Rule2026-19668
Air Plan Approval; Kentucky; Campbell-Clermont Area Maintenance Plan for the 2010 1-Hour SO2 NAAQS
Primary source
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Published
September 25, 2026
Effective
November 24, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA or Agency) is approving a State Implementation Plan (SIP) revision submitted by the Commonwealth of Kentucky, through the Kentucky Division for Air Quality (DAQ), on February 20, 2025. The SIP revision includes the second 10- year maintenance plan for the Kentucky portion of the Campbell- Clermont, Kentucky-Ohio maintenance area ("Campbell-Clermont, KY-OH Area" or "Area") for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standards (NAAQS). The Kentucky portion of the Area is comprised of a part of Campbell County. The EPA is approving Kentucky's second 10-year maintenance plan for the Kentucky portion of the Area because the Commonwealth has demonstrated that it is consistent with the Clean Air Act (CAA or Act).
Full Text
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<title>Federal Register, Volume 91 Issue 185 (Friday, September 25, 2026)</title>
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[Federal Register Volume 91, Number 185 (Friday, September 25, 2026)]
[Rules and Regulations]
[Pages 60840-60846]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-19668]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R04-OAR-2025-0244; FRL-13461-02-R4]
Air Plan Approval; Kentucky; Campbell-Clermont Area Maintenance
Plan for the 2010 1-Hour SO2 NAAQS
AGENCY: Environmental Protection Agency (EPA).
ACTION: Direct final rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA or Agency) is
approving a State Implementation Plan (SIP) revision submitted by the
Commonwealth of Kentucky, through the Kentucky Division for Air Quality
(DAQ), on February 20, 2025. The SIP revision includes the second 10-
year maintenance plan for the Kentucky portion of the Campbell-
Clermont, Kentucky-Ohio maintenance area (``Campbell-Clermont, KY-OH
Area'' or ``Area'') for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>)
National Ambient Air Quality Standards (NAAQS). The Kentucky portion of
the Area is comprised of a part of Campbell County. The EPA is
approving Kentucky's second 10-year maintenance plan for the Kentucky
portion of the Area because the Commonwealth has demonstrated that it
is consistent with the Clean Air Act (CAA or Act).
DATES: This direct final rule is effective November 24, 2026 without
further notice, unless EPA receives adverse comment by October 26,
2026. If adverse comments are received, the EPA will publish a timely
withdrawal of the direct final rule in the Federal Register informing
the public that the rule will not take effect.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2025-0244 at <a href="http://regulations.gov">regulations.gov</a>. Follow the online instructions for
submitting comments. Once submitted, comments cannot be edited or
removed from Regulations.gov. The EPA may publish any comment received
to its public docket. Do not submit electronically any information you
consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia
submissions (audio, video, etc.) must be accompanied by a written
comment. The written comment is considered the official comment and
should include discussion of all points you wish to make. The EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the web, cloud, or other file sharing
system). For additional submission methods, the full EPA public comment
policy, information about CBI or multimedia submissions, and general
guidance on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
FOR FURTHER INFORMATION CONTACT: Nelsha Athauda, Multi Air Pollutant
Coordination Section, Air Planning and Implementation Branch, Air and
Radiation Division, U.S. Environmental Protection Agency, Region 4, 61
Forsyth Street SW, Atlanta, Georgia 30303-8960. The telephone number is
(404) 562-9360. Ms. Athauda can also be reached via electronic mail at
<a href="/cdn-cgi/l/email-protection#4c2d38242d39282d622229203f242d0c293c2d622b233a"><span class="__cf_email__" data-cfemail="4d2c39252c38292c632328213e252c0d283d2c632a223b">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. The EPA's Final Action
II. Background
III. The EPA's Evaluation of Kentucky's SIP Submittal
A. Attainment Emissions Inventory
B. Maintenance Demonstration
C. Monitoring Network
D. Verification of Continued Attainment
E. Contingency Plan
IV. Final Action
V. Statutory and Executive Order Reviews
[[Page 60841]]
I. The EPA's Final Action
In accordance with the CAA, the EPA is approving the second 10-year
maintenance plan for the Kentucky portion of the Campbell-Clermont, KY-
OH Area for the 2010 1-hour SO<INF>2</INF> NAAQS, submitted by DAQ as a
revision to the Kentucky SIP on February 20, 2025. The second
maintenance plan is designed to maintain the 2010 1-hour SO<INF>2</INF>
NAAQS within the Area through the end of the second 10-year portion of
the maintenance period beyond redesignation (through 2037). The EPA is
approving the plan because it meets all applicable requirements under
CAA sections 110 and 175A.
II. Background
On June 2, 2010, the EPA revised the primary SO<INF>2</INF> NAAQS,
establishing a new 1-hour SO<INF>2</INF> standard of 75 parts per
billion (ppb).\1\ The 2010 1-hour SO<INF>2</INF> NAAQS is met at a
monitoring site when the 3-year average of the annual 99th percentile
of 1-hour daily maximum concentrations is less than or equal to 75 ppb,
as determined in accordance with 40 CFR part 50, appendix T.\2\ Ambient
air quality monitoring data for the 3-year period must meet a data
completeness requirement.\3\
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\1\ See 75 FR 35520.
\2\ See 40 CFR 50.17(b).
\3\ A calendar year meets data completeness requirements when
all four quarters are complete, and a quarter is complete when at
least 75 percent of the sampling days for each quarter have complete
data. A sampling day has complete data if 75 percent of the hourly
concentration values, including State-flagged data affected by
exceptional events which have been approved for exclusion by the
Administrator, are reported. See 40 CFR part 50, appendix T, section
3.1(b).
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Upon promulgation of a new or revised NAAQS, CAA section 107(d)
requires the EPA to designate as nonattainment any area that does not
meet (or that contributes to ambient air quality in a nearby area that
does not meet) the NAAQS. The EPA designated the Area as nonattainment
for the 2010 1-hour SO<INF>2</INF> NAAQS, effective on October 4, 2013,
based on a violating 2009-2011 design value of 89 ppb at the Highland
Heights ambient air monitor (Air Quality System (AQS) ID: 21-037-3002)
in Campbell County, Kentucky.<SUP>4 5</SUP> The Area consists of a
portion of Campbell County, Kentucky and Pierce Township in Clermont
County, Ohio.\6\ Under CAA section 192(a), SO<INF>2</INF> nonattainment
areas must attain the NAAQS as expeditiously as practicable but not
later than five years after the effective date of the designation.\7\
The Area's attainment date was no later than October 4, 2018. The EPA's
nonattainment designation for the Area established a requirement for
Kentucky and Ohio to submit an attainment SIP within 18 months
following the effective date of designation (October 4, 2013).\8\
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\4\ See Final Technical Support Document, July 2013, Kentucky
First Round of Nonattainment Area Designations for the 2010
SO<INF>2</INF> Primary NAAQS, Prepared by EPA Region 4 (2013
Kentucky TSD), available at <a href="http://regulations.gov">regulations.gov</a> in Docket EPA-HQ-OAR-
2012-0233 with Document ID No. EPA-HQ-OAR-2012-0233-0308.
\5\ See 40 CFR 50.17(b).
\6\ See 40 CFR 81.318 and 81.336.
\7\ CAA section 192(a) applies to SIPs required under CAA
section 191(a).
\8\ See CAA section 191(a).
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When the EPA designated the Area as nonattainment for the 2010 1-
hour SO<INF>2</INF> NAAQS, the EPA determined that operations at the
Walter C. Beckjord Generating Station (Beckjord) were the major
contributor to the SO<INF>2</INF> NAAQS violations at the Highland
Heights monitor in Campbell County.<SUP>9 10</SUP> In 2014, operations
at Beckjord ceased, and the facility was permanently shut down.\11\ The
source is no longer authorized to operate and cannot restart without
meeting the State of Ohio's prevention of significant deterioration
(PSD) permitting requirements. The shutdown reduced SO<INF>2</INF>
emissions in the Area from approximately 90,851 tons per year (tpy)
\12\ in 2011 to 38 tpy \13\ in 2016, resulting in a significant
improvement in monitored air quality.
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\9\ See 2013 Kentucky TSD.
\10\ See 78 FR 47191.
\11\ See Appendix B of Kentucky's February 20, 2025, SIP
submission for documentation of Walter C. Beckjord's shutdown.
\12\ See Table 5 of 81 FR 86664.
\13\ See Table 5 in Kentucky's February 20, 2025, SIP
submission.
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On March 31, 2015, DAQ submitted a request to the EPA for a clean
data determination (CDD) for the Area based on the then-certified 2012-
2014 SO<INF>2</INF> monitoring design value showing attainment of the
SO<INF>2</INF> NAAQS. On February 22, 2016, DAQ submitted a
redesignation request and first 10-year maintenance plan for the
Kentucky portion of the Area. On March 10, 2017, EPA finalized approval
of the Commonwealth's CDD, redesignation request, and first 10-year
maintenance plan.<SUP>14 15</SUP> The purpose of Kentucky's February
20, 2025, submittal is to fulfill the second 10-year maintenance plan
requirement for the Kentucky portion of the Area pursuant to CAA
section 175A(b) to ensure compliance with the 2010 SO<INF>2</INF> NAAQS
through 2037.\16\
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\14\ EPA finalized approval of the Ohio Environmental Protection
Agency (Ohio EPA) August 11, 2015, redesignation request and
maintenance plan for the Clermont County portion of the Area on
November 21, 2016. See 81 FR 83158.
\15\ See 82 FR 13227.
\16\ EPA published a direct final rule on July 16, 2025,
approving Ohio's second maintenance plan for the Ohio portion of the
Area, effective September 15, 2025. See 90 FR 31872.
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III. The EPA's Evaluation of Kentucky's SIP Submittal
CAA section 175A sets forth the elements of a maintenance plan for
areas seeking redesignation from nonattainment to attainment. Under CAA
section 175A(a), the plan must demonstrate continued attainment of the
applicable NAAQS for at least 10 years after the Administrator approves
a redesignation to attainment. The September 4, 1992, memorandum from
John Calcagni, titled ``Procedures for Processing Requests to
Redesignate Areas to Attainment'' outlines the key elements of a
maintenance plan, which includes an attainment emissions inventory, a
maintenance demonstration, monitoring network requirements,
verification of continued attainment, and contingency plan
elements.\17\ CAA section 175A(b) requires that eight years after the
redesignation, the Commonwealth must submit a revised (second)
maintenance plan demonstrating continued attainment of the relevant
NAAQS for 10 years following the initial 10-year period. To address the
possibility of future NAAQS violations, the maintenance plan must
contain contingency measures deemed necessary to assure prompt
correction of any future 2010 1-hour SO<INF>2</INF> violations.
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\17\ ``Procedures for Processing Requests to Redesignate Areas
to Attainment,'' memorandum from John Calcagni, Director, Air
Quality Management Division, September 4, 1992, available at <a href="https://www.epa.gov/ground-level-ozone-pollution/procedures-processing-requests-redesignate-areas-attainment">https://www.epa.gov/ground-level-ozone-pollution/procedures-processing-requests-redesignate-areas-attainment</a>.
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Kentucky's February 20, 2025, submission provides a plan for
continued maintenance of 2010 SO<INF>2</INF> NAAQS for the Kentucky
portion of the Area through the end of the second 10-year maintenance
period in 2037. The EPA has determined that Kentucky's second
maintenance plan meets all the requirements established at CAA section
175A and is thus approving DAQ's February 20, 2025, SIP submission. The
following is a summary of the EPA's interpretation of the CAA section
175A requirements and the EPA's evaluation of how Kentucky's SIP
submission meets each requirement.
A. Attainment Emissions Inventory
For the second maintenance plan, DAQ, in consultation with the EPA
Region 4 and the Ohio Environmental
[[Page 60842]]
Protection Agency (Ohio EPA), selected 2016 as the base year (i.e.,
attainment emissions inventory year). Also, in consultation with Ohio
EPA, Kentucky's SIP relies on the 2016v2 Emissions Modeling Platform
(EMP) \18\ inventory as the preferred source of the 2016 base year and
future year projected emissions data to demonstrate maintenance of the
SO<INF>2</INF> NAAQS. The 2016v2 EMP draws on data from the 2017
National Emissions Inventory (which was updated to represent the year
2016 through the incorporation of 2016-specific State and local data)
and includes emissions data for all criteria pollutants (and
precursors) for electric utility generating unit (EGU) point sources,
non-EGU point sources, on-road and non-road (mobile) sources,
commercial marine vessels, and fires for the U.S., Canada, and Mexico.
The 2016v2 EMP projects future year emissions for modeling years 2016,
2023, 2026, and 2032.\19\ Area source, on-road, and non-road emissions
were compiled from the 2016v2 EMP for both 2016 and 2037 (with the 2032
modeling year used as a surrogate for 2037) for the Ohio and Kentucky
portions of the Area.\20\ Kentucky's SO<INF>2</INF> emissions for
Campbell County used county-wide SO<INF>2</INF> emissions data rather
than scaling down emissions to the portion of Campbell County in the
Area for each source sector (Ohio EPA's approach for Clermont County).
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\18\ The EPA developed the 2016v2 emissions modeling platform in
2022 as an update to the 2016v1 platform based on new data, model
versions and methods following the release of the 2016v1. See
<a href="https://www.epa.gov/air-emissions-modeling/2016v2-platform">https://www.epa.gov/air-emissions-modeling/2016v2-platform</a>) and
Technical Support Document: Preparation of Emissions Inventories for
the 2016v2 North American Emissions Modeling Platform; February 2022
(<a href="https://www.epa.gov/system/files/documents/2022-02/2016v2_emismod_tsd_february2022.pdf">https://www.epa.gov/system/files/documents/2022-02/2016v2_emismod_tsd_february2022.pdf</a>).
\19\ Documentation of the 2016v2 EMP inputs is provided in
Appendix D of Kentucky's February 20, 2025, SIP submission.
\20\ DAQ relied upon projected 2032 emissions as a surrogate for
2037 emissions based on the ``relatively stagnant population growth
in the Area and existing State and Federal rules in place which
preclude the installation of a new source or group of sources with
SO<INF>2</INF> emissions capable of causing or contributing to an
exceedance of the NAAQS.'' See Second 10-Year Maintenance Plan for
the Kentucky-portion of the Campbell-Clermont, KY-OH Area at pp. 6-
7.
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On September 16, 2025, DAQ transmitted to the EPA a clarification
letter \21\ to the Commonwealth's February 20, 2025, SIP submission,
correcting typographical errors, base year and future year source
sector emissions data, and clarifying how the Commonwealth developed
the source sector emission inventories from the 2016v2 EMP data files.
Specifically, Kentucky's supplement corrects footnote 14 in the
February 20, 2025, SIP submission to reference Appendix D rather than
Appendix C for additional information on emission inventory
development. The supplement also identifies the three 2016v2 EMP input
data files the Commonwealth used to develop the Campbell County
SO<INF>2</INF> source-sector spreadsheet included in Appendix D of the
SIP submission, including weblinks for each data file. Last, Kentucky's
supplement corrects source sector emissions and documentation for Table
3--Kentucky Portion SO<INF>2</INF> Emission Inventory Totals for 2016
Base Year and 2037 Second Maintenance Year (tpy) of Kentucky's February
20, 2025, SIP submission including:
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\21\ Kentucky's September 11, 2025, supplemental letter is in
the docket for this action.
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(1) Adding residential wood combustion and point fire emissions to
the calculation for 2016 and 2037, changing the area source totals from
15.46 tpy for both years to 20.61 tpy for 2016 and 20.39 tpy for 2037;
(2) Updating the non-EGU point source-sector emissions for the 2016
inventory from 2.06 tpy to 2.07 tpy, and;
(3) Clarifying that the non-road source-sector emissions for 2016
and 2037, (0.85 tpy and 0.43 tpy emissions, respectively) were
calculated as a total of the commercial marine vehicles, railroads, and
non-road emissions from the 2016v2 EMP to ensure a comprehensive
accounting of non-road emissions in Campbell County.
Kentucky's corrections to the source-sector SO<INF>2</INF> emission
values in Table 3 of the submittal changed the 2016 base year total
emissions from 22.90 tpy to 28.06 tpy and the 2037 future year total
emissions from 20.63 tpy to 25.56 tpy. Kentucky provided a revised
Table 3 in the supplemental September 16, 2025, letter clarifying that
the source-sector emission updates do not affect the Commonwealth's
conclusion in its February 20, 2025, SIP revision that the Kentucky
portion of the Area demonstrates maintenance of the SO<INF>2</INF>
NAAQS for the second 10-year maintenance period. Kentucky's revised
Table 3 source-sector corrections are reflected in the Campbell County
2016 base year inventory emission data in Table 1, below.\22\
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\22\ The corrections are also reflected in Tables 2 and 3 in
section III.B of this rulemaking below.
Table 1--2016 Base Year SO2 Emission Inventory for the Campbell-Clermont, KY-OH Area (tpy) From the EPA's 2016v2
EMP
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Non-EGU
EGU Point Point Non-road Area On-road Total
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Kentucky (Campbell County)................ 0 * 2.07 0.85 * 20.61 4.53 * 28.06
Ohio (Clermont County).................... 0 0.10 2.83 6.31 0.94 10.18
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Area Total............................ 0 * 2.17 3.68 * 26.92 5.47 * 38.24
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* Source-sector emission values corrected in Kentucky's September 16, 2025, supplemental letter to EPA Region 4.
Table 1 shows that 2016 SO<INF>2</INF> emissions in the Kentucky
portion of the Area were at 28.06 tpy (based on county-level data),
with emissions for the Ohio portion at 10.18 tpy. At the time of the
EPA's 2013 nonattainment designation, there were no SO<INF>2</INF>
point sources in the portion of Campbell County within the Area, and
the Beckjord powerplant in Clermont County was the only SO<INF>2</INF>
EGU point source in Ohio found to cause a violation at the Campbell
County Highland Heights monitor.\23\ Since the EPA redesignated the
Kentucky portion of the Area in 2017, there are no EGU and major point
or non-point SO<INF>2</INF> emitting sources that could cause a
violation of the SO<INF>2</INF> NAAQS at the Highland Heights monitor
(AQS ID 21-
[[Page 60843]]
037-3002) as reflected in the 2023-2025, 3-year design value of 6
ppb.\24\
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\23\ In an August 11, 2015, redesignation request for Clermont
County, the Ohio Environmental Protection Agency evaluated the
potential contribution to elevated SO<INF>2</INF> levels in the
Campbell-Clermont KY-OH Area from the W.H. Zimmer powerplant located
approximately 15 km south of the Beckjord plant in Clermont County
and 27 km southwest of the Campbell County SO<INF>2</INF> monitor.
Ohio determined that emissions from Beckjord only--and not Zimmer--
caused SO<INF>2</INF> violations in the Area. The Zimmer facility
permanently ceased operations on May 31, 2022. See Appendix C of
Kentucky's February 20, 2025, SIP submission for documentation of
Zimmer's shutdown.
\24\ The EPA air quality design values are available at <a href="https://www.epa.gov/air-trends/air-quality-design-values">https://www.epa.gov/air-trends/air-quality-design-values</a>.
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B. Maintenance Demonstration
States may generally demonstrate maintenance by either performing
air quality modeling to show that the future mix of sources and
emission rates will not cause a violation of the NAAQS or by showing
that projected future emissions of a pollutant and its precursors will
not exceed the level of emissions during a year when the area was
attaining the NAAQS (i.e., the 2016 base or attainment year inventory
in Kentucky's SIP submission).\25\ Kentucky's submission establishes
that the 2037 projected inventory is below the level of the 2016 base
year inventory thus demonstrating maintenance through 2037. The 2037
future year is appropriate because it is 10 years beyond the first 10-
year maintenance period. Kentucky projected 2037 future year emissions
for non-EGU point, area, on-road,\26\ and non-road source categories
using the 2016v2 EMP 2032 model year emissions case as a surrogate for
2037. See Appendix D of Kentucky's SIP submission. The 2016 base year
and 2037 future year SO<INF>2</INF> emission inventory totals for the
Area were developed consistent with the EPA guidance and are summarized
in Tables 2 and 3, below.
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\25\ See Calcagni Memo at p. 9.
\26\ Due to the relatively small, and decreasing, amounts of
sulfur in gasoline and on-road diesel fuel, the EPA's transportation
conformity rules provide that they do not apply to SO<INF>2</INF>
unless either the EPA Regional Administrator or the director of the
State air agency has found that transportation-related emissions of
SO<INF>2</INF> as a precursor are a significant contributor to a
fine particulate matter (PM<INF>2.5</INF>) nonattainment problem, or
if the SIP has established an approved or adequate budget for such
emissions as part of the RFP, attainment, or maintenance strategy.
See 40 CFR 93.102(b)(1), (2)(v); ``Guidance for 1-Hour
SO<INF>2</INF> Nonattainment Area SIP Submissions,'' memorandum from
Stephen D. Page, Director, April 23, 2014, available at <a href="https://www.epa.gov/system/files/documents/2025-09/guidance-for-1-hour-so2-nonattainment-area-sip-submissions.pdf">https://www.epa.gov/system/files/documents/2025-09/guidance-for-1-hour-so2-nonattainment-area-sip-submissions.pdf</a>. As with the first 2010 1-
hour SO<INF>2</INF> maintenance plan for the Area, motor vehicle
emission budgets were not established because mobile sources were
insignificant contributors to the Area's violation of the 2010
SO<INF>2</INF> NAAQS. In consultation with Kentucky and Ohio, the
EPA agreed that mobile emissions budgets are not necessary for the
second maintenance plan.
Table 2--2016 Base Year and 2037 Future Year SO2 Emission Inventory
Comparison (tpy) for the Campbell-Clermont, KY-OH Maintenance Area
------------------------------------------------------------------------
Source Sector 2016 Base year 2037 Future year
------------------------------------------------------------------------
Kentucky (Campbell County): ................. .................
EGU Point..................... 0 0
Non-EGU Point................. * 2.07 2.07
Non-road...................... 0.85 0.43
Area.......................... * 20.61 * 20.39
On-road....................... 4.53 2.67
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Total..................... * 28.06 * 25.56
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Ohio (Clermont County): ................. .................
EGU Point..................... 0 0
Non-EGU Point................. 0.10 0.14
Non-road...................... 2.83 1.38
Area.......................... 6.31 6.26
On-road........................... 0.94 0.36
Total..................... 10.18 8.14
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* Source-sector emission values corrected in Kentucky's September 16,
2025, supplemental letter to EPA Region 4.
Table 3--2016 Base Year and 2037 Future Year Total SO2 Emission
Inventory (tpy) for the Campbell-Clermont, KY-OH Area Second Maintenance
Plan
------------------------------------------------------------------------
2037 Future
Source Sector 2016 Base year year
------------------------------------------------------------------------
EGU Point............................... 0 0
Non-EGU Point........................... * 2.17 2.21
Non-road................................ 3.68 1.81
Area.................................... * 26.92 * 26.65
On-road................................. 5.47 3.03
-------------------------------
Total............................... * 38.24 * 33.70
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* Source-sector emission values corrected in Kentucky's September 16,
2025, supplemental letter to EPA Region 4.
The 2014 permanent and enforceable shutdown of the Beckjord
facility in Ohio resulted in significant SO<INF>2</INF> emission
reductions in the Area. As shown in Table 4 below, the design values
since attainment have steadily decreased with the latest design value
being 92 percent below the NAAQS, demonstrating continued maintenance.
Tables 2 and 3 show no base and future year EGU point source emissions
and low non-EGU point source emissions. See Appendix D of Kentucky's
February 21, 2025, SIP revision for additional emissions inventory
information. Currently, there are no large EGU or non-EGU
SO<INF>2</INF> point sources located in either the Kentucky or Ohio
portions of the Area with the potential to cause a monitored violation.
Additionally, while neither the Commonwealth nor Ohio have
projected significant growth in their respective counties, any
potential new major stationary source that seeks to construct during
the second 10-year maintenance period would be subject to each State's
[[Page 60844]]
SIP-approved PSD program permitting requirements. Given the low design
values for the Area, the EPA does not anticipate any future monitored
violation of the SO<INF>2</INF> NAAQS for the Area. For the reasons
discussed above, Kentucky's February 20, 2025, SIP submission
demonstrates maintenance of the 2010 SO<INF>2</INF> NAAQS for the Area.
C. Monitoring Network
The Highland Heights SO<INF>2</INF> monitor (AQS ID: 21-037-3002)
located in Campbell County is the only SO<INF>2</INF> monitor operating
in the Area. The 3-year design values \27\ since the shutdown of the
Beckjord facility in Ohio in 2014 have remained well below the 75 ppb
2010 1-hour SO<INF>2</INF> NAAQS. See Table 4 below and Figure 2 in
Kentucky's February 20, 2025, SIP submission. The most recent complete
and certified 3-year design value (2023-2025) for Highland Heights is 6
ppb. In its SIP revision, Kentucky has committed to continue to operate
an EPA-approved ambient air quality network, in compliance with 40 CFR
part 58 and has thus addressed the requirement for the monitoring. The
EPA approved Kentucky's 2025 Annual Ambient Air Monitoring Network Plan
on October 28, 2025.\28\
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\27\ Design values are calculated as the 3-year average of
annual 99th percentile daily maximum 1-hour values for a monitoring
site. See Appendix T to 40 CFR part 50.
\28\ Kentucky's 2025 Annual Ambient Air Monitoring Network Plan
and EPA's Approval Letter are both available in the docket for this
action. For more information on the Highland Heights monitor (AQS
ID: 21-037-3002), see page 31 of the Network Plan.
Table 4--Campbell-Clermont, KY-OH Area 1-Hour SO2 Design Values
[ppb]
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2013- 2014- 2015- 2016- 2017- 2018- 2019- 2020- 2021- 2022- 2023-
Location AQS ID 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
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Highland Heights--Campbell County, KY 21-037-3002 50 30 15 12 11 9 9 10 8 7 6
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D. Verification of Continued Attainment
An air agency should ensure that it has the legal authority to
implement and enforce all measures necessary to attain and maintain the
NAAQS. Additionally, the air agency should establish how it will track
progress of the maintenance plan for the area. Kentucky, through DAQ,
has the legal authority to enforce and implement the maintenance plan
for the Kentucky portion of the Area. This includes the authority to
adopt, implement, and enforce any subsequent contingency measures
determined to be necessary to correct future attainment issues for the
2010 SO<INF>2</INF> NAAQS. In addition, Kentucky requires major point
sources in all counties to submit SO<INF>2</INF> emissions information
annually and assists in the preparation of new periodic inventories for
all source sectors every three years in accordance with the Air
Emissions Reporting Rule, 40 CFR part 51 subpart A. Kentucky will
compare emissions information to the attainment year and the 2037
projected maintenance year inventories to assess emission trends and to
ensure continued compliance with the standard. Lastly, as mentioned in
section II.C above, the Commonwealth will continue to operate an EPA-
approved ambient air quality network in accordance with monitoring
requirements at 40 CFR part 58.
E. Contingency Plan
CAA section 175A(d) requires that a maintenance plan include such
contingency measures as the EPA deems necessary to assure that the
State will promptly correct a violation of the NAAQS that occurs after
redesignation. The maintenance plan should identify the contingency
measures to be adopted, a schedule and procedure for adoption and
implementation, and a timeframe for action by the State. A State should
also identify specific indicators to be used to determine when the
contingency measures need to be implemented. The maintenance plan must
include a requirement that a State will implement all measures with
respect to control of the pollutant that were contained in the SIP
before redesignation of the area to attainment in accordance with CAA
section 175A(d). With the 2014 permanent shutdown of the Beckjord
Generating Station, there are no EGU point sources in the Area, and
thus DAQ does not anticipate future monitored violations of the 2010
SO<INF>2</INF> NAAQS.
Kentucky has an enforcement program to address NAAQS violations and
will continue to identify violations of the SO<INF>2</INF> NAAQS and
undertake an aggressive follow-up, if a violation occurs, to ensure
compliance and enforcement of the standard. Ambient air SO<INF>2</INF>
monitoring data will serve as the primary trigger for any response to
prevent or correct a NAAQS violation in the area. Kentucky has
established warning and action level responses with specific triggering
indicators. DAQ commits to adopt and expeditiously implement necessary
corrective actions in the event of a warning or action level trigger.
A warning level trigger occurs whenever an annual average 99th
percentile maximum daily 1-hour SO<INF>2</INF> concentration greater
than 75 ppb occurs in a single calendar year within the Area.\29\ A
warning level response will consist of a study to evaluate the Area's
emission inventory for all source sectors, exceptional events, and best
practices for implementing the State's PSD permitting program at any
new stationary source and/or new or modified area source. The study
will determine if the monitored SO<INF>2</INF> concentrations indicate
a trend toward higher values and/or if SO<INF>2</INF> emissions appear
to be increasing. The study will evaluate whether any such trend is
likely to continue and, if so, what control measures are necessary to
reverse the trend. Implementation of controls will take place as
expeditiously as possible, but no later than 12 months from the
conclusion of the most recent calendar year.
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\29\ KDAQ's submittal states that a ``warning level response
shall be prompted whenever the annual average 99th percentile
maximum daily 1-hour SO<INF>2</INF> concentration of 75 ppb occurs
in a single calendar year.'' Per 40 CFR 50.17(b), the 1-hour primary
standard is met at an ambient air quality monitoring site when the
three-year average of the annual (99th percentile) of the daily
maximum 1-hour average concentrations is less than or equal to 75
ppb. On December 29, 2025, DAQ sent an email to the EPA clarifying
that the warning level response will be prompted whenever an annual
average 99th percentile maximum daily 1-hour SO<INF>2</INF>
concentration greater than 75 ppb occurs in a single calendar year.
The email is available in the docket for this action.
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An action level trigger occurs whenever a two-year average of the
99th percentile maximum daily 1-hour SO<INF>2</INF> concentration
greater than 75 ppb
[[Page 60845]]
occurs within the Area. A violation of the NAAQS (the three-year
average of the 99th percentile maximum daily 1-hour value
SO<INF>2</INF> concentration of 75 ppb or greater) shall also prompt an
action level response. In the event that the action level is triggered
and is not found to be due to an exceptional event, malfunction, or
noncompliance with a permit condition or rule requirement, DAQ in
conjunction with the metropolitan planning organization or regional
council of governments, will determine additional control measures
needed to assure future attainment of the 1-hour SO<INF>2</INF> NAAQS.
Measures that can be implemented in the short term will be selected for
implementation within 18 months from the close of the calendar year
that prompted the action level response. The Commonwealth will also
consider the timing of an action level trigger and determine if
additional, significant new regulations not currently included as part
of the maintenance provisions will be implemented in a timely manner
and will constitute the response.
If the Commonwealth determines that a new control measure that is
already promulgated and scheduled to be implemented will be sufficient
to address a violation of the SO<INF>2</INF> NAAQS, additional local
measures may be unnecessary. DAQ will submit to the EPA an analysis to
demonstrate that the proposed control measures are adequate to return
the Area to attainment. If adoption of control measures is necessary,
they will be subject to Kentucky's administrative and legal process.
This process will include publication of notices, an opportunity for
public hearing and comment, and other measures required by State law
for revisions to the SIP. The selection of control measures will be
based on cost-effectiveness, emission reduction potential, economic and
social considerations, or other factors that the Commonwealth deems
appropriate.
IV. Final Action
The EPA is approving the second maintenance plan for the Kentucky
portion of the 2010 1-hour SO<INF>2</INF> Campbell-Clermont, KY-OH Area
for the reasons discussed above. Approval of Kentucky's SIP revision
will make certain commitments related to maintenance of the 2010 1-hour
SO<INF>2</INF> NAAQS in the Kentucky portion of the Campbell-Clermont,
KY-OH Area federally enforceable as part of the Kentucky SIP.
V. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the CAA and applicable
Federal regulations.\30\ Thus, in reviewing SIP submissions, the EPA's
role is to approve State choices, provided that they meet the criteria
of the CAA. Accordingly, this action merely approves State law as
meeting Federal requirements and does not impose additional
requirements beyond those imposed by State law. For that reason, this
action:
---------------------------------------------------------------------------
\30\ See 42 U.S.C. 7410(k); 40 CFR 52.02(a).
---------------------------------------------------------------------------
<bullet> Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Order 12866 (58
FR 51735, October 4, 1993);
<bullet> Is not an Executive Order 14192 (90 FR 9065, February 6,
2025) regulatory action because this action is not significant 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 subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it approves a State program;
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
<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.
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian Tribe
has demonstrated that a Tribe has jurisdiction. In those areas of
Indian country, the rule does not have Tribal implications and will not
impose substantial direct costs on Tribal governments or preempt Tribal
law as specified by Executive Order 13175.\31\
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\31\ See 65 FR 67249, November 9, 2000.
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This action is subject to the Congressional Review Act, and the EPA
will submit a rule report to each House of the Congress and to the
Comptroller General of the United States. This action is not a ``major
rule'' as defined by 5 U.S.C. 804(2).
Under CAA section 307(b)(1), petitions for judicial review of this
action must be filed in the United States Court of Appeals for the
appropriate circuit by November 24, 2026. Filing a petition for
reconsideration by the Administrator of this final rule does not affect
the finality of this action for the purposes of judicial review nor
does it extend the time within which a petition for judicial review may
be filed, and shall not postpone the effectiveness of such rule or
action. Parties with objections to this direct final rule are
encouraged to file a comment in response to the parallel notice of
proposed rulemaking for this action published in the proposed rules
section of this Federal Register, rather than file an immediate
petition for judicial review of this direct final rule, so that the EPA
can withdraw this direct final rule and address the comment in the
proposed rulemaking. This action may not be challenged later in
proceedings to enforce its requirements.\32\
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\32\ See CAA section 307(b)(2).
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List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Reporting and recordkeeping
requirements, Sulfur oxides, Volatile organic compounds.
Dated: September 15, 2026.
Kevin McOmber,
Regional Administrator, Region 4.
For the reasons stated in the preamble, the EPA amends 40 CFR part
52 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. In Sec. 52.920, amend the table in paragraph (e), by adding an
entry for ``2010 1-hour SO<INF>2</INF> Second 10-Year Maintenance Plan
for the Kentucky portion of the Campbell-Clermont, KY-OH Area'' at the
end of the table to read as follows:
[[Page 60846]]
Sec. 52.920 Identification of plan.
* * * * *
(e) * * *
EPA-Approved Kentucky Non-Regulatory Provisions
----------------------------------------------------------------------------------------------------------------
State submittal
Name of non-regulatory SIP provision Applicable geographic date/effective EPA approval Explanations
or nonattainment area date date
----------------------------------------------------------------------------------------------------------------
* * * * * * *
2010 1-hour SO2 Second 10-Year Campbell County portion 2/20/2025 9/25/2026, 91 ..............
Maintenance Plan for the Kentucky of Campbell-Clermont, FR [Insert
portion of the Campbell-Clermont, KY-OH Area. Federal
KY-OH Area. Register page
where the
document
begins]
----------------------------------------------------------------------------------------------------------------
[FR Doc. 2026-19668 Filed 9-24-26; 8:45 am]
BILLING CODE 6560-50-P
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</html>Indexed from Federal Register on September 25, 2026.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.