Document ID: EPA-R07-OAR-2022-0531-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Missouri; Control of Sulfur Dioxide Emissions
Posted Date: 2022-07-08T04:00Z

[Federal Register Volume 87, Number 130 (Friday, July 8, 2022)]
[Proposed Rules]
[Pages 40759-40763]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-14469]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R07-OAR-2022-0531; FRL-9976-01-R7]

Air Plan Disapproval; Missouri; Control of Sulfur Dioxide 
Emissions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
disapprove revisions to the Missouri

[[Page 40760]]

State Implementation Plan (SIP) submitted by Missouri on March 7, 2019. 
In its submission, Missouri requested rescinding a regulation 
addressing sulfur compounds from the SIP and replacing it with a new 
regulation that establishes requirements for units emitting sulfur 
dioxide (SO2). The EPA is proposing to disapprove the SIP 
revision because the state has not demonstrated that the removal of 
SO2 emission limits for the Evergy-Hawthorn (Hawthorn, 
formerly Kansas City Power & Light-Hawthorn) and Ameren Labadie 
(Labadie) power plants from the SIP would not interfere with National 
Ambient Air Quality Standard (NAAQS) attainment and reasonable further 
progress (RFP), or any other applicable requirement of the Clean Air 
Act (CAA) as required under CAA section 110(l). This disapproval action 
is being taken under the CAA to maintain the stringency of the SIP and 
preserve air quality.

DATES: Comments must be received on or before August 8, 2022.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-R07-
OAR-2022-0531 to https://www.regulations.gov. Follow the online 
instructions for submitting comments.
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received will be posted without 
change to https://www.regulations.gov, including any personal 
information provided. For detailed instructions on sending comments and 
additional information on the rulemaking process, see the ``Written 
Comments'' heading of the SUPPLEMENTARY INFORMATION section of this 
document.

FOR FURTHER INFORMATION CONTACT: Wendy Vit, Environmental Protection 
Agency, Region 7 Office, Air Quality Planning Branch, 11201 Renner 
Boulevard, Lenexa, Kansas 66219; telephone number: (913) 551-7697; 
email address: [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' refer to EPA.

Table of Contents

I. Written Comments
II. What is being addressed in this document?
    A. Hawthorn SO2 Emission Limit
    B. Labadie SO2 Emission Limit
III. Have the requirements for approval of a SIP revision been met?
IV. What action is the EPA proposing to take?
V. Statutory and Executive Order Reviews

I. Written Comments

    Submit your comments, identified by Docket ID No. EPA-R07-OAR-2022-
0531, at https://www.regulations.gov. 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 https://www.epa.gov/dockets/commenting-epa-dockets.

II. What is being addressed in this document?

    Missouri revised title 10, division 10 of the code of state 
regulations (CSR) by rescinding 10 CSR 10-6.260 ``Restriction of 
Emission of Sulfur Compounds'' and replacing it with a new regulation, 
10 CSR 10-6.261 ``Control of Sulfur Dioxide Emissions.'' 10 CSR 10-
6.260 was originally approved into the SIP at 40 CFR 52.1320(c) in 1998 
(63 FR 45727, August 27, 1998) and has been revised several times.\1\ 
10 CSR 10-6.261 has not been approved into the SIP. On March 7, 2019, 
the state submitted a request to revise the SIP by removing 10 CSR 10-
6.260 and replacing it with 10 CSR 10-6.261 (effective date March 30, 
2019). Missouri's analysis of the rescission and replacement can be 
found in the technical support document (TSD) submitted to the EPA on 
May 4, 2022 and included in this docket.
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    \1\ See 71 FR 12623 (March 13, 2006), 73 FR 35071 (June 20, 
2008), and 78 FR 69995 (November 22, 2013).
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    In order for the EPA to fully approve a SIP revision, the state 
must demonstrate that the SIP revision meets the requirements of CAA 
section 110(l), 42 U.S.C. 7410(l). Under CAA section 110(l), the EPA 
may not approve a SIP revision that would interfere with any applicable 
requirement concerning NAAQS attainment and RFP, or any other 
applicable requirement of the CAA. The EPA interprets section 110(l) 
such that states have two main options to make this noninterference 
demonstration. First, the state could demonstrate that emissions 
reductions removed from the SIP are replaced with new control measures 
that achieve equivalent or greater emissions reductions. Thus, the SIP 
revision will not interfere with the area's ability to continue to 
attain or maintain the affected NAAQS or other CAA requirements. The 
EPA further interprets section 110(l) as requiring such substitute 
measures to be quantifiable, permanent, and enforceable, among other 
considerations. For section 110(l) purposes, ``permanent'' means the 
state cannot modify or remove the substitute measure without EPA review 
and approval. Second, the state could conduct air quality modeling or 
develop an attainment or maintenance demonstration based on EPA's most 
recent technical guidance to show that, even without the control 
measure or with the control measure in its modified form, the area (as 
well as interstate and intrastate areas downwind) can continue to 
attain and maintain the affected NAAQS.
    As discussed in detail in its TSD, Missouri contends that there are 
substitute measures of comparable or greater stringency to the Hawthorn 
and Labadie SO2 limits, and therefore argues that removal of 
these emission limits from the SIP would satisfy CAA section 110(l) 
requirements without the need for an air quality analysis showing that 
removing the measures will not interfere with NAAQS attainment or other 
applicable requirements.
    We disagree with Missouri's analysis and rationale for removing the 
Hawthorn and Labadie SO2 emission limits from the SIP. The 
substitute SO2 emission limit for Hawthorn is contained in a 
Prevention of Significant Deterioration (PSD) permit that is not 
approved in the SIP and could be later modified without requiring EPA 
approval, and therefore the substitute measure is not considered 
permanent. For Labadie, the substitute SO2 emission limit is 
not as stringent as the limit currently in the SIP-approved 10 CSR 10-
6.260, nor does it result in surplus emission reductions. In addition, 
Missouri has not provided an air quality analysis demonstrating the 
revisions related to the Labadie SO2 emission limits in the 
SIP will not interfere with NAAQS attainment or other applicable 
requirements. For these reasons we are proposing to disapprove the 
rescission of 10 CSR 10-6.260 and replacement with 10 CSR 10-6.261 in 
the SIP.
    This proposed disapproval action, if finalized, would maintain 10 
CSR 10-6.260 requirements at 40 CFR 52.1320(c) as federally approved 
SIP obligations.

[[Page 40761]]

    The EPA's rationale for disapproving removal of the Hawthorn and 
Labadie SO2 emission limits from the SIP is further 
discussed in the sections below.

A. Hawthorn SO2 Emission Limit

    Table 1 of 10 CSR 10-6.260 in the SIP includes a 30-day rolling 
average SO2 emission limit of 0.12 pounds/million British 
thermal units (lb/MMBtu) for the Hawthorn plant. The footnote to Table 
1 in 10 CSR 10-6.260 states: ``The SO2 emission rate comes 
from the Prevention of Significant Deterioration permit for Unit 5A and 
is implemented in accordance with the terms of the permit.'' The 
referenced permit for Hawthorn is Construction Permit Number 888 issued 
by the Kansas City Health Department in August of 1999 and amended in 
2001 after the reconstruction of the unit 5 boiler (which was renamed 
unit 5A). The permit contains the 30-day rolling average SO2 
emission limit of 0.12 lb/MMBtu referenced in Table 1 of 10 CSR 10-
6.260, and it stipulates that the facility must achieve the limit by 
utilizing a dry flue gas desulfurization system and low-sulfur coal. 
This permit has not changed since 2001 when the reconstruction of unit 
5 was completed, and the SO2 limit has also been part of the 
facility's Title V operating permit since that time.
    Missouri's rationale for removing the 0.12 lb/MMBtu SO2 
limit from the SIP is based on using the equivalent SO2 
emission limit in Hawthorn's PSD permit as a substitute measure. 
Missouri contends that removal of the 0.12 lb/MMBtu SO2 
limit from the SIP satisfies CAA section 110(l) because the same limit 
remains in place through Hawthorn's PSD permit. Missouri further states 
that any relaxation of the 30-day rolling average SO2 
emission limit in the PSD permit would subject the facility to PSD 
permitting requirements.
    EPA disagrees with Missouri's assessment because it relies on a 
substitute measure from Hawthorn's PSD permit that is not SIP-approved. 
Although the PSD permit is federally enforceable, it is not considered 
permanent because it is not contained in the Missouri SIP and could be 
modified without requiring EPA approval. While the EPA can provide 
comments on PSD permits during the state's public notice period, 
Missouri can issue or modify PSD permits that are not in the SIP 
without EPA approval pursuant to the state's federally approved 
permitting program. Therefore, because substitute measures must be 
quantifiable, permanent, and enforceable to be used for 110(l) analysis 
purposes, EPA's approval of the removal of a SIP-approved limit based 
on permits that are not SIP-approved would not be consistent with CAA 
section 110(l).

B. Labadie SO2 Emission Limit

    The Labadie SO2 emission limit found at 10 CSR 10-6.260 
(3)(C)3.A.(II) in the SIP is a daily average of 4.8 lb/MMBtu, which 
applies to each of Labadie's four boilers. In 2015, the state entered 
into a Consent Agreement with the operating entity to limit 
SO2 emissions at Labadie. The Consent Agreement includes a 
facility-wide SO2 emission limit of 40,837 pounds per hour 
(lb/hr) for Labadie. As stated in Missouri's TSD included in this 
docket, the purpose of the Consent Agreement was to strengthen the SIP 
related to attainment in the Jefferson County, Missouri nonattainment 
area for the 2010 1-hour SO2 NAAQS. In December 2020, the 
state amended the 2015 Consent Agreement with an addendum to clarify 
that all four of Labadie's units are covered under the facility-wide 
SO2 limit and incorporate the enforceable monitoring, 
recordkeeping, and reporting requirements associated with the facility-
wide limit. The EPA approved the Consent Agreement including the limits 
for Labadie, as amended, into the SIP at 40 CFR 52.1320(d) on January 
28, 2022 (87 FR 4508). 10 CSR 10-6.261 does not include any of the 
limits contained in the Consent Agreement.
    Missouri's rationale for removing the 4.8 lb/MMBtu SO2 
limit from the SIP is based on using the already SIP-approved Consent 
Agreement SO2 emission limit as a substitute measure of 
greater stringency. The state's analysis of the stringency of the 
Consent Agreement facility-wide SO2 limit of 40,837 lb/hr 
compared to the 10 CSR 10-6.260 unit-level SO2 limit of 4.8 
lb/MMBtu assumes all four boilers are operating at their maximum hourly 
design rate, which is a combined total heat input of 24,580 MMBtu/
hr.\2\ Labadie's maximum hourly SO2 emissions allowed under 
10 CSR 10-6.260 is calculated by multiplying 4.8 lb/hour by 24,580 
MMBtu/hr, which equates to 117,984 lb/hr, nearly three times the 
maximum hourly emissions of 40,837 lb/hr allowed by the already SIP-
approved Consent Agreement. Based on these calculations, Missouri 
concludes that the limit in the already SIP-approved Consent Agreement 
is more restrictive than the limit in 10 CSR 10-6.260, and therefore, 
removal of the 4.8 lb/MMBtu SO2 emission limit from the SIP 
will not relax requirements for Labadie, thus satisfying CAA section 
110(l).
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    \2\ Labadie units 1 and 2 each have a rated maximum heat input 
capacity of 6,183 MMBtu/hr. Labadie units 3 and 4 each have a rated 
maximum heat input capacity of 6,107 MMBtu/hr.
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    The EPA agrees that maximum allowable facility-wide hourly 
SO2 emissions for Labadie are lower under the already SIP-
approved Consent Agreement than were under 10 CSR 10-6.260 alone. 
However, our calculations show that under a different set of 
assumptions, there are potential operating scenarios for Labadie in 
which individual units could operate at a rate greater than the current 
4.8 lb/MMBtu SO2 SIP limit if it were removed from the SIP, 
while still complying with the already SIP-approved Consent Agreement 
limit. In our analysis, we converted the Consent Agreement facility-
wide lb/hr limit to a unit-level lb/MMBtu rate for multiple scenarios 
by dividing 40,837 lb/hr by the total heat input for all units assumed 
to be operating. An example of a scenario in which Labadie could 
potentially exceed the emission rate allowed under the 4.8 lb/MMBtu 
SO2 limit but still comply with the Consent Agreement limit 
is when a single unit is operating at 100% load. A maximum hourly heat 
input rate of 6,107 MMBtu/hr (representative of either unit 3 or 4) is 
used in this example. Dividing 40,837 lb/hr by 6,107 MMBtu/hr equates 
to an SO2 rate of 6.69 lb/MMBtu, which is greater than the 
4.8 lb/MMBtu SO2 limit in 10 CSR 10-6.260 in the current 
SIP. If this limit were removed from the SIP, there would not be a 
permanent and enforceable limit or condition in place to prevent 
Labadie from operating a single unit at an SO2 rate higher 
than 4.8 lb/MMBtu.
    In order for a state to use a previously SIP-approved measure (one 
that is already obtaining emissions reductions) as a substitute measure 
to satisfy the requirements of CAA section 110(l), the emissions 
reductions must be surplus, meaning they cannot otherwise be relied on 
for attainment/maintenance or Rate of Progress/Reasonable Further 
Progress requirements. The area should have an approved attainment/
maintenance demonstration in order to ascertain that the emissions 
reductions from the existing SIP-approved measure are indeed surplus. 
As Missouri states in the TSD included in this docket, the purpose of 
the Consent Agreement was to strengthen the SIP related to attainment 
in the Jefferson County, Missouri nonattainment area for the 2010 1-
hour SO2 NAAQS. When the Jefferson County, Missouri area was 
redesignated to attainment for the 1-hour SO2 NAAQS, the 
Consent Agreement was approved into the SIP as

[[Page 40762]]

part of the maintenance plan for the area (87 FR 4508, January 28, 
2022). The Labadie SO2 emission limit in the Consent 
Agreement is not surplus and therefore cannot be relied on as a 
substitute measure to meet the requirements of section 110(l).
    The EPA's approval of the removal of the 4.8 lbs/MMBtu 
SO2 limit from the SIP would not be consistent with CAA 
section 110(l) because the substitute SO2 limit from the 
already SIP-approved Consent Agreement is not as stringent as the SIP's 
4.8 lb/MMBtu limit in all situations, nor is it surplus. Moreover, 
Missouri has not demonstrated that this change in the SIP would be 
protective of all NAAQS.

III. Have the requirements for approval of a SIP revision been met?

    As explained above, because EPA's approval of the revision would 
not be consistent with CAA section 110(l), we are proposing to 
disapprove the submission. However, the state submission has met the 
public notice requirements for SIP submissions in accordance with 40 
CFR 51.102. The submission also satisfied the completeness criteria of 
40 CFR part 51, appendix V. The state provided public notice of the 
revisions from August 1, 2018, to October 4, 2018, and held a public 
hearing on September 27, 2018. The state received and addressed four 
comments from three entities, which included the EPA. The state did not 
make changes to the rule as a result of comments received prior to 
submitting to the EPA.

IV. What action is the EPA proposing to take?

    The EPA is proposing to disapprove a SIP submission from Missouri 
that would rescind 10 CSR 10-6.260 ``Restriction of Emission of Sulfur 
Compounds'' and replace it with 10 CSR 10-6.261 ``Control of Sulfur 
Dioxide Emissions.'' By disapproving these revisions, 10 CSR 10-6.260 
will be retained in the SIP, along with the already SIP-approved 
Consent Agreement. The EPA has determined that Missouri's proposed SIP 
revisions do not meet the requirements of the Clean Air Act because the 
revisions would remove permanent and enforceable emission limits, 
thereby relaxing the stringency of the SIP. Furthermore, Missouri has 
not shown that the proposed SIP revisions would not have an adverse 
impact on air quality.
    Under section 179(a) of the CAA, final disapproval of a submittal 
that addresses a requirement of part D, title I of the CAA (CAA 
sections 171-193) or is required in response to a finding of 
substantial inadequacy as described in CAA section 110(k)(5) (SIP Call) 
starts a sanctions clock. The Missouri SIP submission that we propose 
to disapprove was not submitted to meet either of these requirements. 
Therefore, any action we take to finalize this proposed disapproval 
will not trigger mandatory sanctions under CAA section 179. In 
addition, CAA section 110(c)(1) provides that EPA must promulgate a 
Federal Implementation Plan (FIP) within two years after either finding 
that a State has failed to make a required submission or disapproving a 
SIP submission in whole or in part, unless EPA approves a SIP revision 
correcting the deficiencies within that two-year period. With respect 
to our proposed disapproval of Missouri's SIP submission, however, we 
propose to conclude that any FIP obligation resulting from finalization 
of the proposed disapproval would be satisfied by our determination 
that there is no deficiency in the SIP to correct.\3\ Specifically, the 
limits discussed in this proposed rulemaking would remain in the SIP 
and remain federally enforceable.
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    \3\ The EPA's obligation under CAA section 110(c)(1) to issue a 
FIP following a SIP disapproval is not limited to ``required'' plan 
submissions. However, the EPA can avoid promulgating a FIP if the 
Agency finds that there is no ``deficiency'' in the SIP for a FIP to 
correct. Association of Irritated Residents vs. United States 
Environmental Protection Agency, 632 F.3d 584 (9th Cir. 2011).
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    We are soliciting comments on this proposed action. Final 
rulemaking will occur after consideration of any comments.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was 
therefore not submitted to the Office of Management and Budget for 
review.

B. Paperwork Reduction Act (PRA)

    This proposed action does not impose an information collection 
burden under the PRA because it does not contain any information 
collection activities.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action merely proposes to disapprove a SIP submission as not meeting 
the CAA.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any state, 
local or tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. This action does not apply on any Indian 
reservation land, any other area where the EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction, or non-reservation areas of 
Indian country. Thus, Executive Order 13175 does not apply to this 
action.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This action is not subject to 
Executive Order 13045 because it merely proposes to disapprove a SIP 
submission as not meeting the CAA.

H. Executive Order 13211, Actions That Significantly Affect Energy 
Supply, Distribution or Use

    This action is not subject to Executive Order 13211, because it is 
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    This rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes the human health or environmental risk addressed 
by this

[[Page 40763]]

action will not have potential disproportionately high and adverse 
human health or environmental effects on minority, low-income or 
indigenous populations. This action merely proposes to disapprove a SIP 
submission as not meeting the CAA.

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: June 30, 2022.
Meghan A. McCollister,
Regional Administrator, Region 7.
[FR Doc. 2022-14469 Filed 7-7-22; 8:45 am]
BILLING CODE 6560-50-P