[Federal Register Volume 89, Number 161 (Tuesday, August 20, 2024)]
[Proposed Rules]
[Pages 67341-67368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-18495]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2022-0786; FRL-10405-01-R4]


Air Plan Approval; North Carolina; Second Period Regional Haze 
Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve in part and conditionally approve in part a regional haze State 
Implementation Plan (SIP) revision submitted by the North Carolina 
Department of Environmental Quality, Division of Air Quality (DAQ), 
dated April 4, 2022 (``Haze Plan'' or ``2022 Plan'') under the Clean 
Air Act (CAA or Act) and EPA's Regional Haze Rule (RHR) for the 
regional haze program's second planning period. North Carolina's 2022 
SIP submission addresses the requirement that states must periodically 
revise their long-term strategies for making reasonable progress toward 
the national goal of preventing any future, and remedying any existing, 
anthropogenic impairment of visibility, including regional haze, in 
mandatory Class I Federal areas. The SIP submission also addresses 
other applicable requirements for the second planning period of the 
regional haze program. EPA is taking this action pursuant to sections 
110 and 169A of the Act.

DATES: Written comments must be received on or before September 19, 
2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2022-0786, at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. 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. 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 http://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Michele Notarianni, Multi-Air 
Pollutant Coordination Section, Air Planning and Implementation Branch, 
Air and Radiation Division, U.S. Environmental Protection Agency, 
Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. Ms. 
Notarianni can be reached via telephone at (404) 562-9031 or electronic 
mail at [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. What action is EPA proposing?
II. Background and Requirements for Regional Haze Plans
    A. Regional Haze Background
    B. Roles of Agencies in Addressing Regional Haze
III. Requirements for Regional Haze Plans for the Second Planning 
Period
    A. Identification of Class I Areas
    B. Calculations of Baseline, Current, and Natural Visibility 
Conditions; Progress to Date; and the Uniform Rate of Progress (URP)
    C. Long-Term Strategy (LTS) for Regional Haze
    D. Reasonable Progress Goals (RPGs)

[[Page 67342]]

    E. Monitoring Strategy and Other State Implementation Plan 
Requirements
    F. Requirements for Periodic Reports Describing Progress Toward 
the RPGs
    G. Requirements for State and Federal Land Manager (FLM) 
Coordination
IV. EPA's Evaluation of North Carolina's Regional Haze Submission 
for the Second Planning Period
    A. Identification of Class I Areas
    B. Calculations of Baseline, Current, and Natural Visibility 
Conditions; Progress to Date; and the URP
    C. LTS for Regional Haze
    D. RPGs
    E. Monitoring Strategy and Other Implementation Plan 
Requirements
    F. Requirements for Periodic Reports Describing Progress Toward 
the RPGs
    G. Requirements for State and FLM Coordination
    H. Environmental Justice (EJ) Considerations
V. Incorporation by Reference
VI. Proposed Action
VII. Statutory and Executive Order Reviews

I. What action is EPA proposing?

    On April 4, 2022, the North Carolina DAQ submitted a revision to 
its SIP to address regional haze for the second planning period. DAQ 
made this SIP submission to satisfy the requirements of the CAA's 
regional haze program pursuant to CAA sections 169A and 169B and 40 CFR 
51.308.\1\ EPA is proposing to approve in part and conditionally 
approve in part North Carolina's Haze Plan. For the reasons discussed 
in this document, EPA is proposing to approve the sections of the Haze 
Plan addressing the requirements of 40 CFR 51.308(f)(1), (f)(4) 
through(6), and (g)(1) through(5). EPA is proposing to conditionally 
approve the sections of the Haze Plan addressing the requirements of 40 
CFR 51.308(f)(2), (f)(3), and (i)(2) through(4) due to concerns with 
the legal and practicable enforceability of certain permit conditions 
identified in the Haze Plan for incorporation into the SIP.
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    \1\ In a letter dated August 15, 2022, EPA found that North 
Carolina's Haze Plan meets the completeness criteria outlined in 40 
CFR part 51, Appendix V. A completeness determination does not 
constitute a finding on the merits of the submission or whether it 
meets the relevant criteria for SIP approval. The August 15, 2022, 
letter is included in the docket for this proposed rulemaking.
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    Consistent with CAA section 110(k)(3), EPA may approve in part 
portions of the SIP submittal if those portions meet the all the 
applicable requirements. Under CAA section 110(k)(4), EPA may 
conditionally approve a SIP revision based on a commitment from a state 
to adopt specific enforceable measures by a date certain, but not later 
than one year from the date of conditional approval of the plan 
revision. If the state fails to meet the commitment within one year of 
the final conditional approval, the conditional approval will be 
treated as a disapproval. North Carolina submitted a letter, dated July 
30, 2024, (``Commitment Letter''), requesting partial conditional 
approval of its Haze Plan and committing to submit a SIP revision 
containing specific enforceable measures no later than one year from 
the effective date of a final conditional approval action, should EPA 
finalize this partial conditional approval as proposed.\2\ EPA is 
proposing to conditionally approve the sections of the Haze Plan 
addressing the requirements of 40 CFR 51.308(f)(2), (f)(3), and (i)(2) 
through(4). These elements are fully separable from the elements 
proposed for partial approval. If North Carolina meets its commitment 
to submit the required SIP revision that adequately addresses the 
identified concerns related to the enforceability of certain permit 
conditions by the specified deadline and EPA approves the submission, 
then the conditional approval will be converted to a full approval. See 
Section IV.C.3.b of this document for a discussion of the 
enforceability concerns resulting in the proposed partial conditional 
approval and the commitments in North Carolina's Commitment Letter.
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    \2\ The Commitment Letter is in the docket for this proposed 
rulemaking.
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II. Background and Requirements for Regional Haze Plans

A. Regional Haze Background

    In the 1977 CAA Amendments, Congress created a program for 
protecting visibility in the nation's mandatory Class I Federal areas, 
which include certain national parks and wilderness areas.\3\ CAA 169A. 
The CAA establishes as a national goal the ``prevention of any future, 
and the remedying of any existing, impairment of visibility in 
mandatory class I Federal areas which impairment results from manmade 
air pollution.'' CAA 169A(a)(1). The CAA further directs EPA to 
promulgate regulations to assure reasonable progress toward meeting 
this national goal. CAA 169A(a)(4). On December 2, 1980, EPA 
promulgated regulations to address visibility impairment in mandatory 
Class I Federal areas (hereinafter referred to as ``Class I areas'') 
that is ``reasonably attributable'' to a single source or small group 
of sources. See 45 FR 80084 (December 2, 1980). These regulations, 
codified at 40 CFR 51.300 through 51.307, represented the first phase 
of EPA's efforts to address visibility impairment. In 1990, Congress 
added section 169B to the CAA to further address visibility impairment, 
specifically, impairment from regional haze. CAA 169B. EPA promulgated 
the RHR, codified at 40 CFR 51.308,\4\ on July 1, 1999. 64 FR 35714 
(July 1, 1999). These regional haze regulations are a central component 
of EPA's comprehensive visibility protection program for Class I areas.
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    \3\ Areas statutorily designated as mandatory Class I Federal 
areas consist of national parks exceeding 6,000 acres, wilderness 
areas and national memorial parks exceeding 5,000 acres, and all 
international parks that were in existence on August 7, 1977. CAA 
162(a). There are 156 mandatory Class I areas. The list of areas to 
which the requirements of the visibility protection program apply is 
in 40 CFR part 81, subpart D.
    \4\ In addition to the generally applicable regional haze 
provisions at 40 CFR 51.308, EPA also promulgated regulations 
specific to addressing regional haze visibility impairment in Class 
I areas on the Colorado Plateau at 40 CFR 51.309. The latter 
regulations are applicable only for specific jurisdictions' regional 
haze plans submitted no later than December 17, 2007, and thus, are 
not relevant here.
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    Regional haze is visibility impairment that is produced by a 
multitude of anthropogenic sources and activities which are located 
across a broad geographic area and that emit pollutants that impair 
visibility. Visibility impairing pollutants include fine and coarse 
particulate matter (PM) (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, volatile organic compounds (VOC) and ammonia 
(NH3)). Precursor pollutants react in the atmosphere to form 
fine particulate matter (particles less than or equal to 2.5 
micrometers ([micro]m) in diameter, PM2.5), which impairs 
visibility by scattering and absorbing light. Visibility impairment 
reduces the perception of clarity and color, as well as visible 
distance.\5\
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    \5\ There are several ways to measure the amount of visibility 
impairment, i.e., haze. One such measurement is the deciview, which 
is the principal metric defined and used by the RHR. Under many 
circumstances, a change in one deciview will be perceived by the 
human eye to be the same on both clear and hazy days. The deciview 
is unitless. It is proportional to the logarithm of the atmospheric 
extinction of light, which is the perceived dimming of light due to 
its being scattered and absorbed as it passes through the 
atmosphere. Atmospheric light extinction (b\ext\) is a metric used 
for expressing visibility and is measured in inverse megameters 
(Mm-1). EPA's ``Guidance on Regional Haze State 
Implementation Plans for the Second Implementation Period'' (``2019 
Guidance'') offers the flexibility for the use of light extinction 
in certain cases. Light extinction can be simpler to use in 
calculations than deciviews since it is not a logarithmic function. 
See, e.g., 2019 Guidance at 16, 19, https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period, EPA Office of Air Quality Planning and 
Standards, Research Triangle Park (August 20, 2019). The formula for 
the deciview is 10 ln (b\ext\)/10 Mm-1). See 40 CFR 
51.301.

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[[Page 67343]]

    To address regional haze visibility impairment, the 1999 RHR 
established an iterative planning process that requires both states in 
which Class I areas are located and states ``the emissions from which 
may reasonably be anticipated to cause or contribute to any impairment 
of visibility'' in a Class I area to periodically submit SIP revisions 
to address such impairment. CAA 169A(b)(2); \6\ see also 40 CFR 
51.308(b), (f) (establishing submission dates for iterative regional 
haze SIP revisions); 64 FR at 35768. Under the CAA, each SIP submission 
must contain ``a long-term (ten to fifteen years) strategy for making 
reasonable progress toward meeting the national goal,'' CAA 
169A(b)(2)(B); the initial round of SIP submissions also had to address 
the statutory requirement that certain older, larger sources of 
visibility impairing pollutants install and operate the best available 
retrofit technology (BART). CAA 169A(b)(2)(A); 40 CFR 51.308(d), (e). 
States' first regional haze SIPs were due by December 17, 2007, 40 CFR 
51.308(b), with subsequent SIP submissions containing updated long-term 
strategies (LTSs) originally due July 31, 2018, and every ten years 
thereafter. 64 FR at 35768. EPA established in the 1999 RHR that all 
states either have Class I areas within their borders or ``contain 
sources whose emissions are reasonably anticipated to contribute to 
regional haze in a Class I area''; therefore, all states must submit 
regional haze SIPs.\7\ Id. at 35721.
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    \6\ The RHR expresses the statutory requirement for states to 
submit plans addressing out-of-state Class I areas by providing that 
states must address visibility impairment ``in each mandatory Class 
I Federal area located outside the State that may be affected by 
emissions from within the State.'' See 40 CFR 51.308(d), (f).
    \7\ In addition to each of the 50 states, EPA also concluded 
that the Virgin Islands and District of Columbia must also submit 
regional haze SIPs because they either contain a Class I area or 
contain sources whose emissions are reasonably anticipated to 
contribute regional haze in a Class I area. See 40 CFR 51.300(b), 
(d)(3).
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    Much of the focus in the first planning period of the regional haze 
program, which ran from 2007 through 2018, was on satisfying states' 
BART obligations. First planning period SIPs were additionally required 
to contain LTSs for making reasonable progress toward the national 
visibility goal, of which BART is one component. The core required 
elements for the first planning period SIPs (other than BART) are laid 
out in 40 CFR 51.308(d). Those provisions require that states 
containing Class I areas establish ``reasonable progress goals'' 
(``RPGs'') that are measured in deciviews and reflect the anticipated 
visibility conditions at the end of the planning period including from 
implementation of states' LTSs. The first planning period RPGs were 
required to provide for an improvement in visibility for the most 
impaired days over the period of the implementation plan and ensure no 
degradation in visibility for the least impaired days over the same 
period. In establishing the RPGs for any Class I area in a state, the 
state was required to consider four statutory factors (also referenced 
herein as ``the four factors''): the costs of compliance, the time 
necessary for compliance, the energy and non-air quality environmental 
impacts of compliance, and the remaining useful life of any potentially 
affected sources. See CAA 169A(g)(1); 40 CFR 51.308(d)(1).
    States were also required to calculate baseline (using the five 
year period of 2000-2004) and natural visibility conditions (i.e., 
visibility conditions without anthropogenic visibility impairment) for 
each Class I area, and to calculate the linear rate of progress needed 
to attain natural visibility conditions, assuming a starting point of 
baseline visibility conditions in 2004 and ending with natural 
conditions in 2064. This linear interpolation is known as the uniform 
rate of progress (URP) and is used as a tracking metric to help states 
assess the amount of progress they are making toward the national 
visibility goal over time in each Class I area.\8\ 40 CFR 
51.308(d)(1)(i)(B), and (d)(2). The 1999 RHR also provided that states' 
LTSs must include the ``enforceable emissions limitations, compliance, 
schedules, and other measures as necessary to achieve the reasonable 
progress goals.'' See 40 CFR 51.308(d)(3). In establishing their LTSs, 
states are required to consult with other states that also contribute 
to visibility impairment in a given Class I area and include all 
measures necessary to obtain their shares of the emission reductions 
needed to meet the RPGs. See 40 CFR 51.308(d)(3)(i) and (ii). Section 
51.308(d) also contains seven additional factors states must consider 
in formulating their LTSs, 40 CFR 51.308(d)(3)(v), as well as 
provisions governing monitoring and other implementation plan 
requirements. See 40 CFR 51.308(d)(4). Finally, the 1999 RHR required 
states to submit periodic progress reports--SIP revisions due every 
five years that contain information on states' implementation of their 
regional haze plans and an assessment of whether anything additional is 
needed to make reasonable progress, see 40 CFR 51.308(g) and (h), and 
to consult with the Federal Land Manager(s) \9\ (FLMs) responsible for 
each Class I area according to the requirements in CAA 169A(d) and 40 
CFR 51.308(i).
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    \8\ EPA established the URP framework in the 1999 RHR to provide 
``an equitable analytical approach'' to assess the rate of 
visibility improvement at Class I areas across the country. The 
start point for the URP analysis is 2004 and the endpoint was 
calculated based on the amount of visibility improvement that was 
anticipated to result from implementation of existing CAA programs 
over the period from the mid-1990s to approximately 2005. Assuming 
this rate of progress would continue into the future, EPA determined 
that natural visibility conditions would be reached in 60 years, or 
2064 (60 years from the baseline starting point of 2004). However, 
EPA did not establish 2064 as the year by which the national goal 
must be reached. See 64 FR at 35731-32. That is, the URP and the 
2064 date are not enforceable targets, but are rather tools that 
``allow for analytical comparisons between the rate of progress that 
would be achieved by the state's chosen set of control measures and 
the URP.'' See 82 FR 3078, 3084 (January 10, 2017).
    \9\ EPA's regulations define ``Federal Land Manager'' as ``the 
Secretary of the department with authority over the Federal Class I 
area (or the Secretary's designee) or, with respect to Roosevelt-
Campobello International Park, the Chairman of the Roosevelt-
Campobello International Park Commission.'' See 40 CFR 51.301.
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    On January 10, 2017, EPA promulgated revisions to the RHR (82 FR 
3078) that apply for the second and subsequent planning periods. The 
2017 rulemaking made several changes to the requirements for regional 
haze SIPs to clarify states' obligations and streamline certain 
regional haze requirements. The revisions to the regional haze program 
for the second and subsequent planning periods focused on the 
requirement that states' SIPs contain LTSs for making reasonable 
progress toward the national visibility goal. The reasonable progress 
requirements as revised in the 2017 rulemaking (referred to here as the 
2017 RHR Revisions) are codified at 40 CFR 51.308(f). Among other 
changes, the 2017 RHR Revisions adjusted the deadline for states to 
submit their second planning period SIPs from July 31, 2018, to July 
31, 2021, clarified the order of analysis and the relationship between 
RPGs and the LTSs, and focused on making visibility improvements on the 
days with the most anthropogenic visibility impairment, as opposed to 
the days with the most visibility impairment overall. EPA also revised 
requirements of the visibility protection program related to periodic 
progress reports and FLM consultation. The specific requirements 
applicable to second planning period regional haze SIP submissions are 
addressed in detail below.
    EPA provided guidance to the states for their second planning 
period SIP submissions in the preamble to the 2017

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RHR Revisions as well as in subsequent stand-alone guidance documents. 
In August 2019, EPA issued its 2019 Guidance.\10\ On July 8, 2021, EPA 
issued a memorandum containing ``Clarifications Regarding Regional Haze 
State Implementation Plans for the Second Implementation Period'' 
(``2021 Clarifications Memo'').\11\ Additionally, EPA had clarified the 
recommended procedures for processing ambient visibility data and 
optionally adjusting the URP to account for international anthropogenic 
and prescribed fire impacts in two technical guidance documents: the 
December 2018 ``Technical Guidance on Tracking Visibility Progress for 
the Second Implementation Period of the Regional Haze Program'' (``2018 
Visibility Tracking Guidance''),\12\ and the June 2020 ``Recommendation 
for the Use of Patched and Substituted Data and Clarification of Data 
Completeness for Tracking Visibility Progress for the Second 
Implementation Period of the Regional Haze Program'' and associated 
Technical Addendum (``2020 Data Completeness Memo'').\13\
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    \10\ See footnote 5.
    \11\ ``Clarifications Regarding Regional Haze State 
Implementation Plans for the Second Implementation Period.'' https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf. EPA Office of Air Quality Planning and 
Standards, Research Triangle Park (July 8, 2021).
    \12\ ``Technical Guidance on Tracking Visibility Progress for 
the Second Implementation Period of the Regional Haze Program.'' EPA 
Office of Air Quality Planning and Standards, Research Triangle Park 
(December 20, 2018). https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional.
    \13\ ``Recommendation for the Use of Patched and Substituted 
Data and Clarification of Data Completeness for Tracking Visibility 
Progress for the Second Implementation Period of the Regional Haze 
Program.'' https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program. 
EPA Office of Air Quality Planning and Standards, Research Triangle 
Park (June 3, 2020).
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    As previously explained in the 2021 Clarifications Memo, EPA 
intends the second planning period of the regional haze program to 
secure meaningful reductions in visibility impairing pollutants that 
build on the significant progress states have achieved to date. The 
Agency also recognizes that analyses regarding reasonable progress are 
state-specific and that, based on states' and sources' individual 
circumstances, what constitutes reasonable reductions in visibility 
impairing pollutants will vary from state to state. While there exist 
many opportunities for states to leverage both ongoing and upcoming 
emission reductions under other CAA programs, the Agency expects states 
to undertake rigorous reasonable progress analyses that identify 
further opportunities to advance the national visibility goal 
consistent with the statutory and regulatory requirements. See, 
generally, 2021 Clarifications Memo. This is consistent with Congress's 
determination that a visibility protection program is needed in 
addition to the CAA's National Ambient Air Quality Standards (NAAQS) 
and Prevention of Significant Deterioration (PSD) programs, as further 
emission reductions may be necessary to adequately protect visibility 
in Class I areas throughout the country.\14\
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    \14\ See, e.g., H.R. Rep No. 95-294 at 205 (``In determining how 
to best remedy the growing visibility problem in these areas of 
great scenic importance, the committee realizes that as a matter of 
equity, the national ambient air quality standards cannot be revised 
to adequately protect visibility in all areas of the country.''), 
(``the mandatory class I increments of [the PSD program] do not 
adequately protect visibility in class I areas'').
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B. Roles of Agencies in Addressing Regional Haze

    Because the air pollutants affecting visibility in Class I areas 
can be transported over long distances, successful implementation of 
the regional haze program requires long-term, regional coordination 
among multiple jurisdictions and agencies that have responsibility for 
Class I areas and the emissions that impact visibility in those areas. 
In order to address regional haze, states need to develop strategies in 
coordination with one another, considering the effect of emissions from 
one jurisdiction on the air quality in another. Five regional planning 
organizations (RPOs),\15\ which include representation from state and 
Tribal governments, EPA, and FLMs, were developed in the lead-up to the 
first planning period to address regional haze. RPOs evaluate technical 
information to better understand how emissions from state and Tribal 
land impact Class I areas across the country, pursue the development of 
regional strategies to reduce emissions of PM and other pollutants 
leading to regional haze, and help states meet the consultation 
requirements of the RHR.
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    \15\ RPOs are sometimes also referred to as ``multi-
jurisdictional organizations,'' or MJOs. For the purposes of this 
notice, the terms RPO and MJO are synonymous.
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    The Southeastern States Air Resource Managers, Inc. (SESARM), one 
of the five RPOs described above, is a collaborative effort of state 
and local agencies and Tribal governments established to initiate and 
coordinate activities associated with the management of regional haze, 
visibility, and other air quality issues in the Southeast. SESARM's 
coalition to conduct regional haze work is referred to as Visibility 
Improvement State and Tribal Association of the Southeast (VISTAS).\16\ 
The member states, local air agencies, and Tribal governments of VISTAS 
are Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, 
South Carolina, Tennessee, Virginia, and West Virginia; the local air 
agencies, represented by the President of Metro 4 or designee; \17\ and 
the Tribes located within the VISTAS region, represented by the Eastern 
Band of the Cherokee Indians. The Federal partner members of VISTAS are 
EPA, U.S. National Park Service (NPS), U.S. Fish and Wildlife Service 
(FWS), and U.S. Forest Service (USFS).\18\
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    \16\ The VISTAS technical work under SESARM is described at this 
website: https://www.metro4-sesarm.org/content/vistas-regional-haze-program.
    \17\ Metro 4 is a Tennessee corporation which represents the 
local air pollution control agencies in EPA's Region 4 in the 
Southeast. See https://www.metro4-sesarm.org/content/metro-4-about-us.
    \18\ The NPS, FWS, and USFS are collectively referred to as the 
``Federal Land Managers'' or ``FLMs'' throughout this document.
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III. Requirements for Regional Haze Plans for the Second Planning 
Period

    Under the CAA and EPA's regulations, all 50 states, the District of 
Columbia, and the U.S. Virgin Islands are required to submit regional 
haze SIPs satisfying the applicable requirements for the second 
planning period of the regional haze program by July 31, 2021. Each 
state's SIP must contain a LTS for making reasonable progress toward 
meeting the national goal of remedying any existing and preventing any 
future anthropogenic visibility impairment in Class I areas. CAA 
169A(b)(2)(B). To this end, 40 CFR 51.308(f) lays out the process by 
which states determine what constitutes their LTSs, with the order of 
the requirements in 40 CFR 51.308(f)(1) through (f)(3) generally 
mirroring the order of the steps in the reasonable progress analysis 
\19\ and (f)(4) through (f)(6) containing additional related 
requirements.
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    \19\ EPA explained in the 2017 RHR Revisions that the Agency was 
adopting new regulatory language in 40 CFR 51.308(f) that, unlike 
the structure in 51.308(d), ``tracked the actual planning 
sequence.'' 82 FR 3091 (January 10, 2017).
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    Broadly speaking, a state first must identify the Class I areas 
within the state and determine the Class I areas outside the state in 
which visibility may be affected by emissions from the state. These are 
the Class I areas that must be addressed in the state's LTS. See 40 CFR 
51.308(f), (f)(2). For each Class I area within its borders, a state 
must then

[[Page 67345]]

calculate the baseline, current, and natural visibility conditions for 
that area, as well as the visibility improvement made to date and the 
URP. See 40 CFR 51.308(f)(1). Each state having a Class I area and/or 
emissions that may affect visibility in a Class I area must then 
develop a LTS that includes the enforceable emission limitations, 
compliance schedules, and other measures that are necessary to make 
reasonable progress in such areas. A reasonable progress determination 
is based on applying the four factors in CAA section 169A(g)(1) to 
sources of visibility impairing pollutants that the state has selected 
to assess for controls for the second planning period.
    Additionally, as further explained below, the RHR at 40 CFR 
51.3108(f)(2)(iv) separately provides five ``additional factors'' \20\ 
that states must consider in developing their long-term strategies. See 
40 CFR 51.308(f)(2). A state evaluates potential emission reduction 
measures for those selected sources and determines which are necessary 
to make reasonable progress. Those measures are then incorporated into 
the state's LTS. After a state has developed its LTS, it then 
establishes RPGs for each Class I area within its borders by modeling 
the visibility impacts of all reasonable progress controls at the end 
of the second planning period, i.e., in 2028, as well as the impacts of 
other requirements of the CAA. The RPGs include reasonable progress 
controls not only for sources in the state in which the Class I area is 
located, but also for sources in other states that contribute to 
visibility impairment in that area. The RPGs are then compared to the 
baseline visibility conditions and the URP to ensure that progress is 
being made toward the statutory goal of preventing any future and 
remedying any existing anthropogenic visibility impairment in Class I 
areas. See 40 CFR 51.308(f)(2) and (3).
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    \20\ The five ``additional factors'' for consideration in 
section 51.308(f)(2)(iv) are distinct from the four factors listed 
in CAA section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that states 
must consider and apply to sources in determining reasonable 
progress.
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    In addition to satisfying the requirements at 40 CFR 51.308(f) 
related to reasonable progress, the regional haze SIP revisions for the 
second planning period must address the requirements in 40 CFR 
51.308(g)(1) through (5) pertaining to periodic reports describing 
progress toward the RPGs, 40 CFR 51.308(f)(5), as well as requirements 
for FLM consultation that apply to all visibility protection SIPs and 
SIP revisions. See 40 CFR 51.308(i).
    A state must submit its regional haze SIP and subsequent SIP 
revisions to EPA according to the requirements applicable to all SIP 
revisions under the CAA and EPA's regulations. See CAA 169A(b)(2); CAA 
110(a). Upon EPA approval, a SIP is enforceable by the Agency and the 
public under the CAA. If EPA finds that a state fails to make a 
required SIP revision, or if EPA finds that a state's SIP is incomplete 
or disapproves the SIP, the Agency must promulgate a federal 
implementation plan (FIP) that satisfies the applicable requirements. 
See CAA 110(c)(1).

A. Identification of Class I Areas

    The first step in developing a regional haze SIP is for a state to 
determine which Class I areas, in addition to those within its borders, 
``may be affected'' by emissions from within the state. In the 1999 
RHR, EPA determined that all states contribute to visibility impairment 
in at least one Class I area, 64 FR at 35720-22, and explained that the 
statute and regulations lay out an ``extremely low triggering 
threshold'' for determining ``whether States should be required to 
engage in air quality planning and analysis as a prerequisite to 
determining the need for control of emissions from sources within their 
State.'' Id. at 35721.
    A state must determine which Class I areas must be addressed by its 
SIP by evaluating the total emissions of visibility impairing 
pollutants from all sources within the state. While the RHR does not 
require this evaluation to be conducted in any particular manner, EPA's 
2019 Guidance provides recommendations for how such an assessment might 
be accomplished, including, where appropriate, using the determinations 
previously made for the first planning period. 2019 Guidance at 8-9. In 
addition, the determination of which Class I areas may be affected by a 
state's emissions is subject to the requirement in 40 CFR 
51.308(f)(2)(iii) to ``document the technical basis, including 
modeling, monitoring, cost, engineering, and emissions information, on 
which the State is relying to determine the emission reduction measures 
that are necessary to make reasonable progress in each mandatory Class 
I Federal area it affects.''

B. Calculations of Baseline, Current, and Natural Visibility 
Conditions; Progress to Date; and the Uniform Rate of Progress (URP)

    As part of assessing whether a SIP submission for the second 
planning period is providing for reasonable progress toward the 
national visibility goal, the RHR contains requirements in 40 CFR 
51.308(f)(1) related to tracking visibility improvement over time. The 
requirements of this subsection apply only to states having Class I 
areas within their borders; the required calculations must be made for 
each such Class I area. EPA's 2018 Visibility Tracking Guidance \21\ 
provides recommendations to assist states in satisfying their 
obligations under 40 CFR 51.308(f)(1); specifically, in developing 
information on baseline, current, and natural visibility conditions, 
and in making optional adjustments to the URP to account for the 
impacts of international anthropogenic emissions and prescribed fires. 
See 82 FR at 3103-05.
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    \21\ The 2018 Visibility Tracking Guidance references and relies 
on parts of the 2003 Tracking Guidance: ``Guidance for Tracking 
Progress Under the Regional Haze Rule'' which can be found at 
https://www.epa.gov/sites/default/files/2021-03/documents/tracking.pdf. EPA Office of Air Quality Planning and Standards, 
Research Triangle Park (September 2003).
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    The RHR requires tracking of visibility conditions on two sets of 
days: the clearest and the most impaired days. Visibility conditions 
for both sets of days are expressed as the average deciview index for 
the relevant five-year period (the period representing baseline or 
current visibility conditions).\22\ The RHR provides that the relevant 
sets of days for visibility tracking purposes are the 20 percent 
clearest days (the 20 percent of monitored days in a calendar year with 
the lowest values of the deciview index) and 20 percent most impaired 
days (the 20 percent of monitored days in a calendar year with the 
highest amounts of anthropogenic visibility impairment).\23\ See 40 CFR 
51.301. A state must calculate visibility conditions for both the 20 
percent clearest days and 20 percent most impaired days for the 
baseline period of 2000-2004 and the most recent five-year period for 
which visibility monitoring data are available (representing current 
visibility conditions). See 40 CFR 51.308(f)(1)(i), (iii). States must 
also calculate natural visibility conditions for the clearest days and 
most impaired days \24\ by estimating the conditions that

[[Page 67346]]

would exist on those two sets of days absent anthropogenic visibility 
impairment. See 40 CFR 51.308(f)(1)(ii). Using all these data, states 
must then calculate, for each Class I area, the amount of progress made 
since the baseline period (2000-2004) and how much improvement is left 
to achieve in order to reach natural visibility conditions.
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    \22\ The ``deciview index'' means a value for a day that is 
derived from calculated or measured light extinction, such that 
uniform increments of the index correspond to uniform incremental 
changes in perception across the entire range of conditions, from 
pristine to very obscured. The deciview index is calculated using 
Interagency Monitoring of Protected Visual Environments (IMPROVE) 
aerosol measurements. See 40 CFR 51.301.
    \23\ This notice also refers to the 20 percent clearest and 20 
percent most anthropogenically impaired days as the ``clearest'' and 
``most impaired'' or ``most anthropogenically impaired'' days, 
respectively.
    \24\ The RHR at 40 CFR 51.308(f)(1)(ii) contains an error 
related to the requirement for calculating two sets of natural 
conditions values. The rule says ``most impaired days or the 
clearest days'' where it should say ``most impaired days and 
clearest days.'' This is an error that was intended to be corrected 
in the 2017 RHR Revisions but did not get corrected in the final 
rule language. This is supported by the preamble text at 82 FR 3098: 
``In the final version of 40 CFR 51.308(f)(1)(ii), an occurrence of 
`or' has been corrected to `and' to indicate that natural visibility 
conditions for both the most impaired days and the clearest days 
must be based on available monitoring information.''
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    Using the data for the set of most impaired days only, states must 
plot a line between visibility conditions in the baseline period and 
natural visibility conditions for each Class I area to determine the 
URP--the amount of visibility improvement, measured in deciviews, that 
would need to be achieved during each planning period in order to 
achieve natural visibility conditions by the end of 2064. The URP is 
used in later steps of the reasonable progress analysis for 
informational purposes and to provide a non-enforceable benchmark 
against which to assess a Class I area's rate of visibility 
improvement.\25\ Additionally, in the 2017 RHR Revisions, EPA provided 
states the option of proposing to adjust the endpoint of the URP to 
account for impacts of anthropogenic sources outside the United States 
and/or impacts of certain types of wildland prescribed fires. These 
adjustments, which must be approved by EPA, are intended to avoid any 
perception that states should compensate for impacts from international 
anthropogenic sources and to give states the flexibility to determine 
that limiting the use of wildland prescribed fire is not necessary for 
reasonable progress. See 82 FR 3107, footnote 116.
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    \25\ Being on or below the URP is not a ``safe harbor''; i.e., 
achieving the URP does not mean that a Class I area is making 
``reasonable progress'' and does not relieve a state from using the 
four statutory factors to determine what level of control is needed 
to achieve such progress. See, e.g., 82 FR at 3093.
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    EPA's 2018 Visibility Tracking Guidance can be used to help satisfy 
the 40 CFR 51.308(f)(1) requirements, including in developing 
information on baseline, current, and natural visibility conditions, 
and in making optional adjustments to the URP. In addition, the 2020 
Data Completeness Memo provides recommendations on the data 
completeness language referenced in 40 CFR 51.308(f)(1)(i) and provides 
updated natural conditions estimates for each Class I area.

C. Long-Term Strategy (LTS) for Regional Haze

    The core component of a regional haze SIP submission is a LTS that 
addresses regional haze in each Class I area within a state's borders 
and each Class I area that may be affected by emissions from the state. 
The LTS ``must include the enforceable emissions limitations, 
compliance schedules, and other measures that are necessary to make 
reasonable progress, as determined pursuant to (f)(2)(i) through 
(iv).'' See 40 CFR 51.308(f)(2). The amount of progress that is 
``reasonable progress'' is based on applying the four statutory factors 
in CAA section 169A(g)(1) in an evaluation of potential control options 
for sources of visibility impairing pollutants, which is referred to as 
a ``four-factor'' analysis (FFA). The outcome of that analysis is the 
emission reduction measures that a particular source or group of 
sources needs to implement in order to make reasonable progress toward 
the national visibility goal. See 40 CFR 51.308(f)(2)(i). Emission 
reduction measures that are necessary to make reasonable progress may 
be either new, additional control measures for a source or the existing 
emission reduction measures that a source is already implementing. See 
2019 Guidance at 43; 2021 Clarifications Memo at 8-10. Such measures 
must be represented by ``enforceable emissions limitations, compliance 
schedules, and other measures'' in a state's LTS in its SIP. See 40 CFR 
51.308(f)(2).
    Section 51.308(f)(2)(i) provides the requirements for the FFA. The 
first step of this analysis entails selecting the sources to be 
evaluated for emission reduction measures; to this end, the RHR 
requires states to consider ``major and minor stationary sources or 
groups of sources, mobile sources, and area sources'' of visibility 
impairing pollutants for potential control analysis (i.e., FFA). See 40 
CFR 51.308(f)(2)(i). A threshold question at this step is which 
visibility impairing pollutants will be analyzed. As EPA previously 
explained, consistent with the first planning period, EPA generally 
expects that each state will analyze at least SO2 and 
NOX in selecting sources and determining control measures. 
See 2019 Guidance at 12 and 2021 Clarifications Memo at 4. A state that 
chooses not to consider at least these two pollutants should 
demonstrate why such consideration would be unreasonable. 2021 
Clarifications Memo at 4.
    While states have the option to analyze all sources, the 2019 
Guidance explains that ``an analysis of control measures is not 
required for every source in each implementation period,'' and that 
``[s]electing a set of sources for analysis of control measures in each 
implementation period is consistent with the Regional Haze Rule, which 
sets up an iterative planning process and anticipates that a state may 
not need to analyze control measures for all its sources in a given SIP 
revision.'' 2019 Guidance at 9. However, given that source selection is 
the basis of all subsequent control determinations, a reasonable source 
selection process ``should be designed and conducted to ensure that 
source selection results in a set of pollutants and sources the 
evaluation of which has the potential to meaningfully reduce their 
contributions to visibility impairment.'' See 2021 Clarifications Memo 
at 3.
    EPA explained in the 2021 Clarifications Memo that each state has 
an obligation to submit a LTS that addresses the regional haze 
visibility impairment that results from emissions from within that 
state. Thus, source selection should focus on the in-state contribution 
to visibility impairment and be designed to capture a meaningful 
portion of the state's total contribution to visibility impairment in 
Class I areas. A state should not decline to select its largest in-
state sources on the basis that there are even larger out-of-state 
contributors. See 2021 Clarifications Memo at 4.\26\
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    \26\ Similarly, in responding to comments on the 2017 RHR 
Revisions, EPA explained that ``[a] state should not fail to address 
its many relatively low-impact sources merely because it only has 
such sources and another state has even more low-impact sources and/
or some high impact sources.'' Responses to Comments on Protection 
of Visibility: Amendments to Requirements for State Plans; Proposed 
Rule (81 FR 26942, May 4, 2016) (December 2016), Docket Number EPA-
HQ-OAR-2015-0531, U.S. Environmental Protection Agency at 87-88, 
available at www.regulations.gov.
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    Thus, while states have discretion to choose any source selection 
methodology that is reasonable, whatever choices they make should be 
reasonably explained. To this end, 40 CFR 51.308(f)(2)(i) requires that 
a state's SIP submission include ``a description of the criteria it 
used to determine which sources or groups of sources it evaluated.'' 
The technical basis for source selection, which may include methods for 
quantifying potential visibility impacts such as emissions divided by 
distance metrics, trajectory analyses, residence time analyses, and/or 
photochemical modeling, must also be appropriately documented, as 
required by 40 CFR 51.308(f)(2)(iii).

[[Page 67347]]

    Once a state has selected the set of sources, the next step is to 
determine the emissions reduction measures for those sources that are 
necessary to make reasonable progress for the second planning 
period.\27\ This is accomplished by considering the four factors--``the 
costs of compliance, the time necessary for compliance, and the energy 
and non-air quality environmental impacts of compliance, and the 
remaining useful life of any existing source subject to such 
requirements.'' See CAA 169A(g)(1). EPA has explained that the FFA is 
an assessment of potential emission reduction measures (i.e., control 
options) for sources; ``use of the terms `compliance' and `subject to 
such requirements' in section 169A(g)(1) strongly indicates that 
Congress intended the relevant determination to be the requirements 
with which sources would have to comply in order to satisfy the CAA's 
reasonable progress mandate.'' See 82 FR at 3091. Thus, for each source 
a state has selected for a FFA,\28\ it must consider a ``meaningful 
set'' of technically feasible control options for reducing emissions of 
visibility impairing pollutants. Id. at 3088. The 2019 Guidance 
provides that ``[a] state must reasonably pick and justify the measures 
that it will consider, recognizing that there is no statutory or 
regulatory requirement to consider all technically feasible measures or 
any particular measures. A range of technically feasible measures 
available to reduce emissions would be one way to justify a reasonable 
set.'' See 2019 Guidance at 29.
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    \27\ The CAA provides that ``[i]n determining reasonable 
progress there shall be taken into consideration'' the four 
statutory factors. See CAA 169A(g)(1). However, in addition to four-
factor analyses for selected sources, groups of sources, or source 
categories, a state may also consider additional emission reduction 
measures for inclusion in its long-term strategy, e.g., from other 
newly adopted, on-the-books, or on-the-way rules and measures for 
sources not selected for four-factor analysis for the second 
planning period.
    \28\ ``Each source'' or ``particular source'' is used here as 
shorthand. While a source-specific analysis is one way of applying 
the four factors, neither the statute nor the RHR requires states to 
evaluate individual sources. Rather, states have ``the flexibility 
to conduct four-factor analyses for specific sources, groups of 
sources or even entire source categories, depending on state policy 
preferences and the specific circumstances of each state.'' 82 FR at 
3088. However, not all approaches to grouping sources for four-
factor analysis are necessarily reasonable; the reasonableness of 
grouping sources in any particular instance will depend on the 
circumstances and the manner in which grouping is conducted. If it 
is feasible to establish and enforce different requirements for 
sources or subgroups of sources, and if relevant factors can be 
quantified for those sources or subgroups, then states should make a 
separate reasonable progress determination for each source or 
subgroup. See 2021 Clarifications Memo at 7-8.
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    EPA's 2021 Clarifications Memo provides further guidance on what 
constitutes a reasonable set of control options for consideration: ``A 
reasonable four-factor analysis will consider the full range of 
potentially reasonable options for reducing emissions.'' See 2021 
Clarifications Memo at 7. In addition to add-on controls and other 
retrofits (i.e., new emission reduction measures for sources), EPA 
explained that states should generally analyze efficiency improvements 
for sources' existing measures as control options in their FFAs, as in 
many cases such improvements are reasonable given that they typically 
involve only additional operation and maintenance costs. Additionally, 
the 2021 Clarifications Memo provides that states that have assumed a 
higher emission rate than a source has achieved or could potentially 
achieve using its existing measures should also consider lower emission 
rates as potential control options. That is, a state should consider a 
source's recent actual and projected emission rates to determine if it 
could reasonably attain lower emission rates with its existing 
measures. If so, the state should analyze the lower emission rate as a 
control option for reducing emissions. See 2021 Clarifications Memo at 
7. EPA's recommendations to analyze potential efficiency improvements 
and achievable lower emission rates apply to both sources that have 
been selected for FFA and those that have forgone a FFA on the basis of 
existing ``effective controls.'' See 2021 Clarifications Memo at 5, 10.
    After identifying a reasonable set of potential control options for 
the sources it has selected, a state then collects information on the 
four factors with regard to each option identified. EPA has also 
explained that, in addition to the four statutory factors, states have 
flexibility under the CAA and RHR to reasonably consider visibility 
benefits as an additional factor alongside the four statutory 
factors.\29\ The 2019 Guidance provides recommendations for the types 
of information that can be used to characterize the four factors (with 
or without visibility), as well as ways in which states might 
reasonably consider and balance that information to determine which of 
the potential control options is necessary to make reasonable progress. 
See 2019 Guidance at 30-36. The 2021 Clarifications Memo contains 
further guidance on how states can reasonably consider modeled 
visibility impacts or benefits in the context of a FFA. See 2021 
Clarifications Memo at 12-13, 14-15. Specifically, EPA explained that 
while visibility can reasonably be used when comparing and choosing 
between multiple reasonable control options, it should not be used to 
summarily reject controls that are reasonable given the four statutory 
factors. See 2021 Clarifications Memo at 13. Ultimately, while states 
have discretion to reasonably weigh the factors and to determine what 
level of control is needed, 40 CFR 51.308(f)(2)(i) provides that a 
state ``must include in its implementation plan a description of how 
the four factors were taken into consideration in selecting the measure 
for inclusion in its long-term strategy.''
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    \29\ See, e.g., Responses to Comments on Protection of 
Visibility: Amendments to Requirements for State Plans; Proposed 
Rule (81 FR 26942, May 4, 2016) (December 2016), Docket Number EPA-
HQ-OAR-2015-0531, U.S. Environmental Protection Agency at 186, 
available at www.regulations.gov; 2019 Guidance at 36-37.
---------------------------------------------------------------------------

    As explained above, 40 CFR 51.308(f)(2)(i) requires states to 
determine the emission reduction measures for sources that are 
necessary to make reasonable progress by considering the four factors. 
Pursuant to 40 CFR 51.308(f)(2), measures that are necessary to make 
reasonable progress toward the national visibility goal must be 
included in a state's LTS and in its SIP.\30\ If the outcome of a FFA 
is a new, additional emission reduction measure for a source, that new 
measure is necessary to make reasonable progress toward remedying 
existing anthropogenic visibility impairment and must be included in 
the SIP. If the outcome of a FFA is that no new measures are reasonable 
for a source, continued implementation of the source's existing 
measures is generally necessary to prevent future emission increases 
and thus to make reasonable progress toward the second part of the 
national visibility goal: preventing future anthropogenic visibility 
impairment. See CAA 169A(a)(1). That is, when the result of a FFA is 
that no new measures are necessary to make reasonable progress, the 
source's existing measures are generally necessary to make reasonable 
progress and must be included in the SIP. However, there may be 
circumstances in which a state can demonstrate that a source's existing 
measures are not

[[Page 67348]]

necessary to make reasonable progress. Specifically, if a state can 
demonstrate that a source will continue to implement its existing 
measures and will not increase its emission rate, it may not be 
necessary to have those measures in the LTS in order to prevent future 
emission increases and future visibility impairment. EPA's 2021 
Clarifications Memo provides further explanation and guidance on how 
states may demonstrate that a source's existing measures are not 
necessary to make reasonable progress. See 2021 Clarifications Memo at 
8-10. If the state can make such a demonstration, it need not include a 
source's existing measures in the LTS or its SIP.
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    \30\ States may choose to, but are not required to, include 
measures in their long-term strategies beyond just the emission 
reduction measures that are necessary for reasonable progress. See 
2021 Clarifications Memo at 16. For example, states with smoke 
management programs may choose to submit their smoke management 
plans to EPA for inclusion in their SIPs but are not required to do 
so. See, e.g., 82 FR at 3108-09 (requirement to consider smoke 
management practices and smoke management programs under 40 CFR 
51.308(f)(2)(iv) does not require states to adopt such practices or 
programs into their SIPs, although they may elect to do so).
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    As with source selection, the characterization of information on 
each of the factors is also subject to the documentation requirement in 
40 CFR 51.308(f)(2)(iii). The reasonable progress analysis, including 
source selection, information gathering, characterization of the four 
statutory factors (and potentially visibility), balancing of the four 
factors, and selection of the emission reduction measures that 
represent reasonable progress, is a technically complex exercise, but 
also a flexible one that provides states with bounded discretion to 
design and implement approaches appropriate to their circumstances. 
Given this flexibility, 40 CFR 51.308(f)(2)(iii) plays an important 
function in requiring a state to document the technical basis for its 
decision making so that the public and EPA can comprehend and evaluate 
the information and analysis the state relied upon to determine what 
emission reduction measures must be in place to make reasonable 
progress. The technical documentation must include the modeling, 
monitoring, cost, engineering, and emissions information on which the 
state relied to determine the measures necessary to make reasonable 
progress. This documentation requirement can be met through the 
provision of and reliance on technical analyses developed through a 
regional planning process, so long as that process and its output has 
been approved by all state participants. In addition to the explicit 
regulatory requirement to document the technical basis of their 
reasonable progress determinations, states are also subject to the 
general principle that those determinations must be reasonably moored 
to the statute.\31\ That is, a state's decisions about the emission 
reduction measures that are necessary to make reasonable progress must 
be consistent with the statutory goal of remedying existing and 
preventing future visibility impairment.
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    \31\ See Arizona ex rel. Darwin v. U.S. EPA, 815 F.3d 519, 531 
(9th Cir. 2016); Nebraska v. U.S. EPA, 812 F.3d 662, 668 (8th Cir. 
2016); North Dakota v. EPA, 730 F.3d 750, 761 (8th Cir. 2013); 
Oklahoma v. EPA, 723 F.3d 1201, 1206, 1208-10 (10th Cir. 2013); cf. 
also Nat'l Parks Conservation Ass'n v. EPA, 803 F.3d 151, 165 (3d 
Cir. 2015); Alaska Dep't of Envtl. Conservation v. EPA, 540 U.S. 
461, 485, 490 (2004).
---------------------------------------------------------------------------

    The four statutory factors (and potentially visibility) are used to 
determine what emission reduction measures for selected sources must be 
included in a state's LTS for making reasonable progress. Additionally, 
the RHR at 40 CFR 51.3108(f)(2)(iv) separately provides five 
``additional factors'' \32\ that states must consider in developing 
their LTSs: (1) Emission reductions due to ongoing air pollution 
control programs, including measures to address reasonably attributable 
visibility impairment; (2) measures to reduce the impacts of 
construction activities; (3) source retirement and replacement 
schedules; (4) basic smoke management practices for prescribed fire 
used for agricultural and wildland vegetation management purposes and 
smoke management programs; and (5) the anticipated net effect on 
visibility due to projected changes in point, area, and mobile source 
emissions over the period addressed by the LTS. The 2019 Guidance 
provides that a state may satisfy this requirement by considering these 
additional factors in the process of selecting sources for a FFA, when 
performing that analysis, or both, and that not every one of the 
additional factors needs to be considered at the same stage of the 
process. See 2019 Guidance at 21. EPA provided further guidance on the 
five additional factors in the 2021 Clarifications Memo, explaining 
that a state should generally not reject cost-effective and otherwise 
reasonable controls merely because there have been emission reductions 
since the first planning period owing to other ongoing air pollution 
control programs or merely because visibility is otherwise projected to 
improve at Class I areas. Additionally, states generally should not 
rely on these additional factors to summarily assert that the state has 
already made sufficient progress and, therefore, no sources need to be 
selected or no new controls are needed regardless of the outcome of 
FFAs. See 2021 Clarifications Memo at 13.
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    \32\ The five ``additional factors'' for consideration in 
section 51.308(f)(2)(iv) are distinct from the four factors listed 
in CAA section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that states 
must consider and apply to sources in determining reasonable 
progress.
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    Because the air pollution that causes regional haze crosses state 
boundaries, 40 CFR 51.308(f)(2)(ii) requires a state to consult with 
other states that also have emissions that are reasonably anticipated 
to contribute to visibility impairment in a given Class I area. 
Consultation allows for each state that impacts visibility in an area 
to share whatever technical information, analyses, and control 
determinations may be necessary to develop coordinated emission 
management strategies. This coordination may be managed through inter- 
and intra-RPO consultation and the development of regional emissions 
strategies; additional consultations between states outside of RPO 
processes may also occur. If a state, pursuant to consultation, agrees 
that certain measures (e.g., a certain emission limitation) are 
necessary to make reasonable progress at a Class I area, it must 
include those measures in its SIP. See 40 CFR 51.308(f)(2)(ii)(A). 
Additionally, the RHR requires that states that contribute to 
visibility impairment at the same Class I area consider the emission 
reduction measures the other contributing states have identified as 
being necessary to make reasonable progress for their own sources. See 
40 CFR 51.308(f)(2)(ii)(B). If a state has been asked to consider or 
adopt certain emission reduction measures, but ultimately determines 
those measures are not necessary to make reasonable progress, that 
state must document in its SIP the actions taken to resolve the 
disagreement. See 40 CFR 51.308(f)(2)(ii)(C). EPA will consider the 
technical information and explanations presented by the submitting 
state and the state with which it disagrees when considering whether to 
approve the state's SIP. See Id.; 2019 Guidance at 53. Under all 
circumstances, a state must document in its SIP submission all 
substantive consultations with other contributing states. See 40 CFR 
51.308(f)(2)(ii)(C).

D. Reasonable Progress Goals (RPGs)

    RPGs ``measure the progress that is projected to be achieved by the 
control measures states have determined are necessary to make 
reasonable progress based on a four-factor analysis.'' See 82 FR at 
3091. Their primary purpose is to assist the public and EPA in 
assessing the reasonableness of states' LTSs for making reasonable 
progress toward the national visibility goal. See 40 CFR 
51.308(f)(3)(iii) and (iv). States in which Class I areas are located 
must establish two RPGs--one representing visibility conditions on the 
clearest days and one representing visibility on the most 
anthropogenically impaired days--for each area within their borders. 40 
CFR 51.308(f)(3)(i). The two RPGs, measured in deciviews, are intended 
to reflect the projected impacts, on each set of days,

[[Page 67349]]

of the emission reduction measures the state with the Class I area and 
other contributing states have included in their LTSs for the second 
planning period.\33\ The RPGs also account for the projected impacts of 
implementing other CAA requirements, including non-SIP based 
requirements. Because RPGs are the modeled result of the measures in 
states' LTSs (as well as other measures required under the CAA), they 
cannot be determined before states have conducted their FFAs and 
determined the control measures that are necessary to make reasonable 
progress.\34\ See 2021 Clarifications Memo at 6.
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    \33\ RPGs are intended to reflect the projected impacts of the 
measures all contributing states include in their long-term 
strategies. However, due to the timing of analyses, control 
determinations by other states, and other on-going emissions 
changes, a particular state's RPGs may not reflect all control 
measures and emissions reductions that are expected to occur by the 
end of the implementation period. The 2019 Guidance provides 
recommendations for addressing the timing of RPG calculations when 
states are developing their long-term strategies on disparate 
schedules, as well as for adjusting RPGs using a post-modeling 
approach. See 2019 Guidance at 47-48.
    \34\ The 2019 Guidance allows for the possibility of post-
modeling adjustments to the RPGs to account for the fact that final 
LTS decisions for the state or for other states may not be known 
until late in the process, or even after SIPs are submitted. See 
2019 Guidance at 46-48. See also, 82 FR 3078, 3080 (January 10, 
2017).
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    For the second planning period, the RPGs are set for 2028. RPGs are 
not enforceable targets, 40 CFR 51.308(f)(3)(iii); rather, they 
``provide a way for the states to check the projected outcome of the 
[long-term strategy] against the goals for visibility improvement.'' 
See 2019 Guidance at 46. While states are not legally obligated to 
achieve the visibility conditions described in their RPGs, 40 CFR 
51.308(f)(3)(i) requires that ``[t]he long-term strategy and the 
reasonable progress goals must provide for an improvement in visibility 
for the most impaired days since the baseline period and ensure no 
degradation in visibility for the clearest days since the baseline 
period.'' Thus, states are required to have emission reduction measures 
in their LTSs that are projected to achieve visibility conditions on 
the most impaired days that are better than the baseline period and 
shows no degradation on the clearest days compared to the clearest days 
from the baseline period. The baseline period for the purpose of this 
comparison is the baseline visibility condition--the annual average 
visibility condition for the period 2000-2004. See 40 CFR 
51.308(f)(1)(i), 82 FR at 3097-98.
    So that RPGs may also serve as a metric for assessing the amount of 
progress a state is making toward the national visibility goal, the RHR 
requires states with Class I areas to compare the 2028 RPG for the most 
impaired days to the corresponding point on the URP line (representing 
visibility conditions in 2028 if visibility were to improve at a linear 
rate from conditions in the baseline period of 2000-2004 to natural 
visibility conditions in 2064). If the most impaired days RPG in 2028 
is above the URP (i.e., if visibility conditions are improving more 
slowly than the rate described by the URP), each state that contributes 
to visibility impairment in the Class I area must demonstrate, based on 
the FFA required under 40 CFR 51.308(f)(2)(i), that no additional 
emission reduction measures would be reasonable to include in its LTS. 
40 CFR 51.308(f)(3)(ii). To this end, 40 CFR 51.308(f)(3)(ii) requires 
that each state contributing to visibility impairment in a Class I area 
that is projected to improve more slowly than the URP provide ``a 
robust demonstration, including documenting the criteria used to 
determine which sources or groups [of] sources were evaluated and how 
the four factors required by paragraph (f)(2)(i) were taken into 
consideration in selecting the measures for inclusion in its long-term 
strategy.'' The 2019 Guidance provides suggestions about how such a 
``robust demonstration'' might be conducted. See 2019 Guidance at 50-
51.
    The 2017 RHR, 2019 Guidance, and 2021 Clarifications Memo also 
explain that projecting an RPG that is on or below the URP based on 
only on-the-books and/or on-the-way control measures (i.e., control 
measures already required or anticipated before the FFA is conducted) 
is not a ``safe harbor'' from the CAA's and RHR's requirement that all 
states must conduct a FFA to determine what emission reduction measures 
constitute reasonable progress.\35\ The URP is a planning metric used 
to gauge the amount of progress made thus far and the amount left 
before reaching natural visibility conditions. However, the URP is not 
based on consideration of the four statutory factors and therefore 
cannot answer the question of whether the amount of progress being made 
in any particular planning period is ``reasonable progress.'' See 82 FR 
at 3093, 3099-3100; 2019 Guidance at 22; 2021 Clarifications Memo at 
15-16.
---------------------------------------------------------------------------

    \35\ In lieu of conducting a FFA, states may elect to show the 
source has existing effective controls for the particular pollutants 
under evaluation or that the source is shutting down by the end of 
the planning period (or close to it).
---------------------------------------------------------------------------

E. Monitoring Strategy and Other State Implementation Plan Requirements

    Section 51.308(f)(6) requires states to have certain strategies and 
elements in place for assessing and reporting on visibility. Individual 
requirements under this subsection apply either to states with Class I 
areas within their borders, states with no Class I areas but that are 
reasonably anticipated to cause or contribute to visibility impairment 
in any Class I area, or both. A state with Class I areas within its 
borders must submit with its SIP revision a monitoring strategy for 
measuring, characterizing, and reporting regional haze visibility 
impairment that is representative of all Class I areas within the 
state. SIP revisions for such states must also provide for the 
establishment of any additional monitoring sites or equipment needed to 
assess visibility conditions in Class I areas, as well as reporting of 
all visibility monitoring data to EPA at least annually. Compliance 
with the monitoring strategy requirement may be met through a state's 
participation in the IMPROVE monitoring network, which is used to 
measure visibility impairment caused by air pollution at the 156 Class 
I areas covered by the visibility program. See 40 CFR 51.308(f)(6), 
(f)(6)(i), (f)(6)(iv). The IMPROVE monitoring data is used to determine 
the 20 percent most anthropogenically impaired and 20 percent clearest 
sets of days every year at each Class I area and tracks visibility 
impairment over time.
    All states' implementation plans must provide for procedures by 
which monitoring data and other information are used to determine the 
contribution of emissions from within the state to regional haze 
visibility impairment in affected Class I areas. 40 CFR 
51.308(f)(6)(ii), (iii). Section 51.308(f)(6)(v) further requires that 
all states' implementation plans provide for a statewide inventory of 
emissions of pollutants that are reasonably anticipated to cause or 
contribute to visibility impairment in any Class I area; the inventory 
must include emissions for the most recent year for which data are 
available and estimates of future projected emissions. States must also 
include commitments to update their inventories periodically. The 
inventories themselves do not need to be included as elements in the 
SIP and are not subject to EPA review as part of the Agency's 
evaluation of a SIP revision.\36\ All states' implementation plans must 
also provide for any other

[[Page 67350]]

elements, including reporting, recordkeeping, and other measures, that 
are necessary for states to assess and report on visibility. See 40 CFR 
51.308(f)(6)(vi). Per the 2019 Guidance, a state may note in its 
regional haze SIP that its compliance with the Air Emissions Reporting 
Rule (AERR) in 40 CFR part 51, subpart A satisfies the requirement to 
provide for an emissions inventory for the most recent year for which 
data are available. To satisfy the requirement to provide estimates of 
future projected emissions, a state may explain in its SIP how 
projected emissions were developed for use in establishing RPGs for its 
own and nearby Class I areas.\37\
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    \36\ See ``Step 8: Additional requirements for regional haze 
SIPs'' in 2019 Guidance at 55.
    \37\ Id.
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    Separate from the requirements related to monitoring for regional 
haze purposes under 40 CFR 51.308(f)(6), the RHR also contains a 
requirement at 40 CFR 51.308(f)(4) related to any additional monitoring 
that may be needed to address visibility impairment in Class I areas 
from a single source or a small group of sources. This is called 
``reasonably attributable visibility impairment.'' \38\ Under this 
provision, if EPA or the FLM of an affected Class I area has advised a 
state that additional monitoring is needed to assess reasonably 
attributable visibility impairment (RAVI), the state must include in 
its SIP revision for the second planning period an appropriate strategy 
for evaluating such impairment.
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    \38\ EPA's visibility protection regulations define ``reasonably 
attributable visibility impairment'' as ``visibility impairment that 
is caused by the emission of air pollutants from one, or a small 
number of sources.'' 40 CFR 51.301.
---------------------------------------------------------------------------

F. Requirements for Periodic Reports Describing Progress Toward the 
RPGs

    Section 51.308(f)(5) requires a state's regional haze SIP revision 
to address the requirements of paragraphs 40 CFR 51.308(g)(1) through 
(5) so that the plan revision due in 2021 will serve also as a progress 
report addressing the period since submission of the progress report 
for the first planning period. The regional haze progress report 
requirement is designed to inform the public and EPA about a state's 
implementation of its existing LTS and whether such implementation is 
in fact resulting in the expected visibility improvement. See 81 FR 
26942, 26950 (May 4, 2016), 82 FR 3119 (January 10, 2017). To this end, 
every state's implementation plan revision for the second planning 
period is required to describe the status of implementation of all 
measures included in the state's LTS, including BART and reasonable 
progress emission reduction measures from the first planning period, 
and the resulting emissions reductions. See 40 CFR 51.308(g)(1) and 
(2).
    A core component of the progress report requirements is an 
assessment of changes in visibility conditions on the clearest and most 
impaired days. For second planning period progress reports, 40 CFR 
51.308(g)(3) requires states with Class I areas within their borders to 
first determine current visibility conditions for each area on the most 
impaired and clearest days, 40 CFR 51.308(g)(3)(i), and then to 
calculate the difference between those current conditions and baseline 
(2000-2004) visibility conditions in order to assess progress made to 
date. See 40 CFR 51.308(g)(3)(ii). States must also assess the changes 
in visibility impairment for the most impaired and clearest days since 
they submitted their first planning period progress reports. See 40 CFR 
51.308 (f)(5) and (g)(3)(iii). Since different states submitted their 
first planning period progress reports at different times, the starting 
point for this assessment will vary state by state.
    Similarly, states must provide analyses tracking the change in 
emissions of pollutants contributing to visibility impairment from all 
sources and activities within the state over the period since they 
submitted their first planning period progress reports. See 40 CFR 
51.308 (f)(5) and (g)(4). Changes in emissions should be identified by 
the type of source or activity. Section 51.308(g)(5) also addresses 
changes in emissions since the period addressed by the previous 
progress report and requires states' implementation plan revisions to 
include an assessment of any significant changes in anthropogenic 
emissions within or outside the state. This assessment must include an 
explanation of whether these changes in emissions were anticipated and 
whether they have limited or impeded progress in reducing emissions and 
improving visibility relative to what the state projected based on its 
LTS for the first planning period.

G. Requirements for State and Federal Land Manager (FLM) Coordination

    CAA section 169A(d) requires that before a state holds a public 
hearing on a proposed regional haze SIP revision, it must consult with 
the appropriate FLM or FLMs; pursuant to that consultation, the state 
must include a summary of the FLMs' conclusions and recommendations in 
the notice to the public. Consistent with this statutory requirement, 
the RHR also requires that states ``provide the [FLM] with an 
opportunity for consultation, in person and at a point early enough in 
the State's policy analyses of its long-term strategy emission 
reduction obligation so that information and recommendations provided 
by the [FLM] can meaningfully inform the State's decisions on the long-
term strategy.'' See 40 CFR 51.308(i)(2). Consultation that occurs 120 
days prior to any public hearing or public comment opportunity will be 
deemed ``early enough,'' but the RHR provides that in any event the 
opportunity for consultation must be provided at least 60 days before a 
public hearing or comment opportunity. This consultation must include 
the opportunity for the FLMs to discuss their assessment of visibility 
impairment in any Class I area and their recommendations on the 
development and implementation of strategies to address such 
impairment. 40 CFR 51.308(i)(2). In order for EPA to evaluate whether 
FLM consultation meeting the requirements of the RHR has occurred, the 
SIP submission should include documentation of the timing and content 
of such consultation. The SIP revision submitted to EPA must also 
describe how the state addressed any comments provided by the FLMs. 40 
CFR 51.308(i)(3). Finally, a SIP revision must provide procedures for 
continuing consultation between the state and FLMs regarding the 
state's visibility protection program, including development and review 
of SIP revisions, five-year progress reports, and the implementation of 
other programs having the potential to contribute to impairment of 
visibility in Class I areas. See 40 CFR 51.308(i)(4).

IV. EPA's Evaluation of North Carolina's Regional Haze Submission for 
the Second Planning Period

    On April 4, 2022, DAQ submitted a revision to the North Carolina 
SIP to address the State's regional haze obligations for the second 
planning period, which runs through 2028, in accordance with CAA 
sections 169A and the RHR at 40 CFR 51.308(f).\39\ The following 
sections contain EPA's evaluation of North Carolina's Haze Plan with 
respect to the requirements of the CAA and RHR for the second

[[Page 67351]]

planning period of the regional haze program.
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    \39\ On June 27, 2012, EPA finalized a limited approval of North 
Carolina's first planning period regional haze plan submitted to EPA 
on December 17, 2007 (77 FR 38185). On June 7, 2012 (77 FR 33642), 
EPA finalized a limited disapproval of the December 17, 2007, 
submission. On May 24, 2016, EPA approved North Carolina's October 
31, 2014, BART alternative demonstration, which was a revision to 
its regional haze plan and converted the limited approval of the 
December 17, 2007, submission to a full approval (81 FR 32652). On 
August 25, 2016, EPA approved North Carolina's May 31, 2013, 
progress report for the first planning period (81 FR 58400).
---------------------------------------------------------------------------

    North Carolina has five Class I areas, two of which are shared with 
Tennessee: Linville Gorge National Wilderness Area (``Linville 
Gorge''); Shining Rock National Wilderness Area (``Shining Rock''); 
Swanquarter National Wilderness Area (``Swanquarter''); Great Smoky 
Mountains National Park (``Great Smoky Mountains'') (NC/TN); and Joyce 
Kilmer-Slickrock National Wilderness Area (``Joyce Kilmer'') (NC/TN). 
The following sections describe North Carolina's Haze Plan, including 
analyses conducted by VISTAS and North Carolina's determinations based 
on those analyses, North Carolina's assessment of progress made since 
the first planning period in reducing emissions of visibility impairing 
pollutants, and the visibility improvement progress at its Class I 
areas and nearby Class I areas. This document also contains EPA's 
evaluation of North Carolina's Haze Plan against the requirements of 
the CAA and RHR for the second planning period of the regional haze 
program.

A. Identification of Class I Areas

    1. RHR Requirement: Section 169A(b)(2) of the CAA requires each 
state in which any Class I area is located or ``the emissions from 
which may reasonably be anticipated to cause or contribute to any 
impairment of visibility'' in a Class I area to have a plan for making 
reasonable progress toward the national visibility goal. The RHR 
implements this statutory requirement at 40 CFR 51.308(f), which 
provides that each state's plan ``must address regional haze in each 
mandatory Class I Federal area located within the State and in each 
mandatory Class I Federal area located outside the State that may be 
affected by emissions from within the State,'' and 40 CFR 51.308(f)(2), 
which requires each state's plan to include a LTS that addresses 
regional haze in such Class I areas. To develop a state's LTS, a state 
must first determine which Class I areas may be affected by its own 
emissions. For out-of-state Class I areas, states must assess their 
visibility impacts on a statewide basis which is discussed in Section 
IVA.2, below, and on a source specific basis which is discussed in 
Section IV.C.2, below.
    2. State Assessment: To address 40 CFR 51.308(f), North Carolina 
identified Class I areas affected by North Carolina's statewide 
emissions of visibility impairing pollutants and then consulted with 
states with Class I areas affected by North Carolina's statewide 
emissions. DAQ presented the results of Particulate Matter Source 
Apportionment Technology (PSAT) \40\ modeling which VISTAS conducted to 
estimate the projected impact of statewide SO2 and 
NOX emissions across all emissions sectors in 2028 on total 
light extinction for the 20 percent most impaired days in all Class I 
areas in the VISTAS modeling domain.\41\ In Table 7-14 of the 2022 
Plan, DAQ lists the total sulfate plus nitrate contribution from all 
source sectors in North Carolina to total visibility impairment for the 
20 percent most impaired days at Class I areas in the VISTAS modeling 
domain in inverse megameters (Mm-\1\). North Carolina's top 
three highest sulfate plus nitrate impairment impacts to out-of-state 
Class I areas are: Wolf Island National Wilderness Area (Wolf Island) 
(0.78 Mm-\1\) and Okefenokee National Wilderness Area 
(Okefenokee) (0.67 Mm-\1\) in Georgia and James River Face 
National Wilderness Area (James River Face) (0.45 Mm-\1\) in 
Virginia.\42\
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    \40\ PSAT is Particulate Matter Source Apportionment Technology, 
which is an option in the photochemical visibility impact modeling 
performed by VISTAS that is a methodology to track the fate of both 
primary and secondary PM. PSAT allows emissions to be tracked 
(``tagged'') for individual facilities as well as various 
combinations of sectors and geographic areas (e.g., by state). The 
PSAT results provide the modeled contribution of each of the tagged 
sources or groups of sources to the total visibility impacts.
    \41\ DAQ did not include primary PM (directly emitted) data in 
this analysis because the PSAT analyses performed by VISTAS tagged 
statewide emissions of SO2 and NOX and did not 
tag primary total PM emissions in the analysis after concluding that 
emissions of the PM precursors SO2 and NOX, 
particularly from point sources, are projected to have the largest 
impact on visibility impairment in 2028 and that SO2 and 
NOX are the most significant visibility impairing 
pollutants from controllable anthropogenic sources.
    \42\ In contrast, North Carolina's sulfate plus nitrate 
impairment impacts to the State's Class I areas are: 0.95 
Mm-\1\, 1.13 Mm-\1\, 1.83 Mm-\1\, 
0.89 Mm-\1\, 0.43 Mm-\1\ for Linville Gorge, 
Shining Rock, Swanquarter, Great Smoky Mountains, and Joyce Kilmer, 
respectively.
---------------------------------------------------------------------------

    Based on these results for the out-of-state Class I areas, North 
Carolina consulted with the VISTAS states (see Section 10.1 and 
Appendix F-1 of the 2022 Plan) and the Mid-Atlantic/Northeast 
Visibility Union (MANE-VU) \43\ states (see Section 10.3 and Appendix 
F-4 of the 2022 Plan) which contain Class I areas located nearest to 
North Carolina and to which North Carolina's emissions had the highest 
sulfate plus nitrate contribution to total sulfate plus nitrate 
visibility impairment. The purpose of this consultation was to identify 
whether North Carolina's statewide impacts to the VISTAS and MANE-VU 
states are significant enough to develop coordinated emission 
management strategies containing the emission reductions necessary to 
make reasonable progress.\44\ With respect to MANE-VU, none of the 
states in this RPO contacted North Carolina for consultation with the 
exception of New Hampshire and New Jersey. North Carolina's 
consultation with MANE-VU, New Hampshire, and New Jersey is further 
discussed in Section IV.C.2.e of this document and Section I.E of EPA's 
Technical Support Document (TSD) for this proposed rulemaking.
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    \43\ MANE-VU was established in 2001 to assist the Mid-Atlantic 
and Northeast states in planning and developing their regional haze 
SIP revisions. The MANE-VU states are Connecticut, Delaware, Maine, 
Maryland, Massachusetts, New Hampshire, New Jersey, New York, 
Pennsylvania, Rhode Island, and Vermont.
    \44\ North Carolina did not consult with states with Class I 
areas in the Central States Air Resource Agencies (CENSARA), Lake 
Michigan Air Directors' Consortium (LADCO), and Western Regional Air 
Partnership (WRAP) RPO regions because North Carolina's statewide 
sulfate plus nitrate contribution to total sulfate plus nitrate 
impairment in the Class I areas in these regions was relatively low 
(i.e., ranging from zero percent to 0.12 percent of total sulfate 
plus nitrate impairment). Additionally, no states in CENSARA, LADCO, 
and WRAP requested consultation with North Carolina regarding its 
statewide emissions.
---------------------------------------------------------------------------

    3. EPA Evaluation: EPA proposes to conclude that North Carolina 
adequately addressed 40 CFR 51.308(f) regarding identification of its 
statewide visibility impacts to Class I areas outside of the State and 
consulting with states with Class I areas which may reasonably be 
anticipated to cause or contribute to any impairment of visibility due 
to North Carolina's emissions. EPA proposes to agree with the State's 
approach of focusing on SO2 and NOX impacts from 
North Carolina on the basis that for current visibility conditions 
evaluated for the 2014-2018 period, ammonium sulfate is the dominant 
visibility impairing pollutant at most of the VISTAS Class I areas 
followed by organic carbon and ammonium nitrate (depending on the 
area).\45\ VISTAS focused on controllable emissions from point sources, 
and thus, initially considered impacts from sulfates and nitrates on 
regional haze at Class I areas affected by VISTAS states. EPA agrees 
that North Carolina adequately identified Class I areas outside of 
North Carolina that may be affected by emissions from within the State 
and consulted with affected states. The information submitted by North 
Carolina supports this finding, because it shows that the state 
analyzed its statewide sulfate and nitrate contributions to total 
visibility impairment at out-of-state Class I areas in Table 7-14 of 
the 2022 Plan; none of

[[Page 67352]]

the Class I areas in MANE-VU and VISTAS have 2028 RPGs on the 20 
percent most impaired days above the URP; \46\ with the exception of 
Joyce Kilmer, the visibility impairment due to emissions from North 
Carolina at in-state Class I areas is greater than the impairment due 
to emission from North Carolina at out-of-state Class I areas; and the 
State completed consultation with VISTAS and MANE-VU states via the RPO 
processes and, in some cases, on a state-to-state basis and documented 
those consultations.\47\
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    \45\ See Figures 2-17 and 2-18 of the 2022 Plan for the VISTAS 
Class I areas. See also section IV.C.2.a of this notice.
    \46\ See Memorandum from Richard A. Wayland, OAQPS, to Regional 
Air Division Directors re: Availability of Modeling Data and 
Associated Technical Support Document for the EPA's Updated 2028 
Visibility Air Quality Modeling (September 19, 2019), available at: 
https://www.epa.gov/sites/default/files/2019-10/documents/updated_2028_regional_haze_modeling-tsd-2019_0.pdf.
    \47\ See Section IV.C.2.e of this notice and Section I.E of 
EPA's TSD for additional detail regarding consultation.
---------------------------------------------------------------------------

B. Calculations of Baseline, Current, and Natural Visibility 
Conditions; Progress to Date; and the URP

    1. RHR Requirement: Section 51.308(f)(1) requires states to 
determine the following for ``each mandatory Class I Federal area 
located within the State'': baseline visibility conditions for the 
clearest days and most impaired days, natural visibility conditions for 
clearest days and most impaired days, progress to date for the clearest 
days and most impaired days, the differences between current visibility 
conditions and natural visibility conditions, and the URP. This section 
also provides the option for states to propose adjustments to the URP 
line for a Class I area to account for visibility impacts from 
anthropogenic sources outside the United States and/or the impacts from 
wildland prescribed fires that were conducted for certain, specified 
objectives. See 40 CFR 51.308(f)(1)(vi)(B).
    2. State Assessment: In the 2022 Plan, North Carolina calculated 
baseline visibility conditions (2000-2004) in Table 2-3; current 
visibility conditions (2014-2018) in Table 2-5; \48\ and natural 
visibility conditions in Table 2-2 for the 20 percent most impaired and 
20 percent clearest days for the State's Class I areas in deciviews as 
shown in Table 1, below. North Carolina also calculated for its Class I 
areas the actual progress made toward natural visibility conditions to 
date since the baseline period (current minus baseline), and the 
additional progress needed to reach natural visibility conditions from 
current conditions (natural minus current), in deciviews, in Table 2-6 
(for the 20 percent most impaired days) and Table 2-7 (for the 20 
percent clearest days) as shown in Table 2, below.
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    \48\ The period 2014-2018 represents current visibility 
conditions for North Carolina because it is the most recent five-
year period for which visibility monitoring data were available at 
the time of SIP development.

                    Table 1--Baseline, Current, and Natural Visibility Conditions in North Carolina's Class I Areas in Deciviews (dv)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Baseline 20%                      Current 20%                       Natural 20%
                   Class I area                       Baseline 20%    most impaired     Current 20%     most impaired     Natural 20%     most impaired
                                                     clearest days         days        clearest days         days        clearest days         days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Great Smoky Mountains.............................            13.58            29.11             8.35            17.21             4.62            10.05
Joyce Kilmer......................................            13.58            29.11             8.35            17.21             4.62            10.05
Linville Gorge....................................            11.11            28.05             7.61            16.42             4.07             9.70
Shining Rock......................................             7.70            28.13             4.40            15.49             2.49          * 10.25
Swanquarter.......................................            12.34            23.79            10.61            16.30             5.71          * 10.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The 2022 Plan indicates in Table Ex-1-3 and Table 8-1 that natural conditions are 10.01 and 9.79 deciviews for Shining Rock and Swanquarter,
  respectively. Tables Ex-1-1, Table 2-2, and Tables 2-6 reflect the correct values shown here which are derived from EPA's June 3, 2020, Technical
  Addendum available at: https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf.


     Table 2--Actual Progress for Visibility Conditions in North Carolina's Class I Areas in Deciviews (dv)
----------------------------------------------------------------------------------------------------------------
                                     Current minus       Current minus       Natural minus       Natural minus
          Class I area             baseline for 20%    baseline for 20%     current for 20%     current for 20%
                                     clearest days    most impaired days     clearest days    most impaired days
----------------------------------------------------------------------------------------------------------------
Great Smoky Mountains...........               -5.23              -11.90               -3.73               -7.16
Joyce Kilmer....................               -5.23              -11.90               -3.73               -7.16
Linville Gorge..................               -3.50              -11.63               -3.54               -6.72
Shining Rock....................               -3.30              -12.64               -1.91               -5.24
Swanquarter.....................               -1.73               -7.49               -4.90               -6.29
----------------------------------------------------------------------------------------------------------------

    Additionally, Figures 3-1, 3-2, 3-3, and 3-4 of the 2022 Plan 
provide the URP figures for the 20 percent most impaired days for Great 
Smoky Mountains (which also represents the URP for Joyce Kilmer), 
Linville Gorge, Shining Rock, and Swanquarter, respectively. The URPs 
were developed using EPA guidance \49\ and used data collected from the 
IMPROVE monitoring network which is used to measure visibility 
impairment caused by air pollution at the 156 Class I areas covered by 
the visibility program. All North Carolina Class I areas are projected 
to be below the 2028 URP values for the second planning period based on 
VISTAS' modeling.
---------------------------------------------------------------------------

    \49\ ``Technical Guidance on Tracking Visibility Progress for 
the Second Implementation Period of the Regional Haze Program.'' EPA 
Office of Air Quality Planning and Standards, Research Triangle Park 
(December 20, 2018). https://www.epa.gov/sites/default/files/2018-12/documents/technical_guidance_tracking_visibility_progress.pdf and 
https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf.
---------------------------------------------------------------------------

    3. EPA Evaluation: EPA finds that North Carolina's Haze Plan meets 
the requirements of 40 CFR 51.308(f)(1) because the State provided for 
its five Class I areas: baseline, current, and natural visibility 
conditions for the 20

[[Page 67353]]

percent clearest days and most impaired days; progress to date for the 
20 percent clearest days and most impaired days; differences between 
the current visibility conditions and natural visibility conditions; 
and the URP for each Class I area in North Carolina. Therefore, EPA is 
proposing to approve the portions of the North Carolina SIP submission 
related to 40 CFR 51.308(f)(1).

C. LTS for Regional Haze

    1. RHR Requirement: Each state having a Class I area within its 
borders or emissions that may affect visibility in a Class I area must 
develop a LTS for making reasonable progress toward the national 
visibility goal. CAA 169A(b)(2)(B). As explained in Section II of this 
document, reasonable progress is achieved when all states contributing 
to visibility impairment in a Class I area are implementing the 
measures determined--through application of the four statutory factors 
to sources of visibility impairing pollutants--to be necessary to make 
reasonable progress. 40 CFR 51.308(f)(2)(i). Each state's LTS must 
include the enforceable emission limitations, compliance schedules, and 
other measures that are necessary to make reasonable progress. 40 CFR 
51.308(f)(2). All new (i.e., additional) measures that are the outcome 
of FFAs are necessary to make reasonable progress and must be in the 
LTS. If the conclusion of a FFA and other measures necessary to make 
reasonable progress for a particular source is that no new measures are 
reasonable, that source's existing measures are necessary to make 
reasonable progress, unless the state can demonstrate that the source 
will continue to implement those measures and will not increase its 
emission rate. Existing measures that are necessary to make reasonable 
progress must also be in the LTS. In developing its LTS, a state must 
also consider the five additional factors in 40 CFR 51.308(f)(2)(iv). 
As part of its reasonable progress determinations, the state must 
describe the criteria used to determine which sources or group of 
sources were evaluated (i.e., subjected to FFA) for the second planning 
period and how the four factors were taken into consideration in 
selecting the emission reduction measures for inclusion in the LTS. 40 
CFR 51.308(f)(2)(iii).
    States may rely on technical information developed by the RPOs of 
which they are members to select sources for FFA and to satisfy the 
documentation requirements under 40 CFR 51.308(f). Where an RPO has 
performed source selection and/or FFAs (or considered the five 
additional factors in 40 CFR 51.308(f)(2)(iv)) for its member states, 
those states may rely on the RPO's analyses for the purpose of 
satisfying the requirements of 40 CFR 51.308(f)(2)(i) so long as the 
states have a reasonable basis to do so and all state participants in 
the RPO process have approved the technical analyses. 40 CFR 
51.308(f)(3)(iii). States may also satisfy the requirement of 40 CFR 
51.308(f)(2)(ii) to engage in interstate consultation with other states 
that have emissions that are reasonably anticipated to contribute to 
visibility impairment in a given Class I area under the auspices of 
intra- and inter-RPO engagement.
    The consultation requirements of 40 CFR 51.308(f)(2)(ii) provide 
that states must consult with other states that are reasonably 
anticipated to contribute to visibility impairment in a Class I area to 
develop coordinated emission management strategies containing the 
emission reductions measures that are necessary to make reasonable 
progress. Section 51.308(f)(2)(ii)(A) and (B) require states to 
consider the emission reduction measures identified by other states as 
necessary for reasonable progress and to include agreed upon measures 
in their SIPs, respectively. Section 51.308(f)(2)(ii)(C) speaks to what 
happens if states cannot agree on what measures are necessary to make 
reasonable progress. The documentation requirement of 40 CFR 
51.308(f)(2)(iii) provides that states may meet their obligations to 
document the technical bases on which they are relying to determine the 
emission reductions measures that are necessary to make reasonable 
progress through an RPO, as long as the process has been ``approved by 
all State participants.''
    Section 51.308(f)(2)(iii) also requires that the emissions 
information considered to determine the measures that are necessary to 
make reasonable progress include information on emissions for the most 
recent year for which the state has submitted triennial emissions data 
to the EPA (or a more recent year), with a 12-month exemption period 
for newly submitted data.
    2. State Assessment: To develop North Carolina's LTS, DAQ set 
criteria to identify sources to evaluate for potential controls using 
the four factors outlined in Section II.B, selected sources based on 
those criteria, considered the four factors for the selected sources, 
provided emissions limits and supporting conditions for adoption into 
the regulatory portion of the SIP, and evaluated the five additional 
factors at 40 CFR 51.308(f)(2)(iv).
    a. Source Selection Criteria: With respect to 40 CFR 
51.308(f)(2)(i), North Carolina, through VISTAS, used a two-step source 
selection process: (1) Area of Influence (AoI) analysis, and (2) PSAT 
\50\ modeling for sources exceeding an AoI threshold.\51\ North 
Carolina considered the four factors for sources that exceeded both the 
AoI and PSAT thresholds. Both sulfates and nitrates were considered in 
the source selection process. To identify sources having the most 
impact on visibility at Class I areas for PSAT modeling, DAQ used an 
AoI threshold of greater than or equal to three percent for sulfate and 
nitrate combined at any North Carolina Class I area for all sources 
within and outside of the State. Sources which exceeded North 
Carolina's AoI threshold are listed in Tables 7-20 through 7-24 of the 
Haze Plan. Of these sources, five sources in North Carolina exceeded 
the AoI threshold for any Class I area in the State: Blue Ridge Paper 
Products--Canton Mill (BRPP); Domtar Paper LLC (Domtar); \52\ Duke 
Energy Carolinas LLC (DEC)--Marshall Steam Station (DEC-Marshall); PCS 
Phosphate Inc.--Aurora (PCS); and SGL Carbon LLC.\53\
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    \50\ PSAT modeling is a type of photochemical modeling which 
quantifies individual facility visibility impacts to an area. See 
footnote 40. DAQ applied its PSAT threshold by facility whereas in 
the first period, DAQ applied the threshold by emissions unit at 
selected facilities.
    \51\ The AoI represents the geographical area around a Class I 
area in which emissions sources located in the AoI have the 
potential to contribute to visibility impairment at that Class I 
area. Emissions data from sources in the AoI is then evaluated to 
determine which of those sources are most likely contributing to 
visibility impairment at that Class I area. VISTAS used AoI analysis 
for all point source facilities in the VISTAS modeling domain to 
determine the relative visibility impairment impacts at each Class I 
area associated with sulfate and nitrate. The results of the 
facility-level AoI analyses were then used to rank and prioritize 
facilities for further evaluation via PSAT.
    \52\ On December 1, 2023, DAQ issued Air Quality Permit No. 
04291T51 authorizing modifications to the Domtar facility, which is 
available at: https://edocs.deq.nc.gov/AirQuality/DocView.aspx?id=457541&dbid=0&repo=AirQuality&searchid=c271acf8-6535-4306-8cfb-9a0caa2b3d97. Because these authorized permit 
modifications are subsequent to the North Carolina SIP submission, 
North Carolina did not consider the modification to determine 
reasonable progress in the second planning period.
    \53\ See Table 7-29 on p. 227 of the 2022 Plan.
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    North Carolina, in coordination with the other VISTAS states, set a 
PSAT threshold of greater than or equal to one percent for sulfate or 
nitrate. Sources identified based on the State's PSAT threshold are 
listed in Tables 7-36, 7-37, and 7-38 of the 2022 Plan. Of the 19 
sources that exceeded the sulfate PSAT threshold, 16 sources are 
located in 10 other states and three are located in North Carolina. 
North Carolina selected the three in-state sources

[[Page 67354]]

(BRPP, Domtar, and PCS) for an emissions control analysis.\54\ The 
projected 2028 SO2 emissions (in tons per year (tpy)) from 
BRPP, Domtar, and PCS are 483, 1,120, and 3,045, respectively.\55\ No 
sources modeled for PSAT exceeded the PSAT threshold for nitrates. 
Because no sources exceeded the State's PSAT threshold for nitrates and 
because ammonium sulfate continues to be the dominant visibility 
impairing pollutant at the North Carolina Class I areas (as discussed 
in the following paragraphs), DAQ focused solely on evaluating 
potential SO2 controls from BRPP, Domtar, and PCS to address 
regional haze in potentially affected Class I areas. Section I.A of the 
TSD provides additional detail regarding the State's source selection 
process.
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    \54\ BRPP and Domtar are pulp and paper mills. PCS is a 
fertilizer plant with sulfuric acid plants on site.
    \55\ See Tables 7-48, 7-55, and 7-60 on pp. 271, 275, and 279, 
respectively, of the 2022 Plan.
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    The 2022 Plan shows the VISTAS model projections demonstrating that 
ammonium sulfate is expected to remain the dominant visibility 
impairing pollutant through 2028, by a factor of four or greater, over 
ammonium nitrate at Class I areas in North Carolina.\56\ In Section 7.4 
of the 2022 Plan, DAQ explains the VISTAS analyses relied upon to 
support the State's focus on SO2 control evaluations. 
Additionally, Section 10.4.1 of the Haze Plan provides the State's 
responses to FLM comments on the exclusion of NOX control 
evaluations from the FFAs.
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    \56\ See Figures 2-7 through 2-18 and Figure 10-10 of the 2022 
Plan. Figures 2-7 through 2-10 provide 2009-2013 speciated PM data 
for North Carolina's Class I areas showing that ammonium sulfate is 
the dominant visibility impairing pollutant. Figures 2-11 and 2-12 
provide speciated PM data for 2009-2013 for the VISTAS Class I areas 
and neighboring areas on the 20 percent most impaired days and 20 
percent clearest days, respectively. Figures 2-13 to 2-18 show the 
speciated PM data for North Carolina's Class I areas for the period 
2014-2018 showing that ammonium sulfate is the dominant visibility 
impairing pollutant. Figures 2-17 and 2-18 provide speciated PM data 
for 2014-2018 for the VISTAS Class I areas and neighboring areas on 
the 20 percent most impaired days and 20 percent clearest days, 
respectively.
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    Although ammonium nitrate contributions to light extinction have 
increased in recent years (2016-2018), sulfate is still the highest 
contributor to visibility impairment in North Carolina's Class I areas. 
DAQ provided light extinction data on the 20 percent most impaired and 
20 percent clearest days for the North Carolina Class I areas for the 
2009-2013 modeling base period and the 2014-2018 current conditions 
period which show that ammonium sulfate continues to be the dominant 
visibility impairing pollutant on the 20 percent most impaired 
visibility days during the 2009-2013 period and 2014-2018 period.\57\
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    \57\ See Section 2.5.2 (particularly Figures 2-7 through 2-11 
for the 2009-2013 period and Figures 2-13 through 2-18 for the 2014-
2018 period), and Section 10.4.1 of the 2022 Plan related to 
ammonium nitrate.
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    In Section 10.4.1, DAQ reviewed more recent visibility monitoring 
data for the period 2015-2019 from the IMPROVE monitoring network for 
Great Smoky Mountains, Linville Gorge, and Shining Rock.\58\ Table 3, 
below, summarizes the percent contribution on the 20 percent most 
impaired days at Great Smoky Mountains (also Joyce Kilmer), Linville 
Gorge, and Shining Rock for certain PM species (i.e., ammonium sulfate, 
ammonium nitrate, and organic carbon) in 2009-2013 versus 2015-
2019.\59\
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    \58\ DAQ did not include 2015-2019 IMPROVE monitoring data for 
Swanquarter in Section 10.4.1 because NPS and USFS did not request 
that DAQ consider more recent visibility monitoring data for 
Swanquarter.
    \59\ The data in Table 1 is derived from Figures 10-1, 10-2, and 
10-3 of the 2022 Plan. Swanquarter speciation data is shown in 
Figures 2-10 through 2-12 and 2-16 through 2-18 of the 2022 Plan.
    \60\ DAQ provided IMPROVE monitoring data in Figures 10-1, 10-2, 
and 10-3 regarding Great Smoky Mountains (also for Joyce Kilmer), 
Linville Gorge, and Shining Rock. For Swanquarter, 2015-2019 IMPROVE 
data for the 20 percent most impaired days are: 50 percent, 17 
percent, and 17 percent for ammonium sulfate, ammonium nitrate, and 
organic carbon, respectively. See https://vista.cira.colostate.edu/Improve/rhr-summary-data/ data/.

  Table 3--Five-Year Average (2009-2013 vs. 2015-2019) Percent (%) Particle Contributions to Light Extinction for 20% Most Impaired Days at Great Smoky
                                                    Mountains,* Linville Gorge, and Shining Rock \60\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Great smoky mountains              Linville gorge                   Shining rock
                       PM species                        -----------------------------------------------------------------------------------------------
                                                           2009-2013 (%)   2015-2019 (%)   2009-2013 (%)   2015-2019 (%)   2009-2013 (%)   2015-2019 (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ammonium Sulfate........................................            76.3            54.4            77.2            56.9            74.5            58.1
Ammonium Nitrate........................................             5.2            16.6             2.5             8.0             5.5            10.3
Organic Carbon..........................................            11.1            17.4            12.5            22.4            12.5            19.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Monitoring data for Great Smoky Mountains serves as the IMPROVE data for Joyce Kilmer.

    Figures 7-27 (Swanquarter), 7-28 (Shining Rock), 7-29 (Linville 
Gorge), 7-30 (Joyce Kilmer), and 7-31 (Great Smoky Mountains) in the 
2022 Plan show that the majority of 2028 predicted nitrate light 
extinction on the 20 percent most impaired days at North Carolina's 
Class I areas is not caused by NOX emissions from EGU and 
non-EGU point sources.\61\ At Shining Rock, Linville Gorge, Joyce 
Kilmer, and the Great Smoky Mountains, projected 2028 total sulfate 
extinction is greater than 17 Mm-1 and total projected 2028 
total nitrate extinction is less than 3.5 Mm-1. At 
Swanquarter, the projected 2028 sulfate extinction is 16.6 
Mm-1 and the projected 2028 nitrate extinction is 4.5 
Mm-1. DAQ states that North Carolina sources contribute a 
small percentage to total nitrate impairment in all cases (ranging from 
less than one percent of all nitrate visibility impairment at the Great 
Smoky Mountains to 13 percent at Swanquarter).
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    \61\ Figure 7-26 provides the 2028 visibility impairment from 
nitrate on the 20 percent most impaired days for all 18 Class I 
Areas in VISTAS. The figure shows the EGU and non-EGU contributions 
to total nitrate derived light extinction in 2028.
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    DAQ states that it is unclear why ammonium nitrate has started to 
increase at some but not all VISTAS Class I areas while point and 
mobile source NOX emissions have been declining. VISTAS 
modeling for 2028 suggests that sources outside of North Carolina may 
be the likely contributor. DAQ indicates that further research is 
needed to identify the emission sources and geographic locations of 
those sources contributing to the ammonium nitrate fraction of 
PM2.5 contributing to regional haze. DAQ notes that at some 
locations, one ton of SO2 reduction can have anywhere from 
twice to more than 100 times the impact on visibility impairment as one 
ton of NOX reduction.\62\
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    \62\ See pp. 333-335 and Table 10-8 of the 2022 Plan.

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[[Page 67355]]

    In Section 7.7.3.2 of the 2022 Plan, DAQ reviewed North Carolina 
facilities that were not selected for PSAT modeling and which had an 
AoI contribution between one and three percent for one or more Class I 
areas in North Carolina and which were not selected for FFA evaluation. 
This review included the eight Duke Energy power plants with coal units 
in North Carolina which, with the exception of DEC-Marshall, did not 
meet North Carolina's AoI threshold (see Table 7-43 of the 2022 Plan). 
DAQ reviewed existing SO2 and NOX controls for 
the Duke Energy facilities with coal units and non-EGUs with an AOI 
contribution between one and three percent sulfate plus nitrate and 
based on this review, DAQ did not identify any uncontrolled or lightly 
controlled facilities that were large contributors to anthropogenic 
light extinction at any of North Carolina's Class I areas that were 
missed by North Carolina's source selection process.
    b. Consideration of the Four Factors: North Carolina considered 
each of the four CAA factors for BRPP and Domtar and described how the 
four factors were taken into consideration in selecting the 
SO2 measures for inclusion in the State's LTS. For PCS, DAQ 
considered the four CAA factors for its existing measures for the 
affected units and determined that there are no technically feasible 
control measures beyond the existing measures to further reduce 
SO2 emissions, and thus, no new measures were evaluated 
using the four factors. The following subsections summarize the State's 
evaluation of these facilities. Additional detail is provided in 
Section I.B. of the TSD.
    i. BRPP: During 2017 to 2019, BRPP implemented SO2 
controls on existing processes and replaced two coal-fired boilers with 
new natural gas-fired boilers to comply with a Special Order by Consent 
(SOC) between the North Carolina Environmental Management Commission 
and BRPP.\63\ As a result of the SOC, BRPP reduced actual annual 
SO2 emissions by 93 percent (5,470 tons per year) from 2017-
level emissions.
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    \63\ See Section 7.8.1.1 of the 2022 Plan. North Carolina and 
BRPP entered into the SOC on October 9, 2017, to implement facility 
process modifications, upgrade existing control equipment, as well 
as to install new control equipment to comply with the Boiler 
Maximum Achievable Control Technology (MACT) standard by May 20, 
2019, that cumulatively resulted in the control and reduction of 
facility-wide SO2 emissions. The SOC is available in 
Docket ID No. EPA-R04-OAR-2020-0001 on www.regulations.gov.
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    The FFA focused on the No. 4 Power Boiler, Riley Bark Boiler, and 
the Riley Coal Boiler because these three boilers comprise 90.2 percent 
of the BRPP's total 2019 actual emissions and 91.8 percent of the 
BRRP's total 2028 projected SO2 emissions.\64\ These units 
are equipped with wet flue gas desulfurization (WFGD).\65\ \66\ To 
complete the cost of compliance analysis, BRPP evaluated replacing coal 
with ultra-low sulfur diesel (ULSD) (all three boilers) and adding dry 
sorbent injection (DSI) (for the Riley Coal Boiler and No. 4 Power 
Boiler). Table 7-54 of the 2022 Plan shows that of the new control 
measures considered, the lowest cost effectiveness was $13,477 per ton 
of SO2 removed using a 3.25 percent interest rate and a 30-
year equipment life in the cost calculations. The State notes that 
based on the FFA, BRPP identified no cost-effective control measures to 
further reduce SO2 emissions for the three boilers 
evaluated.
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    \64\ See Table 7-48 on p. 271 of the 2022 Plan.
    \65\ The SO2 removal efficiency from the existing 
control measures at the Riley Coal Boiler, Riley Bark Boiler, and 
the No. 4 Power Boiler is approximately 90 percent. See Section 
7.8.1.1 of the 2022 Plan.
    \66\ WFGD, also referred to as wet scrubbers, are a type of 
control technology which removes SO2 and other pollutants 
from gaseous exhaust streams. WFGD is considered the most efficient 
way to remove SO2 from gaseous waste streams if the 
removal efficiency is optimized.
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    Regarding the other statutory factors, the State identifies the 
remaining useful life of the source is estimated at more than 25 years, 
and the equipment life of the control options evaluated is 30 years for 
both the DSI and ULSD options. The State identifies that the time 
necessary to comply for both the DSI and ULSD options is at least three 
years to accommodate time for corporate funding approval, permitting, 
re-engineering, and planned outage scheduling. Regarding energy and 
non-air quality environmental impacts of compliance, DAQ explains that 
adding DSI would increase energy usage as well as PM emissions from 
materials handling and landfill operations and it would also decrease 
the useful life of the mill landfill and increase truck traffic on 
local streets. Regarding ULSD, no significant energy and non-air 
quality environmental impacts were identified.
    Given the 93 percent decrease in SO2 emissions due to 
the SOC and the State's determination that there are no cost-effective 
control SO2 measures available based on a review of the four 
factors, DAQ concluded that only existing SO2 measures are 
necessary for reasonable progress for the second planning period at 
BRPP's Riley Coal Boiler, Riley Bark Boiler, and the No. 4 Power 
Boiler. No source-specific changes were proposed to the North Carolina 
SIP for BRPP because these existing SO2 measures are already 
incorporated into the SIP.\67\
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    \67\ See 85 FR 74884 (November 24, 2020); 40 CFR 52.1770(d). The 
SIP contains specific SO2 permit limits and associated 
operating restrictions; monitoring, recordkeeping, and reporting; 
and testing compliance parameters from BRPP's title V permit (No. 
08961T29) reflecting the requirements of the SOC.
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    ii. Domtar: The FFA for Domtar focused on Hog Fuel Boiler 2 
(``HFB2'') because this unit is projected to emit approximately 90 
percent of the facility's total projected SO2 emissions in 
2028 (1,010 tpy out of 1,120 tpy).\68\ A hog fuel boiler at a paper 
mill typically burns wood waste known as ``hog fuel'' to generate 
electricity for the mill. In addition, Domtar currently routes the 
majority of its noncondensible waste gases through HFB2. The sulfur 
compounds from the waste gases accounts for the vast majority of the 
SO2 emissions. HFB2 uses low sulfur fuels and inherent bark 
scrubbing to control SO2 emissions. To complete the cost of 
compliance analysis, Domtar evaluated HFB2 for WFGD and DSI.\69\ Table 
7-58 of the 2022 Plan provides summary cost data showing that the cost 
effectiveness of the addition of a WFGD would be $3,660/ton and the 
addition of DSI would cost $22,092/ton of SO2 removed using 
a 3.25 percent interest rate, a 30-year equipment life, and assuming a 
95 percent SO2 control efficiency for the scrubber and a 50 
percent control efficiency for DSI.\70\
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    \68\ With respect to Domtar's Hog Fuel Boiler 1 (``HFB1''), this 
unit is projected to emit 12 tpy SO2 in 2028. HFB1 was 
not included in the FFA because it is currently equipped to burn 
only natural gas and biomass with No. 2 fuel oil as a backup fuel. 
Also, based on updated 2028 emissions projections data, the unit 
will only contribute two percent of the facility's total 
SO2 emissions. In the docket to this proposed rule is a 
legible copy of the May 12, 2020, letter from Domtar to DAQ provided 
in Appendix G-2a of the Haze Plan.
    \69\ In addition to the FFA, DAQ provided, as supplemental 
information, that the use of a WFGD on HFB2 would improve visibility 
by 0.03 deciview and improve visual range by approximately 0.16 mile 
at Swanquarter and that the WFGD would reduce Domtar's contribution 
to total visibility impairment at Swanquarter by 0.33 percent (0.152 
Mm-1). DAQ did not rely upon this supplemental 
information for the Domtar FFA analysis and conclusions.
    \70\ In Appendix I of the Haze Plan, DAQ notes that HFB2 is used 
as a control device for several process gas streams at Domtar. DAQ 
checked EPA's RACT/BACT/LAER Clearinghouse available at https://www.epa.gov/catc/ractbactlaer-clearinghouse-rblc-basic-information 
and was unable to find documentation of similar emissions units to 
HFB2 to compare costs of WFGD at this type of unit.
---------------------------------------------------------------------------

    Regarding the other statutory factors, the remaining useful life of 
HFB2 is 20 years or more, and the equipment life assumed in the cost 
calculations is 30 years for both the WFGD and DSI control options. The 
time necessary to

[[Page 67356]]

comply for both the WFGD and DSI options is at least three years due to 
corporate funding approval, permitting, re-engineering, and planned 
outage scheduling. Regarding energy and non-air quality environmental 
impacts of compliance, additional electricity would be needed to 
operate a DSI system, and a DSI system would create additional solid 
waste. Regarding the WFGD, additional electricity and water would be 
needed to run the system and additional fan power would be required 
overcome the additional pressure drop through the WFGD. Other 
environmental and energy impacts associated with operating a WFGD 
include generation and disposal of wastewater.
    DAQ concluded that there are no cost-effective control 
SO2 measures available based on a review of the four factors 
and that only existing SO2 measures at HFB2 are necessary 
for reasonable progress during the second planning period. North 
Carolina identified permit conditions reflecting these existing 
measures in Section 7.8.3.1 of the 2022 Plan for incorporation into the 
North Carolina SIP. In its Commitment Letter, DAQ committed to revise 
certain permit conditions and submit, no later than one year from the 
effective date of a final conditional approval action (should EPA 
finalize the proposed partial conditional approval), a SIP revision 
requesting incorporation of the revised permit conditions and 
additional existing specific permit conditions into the SIP. DAQ's 
commitments are discussed in Section IV.C.3.b.ii of this document.
    iii. PCS: The FFA for PCS focused on evaluating Sulfuric Acid 
Plants (SAPs) 5, 6, and 7 for additional SO2 controls 
because these three SAPs accounted for over 97 percent of total 
facility SO2 emissions in 2016 and are estimated to account 
for 94 percent of the total facility SO2 emissions in 2028. 
During 2017-2019, PCS implemented upgrades to enhance the 
SO2 conversions in the catalytic systems on SAPs 5, 6, and 7 
pursuant to a consent decree with EPA entered on February 26, 2015.\71\ 
Table 7-61 of the 2022 Plan summarizes the SO2 emissions 
reductions from the upgrades involving a dual absorption process with 
cesium catalyst.\72\ PCS' title V permit includes the SO2 
emissions limits required under the consent decree and prohibits 
relaxation of these emissions limits after the consent decree has been 
terminated.
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    \71\ The consent decree entered by the Court on February 26, 
2015, is located in the docket for this proposed rulemaking. This 
consent decree terminated on April 3, 2023.
    \72\ See Appendix G-3 of the 2022 Plan for additional 
information regarding the dual absorption process with cesium 
catalyst.
---------------------------------------------------------------------------

    For PCS, the State evaluated whether there are any technically 
feasible control technologies available for SAPs 5, 6, and 7 at the 
facility beyond the current SO2 emissions control technology 
in place (dual absorption process with cesium catalyst) to further 
reduce SO2 emissions at these units and concluded that there 
are none. Given this conclusion and the SO2 reductions at 
PCS due to the upgrades, DAQ concluded that only the existing measures 
for SAPs 5, 6, and 7 are necessary for reasonable progress during the 
second planning period. North Carolina identified permit conditions 
reflecting these existing measures in Section 7.8.3.2 of the 2022 Plan 
for incorporation into the North Carolina SIP.\73\ In its Commitment 
Letter, DAQ committed to submit, no later than one year from the 
effective date of a final conditional approval action (should EPA 
finalize the proposed partial conditional approval), a SIP revision 
requesting incorporation of additional existing specific permit 
conditions into the SIP. DAQ's commitments are discussed in Section 
IV.C.3.b.iii of this document.
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    \73\ In an email dated March 28, 2024, DAQ clarified that the 
text of Condition 2.5 A.1.p of PCS' title V permit, proposed for 
adoption into the SIP on page 289 of the Haze Plan, was 
inadvertently excluded from the excerpts of permit conditions 
provided in Section 7.8.3.2 of the Haze Plan under ``Section 2.5 
A.1.k through p--Emissions Monitoring Requirements.''
---------------------------------------------------------------------------

    c. Documentation of Technical Basis: With respect to emissions 
information documentation pursuant to 40 CFR 51.308(f)(2)(iii), Section 
4 of the 2022 Plan explains the State's use of emissions inventories to 
develop the plan with additional documentation provided in Appendix B. 
North Carolina, through VISTAS, developed a 2011 statewide base year 
emissions inventory which was used to project emissions out to 2028, 
the end of the second planning period. DAQ also evaluated emissions 
data from 2017, the year of the most recent triennial emissions data 
available at the time of the development of the 2022 Plan.\74\ DAQ also 
provided annual, statewide anthropogenic SO2, 
NOX, and PM2.5 emissions data from 2011 through 
2019 for North Carolina in Tables 13-9, 13-10, and 13-11, respectively, 
of the 2022 Plan.
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    \74\ 2017 emissions data is included in the following tables and 
figures in the 2022 Plan: Table 7-41 (SO2) and 7-42 
(NOX) for certain non-EGU sources in North Carolina; 
Tables 13-9 (SO2), 13-10 (NOX), 13-11 
(PM2.5), 13-12 (PM10), 13-13 (VOC) for 
anthropogenic statewide emissions of these pollutants; Table 13-14 
(SO2, NOX for all RPOs); Figures 13-9 
(SO2), 13-10 (NOX), 13-11 (PM2.5), 
13-12 (PM10), 13-13 (VOC)) for anthropogenic statewide 
emissions of these pollutants; and Figures 13-14 and 13-15 
(SO2, NOX for all RPOs).
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    With respect to modeling information documentation pursuant to 40 
CFR 51.308(f)(2)(iii), Sections 5 and 6 of the 2022 Plan describe the 
modeling methods used to develop the plan with additional documentation 
provided in Appendix E and results of the RPG modeling in Section 8 of 
the plan. Appendix D contains AoI analyses documentation.
    With respect to cost and engineering information documentation 
pursuant to 40 CFR 51.308(f)(2)(iii), Section 7.8 of the 2022 Plan 
details the State's analysis of proposed FFAs for BRPP and Domtar 
located in Appendix G which evaluated the four factors, including the 
cost of compliance factor, and provided detailed cost calculations for 
potential new control measures assessed as part of the engineering 
analyses.
    With respect to monitoring information documentation pursuant to 40 
CFR 51.308(f)(2)(iii), the State assessed baseline (2000-2004), current 
(2014-2018), and natural visibility conditions for North Carolina's 
Class I areas in Section 2 of the 2022 Plan with supporting information 
located in Appendix C.
    Section I.D of the TSD provides a more detailed summary of the 
State's assessment of the documentation of the technical basis for the 
2022 Plan under 40 CFR 51.308(f)(2)(iii) and 40 CFR 51.308(f)(6)(v).
    d. Assessment of the Five Additional Factors in 40 CFR 
51.308(f)(2)(iv): With respect to 40 CFR 51.308(f)(2)(iv), North 
Carolina considered each of the five additional factors in developing 
the State's LTS and evaluated their relevancy for the second planning 
period. With respect to 40 CFR 51.308(f)(2)(iv)(A), North Carolina 
referenced the State's emissions inventory development for the base 
year of 2011 as projected out to 2028 for the requirement to assess 
emission reductions due to ongoing air pollution control programs, 
including measures to address Reasonably Attributable Visibility 
Impairment (RAVI). With respect to 40 CFR 51.308(f)(2)(iv)(B), North 
Carolina summarized the State's existing regulations that mitigate the 
impacts of construction activities by requiring control of erosion, 
siltation, and pollution from construction activities and requiring 
subject facilities to control PM from fugitive dust emission sources 
generated within plant boundaries.\75\ With respect to 40 CFR

[[Page 67357]]

51.308(f)(2)(iv)(C), North Carolina summarized existing and planned 
source retirements in Section 7.2.2 and Section 8.3.5 of the 2022 Plan. 
With respect to 40 CFR 51.308(f)(2)(iv)(D), North Carolina considered 
the State's Guidelines for Managing Smoke from Forestry Burning 
Operations to mitigate PM2.5 emissions and regional haze 
impacts associated with prescribed burning.\76\ With respect to 40 CFR 
51.308(f)(2)(iv)(E), North Carolina pointed to the development and 
evaluation of the 2028 RPGs for the North Carolina Class I areas which 
reflect the net effect on visibility due to projected changes in point, 
area, and mobile source emissions over the second period. Section I.C 
of the TSD provides a more detailed summary of the State's assessment 
of the five additional factors in 40 CFR 51.308(f)(2)(iv).
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    \75\ DAQ explained that fine soils were a relatively minor 
contributor to visibility impairment on the 20 percent most impaired 
days at the Class I areas in North Carolina during the baseline 
period of 2000-2004.
    \76\ DAQ notes that elemental carbon is the primary visibility 
impairing pollutant related to wildfires, prescribed wildland fires, 
and agricultural burning. Elemental carbon is a relatively minor 
contributor to visibility impairment on the 20 percent most impaired 
days from the base period (2000-2004) through 2018 at the Class I 
areas in North Carolina based on IMPROVE monitoring data as 
discussed in Section 2.4 of the 2022 Plan.
---------------------------------------------------------------------------

    e. Interstate Consultation: North Carolina consulted with states 
\77\ and RPOs that identified North Carolina sources as impacting those 
states' (or states within the RPOs') Class I areas, and DAQ consulted 
with the 10 states with one or more sources exceeding North Carolina's 
PSAT threshold at one or more of North Carolina's Class I areas.
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    \77\ New Hampshire and New Jersey are the only states that 
requested consultation with North Carolina.
---------------------------------------------------------------------------

    i. State/RPOs Requesting Consultation with North Carolina:
    a. MANE-VU Ask: The following summarizes the conclusions of 
consultation related to the MANE-VU Ask for North Carolina.\78\ Section 
I.E of the TSD provides a more detailed summary of the State's 
interstate consultation pursuant to 40 CFR 51.308(f)(2)(ii).
---------------------------------------------------------------------------

    \78\ MANE-VU refers to the emission reduction measures 
identified in other states as being necessary to make reasonable 
progress as ``Asks.'' The MANE-VU Ask to states outside of the MANE-
VU Region is available at: https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf.
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    The MANE-VU Ask for states outside of MANE-VU addresses both 
statewide impacts to visibility and specific emissions units' 
visibility impacts. States that contributed greater than or equal to 
two percent of the visibility impairment to a Class I area and had an 
average mass impact of over one percent (0.01 microgram per cubic 
meter) on a statewide basis were identified for consultation and 
included in the Inter-RPO Ask. Additionally, any emissions units having 
the potential for a 3.0 Mm-1 or greater light extinction 
impact on any MANE-VU Class I area based on CALPUFF modeling of 2011 
SO2 and NOX emissions were identified for 
consultation in the MANE-VU Ask.
    In a letter dated October 16, 2017, MANE-VU requested consultation 
with North Carolina on the basis that North Carolina was identified as 
impacting MANE-VU Class I area(s) on both a statewide basis and 
emission unit basis. On a statewide basis, MANE-VU claimed that North 
Carolina's percent mass-weighted sulfate and nitrate contributions from 
North Carolina to MANE-VU Class I areas in 2015 exceeds the RPO's two 
percent threshold for five Class I areas in MANE-VU.\79\ On an 
emissions unit basis, the No.1 Power Boiler at North Carolina's 
Kapstone Kraft Corporation (``Kapstone'') was identified as having the 
potential to exceed the 3.0 Mm-1 or greater visibility 
impact threshold set by MANE-VU for any Class I area in the MANE-VU 
region.\80\
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    \79\ See Tables 2 and 3 of Appendix F-4 of the Haze Plan.
    \80\ The August 25, 2017, MANE-VU document identifying maximum 
potential visibility impacts from the No. 1 Power Boiler at Kapstone 
Kraft Corporation in North Carolina is located at: https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf.
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    Regarding statewide visibility impacts to MANE-VU Class I areas, 
North Carolina disagreed with MANE-VU that North Carolina's statewide 
emissions are impacting visibility at any MANE-VU Class I areas. North 
Carolina's viewpoints are reflected in the January 27, 2018, letter 
from VISTAS to MANE-VU. To resolve the disagreement, North Carolina 
sent a response letter on February 16, 2018, to MANE-VU and noted 
several disagreements with MANE-VU's analysis.
    Regarding Kapstone's visibility impacts to MANE-VU Class I areas, 
in a letter dated February 16, 2018, DAQ clarified the status of the 
No. 1 Power Boiler at KapStone that was initially identified in a 
September 5, 2017, document from MANE-VU as having the potential for a 
maximum 6.0 Mm-1 light extinction impact on a MANE-VU Class 
I area based on CALPUFF modeling of the facility's 2011 SO2 
and NOX emissions.\81\ DAQ reviewed the modeling 
documentation and found that the maximum potential light extinction 
impact modeled for the power boiler was 0.28 Mm-1 for MANE-
VU Class I areas and 0.47 Mm-1 for Class I areas near the 
MANE-VU region shown in Table 1 of the 2018 letter. Based on 
discussions with MANE-VU representatives, there was agreement that the 
initial light extinction values shown in Table l of the 2018 letter are 
correct for the No. 1 Power Boiler and that the boiler should not be 
included in the MANE-VU Ask.
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    \81\ The September 5. 2017, MANE-VU document, ``Selection of 
States for MANE-VU Regional Haze Consultation (2018)'', is available 
at: https://otcair.org/manevuUpload/Publication/Reports/MANE-VU%20Contributing%20State%20Analysis%20Final.pdf.
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    North Carolina documented the State's responses and viewpoints with 
respect to the MANE-VU Ask in Section 10 and Appendix F-4 of the 2022 
Plan. North Carolina proposes that it fulfilled the consultation 
requirements under 40 CFR 51.308(f)(2)(ii) by the State's active 
participation in the MANE-VU consultation process and by the State's 
documented responses to MANE-VU. Thus, DAQ determined that no further 
action is required under the RHR to address MANE-VU's requests.
    b. Proposed Plan Comments from MANE-VU, New Hampshire, and New 
Jersey: MANE-VU, New Hampshire, and New Jersey provided written 
comments on the North Carolina haze plan proposed for public comment at 
the State level.\82\ In total, there are five MANE-VU Inter-RPO Asks 
for states outside of the MANE-VU Region. Regarding Asks 1, 4, and 5, 
MANE-VU, New Hampshire, and New Jersey acknowledged in their comments 
on the North Carolina prehearing plan that the existing measures in 
North Carolina address these three asks. Regarding Ask 2, MANE-VU 
determined that this ask does not apply to North Carolina. Regarding 
Ask 3, DAQ reviewed the MANE-VU, New Hampshire, and New Jersey 
recommendations for the State to adopt an ultra-low sulfur fuel (ULSF) 
oil standard consistent with Ask 3 and explained in the 2022 Plan why 
it would not be reasonable to do so. DAQ evaluated residual and 
distillate oil use in North Carolina and concluded that adopting an 
ULSF standard would provide ``very little'' reduction in SO2 
emissions or any noticeable improvement in visibility in Class I areas 
in North Carolina and in downwind states.
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    \82\ MANE-VU, New Hampshire, and New Jersey submitted a letter 
dated October 12, 2021, and New Jersey also submitted a letter dated 
October 15, 2021, providing comments on North Carolina's proposed 
haze plan. These letters are included in Appendix I of the 2022 
Plan.

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[[Page 67358]]

    ii. North Carolina's Requests for Consultation with Other States: 
Consultation with other states with sources contributing to regional 
haze at North Carolina's Class I areas is discussed in Section 10 and 
Appendix F of the 2022 Plan. As listed in Tables 7-37 and 7-38 of the 
2022 Plan, North Carolina requested a FFA of 16 sources in 10 other 
states because these sources exceeded the State's sulfate PSAT 
threshold at one or more of North Carolina's Class I areas.\83\ DAQ 
documented the responses from the 10 states in Section 10.1.1 of the 
2022 Plan. Section I.E.3 of the TSD provides more details regarding the 
consultation related to these sources.
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    \83\ The 16 sources are: Entergy Arkansas Inc-Independence Plant 
in Arkansas; Plant Bowen in Georgia; Gibson and Indiana Michigan 
Power DBA AEP Rockport in Indiana; Tennessee Valley Authority (TVA)-
Shawnee in Kentucky; New Madrid Power Plant-Marston in Missouri; 
Cardinal Power Plant--Cardinal Operating Company (Cardinal Power 
Plant); Duke Energy Ohio--Wm. H. Zimmer Station (Duke-Zimmer); and 
General James M. Gavin Power Plant (Gavin Power Plant) in Ohio; 
Homer City Gen LP/Center and Genon NE Mgmt Co/Keystone Station in 
Pennsylvania; Eastman and TVA-Cumberland in Tennessee; Jewell Coke 
Company LLP in Virginia; and Allegheny--Harrison and Monongahela--
Pleasants Power Station in West Virginia. North Carolina requested 
FFAs of non-VISTAS sources through VISTAS.
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    3. EPA Evaluation: EPA has reviewed DAQ's source selection 
criteria, consideration of the four factors, determinations of controls 
necessary for reasonable progress, submitted permit conditions, 
documentation of technical basis, interstate consultation, and 
consideration of the five additional factors. Based on this review, EPA 
finds that North Carolina's LTS satisfies 40 CFR 51.308(f)(2) but for 
concerns with the legal and practicable enforceability of certain 
Domtar and PCS permit conditions identified for incorporation into the 
SIP. As discussed above, North Carolina has committed to provide EPA 
with a SIP submission no later than one year from the effective date of 
a final conditional approval action that would adequately address the 
legal and practicable enforceability concerns identified in this 
document. Therefore, EPA is proposing to conditionally approve the 
sections of the Haze Plan addressing 40 CFR 51.308(f)(2). If North 
Carolina submits the required SIP revision by the specified deadline 
and EPA approves the submission, then the identified enforceability 
concerns will be cured and the conditional approval of the sections of 
the Haze Plan addressing 40 CFR 51.308(f)(2) will be converted to a 
full approval. Sections IV.C.3.b.ii and IV.C.3.b.iii of this document 
discuss the enforceability concerns with the Domtar and PCS permit 
conditions, respectively, and North Carolina's commitments to resolve 
these concerns. Although EPA finds that North Carolina's LTS satisfies 
40 CFR 51.308(f)(2) but for the enforceability concerns with certain 
Domtar and PCS permit conditions identified for incorporation into the 
SIP, EPA is soliciting comment on the adequacy of DAQ's analyses, 
including the FFAs, determination of controls necessary for reasonable 
progress, and the adequacy of the submitted permit conditions, 
including associated monitoring, recordkeeping, and reporting, and 
whether the State has met the requirements of 40 CFR 51.308(f)(2)(i) 
through (iv).
    a. Source Selection Criteria: EPA finds that North Carolina's 
source selection was reasonable. The Haze Plan supports this finding, 
because it contains information such as Appendix C which includes 
monitoring and meteorological data used to support selection of 
sources; Appendix D which provides documentation supporting the AoI 
analyses (first step of the State's source selection process); and 
Appendix E which details the visibility and source apportionment data 
used and results from the PSAT modeling (second step of the State's 
source selection process). However, EPA finds this source selection 
requirement is not separable from the overarching requirement of 40 CFR 
51.308(f)(2) to establish a LTS. As explained previously in this 
document, EPA is proposing to conditionally approve North Carolina's 
LTS due to concerns with the legal and practical enforceability of 
certain permit conditions identified in the Haze Plan for incorporation 
into the SIP. Accordingly, EPA finds that the Haze Plan will only meet 
all requirements of 40 CFR 51.308(f)(2) if North Carolina meets its 
commitment to submit the corrective SIP revision described in its 
Commitment Letter no later than one year from the effective date of a 
final conditional approval action, should EPA finalize the proposed 
partial conditional approval, and EPA approves that SIP revision. North 
Carolina included a description of the criteria that the State used to 
determine which sources the State evaluated for emissions controls.
    EPA also finds that North Carolina's source selection resulted in a 
reasonable set of sources contributing to visibility impairment at 
Class I areas affected by North Carolina's sources. AoI and PSAT are 
acceptable and well-established methods for selecting sources for a 
control analysis and they enable the identification of the sources that 
have the largest impacts on visibility at Class I areas in North 
Carolina and neighboring states,\84\ and the State identified three 
North Carolina sources for a control evaluation and identified 16 out-
of-state sources for which they requested a control evaluation through 
interstate consultation. Additionally, statewide SO2 
emissions are expected to decrease in the second planning period from 
2019 levels of 34,712 tpy SO2 to projected 2028 levels of 
32,644 tpy SO2 (a six percent reduction) which occurred 
after a 63 percent decrease in statewide SO2 emissions from 
2011 to 2018 by 74,830 tpy SO2, and statewide NOX 
emissions are expected to decrease in the second planning period from 
2019 levels of 223,264 tpy NOX to projected 2028 levels of 
138,986 tpy NOX (approximately a 38 percent reduction) which 
occurred after a 37 percent decrease in statewide NOX 
emissions from 2011 to 2018 by 137,820 tpy NOX.\85\ 
Additional emissions reductions from permanent shutdowns which have not 
been reflected in the 2028 emissions projections and 2028 RPGs are 204 
tons of SO2 and 208 tons of SO2 based on 2016 
actual and projected 2028 SO2 emissions, respectively, and 
248 tons of NOX and 287 tons of NOX based on 2016 
and projected 2028 NOX emissions, respectively. Visibility 
conditions in North Carolina's Class I areas in 2028 are estimated to 
improve since the 2000-2004 baseline period by 14.1 deciviews (Great 
Smoky Mountains and Joyce Kilmer), 13.8 deciviews (Linville Gorge), 
14.8 deciviews (Shining Rock), and 8.5 deciviews (Swanquarter).\86\ 
Specific to the second planning period, visibility conditions in North 
Carolina's Class I areas in 2028 are estimated to improve since the 
2014-2018 period by 2.2 deciviews (Great Smoky Mountains, Joyce Kilmer, 
Linville Gorge, Shining Rock), and 1.0 deciview (Swanquarter). These 
projected second planning period visibility improvements represent 
approximately \87\ 30 percent (Great

[[Page 67359]]

Smoky Mountains and Joyce Kilmer); 32 percent (Linville Gorge), 40 
percent (Shining Rock), and 16 percent (Swanquarter) of the additional 
progress needed to reach natural conditions at each Class I area. 
Additionally, using the most recently available 20 percent most 
impaired days IMPROVE data (2018-2022) \88\ for the 20 percent most 
impaired days,\89\ in the first four years of the second planning 
period, North Carolina's Class I areas have already achieved 25 percent 
(Great Smoky Mountains and Joyce Kilmer),\90\ 25 percent (Linville 
Gorge), 27 percent (Shining Rock), and 21 percent (Swanquarter) of the 
remaining progress needed to reach natural conditions. Also, North 
Carolina is not contributing to visibility impairment at any Class I 
areas above the URP, and the State appropriately focused on controlling 
point source SO2 emissions based on data showing ammonium 
sulfate is the dominant visibility impairing pollutant at the North 
Carolina Class I areas.
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    \84\ The State used the AoI process because it identifies the 
largest sources with potential visibility impacts to Class I areas 
and then used sophisticated photochemical source apportionment 
modeling to identify specific sources for control evaluations. See 
also 2019 Guidance, pp. 12-13.
    \85\ North Carolina's statewide emissions of SO2 and 
NOX decreased during the period from 2011 to 2018 from 
118,721 tpy SO2 to 43,891 tpy SO2 and 
decreased from 369,496 to 231,676 tpy NOX. See Tables 13-
9 and 13-10 of the Haze Plan.
    \86\ See Table 8-1 of the Haze Plan.
    \87\ See visibility data for the 20 percent most impaired days 
data from Table 8-1 of the Haze Plan. Percentage of progress toward 
natural conditions = [((2014-2018 IMPROVE data)-(2028 RPG))/((2014-
2018 IMPROVE data)-(Natural visibility conditions))] x 100. Example 
calculation for Great Smoky Mountains: [(17.21-15.03)/(17.21-10.05)] 
x 100 = 30.4 percent.
    \88\ The 2018-2022 IMPROVE data for the 20 percent most impaired 
days was obtained from https://vista.cira.colostate.edu/Improve/rhr-summary-data/ under the header ``Means for Impairment Metric:''. The 
IMPROVE data includes visibility monitoring data for each Class I 
area. This data was filtered for each Class I area, listed as 
``GRSM1'' (Great Smoky Mountains whose data also represents Joyce 
Kilmer), ``LIGO1'' (Linville Gorge), ``SHRO1'' (Shining Rock), 
``SWAN1'' (Swanquarter), respectively, (in column ``A'', titled 
``site''). Then data was filtered for the years 2018 through 2022 
(using column ``B'' titled ``year''). These data points were then 
filtered for the 20 percent most impaired days, indicated by ``90'' 
(in column ``C'' titled ``impairment_Group''). The resulting data 
points for each North Carolina Class I area within the ``haze_dv'' 
column ``AK'', corresponding to each of the five years, were 
averaged to determine the 20 percent most impaired days for the 
2018-2022 five-year period. The 2018-2022 IMPROVE data for North 
Carolina's Class I areas are: 15.4 deciviews (Great Smoky Mountains 
and Joyce Kilmer), 14.7 deciviews (Linville Gorge), 14.0 deciviews 
(Shining Rock), and 14.9 deciviews (Swanquarter).
    \89\ The 2014-2018 IMPROVE data was provided by North Carolina 
in Table 8-1 of the Haze Plan.
    \90\ Percentage of progress toward natural conditions = [((2014-
2018 IMPROVE data)-(2018-2022 IMPROVE data))/((2014-2018 IMPROVE 
data)-(Natural visibility conditions))] x100. Example calculation 
for Great Smoky Mountains: [(17.21-15.4)/(17.21-10.05)] x 100 = 25 
percent.
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    Although North Carolina did not select any Duke Energy sources for 
analysis, EPA conducted further review of five Duke Energy facilities 
to evaluate the reasonableness of North Carolina's source selection--
DEC--Belews Creek Steam Station (DEC-Belews Creek), DEC--Cliffside 
Steam Station (DEC-Cliffside), DEC-Marshall, Duke Energy Progress, LLC 
(DEP)--Mayo Electric Generating Plant (DEP-Mayo), and DEP--Roxboro 
Steam Electric Plant (DEP-Roxboro). EPA identified these five 
facilities for further review because, in the VISTAS AoI analysis, DEC-
Belews Creek, DEC-Cliffside, and DEC-Marshall ranked in the top 10 
facility sulfate impacts at Shining Rock; DEC-Belews Creek and DEC-
Cliffside ranked in the top 10 facility sulfate impacts at Linville 
Gorge; DEP-Roxboro ranked in the top 10 facility sulfate impacts at 
Swanquarter; DEP-Roxboro ranked in the top 10 facility sulfate impacts 
at James River Face in Virginia; and DEP-Mayo ranked in the top 20 
facility sulfate impacts at James River Face. EPA assessed whether 
these five Duke Energy facilities are effectively controlled for 
SO2 \91\ and whether any cost-effective new emissions 
reduction measures for SO2 would have likely resulted from a 
FFA had these sources met the State's source selection criteria.
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    \91\ EPA did not evaluate NOX controls for these 
facilities because EPA proposes to agree with North Carolina's 
conclusion that ammonium sulfate continues to be the dominant 
visibility impairing pollutant at North Carolina's Class I areas. 
See Section IV.C.2.a of this notice.
---------------------------------------------------------------------------

    The 2019 Guidance provides several scenarios in which EPA believes 
it may be reasonable for a state not to select a particular source for 
further analysis. Two of these scenarios are applicable to the five 
Duke facilities--a coal-fired EGU that has add-on flue gas 
desulfurization (FGD) and meets the applicable alternative 
SO2 emission limit of 0.2 pound (lb) per million British 
Thermal Units (MMBtu) (lb/MMBtu) in the Mercury and Air Toxics 
Standards (MATS) rule for power plants; \92\ and an EGU that, during 
the first period, installed a FGD system that operates year-round with 
an effectiveness of at least 90 percent. The 2019 Guidance states that 
in both cases, it is unlikely that an analysis of control measures for 
a source already equipped with a scrubber and meeting a 0.20 lb/MMBtu 
limit or greater than 90 percent efficiency would conclude that even 
more stringent control of SO2 is necessary to make 
reasonable progress. See 2019 Guidance at 23.
---------------------------------------------------------------------------

    \92\ The MATS rule is located at 40 CFR part 63, subpart UUUUU.
---------------------------------------------------------------------------

    Each of the five Duke sources are equipped with WFGD and are 
subject to the alternative SO2 emissions limit from the MATS 
rule. EPA evaluated the WFGD SO2 control efficiencies at 
each of the coal-fired units at these five sources as follows: DEC-
Belews Creek (Units 1, 2); DEC-Cliffside (Units 5 and 6); DEC-Marshall 
(Units 1-4); DEP-Mayo (Units 1A and 1B); DEP-Roxboro (Units 1, 2, 3A, 
3B, 4A, 4B). Data from 2017-2021 indicate that existing WFGD systems at 
these units at the five Duke facilities routinely achieve 92 to 98 
percent SO2 removal efficiencies with some month-to-month 
variation in performance.\93\ Because these coal units are subject to 
the MATS alternative SO2 emission limit of 0.2 lb/MMBtu and 
are equipped with WFGD that routinely achieve a high SO2 
control effectiveness, it reasonable to assume that a FFA would likely 
result in the conclusion that no further controls are necessary.
---------------------------------------------------------------------------

    \93\ This data is available through EPA's Clean Air Markets 
Program at: https://campd.epa.gov/data. A summary of the WFGD 
control efficiency data for the years 2017-2022 for DEC-Belews Creek 
(Units 1, 2); DEC-Cliffside (Units 5 and 6); DEC-Marshall (Units 1-
4); DEP-Mayo (Units 1A and 1B); and DEP-Roxboro (Units 1, 2, 3A, 3B, 
4A, 4B) is compiled in a spreadsheet which is included in the docket 
for this proposed rulemaking.
---------------------------------------------------------------------------

    b. Consideration of the Four CAA Factors: EPA finds that North 
Carolina reasonably evaluated and determined, under the four CAA 
factors, the emission reduction measures for the selected sources that 
are necessary to make reasonable progress but for the concerns with the 
legal and practicable enforceability of certain Domtar and PCS permit 
conditions identified for incorporation into the SIP for the reasons 
discussed below.\94\
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    \94\ See also Section I.B of the TSD for additional details 
regarding North Carolina's FFAs.
---------------------------------------------------------------------------

    i. BRPP: Regarding BRPP, EPA finds that DAQ's conclusions that 
existing SO2 measures at BRPP's Riley Coal Boiler, Riley 
Bark Boiler, and the No. 4 Power Boiler are necessary for reasonable 
progress for the second planning period to be reasonable. The State 
evaluated available and technically feasible SO2 controls 
that were based on, where applicable, estimated values of capital 
costs, annualized costs, and cost per ton of emission reductions, and 
were consistent with recommendations in EPA's ``Air Pollution Control 
Cost Manual'' (Cost Manual).\95\ WFGD with approximately a 90 percent 
control efficiency is an existing SO2 control for these 
units, and the recently installed control measures are estimated to 
reduce the 2028 projected emissions for the facility from approximately 
5,875 tons to 485 tons of SO2.\96\ Additionally, EPA finds 
that DAQ reasonably concluded that the addition of DSI controls at 
$13,477/ton and $14,752/ton for the Riley Coal Boiler and No. 4 power 
Boiler, respectively, and the ULSD at over $126,000/ton for all three 
units, are not necessary to make reasonable progress. The associated

[[Page 67360]]

existing SO2 emissions limits for these boilers, summarized 
in Table 7-48 of the 2022 Plan, are already adopted into the North 
Carolina SIP effective November 24, 2020.\97\
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    \95\ EPA's Cost Manual is available at: https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution.
    \96\ Tables 7-5 and 7-26 of the 2022 Plan display 2028 BRPP 
SO2 emissions projections as 405 tpy. Table 7-49 of the 
2022 Plan identifies the 2028 BRPP SO2 emissions 
projections as 485 tpy.
    \97\ See 85 FR 74884 (November 24, 2020) available at: https://www.govinfo.gov/content/pkg/FR-2020-11-24/pdf/2020-25464.pdf.
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    ii. Domtar: Regarding Domtar, EPA finds that DAQ's exclusion of 
HFB1 from FFA review is reasonable because it is equipped to only burn 
natural gas and biomass with No. 2 fuel oil as a backup unit and is 
projected to emit 12 tpy of SO2 in 2028, which is only one 
percent of Domtar's total SO2 emissions. EPA also finds that 
DAQ's control analysis and conclusions that the existing SO2 
measures at Domtar's HFB2 are necessary for reasonable progress for the 
second planning period are reasonable, except for EPA's concerns with 
the legal and practicable enforceability of certain permit conditions 
identified for incorporation into the SIP from Domtar's title V permit. 
The State evaluated available and technically feasible SO2 
control measures for HFB2 that were based on, where applicable, 
estimated values of capital costs, annualized costs, and cost per ton 
of emission reductions prepared according to EPA's Cost Manual. The 
cost effectiveness of DSI is $22,092/ton and the cost effectiveness of 
the WFGD is $3,660/ton using a conservative 3.25 percent interest 
rate.\98\
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    \98\ See https://fred.stlouisfed.org/series/PRIME for historical 
interest rates. As of July 22, 2024, the current bank prime interest 
rate is 8.5 percent. (See: https://www.federalreserve.gov/releases/h15/).
---------------------------------------------------------------------------

    North Carolina's LTS contains deficiencies that preclude full 
approval and, based on the State's commitment to address these 
concerns, EPA is proposing to conditionally approve the LTS portion of 
the Haze Plan. As discussed in Section III of this document, each 
state's regional haze SIP must include a LTS that contains enforceable 
emissions limitations, compliance schedules, and other measures that 
are necessary to make reasonable progress. See CAA section 169A(b)(2), 
40 CFR 51.308(f)(2). Furthermore, CAA section 110(a)(2)(A) requires 
SIPs to ``include enforceable conditions and other control measures, 
means or techniques . . . as may be necessary or appropriate'' to meet 
the requirements of the Act. As EPA has repeatedly stated, to be 
enforceable, a CAA requirement must be legally and practically 
enforceable, and there is a considerable body of applicable EPA rules, 
EPA guidance, and EPA-approved state practices on the topic of 
practicably enforceable emission limits.\99\ Typically, a primary 
mechanism for ensuring that a SIP provision is legally and practicably 
enforceable is for a state to impose sufficient monitoring, 
recordkeeping, and reporting (MRR) requirements on affected sources.
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    \99\ See, e.g., 57 FR 13497, 13567 (April 16, 1992) (explaining 
principles, including enforceability, to which SIPs and implementing 
instruments must adhere to help assure that planned emission 
reductions will be achieved); 80 FR 33840, 33843, 33865, 33890, 
33891, 33903 (June 12, 2015) (discussing the requirement that SIP 
emission limits must be practicably enforceable and stating that 
``[t]he term practically enforceable means, in the context of a SIP 
emission limitation, that the limitation is enforceable as a 
practical matter (e.g., contains appropriate averaging times, 
compliance verification procedures and recordkeeping 
requirements).''
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    EPA's rules regarding the preparation, adoption, and submittal of 
SIPs at 40 CFR part 51 also contain requirements concerning the 
enforceability of SIP emission limits. For example, SIPs must include 
enforceable test methods for each emission limit included in the plan. 
See 40 CFR 51.212. SIPs must also provide legally enforceable methods 
requiring owners or operators of stationary sources to maintain records 
of and periodically report to the State information regarding the 
nature and number of emissions from a stationary source and other 
information as it may be necessary for a state to determine if the 
source is in compliance with the control strategy. See 40 CFR 51.211. 
Furthermore, the SIP completeness criteria in 40 CFR part 51, appendix 
V state that complete SIPs contain ``evidence that the plan contains 
emission limitations, work practice standards and recordkeeping/
reporting requirements, where necessary, to ensure emission levels'' 
and ``compliance/enforcement strategies, including how compliance will 
be determined in practice.'' See 40 CFR 51.103; 40 CFR part 51, 
appendix V, sections 2.2(g), (h).
    North Carolina's SIP revision relies on certain existing emission 
limits in the title V permit for Domtar to achieve reasonable progress 
towards the national visibility goal. These emission limits must be 
legally and practically enforceable, as required under sections 
110(a)(2)(A) and 169A(b)(2) of the Act, and the SIP must satisfy EPA's 
rules regarding the enforceability of SIP emission limits. Section 
7.8.3.1 of the Haze Plan identifies SO2 emission limits from 
Conditions 2.1 A.4 and 2.1 A.7 of Domtar title V Air Quality Permit No. 
04291T51 for incorporation into the SIP as well as several other 
provisions in these Conditions, including A.4.c.\100\ The conditions 
listed in italics under Section 7.8.3.1 are identified for 
incorporation into the SIP with the exception of any text marked in 
strikeout.
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    \100\ The State requested in the Haze Plan for EPA to 
incorporate specific permit conditions from Domtar title V Air 
Quality Permit No. 04291T50. However, this permit was superseded 
after EPA received the SIP revision. In an email dated March 28, 
2024, DAQ asks EPA to instead incorporate the same terms from the 
current Domtar title V permit (DAQ Air Quality Permit No. 04291T51) 
and confirms that the text of the permit conditions identified for 
incorporation into the SIP in Section 7.8.3.1 of the Haze Plan from 
Permit No. 04291T50 has not changed. The March 28, 2024, email and 
the current Domtar permit are included in the docket for this 
proposed rulemaking.
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    Condition 2.1 A.4.a contains an SO2 emission limit of 
2.3 lbs/MMBtu heat input when firing wood or natural gas. This limit 
also applies when burning waste gases with wood and/or natural gas. 
However, the SIP revision does not include a methodology to evaluate 
compliance with the 2.3 lbs/MMBtu emission limit. EPA considers the 
lack of a compliance methodology as a deficiency because it undermines 
the enforceability of the emission limit. In its Commitment Letter, 
North Carolina has committed to address this concern by revising 
Condition 2.1 A.4 of Permit No. 04291T51 to include a condition 
containing a procedure to monitor and evaluate compliance with the 
SO2 emission limit of 2.3 lbs/MMBtu in Condition 2.1 A.4.a 
and submitting a SIP revision, no later than one year from the 
effective date of a final conditional approval action (should EPA 
finalize the proposed partial conditional approval), requesting 
incorporation of the condition into the SIP.
    Condition 2.1 A.4.c states that monitoring, recordkeeping, and 
reporting are not required for the combustion of wood residue and 
natural gas. However, as discussed above, these SIP-approved emission 
limits must have adequate monitoring, recordkeeping, and periodic 
reporting requirements in order to be legally and practicably 
enforceable, and the SIP must satisfy EPA's rules regarding the 
enforceability of SIP emission limits which require monitoring, 
recordkeeping, and periodic reporting. To address this concern, North 
Carolina submitted a letter dated July 30, 2024, withdrawing from the 
Haze Plan the State's request for EPA to incorporate Condition 2.1 
A.4.c into the SIP,\101\ and in its Commitment Letter, North Carolina 
committed to submit a

[[Page 67361]]

SIP revision, no later than one year from the effective date of a final 
conditional approval action (should EPA finalize the proposed partial 
conditional approval), requesting incorporation of Conditions 4 I.B., 
P, and X into the SIP.\102\
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    \101\ In a July 30, 2024, letter, DAQ withdrew the State's 
request for EPA to incorporate Condition 2.1 A.4.c from Domtar Paper 
Company's title V air permit for its Plymouth facility into the 
North Carolina SIP. This request appeared in Section 7.8.3.l of the 
Haze Plan narrative on pages 284-285. The July 30, 2024, letter of 
withdrawal is included in the docket for this proposed rulemaking.
    \102\ North Carolina's SIP contains a recordkeeping provision at 
15 NCAC 02D .0605 that requires the owner or operator of a source 
subject to the requirements of 15 NCAC 02D or 02Q, such as Domtar, 
to maintain for two years ``(1) records detailing malfunctions 
pursuant to 15A NCAC 02D .0535; (2) records of testing conducted 
pursuant to rules in Subchapter 02D; (3) records of monitoring 
conducted pursuant to Subchapters 02D or 02Q of this Chapter; (4) 
records detailing activities relating to compliance schedules in 
this Subchapter [02D]; and (5) for unpermitted sources, records 
needed to determine compliance with rules in Subchapters 02D or 02Q 
of this Chapter.'' See 15 NCAC 02D .0605(a), (e).
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    Condition 2.1 A.7.a contains an SO2 emission limit of 
0.80 lb/MMBtu heat input when firing oil and wood/lignin. Condition 2.1 
A.7 identifies fuel sampling and analysis as the method to evaluate 
compliance with the 0.80 lb/MMBtu emission limit; however, the 
Condition does not identify a method to convert fuel sampling and 
analysis data into SO2 emissions values comparable with the 
emission limit. This emission limit is not practicably enforceable for 
SIP purposes without inclusion of a corresponding conversion 
methodology. In its Commitment Letter, North Carolina has committed to 
address this concern by revising Condition 2.1 A.6 and/or Condition 2.1 
A.7 of Permit No. 04291T51 to include a condition containing a 
procedure to monitor and evaluate compliance with the SO2 
emission limit of 0.80 lb/MMBtu in Condition 2.1 A.7.a and submitting a 
SIP revision, no later than one year from the effective date of a final 
conditional approval action (should EPA finalize the proposed partial 
conditional approval), requesting incorporation of the monitoring 
condition into the SIP.
    Given the concerns identified above, and North Carolina's 
Commitment Letter containing the aforementioned commitments to address 
these identified concerns related to Domtar, EPA is proposing to 
conditionally approve the sections of the Haze Plan addressing the 
requirements of 40 CFR 51.308(f)(2), (f)(3), and (i)(2) through(4).
    iii. PCS: Regarding PCS, EPA finds that DAQ's control analysis and 
conclusions that the existing SO2 measures at PCS' SAPs 5, 
6, and 7 are necessary for reasonable progress for the second planning 
period are reasonable, except for EPA's concerns with the legal and 
practicable enforceability of certain permit conditions identified for 
incorporation into the SIP from PCS' title V permit. The State 
adequately demonstrated that there are no technically feasible 
SO2 control measures for sulfuric acid plants beyond dual 
absorption process with cesium catalyst, the current SO2 
control measure at SAPs 5, 6, and 7.
    North Carolina's SIP revision relies on certain existing emission 
limits in the title V permit for PCS to achieve reasonable progress 
towards the national visibility goal. However, EPA finds that these 
emission limits are not legally and practicably enforceable. As 
discussed above, these emission limits must be legally and practically 
enforceable, as required under sections 110(a)(2)(A) and 169A(b)(2) of 
the Act, and the SIP must satisfy EPA's rules regarding the 
enforceability of SIP emission limits. Section 7.8.3.2 of the Haze Plan 
identifies SO2 emission limits from Condition 2.4 A.1 of PCS 
title V Air Quality Permit No. 04176T72 for incorporation into the SIP 
as well as several other provisions in Condition 2.4 A.1, including 
Conditions A.1.m and A.1.o.\103\ \104\ The conditions listed in italics 
under Section 7.8.3.2 are identified for incorporation into the SIP 
with the exception of any text marked in strikeout. A summary of EPA's 
finding and North Carolina's commitment to address the lack of 
enforceability of these emission limits is found below.
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    \103\ Condition 2.4 A.1 of Air Quality Permit No. 04176T72 
includes the SO2 emissions limits for Sulfuric Acid 
Plants Nos. 5, 6, and 7 required under a February 26, 2015, consent 
decree between EPA and PCS that terminated on April 3, 2023. The 
consent decree and termination order are in the docket for this 
proposed rulemaking. Although the consent decree is terminated, the 
emission limits ``shall never be relaxed.'' See Condition 2.4 A.1.f.
    \104\ The statement in the first bullet on p. 288 of the 2022 
Plan that reads ``Section 2.5 A.1.b through d, f'' is correct. The 
paragraph letters ``a'', ``b'', and ``c'' in the italicized text are 
incorrect and should read ``b'', ``c'', and ``d'', respectively. The 
State requested in the Haze Plan for EPA to incorporate specific 
permit conditions from PCS title V Air Quality Permit No. 04176T66 
into the SIP. However, this permit was superseded after EPA received 
the SIP revision. In an email dated July 30, 2024, DAQ asks EPA to 
incorporate the same terms from the current PCS title V permit (DAQ 
Air Quality Permit No. 04176T72). The email confirms that the text 
of the permit conditions identified for incorporation into the SIP 
in Section 7.8.3.2 of the Haze Plan from Permit No. 04176T66 has not 
changed with the exception of the renumbering of Section 2.5 to 
Section 2.4 and the correction of a typographical error to a cross-
reference in condition 2.5 A.1.p (currently 2.4 A.1.p) in the PCS 
permit.
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    The monitoring provision in Condition 2.4 A.1.m requires the 
permittee to monitor SO2 emissions in accordance with the 
CEMS Plan (Attachment 2 to the permit). However, the 2022 Plan excludes 
Attachment 2 and the reference to Attachment 2 from the request to 
incorporate Condition 2.4 A.1.m into the SIP. Similarly, the first 
sentence of the monitoring provision in Condition 2.4 A.1.o requires 
the permittee to use analyzer data to determine 3-hour rolling averages 
and 365-day rolling averages per Attachment 2, and the second sentence 
requires the permittee to round calculations associated with these 
averages using the procedures specified in Attachment 2. However, the 
2022 Plan excludes the second sentence and the reference to Attachment 
2 in the first sentence from the request to incorporate Condition 2.4 
A.1.o into the SIP. EPA considers this exclusion of monitoring 
requirements from Conditions 2.4 A.1.m and 2.4 A.1.o to be a deficiency 
because the lack of monitoring requirements undermines the 
enforceability of the SO2 emission limits identified for 
incorporation into the SIP. In its Commitment Letter, North Carolina 
has committed to address these concerns by submitting, no later than 
one year from the effective date of a final conditional approval action 
(should EPA finalize the proposed partial conditional approval), a SIP 
revision requesting incorporation of Conditions 2.4 A.1.m (with the 
exception of Condition 2.4 A.1.m.v) and 2.4 A.1.o in its entirety and 
Attachment 2 of Permit No. 04176T72 into the SIP.
    The SIP revision does not identify any reporting requirements from 
title V permit No. 04176T72 for incorporation into the SIP. As 
discussed above, these emission limits must have adequate monitoring, 
recordkeeping, and periodic reporting requirements in order to be 
legally and practicably enforceable. In its Commitment Letter, North 
Carolina has committed to address this concern by submitting, no later 
than one year from the effective date of a final conditional approval 
action (should EPA finalize the proposed partial conditional approval), 
a SIP revision requesting incorporation of Conditions 4 I.B., P, and X 
into the SIP.\105\
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    \105\ As discussed in Section IV.C.3.b.ii above, North 
Carolina's SIP contains a recordkeeping provision at 15 NCAC 02D 
.0605.
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    Given the concerns identified above and North Carolina's Commitment 
Letter containing the aforementioned commitments to address these 
identified concerns related to PCS, EPA is proposing to conditionally 
approve the sections of the Haze Plan addressing the requirements of 40 
CFR 51.308(f)(2), (f)(3), and (i)(2) through(4).
    c. Documentation of Technical Basis: With respect to 40 CFR 
51.308(f)(2)(iii), EPA finds that North Carolina adequately documented 
cost, engineering, emissions, modeling, and monitoring information to 
determine the measures that are necessary to make reasonable progress. 
With regard to

[[Page 67362]]

emissions information, as required by the RHR, the State included the 
required years of the most recent triennial emissions inventory (2017) 
and the most recent annual emissions data (2019) at the time of the 
development of the 2022 Plan (40 CFR 51.308(f)(2)(iii)). DAQ also 
provided statewide actual emissions inventory data for 2011, 2014, 
2016, 2017, 2018, and 2019 in its 2022 Plan. Additionally, the State 
provided 2028 emissions data used in the source selection process. With 
regard to cost and engineering information, the State provided the 
underlying cost calculations associated with the cost summaries in 
Section 7.8 of the plan for BRPP and Domtar, and the proposed FFAs in 
Appendix G provide engineering analyses evaluating potential new 
control measures.\106\ With regard to monitoring data, the State 
provided IMPROVE data for the modeling base period plus baseline, 
current (2014-2018), updated current (2015-2019), and natural 
conditions for all VISTAS Class I areas with more detailed data 
provided for the North Carolina Class I areas. With regard to modeling 
information, the State documented the modeling input and outputs and 
assumptions in the Haze Plan and the results of the modeling related to 
RPGs and PSAT source impacts at Class I areas.
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    \106\ The State documented that there are no additional 
technical feasible control technologies for SO2 at PCS.
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    d. Assessment of the Five Additional Factors in 40 CFR 
51.308(f)(2)(iv): EPA finds that North Carolina considered each of the 
five additional factors in 40 CFR 51.308(f)(2)(iv), discussed the 
measures the State has in place to address each factor (or discussed 
why such measures are not needed), and, where relevant, explained how 
each factor informed DAQ's and VISTAS' technical analyses for the 
second planning period.
    With respect to 40 CFR 51.308(f)(2)(iv)(A), EPA finds that DAQ 
adequately addressed the requirement to assess emission reductions due 
to ongoing air pollution control programs, including measures to 
address RAVI, through the State's emissions inventory work for the base 
year of 2011 as projected out to 2028.
    With respect to 40 CFR 51.308(f)(2)(iv)(B), EPA finds that North 
Carolina adequately evaluated measures to mitigate the impacts of 
construction activities by describing various State regulations that 
address control of erosion, siltation, and pollution from construction 
activities and that require subject facilities to control PM from 
fugitive dust emission sources generated within plant boundaries.
    With respect to 40 CFR 51.308(f)(2)(iv)(C), EPA finds that North 
Carolina adequately considered source retirement and replacement 
schedules by summarizing existing and planned source retirements 
throughout the 2022 Plan, including in Section 7.2.2 (retirements 
accounted for in the 2028 inventory/RPGs) and Section 8.3.5 
(retirements not accounted for in the 2028 inventory/RPGs). 
Additionally, retirement schedules for various Duke Energy power plant 
facilities are included in Table 7-43 of the 2022 Plan.
    With respect to 40 CFR 51.308(f)(2)(iv)(D), EPA finds that North 
Carolina adequately addressed the requirement to consider the State's 
basic smoke management practices for prescribed fire used for 
agricultural and wildland vegetation management purposes and smoke 
management programs for the following reasons. The State describes its 
Guidelines for Managing Smoke from Forestry Burning Operations to 
mitigate PM2.5 emissions and regional haze impacts 
associated with prescribed burning and highlights interagency 
coordination related to educating North Carolina citizens on open 
burning and related topics.\107\
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    \107\ DAQ notes that elemental carbon is the primary visibility 
impairing pollutant related to wildfires, prescribed wildland fires, 
and agricultural burning. Elemental carbon is a relatively minor 
contributor to visibility impairment on the 20 percent most impaired 
days from the base period (2000-2004) through 2018 at the Class I 
areas in VISTAS and Class I areas neighboring VISTAS based on 
IMPROVE monitoring data as discussed in Section 2.4 of the 2022 
Plan. See Figures 2-17 and 2-18 of the 2022 Plan.
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    With respect to 40 CFR 51.308(f)(2)(iv)(E), EPA finds that North 
Carolina assessed the anticipated net effect on visibility due to 
projected changes in point, area, and mobile source emissions over the 
second period in development of the 2028 RPGs for the North Carolina 
Class I areas. DAQ used the 2011 base year emissions inventory to 
project emissions from various source sectors to 2028, the end of the 
second planning period. DAQ, through VISTAS, completed CAMx modeling to 
estimate visibility impairment in 2028 based on projected 2028 
emissions from the 2011 base year inventory and using IMPROVE 
monitoring data for 2009-2013.\108\ For North Carolina, estimated 
visibility improvements by 2028 in each Class I area are based on: 
estimated emissions reductions associated with existing federal and 
state measures implemented or expected to be implemented during the 
second planning period; emissions reductions associated with facility 
closures that occurred after the 2016 point source emissions base year 
(i.e., January 1, 2017 through November 18, 2018); and estimates of 
emissions changes associated with economic growth and other factors.
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    \108\ In preparing the 2028 emissions for point sources, North 
Carolina started with a 2016 base year inventory which include 
emission reductions associated with federal and state control 
programs and consent decrees included in the LTS for the first 
planning period.
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    e. Interstate Consultation: With respect to interstate consultation 
pursuant to 40 CFR 51.308(f)(2)(ii), EPA finds that North Carolina 
adequately consulted with those states with Class I areas where North 
Carolina emissions may reasonably be anticipated to cause or contribute 
to visibility impairment and to consult with those states whose sources 
may reasonably be anticipated to cause or contribute to visibility 
impairment at North Carolina's Class I areas. No states requested that 
North Carolina perform a FFA of any of the State's sources. With 
respect to the MANE-VU Ask, North Carolina adequately took action to 
resolve disagreements with MANE-VU related to North Carolina's 
statewide impacts and satisfactorily documented the State's 
disagreements by sending the February 16, 2018, letter to MANE-VU 
documenting the State's points of disagreement in addition to 
supporting the January 27, 2018, letter from VISTAS to MANE-VU.\109\ 
With respect to consultation with other states with visibility impacts 
to North Carolina's Class I areas, DAQ adequately documented the 
responses from consulted states in Appendix F and as summarized in 
Section 10.1.1 and identified whether the State agrees with the 
conclusions.
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    \109\ Appendix F-4 of the 2022 Plan contains the January 27, 
2018, and February 16, 2018, letters along with a letter dated 
October 16, 2017, in which MANE-VU requested consultation with North 
Carolina because North Carolina exceeds the MANE-VU visibility 
impact threshold for at least one Class I area in the MANE-VU 
region.
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    f. Conclusions: For the reasons discussed above, EPA finds that 
North Carolina's LTS satisfies 40 CFR 51.308(f)(2) but for the concerns 
with the legal and practicable enforceability of certain Domtar and PCS 
permit conditions identified for incorporation into the SIP. Given this 
finding and North Carolina's commitment to submit a SIP revision 
resolving these concerns, EPA is proposing to conditionally approve the 
sections of the Haze Plan addressing the requirements of 40 CFR 
51.308(f)(2), (f)(3), and (i)(2) through(4).

[[Page 67363]]

D. RPGs

    1. RHR Requirement: Section 51.308(f)(3) contains the requirements 
pertaining to RPGs for each Class I area. Section 51.308(f)(3)(i) 
requires a state in which a Class I area is located to establish RPGs--
one each for the clearest days and the most impaired days--reflecting 
the visibility conditions that will be achieved at the end of the 
planning period as a result of the emission limitations, compliance 
schedules, and other measures required under paragraph (f)(2) to be in 
states' LTSs, as well as the implementation of other CAA requirements. 
The LTSs, as reflected by the RPGs, must provide for an improvement in 
visibility on the most impaired days relative to the baseline period 
and ensure no degradation on the clearest days relative to the baseline 
period. Section 51.308(f)(3)(ii) applies in circumstances in which a 
Class I area's RPG for the most impaired days represents a slower rate 
of visibility improvement than the uniform rate of progress calculated 
under 40 CFR 51.308(f)(1)(vi). Under 40 CFR 51.308(f)(3)(ii)(A), if the 
state in which a mandatory Class I area is located establishes an RPG 
for the most impaired days that provides for a slower rate of 
visibility improvement than the URP, the state must demonstrate that 
there are no additional emission reduction measures for anthropogenic 
sources or groups of sources in the state that would be reasonable to 
include in its LTS. Section 51.308(f)(3)(ii)(B) requires that if a 
state contains sources that are reasonably anticipated to contribute to 
visibility impairment in a Class I area in another state, and the RPG 
for the most impaired days in that Class I area is above the URP, the 
upwind state must provide the same demonstration.
    2. State Assessment: North Carolina identified 2028 RPGs for each 
of its Class I areas in deciviews for the 20 percent clearest days and 
the 20 percent most impaired in Tables 8-1 and 8-2, respectively, of 
the 2022 Plan, which are all well below the 2028 URP value for each 
Class I area by approximately 13 to 23 deciviews (see Table 1) based on 
VISTAS' modeling. Table 4 summarizes the 2028 RPGs and 2028 URP for 
North Carolina's Class I areas.

                   Table 4--North Carolina's Class I Area 2028 RPGs and URP in Deciviews (dv)
----------------------------------------------------------------------------------------------------------------
                                                       2028 RPG for 20%    2028 RPG for 20%    2028 Uniform rate
                    Class I area                         clearest days    most impaired days   of progress (URP)
----------------------------------------------------------------------------------------------------------------
Great Smoky Mountains...............................                8.96               15.03               21.49
Joyce Kilmer........................................                8.96               15.03               21.49
Linville Gorge......................................                8.21               14.25               20.71
Shining Rock........................................                4.54               13.31               20.98
Swanquarter.........................................               10.77               15.27               18.28
----------------------------------------------------------------------------------------------------------------

    Figures 3-1 through 3-4 of the 2022 Plan show the URP for the 20 
percent most impaired days for Great Smoky Mountains and Joyce Kilmer, 
Linville Gorge, Shining Rock, and Swanquarter.
    3. EPA Evaluation: As discussed previously in this document, EPA is 
proposing to conditionally approve the sections of the Haze Plan 
addressing the regional haze requirements contained in 40 CFR 
51.308(f)(2) due to concerns with the legal and practicable 
enforceability of certain permit conditions for Domtar and PCS 
identified for incorporation into the SIP. 40 CFR 51.308(f)(3)(i) 
specifies that RPGs must reflect ``enforceable emissions limitations, 
compliance schedules, and other measures required under paragraph 
(f)(2) of this section.'' Because the RPGs must reflect enforceable 
limits, compliance schedules, and other measures in the LTS and because 
the enforceability issues discussed in Sections IV.C.3.b.ii and 
IV.C.3.b.iii render certain emission limits in the LTS for Domtar and 
PCS unenforceable, EPA finds that North Carolina has satisfied the 
applicable requirements of 40 CFR 51.308(f)(3) related to RPGs but for 
these practicable enforceability concerns and proposes to conditionally 
approve the sections of the Haze Plan addressing the requirements of 40 
CFR 51.308(f)(3). North Carolina established 2028 RPGs expressed in 
deciviews that reflect the visibility conditions that are projected to 
be achieved by the end of the second planning period as a result of 
implementation of the LTS and other CAA requirements; North Carolina's 
RPGs also provide for an improvement in visibility for the 20 percent 
most impaired days since the baseline period (2000-2004) and 
demonstrate that there is no degradation in visibility for the 20 
percent clearest days since the baseline period; and any additional 
unanticipated emissions reductions provide further assurances that the 
State's Class I areas will achieve their 2028 RPGs. However, because 
the EPA is proposing to conditionally approve North Carolina's LTS 
under 40 CFR 51.308(f)(2) through this proposed rulemaking, EPA is also 
proposing to conditionally approve the RPGs under 40 CFR 51.308(f)(3). 
Therefore, if North Carolina submits the required corrective SIP 
revision by the specified deadline in its commitment letter and EPA 
approves the submission, the identified practicable enforceability 
concerns will be cured and the conditional approval of the elements of 
the Haze Plan related to the requirements of 40 CFR 51.308(f)(3) will 
be converted to a full approval.

E. Monitoring Strategy and Other Implementation Plan Requirements

    1. RHR Requirement: Section 51.308(f)(6) specifies that each 
comprehensive revision of a state's regional haze SIP must contain or 
provide for certain elements, including monitoring strategies, 
emissions inventories, and any reporting, recordkeeping, and other 
measures needed to assess and report on visibility. A main requirement 
of this subsection is for states with Class I areas to submit 
monitoring strategies for measuring, characterizing, and reporting on 
visibility impairment. Compliance with this requirement may be met 
through participation in the IMPROVE network.
    Section 51.308(f)(6)(i) requires SIPs to provide for the 
establishment of any additional monitoring sites or equipment needed to 
assess whether RPGs to address regional haze for all mandatory Class I 
areas within the state are being achieved. Section 51.308(f)(6)(ii) 
requires SIPs to provide for procedures by which monitoring data and 
other information are used in determining the contribution of emissions 
from within the state to regional haze visibility impairment at 
mandatory Class I areas both within and outside the state. Section 
51.308(f)(6)(iii) applies only to states

[[Page 67364]]

that do not have a mandatory Class I areas. Section 51.308(f)(6)(iv) 
requires the SIP to provide for the reporting of all visibility 
monitoring data to the Administrator at least annually for each Class I 
area in the state. Section 51.308(f)(6)(v) requires SIPs to provide for 
a statewide inventory of emissions of pollutants that are reasonably 
anticipated to cause or contribute to visibility impairment, including 
emissions for the most recent year for which data are available and 
estimates of future projected emissions. It also requires a commitment 
to update the inventory periodically. Section 51.308(f)(6)(v) also 
requires states to include estimates of future projected emissions and 
include a commitment to update the inventory periodically. Under 40 CFR 
51.308(f)(4), if EPA or the FLM of an affected Class I area has advised 
a state that additional monitoring is needed to assess RAVI, the state 
must include in its SIP revision for the second planning period an 
appropriate strategy for evaluating such impairment.
    2. State Assessment: With respect to 40 CFR 51.308(f)(6)(i), North 
Carolina states that the existing IMPROVE monitors for the State's 
Class I areas are adequate. With respect to 40 CFR 51.308(f)(6)(ii), 
data from these IMPROVE monitors will be used for future haze plans and 
progress reports. 40 CFR 51.308(f)(6)(iii) does not apply to North 
Carolina because it has Class I areas. With respect to 40 CFR 
51.308(f)(6)(iv), NPS manages and oversees the IMPROVE monitoring 
network and reviews, verifies, and validates IMPROVE data before its 
submission to EPA's Air Quality System (AQS). With respect to 40 CFR 
51.308(f)(6)(v), DAQ provided a statewide baseline emissions inventory 
of visibility impairing pollutants for the year 2011 in Table 4-2 of 
the 2022 Plan; provided 2011, 2014, and 2016-2019 \110\ anthropogenic 
emissions data for SO2, NOX, PM2.5, 
PM10, and VOC in Tables 13-9, 13-10, 13-11, 13-12, 13-13, 
respectively; provided EPA and VISTAS 2028 future emissions projections 
for SO2 and NOX in Table 4-3, and for specific 
point sources, 2028 VISTAS emission projections for SO2 and 
NOX in Tables 7-20 through 7-24; and committed to update the 
inventory periodically. With respect to 40 CFR 51.308(f)(6)(vi), North 
Carolina affirms there are no elements, including reporting, 
recordkeeping, or other measures, necessary to address and report on 
visibility for North Carolina's Class I areas or Class I areas outside 
the State that are affected by sources in North Carolina. With respect 
to 40 CFR 51.308(f)(4), the State did not include a strategy for 
evaluating RAVI for any Class I areas because no Federal agency 
requested additional monitoring to assess RAVI. Section II of the TSD 
provides a more detailed summary of the State's assessment of its 
monitoring strategy for regional haze and other plan requirements 
pursuant to 40 CFR 51.308(f)(6).
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    \110\ As discussed above, at the time of development of the 2022 
Plan, the 2017 NEI was the most recent triennial emissions inventory 
and 2019 emissions data were the most recent annual emissions data 
available at the time of the development of the 2022 Plan.
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    3. EPA Evaluation: EPA finds that North Carolina has satisfied the 
applicable requirements of 40 CFR 51.308(f)(4) and (f)(6) related to 
RAVI, visibility monitoring, and emissions inventories. With respect to 
40 CFR 51.308(f)(4), EPA proposes to find that this requirement does 
not apply to North Carolina at this time because neither EPA nor the 
FLMs requested additional monitoring to assess RAVI.
    EPA finds that North Carolina satisfied 40 CFR 51.308(f)(6), which 
is generally met by the State's continued participation in the IMPROVE 
monitoring network and the VISTAS RPO, for the following reasons. With 
respect to 40 CFR 51.308(f)(6)(i), North Carolina stated that the 
existing IMPROVE monitors relied upon for the State's five Class I 
areas are adequate, and thus, additional monitoring sites or equipment 
are not needed to assess whether RPGs for all Class I areas within the 
State are being achieved. With respect to 40 CFR 51.308(f)(6)(ii), 
North Carolina has procedures by which monitoring data and other 
information are used to determine the contribution of emissions from 
within the State to regional haze at Class I areas both within and 
outside the State through North Carolina's continued participation in 
VISTAS' regional haze work. With respect to 40 CFR 51.308(f)(6)(iii), 
this provision is applicable for states with no Class I areas and does 
not apply to North Carolina. Regarding the reporting of visibility 
monitoring data to EPA at least annually for each Class I area in the 
State pursuant to 40 CFR 51.308(f)(6)(iv), EPA finds that North 
Carolina's participation in the IMPROVE Steering Committee and the 
IMPROVE monitoring network addresses this requirement. With respect to 
40 CFR 51.308(f)(6)(v), EPA finds that North Carolina's continued 
participation in VISTAS' efforts for projecting future emissions and 
continued compliance with the requirements of the AERR to periodically 
update emissions inventories satisfies the requirement to provide for 
an emissions inventory for the most recent year for which data are 
available. In addition, EPA finds that North Carolina adequately 
documented that no further elements are necessary at this time for the 
State to assess and report on visibility pursuant to 40 CFR 
51.308(f)(6)(vi). Therefore, EPA is proposing to approve the portions 
of the North Carolina SIP submission related to 40 CFR 51.308(f)(6).

F. Requirements for Periodic Reports Describing Progress Toward the 
RPGs

    1. RHR Requirement: Section 51.308(f)(5) requires that periodic 
comprehensive revisions of states' regional haze plans address the 
progress report requirements of 40 CFR 51.308(g)(1) through (5). The 
purpose of these requirements is to evaluate progress toward the 
applicable RPGs for each Class I area within the state and each Class I 
area outside the state that may be affected by emissions from within 
that state. Sections 51.308(g)(1) and (2) apply to all states and 
require a description of the status of implementation of all measures 
included in a state's first planning period regional haze plan and a 
summary of the emission reductions achieved through implementation of 
those measures. Section 51.308(g)(3) applies only to states with Class 
I areas within their borders and requires such states to assess current 
visibility conditions, changes in visibility relative to baseline 
(2000-2004) visibility conditions, and changes in visibility conditions 
relative to the period addressed in the first planning period progress 
report. Section 51.308(g)(4) applies to all states and requires an 
analysis tracking changes in emissions of pollutants contributing to 
visibility impairment from all sources and sectors since the period 
addressed by the first planning period progress report. This provision 
further specifies the year or years through which the analysis must 
extend depending on the type of source and the platform through which 
its emission information is reported. Finally, 40 CFR 51.308(g)(5), 
which also applies to all states, requires an assessment of any 
significant changes in anthropogenic emissions within or outside the 
state have occurred since the period addressed by the first planning 
period progress report, including whether such changes were anticipated 
and whether they have limited or impeded expected progress toward 
reducing emissions and improving visibility.

[[Page 67365]]

    2. State Assessment: With respect to the progress report elements 
pursuant to 40 CFR 51.308(f)(5), DAQ addressed these elements in 
Section 13 of the 2022 Plan for the period 2011 to 2018, the end of the 
first period.
    Regarding 40 CFR 51.308(g)(1) and (g)(2), DAQ describes the status 
of the implementation of the measures of the LTS from the first 
planning period in Section 13.2 of the 2022 Plan and provides a summary 
of the emission reductions achieved by implementing those measures in 
Section 13.3 of the 2022 Plan. With respect to 40 CFR 51.308(g)(1), 
Table 13-1 of the 2022 Plan identifies key emissions control measures 
and other emission reduction actions included in the LTS of North 
Carolina's first regional haze plan submitted on December 17, 2007 
(``2007 Haze Plan''). Table 13-1 also identifies key measures that 
contributed to emission reductions during the first planning period but 
were not a part of the LTS for the first period (e.g., 2010 
SO2 NAAQS).
    With respect to 40 CFR 51.308(g)(2), North Carolina continued to 
focus on SO2 emissions reductions because the State 
determined that ammonium sulfate was the most important contributor to 
visibility impairment and fine particle mass on the 20 percent best and 
20 percent worst days in the first planning period.\111\ In Section 
13.3 of the 2022 Plan, DAQ summarized EGU and certain non-EGU 
SO2 emissions reductions over the 2013-2018 period. The Duke 
Energy Progress and Duke Progress Carolinas EGU facilities collectively 
emitted a total of 73,456 tons of SO2 emissions in 2011 
which decreased to 15,130 tons in 2018, a reduction of approximately 79 
percent and the EGU sector represents over 50 percent of statewide 
SO2 emissions from stationary sources in North Carolina. 
Regarding EGU NOX emissions reductions, Duke Energy Progress 
and Duke Progress Carolinas EGU facilities together emitted a total of 
39,285 tons of NOX emissions in 2011 which decreased to 
27,305 tons in 2018, a reduction of 30 percent. Additionally, DAQ 
focused on five non-EGU facilities identified in the 2007 Haze Plan for 
a FFA and for which no new measures were found reasonable in that plan: 
BRPP; Domtar; International Paper--New Bern Mill; PCS; and Coastal 
Carolina Clean Power--Kenansville. Except for Domtar, whose 
SO2 emissions increased by 161 tpy from 2011 to 2018, 
SO2 emissions decreased due to new control measures or 
because the facility closed (i.e., Coastal Carolina Clean Power--
Kenansville closed in 2017). DAQ states that there has been a 58 
percent reduction in SO2 emissions associated with these 
five facilities. The data summarized below regarding 40 CFR 
51.308(g)(4) also reflects emissions reductions for the 2013-2018 
period.
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    \111\ For the first planning period, visibility conditions were 
determined for the average of the 20 percent most impaired 
visibility days (referred to as the ``worst'' days) and the 20 
percent least impaired visibility days (referred to as the ``best'' 
days).
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    Regarding 40 CFR 51.308(g)(3), DAQ calculated the following for the 
State's five Class I areas in Tables 13-6, 13-7, and 13-8: the current 
visibility conditions (2014-2018); the difference between current 
visibility conditions compared to the baseline; and the change in 
visibility impairment for the most and least impaired days over the 
past five years. DAQ concluded that IMPROVE monitoring data for 2014-
2018 show that all North Carolina Class I areas are well below the 2018 
RPG for the 20 percent worst days and there is no degradation on the 20 
percent best/clearest days which is illustrated in Figures 13-1 through 
13-8 of the 2022 Plan.\112\
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    \112\ In Figures 13-1 through 13-8 of the 2022 Plan, the ``Model 
Projection'' represents the RPGs and ``Observation'' represents 
IMPROVE data.
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    Regarding 40 CFR 51.308(g)(4), in Section 13.5, DAQ provided 
emissions trends from 2011 through 2019 for SO2, 
NOX, PM2.5, PM10, and VOCs which 
reflect the emissions reductions from the measures in the first 
planning period LTS. In summary, from 2011 to 2019, statewide emissions 
of SO2, NOX, PM2.5, PM10, 
and VOCs have reduced by 71, 40, 20, 4, and 13 percent, respectively. 
Regarding SO2, statewide SO2 emissions decreased 
(in tpy) from 118,721 in 2011 to 34,712 in 2019. Regarding 
NOX, statewide NOX emissions decreased (in tpy) 
from 369,496 in 2011 to 223,264 in 2019.
    Regarding 40 CFR 51.308(g)(5), in Section 13.6, DAQ reviewed 
anthropogenic SO2 and NOX emissions trends based 
on emissions included in the 2011, 2014, and 2017 NEIs for the VISTAS 
states and all of the RPOs. The data show a decline in SO2 
and NOX emissions from 2011 through 2017 in all regions of 
the country as shown in Table 13-14 and Figures 13-14 and 13-15 of the 
2022 Plan. DAQ concluded that there does not appear to be any 
anthropogenic emissions within North Carolina that would have limited 
or impeded progress in reducing pollutant emissions or improving 
visibility.
    Section III of the TSD provides a more detailed summary of the 
State's assessment of how North Carolina addressed requirements for 
periodic reports describing progress toward the RPGs for the State's 
Class I areas pursuant to 40 CFR 51.308(f)(5).
    3. EPA Evaluation: EPA finds that North Carolina has met the 
requirements of 40 CFR 51.308(g)(1)-(5) because the 2022 Plan 
adequately describes the status of the measures included in the LTS 
from the first planning period and the emission reductions achieved 
from those measures; the visibility conditions and changes at the North 
Carolina Class I areas; an analysis tracking the changes in emissions 
since the first planning period progress report using available 
emissions data from 2011-2019, including annual 2018 and 2019 emissions 
data and 2017 NEI data which is the most recent triennial emissions 
inventory submission from North Carolina prior to submission of the 
2022 Plan in accordance with the RHR; and assessed whether any 
significant changes in anthropogenic emissions within or outside the 
State have occurred since 2010 (the end of the period addressed by 
North Carolina's first planning period progress report), including 
whether these changes in anthropogenic emissions were anticipated in 
that most recent plan and whether they have limited or impeded progress 
in reducing pollutant emissions and improving visibility. Thus, EPA is 
proposing to approve the progress report elements pursuant to 40 CFR 
51.308(f)(5).

G. Requirements for State and FLM Coordination

    1. RHR Requirement: Section 169A(d) of the CAA requires states to 
consult with FLMs before holding the public hearing on a proposed 
regional haze SIP and to include a summary of the FLMs' conclusions and 
recommendations in the notice to the public. In addition, the FLM 
consultation provision of 40 CFR 51.308(i)(2) requires a state to 
provide the FLMs with an opportunity for consultation that is early 
enough in the state's policy analyses of its emission reduction 
obligation so that information and recommendations provided by the FLMs 
can meaningfully inform the state's decisions on its LTS. If the 
consultation has taken place at least 120 days before a public hearing 
or public comment period, the opportunity for consultation will be 
deemed early enough. Regardless, the opportunity for consultation must 
be provided at least 60 days before a public hearing or public comment 
period at the state level. Section 51.308(i)(2) also provides two 
substantive topics on which the FLMs must be provided an opportunity to 
discuss with states: assessment of

[[Page 67366]]

visibility impairment in any Class I area and recommendations on the 
development and implementation of strategies to address visibility 
impairment. Section 51.308(i)(3) requires states, in developing their 
implementation plans, to include a description of how they addressed 
FLMs' comments. Section 40 CFR 51.308(i)(4) requires that the regional 
haze SIP revision provide procedures for continuing consultation 
between the state and FLMs regarding the state's visibility protection 
program.
    2. State Assessment: As required by CAA section 169A(d), North 
Carolina consulted with the FLMs prior to opening the State public 
comment period on its proposed haze plan and included a summary of the 
conclusions and recommendations of the FLMs in the proposed plan dated 
August 30, 2021, in Section 10.4 and Appendix H of the 2022 Plan. North 
Carolina consulted with the FLMs on April 5, 2021, which was 147 days 
before the opening of the public comment period on August 30, 2021.
    With respect to 40 CFR 51.308(i)(2), DAQ offered to the three FLM 
agencies the opportunity to consult on the April 5, 2021, draft North 
Carolina Haze Plan. DAQ shared with the FLMs the August 30, 2021, 
proposed North Carolina Haze Plan issued for state public notice and 
comment with a public hearing held October 6, 2021, with the close of 
the comment period on October 15, 2021. A summary of this consultation 
process is discussed and documented in Section 10.4 of the 2022 Plan 
(responses to FLM comments) with supporting information in Appendix H 
(FLM comments received) and Appendix F. Appendix F-3 contains VISTAS 
stakeholder materials which include data and analyses for North 
Carolina that were presented to the FLMs (and EPA). In addition, 
through VISTAS, North Carolina participated in a series of conference 
calls where the FLMs and EPA were given the opportunity review and 
provide feedback regarding technical analyses developed by VISTAS. DAQ 
also participated in calls hosted by VISTAS with other RPOs, FLMs, and 
EPA to discuss VISTAS' approaches to source selection and other related 
topics. See Appendix F of the 2022 Plan.
    To address 40 CFR 51.308(i)(3), North Carolina provided responses 
to comments received from NPS and USFS in Section 10.4 and Appendix I 
(Section 3.2) of the 2022 Plan.\113\
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    \113\ FWS did not provide written comments to DAQ on North 
Carolina's draft and proposed haze plans.
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    With respect to 40 CFR 51.308(i)(4), North Carolina updated its 
existing procedures for continuing consultation with the FLMs, 
including annual discussions with a review of the most recent IMPROVE 
monitoring data. Also, DAQ stated that its New Source Review (NSR) 
regulations for both nonattainment and attainment areas will address 
emissions from new sources that may be located near a Class I area or 
increased emissions from major modifications to existing sources. DAQ 
noted that consultation with the FLMs is also required for sources that 
are subject to its NSR regulations.
    3. EPA Evaluation: EPA is proposing to conditionally approve the 
Haze Plan with respect to the FLM consultation requirements under 40 
CFR 51.308(i)(2)-(4) because EPA is proposing to conditionally approve 
the LTS under 40 CFR 51.308(f)(2) and the RPGs under 40 CFR 
51.308(f)(3). Although North Carolina consulted with the FLMs prior to 
the public hearing on the 2022 Plan and included a summary of the 
conclusions and recommendations of the FLMs in the proposed plan issued 
for public review, provided the FLMs the requisite opportunity to 
review and provide feedback on the State's initial draft plan pursuant 
to 40 CFR 51.308(i)(2), included the FLM comments in the proposed Haze 
Plan pursuant to CAA 169(A)(d), included responses to the FLM comments 
in the Haze Plan pursuant to 40 CFR 51.308(i)(3), and included ongoing 
FLM consultation procedures in the Haze Plan pursuant to 40 CFR 
51.308(i)(4), North Carolina's consultation was based on a SIP revision 
that did not meet the required statutory and regulatory requirements of 
the CAA and the RHR, respectively. If EPA finalizes the partial 
conditional approval of the Plan, as proposed in this document, the 
State will be required to again satisfy the FLM consultation 
requirement under 40 CFR 51.308(i) in the process of submitting to EPA 
the corrective SIP revision identified in its Commitment Letter.

H. Environmental Justice (EJ) Considerations

    As explained in EPA Legal Tools to Advance Environmental Justice 
and the 2021 Clarifications Memo, CAA section 169A and the RHR provide 
states with the discretion to consider EJ in developing rules and 
measures related to regional haze.\114\ In this instance, DAQ exercised 
this discretion, as is described below in summary. In reviewing DAQ's 
analysis, EPA defers to North Carolina's reasonable exercise of its 
discretion in considering EJ in this way. The information associated 
with DAQ's analysis is included in this document for informational 
purposes only; it does not form any part of the basis of EPA's proposed 
action.
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    \114\ EPA Legal Tools to Advance Environmental Justice (May 
2022) is available at: https://www.epa.gov/system/files/documents/2022-05/EJ%20Legal%20Tools%20May%202022%20FINAL.pdf; 2021 
Clarifications Memo at 16.
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    DAQ describes North Carolina's EJ Program for regional haze in 
Section 10.6 of the 2022 Plan which includes outreach plans to provide 
an opportunity for meaningful involvement of all people regardless of 
race, color, national origin, or income during the comment period of 
this regional haze plan for North Carolina. DAQ ran EJScreen,\115\ an 
EJ mapping and screening tool that provided a nationally consistent 
dataset and approach for combining various environmental and 
demographic indicators, around the North Carolina Class I areas except 
for Great Smoky Mountains because the area is too large to perform the 
EJScreen analysis. Based on the EJScreen results, which are included in 
Appendix F-5 of the Haze Plan, DAQ implemented its outreach plan, 
including conducting specific outreach during the comment period on the 
August 30, 2021, proposed haze plan to communities within potentially 
underserved block groups that overlap or are within one mile of the 
North Carolina Class I areas. DAQ also provided project information and 
updates to the Eastern Band of the Cherokee Nation. Section IV of the 
TSD provides a more detailed summary of how North Carolina opted to 
consider EJ in development of the 2022 Plan. While EPA commends North 
Carolina's consideration of EJ when developing its SIP revision, the EJ 
analyses submitted by DAQ were considered but were not the basis for 
EPA's proposed action.
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    \115\ EPA's EJScreen tool is available at: https://www.epa.gov/ejscreen.
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V. Incorporation by Reference

    In this document, EPA is proposing to include in a final EPA rule 
regulatory text that includes incorporation by reference. In accordance 
with the requirements of 1 CFR 51.5, and as discussed above in this 
preamble, EPA is proposing to incorporate by reference into North 
Carolina's SIP the following conditions from DAQ Air Quality Permit No. 
04291T51 issued to Domtar with an effective date of December 1, 2023: 
Conditions 2.1 A.4.a (except for the references to HFB1 and the list of 
systems and sources in A.4.a.i through

[[Page 67367]]

A.4.a.v); \116\ A.6.e (except for the references to HFB1 and the second 
sentence); \117\ A.6.k (except for the references to HFB1); \118\ 
A.6.l; A.6.m (except the word ``above''); \119\ A.7.a (except for the 
text unrelated to the SO2 limit for HFB2); \120\ A.7.d 
(except for the references to particulate matter and the word 
``above''); \121\ A.7.f (except for the phrase ``amounts of each fuel 
fired in the No. 1 Hog Fuel Boiler each month and the''); \122\ and 
A.7.g (except the word ``above'').\123\ EPA is also proposing the 
incorporation by reference into North Carolina's SIP the following 
conditions from DAQ Air Quality Permit No. 04176T72 issued by DAQ to 
PCS with an effective date of May 7, 2024: Conditions 2.4 A.1.b (except 
for the phrase ``By no later than the compliance deadline specified in 
Section 2.4 A.1.g, below,''); \124\ A.1.c (except for the phrase ``By 
no later than the compliance deadline specified in Section 2.4 A.1.g, 
below,''); \125\ A.1.d (except for the phrase ``By no later than the 
compliance deadline specified in Section 2.4 A.1.g, below,'' and the 
last four sentences of A.1.d.ii); \126\ A.1.f; A.1.h; A.1.i; A.1.k 
(except for the phrase ``After the compliance dates listed in Section 
2.1.1 A.6.g, above,''); \127\ A.1.l (except for the phrase ``Beginning 
with the initial RATA as required by Section 2.1.1 A.6.k, above, and 
thereafter''); \128\ A.1.m (except for the phrase ``By no later than 
the compliance deadlines listed in Section 2.4 A.1.g, above,'' the 
phrase ``(see Attachment 2 of this permit),'' and Condition A.1.m.v); 
\129\ A.1.n; A.1.o (except for the phrase ``per Attachment 2 of this 
permit,'' and the second sentence); \130\ A.1.p; and A.1.q. EPA has 
made, and will continue to make, these materials generally available 
through www.regulations.gov and at the EPA Region 4 Office (please 
contact the person identified in the For Further Information Contact 
section of this preamble for more information).
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    \116\ The text incorporated into the SIP would state ``Emissions 
of sulfur dioxide when firing wood or natural gas in the No. 2 Hog 
Fuel Boiler (ID No. ES-65-25-0310) shall not exceed 2.3 pounds per 
million Btu heat input. Sulfur dioxide formed by the combustion of 
sulfur in fuels, wastes, ores, and other substances shall be 
included when determining compliance with this standard, and shall 
include the sulfur dioxide formed by the combustion of sulfur-
containing gases.'' See Section 7.8.3.1 of the 2022 Plan.
    \117\ The text incorporated into the SIP would state ``The 
Permittee shall demonstrate compliance with the sulfur dioxide 
emission limit for the No. 2 Hog Fuel Boiler (ID No. ES-65-25-0310) 
by fuel sampling and analysis. [40 CFR 60.45(b)(2)]'' See Section 
7.8.3.1 of the 2022 Plan.
    \118\ The text incorporated into the SIP would state ``Pursuant 
to 40 CFR 60.7(b), the Permittee shall maintain records of the 
occurrence and duration of any startup, shutdown, or malfunction in 
the operation of the No. 2 Hog Fuel Boiler (ID No. ES 65-25-0310) 
and any malfunctions of the air pollution control equipment, or any 
periods during which a continuous monitoring system or monitoring 
device is inoperative [40 CFR 60.7(b)]. The Permittee shall be 
deemed in noncompliance with 15A NCAC 02D .0524 if the startup, 
shutdown, or malfunction records and records of air pollution 
control equipment malfunctions are not maintained as specified.'' 
See Section 7.8.3.1 of the 2022 Plan.
    \119\ The text incorporated into the SIP would state ``The 
Permittee shall record and maintain records of the amount and type 
of each fuel burned during each day and keep fuel receipts from the 
supplier that certify potential sulfur dioxide content of fuel oil 
fired in the hog fuel boilers as specified in Section 2.1 A.6.e. The 
Permittee shall be deemed in noncompliance with 15A NCAC 02D .0524 
if the fuel records are not maintained as specified.'' See Section 
7.8.3.1 of the 2022 Plan.
    \120\ The text incorporated into the SIP would state ``The 
following Best Available Control Technology (BACT) shall not be 
exceeded:'' and include the row entry for HFB2 containing the 0.80 
lb/MMBtu emission limit. See Section 7.8.3.1 of the 2022 Plan.
    \121\ The text incorporated into the SIP would state ``The 
Permittee shall follow the monitoring and recordkeeping requirements 
for sulfur dioxide in Section 2.1 A.6.e and A.6.i through A.6.m. The 
Permittee shall be deemed in noncompliance with 15A NCAC 02D .0530 
if the monitoring required for sulfur dioxide emissions from the No. 
2 Hog Fuel Boiler is not maintained as required.'' See Section 
7.8.3.1 of the 2022 Plan.
    \122\ The text incorporated into the SIP would state ``The 
Permittee shall record and maintain records of the amounts of each 
fuel fired in the No. 2 Hog Fuel Boiler each month and make these 
records available to an authorized representative of DAQ upon 
request. The Permittee shall be deemed in noncompliance with 15A 
NCAC 02D .0530 if the amounts of fuels fired each month are not 
recorded.'' See Section 7.8.3.1 of the 2022 Plan.
    \123\ The text incorporated into the SIP would state ``The 
Permittee shall submit a semiannual summary report, acceptable to 
the Regional Air Quality Supervisor, of monitoring and recordkeeping 
activities given in Section 2.1 A.7.d through A.7.f, postmarked on 
or before January 30 of each calendar year for the preceding six-
month periods between July and December, and July 30 of each 
calendar year for the preceding six-month period between January and 
June. The report shall identify all periods of noncompliance from 
the requirements of this permit or a statement that no periods of 
noncompliance occurred during the reporting period.'' See Section 
7.8.3.1 of the 2022 Plan.
    \124\ The text incorporated into the SIP would state ``The 
sulfur dioxide emissions from Sulfuric Acid Plant No. 5 (ID No. S-5) 
shall not exceed the following emissions limitations: i. Short-Term 
Limit: 3.2 pounds per ton of 100 percent sulfuric acid production on 
a 3-hour rolling average basis. ii. Long-Term Limit: 2.5 pounds per 
ton of 100 percent sulfuric acid production on a 365-day rolling 
average basis.'' See Section 7.8.3.2 of the 2022 Plan.
    \125\ The text incorporated into the SIP would state ``The 
sulfur dioxide emissions from Sulfuric Acid Plant No. 6 (ID No. S-6) 
shall not exceed the following emissions limitations: i. Short-Term 
Limit: 3.3 pounds per ton of 100 percent sulfuric acid production on 
a 3-hour rolling average basis. ii. Long-Term Limit: 2.5 pounds per 
ton of 100 percent sulfuric acid production on a 365-day rolling 
average basis.'' See Section 7.8.3.2 of the 2022 Plan.
    \126\ The text incorporated into the SIP would state ``The 
sulfur dioxide emissions from Sulfuric Acid Plant No. 7 (ID No. S-7) 
shall not exceed the following emissions limitations: i. Short-Term 
Limit: 3.0 pounds per ton of 100 percent sulfuric acid production on 
a 3-hour rolling average basis. ii. Long-Term Limit: 1.75 pounds per 
ton of 100 percent sulfuric acid production on a 365-day rolling 
average basis.'' See Section 7.8.3.2 of the 2022 Plan.
    \127\ The text incorporated into the SIP would state ``The 
Permittee shall conduct a Relative Accuracy Test Audit (RATA) at 
least once every four calendar quarters at each of the Sulfuric Acid 
Plants No. 5, No. 6, and No. 7 (ID Nos. S-5, S-6, and No. 7) per the 
procedures of 40 CFR 60.85 for sulfur dioxide and oxygen 
concentrations and pounds sulfur dioxide per ton of 100 percent 
sulfuric acid produced as required by 40 CFR part 60 Appendix F, 
Procedure 1, 5.1.1.'' See Section 7.8.3.2 of the 2022 Plan.
    \128\ The text incorporated into the SIP would state ``For every 
triennial RATA (i.e., year 1, 4, 7, etc.), the Permittee shall 
utilize the reference methods and procedures specified in 40 CFR 
60.85(b) to generate the Reference Method values for calculating the 
relative accuracy. In intervening years (i.e., year 2, 3, 5, 6, 
etc.) the Permittee may use the alternative method specified in 40 
CFR 60.85(c) to calculate the Reference Method values.'' See Section 
7.8.3.2 of the 2022 Plan.
    \129\ The text incorporated into the SIP would state ``The 
Permittee shall monitor sulfur dioxide emissions from each of the 
sulfuric acid plants (ID Nos. S-5, S-6, and S-7), in accordance with 
the SO2 CEMS Plan and following procedures: i. The 
Permittee shall measure the sulfur dioxide concentration (lb/DSCF or 
ppmvd) and oxygen concentration (percent by volume) at the exit 
stack at least once every 15 minutes using a sulfur dioxide analyzer 
and oxygen analyzer. ii. During routine calibration checks and 
adjustments of any analyzer, the precalibration level shall be used 
to fill in any analyzer data gaps that occur pending completion of 
the calibration checks and adjustments. iii. If any one or more than 
one analyzer is/are not operating, a like-kind replacement (i.e. a 
redundant analyzer) may be used as a substitute. iv. If any one or 
more than one analyzer is/are not operating for a period of 24 hours 
or greater and no redundant analyzer is available, data gaps in the 
array involving the non-operational analyzer(s) shall be filled is 
as follows: (A) Exit stack gas shall be sampled and analyzed for 
sulfur dioxide at least once every three hours, while the relevant 
sulfuric acid plant is operating. Sampling shall be conducted by 
Reich test or other established method (e.g., portable analyzer). 
The most recent 3-hour average reading shall be substituted for the 
four 15-minute average measurements that would otherwise be utilized 
if the analyzer were operating normally. (B) Oxygen in the exit 
stack gas shall be sampled and analyzed at least once every three 
hours, while the relevant sulfuric acid plant is operating. Sampling 
shall be conducted by Orsat test or other method (e.g., portable 
analyzer). The most recent 3-hour average reading shall be 
substituted for the four 15- minute average measurements that would 
otherwise be utilized if the analyzer were operating normally.'' See 
Section 7.8.3.2 of the 2022 Plan.
    \130\ The text incorporated into the SIP would state ``The 15-
minute analyzer data shall be used to determine the 3-hour rolling 
averages and 365-day rolling averages to demonstration [sic] 
compliance with the short-term and long-term sulfur dioxide 
limits.'' See Section 7.8.3.2 of the 2022 Plan.
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VI. Proposed Action

    For the reasons stated herein, EPA is proposing to approve in part 
and conditionally approve in part North Carolina's April 4, 2022, SIP 
submission as supplemented with a commitment letter on July 30, 2024. 
EPA is proposing to approve the sections of the Haze Plan addressing 
the requirements of 40 CFR 51.308(f)(1), (f)(4) through(6), and (g)(1)

[[Page 67368]]

through(5). EPA is proposing to conditionally approve the sections of 
the Haze Plan addressing the requirements of 40 CFR 51.308(f)(2), 
(f)(3), and (i)(2) through(4) due to concerns with the legal and 
practicable enforceability of certain permit conditions identified in 
the Haze Plan for incorporation into the SIP.

VII. 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. 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. Accordingly, this 
proposed action merely proposes to approve state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this proposed action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 14094 (88 FR 21879, April 11, 2023);
     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 rule does not have Tribal implications and will not impose 
substantial direct costs on Tribal governments or preempt Tribal law as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
Feb. 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. 
EPA defines EJ as ``the fair treatment and meaningful involvement of 
all people regardless of race, color, national origin, or income with 
respect to the development, implementation, and enforcement of 
environmental laws, regulations, and policies.'' EPA further defines 
the term fair treatment to mean that ``no group of people should bear a 
disproportionate burden of environmental harms and risks, including 
those resulting from the negative environmental consequences of 
industrial, governmental, and commercial operations or programs and 
policies.''
    North Carolina DAQ evaluated EJ considerations as part of its SIP 
submittal even though the CAA and applicable implementing regulations 
neither prohibit nor require an evaluation. EPA's evaluation of North 
Carolina DAQ's EJ considerations are described above in the section 
titled, ``Environmental Justice (EJ) Considerations.'' The analysis was 
done for the purpose of providing additional context and information 
about this rulemaking to the public, not as a basis of the proposed 
action. EPA is proposing action under the CAA on bases independent of 
North Carolina's evaluation of EJ. Due to the nature of the action 
being proposed here, this proposed action is expected to have a neutral 
to positive impact on the air quality of the affected area. In 
addition, there is no information in the record upon which this 
decision is based that is inconsistent with the stated goal of 
Executive Order 12898 of achieving EJ for people of color, low-income 
populations, and Indigenous peoples.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Nitrogen dioxide, Particulate matter, Sulfur oxides.

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

    Dated: August 13, 2024.
Jeaneanne Gettle,
Acting Regional Administrator, Region 4.
[FR Doc. 2024-18495 Filed 8-19-24; 8:45 am]
BILLING CODE 6560-50-P