[Federal Register Volume 83, Number 137 (Tuesday, July 17, 2018)]
[Rules and Regulations]
[Pages 33730-33760]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-15143]



[[Page 33729]]

Vol. 83

Tuesday,

No. 137

July 17, 2018

Part V





Environmental Protection Agency





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40 CFR Part 52





Air Plan Approval; Kentucky; 2008 Ozone NAAQS Interstate Transport SIP 
Requirements; Final Rule

Federal Register / Vol. 83 , No. 137 / Tuesday, July 17, 2018 / Rules 
and Regulations

[[Page 33730]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2018-0142; FRL-9980-57--Region 4]


Air Plan Approval; Kentucky; 2008 Ozone NAAQS Interstate 
Transport SIP Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is approving a 
revision to Kentucky's State Implementation Plan (SIP) pertaining to 
the ``good neighbor'' provision of the Clean Air Act (CAA or Act) for 
the 2008 8-hour ozone National Ambient Air Quality Standard (NAAQS). 
Kentucky submitted a draft version of this SIP revision for parallel 
processing by EPA on February 28, 2018, and submitted a final version 
that contained no substantive changes on May 10, 2018. The good 
neighbor provision requires each state's implementation plan to address 
the interstate transport of air pollution in amounts that contribute 
significantly to nonattainment, or interfere with maintenance, of a 
NAAQS in any other state. In this action, EPA is approving Kentucky's 
submission demonstrating that no additional emission reductions are 
necessary to address the good neighbor provision for the 2008 ozone 
NAAQS beyond those required by the Cross-State Air Pollution Rule 
Update (CSAPR Update) federal implementation plan (FIP). Accordingly, 
EPA is approving Kentucky's submission because it partially addresses 
the requirements of the good neighbor provision for the 2008 ozone 
NAAQS, and it resolves any obligation remaining under the good neighbor 
provision after promulgation of the CSAPR Update FIP. The approval of 
Kentucky's SIP submission and the CSAPR Update FIP, together, fully 
address the requirements of the good neighbor provision for the 2008 
ozone NAAQS for Kentucky. EPA is approving this action because it is 
consistent with the CAA.

DATES: This rule is effective August 16, 2018.

ADDRESSES: EPA has established a docket for this action under Docket 
Identification No. EPA-R04-OAR-2018-0142. All documents in the docket 
are listed on the www.regulations.gov website. Although listed in the 
index, some information may not be publicly available, i.e., 
Confidential Business Information 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 either electronically through www.regulations.gov or in hard 
copy at the Air Regulatory Management Section, Air Planning and 
Implementation Branch, Air, Pesticides and Toxics Management Division, 
U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW, 
Atlanta, Georgia 30303-8960. EPA requests that if at all possible, you 
contact the person listed in the FOR FURTHER INFORMATION CONTACT 
section to schedule your inspection. The Regional Office's official 
hours of business are Monday through Friday 8:30 a.m. to 4:30 p.m., 
excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Ashten Bailey, Air Regulatory 
Management Section, Air Planning and Implementation Branch, Air, 
Pesticides and Toxics Management Division, Region 4, U.S. Environmental 
Protection Agency, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. 
Ms. Bailey can be reached by telephone at (404) 562-9164 or via 
electronic mail at <a href="/cdn-cgi/l/email-protection#debcbfb7b2bba7f0bfadb6aabbb09ebbaebff0b9b1a8"><span class="__cf_email__" data-cfemail="4527242c29203c6b24362d31202b052035246b222a33">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

I. Background

    On March 27, 2008 (73 FR 16436), EPA promulgated an ozone NAAQS 
that revised the levels of the primary and secondary 8-hour ozone 
standards from 0.08 parts per million (ppm) to 0.075 ppm or 75 parts 
per billion (ppb). Pursuant to CAA section 110(a)(1), within three 
years after promulgation of a new or revised NAAQS (or shorter, if EPA 
prescribes), states must submit SIPs that meet the applicable 
requirements of section 110(a)(2). EPA has historically referred to 
these SIP submissions made for the purpose of satisfying the 
requirements of sections 110(a)(1) and 110(a)(2) as ``infrastructure 
SIP'' submissions. One of the structural requirements of section 
110(a)(2) is section 110(a)(2)(D)(i), also known as the ``good 
neighbor'' provision, which generally requires SIPs to contain adequate 
provisions to prohibit in-state emissions activities from having 
certain adverse air quality effects on downwind states due to 
interstate transport of air pollution. There are four sub-elements, or 
``prongs,'' within section 110(a)(2)(D)(i) of the CAA. CAA section 
110(a)(2)(D)(i)(I), addressing two of these four prongs, requires SIPs 
to include provisions prohibiting any source or other type of emissions 
activity in one state from emitting any air pollutant in amounts that 
will contribute significantly to nonattainment, or interfere with 
maintenance, of the NAAQS in another state. The two provisions of this 
section are referred to as prong 1 (significant contribution to 
nonattainment) and prong 2 (interference with maintenance). This action 
addresses only prongs 1 and 2 of section 110(a)(2)(D)(i).\1\
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    \1\ All other infrastructure SIP elements for Kentucky for the 
2008 8-hour ozone NAAQS were addressed in separate rulemakings. See 
78 FR 14681 (March 7, 2013) and 79 FR 65143 (November 3, 2014).
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    On July 17, 2012, Kentucky submitted a SIP submission to EPA, 
addressing a number of the CAA requirements for the 2008 8-hour ozone 
NAAQS infrastructure SIPs. With respect to the interstate transport 
requirements of 110(a)(2)(D)(i)(I), EPA disapproved the submission (78 
FR 14681 (March 7, 2013), effective April 8, 2013) because the SIP had 
relied on Kentucky's participation in the Clean Air Interstate Rule 
(CAIR), which did not address the 2008 ozone NAAQS and had been 
remanded by the D.C. Circuit. In October 2016, EPA promulgated the 
CSAPR Update to address the requirements of CAA section 
110(a)(2)(D)(i)(I) concerning interstate transport of air pollution for 
the 2008 ozone NAAQS. See 81 FR 74504 (October 26, 2016). In the CSAPR 
Update rulemaking, EPA determined that air pollution transported from 
Kentucky would unlawfully affect other states' ability to attain or 
maintain the 2008 8-hour ozone NAAQS. EPA's analysis projected that in 
2017, Kentucky would be linked to downwind nonattainment or maintenance 
problems at four monitors, or receptors. Accordingly, EPA established 
an ozone season nitrogen oxides (NO<INF>X</INF>) budget for Kentucky's 
electricity generating units (EGUs) and promulgated a FIP requiring 
affected EGUs to participate in an allowance trading program to 
implement the budget.\2\ At the time it finalized the CSAPR Update, EPA 
determined that, after implementation of the rule, many downwind air 
quality problems would persist in 2017, including at two of the four 
receptors to which Kentucky was linked. EPA therefore found that the 
CSAPR Update FIPs for Kentucky and 20 other states may not fully 
address the good neighbor requirements as to the 2008 8-hour ozone 
NAAQS. EPA explained that further analysis of air quality in a 
potential future compliance year and potential control strategies would 
be needed to determine whether any

[[Page 33731]]

further emission reductions from these states would be necessary to 
fully address the good neighbor obligations.
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    \2\ CSAPR Update, 81 FR at 74507-08.
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    On October 27, 2017, EPA issued a memorandum (October 2017 
Transport Memo) \3\ that provided technical information and related 
analyses to assist states with developing SIPs to address any remaining 
section 110(a)(2)(D)(i)(I) requirements for the 2008 8-hour ozone 
NAAQS. EPA's updated modeling data, released with the October 2017 
Transport Memo, indicate that for the 2023 future base case emissions 
scenario there are no monitoring sites, outside of California, that are 
projected to have nonattainment or maintenance problems with respect to 
the 2008 ozone NAAQS in 2023.
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    \3\ Memorandum, Stephen D. Page, Supplemental Information on the 
Interstate Transport State Implementation Plan Submissions for the 
2008 Ozone National Ambient Air Quality Standards under Clean Air 
Action Section 110(a)(2)(D)(i)(I).
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II. This Action

    On February 28, 2018, Kentucky submitted a draft SIP revision to 
EPA for parallel processing that reviewed air quality modeling and data 
files that EPA disseminated in the October 2017 Transport Memo. The 
draft SIP revision indicated that the air quality problems at monitors 
to which Kentucky remained linked after implementation of the CSAPR 
Update would be resolved by 2023. Kentucky's draft SIP submission 
agreed with the October 2017 Transport Memo's preliminary projections 
and provided information intended to demonstrate that reliance on the 
modeling to evaluate its remaining good neighbor obligation is 
appropriate. The draft submission also contained air quality modeling 
conducted by Alpine Geophysics, LLC (Alpine) that concluded that none 
of the nonattainment and maintenance receptors identified in the CSAPR 
Update are predicted to be in nonattainment or have issues with 
maintenance of the 2008 ozone NAAQS in 2023. Additionally, Kentucky 
cited information related to emissions trends--such as reductions in 
ozone precursor emissions and controls on Kentucky sources--as further 
evidence that, after implementation of all on-the-books measures, 
including those promulgated in the CSAPR Update FIPs, emissions from 
the Commonwealth will no longer contribute significantly to 
nonattainment or interfere with maintenance of the 2008 8-hour ozone 
NAAQS in any other state.
    In a notice of proposed rulemaking (NPRM) published on April 18, 
2018 (83 FR 17123), EPA proposed to approve Kentucky's February 28, 
2018 draft SIP submission. In the NPRM, EPA explained that it was 
basing its proposal to approve Kentucky's February 28, 2018 draft SIP 
submission on a finding that 2023 is a reasonable analytic year for 
evaluating ozone transport problems with respect to the 2008 ozone 
NAAQS and that interstate ozone transport air quality modeling 
projections for 2023 indicate that Kentucky is not expected to 
significantly contribute to nonattainment or interfere with maintenance 
of the 2008 ozone NAAQS in downwind states. As described in more detail 
in the NPRM, EPA based its evaluation on a four-step analytic framework 
by:
    (1) Identifying downwind air quality problems relative to the 2008 
ozone NAAQS considering air quality modeling projections to a future 
compliance year;
    (2) Determining which upwind states are ``linked'' to these 
identified downwind air quality problems and thereby warrant further 
analysis to determine whether their emissions violate the good neighbor 
provision;
    (3) For states linked to downwind air quality problems, identifying 
upwind emissions on a statewide basis that significantly contribute to 
nonattainment or interfere with maintenance of a standard; and
    (4) For states that are found to have emissions that significantly 
contribute to nonattainment or interfere with maintenance of the NAAQS 
downwind, implementing the necessary emission reductions within the 
state.
    EPA explained that its selection of 2023 was a reasonable analytic 
year for evaluating downwind air quality at step one of the framework, 
supported by an assessment of attainment dates for the 2008 ozone NAAQS 
and feasibility of implementing potential control strategies at both 
EGUs and non-EGUs to reduce NO<INF>X</INF> in CSAPR Update states, 
including Kentucky. First, EPA considered the upcoming 2021 and 2027 
attainment dates for the 2008 ozone NAAQS, consistent with the holding 
of the U.S. Court of Appeals for the District of Columbia Circuit (D.C. 
Circuit) in North Carolina v. EPA, 531 F.3d 896, 911-12 (2008). Next, 
EPA assessed the amount of time necessary to implement new 
NO<INF>X</INF> controls at EGUs and non-EGUs across the CSAPR Update 
region, finding that, fleetwide, sources would require four years to 
implement additional, substantial NO<INF>X</INF> emission reductions. 
EPA therefore proposed to find that 2023 is an appropriate future 
analytic year because it is the first ozone season for which 
significant new post-combustion controls to reduce NO<INF>X</INF> could 
be feasibly installed across the CSAPR Update region, and thus 
represents the timeframe that is as expeditious as practicable for 
upwind states to implement additional emission reductions. EPA then 
described its modeling analysis at step one of the four-step framework 
for the 2023 analytic year, which indicates that there are no expected 
nonattainment or maintenance receptors for the 2008 ozone NAAQS in the 
eastern U.S. in this future year. Please refer to the April 18, 2018 
NPRM for additional information on the basis for the proposed approval.
    Based on these proposed findings and the information provided in 
Kentucky's February 28, 2018 SIP submittal, EPA proposed to determine 
that Kentucky's draft SIP submission demonstrates that emission 
activities from the Commonwealth will not contribute significantly to 
nonattainment or interfere with maintenance of the 2008 8-hour ozone 
NAAQS in any other state after implementation of all on-the-books 
measures, including the CSAPR Update. Comments on the NPRM were due on 
or before May 18, 2018. EPA received adverse comments on the proposed 
rulemaking, which are discussed below. Because Kentucky submitted the 
draft SIP revision for parallel processing, EPA's April 18, 2018 
proposed rulemaking was contingent upon Kentucky providing a final SIP 
revision that was substantively the same as the draft SIP revision. See 
83 FR 17123. Kentucky submitted the final version of its SIP revision 
on May 10, 2018.\4\ The May 10, 2018 SIP submission had no substantive 
changes from the February 28, 2018 draft SIP submission.
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    \4\ Both the draft and final SIP revisions are provided in the 
docket for this action.
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    After considering the comments received on the NPRM, for the 
reasons described in the NPRM and in this action,\5\ EPA is now taking 
final action to approve Kentucky's May 10, 2018, final SIP submission 
and find that Kentucky is not required to make any further reductions, 
beyond those required by the CSAPR Update, to address its statutory 
obligation under CAA section 110(a)(2)(D)(i)(I) for the 2008 ozone 
NAAQS. EPA's final approval of Kentucky's submission means that 
Kentucky's obligations under 110(a)(2)(D)(i)(I) are fully addressed 
through the combination of the 2016 CSAPR Update FIP and the 2018 SIP 
demonstration showing that no

[[Page 33732]]

further reductions are necessary. As a result, EPA is also amending the 
regulatory text at 40 CFR 52.940(b)(2) to reflect that the CSAPR Update 
represents a full remedy with respect to Kentucky's transport 
obligation for the 2008 ozone NAAQS.
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    \5\ EPA notes that to the extent there are any conflicts between 
the rationale provided in the NPRM for the proposed approval and the 
rationale provided in this action, statements made in this document 
should be treated as the controlling basis for EPA's final action 
approving Kentucky's SIP submission.
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III. Response to Comments

    The Regional Administrator signed the proposed rule on April 9, 
2018, and on April 12, 2018, EPA made a prepublication version of the 
proposal available on its website. The 30-day public comment period on 
the proposed rulemaking began on April 18, 2018, the day of publication 
of the proposal in the Federal Register, and closed on May 18, 2018. 
EPA received 15 comments on the proposed action, 10 of which are 
relevant to the proposal. The relevant comments were submitted by the 
Connecticut Department of Energy and Environmental Protection, Delaware 
Department of Natural Resources & Environmental Control, Maryland 
Department of the Environment, Midwest Ozone Group, New Jersey 
Department of Environmental Protection, New York State Department of 
Environmental Conservation (NYDEC), New York State Office of the 
Attorney General, Sierra Club and Chesapeake Bay Foundation, and 
Utility Air Regulatory Group. The remaining comments were outside the 
scope of the proposed action. This section contains summaries of the 
relevant comments and EPA's responses to those comments.
    Comment: One commenter states that existing measures, including 
volatile organic compounds (VOC) and NO<INF>X</INF> requirements for 
EGUs, industrial sources, and mobile sources within Kentucky, have 
brought Kentucky into attainment of both the 2008 and 2015 ozone NAAQS. 
The commenter states that the issue being addressed in the proposed SIP 
is whether these existing measures also satisfy Kentucky's ``good 
neighbor'' requirements for the 2008 ozone NAAQS. The commenter states 
that 2023 is the appropriate analytic year for evaluation of ozone 
transport issues related to the 2008 ozone NAAQS. The commenter points 
to the October 2017 Transport Memo and its modeling results as 
demonstrating that there is no need to conduct any further analysis of 
EPA's four-step transport framework. The commenter states its support 
of both EPA and Alpine modeling showing no downwind air quality 
problems related to the 2008 ozone NAAQS and cites a report prepared 
for the commenter by Alpine indicating that all sites identified in the 
final CSAPR Update will have design values below the 2008 ozone NAAQS 
by 2023 and that therefore no states are required to estimate their 
contributions to these monitors. The commenter states in conclusion 
that recent modeling performed by EPA as well as by Alpine indicate 
that implementation of the CSAPR Update, in addition to other on-the-
books controls, are all that are needed to satisfy requirements related 
to the 2008 ozone NAAQS, and indicates commenter's support for 
Kentucky's request that EPA approve its ``good neighbor'' SIP.
    An additional commenter expresses support for EPA to finalize 
approval of Kentucky's section 110(a)(2)(D)(i)(I) SIP submission and 
further states its support for Kentucky's reliance on EPA's modeling 
analysis. The commenter states that the EPA analysis released in the 
October 2017 Transport Memo was consistent with the four-step 
framework, and that it was not necessary to complete all four steps 
because no receptor in the eastern United States is expected to have 
problems attaining or maintaining the 2008 ozone NAAQS in 2023. The 
commenter states that 2023 is the modeling year used in EPA's modeling 
because that is the earliest year by which it is feasible to install 
controls across the CSAPR Update region and states its support of EPA's 
decision to evaluate the feasibility of installing controls on a 
regional basis rather than on a state-by-state or unit-by-unit basis. 
The commenter further states that EPA properly considered upcoming 
attainment dates and the need to consider future effects of local, 
state, and federal emission reduction requirements in order to avoid 
unlawfully mandating over-control. The commenter concludes that EPA's 
modeling analysis is reasonable and that EPA's approval is proper even 
without additional information from Kentucky. In support of its 
assertion that EPA should finalize its approval, the commenter notes 
that Kentucky also provides state-specific information to further 
demonstrate that reliance on EPA's modeling is appropriate in the 
context of this SIP and modeling performed by Alpine that is consistent 
with EPA's results.
    Response: EPA agrees with the commenters' assertions as to the 
appropriateness of 2023 as an analytic year and other specifics of 
EPA's analysis as documented in the October 2017 Transport Memo. EPA 
acknowledges receipt of the Alpine report and recognizes that it 
demonstrates similar 2023 design values to those projected by EPA's 
modeling.
    Comment: One commenter states that, although it appreciates the 
emissions reductions made thus far by Kentucky, EPA must disapprove 
Kentucky's proposed SIP as it does not fulfill the CAA's good neighbor 
obligations. Another commenter states that, while New York will 
continue to control air pollution, it does not have the authority to 
control sources in upwind states and that EPA must disapprove the 
Kentucky submission. Additional commenters state opposition to EPA's 
proposed approval, and assert that EPA should disapprove Kentucky's SIP 
submission.
    Response: EPA disagrees with the commenters' contentions that EPA 
should disapprove Kentucky's submittal because it does not fulfill the 
CAA's good neighbor obligations. As explained in the proposed 
rulemaking and further in this action, based on EPA's modeling and with 
implementation of the CSAPR Update and other measures, Kentucky is not 
expected to significantly contribute to nonattainment or interfere with 
maintenance of the 2008 ozone NAAQS in downwind states in 2023. 
Kentucky provided information showing that the use of the modeling is 
appropriate in this context, and also included additional modeling that 
showed results consistent with EPA's modeling. Thus, Kentucky's draft 
submission is approvable because it demonstrated that emission activity 
from the State will not contribute significantly to nonattainment or 
interfere with maintenance of the 2008 8-hour ozone NAAQS in any other 
state after implementation of all on-the-books measures, including the 
CSAPR Update.
    To the extent that these comments are general statements stating 
opposition to EPA's action and are intended to incorporate other, 
specific comments made by commenters, EPA has addressed the specific 
concerns later in this preamble.
    Comment: One commenter states that EPA's determination of 
significant contribution should be based upon current data, and to base 
the determination on 2023 modeling ignores New York's 2021 attainment 
deadline and adds too much uncertainty and speculation to the 
determination of whether Kentucky significantly contributes to 
nonattainment or interferes with maintenance in New York and other 
states.
    Response: EPA does not agree that it is inappropriate to rely on 
modeled projections for a future year, rather than current data, to 
analyze ozone concentrations in downwind states. Consistent with 
historical practice, Kentucky and EPA have focused their analysis in 
this action on a future year in light of the forward-looking nature of 
the good neighbor obligation in section

[[Page 33733]]

110(a)(2)(D)(i)(I). Specifically, the statute requires that states 
prohibit emissions that ``will'' significantly contribute to 
nonattainment or interfere with maintenance of the NAAQS in any other 
state. EPA reasonably interprets this language as permitting states and 
EPA in implementing the good neighbor provision to evaluate downwind 
air quality problems, and the need for further upwind emission 
reductions, prospectively. In EPA's prior regional transport 
rulemakings, the Agency generally evaluated whether upwind states 
``will'' significantly contribute to nonattainment or interfere with 
maintenance based on projections of air quality in the future year in 
which any emission reductions would be expected to go into effect. See, 
e.g., NO<INF>X</INF> SIP Call, 63 FR 57377 (using the anticipated 2007 
compliance year for its analysis); CAIR, 70 FR 25241 (using the years 
2009 and 2010, the anticipated compliance years for the ozone and fine 
particulate matter (PM<INF>2.5</INF>) NAAQS, respectively); CSAPR, 76 
FR 48211 (using the 2012 compliance year); CSAPR Update, 81 FR 74537 
(using the 2017 compliance year). The D.C. Circuit affirmed EPA's 
interpretation of ``will,'' finding EPA's consideration of future 
projected air quality (in addition to current measured data) to be a 
reasonable interpretation of an ambiguous term. North Carolina, 531 
F.3d at 913-14. Thus, consistent with this precedent, it is reasonable 
for EPA to analyze air quality in an appropriate future compliance year 
to evaluate any remaining obligation for the 2008 ozone NAAQS.
    EPA also does not agree that the 2023 modeling is too uncertain or 
speculative as compared to current data. As discussed in more detail 
later, courts' rulings have deferred to EPA's reasonable reliance on 
modeling to inform its policy choices, notwithstanding that no model is 
perfect and there may be some level of discrepancy between modeled 
predictions what eventually occurs. Comments regarding the relationship 
between the future analytic year and the attainment date are also 
addressed later in this preamble.
    Comment: One commenter states that the plain meaning of section 
110(a)(2)(D) requires Kentucky to prohibit contributing emissions prior 
to the 2008 ozone attainment dates set for downwind states, i.e., by 
2018 for moderate nonattainment areas. The commenter contends that the 
D.C. Circuit adopted this plain reading, finding the statute 
unambiguously requires compliance with NAAQS attainment deadlines in 
North Carolina, 531 F.3d at 911-12. The court based its conclusion on 
the requirement that implementing provisions be consistent with Title I 
of the CAA, finding the plan must be consistent with both the 
substantive and procedural requirements of NAAQS compliance. Id. at 
911. The commenter states that the court also held that compliance must 
be achieved in time for attainment determinations for downwind states 
expected to be close to the NAAQS so as not to ``interfere with 
maintenance.'' Id. at 908-09.
    The commenter further states that the CAA establishes attainment 
dates for the 2008 ozone NAAQS ``as expeditiously as practicable'' but 
no later than 3, 6, 9, 15, or 20 years--depending on area 
classification--after the designation. The commenter contends that, in 
NRDC v. EPA, 777 F.3d 456 (D.C. Cir. 2014), the court rejected EPA's 
attempt to extend the 2008 ozone NAAQS compliance deadlines by several 
months, holding that the CAA requires attainment dates be set at the 
statutorily fixed term of time from the date of designations.
    The commenter therefore asserts that section 110(a)(2)(D)(i)(I) 
does not allow Kentucky to wait until 2023 nor does it grant EPA 
discretion to extend compliance deadlines. The commenter contends that, 
by 2023, the harms the good neighbor provisions were intended to avoid 
will have already befallen downwind states. Accordingly, the commenter 
states that Kentucky must take immediate steps to offset past over-
pollution. In a footnote, the commenter notes that prior legal 
precedent indicates that attainment dates are ``central to the 
regulatory scheme,'' Sierra Club v. EPA, 294 F.3d 155, 161 (D.C. Cir. 
2002), and ``leave no room for claims of technological or economic 
feasibility,'' NRDC, 777 F.3d at 468.
    Another commenter points to 2015-2017 design values at monitors in 
the NJ-NY-CT nonattainment area that are above the standard at 83 ppb 
(the Stratford monitor) and 82 ppb (the Westport monitor). The 
commenter states that design values indicate that the area can expect 
to be reclassified as ``serious'' with an attainment deadline of July 
2021, based on a 2020 design value. The commenter contends that the 
Kentucky SIP is deficient because it relies on a future year that does 
not adequately reflect the appropriate attainment year of the impacted 
nonattainment area. Because the moderate attainment deadline has 
passed, the commenter states that modeling for the next attainment date 
of July 2021 (based on 2020 design values) should be conducted.
    The commenter asserts that downwind states significantly impacted 
by ozone pollution will be unable to meet attainment deadlines if good 
neighbor SIPs are not done prior to the attainment deadline of the 
downwind nonattainment areas. The commenter asserts the CAA recognizes 
this since the good neighbor provision is required to be addressed 
ahead of the attainment demonstration requirements for nonattainment 
areas. The commenter notes that Kentucky's significant contributions 
for the 2008 ozone NAAQS therefore should have been addressed by March 
2011. The commenter states that 2023 is an inappropriate future year 
for modeling because it falls after both the July 2018 moderate 
classification deadline and the July 2021 serious classification 
deadline.
    One commenter states that the tri-state New York City metropolitan 
area struggles to attain the 2008 ozone NAAQS, with 2017 design values 
up to 83 ppb, due in significant part to interstate transport of ozone 
precursors from upwind states like Kentucky. The commenter notes that 
NYDEC requested a reclassification of the area to ``serious'' 
nonattainment due to the inevitability of missing the moderate area 
attainment deadline. The commenter therefore asserts that the 2023 
modeling year relied upon by EPA and Kentucky is well beyond--and fails 
to take into account--the attainment deadline for ``serious'' 
nonattainment areas.
    The commenter further states that had EPA met its 2015 FIP deadline 
for Kentucky, it could have mandated controls that would be installed 
and operating in time to benefit New York's ``serious'' nonattainment 
deadline.
    One commenter contends that EPA's proposed approval fails to 
account for New York's upcoming attainment deadlines for the 2008 ozone 
NAAQS. The commenter asserts that the New York metropolitan area has 
struggled to attain the 2008 ozone NAAQS, with 2017 design values of up 
to 83 ppb. The commenter asserts that EPA admitted the CSAPR Update was 
only a partial remedy for downwind states such as New York, and that 
additional reductions may be required from upwind states, including 
Kentucky. CSAPR Update modeling projected that New York would remain in 
nonattainment past its July 20, 2018 statutory attainment deadline. On 
November 10, 2017, NYDEC requested a reclassification to ``serious'' 
nonattainment, due to the inevitability of missing the July 20, 2018 
moderate area attainment deadline, which the state attributed in large 
part to

[[Page 33734]]

transported emissions from upwind states such as Kentucky. The 
reclassification carries an attainment deadline of July 20, 2021, based 
on 2018-2020 monitoring data.
    The commenter asserts that 2023 modeling analysis takes no account 
of New York's current and likely new attainment deadlines, in direct 
conflict with settled law under the Act. To be fully compliant, the 
commenter believes a good neighbor SIP must eliminate significant 
contribution to downwind nonattainment or interference with maintenance 
by the deadlines for downwind areas to attain the NAAQS. EPA's proposed 
approval only discusses this deadline in its conclusion that emission 
reductions will not be achieved in time to meet it. The commenter 
asserts that EPA cannot approve a SIP that delays eliminating emissions 
that presently contribute to downwind nonattainment past New York's 
attainment deadlines.
    One commenter challenges the future year selection of 2023 and 
states that it perpetuates Connecticut citizens' health and economic 
burdens. The commenter states that Connecticut faces a reclassification 
to serious nonattainment, has previously been reclassified to moderate, 
and has not met attainment due to ``overwhelming'' transport from 
upwind areas, including Kentucky.
    Response: EPA disagrees that it has failed to consider the 
appropriate attainment dates in relying on the 2023 modeling results to 
approve Kentucky's SIP submission.
    First, to the extent the commenters suggest that the current 
measured design values may preclude EPA's reliance on modeled 
projections, EPA does not agree. As explained earlier in this action, 
EPA has reasonably interpreted the term ``will'' in the good neighbor 
provision as permitting states and EPA in implementing the good 
neighbor provision to evaluate downwind air quality problems, and the 
need for further upwind emission reductions, prospectively and 
coordinated with anticipated compliance timeframes. See North Carolina, 
531 F.3d at 913-14.
    EPA further disagrees that the D.C. Circuit's North Carolina 
decision constrains EPA to choosing the next relevant attainment date 
as its future analytic year. The North Carolina decision faulted EPA 
for not giving any consideration to upcoming attainment dates in 
downwind states when setting compliance deadlines for upwind emissions; 
there, EPA had evaluated only the feasibility of implementing upwind 
controls. Id. at 911-12. But the court did not hold that the CAA 
imposes strict deadlines for the implementation of good neighbor 
emission reductions. Nor did the court opine that EPA would never be 
justified in setting compliance dates that post-date downwind 
attainment dates or consider the feasibility of implementing upwind 
emission reductions. Indeed, in remanding the rule, the D.C. Circuit 
acknowledged that upwind compliance dates may, in some circumstances, 
follow attainment dates. Id. at 930 (instructing EPA to ``decide what 
date, whether 2015 or earlier, is as expeditious as practicable for 
states to eliminate their significant contributions to downwind 
nonattainment'').\6\
---------------------------------------------------------------------------

    \6\ EPA also disagrees with the commenters' contention that the 
North Carolina decision explicitly requires emission reductions, 531 
F.3d at 911-912, necessary to address the ``interfere with 
maintenance clause'' of the good neighbor provision to be aligned 
with downwind attainment dates. The commenters are conflating the 
court's holding that EPA should consider downwind attainment dates 
when setting compliance schedules for upwind state emission 
reductions with the court's separate holding that EPA must give 
independent significance to the ``interfere with maintenance'' 
clause when identifying downwind air quality problems. id. at 910-
911. The court did not explicitly indicate whether EPA was required 
to align emission reductions associated with maintenance receptors 
with downwind attainment dates, indicating only that EPA must 
``provide a sufficient level of protection to downwind states 
projected to be in nonattainment as of'' the future analytic year. 
Id. at 912 (emphasis added).
---------------------------------------------------------------------------

    While the commenters suggest that the court's reference to the 
phrase ``consistent with the provisions of this subchapter''--i.e., CAA 
Title I--imports downwind attainment dates from section 181 into the 
good neighbor provision, CAA section 181 itself does not impose 
inflexible deadlines for attainment. The general timeframes provided in 
the section 181(a)(1) table may be (and often are) modified pursuant to 
other provisions in section 181, considering factors such as measured 
ozone concentrations and the feasibility of implementing additional 
emission reductions. For example, the six-year timeframe for attainment 
of the 2008 ozone NAAQS in moderate areas could be extended by up to 
two years (to 2020), pursuant to section 181(a)(5). And pursuant to 
section 181(b)(2), when downwind areas are unable to implement 
sufficient reductions via feasible control technologies by one 
attainment date, those areas will be ``bumped up'' in classification 
and given a new attainment date with additional time to attain. With 
``bump-ups'' like this, the date for an area to attain the 2008 ozone 
NAAQS could be extended to 2021, 2027, and 2032, and each of these 
deadlines could be subject to further extensions of up to two years 
pursuant to section 181(a)(5). See also Whitman v. Am. Trucking Ass'ns, 
Inc., 531 U.S. 457, 493-94 (2001) (Breyer concurring) (considerations 
of costs and technological feasibility may affect deadlines selected by 
EPA). Thus, the commenters' premise that all upwind emission reductions 
must occur before the earliest downwind attainment date, feasible or 
not, is inconsistent with the framework of section 181 as it applies to 
downwind states.
    Similarly, the D.C. Circuit's decision in NRDC, 777 F.3d at 468, 
does not stand for the proposition that EPA should ignore the 
feasibility of implementing emission reductions when addressing the 
good neighbor provision, or that such emission reductions are strictly 
required to be in place by a date certain. There, EPA had set 2008 
ozone standard attainment dates in December 2015 so that downwind 
states could use data from the 2015 ozone season to demonstrate 
attainment. Id. at 465. The NRDC court simply held that section 
181(a)(1) did not allow EPA this type of flexibility. The court's 
holding in NRDC did not speak to state planning or implementation 
requirements that apply for areas subject to those dates, or the 
various ways in which the date may be legally extended under the CAA. 
NRDC is therefore inapposite as to how the good neighbor provision 
should be harmonized with CAA statutory or regulatory dates for 
downwind states.
    Here, EPA has considered the downwind attainment dates for the 2008 
ozone NAAQS, consistent with the court's holding in North Carolina. As 
the commenters note, areas classified as moderate nonattainment areas 
currently have attainment dates of July 20, 2018, but the 2017 ozone 
season was the last full season from which data could be used to 
determine attainment of the NAAQS by that date. Given that the 2017 
ozone season has now passed, it is not possible to achieve additional 
emission reductions by the moderate area attainment date. It is 
therefore necessary to consider what subsequent attainment dates should 
inform EPA's analysis. The next attainment dates for the 2008 ozone 
NAAQS will be July 20, 2021, for nonattainment areas classified as 
serious, and July 20, 2027, for nonattainment areas classified as 
severe.\7\ Because the various attainment

[[Page 33735]]

deadlines are in July, which is in the middle of the ozone monitoring 
season for all states, data from the calendar year immediately prior to 
the attainment date (e.g., data from 2020 for the 2021 attainment date 
and from 2026 for the 2027 attainment date) are the last data that can 
be used to demonstrate attainment with the NAAQS by the relevant 
attainment date.
---------------------------------------------------------------------------

    \7\ While there are no areas (outside of California) that are 
currently designated as serious or severe for the 2008 ozone NAAQS, 
the CAA requires that EPA reclassify to serious any moderate 
nonattainment areas that fail to attain by their attainment date of 
July 20, 2018. Similarly, if any area fails to attain by the serious 
area attainment date, the CAA requires that EPA reclassify the area 
to severe.
---------------------------------------------------------------------------

    As discussed in the NPRM and later in this action, EPA has also 
considered the timeframes that would likely be required for 
implementing further emissions reductions as expeditiously as 
practicable and concluded that additional control strategies at EGUs 
and non-EGUs could not be implemented by the July 2021 serious area 
attainment date, and certainly not by the 2020 ozone season immediately 
preceding that attainment date. This consideration of feasibility is 
consistent with the considerations affecting the statutory timeframes 
imposed on downwind nonattainment areas under section 181. Therefore, 
because new emissions controls for sources in upwind states cannot be 
implemented feasibly for several years, and at that later point in time 
air quality will likely be cleaner due to continued phase-in of 
existing regulatory programs, changing market conditions, and fleet 
turnover, it is reasonable for EPA to evaluate air quality (at step one 
of the four-step framework) in a future year that is aligned with 
feasible control installation timing in order to ensure that the upwind 
states continue to be linked to downwind air quality problems when any 
potential emissions reductions would be implemented and to ensure that 
such reductions do not over-control relative to the identified ozone 
problem.
    Comment: One commenter notes that Delaware's Sussex County is a 
standalone nonattainment area and New Castle County is part of the 
Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE nonattainment area 
(Philadelphia NAA), with an attainment date of July 20, 2015. The CAA 
requires states to attain the ozone standards as expeditiously as 
practicable, but states significantly impacted by ozone pollution from 
upwind states will be unable to do so if good neighbor SIPs are not 
submitted with adequate remedies implemented prior to downwind 
attainment dates. Such SIPs are required to be addressed prior to the 
submission of attainment demonstrations by nonattainment areas, such 
that Kentucky should have addressed its significant contribution for 
the 2008 ozone NAAQS by March 2011. The commenter notes that states, 
including Kentucky, failed to submit SIPs and EPA failed to issue FIPs 
until the CSAPR Update was issued on October 26, 2016, well after the 
attainment dates for many areas, including Delaware.
    The commenter contends that EPA should have acted in a timely 
manner when states failed to adopt good neighbor provisions, and 
contends that Kentucky should have tied its analysis of significant 
contribution to the air quality at the time designations were made. The 
commenter asserts that EPA should have coupled its analysis and remedy 
with marginal attainment dates, as the first deadline for which 
nonattainment areas had to attain the standard. The commenter notes 
that EPA aligned its modeling analysis and implementation of the CSAPR 
Update with the moderate area attainment dates in 2018. While the 
commenter acknowledges that EPA could not have tied implementation of 
the CSAPR Update to the 2015 marginal area attainment date which had 
already passed, the commenter contends EPA should have addressed the 
need for good neighbor reductions relative to marginal nonattainment by 
aligning contribution modeling analysis for those states to some 
timeframe prior to the marginal attainment deadline. Instead, EPA's 
process takes place after the attainment dates, at which point EPA 
concludes that Delaware and all other areas outside of California do 
not need reductions to attain and maintain the NAAQS.
    Response: As explained earlier in this action, EPA has reasonably 
interpreted the term ``will'' in the good neighbor provision as 
permitting states and EPA in implementing the good neighbor provision 
to evaluate downwind air quality problems, and the need for further 
upwind emission reductions, prospectively and coordinated with 
anticipated compliance timeframes. See North Carolina, 531 F.3d at 913-
14. Accordingly, EPA does not agree that Kentucky should tie its 
analysis to either the date when designations were made or the marginal 
area attainment date, both of which have now passed. Were EPA to have 
evaluated good neighbor obligations based on a retrospective analysis 
of downwind air quality, the Agency could not have ensured that any 
emission reductions that may have been required would actually be 
necessary to address downwind air quality problems at the time they 
were implemented, which could result in impermissible over-control 
under the Supreme Court's holding in EPA v. EME Homer City Generation, 
L.P., 134 S. Ct. 1584, 1608 (2014) (EME Homer City). Whether Kentucky 
or EPA acted in a timely manner to develop a SIP or promulgate a FIP, 
respectively, does not lessen the obligation to comply the Supreme 
Court's holding in the present action.
    Comment: One commenter alleges that EPA's decision to untether its 
action from statutory nonattainment dates and instead focus on 2023 is 
arbitrary and capricious, as the ``agency has relied on factors which 
Congress has not intended it to consider'' and ``entirely failed to 
consider an important aspect of the problem.'' Motor Vehicle Mfrs. 
Ass'n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983). The 
commenter suggests that EPA takes a novel approach of selecting an 
analytic year five years in the future based on concerns that by the 
time any controls can be implemented, they may no longer be needed. The 
commenter cites both CSAPR and the CSAPR Update as examples of how EPA 
analyzed projected emissions in the upcoming year. The commenter states 
that EPA's logic is almost tantamount to urging upwind states to wait 
because downwind states will take care of the problem themselves.
    The commenter states that technical feasibility has been 
specifically rejected as a basis for ignoring attainment deadlines in 
North Carolina, and over-control is at best a secondary factor which 
does not justify complete departure from the plain text and controlling 
precedent. The commenter states that EPA's emphasis on over-control is 
contrary to EME Homer City, stating that when the Supreme Court upheld 
the consideration of cost-effectiveness in CSAPR and upheld EPA's 
immediate issuance of a FIP after disapproving a SIP, the Court clearly 
indicated that the key statutory mandate of the good neighbor provision 
is to expeditiously ``maximize achievement of attainment downwind.'' 
134 S. Ct. at 1590. The Court made concern about over-control secondary 
to that goal. Id. at 1609.
    The commenter further asserts that reliance on feasibility of 
implementing controls to justify delaying action or analysis until 2023 
is foreclosed by North Carolina, which specifically rejected the 
compliance deadlines in CAIR that were based on feasibility restraints 
but were not consistent with compliance deadlines for downwind states. 
When EPA has considered feasibility in analyzing ozone related good 
neighbor obligations since North Carolina, it has not been in the 
context of selecting an analytic year, but in allocating emission 
budgets. The commenter states that EPA's argument regarding feasibility 
also includes the

[[Page 33736]]

need for additional time for planning and coordination between EPA and 
states, but asserts that the courts have rejected claims that 
additional time is necessary to improve the quality or soundness of 
regulations. Sierra Club v. Johnson, 444 F. Supp. 2d 46, 53 (D.D.C. 
2006).
    One commenter states that EPA should focus on achieving available 
emission reductions on or before the 2020 ozone season (the next 
applicable attainment date), rather than looking ahead to 2023. The 
commenter states that by focusing on the timeframes to install new 
controls, EPA has not conducted an analysis of reductions available in 
the near term to see if there are additional NO<INF>X</INF> reduction 
strategies that are available prior to 2023. The commenter identified 
optimization of previously installed post-combustion controls as a 
potential NO<INF>X</INF> reduction strategy with reductions available 
immediately and at low cost. The commenter stated that EPA's concern 
with over-control must be evaluated relative to the attainment 
deadlines for the standard. Therefore, relying on EPA's 2023 modeling 
is inconsistent with the intent of the CAA to achieve standards as 
expeditiously as practicable.
    Another commenter states that EPA's rationale for use of a 2023 
modeling year rests on a speculative guess of the time required for two 
categories of cost-effective controls to be installed, starting from 
the date of its approval. The commenter contends that EPA cannot rely 
on the cost-effectiveness of EGU controls as the exclusive 
consideration in justifying a further five-year delay when a full 
remedy for Kentucky has already been unlawfully delayed for years. Even 
if EPA has a general duty to avoid over-control of upwind emissions, it 
cannot point to this duty to justify a strategy that postpones 
necessary controls. Rather, EPA should require these controls now, and 
then reevaluate them in a few years at the point when the purported 
over-control may actually occur.
    Response: EPA disagrees with the commenters' assertion that EPA has 
inappropriately weighted concerns about over-control of upwind state 
emissions. The Supreme Court and the D.C. Circuit have both held that 
EPA may not require emissions reductions (at step three of the 
framework) that are greater than necessary to achieve attainment and 
maintenance of the NAAQS in downwind areas. EME Homer City, 134 S. Ct. 
at 1608; EME Homer City Generation, L.P. v. EPA, 795 F.3d 118, 127 
(D.C. Cir. 2012) (EME Homer City II). While the Supreme Court indicated 
that ``EPA must have leeway'' to balance the possibilities of under-
control and over-control and that ``some amount of over-control . . . 
would not be surprising,'' the Court did not indicate that such over-
control was required. 134 S. Ct. at 1609. Rather, the Court held, ``If 
EPA requires an upwind State to reduce emissions by more than the 
amount necessary to achieve attainment in every downwind State to which 
it is linked, the Agency will have overstepped its authority, under the 
Good Neighbor Provision.'' Id. at 1608. On remand in EME Homer City II, 
the D.C. Circuit gave that holding further meaning when it determined 
that the CSAPR phase 2 ozone season NO<INF>X</INF> budgets for 10 
states were invalid because EPA's modeling showed that the downwind air 
quality problems to which these states were linked when EPA evaluated 
air quality projections in 2012 would be entirely resolved by 2014, 
when the phase 2 budgets were scheduled to be implemented. 795 F.3d at 
129-30. Thus, the Court did not find that over-control was a secondary 
consideration, but rather that it was a constraint on EPA's authority.
    To the extent that the commenters note that EPA chose an earlier 
analytic year in prior rulemakings, EPA notes that it has not done so 
in all rulemakings. In the NO<INF>X</INF> SIP Call, EPA evaluated air 
quality in 2007, nine years after the rule was promulgated. 63 FR 57377 
(October 27, 1998). In CAIR, which was promulgated in 2005, EPA 
evaluated air quality in 2009 and 2010, for the ozone and 
PM<INF>2.5</INF> NAAQS, respectively. 70 FR 25241 (May 12, 2005). Thus, 
EPA's approach in this action is not inconsistent with these prior 
actions. Although EPA evaluated relatively more near-term air quality 
in CSAPR and CSAPR Update, EPA expected that certain cost-effective 
emission reductions could be implemented in the near-term in those 
actions. Here, EPA has already analyzed and implemented those cost-
effective control strategies that could be implemented quickly 
(including the optimization of existing post-combustion controls) to 
address the 2008 ozone NAAQS through the CSAPR Update FIPs. 
Accordingly, any further emission reductions that may be required to 
address the 2008 ozone NAAQS would necessarily be implemented through 
control strategies that cannot be implemented in the near term and 
require a longer period for implementation. In addition, NO<INF>X</INF> 
emissions levels are expected to decline in the future through the 
combination of the implementation of existing local, state, and federal 
emissions reduction programs and changing market conditions for 
generation technologies and fuels.\8\ Therefore, were EPA to evaluate 
downwind ozone concentrations and upwind state linkages in a future 
year that precedes the date when actual compliance is anticipated 
(i.e., the timeframe within which additional control strategies can 
feasibly be implemented), EPA could not ensure that the emission 
reductions will be ``necessary to achieve attainment'' in any downwind 
area by the time they were implemented. Such an approach would only 
replicate the circumstances the D.C. Circuit found impermissible in 
CSAPR.
---------------------------------------------------------------------------

    \8\ Annual Energy Outlook 2018. Electricity Supply, Disposition, 
Prices, and Emissions. Reference Case. Department of Energy, Energy 
Information Administration.
---------------------------------------------------------------------------

    The commenter's citation to Sierra Club v. Johnson is inapposite. 
In that case, EPA sought more time to promulgate regulations under the 
CAA after failing to perform the mandatory duties within the 
statutorily prescribed timeframe. 444 F. Supp. 2d at 52. Therefore, the 
court's reference to the Agency's need for ``additional time'' is in 
reference to the time required to conduct the rulemaking process. Id. 
at 53. The court was not interpreting the requirements of the good 
neighbor provision or any other provision regarding the time required 
for states or sources to implement controls under the CAA.
    Finally, the commenters misunderstand EPA's evaluation to the 
extent they suggest that EPA relied on the cost-effectiveness of 
controls for this action. EPA evaluated the feasibility of implementing 
various control options, without regard to cost, that had not 
previously been included in EPA's analysis of cost-effective controls 
in the CSAPR Update. EPA concluded that additional controls on either 
EGUs or non-EGUs--when considering multiple projects across multiple 
states and allowing for planning and permitting--would generally 
require four years or more to implement, which would lead to an 
implementation timeframe associated with the 2023 ozone season. Because 
the air quality modeling results for 2023 showed that air quality 
problems in the eastern U.S. would be resolved by 2023, EPA did not 
further evaluate the cost-effectiveness of the control options 
considered for the feasibility analysis.
    Comment: One commenter contends that EPA's insistence on fleetwide 
compliance is based on a circular argument wherein such a scheme would

[[Page 33737]]

cause labor and material shortages that would, in turn, require four 
years to implement, at which point they will be unnecessary. The 
commenter points out that this means there will be no labor shortage. 
The commenter notes that this is contrary to EPA's prior approaches in 
CSAPR where the agency segregated controls based on feasibility, 
including multiple phases, and conducted emissions analyses for both 
phases.
    One commenter states that EPA cannot rely on its analysis of 
alleged labor and materials shortages relating to installation of new 
controls at a ``fleet'' level. While EPA may prefer a regional 
approach, Congress did not establish a regional implementation plan 
requirement or mechanism, and EPA is not considering whether to approve 
a regional transport rule, nor a group of SIPs or FIPs. EPA is 
proposing to approve a single SIP from a single state and has not 
undertaken a study of the labor or materials market in Kentucky. 
Therefore, EPA's justification for allowing the delay of EGU controls 
for up to 48 months based on its speculative estimate of the time 
needed to install these controls on all sources within some 
unidentified region is arbitrary and capricious.
    One commenter states EPA's approach to evaluating potential 
NO<INF>X</INF> controls on a regional, rather than state-specific, 
basis ``undermines the intent of the CAA'' and causes Connecticut to be 
required to spend more to attempt to comply with the CAA than states 
that emit and contribute more to Connecticut's ozone problem.'' The 
commenter states as an example that it recently promulgated a 
reasonably available control technology (RACT) rule with a minimum 
control cost of $13,000 per ton. The commenter states that EPA's under 
controlling of emissions has led to delays in attainment and added cost 
for Connecticut despite ozone exceedances being overwhelmingly due to 
transported emissions.
    One commenter states that guidance provided in an informational 
memorandum issued by EPA in January 2015 \9\ specifically references 
upwind state responsibilities in determining the states' good neighbor 
SIP transport obligations. EPA further states in its proposal that it 
believes the most appropriate approach to evaluating potential upwind 
obligations for Kentucky (where several other states are also linked to 
the Harford County receptor) is to evaluate potential NO<INF>X</INF> 
control strategies on a regional, rather than state-specific basis. The 
commenter asserts that this is inconsistent with the scope of EPA's SIP 
approval authority under CAA section 110, which involves intra-state, 
rather than regional, plans to attain the NAAQS. The commenter also 
contends that EPA's position is contrary to its previous positions in 
denying Maryland's request for a super-regional nonattainment area 
under CAA section 107, and in denying Maryland's section 176A petition 
requesting expansion of the Ozone Transport Region (OTR). To the 
contrary, EPA stated in those actions that CAA sections 110 and 126 
were more appropriate mechanisms for controlling interstate pollution 
transport.
---------------------------------------------------------------------------

    \9\ Memorandum from Stephen D. Page to Regional Air Division 
Directors, ``Information on the Interstate Transport `Good Neighbor' 
Provision for the 2008 Ozone National Ambient Air Quality Standards 
(NAAQS) under Clean Air Act (CAA) Section 110(a)(2)(D)(i)(I)'' 
(January 22, 2015) (January 2015 Transport Memo), available at 
https://www.epa.gov/sites/production/files/2015-11/documents/goodneighborprovision2008naaqs.pdf.
---------------------------------------------------------------------------

    Response: EPA disagrees with the commenters that it is 
inappropriate to evaluate the feasibility of implementing 
NO<INF>X</INF> controls on a regional or fleetwide basis. EPA's 
analysis of the feasibility of NO<INF>X</INF> control strategies 
reflects the time needed to plan for, install, test, and place into 
operation new EGU and non-EGU NO<INF>X</INF> reduction strategies 
regionally--i.e., across multiple states. This regional analytic 
approach is consistent with the regional nature of interstate ozone 
pollution transport. The Agency adopted this approach based on previous 
interstate ozone transport analyses showing that where eastern downwind 
ozone problems are identified, multiple upwind states typically are 
linked to these problems. See 81 FR at 74538 (October 26, 2016). 
Specifically of relevance to this action, EPA's assessment in the CSAPR 
Update found that 21 states would continue to contribute greater than 
or equal to 1 percent of the 2008 ozone NAAQS to identified downwind 
nonattainment or maintenance receptors in multiple downwind states in 
2017, even after implementation of the CSAPR Update FIPs. Thus, to 
reasonably address these ozone transport problems, EPA must identify 
and apportion emission reduction responsibility across multiple upwind 
states. In other words, EPA's analysis should necessarily be regional, 
rather than focused on individual linkages. Where such an analysis is 
needed for multiple states, the inquiry into the availability and 
feasibility of control options is necessarily considerably more 
complicated than for a single state or sector.
    EPA further disagrees that this approach is inconsistent with EPA's 
prior rulemakings, like CSAPR, where the Agency implemented controls in 
multiple phases. In CSAPR, EPA evaluated downwind air quality and 
upwind state linkages based on 2012 air quality and contribution 
modeling. The commenter is correct that EPA then implemented two phases 
of emission budgets, with a first phase of reductions implemented 
beginning in 2012 and a second phase of reductions implemented 
beginning in 2014. However, in subsequent litigation, a number of the 
phase 2 ozone season NO<INF>X</INF> emission budgets were remanded 
because EPA's modeling showed that there would no longer be downwind 
air quality problems in many areas in 2014. See EME Homer City II, 795 
F.3d at 129-30. Thus, EPA cannot require additional emission reductions 
in a future year if EPA's data show that there will no longer be 
downwind air quality problems in that year. Here, EPA implemented a 
first phase of post-CSAPR emission reductions in 2017 via the CSAPR 
Update. In this action, Kentucky and EPA have evaluated whether a 
second phase of post-CSAPR emission reductions is necessary and 
authorized by the good neighbor provision and determined that it is not 
because downwind air quality problems identified in 2017 with respect 
to the 2008 ozone NAAQS will be resolved by 2023.
    EPA does not agree that this approach is inconsistent with the 
scope of EPA's authority under section 110. The fact that EPA is, in 
this action, acting on a single SIP does not alter the regional nature 
of ozone pollution transport. As the Supreme Court noted, the good 
neighbor provision presents a ``thorny causation problem'' with respect 
to ozone pollution transport in light of the ``collective and 
interwoven contributions of multiple upwind States,'' EME Homer City, 
134 S. Ct. at 1604. The Court affirmed EPA's consideration of the 
problem on a regional rather than localized scale. Id. at 1606-07 
(affirming EPA's use of cost to apportion upwind state emission 
reduction responsibility). The Court did not indicate that this 
endorsement of a regional assessment was appropriate only when EPA is 
taking a regional action. Rather, it is reasonable for EPA to interpret 
the implementation of the good neighbor provision for a particular 
NAAQS consistently regardless of the scope of the action. Consistent 
with this opinion, it is therefore also reasonable for EPA to view an 
individual state's implementation plan through a regional lens.
    EPA also does not agree that the Agency's approach to evaluating 
interstate ozone transport under section

[[Page 33738]]

110 is inconsistent with its recent action on a section 176A petition 
to expand the OTR or EPA's designations under section 107. EPA denied 
the section 176A petition because it concluded that any remaining 
interstate transport problems could be better addressed via the good 
neighbor provision, which EPA and the states can use to make decisions 
regarding which precursor pollutants to address, which sources to 
regulate, and what amount of emission reductions to require, 
flexibilities that are not available with respect to control 
requirements applicable to sources in the OTR. See 82 FR 51244-46 
(November 3, 2017). EPA did not deny the petition because it concluded 
that ozone transport was not regional; on the contrary, EPA explicitly 
acknowledged the regional nature of ozone transport in its action. See 
82 FR 6511 (January 19, 2017).
    With respect to the request for a super-regional nonattainment area 
under section 107, EPA has consistently explained that such an approach 
is not consistent with the statutory language.\10\ CAA section 
107(d)(1) provides that areas designated nonattainment should include 
any ``nearby'' area contributing to a violation of the NAAQS. EPA has 
repeatedly explained that the proposal for broad super-regional 
nonattainment areas go beyond this statutory definition by including 
areas that are not necessarily ``nearby'' but contribute to 
nonattainment through long-range transport, an issue that other 
sections of the CAA, like the good neighbor provision, are designed to 
address. Thus, rather than contradict EPA's analysis of ozone transport 
regionwide, EPA's prior actions regarding requests for a super-regional 
nonattainment area support EPA's view that such an approach is 
appropriately applied under the good neighbor provision.
---------------------------------------------------------------------------

    \10\ See, e.g., Responses to Significant Comments on the State 
and Tribal Designation Recommendations for the 2008 Ozone National 
Ambient Air Quality Standards (NAAQS), EPA-HQ-OAR-2008-0476-0675, 
Section 3.1.2 (April 2012); New York-Northern New Jersey, Long-
Island, NY-NJ-CT Nonattainment Area, Final Area Designations for the 
2015 Ozone National Ambient Air Quality Standards Technical Support 
Document, at 28-29.
---------------------------------------------------------------------------

    Finally, EPA does not agree that its conclusion that no additional 
emission reductions would be required of upwind states undermines its 
fleetwide analysis of labor and material shortages. EPA's analysis was 
based on the assumption that if additional controls would be required 
of upwind states, they would be required on a region-wide basis. This 
was a reasonable assumption in light of the complex, regional nature of 
ozone pollution transport. Had EPA identified remaining downwind air 
quality problems in the future analytic year, it would have been 
reasonable to assume that multiple upwind states would contribute to 
any remaining air quality problem consistent with EPA's previous ozone 
transport analyses and thus multiple upwind states could be required to 
concurrently implement emission reductions. As explained earlier, while 
EPA has phased-in application of controls in some circumstances, those 
phases were implemented based on consistent, region-wide compliance 
deadlines. The commenters do not explain how EPA could set different 
compliance dates for different states in the CSAPR Update region to 
require additional emission reductions while also insuring that states' 
obligations were addressed in a consistent, non-arbitrary manner that 
did not lead to over- or under-control.
    Comment: One commenter states that EPA's argument that extensive 
planning is required to install controls is uncompelling because EPA 
has had ample time to plan. The CSAPR Update repeatedly emphasizes that 
states, including Kentucky, were expected to have remaining obligations 
after the implementation of the CSAPR Update. Moreover, EPA has been on 
notice that it would be required to take action on Kentucky by June 
2018 as required by court order.
    Response: The commenter misunderstands EPA's reference to the 
planning required to implement additional controls. The individual 
sources, not EPA, must engage in appropriate planning anytime they 
install new control devices. As discussed in more detail later, 
installing new selective catalytic reduction (SCR) or selective non-
catalytic reduction (SNCR) controls for EGUs or non-EGUs generally 
involves the following steps: Conducting an engineering review of the 
facility; advertising and awarding a procurement contract; obtaining a 
construction permit; installing the control technology; testing the 
control technology; and obtaining or modifying an operating permit.\11\ 
Scheduled curtailment, or planned outage, for pollution control 
installation would be necessary to complete either SCR or SNCR 
projects. Given that peak demand for EGUs and rule compliance would 
both fall in the ozone season, such sources would likely try to 
schedule installation projects for the ``shoulder'' seasons (i.e., the 
spring and/or fall seasons), when electricity demand is lower than in 
the summer, reserves are higher, and ozone season compliance 
requirements are not in effect. In addition to the coordination of 
scheduled curtailment, an appropriate compliance timeframe would need 
to accommodate the additional coordination of labor and material supply 
necessary for any fleet-wide mitigation efforts. More details regarding 
these considerations are outlined later in this preamble.
---------------------------------------------------------------------------

    \11\ Final Report: Engineering and Economic Factors Affecting 
the Installation of Control Technologies for Multipollutant 
Strategies, EPA-600/R-02/073 (October 2002), available at https://nepis.epa.gov/Adobe/PDF/P1001G0O.pdf.
---------------------------------------------------------------------------

    Many of these materials, installation, and labor concerns are also 
relevant for non-EGU control technologies. Thus, the implementation of 
new EGU and non-EGU NO<INF>X</INF> reduction strategies, especially 
when implemented across a broad region of states, requires extensive 
time and planning by the affected sources.
    Moreover, while EPA indicated that the CSAPR Update may not fully 
address states' good neighbor obligations, the Agency did not 
definitively conclude that more emission reductions would necessarily 
be required. Nor did the Agency indicate what sources would likely be 
controlled, in which states, or via what control strategies if 
additional emission reductions were in fact required. Thus, EPA does 
not agree with the commenter's suggestion that it was reasonable for 
any particular sources to begin planning for the implementation of new 
controls before EPA or the states completed further analysis and 
promulgated requirements actually requiring additional emission 
reductions.
    Comment: One commenter states that EPA's finding that 
implementation of control strategies is not feasible until during or 
after the 2022 ozone season is false and contradicted by the evidence 
EPA presents. The commenter contends that EPA's conclusion that 48 
months may be necessary to implement emission reductions is contrary to 
EPA's own experience of pollution control and belied by EPA's own 
finding that Kentucky will likely outperform its CSAPR Update 
obligations. Both CSAPR and CSAPR Update were implemented on much 
shorter timescales, with immediate reductions available in both cases 
in under one year, and post-combustion controls being required within 
three years under CSAPR.
    Response: EPA has evaluated the feasibility of implementing 
controls on a region-wide basis, considering markets for labor and 
materials necessary for implementing controls across multiple sources 
in multiple states. Thus, examples where individual sources might have 
installed controls more

[[Page 33739]]

quickly do not speak to what is reasonable to require across a state or 
a region, and therefore do not contradict EPA's analysis.
    Moreover, EPA's projections of EGU emission levels in Kentucky in 
2023 also do not contradict EPA's conclusion that 48 months should be 
provided for the region-wide implementation of new NO<INF>X</INF> post-
combustion controls. Kentucky's CSAPR Update budget is not an emissions 
floor. It represents emission reductions reflecting control strategies 
determined to be cost-effective and feasible to implement by the first 
compliance year in 2017 (e.g., SCR optimization). However, market 
conditions that did not influence quantification of the budgets can 
also drive further emission reductions in future years, including 
variables such as low natural gas prices and new, lower-cost competitor 
generation in downwind states, and can lead to utility decisions to 
retire aging assets. In addition, sources may install new controls 
after the 2017 ozone season that would not have been considered when 
EPA calculated the budgets.\12\ These factors can and do lead to state-
emission levels often being significantly lower than its emission 
budget in future compliance years. EPA's projected emissions level in 
2023 captures these types of recently announced and known 
infrastructure changes and fleet turnover and it is therefore 
reasonable that the 2023 projected EGU emissions would be below 
Kentucky's CSAPR Update budget established for a first compliance year 
of 2017.
---------------------------------------------------------------------------

    \12\ EPA notes that the only new post-combustion controls 
assumed in EPA's projection of 2023 EGU emissions in Kentucky were 
at Shawnee units 1 and 4. Both of these units were required to 
implement SCR as of December 31, 2017 pursuant to a compliance 
agreement with EPA finalized in 2011. See 76 FR 22095 (April 20, 
2011) and https://www.epa.gov/enforcement/tennessee-valley-authority-clean-air-act-settlement.
---------------------------------------------------------------------------

    While CSAPR and CSAPR Update were implemented more quickly than the 
four years considered in this action, neither CSAPR nor CSAPR Update 
anticipated that sources would implement new post-combustion 
NO<INF>X</INF> controls. See 76 FR 48302 (August 8, 2011); 81 FR 74541 
(October 26, 2016). Rather, the ozone season emission budgets for both 
rules only considered the near-term emission reductions that could be 
achieved from implementation of control strategies other than new post-
combustion controls, including the optimization of existing post-
combustion controls and implementation of new combustion controls. See 
76 FR 48256 (August 8, 2011); 81 FR 74541 (October 26, 2016). With 
respect to the 2008 ozone NAAQS, EPA already implemented the near-term 
emission reductions that were cost-effective in the CSAPR Update. 
Accordingly, EPA disagrees with the commenter's suggestion that there 
may be substantial immediate NO<INF>X</INF> reductions available that 
could be implemented on a more immediate timeframe at this time.
    EPA notes that it did evaluate post-combustion controls in CSAPR 
with respect to sulfur dioxide (SO<INF>2</INF>) emission reductions 
necessary to address PM<INF>2.5</INF> and established emission budgets 
reflecting the possible implementation of scrubbers three years 
following rule promulgation. However, to the extent labor and supply 
markets were a consideration for installation timing requirements for 
scrubbers in CSAPR in 2011, those variables may have changed over the 
last seven years. Moreover, EPA established budgets for NO<INF>X</INF> 
in CSAPR based on a cost threshold of $500 per ton, which was not 
anticipated to drive significant, labor- and resource-intensive SCR 
installation within that timeframe. See 76 FR 48302 (August 8, 2011).
    Comment: One commenter asserts that EPA has not explained why it 
still lacks information on the potential for cost-effective emission 
reductions from non-EGUs, two years after the CSAPR Update was 
promulgated. EPA's analysis is lacking any analysis of actual cost-
effectiveness numbers for non-EGU controls, relying instead on an 
``implication'' from two-year old public comments that non-EGU controls 
would be relatively less cost-effective than EGU controls. EPA ignores 
its own framework, which calls for determining the availability and 
cost-effectiveness of non-EGU controls, despite identifying the need to 
do so in the CSAPR Update. In a footnote, the commenter notes that EPA 
represented to the court in a mandatory duty suit that it was taking 
steps to improve its data to evaluate NO<INF>X</INF> reduction 
potential from non-EGUs, which it expected to complete by November 
2017. EPA has not accounted for any of the stakeholder reviewed 
information on non-EGU emissions reductions and costs that it should 
have amassed in the last year and a half.
    The commenter further contends that EPA has changed its regulatory 
position without reasonable explanation. In the CSAPR Update, EPA 
indicated that evaluating full interstate transport obligations is 
subject to an evaluation of the contribution to interstate transport 
from non-EGUs, but EPA has unexpectedly changed course and stated that 
no such evaluation is necessary. This is an unexplained, arbitrary and 
capricious change in policy.
    One commenter states that with respect to non-EGU sources, EPA 
``has documented multiple cost-effective controls that can be 
implemented within one year'' in the ``Assessment of Non-EGU 
NO<INF>X</INF> Emissions Controls, Costs of Controls and Time for 
Compliance Final TSD'' dated August 2016 available in the docket for 
the final CSAPR Update Rule. The commenter notes that EPA has dismissed 
these potential benefits as ``uncertain'' and states that EPA ``cannot 
continue to invoke the prospect of an uncertain future to limit its 
responsibility to satisfy its statutory mandate.''
    Response: EPA first notes that it is not relying on its lack of 
information with respect to the cost-effectiveness of non-EGUs to 
support this final action. EPA evaluated the feasibility of 
implementing various control options, without regard to cost, that had 
not previously been included in EPA's analysis of cost-effective 
controls in the CSAPR Update. EPA concluded that additional controls--
on either EGUs or non-EGUs--would generally require four years to 
implement, which would lead to an implementation timeframe associated 
with the 2023 ozone season. Because the air quality modeling results 
for 2023 showed that air quality problems in the eastern U.S. would be 
resolved by 2023, EPA did not further evaluate the cost-effectiveness 
of the control options considered for the feasibility analysis. This 
approach is consistent with EPA's four-step framework, and does not 
rely on the relative cost-effectiveness of controls for non-EGUs.
    Because EPA did not need to evaluate either the cost-effectiveness 
or NO<INF>X</INF> reduction potential of either EGU or non-EGU sources, 
the commenter's concern with whether EPA has completed steps to improve 
its data on these issues is irrelevant. Nonetheless, EPA notes that the 
particular efforts outlined in the court filing referred to by the 
commenter were in support of EPA's request in a mandatory duty suit 
that the court permit the Agency several years to develop a rulemaking 
to address the good neighbor obligations with respect to the 2008 ozone 
NAAQS for Kentucky and 20 other states. In that filing, EPA outlined 
steps that the Agency believed would be necessary to promulgate a 
rulemaking if EPA's analysis demonstrated that additional emission 
reductions would be required from sources in upwind states, including 
what EPA viewed as necessary analysis regarding non-EGUs. EPA 
acknowledged in that same

[[Page 33740]]

declaration that one possible result of the litigation could be a 
determination that downwind air quality problems would be resolved, in 
which case a cost-effectiveness analysis would be unnecessary. See 
Decl. of Janet G. McCabe para. 98, Sierra Club v. Pruitt, No. 3:15-cv-
04328-JD (N.D. Cal. Dec. 15, 2016). As EPA could not know the results 
of any future air quality modeling before it was performed, EPA's 
proposed timeline assumed that such an analysis could be required. Id. 
para. 170. Ultimately, the court disagreed with EPA's proposed timeline 
and provided only one year--until June 30, 2018--for promulgation of a 
rulemaking addressing Kentucky's good neighbor obligation, which was 
insufficient time to complete all of the steps outlined in EPA's 
declaration, thereby requiring EPA to prioritize certain steps and 
eliminate others, including the additional efforts intended to improve 
data regarding the cost-effectiveness of controls. Nonetheless, because 
the first step of EPA's analysis demonstrated that there would be no 
remaining air quality problems in 2023 in the eastern U.S., it was 
unnecessary for EPA to finalize the efforts to improve its data 
regarding the cost-effectiveness of controls before finalizing this 
action. Thus, the representations that EPA made to the court regarding 
the steps necessary to take this action no longer apply under the 
present circumstances.
    Thus, EPA's analysis is not a change in policy. In the CSAPR 
Update, EPA only stated it could not conclude, at that time, that 
additional reductions from NO<INF>X</INF> sources (including non-EGUs) 
would not be necessary to fully resolve these obligations. While EPA 
did indicate that it anticipated the need to evaluate non-EGUs to fully 
evaluate the full scope of upwind states' good neighbor obligations, 
the Agency has done so here. In selecting the appropriate future 
analytic year in which to evaluate air quality, contributions, and 
NO<INF>X</INF> reduction potential, EPA considered the implementation 
timeframes for controls at EGUs as well as non-EGUs. As noted in the 
NPRM and explained further in this action, EPA's analysis showed that 
there would be no remaining air quality problems in 2023 in the eastern 
U.S., and thus EPA has concluded that no such additional reductions 
beyond those on-the-books or on-the-way are necessary, whether from 
non-EGUs or otherwise, to bring downwind areas into attainment of the 
2008 ozone NAAQS.
    Finally, the commenter is correct that EPA included preliminary 
estimates of installation times for some non-EGU NO<INF>X</INF> control 
technologies in a technical support document for the CSAPR Update 
entitled Assessment of Non-EGU NO<INF>X</INF> Emission Controls, Cost 
of Controls, and Time for Compliance Final Technical Support Document 
(Final Non-EGU TSD). These preliminary estimates were based on research 
from a variety of information sources, including:
    <bullet> Typical Installation Timelines for NOX Emissions Control 
Technologies on Industrial Sources, Institute of Clean Air Companies, 
December 2006 (all sources except cement kilns and reciprocating 
internal combustion engines (RICE)); \13\
---------------------------------------------------------------------------

    \13\ Institute of Clean Air Companies, Typical Installation 
Timelines for NOX Emissions Control Technologies on Industrial 
Sources, December 2006, available at https://c.ymcdn.com/sites/icac.site-ym.com/resource/resmgr/ICAC_NOX_Control_Installatio.pdf.
---------------------------------------------------------------------------

    <bullet> Cement Kilns Technical Support Document for the NOX FIP, 
US EPA, January 2001; \14\ and
---------------------------------------------------------------------------

    \14\ US EPA, Cement Kilns Technical Support Document for the 
NO<INF>X</INF> FIP, January 2001, available at https://www.regulations.gov/document?D=EPA-HQ-OAR-2015-0500-0094.
---------------------------------------------------------------------------

    <bullet> Availability and Limitations of NOX Emission Control 
Resources for Natural Gas-Fired Reciprocating Engine Prime Movers Used 
in the Interstate Natural Gas Transmission Industry, Innovative 
Environmental Solutions Inc., July 2014 (prepared for the INGAA 
Foundation).\15\
---------------------------------------------------------------------------

    \15\ INGAA Foundation, Availability and Limitations of 
NO<INF>X</INF> Emission Control Resources for Natural Gas-Fired 
Reciprocating Engine Prime Movers Used in the Interstate Natural Gas 
Transmission Industry, Innovative Environmental Solutions Inc., July 
2014, available at http://www.ingaa.org/Foundation/Foundation-Reports/NOX.aspx.
---------------------------------------------------------------------------

    EPA's analysis in the Final Non-EGU TSD focused on potential 
control technologies within the range of costs considered in the final 
CSAPR Update for EGUs, i.e., those controls available at a marginal 
cost of $3,400 per ton (2011 dollars) of NO<INF>X</INF> reduced or 
less. EPA's analysis did not evaluate implementation timeframes or 
potential emissions reductions available from controls at higher cost 
thresholds. See Final Non-EGU TSD at 18. This focus excluded some 
emissions source groups with emissions reduction potential at a 
marginal cost greater than $3,400 per ton, including: Industrial/
commercial/institutional boilers using SCR and low-NO<INF>X</INF> 
burners (LNB); and catalytic cracking units, process heaters, and coke 
ovens using LNB and flue gas recirculation. However, while the 
emissions reduction potential from these source groups is uncertain, 
the timeframe for these control technologies would be subject to 
similar considerations and limitations discussed in the following 
paragraphs.
    Among the control technologies that were evaluated in the Final 
Non-EGU TSD, EPA identified six categories of common control 
technologies available for different non-EGU emissions source 
categories. Id. at 19. For four of the technology categories (SNCR, 
SCR, LNB, and mid-kiln firing), EPA preliminarily estimated that such 
controls could be installed in approximately one year or less in some 
unit-specific cases. Installation time estimates presented in the Final 
Non-EGU TSD begin with control technology bid evaluation (bids from 
vendors) and end with the startup of the control technology.\16\ See 
Final Non-EGU TSD at 20. For the other two technology categories 
(biosolid injection technology (BSI) and OXY-firing) as well as one 
emissions source category (RICE), EPA had no installation time 
estimates or uncertain installation time estimates. For example, EPA 
found that the use of BSI is not widespread, and therefore EPA does not 
have reliable information regarding the time required to install the 
technology on cement kilns. The installation timing for OXY-firing is 
similarly uncertain because the control technology is installed only at 
the time of a furnace rebuild, and such rebuilds occur at infrequent 
intervals of a decade or more.
---------------------------------------------------------------------------

    \16\ In the Final Non-EGU TSD, we present different installation 
time estimates for SCRs and non-EGUs than described in the NPRM and 
in this action for EGUs. These installation times are not 
inconsistent because: (i) The EGU time estimate of 39 months 
mentioned in the NPRM is based on multi-boiler installation and 
factors in a pre-vendor bid engineering study consideration, and 
(ii) the non-EGU SCR installation time estimates are based on 
single-unit installation and do not factor in pre-vendor bid 
evaluation.
---------------------------------------------------------------------------

    Moreover, for those categories for which preliminary estimates were 
available, as noted in the Final Non-EGU TSD, the single unit 
installation time estimates provided do not account for additional 
important considerations in assessing the full amount of time needed 
for installation of NO<INF>X</INF> control measures at non-EGUs; those 
considerations include time, labor, and materials needed for 
programmatic adoption of measures and time required for installing 
controls on multiple sources in a few to several non-EGU sectors across 
the region. The preliminary estimates of installation time shown in the 
Final Non-EGU TSD are for installation at a single source and do not 
account for the time required for installing controls to achieve 
sector-wide compliance. When considering installation of control 
measures on sources regionally and across non-EGU sectors, the time for 
full sector-wide compliance is uncertain, but it is likely longer than 
the installation times shown

[[Page 33741]]

for control measures as mentioned above for individual sources in the 
Final Non-EGU TSD. Regional, sector-wide compliance could be slowed 
down by limited vendor capacity, limited available skilled labor for 
manufacturers such as boilermakers (who produce steel fabrications, 
including those for pollution control equipment), availability of raw 
materials and equipment (e.g., cranes) for control technology 
construction, and bottlenecks in delivery and installation of control 
technologies. Some of the difficulties with control technology 
installation as part of regional, sector-wide compliance at non-EGUs, 
such as availability of skilled labor and materials, could also have an 
impact on monitor installation at such sources. EPA currently has 
insufficient information on vendor capacity and limited experience with 
suppliers of control technologies and major engineering firms, which 
results in uncertainty in the installation time estimates for non-EGU 
sectors.
    In summary, there is significant uncertainty regarding the 
implementation timeframes for various NO<INF>X</INF> control 
technologies for non-EGUs. While EPA has developed preliminary 
estimates for some potential control technologies, these estimates do 
not account for additional considerations such as the impacts of 
sector- and region-wide compliance. For purposes of this analysis, EPA 
believes that it is reasonable to assume that it is likely that an 
expeditious timeframe for installing sector- or region-wide controls on 
non-EGU sources may collectively require four years or more.
    Comment: One commenter adds that the CSAPR Update considered SCR to 
be optimized if the unit achieves a rate of 0.10 lbs/mmBtu, but EPA did 
not examine the particular rates that can be achieved by Kentucky's 
EGUs. The commenter states that EPA should require Kentucky's EGUs to 
achieve an optimized emissions rate at each EGU based on the past best 
demonstrated ozone season average rates at the unit. The commenter 
states that such optimized rates would be reflective of a unit's actual 
reported data and would be considered well controlled while still 
allowing for fluctuation in operating conditions, as it would encompass 
a whole ozone season's worth of reported emission data. The commenter 
states that its own analysis indicates that, even after CSAPR Update 
implementation, Kentucky's coal-fired EGUs could have reduced 
NO<INF>X</INF> emissions by an additional 4,100 tons during the 2017 
ozone season and could have reduced daily NO<INF>X</INF> emissions by 
up to an additional 35 tons per day by optimizing existing controls at 
levels the EGUs had previously achieved. The commenter contends that 
optimization of existing controls is cost-effective and has already 
been shown to be achievable from past performance. The commenter 
further asserts that not requiring Kentucky's EGUs to optimize controls 
by this ozone season, at levels consistent with past best-demonstrated 
ozone season average rates at each EGU, goes against the intent of the 
CAA to reduce transported air pollution as expeditiously as 
practicable. The commenter provides suggested language that could be 
used to require specific coal-fired EGUs in Kentucky to optimize use of 
existing control technologies.
    Another commenter states that EPA's argument regarding installation 
of control devices on uncontrolled EGUs being unworkable (based on 
potential for delays due to shortages in qualified labor and material) 
ignores the potential for immediate reductions that can be had by 
optimizing existing EGU controls.
    Response: To the extent the commenters take issue with EPA's 
determination in the CSAPR Update that 0.10 lb/mmBtu was reasonable 
rate to reflect optimized existing SCR controls regionwide, EPA did not 
reopen that issue for comment in this rulemaking. EPA has already 
evaluated and implemented cost-effective NO<INF>X</INF> emission 
reductions associated with the optimization of existing SCRs. In 
establishing the CSAPR Update EGU ozone season NO<INF>X</INF> emissions 
budgets, the Agency quantified the emissions reductions achievable from 
all NO<INF>X</INF> control strategies that were feasible to implement 
in less than one year and cost-effective at a marginal cost of $1,400 
per ton of NO<INF>X</INF> removed.\17\ These EGU NO<INF>X</INF> control 
strategies were: Optimizing NO<INF>X</INF> removal by existing, 
operational SCR controls; turning on and optimizing existing idled SCR 
controls; installing state-of-the-art NO<INF>X</INF> combustion 
controls; and shifting generation to existing units with lower- 
NO<INF>X</INF> emissions rates within the same state. See 81 FR 74541 
(October 26, 2016). Thus, for the purposes of this action, EPA 
considers the turning on and optimizing of existing SCR controls to be 
a NO<INF>X</INF> control strategy that has already been evaluated and 
implemented in the final CSAPR Update. Any concerns regarding whether 
EPA appropriately considered these controls in the CSAPR Update are not 
within the scope of this action.
---------------------------------------------------------------------------

    \17\ The CSAPR Update was signed on September 7, 2016--
approximately eight months before the beginning of the 2017 ozone 
season on May 1.
---------------------------------------------------------------------------

    Moreover, the Agency believes that the resulting CSAPR Update 
emissions budgets are being appropriately implemented under the CSAPR 
NO<INF>X</INF> Ozone Season Group 2 allowance trading program. 
Preliminary data for the 2017 ozone season, which is the first CSAPR 
Update compliance period, indicate that power plant ozone season 
NO<INF>X</INF> emissions across the 22-state CSAPR Update region were 
reduced by 77,420 tons (or 21 percent) from 2016 to 2017.\18\ As a 
result, total 2017 ozone season NO<INF>X</INF> emissions from covered 
EGUs across the 22 CSAPR Update states were approximately 294,478 
tons,\19\ well below the sum of states' emissions budgets established 
in the CSAPR Update of 316,464 tons. At the state-level, preliminary 
2017 ozone season data indicate power plant emissions within Kentucky 
were reduced 5,424 tons (also 21 percent) from 2016 to 2017. As a 
result, emissions were 19,978 tons, well below Kentucky's CSAPR Update 
budget of 21,115 tons. More specifically, emissions from non-optimized 
SCR-controlled units (i.e., units with an emission rate greater than 
0.10 lb/mmBtu) in the CSAPR Update region were 82,321 tons in 2016. 
EPA's 2023 emission estimate for these same units post-optimization was 
40,590. Actual emissions in 2017 from these units was 41,706 tons, 
demonstrating that the CSAPR Update has successfully incentivized 
optimization of controls in Kentucky and across the CSAPR Update 
region.
---------------------------------------------------------------------------

    \18\ https://ampd.epa.gov/ampd/ (Data current as of March 1, 
2018).
    \19\ Id.
---------------------------------------------------------------------------

    To the extent that EPA's NPRM could be interpreted as having 
invited comment on this issue, EPA further notes that, in the CSAPR 
Update the Agency reviewed fleet-wide, SCR-controlled coal units from 
2009 to 2015 and calculated an average ozone season NO<INF>X</INF> 
emission rate across the fleet of coal-fired EGUs with SCR for each of 
these seven years, and used the third lowest average ozone season 
NO<INF>X</INF> rate. As described in that rule, EPA determined that it 
was not prudent to use either the lowest or second-lowest ozone season 
NO<INF>X</INF> rates to represent the optimization of controls because 
such a rate may reflect new SCR systems that have all new components 
(e.g., new layers of catalyst). See 81 FR 74543 (October 26, 2016). EPA 
determined that data from these new systems are not representative of 
ongoing achievable NO<INF>X</INF> rates considering broken-in

[[Page 33742]]

components and routine maintenance schedules. Moreover, there are 
market conditions, maintenance, and outages (scheduled and unscheduled) 
that can impact the utilization rates. These factors can fluctuate 
yearly and provide another set of reasons to not universally assume 
that the lowest rate for a unit can repeat itself on a yearly basis 
going forward. EPA determined instead that the third lowest fleet-wide 
average coal-fired EGU NO<INF>X</INF> rate for EGUs with SCR, or 0.10 
lbs/mmBtu, would be representative of ongoing achievable emission 
rates. The commenter has not provided any information to contradict 
this conclusion.
    EPA further notes that this rate was implemented as an upper limit, 
meaning that EPA did reflect units that had recently operated an a more 
efficient rate in the budget calculations. EPA considered the latest 
available data at the time of that rulemaking (i.e., 2015) that 
captured each unit's operation and performance under the latest fleet 
and market conditions. EPA used 0.10 lb/mmBtu as a ceiling in its 
budget calculation to reflect optimization of existing controls that 
were not achieving that level in 2015. However, the Agency used a rate 
of less than 0.10 lb/mmBtu if the unit was operating at that level in 
2015 and a rate of 0.075 lb/mmBtu for new SCRs. Thus, EPA's budget 
calculation and consequent emission reduction requirements did reflect 
the fact that some units can and do operate below 0.10 lb/mmBtu.
    Comment: One commenter states that EPA's speculative examination of 
the timeline required to install and run new EGU controls based on a 
cost-effectiveness threshold of $1,400 is unreasonable where there are 
existing EGU controls that EPA admits could be run, only at a higher 
cost. EPA's focus on its estimated timeline for design and installation 
of new, cost-effective EGU controls such as SCRs and SNCRs puts cost-
effectiveness above all else, and that EPA must take into account other 
statutory concerns and considerations (such as attainment deadlines for 
downwind states). The commenter contends that, while cost-effectiveness 
thresholds have been upheld as a reasonable consideration in 
prioritizing control of sources, these thresholds cannot conversely be 
used to justify unreasonable, protracted delay in requiring upwind 
emission reductions. If there are no EGU controls at a given cost 
threshold that can be installed in time to permit downwind states to 
meet their attainment deadlines, then EPA has set the cost-
effectiveness threshold too low or has defined the type of controls too 
narrowly.
    The commenter concludes that EPA's refusal to reconsider its cost-
effectiveness threshold of $1,400 per ton of NO<INF>X</INF> is 
arbitrary where EPA has concluded that idled SNCR controls are 
available for immediate emission reductions at a cost of $3,400 per 
ton. Moreover, EPA dismissed this control strategy without any analysis 
of whether SNCRs can be run at less than $3,400 per ton, which is 
arbitrary and capricious when downwind states such as New York are 
forced to reduce NO<INF>X</INF> by implementing RACT controls at costs 
of more than $5,000 per ton.
    One commenter states that the CSAPR Update failed to look at any 
short-term fixes, such as the operation of idled SNCR, that could now 
be benefiting downwind areas. The commenter notes that the CSAPR Update 
also ruled out restarting idled SNCR based on the conclusion that 
$3,400 per ton was not cost effective, despite the fact that New York 
and other downwind states commonly apply RACT at a cost threshold of 
$5,000 per ton and greater.
    Another commenter states that the control costs of $1,400 per ton 
considered in the Kentucky SIP are too low and that EPA should require 
Kentucky to analyze all options available. The commenter states that 
Kentucky should not limit its control costs to those in the CSAPR 
Update since ``EPA considered this rule a partial remedy.'' The 
commenter provides as an example that ``EPA identified an additional 
measure that could be undertaken immediately'' in turning on existing 
idled SNCRs. The commenter states that EPA should also consider 
evaluating cost effectiveness of controls on an ozone season day rather 
than an annual basis, in order to address the need to lower emissions 
on high ozone days.
    Response: EPA first notes that the commenters misunderstand EPA's 
evaluation in this action to the extent they suggest that Kentucky or 
EPA relied on the cost-effectiveness of controls in order to select an 
appropriate future analytic year. As explained earlier, EPA evaluated 
the feasibility of implementing, without regard to cost, various 
control options that had not previously been included in EPA's analysis 
of cost-effective controls in the CSAPR Update. EPA concluded that 
additional controls on either EGUs or non-EGUs would generally require 
four years to implement, which would lead to an implementation 
timeframe associated with the 2023 ozone season. Had EPA identified 
downwind air quality problems to which upwind states continued to be 
linked in 2023, EPA would have proceeded to the next steps in its four-
step analytic framework and evaluated the cost-effectiveness of all 
available controls, considering the achievable emission reductions and 
anticipated improvements in downwind air quality at all cost 
thresholds. However, EPA did not further evaluate the cost-
effectiveness of the control options considered for the feasibility 
analysis because EPA lacks authority to require additional emission 
reductions in 2023 in light of the modeling results showing that air 
quality problems in the eastern U.S. would be resolved by that time. 
See EME Homer City II, 795 F.3d at 129-30 (finding emissions budgets 
for 10 states were invalid because EPA's modeling showed that the 
downwind air quality problems to which these states were linked when 
EPA evaluated projected air quality in 2012 would be entirely resolved 
by 2014).
    Similarly, to the extent the commenter suggests cost-effectiveness 
should be evaluated on particular days, rather than over the ozone 
season, this comment is not material to this action because EPA's 
analysis has concluded at step one of the four-step framework.
    EPA did not reevaluate the feasibility of near-term control 
strategies in order to inform the selection of a future analytic year 
for this action because both the feasibility and cost-effectiveness of 
those control strategies were already fully evaluated in the CSAPR 
Update. Thus, EPA acknowledges that the operation of idled SNCR 
controls could physically be implemented more quickly than four years, 
but EPA already evaluated whether this control was cost-effective to 
implement relative to other near-term control strategies in the CSAPR 
Update and concluded that it was not.\20\ In the CSAPR Update, EPA 
identified a marginal cost of $3,400 per ton as the level of uniform 
control stringency that represents turning on and fully

[[Page 33743]]

operating idled SNCR controls.\21\ Ultimately, the CSAPR Update 
finalized emissions budgets using $1,400 per ton control stringency, 
finding that this level of stringency represented the control level at 
which incremental EGU NO<INF>X</INF> reductions and corresponding 
downwind ozone air quality improvements were maximized with respect to 
marginal cost. In finding that use of the $1,400 control cost level was 
appropriate, EPA established that the more stringent emissions budget 
level reflecting $3,400 per ton (representing turning on idled SNCR 
controls) yielded fewer additional emissions reductions and fewer air 
quality improvements relative to the increase in control costs. 
Specifically, EPA's analysis showed that the additional reductions from 
the operation of idling SNCRs in Kentucky would only result in a 0.5 
percent decrease in the Commonwealth's emission budget (from 21,115 to 
21,007 tons). See 81 FR 74548 (October 26, 2016). In other words, based 
on the CSAPR Update analysis, establishing emissions budgets at $3,400 
per ton, and therefore developing budgets based on operation of idled 
SNCR controls, was determined not to be cost-effective for addressing 
downwind air quality problems under the good neighbor provision 
obligations for the 2008 ozone NAAQS. See 81 FR 74550 (October 26, 
2016). EPA believes that the strategy of turning on and fully operating 
idled SNCR controls was appropriately evaluated in the CSAPR Update 
with respect to addressing interstate ozone pollution transport for the 
2008 ozone NAAQS. Accordingly, EPA is not further assessing this 
control strategy for purposes of identifying an appropriate future 
analytic year. EPA did not reopen that issue for comment in this 
rulemaking, and the comments are therefore not within the scope of this 
action. To the extent that the commenter believes that EPA's analysis 
of SNCR controls in the CSAPR Update was flawed, the time to contest 
that analysis was during that rulemaking.
---------------------------------------------------------------------------

    \20\ EPA notes that this conclusion that the feasibility of 
implementing SNCR should not inform the potential compliance 
timeframe and analytic year would not have precluded EPA from 
considering whether the operation of SNCR would be cost-effective 
relative to the installation of post-combustion controls. Had EPA, 
at step one of the four-step framework, identified continued 
downwind air quality problems in 2023, EPA could have considered in 
subsequent steps whether to require emission reductions consistent 
with operation of existing SNCR in addition to considering whether 
to require emission reductions consistent with implementation of new 
post-combustion controls. However, because EPA has already concluded 
that operation of existing SNCR is not cost-effective in the near-
term, it would not be reasonable for EPA to select an earlier 
analytic year that would only be consistent with the timeframe for 
implementing that non-cost-effective near-term compliance strategy.
    \21\ See EGU NO<INF>X</INF> Mitigation Strategies Final Rule TSD 
(docket ID EPA-HQ-OAR-2015-0500-0554, available at 
www.regulations.gov and https://www.epa.gov/sites/production/files/2017-05/documents/egu_nox_mitigation_strategies_final_rule_tsd.pdf) 
(NO<INF>X</INF> Mitigation Strategies TSD).
---------------------------------------------------------------------------

    To the extent the commenters suggest that EPA must select a higher 
cost threshold in order to ``permit downwind states to meet their 
attainment deadlines,'' the commenters misconstrue the requirements of 
the good neighbor provision and the applicable legal precedent. The 
good neighbor provision does not require upwind states to bring that 
downwind areas into attainment with the NAAQS. Rather, states are 
required to reduce emissions that ``contribute significantly'' to 
nonattainment in downwind areas. Once a state has eliminated its 
significant contribution to downwind nonattainment, it has met the 
requirements of the good neighbor provision, regardless of whether the 
downwind area has actually attained. See, e.g., 76 FR 48258-59 (August 
8, 2011) (determining in CSAPR that SO<INF>2</INF> emission reductions 
available at $2,300 per ton represented good neighbor obligation even 
though some downwind air quality problems would persist). This is 
distinct from the obligations imposed on downwind states containing 
designated nonattainment areas, which are directly obligated to 
demonstrate attainment of the NAAQS. See, e.g., CAA section 
182(c)(2)(A) (requiring the state submit a demonstration that the plan 
will provided for attainment of the ozone NAAQS by the applicable 
attainment date). Because the statutory obligations imposed on upwind 
and downwind states with respect to attainment differs, it is also 
reasonable that the costs of controls implemented in upwind states may 
also differ from those implemented in downwind states. The Supreme 
Court has already affirmed EPA's approach to quantifying and 
apportioning upwind states' significant contribution on the basis of 
cost. See EME Homer City, 134 S. Ct. at 1607. While the Court stated 
that EPA was prohibited from requiring more emission reductions than 
necessary to bring downwind areas into attainment of the NAAQS, id. at 
1608, the Court did not indicate that upwind states were specifically 
responsible for ensuring the downwind states achieve attainment in all 
instances. Thus, EPA does not agree that it must require additional 
emission reductions from upwind states, even if they are not cost-
effective, simply because a downwind area has not yet attained the 
NAAQS.
    Comment: One commenter states that EPA's contention that 
implementation of controls is not feasible until during or after the 
2022 ozone season is unfounded for the following reasons:
    <bullet> SCR installations are typically less time-consuming than 
39 months, noting that one of the resources EPA cites indicates 21 
months is reasonable.
    <bullet> SNCR takes less time, 10-13 months, to implement.
    <bullet> EPA tacitly admits some projects could be completed prior 
to 2022 when it claims that SCR and SNCR should be ``linked'' at the 
fleet-level.
    <bullet> The original CSAPR allowed less than three years for 
compliance with SO<INF>2</INF> limits that were expected to require 
installation of flue gas desulfurization controls, which generally are 
expected to take longer than SCR to install.
    <bullet> EPA's integrated planning model assumes SO<INF>2</INF> 
scrubbers can be installed in three years and SCR units in two years.
    <bullet> Non-EGU controls are widely available on timeframes 
shorter than 48 months according to EPA's Final Non-EGU TSD. Although 
EPA insinuates this document questions the availability of non-EGU 
controls within 48 months, it lists many categories of non-EGU 
NO<INF>X</INF> controls available in about 60 weeks that were also 
cost-effective.
    <bullet> EPA did not exhaust readily available EGU control options. 
Kentucky could require 100 percent operation of already-installed 
control equipment or insist on optimized performance. Kentucky could 
discontinue use of ``banked allowances'' in the CSAPR Update. And CSAPR 
did not require any re-dispatch or shifting power generation from 
higher-emitting to lower-emitting plants, which is also feasible in the 
short term.
    <bullet> EPA's arguments regarding the availability of steel and 
cranes are tenuous. EPA cites only two documents to support its 
assertion about crane shortages, only one of which even mentions a 
shortage. That article only indicates that developers need to book the 
cranes and operators several months in advance, which is not much of an 
obstacle.
    Another commenter states that--based on its experience--EPA's 
estimated installation time frames for SCRs are too conservative 
(short), and provides a range of 28 to 60 months for installation of 
SCRs at one site.
    Response: EPA first notes that responses to comments regarding the 
following issues are addressed earlier in this document: (1) Timeframes 
assumed for installation of post-combustion controls in CSAPR; (2) 
timeframes for installation of controls on non-EGUs; and (3) the 
optimization of existing post-combustion controls. EPA will address the 
remaining comments in the following paragraphs.
    EPA disagrees that the timeframe for implementation of SNCR and SCR 
at an individual unit necessarily indicates that the feasibility 
analysis is flawed. As an initial matter, there are differences between 
these control technologies with respect to the potential viability of 
achieving cost-effective regional NO<INF>X</INF> reductions from EGUs. 
SCR controls generally achieve greater EGU NO<INF>X</INF> reduction 
efficiency (up to 90 percent) than SNCR controls (up to 25 percent). 
Resulting in part from this disparity in NO<INF>X</INF> reduction 
efficiency, when

[[Page 33744]]

considering both control costs and NO<INF>X</INF> reduction potential 
in developing cost per ton analysis for the CSAPR Update, EPA found new 
SCR controls to be more cost-effective than SNCR at removing 
NO<INF>X</INF>. Specifically, EPA found that new SCR controls could 
generally reduce EGU emissions for $5,000 per ton of NO<INF>X</INF> 
removed whereas new SNCR controls could generally reduce EGU emissions 
at a higher cost of $6,400 per ton of NO<INF>X</INF> removed.\22\ In 
other words, the greater NO<INF>X</INF> reduction efficiency for SCR 
controls translates into greater cost-effectiveness relative to SNCR 
controls. The general cost-effectiveness advantage is consistent with 
observed installation patterns where SCR controls (62 percent of coal-
fired capacity) are more prevalent across the east relative to SNCR (12 
percent of coal-fired capacity).\23\ In light of the increased 
NO<INF>X</INF> removal efficiency and the relative cost-effectiveness 
of SCR as compared to SNCR, EPA does not believe that is reasonable to 
focus its analysis on the implementation of the less-efficient control 
strategy (SNCR) at the expense of the greater emission reduction 
potential of SCR controls. Accordingly, EPA believes it is reasonable 
to select a potential compliance timeframe and therefore a future 
analytic year that would permit the region-wide installation of both 
new SCR and new SNCR.
---------------------------------------------------------------------------

    \22\ NO<INF>X</INF> Mitigation Strategies TSD.
    \23\ National Electric Energy Data System (NEEDS) v6. EPA, 
available at https://www.epa.gov/airmarkets/national-electric-energy-data-system-needs-v6.
---------------------------------------------------------------------------

    Moreover, the estimated 39 months and 10 to 13 months for 
implementation of SCR and SNCR, respectively, at an individual unit do 
not account for factors that would influence this timeframe across the 
fleet. Installing new SCR or SNCR controls for EGUs generally involves 
the same steps: Conducting an engineering review of the facility; 
advertising and awarding a procurement contract; obtaining a 
construction permit; installing the control technology; testing the 
control technology; and obtaining or modifying an operating permit.\24\
---------------------------------------------------------------------------

    \24\ Final Report: Engineering and Economic Factors Affecting 
the Installation of Control Technologies for Multipollutant 
Strategies, EPA-600/R-02/073 (October 2002), available at https://nepis.epa.gov/Adobe/PDF/P1001G0O.pdf.
---------------------------------------------------------------------------

    Scheduled curtailment, or planned outage, for pollution control 
installation would be necessary to complete either SCR or SNCR 
projects. Given that peak demand and rule compliance would both fall in 
the ozone season, sources would likely try to schedule installation 
projects for the ``shoulder'' seasons (i.e., the spring and/or fall 
seasons), when electricity demand is lower than in the summer, reserves 
are higher, and ozone-season compliance requirements are not in effect. 
If multiple units were under the same timeline to complete the retrofit 
projects as soon as feasible from an engineering perspective, this 
could lead to bottlenecks of scheduled outages as each unit attempts to 
start and finish its installation in roughly the same compressed time 
period. Thus, any compliance timeframe that would assume installation 
of new SCR or SNCR controls should encompass multiple shoulder seasons 
to accommodate scheduling of curtailment for control installation 
purposes and better accommodate the regional nature of the program.
    In addition to the coordination of scheduled curtailment, an 
appropriate compliance timeframe should accommodate the additional 
coordination of labor and material supply necessary for any fleet-wide 
control installation efforts.\25\ The total construction labor for an 
SCR system associated with a 500-megawatt (MW) EGU is in the range of 
310,000 to 365,000 man-hours, with boilermakers accounting for 
approximately half of this time.\26\ SNCR installations, while 
generally having shorter individual project timeframes of 10 to 13 
months from bid solicitation to startup, share similar labor and 
material resources and the timing of SNCR installation planning is 
therefore linked to the timing of SCR installation planning. In recent 
industry surveys, one of the largest shortages of union craft workers 
was for boilermakers. This shortage of skilled boilermakers is expected 
to rise due to an anticipated nine percent increase in boilermaker 
labor demand growth by 2026, coupled with expected retirements and 
comparatively low numbers of apprentices joining the workforce.\27\ The 
shortage of and demand for skilled labor, including other craft workers 
critical to pollution control installation, is pronounced in the 
manufacturing industry. The Association of Union Constructors conducted 
a survey of identified labor shortages and found that boilermakers were 
the second-most frequently reported skilled labor market with a labor 
shortage.\28\ Moreover, recovery efforts from the natural disasters of 
Hurricanes Harvey and Irma and wildfires in 2017 are expected to 
further tighten the labor supply market in manufacturing in the near 
term.\29\ EPA determined that these tight labor market conditions 
within the relevant manufacturing sectors, combined with fleet-level 
mitigation initiatives, would likely lead to some sequencing and 
staging of labor pool usage, rather than simultaneous construction 
across all efforts. This sector-wide trend supports SCR and SNCR 
installation timeframes for a fleet-wide program that exceed the 
demonstrated single-unit installation timeframe.
---------------------------------------------------------------------------

    \25\ EPA considers these additional labor and supply 
requirements in the context of the already committed labor and 
supply requirements associated with projects already underway.
    \26\ Id.
    \27\ Occupational Outlook Handbook, Bureau of Labor Statistics, 
available at https://www.bls.gov/ooh/construction-and-extraction/boilermakers.htm.
    \28\ Union Craft Labor Supply Survey, The Association of Union 
Constructors, Exhibit 4-2 at page 29, available at https://www.tauc.org/files/2017_TAUC_UNION_CRAFT_LABOR_SUPPLY_REVISEDBC_FINAL.pdf.
    \29\ Skilled Wage Growth Less Robust, Worker Shortage Still an 
Issue, Industry Week, October 23, 2017, available at http://www.industryweek.com/talent/skilled-wage-growth-less-robust-worker-shortage-still-issue.
---------------------------------------------------------------------------

    Moreover, NO<INF>X</INF> post-combustion control projects also 
require materials and equipment such as steel and cranes. Sheet metal 
workers, necessary for steel production, are also reported as having 
well above an average supply-side shortage of labor.\30\ This, coupled 
with growth in steel demand estimated at three percent in 2018, and 
simultaneous global economic growth, suggests that there may be a 
constricted supply of steel needed for installation of new post-
combustion controls.\31\ Similarly, cranes are critical for 
installation of SCRs, components of which must be lifted hundreds of 
feet in the air during construction. Cranes are also facing higher 
demand during this period of economic growth, with companies reporting 
a shortage in both equipment and manpower.<SUP>32 33</SUP> The 
tightening markets in relevant skilled labor, materials, and equipment, 
combined with the large number of installations that could be required 
fleet-wide under a regional air pollution transport program, 
necessitate longer installation

[[Page 33745]]

time-tables relative to what has been historically demonstrated at the 
unit-level.
---------------------------------------------------------------------------

    \30\ Union Craft Labor Supply Survey, The Association of Union 
Constructors, Exhibit 4-2 at page 29, available at https://www.tauc.org/files/2017_TAUC_UNION_CRAFT_LABOR_SUPPLY_REVISEDBC_FINAL.pdf.
    \31\ Worldsteel Short Range Outlook, October 16, 2017, available 
at https://www.worldsteel.org/media-centre/press-releases/2017/worldsteel-Short-Range-Outlook-2017-2018.html.
    \32\ See, e.g., Seattle Has Most Cranes in the Country for 2nd 
Year in a Row--and Lead is Growing, Seattle Times, July 11, 2017, 
available at https://www.seattletimes.com/business/real-estate/seattle-has-most-cranes-in-the-country-for-2nd-year-in-a-row-and-lead-is-growing/.
    \33\ See RLB Crane Index, January 2018, in the docket for this 
action.
---------------------------------------------------------------------------

    EPA disagrees with the commenter's assertion that these 
observations regarding crane and steel markets are tenuous and thus 
should not influence EPA's analysis. While this is not the sole reason 
for EPA's conclusion that 48 months would be necessary for region-wide 
control installation, EPA believes the market for labor and materials 
is a relevant factor to consider in light of reports from companies 
that supply the tower cranes that there is a shortage of both equipment 
and manpower. The crane index, along with quarterly construction costs 
reports, are metrics regularly used to evaluate construction activity 
by construction consultancies and can provide information useful to 
demonstrate the level of equipment demand.\34\ Moreover, the commenter 
provides no evidence to contradict the EPA's finding that these 
equipment markets are facing periods of higher demand.
---------------------------------------------------------------------------

    \34\ Kalinoski, Gail, North American Construction Trends: RLB 
Reports, available at https://www.cpexecutive.com/post/north-america-construction-trends-rlb-reports/.
---------------------------------------------------------------------------

    The time lag observed between the planning phase and in-service 
date of SCR and SNCR operations in certain cases also illustrates that 
site-specific conditions sometimes lead to installation times of four 
years or longer. For instance, SCR projects for units at Ottumwa 
Generating Station (Iowa), Columbia Energy Center (Wisconsin), and 
Oakley Generating Station (California) were all in the planning phase 
in 2014. However, these projects have estimated in-service dates 
ranging between 2018 and 2021.\35\ Similarly, individual SNCR projects 
can exceed their estimated 10-13-month time frame. For example, 
projects such as SNCR installation at Jeffrey Energy Center (Kansas) 
were in the planning phase in 2013, but not in service until 2015.\36\ 
Completed projects, when large in scale, also illustrate how timelines 
can extend beyond the bare minimum necessary for a single unit when the 
project is part of a larger air quality initiative involving more than 
one unit at a plant. For instance, the Big Bend Power Station in 
Florida completed a multi-faceted project that involved adding SCRs to 
all four units as well as converting furnaces, over-fire air changes, 
and making windbox modifications. The time from the initial planning 
stages to completion was a decade.\37\
---------------------------------------------------------------------------

    \35\ 2014 EIA Form 860, Schedule 6, Environmental Control 
Equipment.
    \36\ 2013 EIA Form 860, Schedule 6, Environmental Control 
Equipment.
    \37\ Big Bend's Multi-Unit SCR Retrofit, Power Magazine, March 
1, 2010, available at http://www.powermag.com/big-bends-multi-unit-scr-retrofit/.
---------------------------------------------------------------------------

    While individual unit-level SCR and SNCR projects can average 39 
and 10 months, respectively, from bid to startup, a comprehensive and 
regional emissions reduction effort also requires more time to 
accommodate the labor, materials, and outage coordination for these two 
types of control strategies. Because these post-combustion control 
strategies share similar resource inputs and are part of regional 
emissions reduction programs rather than unit-specific technology 
mandates, the timeframes for one type are inherently linked to the 
other type. This means that SNCR projects cannot be put on an early 
schedule in light of their reduced construction timing without 
impacting the availability of resources for the manufacture and 
installation of SCRs and thus the potential start dates of those 
projects.
    In short, given the market and regulatory circumstances in which 
EPA evaluated this effort, we determined that four years would be an 
expeditious timeframe to coordinate the planning and completion of any 
mitigation efforts that might be necessary in this instance. In regard 
to the commenter who noted a range of 28 to 60 months for SCR 
installation, EPA notes that a period of 48 months falls reasonably 
within that range, and is consistent with the region-wide evaluation of 
control feasibility that EPA has conducted in this action.
    EPA notes that the commenters' assertions about assumptions in IPM 
regarding control installation timeframes are unfounded. Post-
combustion control installation times are an exogenous assumption in 
EPA's power sector modeling--i.e., EPA determines the number of years 
for installation and provides that figure as an input to the model; the 
figure is not the product of a function that the model performs 
internally. EPA makes this installation determination independently for 
each model run. For instance, if EPA is using IPM to model a run year 
that is three years from a present date, it may choose to allow 
scrubber installation to occur in that first model run year if the 
volume of installations is expected to be small (consistent with the 
notion that some units may be able to install controls more quickly). 
However, if the volume of scrubber installations is expected to be 
larger, reflecting more region-wide resource coordination requirements 
and resource requirements, EPA may not allow the retrofit option in the 
model until after three years. Thus, the assumption can vary according 
to the policy context being considered.
    Finally, EPA notes that the commenter is incorrect in asserting 
that the CSAPR Update failed to account for generation shifting. The 
CSAPR Update budgets accounted for generation shifting that was 
considered to be available at the $1,400 cost threshold and feasible to 
implement by the 2017 compliance timeframe. See 81 FR 74544-45 (October 
26, 2016). The commenter does not otherwise explain whether or how any 
potential for additional generation shifting should influence EPA's 
analysis in this action.\38\
---------------------------------------------------------------------------

    \38\ Because EPA did not evaluate additional generation shifting 
possibilities in this action, it does not at this time need to 
revisit the question whether it is within the EPA's authority or 
otherwise proper to consider generation shifting in implementing the 
good neighbor provision. The EPA is aware that this has been an 
issue of contention in the past. See, e.g., 81 FR at 74545 (October 
26, 2016) (responding to comments); CSAPR Update Rule--Response to 
Comment, at 534-50 (EPA-HQ-OAR-2015-0500-0572) (summarizing and 
responding to comments). The EPA may revisit this question in 
addressing good neighbor requirements for other NAAQS but is not 
revisiting this issue with regard to the 2008 ozone NAAQS.
---------------------------------------------------------------------------

    Comment: Several commenters advocate for the adoption of short-term 
NO<INF>X</INF> emission rate limits for EGUs. The ozone NAAQS is based 
on an 8-hour standard and the allowance trading under the CSAPR Update 
is done over a multi-month ozone season. The commenters believe that 
the lack of federally enforceable short-term NO<INF>X</INF> emission 
rates in Kentucky will facilitate the continued operation of EGUs with 
inadequate NO<INF>X</INF> emission controls, to include units that have 
NO<INF>X</INF> controls that are not always operated during the ozone 
season. While the CSAPR Update has encouraged improved utilization of 
SCR and SNCR controls during the 2017 ozone season, the commenter 
contends that there are additional cost-effective NO<INF>X</INF> 
reductions that can be achieved by requiring optimization of these 
existing controls, every day of the ozone season, at coal-fired EGUs. 
The commenter therefore states that Kentucky should establish emission 
limits for its EGUs with appropriate magnitudes and averaging periods.
    Another commenter also states that EPA should require Kentucky to 
adopt targeted strategies for reducing emissions on ``high emitting 
days.''
    One commenter contends that compliance with a cap-and-trade program 
like the CSAPR Update is an

[[Page 33746]]

inadequate mechanism to ensure permanent NO<INF>X</INF> reductions on 
high ozone days that determine attainment or nonattainment of the 
NAAQS. The commenter states that its analysis shows that many coal-
fired EGUs in Kentucky were not optimizing their controls in 2017 and 
failed to operate at rates assumed in EPA's 2023 modeling analysis. The 
commenter states that a cap and trade program allows emissions to 
fluctuate above the state-wide budgets if the owners or operators (1) 
have adequate banked allowances, or (2) can purchase allowances to 
cover excess emissions. Ozone is an air pollutant to which prevention 
of short-term exposure to excessive levels over an eight-hour period is 
critical to protect public health, and compliance with the NAAQS can be 
negatively impacted by inconsistent day-to-day operation of pollution 
controls. Allowing a plant to cycle back the efficiency or altogether 
turn off control equipment is an inappropriate control measure for 
ozone because this can result in excessive rates on high ozone days, 
when it is most important to ensure low emission rates.
    Response: EPA first notes that it is unnecessary to evaluate what 
strategy would be appropriate for the implementation of additional 
emission reductions because EPA has determined that they are 
unnecessary and unauthorized in light of the modeling data showing that 
downwind air quality problems will be resolved by 2023, when additional 
control strategies could be feasibly implemented.
    To the extent the commenter is raising concerns with the use of an 
allowance trading program to implement the emission reductions required 
by the CSAPR Update to address the 2008 ozone NAAQS, EPA considers it 
untimely for the commenter to raise such a challenge in this action. 
Those emission reductions were finalized in a separate rulemaking, and 
the appropriate venues to raise concerns over the adequacy for 
reduction implementation of the CSAPR allowance trading program, as 
compared to other measures such as short-term emission limits, were 
that rulemaking process and subsequent petitions for judicial review of 
that final rule. Thus, this issue is outside the scope of the present 
rulemaking. Similarly, as discussed earlier in this action, to the 
extent the commenter also disagrees with EPA's determinations regarding 
the optimization of SCR controls or the cost-effectiveness of SCNR 
controls in the CSAPR Update, those comments are also outside the scope 
of this action.
    Nonetheless, EPA has examined the hourly NO<INF>X</INF> emissions 
data reported to EPA and observed very few instances of units 
selectively turning down or turning off their emissions control 
equipment during hours with high generation.\39\ SCR-controlled units 
generally operated with lower emissions rates on high generation hours, 
suggesting SCRs generally were in better operating condition--not 
worse, let alone idling--on those days/hours. In other words, EPA 
compared NO<INF>X</INF> rates on hours with high demand and compared 
them with seasonal average NO<INF>X</INF> rates and found very little 
difference. The data do not support the notion that units are reducing 
SCR operation on high demand days (when ozone concentrations often 
peak). In fact, EPA noticed that SCR performance rates--on average--
were better on high demand days. EPA, therefore, concludes that 
increases in total emissions on days with high generation are a result 
of additional units coming online and units increasing hourly 
utilization, rather than units decreasing the functioning of control 
equipment. Moreover, SCR performance is not purely a matter of 
operational decisions of the control. EPA's review of hourly 2017 data 
suggests that SCR performance often decreases as hourly load levels 
drop below a particular level (e.g., 30 percent of maximum rated hourly 
heat input rate).<SUP>40 41</SUP> A drop in SCR performance at a lower 
load level is consistent with engineering-based performance challenges 
associated with minimum operating temperatures (among other factors) 
for the SCR system.\42\ In other words, SCR systems with typical 
catalyst formulations are not effective at removing NO<INF>X</INF> 
during low-load operations when the unit might not achieve sufficient 
temperatures to promote the necessary chemical reactions. Decreases in 
SCR removal efficiency at low load levels appear to be consistent with 
known engineering limitations. The 2017 data do not provide any 
indication of broad regional patterns of scaling back SCR operations 
during particular hours of an ozone season for reasons other than 
engineering limitations. Thus, EPA does not have any basis, at this 
time, to believe that short-term emission rates are necessary to 
address regional SCR operation patterns on high demand days in the 
context of this action.
---------------------------------------------------------------------------

    \39\ See Discussion of Short-term Emission Limits, available in 
the docket for this action.
    \40\ Id.
    \41\ Maximum rated hourly heat input rate is the higher of the 
manufacturer's maximum rated hourly heat input rate or the highest 
observed hourly heat input rate.
    \42\ Gray, Sterling; Jarvis, Jim; Donner Chad, and Estep John, 
SCR Performance, Power Engineering, March 9, 2017, available at 
https://www.power-eng.com/articles/print/volume-121/issue-3/features/scr-performance.html.
---------------------------------------------------------------------------

    Moreover, even if it were appropriate to assess the merits of 
particular remedies as part of this action, EPA does not agree that an 
allowance trading program would be an inadequate means of implementing 
any additional statewide emission reductions that may have been 
necessary under a scenario where more reductions were required to fully 
address the good neighbor provision. Implementation mechanisms based on 
seasonal NO<INF>X</INF> requirements have demonstrated success at 
reducing peak ozone concentrations. For example, over the past decade, 
there has been significant improvement in ozone across the eastern 
U.S., in part due to season-long allowance trading programs such as the 
NO<INF>X</INF> Budget Trading Program and the CSAPR NO<INF>X</INF> 
ozone season allowance trading program. As a result, areas are now 
attaining the 1997 ozone NAAQS. Further, EPA notes that the standard is 
a 3-year average value of three individual seasonal values. Thus, a 
seasonal program is harmonious with the form of the standard.
    Comment: One commenter states that EPA should require Kentucky to 
ensure all ``minimum control strategies'' identified in a recent Ozone 
Transport Commission (OTC) statement regarding ``good neighbor'' SIPs 
are adopted, along with other points noted in the document.
    Another commenter states that other measures should be undertaken 
to reduce Kentucky's impact on other states, including NO<INF>X</INF> 
RACT on EGUs and other large NO<INF>X</INF> sources at the same 
stringent levels used within the OTR, along with controls on mobile 
sources (inspection and maintenance, and anti-idling).
    One commenter recommends that any full remedy of a state's good 
neighbor obligations must require, at minimum, RACT on all major 
NO<INF>X</INF> and VOC sources, best available control technology 
(BACT) on all existing EGUs and large industrial boilers, BACT on all 
sources with high ozone-day emissions, and regional measures such as 
those recommended by the OTR.
    Response: EPA lacks authority to require control measures or 
emission reductions unless the Agency first identifies a downwind air 
quality problem to which an upwind state is contributing. See EME Homer 
City, 134 S. Ct. at 1608 (``If EPA requires an upwind State to reduce 
emissions by more than the amount necessary to achieve attainment in 
every downwind State to which it is linked, the Agency will have 
overstepped its authority, under the Good Neighbor Provision.'');

[[Page 33747]]

EME Homer City II, 795 F.3d at 129-30 (finding emissions budgets for 10 
states were invalid because EPA's modeling showed that the downwind air 
quality problems to which these states were linked when EPA evaluated 
projected air quality in 2012 would be entirely resolved by 2014). With 
respect to the recommended control strategies, the commenters do not 
explain why they believe the control strategies applicable to the OTR, 
RACT, BACT, or other measures are necessary to achieve attainment or 
maintenance of the NAAQS in downwind states. While EPA determined that 
Kentucky would be linked to downwind air quality problems in 2017, EPA 
has also determined that those air quality problems would be resolved 
by 2023. Thus, EPA has no authority to require additional emission 
reductions--via the control strategies suggested by the commenters or 
otherwise--from Kentucky or other upwind states in 2023.
    Comment: One commenter states that EPA's 2023 modeling is based on 
numerous flawed assumptions. EPA adjusted projected NO<INF>X</INF> 
emissions for dozens of EGUs based on assumptions of new or optimized 
controls. However, the Kentucky SIP contains no enforceable mechanisms, 
schedules, or timetables for compliance to ensure the relied-upon 
assumptions are valid and will actually occur or remain in place in 
2023. The commenter contends that EPA's demonstration or verification 
of enforceable commitments to support Kentucky's assumptions, as well 
as EPA's assumptions for all other states, are required by the CAA, 
citing section 110(a)(2)(A) and (C).
    One commenter also contends that Kentucky's SIP fails to satisfy 
section 110(a)(2)(A) because, even if reliance on 2023 were valid, it 
lacks any proposed enforceable limitations or compliance timelines.
    One commenter states that Kentucky has not shown that the EPA-
modeled shutdowns of E.W. Brown Generating Station and Elmer Smith 
plant will occur in a federally enforceable manner, and that therefore, 
EPA should not approve Kentucky's SIP since the modeling includes such 
reductions.
    One commenter states that although EPA and Alpine modeling indicate 
all areas outside California will achieve attainment with the 2008 
ozone NAAQS by 2023, some Connecticut monitors will ``only barely'' 
comply. Commenter states that Kentucky's reliance on the 2023 modeling 
should be accompanied by enforceable regulations that ensure the lower, 
modeled 2023 emissions are achieved, including the decrease in EGU 
emissions.
    One commenter includes a table summarizing adjusted projected 
NO<INF>X</INF> emissions for Kentucky EGUs used in EPA's 2023 modeling 
based on assumptions of new or optimized controls. The commenter states 
that there are no enforceable commitments in Kentucky's SIP to support 
these assumptions, which the commenter asserts are required by EPA's 
own methodology, citing a March 2018 EPA memorandum. Without 
enforceable measures, the commenter asserts the modeling is not a 
proper basis for a good neighbor SIP.
    One commenter contends that EPA's modeling relies on reductions 
that are not federally enforceable, and Kentucky failed to demonstrate 
that the emission reductions EPA relied on across the modeling domain 
are federally enforceable. The commenter contends that the upwind state 
good neighbor obligations cannot be deemed satisfied if large portions 
of their emissions inventory remain poorly controlled.
    One commenter states that an approvable good neighbor SIP must 
include permanent and federally enforceable emissions reductions. The 
commenter contends that section 110 requires that a SIP (1) include 
enforceable emission limitations and other control measures, means, or 
techniques, (2) include a program to provide for the enforcement of the 
measures, and (3) provide adequate provisions prohibiting emissions 
activity within the state from emitting any air pollutant in amounts 
which will contribute significantly to nonattainment in or interfere 
with maintenance by any other state with respect to the NAAQS. EPA's 
four-step analysis also requires the adoption of ``permanent and 
enforceable measures.''
    The commenter states that compliance with the rates reflected in 
the 2023 modeling are not permanent or federally enforceable under the 
CSAPR Update or any other federal rule, including the assumption that 
most units will emit at 2016 levels and that 25 units will take 
additional emission reduction actions, including unit retirement, 
increased use of post-combustion controls, or addition of new 
combustion controls. The commenter contends these actions are therefore 
speculative and cannot be properly considered when determining if a 
state met its good neighbor obligations. Downwind states cannot rely on 
speculative reduction, and without federally enforceable limits, there 
is no guarantee that Maryland will maintain the 2008 ozone NAAQS. The 
commenter notes that Maryland's section 126(b) petition proposed 
specific language and NO<INF>X</INF> emission rates for EGUs with SCR 
and SNCR in Kentucky that EPA should consider making federally 
enforceable as a near-term NO<INF>X</INF> reduction strategy. EPA 
should also modify operating permits for other units to require 
implementation of specific emission rates, fuel switches, and control 
installations for EGUs that are not equipped with controls, which were 
relied on in the modeling.
    Response: EPA does not agree that Kentucky is required to adopt 
permanent and enforceable control measures to ensure that the projected 
emission levels used in the 2023 modeling will be maintained. Within 
EPA's four-step interstate transport framework, EPA only requires 
sources in upwind states to implement enforceable emission limitations 
if: (1) Downwind air quality problems are identified in at step one, 
(2) an upwind state is linked to a downwind air quality problem at step 
two, and (3) sources in the linked upwind state are identified at step 
three as having emissions that significantly contribute to 
nonattainment and interfere with maintenance of the NAAQS considering 
cost- and air-quality-based factors. If all three of these steps are 
not satisfied, then the state is not required to include provisions in 
its SIP prohibiting any level of reductions because the EPA has 
determined that the state will not significantly contribute to 
nonattainment or interfere with maintenance of the NAAQS downwind. For 
the reasons described in the following paragraphs, EPA believes this 
approach is a reasonable interpretation of the good neighbor provision.
    The good neighbor provision instructs EPA and states to apply its 
requirements ``consistent with the provisions of'' title I of the CAA. 
EPA is therefore interpreting the requirements of the good neighbor 
provision, and the elements of its four-step interstate transport 
framework, to apply in a manner consistent with the designation and 
planning requirements in title I that apply in downwind states. See 
North Carolina, 531 F.3d at 912 (holding that the good neighbor 
provision's reference to title I requires consideration of both 
procedural and substantive provisions in title I). EPA notes that this 
consistency instruction follows the requirement that plans ``contain 
adequate provisions prohibiting'' certain emissions in the good 
neighbor provision. The following paragraphs will therefore explain how 
EPA's interpretation of the circumstances

[[Page 33748]]

under which the good neighbor provision requires that plans 
``prohibit'' emissions through enforceable measures is consistent with 
the circumstances under which downwind states are required to implement 
emissions control measures in nonattainment areas.
    For purposes of this analysis, EPA notes specific aspects of the 
title I designations process and attainment planning requirements for 
the ozone NAAQS that provide particularly relevant context for 
evaluating the consistency of EPA's approach to the good neighbor 
provision in upwind states. EPA notes that this discussion is not 
intended to suggest that the specific requirements of designations and 
attainment planning apply to upwind states pursuant to the good 
neighbor provision, but rather to explain why EPA's approach to 
interpreting the good neighbor approach is reasonable in light of 
relevant, comparable provisions found elsewhere in title I. In 
particular, these provisions demonstrate that EPA's approach is 
consistent with other relevant provisions of title I with respect to 
what data is considered in EPA's analysis and when states are required 
to implement enforceable measures.
    First, areas are initially designated attainment or nonattainment 
for the ozone NAAQS based on actual measured ozone concentrations. CAA 
section 107(d) (noting that an area shall be designated attainment 
where it ``meets'' the NAAQS and nonattainment where it ``does not 
meet'' the NAAQS). Therefore, a designation of nonattainment does not 
in the first instance depend on what specific factors have influenced 
the measured ozone concentrations or whether such levels are due to 
enforceable emissions limits. If an area measures a violation of the 
relevant ozone NAAQS, then the area is designated nonattainment. In 
cases where the nonattainment area is classified moderate or higher, 
the responsible state is required to develop an attainment plan, which 
generally includes the application of various enforceable control 
measures to sources of emissions located in the nonattainment area, 
consistent with the requirements in Part D of title I of the Act.\43\ 
See generally CAA section 182, 42 U.S.C. 7511a. If, however, an area 
measures compliance with the ozone NAAQS, the area is designated 
attainment, and sources in that area generally are not subject to any 
new enforceable control measures under Part D.\44\
---------------------------------------------------------------------------

    \43\ Nonattainment areas classified as marginal are required to 
submit emissions inventories and implement a nonattainment new 
source review permitting program, but are not generally required to 
implement controls at existing sources. See CAA section 182(a), 42 
U.S.C. 7511a(a).
    \44\ CAA section 184 contains the exception to this general 
rule: States that are part of the OTR are required to provide SIPs 
that include specific enforceable control measures, similar to those 
for nonattainment areas, that apply to the whole state, even for 
areas designated attainment for the ozone NAAQS. See generally 42 
U.S.C. 7511c.
---------------------------------------------------------------------------

    Similarly, in determining the boundaries of an ozone nonattainment 
area, the CAA requires EPA to consider whether ``nearby'' areas 
``contribute'' to ambient air quality in the area that does not meet 
the NAAQS. See 42 U.S.C. 7407(d). For each monitor or group of monitors 
indicating a violation of the ozone NAAQS, EPA assesses information 
related to five factors, including current emissions and emissions-
related data from the areas near the monitor(s), for the purpose of 
establishing the appropriate geographic boundaries for the designated 
ozone nonattainment areas. A nearby area may be included within the 
boundary of the ozone nonattainment area only after assessing area-
specific information, including an assessment of whether current 
emissions from that area contribute to the air quality problem 
identified at the violating monitor.\45\ If such a determination is 
made, sources in the nearby area are also subject to the applicable 
Part D control requirements. However, if EPA determines that the nearby 
area does not contribute to the measured nonattainment problem, then 
the nearby area is not part of the designated nonattainment area and 
sources in that area are not subject to such nonattainment control 
requirements.
---------------------------------------------------------------------------

    \45\ See Memorandum from Robert J. Meyers, Principal Deputy 
Assistant Administrator, US EPA to Regional Administrators, Area 
Designations for the 2008 Ozone National Ambient Air Quality 
Standards, at Attachment 2, December 4, 2008, available at https://archive.epa.gov/ozonedesignations/web/pdf/area_designations_for_the_2008_revised_ozone_naaqs.pdf.
---------------------------------------------------------------------------

    EPA's historical approach to addressing the good neighbor provision 
via the four-step interstate transport framework, and the approach EPA 
continues to apply here, is consistent with these title I requirements. 
That is, in steps 1 and 2 of the framework, EPA evaluates whether there 
is a downwind air quality problem (either nonattainment or 
maintenance), and whether an upwind state impacts the downwind area 
such that it contributes to and is therefore ``linked'' to the area. 
EPA's determination at step one of the good neighbor analysis that it 
has not identified any downwind air quality problems to which an upwind 
state could contribute is analogous to EPA's determination in the 
designation analysis that an area should be designated attainment. 
Similarly, EPA's determination at step two of the good neighbor 
analysis that, while it has at step one identified downwind air quality 
problems, an upwind state does not sufficiently impact the downwind 
area such that the state is linked is analogous to EPA's determination 
in the designation analysis that a nearby area does not contribute to a 
NAAQS violation in another area. Thus, under the good neighbor 
provision, EPA determines at step one or two, as appropriate, that the 
upwind state will not significantly contribute to nonattainment or 
interfere with maintenance of the NAAQS in the downwind area. See, 
e.g., 81 FR 74506 (October 26, 2016) (determining that emissions from 
14 states whose contributions to downwind receptors are below the air 
quality threshold will not significantly contribute to nonattainment or 
interfere with maintenance of the 2008 ozone NAAQS); 76 FR 48236 
(August 8, 2011) (finding that states whose contributions to downwind 
receptors are below the air quality threshold will not significantly 
contribute to nonattainment or interfere with maintenance of the 
relevant NAAQS). Under such circumstances, sources in the upwind state 
are not obligated to implement any control measures under the good 
neighbor provision, which is consistent with the fact that sources 
located in attainment areas generally are not required to implement the 
control measures found in Part D of the Act. Cf. EME Homer City II, 795 
F.3d at 130 (determining that CSAPR ozone season NO<INF>X</INF> budgets 
for 10 states were invalid based on determination that modeling showed 
no future air quality problems); 81 FR 74523-24 (October 26, 2016) 
(removing three states from CSAPR ozone season NO<INF>X</INF> program 
based on determination that states are not linked to any remaining air 
quality problems for the 1997 ozone NAAQS).
    EPA acknowledges that one distinction between the good neighbor and 
designation analyses: The good neighbor analysis relies on future year 
projections of emissions to calculate ozone concentrations and upwind 
state contributions, compared to the designation analysis's use of 
current measured data. As described in more detail earlier, this 
approach is a reasonable interpretation of the term ``will'' in the 
good neighbor provision, see North Carolina, 531 F.3d at 913-14, and 
interpreting language specific to that provision does not create an

[[Page 33749]]

impermissible inconsistency with other provisions of title I. Moreover, 
EPA's use of future-year modeling in the good neighbor analysis to 
identify downwind air quality problems and linked states is consistent 
with its use of current measured data in the designations process. 
EPA's future year air quality projections are influenced by a variety 
of factors, including current emissions data, anticipated future 
control measures, economic market influences, and meteorology. Many of 
these same factors, e.g., current control measures, economic market 
influences, and meteorology, can affect the NO<INF>X</INF> emissions 
levels and consequent measured ozone concentrations that inform the 
designations process. Like the factors that affect measured ozone 
concentrations used in the designations process, not all of the factors 
influencing EPA's modeling projections are or can be enforceable 
limitations on emissions or ozone concentrations. However, EPA believes 
that consideration of these factors contributes to a reasonable 
estimate of anticipated future ozone concentrations. See EME Homer City 
II, 795 F.3d at 135 (declining to invalidate EPA's modeling projections 
``solely because there might be discrepancies between those predictions 
and the real world''); Chemical Manufacturers Association v. EPA, 28 
F.3d 1259, 1264 (D.C. Cir. 1994) (``a model is meant to simplify 
reality in order to make it tractable''). Thus, EPA believes that 
consideration of these factors in its future-year modeling projections 
used at steps 1 and 2 of the good neighbor analysis is reasonable and 
consistent with the use of measured data in the designations 
analysis.\46\
---------------------------------------------------------------------------

    \46\ EPA also notes that the consideration of projected actual 
emissions in the future analytic year--as opposed to allowable 
levels--is also consistent with the statute's instruction that 
states (or EPA in the states' stead) prohibit emissions that 
``will'' impermissibly impact downwind air quality. This term is 
reasonably interpreted to mean that EPA should evaluate anticipated 
emissions (what sources will emit) rather than potential emissions 
(what sources could emit).
---------------------------------------------------------------------------

    EPA notes that there is a further distinction between the section 
107(d) designations provision and the good neighbor provision in that 
the latter provision uses different terms to describe the threshold for 
determining whether emissions in an upwind state should be regulated 
(``contribute significantly'') as compared to the standard for 
evaluating the impact of nearby areas in the designations process 
(``contribute'').
    Thus, at step three of the good neighbor analysis EPA evaluates 
additional factors, including cost and air-quality considerations, to 
determine whether emissions from a linked upwind state would violate 
the good neighbor provision (i.e., cost-effectiveness). Only if EPA at 
step three determines that the upwind state's emissions would violate 
the good neighbor provision will it proceed to step four, at which 
point emissions in the upwind state must be controlled so as to address 
the identified violation, analogous to the trigger for the application 
of Part D requirements to sources located in designated nonattainment 
areas. EPA interprets the good neighbor provision to not require the 
Agency or the upwind state to proceed to step four and implement any 
enforceable measures to ``prohibit'' emissions unless it identifies a 
violation of the provision at step three. See, e.g., 76 FR 48262 
(August 8, 2011) (finding at step three that the District of Columbia 
will not violate the good neighbor provision, and therefore will not at 
step four be subject to any control requirements in CSAPR, because no 
cost-effective emissions reductions were identified).
    For these reasons, EPA also does not agree that either section 
110(a)(2)(A) or section 110(a)(2)(C) requires the state to include 
measures to make the projected emission limitations enforceable in 
order to address the good neighbor provision. Section 110(a)(2)(A) 
states that a SIP should ``include enforceable emission limitations and 
other control measures, means, or techniques . . . as may be necessary 
or appropriate to meet the applicable requirements'' of the CAA 
(emphasis added). As just described, a finding at step one that there 
is no air quality problem supports a conclusion that a state simply 
will not contribute significantly or interfere with maintenance of the 
NAAQS in another state, and thus that the state need not prohibit any 
particular level of emissions under the good neighbor provision. Thus, 
under section 110(a)(2)(A), no emission limitations would be necessary 
or appropriate to meet the good neighbor provision. Section 
110(a)(2)(C) similarly indicates that SIPs should provide for the 
enforcement of measures cited to support the requirements of section 
110(a)(2)(A), but it does not independently require the imposition of 
additional control measures.
    Comment: One commenter states that Kentucky proposes to rely on 
projections of future emissions based on a current regulatory framework 
that EPA is actively attempting to dismantle. Actions that the 
commenter contends EPA has not accounted for in the modeling include 
EPA's proposed repeal of glider rules, which if finalized would permit 
vehicles that emit significant amounts of NO<INF>X</INF>. In its 
original rule, EPA estimated that unregulated glider vehicles would 
increase emissions from heavy-duty highway vehicles by approximately 
300,000 tons annually in 2025. Conversely, the CSAPR Update only 
reduces annual NO<INF>X</INF> emissions by 75,000 tons, meaning the 
proposed regulatory action would swamp multiple times over the emission 
reductions from the CSAPR Update and undercut the assumptions in EPA's 
estimates.
    The commenter also cites efforts to weaken the Corporate Average 
Fuel Economy standards, which were anticipated to reduce annual light-
duty highway vehicle emissions of NO<INF>X</INF> by 904 tons in 2020 
and 6,509 tons in 2030, and emissions of VOCs, another ozone precursor, 
by 11,712 and 123,070 tons in 2020 and 2030, respectively. EPA is also 
considering rescinding 2016 Control Techniques Guidelines (CTG) for oil 
and natural gas industry, estimated to reduce emissions by 80,000 tons 
annually.
    The commenter contends that these actions, if finalized, would 
ensure that the exceedingly narrow compliance margins assumed by its 
modeling in 2023 are not achieved. To the extent Kentucky stakes good 
neighbor compliance entirely on an unenforced and actively undercut 
prediction, the commenter claims its reliance is arbitrary and 
capricious.
    Another commenter states that EPA's 2023 modeling fails to account 
for potential federal rule repeals and delays, such as those for: 
``glider'' vehicles and engines (proposed November 2017); oil and gas 
CTG guidelines (March 2018); and the NSPS for the oil and gas sector. 
The commenter also states that relaxation or elimination of control 
requirements will result in increased ozone concentrations and that the 
2023 design values are therefore an underestimate of actual levels that 
will occur. The commenter states that given EPA predicts a maximum 
design value of 75.9 ppb in 2023 at the Westport, Connecticut monitor, 
coupled with the fact that ``Kentucky significantly contributes to this 
monitor,'' the ``unenforceable commitments'' in Kentucky's SIP, and 
federal rule repeals and relaxations that EPA ignores, nonattainment 
can be expected to result at this monitor.
    One commenter asserts that the 2023 modeling fails to account for 
the proposed weakening, repeal, and/or delay of numerous federal rules 
that directly impact ozone levels, including for glider vehicles, CTGs 
for oil and gas,

[[Page 33750]]

and reconsideration of new source performance standards (NSPS) for the 
oil and gas sector, which will increase ozone concentrations near and 
downwind of affected sources. The commenter contends that the Westport, 
Connecticut monitor (part of the New York metropolitan area (NYMA)) is 
projected to have design value of 75.9 ppb in 2023, only 0.1 ppb below 
the standard (and above the 2015 ozone NAAQS), and Kentucky 
significantly contributes to this monitor. The inevitable increase of 
ozone levels from EPA's deregulatory activities will drive the Westport 
monitor above the 2008 ozone NAAQS.
    Response: EPA disagrees that its 2023 projections are unreliable 
because of potential changes to other regulations. EPA first notes any 
potential regulatory changes to the ``glider'' regulations and the oil 
and gas CTG have not been finalized, nor have any relevant changes to 
the NSPS for the oil and gas sector been finalized. EPA's normal 
practice is to only include changes in emissions from final regulatory 
actions in its modeling because, until such rules are finalized, any 
potential changes in NO<INF>X</INF> or VOC emissions are speculative. 
In addition, even if emissions were to change as a result of any such 
final rules, commenters have not indicated how and whether these 
additional emissions would affect downwind ozone concentrations. If 
circumstances change such that EPA's projections may be affected, 
commenters are free to submit an administrative petition to the Agency.
    Comment: One commenter contends that EPA's modeling over-predicts 
actions taken in compliance with CSAPR. The commenter notes that the 
2023 modeling TSD reveals assumptions that facilities that retrofit 
between 2016 and 2023 to install SCR will achieve an emission rate of 
0.075 lb NO<INF>X</INF>/mmBtu. The commenter asserts this is 
unrealistic given the CSAPR Update itself relies on the idea that SCR-
equipped units will only achieve 0.10 lb/mmBtu NO<INF>X</INF> emission 
rates. EPA itself considered the 0.075 lb/mmBtu rate to be unachievable 
fleetwide in the CSAPR Update.
    Response: The commenter conflates EPA's assumptions in the CSAPR 
Update regarding emission rates achievable by units with existing SCR 
controls (i.e., 0.10 lb/mmBtu) that are idled or not being optimized 
with its assumptions regarding new SCR retrofits (i.e., 0.075 lb/
mmBtu). As explained in the CSAPR Update, EPA selected a different rate 
for existing SCRs that were viewed as likely to ``optimize'' than it 
did for new SCR installations. This difference reflects both 
differences in historical data values for the two populations sets, and 
also the increased technology performance expected from more recent 
technology vintages.\47\
---------------------------------------------------------------------------

    \47\ See NO<INF>X</INF> Mitigation Strategy TSD available at 
https://www.epa.gov/sites/production/files/2017-05/documents/egu_nox_mitigation_strategies_final_rule_tsd.pdf.
---------------------------------------------------------------------------

    EPA's assumption of 0.075 lb/mmBtu for SCR retrofits is supported 
by historical data on emission rates for new SCR controlled units, is 
consistent with its prior engineering and technology assumptions, and 
is a conservative estimate of new SCR performance.
    New SCR controlled units often perform equal to or better than 
older SCRs reflecting advancements in both technology and installation 
practices. New SCRs have regularly operated at or below EPA's assumed 
emission rate of 0.075 lb/mmbtu. For 12 coal units where SCR was 
installed and operating between 2014 and 2016, the average ozone season 
NO<INF>X</INF> emission rate for 2017 was 0.059 lb/mmBtu. When this 
time horizon is extended to the 25 SCRs that came online between 2012 
and 2016, the 23 that operated in 2017 ozone season operated at a rate 
of 0.060 lb/mmBtu. Either measure demonstrates that 0.075 lb/mmBtu is 
not only possible for newly controlled units, but regularly achieved 
and surpassed. This historical data strongly contradicts the commenters 
assertion that EPA's assumption that new units would operate at an 
emission rate of 0.075 lb/mmBtu is unrealistically low, but rather 
supports EPA performance capability assumption as both reasonable and 
conservative.
    Additionally, the 0.075 lb/mmBtu emission rate assumption for new 
SCRs is consistent with EPA's historical levels of assumed performance 
in its power sector modeling and consistent with the engineering 
assessment by Sargent and Lundy underpinning those performance 
assumptions.\48\
---------------------------------------------------------------------------

    \48\ Sargent & Lundy, IPM Model--Updates to Cost and Performance 
for APC Technologies, SCR Cost Development Methodology, Final, 
Project 12847-002 (March 2013), available at https://www.epa.gov/sites/production/files/2015-08/documents/attachment_5-3_scr_cost_methodology.pdf.
---------------------------------------------------------------------------

    Comment: One commenter asserts that the modeling predicts that 
existing units will either install new controls or operate controls at 
higher efficiencies following the CSAPR Update, despite limited 
incentives to do so. The commenter cites as an example the Paradise 
unit 3 in Kentucky that EPA assumed will optimize its SCR (0.10 lb/
mmBtu) and reduce its NO<INF>X</INF> output to about 1,000 tons per 
ozone season, but in 2017, the unit emitted over twice that amount 
(about 2,400 tons or 0.22 lb/mmBtu). Moreover, the Additional Updates 
to Emissions Inventories for the Version 6.3, 2011 Emissions Modeling 
Platform for the Year 2023 TSD generally assumes that facilities that 
emitted at a rate higher than 0.10 lb/mmBtu in 2016 will come down to 
0.10 lb/mmBtu in 2023, which ignores the reality of emission trading 
under CSAPR. The commenter contends that this effectively assumes that 
the market for emissions credits will price those credits so highly 
that no emitter will choose to buy credits rather than reduce 
emissions, which is belied by purpose and experience of the CSAPR 
trading scheme.
    Response: EPA's assumption of 0.010 lb/mmBtu for optimized SCR 
performance at units with existing SCRs is both reasonable and 
consistent with recent historical data.
    As explained in the CSAPR Update, EPA evaluated SCR emission rates 
at existing units from 2009-2015 and found that the third lowest fleet-
wide yearly ozone season average was an appropriate metric to use for 
SCR performance. See 81 FR 74543 (October 26, 2016). These emission 
rates were used to calculate states' emissions budgets in the CSAPR 
Update. In order to project emission levels representing CSAPR Update 
implementation in 2023, it is reasonable to use the same assumptions 
regarding the average, fleet-wide emissions rate for affected units, 
even if individual unit operation may vary. Thus, consistent with that 
assumption, EPA used a 0.10 lb/mmBtu to represent operation of existing 
SCRs its 2023 projections as well. While unit-level performance will 
vary relative to this fleet-wide assumption (with some SCR controlled 
units operating below and some above), using a fleet-wide average for 
each unit-level estimate captures aggregate emission impacts to the air 
shed and minimizes the net residuals between unit-level estimates and 
the eventual observed unit-level performance.
    Data from 2017, the first year of ozone season data that would be 
influenced by the CSAPR Update compliance requirements, is consistent 
with this assumption on a fleet-wide level. EPA began its engineering 
analysis to project 2023 EGU emissions with 2016 monitored and reported 
data. For the units with existing SCRs that were operating above 0.10 
lb/mmBtu in 2016 (totaling 82,321 tons of emissions in that year), EPA 
assumed that SCRs would be optimized under a CSAPR Update scenario to 
0.10 lb/mmBtu on average for 2023. This results in 2023 emissions 
estimates for these units being adjusted

[[Page 33751]]

down to 40,590 tons for these units. In 2017, the very first year of 
CSAPR Update, collective emissions from these units were 41,706 tons. 
This 2017 value is already very close to the 2023 estimated value, and 
supports the assumed behavior of optimized SCR performance to 0.10 lb/
mmBtu on average. Some of these units operated above 0.10 lb/mmBtu in 
2017 (as the commenter points out), but many operated below 0.10 lb/
mmBtu, as well. Relying on the fleet-wide average estimate was very 
consistent with the fleet-wide observed behavior in 2017.
    EPA disagrees with the notion that EGU emissions will increase, 
rather than decrease, in future years of the CSAPR Update 
implementation, or that the market for allowances would have to price 
allowances much higher in order for emission reductions to continue. 
This is not borne out by historical precedent or any economic models. 
There are a variety of policy and market forces at work beyond CSAPR 
allowance prices that are anticipated to continue to drive generation 
to shift from higher emitting to lower emitting sources. As evidenced 
in prior EPA allowance trading programs, emissions from covered sources 
generally trend downwards (regardless of allowance price) as time 
extends further from the initial compliance year.\49\ Both the Acid 
Rain Program and CSAPR SO<INF>2</INF> allowance banks grew in 2017 from 
their 2016 levels, indicating that sources are collectively adding to 
the bank (by emitting below state budgets) rather than drawing down the 
bank because of the availability of low cost allowances. This 
illustrates that there are multiple drivers affecting emissions, and it 
is reasonable for EPA to consider those, in addition to CSAPR update 
incentives, in its projection of 2023 ozone season NO<INF>X</INF> 
levels for EGUs.
---------------------------------------------------------------------------

    \49\ 2014 Program Progress, Clean Air Interstate Rule, Acid Rain 
Program, and Former NO<INF>X</INF> Budget Trading Program. EPA, 
available at https://www.epa.gov/sites/production/files/2017-09/documents/2014_full_report.pdf.
---------------------------------------------------------------------------

    Comment: One commenter states that EPA's 2023 modeling contains 
aspects that ``deviate from past guidance and have not undergone peer 
review,'' including a new approach to coastal grid cells. The commenter 
states that the affected community needs to be afforded the opportunity 
for review and public comment on such approaches.
    Response: EPA released 2023 projected ozone design value data for 
individual monitoring sites in October 2017.\50\ These data include 
ozone design value projections for each site based on the methodology 
recommended in EPA's photochemical modeling guidance.\51\ In addition, 
EPA provided a companion set of 2023 design values based on an 
alternative approach for coastal monitoring sites. The commenter had an 
opportunity to review and analyze the alternative coastal grid cell 
approach during the public comment period for this action, as well as 
when the data were released in October 2017. The commenter did not 
provide any substantive feedback on the alternative approach including 
reasons why the approach would not be appropriate. EPA also notes that 
both methods result in the same outcome that all monitoring sites 
outside of California are not expected to have problems attaining or 
maintaining the 2008 NAAQS by 2023.
---------------------------------------------------------------------------

    \50\ https://www.epa.gov/airmarkets/october-2017-memo-and-supplemental-information-interstate-transport-sips-2008-ozone-naaqs.
    \51\ Modeling Guidance for Demonstrating Attainment of Air 
Quality Goals for Ozone, PM<INF>2.5</INF>, and Regional Haze, U.S. 
Environmental Protection Agency, Research Triangle Park, NC, 
available at http://www.epa.gov/ttn/scram/guidance/guide/Draft_O3-PM-RH_Modeling_Guidance-2014.pdf.
---------------------------------------------------------------------------

    Comment: One commenter contends that reliance on modeling that 
predicts future compliance by 0.1 ppb when inherent uncertainties are 
much larger is arbitrary and capricious. The commenter states that the 
October 2017 Transport Memo speculatively suggests ozone NAAQS 
attainment without performance of any sensitivity analyses and through 
incorporation of a series of dubious assumptions, projecting attainment 
by only 0.1 ppb. Prediction of near-nationwide compliance by 2023 is 
the product of thousands of inputs, assumptions, and simplifications 
related to emissions inventories, future power consumption, 
meteorological conditions, and chemical reactions. The commenter notes 
natural gas prices as an example of the huge degree of uncertainty in 
this prediction. The modeling is based on predictions of 2023 
emissions, which is based on predictions of power plant fuel 
utilization based on a guess of future fuel prices in 2023. If gas 
prices are higher than predicted, the modeling will predict greater 
dependence on coal-fired generation, predicting higher NO<INF>X</INF> 
emissions, and ultimately under-predict ozone formation.
    Response: EPA's modeling results that show the site the commenter 
refers to, site 090019003 in Fairfield County, Connecticut, is 
projected to be in compliance of the 2008 NAAQS by three ppb (i.e., 
2023 projected average design value is 73.0 ppb). When considering the 
effects of meteorological variability this site is still projected to 
be below the level of the NAAQS (i.e., projected maximum design value 
is 75.9 ppb). Additionally, continuing ozone reductions are expected in 
future years at all sites due to an estimated 19 percent reduction in 
ozone season NO<INF>X</INF> emissions expected to occur between 2017 
and 2023 in the aggregate for the states covered by the CSAPR Update. 
The commenter provides no data to substantiate their claim that EPA's 
projected design values are not technically sound and appropriate for 
use in this rulemaking.
    EPA recognizes that there are inherent uncertainties in modeling 
the future, but EPA believes that the model platform and inputs 
selected are well-supported and reasonable. The commenter did not 
provide information to suggest that there is an overall bias in the 
modeling-based projections. As it has for every air quality modeling 
exercise, EPA performed a model evaluation, as described in the Air 
Quality Modeling Technical Support Document for the final CSAPR Update, 
which compared ozone predictions for 2011 from the modeling platform to 
actual measured data from that year, in order to test how well the 
model characterized reality. The model evaluation indicates that the 
model's predictions corresponded closely to actual measured 
concentrations in terms of the magnitude, temporal fluctuations, and 
spatial differences for 8-hour daily maximum ozone.\52\ The commenter 
is correct that EPA's modeling predictions are the result of thousands 
of inputs, assumptions, and simplifications; this is by definition the 
exercise of modeling. Moreover, because of the complexity of air 
quality modeling, courts are deferential to EPA's with respect to those 
inputs, assumptions, and simplifications. The D.C. Circuit has declined 
to ``invalidate EPA's predictions solely because there might be 
discrepancies between those predictions and the real world.'' EME Homer 
City II, 795 F.3d at 135-36. The fact that a ``model does not fit every 
application perfectly is not criticism; a model is meant to simplify 
reality in order to make it tractable.'' Chemical Manufacturers 
Association v EPA, 28 F.3d 1259, 1264, 307 U.S. App. DC 392 (D.C. Cir. 
1994). The court has held that ``it is only when the model bears no 
rational relationship to the characteristics of the data to which it is 
applied that we will hold that the use of the model was arbitrary and 
capricious.'' Appalachian Power Co. v. EPA, 135 F.3d 791, 802 (D.C. 
Cir. 1998).

[[Page 33752]]

As demonstrated by EPA's model performance evaluation, the modeling 
platform used in this rulemaking and EPA's choices as to inputs and 
assumptions provide reasonable projections of expected future year 
ozone concentrations and contributions, and is thus an appropriate 
basis on which to base the findings made in this action.
---------------------------------------------------------------------------

    \52\ Air Quality Modeling TSD, available at https://www.epa.gov/airmarkets/air-quality-modeling-technical-support-document-final-cross-state-air-pollution-rule.
---------------------------------------------------------------------------

    EPA further disagrees with the commenter's assertion that EGU 
projections are too uncertain because natural gas fuel prices may be 
different than those underlying EPA's projections, resulting in greater 
coal-fired generation and consequently higher emissions. First, EPA 
notes that power plant emissions are a small portion (approximately 15 
percent) of the 2023 eastern states total NO<INF>X</INF> emission 
inventory used to inform the air quality modeling.\53\ Relative to 
mobile sources and other emission categories, EGU emissions projections 
are a smaller segment of the inventory and just a portion of the impact 
on the Connecticut modeled attainment status.
---------------------------------------------------------------------------

    \53\ Available at ftp://newftp.epa.gov/Air/emismod/2011/v3platform/reports/2011en_and_2023en/2023en_cb6v2_v6_11g_state_sector_totals.xlsx.
---------------------------------------------------------------------------

    Moreover, EPA believes its EGU projections are reasonable and 
conservative. In developing the 2023 EGU emissions projections, EPA 
relied on 2016 monitored and reported data and only made emissions 
adjustments to account for (1) control optimization expected in 
response to the CSAPR Update implementation beginning in 2017, and (2) 
any known (e.g., planned and under construction) power plant 
infrastructure changes, including new builds, retirements, coal-to-gas 
switching, and SCR retrofit project underway and reported by the owner 
or operators to the Department of Energy's (DOE) Energy Information 
Administration (EIA) in EIA Form 860.\54\ No adjustments were made for 
projected, but unannounced, fleet changes estimated to occur by 2023 in 
response to market conditions and an aging fleet. Because these 
projected fleet wide changes would have resulted in lower 2023 EGU 
emission estimates, the EGU emission projections EPA actually used in 
the modeling were conservative.
---------------------------------------------------------------------------

    \54\ Additional Updates to Emissions Inventories for the Version 
6.3, 2011 Emissions Modeling Platform for the Year 2023 Technical 
Support Document, EPA, October 2017, available at https://www.epa.gov/sites/production/files/2017-11/documents/2011v6.3_2023en_update_emismod_tsd_oct2017.pdf.
---------------------------------------------------------------------------

    EPA also does not agree with the commenter that gas prices are 
likely to be higher in future years. Average annual natural gas prices 
ranged from $2.52/mmBtu to $4.37/mmBtu between 2009 and 2016.\55\ EPA 
and other independent analysts expect future natural gas prices to 
remain low and within this 2009 to 2016 range due both to supply and 
distribution pipeline build-out. For example, the EIA's 2018 Annual 
Energy Outlook (AEO) natural gas price projections for Henry Hub spot 
price range from $3.06/mmBtu in 2018 to $3.83/mmBtu in 2023.\56\ 
Moreover, the AEO short-term energy outlook and New York Mercantile 
Exchange futures further support the estimates of a continued low-cost 
natural gas supply.\57\ These independent analyses of fuel price data 
and projections lead to EPA's expectation that fuel-market economics 
will continue to support natural gas consumption during future ozone 
seasons through at least 2023 in a manner similar to recent historical 
levels. These lower natural gas price outlooks suggest, if anything, 
lower emissions projections, not higher. Consistent with this outlook, 
industry has announced significant new waves of coal retirements since 
2016--which is also consistent with a less emissions-intensive outlook 
than that captured by EPA's use of 2016 EGU data as its starting point 
for emissions inventory purposes in this action. EPA agrees that there 
is some uncertainty in fuel prices that consequently casts uncertainty 
on future emissions projections. However, for the reasons discussed 
herein, EPA believes its assumptions are both reasonable and 
conservative. Moreover, EPA notes that many of the assumptions factored 
into its 2023 projections are firm (e.g., retirements) and therefore 
not sensitive to future fuel price changes.
---------------------------------------------------------------------------

    \55\ http://tonto.eia.gov/dnav/ng/hist/rngwhhda.htm.
    \56\ In the 2018 reference case AEO released February 6, 2018, 
created by the U.S. EIA, natural gas prices for the power sector for 
2018 through 2023. Available at https://www.eia.gov/outlooks/aeo/data/browser/#/?id=13-AEO2018&cases=ref2018&sourcekey=0.
    \57\ AEO short-term energy outlook, available at https://www.eia.gov/outlooks/steo/report/natgas.php.
---------------------------------------------------------------------------

    The reasonableness, conservativeness, and feasibility of EPA 
assumptions are illustrated by the first year of CSAPR compliance 
emission levels in 2017. Emissions in 2017 dropped (in just one year) 
by 21 percent from 2016 levels and were 7 percent below the CSAPR 
budget for the 22 affected states. EPA 2023 projections for the same 
set of states were 10 percent below the CSAPR budget, meaning in just 
one-year states have already achieved the majority of the EGU reduction 
anticipated by EPA and are well above pace to be at or below that level 
by 2023. For Kentucky specifically, ozone season NO<INF>X</INF> EGU 
emissions dropped from 25,402 tons in 2016 to 19,978 tons in 2017 for 
EGUs greater than 25 MW. This reflects a 21 percent reduction in just 
one year of the total 33 percent reduction assumed for the state by 
2023.\58\
---------------------------------------------------------------------------

    \58\ See Engineering Analysis--Unit File, available at ftp://ftp.epa.gov/EmisInventory/2011v6/v3platform/reports/2011en_and_2023en/.
---------------------------------------------------------------------------

    Comment: One commenter provided 2017, 2020, and 2023 projected 
design values based on air quality modeling by the Ozone Transport 
Commissions (OTC) using the Community Multi-scale Air Quality Model 
(CMAQ) and design values for 2023 using the Comprehensive Air Quality 
Model with Extensions (CAMx) in conjunction with emissions inventory 
projections from the Mid-Atlantic Regional Air Management Association 
(MARAMA). The commenter also included the 2023 projected design values 
based on EPA's CAMx modeling. The commenter includes a sample of the 
results and points to predicted 2023 design values based on CMAQ that 
are above the NAAQS at the Westport, Connecticut and Susan Wagner, New 
York monitors. The commenter states that the CMAQ results are 
``considerably different'' from EPA's CAMx modeling.
    Another commenter states that EPA's modeling as well as modeling 
conducted by Alpine produce overly optimistic projection of future year 
ozone levels. The commenter includes a table that the commenter 
characterizes as indicating 2017 measured design values considerably 
higher than those projected at all Connecticut monitoring sites as well 
as indicating Kentucky contributions of greater than 1 percent at two 
Connecticut monitors after contributions are scaled relative to 2017 
measured air quality levels. The commenter states that Kentucky's 
proposed SIP fails to address the underprediction of the modeling.
    Response: EPA does not agree that the modeling provided by 
commenters should affect EPA's reliance on its own 2023 modeling. The 
first commenter provided projected design values at 41 monitoring sites 
along the Northeast Corridor for each model run. Of these 41 sites, all 
but two had base year design values that exceeded the 2008 NAAQS. The 
modeling results show that the EPA and OTC CAMx-based 2023 design value 
projections are consistent on an individual site basis for all 41 
sites. Both sets of CAMx modeling indicate that the 41 sites will be 
below the 2008 NAAQS by 2023.
    In addition, the CMAQ 2023 design values are consistent with both 
sets of CAMx-based 2023 projections at nearly

[[Page 33753]]

all sites. That is, CMAQ modeling indicates that all but two of the 41 
sites will be below the 2008 NAAQS by 2023. The two sites projected to 
exceed the 2008 NAAQS in 2023 with CMAQ, but not the OTC and EPA CAMx 
modeling, are the Westport site in Connecticut and the Susan Wagner 
High School site in New York.
    The CMAQ projections for these two sites are not only inconsistent 
with the CAMx modeling, but they are also inconsistent with the CMAQ 
modeling for other nearby sites in Connecticut, New York, and New 
Jersey. For example, based on the CMAQ modeling, ozone at the Susan 
Wagner site is projected to decline by only five percent between 2011 
and 2023, whereas at a site in nearby Bayonne, New Jersey, ozone is 
projected to decline by 13 percent over this same period. Similarly, 
ozone at the Westport site is projected to decline by only three 
percent between 2011 and 2023 with CMAQ, but at other sites along the 
Connecticut coastline (i.e., sites in Greenwich, Stratford, and 
Madison) ozone is projected to decline by 10 to 19 percent. In 
addition, the CMAQ results for these two sites are inconsistent with 
ozone reductions predicted by CMAQ at other sites in the New York City 
area which range from 11 to 18 percent. While it is possible ozone 
levels in 2023 at the Westport and/or Susan Wagner sites may be higher 
than at other sites in the New York City area, the commenter fails to 
provide any explanation regarding the large difference in the CMAQ-
based model response to emissions reductions at these two sites 
compared to nearby sites and to other sites in the New York area. Based 
on the complicated photochemistry in the New York City area, it is 
possible that ozone monitoring sites closest to the New York City 
NO<INF>X</INF> emissions plume may be less responsive to NO<INF>X</INF> 
controls compared to sites further downwind. Due to non-linear 
chemistry, sites very close to the city may experience increases in 
ozone or less reduction than other nearby sites on some days in 
response to local emissions reductions in NO<INF>X</INF>. Thus, we 
might expect that monitoring sites in Connecticut that are closer to 
New York City would show less reduction in ozone than sites in 
Connecticut that are further downwind. However, as noted above, in the 
OTC CMAQ modeling, the closest downwind Connecticut site (Greenwich) 
has a 10-percent modeled ozone reduction, while the Westport site, 
which is further downwind, has only a 3-percent modeled ozone 
reduction. The commenter did not provide any information to explain why 
the OTC CMAQ modeling results for the Westport, Connecticut and Susan 
Wagner, New York monitoring sites are dissimilar to other near-by sites 
or why the CMAQ modeling provides a more representative ozone 
projection for these two sites compared to the EPA and OTC CAMx-based 
modeling results.
    The second commenter contends that modeling by EPA and Alpine for 
2023 is overly optimistic because EPA's modeled ozone design values for 
2017 are higher than the preliminary 2017 design values for certain 
monitoring sites in Connecticut. The results of the air quality 
modeling performed by the OTC show that the results of the CAMx 
modeling by EPA and Alpine are consistent with the OTC's 2023 CAMx 
modeling results. Specifically, the EPA, Alpine, and OTC CAMx modeling 
all project that all sites identified by the commenter as having 
preliminary 2017 measured design values exceeding the 2008 NAAQS will 
be in compliance with that NAAQS by 2023. These CAMx results are also 
consistent with the OTC CMAQ modeling, except for one site in Westport, 
Connecticut, that CMAQ predicts will still violate the 2008 NAAQS in 
2023. However, the CMAQ modeling for this site is inconsistent with 
other available modeling from EPA, the OTC, and Alpine, as described in 
the paragraph above.
    In addition, the commenter compared the preliminary 2017 measured 
design values to EPA's projected 2017 average design values, but did 
not demonstrate that the modeling was generally biased. In particular, 
the commenter ignored EPA's projected maximum design values. The 
projected maximum design values are intended to represent future ozone 
concentrations when meteorological conditions are more favorable to 
ozone formation than the average. Comparing both the 2017 modeled 
average design values and maximum projected design values to the 
preliminary 2017 measured design values indicates that the projected 
maximum design values are, in most cases, closer in magnitude to the 
2017 preliminary measured design values than the 2017 model-projected 
average design values listed in the comments.
    Further, while the modeling-based projections may have understated 
observed design values at certain monitoring sites in Connecticut, this 
was not the case for other 2017 receptor sites in the Northeast 
Corridor. For example, at other receptor sites in the New York area in 
Suffolk and Richmond counties, New York, the measured 2017 design 
values were within 0.2 ppb of the model-predicted average design 
values. At the site in Philadelphia County, Pennsylvania the modeled 
2017 maximum design value was 1.1 ppb lower than the corresponding 
measured value and at the site in Harford County, Maryland, the modeled 
value was higher, not lower, than the measured 2017 design value. It is 
not unreasonable that there may be some differences between the 
modeling-based projections for a future year in part because the 
meteorology of the future year cannot be known in advance. While EPA 
recognizes that there are uncertainties in the modeling, the results 
for the 2017 receptor sites in the Northeast do not, on balance, show a 
consistent bias.
    Even though the preliminary 2017 measured design values at the 
eight sites identified by the commenter are still measuring violations 
of the 2008 NAAQS, it is entirely reasonable to project that these 
sites will be in attainment by 2023 as a result of the roughly 19 
percent reduction in aggregate ozone season NO<INF>X</INF> emissions 
that is expected to occur between 2017 and 2023 for the states covered 
by the CSAPR Update. As mentioned earlier, because of the high 
NO<INF>X</INF> emissions in the New York City area and the non-linear 
chemistry associated with ozone formation, the benefits of 
NO<INF>X</INF> emissions reductions may not have been fully realized to 
date at downwind sites in Connecticut. More notable reductions in ozone 
at these sites are expected as NO<INF>X</INF> emissions decline 
further, in response to existing control programs and other factors 
influencing emissions. A large short-term reduction in ozone is not 
unprecedented at historically high ozone sites in other parts of the 
Northeast Corridor. Specifically, the measured design values at the 
Edgewood monitoring site in Harford County, Maryland, which is downwind 
of the Baltimore/Washington, DC urban area, declined by nearly 20 
percent between 2012 and 2014 and have been below the level of the 2008 
NAAQS since 2014, as shown by the data in the table below. Thus, EPA 
disagrees that the monitored data cited by the commenter indicates that 
the modeling projections are unreliable.

[[Page 33754]]



                                      Design Values (ppb) at Edgewood Site in Harford County, MD, 2007 Through 2017
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                             Preliminary
             Year                 2007       2008       2009       2010       2011       2012       2013       2014       2015       2016        2017
--------------------------------------------------------------------------------------------------------------------------------------------------------
Design Value.................         94         91         87         89         92         93         85         75         71         73           75
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Comment: One commenter asserts that the 2023 modeling provided by 
EPA does not provide a ``full remedy'' because it shows that Kentucky 
still significantly contributes to ozone levels (which the commenter 
contends is defined by a contribution greater than 1 percent of the 
NAAQS, or 0.75 ppb) across Delaware between 1.10 and 2.53 ppb in 2023. 
Although the modeling shows attainment in Delaware in 2023, the 
commenter contends that Kentucky should not presume Delaware or any 
other state will be attaining the 2008 ozone NAAQS in 2023. The 
commenter notes that monitors in Delaware are currently meeting the 
2008 ozone NAAQS, but that other monitors in the Philadelphia 
nonattainment area are exceeding the NAAQS (noting the Bristol, 
Pennsylvania monitor with a 2014-2016 design value of 77 ppb), despite 
the fact that EPA officially declared the nonattainment area had 
attained.
    Another commenter states that the CSAPR Update ``clearly 
established'' Kentucky's significant contribution to the Richmond 
County monitor, and disagrees with EPA's proposed amendment to reflect 
that the CSAPR Update provides a full remedy to Kentucky's transport 
obligation because in EPA's 2023 modeling ``Kentucky is still shown to 
be significantly contributing to monitors'' in the New York City 
metropolitan area, the area currently exceeds the NAAQS ``by a 
significant margin,'' and the area will likely continue to exceed the 
NAAQS in 2023 ``once the issues with EPA's projection modeling are 
addressed.
    Response: EPA disagrees with the commenters' assertion that an 
impact in a downwind area above the 1 percent threshold necessarily 
indicates that an upwind state significantly contributes to 
nonattainment or interferes with maintenance of the NAAQS in a downwind 
state. The good neighbor provision first requires the identification of 
a downwind nonattainment or maintenance problem before emission 
reductions may be required, regardless of the upwind state impact on 
downwind ozone concentrations. See EME Homer City II, 795 F.3d at 129-
30 (finding emission budgets invalid where air quality modeling showed 
downwind nonattainment and maintenance problems would be resolved). As 
the commenter notes, EPA's modeling shows that no areas in the East 
will have downwind air quality problems with respect to the 2008 ozone 
NAAQS in 2023, and thus EPA's analysis is complete at step one of the 
four-step framework. As discussed earlier, although monitors may 
currently measure exceedances of the NAAQS, EPA interprets the term 
``will'' in the good neighbor provision to permit consideration of 
projected air quality in an appropriate future year. See North 
Carolina, 531 F.3d at 913-14.
    Moreover, even if a downwind air quality problem had been 
identified, the fact that an upwind state would contribute at or above 
the 1 percent threshold to downwind nonattainment and maintenance 
receptors in step two of EPA's framework does not by itself indicate 
that the state would be considered to ``contribute significantly'' or 
``interfere with maintenance'' of the NAAQS. The finding that a state's 
downwind impact would meet or exceed this threshold only indicates that 
further analysis is appropriate to determine whether any of the upwind 
state's emissions meet the statutory criteria of significantly 
contributing to nonattainment or interfering with maintenance. This 
further analysis in step three of EPA's four-step framework considers 
cost, technical feasibility and air quality factors to determine 
whether any emissions deemed to contribute to the downwind air quality 
problem must be controlled pursuant to the good neighbor provision.
    Thus, the commenter is incorrect to assert that EPA's 2023 modeling 
shows that Kentucky significantly contributes to ozone levels in 
Delaware.
    Comment: One commenter points to the 2023 modeling performed by 
Alpine indicating greater than a 1 percent contribution by Kentucky to 
New Jersey. The commenter points specifically to the Ocean County and 
Colliers Mill monitoring sites in New Jersey as receiving 1.48 ppb of 
ozone from Kentucky.
    Response: There is only one ozone monitoring site in Ocean County 
New Jersey and that site is located in Colliers Mills.\59\ This site is 
currently monitoring attainment of the 2008 ozone NAAQS based on a 
2014-2016 design value of 73 ppb, and preliminary data indicates that 
the 2015-2017 design value remains at 73 ppb. This site is also 
projected to be in attainment of the 2008 ozone NAAQS in 2023. That is, 
this site is not expected to have a problem attaining or maintaining 
the 2008 NAAQS in 2023 that would warrant consideration of further 
upwind reductions in Kentucky.
---------------------------------------------------------------------------

    \59\ See Figure 4-5 in the 2016 New Jersey Air Quality Report, 
New Jersey Department of Environmental Protection, Bureau of Air 
Monitoring, December 7, 2017, available at http://www.njaqinow.net/.
---------------------------------------------------------------------------

    Comment: One commenter states that EPA's 2023 contribution 
assessment methodology, which uses average exceedance day ozone 
contribution, does not capture what happens on a daily basis for ozone 
formation and is inconsistent with how the states are required to use 
``peak'' ozone days when they demonstrate attainment of the ozone 
standard. Ozone episodes are dependent on variation in daily weather 
patterns and energy generation dispatch.
    The commenter notes that Maryland has recently conducted modeling 
that shows that certain meteorological regimes will show very large 
contribution while other meteorological regimes show lower 
contribution. The commenter states that the days when Kentucky's 
contribution in the model is very high are generally the same type of 
days that Maryland expects will drive the attainment process, where 
peak days are used to calculate design values using measured, not 
modeled data. The commenter states that this can be resolved by 
requiring the largest emitters of ozone precursors, coal-fired EGUs 
with SCR and SNCR, to optimize those controls every day of the ozone 
season.
    Response: EPA does not believe the methodology used to evaluate 
upwind state contributions to downwind air quality problems is relevant 
to this action, because, as noted in the NPRM and earlier this action, 
EPA's modeling shows that there are projected to be no remaining air 
quality problems identified in the East in 2023. Accordingly, EPA's 
analysis concludes at step one of the four-step framework, and as 
discussed earlier in this action, the level of Kentucky's contribution 
to any downwind monitoring cites in 2023, which would not be addressed 
until step two of the four-step

[[Page 33755]]

framework, is therefore irrelevant. Moreover, to the extent the 
commenter refers to Kentucky's contribution to downwind air quality 
problems in EPA's 2017 modeling conducted for the CSAPR Update, EPA has 
already acknowledged that Kentucky was linked to the ozone monitoring 
site in Harford County, Maryland. Thus, whether or not Kentucky's 
contribution would have been higher in 2017 based on examining impacts 
on ``peak'' ozone days is also irrelevant because EPA already 
quantified and implemented emission reductions for Kentucky in the 
CSAPR Update based on this linkage.
    Nonetheless, EPA disagrees that its method for calculating 
contribution from upwind states to downwind receptors is inconsistent 
with how the states are required to demonstrate attainment of the ozone 
NAAQS. EPA's modeling guidance recommends that states calculate future 
year ozone projections based on 5-year weighted average design values 
and on the average base year and future year concentrations across the 
highest base year concentration days.\60\ Similarly, EPA's method for 
calculating the average contribution metric in the CSAPR Update was 
based on the average contribution across the days with the highest 
future year concentrations.
---------------------------------------------------------------------------

    \60\ Modeling Guidance for Demonstrating Attainment of Air 
Quality Goals for Ozone, PM<INF>2.5</INF>, and Regional Haze, U.S. 
Environmental Protection Agency, Research Triangle Park, NC, 
available at http://www.epa.gov/ttn/scram/guidance/guide/Draft_O3-PM-RH_Modeling_Guidance-2014.pdf.
---------------------------------------------------------------------------

    Comment: One commenter states that the CSAPR Update, by its own 
terms, does not fully satisfy section 110(a)(2)(D) for the 2008 ozone 
NAAQS. Rather than rely on the CSAPR Update, Kentucky's SIP revision 
must evaluate the Commonwealth's expected contribution to downwind 
nonattainment and include provisions to prevent those contributions in 
a timely fashion. The commenter cites North Carolina's conclusion that 
``a complete remedy to section 110(a)(2)(D)(i)(I) . . . must do more 
than achieve something measurable; it must actually require elimination 
of emissions from sources that contribute significantly and interfere 
with maintenance in downwind nonattainment areas.'' 531 F.3d at 908.
    The commenter notes that, in the final CSAPR Update, EPA explained 
that downwind air quality problems would remain after implementation, 
and that the rule was limited by EPA's focus on ``immediately available 
reductions'' that could be implemented by the 2017 ozone season. The 
commenter further states that EPA's October 2017 Transport Memo 
conceded that the CSAPR update only partially addressed the 
requirements of the good neighbor provision, noting in a footnote that 
the memo indicates continued nonattainment in Philadelphia, which is 
linked to Kentucky in the CSAPR Update.
    The commenter contends that Kentucky has undertaken no independent 
analysis of whether any emission reductions that have occurred as a 
result of its implementation of the CSAPR Update have actually 
eliminated the Commonwealth's significant contribution to nonattainment 
or maintenance monitors in linked downwind states. Given Kentucky's 
largest downwind contribution was 10.8 ppb to ozone concentrations at a 
maintenance monitor in Ohio in 2017, the commenter asserts that it is 
highly improbable that the modest reductions in NO<INF>X</INF> 
emissions from Kentucky plants that have occurred since the 
implementation of the CSAPR Update have eliminated this significant 
linkage. The commenter notes in a footnote that Kentucky reduced 
NO<INF>X</INF> emissions during the ozone season by about a third in 
implementing the CSAPR Update, and accordingly retained a similar 
majority of its downwind impacts, well above the 0.75 ppb threshold of 
``significant contributions.''
    Response: While EPA indicated that the CSAPR Update FIPs ``may not 
be sufficient to fully address these states' [including Kentucky's] 
good neighbor obligations'' for the 2008 ozone NAAQS (emphasis added), 
EPA did not definitely determine that additional reductions were 
required. 81 FR 74521. Rather, EPA acknowledged that additional 
analysis would be required to determine the full extent of the good 
neighbor obligation. Kentucky's SIP submission and EPA's review in this 
action conduct this additional assessment by analyzing downwind ozone 
concentrations relative to the 2008 ozone NAAQS in a future analytic 
year, considering downwind attainment dates and anticipated compliance 
timeframes for potential, additional emission reductions. The results 
of this analysis show that the downwind air quality problems to which 
Kentucky was linked in 2017 are resolved by 2023, and thus concludes 
that the emission reductions required by the CSAPR Update provide a 
complete remedy under the good neighbor provision for the 2008 ozone 
NAAQS. EPA therefore disagrees that EPA's approval of Kentucky's SIP is 
inconsistent with the court's holding in North Carolina, because EPA 
has in fact required meaningful emission reductions from sources in 
Kentucky via the CSAPR Update FIP.
    Moreover, as explained earlier in this action, an impact in a 
downwind area above the 1 percent threshold does not necessarily 
indicate that an upwind state significantly contributes to 
nonattainment or interferes with maintenance of the NAAQS in a downwind 
state. The good neighbor provision first requires the identification of 
a downwind nonattainment or maintenance problem before emission 
reductions may be required, regardless of the upwind state impact on 
downwind ozone concentrations. See EME Homer City II, 795 F.3d at 129-
30 (finding emission budgets invalid where air quality modeling showed 
downwind nonattainment and maintenance problems would be resolved). 
Thus, although emissions from Kentucky may continue to impact air 
quality in other states in 2023, this impact is not impermissible under 
the good neighbor provision given EPA has projected that there will be 
no air quality problems that could trigger upwind control obligations.
    Comment: One commenter contends that EPA takes two contradictory 
positions regarding its application of the four-step framework designed 
to assist states in determining good neighbor SIP obligations under the 
CAA, citing the January 2015 Transport Memo. The commenter notes that, 
based on 2017 modeling conducted for the CSAPR Update, EPA acknowledged 
that Kentucky is linked to Maryland's Harford County monitor, which 
will continue to have maintenance problems in the near future. However, 
instead of completing the analysis at steps 3 and 4 using 2017 as a 
baseline, EPA returned to step one, performed new modeling for 2023, 
and used that modeling to determine that there will be no remaining air 
quality problems outside of California.
    The commenter further contends that reliance on 2023 modeling is 
inappropriate because the attainment deadline for Harford County is 
July 2018, and Maryland must continue to maintain thereafter. The 
commenter states that EPA should have completed all steps of the four-
step framework using a consistent base year since EPA's own modeling 
identified Kentucky as currently linked to the Harford County receptor. 
EPA should have identified the emissions reductions necessary to 
prevent Kentucky from significantly contributing to nonattainment or 
interfering with maintenance in Maryland, and required Kentucky to

[[Page 33756]]

adopt permanent and enforceable measures needed to achieve identified 
emission reductions as expeditiously as practicable. The commenter 
asserts that Kentucky's obligation to reduce its current contribution 
to Maryland's 2017 maintenance monitor cannot properly be offset based 
on projections about future air quality which may or may not occur in 
2023.
    Response: The commenter misunderstands EPA's analysis in this rule 
and the operation of the four-step framework. EPA agrees that Kentucky 
was linked to the Harford County receptor in step two of EPA's four-
step framework based on the 2017 modeling conducted for the CSAPR 
Update. Based on that determination, EPA already evaluated and 
quantified, at step three, feasible and cost-effective emission 
reductions that were required to address Kentucky's good neighbor 
obligation with respect to that receptor in the CSAPR Update, and 
implemented those emission reductions at step four through the 
requirement that EGUs in Kentucky participate in the CSAPR 
NO<INF>X</INF> Ozone Season Group 2 allowance trading program. Thus, 
EPA has completed steps 3 and 4 with respect to the 2017 modeling 
analysis.
    However, as explained in the CSAPR Update, EPA could not conclude 
that the rule fully addressed CAA section 110(a)(2)(D)(i)(I) 
obligations for 21 of the 22 CSAPR Update states, including Kentucky. 
Specifically, EPA determined that downwind air quality problems would 
remain after implementation of the CSAPR Update, including at the 
Harford County monitor, and EPA could not conclude at that time whether 
additional EGU and non-EGU reductions implemented on a longer timeframe 
than 2017 would be feasible, necessary, and cost-effective to address 
states' good neighbor obligations for this NAAQS.
    Given that any additional emission reductions, if necessary, would 
be implemented at some point after 2017, it is reasonable for Kentucky 
and EPA to evaluate air quality (at step one of the framework) in a 
future year that is aligned with feasible control installation timing 
in order to ensure that the upwind states continue to be linked to 
downwind air quality problems when any potential emissions reductions 
would be implemented and to ensure that such reductions do not over-
control relative to the identified downwind ozone problem. See EME 
Homer City, 134 S. Ct. at 1608. Here, EPA has determined that the air 
quality problems identified at the Harford receptor with respect to the 
2008 ozone NAAQS will be resolved by 2023. Accordingly, EPA does not 
have the authority to require additional emission reductions from 
sources in Kentucky in that year. See EME Homer City II, 795 F.3d at 
130 (determining that CSAPR ozone season budgets for 10 states are 
invalid based on determination that modeling showed no future air 
quality problems).
    Comment: One commenter asserts that the good neighbor provision 
does not permit a state to delay its elimination of significant 
downwind contribution indefinitely. EPA made nonattainment designations 
for areas where Kentucky is making a significant contribution and 
therefore EPA's proposal to delay enforcing Kentucky's good neighbor 
obligations for another five years violates the good neighbor 
provision. Kentucky's SIP fails to address Kentucky's present and 
ongoing significant contribution to nonattainment or interference with 
maintenance of the NAAQS in downwind areas including the New York-
Northern New Jersey-Long Island, NY-NJ-CT nonattainment area in the 
NYMA.
    The commenter states that the CSAPR Update established Kentucky's 
significant contribution to the Richmond County monitor in 2017, which 
is part of the NYMA that measured nonattainment for the 2008 ozone 
NAAQS during 2017. The commenter contends that EPA's proposed approval 
provides no modeling or monitoring data showing that Kentucky's 
significant contribution to NYMA nonattainment has presently ceased or 
that it will cease at any time prior to 2023. Therefore, the commenter 
opposes the modification of EPA regulations to reflect that the CSAPR 
Update fully addresses Kentucky's transport obligation.
    The commenter states that Kentucky's significant contribution to 
nonattainment and/or maintenance problems for New York under the 2008 
ozone NAAQS are present nearly 10 years after EPA promulgated the 
NAAQS, seven years after the SIP was due, and five years after EPA's 
FIP was due. Yet Kentucky's SIP looks out another five years before 
concluding it is feasible for Kentucky to comply with its good neighbor 
obligations. EPA's 2023 modeling is 15 years after promulgation of the 
NAAQS and delays compliance without statutory authority, effectively 
permitting Kentucky's continuing violation of the good neighbor 
provision.
    Response: EPA disagrees that it has allowed Kentucky to delay 
addressing its good neighbor obligation indefinitely. Rather, EPA 
promulgated a FIP for the Kentucky in the CSAPR Update that has 
required EGUs in the Commonwealth to limit their collective emissions 
beginning 2017. As discussed earlier, EPA could not conclude whether or 
not the FIP was sufficient to address the state's good neighbor 
obligation for Kentucky without further analysis, and EPA therefore 
further disagrees with the commenter's assertion that Kentucky has 
continued to violate its obligation after implementation of the CSAPR 
Update. As discussed earlier, the fact that emissions from the 
Commonwealth may continue to impact air quality in other states does 
not conclude the question of whether that impact constitutes a 
significant contribution or interference with maintenance of the NAAQS 
under the good neighbor provision.
    In order to determine whether Kentucky had any remaining emission 
reduction obligations with respect to the 2008 ozone NAAQS, additional 
analysis was necessary. EPA explained in the NPRM and earlier in this 
action why it was appropriate to evaluate air quality in a future 
analytic year to determine whether the Commonwealth would have any 
further emission reduction after implantation of the CSAPR Update and 
how the choice of a 2023 analytic year was consistent with legal 
precedent. Thus, EPA does not agree that its approval of Kentucky's SIP 
improperly delays compliance with the good neighbor provision for the 
2008 ozone NAAQS.
    Comment: One commenter states that EPA must issue a FIP for the 
Commonwealth of Kentucky consistent with the obligations of CAA section 
110(a)(2)(D) as well as the court's order in Sierra Club v. Pruitt, No. 
3:15-cv-04328-JD (N.D. Cal. May 23, 2017), directing EPA ``to 
promulgate the Kentucky FIP by June 30, 2018.''
    Another commenter contends that EPA's proposed approval of the 
Kentucky SIP does not obviate its duty to issue a fully compliant FIP 
for Kentucky by the June 30, 2018 deadline in accordance with the 
court's order.
    A further commenter states that states were required to submit SIPs 
addressing the good neighbor provision for the 2008 ozone NAAQS by 
March 2011, and that EPA disapproved Kentucky's SIP on March 4, 2013. 
This finding triggered EPA's mandatory duty under CAA section 110(c)(1) 
to promulgate a FIP for Kentucky within two years: By March 7, 2015. 
When EPA failed to act, Sierra Club and New York sued EPA in the United 
States District Court for the Northern District of California to 
require EPA to adopt a FIP addressing Kentucky's good neighbor 
obligations. The commenter notes that the Supreme

[[Page 33757]]

Court found that section 110(c)(1) ``impose[s] an absolute duty on EPA 
to issue [a] FIP within two years of Kentucky's failure to adopt an 
adequate state implementation plan,'' EME Homer City, 134 S. Ct. at 
1600, and that EPA did not contest its liability to issue a FIP for 
Kentucky based on the SIP disapproval. The District Court ordered EPA 
``to promulgate the Kentucky FIP by June 30, 2018.''
    The commenter contends that the Kentucky SIP cannot be approved 
because it requires insufficient action to reduce Kentucky's 
significant contribution to nonattainment in the NY-NJ-CT multistate 
nonattainment area by the CAA's mandatory attainment deadlines of July 
2018 (moderate areas) and July 2021 (serious areas). The commenter 
asserts that EPA's failure to propose a FIP by June 30, 2018, is 
another instance of EPA's failure to carry out its mandatory duty under 
section 110(c) with respect to Kentucky's transport obligations, and a 
clear violation of the District Court's order.
    Response: EPA disagrees that this action fails to satisfy the 
requirements of the court's order in Sierra Club v. Pruitt. While the 
commenters are correct that section 110(c)(1)(B) requires the 
Administrator to promulgate a FIP within two years after the 
Administrator disapproves a SIP in whole or in part, the provision 
further qualifies this obligation. The Administrator is to promulgate a 
FIP ``unless the State corrects the deficiency, and the Administrator 
approves the plan or plan revision, before the Administrator 
promulgates such [FIP].'' Thus, once EPA has approved a SIP that EPA 
determines addresses the deficiency that was the subject of the prior 
SIP disapproval, the Administrator no longer has the authority (much 
less the obligation) to promulgate a FIP.
    As to the requirements of the good neighbor provision for the 2008 
ozone NAAQS, EPA has promulgated a FIP for Kentucky in the CSAPR 
Update. While EPA indicated that the CSAPR Update FIPs ``may not be 
sufficient to fully address these states' [including Kentucky's] good 
neighbor obligations'' for the 2008 ozone NAAQS (emphasis added), EPA 
did not definitely determine that additional reductions were required. 
See 81 FR 74521 (October 26, 2016). Rather, EPA acknowledged that 
additional analysis would be required to determine the full extent of 
the good neighbor obligation. Thus, the only remaining deficiency after 
promulgation of the CSAPR Update FIP was to determine what, if any 
remaining emission reduction obligation would apply to the states, 
including Kentucky. EPA has determined, in this SIP action, that no 
further emission reductions are required for the 2008 ozone NAAQS, and 
thus, that the CSAPR Update FIP fully addresses Kentucky's good 
neighbor obligation. Accordingly, EPA lacks authority to issue any 
further FIP since the CSAPR Update has fully addressed the deficiency 
identified in the initial SIP disapproval that triggered EPA's FIP 
obligation.
    Moreover, to the extent the commenters contend that the court's 
citation to the Supreme Court's decision in EME Homer City, 134 S. Ct. 
at 1600, precludes EPA's use of a SIP approval to address the remaining 
deficiency, the commenters misrepresent the holding of the Court. 
Importantly, the Court was emphasizing the ``absolute'' nature of EPA's 
mandate in order to counter arguments from the respondents and the 
lower court that EPA's FIP authority was contingent on an obligation to 
take some action other than to find that the state has failed to submit 
an approvable SIP. While the Court did state that EPA has an absolute 
mandate to promulgate a FIP upon a SIP disapproval, the court also 
acknowledged, repeatedly, that the state could first ``correct the 
deficiency'' through submission of a SIP. Id. at 1600-01 (emphasizing 
twice that EPA's obligation to issue a FIP can be affected if the state 
``correct[s] the deficiency'' on its own). That is precisely what has 
occurred here with respect to the portion of the good neighbor 
deficiency not already addressed by the CSAPR Update. Thus, EPA's 
action is consistent with section 110(c) and therefore consistent with 
the Northern District of California's order that EPA address its 
obligation under section 110(c) as it pertains to Kentucky's good 
neighbor obligation for the 2008 ozone NAAQS.
    Comment: Several commenters contend that EPA is inappropriately 
parallel processing the Kentucky SIP in light of the ``significant 
number and scope'' of public comments raised during the state public 
comment process. The commenters state that Kentucky should have been 
required to address comments prior to EPA's proposed approval. One 
commenter contends that EPA's proposed approval of the Kentucky SIP on 
the condition that the final SIP contain no substantial changes removes 
any incentive for Kentucky to address the public comments by making 
necessary changes. The commenter further asserts that Kentucky's SIP is 
controversial and contested, and thus, parallel processing is 
inappropriate. To support this assertion, the commenter notes that EPA 
denied a petition brought under section 176A, which is currently 
subject to review in the D.C. Circuit, that involves claims of 
transported ozone pollution from Kentucky and other upwind states. The 
commenter further states that EPA's only apparent reason for parallel 
processing is the court-ordered deadline to promulgate a FIP by June 
30, 2018, and that EPA's own inaction is no excuse for taking rushed, 
unreasonable, arbitrary and capricious action to approve a deficient 
SIP.
    Response: EPA disagrees with the commenters' assertions that 
parallel processing is inappropriate in these circumstances. Parallel 
processing is a well-established procedure for acting on SIP 
submissions that is allowed under long-standing EPA regulations. 
Appendix V to 40 CFR part 51 (Appendix V) provides the criteria for 
determining the completeness of SIP submittals and the procedures for 
parallel processing. These procedures, set forth in paragraph 2.3 of 
Appendix V, allow a state to request parallel processing as the state 
is accepting comments and finalizing its SIP revision. Under parallel 
processing, the state submits a copy of a draft SIP submittal to EPA 
before conducting its public hearing. EPA reviews the draft submittal 
and, if EPA believes it is approvable, publishes an NPRM during the 
same timeframe that the state is holding its public hearing. The state 
and EPA then provide for concurrent public comment periods on both the 
state action and the federal action, respectively.
    Although parallel processing expedites action on SIP submissions, 
it does not limit EPA's substantive review. EPA evaluates the draft 
submittal against the same approvability criteria as any other SIP 
submission, and the final submission must meet all of the necessary SIP 
completeness criteria, including the requirement that the submission 
contain a ``[c]ompilation of public comments and the State's response 
thereto.'' See Appendix V, paragraphs 2.1(h) and 2.3.2. Therefore, a 
state must respond to comments received during the state public comment 
period. Parallel processing does not remove the incentive for a state 
to revise its SIP submission in response to comments that raise valid 
approvability concerns because ultimately EPA cannot approve a 
submission that fails to meet all approvability criteria.
    EPA is not taking a rushed, unreasonable, or arbitrary and 
capricious action by using parallel processing to act on Kentucky's SIP 
submission. Kentucky submitted a

[[Page 33758]]

parallel processing request, as allowed under paragraph 2.3.1 of 
Appendix V, and EPA is following the criteria set forth in Appendix V 
to approve the Commonwealth's final submittal. These criteria do not 
exclude certain types of SIP submissions from parallel processing 
because all SIP submissions reviewed through this process must 
ultimately meet all completeness and approvability criteria regardless 
of the number of comments received or the degree of controversy. 
Furthermore, EPA provided the public with a full opportunity to comment 
on the draft submittal and has fully evaluated all of the submitted 
comments. If these comments had identified specific issues that would 
not allow EPA to approve the draft SIP submission, EPA could not have 
taken this final action.
    Comment: One commenter suggests that a declaration filed in another 
pending lawsuit demonstrates that EPA has prejudged its approval of 
Kentucky's proposed SIP submission, by noting that the declaration 
states EPA has proposed an ``unconditional approval.'' This appears to 
be contrary to what was stated in EPA's proposed approval, wherein EPA 
stated that the approval is contingent on Kentucky addressing any 
comments in the state-level process. The declaration further states 
that ``EPA intends to finalize an appropriate action for Kentucky'' by 
the court-ordered deadline. The commenter contends that, because of the 
public notice and hearing requirements under CAA section 307(d), and 
because EPA has not yet proposed a FIP, the only action EPA has left 
itself is to approve Kentucky's deficient SIP regardless of any public 
comments it receives.
    Response: The commenter misinterprets the reference to proposed 
``unconditional approval'' of Kentucky's SIP made in the declaration of 
Reid Harvey filed in New York v. Pruitt, No. 18-cv-406 (S.D.N.Y.). 
Section 110(k)(4) permits the Administrator to issue a ``conditional'' 
approval of a SIP based on a commitment of a state to adopt specific 
measures within one year of the final action. If the state fails to 
meet this commitment, the conditional approval is treated as a 
disapproval. Mr. Harvey's declaration used the term ``unconditional 
approval'' to indicate that the proposed approval was not made pursuant 
to section 110(k)(4). The use of this term is unrelated to the 
contingencies associated with the parallel processing requirements, 
which are laid out in Appendix V to 40 CFR part 51 rather than in 
section 110.
    Moreover, EPA does not agree that the Agency has been forced to 
approve a deficient SIP based on the court-ordered deadline and the 
procedural requirements for the promulgation of a FIP. For the reasons 
explained in the NRPM and in this action, EPA finds that Kentucky's SIP 
submission, together with the CSAPR Update, fully satisfies the 
requirements of the good neighbor provision with respect to the 2008 
ozone NAAQS. However, had EPA determined that it could not finalize 
approval of Kentucky's SIP and would instead need to promulgate a FIP, 
EPA would have filed an appropriate motion with the district court 
requesting an extension of the court-ordered deadline.
    Comment: One commenter contends that approving the Kentucky SIP and 
putting the October 2017 Transport Memo into effect will effectively 
foreclose any further good neighbor activities under the 2008 ozone 
NAAQS and EPA will have reversed its position in the CSAPR Update that 
more NO<INF>X</INF> controls were necessary. EPA deferred action under 
section 176A of the CAA by indicating it would enforce good neighbor 
obligations through other mechanisms like the transport rule framework. 
The commenter asserts that EPA effectively shifts the burden onto 
downwind states to cope with upwind pollution sources while denying 
downwind state any means to enforce good neighbor obligations.
    The commenter continues that EPA's failure is forcing downwind 
states to attempt to address Kentucky's and other upwind states' 
contributions to ozone concentrations via other, resource-intensive CAA 
mechanisms. The commenter cites a recent petition submitted by Maryland 
under CAA section 126 identifying three coal-fired units in Kentucky to 
which EPA has to date failed to respond. The commenter also cites a 
petition submitted pursuant to CAA section 176A to expand the OTR, 
which EPA denied. The commenter claims it is arbitrary and capricious 
for EPA to point to separate CAA provisions as an excuse for inaction 
on the ozone transport problem, and to reverse itself without 
confronting its prior position.
    Another commenter states that New York's recent submittal of a 
section 126 petition to EPA buttresses Connecticut's claims and that 
notes that such petition names stationary sources in Kentucky as 
``interfer[ing] with attainment'' of the New York-New Jersey-
Connecticut nonattainment area. The commenter states that EPA has 
referred to section 126 petitions as one of the tools available to 
states seeking attainment with the ozone NAAQS, yet they would not be 
required if upwind states and EPA satisfied their obligations in a 
timely matter.
    Response: EPA disagrees that it has changed its position in the 
CSAPR Update regarding the need for additional emission reductions. In 
that rulemaking, EPA only stated it could not conclude, without further 
analysis, whether additional reductions from NO<INF>X</INF> sources 
would be necessary to fully resolve these obligations. This conclusion 
is not inconsistent with EPA's action on the section 176A petition 
seeking to expand the OTR. EPA denied the section 176A petition because 
it concluded that any remaining interstate transport problems could be 
better addressed via the good neighbor provision, which EPA and the 
states can use to make decisions regarding which precursor pollutants 
to address, which sources to regulate, and what amount of emission 
reductions to require, flexibilities that are not available with 
respect to control requirements applicable to sources in the OTR. See 
82 FR 51244-46 (November 3, 2017). EPA has subsequently completed 
further analysis that shows that there will be no remaining air quality 
problems in 2023 in the eastern U.S., and thus EPA has concluded that 
no additional reductions from upwind states, beyond those required by 
the CSAPR Update and other on-the-books or on the way measures, are 
necessary to bring downwind areas into attainment of the 2008 ozone 
NAAQS. While downwind states may continue to have current planning 
obligations associated with designated nonattainment areas, EPA lacks 
the authority to require additional emissions reductions from upwind 
states under the good neighbor provision in a future year where EPA's 
analysis shows that current nonattainment problems will be resolved.
    While EPA is concluding in this action that Kentucky has no 
remaining good neighbor obligation with respect to the 2008 ozone NAAQS 
after implementation of the CSAPR Update, EPA disagrees that this 
action necessarily forecloses all further good neighbor activities with 
respect to that NAAQS. This action does not address remaining good 
neighbor obligations for any other states, and EPA will address any 
such obligations in a separate rulemaking. Moreover, the commenters 
acknowledge and EPA agrees that section 126 provides a process for 
states to bring claims to the Agency if the petitioning state can 
present information demonstrating that sources in upwind states will 
have impacts on downwind air quality in violation of the good neighbor 
provision. However, the right to submit such petitions does not

[[Page 33759]]

presuppose that any pending or future petitions will necessarily make 
the requisite demonstration. To the extent that the commenters invokes 
separate, pending section 126 petitions, EPA will address those claims 
in separate actions.

IV. Final Action

    For the reasons discussed above, EPA is taking final action to 
approve Kentucky's May 10, 2018, SIP submission and find that Kentucky 
is not required to make any further reductions, beyond those required 
by the CSAPR Update, to address its statutory obligation under CAA 
section 110(a)(2)(D)(i)(I) for the 2008 ozone NAAQS. EPA's final 
approval of Kentucky's submission means that Kentucky's obligations 
under 110(a)(2)(D)(i)(I) are fully addressed through the combination of 
the CSAPR Update FIP and the SIP demonstration showing that no further 
reductions are necessary. EPA is also amending the regulatory text at 
40 CFR 52.940(b)(2) to reflect that the CSAPR Update represents a full 
remedy with respect to Kentucky's transport obligation for the 2008 
ozone NAAQS.

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations. See 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. 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:
    <bullet> 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);
    <bullet> Is not an Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory action because SIP approvals are exempted under 
Executive Order 12866;
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> 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.);
    <bullet> 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);
    <bullet> Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
    <bullet> 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
    <bullet> 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).
    The SIP is not approved to apply on any Indian reservation land or 
in any other area where EPA or an Indian tribe has demonstrated that a 
tribe has jurisdiction. In those areas of Indian country, the rule does 
not have tribal implications as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000), nor will it impose substantial direct 
costs on tribal governments or preempt tribal law.
    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).
    Under section 307(b)(1) of the Act, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by September 17, 2018. Under section 307(b)(2) 
of the Act, the requirements of this final action may not be challenged 
later in civil or criminal proceedings for enforcement.

List of Subjects in 40 CFR Part 52

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Incorporation by reference, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Reporting and recordkeeping 
requirements.

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

    Dated: June 28, 2018.
Onis ``Trey'' Glenn, III,
Regional Administrator, Region 4.
    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 S--Kentucky

0
2. Section 52.920(e) is amended by adding an entry for 
``110(a)(2)(D)(i)(I) Infrastructure Requirement for the 2008 8-Hour 
Ozone National Ambient Air Quality Standards'' at the end of the table 
to read as follows:


Sec.  52.920  Identification of plan.

    (e) * * *

                                 EPA-Approved Kentucky Non-regulatory Provisions
----------------------------------------------------------------------------------------------------------------
                                        Applicable           State
    Name of non-regulatory SIP        geographic or     submittal date/  EPA approval date       Explanations
            provision               nonattainment area  effective date
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
110(a)(2)(D)(i)(I) Infrastructure  Commonwealth of          05/10/2018  07/17/2018, [Insert
 Requirement for the 2008 8-Hour    Kentucky.                            Federal Register
 Ozone National Ambient Air                                              citation].
 Quality Standards.
----------------------------------------------------------------------------------------------------------------


[[Page 33760]]


0
3. Section 52.940 is amended by revising paragraph (b)(2) to read as 
follows:


Sec.  52.940   Interstate pollutant transport provisions; What are the 
FIP requirements for decreases in emissions of nitrogen oxides?

* * * * *
    (b) * * *
    (2) The owner and operator of each source and each unit located in 
the State of Kentucky and for which requirements are set forth under 
the CSAPR NO<INF>X</INF> Ozone Season Group 2 Trading Program in 
subpart EEEEE of part 97 of this chapter must comply with such 
requirements with regard to emissions occurring in 2017 and each 
subsequent year. The obligation to comply with such requirements will 
be eliminated by the promulgation of an approval by the Administrator 
of a revision to Kentucky's State Implementation Plan (SIP) as 
correcting the SIP's deficiency that is the basis for the CSAPR Federal 
Implementation Plan (FIP) under Sec.  52.38(b), except to the extent 
the Administrator's approval is partial or conditional.
* * * * *
[FR Doc. 2018-15143 Filed 7-16-18; 8:45 am]
 BILLING CODE 6560-50-P


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