Modeled rate CEV limit (lbs/
Facility (g/s) hr)
------------------------------------------------------------------------
Conemaugh Generating Station............ 398.02731 3,159
Homer City Generating Station, Unit 1... 195.29672 1,550
Homer City Generating Station, Unit 2... 195.29672 1,550
Homer City Generating Station, Unit 3... 410.75310 3,260
Keystone Generating Station............. 1,224.44741 9,718
Seward Generating Station............... 482.57189 3,830
------------------------------------------------------------------------
Using the EPA conversion factor for the SO2 NAAQS, the
maximum 1-hour CEV model run design values for Domain 1 (196.00 [mu]g/
m\3\), Domain 2 (187.51 [mu]g/m\3\) and Domain 3 (195.99 [mu]g/m\3\) of
the Indiana Area are less than 75 ppb.\10\ EPA has reviewed the
modeling that Pennsylvania submitted to support the attainment
demonstration for the Indiana Area and has determined that the AERMOD
modeling is consistent with CAA requirements, appendix W to 40 CFR part
51, and EPA's 2014 SO2 Guidance for SO2
attainment demonstration modeling. Unlike the 2017 SIP submittal which
the EPA partially disapproved in 2022 (87 FR 50778, August 18, 2022),
PADEP's 2023 SIP submittal used an appropriate analysis to show that
the modeled 1-hour CEV and longer-term emission limits were comparably
stringent. In doing so, the 2023 SIP submission followed EPA guidance
to develop an adjustment factor to convert the modeled 1-hour CEV to
the comparably stringent longer-term emission limit. The 2023 SIP
submission appropriately developed the adjustment factor by comparing
the 99th percentile of historic hourly emissions to the 99th percentile
of the longer-term averaged emissions of the same dataset to develop
the longer-term emission limits. Conversely, the 2017 SIP submittal
developed longer-term limits based on a novel modeling approach with a
different variability metric without appropriate justification--PADEP
had not demonstrated that the longer-term emission limits would provide
for attainment under worst-case scenarios permissible under the limits.
(87 FR 15166 at 15171-74, March 17, 2022).
---------------------------------------------------------------------------
\10\ The SO2 NAAQS level is expressed in ppb but
AERMOD gives results in [mu]g/m\3\. The conversion factor for
SO2 (at the standard conditions applied in the ambient
SO2 reference method) is 1 ppb = approximately 2.619
[mu]g/m\3\. See Pennsylvania's SO2 Round 3 Designations
Proposed Technical Support Document at www.epa.gov/sites/production/files/2017-08/documents/35_pa_so2_rd3-final.pdf.
---------------------------------------------------------------------------
EPA's review supports PADEP's modeling methodology and conclusions.
More information about EPA's review of PADEP's attainment demonstration
and modeling can be found in EPA's March 2024 ``Technical Support
Document the Critical Emissions Value Modeling Analysis for the
Indiana, PA 1-Hour SO2 Nonattainment Area'' under Docket ID
No. EPA-R03-OAR-2024-0024 and online at www.regulations.gov.
1. Longer-Term Emission Limits
The 2017 SIP submittal established longer-term average
SO2 limits for Keystone, Conemaugh, and Seward, and a 1-hour
SO2 limit for Homer City. As described above, the limits in
the 2017 submittal for Keystone and Seward were based on a novel
modeling approach and an analysis that did not demonstrate that the
longer-term emission limits were comparably stringent to the 1-hour
CEV. (87 FR 15166 at 15171-74, March 17, 2022). EPA thus disapproved
the longer-term average SO2 limits for Keystone and Seward
as not properly characterizing maximally possible emissions. (87 FR
15166 at 15173, March 17, 2022). Nonetheless, the EPA retained the
limits as SIP strengthening in its partial approval and partial
disapproval. (87 FR 15166 at 15176, March 17, 2022).
PADEP's 2023 SIP submittal established revised longer-term average
SO2 emission limits for Keystone, Conemaugh, and Seward
facilities and retained the 1-hour SO2 emission limit
previously established and approved for the Homer City facility.\11\
PADEP's 2023 SIP submittal established comparably stringent limits
because PADEP used the ratio of the 99th percentile values of the
hourly and longer-term emission rates as the adjustment factors for
calculating
[[Page 48529]]
the longer-term limits.\12\ The revised longer-term emission limits
were calculated from the 1-hour SO2 CEVs using adjustment
factors that correspond to the averaging periods already established in
emission limits for each facility (i.e., Seward's emission limit uses a
30-operating day averaging period, Keystone uses a 24-hour block
averaging period, and Conemaugh uses a 3-hour block averaging period).
The adjustment factors which are used for deriving longer-term emission
limits that are as comparably stringent as the 1-hour SO2
CEVs were calculated in accordance with the EPA's 2014 SO2
Nonattainment Guidance. All and only operating hours with measured
values were used in the calculations.\13\ PADEP utilized four years of
stable operations hourly emissions data from 2018-2022. In accordance
with the 2014 SO2 Nonattainment Guidance's recommendation to
use data from years with stable operations, data from March through
September of 2020, during which operations at Keystone and Conemaugh
shifted toward low-load conditions as a result of the COVID-19
pandemic, were excluded from adjustment factor calculations for both
stations. To have a complete four calendar years' worth of data, data
from March through September of 2022 were used as replacement for the
March through September of 2020 data. The calculation of the adjustment
factors is described in detail in appendix B of the state submittal and
was based on the data reduction criteria and average emission rate
calculation established for demonstrating compliance with the longer-
term emission limits. For example, Seward's 30-operating day rolling
average is the average of all the hourly emission data, using only
hours during which fuel is combusted from the preceding 30 operating
days. An operating day is defined as a 24-hour period between
12midnight and the following 12 midnight during which any fuel is
combusted at any time. This compliance approach is the same as the
calculations and definitions used in developing the adjustment factor
for this source.
---------------------------------------------------------------------------
\11\ While at the time of publication, the evidence suggests
that Homer City's three units have ceased operations, EPA's approval
of this attainment plan is independent of Homer City's ceasing
operations. Emissions data indicates that Units 1 and 2 last emitted
on March 24, 2023, and December 11, 2022, and Unit 3 on May 17,
2023. However, as the EPA is not aware of PADEP rescinding Homer
City's operating permits,-Homer City ceasing operations does not
guarantee that the units are permanently and enforceably shutdown.
Importantly, PADEP's 2023 SIP submittal and the accompanying
attainment demonstration, which the EPA is proposing to approve,
properly accounted for Homer City's continued operation. To be
clear, the EPA's proposed approval of this attainment plan is based
on Homer City's possible continued operation.
\12\ Conemaugh's 3-hour block average emission limits in PADEP's
October 11, 2017 submission for each individual unit was roughly in
line with the CEV modeled limit and the ratio from appendix C in
EPA's 2014 SO2 Guidance. (87 FR 15166 at 15175, March 17,
2022). Nonetheless, in its 2023 SIP submittal PADEP included a
combined 3-hour block average emission limit using the 99th
percentile ratio to develop the adjustment factor to calculate
Conemaugh's 3-hour block combined averaging SO2 limit.
\13\ Substituted values and nonoperating hours were not used in
the calculations.
---------------------------------------------------------------------------
The 1-hour SO2 CEVs, the adjustment factors, the longer-
term SO2 emission limits, and the averaging periods for the
three other facilities are summarized in Table 2, in this document.
Table 2--Sources in Indiana, PA NAA With Longer-Term SO2 Emission Limits
----------------------------------------------------------------------------------------------------------------
1-Hour CEV Adjustment Longer-term limit
Source (lbs/hr) factor (lbs/hr) Averaging period
----------------------------------------------------------------------------------------------------------------
Keystone............................ 9,718 0.857 8,328 24-hr block.
Conemaugh........................... 3,159 0.975 3,080 3-hour block.
Seward.............................. 3,830 0.756 2,895 30-operating day
rolling.
----------------------------------------------------------------------------------------------------------------
Additionally, PADEP implemented a supplemental measure to control
any potential hourly emissions spikes at Seward station. Seward shall
inject limestone into Source ID 034 and Source ID 035 during initial
firing each time Source ID 034 and Source ID 035 are operated to reduce
the magnitude and frequency of SO2 emission spikes in
accordance with good air pollution control practices.
The EPA reviewed PADEP's adjustment factor calculations, including
the selected years of emissions data and the exclusion of March through
September of 2020 due to the COVID pandemic and the claim that the
operation of Keystone and Conemaugh was not considered stable during
that time period. The EPA notes that removing this period of time, and
adding the period of March through September of 2022, produced similar
adjustment factors as would have been calculated without replacing the
data. The EPA reviewed the justification provided by PADEP regarding
this issue and concludes that PADEP properly characterized the hourly
load impact of the COVID pandemic in the data (i.e., shift from high
load to low load operation during this time), and properly included
data where stable operation of the sources was verified. PADEP followed
the EPA's 2014 SO2 Nonattainment Guidance in developing the
comparably stringent longer-term limits for Seward, Conemaugh and
Keystone. The EPA is proposing to approve the longer-term emission
limits described above as being comparably stringent to the 1-hour CEV
for Seward, Conemaugh and Keystone, and as correcting the deficiencies
of the 2017 submittal previously identified in 2022 by removing the
previously approved (and retained as SIP strengthening) longer-term
averaging SO2 limits for Keystone, Conemaugh, and Seward as
described in the RACM/RACT section that follows.
B. RACM/RACT and Enforceable Emission Limitations
Section 172(c)(1) of the CAA requires states to adopt and submit
all RACM, including RACT, as needed to attain the standards as
expeditiously as practicable. Section 172(c)(6) requires the SIP to
contain enforceable emission limits and control measures necessary to
provide for timely attainment of the standard.
Pennsylvania's submittal discusses that the main SO2
emitting sources at Conemaugh, Homer City, Keystone, and Seward are all
equipped with FGD systems (wet limestone scrubbers, dry FGD, or in-
furnace limestone injection systems) to reduce SO2
emissions. Table 3, in this document, lists the control technology at
each of the main SO2 emitting sources at each facility.
[[Page 48530]]
Table 3--Control Technology at the Four Major SO2 Sources in the Indiana Area
----------------------------------------------------------------------------------------------------------------
Control
Facility Unit SO2 control installation
date
----------------------------------------------------------------------------------------------------------------
Conemaugh............................... 031--Main Boiler 1........ Wet limestone scrubber.... ~1994
031--Main Boiler 2........ Wet limestone scrubber.... ~1995
Homer City.............................. 031--Boiler 1............. Dry FGD................... 11/18/2015
032--Boiler 2............. Dry FGD................... 5/23/2016
033--Boiler 3............. Wet limestone scrubber.... ~2002
Keystone................................ 031--Boiler 1............. Wet limestone scrubber.... 9/24/2009
032--Boiler 2............. Wet limestone scrubber.... 11/22/2009
Seward.................................. 034--CFB Boiler 1......... In-furnace limestone ~2004
injection.
035--CFB Boiler 2......... In-furnace limestone ~2004
injection.
----------------------------------------------------------------------------------------------------------------
With these controls installed, Pennsylvania's submittal discusses
facility-specific control measures, namely SO2 emission
limits for Homer City, Conemaugh, Seward and Keystone. Homer City has a
1-hour averaging period emission limit which was previously in its
existing Title V Operating Permit (TVOP). The 1-hour SO2 CEV
is equivalent to the 1-hour SO2 emission limit in the
current TVOP #32-00055.
PADEP issued Consent Order and Agreements (COAs) with both Keystone
and Conemaugh on August 15, 2023, as well as Seward on August 17, 2023
(2023 COAs), which established new emission limits that were
demonstrated to provide for attainment in the Indiana, PA Area. PADEP
has asked the EPA to incorporate into the SIP the following updated
combination of SO2 emission limits for these three
facilities (as well as the compliance strategies listed in the
unredacted portion of the COAs found in appendix C of the state
submittal):
Keystone--Remove 9,600 lbs/hr on a 24-hour (daily) block
average and replace with 8,328 lbs/hr combined based on a 24-hour block
average for Boiler 1 & Boiler 2 (Source IDs 031 & 032).
Seward--Remove 3,038.4 lbs/hr and replace with 2,895 lbs/
hr combined based on a 30-day operating hours average rolling by one
day for Source IDs 034 & 035. Remove 13,308 tpy and replace with 12,680
tpy combined for Source IDs 034 & 035.\14\ Add the requirement to
inject limestone into Source ID 034 and Source ID 035 during initial
firing each time Source ID 034 and Source ID 035 are operated to reduce
the magnitude and frequency of SO2 emission spikes in
accordance with good air pollution control practices.
---------------------------------------------------------------------------
\14\ The new annual limit is calculated to be consistent with
the new 30-day limit, and is considered a supplemental limit.
---------------------------------------------------------------------------
Conemaugh--Add 3,080 lbs/hr combined on a 3-hour block
average for Units 1 & 2 (Source IDs 031 & 032).\15\
---------------------------------------------------------------------------
\15\ Conemaugh's new 3,080 lbs/hr combined 3-hour block average
limit for Units 1 and 2 is in addition to the emission limits
retained as SIP strengthening in the 2022 Partial Approval/Partial
Disapproval. Specifically, this action does not remove the 1,656
lbs/hr emission limit on a 3-hour block average for Units 1 and 2
individually.
---------------------------------------------------------------------------
These emissions limits and associated compliance parameters will be
federally enforceable upon the EPA's approval of the SIP. The EPA
retained Homer City's 1-hour SO2 emission limit as a SIP
strengthening measure in its 2022 Partial Approval/Partial Disapproval
and now proposes to retain that limit as part of PADEP's attainment
demonstration here.
The emission limits described here have been shown to provide for
attainment of the NAAQS, and thus the EPA is proposing to determine
that these are emissions limitations as defined under CAA section
302(k) that are necessary and appropriate to meet the applicable
requirements of the CAA under CAA section 110(a)(2)(A), including that
the state's plan satisfies requirements for RACM/RACT under CAA section
172(c)(1) and includes enforceable emission limitations as may be
necessary and appropriate to provide for attainment of the NAAQS under
CAA section 172(c)(6). The EPA is also proposing to determine that the
removal of Keystone and Seward's previously SIP-approved SO2
emission limits (87 FR 50778, August 18, 2022) and replacement with the
new SO2 emission limits listed in Table 2 of this document
does not pose an issue with respect to CAA section 110(l) or 193.\16\
---------------------------------------------------------------------------
\16\ Under CAA sections 110(l) and 193, the EPA may not approve
a SIP that would interfere with any applicable requirement
concerning NAAQS attainment and RFP, or any other applicable
requirement, and no requirement in effect before November 15, 1990
(or required to be adopted by an order, settlement, agreement, or
plan in effect before November 15, 1990), in any area which is a
nonattainment area for any air pollutant, may be modified in any
manner unless it ensures equivalent or greater emission reductions
of such air pollutant. The newly established emissions limit for
Keystone of 8,328 on 24-hour block period is more stringent that the
previously SIP-approved emission limit of 9,600 lb/hr on a 24-hour
block period, and the newly established emission limits for Seward
of 2,895 lb/hr on a 30-operating day rolling average is more
stringent that the previously SIP-approved emission limit of 3,084.4
lb/hr on a 30-operating day rolling average.
---------------------------------------------------------------------------
C. Reasonable Further Progress (RFP)
Section 172 of the CAA requires Pennsylvania's attainment plan to
provide for RFP toward attainment. The relationship between
SO2 and sources is more directly quantifiable as compared to
other NAAQS pollutants, and there is usually a single step between pre-
control nonattainment and post-control attainment. Therefore, for
SO2 SIPs, which address a small number of affected sources,
requiring expeditious compliance with attainment emission limits can
address the RFP requirement. To be approved by the EPA under CAA
section 192(a), attainment plans need to provide for future attainment
of the NAAQS as expeditiously as practicable, but no later than 5 years
from the effective date of the area's designation as nonattainment. For
areas designated nonattainment effective October 4, 2013, attainment
plans were required to contain demonstrations that the area would
attain as expeditiously as practicable, but no later than October 4,
2018.
The four sources in the Indiana, PA NAA were subject to federally
enforceable SO2 emissions limits since the EPA's initial
approval of the 2017 SIP submittal on October 19, 2020 (85 FR 66240,
October 19, 2020). After the 2022 Partial Approval/Partial Disapproval
of the 2017 SIP submittal, those emission limits remained in the SIP as
SIP strengthening measures. The appropriate SO2 limits were
already established for Homer City effective February 28, 2017 in the
state permit, and remain the same as they were since being incorporated
into the SIP effective November 18, 2020. For the remaining three
sources, Keystone, Seward, and
[[Page 48531]]
Conemaugh, due to the timeline of events, it was not practical for
Pennsylvania to have a compliance schedule which provided for
attainment no later than 5 years from the area's designation of
nonattainment (i.e., October 4, 2018). However, in response to the
EPA's 2022 partial disapproval of its SIP for the Indiana, PA NAA,
Pennsylvania acted quickly in establishing new emission limits which
provide for attainment in the Indiana, PA NAA as expeditiously as
practicable with this 2023 SIP submittal. Through the aforementioned
COAs dated August 15, 2023 for Keystone and Conemaugh and August 17,
2023 for Seward, the new limits were effective immediately after the
date of each of the 2023 COAs. The EPA asserts that PADEP established
the emission limits as expeditiously as practicable to provide for
attainment in the Indiana, PA NAA and to remedy the EPA's 2022 partial
disapproval, and therefore the EPA proposes to find that Pennsylvania's
plan provides for RFP, based on the proposed determination that the
revised emissions limitations as defined under CAA section 302(k) are
necessary and appropriate to meet the applicable requirements of the
CAA, including the RFP requirement of CAA section 172(c)(2).
D. Contingency Measures
Section 172 of the CAA requires that attainment plans include
additional measures, called contingency measures, which will take
effect if an area fails to meet RFP or fails to attain the standard by
the attainment date. The EPA's 2014 SO2 Nonattainment
Guidance describes special features of SO2 planning that
influence the suitability of alternative means of addressing the
requirement in CAA section 172(c)(9) for contingency measures for
SO2. That is, SO2 control measures are based on
what is directly and quantifiably necessary to attain the
SO2 NAAQS, and consequently, an area that implements such
control measures would be unlikely to fail to attain the NAAQS.\17\
Therefore, an appropriate means of satisfying the contingency measures
requirement is for the state to have a comprehensive enforcement
program that identifies sources of violations of the SO2
NAAQS and for the state to undertake aggressive follow-up for
compliance and enforcement. Pennsylvania's plan provides for satisfying
the contingency measure requirement in this manner for the
nonattainment area. PADEP has a comprehensive compliance and
enforcement program to identify sources of violations of the 2010 1-
hour SO2 NAAQS and can undertake aggressive follow-up for
compliance and enforcement including the ability to enact a COA in a
timely manner (section 4(27) of the Pennsylvania Air Pollution Control
Act, 35 P.S. section 4004(27)). The EPA is proposing to approve the
emissions limits from the 2023 SIP submittal as enforceable limitations
under CAA section 302(k) which are necessary and appropriate to provide
for attainment of the standard in the Indiana, PA NAA and meet the
requirements of the CAA, including sections 110(a)(2)(A), 172(c)(1),
172(c)(2), and 172(c)(6). Consequently, the EPA is proposing to find
that PA's comprehensive enforcement program for such necessary and
appropriate emission limitations is an appropriate contingency measure
for this area and meets the requirement of CAA section 172(c)(9).
---------------------------------------------------------------------------
\17\ See 75 FR 35520 at 35576 (June 22, 2010) and the 2014
SO2 Nonattainment Guidance.
---------------------------------------------------------------------------
III. Proposed Action
The EPA is proposing to approve Pennsylvania's SIP revision
submitted to the EPA on October 5, 2023, for the purpose of attaining
the 2010 1-hour SO2 NAAQS for the Indiana, PA NAA.
Specifically, the EPA is proposing to approve the following elements of
this SO2 attainment plan: Pennsylvania's attainment
demonstration for the nonattainment area, RACT/RACM and emission
limitations, RFP plan, and contingency measures. The EPA previously
approved Pennsylvania's attainment plan requirements regarding
nonattainment area Emissions Inventory and NNSR.
The EPA is proposing to conclude that the modeling and comparably
stringent longer-term emission limits in Pennsylvania's plan adequately
demonstrate that the control requirements in the COAs provide for
attainment in the area. This attainment plan also properly addresses
requirements for RACT/RACM and emission limitations, RFP, and
contingency measures because the plan now includes emission limits that
provide for attainment. Thus, the EPA is proposing to determine that
Pennsylvania's Indiana Area SO2 attainment plan meets the
applicable requirements of CAA sections 172, 191, and 192. The EPA is
taking public comments for thirty days following the publication of
this proposed action in the Federal Register. The EPA will take these
comments into consideration in our final action.
IV. Incorporation by Reference
In accordance with requirements of 1 CFR 51.5, the EPA is proposing
to incorporate by reference the SO2 emission limits and
compliance parameters established in (the unredacted portions of) the
COAs for Seward, Conemaugh and Keystone facilities as discussed in
section II. of this document. The EPA has made, and will continue to
make, these materials generally available through https://www.regulations.gov and at the EPA Region III Office (please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section of
this preamble for more information).
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, the 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 proposed 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); and
[[Page 48532]]
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 Clean Air Act.
Executive Order 12898 (Federal Actions to Address Environmental
Justice in Minority Populations and Low-Income Populations, 59 FR 7629,
February 16, 1994) directs Federal agencies to identify and address
``disproportionately high and adverse human health or environmental
effects'' of their actions on minority populations and low-income
populations to the greatest extent practicable and permitted by law.
The EPA defines environmental justice (EJ) as ``the fair treatment and
meaningful involvement of all people regardless of race, color,
national origin, or income with respect to the development,
implementation, and enforcement of environmental laws, regulations, and
policies.'' The EPA further defines the term fair treatment to mean
that ``no group of people should bear a disproportionate burden of
environmental harms and risks, including those resulting from the
negative environmental consequences of industrial, governmental, and
commercial operations or programs and policies.'' PADEP did not
evaluate environmental justice considerations as part of its SIP
submittal; the CAA and applicable implementing regulations neither
prohibit nor require such an evaluation. The EPA did not perform an EJ
analysis and did not consider EJ in this action. Due to the nature of
the action being taken here, this action is expected to have a neutral
to positive impact on the air quality of the affected area.
Consideration of EJ is not required as part of this action, and there
is no information in the record inconsistent with the stated goal of
E.O. 12898 of achieving environmental justice for people of color, low-
income populations, and Indigenous peoples.
In addition, this proposed rulemaking, approval of Pennsylvania's
Indiana Area SO2 attainment plan, does not have tribal
implications as specified by Executive Order 13175 (65 FR 67249,
November 9, 2000), because the SIP is not approved to apply in Indian
country located in the State, and EPA notes that it will not impose
substantial direct costs on tribal governments or preempt tribal law.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Reporting and recordkeeping
requirements, Sulfur oxides.
Adam Ortiz,
Regional Administrator, Region III.
[FR Doc. 2024-11175 Filed 6-6-24; 8:45 am]
BILLING CODE 6560-50-P