[Federal Register Volume 86, Number 191 (Wednesday, October 6, 2021)]
[Rules and Regulations]
[Pages 55501-55509]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-21562]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2019-0447; FRL-9006-02-R4]


Air Plan Approval; MS; BART SIP and Regional Haze Progress Report

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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[[Page 55502]]

SUMMARY: The Environmental Protection Agency (EPA) is approving two 
Mississippi State Implementation Plan (SIP) revisions from the 
Mississippi Department of Environmental Quality (MDEQ) dated October 4, 
2018, and August 13, 2020. The October 4, 2018, SIP revision contains 
the State's first periodic report describing progress towards 
reasonable progress goals (RPGs) established for regional haze and 
contains the associated determination that the State's regional haze 
SIP is adequate to meet these RPGs for the first implementation period 
(Progress Report). The August 13, 2020, SIP revision addresses best 
available retrofit technology (BART) determinations for 14 electric 
generating units (EGUs) (BART SIP). These EGUs were initially addressed 
in EPA's prior limited approval and limited disapproval actions on 
Mississippi's regional haze SIP because of deficiencies arising from 
the State's reliance on the Clean Air Interstate Rule (CAIR) to satisfy 
certain regional haze requirements. EPA is approving the BART SIP and 
finds that it corrects the deficiencies that led to the limited 
approval and limited disapproval of the State's regional haze SIP. EPA 
is therefore withdrawing the limited disapproval of Mississippi's 
regional haze SIP and replacing the prior limited approval with a full 
approval of the regional haze SIP as meeting all regional haze 
requirements of the Clean Air Act (CAA or Act) for the first 
implementation period. EPA is also approving the Progress Report and 
associated adequacy determination.

DATES: This rule is effective November 5, 2021.

ADDRESSES: EPA has established a docket for this action under Docket 
Identification No. EPA-R04-OAR-2019-0447. 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 can either 
be retrieved electronically through www.regulations.gov or in hard copy 
at the Air Regulatory Management 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. 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: Michele Notarianni, Air Regulatory 
Management 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. Ms. Notarianni can be 
reached via telephone at (404) 562-9031 or electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION:

I. Background

A. Regional Haze

    Regional haze is visibility impairment that is produced by a 
multitude of sources and activities which are located across a broad 
geographic area and emit fine particulate matter (PM2.5) 
(e.g., sulfates, nitrates, organic carbon, elemental carbon, and soil 
dust) and their precursors (e.g., sulfur dioxide (SO2), 
nitrogen oxides (NOX), and in some cases, ammonia 
(NH3) and volatile organic compounds (VOC)). Fine particle 
precursors react in the atmosphere to form PM2.5 which 
impairs visibility by scattering and absorbing light. Visibility 
impairment (i.e., light scattering) reduces the clarity, color, and 
visible distance that one can see. PM2.5 can also cause 
serious health effects (including premature death, heart attacks, 
irregular heartbeat, aggravated asthma, decreased lung function, and 
increased respiratory symptoms) and mortality in humans and contributes 
to environmental effects such as acid deposition and eutrophication.
    In section 169A of the 1977 Amendments to the CAA, Congress created 
a program for protecting visibility in the nation's national parks and 
wilderness areas. This section of the CAA establishes as a national 
goal the prevention of any future, and the remedying of any existing, 
anthropogenic impairment of visibility in 156 national parks and 
wilderness areas designated as mandatory Class I federal areas. 
Congress added section 169B to the CAA in 1990 to further address 
regional haze issues, and EPA subsequently promulgated the Regional 
Haze Rule (RHR).\1\ The RHR established a requirement to submit a 
regional haze SIP which applies to all 50 states, the District of 
Columbia, and the Virgin Islands.\2\ Each jurisdiction was required to 
submit a SIP addressing regional haze requirements for the first 
implementation period no later than December 17, 2007.\3\
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    \1\ See 64 FR 35713 (July 1, 1990).
    \2\ See 40 CFR 51.300(b).
    \3\ See 40 CFR 51.308(b).
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B. BART

    Section 169A of the CAA directs states to evaluate the use of 
retrofit controls at certain larger, often uncontrolled, older 
stationary sources in order to address visibility impacts from these 
sources. Specifically, section 169A(b)(2) of the CAA requires states to 
revise their SIPs to contain such measures as may be necessary to make 
reasonable progress towards natural visibility conditions, including a 
requirement that certain categories of existing major stationary 
sources built between 1962 and 1977 procure, install, and operate 
``Best Available Retrofit Technology'' as determined by the state. On 
July 6, 2005, EPA published the Guidelines for BART Determinations 
Under the Regional Haze Rule at Appendix Y to 40 CFR part 51 (BART 
Guidelines) to assist states in the BART evaluation process. Under the 
RHR and the BART Guidelines, the BART evaluation process consists of 
three steps: (1) An identification of all BART-eligible sources, (2) an 
assessment of whether the BART-eligible sources are subject to BART, 
and (3) a determination of the BART controls.\4\ States must conduct 
BART determinations for all BART-eligible sources that may reasonably 
be anticipated to cause or contribute to any visibility impairment in a 
Class I area, or in the alternative, adopt an emissions trading program 
or other alternative program as long as the alternative provides 
greater reasonable progress towards improving visibility than BART. In 
making a BART determination for a fossil fuel-fired electric generating 
plant with a total generating capacity in excess of 750 megawatts, a 
state must use the approach set forth in the BART Guidelines. A state 
is generally encouraged, but not required, to follow the BART 
Guidelines in other aspects.
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    \4\ See 40 CFR 51.308(e); BART Guidelines, section I.F.
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    On September 22, 2008, Mississippi submitted a SIP revision to 
address regional haze in Class I areas impacted by emissions from the 
State and subsequently amended that submittal on May 9, 2011. EPA 
finalized a limited approval and a limited disapproval of Mississippi's 
regional haze SIP in June 2012 because of deficiencies in the regional 
haze SIP arising from the

[[Page 55503]]

State's reliance on CAIR as an alternative to BART for the State's 
BART-eligible EGUs.\5\ See 77 FR 38191 (June 27, 2012) (limited 
approval); 77 FR 33642 (June 7, 2012) (limited disapproval). In the 
limited disapproval action, EPA did not subject Mississippi to a 
Federal Implementation Plan (FIP). Mississippi had requested that EPA 
not issue a FIP and instead provide the State with additional time to 
correct the deficiencies in its regional haze SIP through a SIP 
revision.\6\
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    \5\ The State's analysis of reasonable progress controls was not 
dependent on CAIR, and thus, was not affected by CAIR's 
invalidation. See 77 FR 11879, 11888 (February 28, 2012) (finding 
that no controls were necessary for reasonable progress given the 
areas of influence and consultation with neighboring states).
    \6\ See 77 FR 33654.
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    Through a letter dated April 23, 2020,\7\ Mississippi submitted a 
draft SIP revision addressing BART for 14 EGUs formerly subject to CAIR 
(draft BART SIP) to EPA for parallel processing and provided public 
notice for comment on the same date. The State's public comment period 
closed on May 23, 2020. Mississippi submitted its final BART SIP to EPA 
on August 13, 2020.
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    \7\ EPA received MDEQ's April 23, 2020, draft BART SIP on April 
24, 2020.
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C. Regional Haze Progress Report

    The RHR requires each state to submit progress reports that 
evaluate progress towards the RPGs \8\ for each mandatory Class I area 
within the state and for each Class I area outside the state which may 
be affected by emissions from within the state. See 40 CFR 51.308(g). 
In addition, the provisions of 40 CFR 51.308(h) require each state to 
submit, at the same time as each progress report, a determination of 
the adequacy of the state's existing regional haze plan. The first 
progress report is due five years after submittal of the initial 
regional haze plan and must be submitted as a SIP revision. Mississippi 
submitted its progress report for the first implementation period and a 
determination of the adequacy of the State's existing regional haze 
plan to EPA on October 4, 2018.\9\
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    \8\ An RPG is a visibility goal for a Class I area, in deciviews 
(dv), as of the end of an implementation period, that provides for 
reasonable progress towards achieving natural visibility conditions. 
There are two RPGs for each Class I area for an implementation 
period: one for the most impaired days and one for the clearest 
days.
    \9\ EPA received Mississippi's Progress Report on October 15, 
2018.
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D. EPA's Notice of Proposed Rulemaking (NPRM)

    In a NPRM published on August 4, 2020 (85 FR 47134), EPA proposed 
to approve Mississippi's draft BART SIP via parallel processing. 
Contingent on the Agency finalizing its proposal to approve the BART 
SIP, EPA also proposed to approve the Progress Report under 40 CFR 
51.308(g) and the State's determination of adequacy under 40 CFR 
51.308(h). The details of these submissions and the rationale for EPA's 
proposed approval of the two submissions are further explained in the 
NPRM. Subsequently, Mississippi submitted its final BART SIP on August 
13, 2020, and EPA has concluded that there are no significant changes 
between the draft and final BART SIPs that warrant a different approach 
at the final rule stage.\10\
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    \10\ The changes between the draft and final BART SIP 
submissions include: Different transmittal letters, proof of 
adoption in the final BART SIP dated August 13, 2020, and the 
addition of Appendix M: Comments and Responses to provide a summary 
of responses to public comments and EPA's comments. In response to 
EPA comments, MDEQ made changes which expanded on Appendix R in the 
Table of Contents, clarified the emissions units in Table 2, updated 
the values in Table L.2.3, and added the source of the data used in 
Tables L.2.2, L.5.2, L.6.2, and L.7.2. The final BART SIP satisfies 
the completeness criteria in 40 CFR part 51, Appendix V.
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    The comment period for the NPRM originally closed on September 3, 
2020. EPA reopened the comment period until October 5, 2020, based on a 
request from Sierra Club for visibility modeling files related to the 
NPRM and for a 30-day extension.\11\
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    \11\ See 85 FR 58319 (September 18, 2020).
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II. Response to Comments

    EPA received one set of adverse comments from Sierra Club and the 
National Parks Conservation Association (hereinafter collectively 
referred to as the ``Commenter'') regarding the proposed approval of 
Mississippi's BART SIP. These comments are included in the docket for 
this rulemaking. EPA has summarized the comments and provided responses 
below.\12\
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    \12\ EPA did not receive any adverse comments on the Agency's 
proposed approval of the Progress Report.
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    Comment 1: The Commenter asserts that EPA cannot approve 
Mississippi's BART SIP because neither the Agency nor the State 
reviewed the visibility modeling used to exempt every EGU in 
Mississippi from BART. The Commenter then focuses on Mississippi Power 
Company--Plant Daniel (Plant Daniel), claiming that EPA admits it has 
not verified the visibility modeling analyses for this facility and 
that EPA could not have verified the analyses because the Agency does 
not possess any of the underlying modeling files. The Commenter also 
argues that EPA violated CAA section 307(d) by failing to include the 
modeling files in the rulemaking docket.
    Response 1: EPA disagrees with the Commenter. In formulating the 
NPRM, EPA had received from MDEQ all of the modeling files needed to 
thoroughly review the visibility modeling analyses for all six 
operational BART-eligible facilities,\13\ including Plant Daniel, to 
assess whether these sources are subject to BART. For each facility, 
EPA reviewed these modeling files as well as the BART exemption 
modeling report included in the BART SIP, MDEQ's exemption analysis, 
the modeling protocol for each facility,\14\ and the Visibility 
Improvement State and Tribal Association of the Southeast (VISTAS) 
Modeling Protocol.\15\ Based upon EPA's thorough review of these 
documents and modeling files, the Agency proposed to approve the SIP 
submission.
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    \13\ The BART-eligible emissions units at Cooperative Energy 
(formerly South Mississippi Electric Power Association)--Plant 
Morrow (Plant Morrow) were permanently retired on November 17, 2018; 
therefore, MDEQ did not perform visibility modeling analyses for the 
facility. See Appendix L.4 of the BART SIP.
    \14\ The modeling protocols for each of the six operational 
facilities are included in Appendix L of the BART SIP.
    \15\ The VISTAS states, including Mississippi, developed a 
``Protocol for the Application of CALPUFF for BART Analyses'' 
(VISTAS BART Modeling Protocol). Mississippi, in coordination with 
VISTAS, used this modeling protocol to apply CALPUFF to determine 
whether individual sources in Mississippi were subject to BART. The 
VISTAS BART Modeling Protocol, December 22, 2005, Revision 3.2 
(August 31, 2006), is included in Appendix L.8 of the BART SIP. EPA 
approved Mississippi's use of this modeling protocol in 2012. See 77 
FR 11879, 11888-89 (February 28, 2012) (proposal) and 77 FR 38191 
(June 27, 2012) (final).
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    The Commenter is correct that EPA does not possess the 
meteorological data input files (meteorological files) used in the 
modeling. However, this did not affect EPA's ability to meaningfully 
review the SIP for several reasons. First, MDEQ provided EPA with all 
of the other input and output files used in the visibility modeling. 
The Agency, by analyzing the model input and output files that MDEQ did 
provide, was able to confirm that the modeling used the correct 
meteorological data and VISTAS meteorological domain.\16\ Thus, EPA did 
not need to review the meteorological files.
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    \16\ One of the CALPUFF model output files identifies, among 
other things, the names of the meteorological data files, format of 
the files (binary), data years, coordinate system, meteorological 
grid cell spacing (four kilometers as specified by the VISTAS 
modeling protocol), and the number of vertical layers used in the 
meteorological input files.
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    Second, the meteorological files used here were standard files 
originally developed for VISTAS. They were used

[[Page 55504]]

by the states in Region 4 to support their regional haze SIPs during 
the first implementation period and continue to be used by many 
facilities in the southeastern United States for major source 
preconstruction permit modeling. To date, EPA has already approved 
numerous SIPs relying on the same files. Thus, these were not new data 
files specifically developed by these BART-eligible sources that would 
merit additional scrutiny.
    Third, to the extent the Commenter thinks that EPA should 
scrutinize the meteorological files every time it reviews visibility 
modeling conducted for a haze SIP, EPA disagrees. The Act vests the 
Agency with discretion in reaching its technical determinations as well 
as in how to best marshal its limited resources to meet statutory 
mandates. Based on EPA's long experience with visibility and 
preconstruction permit modeling, the Agency generally does not believe 
that re-assessing standard meteorological files every time they are 
used by a state or source is the best use of scarce Agency resources. 
Furthermore, the Commenter has not alleged, much less demonstrated, any 
deficiency with the meteorological files.
    EPA also disagrees with Commenter's claim that EPA violated CAA 
section 307(d) by not placing the modeling files in the docket. To 
begin with, CAA section 307(d) does not apply to this SIP action at 
all. See CAA section 307(d)(1) (expressly listing actions to which CAA 
section 307(d) applies and not including SIPs). Thus, the Commenter's 
claim lacks merit.
    In any event, the Commenter does not and cannot claim any prejudice 
as a result of the alleged deficiency. EPA did not post the modeling 
files to the electronic docket for the proposed rulemaking because the 
majority of these files are a file type that is not on the list of 
acceptable file types for upload into the Federal Docket Management 
System (FDMS).\17\ However, the NPRM provided EPA contacts that the 
public could reach out to for further information, and the Commenter 
requested the input files for Plant Daniel from the listed EPA contacts 
during the initial 30-day public comment period. EPA promptly provided 
the Commenter with all the files in its possession and worked with MDEQ 
to obtain the meteorological files. Due to the limited amount of time 
remaining in the comment period after the Commenter received the 
meteorological files, the Commenter requested an extension of the 
comment period for an additional 30 days. EPA granted the request, 
affording the Commenter ample time to review the files and perform its 
own modeling.\18\
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    \17\ There are two files related to the BART SIP modeling that 
are technically compatible with FDMS (which is the interface for 
federal employees to upload files to display at www.regulations.gov) 
but were not posted to the electronic docket. EPA did not upload 
these two files to FDMS because they are integral to the entire set 
of modeling files and therefore are maintained with the remaining 
modeling files. The Agency's management of the BART SIP modeling 
files is consistent with Region 4's standard practice.
    \18\ See 85 FR 58319 (September 18, 2020). The Commenter did not 
allege any errors in the modeling input files other than the 
NOX and SO2 emission rates and used all of the 
input files (with revisions to the NOX and SO2 
emissions rates as noted in Exhibit A to its comments) in its 
modeling. The NOX and SO2 emissions rates, 
moreover, were included in Appendix L.3 of the BART SIP which was 
part of the docket at the time of the proposal. See also Comments 
and Responses 2 and 3 for additional information and analysis 
regarding the NOX and SO2 emissions rates.
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    Comment 2: The Commenter states that EPA cannot approve MDEQ's 
determination that Plant Daniel is not subject to BART because that 
determination is based on unenforceable emissions reductions and an 
unjustified 2015-2018 emissions baseline in lieu of the 2001-2003 
baseline the Commenter prefers. The Commenter advances several 
supporting arguments. First, the Commenter contends that the BART SIP 
must contain enforceable BART emission limitations for the facility 
pursuant to CAA sections 110(a)(2) and 110(k)(3), section 51.308(d)(3) 
of the RHR, and sections IV and V of the BART Guidelines.
    Second, citing to section IV.D.4.d of the BART Guidelines, the 
Commenter asserts that the emissions baseline should represent a 
realistic depiction of anticipated annual emissions and, if a utility 
projects that future operating parameters will differ from past 
practice and the projection has a deciding effect in the BART 
determination, those operating parameters or assumptions must be 
enforceable limitations in the SIP. The Commenter then argues that the 
baseline used in the Plant Daniel BART modeling analysis is improper 
because it accounts for flue gas desulfurization (FGD) systems on Units 
1 and 2 that are not associated with federally enforceable emission 
limitations commensurate with BART. The Commenter states that MDEQ's 
email regarding the enforceability of the FGD emissions limitations 
identified in Plant Daniel's title V permit application is focused 
solely on SO2 and is conclusory, vague, unenforceable, and 
insufficient to create an enforceable emissions limit for determining 
whether Plant Daniel is subject to BART.
    Third, the Commenter further asserts that the baseline used in 
Plant Daniel's modeling is improper because it is inconsistent with the 
RHR's provision regarding baseline visibility conditions and the 
facility's potential emissions. According to the Commenter, the RHR 
requires states to determine baseline visibility conditions using a 
2000-2004 emissions baseline and it is nonsensical to use a baseline 
from nearly two decades later.
    Finally, the Commenter also claims that the 2015-2018 baseline is 
arbitrary and capricious as it does not realistically depict potential 
impacts from Plant Daniel because the facility's capacity factor has 
steadily dropped since 2015. The Commenter argues that the emissions 
reductions due to this reduced capacity are not enforceable, and 
therefore, should not serve as the emissions baseline for the purposes 
of determining whether the facility is subject to BART.
    Response 2: EPA disagrees with the Commenter. The CAA, RHR, and 
BART Guidelines do not require the result the Commenter seeks. Under 
the CAA's cooperative federalism framework, states have the primary 
responsibility for implementing federal standards by promulgating SIPs, 
and EPA must approve SIP revisions that meet CAA requirements. The CAA 
and RHR require states to classify a BART-eligible source as a BART-
subject source if it may reasonably be anticipated to cause or 
contribute to any impairment of visibility in any mandatory Class I 
federal area, but they do not set forth any specific, additional 
criteria for determining whether a source is subject to BART.\19\ For 
states that do not choose to treat all BART-eligible sources as BART-
subject sources, section III of the BART Guidelines provides 
recommendations on how to determine which BART-eligible sources are 
subject to BART. The recommendations address, among other things, how 
to establish a contribution threshold, what kind of modeling to use, 
how to develop a modeling protocol, and the selection of an emissions 
baseline for states such as Mississippi that opt to use an individual 
source attribution approach. They do not, however, recommend or require 
that the emissions baseline correspond to enforceable limitations.
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    \19\ See CAA section 169A; 40 CFR 51.308(e).
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    Here, Mississippi used the 24-hour average actual emission rate 
from the highest emitting day over a three-year period from 2015 to 
2018, after the source installed new control equipment for 
SO2. As explained further below, EPA believes this was a 
reasonable

[[Page 55505]]

choice. More generally, EPA has reviewed Mississippi's BART exemption 
determination for Plant Daniel and concluded that Mississippi 
reasonably exercised the discretion provided by the CAA and RHR. 
Therefore, EPA must approve Mississippi's BART SIP revision as it 
relates to Plant Daniel.\20\
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    \20\ EPA generally treats all of the Commenter's comments 
regarding the subject-to-BART determinations as going to the 
application of the CAA, RHR, and BART Guidelines in this SIP action. 
To the extent the Commenter is trying to collaterally attack the RHR 
or BART Guidelines themselves, those challenges are all beyond the 
scope of this rulemaking. See Sierra Club v. EPA, 939 F.3d 649, 678-
79 (5th Cir. 2019), reh'g denied (Dec. 9, 2019).
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    EPA now addresses and rejects the Commenter's supporting arguments. 
First, contrary to the Commenter's assertions, the CAA, RHR, and the 
BART Guidelines do not require a subject-to-BART determination to be 
based on enforceable emissions limits or reductions. The CAA sections 
cited by the Commenter are general SIP provisions that do not 
specifically address subject-to-BART determinations. Section 
110(a)(2)(A) generally requires a SIP to contain enforceable 
limitations and other control measures to meet the applicable 
requirements of the Act. As the Commenter notes, this obligation only 
applies with respect to measures that are ``necessary or appropriate to 
meet the applicable requirements'' of the Act, but the provision does 
not otherwise define the scope of the applicable requirements to which 
it applies.
    The portion of sections 110(a)(2)(C) that the Commenter refers to 
requires states to demonstrate, in developing infrastructure SIPs, that 
the state has statutes, regulations, or other provisions that provide 
for the enforcement of emission limitations included in the SIP 
pursuant to other applicable requirements of the Act.\21\ Similarly, 
section 110(a)(2)(E) requires that states have adequate personnel, 
funding, and authority to adequately implement the provisions of the 
SIP that are included pursuant to other applicable requirements of the 
Act.\22\ The Commenter has not alleged that the State provides 
inadequate enforcement or implementation of its existing SIP 
provisions.
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    \21\ Memorandum from Stephen D. Page, Director of Office of Air 
Quality Planning and Standards, to Regional Air Directors, Regions 
1-10, ``Guidance on Infrastructure State Implementation Plan (SIP) 
Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2),'' pp. 
23-24 (Sept. 13, 2013).
    \22\ Id. at pp. 39-44. The Commenter's citation to the language 
from section 110(a)(2)(E) requiring the State to bear 
``responsibility for ensuring adequate implementation'' of the SIP 
is particularly inapt as that language refers to specific 
circumstances where the state relies on a local or regional 
government, agency, or instrumentality for the implementation of a 
particular SIP provision. The Commenter has not alleged that the 
State has abdicated this responsibility in any way.
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    Section 110(k)(3) requires EPA to approve SIP revisions that meet 
all applicable requirements of the Act, but it also does not define the 
parameters of the applicable requirements of the Act. In fact, none of 
these sections address whether SIPs must contain enforceable limits to 
support subject-to-BART determinations. To the contrary, CAA section 
169A(b)(2) directly addresses this issue and requires SIP limits only 
for BART-eligible sources that ``may reasonably be anticipated to cause 
or contribute to any impairment of visibility'' in a Class I area. 
These sources are ``subject to BART.'' See 40 CFR 51.308(e)(1)(ii); see 
also BART Guidelines at section III (providing guidelines for 
determining which sources are subject to BART). For these sources, the 
State must conduct a BART determination and impose SIP limits 
representing BART. See CAA section 169A(b)(2); 40 CFR 51.308(e), 
(e)(1)(ii). Conversely, a source that is not reasonably anticipated to 
cause or contribute to visibility impairment is not subject to BART, 
and there is thus no need for either a BART determination or 
corresponding enforceable emission limits. As the NPRM and this final 
rulemaking notice explain, Plant Daniel is not subject to BART, and 
therefore, does not need enforceable limits that represent BART.
    The provisions of the RHR and BART Guidelines cited by the 
Commenter are also inapplicable because they only address sources that 
are subject to BART. The Commenter cites generally to 40 CFR 
51.308(d)(3), which requires each regional haze SIP to contain a long-
term strategy (LTS). The LTS is the compilation of all control measures 
a state will use during the implementation period of the SIP submittal 
to meet any applicable RPGs. Although the LTS must include BART 
emissions limits, Plant Daniel is not subject to BART. Thus, Plant 
Daniel does not have any BART emissions limits that must be included in 
the LTS. See 40 CFR 51.308(e), (e)(1)(ii) (requiring limits 
representing BART only for sources that are subject to BART).
    Similarly, the Commenter's reliance on sections IV and V of the 
BART Guidelines is misplaced. Section IV of the BART Guidelines 
addresses BART determinations (i.e., the analysis of BART options for 
subject-to-BART sources). Section V addresses how enforceable limits 
reflecting BART are to be established. Both sections, however, deal 
specifically with sources that are subject to BART. Plant Daniel, as 
already noted, is not subject to BART, and thus, these sections of the 
BART Guidelines are inapposite. By contrast, section III, which the 
Commenter conspicuously neglects to cite, specifically addresses how to 
determine whether a source is subject to BART and recommends the use of 
actual, not enforceable, emissions levels.
    The Commenter's allegations regarding section IV.D.4.d of the BART 
Guidelines is misplaced for the same reason. As just explained, that 
portion of the Guidelines only applies to sources that are subject to 
BART, and Plant Daniel is not subject to BART. In addition, even if 
section IV.D.4.d of the BART Guidelines was applicable to subject-to-
BART determinations, it would not preclude the baseline approach used 
for Plant Daniel because that baseline relies on past actual emissions 
from 2015-2018, not on future operating parameters. See 82 FR 60520, 
60533-34 (December 21, 2017) (explaining that use of recent actual 
emissions data is consistent with BART Guidelines section IV.D.4.d); 
Nat'l Parks Conservation Ass'n v. EPA, 788 F.3d 1134, 1143 (9th Cir. 
2015) (upholding EPA's use of 2008-2010 emissions notwithstanding the 
lack of corresponding enforceable limitations because they reflected 
``a realistic depiction of anticipated annual emissions for the 
source'').
    The Commenter's assertion that the Plant Daniel subject-to-BART 
evaluation must use a 2000-2004 emissions baseline is also based on 
inapplicable provisions of the RHR. The 2000-2004 period established in 
40 CFR 51.308(d)(2)(i) is the baseline for purposes of measuring 
reasonable progress at Class I areas. Neither the RHR nor the BART 
Guidelines requires the use of this particular timeframe as the 
baseline for a subject-to-BART determination.
    Finally, EPA disagrees that Mississippi's use of the 2015-2018 
baseline for Plant Daniel was arbitrary and capricious. The three-year 
period relied on by the State, from October 1, 2015, through September 
30, 2018, was a reasonable exercise of discretion for three reasons. 
First, while the Commenter takes issue with the potential for an 
increased annual capacity factor in the future, the visibility modeling 
is not based on the annual capacity factor, but rather based on the 
maximum daily emissions over a three-year time period. The model is run 
for every day over a three-year period using the same maximum day 
emissions. Based on these daily model

[[Page 55506]]

results, the model estimates the 98th percentile highest visibility 
impacts for each year. Then, the highest of the three yearly 98th 
percentile impacts, or the 22nd highest visibility impact over the 
three years, whichever is more conservative, is compared to the state's 
BART contribution threshold, which is 0.5 dv for Mississippi. Since the 
highest daily emissions are used for each day in the modeling, the 
Commenter fails to allege how an increase in capacity factor here would 
affect the maximum daily emissions or the visibility modeling results. 
In any event, the Commenter's suggestion that emissions might increase 
in the future is beside the point; as already noted, the BART 
Guidelines specifically recommend the use of past actual emissions 
data.
    Second, the emissions data used was from the most recent three 
years when the modeling was conducted. That is, the source did not 
cherry pick data from three years of low emissions, but simply used the 
most recent data from after the FGD was installed and operating.
    Third, prior to the start of the modeled period, the facility had 
installed control equipment for the purposes of complying with legal 
requirements outside of the regional haze program. Specifically, Plant 
Daniel installed low NOX burners on Units 1 and 2 in 2008 
and 2010, respectively, to ensure compliance with CAIR,\23\ and later 
installed FGD on these units in 2015 to comply with EPA's Mercury and 
Air Toxics Standards (MATS). Plant Daniel's federally-enforceable title 
V permit \24\ requires compliance with MATS \25\ and applicable New 
Source Performance Standard (NSPS) \26\ emissions limits for 
SO2, and Acid Rain Program \27\ and applicable NSPS \28\ 
emissions limits for NOX.\29\ The operation of the above 
equipment has resulted in significant emissions reductions that reduced 
visibility impacts at the Breton Wilderness Area (Breton). The State 
chose to use an emissions baseline with data beginning shortly after 
the most recent emission control equipment, FGD, was installed. EPA is, 
moreover, not aware of evidence that any of these controls will be 
removed in the future.
---------------------------------------------------------------------------

    \23\ See the Prevention of Significant Determination permit 
applications dated May 4, 2009, and January 22, 2008, for Plant 
Daniel Units 1 and 2, respectively, at page 1 of the ``APPLICATION 
OVERVIEW'' section (page 3 of the pdf file) for each application. 
These applications are included in the docket for this rulemaking.
    \24\ MDEQ issued a title V permit to Plant Daniel containing 
MATS limits on December 31, 2020, after publication of the NPRM. See 
State of Mississippi Air Pollution Control Title V Permit No. 1280-
00090 (Plant Daniel Title V Permit) which is included in the docket 
for this rulemaking. The Commenter's arguments regarding the 
enforceability of the title V permit application are therefore moot.
    \25\ The permit requires compliance with a SO2 
alternative emissions limit under MATS for hydrochloric acid of 0.20 
pounds of SO2 per million British thermal units (lbs/
MMBtu) (input based) or 1.5 lbs/megawatt-hour (output based) 
(rolling 30-boiler operating day average) for Units 1 and 2. See 
Plant Daniel Title V Permit Section 3.B.11 (citing 40 CFR 
63.9991(a)(1), 63.10000(a) and (b), and Table 2, subpart UUUUU).
    \26\ The permit requires compliance with a SO2 limit 
of 1.2 lbs/MMBtu heat input when firing coal alone or with wood 
residue or a <=ng/J value obtained from the equation in Condition 
3.B.8 when firing a combination of fuels (rolling 3-hour average) 
for Units 1 and 2. See id. at Section 3.B.8 (citing 40 CFR 
60.43(a)(2) and (b), subpart D). The permit also requires compliance 
with the applicable requirements of 40 CFR part 60, subparts A and D 
regarding SO2 (Section 3.B.5) and SO2 
allowances for Units 1 and 2 under the Acid Rain Program (Sections 
3.B.35, 8, and Appendix C (citing 40 CFR parts 72-78)).
    \27\ Under the permit's Acid Rain Program conditions, 
NOX emissions from Units 1 and 2 shall not exceed the 
annual average alternative contemporaneous emission limitation of 
0.45 lbs/MMBtu, Unit 1 has an annual heat input limit of 20,000,000 
MMBtu, and Unit 2 has an annual heat input limit of 15,000,000 
MMBtu. See id. at Sections 3.B.35, 8, and Appendix C (citing 40 CFR 
parts 72-78).
    \28\ The permit requires compliance with a NOX 
(expressed as nitrogen dioxide) limit of 0.70 lbs/MMBtu heat input 
when firing coal alone or with wood residue or <=ng/J value obtained 
from the equation in Condition 3.B.9 when firing a combination of 
fuels (rolling 3-hour average) for Units 1 and 2. See id. at Section 
3.B.9 (citing 40 CFR 60.44(a)(3) and (b), subpart D). The permit 
also requires compliance with the applicable requirements of 40 CFR 
part 60, subparts A and D regarding NOX. See id. at 
Section 3.B.5.
    \29\ The permit also requires compliance with the Cross-State 
Air Pollution Rule (CSAPR) NOX Ozone Group 2 Trading 
Program. See id. at Sections 3.B.36 and 9.
---------------------------------------------------------------------------

    Given the above facts, EPA believes the State's decision to use the 
more recent baseline was reasonable. Cf. Nat'l Parks Conservation Ass'n 
v. EPA, 788 F.3d 1134, 1143 (9th Cir. 2015) (approving EPA's decision 
to rely on a more recent, albeit unenforceable, emissions baseline in 
determining BART where there was ``no reason to believe that [the 
source] would change course and remove the additional combustion 
controls it had already installed'').
    Comment 3: The Commenter contends that the modeling underlying the 
Plant Daniel BART exemption analysis demonstrates that the source 
should be subject to BART using a corrected emissions baseline. The 
Commenter asserts that Plant Daniel excluded several days in May and 
November 2017 with high SO2 emissions from the emissions 
baseline on the grounds that they were attributable to startup, 
shutdown, and malfunction (SSM) events. The Commenter claims that these 
days should have been included in the modeling baseline because they 
are not associated with SSM events and are not identified in the 
facility's MATS compliance reports.
    The Commenter conducted its own BART exemption modeling for Units 1 
and 2 at Plant Daniel using emissions input data from 2015-2018 that 
includes the excluded days. Using the revised emissions input data, the 
existing modeling protocol, and the 2001-2003 meteorological modeling 
inputs, the Commenter's revised CALPUFF modeling predicts that the 
visibility impact at Breton from Units 1 and 2 at Plant Daniel using 
the 8th highest (98th percentile) day is 0.55 dv, exceeding 
Mississippi's 0.5 dv subject-to-BART contribution threshold. According 
to the Commenter, the modeling results also show that visibility 
impairment due to Plant Daniel during most of the high impact days is 
dominated by nitrates which underscores the need to evaluate 
NOX BART for the facility. The Commenter also ran the model 
using emissions from 2001-2003 and concluded that the modeled 
visibility impact using the 8th highest day from Units 1 and 2 exceeds 
2.5 dv at Breton.
    Response 3: EPA does not agree that the emissions baseline used in 
the BART modeling needs to be corrected as suggested by the Commenter. 
Although the Commenter is correct that certain excluded high-emission 
days were not associated with SSM, the State nonetheless reasonably 
excluded these days because they did not ``reflect steady-state 
operating conditions during periods of high capacity utilization.'' 
\30\ Rather, the source was temporarily testing new coal blends on 
these days, and thus, experienced atypical and higher than normal 
emissions during this time.\31\
---------------------------------------------------------------------------

    \30\ See BART Guidelines, section III.
    \31\ See the file named ``Plant Daniel Regional Haze BART Info 
Request-Response'' (Plant Daniel Information Response) attached to 
MDEQ's December 9, 2020, email to EPA. The email and attachment are 
included in the docket for this rulemaking.
---------------------------------------------------------------------------

    Regarding the excluded days in May and November 2017 referenced by 
the Commenter, the BART SIP does not identify these dates as SSM. The 
BART modeling protocol for Plant Daniel, located in Appendix L.3.2 of 
the BART SIP, states that the modeled emissions excluded ``startup, 
shutdown, or other nonrepresentative operations, etc.'' as identified 
in Appendix E of the protocol. Table E-1 of the protocol, titled 
``Summary of Days with Nonrepresentative Emissions,'' lists the days 
between October 1, 2015, to September 30, 2018, with periods of 
nonrepresentative operations and

[[Page 55507]]

describes the nature of the operations. Dates associated with startups, 
malfunctions, and shakedowns are marked accordingly whereas the 
operations on the excluded days in May and November 2017 are described 
as ``test burn/additional FGD pumps not in operation'' or ``test burn/
OFA damper not tuned'' (test burn days).\32\
---------------------------------------------------------------------------

    \32\ See Appendix L.3.2.3 at p. E-2. Table E-1 on p. E-2 does 
not include August 22, 2018, where data was substituted for two 
hours (8:00-9:00 p.m. and 10:00-11:00 p.m.) for Unit 1. According to 
EPA's Field Audit Checklist Tool (https://www.epa.gov/airmarkets/field-audit-checklist-tool-fact) these hours were associated with 
startup.
---------------------------------------------------------------------------

    EPA obtained clarification from Mississippi Power via MDEQ that the 
company excluded the test burn days in May and November 2017 from the 
model because they represent atypical operations, not SSM.\33\ On the 
days in Table E-1 marked with a test burn entry, Plant Daniel tested 
blending Powder River Basin subbituminous coal with Illinois Basin 
bituminous coal to determine the effects of the test coal blends on 
boiler operations and auxiliary equipment. In order to obtain baseline 
data on the impacts of these test coal blends on unit operations, Plant 
Daniel did not optimize the boiler, the emission controls, and the 
auxiliary equipment for extended operation with these test blends. If 
Plant Daniel were to use the test coal blends as part of normal 
operations, the source avers that the boiler and auxiliary equipment 
would be tuned appropriately, resulting in lower SO2 and 
NOX emission rates than those experienced during the tests.
---------------------------------------------------------------------------

    \33\ See Plant Daniel Information Response.
---------------------------------------------------------------------------

    The Commenter correctly noted that the source also did not identify 
these days on its MATS compliance reports as test burn days. The MATS 
compliance reporting asks facilities to answer, ``Did the facility burn 
new types of fuel during the reporting period?'' and the source 
answered ``No.'' This was because there was no change in fuel type. 
MATS defines ``fuel type'' as ``each category of fuels that share a 
common name or classification'' (e.g., bituminous coal, subbituminous 
coal); \34\ Plant Daniel burns a blend of bituminous (West Elk) and 
subbituminous (Powder River Basin) coal during normal operations; \35\ 
and the facility burned a blend of the same fuel types--bituminous and 
subbituminous coal--on the test burn days. In other words, although the 
source changed the coal blend it burned, it did not change the ``fuel 
type'' as defined by MATS.
---------------------------------------------------------------------------

    \34\ See 40 CFR 63.10042 (``Fuel type means each category of 
fuels that share a common name or classification. Examples include, 
but are not limited to, bituminous coal, subbituminous coal, 
lignite, anthracite, biomass, and residual oil. Individual fuel 
types received from different suppliers are not considered new fuel 
types.'').
    \35\ The MATS compliance reports provided by the Commenter list 
bituminous and subbituminous coal and No. 2 fuel oil as the fuels 
burned in Units 1 and 2.
---------------------------------------------------------------------------

    Excluding the test burn days from the BART exemption modeling is 
consistent with the BART Guidelines and the VISTAS BART Modeling 
Protocol because they do not represent normal operations. The BART 
Guidelines state that ``emissions estimates used in the models are 
intended to reflect steady-state operating conditions during periods of 
high capacity utilization.'' \36\ Although the Guidelines go on to 
specifically discourage the use of emissions reflecting SSM, SSM is 
only one example of an event that does not represent steady-state 
operating conditions where ``such emission rates could produce higher 
than normal effects than would be typical of most facilities.'' 
Further, the VISTAS BART Modeling Protocol states that ``source 
emissions should be defined using the maximum 24-hour actual emission 
rate during normal operation for the most recent 3 or 5 years'' for 
CALPUFF modeling.\37\ The Plant Daniel modeling protocol in Appendix 
L.3.2 of the BART SIP explains that the modeling excluded the days 
identified in Table E-1 pursuant to the BART Guidelines because those 
days included periods of nonrepresentative operations.\38\ Based on the 
information submitted by Plant Daniel and MDEQ, EPA believes that MDEQ 
reasonably concluded that the test burn days do not represent steady-
state operations, and thus, appropriately excluded them from the 
modeling analysis consistent with EPA's BART Guidelines and the VISTAS 
BART Modeling Protocol.
---------------------------------------------------------------------------

    \36\ See BART Guidelines, Section III.A.3 (emphasis added) 
(discussing the kind of modeling used to determine which sources and 
pollutants need not be subject to BART).
    \37\ See VISTAS BART Modeling Protocol at p. S-3 (emphasis 
added) and p. 43.
    \38\ See Appendix L.3.2.3 at p. E-2. The protocol also states 
that a total of 25 out of 834 days (2.9 percent) were excluded for 
SO2 and 6 out of 834 days (0.7 percent) were excluded for 
NOX. Id.
---------------------------------------------------------------------------

    Regarding the Commenter's assertion that modeled visibility 
impairment due to Plant Daniel at Breton is dominated by nitrates which 
underscores the need to evaluate NOX BART, the dominance of 
one visibility impairing pollutant over another at a Class I area is 
irrelevant to a subject-to-BART determination. If the total modeled 
visibility impairment from a source due to NOX, 
SO2, and PM combined meets or exceeds Mississippi's BART 
contribution threshold, the source is subject-to-BART. In this 
instance, MDEQ determined that Plant Daniel is not subject-to-BART 
based on modeling the visibility impacts of all three pollutants 
(including NOX), and therefore, no BART determination is 
required for NOX, SO2, or PM.\39\
---------------------------------------------------------------------------

    \39\ EPA notes that the 2009-2018 IMPROVE monitoring data 
indicates that sulfates are the predominant pollutant at Breton on 
the most impaired days. For example, for the period 2014-18, the 
most recent 5-year period with available data, sulfates accounted 
for approximately 64 percent of the visibility impairment at Breton 
on the most impaired days whereas nitrates accounted for only 
approximately 10 percent of the impairment. This data is available 
at http://vista.cira.colostate.edu/Improve/.
---------------------------------------------------------------------------

    Regarding the Commenter's use of a 2001-2003 baseline emissions 
period, EPA disagrees that the State was required to use that specific 
period for modeling visibility impacts. The State reasonably determined 
that the facility's use of the 2015-2018 updated baseline period 
reflecting operation of new SO2 and NOX controls 
is appropriate, as discussed in Response 2.
    Comment 4: The Commenter claims that although Plant Daniel is 
regularly able to achieve SO2 emission rates as low as 0.03 
lbs/MMBtu, spikes up to 0.6 to 0.8 lbs/MMBtu indicate that the facility 
operates its FGD systems periodically or inefficiently. According to 
the Commenter, the spikes appear to be the result of occasional 
scrubber bypass and an unlawful failure to impose a federally 
enforceable requirement to continually achieve an emissions limit 
commensurate with BART.
    Response 4: As discussed in the NPRM and this notice, Plant Daniel 
is not subject to BART, and therefore, no BART emissions limits are 
required. Furthermore, as discussed in Responses 2 and 3, Mississippi 
reasonably exercised its discretion in selecting the 2015-2018 baseline 
for the subject-to-BART modeling for Plant Daniel and excluding the 
spikes associated with the test burn days. EPA has nonetheless 
evaluated the Commenter's assertions that Plant Daniel is experiencing 
spikes in its SO2 emission rates due to alleged scrubber 
inefficiency or intermittent scrubber operation.
    The majority of the spikes shown in Figure 2 of the Commenter's 
October 5, 2020, submission occurred after the baseline period ended on 
September 30, 2018.\40\ EPA requested supplemental

[[Page 55508]]

information from MDEQ regarding these post-baseline period spikes, and 
in response, Mississippi Power explained that the spikes beginning in 
the third quarter of 2018 do not reflect actual SO2 
emissions because they are the result of data substitution in 
accordance with 40 CFR 75.33 and Appendix A to 40 CFR part 75 
(Specifications and Test Procedures) due to FGD bypasses during 
malfunction/emergency events.\41\ The bypasses were infrequent (less 
than one percent of unit operating time) and short in duration (less 
than two hours). Due to the short duration of each bypass, the bypass 
continuous emission monitoring system (CEMS) did not have time to 
calibrate and provide valid emissions data. A combination of short 
duration events beginning in September 2018 and associated CEMS data 
invalidation resulted in CEMS availability dropping below 90 percent, 
triggering data substitution requirements under Part 75. Part 75 
requires data to be substituted at the maximum potential concentration 
when CEMS availability is less than 90 percent, resulting in the spikes 
shown on Figure 2 beginning in the third quarter of 2018.\42\ 
Mississippi Power affirmed in its response that it operates the FGD 
systems efficiently and at all times, except during SSM events,\43\ and 
notes that MATS requires continuous operation of the FGD system.\44\
---------------------------------------------------------------------------

    \40\ The spikes in Figure 2 that occurred during the baseline 
period and are associated with nonrepresentative emissions are 
explained in Table E-1 of the Plant Daniel BART Modeling Protocol 
with the exception of the spikes on August 22, 2018, where the 
facility substituted data for two hours at 8:00-9:00 p.m. and 10:00-
11:00 p.m. for Unit 1 due to startup. As discussed in Response 3, 
Table E-1 identifies days with nonrepresentative emissions 
associated with SSM and test burns. The table also identifies days 
with nonrepresentative emissions associated with the shakedown of 
the FGD systems. Control system shakedowns occur over a limited 
period of time following installation and, among other things, are 
used to identify any potential installation problems and to ensure 
that the new system is operating properly. Therefore, the shakedowns 
identified in Table E-1 are not evidence of inefficient or routine 
FGD operation.
    \41\ See Plant Daniel Information Response.
    \42\ See 40 CFR part 75, Appendix A, Section 2.1--Instrument 
Span and Range.
    \43\ Elsewhere, Mississippi Power also acknowledges that it did 
not optimize its scrubber operation on test burn days in order to 
determine the effects of test coal blends on facility operations. 
See Response 3.
    \44\ The MATS rule requires continuous operation of the FGD 
system if the source chooses to comply with the SO2 
surrogate standard. See 40 CFR 63.9991(c)(2). See generally 40 CFR 
Subpart UUUUU.
---------------------------------------------------------------------------

    Comment 5: The Commenter argues that Mississippi's BART SIP 
arbitrarily fails to address BART for NOX emissions from 
EGUs and that the State cannot rely on CSAPR as a BART alternative. The 
Commenter claims that Mississippi has not corrected its SIP to formally 
adopt CSAPR in lieu of source-specific BART for NOX 
emissions so that it could rely on CSAPR as a BART alternative and 
claims that CSAPR is not a valid BART alternative for the following 
reasons. First, Mississippi cannot exempt Plant Daniel from 
NOX BART without going through the BART exemption process, 
the State has not demonstrated that Plant Daniel meets the BART 
exemption requirements, and the State has not obtained the concurrence 
of the Federal Land Managers (FLMs) to exempt the source from BART. 
Second, the CSAPR ``Better than BART'' (CSAPR BTB) rule is flawed 
because it evaluated CSAPR allocations that are more stringent than now 
required, used presumptive BART limits that are less stringent than 
required under the statute, and failed to account for uncertainties in 
emissions reductions under CSAPR. Third, the CSAPR BTB rule is no 
longer valid given the substantial changes in CSAPR allocations and 
compliance deadlines, including the United States Court of Appeals for 
the District of Columbia Circuit's (D.C. Circuit's) 2015 invalidation 
of certain states' emission budgets and EPA's withdrawal of Texas from 
the CSAPR trading program. Fourth, NOX emissions from 
Mississippi's EGUs are only covered by CSAPR during the ozone season, 
and therefore, CSAPR does not protect Breton and other Class I areas 
during the remaining seven months of the year. The Commenter attached 
comments submitted by Earthjustice, National Parks Conservation 
Association, and Sierra Club on the CSAPR BTB rule.
    Response 5: Mississippi did not rely on CSAPR BTB in its SIP 
submission, nor does EPA rely on CSAPR BTB in the Agency's approval. 
Therefore, all comments addressing the State's or EPA's application of 
CSAPR BTB in this SIP action are incorrect. Moreover, EPA did not 
purport to revisit CSAPR BTB in this action. All comments generally 
addressing the validity of CSAPR BTB are therefore beyond the scope. 
EPA notes that the Commenter's general claims regarding CSAPR BTB have 
been and are being addressed in separate proceedings.\45\ Finally, to 
the extent the Commenter is asserting that the sole mechanism by which 
Plant Daniel can be exempted from BART is under CAA section 169A(c), 
that is incorrect. See Am. Corn Growers Ass'n v. EPA, 291 F.3d 1, 8 
(D.C. Cir. 2002) (rejecting this argument). The subject-to-BART 
assessment provides a separate method for exempting BART-eligible 
sources such as Plant Daniel.
---------------------------------------------------------------------------

    \45\ See, e.g., Nat'l Parks Conservation Ass'n v. EPA, Nos. 17-
1253, 20-1341 (D.C. Cir.); 82 FR 45481 (September 29, 2017) (2017 
rule affirming that CSAPR remains better-than-BART after the changes 
made to CSAPR's geographic scope due to the 2015 D.C. Circuit 
decision cited by the Commenter); EPA's June 29, 2020, denial of the 
Commenter's petition for reconsideration of the 2017 Rule, available 
at https://www.epa.gov/sites/production/files/2020-06/documents/csapr_btb_petition_denial_sierra_club_06-29-20.pdf and https://www.epa.gov/sites/production/files/2020-06/documents/csapr_btb_petition_denial_npca_06-29-20_0.pdf.
---------------------------------------------------------------------------

III. Final Action

    Based on the rationale articulated in the NPRM and in this final 
rule, EPA is approving the August 13, 2020, BART SIP and finds that it 
corrects the deficiencies that led to the limited approval and limited 
disapproval of the State's regional haze SIP. EPA is therefore 
withdrawing the limited disapproval of the regional haze SIP and 
replacing the prior limited approval with a full approval of the 
regional haze SIP as meeting all regional haze requirements of the CAA 
for the first implementation period. EPA is also approving 
Mississippi's October 4, 2018, Progress Report as meeting the 
applicable regional haze requirements set forth in 40 CFR 51.308(g) and 
the State's determination of adequacy under 40 CFR 51.308(h).

IV. 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. These actions merely 
approve state law as meeting Federal requirements and do not impose 
additional requirements beyond those imposed by state law. For that 
reason, these actions:
     Are not significant regulatory actions 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);
     Do not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are 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.);
     Do 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);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);

[[Page 55509]]

     Are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are 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
     Do 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 these actions 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. These actions are not a ``major rule'' as defined by 5 U.S.C. 
804(2).
    Under section 307(b)(1) of the CAA, petitions for judicial review 
of these actions must be filed in the United States Court of Appeals 
for the appropriate circuit by December 6, 2021. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of these actions 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. These actions may not be challenged later in proceedings to 
enforce its requirements. See section 307(b)(2).

List of Subjects in 40 CFR Part 52

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

    Dated: September 29, 2021.
John Blevins,
Acting 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 Z--Mississippi

0
2. In Sec.  52.1270 amend the table in paragraph (e) by adding entries 
for ``Regional Haze Progress Report'' and ``BART SIP'' at the end of 
the table to read as follows:


Sec.  52.1270  Identification of plan.

* * * * *
    (e) * * *

                               EPA Approved Mississippi Non-Regulatory Provisions
----------------------------------------------------------------------------------------------------------------
                                       Applicable           State
   Name of non-regulatory SIP        geographic or     submittal date/  EPA approval date       Explanation
            provision              nonattainment area  effective date
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Regional Haze Progress Report...  Mississippi........       10/4/2018  10/6/2021, [Insert  .....................
                                                                        citation of
                                                                        publication].
BART SIP........................  Mississippi........       8/13/2020  10/6/2021, [Insert  .....................
                                                                        citation of
                                                                        publication].
----------------------------------------------------------------------------------------------------------------

Sec.  52.1279  [Amended]

0
3. Section 52.1279 is amended by removing and reserving paragraph (a).
[FR Doc. 2021-21562 Filed 10-5-21; 8:45 am]
BILLING CODE 6560-50-P