Proposed Rule2024-18495
Air Plan Approval; North Carolina; Second Period Regional Haze Plan
Primary source
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Published
August 20, 2024
Issuing agencies
Environmental Protection Agency
Abstract
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.
Full Text
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<title>Federal Register, Volume 89 Issue 161 (Tuesday, August 20, 2024)</title>
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[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. 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 <a href="http://www.epa.gov/dockets/commenting-epa-dockets">http://www.epa.gov/dockets/commenting-epa-dockets</a>.
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 <a href="/cdn-cgi/l/email-protection#c6a8a9b2a7b4afa7a8a8afe8abafa5aea3aaa386a3b6a7e8a1a9b0"><span class="__cf_email__" data-cfemail="5f31302b3e2d363e3131367132363c373a333a1f3a2f3e71383029">[email protected]</span></a>.
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 (SO<INF>2</INF>), nitrogen oxides (NO<INF>X</INF>), and, in
some cases, volatile organic compounds (VOC) and ammonia
(NH<INF>3</INF>)). Precursor pollutants react in the atmosphere to form
fine particulate matter (particles less than or equal to 2.5
micrometers ([micro]m) in diameter, PM<INF>2.5</INF>), 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<SUP>-1</SUP>). 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, <a href="https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period">https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period</a>, 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<SUP>-1</SUP>). 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
[[Page 67344]]
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.'' <a href="https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf">https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf</a>. 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). <a href="https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional">https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional</a>.
\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.'' <a href="https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program">https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program</a>.
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: <a href="https://www.metro4-sesarm.org/content/vistas-regional-haze-program">https://www.metro4-sesarm.org/content/vistas-regional-haze-program</a>.
\17\ Metro 4 is a Tennessee corporation which represents the
local air pollution control agencies in EPA's Region 4 in the
Southeast. See <a href="https://www.metro4-sesarm.org/content/metro-4-about-us">https://www.metro4-sesarm.org/content/metro-4-about-us</a>.
\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
<a href="https://www.epa.gov/sites/default/files/2021-03/documents/tracking.pdf">https://www.epa.gov/sites/default/files/2021-03/documents/tracking.pdf</a>. 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 SO<INF>2</INF> and
NO<INF>X</INF> 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 <a href="http://www.regulations.gov">www.regulations.gov</a>.
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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 <a href="http://www.regulations.gov">www.regulations.gov</a>; 2019 Guidance at 36-37.
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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).
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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.
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\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).
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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.
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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).
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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 SO<INF>2</INF> and
NO<INF>X</INF> 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<SUP>-</SUP>\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<SUP>-</SUP>\1\) and Okefenokee National Wilderness Area
(Okefenokee) (0.67 Mm<SUP>-</SUP>\1\) in Georgia and James River Face
National Wilderness Area (James River Face) (0.45 Mm<SUP>-</SUP>\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 SO<INF>2</INF> and NO<INF>X</INF> and did not
tag primary total PM emissions in the analysis after concluding that
emissions of the PM precursors SO<INF>2</INF> and NO<INF>X</INF>,
particularly from point sources, are projected to have the largest
impact on visibility impairment in 2028 and that SO<INF>2</INF> and
NO<INF>X</INF> 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<SUP>-</SUP>\1\, 1.13 Mm<SUP>-</SUP>\1\, 1.83 Mm<SUP>-</SUP>\1\,
0.89 Mm<SUP>-</SUP>\1\, 0.43 Mm<SUP>-</SUP>\1\ for Linville Gorge,
Shining Rock, Swanquarter, Great Smoky Mountains, and Joyce Kilmer,
respectively.
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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.
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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 SO<INF>2</INF> and NO<INF>X</INF> 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:
<a href="https://www.epa.gov/sites/default/files/2019-10/documents/updated_2028_regional_haze_modeling-tsd-2019_0.pdf">https://www.epa.gov/sites/default/files/2019-10/documents/updated_2028_regional_haze_modeling-tsd-2019_0.pdf</a>.
\47\ See Section IV.C.2.e of this notice and Section I.E of
EPA's TSD for additional detail regarding consultation.
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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
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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: <a href="https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf">https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf</a>.
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.
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\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). <a href="https://www.epa.gov/sites/default/files/2018-12/documents/technical_guidance_tracking_visibility_progress.pdf">https://www.epa.gov/sites/default/files/2018-12/documents/technical_guidance_tracking_visibility_progress.pdf</a> and
<a href="https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf">https://www.epa.gov/sites/default/files/2020-06/documents/memo_data_for_regional_haze_technical_addendum.pdf</a>.
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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: <a href="https://edocs.deq.nc.gov/AirQuality/DocView.aspx?id=457541&dbid=0&repo=AirQuality&searchid=c271acf8-6535-4306-8cfb-9a0caa2b3d97">https://edocs.deq.nc.gov/AirQuality/DocView.aspx?id=457541&dbid=0&repo=AirQuality&searchid=c271acf8-6535-4306-8cfb-9a0caa2b3d97</a>. 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> control evaluations.
Additionally, Section 10.4.1 of the Haze Plan provides the State's
responses to FLM comments on the exclusion of NO<INF>X</INF> 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 <a href="https://vista.cira.colostate.edu/Improve/rhr-summary-data/">https://vista.cira.colostate.edu/Improve/rhr-summary-data/</a> 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 NO<INF>X</INF> 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<SUP>-1</SUP> and total projected 2028
total nitrate extinction is less than 3.5 Mm<SUP>-1</SUP>. At
Swanquarter, the projected 2028 sulfate extinction is 16.6
Mm<SUP>-1</SUP> and the projected 2028 nitrate extinction is 4.5
Mm<SUP>-1</SUP>. 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 NO<INF>X</INF> 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
PM<INF>2.5</INF> contributing to regional haze. DAQ notes that at some
locations, one ton of SO<INF>2</INF> reduction can have anywhere from
twice to more than 100 times the impact on visibility impairment as one
ton of NO<INF>X</INF> 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 SO<INF>2</INF> and NO<INF>X</INF> 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
SO<INF>2</INF> 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
SO<INF>2</INF> 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 SO<INF>2</INF>
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
SO<INF>2</INF> 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 SO<INF>2</INF> emissions. The SOC is available in
Docket ID No. EPA-R04-OAR-2020-0001 on <a href="http://www.regulations.gov">www.regulations.gov</a>.
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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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> emissions for the three boilers
evaluated.
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\64\ See Table 7-48 on p. 271 of the 2022 Plan.
\65\ The SO<INF>2</INF> 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 SO<INF>2</INF> and other pollutants
from gaseous exhaust streams. WFGD is considered the most efficient
way to remove SO<INF>2</INF> 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 SO<INF>2</INF> emissions due to
the SOC and the State's determination that there are no cost-effective
control SO<INF>2</INF> measures available based on a review of the four
factors, DAQ concluded that only existing SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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
SO<INF>2</INF> emissions. HFB2 uses low sulfur fuels and inherent bark
scrubbing to control SO<INF>2</INF> 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 SO<INF>2</INF> removed using
a 3.25 percent interest rate, a 30-year equipment life, and assuming a
95 percent SO<INF>2</INF> 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 SO<INF>2</INF> 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
SO<INF>2</INF> 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<SUP>-1</SUP>). 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 <a href="https://www.epa.gov/catc/ractbactlaer-clearinghouse-rblc-basic-information">https://www.epa.gov/catc/ractbactlaer-clearinghouse-rblc-basic-information</a>
and was unable to find documentation of similar emissions units to
HFB2 to compare costs of WFGD at this type of unit.
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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
SO<INF>2</INF> measures available based on a review of the four factors
and that only existing SO<INF>2</INF> 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 SO<INF>2</INF> controls
because these three SAPs accounted for over 97 percent of total
facility SO<INF>2</INF> emissions in 2016 and are estimated to account
for 94 percent of the total facility SO<INF>2</INF> emissions in 2028.
During 2017-2019, PCS implemented upgrades to enhance the
SO<INF>2</INF> 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 SO<INF>2</INF> emissions
reductions from the upgrades involving a dual absorption process with
cesium catalyst.\72\ PCS' title V permit includes the SO<INF>2</INF>
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.
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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 SO<INF>2</INF> emissions control technology
in place (dual absorption process with cesium catalyst) to further
reduce SO<INF>2</INF> emissions at these units and concluded that there
are none. Given this conclusion and the SO<INF>2</INF> 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.''
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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 SO<INF>2,</INF>
NO<INF>X</INF>, and PM<INF>2.5</INF> 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 (SO<INF>2</INF>) and 7-42
(NO<INF>X</INF>) for certain non-EGU sources in North Carolina;
Tables 13-9 (SO<INF>2</INF>), 13-10 (NO<INF>X</INF>), 13-11
(PM<INF>2.5</INF>), 13-12 (PM<INF>10</INF>), 13-13 (VOC) for
anthropogenic statewide emissions of these pollutants; Table 13-14
(SO<INF>2</INF>, NO<INF>X</INF> for all RPOs); Figures 13-9
(SO<INF>2</INF>), 13-10 (NO<INF>X</INF>), 13-11 (PM<INF>2.5</INF>),
13-12 (PM<INF>10</INF>), 13-13 (VOC)) for anthropogenic statewide
emissions of these pollutants; and Figures 13-14 and 13-15
(SO<INF>2</INF>, NO<INF>X</INF> 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 PM<INF>2.5</INF> 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.
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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.
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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).
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\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: <a href="https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf">https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf</a>.
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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<SUP>-1</SUP> or greater light extinction
impact on any MANE-VU Class I area based on CALPUFF modeling of 2011
SO<INF>2</INF> and NO<INF>X</INF> 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<SUP>-1</SUP> 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: <a href="https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf">https://otcair.org/manevu/Upload/Publication/Formal%20Actions/MANE-VU%20Inter-Regional%20Ask%20Final%208-25-2017.pdf</a>.
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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<SUP>-1</SUP> light extinction impact on a MANE-VU Class
I area based on CALPUFF modeling of the facility's 2011 SO<INF>2</INF>
and NO<INF>X</INF> 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<SUP>-1</SUP> for MANE-
VU Class I areas and 0.47 Mm<SUP>-1</SUP> 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: <a href="https://otcair.org/manevuUpload/Publication/Reports/MANE-VU%20Contributing%20State%20Analysis%20Final.pdf">https://otcair.org/manevuUpload/Publication/Reports/MANE-VU%20Contributing%20State%20Analysis%20Final.pdf</a>.
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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 SO<INF>2</INF>
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 SO<INF>2</INF>
emissions are expected to decrease in the second planning period from
2019 levels of 34,712 tpy SO<INF>2</INF> to projected 2028 levels of
32,644 tpy SO<INF>2</INF> (a six percent reduction) which occurred
after a 63 percent decrease in statewide SO<INF>2</INF> emissions from
2011 to 2018 by 74,830 tpy SO<INF>2</INF>, and statewide NO<INF>X</INF>
emissions are expected to decrease in the second planning period from
2019 levels of 223,264 tpy NO<INF>X</INF> to projected 2028 levels of
138,986 tpy NO<INF>X</INF> (approximately a 38 percent reduction) which
occurred after a 37 percent decrease in statewide NO<INF>X</INF>
emissions from 2011 to 2018 by 137,820 tpy NO<INF>X</INF>.\85\
Additional emissions reductions from permanent shutdowns which have not
been reflected in the 2028 emissions projections and 2028 RPGs are 204
tons of SO<INF>2</INF> and 208 tons of SO<INF>2</INF> based on 2016
actual and projected 2028 SO<INF>2</INF> emissions, respectively, and
248 tons of NO<INF>X</INF> and 287 tons of NO<INF>X</INF> based on 2016
and projected 2028 NO<INF>X</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> and
NO<INF>X</INF> decreased during the period from 2011 to 2018 from
118,721 tpy SO<INF>2</INF> to 43,891 tpy SO<INF>2</INF> and
decreased from 369,496 to 231,676 tpy NO<INF>X</INF>. 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 <a href="https://vista.cira.colostate.edu/Improve/rhr-summary-data/">https://vista.cira.colostate.edu/Improve/rhr-summary-data/</a> 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
SO<INF>2</INF> \91\ and whether any cost-effective new emissions
reduction measures for SO<INF>2</INF> 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 NO<INF>X</INF> 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.
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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
SO<INF>2</INF> 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 SO<INF>2</INF> is necessary to make
reasonable progress. See 2019 Guidance at 23.
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\92\ The MATS rule is located at 40 CFR part 63, subpart UUUUU.
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Each of the five Duke sources are equipped with WFGD and are
subject to the alternative SO<INF>2</INF> emissions limit from the MATS
rule. EPA evaluated the WFGD SO<INF>2</INF> 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 SO<INF>2</INF> removal efficiencies with some month-to-month
variation in performance.\93\ Because these coal units are subject to
the MATS alternative SO<INF>2</INF> emission limit of 0.2 lb/MMBtu and
are equipped with WFGD that routinely achieve a high SO<INF>2</INF>
control effectiveness, it reasonable to assume that a FFA would likely
result in the conclusion that no further controls are necessary.
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\93\ This data is available through EPA's Clean Air Markets
Program at: <a href="https://campd.epa.gov/data">https://campd.epa.gov/data</a>. 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.
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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.
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i. BRPP: Regarding BRPP, EPA finds that DAQ's conclusions that
existing SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2.</INF>\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 SO<INF>2</INF> 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: <a href="https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution">https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution</a>.
\96\ Tables 7-5 and 7-26 of the 2022 Plan display 2028 BRPP
SO<INF>2</INF> emissions projections as 405 tpy. Table 7-49 of the
2022 Plan identifies the 2028 BRPP SO<INF>2</INF> emissions
projections as 485 tpy.
\97\ See 85 FR 74884 (November 24, 2020) available at: <a href="https://www.govinfo.gov/content/pkg/FR-2020-11-24/pdf/2020-25464.pdf">https://www.govinfo.gov/content/pkg/FR-2020-11-24/pdf/2020-25464.pdf</a>.
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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 SO<INF>2</INF> in 2028, which is only one
percent of Domtar's total SO<INF>2</INF> emissions. EPA also finds that
DAQ's control analysis and conclusions that the existing SO<INF>2</INF>
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 SO<INF>2</INF>
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 <a href="https://fred.stlouisfed.org/series/PRIME">https://fred.stlouisfed.org/series/PRIME</a> for historical
interest rates. As of July 22, 2024, the current bank prime interest
rate is 8.5 percent. (See: <a href="https://www.federalreserve.gov/releases/h15/">https://www.federalreserve.gov/releases/h15/</a>).
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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 SO<INF>2</INF> 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 SO<INF>2</INF> 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
SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF>
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 SO<INF>2</INF> 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
SO<INF>2</INF> control measures for sulfuric acid plants beyond dual
absorption process with cesium catalyst, the current SO<INF>2</INF>
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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 SO<INF>2</INF> 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 PM<INF>2.5</INF> 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
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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 u
[…truncated; see source link]Indexed from Federal Register on August 20, 2024.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.