Document ID: EPA-R03-OAR-2017-0681-0018
Agency: epa
Document Type: Rule
Title: Air Quality State Implementation Plans; Approval and Promulgation: Pennsylvania; Attainment Plan for the Beaver, Pennsylvania Nonattainment Area for the 2010 Sulfur Dioxide Primary National Ambient Air Quality Standard
Posted Date: 2019-10-01T04:00Z

[Federal Register Volume 84, Number 190 (Tuesday, October 1, 2019)]
[Rules and Regulations]
[Pages 51988-52001]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-20848]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R03-OAR-2017-0681; FRL-10000-28-Region 3]

Approval and Promulgation of Air Quality Implementation Plans; 
Pennsylvania; Attainment Plan for the Beaver, Pennsylvania 
Nonattainment Area for the 2010 Sulfur Dioxide Primary National Ambient 
Air Quality Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is approving a state 
implementation plan (SIP) revision submitted by the Commonwealth of 
Pennsylvania. The revision is an attainment plan for the purpose of 
providing for attainment of the 2010 sulfur dioxide (SO2) 
primary national ambient air quality standard (NAAQS) in the Beaver 
County, Pennsylvania SO2 nonattainment area (hereafter 
referred to as the ``Beaver Area'' or ``Area''). The attainment plan 
includes the base year emissions inventory, an analysis of the 
reasonably available control technology (RACT) and reasonably available 
control measure (RACM) requirements, a reasonable further progress 
(RFP) plan, a modeling demonstration of SO2 attainment, 
enforceable emission limitations and control measures, contingency 
measures for the Beaver Area, and Pennsylvania's new source review 
(NSR) permitting program. As part of approving the attainment plan, EPA 
is approving into the Pennsylvania SIP new SO2 emission 
limits and associated compliance parameters for the FirstEnergy 
Generation, LLC (FirstEnergy) Bruce Mansfield Power Station (Bruce 
Mansfield) and a consent order with Jewel Acquisition Midland steel 
plant (Jewel Facility). EPA is approving these revisions that 
demonstrate attainment of the SO2 NAAQS in the Beaver Area 
in accordance with the requirements of the Clean Air Act (CAA).

DATES: This final rule is effective on October 31, 2019.

[[Page 51989]]

ADDRESSES: EPA has established a docket for this action under Docket ID 
Number EPA-R03-OAR-2017-0681. All documents in the docket are listed on 
the https://www.regulations.gov website. Although listed in the index, 
some information is not publicly available, e.g., confidential business 
information (CBI) or other information whose disclosure is restricted 
by statute. Certain other material, such as copyrighted material, is 
not placed on the internet and will be publicly available only in hard 
copy form. Publicly available docket materials are available through 
https://www.regulations.gov, or please contact the person identified in 
the FOR FURTHER INFORMATION CONTACT section for additional availability 
information.

FOR FURTHER INFORMATION CONTACT: Megan Goold, Planning & Implementation 
Branch (3AD30), Air & Radiation Division, U.S. Environmental Protection 
Agency, Region III, 1650 Arch Street, Philadelphia, Pennsylvania 19103. 
The telephone number is (215) 814-2027. Ms. Goold can also be reached 
via electronic mail at goold.megan@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. Background

    On June 2, 2010, the EPA Administrator signed a final rule 
establishing a new SO2 primary NAAQS as a 1-hour standard of 
75 parts per billion (ppb), based on a 3-year average of the annual 
99th percentile of daily maximum 1-hour average concentrations. See 75 
FR 35520 (June 22, 2010), codified at 40 CFR 50.17. This action also 
provided for revocation of the existing 1971 primary annual and 24-hour 
standards, subject to certain conditions.\1\ Following promulgation of 
a new or revised NAAQS, EPA is required by the CAA to designate areas 
throughout the United States as attaining or not attaining the NAAQS; 
this designation process is described in section 107(d)(1)-(2) of the 
CAA. On August 5, 2013, EPA promulgated initial air quality 
designations for 29 areas for the 2010 SO2 NAAQS (78 FR 
47191), which became effective on October 4, 2013, based on violating 
air quality monitoring data for calendar years 2009-2011, where there 
were sufficient data to support a nonattainment designation.\2\
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    \1\ EPA's June 22, 2010, final action provided for revocation of 
the 1971 primary 24-hour standard of 140 ppb and the annual standard 
of 30 ppb because they were determined not to add additional public 
health protection given a 1-hour standard at 75 ppb. See 75 FR 
35520. However, the secondary 3-hour SO2 standard was 
retained. Currently, the 24-hour and annual standards are only 
revoked for certain of those areas the EPA has already designated 
for the 2010 1-hour SO2 NAAQS. See 40 CFR 50.4(e).
    \2\ EPA is continuing its designation efforts for the 2010 
SO2 NAAQS. Pursuant to a court-order entered on March 2, 
2015, by the U.S. District Court for the Northern District of 
California, EPA must complete the remaining designations for the 
rest of the country on a schedule that contains three specific 
deadlines. Sierra Club, et al. v. Environmental Protection Agency, 
13-cv-03953-SI (N.D. Cal. 2015).
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    Effective on October 4, 2013, the Beaver Area was designated as 
nonattainment for the 2010 SO2 NAAQS for an area that 
encompasses the primary SO2 emitting source Bruce Mansfield 
and the nearby SO2 monitor (Air Quality Site ID: 42-007-
0005). The final designation triggered a requirement for Pennsylvania 
to submit a SIP revision with an attainment plan for how the Area would 
attain the 2010 SO2 NAAQS as expeditiously as practicable, 
but no later than October 4, 2018, in accordance with CAA section 
192(a).
    For a number of areas, including the Beaver Area, EPA published a 
document on March 18, 2016, effective April 18, 2016, that Pennsylvania 
and other pertinent states had failed to submit the required 
SO2 attainment plan by this submittal deadline. See 81 FR 
14736. This finding initiated a deadline under CAA section 179(a) for 
the potential imposition of new source review and highway funding 
sanctions. However, pursuant to Pennsylvania's submittal of September 
29, 2017, and EPA's subsequent letter dated October 5, 2017 to 
Pennsylvania finding the submittal complete and noting the stopping of 
the sanctions clock, these sanctions under section 179(a) will not be 
imposed as a consequence of Pennsylvania's having missed the SIP 
submission deadline. Additionally, under CAA section 110(c), the March 
18, 2016 finding triggered a requirement that 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 EPA has approved the submittal as meeting applicable 
requirements. This FIP obligation will not apply as a result of this 
action to finalize this SIP approval.
    Attainment plans for SO2 must meet the applicable 
requirements of the CAA, and specifically, CAA sections 110, 172, 191, 
and 192. The required components of an attainment plan submittal are 
listed in section 172(c) of Title I, part D of the CAA, and in EPA's 
implementing regulations at 40 CFR part 51. On April 23, 2014, EPA 
issued guidance (hereafter 2014 SO2 Nonattainment Guidance) 
recommending how state submissions could address the statutory 
requirements for SO2 attainment plans.\3\ In this guidance, 
EPA described the statutory requirements for an attainment plan, which 
include: An accurate base year emissions inventory, of current 
emissions, for all sources of SO2 within the nonattainment 
area (172(c)(3)); an attainment demonstration that includes a modeling 
analysis showing that the enforceable emissions limitations and other 
control measures taken by the state will provide for expeditious 
attainment of the NAAQS (172(c)); demonstration of RFP (172(c)(2)); 
implementation of RACM, including RACT (172(c)(1)); Nonattainment NSR 
requirements (172(c)(5)); and adequate contingency measures for the 
affected area (172(c)(9)).
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    \3\ See ``Guidance for 1-Hour SO2 Nonattainment Area 
SIP Submissions'' (April 23, 2014), available at https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
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II. Summary of SIP Revision and EPA Analysis

    In accordance with section 172(c) of the CAA, the Pennsylvania 
attainment plan for the Beaver Area includes: (1) An emissions 
inventory for SO2 for the plan's base year (2011); and (2) 
an attainment demonstration. The formal SIP revision was submitted by 
Pennsylvania on September 29, 2017. The attainment demonstration 
includes the following: Analyses that locate, identify, and quantify 
sources of emissions contributing to violations of the 2010 
SO2 NAAQS; a determination that the control strategy for the 
primary SO2 source within the nonattainment area constitutes 
RACM/RACT; a dispersion modeling analysis of an emissions control 
strategy for the primary SO2 source (Bruce Mansfield), 
showing attainment of the SO2 NAAQS by the October 4, 2018 
attainment date; requirements for RFP toward attaining the 
SO2 NAAQS in the Area; contingency measures; the assertion 
that Pennsylvania's existing SIP-approved NSR program meets the 
applicable requirements for SO2; and the request that 
emission limitations and compliance parameters for Bruce Mansfield be 
incorporated into the SIP. On October 5, 2018 (83 FR 50314), EPA 
published a notice of proposed rulemaking (NPRM) for the Commonwealth 
of Pennsylvania. In the NPRM, EPA proposed approval of the attainment 
plan for the Beaver Area for the 2010 SO2 NAAQS. Comments on 
EPA's proposed rulemaking were due on or before November 5, 2018.
    Other specific requirements of the Beaver Area attainment plan and 
the

[[Page 51990]]

rationale for EPA's proposed action are explained in the NPRM and will 
not be restated here. This final action incorporates the rationale 
provided in the NPRM, except to the extent necessary to reflect any 
changes in the rationale in response to the public comments. Multiple 
comments on the NPRM were received from one entity. Several of the 
comments had various points and are addressed point by point by EPA. To 
review the full set of comments received, refer to the Docket for this 
rulemaking, as identified above. A summary of the comments received and 
EPA's responses are provided below.
    Comment 1. The commenter asserts that considering FirstEnergy's 
announcement that the Bruce Mansfield Plant will retire in 2021, the 
proper path forward is for the Pennsylvania Department of Environmental 
Protection (PADEP) to incorporate that retirement into the SIP and set 
emission limits for the plant of zero.
    Response 1. EPA disagrees with the commenter that PADEP needs to 
revise their SIP submission to incorporate the retirement of Bruce 
Mansfield. The Commonwealth of Pennsylvania correctly submitted a 
complete attainment plan SIP on September 29, 2017, and EPA is 
finalizing approval of that submittal with this action. The Beaver Area 
Attainment Plan includes modeling using the Bruce Mansfield critical 
emissions values (CEVs) and operational restrictions for other 
SO2 sources in the area that demonstrates attainment of the 
1-hour SO2 NAAQS. PADEP developed comparably stringent 30-
day emissions limits for Bruce Mansfield based on the modeled CEVs. The 
attainment plan meets the requirements of CAA Section 172(c) as 
submitted, and there is no need to amend the plan to incorporate the 
planned shutdown of Bruce Mansfield. In addition to the planned 
shutdown which the commenter mentioned, EPA is aware that Units 1 and 2 
of the Bruce Mansfield Plant have been listed on PJM's (Pennsylvania 
New Jersey Maryland Interconnection LLC) deactivation list as of 
February 5, 2019 (which was after the public comment period for this 
action); nevertheless, EPA continues to assert that even though Bruce 
Mansfield Units 1 and 2 are already deactivated, the SIP does not need 
to be amended. The permits for these units have not been retired, and, 
thus, the units are still permitted to emit SO2 to the 
allowable emission limit. The emission limits and operational 
restrictions being incorporated into the SIP in this action are still 
in effect, and still provide for attainment of the 1-hour 
SO2 NAAQS, as the attainment modeling demonstrated.
    Comment 2. The commenter claims that EPA has failed to issue a FIP 
or impose sanctions against the state for not having a Federally 
enforceable SIP that demonstrates how the Beaver Area will reach 
attainment by the statutorily required compliance deadline of October 
4, 2018. The commenter asserts that it is unclear how the SIP can meet 
this now passed compliance deadline when the limits proposed in the 
Pennsylvania submission are not presently Federally enforceable.
    Response 2. EPA disagrees with the commenter that sanctions should 
have been applied in this case because, as discussed in the NPRM, the 
sanctions clock was turned off when EPA determined a complete SIP was 
submitted as stipulated in CAA 179(a). See also 40 CFR 52.31(d)(5), 
which provides that a sanctions clock started by a finding of failure 
to submit a required SIP will be permanently stopped upon a final 
finding that the deficiency forming the basis of the finding of failure 
to submit has been corrected, and that in such a case a letter from EPA 
to the State would be how EPA issues a finding that the deficiency has 
been corrected.
    EPA agrees with the commenter that the approval of this SIP did not 
occur before the October 4, 2018 deadline for NAAQS attainment. 
However, EPA disagrees that the proposed emission limits at Bruce 
Mansfield and operational restrictions at the Jewel Facility in the 
SIP, which have been in effect and enforceable at the state level since 
October 1, 2018, and September 21, 2017, respectively, have not brought 
the SO2 concentrations in the area under the 75-ppb standard 
by the applicable deadline. Supporting evidence of timely attainment is 
available from the most recent SO2 concentrations at the 
Brighton Township monitor (AQS 42-007-0005) in the nonattainment area 
being well below the 75-ppb standard. Specifically, the 99th percentile 
of the 1-hour maximum SO2 concentrations at the (previously 
violating) Brighton Township monitor was 18 ppb in 2018, and the most 
recent design value (3-year average of the annual 99th percentile of 1-
hour daily maximum concentrations using 2016-2018 data) was 22 ppb.\4\
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    \4\ The Brighton Township monitor was the highest violating 
monitor in Beaver County in 2011 when the area was designated 
nonattainment. The 2009-2011 Design Value (3-year average of the 
annual 99th percentile of 1-hour daily maximum concentrations) was 
158 ppb, and the 2008-2010 design value was 167 ppb.
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    EPA also disagrees with the apparent view of the commenter that 
because EPA did not approve, and thereby make Federally enforceable, 
the Commonwealth's emission limits before the October 4, 2018 
attainment deadline, Pennsylvania's plan itself is somehow no longer 
approvable and EPA cannot thereafter approve the emissions limits and 
make them Federally enforceable. Such a view cannot be correct, as 
adopting it would preclude EPA from ever being able to approve a SIP 
that has fully adequate emissions limits that reduce emissions 
concentrations to attaining levels merely due to EPA's timing of 
action, rather than based on the technical merits of the SIP, and force 
EPA to possibly adopt in a FIP the exact same emissions limits but on 
an even more belated schedule. Such a result is not compelled by the 
CAA, and would offend the value of cooperative federalism reflected in 
the Act. In addition, EPA believes its obligation is to evaluate the 
state's plan, and to evaluate whether the state has established timely 
obligations for pertinent sources, without regard to the timing by 
which the state enforceable obligations become Federally enforceable.
    In any case, EPA has proposed approval, and with this action, 
finalizes approval of the Beaver, PA attainment plan, which makes 
Federally enforceable the 30-day average SO2 limits at Bruce 
Mansfield and operational restrictions at the Jewel Facility. The 30-
day average SO2 limits for Bruce Mansfield were developed 
using procedures recommended in EPA's 2014 SO2 Nonattainment 
Area Guidance and are a comparably stringent substitute for a 1-hour 
limit at the modeled CEV. The CEV for Bruce Mansfield and the 
operational restrictions for the Jewel Facility were modeled as 
resulting in attainment of the NAAQS, Bruce Mansfield is complying with 
the comparably stringent 30-day limits, Jewel is complying with the 
operational restrictions, and the limits have been enforceable 
Pennsylvania since October 1, 2018 for Bruce Mansfield, and since 
September 21, 2017 for the Jewel Facility.
    In regard to EPA's failure to issue a FIP, EPA believes that the 
most expeditious way to bring this area into attainment and maintain 
attainment is to approve the submitted SIP with the limits and 
restrictions adopted by the Commonwealth, making those limits and 
restrictions Federally enforceable. Also, any FIP for this area would 
likely mirror what Pennsylvania has proposed in the SIP, so approval of 
the SIP is likely just as effective and a more efficient way to ensure 
that the limits

[[Page 51991]]

and other elements of the SIP become Federally enforceable. Thus, it is 
reasonable to conclude that the most expeditious approach to having a 
Federally enforceable plan to bring the area into attainment and keep 
it in attainment is to approve this SIP, and not issue a FIP.
    Comment 3. The commenter asserts that the 30-day average emission 
limits in the Proposal for Bruce Mansfield are fundamentally incapable 
of protecting a 1-hour standard. The commenter provided two references 
to EPA documents where EPA states that averaging periods for emissions 
limits should be consistent with the NAAQS averaging time periods.\5\
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    \5\ EPA Region 7 Comments re: Sunflower Holcomb Station 
Expansion Project 4 (August 12, 2010); EPA Region 5 comments re: 
Monroe Power Plant Construction Permit 1 (February 1, 2012).
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    Response 3. EPA disagrees with the commenter's statement that the 
proposed 30-day limit is fundamentally incapable of protecting the 1-
hour NAAQS. EPA believes as a general matter that properly set, longer 
term average limits are comparably effective in providing for 
attainment of the 1-hour SO2 standard as 1-hour limits. 
EPA's 2014 SO2 Nonattainment Area Guidance sets forth in 
detail the reasoning supporting its view that the distribution of 
emissions that can be expected in compliance with a properly set longer 
term average limit is likely to yield comparable overall air quality 
than constant hourly emissions set at a level that provides for 
attainment. See 2014 SO2 Nonattainment Guidance, including 
Appendix B. This reasoning is also expressed in detail in the NPRM for 
this action.
    At the outset, EPA notes that the specific examples of earlier EPA 
statements cited by the commenter (i.e., those contained in Exhibits 1 
and 2 to Appendix A of the comment submission) pre-date the release of 
EPA's 2014 SO2 Nonattainment Area Guidance. As such, these 
examples only reflect the Agency's development of its policy for 
implementing the 2010 SO2 NAAQS as of the dates of the 
issuance of the statements. At the time these statements were issued, 
EPA had not yet addressed the specific question of whether it might be 
possible to devise an emission limit with an averaging period longer 
than 1-hour, with appropriate adjustments that would make it comparably 
stringent to an emission limit shown to attain 1-hour emission levels, 
that could adequately ensure attainment of the SO2 NAAQS. 
None of the pre-2014 EPA documents cited by the commenter address this 
question; consequently, it is not reasonable to read any of them as 
rejecting that possibility.
    In contrast, EPA's 2014 SO2 Nonattainment Area Guidance 
specifically addressed this issue as it pertains to requirements for 
SIPs for SO2 nonattainment areas under the 2010 NAAQS, 
especially with regard to the use of appropriately set comparably 
stringent limitations based on averaging times as long as 30 days. EPA 
found that a longer term average limit which is comparably stringent to 
a short-term average limit is likely to yield comparable air quality; 
and that the net effect of allowing emissions variability over time but 
requiring a lower average emission level is that the resulting worst-
case air quality is likely to be comparable to the worst-case air 
quality resulting from the corresponding higher constant short-term 
average emission limit. See 2014 SO2 Nonattainment Guidance.
    Any accounting of whether a 30-day average limit provides for 
attainment must consider factors reducing the likelihood of 1-hour 
average concentrations that exceed the NAAQS level as well as factors 
creating a risk of additional concentrations that exceed the NAAQS 
level. To facilitate this analysis, EPA used the concept of a CEV for 
the SO2-emitting facilities which are being addressed in a 
nonattainment SIP. The CEV is the continuous 1-hour emission rate which 
is expected to result in the 3-year average of annual 99th percentile 
daily maximum 1-hour average concentrations being at or below 75 ppb, 
which in a typical year means that fewer than four days have maximum 
hourly ambient SO2 concentrations exceeding 75 ppb. See 2014 
SO2 Nonattainment Guidance, Appendix B.
    EPA recognizes that a 30-day limit can allow occasions in which 
emissions exceed the CEV, and such occasions yield the possibility of 
concentrations exceeding the NAAQS level that would not be expected if 
emissions were always at the CEV. At the same time, the establishment 
of the 30-day average limit at a level below the CEV means that 
emissions must routinely be lower than they would be required to be 
with a 1-hour emission limit set at the CEV. On those critical modeled 
days in which emissions at the CEV are expected to result in 
concentrations exceeding 75 ppb, emissions set to comply with a 30-day 
average level which is below the CEV may well result in concentrations 
below 75 ppb. Requiring emissions on average to be below the CEV 
introduces significant chances that emissions will be below the CEV on 
critical days, so that such a requirement creates significant chances 
that air quality would be better than 75 ppb on days that, with 
emissions at the CEV, concentrations would have exceeded 75 ppb.
    The NPRM for this area provides an illustrative example of the 
effect that application of a limit with an averaging time longer than 1 
hour can have on air quality. This example illustrates both (1) the 
possibility of elevated emissions (emissions above the CEV) causing 
concentrations exceeding the NAAQS level not expected with emissions at 
or below the CEV and (2) the possibility that the requirement for 
routinely lower emissions would result in avoiding concentrations 
exceeding 75 ppb that would be expected with emissions at the CEV. In 
this example, moving from a 1-hour limit to a 30-day average limit 
results in one day that exceeds 75 ppb that would otherwise be below 75 
ppb, one day that is below 75 ppb that would otherwise be above 75 ppb, 
and one day that is below 75 ppb that would otherwise be at 75 ppb. In 
net, the 99th percentile of the 30-day average limit scenario is lower 
than that of the 1-hour limit scenario, with a design value of 67.5 ppb 
rather than 75 ppb. Stated more generally, this example illustrates 
several points: (1) The variations in emissions that are accounted for 
with a longer term average limit can yield higher concentrations on 
some days and lower concentrations on other days, as determined by the 
factors influencing dispersion on each day, (2) one must account for 
both possibilities, and (3) accounting for both effects can yield the 
conclusion that a properly set longer term average limit can provide as 
good or better air quality than allowing constant emissions at a higher 
level. The commenter has not disputed this rationale that longer term 
limits can suitably provide for attainment, and thus EPA continues to 
assert that appropriately set 30-day emission limits can be protective 
of the 1-hour SO2 standard.
    Comment 3a. The commenter states that the Bruce Mansfield 30-day 
average emission limits are 720 times the standard, and they would do 
nothing to change Bruce Mansfield's current behavior. The commenter 
provided data from the last four years of publicly available emissions 
data for the facility and notes that the proposed 30-day average 
emission limits for Units 1 and 2 combined, and for Unit 3, 
respectively, are far higher than actual historical emissions. The 
commenter also provided hourly emissions data from Bruce Mansfield 
Units 1 and 2 combined from June 1, 2013 to May 30,

[[Page 51992]]

2017 \6\ and states that during this time period, there are 101 hours 
in which emissions from Units 1 and 2 exceed the hourly limit. The 
commenter further asserts that using their 30-day average analysis, 
Bruce Mansfield would have been in ``compliance'' with the proposed 30-
day emission limits during this time period. In the commenter's view, 
given that exceedances of the NAAQS can occur if as few as four hours 
over the course of a year are above the 75-ppb threshold, the commenter 
states that it is impossible that the proposed 30-day limit will 
protect the standard.
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    \6\ The Appendix B spreadsheet submitted with this comment shows 
the data analysis for the hourly emissions at Bruce Mansfield Units 
1 and 2 was for the time period June 1, 2013 through June 30, 2017. 
However, the text of the comment states the analysis was completed 
for emissions from June 1, 2013 to May 30, 2017.
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    Response 3a. EPA disagrees with the commenter that the 30-day 
average emission limits are 720 times the standard. The averaging 
period for the emissions limit is 30 days, or 720 hours, which is 720 
times the length of the averaging time of the standard. The 30-day 
emission limits are not 720 times the 1-hour CEV, and the resulting 
concentrations are not 720 times the NAAQS (75 ppb). More importantly, 
this comment does not include a rationale that a limit with this 
averaging time necessarily fails to assure attainment.
    The SO2 emissions and SO2 concentrations have 
significantly declined in the Beaver Area. As described in the NPRM for 
this action, two facilities within the nonattainment area have 
permanently shut down--AES Beaver, a coal fired power plant, shut down 
in 2015, and Horsehead Monaca, a zinc smelter, shut down in 2014. In 
addition, the Jewel Facility, a steel mill, has entered into a Consent 
Order and Agreement (COA) with PADEP to prohibit operation of the 
Meltshop (the primary source of sulfur dioxide). The closure of two 
facilities and the operational restrictions on a third facility have 
provided SO2 emission reductions, and a significant portion 
of these reductions are enforceable pursuant to Pennsylvania's plan. 
These reduced allowable emissions, along with the allowable emissions 
at Bruce Mansfield, have been modeled in accordance with Appendix W to 
40 CFR part 51 and the EPA's 2014 SO2 Nonattainment Area 
Guidance and demonstrate that the area will attain the standard by its 
attainment date. PADEP developed a comparably stringent 30-day average 
emission limit for Bruce Mansfield using the modeled emission levels as 
a starting point and adjusted downward, in accordance with procedures 
recommended in EPA's SO2 Nonattainment Area Guidance. In 
response 3 above and in EPA's 2014 SO2 Nonattainment Area 
Guidance, EPA has explained at length its reasoning that a comparably 
stringent 30-day average limit is a suitable substitute for a 1-hour 
limit at the CEV in providing for attainment.
    Furthermore, although the focus of this rulemaking is on whether 
the plan has limits that assure attainment, it is worth noting that 
significant emission reductions have also occurred and will occur in 
the future at Bruce Mansfield. Compared to emissions for 2010 to 2012 
(the period of the air quality data that resulted in this area being 
designated nonattainment), when emissions from Bruce Mansfield averaged 
20,700 tons per year, emissions for 2017 to 2018 averaged 7,000 tons 
per year. As stated in the attainment plan, in order to comply with the 
new limit, Bruce Mansfield planned to make operational and physical 
changes prior to October 2018 to ensure compliance with the new limits 
(Appendix E-1, p. 7). Also, although shutdowns at Bruce Mansfield are 
beyond the planning horizon of the SIP and are not part of the SIP, the 
shutdown of this full facility that is slated for 2021 provides further 
confidence that the area will continue to attain the standard.
    Therefore, EPA continues to believe that the emission limits at 
Bruce Mansfield, in concert with the shutdown of AES Beaver and 
Horsehead Monaca, and operating restrictions on the Jewel plant, 
provide the SO2 emission reductions required to demonstrate 
attainment. EPA notes that attainment is not solely dependent on 
reducing emissions or changing the operations at Bruce Mansfield, but 
on all the SO2 emission reductions that have occurred and 
were modeled in the nonattainment area.
    Furthermore, EPA disagrees with the commenter's premise that the 
existence of hours with emissions exceeding modeled attainment levels 
despite compliance with the 30-day average limit necessarily means that 
the 30-day limit is not protective of the NAAQS. (The commenter claims 
the existence of 101 hours from mid-2013 to mid-2017 when the emissions 
from Units 1 and 2 exceeded the ``hourly limit'' despite being in 
compliance with the 30-day limit. In fact, there is no hourly limit; as 
discussed further below, the commenter identified an equation, based on 
Pennsylvania's simulations of attainment level emissions, for 
characterizing the range of combinations of hourly Unit 1, Unit 2, and 
Unit 3 emissions that would model attainment, and found that 101 hours 
had emissions exceeding those levels.) Indeed, the NPRM provides an 
extensive discussion of EPA's rationale for believing that a 30-day 
average limit, which creates risk of occasions of emissions exceeding 
the CEV but also creates a compensating likelihood that the mandate for 
lower average emissions will avert some of the exceedances that would 
be allowed with a higher 1-hour average limit, will have the net effect 
of assuring attainment.
    However, the commenter does not address EPA's full rationale for 
concluding that properly set 30-day average limits are a suitable basis 
for providing for attainment of the 1-hour SO2 standard. 
Instead, the commenter merely notes that there were 101 hours when the 
emissions from Unit 1 and 2 exceeded attainment levels (which is 0.36 
percent of the operating hours that the commenter examined) but fails 
to address the effect of the adjusted 30-day average limit requiring 
emissions to be well below critical emission levels, namely avoiding 
some exceedances that would be expected to occur with emissions allowed 
always to be at the CEV. Consequently, the commenter does not 
acknowledge or address the occasions in which the longer term limit 
provides better air quality, which is a key element of EPA's rationale 
for concluding that the net effect of limiting longer term average 
emissions to a downward adjusted level can be comparably effective in 
providing for attainment as limiting 1-hour emissions to the level of 
the CEV. Because the pertinent question is whether Pennsylvania's plan 
provides for attainment, EPA must address the net effect of applying a 
long-term average, not just considering those factors that increase the 
likelihood of exceedances or just considering those factors that reduce 
the likelihood of exceedances.
    At issue here is how often emissions from Bruce Mansfield, upon 
compliance with Pennsylvania's 30-day average limits, might be expected 
to have hourly emission rates above the level modeled to result in 
attainment. Ordinarily, a single model run establishes upper bound 
hourly emission rates at which the area attains the standard; EPA calls 
these hourly emission rates CEVs. However, in this case, Pennsylvania 
conducted numerous runs reflecting the combined effect of emissions 
from the three units (two stacks) at Bruce Mansfield. These model runs 
were used to determine the relationship between emissions from Stacks 1 
and 2 which would result in attainment.

[[Page 51993]]

    Therefore, to determine the historic frequency of excess emission 
events, a more complicated analysis is warranted. Part of such analysis 
should be to establish criteria for defining excess emission events, 
i.e., hours when emissions exceed the level demonstrated in the state's 
plan to provide for attainment. Ordinarily, excess emission events may 
be defined simply as hours when emissions exceed the CEV. However, in 
this case, Pennsylvania has defined attainment level emissions in 
significant part as an interactive function of the emissions of both 
stacks at Bruce Mansfield. In particular, using the results of 17 
modeling runs reflecting a range of combinations of emissions from 
Bruce Mansfield Stack 1 and Stack 2, the Commonwealth determined an 
equation defining the range of combinations of 1-hour emissions that 
provide for attainment, as indicated in their correction email dated 6/
11/18 which was included in the docket for this action, and discussed 
in the NPRM. The equation contains a critical value, which is the 
equation result (applying the equation to Stack 1 and Stack 2 
emissions) that is considered to correspond to the sets of 1-hour 
emission rates that Pennsylvania modeled as providing attainment. EPA 
will call this critical value the critical formula value (CFV), and 
will call the analysis to determine how many exceedance events over the 
CFV occurred, the CFV exceedance analysis.
    The commenter developed a different CFV, based on a different 
equation (again based on the modeled combinations of Stack 1 and Stack 
2 emissions) to define the combinations of 1-hour emissions from these 
stacks that could be considered to yield attainment.
    Finally, EPA developed a third equation (with a third CFV), again 
designed around a graph of the emission values that modeled attainment 
from Stack 1 and Stack 2.
    These three equations (reflecting different order polynomials and 
having different CFVs) provide three different expressions of the 
maximum combinations of Stack 1 and Stack 2 emissions that may be 
considered to yield attainment, and thus provide three different means 
of assessing whether a particular historic combination of Stack 1 and 
Stack 2 emissions should be considered to be an excess emission event. 
These equations are presented in Pennsylvania's correction email, in 
the commenter's comment letter, and in EPA's technical support document 
(TSD) for this rulemaking, respectively.
    These three approaches all yielded similar results. Pennsylvania, 
examining data for 2012 to 2016, found that 219 hours out of 43,848 
hours, or 0.50 percent of hours, exceed Pennsylvania's CFV. (Dividing 
this 219 hours over the number of hours in which at least one unit is 
operating, 43,030 hours, suggests 0.51 percent of operating hours 
exceeded the CFV.) The commenter, examining data for mid-2013 to mid-
2017, found that 101 hours (which, out of 28,074 operating hours, is 
0.36 percent) exceeded the CFV. EPA, examining data for 2011 to 2017, 
found that 226 hours out of 56,503 operating hours, or 0.40 percent, 
constituted excess emission events, including 221 hours that exceeded 
the CFV and 5 hours in which Unit 3, operating alone, exceeded its CEV. 
Additional information regarding these three analyses are provided 
respectively in the submittal, the comment letter, and the TSD noted 
above.
    These results should be put in the context of whether the baseline 
periods for these analyses reflected compliance with Pennsylvania's 
emission limits and, if not, the frequency with which the facility 
exceeded these limits. Pennsylvania did not assess whether Bruce 
Mansfield met its adopted limits. The commenter did conduct this 
assessment and concluded that the facility met all three limits for all 
30-day average periods. However, EPA believes that the commenter 
analyzed these data incorrectly, using averaging procedures different 
from the procedures that Pennsylvania would use in assessing 
compliance.
    The COA that Pennsylvania adopted and submitted to govern emissions 
from Bruce Mansfield does not precisely define the data handling 
procedures that it would use in assessing compliance with the pertinent 
limits. However, Pennsylvania states, ``The 30-operating day rolling 
average SO2 emissions rate shall be calculated using the 
procedures outlined in the Mercury and Air Toxics Standards (MATS) 
regulations in 40 CFR parts 60 and 63.'' EPA interprets this statement 
to mean that compliance shall be assessed by calculating an average of 
the hourly emission rates applicable while the facility is operating. 
While the SO2 limit in MATS, which regulates mass of 
emissions per unit heat input, has a different form from Pennsylvania's 
limit, which regulates mass per hour, EPA interprets Pennsylvania to 
intend the same feature of conducting its compliance calculations in a 
manner that gives no weight to periods in which the unit(s) is not 
operating. (While these procedures may be a moot point if Bruce 
Mansfield does not resume operation, EPA's evaluation of the 
approvability of Pennsylvania's SIP necessitates review of whether the 
applicable limits provide for attainment should the facility restart.)
    The commenter computed 30-day averages by computing daily average 
emission rates (including only operating hour emission rates) and then 
by computing the unweighted average of these daily average values. This 
approach gives days with partial operation the same weight as days with 
24 hours of operation, and thus overweights the hours on the partial 
operation days.
    EPA then conducted its own evaluation of whether Bruce Mansfield 
was complying with the limits in Pennsylvania's SIP during the period 
being evaluated for excess emission events. In this evaluation, EPA 
examined data for 2011 to 2017.\7\ During this period, EPA concluded 
that Bruce Mansfield was in compliance with the prospective limits for 
Stack 1 (Units 1 and 2) and for Stack 2 (Unit 3) at all times but 
exceeded the formula limit for 16 out of 2116 averaging periods, or 
0.76 percent. Therefore, EPA believes that compliance with the limits 
in Pennsylvania's SIP will require Bruce Mansfield to have a slightly 
smaller fraction of hours exceeding the CFV than occurred in the 
historical record. EPA, Pennsylvania, and the commenter nevertheless 
agree that the frequency with which Bruce Mansfield could be expected 
to exceed the CFV (or either of the stack-specific CEVs) is less that 
0.6 percent of operating hours.
---------------------------------------------------------------------------

    \7\ Consistent with the characteristics of data handling in 
MATS, EPA interprets Pennsylvania's limits to reflect data handling 
in which compliance with these mass per hour limits is assessed by 
dividing total mass by total operating time, thereby giving hours 
with fractional operating time the appropriate fractional weight. 
For simplicity in this analysis, EPA gave the same weight to all 
hours with any operation, averaging the hourly mass values 
regardless of what portion of the hour was operational. However, EPA 
expects in this case that a more precise analysis would give similar 
results.
---------------------------------------------------------------------------

    However, EPA disagrees with the commenter on the air quality 
consequences of these occasions of elevated emissions. EPA believes 
that a full analysis of the air quality impact of Pennsylvania's limits 
must consider these hours of elevated emissions in conjunction with the 
far greater number of hours when emissions are required to be well 
below the level (on average, on the order of 20 to 30 percent below the 
level) that would model violations. For reasons described in more 
detail in EPA's guidance and in the NPRM for this action, EPA believes 
that the net effect of these compensating factors is that 
Pennsylvania's limits provide adequate assurance that the area will

[[Page 51994]]

attain the SO2 standard. EPA notes that the data used for 
these analyses were from time periods prior to the adoption of 30-day 
emission limits, prior to the requirement of 95% scrubber control 
efficiency, and prior to the operational and physical changes that were 
made to meet the new lower emission limits. Through the adoption of 
these new requirements, Bruce Mansfield will restrict the variability 
in emissions and will need to comply with new emission limits.
    After reviewing Pennsylvania's submittal, EPA finds that the limits 
established for Bruce Mansfield provide a suitable alternative to 
establishing 1-hour average emission limits for this source. Consistent 
with EPA guidance, EPA anticipates that, if Bruce Mansfield resumes 
operation and complies with Pennsylvania's limits, excess emission 
events will be sufficiently infrequent that compliance with the 30-day 
average limits will provide for attainment.
    Comment 3b. The commenter states that EPA suggests that because 
Bruce Mansfield has exceeded the polynomial-based emission limits on an 
hourly basis only ``0.50%'' of the time during 2012-2016, that the 30-
day limits are therefore adequately protective.\8\ However, the 
commenter asserts that EPA's reliance on FirstEnergy's math is 
misplaced and its reasoning is incorrect. First, FirstEnergy and EPA 
improperly compare the exceedances not to plant operating hours, but to 
the number of hours in the calendar. The commenter states that 
FirstEnergy and EPA significantly understate the significance of those 
nonoperating hours because there are thousands of hours in which one or 
another boiler at Bruce Mansfield was not operating, and nearly a 
thousand hours during the examined time period in which no boiler was 
operating. The commenter asserts that the 219 hours that FirstEnergy 
concedes Bruce Mansfield exceeded the polynomial hourly attainment 
level emissions is significant, given the commenter's view that the 
NAAQS can be violated with heightened emissions in as few as four hours 
a year over three years. Second, FirstEnergy's analysis only looks at 
times in which the emissions from Units 1 and 2 together exceed the 
polynomial function, and not at those times when emissions from Unit 3 
exceed the polynomial function. As such, the commenter states that the 
analysis only looks at a part of the story--there are numerous hours 
where emissions from Unit 3 all by itself are enough to mean that, even 
with their emission limits governed by the polynomial function, Units 1 
and 2 would need to emit negatively. As such, the commenter asserts 
that FirstEnergy and EPA are arbitrarily ignoring a significant aspect 
of the problem.
---------------------------------------------------------------------------

    \8\ The commenter misrepresented EPA's statement. The emission 
limits are expressed as 30-day average limits. As such, the limits 
cannot be exceeded on an hourly basis. The commenter presumably 
meant to refer to the frequency with which the facility exceeded the 
attainment level hourly emission values, computed by the state's 
unadjusted polynomial-based formula, which is the frequency that EPA 
described as being 0.50 percent.
---------------------------------------------------------------------------

    Response 3b. EPA agrees with the commenter regarding mistakes in 
FirstEnergy's math, but disagrees with the commenter regarding its 
claims that a 30-day limit cannot be protective of a 1-hour standard. 
EPA has addressed the latter issue above in Response 3a.
    Pennsylvania/FirstEnergy's CFV analysis contained two mistakes. 
FirstEnergy failed to only use plant operating hours in their CFV 
analysis. They also failed to count hours as exceeding the attainment 
emission level when the emissions from Unit 3 would have exceeded the 
limits on its own, thereby understating the number of hours in which 
that, if modeled as occurring constantly for every hour of the year, 
would be expected to estimate a violation. (The commenter describes 
hours with excessive emissions from Unit 3 as hours in which ``Units 1 
and 2 would need to emit negatively.'' EPA agrees that these hours when 
Unit 3 emits above its own CEV need to be counted as excess emissions 
hours for purposes of this analysis, but EPA believes that the 
pertinent issue is whether the plant emitted excessively, not whether 
the limits require impossible emission levels.) EPA addressed these 
mistakes in its analysis. In order to determine exceedance events in 
respect to the CFV, EPA kept all hours where Stack 1 (unit 1 and 2) and 
Stack 2 had emission values. EPA included these occurrences in the 
analysis because the formula applies when Stack 1 and Stack 2 are in 
service, and therefore, the analysis to determine how many times the 
formula was exceeded should include any hours when emissions were 
coming out of both stacks. As described above, EPA's CFV exceedance 
analysis shows that 0.4% of operating hours during 2011 through 2017 
constituted an excess emissions event.
    Consequently, EPA continues to have reasonable confidence that 
occasions with emissions above the CFV will be infrequent and limited 
in magnitude. EPA's revised CFV analysis is available in the docket for 
this action and is described in more detail in the TSD for this action. 
EPA provided a full rationale for comparably stringent longer term 
averages in Responses 3 and 3a above, concluding that the net effect of 
limiting longer term average emissions to a downward adjusted level can 
be comparably effective in providing for attainment as limiting 1-hour 
emissions to the level of the CEV.
    Comment 3c. The commenter asserts that Pennsylvania's contingency 
measures are limited and do not support Pennsylvania's claims that the 
measures will minimize further the chance of an exceedance. The 
commenter asserts that the contingency measures will require Bruce 
Mansfield to (1) audit their systems if the emissions become close to 
the emission limits and (2) require Bruce Mansfield to monitor their 
systems to ensure the facility does not cause a violation at the 
monitor. The commenter claims that number 1 above is what Bruce 
Mansfield ought to be doing anyway to ensure that they are in 
compliance with their permit limits, and number 2 incorrectly relies on 
one monitor when attainment should be reached throughout the 
nonattainment area.
    Response 3c. EPA disagrees with the commenter that the contingency 
measures are too limited and do not support Pennsylvania's claims that 
the measures will minimize further the chance of an exceedance. The CAA 
requires a Nonattainment SIP to model attainment throughout the 
nonattainment area. Section 172(c)(9) of the CAA defines contingency 
measures as such measures in a SIP that are to be implemented in the 
event that an area fails to make RFP, or fails to attain the NAAQS by 
the applicable attainment date. Contingency measures are to become 
effective without further action by the state or EPA, where the area 
has failed to (1) achieve RFP or, (2) attain the NAAQS by the statutory 
attainment date for the affected area. These control measures are to 
consist of other available control measures that are not included in 
the control strategy for the attainment plan SIP for the affected area. 
However, EPA has also explained that SO2 presents special 
considerations.\9\ First, for some of the other criteria pollutants, 
the analytical tools for quantifying the relationship between 
reductions in precursor emissions and resulting air quality 
improvements remains subject to

[[Page 51995]]

significant uncertainties, in contrast with procedures for directly-
emitted pollutants such as SO2. Second, emission estimates 
and attainment analyses for other criteria pollutants can be strongly 
influenced by overly optimistic assumptions about control efficiency 
and rates of compliance for many small sources. This is not the case 
for SO2.
---------------------------------------------------------------------------

    \9\ See SO2 Guideline Document, U.S. Environmental 
Protection Agency, Office of Air Quality Planning and Standards, 
Research Triangle Park, N.C. 27711, EPA-452/R-94-008, February 1994. 
See also EPA's 2014 SO2 Nonattainment Guidance. See 
General Preamble for the Implementation of Title I of the Clean Air 
Act Amendments of 1990 at 57 FR 13498 (April 16, 1992).
---------------------------------------------------------------------------

    In contrast, the control efficiencies for SO2 control 
measures are well understood and are far less prone to uncertainty. 
Because SO2 control measures are based on what is directly 
and quantifiably necessary to attain the SO2 NAAQS, it would 
be unlikely for an area to implement the necessary emission controls 
yet fail to attain the NAAQS. See 2014 SO2 Nonattainment 
Area Guidance, page 41. Therefore, for SO2 programs, EPA has 
explained that contingency measures can mean that the air agency has a 
comprehensive program to identify sources of violations of the 
SO2 NAAQS and to undertake an aggressive follow-up for 
compliance and enforcement, including expedited procedures for 
establishing enforceable consent agreements pending the adoption of the 
revised SIP. EPA believes that this approach continues to be valid for 
the implementation of contingency measures to address the 2010 
SO2 NAAQS, and consequently concludes that Pennsylvania's 
comprehensive enforcement program, as discussed below, satisfies the 
contingency measure requirement.
    This approach to contingency measures for SO2 does not 
preclude an air agency from requiring additional measures that are 
enforceable and appropriate for a particular source category if the 
state determines such supplementary measures are appropriate. As EPA 
has stated in our 2014 SO2 Nonattainment Area Guidance, in 
order for EPA to rely on these measures to approve the SIP, the 
supplementary contingency measures would need to be fully adopted 
provisions in the SIP that become effective where the area has failed 
to meet RFP or fails to attain the standard by the statutory attainment 
date. See 2014 SO2 Nonattainment Guidance, page 42.
    As noted in EPA's NPRM, EPA's 2014 SO2 Nonattainment 
Area Guidance describes special features of SO2 planning 
that influence the suitability of alternative means of addressing the 
requirement in section 172(c)(9) for contingency measures. One 
effective alternative means identified by the Guidance is a 
comprehensive enforcement program for sources emitting SO2. 
Pennsylvania has a comprehensive enforcement program as specified in 
Section 4(27) of the Pennsylvania Air Pollution Control Act (APCA), 35 
P.S. Sec.  4004(27). Under this program, PADEP is authorized to take 
any action it deems necessary or proper for the effective enforcement 
of the Act and the rules and regulations promulgated under the Act. 
Such actions include the issuance of orders (for example, enforcement 
orders and orders to take corrective action to address air pollution or 
the danger of air pollution from a source) and the assessment of civil 
penalties. Sections 9.1 and 10.1 of the APCA, 35 P.S. Sec. Sec.  4009.1 
and 4010.1, also expressly authorize PADEP to issue orders to aid in 
the enforcement of the APCA and to assess civil penalties.
    Any person in violation of the APCA, the rules and regulations, any 
order of PADEP, or a plan approval or operating permit conditions could 
also be subject to criminal fines upon conviction under Section 9, 35 
P.S. Sec.  4009. Section 7.1 of the APCA, 35 P.S. Sec.  4007.1, 
prohibits PADEP from issuing plan approvals and operating permits for 
any applicant, permittee, or a general partner, parent or subsidiary 
corporation of the applicant or the permittee that is placed on PADEP's 
Compliance Docket until the violations are corrected to the 
satisfaction of PADEP.
    In addition to having a fully approved enforcement program, 
Pennsylvania has included contingency measures that are triggered when 
a source's emissions reach a certain percentage of the allowable 
emissions and based on any monitor in the nonattainment area 
registering a 1-hour daily maximum concentration exceeding 75 ppb. 
These measures are in line with the supplemental contingency measure 
guidance EPA mentions above and are included in the FirstEnergy COA and 
the Jewel COA and thus will be fully approved provisions within the 
SIP.
    In regard to the monitoring contingency measure, the commenter 
erroneously confuses the requirement for Pennsylvania to plan for 
attainment in the entire Nonattainment area with the ability of the 
Commonwealth to use monitoring data from a single location as a trigger 
for a contingency measure. Pennsylvania has demonstrated attainment 
throughout the entire Beaver Nonattainment area through their modeling 
demonstration discussed previously. Using monitoring data to trigger 
supplemental contingency measures is a defensible approach for helping 
achieve attainment throughout the area in cases where the plan has 
unexpectedly not achieved attainment.
    EPA concludes that Pennsylvania's enforcement program by itself 
suffices to satisfy the contingency measure requirements. The magnitude 
of prospective benefit from Pennsylvania's supplemental contingency 
measures is unclear, but it is clear that these measures can only 
improve and will not worsen air quality. Therefore, notwithstanding the 
commenter's concerns about the specificity and triggering of the 
supplementary measures identified in the Pennsylvania SIP and the 
FirstEnergy and Jewel COAs, EPA believes that Pennsylvania's 
enforcement program, which is enhanced by the supplementary provisions 
in the COAs, suffice to meet Section 172(c)(9) requirements as 
interpreted in the 1992 General Preamble and the 2014 SO2 
Nonattainment Guidance.
    Comment 4. The commenter states that the conversion factors used to 
determine the comparably stringent longer term limit for Bruce 
Mansfield are arbitrary and insufficiently protective. The commenter 
asserts that the conversion factors are highly dependent on the time 
period selected. The commenter provided a table of varying time 
periods, and corresponding adjustment factors. The commenter notes that 
depending on the time period selected the adjustment factors can range 
from 0.558 to 0.673.
    Response 4. EPA disagrees with the commenter's assertion that Bruce 
Mansfield's SO2 limits are arbitrary and insufficiently 
protective. As stated in EPA's 2014 SO2 Nonattainment Area 
Guidance, EPA expects that establishing an appropriate longer-term 
average limit will involve assessing a downward adjustment in the level 
of the limit that would provide for comparable stringency. This 
assessment should generally be conducted using data obtained by a 
Continuous Emissions Monitoring System (CEMS), in order to have 
sufficient data to obtain a robust and reliable assessment of the 
anticipated relationship between longer-term average emissions and 1-
hour emission values. This is necessary to suitably assess the 
warranted degree of adjustment of the longer-term average limit in 
order to provide comparable stringency to the 1-hour emission rate that 
is determined to provide for attainment.
    EPA generally expects that datasets reflecting hourly data for at 
least three to five years of stable operation (i.e., without changes 
that significantly alter emissions variability) would be needed to 
conduct a suitably reliable analysis. PADEP's use of 2012-2016 CEM data 
represents five years of historic data of

[[Page 51996]]

stable operation for the Bruce Mansfield facility, and provides the 
robustness recommended in EPA's guidance.
    In contrast, the commenter's adjustment factors were based on time 
intervals that varied from six months to three and a half years, which 
are all less than the time interval used by Pennsylvania. The 
commenter's adjustment factors resulting from using shorter time 
periods illustrate a point that EPA considered in formulating its 
guidance, which is that using an insufficient amount of data is prone 
to yield results that vary unduly by data period and may not be a 
sufficiently robust basis for determining a reliable adjustment factor. 
The variability in adjustment factors using time intervals from six 
months to three and a half years provided by the commenter demonstrates 
the insufficiency of these shorter time periods for use in development 
of such an adjustment factor, but does not demonstrate the 
insufficiency of the overall method in EPA's 2014 SO2 
Nonattainment Area Guidance had it been appropriately applied, nor does 
it demonstrate that Pennsylvania's adjustment factor is inappropriate.
    EPA's guidance recommends calculating adjustment factors using 
statistics calculated according to the data handling procedures by 
which compliance is determined. The COA between Pennsylvania and 
FirstEnergy indicates that ``the 30-operating day rolling average 
SO2 emissions rate shall be calculated using the procedures 
outlined in the MATS regulations in 40 CFR parts 60 and 63.'' 
Pennsylvania and EPA calculated adjustment factors accordingly.
    Pennsylvania imposed three separate limits, and EPA considered the 
adjustment inherent in each limit. For the limit on Unit 3 emissions, 
Pennsylvania appropriately compared the 99th percentile of 30-day 
averages of Unit 3 emissions against the 99th percentile of 1-hour 
values of Unit 3 emissions, computing an adjustment factor of 0.794. 
The commenter does not contest this adjustment factor. EPA computed 
similar statistics for seven years of emissions (2011 to 2017) and 
computed a similar emission factor, 0.786.
    For the limit on the sum of Unit 1 and Unit 2 emissions, 
Pennsylvania conducted separate calculations for Unit 1 and for Unit 2, 
computing adjustment factors of 0.59 and 0.717, respectively. The 
commenter objects to the use of the Unit 2 adjustment factor for both 
units, thereby disregarding the variability of Unit 1. EPA agrees that 
the variability of Unit 1 may not be disregarded, and that the 
variability of Unit 2 should not be used as a surrogate for the 
variability of both units.
    However, since the limit governs the sum of emissions from both 
units, the more pertinent question is how much variability exists in 
the sum of emissions from the two units. That is, the appropriate 
method for computing an adjustment factor for this limit is to use 
statistics for the sum of emissions from the two units, comparing the 
99th percentile of the 30-day average sum of emissions against the 99th 
percentile of the 1-hour sum of emissions. As discussed in the TSD, EPA 
computed an adjustment factor in this manner using 2011 to 2017 data 
for these units, computing a value of 0.72. This indicates that proper 
calculation of an adjustment factor for this limit yields a result that 
is very similar to the adjustment that Pennsylvania applied, resulting 
in a limit that may be considered comparably stringent to the 1-hour 
limit that Pennsylvania would otherwise have imposed.
    The third limit governs the combination of emissions from all three 
units, in particular mandating that the value of an equation adding the 
sum of 30-day average emissions from Units 1 and 2 plus two terms 
(respectively first order and second order) based on emissions from 
Unit 3 shall not exceed 7,100.\10\ Consequently, the most pertinent 
approach for assessing the effect of using 30-day emission averages in 
determining compliance with this limit is to apply EPA's recommended 
procedure to statistics calculated using the equation of Pennsylvania's 
limit. That is, EPA believes that the best assessment of the 
appropriate adjustment to the level to be mandated with this equation 
is to compare the 99th percentile of the values computed with this 
equation (as would be calculated to determine compliance with the 
limit) against the 99th percentile of the 1-hour values computed with 
this equation. Using Pennsylvania's 2012 to 2016 data, EPA in this 
manner computed an adjustment factor of 75.2 percent. Among the 14 
model runs in which Unit 3 emissions comply with the Unit 3 emissions 
limit, the lowest formula result (i.e., the level of the 1-hour formula 
limit that would yield attainment in all scenarios) is 9,821. This 
value multiplied by 75.2 percent yields a comparably stringent 30-day 
average-based value of 7,385. Since Pennsylvania has imposed a more 
stringent requirement for the results of this equation (i.e., 7,100), 
EPA believes that Pennsylvania's limit is at least comparably stringent 
to the 1-hour-based limit that they would otherwise have imposed.
---------------------------------------------------------------------------

    \10\ As noted previously, although Pennsylvania's limit is 
expressed as limiting the sum of Units 1 and 2 emissions to 7100 
minus the value of the two terms based on Unit 3 emissions, this 
translation of the limit provides a more appropriate perspective 
from which to examine the effect of the collective variability of 
all three units on the stringency of the collective 30-day average 
limit.
---------------------------------------------------------------------------

    The commenter's adjustment factors are approximately 0.017 to 0.159 
less than the adjustment factor calculated by PADEP, depending upon the 
time period selected. However, EPA's calculations, using seven years of 
hourly data from 2011 to 2017, and calculated in accordance with the 
data handling procedures that will be used in assessing compliance, 
provide a more robust and more pertinent assessment of the degree of 
adjustment needed to identify 30-day average-based limits that may be 
considered comparably stringent to the 1-hour limits that would 
otherwise have been set. This analysis resulted in an adjustment factor 
of 0.72 for Units 1 and 2 combined, and a formula limit value of 7,385 
rather than the value of 7,100 that Pennsylvania imposed. These values 
are closely aligned with the adjustment factors reflected in 
Pennsylvania's limits, and support the limits that Pennsylvania 
established.
    Comment 4a. The commenter notes that the years 2012-2016 used by 
PADEP in calculating the Bruce Mansfield adjustment factor are 
problematic. The commenter notes that the facility's dispatch has been 
steadily declining, that there is a trend of increased start ups and 
shut downs, and therefore, an increase in short term emission spikes. 
Specifically, the commenter claims the use of years 2012-2014 are not 
likely to be representative of future operation as in those years, 
Bruce Mansfield's operation and emissions were more consistent. The 
commenter asserts that future operation will be even more variable 
considering a 2018 fire at the scrubber system and the need to rebuild 
part of that system, noting that rebuilding will result in changes to 
scrubber operation.
    Response 4a. EPA disagrees with the commenter that increased start-
ups and shutdowns will lead to an increase in SO2 emission 
spikes at Bruce Mansfield and disagrees with the commenter that PADEP's 
use of 2012-2016 emissions data was not representative of future 
operations (PADEP used 2012 through 2016 emissions, and the commenter's 
concern is with 2012-2014). EPA notes that the commenter did not 
provide any material supporting the claim that more start-ups and 
shutdowns increase SO2 emissions or cause emission spikes at

[[Page 51997]]

Bruce Mansfield. EPA analyzed hourly emissions data for Bruce 
Mansfield's units from 2011 through 2017. This analysis shows that 
there was an increasing number of start-ups and shutdowns during this 
time period for Units 1, 2 and 3. However, EPA's analysis also shows 
that SO2 emissions at these units do not spike during start-
up and shutdowns. In fact, the emissions are generally lower than 100 
pounds per hour (lbs/hr) during these time periods for these units. 
Absent any specific evidence from the commenter supporting their claim 
that increased start-ups and shutdowns at Bruce Mansfield will increase 
SO2 emissions spikes, EPA does not believe that the 
commenter has justified its claims that Bruce Mansfield can expect to 
experience more emission spikes due to start-ups and shutdowns or that 
expected differences between operation from 2012 to 2016 and future 
operation warrants a lower adjustment factor.
    In addition, EPA's 2014 SO2 Nonattainment Guidance 
recommends using emissions data that reflect the distribution of 
emissions that is expected once the attainment plan is implemented. 
PADEP was correct to assume that the Bruce Mansfield Facility (if it 
resumes full operation) would continue to operate with a similar 
distribution of emissions as it did during 2012 through 2016, since the 
attainment plan was not requiring any new control technology. 
SO2 emissions from each of the three boilers were already 
controlled by three individual Flue Gas Desulfurization (FGD) systems. 
Unit 1 and Unit 2 each vent through two flues within a common stack. 
Unit 3 vents through two flues in the other stack. Through the COA, 
PADEP required Bruce Mansfield FGD units to achieve at least a 95% 
removal efficiency. The recent fire at the scrubber system which was 
identified as an issue by the commenter does not remove the requirement 
to achieve at least a 95% removal efficiency from the FGD units, and to 
meet the emission limits outlined in the COA. As such, the control 
technology after the implementation of the attainment plan remains the 
same as the control technology prior to the development of the 
attainment plan, and therefore EPA reasonably believes that emissions 
variability during the historic period of 2012-2016 continues to be 
representative regardless of any rebuilding of the FGD system (if that 
does need to occur as the commenter asserts).
    EPA notes that Bruce Mansfield Units 1 and 2 have been listed on 
the PJM deactivation list as of February 2019. Therefore, EPA 
anticipates not that these units will start up and shut down more often 
but instead that these units will not resume operation and will not 
start up or shut down at all. However, EPA's task here is to assess 
whether Pennsylvania's plan provides for attainment, including in the 
scenario that these units resume operation. In this scenario, EPA 
presumes that satisfaction of emission limits will reflect full repair 
of emission control systems and the resumption of normal, stable 
operations, which may resume the trend toward more startups and 
shutdowns but which can be expected to have a distribution of upper 
level emissions that is similar to the distribution seen in 2012 to 
2016. Thus, the deactivation of these units does not impact the 
approval of this attainment plan. The emission limits for the three 
units at Bruce Mansfield are still in effect.
    Comment 4b. The commenter asserts that Pennsylvania's use of Unit 
2's adjustment factor (0.717) for Unit 1 was incorrect and by using 
this higher adjustment factor, the 30-day emission limit calculated is 
significantly higher than the one that would be calculated using Unit 
1's adjustment factor. The commenter asserts that EPA incorrectly 
determined that it was appropriate to use Unit 2's adjustment factor 
for Unit 1, because Unit 2's hourly emissions tend to be higher more 
frequently than those of Unit 1. The commenter asserts that during the 
time period 2012-2016, Unit 2's emissions were actually lower than Unit 
1's for nearly 5,000 hours. Thus, the commenter claims EPA's own logic 
actually supports using the 0.59 conversion factor for Unit 1, not the 
0.717 ratio.
    The commenter continues that neither EPA nor Pennsylvania provides 
any evidence or enforceable mechanism to ensure that the future 
operations of Bruce Mansfield will demonstrate variability 
representative of Unit 2 rather than Unit 1, and as such there is no 
demonstrable mechanism to ensure compliance with the NAAQS.
    Response 4b. PADEP followed the recommendation in EPA's 2014 
SO2 Nonattainment Guidance to use an appropriate emissions 
data set when determining the adjustment factors. The data set used 
should be sufficiently robust in terms of time covered, should be 
representative of the type of control strategy that is expected after 
the attainment plan controls are in place and should reflect the 
emissions variability that might be expected at the source once the SIP 
is implemented. However, PADEP did not use the same data handling 
procedures for development of the adjustment factor as for the 
calculation of compliance with the limit, which is recommended in EPA's 
2014 SO2 Nonattainment Guidance. PADEP calculated unit 
specific adjustment factors even though the form of the limit was for 
combined units. PADEP's use of Unit 2's adjustment factor for Unit 1 
did provide for a higher 30-day average limit than would have resulted 
from the use of separate adjustment factors for the two limits. 
However, if PADEP followed EPA's Guidance in calculating the adjustment 
factor using the same data handling proecures as the form of the limit, 
they would have combined Units 1 and 2, and developed one adjustment 
factor based on the sum of the two units' emissions. EPA did this 
analysis and obtained an adjustment factor of 0.72. EPA's analysis 
supports the adjustment factor that PADEP applied. In fact, PADEP's 
approach provides for a slightly lower adjustment factor than would 
have been calculated using EPA's recommended approach. EPA's analysis 
is described in the TSD for this action.
    EPA reviewed the hourly emissions data from 2012 to 2016 for Units 
1 and 2, and continues to assert that Unit 2's emissions tend to be 
higher more frequently. Based on the commenter's explanation of the 
analysis they conducted to claim that Unit 2's emissions were lower 
than Unit 1's emissions for nearly 5,000 hours, EPA believes the 
commenter may be comparing the hourly emission value per hour of each 
specific day (i.e., Unit 1, Day 1-Hour 1 versus Unit 2, Day 1-Hour 1). 
However, EPA does not believe this type of comparison is relevant to 
the adjustment factor analysis for a limit. EPA believes that a larger 
data set and more robust statistical analysis over a longer period of 
time, such as five years (as PADEP did), and use of data calculated in 
the same manner in which Pennsylvania will be determining compliance, 
provides a better portrayal of the influence of variability on the 
stringency of each limit and thus the degree of adjustment each limit 
needs to be comparably stringent to the 1-hour limits that Pennsylvania 
would otherwise have imposed.
    Providing further support for the use of a 0.717 adjustment factor 
for Unit 1 and Unit 2, the adjustment factor listed in Appendix D of 
EPA's SO2 Nonattainment Guidance for Sources with Wet 
Scrubbers (30-day average vs. 1-hour adjustment factor) is 0.71. 
Therefore, EPA continues to believe that the adjustment factors used 
for Units 1 and 2 provide for a comparably stringent 30-day emission 
limit.

[[Page 51998]]

    Regarding the commenter's concern that there is no enforceable 
mechanism provided to ensure that future emissions variability of Bruce 
Mansfield will reflect the emissions variability representative of Unit 
2 rather than Unit 1, EPA has provided options to states in the 2014 
SO2 Nonattainment Guidance to reduce the likelihood of 
increased emissions varaiability in the future. PADEP followed EPA's 
Guidance of adopting a direct work practice requirement for control 
equipment which could set a minimum level of control efficiency. The 
Bruce Mansfield plant is required to use this work practice in order to 
ensure that the NAAQS is not exceeded. To this end, the Bruce Mansfield 
plant FGDs must achieve at least a 95% design removal efficiency on 
Units 1, 2, and 3 during normal operating conditions following the 
general requirements of 25 Pa. Code Chapter 139.11 and the testing 
frequency contained in the COA. This additional work practice 
requirement provides greater assurance that there will be less 
variability in emissions when complying with the 30-day limits, as well 
as minimizing the likely frequency and magnitude of elevated emissions. 
In addition, as stated in the 2014 SO2 Nonattainment 
Guidance, if the source is exceeding the expected variability, such 
that the plan proves not to provide the expected confidence that the 
NAAQS is being attained, EPA will use its available authority to pursue 
any necessary correction of the plan.
    Comment 5. The commenter states that the emission limits for Bruce 
Mansfield are needlessly complex and prevent transparency in 
determining compliance. The commenter asserts that the emission limit 
formula only applies when both Chimney 1 and Chimney 2 are operating, 
and as such it is unclear what limits apply when one chimney is not 
operating. In addition, the commenter states that when Chimney 2 emits 
over 3584 lbs/hour on a 30-day average, it is not clear what the 
allowable emission limits are for Chimney 1. The commenter states that 
a Federal plan with transparent emission limits should be adopted.
    Response 5. EPA disagrees with the commenter that the emission 
limits for Bruce Mansfield are needlessly complex and lack the 
transparency needed to determine compliance. While the formula-based 
emission limit requires extra calculation to determine compliance, and 
therefore is more complex than a Unit-specific 30-day limit, all the 
data needed to calculate whether Bruce Mansfield is complying with the 
limit are available from the PADEP certified CEM data and are reported 
to EPA's Clean Air Markets Division. The CEM data are available at 
https://ampd.epa.gov/ampd/. Anyone may then determine Bruce Mansfield's 
compliance status simply by retrieving those data into a spreadsheet 
(or other suitable software) and applying the formula in the 
Pennsylvania's rule. As such, the limit is sufficiently transparent for 
Federal, state and public scrutiny.
    EPA disagrees that the emission limit is not clear when one chimney 
is not operating. As described in the NPRM, Unit 1 and Unit 2 each vent 
through two flues within Chimney 1, and Unit 3 vents through two flues 
in Chimney 2. The 30-operating day rolling average SO2 
emissions rate for Units 1 and 2 cannot exceed the result of equation 
one (EQ-1), below, with Chimney 1 and Chimney 2 in service, calculated 
daily. Pursuant to this equation, the limit for the sum of emissions 
from Unit 1 and Unit 2 is a function of the emissions from Unit 3, with 
a maximum limit (when Unit 3 has low emissions) under 7,100 lb/hr. In 
addition, if Unit 3 is not operating (and therefore only Chimney 1 is 
operating), the 30-operating day rolling average emissions rate cannot 
exceed 7,362 lb/hr for Units 1 and 2 combined. The 30-operating day 
rolling average SO2 emissions rate for Chimney 2 (Unit 3) 
cannot exceed 3,584 lb/hr.

EQ-1: CH1SO2 Lim = -1.38E-04 x CH2SO2\2\-0.920 x 
CH2SO2 + 7100

Where:

CH1SO2 Lim: Chimney 1 SO2 lb/hr 30-day rolling 
average
CH1SO2 Lim <=7,362 lb/hr
CH2SO2: Chimney 2 SO2 lb/hr 30-day rolling 
average
CH2SO2 <=3,584 lb/hr

    In other words, if Chimney 1 is not in service, the stand-alone 30-
operating day rolling average emission limit for Chimney 2 (Unit 3) is 
set at 3,584 lb/hr. If Chimney 2 is not in service, Chimney 1's 30-
operating day average emission limit is 7,362 lb/hr. EPA continues to 
assert that the 30-operating day limit established for Bruce Mansfield 
is clear and transparent and therefore a Federal plan with a different 
limit is unnecessary.
    Comment 5a. The commenter asserts that the emission inventories are 
improper because the projected 2018 emissions of 32,443 tons of 
SO2 are greater than the actual emissions of 26,622 tons 
reported for 2011, when the Beaver County SO2 monitor had a 
design value of 136 ppb. The commenter asserts that this increase in 
emissions is particularly egregious for Bruce Mansfield with 21,196 
tons of SO2 in 2011, and allowable 2018 emissions of 32,246 
tons.
    Response 5a. The commenter is comparing allowable emissions for 
2018 against actual emissions for 2011. EPA agrees with the commenter 
that the allowable annual 2018 emissions for Bruce Mansfield (and for 
all sources combined in the Beaver Area) are greater than the base year 
2011 annual actual emissions for Bruce Mansfield (and for all sources 
in the Beaver Area combined, respectively). However, air quality in a 
multi-source area like this is not a function of total allowable 
emissions, since sources with different stack heights, different 
locations, and other differences will have different impacts per ton of 
emissions. For example, the monitor is near the former Horsehead 
facility and the former AES Beaver facility, and the improvements in 
air quality at the monitor have clearly been more influenced by the 
shutdown of these facilities than by the decline in actual emissions at 
Bruce Mansfield. In this area, modeling provides the best information 
regarding the impact per ton of emissions from each facility. 
Pennsylvania has conducted an appropriate modeling analysis of this 
area, and EPA concurs with the state's finding that its limits for 
Bruce Mansfield (which reduce allowable emissions), in combination with 
the other emission reductions in the area, will assure that the area 
attains the standard, notwithstanding the fact that these limits allow 
more total emissions than were actually emitted in 2011.
    Comment 5b. The commenter further claims that assuming 8,760 hours 
in a year, Bruce Mansfield's allowable annual emissions of 32,246 tons 
translates to an hourly allowable rate of 7,362 lbs/hr, an emission 
rate that is higher than many of the emission rate scenarios modeled by 
FirstEnergy. Also, because these modeled scenarios model attainment 
less than one microgram per cubic meter below the NAAQS, the annual 
allowable maximum SO2 emissions for Bruce Mansfield are much 
greater than what the modeling indicates are protective of the NAAQS.
    Response 5b. EPA disagrees with commenter that the allowable 
emissions for Bruce Mansfield are not protective of the NAAQS. EPA 
understands the commenter's concern as follows: Since there are modeled 
scenarios where the combined hourly emission value of Units 1, 2 and 3, 
are less than 7,362 lb/hr (which is the highest 30-day average emission 
value allowed under the emission limits) and those model runs show 
SO2 concentrations very close to the standard, then an 
allowable emissions rate of 7,362 lb/hr is much

[[Page 51999]]

greater than what several modeling runs indicate is protective of the 
NAAQS.
    The commenter incorrectly assumes that all modeled scenarios are 
permitted. However, that is not the case. Seventeen scenarios with 
varying combinations of 1-hour critical emission values for Unit 1 and 
2, and Unit 3 were modeled and used to develop an equation for limiting 
the combination of emissions from Units 1, 2 and 3 at Bruce Mansfield. 
As shown in Table 1, all 17 scenarios modeled attainment.
    In addition to the limit on the combination of the three units' 
emissions, Pennsylvania also set a limit specifically limiting the 
emissions from Unit 3, that Unit 3 30-operating day average emissions 
shall not exceed 3,584 lb/hr. In model runs 9 through 11, Unit 3's 
emissions correspond to an adjusted 30-day average value that would 
have been greater than 3,584 lb/hr. Thus, these runs are disallowed 
scenarios.
    It is these three model runs that the commenter refers to as those 
showing SO2 concentrations very close to the standard, and 
asserts that the allowable emissions (calculated from these 1-hour 
values; i.e., for model run 9 from Table 1, using the 1-hour CEVs, 
2056.54 + 4743.88 = 6800.42 lb/hr combined CEV for all units) are much 
less than the allowable emissions that PADEP calculates. Although the 
relevant values are hourly emissions, adjusted to be limited with 30-
day average limits, both the commenter and PADEP calculated the 
corresponding annual emission rates. The model run 9 values correspond 
to annual emissions of 29,786 tons per year, which is much less than 
PADEP's calculated allowable annual emissions of 32,246 tons per year. 
If the emission rates in model runs 9 through 11 were allowable, they 
would indicate that Pennsylvania's limits are not protective of the 
NAAQS. However, these model runs contain disallowed emission rates, and 
so these runs are not indicative of the emission rates necessary to 
attain the standard. Therefore, EPA continues to support Bruce 
Mansfield's 30-day emission limits as demonstrating attainment of the 
1-hour SO2 NAAQS.

                                     Table 1--Modeling Results and Emission Values for the Bruce Mansfield Facility
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Corresponding                   Corresponding  30-day average SO2 limit for      Modeled
                                                Modeled     30-day average      Modeled     30-day average   Units 1 + 2 based on 30-day  maximum  using
                 Model run                   emissions for   emissions for   emissions for   emissions for      average equivalent to      the  1-hr CEV
                                              Units 1 + 2     Units 1 + 2   Unit 3 (lb/hr)  Unit 3 (lb/hr)  modeled Unit 3 emissions (lb/ from column  1
                                                (lb/hr)       (lb/hr) **                          **                   hr) ***                 and 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
1 **......................................       10,282.70        7,372.70            0.00            0.00  Disallowed..................       196.17563
2.........................................        9,254.43        6,635.43          761.19          604.38  6493.6......................       196.18089
3.........................................        8,226.16        5,898.16        1,482.72        1,177.28  5825.6......................       196.17966
1FE *.....................................        7,484.24        5,366.20        2,006.14        1,592.88  5284.4......................       196.18033
4.........................................        7,197.89        5,160.89        2,206.62        1,752.06  5064.5......................       196.17977
2FE *.....................................        6,765.97        4,851.20        2,507.57        1,991.01  4721.2......................       196.14426
5.........................................        6,169.62        4,323.62        2,885.44        2,291.04  4267.9......................       196.18044
3FE *.....................................        5,952.47        4,267.92        3,009.17        2,389.28  4114.1......................       196.07897
6.........................................        5,141.35        3,686.35        3,469.90        2,755.10  3517.8......................       196.17912
4FE *.....................................        5,051.66        3,622.04        3,510.68        2,787.48  3463.3......................       196.11106
7.........................................        4,113.08        2,949.08        3,985.46        3,164.46  2806.8......................       196.17974
5FE *.....................................        4,015.93        2,879.42        4,012.20        3,185.69  2768.7......................       196.04158
8.........................................        3,084.81        2,211.81        4,407.53        3,499.58  2190.3......................       196.18032
6FE *.....................................        2,857.18        2,048.60        4,513.72        3,583.89  2030.3......................       196.10031
9 **......................................        2,056.54        1,474.54        4,743.88        3,766.64  Disallowed..................       196.18082
10 **.....................................        1,028.27          737.27        4,956.43        3,935.41  Disallowed..................       196.18081
11 **.....................................            0.00            0.00        5,041.58        4,003.01  Disallowed..................       196.17832
--------------------------------------------------------------------------------------------------------------------------------------------------------
* FirstEnergy Model run.
** Disallowed modeled scenarios. Model run 1 is disallowed because the emission limit equation only applies when both Chimneys are operating. Model runs
  9-11 are prohibited as Unit 3's 30-day average emission rate is greater than the comparably stringent 30-day emission limit of 3,584 lb/hr.
*** The limit that would result from the compliance equation (EQ-1) using the Unit 3 30-operating day average emission rate that corresponds to the
  modeled 1-hour rate (from fifth column of this table).

III. Final Action

    EPA is approving Pennsylvania's SIP revision submittal for the 
Beaver Area, as submitted by PADEP to EPA on September 29, 2017 for the 
purpose of demonstrating attainment of the 2010 1-hour SO2 
NAAQS. EPA has determined that Pennsylvania's SO2 attainment 
plan for the 2010 1-hour SO2 NAAQS for the Beaver Area meets 
the applicable requirements of the CAA in sections 110, 172 and 191-
192, and comports with EPA's recommendations discussed in the 2014 
SO2 Nonattainment Area Guidance. Specifically, EPA is 
approving the base year emissions inventory, a modeling demonstration 
of SO2 attainment, an analysis of RACM/RACT, an RFP plan, 
and contingency measures for the Beaver Area, and concludes that the 
Pennsylvania SIP has met requirements for NSR for the 2010 1-hour 
SO2 NAAQS. Additionally, EPA is approving into the 
Pennsylvania SIP specific SO2 emission limits, compliance 
parameters and contingency measures established for Bruce Mansfield, 
and operational restrictions for the Jewel Facility. Furthermore, 
approval of this SIP submittal removes EPA's duty to promulgate and 
implement a FIP under CAA section 110(c) for the Beaver Area.

IV. Incorporation by Reference

    In this document, EPA is finalizing regulatory text that includes 
incorporation by reference. In accordance with requirements of 1 CFR 
51.5, EPA is finalizing the incorporation by reference of the 
unredacted portions of the COA entered between Pennsylvania and 
FirstEnergy Generation, LLC for the Bruce Mansfield Generating Station, 
and the COA entered between Pennsylvania and Jewel Acquisition, LLC on 
September 21, 2017 as described in the amendments to 40 CFR part 52 set 
forth below. This includes emission limits and associated compliance 
parameters,

[[Page 52000]]

record-keeping and reporting, and contingency measures for Bruce 
Mansfield; and operational restrictions for the Jewel Facility. EPA has 
made, and will continue to make, these materials generally available 
through https://www.regulations.gov/ or at the EPA Region III Office 
(please contact the person identified in the For Further Information 
Contact section of this preamble for more information). Therefore, 
these materials have been approved by EPA for inclusion in the SIP, 
have been incorporated by reference by EPA into that plan, are fully 
Federally enforceable under sections 110 and 113 of the CAA as of the 
effective date of the final rulemaking of EPA's approval, and will be 
incorporated by reference in the next update to the SIP 
compilation.\11\
---------------------------------------------------------------------------

    \11\ 62 FR 27968 (May 22, 1997).
---------------------------------------------------------------------------

V. Statutory and Executive Order Reviews

A. General Requirements

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves state law as meeting Federal requirements and 
does not impose additional requirements beyond those imposed by state 
law. For that reason, this action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory action because SIP approvals are exempted under 
Executive Order 12866.
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, this rule 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.

B. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this action and 
other required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).

C. Petitions for Judicial Review

    Under section 307(b)(1) of the CAA, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by December 2, 2019. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this action for the purposes of judicial review nor 
does it extend the time within which a petition for judicial review may 
be filed, and shall not postpone the effectiveness of such rule or 
action. This action to approve the Beaver Area attainment plan for the 
1-hour SO2 NAAQS into the Pennsylvania SIP may not be 
challenged later in proceedings to enforce its requirements. (See 
section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Reporting and recordkeeping 
requirements, Sulfur oxides.

    Dated: September 13, 2019.
Diana Esher,
Acting Regional Administrator, Region III.

    40 CFR part 52 is amended as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for part 52 continues to read as follows:

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

Subpart NN--Pennsylvania

0
2. In Sec.  52.2020:
0
a. The table in paragraph (d)(3) is amended by adding an entry for 
``Bruce Mansfield Generating Station and an entry for Jewel 
Acquisition, LLC'' at the end of the table; and
0
b. The table in paragraph (e)(1) is amended by adding an entry for 
``Attainment Plan for the Beaver, Pennsylvania Nonattainment Area for 
the 2010 Sulfur Dioxide Primary National Ambient Air Quality Standard'' 
at the end of the table.
    The additions read as follows:

Sec.  52.2020  Identification of plan.

* * * * *
    (d) * * *
    (3) * * *

[[Page 52001]]

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           State
           Name of source                  Permit No.                  County            effective      EPA approval date    Additional explanation/Sec.
                                                                                            date                                    52.2063 citation
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
Bruce Mansfield Generating Station.  FirstEnergy Redacted    Beaver...................      10/1/18  10/1/19, [Insert        Sulfur dioxide emission
                                      Consent Order and                                               Federal Register        limits and related
                                      Agreement.                                                      citation].              parameters in unredacted
                                                                                                                              portions of the Consent
                                                                                                                              Order and Agreement dated
                                                                                                                              9/21/17.
Jewel Acquisition, LLC, Midland      Jewel Acquisition       Beaver...................      9/21/17  10/1/19, [Insert        Operational restrictions
 Facility.                            Redacted Consent                                                Federal Register        and related parameters in
                                      Order and Agreement.                                            citation].              unredacted portions of the
                                                                                                                              Consent Order and
                                                                                                                              Agreement.
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (e) * * *
    (1) * * *

----------------------------------------------------------------------------------------------------------------
                                                                  State
 Name of non-regulatory SIP revision   Applicable geographic    submittal      EPA approval date      Additional
                                                area               date                              explanation
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Attainment Plan for the Beaver,       Industry Borough,            9/29/17  10/1/19, [Insert          52.2033(d)
 Pennsylvania Nonattainment Area for   Shippingport Borough,                 Federal Register
 the 2010 Sulfur Dioxide Primary       Midland Borough,                      citation].
 National Ambient Air Quality          Brighton Township,
 Standard.                             Potter Township and
                                       Vanport Township.
----------------------------------------------------------------------------------------------------------------

* * * * *

0
3. Section 52.2033 is amended by adding paragraph (d) to read as 
follows:

Sec.  52.2033  Control strategy: Sulfur oxides.

* * * * *
    (d) EPA approves the attainment demonstration State Implementation 
Plan for the Beaver, PA Nonattainment Area submitted by the 
Pennsylvania Department of Environmental Protection on September 29, 
2017.

[FR Doc. 2019-20848 Filed 9-30-19; 8:45 am]
BILLING CODE 6560-50-P