[Federal Register Volume 90, Number 150 (Thursday, August 7, 2025)]
[Proposed Rules]
[Pages 38093-38095]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-14989]



[[Page 38093]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R05-OAR-2024-0549; FRL-12784-01-R5]


Air Plan Approval; Ohio; Carmeuse Lime, Inc. SO2

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve the addition of Director's Final Findings and Orders (DFFOs) 
issued by the Ohio Environmental Protection Agency (Ohio EPA) to 
Carmeuse Lime, Inc. into the Ohio State Implementation Plan (SIP) for 
the 2010 sulfur dioxide (SO2) National Ambient Air Quality 
Standards (NAAQS). The DFFOs establish a new emissions limit for 
SO2 emissions from the combined lime kiln stack that 
receives and emits SO2 emissions from two rotary lime kilns 
at the Carmeuse Lime Maple Grove Facility in Seneca County, Ohio.

DATES: Comments must be received on or before September 8, 2025.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2024-0549 at https://www.regulations.gov, or via email to 
[email protected]. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from the docket. EPA may publish 
any comment received to its public docket. Do not submit to EPA's 
docket at https://www.regulations.gov any information you consider to 
be Confidential Business Information (CBI), Proprietary Business 
Information (PBI), or other information the disclosure of which is 
restricted by statute. Multimedia submissions (audio, video, etc.) must 
be accompanied by a written comment. The written comment is considered 
the official comment and should include discussion of all points you 
wish to make. EPA will generally not consider comments or comment 
contents located outside of the primary submission (i.e., on the web, 
cloud, or other file sharing system). For additional submission 
methods, please contact the person identified in the FOR FURTHER 
INFORMATION CONTACT section. For the full EPA public comment policy, 
information about CBI, PBI, or multimedia submissions, and general 
guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Cecilia Magos, Air and Radiation 
Division (AR18J), Environmental Protection Agency, Region 5, 77 West 
Jackson Boulevard, Chicago, Illinois 60604, (312) 886-7336, 
[email protected]. The EPA Region 5 office is open from 8:30 a.m. 
to 4:30 p.m., Monday through Friday, excluding Federal holidays.

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' or ``our'' is used, we mean EPA.

I. Background

    On August 21, 2015 (80 FR 51052), EPA finalized the Data 
Requirements Rule (DRR) which required State air agencies to 
characterize ambient SO2 levels in areas with large sources 
of SO2 emissions to help implement the 2010 SO2 
NAAQS. Under the DRR, State air agencies must at a minimum, model or 
monitor air quality around sources that emit 2,000 tons per year (tpy) 
or more of SO2, and that are not located in an area already 
designated nonattainment. An air agency could have avoided this 
requirement for a source emitting more than 2,000 tpy by adopting 
federally enforceable emission limits by January 13, 2017, that ensured 
the source would emit less than 2,000 tpy of SO2. The DRR 
required State air agencies to notify EPA of their selected approach 
for characterizing air quality around SO2 sources subject to 
the DRR by July 1, 2016.
    On January 13, 2017, Ohio EPA submitted a list of applicable 
sources with SO2 emissions of 2,000 tpy or more, subject to 
the DRR pursuant to 40 CFR 51.1203.\1\ The list of sources included 
Carmeuse Lime Maple Grove, Inc. (referred to as Carmeuse Lime) (Ohio 
EPA Facility ID #0374000010) in Seneca County, Ohio. On January 9, 2018 
(83 FR 1098), EPA designated Seneca County as unclassifiable/attainment 
under the 2010 SO2 NAAQS Round 3 designations process and 
required the identified sources to adopt DRR requirements by July 1.
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    \1\ Ohio EPA's ``State of Ohio 2010 Revised Sulfur Dioxide 
National Ambient Air Quality Standard Recommended Area Designations 
Round 3'' can be found at https://www.epa.gov/system/files/documents/2025-04/recommendation-round-3-ohio.pdf.
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    Under the DRR (40 CFR 51.1205), for any area where modeling of 
actual SO2 emissions served as a basis for designating such 
area as attainment for the 2010 SO2 NAAQS, the State air 
agency shall submit to EPA an annual ambient SO2 emissions 
report of applicable sources by July 1 of each year, including an 
assessment of the cause of any emission increases from the previous 
year and a recommendation regarding the need for additional dispersion 
modeling to determine if an area is still meeting the 2010 
SO2 NAAQS.
    After analyzing data from Ohio's 2023 Annual SO2 
Emissions Review, Ohio EPA determined that new emission limits at 
Carmeuse Lime were needed to ensure that air quality standards are 
protected. On August 31, 2023, in preparation for Ohio's 2024 Annual 
SO2 Emissions Review, as recommended by Ohio EPA, new 
modeling using data from the 2020-2022 period for the Carmeuse Lime 
facility, showed a maximum modeled 3-year DV of 211.003 [mu]g/m\3\, 
representing a modeled violation of the 2010 SO2 NAAQS value 
of 196.4 [mu]g/m\3\. The updated modeling included WIN Waste 
Innovations of Seneca County at maximum permitted emission rates. In 
response to the modeled violation, Ohio EPA conducted new modeling 
based on allowables, using a critical emission rate of 1,350.00 pounds 
per hour (lbs/hr) from the combined lime kiln stack at the Carmeuse 
Lime facility that would model compliance with the 2010 SO2 
NAAQS. This updated dispersion modeling showed a maximum modeled 3-year 
DV for SO2 of 192.2 [mu]g/m\3\. In accordance with EPA's 
April 2014 ``Guidance for 1-Hour SO2 Nonattainment Area SIP 
Submissions'' (April 2014 SO2 Guidance) \2\ and 40 CFR 
63.10021, Equation 9, Ohio EPA determined the allowable emission rate 
for SO2 from the combined lime kiln stack at Carmeuse Lime, 
resulting in an allowable emission rate of 1,170.0 lbs/hr as a 30-day 
rolling average.
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    \2\ EPA's ``Guidance for 1-Hour Sulfur Dioxide (SO2) 
Nonattainment Area State Implementation Plans (SIP) Submissions'' 
can be found at https://www.epa.gov/so2-pollution/guidance-1-hour-sulfur-dioxide-so2-nonattainment-area-state-implementation-plans-sip.
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    On November 13, 2024, Ohio EPA submitted a request to incorporate 
into the Ohio SIP for the 2010 SO2 NAAQS the DFFOs issued by 
Ohio EPA to Carmeuse Lime, establishing a new allowable 30-day rolling 
average SO2 emissions limit of 1,170.0 lbs/hr for the 
combined lime kiln stack shared by two rotary lime kilns. EPA proposes 
to determine that the adoption of the revised enforceable emission 
limit (alternatively ``the revised DFFOs'') will ensure continued 
attainment of the 2010 SO2 NAAQS.

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II. Analysis of Ohio EPA's Request

    Ohio EPA's November 13, 2024, SIP submittal requests to incorporate 
a new limit for Carmeuse Lime into the Ohio SIP through Ohio's DFFOs 
process and in accordance with the Data Requirements Rule at 40 CFR 
51.1205. Ohio EPA is acting under Clean Air Act (CAA) section 
110(a)(2)(B) and section 110(a)(2)(K) authorities that provide for the 
appropriate operation to monitor, compile, and analyze ambient air 
quality data and modeling for a pollutant with an established NAAQS. 
Ohio EPA is also acting under CAA section 116, to adopt the DFFOs into 
the Ohio SIP, if the State elects to do so. Ohio EPA followed EPA's 
April 2014 SO2 Guidance to calculate the new limit issued to 
Carmeuse Lime that would provide for attainment of the 2010 
SO2 NAAQS. EPA's April 2014 SO2 Guidance is 
intended to provide guidance and recommendations to States to consider 
as they develop information used in future actions, which may involve 
SIPs, for the 2010 SO2 NAAQS nonattainment areas. EPA finds 
the application of this guidance for the purpose of development of Ohio 
EPA's DFFOs appropriate to address the modeled violations of the 2010 
SO2 NAAQS. Under 40 CFR 51.1205(d), EPA may take appropriate 
action in an area that modeling indicates is not attaining the 2010 
SO2 NAAQS, including but not limited to requiring the 
adoption of enforceable emission limits to ensure continued attainment 
of the 2010 SO2 NAAQS, designation or redesignation of the 
area to nonattainment, or issuance of a SIP Call. Therefore, as a 
result of modeled 2010 SO2 NAAQS violations, EPA proposes to 
find Ohio EPA's issuance of DFFOs establishing new SO2 
emission limits for Carmeuse Lime is appropriate, and no further action 
is needed by EPA for this area.
    Due to modeled violations of the 2010 SO2 NAAQS, Ohio 
EPA performed updated modeling for the 2021-2023 period resulting in an 
SO2 critical emission rate of 1,350 lbs/hr from the combined 
kiln stack at Carmeuse Lime that receives and emits SO2 
emissions from rotary lime kiln #1 (EU P003) and rotary lime kiln #2 
(EU P004). According to EPA's April 2014 SO2 Guidance, 
determining a source's critical emission rate can serve ``as a baseline 
for determining a longer-term average limit consistent with this 
guidance.'' To derive a longer-term limit, the 2014 SO2 
Guidance establishes a six-step process summarized as follows:

    1. Establish a critical emission value via dispersion modeling 
that serves as compliance with the 1-hour SO2 standard,
    2. Compile hourly emissions rate data reflecting the 
distribution of emissions that is expected once the limit is in 
place,
    3. Calculate the longer-term emission rate average using hourly 
emission rate data from Step 2,
    4. Determine the 99th percentile of the 1-hour average emission 
values compiled in Step 2 and the 99th percentile of the 30-day 
average emission values computed in Step 3,
    5. Compute the ratio of the two 99th percentile values,
    6. Multiply the ratio by the critical emission value in Step 1 
to find the 30-day average emission limit that is comparably 
stringent to the 1-hour limit.

    As part of the DFFOs, Ohio EPA used the process in the 2014 
SO2 Guidance to calculate the allowable 30-day 
SO2 emission limit with which the Carmeuse Lime facility 
must comply. Ohio EPA provided documentation of its calculations in its 
2024 Annual SO2 Emissions Review, which is included in the 
docket for this action.\3\ The ratio of the 99th percentile of 1-hour 
average SO2 emission rates and 99th percentile of 30-day 
average SO2 emission rates from Carmeuse Lime based on 
actual emissions data from 2017-2022 was 0.8665. This ratio was 
multiplied by the critical emission value of 1,350 lbs/hr determined 
via dispersion modeling, resulting in an allowable 30-day average 
SO2 emission rate of 1,170.0 lbs/hr from the combined lime 
kiln stack at the Carmeuse Lime facility by no later than 12 months 
from the effective date of the orders, in this case by November 8, 
2025. EPA proposes to find Ohio EPA's allowable 30-day average 
SO2 emission rate of 1,170.0 lbs/hr from the combined lime 
kiln stack at Carmeuse Lime issued in the DFFOs as sufficient to ensure 
continued attainment of the 2010 SO2 NAAQS.
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    \3\ Ohio EPA's ``Ohio's 2024 Annual Sulfur Dioxide 
(SO2) Emissions Review'' can be found at https://dam.assets.ohio.gov/image/upload/epa.ohio.gov/Portals/27/sip/SO2/2024_SO2_annual_emissions_Final.pdf.
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    Per EPA's April 2014 SO2 Guidance, sources would 
ordinarily rely on data obtained by continuous emissions monitoring 
system (CEMS) for sources with CEMS to demonstrate compliance with 
existing emission limits. Sources without CEMS wishing to apply longer 
term averaging need to establish an appropriate emission limit and an 
appropriate compliance method. The facilities without CEMS, such as 
Carmeuse Lime, would need sufficient data to demonstrate that the 
established emission limits adequately represent hourly emissions 
variability and consider a range of factors that influence emissions 
variability.
    In consideration of EPA's April 2014 SO2 Guidance, Ohio 
EPA's DFFOs include an order for the Carmeuse Lime facility, or any 
subsequent owner of the facility, to collect two random samples of coal 
and coke burned from each rotary lime kiln feed belt each day. These 
samples shall be combined into a weekly composite sample of each coal 
and coke respectively, and will be analyzed for sulfur content, in 
accordance with ASTM method D4239, ``Standard Test Method for Sulfur in 
the Analysis Sample of Coal and Coke Using High-Temperature Furnace 
Combustion,'' or an equivalent method approved by Ohio EPA. The 
analysis methods will satisfy the Facility's title V operating permit 
(permit #P0128727) monitoring and recordkeeping requirements for the 
emission unit group--rotary lime kilns P003 and P004.
    To demonstrate compliance with the established emission limit, Ohio 
EPA relies on compliance methods based on a mass balance approach. This 
includes instructions to calculate the rolling 30-day average of 
SO2 emissions in lbs/hr following a mass balance-based 
methodology in the orders. Additionally, the DFFOs will allow for the 
installation and use of a CEMS at the facility to monitor 
SO2 emissions from the combined lime kiln stack for CEMS-
based compliance methods consistent with 40 CFR part 60, appendix F. 
This will allow the replacement of existing mass balance-based 
compliance methods without a SIP revision submittal requirement in the 
event the facility installs CEMS.
    In accordance with the mass balance-based compliance methods in the 
orders, the DFFOs describe the methodology to calculate the rolling 30-
day average SO2 emissions rate in lbs/hr from the combined 
lime kiln stack. This relies on a calculated scrubbing factor (F) 
determined by using the most recent valid stack test data of the 
facility's combined lime kiln stack.
    Per the April 2014 SO2 Guidance, an absence of CEMS can 
pose two challenges: (1) establishing an appropriate emission limit, 
and (2) establishing an appropriate compliance determination method. 
Because the facility is opting to apply a longer-term average, 
exhaustive fuel quality data and exhaustive operating information are 
required to support an adequate assessment of emissions variability.\4\ 
As such, Ohio EPA's DFFOs include orders to perform daily fuel 
consumption monitoring and maintain daily fuel

[[Page 38095]]

consumption records that include type and quantity of fuel burned in 
the lime kilns each day. The facility is also required to maintain 
monthly fuel records that include the quantity of each fuel type 
received and the results of each sulfur content analyses of the 
required weekly composite sample. In select cases, routine fuel sulfur 
content measurements averaged as a rolling average over the appropriate 
period and established as an enforceable indicator of average emissions 
may suffice to assess compliance with a longer-term average limit.\5\ 
Further, when approved and appropriate, the DFFOs require a record of 
the type and quantity of fuel burned to be maintained if a fuel other 
than coal, coke, or natural gas is burned at the facility. Ohio EPA 
also includes orders to submit deviation reports of days in which fuel 
other than coal, coke, or natural gas are burned, unless approved by 
the appropriate agency. These reports shall be submitted within thirty 
days after the deviation. EPA is proposing to determine these orders 
adequately address hourly emissions variability from the application of 
a longer-term average emission limit per EPA's April 2014 
SO2 Guidance.
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    \4\ See April 2014 SO2 Guidance, page 37.
    \5\ See April 2014 SO2 Guidance, page 45.
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III. What action is EPA taking?

    EPA is proposing to approve Ohio EPA's DFFOs issued to the Carmeuse 
Lime facility, which Ohio EPA submitted on November 13, 2024, into the 
Ohio 2010 SO2 NAAQS SIP. The DFFOs establish a new 
SO2 emissions limit of 1,170.0 lbs/hr for the combined lime 
kiln stack that receives and emits SO2 emissions from two 
rotary lime kilns that will ensure continued attainment of the 2010 
SO2 NAAQS.

IV. Incorporation by Reference

    In this rulemaking, EPA is proposing to include in a final EPA rule 
regulatory text that includes incorporation by reference. In accordance 
with requirements of 1 CFR 51.5, EPA is proposing to incorporate by 
reference Ohio's DFFOs for Carmeuse Lime, Inc. Maple Grove facility 
issued by Ohio EPA, effective November 8, 2024, discussed in sections I 
and II of this preamble. EPA has made, and will continue to make, these 
documents generally available through www.regulations.gov and at the 
EPA Region 5 Office (please contact the person identified in the FOR 
FURTHER INFORMATION CONTACT section of this preamble for more 
information).

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). In reviewing 
SIP submissions, EPA's role is to approve State choices provided they 
meet the criteria of the CAA. Accordingly, this action merely approves 
State law as meeting Federal requirements and does not impose 
additional requirements beyond those imposed by State law. For that 
reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Order 12866 (58 
FR 51735, October 4, 1993);
     Is not subject to Executive Order 14192 (90 FR 9065, 
February 6, 2025) because SIP actions are exempt from review under 
Executive Order 12866;
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it approves a State program;
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
     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 EPA or an Indian Tribe has 
demonstrated that a Tribe has jurisdiction. In those areas of Indian 
country, the rulemaking 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 (65 FR 67249, November 9, 
2000).

List of Subjects in 40 CFR Part 52

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

    Dated: July 29, 2025.
Cheryl Newton,
Acting Regional Administrator, Region 5.
[FR Doc. 2025-14989 Filed 8-6-25; 8:45 am]
BILLING CODE 6560-50-P