[Federal Register Volume 77, Number 39 (Tuesday, February 28, 2012)]
[Proposed Rules]
[Pages 11858-11879]
[FR Doc No: 2012-4711]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2010-0219-201148; FRL-9639-2]

Approval and Promulgation of Air Quality Implementation Plans;
State of North Carolina; Regional Haze State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing a limited approval of a revision to the North
Carolina state implementation plan (SIP) submitted by the State of
North Carolina through the North Carolina Department of Environment and
Natural Resources, Division of Air Quality (NCDAQ), on December 17,
2007, that addresses regional haze for the first implementation period.
This revision addresses the requirements of the Clean Air Act (CAA) and
EPA's rules that require states to prevent any future and remedy any
existing anthropogenic impairment of visibility in mandatory Class I
areas (national parks and wilderness areas) caused by emissions of air
pollutants from numerous sources located over a wide geographic area
(also referred to as the ``regional haze program''). States are
required to assure reasonable progress toward the national goal of
achieving natural visibility conditions in Class I areas. EPA is
proposing a limited approval of this SIP revision to implement the
regional haze requirements for North Carolina on the basis that the
revision, as a whole, strengthens the North Carolina SIP. In a separate
action, EPA has proposed a limited disapproval of the North Carolina
regional haze SIP because of deficiencies in the State's regional haze
SIP submittal arising from the remand by the U.S. Court of Appeals for
the District of Columbia Circuit (DC Circuit) to EPA of the Clean Air
Interstate Rule (CAIR). Consequently, EPA is not proposing to take
action in this rulemaking to address the State's reliance on CAIR to
meet certain regional haze requirements.

DATES: Comments must be received on or before March 29, 2012.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2010-0219, by one of the following methods:
    1. www.regulations.gov: Follow the on-line instructions for
submitting comments.
    2. Email<EMAIL_ADDRESS>    3. Fax:<PHONE_NUMBER>.
    4. Mail: EPA-R04-OAR-2010-0219, Regulatory Development Section, Air
Planning Branch, Air, Pesticides and Toxics Management Division, U.S.
Environmental Protection Agency, Region 4, 61 Forsyth Street SW.,
Atlanta, Georgia 30303-8960.
    5. Hand Delivery or Courier: Lynorae Benjamin, Chief, Regulatory
Development Section, Air Planning Branch, Air, Pesticides and Toxics
Management Division, U.S. Environmental Protection Agency, Region 4, 61
Forsyth Street SW., Atlanta, Georgia 30303-8960. Such deliveries are
only accepted during the Regional Office's normal hours of operation.
The Regional Office's official hours of business are Monday through
Friday, 8:30 to 4:30, excluding federal holidays.

    Instructions: Direct your comments to Docket ID No. ``EPA-R04-OAR-
2010-0219.'' EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit through
www.regulations.gov or email, information that you consider to be CBI
or otherwise protected. The www.regulations.gov Web site is an
``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an email comment directly to EPA without
going through www.regulations.gov, your email address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses. For additional information about EPA's public
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the electronic docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, i.e., CBI 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 in www.regulations.gov or
in hard copy at the Regulatory Development Section, Air Planning
Branch, Air, Pesticides and Toxics Management 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 to 4:30, excluding
federal holidays.

FOR FURTHER INFORMATION CONTACT: Sara Waterson or Michele Notarianni,
Regulatory Development Section, Air Planning Branch, Air, Pesticides
and Toxics Management Division, U.S. Environmental Protection Agency,
Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Sara
Waterson can be reached at telephone number<PHONE_NUMBER> and by
electronic mail at<EMAIL_ADDRESS>Michele Notarianni can be
reached at telephone number<PHONE_NUMBER> and by electronic mail at
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

I. What action is EPA proposing?
II. What is the background for EPA's proposed action?
    A. The Regional Haze Problem
    B. Requirements of the CAA and EPA's Regional Haze Rule (RHR)
    C. Roles of Agencies in Addressing Regional Haze
III. What are the requirements for the regional haze SIPs?
    A. The CAA and the RHR
    B. Determination of Baseline, Natural, and Current Visibility
Conditions
    C. Determination of Reasonable Progress Goals (RPGs)
    D. Best Available Retrofit Technology (BART)
    E. Long-Term Strategy (LTS)
    F. Coordinating Regional Haze and Reasonably Attributable
Visibility Impairment (RAVI) LTS
    G. Monitoring Strategy and Other Implementation Plan
Requirements
    H. Consultation With States and Federal Land Managers (FLMs)
IV. What is EPA's analysis of North Carolina's regional haze
submittal?
    A. Affected Class I Areas
    B. Determination of Baseline, Natural, and Current Visibility
Conditions
    1. Estimating Natural Visibility Conditions
    2. Estimating Baseline Conditions
    3. Summary of Baseline and Natural Conditions
    4. Uniform Rate of Progress
    C. Long-Term Strategy/Strategies
    1. Emissions Inventory for 2018 With Federal and State Control
Requirements
    2. Modeling To Support the LTS and Determine Visibility
Improvement for Uniform Rate of Progress
    3. Relative Contributions to Visibility Impairment: Pollutants,
Source Categories, and Geographic Areas
    4. Procedure for Identifying Sources To Evaluate for Reasonable
Progress Controls in North Carolina and Surrounding Areas
    5. Application of the Four CAA Factors in the Reasonable
Progress Analysis
    6. BART
    7. RPGs
    D. Coordination of RAVI and Regional Haze Requirements
    E. Monitoring Strategy and Other Implementation Plan
Requirements
    F. Consultation With States and FLMs
    1. Consultation With Other States
    2. Consultation With the FLMs
    G. Periodic SIP Revisions and Five-Year Progress Reports
V. What action is EPA proposing?
VI. Statutory and Executive Order Reviews

I. What action is EPA proposing?

    EPA is proposing a limited approval of North Carolina's December
17, 2007, SIP revision addressing regional haze under CAA sections
301(a) and 110(k)(3) because the revision as a whole strengthens the
North Carolina SIP. This proposed rulemaking and the accompanying
Technical Support Document \1\ (TSD) explain the basis for EPA's
proposed limited approval action.\2\
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    \1\ EPA's TSD to this action, entitled ``Technical Support
Document for North Carolina Regional Haze SIP Submittal,'' is
included in the public docket for this action.
    \2\ Under CAA sections 301(a) and 110(k)(6) and EPA's long-
standing guidance, a limited approval results in approval of the
entire SIP submittal, even of those parts that are deficient and
prevent EPA from granting a full approval of the SIP revision.
Processing of State Implementation Plan (SIP) Revisions, EPA
Memorandum from John Calcagni, Director, Air Quality Management
Division, OAQPS, to Air Division Directors, EPA Regional Offices I-
X, September 7, 1992, (1992 Calcagni Memorandum) located at: http://www.epa.gov/ttn/caaa/t1/memoranda/siproc.pdf.
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    In a separate action, EPA has proposed a limited disapproval of the
North Carolina regional haze SIP because of deficiencies in the State's
regional haze SIP submittal arising from the State's reliance on CAIR
to meet certain regional haze requirements. See 76 FR 82219 (December
30, 2011). EPA is not proposing to take action in today's rulemaking on
issues associated with North Carolina's reliance on CAIR in its
regional haze SIP. Comments on EPA's proposed limited disapproval of
North Carolina's regional haze SIP are accepted at the docket for EPA's
December 30, 2011, proposed rulemaking (see Docket ID No. EPA-HQ-OAR-
2011-0729). The comment period for EPA's December 30, 2011, proposed
rulemaking is scheduled to end on February 28, 2012.

II. What is the background for EPA's proposed action?

A. The Regional Haze Problem

    Regional haze is visibility impairment that is produced by a
multitude of sources and activities which are located across a broad
geographic area and emit fine particles (PM2.5) (e.g.,
sulfates,

nitrates, organic carbon, elemental carbon, and soil dust), and their
precursors (e.g., sulfur dioxide (SO2), nitrogen oxides
(NOX), and in some cases, ammonia (NH3) and
volatile organic compounds (VOC)). Fine particle precursors react in
the atmosphere to form fine particulate matter which impairs visibility
by scattering and absorbing light. Visibility impairment reduces the
clarity, color, and visible distance that one can see. PM2.5
can also cause serious health effects and mortality in humans and
contributes to environmental effects such as acid deposition and
eutrophication.
    Data from the existing visibility monitoring network, the
``Interagency Monitoring of Protected Visual Environments'' (IMPROVE)
monitoring network, show that visibility impairment caused by air
pollution occurs virtually all the time at most national park and
wilderness areas. The average visual range \3\ in many Class I areas
\4\ (i.e., national parks and memorial parks, wilderness areas, and
international parks meeting certain size criteria) in the western
United States is 100-150 kilometers, or about one-half to two-thirds of
the visual range that would exist without anthropogenic air pollution.
In most of the eastern Class I areas of the United States, the average
visual range is less than 30 kilometers, or about one-fifth of the
visual range that would exist under estimated natural conditions. See
64 FR 35715 (July 1, 1999).
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    \3\ Visual range is the greatest distance, in kilometers or
miles, at which a dark object can be viewed against the sky.
    \4\ Areas designated as mandatory 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. See 42 U.S.C. 7472(a). In
accordance with section 169A of the CAA, EPA, in consultation with
the Department of Interior, promulgated a list of 156 areas where
visibility is identified as an important value. See 44 FR 69122
(November 30, 1979). The extent of a mandatory Class I area includes
subsequent changes in boundaries, such as park expansions. See 42
U.S.C. 7472(a). Although states and tribes may designate as Class I
additional areas which they consider to have visibility as an
important value, the requirements of the visibility program set
forth in section 169A of the CAA apply only to ``mandatory Class I
Federal areas.'' Each mandatory Class I Federal area is the
responsibility of a ``Federal Land Manager.'' See 42 U.S.C. 7602(i).
When the term ``Class I area'' is used in this action, it means a
``mandatory Class I Federal area.''
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B. Requirements of the CAA and EPA's Regional Haze Rule (RHR)

    In section 169A of the 1977 Amendments to the CAA, Congress created
a program for protecting visibility in the nation's national parks and
wilderness areas. This section of the CAA establishes as a national
goal the ``prevention of any future, and the remedying of any existing,
impairment of visibility in mandatory Class I areas which impairment
results from manmade air pollution.'' On December 2, 1980, EPA
promulgated regulations to address visibility impairment in Class I
areas that is ``reasonably attributable'' to a single source or small
group of sources, i.e., ``reasonably attributable visibility
impairment.'' See 45 FR 80084. These regulations represented the first
phase in addressing visibility impairment. EPA deferred action on
regional haze that emanates from a variety of sources until monitoring,
modeling and scientific knowledge about the relationships between
pollutants and visibility impairment were improved.
    Congress added section 169B to the CAA in 1990 to address regional
haze issues. EPA promulgated a rule to address regional haze on July 1,
1999 (64 FR 35713), the RHR. The RHR revised the existing visibility
regulations to integrate into the regulation provisions addressing
regional haze impairment and established a comprehensive visibility
protection program for Class I areas. The requirements for regional
haze, found at 40 CFR 51.308 and 51.309, are included in EPA's
visibility protection regulations at 40 CFR 51.300-309. Some of the
main elements of the regional haze requirements are summarized in
section III of this preamble. The requirement to submit a regional haze
SIP applies to all 50 states, the District of Columbia, and the Virgin
Islands.\5\ 40 CFR 51.308(b) requires states to submit the first
implementation plan addressing regional haze visibility impairment no
later than December 17, 2007.
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    \5\ Albuquerque/Bernalillo County in New Mexico must also submit
a regional haze SIP to completely satisfy the requirements of
section 110(a)(2)(D) of the CAA for the entire State of New Mexico
under the New Mexico Air Quality Control Act (section 74-2-4).
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C. Roles of Agencies in Addressing Regional Haze

    Successful implementation of the regional haze program will require
long-term regional coordination among states, tribal governments and
various federal agencies. As noted above, pollution affecting the air
quality in Class I areas can be transported over long distances, even
hundreds of kilometers. Therefore, to effectively address the problem
of visibility impairment in Class I areas, states need to develop
strategies in coordination with one another, taking into account the
effect of emissions from one jurisdiction on the air quality in
another.
    Because the pollutants that lead to regional haze can originate
from sources located across broad geographic areas, EPA has encouraged
the states and tribes across the United States to address visibility
impairment from a regional perspective. Five regional planning
organizations (RPOs) were developed to address regional haze and
related issues. The RPOs first evaluated technical information to
better understand how their states and tribes impact Class I areas
across the country, and then pursued the development of regional
strategies to reduce emissions of particulate matter (PM) and other
pollutants leading to regional haze.
    The Visibility Improvement State and Tribal Association of the
Southeast (VISTAS) RPO is a collaborative effort of state governments,
tribal governments, and various federal agencies established to
initiate and coordinate activities associated with the management of
regional haze, visibility and other air quality issues in the
Southeastern United States. Member state and tribal governments
include: Alabama, Florida, Georgia, Kentucky, Mississippi, North
Carolina, South Carolina, Tennessee, Virginia, West Virginia, and the
Eastern Band of the Cherokee Indians.

III. What are the requirements for regional haze SIPs?

A. The CAA and the RHR

    Regional haze SIPs must assure reasonable progress towards the
national goal of achieving natural visibility conditions in Class I
areas. Section 169A of the CAA and EPA's implementing regulations
require states to establish long-term strategies for making reasonable
progress toward meeting this goal. Implementation plans must also give
specific attention to certain stationary sources that were in existence
on August 7, 1977, but were not in operation before August 7, 1962, and
require these sources, where appropriate, to install BART controls for
the purpose of eliminating or reducing visibility impairment. The
specific regional haze SIP requirements are discussed in further detail
below.

B. Determination of Baseline, Natural, and Current Visibility
Conditions

    The RHR establishes the deciview as the principal metric or unit
for expressing visibility. This visibility metric expresses uniform
changes in haziness in terms of common increments across the entire
range of visibility conditions, from pristine to

extremely hazy conditions. Visibility expressed in deciviews is
determined by using air quality measurements to estimate light
extinction and then transforming the value of light extinction using a
logarithm function. The deciview is a more useful measure for tracking
progress in improving visibility than light extinction itself because
each deciview change is an equal incremental change in visibility
perceived by the human eye. Most people can detect a change in
visibility at one deciview.\6\
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    \6\ The preamble to the RHR provides additional details about
the deciview. See 64 FR 35714, 35725 (July 1, 1999).
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    The deciview is used in expressing RPGs (which are interim
visibility goals towards meeting the national visibility goal),
defining baseline, current, and natural conditions, and tracking
changes in visibility. The regional haze SIPs must contain measures
that ensure ``reasonable progress'' toward the national goal of
preventing and remedying visibility impairment in Class I areas caused
by anthropogenic air pollution by reducing anthropogenic emissions that
cause regional haze. The national goal is a return to natural
conditions, i.e., anthropogenic sources of air pollution would no
longer impair visibility in Class I areas.
    To track changes in visibility over time at each of the 156 Class I
areas covered by the visibility program (40 CFR 81.401-437), and as
part of the process for determining reasonable progress, states must
calculate the degree of existing visibility impairment at each Class I
area at the time of each regional haze SIP submittal and periodically
review progress every five years midway through each 10-year
implementation period. To do this, the RHR requires states to determine
the degree of impairment (in deciviews) for the average of the 20
percent least impaired (``best'') and 20 percent most impaired
(``worst'') visibility days over a specified time period at each of
their Class I areas. In addition, states must also develop an estimate
of natural visibility conditions for the purpose of comparing progress
toward the national goal. Natural visibility is determined by
estimating the natural concentrations of pollutants that cause
visibility impairment and then calculating total light extinction based
on those estimates. EPA has provided guidance to states regarding how
to calculate baseline, natural and current visibility conditions in
documents titled, EPA's Guidance for Estimating Natural Visibility
conditions under the Regional Haze Rule, September 2003, (EPA-454/B-03-
005 located at http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf), (hereinafter referred to as ``EPA's 2003 Natural Visibility
Guidance''), and Guidance for Tracking Progress Under the Regional Haze
Rule, September 2003, (EPA-454/B-03-004 located at http://www.epa.gov/ttncaaa1/t1/memoranda/rh_tpurhr_gd.pdf), (hereinafter referred to as
``EPA's 2003 Tracking Progress Guidance'').
    For the first regional haze SIPs that were due by December 17,
2007, ``baseline visibility conditions'' were the starting points for
assessing ``current'' visibility impairment. Baseline visibility
conditions represent the degree of visibility impairment for the 20
percent least impaired days and 20 percent most impaired days for each
calendar year from 2000 to 2004. Using monitoring data for 2000 through
2004, states are required to calculate the average degree of visibility
impairment for each Class I area, based on the average of annual values
over the five-year period. The comparison of initial baseline
visibility conditions to natural visibility conditions indicates the
amount of improvement necessary to attain natural visibility, while the
future comparison of baseline conditions to the then current conditions
will indicate the amount of progress made. In general, the 2000-2004
baseline period is considered the time from which improvement in
visibility is measured.

C. Determination of Reasonable Progress Goals (RPGs)

    The vehicle for ensuring continuing progress towards achieving the
natural visibility goal is the submission of a series of regional haze
SIPs from the states that establish two RPGs (i.e., two distinct goals,
one for the ``best'' and one for the ``worst'' days) for every Class I
area for each (approximately) 10-year implementation period. The RHR
does not mandate specific milestones or rates of progress, but instead
calls for states to establish goals that provide for ``reasonable
progress'' toward achieving natural (i.e., ``background'') visibility
conditions. In setting RPGs, states must provide for an improvement in
visibility for the most impaired days over the (approximately) 10-year
period of the SIP, and ensure no degradation in visibility for the
least impaired days over the same period.
    States have significant discretion in establishing RPGs, but are
required to consider the following factors established in section 169A
of the CAA and in EPA's RHR at 40 CFR 51.308(d)(1)(i)(A): (1) The costs
of compliance; (2) the time necessary for compliance; (3) the energy
and non-air quality environmental impacts of compliance; and (4) the
remaining useful life of any potentially affected sources. States must
demonstrate in their SIPs how these factors are considered when
selecting the RPGs for the best and worst days for each applicable
Class I area. States have considerable flexibility in how they take
these factors into consideration, as noted in EPA's Guidance for
Setting Reasonable Progress Goals Under the Regional Haze Program,
(``EPA's Reasonable Progress Guidance''), July 1, 2007, memorandum from
William L. Wehrum, Acting Assistant Administrator for Air and
Radiation, to EPA Regional Administrators, EPA Regions 1-10 (pp. 4-2,
5-1). In setting the RPGs, states must also consider the rate of
progress needed to reach natural visibility conditions by 2064
(referred to as the ``uniform rate of progress'' or the ``glidepath'')
and the emissions reduction measures needed to achieve that rate of
progress over the 10-year period of the SIP. Uniform progress towards
achievement of natural conditions by the year 2064 represents a rate of
progress which states are to use for analytical comparison to the
amount of progress they expect to achieve. In setting RPGs, each state
with one or more Class I areas (``Class I state'') must also consult
with potentially ``contributing states,'' i.e., other nearby states
with emissions sources that may be affecting visibility impairment at
the Class I state's areas. See 40 CFR 51.308(d)(1)(iv).

D. Best Available Retrofit Technology (BART)

    Section 169A of the CAA directs states to evaluate the use of
retrofit controls at certain larger, often uncontrolled, older
stationary sources in order to address visibility impacts from these
sources. Specifically, section 169A(b)(2)(A) of the CAA requires states
to revise their SIPs to contain such measures as may be necessary to
make reasonable progress towards the natural visibility goal, including
a requirement that certain categories of existing major stationary
sources \7\ built between 1962 and 1977 procure, install, and operate
the ``Best Available Retrofit Technology'' as determined by the state.
Under the RHR, states are directed to conduct BART determinations for
such ``BART-eligible'' sources that may be anticipated to cause or
contribute to any visibility impairment in a Class I area. Rather than
requiring source-specific

BART controls, states also have the flexibility to adopt an emissions
trading program or other alternative program as long as the alternative
provides greater reasonable progress towards improving visibility than
BART.
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    \7\ The set of ``major stationary sources'' potentially subject
to BART is listed in CAA section 169A(g)(7).
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    On July 6, 2005, EPA published the Guidelines for BART
Determinations Under the Regional Haze Rule at Appendix Y to 40 CFR
Part 51 (hereinafter referred to as the ``BART Guidelines'') to assist
states in determining which of their sources should be subject to the
BART requirements and in determining appropriate emissions limits for
each applicable source. In making a BART determination for a fossil
fuel-fired electric generating plant with a total generating capacity
in excess of 750 megawatts (MW), a state must use the approach set
forth in the BART Guidelines. A state is encouraged, but not required,
to follow the BART Guidelines in making BART determinations for other
types of sources.
    States must address all visibility-impairing pollutants emitted by
a source in the BART determination process. The most significant
visibility impairing pollutants are SO2, NOX, and
PM. EPA has stated that states should use their best judgment in
determining whether VOC or NH3 compounds impair visibility
in Class I areas.
    Under the BART Guidelines, states may select an exemption threshold
value for their BART modeling, below which a BART-eligible source would
not be expected to cause or contribute to visibility impairment in any
Class I area. The state must document this exemption threshold value in
the SIP and must state the basis for its selection of that value. Any
source with emissions that model above the threshold value would be
subject to a BART determination review. The BART Guidelines acknowledge
varying circumstances affecting different Class I areas. States should
consider the number of emission sources affecting the Class I areas at
issue and the magnitude of the individual sources' impacts. Any
exemption threshold set by the state should not be higher than 0.5
deciview.
    In their SIPs, states must identify potential BART sources,
described as ``BART-eligible sources'' in the RHR, and document their
BART control determination analyses. In making BART determinations,
section 169A(g)(2) of the CAA requires that states consider the
following factors: (1) The costs of compliance, (2) the energy and non-
air quality environmental impacts of compliance, (3) any existing
pollution control technology in use at the source, (4) the remaining
useful life of the source, and (5) the degree of improvement in
visibility which may reasonably be anticipated to result from the use
of such technology. States are free to determine the weight and
significance to be assigned to each factor.
    A regional haze SIP must include source-specific BART emission
limits and compliance schedules for each source subject to BART. Once a
state has made its BART determination, the BART controls must be
installed and in operation as expeditiously as practicable, but no
later than five years after the date of EPA approval of the regional
haze SIP. See CAA section 169(g)(4); see 40 CFR 51.308(e)(1)(iv). In
addition to what is required by the RHR, general SIP requirements
mandate that the SIP must also include all regulatory requirements
related to monitoring, recordkeeping, and reporting for the BART
controls on the source.
    As noted above, the RHR allows states to implement an alternative
program in lieu of BART so long as the alternative program can be
demonstrated to achieve greater reasonable progress toward the national
visibility goal than would BART. Under regulations issued in 2005
revising the regional haze program, EPA made just such a demonstration
for CAIR. See 70 FR 39104 (July 6, 2005). EPA's regulations provide
that states participating in the CAIR cap-and trade program under 40
CFR part 96 pursuant to an EPA-approved CAIR SIP or which remain
subject to the CAIR Federal Implementation Plan in 40 CFR part 97 need
not require affected BART-eligible electrical generating (EGUs) to
install, operate, and maintain BART for emissions of SO2 and
NOX. See 40 CFR 51.308(e)(4). Because CAIR did not address
direct emissions of PM, states were still required to conduct a BART
analysis for PM emissions from EGUs subject to BART for that pollutant.
Challenges to CAIR, however, resulted in the remand of the rule to EPA.
See North Carolina v. EPA, 550F.3d 1175 (DC Cir. 2008).
    EPA issued a new rule in 2011 to address the interstate transport
of NOX and SO2 in the eastern United States. See
76 FR 48208 (August 8, 2011) (``the Transport Rule,'' also known as the
Cross-State Air Pollution Rule). On December 30, 2011, EPA proposed to
find that the trading programs in the Transport Rule would achieve
greater reasonable progress towards the national goal than would BART
in the states in which the Transport Rule applies. See 76 FR 82219.
Based on this proposed finding, EPA also proposed to revise the RHR to
allow states to substitute participation in the trading programs under
the Transport Rule for source-specific BART. EPA has not yet taken
final action on that rule. Also on December 30, 2011, the DC Circuit
issued an order addressing the status of the Transport Rule and CAIR in
response to motions filed by numerous parties seeking a stay of the
Transport Rule pending judicial review. In that order, the DC Circuit
stayed the Transport Rule pending the court's resolutions of the
petitions for review of that rule in EME Homer Generation, L.P. v. EPA
(No. 11-1302 and consolidated cases). The court also indicated that EPA
is expected to continue to administer CAIR in the interim until the
court rules on the petitions for review of the Transport Rule.

E. Long-Term Strategy (LTS)

    Consistent with the requirement in section 169A(b) of the CAA that
states include in their regional haze SIP a 10 to 15 year strategy for
making reasonable progress, section 51.308(d)(3) of the RHR requires
that states include a LTS in their regional haze SIPs. The LTS is the
compilation of all control measures a state will use during the
implementation period of the specific SIP submittal to meet applicable
RPGs. The LTS must include ``enforceable emissions limitations,
compliance schedules, and other measures as necessary to achieve the
reasonable progress goals'' for all Class I areas within, or affected
by emissions from, the state. See 40 CFR 51.308(d)(3).
    When a state's emissions are reasonably anticipated to cause or
contribute to visibility impairment in a Class I area located in
another state, the RHR requires the impacted state to coordinate with
the contributing states in order to develop coordinated emissions
management strategies. See 40 CFR 51.308(d)(3)(i). In such cases, the
contributing state must demonstrate that it has included, in its SIP,
all measures necessary to obtain its share of the emissions reductions
needed to meet the RPGs for the Class I area. The RPOs have provided
forums for significant interstate consultation, but additional
consultations between states may be required to sufficiently address
interstate visibility issues. This is especially true where two states
belong to different RPOs.
    States should consider all types of anthropogenic sources of
visibility impairment in developing their LTS, including stationary,
minor, mobile, and area sources. At a minimum, states must describe how
each of the following seven factors listed below are taken into

account in developing their LTS: (1) Emissions reductions due to
ongoing air pollution control programs, including measures to address
RAVI; (2) measures to mitigate the impacts of construction activities;
(3) emissions limitations and schedules for compliance to achieve the
RPG; (4) source retirement and replacement schedules; (5) smoke
management techniques for agricultural and forestry management purposes
including plans as currently exist within the state for these purposes;
(6) enforceability of emissions limitations and control measures; and
(7) the anticipated net effect on visibility due to projected changes
in point, area, and mobile source emissions over the period addressed
by the LTS. See 40 CFR 51.308(d)(3)(v).

F. Coordinating Regional Haze and Reasonably Attributable Visibility
Impairment (RAVI) LTS

    As part of the RHR, EPA revised 40 CFR 51.306(c) regarding the LTS
for RAVI to require that the RAVI plan must provide for a periodic
review and SIP revision not less frequently than every three years
until the date of submission of the state's first plan addressing
regional haze visibility impairment, which was due December 17, 2007,
in accordance with 40 CFR 51.308(b) and (c). On or before this date,
the state must revise its plan to provide for review and revision of a
coordinated LTS for addressing RAVI and regional haze, and the state
must submit the first such coordinated LTS with its first regional haze
SIP. Future coordinated LTS's, and periodic progress reports evaluating
progress towards RPGs, must be submitted consistent with the schedule
for SIP submission and periodic progress reports set forth in 40 CFR
51.308(f) and 51.308(g), respectively. The periodic review of a state's
LTS must report on both regional haze and RAVI impairment and must be
submitted to EPA as a SIP revision.

G. Monitoring Strategy and Other Implementation Plan Requirements

    Section 51.308(d)(4) of the RHR includes the requirement for a
monitoring strategy for measuring, characterizing, and reporting of
regional haze visibility impairment that is representative of all
mandatory Class I areas within the state. The strategy must be
coordinated with the monitoring strategy required in section 51.305 for
RAVI. Compliance with this requirement may be met through
``participation'' in the IMPROVE network, i.e., review and use of
monitoring data from the network. The monitoring strategy is due with
the first regional haze SIP, and it must be reviewed every five years.
The monitoring strategy must also provide for additional monitoring
sites if the IMPROVE network is not sufficient to determine whether
RPGs will be met.
    The SIP must also provide for the following:
     Procedures for using monitoring data and other information
in a state with mandatory Class I areas to determine the contribution
of emissions from within the state to regional haze visibility
impairment at Class I areas both within and outside the state;
     Procedures for using monitoring data and other information
in a state with no mandatory Class I areas to determine the
contribution of emissions from within the state to regional haze
visibility impairment at Class I areas in other states;
     Reporting of all visibility monitoring data to the
Administrator at least annually for each Class I area in the state, and
where possible, in electronic format;
     Developing a statewide inventory of emissions of
pollutants that are reasonably anticipated to cause or contribute to
visibility impairment in any Class I area. The inventory must include
emissions for a baseline year, emissions for the most recent year for
which data are available, and estimates of future projected emissions.
A state must also make a commitment to update the inventory
periodically; and
     Other elements, including reporting, recordkeeping, and
other measures necessary to assess and report on visibility.
    The RHR requires control strategies to cover an initial
implementation period extending to the year 2018, with a comprehensive
reassessment and revision of those strategies, as appropriate, every 10
years thereafter. Periodic SIP revisions must meet the core
requirements of section 51.308(d) with the exception of BART. The
requirement to evaluate sources for BART applies only to the first
regional haze SIP. Facilities subject to BART must continue to comply
with the BART provisions of section 51.308(e), as noted above. Periodic
SIP revisions will assure that the statutory requirement of reasonable
progress will continue to be met.

H. Consultation With States and Federal Land Managers (FLMs)

    The RHR requires that states consult with FLMs before adopting and
submitting their SIPs. See 40 CFR 51.308(i). States must provide FLMs
an opportunity for consultation, in person and at least 60 days prior
to holding any public hearing on the SIP. This consultation must
include the opportunity for the FLMs to discuss their assessment of
impairment of visibility in any Class I area and to offer
recommendations on the development of the RPGs and on the development
and implementation of strategies to address visibility impairment.
Further, a state must include in its SIP a description of how it
addressed any comments provided by the FLMs. Finally, a SIP must
provide procedures for continuing consultation between the state and
FLMs regarding the state's visibility protection program, including
development and review of SIP revisions, five-year progress reports,
and the implementation of other programs having the potential to
contribute to impairment of visibility in Class I areas.

IV. What is EPA's analysis of North Carolina's regional haze submittal?

    On December 17, 2007, NCDAQ submitted revisions to the North
Carolina SIP to address regional haze in the State's Class I areas as
required by EPA's RHR.

A. Affected Class I Areas

    North Carolina has five Class I areas within its borders: Great
Smoky Mountains National Park, Joyce Kilmer-Slickrock Wilderness Area,
Linville Gorge Wilderness Area, Shining Rock Wilderness Area, and
Swanquarter Wilderness Area. Two of these Class I areas (Great Smoky
Mountains and Joyce Kilmer) also fall within the geographic boundaries
of Tennessee. Therefore, both North Carolina and Tennessee are
responsible for developing their own regional haze SIPs that address
these two Class I areas and for consulting with other states that
impact the areas. The two states worked together to determine
appropriate RPGs, including consulting with other states that impact
these two Class I areas, as discussed in section IV.F.1 of this
rulemaking. In addition, both North Carolina and Tennessee are
responsible for describing their own long-term emissions strategies,
their role in the consultation processes, and how their particular
state SIP meets the other requirements in EPA's regional haze
regulations.
    The North Carolina regional haze SIP establishes RPGs for
visibility improvement at each of these Class I areas and a LTS to
achieve those RPGs within the first regional haze implementation period
ending in 2018. In developing the LTS for each area, North Carolina
considered both emissions sources inside and outside of North Carolina
that may cause or

contribute to visibility impairment in North Carolina's Class I areas.
The State also identified and considered emissions sources within North
Carolina that may cause or contribute to visibility impairment in Class
I areas in neighboring states as required by 40 CFR 51.308(d)(3). The
VISTAS RPO worked with the State in developing the technical analyses
used to make these determinations, including state-by-state
contributions to visibility impairment in specific Class I areas, which
included the five areas in North Carolina and those areas affected by
emissions from North Carolina.

B. Determination of Baseline, Natural, and Current Visibility
Conditions

    As required by the RHR and in accordance with EPA's 2003 Natural
Visibility Guidance, North Carolina calculated baseline/current and
natural visibility conditions for each of its Class I areas, as
summarized below (and as further described in sections III.B.1 and
III.B.2 of EPA's TSD to this Federal Register action).
1. Estimating Natural Visibility Conditions
    Natural background visibility, as defined in EPA's 2003 Natural
Visibility Guidance, is estimated by calculating the expected light
extinction using default estimates of natural concentrations of fine
particle components adjusted by site-specific estimates of humidity.
This calculation uses the IMPROVE equation, which is a formula for
estimating light extinction from the estimated natural concentrations
of fine particle components (or from components measured by the IMPROVE
monitors). As documented in EPA's 2003 Natural Visibility Guidance, EPA
allows states to use ``refined'' or alternative approaches to the 2003
EPA guidance to estimate the values that characterize the natural
visibility conditions of the Class I areas. One alternative approach is
to develop and justify the use of alternative estimates of natural
concentrations of fine particle components. Another alternative is to
use the ``new IMPROVE equation'' that was adopted for use by the
IMPROVE Steering Committee in December 2005.\8\ The purpose of this
refinement to the ``old IMPROVE equation'' is to provide more accurate
estimates of the various factors that affect the calculation of light
extinction. North Carolina opted to use the default estimates for the
natural concentrations combined with the ``new IMPROVE equation'' for
all of its Class I areas. Using this approach, natural visibility
conditions using the new IMPROVE equation were calculated separately
for each Class I area by VISTAS.
---------------------------------------------------------------------------

    \8\ The IMPROVE program is a cooperative measurement effort
governed by a steering committee composed of representatives from
federal agencies (including representatives from EPA and the FLMs)
and RPOs. The IMPROVE monitoring program was established in 1985 to
aid the creation of Federal and State implementation plans for the
protection of visibility in Class I areas. One of the objectives of
IMPROVE is to identify chemical species and emissions sources
responsible for existing anthropogenic visibility impairment. The
IMPROVE program has also been a key participant in visibility-
related research, including the advancement of monitoring
instrumentation, analysis techniques, visibility modeling, policy
formulation and source attribution field studies.
---------------------------------------------------------------------------

    The new IMPROVE equation takes into account the most recent review
of the science \9\ and it accounts for the effect of particle size
distribution on light extinction efficiency of sulfate, nitrate, and
organic carbon. It also adjusts the mass multiplier for organic carbon
(particulate organic matter) by increasing it from 1.4 to 1.8. New
terms are added to the equation to account for light extinction by sea
salt and light absorption by gaseous nitrogen dioxide. Site-specific
values are used for Rayleigh scattering (scattering of light due to
atmospheric gases) to account for the site-specific effects of
elevation and temperature. Separate relative humidity enhancement
factors are used for small and large size distributions of ammonium
sulfate and ammonium nitrate and for sea salt. The terms for the
remaining contributors, elemental carbon (light-absorbing carbon), fine
soil, and coarse mass terms, do not change between the original and new
IMPROVE equations.
---------------------------------------------------------------------------

    \9\ The science behind the revised IMPROVE equation is
summarized in numerous published papers. See, e.g., Hand, J.L., and
Malm, W.C., 2006, Review of the IMPROVE Equation for Estimating
Ambient Light Extinction Coefficients--Final Report. March 2006.
Prepared for Interagency Monitoring of Protected Visual Environments
(IMPROVE), Colorado State University, Cooperative Institute for
Research in the Atmosphere, Fort Collins, Colorado. http://vista.cira.colostate.edu/improve/publications/GrayLit/016_IMPROVEeqReview/IMPROVEeqReview.htm; and Pitchford, Marc., 2006,
Natural Haze Levels II: Application of the New IMPROVE Algorithm to
Natural Species Concentrations Estimates. Final Report of the
Natural Haze Levels II Committee to the RPO Monitoring/Data Analysis
Workgroup. September 2006. http://vista.cira.colostate.edu/improve/Publications/GrayLit/029_NaturalCondII/naturalhazelevelsIIreport.ppt.
---------------------------------------------------------------------------

2. Estimating Baseline Conditions
    NCDAQ estimated baseline visibility conditions at the State's five
Class I areas using available monitoring data from four IMPROVE
monitoring sites. The Joyce Kilmer-Slickrock Wilderness Area does not
contain an IMPROVE monitor. In cases where onsite monitoring is not
available, 40 CFR 51.308(d)(2)(i) requires states to use the most
representative monitoring available for the 2000-2004 period to
establish baseline visibility conditions, in consultation with EPA.
North Carolina used, and EPA is proposing to find adequate North
Carolina's use of, 2000-2004 data from the IMPROVE monitor at Great
Smoky Mountains National Park for the Joyce Kilmer-Slickrock Wilderness
Area. The IMPROVE Steering Committee considers the IMPROVE monitor at
the Great Smoky Mountains to be representative of visibility in Joyce
Kilmer. The Great Smoky Mountains National Park is the nearest Class I
area and contiguous to Joyce Kilmer and they possess similar
characteristics, such as meteorology and topography.
    As explained in section III.B, for the first regional haze SIP,
baseline visibility conditions are the same as current conditions. A
five-year average of the 2000 to 2004 monitoring data was calculated
for each of the 20 percent worst and 20 percent best visibility days at
each North Carolina Class I area. IMPROVE data records for Great Smoky
Mountains National Park and the Linville Gorge Wilderness Area for the
period 2000 to 2004 meet the EPA requirements for data completeness.
See page 2-8 of EPA's 2003 Tracking Progress Guidance. Shining Rock and
Swanquarter Class I areas had missing data in more than one year
between the years 2000 to 2004. Data records for these sites were
filled using data substitution procedures. Tables 3.3-1, 3.3-2, 3.3-3,
and 3.3-4 from Appendix G of the North Carolina regional haze SIP, also
provided in section III.B.3 of EPA's TSD to this action, list the 20
percent best and worst days for the baseline period of 2000-2004 for
the Great Smoky Mountains, Linville Gorge, Shining Rock, and
Swanquarter areas, respectively. These data are also provided at the
following Web site: http://www.metro4-sesarm.org/vistas/SesarmBext_20BW.htm.
3. Summary of Baseline and Natural Conditions
    For the North Carolina Class I areas, baseline visibility
conditions on the 20 percent worst days range between approximately
24.5 and 30.5 deciviews. Natural visibility in these areas is predicted
to be between approximately 11 and 12 deciviews on the 20 percent worst
days. The natural and baseline conditions for North Carolina's Class I
areas for both the 20 percent worst and

best days are presented in Table 1 below.

Table 1--Natural Background and Baseline Conditions for North Carolina's
                              Class I Areas
------------------------------------------------------------------------
                                            Average for     Average for
              Class I area                   20% worst    20% best  days
                                          days (dv \10\)       (dv)
------------------------------------------------------------------------
Natural Background Conditions:
    Great Smoky Mountains National Park.           11.05            4.54
    Joyce Kilmer-Slickrock Wilderness              11.05            4.54
     Area...............................
    Linville Gorge Wilderness Area......           11.19            4.08
    Shining Rock Wilderness Area........           11.47            2.51
    Swanquarter Wilderness Area.........           11.55            5.46
Baseline Visibility Conditions (2000-
 2004):
    Great Smoky Mountains National Park.           30.28           13.58
    Joyce Kilmer-Slickrock Wilderness              30.28           13.58
     Area...............................
    Linville Gorge Wilderness Area......           28.77           11.11
    Shining Rock Wilderness Area........           28.46            7.69
    Swanquarter Wilderness Area.........           24.74           11.99
------------------------------------------------------------------------

4. Uniform Rate of Progress
    In setting the RPGs, North Carolina considered the uniform rate of
progress needed to reach natural visibility conditions by 2064
(``glidepath'') and the emissions reduction measures needed to achieve
that rate of progress over the period of the SIP to meet the
requirements of 40 CFR 51.308(d)(1)(i)(B). As explained in EPA's
Reasonable Progress Guidance document, the uniform rate of progress is
not a presumptive target, and RPGs may be greater than, less than, or
equivalent to the glidepath.
---------------------------------------------------------------------------

    \10\ The term, ``dv,'' is the abbreviation for ``deciview.''
---------------------------------------------------------------------------

    The State's implementation plan presents two sets of graphs, one
for the 20 percent best days, and one for the 20 percent worst days,
for its five Class I areas. North Carolina constructed the graph for
the worst days (i.e., the glidepath) in accordance with EPA's 2003
Tracking Progress Guidance by plotting a straight graphical line from
the baseline level of visibility impairment for 2000-2004 to the level
of visibility conditions representing no anthropogenic impairment in
2064 for its areas. For the best days, the graph includes a horizontal,
straight line spanning from baseline conditions in 2004 out to 2018 to
depict no degradation in visibility over the implementation period of
the SIP. North Carolina's SIP shows that the State's RPGs for its areas
provide for improvement in visibility for the 20 percent worst days
over the period of the implementation plan and ensure no degradation in
visibility for the 20 percent best days over the same period, in
accordance with 40 CFR 51.308(d)(1).
    For the Great Smoky Mountain and Joyce Kilmer Class I areas, the
overall visibility improvement necessary to reach natural conditions is
the difference between baseline visibility of 30.28 deciviews for the
20 percent worst days and natural conditions of 11.05 deciviews, i.e.,
19.23 deciviews. Over the 60-year period from 2004 to 2064, this would
require an approximate improvement of 0.321 deciview per year (i.e.,
19.23 deciviews/60 years) to reach natural conditions. Hence, for the
14-year period from 2004 to 2018, in order to achieve visibility
improvement at least equivalent to the uniform rate of progress for the
20 percent worst days at the Great Smoky Mountain and Joyce Kilmer
areas, North Carolina would need to project at least 4.49 deciviews
over the first implementation period (i.e., 0.321 deciview x 14 years =
4.49 deciviews) of visibility improvement from the 30.28 deciviews
baseline in 2004, resulting in visibility levels at or below 25.79
deciviews in 2018. As discussed below in section IV.C.7, for the Great
Smoky Mountain and Joyce Kilmer areas, North Carolina projects a 6.78
deciview improvement to visibility from the 30.28 deciview baseline to
23.50 deciviews in 2018 for the 20 percent most impaired days, and a
1.47 deciview improvement to 12.11 deciviews from the baseline
visibility of 13.58 deciviews for the 20 percent least impaired days.
Similar computations can be made for the other three North Carolina
Class I areas.

C. Long-Term Strategy/Strategies

    As described in section III.E of this action, the LTS is a
compilation of state-specific control measures relied on by a state for
achieving its RPGs. North Carolina's LTS for the first implementation
period addresses the emissions reductions from federal, state, and
local controls that take effect in the State from the end of the
baseline period starting in 2004 until 2018. The North Carolina LTS was
developed by the State, in coordination with the VISTAS RPO, through an
evaluation of the following components: (1) Identification of the
emissions units within North Carolina and in surrounding states that
likely have the largest impacts currently on visibility at the State's
Class I areas; (2) estimation of emissions reductions for 2018 based on
all controls required or expected under federal and state regulations
for the 2004-2018 period (including BART); (3) comparison of projected
visibility improvement with the uniform rate of progress for the
State's Class I areas; and (4) application of the four statutory
factors in the reasonable progress analysis for the identified
emissions units to determine if additional reasonable controls were
required.
    In a separate action proposing limited disapproval of the regional
haze SIPs of a number of states, EPA noted that these states relied on
the trading programs of CAIR to satisfy the BART requirement and the
requirement for a LTS sufficient to achieve the state-adopted RPGs. See
76 FR 82219 (December 30, 2011). In that action, EPA proposed a limited
disapproval of North Carolina's regional haze SIP submittal insofar as
the SIP relied on CAIR. For that reason, EPA is not taking action on
that aspect of North Carolina's regional haze SIP in this action.
Comments on the December 30, 2011, proposed determination are accepted
at Docket ID No. EPA-HQ-OAR-2011-0729. The comment period for EPA's
December 30, 2011, proposed rulemaking is scheduled to end on February
28, 2012.

1. Emissions Inventory for 2018 With Federal and State Control
Requirements
    The emissions inventory used in the regional haze technical
analyses was developed by VISTAS with assistance from North Carolina.
The 2018 emissions inventory was developed by projecting 2002 emissions
and applying reductions expected from federal and state regulations
affecting the emissions of VOC and the visibility-impairing pollutants
NOX, PM, and SO2. The BART Guidelines direct
states to exercise judgment in deciding whether VOC and NH3
impair visibility in their Class I area(s). As discussed further in
section IV.C.3, VISTAS performed modeling sensitivity analyses, which
demonstrated that anthropogenic emissions of VOC and NH3 do
not significantly impair visibility in the VISTAS region. Thus, while
emissions inventories were also developed for NH3 and VOC,
and applicable federal VOC reductions were incorporated into North
Carolina's regional haze analyses, North Carolina did not further
evaluate NH3 and VOC emissions sources for potential
controls under BART or reasonable progress.
    VISTAS developed emissions for five inventory source
classifications: stationary point and area sources, off-road and on-
road mobile sources, and biogenic sources. Stationary point sources are
those sources that emit greater than a specified tonnage per year,
depending on the pollutant, with data provided at the facility level.
Stationary area sources are those sources whose individual emissions
are relatively small, but due to the large number of these sources, the
collective emissions from the source category could be significant.
VISTAS estimated emissions on a countywide level for the inventory
categories of: (a) Stationary area sources; (b) off-road (or non-road)
mobile sources (i.e., equipment that can move but does not use
roadways); and (c) biogenic sources (which are natural sources of
emissions, such as trees). On-road mobile source emissions are
estimated by vehicle type and road type, and are summed to the
countywide level.
    There are many federal and state control programs being implemented
that VISTAS and North Carolina anticipate will reduce emissions between
the end of the baseline period and 2018. Emissions reductions from
these control programs are projected to achieve substantial visibility
improvement by 2018 in the North Carolina Class I areas. The control
programs relied upon by North Carolina include CAIR; EPA's
NOX SIP Call; North Carolina's Clean Smokestacks Act (CSA);
Georgia Rule 391-3-1-.02(2)(sss), ``Multipollutant Control for Electric
Utility Steam Generating Units;'' consent decrees for Tampa Electric,
Virginia Electric and Power Company, Gulf Power-Plant Crist, and
American Electric Power; NOX and/or VOC reductions from the
control rules in 1-hour ozone SIPs for Atlanta, Birmingham, and
Northern Kentucky; North Carolina's NOX Reasonably Available
Control Technology state rule for Philip Morris USA and Norandal USA in
the Charlotte/Gastonia/Rock Hill 1997 8-hour ozone nonattainment area;
federal 2007 heavy duty diesel engine standards for on-road trucks and
buses; federal Tier 2 tailpipe controls for on-road vehicles; federal
large spark ignition and recreational vehicle controls; and EPA's non-
road diesel rules. Controls from various federal Maximum Achievable
Control Technology (MACT) rules were also utilized in the development
of the 2018 emissions inventory projections. These MACT rules include
the industrial boiler/process heater MACT (referred to as ``Industrial
Boiler MACT''), the combustion turbine and reciprocating internal
combustion engines MACTs, and the VOC 2-, 4-, 7-, and 10-year MACT
standards.
    Effective July 30, 2007, the D.C. Circuit mandated the vacatur and
remand of the Industrial Boiler MACT Rule.\11\ This MACT was vacated
since it was directly affected by the vacatur and remand of the
Commercial and Industrial Solid Waste Incinerator Definition Rule. EPA
proposed a new Industrial Boiler MACT rule to address the vacatur on
June 4, 2010, (75 FR 32006) and issued a final rule on March 21, 2011
(76 FR 15608). The VISTAS modeling included emissions reductions from
the vacated Industrial Boiler MACT rule, and North Carolina did not
redo its modeling analysis when the rule was re-issued. Even though
North Carolina's modeling is based on the vacated Industrial Boiler
MACT limits, the State's modeling conclusions are unlikely to be
affected because the expected reductions due to the vacated rule were
relatively small compared to the State's total SO2,
PM2.5, and coarse particulate matter (PM10)
emissions in 2018 (i.e., 0.1 to 0.4 percent, depending on the
pollutant, of the projected 2018 SO2, PM2.5, and
PM10 inventory). Thus, EPA does not expect that differences
between the vacated and final Industrial Boiler MACT emissions limits
would affect the adequacy of the existing North Carolina regional haze
SIP. If there is a need to address discrepancies between projected
emissions reductions from the vacated Industrial Boiler MACT and the
Industrial Boiler MACT issued March 21, 2011 (76 FR 15608), EPA expects
North Carolina to do so in the State's five-year progress report.
---------------------------------------------------------------------------

    \11\ See NRDC v. EPA, 489 F.3d 1250 (D.C. Cir. 2007).
---------------------------------------------------------------------------

    Below in Tables 2 and 3 are summaries of the 2002 baseline and 2018
estimated emissions inventories for North Carolina.

                                              Table 2--2002 Emissions Inventory Summary for North Carolina
                                                                     [Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                VOC             NOX            PM2.5           PM10             NH3             SO2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point...................................................          61,484         196,731          26,953          36,539           1,233         522,093
Area....................................................         250,044          41,517          83,520         300,838         162,183           5,815
On-Road Mobile..........................................         263,766         327,329           4,623           6,579           9,702          12,420
Off-Road Mobile.........................................          94,480          84,284           7,348           7,348              65           7,693
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................         669,774         649,861         122,444         351,304         173,183         548,021
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                              Table 3--2018 Emissions Inventory Summary for North Carolina
                                                                     [Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                VOC             NOX            PM2.5           PM10             NH3             SO2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point...................................................          71,247          94,276          37,789          48,354           2,073         148,972
Area....................................................         203,132          49,514          93,406         338,872         181,333           6,674
On-Road Mobile..........................................         101,099          87,791           2,123           4,392          14,065           1,481
Off-road Mobile.........................................          61,327          49,046           4,069           4,298              83             905
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................         436,805         280,627         137,387         395,916         197,554         158,032
--------------------------------------------------------------------------------------------------------------------------------------------------------

2. Modeling To Support the LTS and Determine Visibility Improvement for
Uniform Rate of Progress
    VISTAS performed modeling for the regional haze LTS for the 10
southeastern states, including North Carolina. The modeling analysis is
a complex technical evaluation that began with selection of the
modeling system. VISTAS used the following modeling system:
     Meteorological Model: The Pennsylvania State University/
National Center for Atmospheric Research Mesoscale Meteorological Model
is a nonhydrostatic, prognostic meteorological model routinely used for
urban- and regional-scale photochemical, PM2.5, and regional
haze regulatory modeling studies.
     Emissions Model: The Sparse Matrix Operator Kernel
Emissions modeling system is an emissions modeling system that
generates hourly gridded speciated emissions inputs of mobile, non-road
mobile, area, point, fire and biogenic emissions sources for
photochemical grid models.
     Air Quality Model: The EPA's Models-3/Community Multiscale
Air Quality (CMAQ) modeling system is a photochemical grid model
capable of addressing ozone, PM, visibility and acid deposition at a
regional scale. The photochemical model selected for this study was
CMAQ version 4.5. It was modified through VISTAS with a module for
Secondary Organics Aerosols in an open and transparent manner that was
also subjected to outside peer review.
    CMAQ modeling of regional haze in the VISTAS region for 2002 and
2018 was carried out on a grid of 12x12 kilometer cells that covers the
10 VISTAS states (Alabama, Florida, Georgia, Kentucky, Mississippi,
North Carolina, South Carolina, Tennessee, Virginia, West Virginia) and
states adjacent to them. This grid is nested within a larger national
CMAQ modeling grid of 36x36 kilometer cells that covers the continental
United States, portions of Canada and Mexico, and portions of the
Atlantic and Pacific Oceans along the east and west coasts. Selection
of a representative period of meteorology is crucial for evaluating
baseline air quality conditions and projecting future changes in air
quality due to changes in emissions of visibility-impairing pollutants.
VISTAS conducted an in-depth analysis which resulted in the selection
of the entire year of 2002 (January 1-December 31) as the best period
of meteorology available for conducting the CMAQ modeling. The VISTAS
states modeling was developed consistent with EPA's Guidance on the Use
of Models and Other Analyses for Demonstrating Attainment of Air
Quality Goals for Ozone, PM2.5, and Regional Haze, located
at http://www.epa.gov/scram001/guidance/guide/final-03-pm-rh-guidance.pdf, (EPA-454/B-07-002), April 2007, and EPA document,
Emissions Inventory Guidance for Implementation of Ozone and
Particulate Matter National Ambient Air Quality Standards (NAAQS) and
Regional Haze Regulations, located at http://www.epa.gov/ttnchie1/eidocs/eiguid/index.html, EPA-454/R-05-001, August 2005, updated
November 2005 (``EPA's Modeling Guidance'').
    VISTAS examined the model performance of the regional modeling for
the areas of interest before determining whether the CMAQ model results
were suitable for use in the regional haze assessment of the LTS and
for use in the modeling assessment. The modeling assessment predicts
future levels of emissions and visibility impairment used to support
the LTS and to compare predicted, modeled visibility levels with those
on the uniform rate of progress. In keeping with the objective of the
CMAQ modeling platform, air quality model performance was evaluated
using graphical and statistical assessments based on measured ozone,
fine particles, and acid deposition from various monitoring networks
and databases for the 2002 base year. VISTAS used a diverse set of
statistical parameters from the EPA's Modeling Guidance to stress and
examine the model and modeling inputs. Once VISTAS determined the model
performance to be acceptable, VISTAS used the model to assess the 2018
RPGs using the current and future year air quality modeling
predictions, and compared the RPGs to the uniform rate of progress.
    In accordance with 40 CFR 51.308(d)(3), the State of North Carolina
provided the appropriate supporting documentation for all required
analyses used to determine the State's LTS. The technical analyses and
modeling used to develop the glidepath and to support the LTS are
consistent with EPA's RHR and interim and final EPA Modeling Guidance.
EPA proposes to accept the VISTAS technical modeling to support the LTS
and to determine visibility improvement for the uniform rate of
progress because the modeling system was chosen and simulated according
to EPA Modeling Guidance. EPA proposes to concur with the VISTAS model
performance procedures and results, and that the CMAQ is an appropriate
tool for the regional haze assessments for the North Carolina LTS and
regional haze SIP.
3. Relative Contributions to Visibility Impairment: Pollutants, Source
Categories, and Geographic Areas
    An important step toward identifying reasonable progress measures
is to identify the key pollutants contributing to visibility impairment
at each Class I area. To understand the relative benefit of further
reducing emissions from different pollutants, source sectors, and
geographic areas, VISTAS developed emissions sensitivity model runs
using CMAQ to evaluate visibility and air quality impacts from various
groups of emissions and pollutant scenarios in the Class I areas on the
20 percent worst visibility days.
    Regarding which pollutants are most significantly impacting
visibility in the VISTAS region, VISTAS' contribution assessment, based
on IMPROVE monitoring data, demonstrated that ammonium sulfate is the
major contributor to PM2.5 mass and visibility impairment at
Class I areas in the VISTAS and neighboring states. On the 20 percent
worst visibility days in 2000-2004, ammonium sulfate

accounted for 75 to 87 percent of the calculated light extinction at
the inland Class I areas in VISTAS, and 69 to 74 percent of the
calculated light extinction for all but one of the coastal Class I
areas in the VISTAS states. In particular, sulfate particles resulting
from SO2 emissions contribute to the calculated light
extinction on the haziest days roughly 74 percent for the Swanquarter
area, and 84 to 87 percent for the Great Smoky Mountains, Linville
Gorge, and Shining Rock areas, depending on the area. In contrast,
ammonium nitrate contributed less than five percent of the calculated
light extinction at the VISTAS Class I areas on the 20 percent worst
visibility days. Particulate organic matter (organic carbon) accounted
for 20 percent or less of the light extinction on the 20 percent worst
visibility days at the VISTAS Class I areas.
    VISTAS grouped its 18 Class I areas into two types, either
``coastal'' or ``inland'' (sometimes referred to as ``mountain'')
sites, based on common/similar characteristics (e.g. terrain,
geography, meteorology), to better represent variations in model
sensitivity and performance within the VISTAS region and to describe
the common factors influencing visibility conditions in the two types
of Class I areas. All of North Carolina's Class I areas, except for
Swanquarter, are ``inland'' areas. Swanquarter is considered a
``coastal'' area.
    Results from VISTAS' emissions sensitivity analyses indicate that
sulfate particles resulting from SO2 emissions are the
dominant contributor to visibility impairment on the 20 percent worst
days at all Class I areas in VISTAS. North Carolina concluded that
reducing SO2 emissions from EGU and non-EGU point sources in
the VISTAS states would have the greatest visibility benefits for the
North Carolina Class I areas.
    Because ammonium nitrate is a small contributor to PM2.5
mass and visibility impairment on the 20 percent worst days at the
inland Class I areas in VISTAS, which include all of the North Carolina
Class I areas except for the Swanquarter area, the benefits of reducing
NOX and NH3 emissions at these sites are small.
Some of the worst days at Swanquarter, and other coastal sites within
the VISTAS region, occur in the winter when ammonium nitrate has a
somewhat larger contribution to visibility impairment. North Carolina
concluded that reducing ammonia emissions would be more beneficial for
reducing ammonium nitrate contributions to visibility impairment in
wintertime than further reducing NOX emissions from either
ground-level or point (elevated) sources. NCDAQ notes that for
Swanquarter, the numerous hog farms in eastern North Carolina are the
likely primary emissions sources for ammonia.
    The VISTAS sensitivity analyses show that VOC emissions from
biogenic sources such as vegetation also contribute to visibility
impairment. However, control of these biogenic sources of VOC would be
extremely difficult, if not impossible. The anthropogenic sources of
VOC emissions are minor compared to the biogenic sources. Therefore,
controlling anthropogenic sources of VOC emissions would have little,
if any, visibility benefits at the Class I areas in the VISTAS region,
including North Carolina. The sensitivity analyses also show that
reducing primary carbon from point sources, ground level sources, or
fires is projected to have small to no visibility benefit at the VISTAS
Class I areas.
    North Carolina considered the factors listed under 40 CFR
51.308(d)(3)(v) and in section III.E. of this action to develop its LTS
as described below. North Carolina, in conjunction with VISTAS,
demonstrated in its SIP that elemental carbon (a product of highway and
non-road diesel engines, agricultural burning, prescribed fires, and
wildfires), fine soils (a product of construction activities and
activities that generate fugitive dust), and ammonia are relatively
minor contributors to visibility impairment at the Class I areas in
North Carolina. North Carolina considered agricultural and forestry
smoke management techniques to address visibility impacts from
elemental carbon. NCDAQ stated in its SIP that it is working with the
North Carolina Division of Forest Resources to develop a smoke
management program that utilizes basic smoke management practices and
addresses the issues laid out in the EPA's 1998 Interim Air Quality
Policy on Wildland and Prescribed Fires available at: http://www.epa.gov/ttncaaa1/t1/memoranda/firefnl.pdf. Additionally, NCDAQ is
working with the North Carolina Department of Agriculture to develop a
Memorandum of Understanding regarding agricultural burning.
    With regard to fine soils, the State considered those activities
that generate fugitive dust, including construction activities. With
regard to construction activities, the North Carolina Department of
Transportation's Division of Highways has issued regulations addressing
control of erosion, siltation, and pollution from construction
activities. In addition, NCDAQ promulgated state rule 15A NCAC
02D.0540, ``Particulates From Fugitive Dust Emission Sources,''
effective on September 1, 2007, to control particulates from fugitive
dust emissions sources generated within plant boundaries from
activities such as ``unloading and loading areas, process areas,
stockpiles, stock pile working, plant parking lots, and plant roads
(including access roads and haul roads).'' The State has chosen not to
develop controls for fine soils in this first implementation period
because of their relatively minor contribution to visibility
impairment.
    With regard to ammonia emissions from agricultural sources, NCDAQ,
as a continuation of the State's CSA, initiated the Climate Action
Planning Advisory Group to develop options for the reduction of
greenhouse gas emissions in North Carolina, including the emissions
from agriculture and agricultural waste in North Carolina. The Group
issued a report that supports expanded research, regulatory actions,
and grant guarantees as key implementation tools to accomplish the
expanded utilization of methane (a greenhouse gas) from hog/cattle
waste for energy. The report also highlights improved waste management
practices as important. A co-benefit of any resulting measures will be
the reduction of ammonia emissions from animal waste. In addition, the
North Carolina Legislature approved a bill on July 26, 2007, that
permanently bans new lagoons at hog farms and orders state regulators
to set environmental standards for new hog farm waste systems. The new
legislation phases-out the use of waste lagoons by hog farmers,
replacing them with more environmentally friendly systems.
    EPA preliminarily concurs with the State's technical demonstration
showing that elemental carbon, fine soils, and ammonia are not
significant contributors to visibility in the State's Class I areas,
and therefore, proposes to find that North Carolina has adequately
satisfied 40 CFR 51.308(d)(3)(v). EPA's TSD to this Federal Register
action and North Carolina's SIP provide more details on the State's
consideration of these factors for North Carolina's LTS.
    The emissions sensitivity analyses conducted by VISTAS predict that
reductions in SO2 emissions from EGU and non-EGU industrial
point sources will result in the greatest improvements in visibility in
the Class I areas in the VISTAS region, more than any other visibility-
impairing pollutant. Specific to North Carolina, the VISTAS sensitivity
analysis projects visibility benefits on the 20 percent worst days at
the State's four inland Class I areas from

SO2 reductions from EGUs in eight of the 10 VISTAS states:
Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee,
Virginia, and West Virginia. For the Swanquarter area, reductions from
EGUs in North Carolina and South Carolina would have the greatest
benefits; the contributions from other VISTAS states are comparatively
small. Additional, smaller benefits are projected for North Carolina's
Class I areas from SO2 emissions reductions from non-utility
industrial point sources in the VISTAS states. SO2 emissions
contributions to visibility impairment from other RPO regions are
comparatively small in contrast to the VISTAS states' contributions,
and thus, controlling sources outside of the VISTAS region is predicted
to provide less significant improvements in visibility in the Class I
areas in VISTAS.
    Taking the VISTAS sensitivity analyses results into consideration,
North Carolina concluded that reducing SO2 emissions from
EGU and non-EGU point sources in certain VISTAS states would have the
greatest visibility benefits for the North Carolina Class I areas. The
State chose to focus solely on evaluating certain SO2
sources contributing to visibility impairment to the State's Class I
areas for additional emissions reductions for reasonable progress in
this first implementation period (described in sections IV.C.4 and
IV.C.5 of this action). EPA proposes to agree with the State's analyses
and conclusions used to determine the pollutants and source categories
that most contribute to visibility impairment in the North Carolina
Class I areas, and proposes to find the State's approach to focus on
developing a LTS that includes largely additional measures for point
sources of SO2 emissions to be appropriate.
    SO2 sources for which it is demonstrated that no
additional controls are reasonable in this current implementation
period will not be exempted from future assessments for controls in
subsequent implementation periods or, when appropriate, from the five-
year periodic SIP reviews. In future implementation periods, additional
controls on these SO2 sources evaluated in the first
implementation period may be determined to be reasonable, based on a
reasonable progress control evaluation, for continued progress toward
natural visibility conditions for the 20 percent worst days and to
avoid further degradation of the 20 percent best days. Similarly, in
subsequent implementation periods, the State may use different criteria
for identifying sources for evaluation and may consider other
pollutants as visibility conditions change over time.
4. Procedure for Identifying Sources To Evaluate for Reasonable
Progress Controls in North Carolina and Surrounding Areas
    As discussed in section IV.C.3 of this action, through
comprehensive evaluations by VISTAS and the Southern Appalachian
Mountains Initiative (SAMI),\12\ the VISTAS states concluded that
sulfate particles resulting from SO2 emissions account for
the greatest portion of the regional haze affecting the Class I areas
in VISTAS states, including those areas in North Carolina. Utility and
non-utility boilers are the main sources of SO2 emissions
within the southeastern United States. VISTAS developed a methodology
for North Carolina that enables the State to focus its reasonable
progress analysis on those geographic regions and source categories
that impact visibility at its Class I areas. Recognizing that there was
neither sufficient time nor adequate resources available to evaluate
all emissions units within a given area of influence (AOI) around each
of the Class I areas that North Carolina's sources impact, the State
established a threshold to determine which emissions units would be
evaluated for reasonable progress control. In applying this
methodology, NCDAQ first calculated the fractional contribution to
visibility impairment from all emissions units within the
SO2 AOI for its Class I areas, and from those units within
the SO2 AOIs surrounding Class I areas in other states
potentially impacted by emissions from emissions units in North
Carolina. The State then identified those emissions units with a
contribution of one percent or more to the visibility impairment at
that particular Class I area, and evaluated each of these units for
control measures for reasonable progress using the following four
``reasonable progress factors'' required under 40 CFR
51.308(d)(1)(i)(A): (i) Cost of compliance; (ii) time necessary for
compliance; (iii) energy and non-air quality environmental impacts of
compliance; and (iv) remaining useful life of the emissions unit.
---------------------------------------------------------------------------

    \12\ Prior to VISTAS, the southern states cooperated in a
voluntary regional partnership ``to identify and recommend
reasonable measures to remedy existing and prevent future adverse
effects from human-induced air pollution on the air quality related
values of the Southern Appalachian Mountains.'' States cooperated
with FLMs, EPA, industry, environmental organizations, and academia
to complete a technical assessment of the impacts of acid
deposition, ozone, and fine particles on sensitive resources in the
Southern Appalachians. The SAMI Final Report was delivered in August
2002.
---------------------------------------------------------------------------

    North Carolina's SO2 AOI methodology captured greater
than 60 percent of the total point source SO2 contribution
to visibility impairment in four of the five Class I areas in North
Carolina, and required an evaluation of 21 emissions units at seven
facilities in North Carolina. At the remaining Class I area,
Swanquarter, the one percent threshold represents 47 percent of the
total point source SO2 contribution, while requiring an
evaluation of 12 additional units at six facilities in North Carolina.
The NCDAQ also looked at what sources in North Carolina may be
impacting Class I areas located outside of the State, as well as what
sources located outside of North Carolina may be impacting the North
Carolina Class I areas. By applying the State's AOI SO2
methodology, the only North Carolina source that was identified as
potentially impacting visibility in a Class I area outside the State
was the Duke Power-Dan River facility, which may impact the James River
Face Wilderness Area in Virginia. To capture a higher percentage of
emissions units contributing to the total sulfate visibility impairment
would involve an evaluation of many more units that have substantially
less impact.
    NCDAQ believes that the one percent threshold is appropriate given
the contribution to the total sulfate visibility impairment at each
Class I area and the limited resources available to conduct a unit-by-
unit evaluation for reasonable progress. EPA believes the approach
developed by VISTAS and implemented for the Class I areas in North
Carolina is a reasonable methodology to prioritize the most significant
contributors to regional haze and to identify sources to assess for
reasonable progress control. The approach is consistent with EPA's
Reasonable Progress Guidance. The technical approach of VISTAS and
North Carolina was objective and based on several analyses, including
the evaluation of a large universe of emissions units within and
surrounding the State of North Carolina and all of the 18 VISTAS Class
I areas. It also included an analysis of the VISTAS emissions units
affecting nearby Class I areas surrounding the VISTAS states that are
located in other RPOs' Class I areas.
5. Application of the Four CAA Factors in the Reasonable Progress
Analysis
    NCDAQ identified 34 emissions units at 14 facilities in North
Carolina (see Table 4) with SO2 emissions that were above
the State's minimum threshold for reasonable progress evaluation

because they were modeled to fall within the SO2 AOI of any
Class I area and have a one percent or greater contribution to the
sulfate visibility impairment in at least one Class I area.\13\ Of
these 34 units, seven emissions units were not subject to a reasonable
progress analysis because they were already subject to BART or had shut
down. In addition, as discussed in section IV.C.5.B, 16 units are
subject to CAIR, and NCDAQ concluded that no additional controls for
SO2 beyond CAIR for subject EGUs are reasonable for this
first implementation period. NCDAQ evaluated 11 units at five
facilities.
---------------------------------------------------------------------------

    \13\ See also EPA's TSD, section III.C.2, fractional
contribution analysis tables for each Class I area, excerpted from
the North Carolina SIP, Appendix H.

  Table 4--North Carolina Facilities With Emissions Unit(s) Subject to
                      Reasonable Progress Analysis:
------------------------------------------------------------------------

-------------------------------------------------------------------------
Facilities With Emissions Unit(s) Subject to Reasonable Progress
 Analysis
    Blue Ridge Paper Products--Canton Mill G-24, G-25, G-65, G-66
    Cogentrix Kenansville--Gen1
    PCS Phosphate Company Inc.--Aurora G-1034, G-1035
    Weyerhaeuser Company--New Bern G-42
    Weyerhaeuser Company--Plymouth G-140, G-143, G-148
Facilities With Unit(s) Found Not Subject to Reasonable Progress
 Analysis:
    EGUs Subject to CAIR Within AOI of Any Class I Area:
        Carolina Power & Light Asheville Steam E1, E2
        Duke Energy Corporation--Buck Steam Station G-4, G-5
        Duke Energy Corporation--Dan River Station G-21
        Duke Energy Corporation--Cliffside Steam G-86, G-87, G-88
        Duke Energy Corporation--Marshall Steam G-1, G-2
        Duke Energy Corporation--Riverbend Steam G-17, G-19, G-20
        L V Sutton Steam Electric Plant G-188
        Progress Energy--F Lee Plant G-2, G-3
    Emissions Units Subject to BART:
        Blue Ridge Paper Products--Canton Mill G-26, G-31, G-32
    Emissions Units that Shut Down:
        PCS Phosphate Company Inc.--Aurora G-1032, G-1033
        Ecusta Business Development Center LLC--G-28, G-29
------------------------------------------------------------------------

A. Facilities With Emissions Unit(s) Subject to Reasonable Progress
Analysis
    NCDAQ analyzed whether SO2 controls should be required
for 11 emissions units at five facilities based on a consideration of
the four factors set out in the CAA and EPA's regulations. For the
limited purpose of evaluating the cost of compliance for the reasonable
progress assessment in this first regional haze SIP, NCDAQ believed
that it was not equitable to require non-EGUs to bear a greater
economic burden than EGUs for a given control strategy. The facility-
by-facility costs for EGUs under CSA ranged from 912 to 1,922 dollars
per ton of SO2 removed ($/ton SO2), and the
average costs per utility system ranged from $1,231 to $1,375/ton
SO2. These costs were estimated using the capital costs from
the CSA 2006 compliance plans and the projected operating costs
provided by Duke Energy and Progress Energy. These costs were used as a
guide in determining cost effectiveness.
    During the current reasonable progress assessment, no emissions
units in North Carolina were identified for additional control since no
measures were found to be below the cost threshold discussed above.
NCDAQ did not perform an exhaustive review of the remaining three
statutory factors for reasonable progress since it did not identify any
cost-effective control measures for the specific sources with
contributions to Class I areas in North Carolina or neighboring states.
Neither the time necessary for compliance nor the energy and non-air
quality environmental impacts of compliance appear to be out of the
ordinary for the control measures identified for these facilities. A
likely short remaining useful life for two units was noted in one case,
but a longer remaining useful life would not alter the reasonable
progress determination for those units.
    North Carolina also noted that, in order to show continued progress
past 2018, the criteria will likely be different in the next reasonable
progress assessment in order to maintain continuous visibility
improvement toward natural background conditions by 2064. The
facilities in North Carolina that have units that contribute at least
one percent to visibility impairment at any Class I area in the State,
or in neighboring states, were sent letters from NCDAQ indicating that
while no additional controls were identified during this reasonable
progress assessment, these sources will evaluate possible
SO2 reduction strategies for the next regional haze SIP due
July 31, 2018.
1. Blue Ridge Paper Products
    Four coal-fired Power Boilers at Blue Ridge Paper Products were
evaluated for reasonable progress: No. 4 Power Boiler (G-66) with a
capacity of 535 million British thermal units per hour (MMBtu/hr) and
boilers G-24, G-25, and G-65, each with a capacity of 364-399 MMBtu/hr.
Boilers G-24, G-25, and G-65 burn a washed and blended coal from
different portions of the coal seam at the Apollo mine to meet Blue
Ridge Paper's specifications for heat, ash and sulfur content. Coal
from the Apollo mine has high heat content, low to moderate ash, and
low to moderate sulfur, and it averages from 1.4 to 1.5 pounds
SO2 per million British Thermal Units (lbs SO2/
MMBtu). The electrostatic precipitators (ESPs) on these boilers perform
well on this moderate sulfur coal and test well below applicable PM
standards. They are not designed, however, to burn low sulfur coal. Ash
from low sulfur coal has a higher resistivity than ash from the
moderate sulfur coal that Blue Ridge Paper burns in these boilers. The
No. 4 Power Boiler burns washed, low sulfur coal subject to new source
performance standards (NSPS) with a sulfur limit of 1.2 lbs
SO2/MMBtu.
    Based on information from the company, this lower sulfur coal is
$75-$90/ton SO2, and the other coal used at

the facility is $65/ton SO2. The cost difference is $10-25/
ton SO2. The company burned 277,214 tons of higher sulfur
coal in 2005; switching to lower sulfur coal would cost approximately
$2,772,140-$6,930,350 extra per year. If 1,400 tons of SO2
were reduced by switching from the current higher sulfur coal (one
percent sulfur or approximately 1.6 lb SO2/MMBtu) to lower
sulfur coal (0.75 percent sulfur or approximately 1.2 lb
SO2/MMBtu) at the 2005 rate of coal consumption, associated
costs would range from $1,980-$4,950/ton SO2 with an average
cost of $3,465/ton SO2. NCDAQ determined that the cost for
add-on control technology for these units ranges from $12,055 to
$100,961/ton SO2. NCDAQ concluded that there are no cost-
effective controls available for these units at this time within the
cost threshold established for this reasonable progress assessment.
Although NCDAQ has concluded that there are no cost-effective controls
for this reasonable progress period, the State acknowledges that the
emissions from Blue Ridge Paper Products impact North Carolina's inland
Class I areas. NCDAQ notified the company that although additional
controls are not required during this implementation period, the State
may require the installation and operation of controls for future
implementation periods. NCDAQ is committed to working with this company
over the next review period and encouraging the company to modernize
some of its processes with more efficient equipment with lower
emissions.
2. PCS Phosphate
    Two of the four sulfuric acid units at PCS Phosphate identified for
further analysis under reasonable progress remain in operation (units
1034 and 1035). On February 7, 2011, NCDAQ provided a technical
supplement to the December 17, 2007, regional haze SIP for these units.
The two PCS Phosphate units currently utilize dual absorption systems
with a vanadium catalyst. The four technologies reviewed included
sodium bisulfite scrubbing, molecular sieve, ammonia scrubbing, and
dual absorption process with cesium-promoted catalyst.
    The first three technologies were rejected because they have not
been commercially demonstrated to reliably meet current NSPS and state
permit limits. The use of cesium-promoted catalyst was further
evaluated, looking at three scenarios. The first scenario evaluated,
changing to a cesium-promoted catalyst without making other major
capital investments, was estimated to cost $2,879/ton SO2
and reduce SO2 emissions by only 165 tons per year. This
estimate was based on reducing SO2 emissions from 3.8 to 3.5
lbs SO2/ton of sulfuric acid produced. The other two
scenarios evaluated meeting a 2.0 lbs SO2/ton of sulfuric
acid produced limit by either making operational changes or by
modifying the reactor vessel. The operational changes could be made
without significant capital expenditures but would significantly reduce
production capacity. Modifying the unit to increase the amount of
catalyst available required significant capital investment. NCDAQ
estimated that these options would reduce SO2 emissions by
2,073 tons/year with a cost effectiveness of approximately $11,347/ton
of SO2 reduced for the operational change and a cost
effectiveness of approximately $12,816 to $13,651/ton SO2
for the unit modification. NCDAQ also cited modeling analyses which
concluded that the visibility improvement at the Swanquarter Wilderness
Area resulting from reducing the SO2 emissions rate by 1.0
lb SO2/ton sulfuric acid produced (i.e., a change in
emissions rate from 4.0 to 3.0 lbs SO2/ton sulfuric acid
produced) would only be 0.16 deciview. Therefore, NCDAQ concluded that
there are no cost-effective controls available for these units at this
time within the cost threshold established for this reasonable progress
assessment. NCDAQ notified the company that although additional
controls are not being required during this planning period, the State
may require the installation and operation of controls for future-
planning periods.
3. Weyerhaeuser--Plymouth
    Weyerhaeuser--Plymouth has three power boilers subject to analysis:
Riley No. 1 Combination Boiler, No. 1 Hog Fuel Boiler, and No. 2 Hog
Fuel Boiler. The Riley No. 1 Combination Boiler burns coal, No. 6 fuel
oil, Low Volume High Concentration (LVHC) gases, and Stripper Off Gas
(SOG) gases and is fired at 624 MMBtu/hr maximum heat input. The No. 1
Hog Fuel Boiler burns hog fuel (wood waste), No. 6 fuel oil, coal, used
oil, sludge, and High Volume Low Concentration (HVLC) gases. This
boiler is fired at 835 MMBtu/hr maximum heat input from hog fuel, 617
MMBtu/hr maximum heat input from No. 6 fuel oil, or for combination
firing, 701.2 and 319.8 MMBtu/hr maximum heat input from hog fuel and
coal, respectively. The No. 2 Hog Fuel Boiler burns hog fuel, No. 6
fuel oil, coal, used oil, sludge, HVLC, LVHC, and SOG gases. It is
fired at 889 MMBtu/hr maximum heat input from combined fuels or 800
MMBtu/hr maximum heat input from No. 6 fuel oil.
    NCDAQ did not identify any available controls for the Hog Boiler 1
or 2. For the Riley Boiler, the only available control that NCDAQ
identified is a flue gas desulfurization (FGD) scrubber at a cost of
$20,460/ton SO2. Therefore, NCDAQ concluded that there are
no cost-effective controls for these units at this time within the cost
threshold established for this reasonable progress assessment.
4. Weyerhaeuser--New Bern
    Weyerhaeuser--New Bern has one power boiler which burns residual
oil. It is fired at 579 MMBtu/hr maximum heat input rate. The only
available control identified by NCDAQ is an FGD at a cost of $17,317/
ton SO2. Therefore, the NCDAQ concluded that there are no
cost-effective controls available for this unit at this time within the
cost threshold established for this reasonable progress assessment.
5. Cogentrix Kenansville
    The affected emissions unit at Cogentrix Kenansville is Gen1, a 215
MMBtu/hr heat input mixed fuel-fired EGU capable of burning coal,
natural gas, No. 2 and No. 4 fuel oil, tire-derived fuel, pelletized
paper fuel, flyash briquette, and wood. Although the company retains
coal as a permitted fuel on the permit, it is currently burning
unadulterated wood (pure wood with up to five percent impurities), and
its new business plan is to continue burning only wood as part of the
``green power'' movement in North Carolina.
    The 2005 actual SO2 emissions for this unit were 23.25
tons, whereas the projected 2018 SO2 emissions were 1,833.8
tons based on using coal. In the final SIP submittal, the NCDAQ stated
that it is sending the company a letter indicating that they are
currently on the list of sources contributing greater than one percent
to the total sulfate visibility impairment at the Swanquarter
Wilderness Area based on the estimated emissions from burning coal. The
SIP submittal indicated that the letter will suggest that the facility
change its permit to remove coal as a possible fuel source for this
unit.
6. EPA Assessment
    As noted in EPA's Reasonable Progress Guidance, the states have
wide latitude to determine appropriate additional control requirements
for ensuring reasonable progress, and there are many ways for a state
to approach identification of additional reasonable measures. States
must consider, at a minimum, the four statutory factors in

determining reasonable progress, but states have flexibility in how to
take these factors into consideration.
    NCDAQ applied the methodology developed by VISTAS for identifying
appropriate sources to be considered for additional controls under
reasonable progress for the implementation period ending in 2018 that
is addressed by this SIP. Using this methodology, NCDAQ first
identified those emissions and emissions units most likely to have an
impact on visibility in the State's and neighboring Class I areas.
Units with emissions of SO2 with a relative contribution to
visibility impairment of at least a one percent contribution at any
Class I area were then subject to a reasonable progress control
analysis except for utilities subject to CAIR.
    After reviewing NCDAQ's methodology and analyses and the record
prepared by NCDAQ, EPA proposes to find North Carolina's conclusion
that no further controls are necessary at this time acceptable. EPA
proposes to find that North Carolina adequately evaluated the control
technologies available at the time of its analysis and applicable to
this type of facility and consistently applied its criteria for
reasonable compliance costs. The State also included appropriate
documentation in its SIP of the technical analysis it used to assess
the need for and implementation of reasonable progress controls.
Although the use of a specific threshold for assessing costs means that
a state may not fully consider available emissions reduction measures
above its threshold that would result in meaningful visibility
improvement, EPA believes that the North Carolina SIP still ensures
reasonable progress. In proposing to approve North Carolina's
reasonable progress analysis, EPA is placing great weight on the fact
that there is no indication in the SIP submittal that North Carolina,
as a result of using a specific cost effectiveness threshold, rejected
potential reasonable progress measures that would have had a meaningful
impact on visibility in its Class I areas. EPA notes that given the
emissions reductions resulting from CAIR and the measures in nearby
states, the visibility improvements projected for the affected Class I
areas are in excess of that needed to be on the uniform rate of
progress.
B. Facilities With Emissions Units Subject to CAIR Within AOI of Any
Class I Area
    NCDAQ identified 16 EGUs at eight facilities which met the State's
minimum threshold for reasonable progress evaluation because they were
modeled to fall within the SO2 AOI of any Class I area and
have a one percent or greater contribution to the sulfate visibility
impairment to at least one Class I area. North Carolina determined that
no additional controls for the State's EGUs for SO2 were
reasonable during the first implementation period. In reaching this
decision, NCDAQ evaluated the amount of SO2 emissions
reductions from the EGU sector expected from the implementation of
North Carolina's CSA and CAIR. The EGUs in North Carolina are expected
to reduce their SO2 emissions by greater than 80 percent
between 2002 and 2018.
    Additionally, NCDAQ considered the four reasonable progress factors
set forth in EPA's RHR as they apply to the State's entire EGU sector
in sections 7.7 and 7.8 of the North Carolina SIP. In particular, the
State took into account the factors of cost and time necessary for
compliance in view of EPA's analysis supporting CAIR.
    Based on this analysis, NCDAQ concluded that the emissions
reductions required by CAIR constitute reasonable measures for North
Carolina EGUs during this first assessment period. This conclusion is
bolstered by the fact that, as discussed in section IV.C.7, visibility
improvement at the State's Class I areas is projected to exceed the
uniform rate of progress in this first implementation period. NCDAQ
intends to re-evaluate EPA's Integrated Planning Model (IPM)
predictions of SO2 emissions reductions for CAIR at the time
of the next periodic progress report to ensure that the reductions are
in fact taking place where they were predicted. Based on the controls
required by CSA, and predicted by IPM under CAIR, NCDAQ has concluded
that, at this time, these existing regulatory programs constitute
reasonable control measures for these 16 EGUs during the first
implementation period (between the baseline and 2018). EPA proposes a
limited approval of North Carolina's methodology and determination that
no additional controls beyond CAIR and CSA are reasonable for
SO2 for affected North Carolina EGUs for the first
implementation period.
C. Facilities With Unit(s) Found Not Subject to Reasonable Progress
Analysis
1. Non-EGUs Subject to BART
    Three emissions units at Blue Ridge Paper that met the State's
minimum threshold for a reasonable progress control evaluation are
emissions units that NCDAQ also found to be subject to BART. NCDAQ
concluded that the application of BART constitutes reasonable progress
for these three units for this implementation period, and thus, it is
not requiring any additional controls for reasonable progress at this
time. As discussed in EPA's Reasonable Progress Guidance, since the
BART analysis is based, in part, on an assessment of many of the same
factors that must be addressed in establishing the RPGs, EPA believes
that it is reasonable to conclude that any control requirements imposed
in the BART determination also satisfy the RPG-related requirements for
source review in the first implementation period.\14\ Thus, EPA
proposes to concur with the State's conclusions that BART satisfies
reasonable progress for the first implementation period for these three
emissions units at Blue Ridge Paper.
---------------------------------------------------------------------------

    \14\ EPA's Reasonable Progress Guidance, pages 4.2-4-3.
---------------------------------------------------------------------------

2. Other Units Exempted from Preparing a Reasonable Progress Control
Analysis
    NCDAQ did not evaluate the two emissions units at Ecusta Business
Development Center since they ceased operation prior to the regional
haze SIP submittal date. Two of the four units at PCS Phosphate in
Aurora that were identified for assessment for reasonable progress have
since permanently ceased operation and therefore were not evaluated
further.
6. BART
    BART is an element of North Carolina's LTS for the first
implementation period. The BART evaluation process consists of three
components: (a) An identification of all the BART-eligible sources, (b)
an assessment of whether the BART-eligible sources are subject to BART
and (c) a determination of the BART controls. These components, as
addressed by NCDAQ and NCDAQ's findings, are discussed as follows.
A. BART-Eligible Sources
    The first phase of a BART evaluation is to identify all the BART-
eligible sources within the State's boundaries. NCDAQ identified the
BART-eligible sources in North Carolina by utilizing the three
eligibility criteria in the BART Guidelines (70 FR 39158) and EPA's
regulations (40 CFR 51.301): (1) One or more emissions units at the
facility fit within one of the 26 categories listed in the BART
Guidelines; (2) the emissions units were not in operation prior to
August 7, 1962, and were in existence on August 7, 1977; and (3) these
units have the potential to emit 250 tons or more per year of any
visibility-impairing pollutant.

    The BART Guidelines also direct states to address SO2,
NOX, and direct PM (including both PM10 and
PM2.5) emissions as visibility-impairment pollutants and to
exercise judgment in determining whether VOC or ammonia emissions from
a source impair visibility in a Class I area. See 70 FR 39160. VISTAS
modeling demonstrated that VOC from anthropogenic sources and ammonia
from point sources, except for potentially one ammonia source, are not
significant visibility-impairing pollutants in North Carolina, as
discussed in section IV.C.3 of this action. Based on the VISTAS
modeling, NCDAQ has determined that ammonia emissions from the State's
point sources are not anticipated to cause or contribute significantly
to any impairment of visibility in Class I areas and should be exempt
for BART purposes. No ammonia source in North Carolina was identified
by VISTAS as a possible contributor to visibility impairment.
B. BART-Subject Sources
    The second phase of the BART evaluation is to identify those BART-
eligible sources that may reasonably be anticipated to cause or
contribute to visibility impairment at any Class I area, i.e., those
sources that are subject to BART. The BART Guidelines allow states to
consider exempting some BART-eligible sources from further BART review
because they may not reasonably be anticipated to cause or contribute
to any visibility impairment in a Class I area. Consistent with the
BART Guidelines, North Carolina required each of its BART-eligible
sources to develop and submit dispersion modeling to assess the extent
of their contribution to visibility impairment at Class I areas in
surrounding states.
1. Modeling Methodology
    The BART Guidelines allow states to use the CALPUFF \15\ modeling
system (CALPUFF) or another appropriate model to predict the visibility
impacts from a single source on a Class I area and therefore, to
determine whether an individual source is anticipated to cause or
contribute to impairment of visibility in Class I areas, i.e., ``is
subject to BART.'' EPA believes that CALPUFF is the best regulatory
modeling application currently available for predicting a single
source's contribution to visibility impairment (70 FR 39162). North
Carolina, in coordination with VISTAS, used the CALPUFF modeling system
to determine whether individual sources in North Carolina were subject
to BART.
---------------------------------------------------------------------------

    \15\ Note that EPA's reference to CALPUFF encompasses the entire
CALPUFF modeling system, which includes the CALMET, CALPUFF, and
CALPOST models and other pre and post processors. The different
versions of CALPUFF have corresponding versions of CALMET, CALPOST,
etc. which may not be compatible with previous versions (e.g., the
output from a newer version of CALMET may not be compatible with an
older version of CALPUFF). The different versions of the CALPUFF
modeling system are available from the model developer on the
following Web site: http://www.src.com/verio/download/download.htm.
---------------------------------------------------------------------------

    The BART Guidelines also recommend that states develop a modeling
protocol for making individual source attributions and suggest that
states may want to consult with EPA and their RPO to address any issues
prior to modeling. The VISTAS states, including North Carolina,
developed a ``Protocol for the Application of CALPUFF for BART
Analyses.'' Stakeholders, including EPA, FLMs, industrial sources,
trade groups, and other interested parties, actively participated in
the development and review of the VISTAS protocol.
    VISTAS developed a post-processing approach to use the new IMPROVE
equation with the CALPUFF model results so that the BART analyses could
consider the old and new IMPROVE equations. North Carolina's
justification included a method to process the CALPUFF output and a
rationale on the benefits of using the new IMPROVE equation.
2. Contribution Threshold
    For states using modeling to determine the applicability of BART to
single sources, the BART Guidelines note that the first step is to set
a contribution threshold to assess whether the impact of a single
source is sufficient to cause or contribute to visibility impairment at
a Class I area. The BART Guidelines state that ``[a] single source that
is responsible for a 1.0 deciview change or more should be considered
to `cause' visibility impairment.'' The BART Guidelines also state that
``the appropriate threshold for determining whether a source
`contributes to visibility impairment' may reasonably differ across
states,'' but, ``[a]s a general matter, any threshold that you use for
determining whether a source `contributes' to visibility impairment
should not be higher than 0.5 deciviews.'' The Guidelines affirm that
states are free to use a lower threshold if they conclude that the
location of a large number of BART-eligible sources in proximity of a
Class I area justifies this approach.
    North Carolina used a contribution threshold of 0.5 deciview for
determining which sources are subject to BART. NCDAQ concluded that,
considering the results of the visibility impacts modeling conducted, a
0.5 deciview threshold was appropriate in this situation and a lower
threshold was not warranted for the following reasons. The State
demonstrated that there are a limited number of in and out of state
sources that impact the Class I areas in the State, and that there are
a limited number of sources in close proximity to each of the affected
Class I areas. Additionally, the majority of the visibility impacts
were well below 0.5 deciview. Also, even though several sources
impacted each Class I area, the overall impacts were low from the
sources. EPA is proposing to agree with North Carolina that the overall
impacts of these sources are not sufficient to warrant a lower
contribution threshold and that a 0.5 deciview threshold was
appropriate in this instance.
3. Identification of Sources Subject to BART
    North Carolina identified 17 facilities with BART-eligible sources.
All of North Carolina's 17 BART-eligible sources were required by the
State to submit exemption-modeling demonstrations. North Carolina found
that two of its BART-eligible sources (Blue Ridge Paper and PCS
Phosphate) had modeled visibility impacts of more than the State's 0.5
deciview threshold. Therefore, these two facilities are subject to BART
and submitted State permit applications including their proposed BART
determinations. PCS Phosphate subsequently shut down its two sulfuric
acid units subject to BART and these units were not further evaluated.
    The 15 remaining sources were able to demonstrate that they are not
subject to BART by modeling less than a 0.5 deciview visibility impact
at the affected Class I areas. This modeling involved emissions of
NOX, SO2, and PM10 as applicable to
individual facilities.
    Six of North Carolina's BART-eligible sources are facilities with
EGUs that are subject to CAIR. As noted above, the RHR allows states to
implement an alternative program in lieu of BART so long as the
alternative program can be demonstrated to achieve greater reasonable
progress toward the national visibility goal than would BART. Under
regulations issued in 2005 revising the regional haze program, EPA made
just such a demonstration for CAIR. See 70 FR 39104 (July 6, 2005).
EPA's regulations provide that states participating in the CAIR cap-and
trade program under 40 CFR part 96 pursuant to an EPA-approved CAIR SIP
or which

remain subject to the CAIR Federal Implementation Plan in 40 CFR part
97 need not require affected BART-eligible EGUs to install, operate,
and maintain BART for emissions of SO2 and NOX.
See 40 CFR 51.308(e)(4). Because CAIR did not address direct emissions
of PM, states were still required to conduct a BART analysis for PM
emissions from EGUs subject to BART for that pollutant. Thus, North
Carolina's EGUs were allowed to submit BART exemption modeling
demonstrations for PM emissions only. All of the BART-eligible EGUs
demonstrated that their PM emissions do not contribute to visibility
impairment in any Class I area. Table 5 identifies the 17 BART-eligible
sources located in North Carolina.
---------------------------------------------------------------------------

    \16\ EGUs were only evaluated for PM emissions. North Carolina
relied on CAIR to satisfy BART for SO2 and NOX
for its EGUs in CAIR, in accordance with 40 CFR 51.308(e)(4). Thus,
SO2 and NOX were not analyzed.

   Table 5--North Carolina BART--Eligible and Subject-to-BART Sources
------------------------------------------------------------------------

-------------------------------------------------------------------------
Facilities With Unit(s) Subject to BART:
    Blue Ridge Paper
Facilities With Unit(s) Not Subject to BART:
    EGU CAIR and BART Modeling (PM only) Exempt Sources \16\:
        Duke Energy--Belews Creek Steam Station
        Duke Energy--Cliffside Steam Station
        Duke Energy--Marshall Steam Station
        Progress Energy--Asheville Plant
        Progress Energy--Roxboro Steam Electric Plant
        Progress Energy--Sutton Plant
    Non-EGU BART Modeling Exempt:
        Alcoa, Inc.-Badin Works
        DAK Americas--Cape Fear
        DAK Americas--Cedar Creek
        Elementis Chromium
        International Paper--Riegelwood Mill
        International Paper--Roanoke Rapids
        Invista, S.A.R.L.
        Weyerhaeuser Company--Plymouth
        Weyerhaeuser Company--New Bern
    Shut Down:
        PCS Phosphate
------------------------------------------------------------------------

    Prior to the CAIR remand, the State's reliance on CAIR to satisfy
BART for NOX and SO2 for affected CAIR EGUs was
fully approvable and in accordance with 40 CFR 51.308(e)(4). However,
the BART assessments for CAIR EGUs for NOX and
SO2 and other provisions in this SIP revision are based on
CAIR. In a separate action, EPA has proposed a limited disapproval of
the North Carolina regional haze SIP because of deficiencies in the
State's regional haze SIP submittal arising from the remand by the D.C.
Circuit to EPA of CAIR. See 76 FR 82219. Consequently, EPA is not
taking action in this proposed rulemaking to address the State's
reliance on CAIR to meet certain regional haze requirements.
C. BART Determination
    The five BART-eligible units at Blue Ridge Paper modeled visibility
impacts of more than the 0.5 deciview threshold and are therefore
subject to BART. Consequently, Blue Ridge Paper submitted to the State
a permit application that included their proposed BART determination.
    In accordance with the BART Guidelines, to determine the level of
control that represents BART for each source, the State first reviewed
existing controls on these units to assess whether these constituted
the best controls currently available, then identified what other
technically feasible controls are available, and finally, evaluated the
technically feasible controls using the five BART statutory factors.
The State's evaluations and conclusions, and EPA's assessment, are
summarized below. The units subject to the BART requirements at Blue
Ridge Paper include the two recovery furnaces, their associated smelt
dissolving tanks, and the black liquor oxidation system (BLOX). NCDAQ
concluded that BART for all of these emissions sources is the existing
emissions control systems currently in place.
    The recovery furnaces emit PM, SO2, and NOX.
For the recovery furnaces, potential retrofit control technologies for
PM emissions were not further evaluated since the units are already
equipped with the most stringent controls and since the operation of
these controls is required by the facility's title V operating permit.
For NOX, several potential control alternatives were
evaluated; however, NCDAQ believes that the installation of
NOX reduction controls for the recovery furnaces is not
economically feasible. For SO2, installation of a wet
scrubber following the ESP was identified as technically feasible;
however, it was not considered economically feasible and would result
in only a marginal visibility improvement at one Class I area (Great
Smoky Mountains) and degradation in visibility at another (Shining
Rock). Therefore, the State determined that retrofit controls are not
warranted as BART for SO2 emissions from the recovery
furnaces.
    The smelt dissolving tanks emit PM, SO2, and
NOX. No NOX controls are available for this
source type. For PM and SO2, the number of technically
feasible controls is limited due to the fact that the emissions are
minimal and of low velocity. Although several options were evaluated,
they would only minimally reduce the number of days above 0.5 deciview
at Shining Rock and Great Smoky Mountains, and NCDAQ believes that the
installation of retrofit controls on the smelt dissolving tanks as BART
is not economically feasible (in excess of $13,000/ton for less than 44
tons/year of particulate reduction).
    The BLOX system emits PM, SO2 and NOX. Blue
Ridge is complying with MACT Subpart S through alternative requirements
approved by the EPA under an equivalency by permit

approach. Under these alternative requirements, Blue Ridge is
controlling the BLOX system to achieve a greater level of hazardous air
pollutant (HAP) reduction by controlling emissions from the BLOX system
in a new Regenerative Thermal Oxidizer (RTO) equipped with a wet
scrubber for SO2 control. Proper operation of the RTO and
combustion of natural gas as auxiliary fuel minimize PM and
NOX emissions.
    Because the unit is already equipped with the most stringent
controls as required by the MACT standards, and permit limits are in
place to ensure these controls are operated properly, the NCDAQ has
determined that BART for the BLOX is existing controls.
    EPA proposes to agree with North Carolina's analyses and
conclusions for the BART emissions units located at the Blue Ridge
Paper facility. EPA has reviewed the North Carolina analyses and
proposes to conclude that they were conducted in a manner that is
consistent with EPA's BART Guidelines and EPA's Air Pollution Control
Cost Manual (http://www.epa.gov/ttncatc1/products.html#cccinfo).
Therefore, the conclusions reflect a reasonable application of EPA's
guidance to these sources.
7. RPGs
    The RHR at 40 CFR 51.308(d)(1) requires states to establish RPGs
for each Class I area within the state (expressed in deciviews) that
provide for reasonable progress towards achieving natural visibility.
VISTAS modeled visibility improvements under existing federal and state
regulations for the period 2004-2018 and additional control measures
which the VISTAS states planned to implement in the first
implementation period. At the time of VISTAS modeling, some of the
other states with sources potentially impacting visibility at the North
Carolina Class I areas had not yet made final control determinations
for BART and/or reasonable progress, and thus, these controls were not
included in the modeling submitted by North Carolina. Any controls
resulting from those determinations will provide additional emissions
reductions and resulting visibility improvement, which give further
assurances that North Carolina will achieve its RPGs. This modeling
demonstrates that the 2018 base control scenario provides for an
improvement in visibility better than the uniform rate of progress for
both of the North Carolina Class I areas for the most impaired days
over the period of the implementation plan and ensures no degradation
in visibility for the least impaired days over the same period.
    On February 16, 2010, NCDAQ sent a letter to EPA Region 4
clarifying the reason for the differences in the RPGs for Great Smoky
Mountains and Joyce Kilmer presented in the North Carolina and
Tennessee regional haze SIP submittals. For the 20 percent worst days,
the April 4, 2008, Tennessee submittal used 23.50 deciviews while the
North Carolina submittal states the RPG as 23.7 (or 23.66) deciviews.
(Similarly, for the 20 percent best days, the RPG differences between
the two states' submittals were 12.2 (or 12.15) deciviews in the North
Carolina submittal vs 12.11 deciviews in the Tennessee submittal.)
NCDAQ explained that the differences are due to different modeling runs
used by each state. At the time of SIP development, only the earlier
version of the VISTAS modeling run was available to NCDAQ. NCDAQ
acknowledges that the RPGs in the Tennessee regional haze SIP represent
the most current information and commits to revise the RPGs for Great
Smoky Mountains and Joyce Kilmer in the periodic progress report SIP.
In accordance with this letter of clarification, Table 6 below reflects
the updated RPGs of 12.11 (approximated to 12.1) and 23.50 for both the
best and worst days, respectively, for these two Class I areas.
    As shown in Table 6 below, North Carolina's RPGs for the 20 percent
worst days provide greater visibility improvement by 2018 than the
uniform rate of progress for the State's Class I areas. Also, the RPGs
for the 20 percent best days provide greater visibility improvement by
2018 than current best day conditions. The regional haze provisions
specify that a state may not adopt a RPG that represents less
visibility improvement than is expected to result from other CAA
requirements during the implementation period. 40 CFR 51.308(d)(1)(vi).
Therefore, the CAIR states with Class I areas, like North Carolina,
took into account emissions reductions anticipated from CAIR in
determining their 2018 RPGs.\17\ The modeling supporting the analysis
of these RPGs is consistent with EPA guidance at the time.
---------------------------------------------------------------------------

    \17\ Many of the CAIR states without Class I areas similarly
relied on CAIR emissions reductions within the state to address some
or all of their contribution to visibility impairment in other
states' Class I areas, which the impacted Class I area state(s) used
to set the RPGs for their Class I area(s). Certain surrounding non-
CAIR states also relied on reductions due to CAIR in nearby states
to develop their regional haze SIP submittals.

                                                            Table 6--North Carolina 2018 RPGs
                                                                     [In deciviews]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                2018 RPG--  20%  Uniform rate  of                     2018 RPG--  20%
                                                                    Baseline         worst days        progress at        Baseline          best days
                         Class I area                            visibility--20%    (improvement    2018--20%  worst    visibility--      (improvement