Rule2024-26980
Air Plan Partial Approval and Partial Disapproval; North Carolina; Second Period Regional Haze Plan
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
November 22, 2024
Effective
December 23, 2024
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is approving in part and disapproving 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 was submitted to address 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 (hereinafter referred to as "Class I 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 226 (Friday, November 22, 2024)</title>
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[Federal Register Volume 89, Number 226 (Friday, November 22, 2024)]
[Rules and Regulations]
[Pages 92573-92600]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-26980]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R04-OAR-2022-0786; FRL-10405-02-R4]
Air Plan Partial Approval and Partial Disapproval; North
Carolina; Second Period Regional Haze Plan
AGENCY: Environmental Protection Agency (EPA).
[[Page 92574]]
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency (EPA) is approving in part
and disapproving 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 was
submitted to address 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 (hereinafter referred to as ``Class I
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: This rule is effective December 23, 2024.
ADDRESSES: EPA has established a docket for this action under Docket
Identification No. EPA-R04-OAR-2022-0786. All documents in the docket
are listed on the <a href="http://regulations.gov">regulations.gov</a> website. Although listed in the
index, some information may not be publicly available, i.e.,
Confidential Business Information or other information whose disclosure
is restricted by statute. Certain other material, such as copyrighted
material, is not placed on the internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available either electronically through <a href="http://www.regulations.gov">www.regulations.gov</a> or in hard
copy at the Air Regulatory Management Section, Air Planning and
Implementation Branch, Air and Radiation Division, U.S. Environmental
Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia
30303-8960. EPA requests that, if at all possible, you contact the
person listed in the FOR FURTHER INFORMATION CONTACT section to
schedule your inspection. The Regional Office's official hours of
business are Monday through Friday 8:30 a.m. to 4:30 p.m., excluding
Federal holidays.
FOR FURTHER INFORMATION CONTACT: Michele Notarianni, 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#adc3c2d9ccdfc4ccc3c3c483c0c4cec5c8c1c8edc8ddcc83cac2db"><span class="__cf_email__" data-cfemail="244a4b5045564d454a4a4d0a494d474c414841644154450a434b52">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
I. Background
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
Code of Federal Regulations (CFR) 51.308.\1\ Subsequently, 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.\2\ Through a notice of proposed rulemaking published
on August 20, 2024, (89 FR 67341) (hereinafter referred to as the
NPRM), EPA proposed to approve in part and conditionally approve in
part North Carolina's April 4, 2022, SIP submission addressing the
regional haze requirements for the second planning period contained in
the CAA and 40 CFR 51.308. Comments on the NPRM were due on or before
September 19, 2024. EPA received four sets of relevant comments on the
NPRM.
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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 rulemaking.
\2\ The Commitment Letter is in the docket for this rulemaking.
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After reviewing the entirety of the record including comments
submitted, EPA is now taking final action to approve in part and
disapprove in part North Carolina's Haze Plan. Specifically, EPA is
approving the portions 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
disapproving the portions of the Haze Plan addressing the requirements
of 40 CFR 51.308(f)(2) and (3) and (i)(2) through (4) due to the
inadequate record associated with the four-factor analysis (FFA) for
Domtar Paper, LLC (Domtar) located in Plymouth, North Carolina, as
described in more detail in section II. EPA is not finalizing its
previously proposed conditional approval.\3\ Therefore, the issues
identified as part of the proposed conditional approval and in the
Commitment Letter are now subsumed under the broader partial
disapproval.
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\3\ 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. In its
Commitment Letter, the State committed to submit a SIP revision
containing specific enforceable measures no later than one year from
the effective date of a final conditional approval action. Because
EPA is not finalizing the proposed conditional approval, North
Carolina is not required to submit that SIP revision.
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Disapproving a SIP submission establishes a two-year deadline for
EPA to promulgate a Federal Implementation Plan (FIP) to address the
relevant requirements under CAA section 110(c), unless EPA approves a
subsequent SIP submission that meets these requirements.\4\ Therefore,
EPA will be obligated under CAA section 110(c)(1) to promulgate a FIP
within two years after the effective date of this partial disapproval,
unless the State submits, and EPA approves, a SIP revision that
satisfies the requirements of 40 CFR 51.308(f)(2) and (3) and (i)(2)
through (4).
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\4\ North Carolina's Haze Plan was not submitted to address a
requirement of part D, title I of the CAA, and is not required in
response to a finding of substantial inadequacy as described in CAA
section 110(k)(5) (SIP Call), so the partial disapproval will not
trigger any offset or highway sanctions clocks. See CAA section
179(a).
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This final action represents a logical outgrowth of the proposal,
following EPA's proposed partial approval and partial conditional
approval, and receipt of public comments. EPA specifically solicited
comments 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 met the
requirements of 40 CFR 51.308(f)(2)(i) through (iv). See 89 FR 67358.
Through this solicitation of comment, the public was on notice that EPA
was specifically interested in the public's perspective on its
conclusions and may ultimately change its conclusions. A logical
outgrowth of a proposal is to refrain from taking the proposed step.
See Am. Iron & Steel Inst. v. EPA, 886 F.2d 390, 400 (D.C. Cir. 1989).
For action on SIP submittals, EPA is required to act, so the Agency may
not refrain from acting. As such, it is reasonable to view a
disapproval as a logical outgrowth of a proposed approval (or proposed
conditional approval) if comments
[[Page 92575]]
cause EPA to change its proposed conclusions. Consistent with CAA
section 110(k)(3), EPA may approve in part portions of the SIP
submittal if those portions meet all applicable requirements.
II. Response to Comments
In response to the NPRM, EPA received comment letters from the
National Parks Conservation Association (NPCA), Sierra Club, the
Coalition to Protect America's National Parks, Center for Biological
Diversity, and Southern Environmental Law Center (collectively referred
to as the ``Conservation Groups''); U.S. National Park Service (NPS);
and 7 Directions of Service, Blue Ridge Outdoors Magazine, Center for
Biological Diversity, CleanAIRE NC, Coalition to Protect America's
National Parks, Dogwood Alliance, Forest Keeper, Friends of Big Ivy, I
Heart Pisgah, Mountain True, NPCA, North Carolina Black Alliance, and
Toxic Free North Carolina (collectively referred to as the
``Organizations''). Additionally, EPA received comments from two
members of the public. One set of comments from a member of the public
is not relevant to this action, and the other set of comments is
addressed below. All comments received are available in the docket for
this action. A summary of the significant comments received from these
commenters and EPA's responses to these comments is below.
Comment 1: The Conservation Groups contend that EPA's proposal to
approve North Carolina's reliance on the Visibility Improvement State
and Tribal Association of the Southeast's (VISTAS') visibility modeling
is arbitrary and capricious because the Agency ignored significant
flaws in this modeling. They state that they informed VISTAS and EPA of
significant errors in the visibility modeling through a 2021 letter,\5\
EPA did not acknowledge these errors in the NPRM, and these errors
affected the source selection process for all of the VISTAS states.
Consequently, they assert that North Carolina improperly excluded major
sources of haze-forming pollution from FFAs.\6\ These alleged errors
are addressed in comments 1.a through 1.c below.
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\5\ Exhibit 11 of the Conservation Groups' comments contains the
May 12, 2021, letter regarding the VISTAS regional haze modeling for
the second planning period.
\6\ 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.''
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Comment 1.a: The Conservation Groups contend that the VISTAS
modeling significantly underpredicted the contribution of sulfates to
visibility impairment at Class I areas on the 20 percent most impaired
days and that this underprediction was largest during the summer months
when visibility impairment is most problematic.\7\ They also assert
that these errors resulted in the modeling not meeting VISTAS' model
performance goals and modeling acceptance criteria for a number of
Class I areas. They further assert that although North Carolina claims
that it corrected for this underprediction through the use of relative
response factors (RRFs), neither North Carolina nor EPA assessed
whether use of RRFs adequately corrected for errors in the modeling.
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\7\ Areas statutorily designated as mandatory Federal Class I
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
section 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.
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Response 1.a: EPA disagrees that there are significant flaws in
North Carolina's 2028 visibility modeling that resulted in excluding
major sources of haze-forming pollution from evaluation via FFAs for
the second planning period. As the Conservation Groups state, North
Carolina relied upon the photochemical visibility modeling performed by
VISTAS to project the impact of the State's 2028 sulfur dioxide
(SO<INF>2</INF>) and nitrogen oxides (NO<INF>X</INF>) emissions on
visibility in both in-state and out-of-state Class I areas. VISTAS
performed the modeling in accordance with the principles described
within EPA's ``Modeling Guidance for Demonstrating Air Quality Goals
for Ozone, PM<INF>2.5</INF> and Regional Haze'' (2018 Modeling
Guidance).\8\ In 2018, EPA approved \9\ the Quality Assurance Project
Plan prepared by VISTAS for performing the modeling and also reviewed
and provided comments on the VISTAS Modeling Protocol. EPA also
reviewed the VISTAS final modeling reports and data relied upon by
North Carolina, and they appear reasonable.
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\8\ ``Modeling Guidance for Demonstrating Air Quality Goals for
Ozone, PM<INF>2.5</INF> and Regional Haze,'' EPA 454/R-18-009,
November 29, 2018, available at: <a href="https://www.epa.gov/sites/default/files/2020-10/documents/o3-pm-rh-modeling_guidance-2018.pdf">https://www.epa.gov/sites/default/files/2020-10/documents/o3-pm-rh-modeling_guidance-2018.pdf</a>.
\9\ The April 3, 2018, Quality Assurance Project Plan for the
VISTAS II Regional Haze Project is located in appendix A-1 of the
Haze Plan.
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Regarding sulfate predictions, figure 6-7 in North Carolina's Haze
Plan shows the results of the normalized mean bias and normalized mean
error statistical model performance tests for sulfates across the
VISTAS region. Figure 6-7 does show that the modeled sulfate levels are
biased low, with some values falling outside of the model performance
criteria. However, as discussed below, these biases are not uncommon in
photochemical modeling analyses and can be addressed with additional
analyses. Table 6-10 in the Haze Plan summarizes the sulfate model
performance criteria for multiple statistical tests, and figures 6-32
through 6-55 in the Haze Plan graphically depict model performance at
the Great Smoky Mountains National Park (Great Smoky Mountains) (North
Carolina/Tennessee); Linville Gorge National Wilderness Area (Linville
Gorge); and Swanquarter National Wilderness Area (Swanquarter) which
are three of the five Class I areas in North Carolina.\10\
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\10\ North Carolina has five Class I areas, two of which are
shared with Tennessee: Great Smoky Mountains (North Carolina/
Tennessee); Linville Gorge; Swanquarter; Shining Rock National
Wilderness Area (Shining Rock); and Joyce Kilmer-Slickrock National
Wilderness Area (Joyce Kilmer) (North Carolina/Tennessee). Joyce
Kilmer relies on data from the Great Smoky Mountains IMPROVE
monitoring site (GRSM1) because it does not have an IMPROVE monitor
and the Shining Rock IMPROVE monitor did not have valid data in 2011
so model performance could not be evaluated.
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Model bias and error, either high or low, is not uncommon in
photochemical modeling analyses due to uncertainties in model inputs
and the scientific model formulation, and the fact that all air quality
models are simplified approximations of the complex phenomena of
atmospheric chemistry, fate, and transport of pollutants. Section 6.0
of EPA's 2018 Modeling Guidance discusses uncertainties that may affect
model results and states that following the recommendations in the
Guidance should help mitigate the uncertainty as much as possible.
North Carolina acknowledges in the Haze Plan that model performance is
biased low on the 20 percent most impaired days and provided an
explanation of why this modeling was nonetheless appropriate for its
regulatory determinations in the Haze Plan (which references the 2018
Modeling Guidance in several instances). The 2018 Modeling Guidance
states that it is not appropriate to use a ``bright-line test'' for
distinguishing between adequate and inadequate photochemical model
performance for a single performance test statistic.\11\ EPA's 2018
Modeling Guidance instead recommends using a ``weight of evidence''
approach for
[[Page 92576]]
evaluating model performance holistically.\12\
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\11\ See 2018 Modeling Guidance at p. 69 (``Further, even with a
single performance test, it is not appropriate to assign ``bright
line'' criteria that distinguish between adequate and inadequate
model performance.'').
\12\ See id. (``[T]he EPA recommends that a ``weight of
evidence'' approach be used to determine whether a particular
modeling application is valid for assessing the future attainment
status of an area.'').
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As discussed in section 5.2(d) of EPA's ``Guideline on Air Quality
Models'' contained in 40 CFR part 51, appendix W, there are no specific
levels of any model performance metric that indicate acceptable model
performance. The decision regarding acceptability is heavily influenced
by professional judgment of the reviewing authority, which is EPA in
this case. Based upon the overall performance of the model for all
pollutants affecting visibility, considered holistically, North
Carolina's conclusions that the modeling is acceptable for use in the
regional haze SIP analyses appear reasonable, and North Carolina
provided a reasonable explanation of the model bias.
Just as importantly, North Carolina's steps to correct for this
model bias appear reasonable. The Haze Plan explains that the model is
applied in a relative sense through the calculation of RRFs following
the procedures in 2018 Modeling Guidance for calculating 2028 future
year visibility impacts, which mitigates concerns about the low bias in
the sulfate model predictions. As described in EPA's 2018 Modeling
Guidance, RRFs are ``the fractional change in air quality
concentrations that is simulated due to emissions changes between a
base and a future year emissions scenario.'' \13\
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\13\ See id. at p. 103.
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Applying the model in a relative sense using the RRFs is an
important tool in mitigating the impacts of the sulfate modeling
underpredictions in the 2011 baseline year on the model projections for
the 2028 future year. Section 4.1 of the 2018 Modeling Guidance
provides a detailed explanation of why EPA recommends photochemical
modeling be applied in a relative sense and explains that problems
posed by model bias are expected to be reduced when using the relative
approach. Section 7.2.6.1 of North Carolina's Haze Plan explains the
calculation of 2028 visibility estimates using the RRF approaches
contained in EPA's 2018 Modeling Guidance. Using the RRF approach with
an average of five years of Interagency Monitoring of Protected Visual
Environments (IMPROVE) \14\ data on the 20 percent most impaired days
and 20 percent clearest days along with the relative percent modeled
change in all of the particulate matter (PM) species between 2011 and
2028 reduces the influence of the low bias in sulfate-modeled (and
other PM species) values in the 2011 baseline year. The 2028 visibility
impairment projection is derived primarily from the five-year average
of actual IMPROVE monitoring data in 2009-2013 that was then scaled in
a relative sense by the modeling results. If the model was being
applied in an absolute sense, the low bias in the sulfate modeled
values would have a larger impact on the 2028 visibility projections.
For these reasons, North Carolina's use of the VISTAS model results to
inform source selection appears reasonable due to the use of RRFs to
minimize the impacts of model bias.
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\14\ IMPROVE visibility monitoring data is available at: <a href="https://vista.cira.colostate.edu/Improve/">https://vista.cira.colostate.edu/Improve/</a>.
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Comment 1.b: The Conservation Groups state that VISTAS relied on an
``outdated'' 2011 baseline year for its 2028 future year emissions
projections and assumed that electric generating units (EGUs) would
operate in the exact same manner in 2028 as they did in 2011. Thus,
they assert that the model assumptions and results are incorrect
because EGUs are likely to have different load utilization in 2028 than
in 2011.
Response 1.b: North Carolina's use of a 2011 base emissions
inventory year to project emissions out to 2028 (the end of the second
planning period) appears reasonable in this instance. Although it is
always preferable to use the most recent information available for
modeling, the 2011 baseline year inventory used by VISTAS was the
latest region-wide inventory available at the time that North
Carolina's SIP submittal was being developed during the VISTAS
technical work, which took place from December 2017 to February 26,
2021.\15\ In EPA's experience, coordination among states such as those
in the VISTAS region takes time, and the modeling involved is time-
consuming, highly technical, and resource intensive. The modeling
generally requires hundreds of hours of time to gather the model input
data (e.g., emissions, meteorology, land-use, etc.), prepare modeling
protocols, perform the modeling, and analyze the results. The
computational resources to run photochemical models are also very
large. ``Mainframe'' clusters of a large number of computer processors
are required to run the models, and even using these powerful
computers, it takes weeks of computer run-time for a full-year model
simulation. Additionally, EPA's newer 2016-based modeling platform only
became available in September 2019, after VISTAS had already invested a
considerable amount of time and money into the regional haze modeling
analysis.\16\ EPA develops the National Emissions Inventory (NEI)
suitable for use in such models every three years.\17\ By design, the
regional haze program requires states to spend significant time in the
planning phase, and this generally necessitates the use of a baseline
year that is substantially earlier than the date the state submits its
SIP to EPA.
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\15\ See ``Timeline'' for the VISTAS II Regional Haze Project
at: <a href="https://www.metro4-sesarm.org/content/vistas-regional-haze-project-intro">https://www.metro4-sesarm.org/content/vistas-regional-haze-project-intro</a>.
\16\ See ``Technical Support Document for EPA's Updated 2028
Regional Haze Modeling'' at: <a href="https://www.epa.gov/visibility/technical-support-document-epas-updated-2028-regional-haze-modeling">https://www.epa.gov/visibility/technical-support-document-epas-updated-2028-regional-haze-modeling</a>.
\17\ For more information on the NEI, see: <a href="https://www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei">https://www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei</a>.
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In addition, there is no RHR requirement regarding the baseline
year for regional photochemical modeling (nor is photochemical modeling
required). At the time VISTAS began their regional haze modeling, EPA
did not have a more recent baseline emissions inventory year available
for state use in the second period regional haze plans. Furthermore,
North Carolina explains the use of this particular baseline year and
states that the 2011 emissions inventory was the most recently
available quality assured statewide emissions inventory when the VISTAS
project began.\18\ Moreover, prior to using this data, the State
discussed the selection of this baseline year emissions inventory and
received confirmation from EPA to use this emissions inventory.\19\
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\18\ See Haze Plan at p. 24 (``The year 2011 was selected as the
modeling base year because the VISTAS 2028 emissions inventory is
based on the 2011 Version 6 EPA modeling platform, which at the
commencement of the VISTAS second round of planning for regional
haze was the most current, complete modeling platform available. For
the analyses in this SIP, this period consists of those years
surrounding 2011 (i.e., 2009-2013).''). See also Haze Plan, p. 49
(``Calendar year 2011 satisfies the criteria in EPA's modeling
guidance episode selection discussion and is consistent with the
base year modeling platform. In addition, the 2011/2028 modeling
platform was the most recent available platform when VISTAS started
its modeling work. EPA's 2016-based platform became available at a
later date after VISTAS had already invested a considerable amount
of time and money into the modeling analysis. Using the 2016-based
platform was not feasible from a monetary perspective, nor could
such work be done in a timely manner.'').
\19\ See the January 29, 2018, email from EPA (Richard Wayland)
regarding use of a 2011 base year by VISTAS for regional haze in the
docket for this rulemaking.
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The 2011 emissions inventory was used to estimate emissions of
visibility impairing pollutants in 2028. VISTAS applied reductions
expected from
[[Page 92577]]
Federal and state regulations on the visibility impairing pollutants
NO<INF>X</INF>, PM, and SO<INF>2</INF>. North Carolina's 2028 emissions
projections are based on the State's technical analysis of the
anticipated emissions rates and level of activity for EGUs, other point
sources, non-point sources, on-road sources, and off-road sources based
on their emissions in the 2011 base year, considering growth and
additional emissions controls to be in place by 2028. In addition, the
VISTAS emissions inventory for 2028 accounts for post-2011 emission
reductions from promulgated Federal, state, local, and site-specific
control programs. North Carolina's modeling of the EGUs and non-EGUs
for the growth factors appears reasonable. The 2011 baseline year to
2028 future year emissions projections were modeled to account for
projected changes in emissions over the second planning period.
Although North Carolina used the 2011 year as its emissions
inventory base year, North Carolina also examined more recent emission
inventory information for SO<INF>2</INF> and NO<INF>X</INF> for the
years 2017, 2018, and 2019 and compared these emissions to the 2028
emission projections that were used for modeling purposes in section
7.7.3 and tables 7-41 and 7-42 of its Haze Plan. This appears compliant
with 40 CFR 51.308(f)(2)(iii) and is another backstop that helps to
ensure that the State adequately considered more recent emissions
inventory information. The technical information provided in the docket
documents the projected 2028 emissions inventory in the Haze Plan.
Given the aforementioned reasons, the use of the 2011 baseline year by
VISTAS (and thus North Carolina) appears reasonable.
Comment 1.c: The Conservation Groups state that VISTAS used
``outdated'' monitoring data for its 2028 future year projections that
did not reflect an observed shift in nitrate contribution to visibility
impairment in the southeastern United States in the recent past. They
therefore contend that this resulted in the exclusion of major
NO<INF>X</INF> sources from the modeling results.
Response 1.c: Regarding the Conservation Groups' claims that the
2009-2013 modeling base period did not reflect more recent changes in
nitrate contributions, EPA discussed its views on this issue in detail
in the NPRM. Nitrates are also discussed in response 3, below. EPA
agrees that during the 2009-2013 timeframe, nitrate impacts have become
more significant on some of the 20 percent most impaired days,
especially taking into account the significant decrease in
SO<INF>2</INF> emissions and acknowledged this in the NPRM. However,
North Carolina's focus on SO<INF>2</INF> emitting sources during this
period appears reasonable because sulfates remain the dominant
visibility impairing pollutant at the Class I areas affected by North
Carolina.
For the reasons discussed in responses 1.a through 1.c, the VISTAS
modeling appears adequate for North Carolina's use in selecting sources
for a FFA for the second planning period. However, the requirement to
consider the four factors in establishing the long-term strategy (LTS)
at 40 CFR 51.308(f)(2) and CAA section 169A(g)(1) encompasses the
selection of sources for further analysis, and as discussed above, EPA
is disapproving the portions of the Haze Plan addressing 40 CFR
51.308(f)(2) due to the inadequate record associated with the Domtar
FFA.
Comment 2: The Conservation Groups claim the errors in the VISTAS
modeling discussed in comment 1 above were carried forward into the
source selection process for VISTAS states, including North Carolina,
and that those errors caused VISTAS, and the states that relied on the
VISTAS process, to improperly exclude sources from FFAs. In addition to
the impact of the modeling errors, they state that North Carolina used
VISTAS' unreasonable source screening process using Area of Influence
(AoI) and Particulate Matter Source Apportionment Technology (PSAT)
analyses and unreasonably high source selection thresholds. They
therefore contend that EPA's proposal to approve the State's source
selection method is arbitrary and capricious. The Conservation Groups'
specific comments on this topic are addressed in comments 2.a through
2.g, below.
Comment 2.a: The Conservation Groups claim that the State employed
unreasonably high source selection thresholds for AoI, which were too
restrictive and resulted in the identification of only five North
Carolina sources at that step. They assert that by using a percentage
source selection threshold, the calculated threshold in absolute
visibility impact terms was higher for Class I areas with the most
severe visibility impairment. The Conservation Groups contend that
fewer sources were identified at the AoI step for Class I areas with
the worst visibility impairment. They also state that for the areas
with the worst visibility impairment, more sources should be selected
to make progress toward the natural visibility goal. In addition, they
assert that neither North Carolina nor EPA provide justification for a
three percent threshold at the AoI step, making its use arbitrary.
Response 2.a: EPA disagrees with this comment. As explained in the
NPRM, the RHR does not require states to consider controls for all
sources, all source categories, or any or all sources in a particular
source category. See 89 FR 67346. Nor does the RHR expressly specify
criteria for minimum source selection thresholds.
These flexibilities, however, are not unbounded. The RHR requires
that ``[t]he State should consider evaluating major and minor
stationary sources or groups of sources, mobile sources, and area
sources. The State must include in its implementation plan a
description of the criteria it used to determine which sources or
groups of sources it evaluated and how the four factors were taken into
consideration in selecting the measures for inclusion in its long-term
strategy.'' \20\ In addition, the technical basis for source selection
must also be documented, as required by 40 CFR 51.308(f)(2)(iii), and
North Carolina discussed the criteria it used to determine which
sources or groups of sources were evaluated by the State, including the
use of AoI analysis, photochemical modeling (e.g., PSAT), and
associated source selection thresholds for AoI and PSAT tagging in its
Haze Plan. North Carolina documented its use of these approaches in
extensive detail within section 7.5 of the Haze Plan and appendices D-1
and D-2 of the Haze Plan (relating to AoI analysis) and section 7.6 of
the Haze Plan and appendices E-1a, E-1b, E-2a, E-2b, E-2c, E-2d, E-2e,
E-2f, E-3, E-4, E-5, E-6, E-7a, E-7b, and E-8 of the Haze Plan
(relating to PSAT modeling).
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\20\ See 40 CFR 51.308(f)(2)(i).
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North Carolina's source selection methodology--including the use of
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 for follow-up PSAT tagging, and a one
percent PSAT threshold on a pollutant-by-pollutant basis for source
selection--appears reasonable and is documented in the Haze Plan. A
specific approach is not required by the RHR.\21\
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\21\ Both of these approaches (AoI and PSAT) are example methods
in EPA's August 20, 2019, guidance titled: ``Guidance on Regional
Haze State Implementation Plans for the Second Implementation
Period'' (``2019 Guidance'') which is available at: <a href="https://www.epa.gov/sites/default/files/2019-08/documents/8-20-2019_-_regional_haze_guidance_final_guidance.pdf">https://www.epa.gov/sites/default/files/2019-08/documents/8-20-2019_-_regional_haze_guidance_final_guidance.pdf</a>. See subsection ``b)
Estimating baseline visibility impacts for source selection'' on
pages 12-15 of the 2019 Guidance. Photochemical modeling (zero-out
and/or source apportionment is listed as item 4 on page 13 of the
2019 Guidance. VISTAS' AoI analyses involve items 1-3 on p. 13 of
the 2019 Guidance.
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[[Page 92578]]
The results of this methodology also appear reasonable. North
Carolina selected for further analysis the three sources with the
largest visibility impacts (accounting for both SO<INF>2</INF>/sulfate
and NO<INF>X</INF>/nitrate \22\) at North Carolina and nearby Class I
areas. On the whole, SO<INF>2</INF> emissions from the three in-state
sources selected by North Carolina for FFAs--Blue Ridge Paper
Products--Canton Mill (BRPP); Domtar; \23\ and PCS Phosphate Inc.--
Aurora (PCS)--are projected to impact visibility at Class I areas above
North Carolina's one percent PSAT threshold.
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\22\ North Carolina selected sources for PSAT modeling based on
the combined impact of sulfate plus nitrate. Sulfates and nitrates
were modeled together in the PSAT modeling with the other PM species
that impact visibility (e.g., direct PM, organic carbon, elemental
carbon, etc.). There were no sources with a sulfate impact below the
PSAT threshold(s), but a sulfate plus nitrate impact above the
threshold(s).
\23\ 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.
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Most anthropogenic impacts to visibility at the North Carolina
Class I areas come from outside of North Carolina and, in fact, they
primarily come from outside of the VISTAS states. This is also
illustrated in table 7-14 of the Haze Plan, which provides the
contributions from 2028 SO<INF>2</INF> and NO<INF>X</INF> emissions to
visibility impairment from all source sectors for the 20 percent most
impaired days in units of inverse megameters (Mm<SUP>-1</SUP>). The
entries in table 1, below, taken from table 7-14 of the Haze Plan, show
the contributions made from North Carolina, all other VISTAS states,
and other Regional Planning Organizations (RPOs) to North Carolina's
Class I areas.
Table 1--Contributions of 2028 SO2 and NOX Emissions From All Source Sectors to Visibility Impairment for the 20 Percent Most Impaired Days for Class I
Areas in North Carolina
[Mm-1] *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sulfate + nitrate visibility impairment (Mm-1)
------------------------------------------------------------------------------------------------------------
Boundary +
all other
Class I area 2028 total 2028 sulfate + All other regions
impairment nitrate NC VISTAS CENRAP LADCO MANE-VU within
(all species) impairment states region ** region ** region ** VISTAS
modeling
domain
--------------------------------------------------------------------------------------------------------------------------------------------------------
Great Smoky Mountains...................... 45.75 24.17 0.89 9.77 1.87 3.74 1.57 6.33
Joyce Kilmer............................... 45.12 22.48 0.43 5.62 2.96 6.84 0.82 5.81
Linville Gorge............................. 42.52 19.47 0.95 4.19 2.55 5.54 1.15 5.09
Shining Rock............................... 42.09 19.20 1.13 3.97 2.80 5.11 0.75 5.44
Swanquarter................................ 46.39 21.14 1.83 3.87 0.72 4.19 3.23 7.30
--------------------------------------------------------------------------------------------------------------------------------------------------------
* As noted in North Carolina's Haze Plan, the columns to the right of ``Projected 2028 Impairment on 20% Most Impaired Days'' do not add up to the
values in the ``Projected 2028 Impairment on 20% Most Impaired Days'' column due to international emissions and boundary emissions.
** ``CENRAP'' refers to Central Regional Air Planning Association (which is associated with the Central States Air Resource Agencies (CENSARA));
``LADCO'' refers to Lake Michigan Air Directors Consortium; ``MANE-VU'' refers to Mid-Atlantic/Northeast Visibility Union; ``WRAP'' refers to Western
Regional Air Partnership. See also: <a href="https://www.epa.gov/visibility/visibility-regional-planning-organizations">https://www.epa.gov/visibility/visibility-regional-planning-organizations</a>.
Table 1 illustrates that North Carolina's in-state emissions
account for a relatively small fraction of total sulfate plus nitrate
visibility impairment at North Carolina's Class I areas which is as
follows: approximately 3.68 percent for Great Smoky Mountains; 1.91
percent for Joyce Kilmer; 4.88 percent for Linville Gorge; 5.89 percent
for Shining Rock; and 8.66 percent for Swanquarter.\24\
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\24\ These percentages were calculated by dividing the ``NC''
column by the ``2028 Sulfate + Nitrate Impairment'' column and
multiplying by 100.
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The RHR affords North Carolina flexibility in its choice of both
AoI and PSAT thresholds. North Carolina's source selection methodology
appears reasonable, and therefore, North Carolina's choice of the three
largest impacting sources in the State using its AoI and PSAT criteria
appears adequate.
Comment 2.b: The Conservation Groups state that VISTAS considered
sulfate and nitrate separately in the PSAT model analyses, which the
Conservation Groups allege does not align with how these pollutants
actually function in the atmosphere, where sulfate and nitrate act in
combination, along with other precursors, to contribute to visibility
impairment. As a result, they argue that VISTAS likely underestimated
the overall visibility impact of individual sources in its PSAT
analysis.
Response 2.b: EPA disagrees with this comment. In the AoI screening
analysis, VISTAS used the combined sulfate plus nitrate values to
select sources to tag for the refined PSAT source apportionment
modeling analyses. Section 7.5.5 of the Haze Plan explains how North
Carolina used the results of the AoI analysis to select sources for
further evaluation with PSAT. This section shows that facilities
contributing 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 were selected for PSAT tagging. See
tables 7-20 through 7-24 for the specific sources with sulfate plus
nitrate values greater than North Carolina's AoI source selection
threshold.
Also, contrary to the Conservation Groups' assertion, sulfates and
nitrates were modeled together in the PSAT modeling with the other PM
species that impact visibility (e.g., direct PM, organic carbon,
elemental carbon, etc.). Section 7.6.2 of the Haze Plan summarizes the
results of the PSAT modeling. This section states that: ``The adjusted
PSAT results were used to calculate the percent contribution of each
tagged facility to the total sulfate and nitrate point source (EGU +
non-EGU) contribution at each Class I area.'' \25\ Tables 7-31 through
7-35 contain the specific PSAT results for each of North Carolina's
Class I areas. It is true that North Carolina considered the PSAT
modeled results for sulfate and nitrate separately to compare against
its selected one percent threshold. However, no additional sources
would have been identified by using a combined sulfate plus nitrate
metric. For these reasons, North Carolina's approach appears
reasonable.
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\25\ See Haze Plan at p. 227.
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[[Page 92579]]
Comment 2.c: The Conservation Groups state that VISTAS used an
outdated 2028 emissions projection to ``tag'' sources. They note that
although VISTAS documented that the initial 2028 emission inventory
projections were updated for the final modeling, the associated PSAT
modeling did not use the final 2028 inventory. They state that VISTAS
scaled predicted sulfate and nitrate to the corresponding changes in
SO<INF>2</INF> and NO<INF>X</INF> emissions using a linear relationship
between SO<INF>2</INF> and NO<INF>X</INF> emissions and sulfate and
nitrate concentrations. They argue ample evidence shows that there is a
non-linear relationship between emissions and sulfate/nitrate
concentrations. Moreover, the Conservation Groups contend that North
Carolina significantly underestimated future 2028 emissions for
multiple sources, pointing to a comparison of North Carolina's 2028
future emission projections against recent actual emissions for five
Duke Energy EGUs as an example: Duke Energy Carolinas (DEC)--Belews
Creek Steam Station (DEC--Belews Creek), DEC--Cliffside Steam Station
(DEC--Cliffside), DEC--Marshall Steam Station (DEC--Marshall), Duke
Energy Progress, LLC (DEP)--Mayo Electric Generating Plant (DEP--Mayo),
and DEP--Roxboro Steam Electric Plant (DEP--Roxboro).\26\
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\26\ See table 2 of the 2024 Kordzi Report in Exhibit 1 of the
Conservation Groups' comment letter.
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They argue that this comparison shows that the State severely
underestimated future emissions for these facilities and note that
nothing in the Haze Plan indicates that there have been federally
enforceable changes to these Duke Energy EGUs' operating parameters
that would justify such large differences between recent actual
emissions and future year 2028 projections.
Response 2.c: Regarding the Conservation Groups' claim that VISTAS
used an outdated 2028 emissions projection to select sources for the
PSAT modeling and that the linear scaling used to adjust the PSAT
results for the updated 2028 emissions inventory introduced errors into
the modeling, EPA acknowledges that VISTAS used the original 2028
emissions inventory to perform the PSAT modeling and that the original
PSAT results were linearly scaled to reflect the updated 2028
emissions. Although linear scaling introduces some uncertainty to the
final PSAT results, EPA agrees that adjusting the results to account
for VISTAS' updated 2028 emissions inventory using linear scaling is a
better approach than relying on the original PSAT modeling. Linear
scaling of photochemical modeling results to account for changes in
emissions is an accepted practice by EPA. An example is provided by
EPA's Modeled Emission Rates for Precursors (MERPs) for evaluating
secondary particulate matter of 2.5 micrometers or less in diameter
(PM<INF>2.5</INF>) impacts in Prevention of Significant Deterioration
(PSD) modeling analyses.\27\ This guidance recommends an approach where
the PM<INF>2.5</INF> impacts are estimated using an archived national-
scale photochemical modeling analysis, performed using Comprehensive
Air Quality Model with Extensions (CAMx) and Community Multiscale Air
Quality Modeling (CMAQ) \28\ photochemical models, that uses
hypothetical emissions sources, and then linearly scaling the
photochemical modeling results using the ratio of the PSD project-
specific source emissions to the modeled emissions from the
hypothetical source (see Equation 1 on page 3 of the April 30, 2024,
MERPs memorandum). This approach is widely used and accepted by state
air quality agencies and EPA to account for secondarily formed
PM<INF>2.5</INF> resulting from precursor emissions (SO<INF>2</INF> and
NO<INF>X</INF>) for PSD modeling analyses. Since the MERPs analyses use
linear scaling with CAMx and for the same PM<INF>2.5</INF> precursors
(SO<INF>2</INF> and NO<INF>X</INF>) as VISTAS used for their regional
haze modeling, this example clearly shows that linear scaling of PM
precursor emissions is an accepted practice.
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\27\ ``Clarification on the Development of Modeled Emission
Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for
Ozone and PM<INF>2.5</INF> under the PSD Permitting Program,'' April
30, 2024, Memorandum from Tyler Fox to Regional Office Modeling
Contacts is available at: <a href="https://www.epa.gov/sites/default/files/2020-09/documents/epa-454_r-19-003.pdf">https://www.epa.gov/sites/default/files/2020-09/documents/epa-454_r-19-003.pdf</a>.
\28\ See <a href="https://www.epa.gov/cmaq">https://www.epa.gov/cmaq</a> for further information on
CMAQ.
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Regarding the Conservation Groups' assertion that ``[n]othing in
the SIP Revision indicates that there have been federally enforceable
changes to the Duke Energy EGUs' operating parameters that would
justify such large differences between recent actual emissions and
future year 2028 projections,'' as explained in response 4.f, under the
RHR, sources that do not meet a state's reasonable source selection
criteria (such as these five Duke Energy EGUs) are not selected for a
FFA and are therefore not required to have emission limits and
supporting conditions adopted into the LTS in the SIP to support
reasonable progress for the planning period.
With respect to the 2028 emissions projections for the Duke Energy
EGUs, North Carolina appears to have used the best assumptions
available at the time of SIP development to project the 2011 base year
emissions out to 2028 for the five Duke Energy EGUs discussed in this
response. The State compared 2017, 2018, and 2019 actual SO<INF>2</INF>
and NO<INF>X</INF> emissions to 2028 projected emissions in tables 7-41
and 7-42 of their Haze Plan. The methodology used to make the 2028
projections is discussed in appendix B-3 of North Carolina's Haze Plan.
Table 9 in appendix B-3 provides a comparison of the different
projection methodologies used by North Carolina including a comparison
to the 2028 emissions projections performed separately by EPA for its
2028 Regional Haze Modeling.\29\ The total of North Carolina's 2028
projected SO<INF>2</INF> emissions for the five Duke Energy EGUs in
table 9 of appendix B-3 used for its reasonable progress and PSAT
modeling (VISTAS 2028elv5 inventory) is 8,732 tons per year (tpy),
which is approximately eight percent less than the 9,456 tpy of
emissions projected by EPA for 2028 for these five sources. EPA's 2028
emissions for EGUs were projected from the more recent 2016 base-year
emissions inventory using the Integrated Planning Model.\30\ While
North Carolina's 2028 projection emissions are much less than the
recent actual emissions in 2017-2019, North Carolina's and EPA's
projected 2028 projections are similar. Therefore, North Carolina's
2028 emissions projections appear reasonable for the reasonable
progress and PSAT modeling analyses.
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\29\ Memorandum from Richard A. Wayland to Regional Air Division
Directors, ``Availability of Modeling Data and Associated Technical
Support Document for EPA's Updated 2028 Visibility Air Quality
Modeling,'' September 19, 2019, available at: <a href="https://www.epa.gov/visibility/technical-support-document-epas-updated-2028-regional-haze-modeling">https://www.epa.gov/visibility/technical-support-document-epas-updated-2028-regional-haze-modeling</a>.
\30\ ``Documentation for EPA's Power Sector Modeling Platform v6
Using the Integrated Planning Model,'' November 2018, available at:
<a href="https://www.epa.gov/power-sector-modeling/documentation-epas-power-sector-modeling-platform-v6-november-2018-reference">https://www.epa.gov/power-sector-modeling/documentation-epas-power-sector-modeling-platform-v6-november-2018-reference</a>.
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Comment 2.d: The Conservation Groups note that North Carolina
relied on the PSAT modeling results for its multiple in-state sources
that are located less than 50 kilometers (km) from a Class I area and
claim that PSAT modeling has been shown to be unreliable for sources
that are within a short distance from a Class I area, referencing
Federal Land Manager (FLM) \31\ guidance that addresses
[[Page 92580]]
regional grid models. According to the Conservation Groups, this
guidance shows that regional grid models are not preferred for sources
located close to Class I areas and that the grid size used by VISTAS is
too small to produce accurate results for those sources.
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\31\ 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. The
U.S. National Park Service (NPS), U.S. Fish and Wildlife Service
(FWS), and U.S. Forest Service (USFS) are collectively referred to
as the ``Federal Land Managers'' or ``FLMs'' throughout this notice.
---------------------------------------------------------------------------
Response 2.d: The Conservation Groups state that PSAT modeling has
been shown to be unreliable for sources located less than 50 km from a
Class I area, which caused North Carolina to inappropriately screen out
sources which should have undergone an FFA. However, they do not
provide any specific model performance information demonstrating that
the CAMx model nor the PSAT source apportionment tool have poor model
performance for evaluating visibility impacts from sources located
within 50 km of any of the Class I areas located in North Carolina.
Instead, the Conservation Groups provide qualitative arguments to
support their assertion. They assert that the FLMs' Air Quality Related
Values Work Group (FLAG) Guidance indicates that photochemical grid
models are not the preferred model for evaluating visibility impacts
from sources less than 50 km from Class I areas and reference the use
of direct plume impact models. However, they are inappropriately citing
the FLAG guidance and recommendations, which is not intended to apply
to photochemical grid modeling or outside of the permitting context.
The FLAG reference to direct plume models (e.g., Plume Visibility
Model) \32\ is only for evaluating visibility impacts under the New
Source Review (NSR)/PSD (NSR/PSD) permitting regulations and is not
applicable to regional haze analyses. EPA's regional haze regulations
and guidance do not require evaluations of direct plume impacts
separate from the photochemical modeling analyses used for regional
haze visibility analyses. Therefore, the argument is not relevant for
the visibility analyses for regional haze.
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\32\ The Plume Visibility Model ``PLUVUE'' is used for
estimating visual range reduction and atmospheric discoloration
caused by plumes resulting from the emissions of particles, nitrogen
oxides, and sulfur oxides from a single source. See ``PLUVUE II''
at: <a href="https://www.epa.gov/scram/air-quality-dispersion-modeling-alternative-models">https://www.epa.gov/scram/air-quality-dispersion-modeling-alternative-models</a>. The User's Guide is available at: <a href="https://gaftp.epa.gov/Air/aqmg/SCRAM/models/other/pluvueii/PluvueUG.pdf">https://gaftp.epa.gov/Air/aqmg/SCRAM/models/other/pluvueii/PluvueUG.pdf</a>.
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The Conservation Groups also assert that since the horizontal grid
size used in the VISTAS CAMx modeling was 12 km, it is insufficient to
resolve the details of emissions plumes from facilities within 50 km of
a Class I area and that the model performance degrades substantially at
the close-in distances. The general statement from the Conservation
Groups is that model performance substantially degrades within 50 km is
not supported by any specific evidence in the comments. Therefore,
North Carolina's CAMx PSAT modeling appears reasonable for selecting
sources for reasonable progress analyses.
The Conservation Groups separately contend that North Carolina's
correlation analysis of the sulfate AoI versus PSAT presented in
section 7.6.3 of the Haze Plan is flawed. They point out the scatter in
the AoI/PSAT ratio data for distances less than 100 km in figure 7-77
of the Haze Plan and argue this makes the State's correlation
conclusions invalid. They also refer to the scatter in the sulfate
fractional bias values in figure 7-78 in the Haze Plan and argue the
AoI versus PSAT correlation is invalid. EPA disagrees. While there is
more scatter between the data points less than 100 km from the Class I
area, there is clearly a trend that the AoI values are much larger than
the PSAT values within 100 km compared to the ratios for further
distances. There is logic to this result due to the way the AoI metric
is calculated using the Extinction Weighted Residence Times (EWRT)
multiplied by the Emissions (Q) divided Distance (d) (EWRTxQ/d). The
EWRT is calculated using the frequency that winds (represented by
Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back
trajectories) pass over a specific geographic area (represented by a
modeling grid cell) on the path to the Class I area.\33\ For sources
located less than 100 km from a Class I area, there is likely to be a
higher frequency of the HYSPLIT back trajectories passing over the 12
km grid cell containing the source, thus the EWRT and AoI value will be
larger. The CAMx PSAT modeling is a more refined photochemical modeling
approach that calculates the atmospheric fate and transport of the PM
precursors and their chemical reactions to form visibility impairing
pollutants (e.g., ammonium sulfate). Therefore, compared to the AoI
screening process, the refined PSAT technique is less likely to
overestimate the visibility impacts for sources located within 100 km
of the Class I area. Regarding the scatter of the data resulting in the
AoI to PSAT fractional bias correlation, EPA acknowledges that there is
scatter in the data which is reflected in the 0.72 coefficient of
determination (R\2\) value shown in figure 7-78 in the Haze Plan.
However, this level of correlation is not uncommon in these types of
modeling data analyses, and the results are reasonable. For these
reasons, North Carolina's correlation approach appears valid.
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\33\ See section 7.5 of the Haze Plan for additional detail.
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The photochemical modeling employed by VISTAS and North Carolina is
the most refined methodology available for evaluating regional haze
visibility impacts. Moreover, North Carolina's AoI screening process
identified sources located within 50 km of its Class I areas, including
the BRPP facility located approximately 17 km from Swanquarter that met
the PSAT source selection criteria and underwent an FFA to evaluate
reasonable progress. As discussed above, North Carolina demonstrated in
section 7.6.3 of the Haze Plan that the AoI screening technique tends
to overestimate visibility impacts for sources located within 100 km of
a Class I area. Based upon this AoI overestimation, in section 7.7.3 of
the Haze Plan, North Carolina explains why some sources located less
than 100 km from its Class I areas were not tagged for PSAT modeling
and thus were not selected for FFAs. North Carolina's justification
regarding why the other sources within 100 km were not selected for
FFAs appears reasonable.
Comment 2.e: The Conservation Groups claim that North Carolina did
not justify its application of the one percent PSAT threshold and that
North Carolina's use of this threshold at the PSAT step biased the
process against heavily polluted Class I areas. They note that NPS'
comments on the draft SIP revision explain that reliance on the
percent-based threshold required source impacts to be 80 times larger
for the most visually impaired Class I areas versus the least visually
impaired Class I areas in order to be selected for an FFA. They also
argue that PSAT tagging was unnecessary because the AoI step already
identified the sources that contributed to impairment at Class I areas.
Response 2.e: EPA disagrees with the Conservation Groups' assertion
that North Carolina did not justify its application of the one percent
PSAT threshold. Section 7.7.1 of the Haze Plan explains the State's
rationale for using a one percent PSAT threshold to select sources for
a reasonable progress evaluation. Using a percentage-based threshold
enabled the State to identify
[[Page 92581]]
the sources that contribute the largest amount of impact on visibility
at the Class I areas. While it is true that using a one percent PSAT
threshold identifies sources which contribute larger visibility impacts
at the most visually impaired Class I areas than at the least visually
impaired Class I areas, North Carolina's targeting of sources with the
largest visibility contributions to each Class I area regardless of
magnitude of visibility impairment at a Class I area appears
reasonable. Use of a percentage-based threshold produced a relative
ranking of visibility impairment to allow the State to focus on the
sources contributing to the largest amount of visibility impact at each
individual Class I area, which has the potential to reduce visibility
impacts the most. Regardless of whether a relative or absolute
threshold is used, the number of sources selected depends on the chosen
value of the threshold. North Carolina's source contribution threshold,
which identified the largest sources to evaluate emissions measures
using an FFA, appears reasonable.
Regarding the Conservation Groups' assertion that the PSAT tagging
process was unnecessary, as the AoI step already identified the sources
that contributed to impairment at Class I areas, EPA disagrees with the
premise of this comment. The standard is not whether the approach is
necessary or required, but rather, whether the approach is reasonable
and is reasonably explained.\34\ The two-step process of screening with
the AoI analysis and then applying the more refined PSAT source
apportionment modeling to sources that met the initial AoI screening
criteria is a sound technical approach for identifying sources to
evaluate for reasonable progress. Elements of North Carolina's AoI
approach are discussed in EPA's 2019 Guidance as a viable method to
assess source's visibility impacts to Class I areas.\35\ North
Carolina, along with many of the VISTAS states, also relied upon the
AoI initial screening approach in its first planning period haze
plan.\36\ VISTAS used the AoI analysis as an initial screening step
because it is a much simpler and less resource intensive approach than
using PSAT tagging to model hundreds to thousands of potential sources.
The AoI screening approach identified a smaller subset of sources that
could undergo refined analysis using PSAT modeling. The two-step
process of the screening AoI analysis along with using the more refined
PSAT source apportionment modeling appears valid and reasonable. Also,
as discussed above, states have discretion under the RHR regarding
choice of source selection methodology.
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\34\ See 40 CFR 51.308(f)(2)(i), (iii); see also sections 2 and
2.1 of 2021 Clarifications Memo.
\35\ EPA's 2019 Guidance at pp. 12-14 describes components of
North Carolina's AoI approach, including Q/d, trajectory analyses,
residence time analyses, and source apportionment photochemical
modeling (e.g., CAMx PSAT).
\36\ See, e.g., 77 FR 11858, 11869 (February 28, 2012) for a
description of North Carolina's AoI approach in the first planning
period. On May 24, 2016, EPA fully approved North Carolina's first
period regional haze plan, effective June 23, 2016. See 81 FR 32652.
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Comment 2.f: The Conservation Groups contend that EPA did not
address the ``significant flaws'' in the VISTAS modeling and source
selection process and that EPA concluded that North Carolina's
selection of three in-state sources was reasonable because it enabled
the identification of sources with the largest visibility impacts. They
argue that this is contrary to EPA's guidance which states that a
source selection threshold that captures only a small portion of a
state's contribution to visibility impairment in Class I areas is more
likely to be unreasonable and contrary to the CAA which does not
authorize states or EPA to select only the largest contributors to
visibility impairment. They assert that North Carolina should have used
a different selection method with a lower threshold, such as a ``Q/d''
(emissions (Q) divided by distance to a Class I area (d)) with a
threshold of five or lower, to capture the largest portion of in-state
sources.
Response 2.f: EPA disagrees with the assertion that North
Carolina's selection of the three largest sources contributing to
visibility impairment at Class I areas is contrary to EPA's guidance.
The PSAT modeling performed by VISTAS found that the three sources
selected by North Carolina for FFAs have the largest contribution to
visibility impairment of any point sources in the State. As discussed
in response 2.a., the PSAT modeling results show that the total
cumulative contribution to visibility impairment on the 20 percent most
impaired days at North Carolina's Class I areas from all SO<INF>2</INF>
and NO<INF>X</INF> emitting sources in the State are relatively small,
ranging from 1.91 percent for Joyce Kilmer to 8.66 percent for
Swanquarter. Given state discretion in selecting sources to evaluate
for emissions controls, and since the SO<INF>2</INF> and NO<INF>X</INF>
emissions from all point sources in North Carolina contribute a
relatively small amount to the visibility impairment at its Class I
areas, the State's selection of the three largest source contributors
to visibility impairment appears reasonable.
Regarding the Conservation Groups' claim that the State should have
adopted a different selection method (such as Q/d) with a lower
threshold to select more sources in North Carolina being selected, as
discussed above, a state is not required to evaluate all sources of
emissions in each planning period. Instead, a state may reasonably
select a set of sources for an analysis of control measures. Selecting
a set of sources for analysis of control measures in each planning
period is also consistent with the RHR, 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.\37\
Moreover, use of Q/d (which simply involves dividing the quantity of
emissions by the distance to a Class I area) does not consider
transport direction/pathway, dispersion and photochemical processes, or
the particular days that have the most anthropogenic impairment due to
all sources.\38\ Therefore, compared to photochemical modeling, using a
simple Q/d technique, as the Conservation Groups suggest, would have
resulted in a less accurate quantification of visibility impacts on
Class I areas. As discussed in detail above, North Carolina's reliance
on VISTAS modeling and the State's source selection methodology were
well documented and appear reasonable.
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\37\ See 2019 Guidance at 9.
\38\ See 2019 Guidance at 13.
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Comment 2.g: The Conservation Groups state that EPA asserts North
Carolina's source selection method is reasonable because: (1)
SO<INF>2</INF> and NO<INF>X</INF> emissions have decreased since the
first planning period and are projected to continue decreasing, (2)
visibility conditions at in-state Class I areas are projected to
improve and have improved since the baseline period, and (3) North
Carolina sources do not contribute to any Class I areas above their
respective Uniform Rate of Progress (URP). They argue that projected
visibility improvement at North Carolina's Class I areas and the fact
that those areas are below their respective URPs are not a valid basis
to approve the State's flawed selection method. They cite to EPA
guidance stating that the URP is not a safe harbor and that states
cannot avoid requiring sources to install reasonable controls merely
because there have been emissions reductions owing to ongoing air
pollution controls since the first planning period or because
visibility is projected to improve at Class I areas.
[[Page 92582]]
Response 2.g: EPA agrees that the URP is not a ``safe harbor'' to
avoid requiring additional reasonable progress measures. However,
factual information that all of the North Carolina and nearby Class I
areas are below the URP was provided because being below the URP is
relevant to whether a state needs to perform a ``robust demonstration''
based on the requirements in 40 CFR 51.308(f)(3)(ii)(A) and (B).
Therefore, a comparison of the URP to projected visibility impairment
in 2028 is needed to inform that requirement. Additionally, other
information about measured progress towards natural conditions can be
relevant in evaluating the source selection process. For example,
significant improvements in visibility at impacted Class I areas since
the beginning of the second planning period (starting in 2018) is
relevant to whether a state is making progress towards natural
conditions and may provide information that could influence the
selection of sources to be analyzed for emissions controls in the
second planning period. Regardless of the visibility information listed
in the proposed rule, EPA independently evaluated North Carolina's SIP
documentation and came to the conclusion that North Carolina's source
selection methodology and thresholds for this second planning period
appear reasonable for the reasons stated earlier in this response.
For the reasons discussed in responses 2.a through 2.g, North
Carolina's source selection methodology appears reasonable. However,
the requirement to consider the four factors in establishing the LTS at
40 CFR 51.308(f)(2) and CAA section 169A(g)(1) encompasses the
selection of sources for further analysis, and as discussed above, EPA
is disapproving the portions of the Haze Plan addressing 40 CFR
51.308(f)(2) due to the inadequate record associated with the Domtar
FFA.
Comment 3: The Conservation Groups assert that EPA incorrectly
endorses North Carolina's decision to exclude consideration of
NO<INF>X</INF> controls in any FFAs. They contend that VISTAS' modeling
did not accurately reflect the shift in the 20 percent most impaired
days and the corresponding increase in the contribution of nitrate to
visibility impairment at Southeastern Class I areas. They state that
nitrate concentrations are higher on winter days, nitrate contributes
to a substantial portion of light extinction at Great Smoky Mountains
and Joyce Kilmer, and nitrate is the biggest contributor to light
extinction on multiple 20 percent most impaired days for these areas.
They also note EPA's general expectation that states will, at a
minimum, consider both SO<INF>2</INF> and NO<INF>X</INF> in this
planning period, and assert that there are multiple sources of
significant NO<INF>X</INF> emissions that North Carolina should have
analyzed for NO<INF>X</INF> controls.
Response 3: EPA disagrees with this comment. The RHR does not
prescribe which visibility impairing pollutants must be evaluated in
the FFAs. EPA's 2019 Guidance on page 11 states: ``When selecting
sources for analysis of control measures, a state may focus on the PM
species that dominate visibility impairment at the Class I areas
affected by emissions from the state and then select only sources with
emissions of those dominant pollutants and their precursors.'' On July
8, 2021, EPA issued a memorandum containing ``Clarifications Regarding
Regional Haze State Implementation Plans for the Second Implementation
Period'' (``2021 Clarifications Memo'').\39\ Section 2.2 of EPA's 2021
Clarifications Memo recommends that states which do not evaluate
SO<INF>2</INF> and NO<INF>X</INF> in both source selection and control
evaluations show why such consideration of these pollutants would be
unreasonable, especially if the state considered both of these
pollutants in the first planning period.\40\
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\39\ ``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).
\40\ North Carolina considered SO<INF>2</INF> for FFAs conducted
in the first planning period.
---------------------------------------------------------------------------
North Carolina appears to have followed these recommended
approaches here. North Carolina considered both SO<INF>2</INF>
emissions (via sulfates visibility impacts) and NO<INF>X</INF>
emissions (via nitrates visibility impacts) in the source selection
process. As part of the Haze Plan, DAQ presented the results of PSAT
modeling conducted by VISTAS 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.
The result of this process was that while sources were selected for
SO<INF>2</INF> control analysis determinations, no sources in North
Carolina met the State's nitrate source selection thresholds, and
therefore, North Carolina did not select any sources for a
NO<INF>X</INF> emissions control evaluation. Contrary to the
Conservation Groups' assertion that North Carolina made a ``decision''
not to consider NO<INF>X</INF> controls in any FFA, it was North
Carolina's application of its source selection process in combination
with data and modeling showing that SO<INF>2</INF> and not
NO<INF>X</INF> is the dominant visibility impairing pollutant that
resulted in North Carolina only selecting sources for SO<INF>2</INF>
emissions control analyses and not NO<INF>X</INF> emissions control
analyses.
Additionally, in order to better understand the trends in PM
species contributions to visibility impairment, North Carolina examined
more recent IMPROVE monitoring data. More recent IMPROVE monitoring
data shows that ammonium sulfate remains the dominant visibility
impairing pollutant at North Carolina's Class I areas as discussed in
section 2.5.2 of the Haze Plan (particularly figures 2-7 through 2-10
for the 2009-2013 period) and in section 2.6.2 (particularly figures 2-
13 through 2-16 for the 2014-2018 period). The 2015-2019 IMPROVE
monitoring data (the most recent data available at the time) cited
within the Haze Plan (figures 10-1, 10-2, and 10-3) identifies the
relative contributions of PM species contributing to the total
visibility impairment at the North Carolina Class I areas, which are
shown in table 2, below. In spite of increased nitrate contributions on
the 20 percent most impaired days (as the Conservation Groups note,
often on winter days), as indicated in that table, ammonium nitrate
contributions to regional haze at the State's Class I areas remain
relatively low at 8 to 17 percent of the total visibility impairment as
compared to ammonium sulfate at 50 to 58 percent.
[[Page 92583]]
Table 2--2015-2019 Speciated IMPROVE Monitoring Data for North Carolina's Class I Areas
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ammonium Ammonium Organic Coarse Elemental Fine sea Fine soils
sulfate (%) nitrate (%) carbon (%) mass (%) carbon (%) salt (%) (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Great Smoky Mountains............................................ 54 17 17 5 6 1 1
Joyce Kilmer..................................................... 54 17 17 5 6 1 1
Linville Gorge................................................... 57 8 22 5 7 0 1
Shining Rock..................................................... 58 10 19 5 5 1 1
Swanquarter...................................................... 50 17 17 7 5 3 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Additionally, in figure 10-7 of the Haze Plan, North Carolina
provides a comparison of the sulfate and nitrate five-year averages for
the 2009-2013 and 2015-2019 periods for all the Class I areas in the
VISTAS region. North Carolina's conclusion that although nitrate
contributions have increased for some Class I areas, sulfate remains
the dominant visibility impairing species through 2019, appears
reasonable.
Furthermore, in tables 7-20 through 7-24 of the Haze Plan, the
State provided a calculation of the sulfate and nitrate EWRT used in
the AoI analysis for Great Smoky Mountains, Joyce Kilmer, Linville
Gorge, Shining Rock, and Swanquarter for the 20 percent most impaired
days, demonstrating that the sulfate EWRT are significantly higher than
the nitrate EWRT. This further supports the importance of focusing on
SO<INF>2</INF> emissions reductions for this planning period. The
State's rationale for focusing on SO<INF>2</INF> controls in the FFAs
is summarized in North Carolina's SIP submittal and the NPRM.\41\
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\41\ See Haze Plan, section 2 (particularly figures 2-13 through
2-18), section 7 (particularly figures 7-25 through 7-31), and
section 10 (particularly figures 10-1 through 10-7); 89 FR 67353-54.
---------------------------------------------------------------------------
With respect to the Conservation Groups' assertion that nitrate is
the biggest contributor to light extinction on multiple of the 20
percent of most impaired days for these North Carolina Class I areas
during the 2014-2018 period (especially on winter days), as described
above, the average nitrate contribution across the 20 percent most
impaired days is still relatively small. Thus, while nitrate impairment
may be relatively high on a particular day, the data that states are
required to use for regional haze as specified in 40 CFR 51.301 and 40
CFR 51.308(f)(1) shows ammonium nitrate only contributes 8 to 17
percent of the total visibility impairment (during the 2015-2019
period).
North Carolina's justification for not evaluating sources selected
for SO<INF>2</INF> emission control analyses for a separate
NO<INF>X</INF> emission control analysis appears reasonable for this
planning period. The trends in PM species' contributions to visibility
impairment will continue to be evaluated in future planning periods. If
the data warrants consideration of NO<INF>X</INF> controls in future
planning periods, EPA expects that North Carolina will address
potential NO<INF>X</INF> controls in future regional haze SIP
revisions. However, the requirement to consider the four factors in
establishing the LTS at 40 CFR 51.308(f)(2) and CAA section 169A(g)(1)
encompasses decisions regarding the visibility impairing pollutants
evaluated in the FFAs, and as discussed above, EPA is disapproving the
portions of the Haze Plan addressing 40 CFR 51.308(f)(2) due to the
inadequate record associated with the Domtar FFA.
Comment 4: The Conservation Groups assert that, to correct errors
in the source selection method, EPA must require North Carolina to
assess additional EGU sources identified by NPS and NPCA with emissions
that likely contribute to visibility impairment at Class I areas. The
Conservation Groups argue that the State arbitrarily refused to
consider cost-effective control efficiency improvements at each Duke
Energy EGU and identify specific concerns for DEC--Belews Creek, DEC--
Cliffside, DEC--Marshall, and DEP--Roxboro.\42\ They contend that EPA
must disapprove the State's reliance on unenforceable emission
reductions to avoid conducting FFAs at these EGUs, and that EPA must
disapprove the State's refusal to conduct FFAs for sources that the
State's analysis shows are reasonably anticipated to contribute to
visibility impairment. These specific arguments are addressed in
comments 4.a through 4.g, below.
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\42\ The Conservation Groups' letter identifies five Duke Energy
EGUs on pages iv and 46 and identifies four Duke Energy EGUs in the
Table of Contents on page v and in sections III.D.1.i-iv of the
letter. The five Duke Energy EGUs listed on pages iv and 46 that the
Conservation Groups recommend to be evaluated for emissions controls
are: DEC--Belews Creek, DEC--Cliffside, DEC--Marshall, DEP--Roxboro,
and DEP--Mayo. Sections III.D.1.i-iv do not include recommendations
regarding improved control efficiencies specific to DEP-Mayo.
---------------------------------------------------------------------------
Comment 4.a: The Conservation Groups contend that states must
consider recent actual and projected emission rates to determine if a
source could reasonably attain a lower rate with existing measures. For
DEC--Belews Creek, DEC--Cliffside, DEC--Marshall, and DEP--Roxboro, the
Conservation Groups assert errors in North Carolina's analysis of
potential emission reductions for NO<INF>X</INF> and SO<INF>2</INF> and
that, in each instance, EPA must disapprove the State's analysis,
conduct its own FFA, and require cost effective control upgrades in a
FIP.\43\ The alleged errors for these four facilities are addressed in
comments 4.b through 4.e, below.
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\43\ The Conservation Groups provide the following information
for these four Duke Energy EGUs: DEC--Belews Creek contributes to up
to 2.01 percent of the sulfate plus nitrate impairment at Linville
Gorge and up to 1.56 percent of the sulfate plus nitrate impairment
at Shining Rock; DEC--Cliffside contributes to up to 1.85 percent of
the sulfate plus nitrate impairment at Shining Rock and 2.49 percent
at Linville Gorge; DEC--Marshall contributes to up to 6.73 percent
of the sulfate plus nitrate impairment at Linville Gorge and up to
2.68 percent of the sulfate plus nitrate impairment at Shining Rock;
and DEP--Roxboro contributes to up to 2.23 percent of the sulfate
plus nitrate impairment at Swanquarter.
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Response 4.a: As explained in response 2.a and in the NPRM (89 FR
67346), the RHR does not require states to select and consider controls
for all sources, all source categories, or any or all sources in a
particular source category. Nor does the RHR expressly specify criteria
for minimum source selection thresholds. States have discretion to
choose reasonable source selection criteria, and sources that meet the
state's criteria are selected for an evaluation of potential control
options for specific visibility impairing pollutants by applying the
four statutory factors in CAA section 169A(g)(1), which is referred to
as an FFA.
The Conservation Groups contend that DEC--Marshall exceeded the AoI
threshold set by North Carolina, but EPA notes that no Duke Energy EGU
exceeded the State's PSAT threshold at any Class I area. Therefore,
North Carolina did not evaluate any Duke Energy EGU for potential
emissions
[[Page 92584]]
controls. This approach is consistent with the State's source selection
results summarized in tables 7-30 through 7-35,\44\ and North
Carolina's decision not to assess Duke Energy EGUs for control
efficiency improvements because they did not meet the State's source
selection criteria appears reasonable.
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\44\ Table 7-29 of the Haze Plan lists facilities that met North
Carolina's AoI threshold and thus were selected by the State for
PSAT tagging. Tables 7-30 through 7-35 provide PSAT results for the
North Carolina Class I areas.
---------------------------------------------------------------------------
As described in the 2019 Guidance,\45\ North Carolina completed an
additional reasonableness check on their source selection process by
examining the unselected sources to see if there were any
``uncontrolled or lightly controlled facilities that were large
contributors to anthropogenic light extinction,'' and found none.\46\
In the NPRM (89 FR 67359), EPA documented an analysis that further
examined the Duke Energy sources to verify North Carolina's claim that
there were no uncontrolled or lightly controlled sources that were not
selected. EPA evaluated the existing SO<INF>2</INF> controls at DEC--
Belews Creek, DEC--Cliffside, DEC--Marshall, DEP--Mayo, and DEP--
Roxboro. EPA analyzed whether these EGUs are well controlled for
SO<INF>2</INF> 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.\47\ Based on
that analysis, it appears reasonable to assume that a FFA would likely
result in the conclusion that no further SO<INF>2</INF> emissions
controls are needed for these sources. All of these EGUs are subject to
the Mercury and Air Toxics Standards (MATS) rule \48\ alternative
SO<INF>2</INF> emission limit of 0.2 pound (lb)/million British thermal
units (MMBtu) and are equipped with wet flue gas desulfurization (WFGD)
that routinely achieve a high SO<INF>2</INF> control effectiveness
(approximately 93.8-99.2 percent).\49\ EPA did not evaluate
NO<INF>X</INF> controls for these EGUs because North Carolina's
conclusion that ammonium sulfate continues to be the dominant
visibility impairing pollutant at North Carolina's Class I areas
appears reasonable. See section IV.C.2.a of the NPRM and response 3.
---------------------------------------------------------------------------
\45\ See 2019 Guidance at p. 19 (``For example, it may be
difficult to show reasonableness of a threshold set so high that an
uncontrolled or lightly controlled source that is one of the largest
contributors to anthropogenic light extinction at a Class I area is
excluded.'').
\46\ See Haze Plan at p. 251.
\47\ Between the years 2017-2022, the calculated annual FGD
SO<INF>2</INF> control efficiencies for DEP--Mayo Unit 1A were
between 96.3 and 97.9 percent.
\48\ The MATS rule is located at 40 CFR part 63, subpart UUUUU.
\49\ See North Carolina Duke Energy scrubber efficiency data
file that is included in the docket for this action. See also 89 FR
67359; 2019 Guidance at 23.
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Comment 4.b: The Conservation Groups argue that North Carolina's
analysis of potential emission reductions for DEC--Marshall suffer from
the following errors regarding SO<INF>2</INF>: (1) the wet scrubbers
are operated erratically; (2) the units have the ability to
continuously operate well below 0.10 lb/MMBtu for SO<INF>2</INF>; (3)
``EPA has concluded that underperforming wet scrubbers should be
evaluated at 98 percent control (with a floor of 0.04 lb/MMBtu), and 95
percent control (with a floor of 0.06 lb/MMBtu) for dry scrubbers;''
(4) ``even lower limits can be achieved;'' and (5) ``Without any
capital upgrade cost (and likely minimal operating and maintenance
costs) the DEC-Marshall units are likely quite capable of much better
SO<INF>2</INF> and NO<INF>X</INF> removal efficiencies that could
likely be achieved with cost-effective upgrades.'' They also argue that
North Carolina's analysis of potential NO<INF>X</INF> emission
reductions suffer from the following errors: (1) ``Units 1, 2, and 4
are equipped with selective non-catalytic reduction (SNCR) systems that
have achieved lower NO<INF>X</INF> emission levels of approximately
0.20 lb/MMBtu, `with some months significantly below that level;' ''
(2) the selective catalytic reduction (SCR) system for Unit 3 is
``operated very erratically, but has demonstrated the ability from
2010-2011 to consistently operate below 0.05 lbs/MMBtu;'' and (3)
``Without any capital upgrade cost (and likely minimal operating and
maintenance costs) the DEC--Marshall units are quite capable of much
better NO<INF>X</INF> removal efficiencies with likely cost-effective
upgrades.
Response 4.b: Regarding potential NO<INF>X</INF> control upgrades
at DEC--Marshall, North Carolina's decision to focus on SO<INF>2</INF>
emission controls in the second planning period appears reasonable
given the documented dominance of sulfate contributions to visibility
impairment at North Carolina's Class I areas. See section IV.C.2.a of
the NPRM and response 3. Thus, it appears reasonable to conclude that
even if DEC--Marshall had met the State's source selection criteria, no
NO<INF>X</INF> emissions control analyses would be necessary for
reasonable progress during this planning period. Additionally, North
Carolina did not select this facility, and therefore, no FFA
information is available. However, EPA's analysis confirms that the
units are not uncontrolled or lightly controlled, are subject to the
MATS rule 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 (approximately 93.8 to 97.9 percent).\50\
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\50\ Between 2017 to 2022, the yearly average FGD SO<INF>2</INF>
control efficiencies for Unit 1 ranged from 94.7 to 96.2 percent,
Unit 2 ranged from 93.8 to 96.1 percent, Unit 3 ranged from 95.2 to
97.1 percent, and Unit 4 ranged from 96.7 to 97.9 percent. See North
Carolina Duke Energy scrubber efficiency data file that is included
in the docket for this action.
---------------------------------------------------------------------------
Comment 4.c: The Conservation Groups argue that North Carolina's
analysis of potential emission reductions at DEC--Belews Creek suffer
from the following errors regarding SO<INF>2</INF>: (1) the wet
scrubbers ``are underperforming, with emission rates, at times, spiking
above 0.30 lb/MMBtu;'' (2) the scrubbers ``have demonstrated the
capability to consistently control SO<INF>2</INF> to 0.05 lbs/MMBtu or
better on a monthly average basis for both units;'' (3) ``[s]imply
increasing the amount of reagent used would be very cost-effective,
require little or no capital investments, and would likely achieve much
lower emissions;'' and (4) the ``assumption that SO<INF>2</INF>
emissions will be reduced from 4,946 to 1,385 tons annually is not
supported in the record, and not based on any enforceable
requirement.'' They also argue that North Carolina's analysis of
potential emission reductions suffer from the following errors
regarding NO<INF>X</INF>: (1) the ``2028 NO<INF>X</INF> emission
projections for Belews Creek are significantly less than the facility
has emitted in recent years, yet there are no enforceable emission
limitations in the SIP Revision that would ensure those 2028
estimates;'' (2) the ``SCR systems perform erratically, with emissions
above 0.40 lb/MMBtu at times;'' (3) ``Belews Creek could likely achieve
NO<INF>X</INF> emission rates of 0.05 lbs/MMBtu or better on a
consistent basis with better catalyst and absorber management;'' and
(4) ``[s]imple upgrades to the SCR system would likely be cost-
effective.''
Response 4.c: Regarding potential NO<INF>X</INF> control upgrades
at DEC--Belews Creek, North Carolina's decision to focus on
SO<INF>2</INF> emission controls in the second planning period appears
reasonable given the documented dominance of sulfate contributions to
visibility impairment at North Carolina's Class I areas. See section
IV.C.2.a of the NPRM and response 3. Thus, it appears reasonable to
conclude that even if DEC--Belews Creek had met the State's source
selection criteria, no NO<INF>X</INF> emissions control analyses would
be warranted.
Regarding the original and revised 2028 SO<INF>2</INF> emissions
projections of 4,946 tpy and 1,385 tpy, respectively, for
[[Page 92585]]
DEC--Belews Creek listed in table 7-41 of the Haze Plan, as explained
in responses 1 and 2.c, North Carolina used the best assumptions
available at the time of SIP development to project the 2011 base year
emissions out to 2028 for sources in the State, including DEC--Belews
Creek. North Carolina did document its 2028 point source emissions
projection methodology in appendix B-3 of the Haze Plan. Table 9 in
appendix B-3 shows that the 1,385 tpy 2028 projected SO<INF>2</INF>
value in table 7-41 of the plan is from a blend of two versions (2.7
and 16.0) of the Eastern Regional Technical Advisory Committee (ERTAC)
EGU Emissions Projection Tool \51\ that was used to create the VISTAS
2028elv5 emissions inventory. As stated in response 2.c, North
Carolina's and EPA's projected 2028 emissions projections, summarized
in appendix B-3 of the Haze Plan, are similar. Therefore, North
Carolina's 2028 SO<INF>2</INF> emissions projections for DEC--Belews
Creek appear to be reasonable estimates.
---------------------------------------------------------------------------
\51\ See <a href="https://www.epa.gov/air-emissions-inventories/eastern-regional-technical-advisory-committee-ertac-electricity">https://www.epa.gov/air-emissions-inventories/eastern-regional-technical-advisory-committee-ertac-electricity</a>.
---------------------------------------------------------------------------
Additionally, North Carolina did not select this facility, and
therefore, no FFA information is available. However, EPA's analysis
confirms that the units are not uncontrolled or lightly controlled, are
subject to the MATS rule 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 (approximately 94.1 to 96.5
percent).\52\
---------------------------------------------------------------------------
\52\ Between 2017 to 2022, the yearly average FGD SO<INF>2</INF>
control efficiencies for Unit 1 ranged from 94.1 to 96.5 percent and
Unit 2 ranged from 95.0 to 96.2 percent. See North Carolina Duke
Energy scrubber efficiency data file that is included in the docket
for this action.
---------------------------------------------------------------------------
Comment 4.d: The Conservation Groups argue that North Carolina's
analysis of potential emission reductions for DEP--Roxboro suffer from
the following errors regarding SO<INF>2</INF>: (1) the ``projections
for 2028 SO<INF>2</INF> are not based on historical data, but instead
rely on unenforceable, predicted emission reductions, from 6,665 in
2020, to 2,258 tons in 2028;'' (2) the wet scrubbers ``are
underperforming with emissions as high as 0.35 lb/MMBtu;'' (3) the
scrubbers ``have `demonstrated the capability to consistently control
SO<INF>2</INF> to approximately 0.075 lb/MMBtu or better on a monthly
average;' '' and (4) there are ``likely very cost-effective scrubber
upgrades available.'' They also argue that North Carolina's analysis of
potential emission reductions suffer from the following errors
regarding NO<INF>X</INF>: (1) the ``projections for 2028 NO<INF>X</INF>
emissions are not based on historical data, but instead rely on
unenforceable, predicted emission reductions;'' (2) the ``SCR systems
perform erratically, with emissions sometimes spiking to nearly 0.5 lb/
MMBtu, which is far worse than the rates commonly achievable and
required of well-functioning SCR systems;'' (3) the ``SCR systems have
`all have demonstrated the ability to continuously operate at
approximately 0.10 lbs/MMBtu;' '' and (4) there are ``likely very cost-
effective control upgrades available.''
Response 4.d: Regarding potential NO<INF>X</INF> control upgrades
and SCR performance at DEP--Roxboro, North Carolina's decision to focus
on SO<INF>2</INF> emission controls in the second planning period
appears reasonable given the documented dominance of sulfate
contributions to visibility impairment at North Carolina's Class I
areas. See section IV.C.2.a of the NPRM and response 3. Thus, it
appears reasonable to conclude that even if DEP--Roxboro had met the
State's source selection criteria, no NO<INF>X</INF> emissions control
analyses would be warranted.
Regarding the original and revised 2028 SO<INF>2</INF> emissions
projections of 6,665 tpy and 2,258 tpy, respectively, for DEP--Roxboro
listed in table 7-41 of the Haze Plan, as explained in responses 1 and
2.c, North Carolina used the best assumptions available at the time of
SIP development to project the 2011 base year emissions out to 2028 for
sources in the State, including DEP--Roxboro. North Carolina did
document its 2028 point source emissions projection methodology in
appendix B-3 of the Haze Plan. Table 9 in appendix B-3 shows a 2028
projection of 6,666 tpy SO<INF>2</INF> for DEP--Roxboro is derived from
ERTAC2.7 (2011 base year) whereas the VISTAS 2028 elv5 uses a 2,258 tpy
SO<INF>2</INF> 2028 emissions projection. As stated in response 2.c,
North Carolina's and EPA's projected 2028 emissions projections,
summarized in appendix B-3 of the Haze Plan, are similar. Therefore,
North Carolina's 2028 SO<INF>2</INF> emissions projections for DEP--
Roxboro appear to be reasonable estimates.
Additionally, North Carolina did not select this facility, and
therefore, no FFA information is available. However, EPA's analysis
confirms that the units are not uncontrolled or lightly controlled, are
subject to the MATS rule 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 (approximately 94.3 to 98.8
percent).\53\
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\53\ Between 2017 to 2022, the yearly average FGD SO<INF>2</INF>
control efficiencies for Unit 1 ranged from 95.9 to 97.1 percent,
Unit 2 ranged from 94.3 to 96.6 percent, Unit 3A ranged from 98.2 to
98.8 percent, and Unit 4A ranged from 97.1 to 98.3 percent. See
North Carolina Duke Energy scrubber efficiency data file that is
included in the docket for this action.
---------------------------------------------------------------------------
Comment 4.e: The Conservation Groups argue that North Carolina's
analysis of potential emission reductions from DEC--Cliffside suffer
from the following errors regarding SO<INF>2</INF>: (1) the ``scrubber
performance is erratic, with SO<INF>2</INF> spikes at Unit 5
periodically exceeding 0.35 lb/MMBtu;'' (2) ``Nevertheless, each of the
scrubbers have demonstrated an ability to consistently achieve
SO<INF>2</INF> emissions of 0.04 lb/MMBtu;'' and (3) `` `[V]ery cost-
effective controls are available for these units for likely just the
increase in reagent,' yet the State failed to even consider such
upgrades.'' They also argue that North Carolina's analysis of potential
emission reductions suffer from the following errors regarding
NO<INF>X</INF>: (1) the ``SCR systems are similarly irregular, with
spikes at Unit 5 exceeding 0.30 lb/MMBtu NO<INF>X</INF>;'' (2) the
``SCR systems have demonstrated an ability to consistently achieve
NO<INF>X</INF> emissions of 0.05 lb/MMBtu;'' and (3) ``Cost-effective
improvements, such as optimizing the catalyst controls would likely be
very cost-effective, but the State failed to even run such cost
calculation.''
Response 4.e: Regarding potential NO<INF>X</INF> control upgrades
and SCR performance at DEC--Cliffside, North Carolina's decision to
focus on SO<INF>2</INF> emission controls in the second planning period
appears reasonable given the documented dominance of sulfate
contributions to visibility impairment at North Carolina's Class I
areas. See section IV.C.2.a of the NPRM and response 3. Thus, it
appears reasonable to conclude that even if DEC--Cliffside had met the
State's source selection criteria, no NO<INF>X</INF> emissions control
analyses would be warranted. Additionally, North Carolina did not
select this facility, and therefore, no FFA information is available.
However, EPA's analysis confirms that the units are not uncontrolled or
lightly controlled, are subject to the MATS rule 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
(96.2 to 99.2 percent).\54\
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\54\ Between 2017 to 2022, the yearly average FGD SO<INF>2</INF>
control efficiencies for Unit 5 ranged from 96.2 to 98.6 percent and
Unit 6 ranged from 98.0 to 99.2 percent. See North Carolina Duke
Energy scrubber efficiency data file that is included in the docket
for this action.
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[[Page 92586]]
Comment 4.f: The Conservation Groups assert that EPA must
disapprove North Carolina's reliance on unenforceable, hypothetical
emission reductions for the Duke Energy EGUs to avoid conducting
control analyses, to demonstrate reasonable progress, and to achieve
the State's reasonable progress goals (RPGs). They note that the CAA
and RHR require the Haze Plan to include enforceable limitations and
other control measures to meet the RPGs for each Class I area and that
EPA has made it clear that, to the extent that a state declines to
evaluate pollution controls to reduce haze for any source based on that
source's planned decline in utilization or reductions in emissions, it
must incorporate those operating parameters or assumptions as
enforceable limitations into the SIP.
The Conservation Groups disagree with North Carolina's statement
that the ``obligation to make reductions permanent and enforceable does
not extend to any control or emissions reduction determination outside
of the reasonable progress/four-factor analysis.'' The Conservation
Groups state that the requirement to ensure that emission reductions
are enforceable stems from the CAA and the RHR itself and quote the
2021 Clarification Memo for the proposition that existing and ``on-the-
way'' measures must be included in the SIP if they are necessary for
reasonable progress. The Conservation Groups also contend that neither
the State, EPA, nor the public can verify that reasonable progress will
be made if the State's assumed pollution reductions to achieve
reasonable progress are not enforceable.
Response 4.f: EPA disagrees with the Conservation Groups assertion
that North Carolina's analysis inappropriately relied on unenforceable
emission reductions to avoid conducting control analyses for the DEC--
Belews Creek, DEC--Cliffside, DEC--Marshall, DEP--Roxboro, and DEP--
Mayo. North Carolina followed the recommendations in the 2019 Guidance
to select sources based on 2028 emissions projections.\55\ As explained
in the NPRM, the State (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. See 89 FR 67356. The
accuracy of the 2028 emissions projections for these five Duke Energy
EGUs is discussed in response 2.c. North Carolina relied on
sophisticated PSAT modeling to identify visibility impacts of the
State's AoI sources to any Class I areas, and no Duke Energy EGU met
the State's PSAT threshold for sulfate or nitrate. Because none of
these Duke Energy EGUs met the State's source selection criteria, North
Carolina's decision to not consider whether control measures at these
sources are necessary for reasonable progress appears reasonable. With
respect to arguments that the RPGs must be developed based on
enforceable measures, the RPGs reflect a state's best estimate of
visibility conditions in the Class I area at the end of planning period
(e.g., 2028 for the second planning period). Under the RHR, RPGs should
account for all measures included in a state's LTS, other states' LTSs,
as well as the implementation of other CAA requirements, including non-
SIP based requirements. The measures underlying the RPGs--except for
the LTS measures found necessary for reasonable progress--are not
required to be adopted into the SIP.
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\55\ See 2019 Guidance at p. 17 (``Generally, we recommend that
states use estimates of 2028 emissions (resolved by day and hour, as
appropriate) to estimate visibility impacts (or related surrogates)
when selecting sources, rather than values of recent year
emissions.'').
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Regarding the statement that ``[t]he RHR provides that the measures
necessary to the State's long-term strategy for ensuring reasonable
progress and its reasonable progress goals must be `as a result of [ ]
enforceable emissions limitations . . .' '' EPA agrees.\56\ As
explained in the NPRM (89 FR 67347), 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 determined
necessary to make reasonable progress toward the national visibility
goal must be included in a state's LTS and in its SIP. As noted above,
however, the Duke Energy EGUs did not meet the State's source selection
criteria, and therefore, North Carolina's decision to not to evaluate
them for controls appears reasonable.
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\56\ ``The long-term strategy 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). Measures
necessary to make reasonable progress must be incorporated into the
SIP and LTS. The CAA also requires that States incorporate these
measures into their SIPs. See 42 U.S.C. 7491(b)(2), (b)(2)(B). The
State may also elect to include additional measures that address
regional haze, beyond those identified as necessary to make
reasonable progress, to strengthen the SIP.
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Regarding the Conservation Groups' references to the 2021
Clarification Memo regarding in-place and on-the-way measures, these
references relate to measures necessary for reasonable progress. They
do not apply to the Duke Energy EGUs because these units did not meet
the State's source selection criteria, and therefore, they do not have
measures necessary for reasonable progress. As a result, no measures
must be adopted into the SIP for these EGUs.
North Carolina provided a summary in table 7-43 of the
SO<INF>2</INF> and NO<INF>X</INF> controls, operating status, and
applicable Federal rules for Duke Energy facilities with coal
units.\57\ There is no indication in the Haze Plan that the State is
relying upon these existing measures listed in table 7-43 as existing
effective controls pursuant to the 2019 Guidance at pages 22-25. In
fact, North Carolina states on page 254 of its Haze Plan that ``Based
on current controlled and projected 2028 emissions, the NCDAQ concluded
that it was not necessary to request that the facilities complete a
reasonable progress/four-factor analysis to demonstrate progress toward
achieving the modeled 2028 RPGs discussed in Section 8 of this SIP.''
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\57\ See section 7.7.3.2, ``Facilities Not Selected for PSAT
Modeling,'' of the Haze Plan.
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Comment 4.g: The Conservation Groups contend that North Carolina
arbitrarily and unlawfully refused to conduct FFAs for the Duke Energy
EGUs despite their undisputed contribution to visibility impairment in
numerous Class I areas. They provide the following arguments to support
this contention. First, the text of the CAA and the RHR require the
State to evaluate the four statutory factors for any source reasonably
anticipated to cause or contribute to any visibility impairment at any
Class I area. The Conservation Groups state that North Carolina
improperly rewrites the statute and regulation to require consideration
of the four factors only when a source ``significantly contributes'' to
visibility impairment. Second, the structure of the CAA makes clear the
requirement to implement emission reductions to ensure reasonable
progress is not contingent on whether a source significantly
contributes to visibility impairment. They note that Congress expressly
uses the modifier ``significant'' in numerous sections of the CAA and
argue that the modifier is conspicuously absent from CAA section 169A.
Third, the purpose of the CAA's visibility provisions to reduce and
ultimately eliminate ``any impairment of visibility'' makes clear that
Congress ``intended for the term `contributes' as used in 7491(b)(2) to
encompass smaller
[[Page 92587]]
impacts than would be required to regulate only those sources that
contribute `significantly.' '' They claim that North Carolina
``effectively rewrites those provisions of the Act and requires only
the evaluation of emissions that it deems significant or large
enough.'' The Conservation Groups acknowledge that there is no bright
line test for assessing contribution under the RHR, but state that EPA
has ``made clear that a state's reasonable progress analysis must
consider a meaningful set of sources and controls that impact
visibility'' and that if a state fails to do so, EPA must disapprove
the SIP revision and issue a FIP.
Response 4.g: EPA agrees that CAA section 169A and the RHR do not
use the phrases ``significant contribution'' or ``significantly
contribute'' when discussing the four factors. The CAA and RHR do not
explicitly list factors that a state must or may not consider when
selecting the sources for which it will determine what control measures
are necessary to make reasonable progress.\58\ The appropriate
threshold for selecting sources may reasonably differ across states and
Class I areas due to varying circumstances. In setting a threshold, a
state may consider the number of emissions sources affecting the Class
I areas at issue, the magnitude of the individual sources' impacts, and
the amount of anthropogenic visibility impairment at the Class I
areas.\59\ As discussed in response 2.a, North Carolina considered the
magnitude of the individual sources' impacts at Class I areas using AoI
screening and PSAT modeling which appears to be a reasonable approach
to identifying sources in the State that are reasonably anticipated to
cause or contribute to visibility impairment in any Class I area.
---------------------------------------------------------------------------
\58\ See 2019 Guidance at 10.
\59\ See id. at 19.
---------------------------------------------------------------------------
Comment 5: The Conservation Groups assert that EPA must disapprove
North Carolina's SIP revision because the public was not given the
opportunity to comment on VISTAS modeling and other work products when
they were being developed. Instead, they contend that North Carolina
presented the VISTAS work products in its draft SIP as final products
that are not subject to change, regardless of public input. The
Conservation Groups also assert that a state must make its regional
haze SIP and the associated technical work products from the RPOs that
support the SIP available for public notice and comment. Additionally,
they contend that when RPOs, like VISTAS, receive funding from EPA to
develop work products that states rely on when developing their
regional haze SIPs, EPA must use its grant oversight authority to
ensure the RPOs' work products comply with all statutory and regulatory
requirements.
Response 5: EPA agrees that technical information supporting North
Carolina's regional haze plan should be available for public review and
comment but disagrees that the public was not given an opportunity to
comment on relevant VISTAS work products relied upon by North Carolina
for the Haze Plan. On August 30, 2021, the State opened the public
comment period on its proposed Haze Plan through October 15, 2021, and
on October 6, 2021, it held a public hearing on the Haze Plan. This
proposed Haze Plan included VISTAS work products (located in appendices
A-E) that the State relied upon in developing its plan.
North Carolina exceeded the minimum public notice and comment
requirements for SIP revisions which are set forth in 40 CFR part
51.\60\ The CAA does not require states to engage in public notice and
comment while they are developing modeling and other technical work
products for use in preparing SIP revisions.
---------------------------------------------------------------------------
\60\ See 40 CFR 51.102, 51.103, and 40 CFR part 51, appendix V,
2.1.
---------------------------------------------------------------------------
Furthermore, the RHR allows states to rely on technical analyses
developed by RPOs when that analysis is approved by all state
participants, does not require RPOs to provide notice and comment for
its work products, and does not require states to provide notice and
comment during the technical development of their regional haze SIPs.
See 40 CFR 51.308(f)(2)(iii). The RHR does require states to document
the technical basis, including modeling, monitoring, cost, engineering,
and emissions information, on which the State relied to determine the
emission reduction measures that are necessary to make reasonable
progress in each Class I area it affects. See id. As discussed above,
the Haze Plan includes the VISTAS work products relied upon by the
State.
EPA also disagrees with the comment that North Carolina
``communicated in its Haze Plan that the VISTAS products on which the
State relied for source selection and in setting its reasonable
progress goals were complete and done'' and presented the VISTAS work
products as ``final products that would not be changed, regardless of
any public input.'' The Conservation Groups did not cite to any such
express language in the Haze Plan. To the extent that North Carolina
relied on the VISTAS' work products to satisfy regional haze
requirements, those work products were subject to public notice and
comment at the state level; EPA evaluated the relevant aspects of the
VISTAS work products as they relate to the review of the State's Haze
Plan; they were subject to notice and comment as part of EPA's proposed
rulemaking, and EPA would not fully approve a SIP revision that it
determined does not meet regional haze requirements due to flawed work
products.
With respect to the comment concerning grant obligations and
``grant oversight authority,'' EPA has not directly provided any grant
money to VISTAS for the second planning period. Regardless, EPA
disagrees with the Conservation Groups' comments regarding the VISTAS
work products for the reasons discussed in this notice of final
rulemaking.
Comment 6: The Conservation Groups assert that EPA shirks its duty
to review North Carolina's source-specific FFAs. They state that EPA
proposes to ``rubber stamp'' the SIP submission without engaging in any
meaningful and independent analysis of North Carolina's FFAs to ensure
they comply with the CAA and the RHR. Moreover, they assert that
``[d]espite EPA's stated expectations for this planning period, North
Carolina does not require any of the sources to adopt additional
control measures to make reasonable progress'' and that EPA accepts
North Carolina's decision to ignore ``readily available, feasible, and
cost-effective controls'' which violates the CAA and RHR. The
Conservation Groups' specific comments on the FFAs for Domtar, PCS, and
BRPP are addressed in comments 7 through 9, below.
Response 6: For various reasons, EPA disagrees with the
Conservation Groups' contentions. EPA's partial approval and partial
disapproval of the Haze Plan is a proper exercise of EPA's authority
under the CAA. Congress crafted the CAA to provide for states to take
the lead in developing implementation plans, but balanced that decision
by requiring EPA to review the plans to determine whether a SIP meets
the requirements of the CAA. When reviewing SIPs, EPA must consider not
only whether the state considered the appropriate factors in making
decisions, but also whether it acted reasonably in doing so. In
undertaking such a review, EPA does not usurp the state's authority but
ensures that such authority is reasonably exercised.
Contrary to the comment that the Agency ``shirks'' its CAA
obligations, EPA has performed its duties with diligence and integrity.
EPA carefully evaluated the Haze Plan and the
[[Page 92588]]
associated record and engaged in a thorough analysis of each control
option, including each of the underlying cost assumptions used in the
calculations. EPA independently evaluated each FFA, including costs,
and compared each FFA's control determination against EPA's ``Air
Pollution Control Cost Manual'' (CCM).\61\ After carefully considering
the submitted comments and the entirety of the record, EPA is now
shifting from its initial proposal of a partial approval and partial
conditional approval to a partial approval and partial disapproval. At
proposal, EPA specifically solicited comment on the adequacy of North
Carolina's analyses, including the FFAs and determination of controls
necessary for reasonable progress, and whether the State met the
requirements of 40 CFR 51.308(f)(2)(i) through (iv). See 89 FR 67358.
The partial disapproval represents a logical outgrowth of EPA's
proposal which specifically solicited comments on these determinations
and conclusions and reflects EPA's receipt and consideration of public
comments. EPA responds to the Conservation Groups' specific comments on
the FFAs for Domtar, PCS, and BRPP in responses 7 through 9, below.
---------------------------------------------------------------------------
\61\ The CCM 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>.
---------------------------------------------------------------------------
Comment 7: The Conservation Groups provided several comments on the
Domtar FFA.\62\ These comments are summarized in comments 7.a through
7.c below.
---------------------------------------------------------------------------
\62\ The Conservation Groups erred in reporting the 2020 NEI
SO<INF>2</INF> emissions for Domtar at p. 28 of their comment
letter. According to the 2020 NEI, the facility emitted 1,054 tons
for Domtar, not 1,504 tons. The 2020 NEI is located at: <a href="https://www.epa.gov/air-emissions-inventories/2020-national-emissions-inventory-nei-data">https://www.epa.gov/air-emissions-inventories/2020-national-emissions-inventory-nei-data</a>.
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Comment 7.a: The Conservation Groups argue that EPA cannot approve
North Carolina's flawed FFA for Domtar and must require the
installation of reasonable and cost-effective controls via a FIP. They
contend that North Carolina ``baldly rejected wet scrubber controls as
not cost-effective'' at a cost of $3,660/ton SO<INF>2</INF> removed for
the No. 2 Hog Fuel Boiler (HFB2) and that EPA did not provide any
rationale to support approval of the State's determination. They also
contend that EPA does not acknowledge multiple errors in North
Carolina's FFA of wet scrubber controls for HFB2, summarized as
follows.
Control Efficiency--The Conservation Groups state that North
Carolina underestimated the control efficiency that a wet scrubber can
achieve. They note that modern wet scrubbers can achieve at least 98
percent control efficiency, the vendor providing the wet scrubber quote
states that its scrubbers can achieve up to 99 percent control, and the
FFA does not explain these discrepancies with the 95 percent control
efficiency assumed by North Carolina.
Costs--The Conservation Groups assert that North Carolina
overestimated the cost of a wet scrubber by including unjustified or
undocumented costs. They allege that the State unreasonably accepted
the use of an inflated 1.3 retrofit factor, which Domtar attributed to
``unanticipated delays for installing a wet scrubber.'' However, they
contend that there is no indication in the FFA that retrofitting HFB2
with a wet scrubber is unusual and the delays are already considered in
the contingency fee. The Conservation Groups also argue that the State,
without adequate explanation or documentation, included sales tax
although pollution control equipment is tax exempt, increased the
quoted freight and construction management charges, and included a new
induced fan at a cost of $3,000,000.
Cost Effectiveness--The Conservation Groups assert that, after
correcting for the control analysis errors, the cost effectiveness
values are $2,968/ton without a new induced fan and $3,244/ton with a
fan. They contend that these cost-effectiveness values and the $3,660/
ton value are below the cost threshold established by other states,
claiming that Colorado, Nevada, and New Mexico used a threshold of
$10,000/ton of pollution reduced. While acknowledging the CAA does not
require the State to use a bright line rule, they contend that the law
requires states to explain why it has exercised it discretion in a
given matter. The Conservation Groups argue that North Carolina must
establish a threshold, or explain and justify some other objective
measure, for determining cost-effectiveness that is in line with other
states' chosen measures and apply that threshold consistently across
its FFAs. They also note that EPA proposed to disapprove other second
planning period SIPs where the states ``applied arbitrary cost-
effectiveness threshold or rejected controls that were reasonable and
cost-effective.''
Visibility Impact--The Conservation Groups argue that North
Carolina and EPA disingenuously suggested that the State did not
utilize visibility impact when rejecting wet scrubber controls for
Domtar. They contend that North Carolina improperly considered
visibility as a fifth factor in its decision to reject reasonable and
cost-effective controls, which they state is contrary to EPA's previous
assertions and Congress' express exclusion of visibility impact as one
of the four statutory reasonable progress factors. Therefore, the
Conservation Groups argue that North Carolina's consideration of
visibility impacts violates the CAA and the RHR and note that EPA has
proposed to disapprove second planning period SIPs where states
improperly relied of the lack of visibility benefit to reject
reasonable controls.
Response 7a: EPA agrees in part and disagrees in part with the
assertion that North Carolina did not provide an adequate rationale to
support the State's determination that wet scrubber controls at HFB2
are not cost-effective. As described in more detail below, EPA
disagrees with certain characterizations by the Conservation Groups
about the rejected controls and cost analysis. At proposal, EPA
specifically solicited comment on the adequacy of DAQ's analyses,
including the FFAs and determination of controls necessary for
reasonable progress, and whether the State met the requirements of 40
CFR 51.308(f)(2)(i) through (iv). See 89 FR 67358. After further
consideration of the analyses, as well as the comments received, EPA
agrees that overall, North Carolina did not provide an adequate
rationale to explain why the wet scrubber controls were not cost-
effective, and therefore, not included in the LTS as being necessary
for reasonable progress. EPA's evaluation of the State's FFA, and
explanation for why the justification is inadequate, is provided below.
Due to the inadequate record substantiating the FFA conclusion
regarding HFB2, together with the concerns discussed in response 7.b
regarding the lack of enforceable measures in the record for HFB1, EPA
is disapproving the portions of the Haze Plan addressing 40 CFR
51.308(f)(2) and (3) and (i)(2) through (4).
EPA's first basis for disapproval of North Carolina's LTS is the
inadequate justification that the wet scrubber controls are not cost-
effective for HFB2. There is no requirement in the CAA or the RHR for
states to establish bright line cost effectiveness thresholds when
evaluating control costs in FFAs. The CAA and the RHR require states to
evaluate the costs of compliance, and EPA's 2019 Guidance recommends
that states follow the recommendations in EPA's CCM to facilitate
apples-to-apples comparisons of different controls options for the same
source, and comparisons across different sources.\63\
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\63\ See 2019 Guidance at 31.
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As described in section 7.8 and appendix I of the Haze Plan, the
State did not set a specific cost per ton
[[Page 92589]]
threshold for the cost of compliance factor, but rather analyzed each
facility using the information in EPA's CCM and 2019 Guidance to
determine whether a given control measure is cost-effective. North
Carolina determined the cost-effectiveness value for a wet scrubber on
HFB2 to be $3,660/ton SO<INF>2</INF>, which is somewhat higher than the
values calculated by the Conservation Groups ($3,244/ton with a new
induction fan and $2,968/ton without a new induction fan). As explained
below, regardless of the range of costs presented by both the State and
the Conservation Groups, EPA finds that North Carolina did not
adequately justify why a wet scrubber emissions control in that cost
range was not necessary for reasonable progress.
North Carolina states in appendix I that HFB2 is a unique set-up.
It combusts fuels such as, lignin, natural gas, biomass fuel (including
paper cores and bleached and unbleached pulp stock), No. 2 fuel oil,
used oil, sludge, gases collected in the High-Volume Low-Concentration
(HVLC) system, Low-Volume High-Concentration gases, and stripper off
gases, and it is used as a control device for several process gas
streams at the facility. The State reviewed the RACT/BACT/LAER
Clearinghouse \64\ and did not identify devices similar to HFB2 to
which the cost effectiveness of a wet scrubber could be compared.
Therefore, as explained in section 7.8.3.1 of the Haze Plan, it
requested that EPA adopt the existing measures into the SIP as required
by CAA section 169A(b)(2) and 40 CFR 51.208(f)(2). Given the lack of
other hog fuel boilers with similar controls, and the cost of
compliance and the other statutory factors, North Carolina determined
the control to not be necessary for reasonable progress.
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\64\ EPA's RACT/BACT/LAER Clearinghouse is 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>.
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For several reasons, including consideration of the comments
received after proposal, EPA ultimately does not find North Carolina's
justification for rejecting the controls compelling. First, although it
may be accurate that most if not all hog fuel boilers in the country do
not have wet scrubbers installed, Domtar and the State submitted a
complete cost analysis and a vendor quote to install a wet scrubber on
HFB2. It appears that it is possible to install a wet scrubber on the
particular unit (and achieve at least a 95 percent SO<INF>2</INF>
reduction), and neither Domtar nor the State argued otherwise. Unless a
wet scrubber cannot be installed on HFB2, the lack of a similar
scrubber in the RACT/BACT/LAER Clearinghouse is not a relevant reason
for rejecting the control. Second, although EPA has not established a
bright line cost-effectiveness threshold and all regional haze FFAs and
SIP decisions will be evaluated on a SIP-by-SIP basis, EPA notes that
it has found or proposed to find, based on its state-specific
evaluation of other SIPs, that at least one other state did not
adequately justify its determination to not adopt controls as part of
its FFA at cost-effectiveness values higher than the value North
Carolina considered for Domtar. See, e.g., Air Plan Partial Approval
and Partial Disapproval; Utah; Regional Haze State Implementation Plan
for the Second Implementation Period; Air Plan Disapproval; Utah;
Interstate Transport of Air Pollution for the 2015 8-Hour Ozone
National Ambient Air Quality Standards; proposed rule, 89 FR 67208
(August 19, 2024). It is up to each state to adequately justify
particular cost decisions on a SIP-by-SIP basis, and in this case, EPA
believes that North Carolina did not provide adequate information in
the record for rejecting this particular emissions control. Due to this
inadequate record, it was not reasonable for the State to conclude that
a wet scrubber at HFB2 is not necessary for reasonable progress.
EPA acknowledges the Conservation Groups' assertions that the cost
effectiveness values for HFB2 are below the thresholds used by other
states during the second planning period, such as Colorado, Nevada, and
New Mexico which elected to set cost effectiveness thresholds of
$10,000/ton of pollutant removed. However, North Carolina was not
required by the CAA or RHR to adopt a similar bright-line cost
effectiveness threshold when evaluating control costs in FFAs, and the
relatively high thresholds of up to $10,000/ton set by Colorado,
Nevada, and New Mexico, do not automatically compel other states to
follow suit. Each state has discretion to set (or not set) a reasonable
cost threshold and provide a justification for FFA outcomes.
While EPA agrees with the Conservation Groups' overall conclusion
that North Carolina did not adequately justify the cost control
decisions, EPA does not necessarily agree with all of their specific
contentions. For example, EPA disagrees with the argument that North
Carolina underestimated the scrubber control efficiency at HFB2. The
control efficiency of a wet scrubber is dependent upon a number of
variables, including the type and design of the wet scrubber system
used, the absorbing and/or reacting solution or slurry used, packed bed
height, sump fluid and makeup water balance, scrubber pH, and the
concentration of SO<INF>2</INF> in the inlet waste gas flow.\65\ Domtar
justified the use of 95 percent control efficiency by citing to a wet
scrubber estimate from a vendor stating that the scrubber system has
been designed to achieve a 95 percent collection of SO<INF>2</INF>
emissions.\66\ The vendor's estimate for Domtar is tailored based on
the facility's specifications using Domtar's emission test reports and
assumptions from similar applications. EPA agrees with the State that
the 95 percent control efficiency used in the FFA is reasonable given
the vendor's estimate based on facility-specific information, the
typical SO<INF>2</INF> removal efficiency range for wet scrubbers (90
to 98 percent),\67\ and the fuel types burned in HFB2.
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\65\ See page 1-21, section 5, Chapter 1 of the CCM.
\66\ The wet scrubber quote from LDX Solutions to Domtar is
included at pp. 48-53 (pdf numbering) in appendix G-2 of the Haze
Plan.
\67\ See table 1.1 on page 1-3, section 5, Chapter 1 of the CCM.
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The Conservation Groups included numerous comments on specific
elements of the cost calculations for the wet scrubber at HFB2. Since
EPA is partially disapproving the LTS with respect to the emissions
control decisions at Domtar, it is not necessary to weigh-in on all of
the specific deficiencies. However, there are some specific issues
where information provided here may help when re-evaluating the need
for controls in a potential SIP revision.
EPA's CCM cannot properly account for all uncertainties, and thus,
provides that a ``retrofit factor'' can be applied. The CCM states that
it is typical for the retrofit factor of a wet scrubber to be between
0.7 and 1.3, depending on the level of difficulty. In any SIP revision,
a retrofit factor greater than 1.0 should be adequately documented with
a detailed justification to explain why it is appropriate to inflate
the costs above those with an average retrofit difficulty.\68\ Based on
the information provided, EPA is not able to adequately discern whether
a 1.3 retrofit factor in
[[Page 92590]]
the cost analysis for the wet scrubber for HFB2 is inflated.
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\68\ See CCM section 5, Chapter 1, page 1-16: <a href="https://www.epa.gov/sites/default/files/2021-05/documents/wet_and_dry_scrubbers_section_5_chapter_1_control_cost_manual_7th_edition.pdf">https://www.epa.gov/sites/default/files/2021-05/documents/wet_and_dry_scrubbers_section_5_chapter_1_control_cost_manual_7th_edition.pdf</a> (``An RF of 1 should be used to estimate costs for a
project of average difficulty. For retrofits that are more
complicated than average, a retrofit factor of greater than 1 can be
used to estimate capital costs provided the reasons for using a
higher retrofit factor are appropriate and fully documented.
Similarly, new construction and retrofits of existing plants that
are less complicated should use an RF less than 1. Each project
should be evaluated to determine the appropriate value for RF.'')
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EPA disagrees with the Conservation Groups' statement that the
costs of the ``unanticipated delays'' are included in the contingency
costs. Domtar only included the costs of ``unanticipated delays'' in
the retrofit costs. These retrofit costs address the unexpected
magnitude of anticipated cost elements; the cost of unexpected delays;
the cost of re-engineering and re-fabrication; the cost of correcting
design errors; the cost that reflect additional difficulty associated
with installing auxiliary equipment; additional insulation and painting
of piping and ductwork; costs associated with engineering or
supervision during installation; and unanticipated delays that cause
production cost. The contingency costs include other unforeseen costs
such as the cost difference from a change in bank interest rate from
the historically low 3.25 percent that was used at the time the Haze
Plan was submitted as well as accounting for the cost difference for
assuming a higher end of the range equipment life. The contingency
costs also take into account that any capital investment dollars in
controls that are deemed reasonable under regional haze would be taking
investment dollars away from mill projects that would have a return on
investments. The retrofit costs are completely separate from the
contingency costs, and therefore, EPA disagrees that any unanticipated
delay costs in Domtar's FFA are being double counted.
EPA agrees with the Conservation Groups that a sales tax charge
should not have been included in the cost analysis for the wet scrubber
due to North Carolina's Sales and Use Tax Exemption for pollution
abatement equipment (for air or stream) for manufacturing.\69\ However,
removing the sales tax from the cost analysis for the wet scrubber
accounts for approximately one percent of the total direct cost, which
would not appreciably change the overall cost/ton identified by the
FFA.
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\69\ Information regarding North Carolina's Sales and Use Tax
Exemption is available at: https://edpnc.com/incentives/pollution-
abatement-and-recycling/
#:~:text=Pollution%20abatement%20equipment%20for%20manufacturing,from
%20sales%20and%20use%20tax.
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EPA disagrees with the contention that North Carolina increased the
quoted amounts for the freight charge and construction management
without explanation. As explained in appendix I of the Haze Plan, North
Carolina's approval of Domtar's decision to use the CCM's methodology,
instead of the vendor quote for the calculation of the freight cost, is
reasonable because the quote was not detailed and was an estimate that
did not consider the exact physical specifications and parameters of
the plant. Furthermore, EPA disagrees that the construction cost was
double-counted in the overall calculated $/ton based on EPA's review of
Domtar's FFA calculations because they are using the $344,196 cost, as
calculated using the methodologies from the CCM, instead of the
$125,000 vendor quote.
EPA also disagrees that a $3,000,000 new induced fan was included
in the FFA without any documentation or explanation. In section 7.8.1.2
of the Haze Plan, North Carolina notes that an additional fan power
would be required to overcome the additional pressure drop through the
wet scrubber. Specifically, in appendix I, North Carolina notes that
Domtar monitored the existing fan at the facility during startup and
commissioning of the new electrostatic precipitator (ESP) and found it
to be sufficient to accommodate the ESP but without excess capacity.
Therefore, a new induction fan is needed to operate a wet scrubber as
well as the ESP and Domtar notes that the $3,000,000 was a quote that
it had received for a new induction fan. EPA notes that North Carolina
has included appropriate justification for the need for a new induction
fan in appendix G-2 and appendix I of the Haze Plan and also finds that
the $3,000,000 cost estimate was developed using reasonable cost
assumptions and with adequate justification.\70\
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\70\ The CCM allows for vendor quotes to be incorporated into
the cost analysis. See page 1-1, section 5, Chapter 1 of EPA`s CCM.
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EPA also disagrees with the Conservation Groups' assertion that
North Carolina relied on visibility considerations to reject the wet
scrubber at HFB2. This is clear from statements in the Haze Plan and
the NPRM. The Haze Plan states that North Carolina ``evaluated the
SO<INF>2</INF> emission reductions and associated improvements in
visibility at the Swanquarter Wilderness Area associated with the wet
scrubber control option for the No. 2 Hog Fuel Boiler. This information
is included solely as supplementary information and is not relied upon
by the State for its conclusions as noted in Section 7.8.2.2.''
Appendix I of the Haze Plan explains in section 3.1.2 that EPA
requested clarification in section 7.8.1.2 that the visibility benefits
modeling for the wet scrubber option related to the Domtar HFB2 FFA is
supplementary information and is not being relied upon by the State for
its conclusions as noted in section 7.8.2.2. North Carolina responded
that the ``last paragraph of 7.8.1.2 of the SIP was revised to explain
that the information is included solely as supplementary information
and that North Carolina did not rely upon the information to support
its conclusions documented in section 7.8.2.2 of the SIP. This
clarification was also added to section 7.8.1.1 of the SIP for BRPP and
section 7.8.1.3 of the SIP for PCS Phosphate.'' Furthermore, the NPRM
states that North Carolina did not rely on the supplemental visibility
information for the Domtar FFA analysis and conclusions and limits its
evaluation to the four factors. See 89 FR 67355 n.69, 67359-61.
Comment 7.b: According to the Conservation Groups, EPA must require
North Carolina's SIP to include enforceable fuel restrictions for the
No. 1 Hog Fuel Boiler (HFB1). They state that EPA proposed to approve
North Carolina's exclusion of HFB1 from a FFA because it is equipped to
only burn natural gas and biomass with No. 2 fuel oil, which is
projected to emit 12 tpy of SO<INF>2</INF> in 2028 (representing one
percent of Domtar's total SO<INF>2</INF> emissions). However, they
contend that EPA and North Carolina ignore that Domtar's permit
authorizes HFB1 to burn HVLC gases and No. 2 fuel oil. While
acknowledging the facility's assertion that it intends to keep the HVLC
supply line disconnected indefinitely, the Conservation Groups state
that there are no provisions in the SIP preventing the facility from
reconnecting the supply line and burning high sulfur content fuel or
requiring the facility to operate the unit ``infrequently.'' Citing
EPA's 2019 Guidance, they state that if a SIP lacks the necessary
provisions to make reasonable progress, the state is required to adopt
emissions limits as part of its LTS for incorporation into the
regulatory portion of the SIP. Therefore, they assert that EPA, in a
FIP, must make the fuel use restrictions enforceable or perform an FFA
based on any fuels that HFB1 could burn in the future.
Response 7.b: Concerns regarding the lack of enforceable fuel
restrictions for Domtar's HFB1 form the second basis for disapproval of
North Carolina's LTS. North Carolina exempted HFB1 from FFA review
based on the revised 2028 SO<INF>2</INF> emissions projection of 12 tpy
SO<INF>2</INF> (comprising 1.2 percent of Domtar's total 2028 projected
SO<INF>2</INF> emissions) and evaluated HFB2 via a FFA based on 2028
projected emissions of 1,010 tpy SO<INF>2</INF> (comprising 98.8
percent of Domtar's total 2028 projected SO<INF>2</INF>
[[Page 92591]]
emissions).\71\ HFB1 did not operate in 2020, 2021, and 2022, and as
the Conservation Groups note, the HVLC supply line is disconnected
indefinitely.\72\ EPA acknowledges that performing a control analysis
on an emissions unit with very low annual emissions, such as 12 tpy,
would not likely yield any cost-effective controls because the low
amount of SO<INF>2</INF> removed would result in a higher cost per ton
calculated for each control evaluated. However, the information
submitted in the Haze Plan documents higher SO<INF>2</INF> emissions
from HFB1 in 2015, 2016, 2017, 2018, and 2019, and notes that there are
no state or federally enforceable fuel restrictions on HFB1.\73\ Based
on the comments received and the information in the submitted SIP, EPA
is concerned that the SIP submission does not include enforceable fuel
restrictions for HFB1 at Domtar. See Comm. for a Better Arvin v. EPA,
786 F.3d 1169, 1175-77 (9th Cir. 2015). This concern regarding the lack
of enforceable measures in the record for HFB1, together with the
inadequate record substantiating the FFA conclusion regarding HFB2,
collectively form the basis for EPA's disapproval of the portions of
the Haze Plan addressing 40 CFR 51.308(f)(2) and (3) and (i)(2) through
(4).
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\71\ See ``Projected 2028 Emissions, Revised (tons)'' in table
7-55 of the Haze Plan for the 2028 projected SO<INF>2</INF>
emissions used in the percent calculations. As discussed in
responses 2 and 4.f, the State's use of 2028 projected emissions
appears reasonable.
\72\ See EPA's Emissions Inventory System (EIS) Gateway
available at: <a href="https://www.epa.gov/air-emissions-inventories/emissions-inventory-system-eis-gateway">https://www.epa.gov/air-emissions-inventories/emissions-inventory-system-eis-gateway</a>. The 2023 annual emissions
data for HFB1 will not be available until 2025.
\73\ See Haze Plan at p. 276. See table 7-56 of the Haze Plan at
p. 277 for HFB1 SO<INF>2</INF> emissions from 2015 through 2020 and
appendix G-2 at p.12/280 pdf for HFB1 SO<INF>2</INF> emissions from
2016-2018 and p.71/280 pdf for HFB1 SO<INF>2</INF> emissions from
2018-2020.
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Comment 7.c: The Conservation Groups assert that EPA's proposal to
endorse North Carolina's decision to not conduct analyses of
NO<INF>X</INF> controls for Domtar was arbitrary and capricious,
identify three boilers (No. 5 Recovery Boiler, HFB1, and HFB2) as
significant sources of NO<INF>X</INF> emissions, and state that North
Carolina failed to respond to its state-level comments related to
NO<INF>X</INF> control at the facility. Therefore, they contend that
EPA must assess NO<INF>X</INF> controls at the No. 5 Recovery Boiler,
HFB1, and HFB2 and require the facility to install reasonable and cost-
effective controls.
Response 7.c: For the reasons provided in response 3, EPA disagrees
that the Agency's proposal to not require NO<INF>X</INF> FFA control
evaluations of Domtar is arbitrary and capricious. As discussed therein
and in the NPRM, North Carolina's decision to focus on SO<INF>2</INF>
controls in this planning period appears reasonable given, among other
things, IMPROVE monitoring data from the 2015-2019 five-year period
showing that ammonium sulfate is the dominant visibility impairing
pollutant contributing to regional haze at the Class I areas in the
State.
EPA also disagrees that North Carolina failed to respond to the
comments regarding a NO<INF>X</INF> control evaluation of Domtar. The
State provided responses to public comments regarding the August 30,
2021, proposed Haze Plan in appendix I of the final plan. North
Carolina's responses to public comments on nitrate and NO<INF>X</INF>
are included in section 3.4.3 (``Exclusion of NO<INF>X</INF>/Nitrate/
PM'') of appendix I, pages 37-38, where the State explains why it did
not evaluate NO<INF>X</INF> controls during this planning period.\74\
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\74\ In section 10.4.1 ``Exclusion of NO<INF>X</INF> from Four-
Factor Analysis'' of the Haze Plan, North Carolina responded to FLM
comments on this subject.
---------------------------------------------------------------------------
Comment 8: The Conservation Groups note that North Carolina relied
on PCS' current title V permit limits for reasonable progress, which
limits SO<INF>2</INF> emissions from Sulfur Acid Plants (SAPs) 5, 6,
and 7 to 2.5, 2.5, and 1.75 pounds (lbs) per ton of sulfuric acid
produced, respectively, on a 365-day rolling average. They also note
that facility upgrades have lowered actual SO<INF>2</INF> emissions
from SAPs 5, 6 and 7 to 1.1, 1.2, and 1.2 lbs per ton of sulfuric acid
produced.
The Conservation Groups contend that the State did not analyze
lowering the SO<INF>2</INF> emission limits or imposing work practice
standards that are reflective of the actual emissions due to the plant
upgrades; quote the statement in EPA's 2021 Clarification Memo that
``[a] limit that is significantly higher than the emission rate a
source is actually achieving does not keep the source from increasing
its rate in the future;'' and contend that if a control can achieve
lower emissions rate, the State must assess it as part of an FFA. They
disagree with North Carolina's interpretation that the quoted statement
is only applicable to situations where current measures are not
necessary to make reasonable progress, noting that the quote is located
in a section of the 2021 Clarification Memo titled ``Determining When
Existing Measures are Necessary for Reasonable Progress.'' The
Conservation Groups also state that North Carolina relied on the
upgrades and actual emissions rates in determining that no additional
controls are available for the purpose of addressing the existing
visibility impairment attributable to anthropogenic sources at
Swanquarter. They argue that the plant upgrades resulting in the actual
lower emissions rates are existing measures and that the actual
emission rates must form the basis for the lower emission limits for
the plant, disagreeing with North Carolina's statement that there is no
need to impose lower arbitrary limits and no basis on which a lower
limit could be set that guarantees compliance. The Conservation Groups
contend that EPA must disapprove North Carolina's control
determinations for PCS because the State did not consider reasonable
and highly cost-effective controls for the facility, and that the
Agency must prepare a FIP that analyzes and requires lower emission
limits that are reflective of actual emissions.
Response 8: EPA acknowledges the comments related to the PCS FFA.
However, because EPA is partially disapproving the portions of the Haze
Plan addressing 40 CFR 51.308(f)(2), it is not necessary to address the
Conservation Groups' concerns regarding the PCS FFA at this time. At
proposal, EPA solicited comments on, among other things, ``the adequacy
of the 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).'' \75\ The
decision to disapprove the portions of the Haze Plan addressing 40 CFR
51.308(f)(2) is a logical outgrowth of the proposal; EPA has given
further consideration to the question of the adequacy of these
provisions, the comments received, and the totality of the analyses
that constitute the LTS and RPGs. As discussed above, EPA will be
obligated under CAA section 110(c)(1) to promulgate a FIP within two
years after the effective date of this partial disapproval, unless the
state submits, and the EPA approves, a SIP revision that satisfies the
requirements of 40 CFR 51.308(f)(2) and (3) and (i)(2) through (4)
before EPA promulgates the FIP. The public will have the opportunity to
comment on, among other things, whether the proposed FIP or the
proposed SIP action satisfies the FFA requirements of 40 CFR
51.308(f)(2).
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\75\ See 89 FR 67358.
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Comment 9: The Conservation Groups contend that the State's and
EPA's analyses of BRPP are no longer relevant since, according to EPA's
Enforcement and Compliance History Online database, the facility is
permanently
[[Page 92592]]
closed as of June 2023. Therefore, they assert that EPA's final SIP
action must include coordinating and acting in accordance with the
Comprehensive Environmental, Response, Compensation, and Liability Act
(CERCLA) Superfund efforts for the site, along with ensuring all
existing air permits for the facility are revoked.
Response 9: EPA agrees that North Carolina's FFA analysis and the
Agency's evaluation of BRPP in the NPRM are no longer relevant. On
September 18, 2024, BRPP requested the termination of its title V
permit for the BRPP Canton Mill, Air Quality Permit No. 08961T32, with
Facility ID 4400159, effective immediately.\76\ This letter states that
none of the sources in the BRPP title V permit have been operating
since June 2023. On September 23, 2024, DAQ sent a letter rescinding
the permit effective on the date of the letter.\77\ Regarding CERCLA,
the CAA does not require regional haze SIPs to provide for coordination
and consistency with Superfund efforts.
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\76\ The September 18, 2024, letter requesting permit
termination is in the docket for this rulemaking.
\77\ The September 24, 2024, permit recission letter is in the
docket for this rulemaking.
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Comment 10: The Conservation Groups assert that EPA cannot approve
North Carolina's SIP revision because it does not include practically
enforceable emissions limitations and because this deficiency is not
cured in the Commitment Letter supporting the conditional approval.
They also assert that EPA must disapprove the SIP revision because the
Commitment Letter does not identify specific enforceable measures as
required under CAA section 110(k)(4) and only contains mere promises to
adopt unspecified and sometimes unenforceable monitoring,
recordkeeping, and reporting measures to correct the deficiencies in
the SIP revision and because EPA ignores additional practical
enforceability issues in the permit provisions identified for
incorporation into the SIP.
Response 10: It is unnecessary to respond to the Conservation
Groups' comments regarding the sufficiency of the Commitment Letter or
the practicable enforceability of the permit terms identified for
incorporation into the SIP because EPA is shifting from its initial
proposal of a partial approval and partial conditional approval to a
partial approval and partial disapproval. This action does not
incorporate any permit conditions into the SIP because the partial
disapproval includes the LTS, and the Commitment Letter is now moot.
EPA's decision to disapprove the portions of the Haze Plan addressing
40 CFR 51.308(f)(2) is a logical outgrowth of the initial proposal and
EPA's consideration of the comments received. As discussed above, EPA
will be obligated under CAA section 110(c)(1) to promulgate a FIP
within two years after the effective date of this partial disapproval,
unless the State submits, and EPA approves, a SIP revision that
satisfies the requirements of 40 CFR 51.308(f)(2) and (3) and (i)(2)
through (4) before EPA promulgates the FIP. Any emission limitations
identified for incorporation into the SIP in such a SIP revision (or
into a FIP in the case of an eventual FIP) must be legally and
practicably enforceable, and EPA encourages the State to consider the
Conservation Groups' comments if the State opts to develop a SIP
revision.
Comment 11: The Conservation Groups contend that EPA's proposal to
conditionally approve North Carolina's RPGs violates the CAA and RHR.
They assert that North Carolina impermissibly reversed the ``long-
standing'' SIP planning sequence by setting its RPGs before conducting
FFAs or finalizing its LTS. They argue that since the RPGs are based on
VISTAS' modeling conducted in 2020, before the State identified the
controls necessary for reasonable progress based on the four statutory
factors and proposed its LTS, the RPGs do not meet the RHR requirement
that they must be based on enforceable SIP measures. They also assert
that the State and EPA ignored the 2019 Guidance explaining that a
state must adjust its RPGs if it conducted modeling for RPGs before
making final LTS determinations. The Conservation Groups maintain that
EPA ignores that the State's RPGs do not reflect the visibility
improvements that the LTS controls will achieve, must disapprove the
RPGs, and must require the State to adjust them to reflect enforceable
limitations in the SIP.
Response 11: EPA agrees with disapproving North Carolina's RPGs but
differs on the reason for disapproval. EPA reiterates that the process
for establishing RPGs for each Class I area is prescribed in the RHR
amendments and discussed in related guidance.<SUP>78 79 80</SUP> The
RHR requires states with Class I areas to establish RPGs that reflect
the visibility conditions projected to be achieved by the end of the
second planning period as a result of the ``enforceable emission
limitations, compliance schedules, and other measures required under
the long-term strategy.'' See 40 CFR 51.308(f)(3). As previously
explained, EPA is disapproving the portions of the Haze Plan addressing
40 CFR 51.308(f)(2). Therefore, because the requirements in 40
CFR51.308(f)(3) are dependent upon 40 CFR 51.308(f)(2), EPA is
disapproving the RPGs because they reflect a deficient LTS.
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\78\ See 40 CFR 51.308; 64 FR 35714 (July 1, 1999); and 82 FR
3078 (January 10, 2017).
\79\ See 2019 Guidance at pp. 46-48.
\80\ See 2021 Clarifications Memo at p. 6.
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The sequencing of the development of the RPGs is inconsequential
here because EPA has determined that the State's LTS is deficient.
Therefore, because the Haze Plan does not include an approvable LTS,
and compliance with 40 CFR 51.308(f)(3) is dependent on compliance with
40 CFR 51.308(f)(2), EPA is disapproving the RPGs, and the State should
re-evaluate them as part of its potential SIP revision.
Comment 12: The Conservation Groups assert that EPA's proposal to
approve North Carolina's interstate consultations is arbitrary and
capricious, and violates the CAA and RHR. They contend that EPA did not
conduct an independent analysis of the State's consultation process to
determine whether it satisfies the regulatory requirements.
Additionally, they argue that State's consultations were ``incomplete,
inadequately documented, and failed to provide for coordinated
emissions management strategies with other states.''
The Conservation Groups maintain that the VISTAS modeling was
flawed and the source selection process was unreasonable, both of which
were relied on by North Carolina to identify sources from other states
that contribute to visibility impairment in its five Class I areas.
They cite NPCA's analysis using the 2020 NEI and the 2023 Clean Air
Markets Program Data (CAMPD) to show that there are 169 sources with Q/
d greater than or equal to five, spanning 19 different states, that
likely contribute to visibility impairment at North Carolina's Class I
areas. They note that North Carolina did not request consultation with
some of the states or regarding some sources that were identified by
the NPCA, including consulting with Kentucky on Ghent Station that they
contend is likely contributing to visibility impairment at Great Smoky
Mountains with a Q/d of 40.36, and Louisiana, which has nine sources
that they contend likely contribute to visibility impairment in North
Carolina's Class I areas.
Regarding the adequacy of documentation of consultations, the
Conservation Groups point to North Carolina's statement in its SIP
revision that appendix F-1 contains the consultation letters from North
Carolina to each VISTAS state, along with the
[[Page 92593]]
responses. However, the Conservation Groups found that appendix F-1
only contains North Carolina's letters. Instead of providing the
responses it received (only from Tennessee and West Virginia), the
State provides only summaries of the responses. Furthermore, while
North Carolina requested consultations with Kentucky, Georgia, and
Virginia, the responses were not documented, including whether those
states shared their FFAs for the identified sources, whether there were
agreements or disagreements between the parties, or whether
disagreements were reconciled.
Next, the Conservation Groups assert that North Carolina
``effectively conducted an `agree to do nothing' consultation
process,'' which violates the CAA and RHR requirement to engage in
substantive consultation to develop coordinated strategies that reduce
emissions with other states in order to make reasonable progress during
the second planning period. They note that only one (Eastman Chemical
Company in Tennessee) out of the 16 sources that the State requested
consultation was required to install new emission controls. The
Conservation Groups argue that North Carolina acquiesced to other
states' determinations for their respective sources. For example, they
state that based on the VISTAS modeling and source selection process
North Carolina relied on, the General James M. Gavin Power Plant (Gavin
Plant) in Ohio is the biggest contributor to visibility impairment in
Great Smoky Mountains, Joyce Kilmer, and Shining Rock, the second
biggest contributor at Linville Gorge, and the fourth biggest
contributor at Swanquarter. Nonetheless, they state that North Carolina
decided it was satisfied with Ohio's determination that the Gavin Plant
would not be required to install new emission controls.
Response 12: In response to the Conservation Groups' comments that
the VISTAS modeling was flawed, North Carolina's source selection
process was unreasonable, and the State should have requested
consultation based on NPCA's Q/d analysis, see responses 1 and 2.
EPA disagrees with the contention that EPA's review of North
Carolina's interstate consultation process was a box checking exercise.
EPA independently reviewed all of the consultation documentation
provided by North Carolina within its Haze Plan. EPA also disagrees
with the comment that North Carolina conducted a ``do-nothing''
approach to consultation, which violates CAA and RHR requirements to
engage in substantive consultation to develop ``coordinated emission
reduction strategies'' with other states. 40 CFR 51.308(f)(2) requires
a state to consult with those states that have emissions that are
reasonably anticipated to contribute to visibility impairment in the
mandatory Class I area. The State appears to have reasonably complied
with 40 CFR 51.308(f)(2)(ii) by consulting with 10 other states and
requesting FFAs for 16 facilities located within those states with
visibility impacts to North Carolina's Class I areas exceeding the
State's sulfate PSAT threshold at one or more of North Carolina's Class
I areas.\81\ Further, EPA disagrees with the Conservation Groups'
assertion that North Carolina acquiesced to other states'
determinations for their respective sources. For example, North
Carolina assessed and agreed with Ohio's response on the Gavin Plant,
and therefore, no further action is required under the RHR's
consultation provisions.\82\ 40 CFR 51.308(f)(2)(ii) does not require
further action when a state agrees with another state's determination
that no emission reductions are necessary to make reasonable progress.
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\81\ 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.
\82\ Appendix F-3d of the Haze Plan includes the June 22, 2020,
letter from North Carolina, through VISTAS, requesting a FFA of the
Gavin Plan and a October 29, 2020, letter of response from Ohio. The
2020 Ohio letter states that the Gavin Plant operates two coal-fired
boilers (B003 and B004) which have FGDs that operate year-round with
a 95 percent control efficiency. Ohio requested an SO<INF>2</INF>
FFA from the Gavin Plant, and Ohio stated in its letter that the
plant was considered effectively controlled for NO<INF>X</INF> with
a SCR system with 90 percent control efficiency.
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Moreover, EPA disagrees with the Conservation Groups' contention
that North Carolina did not adequately document its consultation
process within its Haze Plan. Although the RHR requires a state to
demonstrate that it has included in its implementation plan all
measures agreed to during interstate consultations or a regional
planning process, or measures that will provide equivalent visibility
improvement, and to describe any actions taken in the event states
disagree with one another on the emission reduction measures necessary
to achieve reasonable progress in Class I areas, the RHR does not
prescribe a specific type of documentation to demonstrate that the
interstate consultation requirements of 40 CFR 51.308(f)(2)(ii) have
been met. North Carolina documented its correspondence in appendix F-1
with the states listed in table 10-2 and summarized responses from
those states in section 10.1.1 of the Haze Plan. Therefore, it appears
that the State reasonably satisfied the RHR's documentation
requirements. However, the interstate consultation requirement at 40
CFR 51.308(f)(2)(ii) is a part of 40 CFR 51.308(f)(2), which is subject
to the partial disapproval. To the extent that the Domtar facility
contributes to visibility impairment at out-of-state Class I areas, EPA
recognizes that the State (or EPA in the case of an eventual FIP), may
need to reconsider the interstate consultation element under 40 CFR
51.308(f)(2)(ii). To the extent that the Conservation Groups have
concerns about facilities outside of North Carolina, including the
Gavin Plant in Ohio and Ghent Station in Kentucky, any public comments
related to out-of-state sources should be provided during the public
comment periods regarding those states' haze plans. North Carolina
lacks authority to regulate these out-of-state sources, and therefore,
EPA cannot require other states to implement control measures through
action on North Carolina's Haze Plan.
Comment 13: The Conservation Groups maintain that EPA blindly
proposes to approve the State's consultation with the FLMs by not
conducting an independent review or analysis. They note that North
Carolina provided the FLMs an opportunity to consult on the draft SIP
revision, but argue that the State failed to engage in meaningful
consultation with the FLMs and largely ignored and failed to adequately
respond to the FLMs' comments. For these reasons, they argue EPA's
proposal to approve the State's FLM consultation process is arbitrary
and capricious and violates the CAA and RHR.
The Conservation Groups argue that North Carolina treated the FLM
consultation process as a ``box checking exercise'' by providing terse
and inadequate responses to FLMs' recommendations. The Conservation
Groups contend that North Carolina did not incorporate FLM suggestions
that North Carolina should conduct FFAs of NO<INF>X</INF> controls for
the State's major sources due to inaccurate modeling results; the
source screening process used ``unreasonably high thresholds;''
[[Page 92594]]
lower thresholds \83\ would have led to identification of additional
facilities; and the State should conduct FFAs of NO<INF>X</INF>
controls for the Duke Energy EGUs.
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\83\ The Conservation Groups say ``higher thresholds'' on page
46 of their comments, but EPA believes that this is an error because
the context of the statement indicates that they intended to say
``lower thresholds.''
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The Conservation Groups contend that since North Carolina's source
selection, source-specific analyses, LTS, and RPGs violate the CAA and
RHR, the State's FLM consultations were based on a SIP revision that
did not meet the statutory and regulatory requirements. They argue that
EPA must issue a FIP that corrects the errors in the SIP revision and
consult with the FLMs anew, meaningfully considering, incorporating,
and responding to FLM recommendations.
Response 13: The FLMs play important roles in addressing visibility
at Class I areas, and 40 CFR 51.308(i)(3) requires states to include a
description of how they address any comments provided by the FLMs
during the opportunity for consultation. However, neither the CAA nor
the RHR require a state to agree with the FLM recommendations, nor do
they specify the degree of consideration that must be given to those
comments. Rather, 40 CFR 51.308(i)(3) requires a state to ``include a
description of how it addressed any comments provided by the Federal
Land Managers'' within its haze plan.
North Carolina appears to have reasonably complied with this
requirement by documenting how it addressed the FLMs' comments
contained in appendix H and appendix I in both section 10.4 of the Haze
Plan and in section 3.2 of appendix I of its Haze Plan.\84\ For
example, North Carolina provides an in-depth rationale (approximately
15 pages) for why it disagrees with NPS' comment recommending inclusion
of NO<INF>X</INF> in the FFAs in section 10.4.1 of the Haze Plan.\85\
Further, FLM consultation must take place at least 60 days prior to the
state public comment period on any haze plan or plan revision pursuant
to 40 CFR 51.308(i)(2). North Carolina initiated consultation with the
FLMs on April 5, 2021, which was 147 days before the opening of the
State's public comment period on August 30, 2021. In addition, North
Carolina met with NPS upon request on May 14 and May 25, 2021, to
discuss NPS' feedback in more detail.\86\
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\84\ Section 3.2 of appendix I addresses NPS comments received
during the State comment period on the proposed Haze Plan. Section
10.4 of the Haze Plan addresses FLM comments received prior to the
State comment period on a draft plan, including section 10.4.2
related to source selection and section 10.4.3 related to evaluation
of NO<INF>X</INF> controls for the Duke Energy EGUs.
\85\ See section 10.4.1 of the Haze Plan at pp. 320-335.
\86\ FWS and USFS representatives were also invited to attend
the May 14 and 25, 2021, North Carolina-NPS consultation meeting.
See section 10.4 of the Haze Plan.
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EPA recognizes that North Carolina appears to have reasonably
followed all of processes required for FLM consultation consistent with
40 CFR 51.308(i). However, EPA is disapproving North Carolina's FLM
consultation under 40 CFR 51.308(i)(2) through (4) because compliance
with that requirement is dependent on fulfilling the substantive
requirements of 40 CFR 51.308(f)(2) (LTS). For reasons discussed
elsewhere in this notice, EPA is disapproving the portions of the Haze
Plan addressing 40 CFR 51.308(f)(2) and (3). When EPA disapproves an
LTS, the state (in the case of a SIP revision) or EPA (in the case of a
FIP) must redevelop an LTS that complies with the statutory and
regulatory requirements and provide meaningful consultation on the
substance of the LTS created to replace the substantively disapproved
one. Even though it appears North Carolina reasonably consulted with
the FLMs to develop the LTS, because the LTS is disapproved, the
consultation component must also be disapproved. Therefore, the State
(for a SIP revision) or EPA (for a FIP) must again consult with the
FLMs on a revised LTS in order to develop an approvable LTS.
Regarding the merits of the FLM comments summarized by the
Conservation Groups and repeated by the NPS in its comments on this
rulemaking, see responses 17 and 18. Regarding a FIP, as discussed
above, EPA will be obligated under CAA section 110(c)(1) to promulgate
a FIP within two years after the effective date of this partial
disapproval, unless the State submits, and EPA approves, a SIP revision
that satisfies the requirements of 40 CFR 51.308(f)(2) and (3) and
(i)(2) through (4) before EPA promulgates the FIP.\87\
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\87\ See response 15.
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Comment 14: The Conservation Groups assert that EPA should not rely
on North Carolina's environmental justice (EJ) analysis due to
deficiencies and that the Agency should conduct an independent
analysis. The Conservation Groups contend that North Carolina failed to
respond to their and other commenters' EJ concerns raised during the
State's public hearing. They also maintain that North Carolina's EJ
analysis is inadequate because it does not consider the communities
surrounding the facilities but instead focuses on the communities
surrounding the Class I areas and that they are not aware of any other
state that employed this approach. They state that out of the 400-page
SIP revision (not including appendices), North Carolina's efforts only
include two pages discussing public participation plans, three pages of
maps, and less than one page in its response to comments. The
Conservation Groups assert that the SIP revision is ``entirely void of
any analysis of how it would benefit North Carolina-identified
communities of concern for environmental justice.''
The Conservation Groups argue that EPA's proposal fails to
recognize the unreasonable approach that the State used to identify the
geographic areas for consideration in the EJScreen Reports, an approach
they describe as unique, and that they are not aware of any other state
that employed this approach. They also assert that EPA's final action
must provide clarification to the states that impacts local to the
sources should be considered because North Carolina's analysis failed
to consider the impacts of SO<INF>2</INF> and NO<INF>X</INF> on
communities near the emission sources. They argue that North Carolina's
SIP revision does not contain any analysis on how it would benefit the
identified communities with EJ concerns, except in the State's
assertion about the visibility improvement in its Class I areas through
reductions in SO<INF>2</INF> and NO<INF>X</INF> have reduced impacts on
the public, including vulnerable communities.
The Conservation Groups state that the pollutants that contribute
to visibility impairment in Class I areas can also cause significant
public health impacts in the area surrounding the source, particularly
communities of color and low-income communities. They argue that EPA's
final action should consider and independently analyze the impacts the
sources have on communities across the State, particularly in
communities that are disproportionately burdened by environmental
pollution and explain how a strong regional haze plan will address
those adverse impacts.
Based on the Executive Orders (E.O.s) in place since 1994, they
maintain that EPA is required to incorporate EJ as ``part of its
mission by identifying and addressing . . . disproportionately high and
adverse human health or environmental effects of its program, policies,
and activities,'' which they argue to be applicable to regional haze
SIP actions' impacts on minority populations and low-income
[[Page 92595]]
populations. Additionally, they argue the directive to incorporate EJ
into all of the Agency's actions was reaffirmed by the Biden
Administration through back-to-back E.O.s directed to Federal agencies,
including EPA, and again in 2023 when the Administration issued the
``Executive Order on Revitalizing Our Nation's Commitment to
Environmental Justice for All.'' \88\
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\88\ The ``Executive Order on Revitalizing Our Nation's
Commitment to Environmental Justice for All'' is available at:
<a href="https://www.whitehouse.gov/briefing-room/presidential-actions/2023/04/21/executive-order-on-revitalizing-our-nations-commitment-to-environmental-justice-for-all/">https://www.whitehouse.gov/briefing-room/presidential-actions/2023/04/21/executive-order-on-revitalizing-our-nations-commitment-to-environmental-justice-for-all/</a>.
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The Conservation Groups maintain that EPA has the resources,
including EJScreen, to provide a robust analysis of the EJ impacts of
North Carolina's SIP revision. Using the EJScreen toolkit, their
analysis shows five facilities (DEC--Belews Creek; DEC--Cliffside,
DEC--Marshall, Domtar, and PCS) are surrounded by communities that have
EJ indicators in the high percentiles.
Response 14: EPA disagrees with this comment but acknowledges the
EJScreen information provided by the Conservation Groups. The regional
haze statutory provisions do not explicitly address considerations of
EJ and neither do the regional haze regulatory requirements of the
second planning period in 40 CFR 51.308(f), (g), and (i). However, the
lack of explicit direction does not preclude the State from addressing
EJ in its SIP submission. As explained in ``EPA Legal Tools to Advance
Environmental Justice,'' \89\ the CAA provides states with the
discretion to consider EJ in developing rules and measures related to
regional haze. While a state may consider EJ under the reasonable
progress factors, neither the statute nor the regulation requires
states to conduct an EJ analysis for EPA to approve a SIP submission.
The 2021 Clarifications Memo states in section 5.6: ``EPA encourages
states to consider whether there may be equity and environmental
justice impacts when developing their regional haze strategies for the
second planning period. . . . States have discretion to consider
environmental justice in determining the measures that are necessary to
make reasonable progress and formulating their long-term strategies, as
long as such consideration is reasonable and not contrary to the
regional haze requirements.''
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\89\ See ``EPA Legal Tools to Advance Environmental Justice'',
May 2022, available at: <a href="https://www.epa.gov/system/files/documents/2022-05/EJ%20Legal%20Tools%20May%202022%20FINAL.pdf">https://www.epa.gov/system/files/documents/2022-05/EJ%20Legal%20Tools%20May%202022%20FINAL.pdf</a> at pp. 35-36.
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In this instance, North Carolina elected to consider EJ under the
reasonable progress factors in section 10.6 and appendix F-5 of the
Haze Plan. The State ran EJScreen for four of its five Class I areas
(excluding the Great Smoky Mountains due to its size), and based on the
results of the EJScreen, it outlined a five-step outreach plan in
section 10.6 to ensure the opportunity for meaningful community
involvement during the state-level comment period for the Haze Plan. In
appendix I of the Haze Plan, in response to an EJ comment received
during the public comment period, the State notes that EPA's 2021
Clarifications Memo encourages states to consider EJ and encourages
states to consider whether there may be equity and EJ impacts when
developing their regional haze strategies for the second planning
period while noting that states have discretion to consider EJ in
determining the measures that are necessary to make reasonable progress
and formulating LTS, as long as such consideration is reasonable and
not contrary to the regional haze requirements. North Carolina explains
in its response that at the time of the issuance of the memo, the State
had mostly completed the proposed plan for public comment which was
issued on August 30, 2021. The response also states that North
Carolina's EJ analysis and additional outreach was an adequate response
given the short amount of time between when EPA issued its July 8,
2021, guidance and when regional haze SIPs were due to EPA on July 31,
2021.
As discussed above, the CAA and RHR neither prohibit nor require an
evaluation of EJ with a regional haze SIP. EPA has evaluated North
Carolina's SIP submission against the statutory and regulatory regional
haze requirements and determined that it satisfies those minimum
requirements. For these reasons, the State is not required to address
the Conservation Groups' alleged EJ inadequacies in its SIP revision,
and EPA is not required to conduct an independent EJ analysis.
Comment 15: The Conservation Groups assert that EPA must disapprove
North Carolina's SIP revision and issue a regional haze FIP for the
State for the reasons discussed in the comments summarized in comments
1 through 14, above. They also contend that the Agency should issue a
regional FIP covering the Region 4 states because ``multiple states in
Region 4 have developed second planning period SIPs that violate'' the
CAA and RHR, pointing to reliance on ``invalid VISTAS modeling and
source selection process,'' and must disapprove Georgia's SIP revision.
The Conservation Groups also contend that EPA must act swiftly to issue
a FIP because North Carolina's Haze Plan for the second planning is
years behind schedule.
Response 15: EPA has responded to the Conservation Groups'
rationale for disapproval and a FIP in responses 1 through 14. As
discussed above, the Agency is approving in part and disapproving in
part North Carolina's Haze Plan. Therefore, EPA will be obligated under
CAA section 110(c)(1) to promulgate a FIP within two years after the
effective date of this partial disapproval, unless the State submits,
and EPA approves, a SIP revision that satisfies the requirements of 40
CFR 51.308(f)(2) and (3) and (i)(2) through (4) before EPA promulgates
the FIP. The Conservation Groups' comments regarding a regional FIP are
beyond the scope of this rulemaking because this rulemaking relates
solely to North Carolina's Haze Plan and EPA has not proposed action on
all of the regional haze SIPs submitted by other states in Region 4.
Regarding Georgia's regional haze plan, EPA proposed to approve that
SIP revision in a separate rulemaking on June 3, 2024, and the Agency
will take final action through that separate rulemaking.\90\
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\90\ See 89 FR 47481.
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Comment 16: NPS states that North Carolina's SIP process missed a
key CAA section 169A(d) consultation requirement because the State's
public notice of its regional haze SIP did not include a summary of the
FLMs' conclusions and recommendations. NPS asserts that this statutory
requirement ensures public transparency in the SIP development process
by requiring states to alert the public that the FLMs provide comments
and to provide a short summary of the recommendations in the notice to
ease the burden of locating and interpreting these comments in the
draft SIP revisions. Therefore, NPS recommends that EPA acknowledge and
address this procedural error when taking final action on North
Carolina's SIP.
Response 16: Section 169A(d) of the CAA requires states to include
a summary of the conclusions and recommendations of the FLMs in the
notice to the public. This section sets the expectation as to what
states must share with the public regarding the FLMs' comments. North
Carolina's August 30, 2021, proposed haze plan subject to public notice
contained the FLMs' conclusions and recommendations in appendix H,
which is sufficient because it provides the entirety of the FLMs'
conclusions and recommendations, rather than a state-generated summary.
However, because EPA is disapproving the portions of the
[[Page 92596]]
Haze Plan addressing 40 CFR 51.308(f)(2) and (3), North Carolina (for a
SIP revision) or EPA (for a FIP) must again satisfy the requirements of
CAA section 169A(d).
Comment 17: NPS disagrees with EPA's proposal to approve the source
and pollutant selection portion of the LTS. NPS states that North
Carolina unreasonably applied the AoI and PSAT results to exclude
significant sources and pollutants from analysis, that it has raised
these concerns with the State since May 2021, and that neither North
Carolina nor EPA substantively addressed these concerns.
Source Selection Approach--NPS argues that North Carolina's source
selection thresholds are ``excessively high'' and are ``flawed and
counterproductive'' to remedying existing visibility impairment.
According to NPS, the VISTAS source selection approach, relying on a
percent-of-total-impact threshold for selecting each facility, results
in an individual facility needing to have a greater impact on
visibility to be selected for more impaired Class I areas than with
less impaired ones. NPS states that the AoI percent-of-total-impact
threshold for selecting a facility is 74 times higher for Mammoth Cave
National Park (Mammoth Cave) and 19 times higher for Great Smoky
Mountains when compared to Everglades National Park, the least impacted
NPS Class I area in the region. NPS argues that this approach resulted
in the selection of very few sources for FFAs in a region experiencing
significant visibility impairment and states that no North Carolina
source was selected for impacts to Great Smoky Mountains or other NPS
Class I areas. NPS also argues that it is difficult to assess
reasonable progress if few sources are brought forward for FFAs. NPS
asserts that neither EPA nor North Carolina substantively addressed
this issue or described how the source selection thresholds are
consistent with the need to demonstrate reasonable progress.
Pollutant Selection Approach--NPS asserts that North Carolina used
an outdated 2011 modeling platform to draw conclusions about which
pollutants are responsible for visibility impairment. NPS states that
recent monitoring data shows that the ammonium nitrate contribution on
the 20 percent most-impaired days has increased since 2011 and is now a
significant component of visibility impairment in Mammoth Cave and
Shenandoah National Park (Shenandoah). While NPS agrees that sulfate is
the dominant contributor to visibility impairment in those areas, it
notes that nitrate contributions have more than doubled in recent years
and are also significant. NPS encourages EPA to consider the 2021
Clarification Memo's direction on pollutant selection in assessing
North Carolina's approach and recommends the evaluation of North
Carolina's sources for opportunities to reduce NO<INF>X</INF>
emissions.
Response 17: See response 1 regarding the 2011 base year and
response 2 regarding North Carolina's source selection approach. See
response 3 regarding nitrate contributions at the North Carolina Class
I areas and pollutant selection. Additionally, there is no evidence
provided by NPS that Mammoth Cave or Shenandoah are affected by
emissions from within North Carolina (in particular, NO<INF>X</INF>
emissions which may impact nitrate). Therefore, contributions to
nitrate at those Class I areas are not relevant to North Carolina's
Haze Plan.
Comment 18: NPS notes that North Carolina did not conduct FFAs of
NO<INF>X</INF> and SO<INF>2</INF> emissions at five Duke Energy EGUs
identified by NPS for such an evaluation, instead concluding that
SO<INF>2</INF> emissions from these EGUs are effectively controlled
without any substantive analysis.\91\ NPS asserts that EPA's proposed
determination that FFAs are not necessary for these EGUs and that they
are effectively controlled for SO<INF>2</INF> is flawed and
inconsistent with EPA guidance because it: (1) does not consider the
full suite of EPA guidance on effective controls, (2) relied on flawed
assumptions to estimate SO<INF>2</INF> control efficiencies, and (3)
did not assess NO<INF>X</INF> emissions. NPS recommends that EPA
require FFAs for SO<INF>2</INF> and NO<INF>X</INF> at these EGUs which
should consider whether scrubber upgrades or optimizations are cost
effective.
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\91\ The five Duke Energy EGUs identified by NPS are DEC--Belews
Creek, DEC--Cliffside, DEC--Marshall, DEP--Roxboro, and DEP--Mayo.
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EPA Guidance--NPS maintains that EPA narrowly viewed the Agency's
guidance in relying heavily on two effective control examples in the
2019 Guidance--(1) EGUs with add-on flue gas desulfurization (FGD) that
meet the 0.2 lb/MMBtu MATS SO<INF>2</INF> limit for coal-fired EGUs,
and (2) EGUs that installed FGD during the first implementation period
that operates year-round with an effectiveness of at least 90 percent.
NPS states that EPA did not consider additional guidance that ``caveats
how `off-ramps' to source selection should be used,'' pointing to
section 2.3 of the 2021 Clarifications Memo. NPS states that, with
respect to MATS, the guidance recommends that states should also
consider control equipment past performance in their reasonable
progress determinations and recommends reasonable actions to ensure
controls are maintained and operated to achieve optimal performance.
NPS states that the Duke Energy EGUs have operated at lower emission
rates in the past and that its evaluation of SO<INF>2</INF> and
NO<INF>X</INF> emissions information in the CAMPD demonstrates that
SO<INF>2</INF> and NO<INF>X</INF> emissions generally increased in
recent years, suggesting that the controls at these facilities may not
be operating to maintain optimum performance or achievable emission
rates.
NPS also argues that FGD installed after 2007 should meet a control
effectiveness of 95 percent or higher, pointing to a ``caveat'' in the
2019 Guidance regarding the 90 percent control efficiency ``off-ramp''
that EPA cites in its proposal to approve. This ``caveat'' states that
EPA expects any FGD system installed to meet CAA requirements since
2007 would have an effectiveness of 95 percent or higher. NPS also
points to EPA's January 4, 2017, Texas Best Available Retrofit
Technology (BART) FIP in which it contends that EPA set a 95 percent
SO<INF>2</INF> control benchmark for deciding if a scrubber should be
evaluated for upgrades or replacement.
SO2 Control Assumptions--NPS states that EPA's evaluation of
SO<INF>2</INF> removal efficiency at the Duke Energy EGUs relied on
assumptions that may slightly overestimate scrubber efficiency. NPS
maintains that the equation used by EPA to estimate uncontrolled
emissions overestimated these emissions and the resulting control
efficiencies. NPS recommends using AP-42 emission factors for
bituminous coal, and other fuels, to estimate the uncontrolled
emissions. Using the AP-42 factor for bituminous coal, NPS estimates
that scrubber performance is periodically lower than 95 percent for
DEC--Cliffside Unit 5, DEC--Belews Creek Units 1 and 2, DEP--Roxboro
Units 2 and 4A, and DEC--Marshall Units 1 and 2 and is periodically
lower than 90 percent for units at DEP--Roxboro, DEC--Belews Creek, and
DEC--Cliffside. NPS recommends reviewing permit limits to ensure that
optimum scrubber performance is consistently achieved and to prevent
backsliding.
NOX Emissions--NPS recommends that EPA and North Carolina evaluate
the NO<INF>X</INF> controls at the Duke EGUs. According to the NPS,
replacing existing SNCR systems with modern SCR systems at DEC--
Marshall (Units 1, 2, and 4) would be cost effective at $4,000-$6,000/
ton and would reduce
[[Page 92597]]
NO<INF>X</INF> emissions by up to 5,700 tpy. Additionally, NPS found
that performance of the SCR for Duke Energy's EGUs have deteriorated in
recent years. NPS recommends analyzing past performance as a potential
control option for the Duke EGUs with SCR.
Response 18: EPA Guidance--See response 4 regarding evaluation of
these Duke Energy sources via a SO<INF>2</INF> FFA. Regarding the NPS
comments that the SO<INF>2</INF> and NO<INF>X</INF> emissions at these
Duke Energy EGUs have generally increased in recent years, which
suggests that the controls at these facilities may not be operating to
maintain optimum performance or achievable emission rates, North
Carolina did not select DEC--Belews Creek, DEC--Cliffside, DEC--
Marshall, DEP--Mayo, or DEP--Roxboro for an FFA because the visibility
impacts from these sources were below North Carolina's source selection
thresholds. Because these sources were not selected for an FFA, North
Carolina's decision not to evaluate them for controls appears
reasonable.
EPA clarifies that North Carolina and EPA are not relying on
section 2.3 (``Sources that are Not Selected Based on Existing
Effective Controls'') of the 2021 Clarifications Memo and 2019 Guidance
(pp. 22-25) for DEC--Belews Creek, DEC--Cliffside, DEC--Marshall, DEP--
Mayo, or DEP--Roxboro. Section 2.3 of the 2021 Memo is applicable to
sources that met the source selection criteria set by the State under
the RHR and, instead of a FFA, the State provided a showing that the
source has existing, effective controls such that a FFA is unlikely to
result in new additional controls. None of these five Duke Energy EGUs
met North Carolina's source selection criteria for a FFA (i.e., none
met or exceeded the PSAT sulfate or nitrate thresholds). However, in
the NPRM (89 FR 67359), EPA evaluated these Duke Energy EGUs to
evaluate the reasonableness of North Carolina's source selection
thresholds.\92\ EPA documented an analysis that further examined the
Duke Energy sources to verify North Carolina's claim that there were no
uncontrolled or lightly controlled sources in North Carolina that were
not selected. Regarding scrubber control efficiencies, in the NPRM (89
FR 67359), EPA provided data from 2017-2021 indicating that existing
WFGD systems at the five Duke Energy facilities routinely achieve 92 to
98 percent SO<INF>2</INF> removal efficiencies. In this rulemaking
action, EPA also considered data from 2022 and found that the Duke
Energy emissions units have annual average scrubber removal
efficiencies ranging between 93.8-99.2 percent with all units having a
six year average (2017-2022) SO<INF>2</INF> removal efficiency of
greater than 95 percent.\93\ Therefore, it appears reasonable to assume
that an FFA would likely result in the conclusion that no further
SO<INF>2</INF> emissions controls (including WFGD upgrades) are
necessary. See 89 FR 67359.
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\92\ See 2019 Guidance at p. 19 (``For example, it may be
difficult to show reasonableness of a threshold set so high that an
uncontrolled or lightly controlled source that is one of the largest
contributors to anthropogenic light extinction at a Class I area is
excluded.'').
\93\ See North Carolina Duke Energy scrubber efficiency data
file that is inc
[…truncated; see source link]Indexed from Federal Register on November 22, 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.