[Federal Register Volume 77, Number 39 (Tuesday, February 28, 2012)]
[Proposed Rules]
[Pages 11937-11958]
[FR Doc No: 2012-4689]

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 ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2009-0782-201149, FRL-9638-8]

Approval and Promulgation of Air Quality Implementation Plans;
State of Alabama; 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
Alabama state implementation plan (SIP) submitted by the State of
Alabama through the Alabama Department of Environmental Management
(ADEM), on July 15, 2008, that addresses regional haze for the first
implementation period. This revision addresses the requirements of the
Clean Air Act (CAA or Act) 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
towards 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 Alabama on the basis
that the revision, as a whole, strengthens the Alabama SIP.
Additionally, EPA is proposing to rescind the federal regulations
previously approved into the Alabama SIP on November 24, 1987, and to
rely on the provisions in Alabama's July 15, 2008, SIP submittal to
meet the long-term strategy (LTS) requirements for reasonably
attributable visibility impairment (RAVI). EPA has previously proposed
a limited disapproval of the Alabama 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-2009-0782, 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-2009-0782, 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-
2009-0782.'' 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 to take?
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 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 Alabama's regional haze submittal?
    A. Affected Class I Area
    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 Alabama 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 taking?
VI. Statutory and Executive Order Reviews

I. What action is EPA proposing to take?

    EPA is proposing a limited approval of Alabama's July 15, 2008, SIP
revision addressing regional haze under CAA sections 301(a) and
110(k)(3) because the revision as a whole strengthens the Alabama 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 Alabama Regional Haze 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
Alabama 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 Alabama's reliance on CAIR in its regional haze SIP. Comments on
EPA's proposed limited disapproval of Alabama's regional haze SIP are
accepted at the docket for EPA's December 30, 2011 (see Docket ID No.
EPA-HQ-OAR-2011-0729). The comment period for EPA's December 30, 2011,
rulemaking is scheduled to end on February 28, 2012.
    In this action, EPA is also proposing to rescind the federal
regulations in 40 CFR 52.61 that were approved into the Alabama SIP.
See 52 FR 45138 (November 24, 1987). EPA is proposing to rely on the
provisions in Alabama's July 15, 2008, SIP submittal to meet the
monitoring and LTS requirements for RAVI at 40 CFR 51.305 and 40 CFR
51.306.

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
(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.
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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 \4\ 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.
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    \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 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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    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 the 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, i.e., 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 emission 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 emission 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, 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 emissions 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 emissions
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 units (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 resulted in the remand of the rule to
EPA. See North Carolina v. EPA, 550 F.3d 1176 (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 emission 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) Emission 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 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 Alabama's regional haze submittal?

    On July 15, 2008, ADEM submitted revisions to the Alabama SIP to
address regional haze in the State's Class I area as required by EPA's
RHR.

A. Affected Class I Area

    Alabama has one Class I area within its borders: Sipsey Wilderness
Area. Alabama is responsible for developing

its a regional haze SIP that addresses the Class I area. The State
determined RPGs, including consulting with other states that impact the
Class I area, as discussed in IV.F.1. In addition, Alabama is
responsible for describing its long-term emission strategies, its role
in the consultation processes, and how its particular state SIP meets
the other requirements in EPA's regional haze regulations.
    The Alabama regional haze SIP establishes RPGs for visibility
improvement at this Class I area and a LTS to achieve those RPGs within
the first regional haze implementation period ending in 2018. In
developing the LTS, Alabama considered both emissions sources inside
and outside of Alabama that may cause or contribute to visibility
impairment in Alabama's Class I area. The State also identified and
considered emissions sources within Alabama 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 one Class I
area in Alabama and those areas affected by emissions from Alabama.

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

    As required by the RHR and in accordance with EPA's 2003 Natural
Visibility Guidance, Alabama calculated baseline/current and natural
visibility conditions for its Class I area, 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. Alabama opted to use the default estimates for the natural
concentrations, combined with the ``new IMPROVE equation,'' for its
area. 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
    ADEM estimated baseline visibility conditions at the Sipsey
Wilderness Area using available monitoring data from a single IMPROVE
monitoring site. As explained in section III.B, baseline visibility
conditions are the same as current conditions for the first regional
haze SIP. 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 the Alabama Class I area. IMPROVE data records for
the Sipsey 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. Table 3.3-1 from Appendix G of the Alabama regional
haze SIP, also provided in section III.B.3 of EPA's TSD to this action,
lists the 20 percent best and worst days for the baseline period of
2000-2004 for the Sipsey Wilderness Area. 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 Alabama Class I area, baseline visibility on the 20 percent
worst days is approximately 29 deciviews. Natural visibility in this
area is predicted to be approximately 11 deciviews on the 20 percent
worst days. The natural and baseline conditions for Alabama's Class I
area for both the 20 percent worst and best days are presented in Table
1 below.

 Table 1--Natural Background and Baseline Conditions for Alabama's Class
                                 I Area
------------------------------------------------------------------------
                                     Average for 20%
           Class I area               worst days (dv    Average for 20%
                                          \10\)          best days (dv)
------------------------------------------------------------------------
Natural Background Conditions:
    Sipsey Wilderness Area........              10.90               5.03
Baseline Visibility Conditions
 (2000-2004)
    Sipsey Wilderness Area........              29.03              15.57
------------------------------------------------------------------------

4. Uniform Rate of Progress
    In setting the RPGs, Alabama considered the uniform rate of
progress needed to reach natural visibility conditions by 2064
(``glidepath'') and the emission 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, lesser, 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 Class I area. Alabama 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
area. 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.
Alabama's SIP shows that the State's RPGs for its area 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 Sipsey Wilderness Area, the overall visibility improvement
necessary to reach natural conditions is the difference between
baseline visibility of 29.03 deciviews for the 20 percent worst days
and natural conditions of 10.90 deciviews, i.e., 18.13 deciviews. Over
the 60-year period from 2004 to 2064, this would require an approximate
average improvement of 0.302 deciview per year (i.e., 18.13 deciviews/
60 years) to reach natural conditions. Hence, for the 14-year period
from 2004 to 2018, in order to achieve visibility improvements at least
equivalent to the uniform rate of progress for the 20 percent worst
days at the Sipsey Wilderness Area, Alabama would need to project at
least 4.23 deciviews over the first implementation period (i.e., 0.302
deciviews x 14 years = 4.23 deciviews) of visibility improvement from
the 29.03 deciviews baseline in 2004, resulting in visibility levels at
or below 24.80 deciviews in 2018. As discussed below in section IV.C.7,
Alabama projects a 5.50 deciview improvement to visibility from the
29.03 deciview baseline to 23.53 deciviews in 2018 for the 20 percent
most impaired days, and a 1.35 deciview improvement to 14.22 deciviews
from the baseline visibility of 15.57 deciviews for the 20 percent
least impaired days.

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 the state
for achieving its RPGs. Alabama'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 Alabama 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 Alabama and in surrounding states that likely
have the largest impacts currently on visibility at the State's Class I
area; (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 area; 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 notice 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
reasonable progress goals. See 76 FR 82219 (December 30, 2011). In that
action, EPA proposed a limited disapproval of Alabama's regional haze
SIP submittal insofar as the SIP relied on CAIR. For that reason, EPA
is not taking action on that aspect of Alabama'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 Alabama. 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 Alabama's
regional haze analyses, Alabama 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 the 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 Alabama 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 Sipsey Wilderness Area. The control programs
relied upon by Alabama include CAIR; EPA's NOX SIP Call;
North Carolina's Clean Smokestacks Act; consent decrees for Tampa
Electric, Virginia Electric and Power Company, Gulf Power-Plant Crist,
Santee Cooper, East Kentucky Power Cooperative, and Alabama Power
Company-Plant Miller; a consent decree for Cargill, Inc.;
NOX and/or VOC reductions from the control rules in 1-hour
ozone SIPs for Atlanta, Birmingham, and Northern Kentucky; 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 emission 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 Alabama did not redo its
modeling analysis when the rule was re-issued. Even though the State's
modeling is based on the vacated Industrial Boiler MACT limits,
Alabama'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.,
0.2 to 0.5 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 emission limits would affect the adequacy of the
existing Alabama 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 on March
21, 2011 (76 FR 15608), EPA expects Alabama to do so in the State's
five-year progress report.
---------------------------------------------------------------------------

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

    Tables 2 and 3, below, summarize the 2002 baseline and 2018
estimated emissions inventories for Alabama.

                              Table 2--2002 Emissions Inventory Summary for Alabama
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                              VOC         NOX        PM2.5       PM10         NH3         SO2
----------------------------------------------------------------------------------------------------------------
Point...................................      49,332     244,348      23,291      32,886       2,200     544,309
Area....................................     207,952      34,172      98,671     440,663      60,007      54,462
On-Road Mobile..........................     127,295     158,212       2,799       3,903       5,588       6,900
Off-Road Mobile.........................      60,487      65,366       4,526       4,949          33       7,584
                                         -----------------------------------------------------------------------
    Total...............................     445,065     502,098     129,287     482,401      67,828     613,255
----------------------------------------------------------------------------------------------------------------

                              Table 3--2018 Emissions Inventory Summary for Alabama
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                              VOC         NOX        PM2.5       PM10         NH3         SO2
----------------------------------------------------------------------------------------------------------------
Point...................................      57,243     142,676      27,366      37,746       3,536     249,075
Area....................................     181,116      36,945     108,892     497,924      73,969      52,950
On-Road Mobile..........................      49,175      47,298       1,192       2,410       7,298         720
Off-road Mobile.........................      40,407      43,799       2,874       3,300          42       2,818
                                         -----------------------------------------------------------------------
    Total...............................     327,941     270,718     140,324     541,380      84,845     305,563
----------------------------------------------------------------------------------------------------------------

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 Alabama. 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 emission 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 12 x 12 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, the 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), Alabama provided EPA with
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 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 agree with the VISTAS model performance
procedures and results, and that the CMAQ is an appropriate tool for
the regional haze assessments for the Alabama 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 emission 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 roughly 75 percent to the calculated light
extinction on the haziest days for the Sipsey Wilderness Area. In
contrast, ammonium nitrate contributed less than five percent of the
calculated light extinction at 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. Alabama's Class I area is an ``inland'' 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. Alabama concluded that reducing
SO2 emissions from EGU and non-EGU point sources in the
VISTAS states would have the greatest visibility benefits for the
Sipsey Wilderness Area. 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 the
Sipsey Wilderness Area, the benefits of reducing NOX and
NH3 emissions at these sites is small.
    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 the Sipsey Wilderness Area. 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.
    Alabama considered the factors listed in 40 CFR 51.308(d)(3)(v) and
in section III.E of this action to develop its LTS as described below.
Alabama, 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 area in Alabama. The State
considered agricultural and forestry smoke management techniques to
address visibility impacts from elemental carbon. ADEM has an approved
smoke management program that addresses the issues laid out in EPA's
1998 Interim Air Quality Policy on Wildland and Prescribed Fires
available at: http://www.epa.gov/ttncaaa1/t1/memoranda/firefnl.pdf.
With regard to fine soils, the State considered those activities that
generate fugitive dust, including construction activities. Fine soil
particles are minor contributors to visibility at the Sipsey Wilderness
Area. With regard to construction activities, ADEM has issued
regulations (ADEM Admin. Code 335-3-4-.02) to control fugitive dust
from construction activities and to control particulates from fugitive
dust emissions sources generated within plant boundaries. 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, ADEM notes in its SIP that the State currently
has no regulations and there are currently no Federal regulations
related to the control of ammonia from animal feeding operations. Once
EPA has proposed regulations for these sources, ADEM will commit to
evaluating potential controls on applicable sources in Alabama.
    EPA preliminary 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 area, and
therefore, proposes to find that Alabama has adequately satisfied 40
CFR 51.308(d)(3)(v). EPA's TSD to this Federal Register action and
Alabama's SIP provide more details on the State's consideration of
these factors for Alabama'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 Alabama, the VISTAS sensitivity
analysis projects that visibility benefits in the Sipsey Wilderness
Area from SO2 reductions from Alabama's EGUs would have the
greatest visibility benefits in the Sipsey Wilderness Area.
Contributions from other VISTAS states, other RPOs, and from the
boundary conditions are smaller but not insignificant. Smaller benefits
are projected from additional SO2 emission reductions from
non-utility industrial point sources. Thus, controlling sources outside
of the VISTAS region is predicted to provide less significant
improvements in visibility in the Sipsey Wilderness area.
    Taking the VISTAS sensitivity analyses results into consideration,
Alabama concluded that reducing SO2 emissions from EGU and
non-EGU point sources in the VISTAS states would have the greatest
visibility benefits for the Sipsey Wilderness Area. The State chose to
focus solely on evaluating certain SO2 sources contributing
to visibility impairment to the State's Class I area 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 Alabama Class I area,
and proposes to find that the State's approach to focus on developing a
LTS that includes largely additional measures for point sources of
SO2 emissions is 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 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 Alabama 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 the Sipsey Wilderness Area in Alabama.
Utility and non-utility boilers are the main sources of SO2
emissions within the southeastern United States. VISTAS developed a
methodology for Alabama which enables the State to focus its reasonable
progress analysis on those geographic regions and source categories
that impact visibility at its Class I area. 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
Class I area that Alabama's sources impact, the State established a
threshold to determine which emissions units would be evaluated for
reasonable progress control. In applying this methodology, ADEM first
calculated the fractional contribution to visibility impairment from
all emissions units within the SO2 AOI for the Sipsey
Wilderness Area and those surrounding areas in other states potentially
impacted by emissions from emissions units in Alabama. 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'' as 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.
---------------------------------------------------------------------------

    Alabama's SO2 AOI methodology captured 55 percent of the
total point source SO2 contribution to visibility impairment
in the Class I area in Alabama and 61 to 73 percent of the total
contribution at the Class I areas in neighboring states, and required
an evaluation of 29 sources. Capturing a significantly greater
percentage of the total contribution would involve an evaluation of
many more emissions units that have substantially less impact. EPA
believes the approach developed by VISTAS and implemented for the Class
I area in Alabama is a reasonable methodology to prioritize the most
significant contributors to regional haze and to identify sources to
assess for reasonable progress control in the State's Class I area. EPA
proposes to find that the approach is consistent with the Agency's
Reasonable Progress Guidance. The technical approach of VISTAS and
Alabama was objective and based on several analyses, which included a
large universe of emissions units within and surrounding the State of
Alabama 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
    ADEM identified 29 emissions units at 12 facilities in Alabama (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 sulfate 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.\13\ Of these 29 units, 19
emissions units were already subject to CAIR, five units were subject
to BART, and one facility provided additional information documenting
that they had been improperly identified as meeting the State's minimum
threshold for reasonable progress evaluation. Using the expected costs
of controls for EGUs complying with CAIR as an indicator of what might
be reasonable for non-EGU sources, ADEM established a threshold of
$2,000 per ton of SO2 for controls. As explained in section
IV.C.5, 19 of these 29 emissions units were already subject to CAIR or
were determined to not have a reasonable expectation of having control
costs less than $2,000 per ton. Of the four emissions units, three
initially listed as having potential impacts on Class I areas in other
states were not identified by these states as impacting their Class I
areas.
---------------------------------------------------------------------------

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

   Table 4--Alabama Facilities Subject to Reasonable Progress Analysis
------------------------------------------------------------------------

-------------------------------------------------------------------------
Facility With a Unit Subject to Reasonable Progress Analysis:
    Cargill, Inc. Unit S-407
Facilities With Unit(s) Subject to CAIR Within AOI of Any Class I Area:
    Alabama Power Co--Barry Units 002, 003, 004, 005, 006
    Alabama Power Co--Gorgas Units 004, 005, 008
    Alabama Power Co--Gaston Unit 006
    Alabama Power Co--Miller Units 001, 002, 004, 005
    TVA--Colbert Unit 014
    TVA--Widows Creek, Units 002, 004, 005, 008, 009
Facilities With Unit(s) Found Not Subject to a Reasonable Progress
 Analysis:
    Non-EGUs Subject to BART
        Solutia, Inc. Units 009, 013, 014, 015
        International Paper Co. Unit 006
    Not Subject to Evaluation Based on Updated Information
        Akzo Nobel Chemicals Inc., Unit 003
    Analysis Not Required By Impacted State
        Escambia Operating Co (Exxon Mobile Co.) Unit 014
        Sanders Lead Co. Units 003, 008
------------------------------------------------------------------------

A. Facility With an Emissions Unit Subject to Reasonable Progress
Analysis

    ADEM analyzed whether SO2 controls should be required
for the Cargill, Inc., stoker boiler (S-407) 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 for the non-EGUs,
ADEM concluded that it was not equitable to require non-EGUs to bear a
greater economic burden than EGUs for a given control strategy. Using
CAIR as a guide, ADEM used a cost of $2,000 per ton of SO2
controlled or reduced as a threshold for cost effectiveness.
    Cargill's S-407 unit is permitted to burn coal, natural gas, or No.
2 fuel oil. Coal with a sulfur content of 1.2 to 1.3 pounds/million
British Thermal units (lb/MMBtu) is the primary fuel source. S-407
emits about 780 tons per year of SO2. Cargill evaluated
three control options: lower sulfur content coal, wet scrubbers, and
dry scrubbers. Lower sulfur content coal could not be used because of
its lack of availability. Also, even if lower sulfur western coal were
available, significant boiler modification would be necessary to burn
it and the coal would challenge the boiler's combustion integrity due
to its higher dust content. Therefore, lower sulfur coal was determined
to be technically infeasible. As for the add-on controls (wet and dry
scrubbers), Cargill estimated that it would cost $2,946/ton to control
SO2 with these technologies. Although no modeling was
submitted, Cargill also questioned whether S-407 contributed to
visibility impairment at the Sipsey Wilderness Area. Cargill submitted
a wind rose with five years of data from the nearby Huntsville,
Alabama, airport that indicates that winds coming from the northeast
blow from the facility toward the Sipsey Wilderness Area only three
percent of

the time. Based on Cargill's submittal, ADEM determined that none of
the evaluated controls are cost effective for this unit.
    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. In
determining reasonable progress, states must consider, at a minimum,
the four statutory factors, but states have flexibility in how to take
these factors into consideration.
    Alabama applied the methodology developed by VISTAS for identifying
appropriate sources to be considered for additional controls under
reasonable progress for the implementation period addressed by this
SIP, which ends in 2018. Using this methodology, ADEM first identified
those emissions and emissions units most likely to have an impact on
visibility in the State's Class I area. Units with emissions of
SO2 with a relative contribution of at least a one percent
to the visibility impairment at any Class I area were then subject to a
reasonable progress control analysis. As noted above, of the emissions
units in Alabama, one emissions unit at Cargill was subject to this
analysis. ADEM concluded, based on their evaluation of the Cargill
analyses, that no further controls were warranted at this time.
    After reviewing ADEM's methodology and analyses presented in the
SIP materials prepared by ADEM, EPA is proposing to approve Alabama's
conclusion that no further controls are necessary at this time for S-
407. EPA proposes to agree with the State's approach of identifying the
key pollutants contributing to visibility impairment at its Class I
area, and considers ADEM's methodology to identify sources of
SO2 most likely to have an impact on visibility on any Class
I area to be an appropriate methodology for narrowing the scope of the
State's analysis. In general, EPA also proposes to find Alabama's
evaluation of the four statutory factors for reasonable progress to be
reasonable. In addition, EPA proposes to find that ADEM fully evaluated
all control technologies available at the time of its analysis and
applicable to the one emissions unit at the Cargill facility. Although
the use of a specific threshold for assessing costs means that Alabama
may not have fully considered other available emissions reduction
measures above its threshold, EPA believes that the Alabama SIP still
ensures reasonable progress. In considering Alabama's approach, EPA is
also proposing to place great weight on the fact that there is no
indication in the SIP submittal that Alabama, 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 area. EPA notes that given the emissions reductions
resulting from CAIR, Alabama's BART determinations, and the measures in
nearby states, the visibility improvements projected for the affected
Class I area are in excess of that needed to be on the uniform rate of
progress.

B. Emissions Units Subject to CAIR Within AOI of Any Class I Area

    Nineteen emissions units identified for a reasonable progress
control analysis are EGUs and are subject to CAIR. These EGUs, located
at six facilities, are: Alabama Power Co--Barry Units 002, 003, 004,
005, 006; Alabama Power Co--Gorgas Units 004, 005, 008; Alabama Power
Co--Gaston Unit 006; Alabama Power Co--Miller Units 001, 002, 004, 005;
TVA--Colbert Unit 014; and TVA--Widows Creek, Units 002, 004, 005, 008,
009.
    In reaching this decision, ADEM considered the four reasonable
progress factors set forth in EPA's RHR as they apply to the State's
entire EGU sector (see section 7.6 of the Alabama SIP and section
III.C.2 of EPA's TSD for this action). 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 the analysis, ADEM
concluded that additional SO2 control measures, beyond those
needed to meet CAIR requirements, for Alabama's EGUs would not be
reasonable during this first implementation period based on a
consideration of the reasonable progress statutory factors. This
conclusion is bolstered by the fact that visibility improvement at the
Sipsey Wilderness Area is projected to exceed the uniform rate of
progress in this first implementation period. EPA proposes to find
acceptable Alabama's methodology and determination that no additional
controls beyond CAIR are reasonable for SO2 for affected
Alabama EGUs for the first implementation period.

C. Facilities With Unit(s) Found Not Subject to a Reasonable Progress
Analysis

    1. Non-EGUs Subject to BART.
    At both the International Paper-Courtland Mill and the Solutia,
Inc., facilities, all five units identified as being subject to
analysis for reasonable progress for the Sipsey Wilderness Area are
subject to BART and subsequently were evaluated for BART controls. ADEM
believes that BART is equivalent to reasonable progress for these five
units, and thus, is not requiring any additional controls for
reasonable progress. 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 agree with the State's conclusions
that BART satisfies reasonable progress for the first implementation
period for these five non-EGU emissions units at International Paper-
Courtland Mill and the Solutia facility.
---------------------------------------------------------------------------

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

    2. Other Units Found Not Subject to a Reasonable Progress Control
Analysis.
    Four other emissions units at three Alabama facilities were
determined to not be subject to a reasonable progress control analysis
(see Table 4). ADEM initially identified one emissions unit, a sulfuric
acid plant at the Akzo Nobel facility, which met the State's minimum
threshold for reasonable progress evaluation. ADEM determined that the
2018 projected SO2 emissions rate for Akzo Nobel's sulfuric
acid plant exceeded the allowable emissions rate for that unit. When
the analysis was revised to incorporate the allowable emissions rate,
the contribution from the sulfuric acid unit was below the State's one
percent contribution threshold for consideration.
    ADEM had initially determined that a sulfur recovery unit at
Escambia was contributing one percent or more to the sulfate visibility
impairment at the Breton Wilderness Area in Louisiana. It is the
responsibility of the state in which the Class I area resides to
determine which sources need to be assessed to evaluate for reasonable
progress for that state's Class I area. Subsequently, the State of
Louisiana completed its analyses for the Breton area and did not
identify this unit as meeting Louisiana's minimum threshold for
evaluation for reasonable progress, and did not request a reasonable
progress analysis for this source. Alabama also notes in its SIP that
this unit at Escambia took a permit limit of approximately 7,963 tons
of actual SO2 emissions (equivalent to approximately a 40
percent reduction in emissions) so

that it would not be subject to BART. The State issued a permit
enforcing this limit in 2006.
    For the St. Marks Wilderness area in Florida, ADEM initially
determined that two emissions units at the Sanders Lead Company met
Alabama's minimum threshold for reasonable progress evaluation.
Subsequently, the State of Florida completed its analyses and did not
identify these units as meeting its minimum threshold for evaluation
for reasonable progress and did not request a reasonable progress
analysis of these units. Based on consultations with the States of
Florida and Louisiana, Alabama conducted no further evaluation of the
three emissions units at Escambia and Sanders Lead.
6. BART
    BART is an element of Alabama'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
ADEM and ADEM'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. ADEM identified the
BART-eligible sources in Alabama 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 an area. See 70 FR 39160. VISTAS modeling
demonstrated that VOC from anthropogenic sources and ammonia from point
sources are not significant visibility-impairing pollutants in Alabama,
as discussed in section IV.C.3. of this action. Based on the VISTAS
modeling, analyses of spatial and temporal distributions of ammonia
concentrations indicate that 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.
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, Alabama required each of its BART-eligible sources to
develop and submit dispersion modeling to assess the extent of their
contribution to visibility impairment at surrounding Class I areas.
    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.'' The Guidelines state that 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). Alabama, in coordination with VISTAS, used the CALPUFF
modeling system to determine whether individual sources in Alabama were
subject to or exempt from 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 Alabama, 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 both the old and new IMPROVE equations. Alabama's
justification included a method to process the CALPUFF output and a
rationale on the benefits of using the new IMPROVE equation, in
Appendix B of its July 15, 2008, submittal.
    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.
    Alabama used a contribution threshold of 0.5 deciview for
determining which sources are subject to BART and concluded that the
threshold of 0.5 deciview was appropriate in this situation. ADEM
concluded that, considering the results of the visibility impacts
modeling conducted, a 0.5 deciview threshold was appropriate and a
lower threshold was not warranted since there is a clear spatial
variability of sources across the State. ADEM notes that it does not
have a technical justification for lowering the threshold based on
consideration of multiple plume interaction. In addition, there are a
limited number of BART-eligible sources in close proximity to Class I
areas. The State also believes that 0.5 deciview is sufficiently
stringent since it is half of the threshold established by EPA for
causing visibility impairment. As stated in the BART Guidelines, where
a state concludes that

a large number of these BART-eligible sources within proximity of a
Class I area justify a lower threshold, it may warrant establishing a
lower contribution threshold. See 70 FR 39161-39162 (July 6, 2005). EPA
proposes to agree with Alabama 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.
    Alabama identified 43 facilities with BART-eligible sources. All of
Alabama's 43 BART-eligible sources were required by the State to submit
BART exemption modeling demonstrations. Alabama found that three of its
BART-eligible sources, Solutia-Decatur, International Paper-Courtland,
and Escambia Operating Co-Big Escambia Creek, had modeled visibility
impacts of more than Alabama's 0.5 deciview threshold for BART
exemption. Escambia took permit limits to no longer be subject to BART.
Solution-Decatur and International Paper-Courtland are considered to be
subject to BART and submitted State permit applications including their
proposed BART determinations.
    Of the 41 exempted sources, three were exempted because they
emitted only VOC in excess of 250 tons per year, three accepted permit
limits which reduced their potential to emit to below 250 tons per year
of any affected pollutant, and one, Escambia, took permit limits that
reduced its impact to below 0.5 deciview.
    The 34 remaining sources are not subject to BART as they modeled
visibility impacts less than a 0.5 deciview at the affected Class I
areas. This modeling involved emissions of NOX,
SO2, and PM10, as applicable to individual
facilities. Eight of the 34 sources are power plants (i.e., Alabama
Electric Coop--Lowman, Alabama Power Co--Barry, Alabama Power Co--EC
Gaston, Alabama Power Co--Gorgas, Alabama Power Co--Greene Co, Alabama
Power Co--Miller, TVA--Colbert, and TVA--Widows Creek). Only
PM10 emissions were used in the modeling for EGU sources.
The SO2 and NOX BART-eligible emissions were not
modeled, because Alabama opted to have CAIR satisfy BART for
SO2 and NOX for affected CAIR EGUs, as allowed
under the regional haze regulations. The remaining 26 non-EGU sources
demonstrated that they are not subject to BART since they modeled less
than a 0.5 deciview visibility impact at the affected Class I areas.
Table 5 identifies the 43 BART-eligible sources located in Alabama and
identifies the two sources subject to BART.

       Table 5--Alabama BART-Eligible and Subject-to-BART Sources
------------------------------------------------------------------------

-------------------------------------------------------------------------
Facilities With Unit(s) Subject to BART:
    Solutia--Decatur
    International Paper Co--Courtland
Facilities With Unit(s) Not Subject to BART
    EGU CAIR and BART Modeling (PM only) Exempt Sources \16\
        Alabama Electric Coop--Lowman
        Alabama Power Co--Barry
        Alabama Power Co--EC Gaston
        Alabama Power Co--Gorgas
        Alabama Power Co--Greene Co
        Alabama Power Co--Miller
        TVA--Colbert
        TVA--Widows Creek
    Non-EGUs Exempt with Additional Model-Based Emissions Limits
        Escambia Operating Co--Big Escambia Creek
    Non-EGUs Exempt with Potential Emissions Limits below 250 Tons per
     Year
        Mobile Energy Services
        Rock Tenn (Gulf States Paper)
        Tronox, LLC (Kerr McGee Chemical)
    Non-EGU Exempt for VOC Only Emissions
        3M Company, Decatur Plant
        Ciba Specialty Chemicals Corp
        Wise Alloys LLC, Alloys Plant
    Non-EGUs Exempt by BART Modeling
        American Cast Iron Pipe
        Boise White Paper
        Bowater Inc.--Alabama
        BP Amoco Chemicals
        Carmeuse Lime & Stone
        CEMEX, Inc.
        Chemical Lime Co--Alabaster
        Chemical Lime Co--Montevallo
        ConocoPhillips Co--Chatom
        Degussa Corporation
        Ft James-Pennington--Naheola
        Hunt Refining Co--Tuscaloosa
        International Paper Co--Prattville
        International Paper Co--Riverdale
        JSC Brewton (Smurfit Stone)
        Lehigh Cement
        MeadWestvaco--Mahrt Mill
        National Cement Co of Alabama
        Oak Grove Resources
        Sanders Lead Co
        Shell Chemical Co--Saraland
        Sloss Industries
        US Pipe & Co--Bessemer

        US Steel--Fairfield
        Weyerhaeuser
        Vintage Petroleum, Inc.--Flomaton
------------------------------------------------------------------------

    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 Alabama 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.
---------------------------------------------------------------------------

    \16\ EGUs were only evaluated for PM emissions. Alabama 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.
---------------------------------------------------------------------------

    C. BART Determinations
    Three BART-eligible sources (i.e., Solutia-Decatur, International
Paper-Courtland, and Escambia-Big Escambia Creek) had modeled
visibility impacts of more than Alabama's 0.5 deciview threshold for
BART exemption. Escambia accepted permit limits to reduce its
visibility impacts to below 0.5 deciview. Only Solutia-Decatur and
International Paper-Courtland are therefore considered to be subject to
BART. Consequently, they each submitted permit applications to the
State that included their proposed BART determinations.
    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.
    1. Solutia--Decatur.
    Solutia--Decatur has five BART-eligible emissions units that
comprise the BART-eligible source. Boiler No. 5 is a 290 MMBtu per hour
(MMBtu/hr) coal-fired spreader-stoker boiler; Boiler No. 6 is a 320
MMBtu/hr coal-fired spreader-stoker boiler; Boiler No. 7 is a 536.1
MMBtu/hr pulverized coal-fired boiler; and Coking Boilers No. 1 and No.
2 are each 384 MMBtu/hr coal-fired stoker boilers. Each of the boilers
is equipped with an electrostatic precipitator (ESP) for particulate
control, and the boilers have SO2 emissions limits to
address modeled SO2 NAAQS exceedances in the area. In
addition, Solutia has installed a rotating opposed fired air system
(ROFA) combustion control to reduce NOX formation on Boiler
No. 7. The manufacturer has guaranteed a NOX reduction of 48
percent with the system. This unit is subject to New Source Performance
Standards, Subpart D. As required by Subpart D, this boiler has
limitations for particulate, SO2, and NOX
emissions.
    ADEM has concluded that no additional particulate controls would be
reasonable for the BART units at Solutia. For Boilers No. 5 and 6,
stack tests have shown an overall PM control efficiency for the ESPs to
be 98.8 percent. For Boiler 7, the PM control efficiency has been
estimated from stack tests as 99 percent. Although the coking boilers
have not been tested, the particulate control efficiency from the ESPs
has been estimated at 96 percent. ADEM evaluated the option of adding a
baghouse to each of the boilers and coking units following the existing
ESPs. The cost effectiveness of this control option ranged from $5,462
to $79,995 per ton of particulate and the visibility improvement for
the 98th percentile day ranged from 0.19 to 0.52 deciview.
    ADEM determined that no additional controls for Boiler 5, Boiler 6,
and the coking boilers would be required for the control of
NOX emissions for BART. However, Boiler 7 would be required
to meet an emission limit of 0.36 lb NOX/MMBtu with the
installation of a ROFA system or a comparable technology. Although the
basis for the installation of the ROFA system for Boiler No.7 was the
Boiler MACT, the system has been installed and was considered as
existing equipment for this case-by-case BART analysis. Solutia
evaluated additional control options for NOX. The available
combustion control options included low excess air, burners out of
service, biased burner firing, overfire air, low NOX
burners, and reburn. Available post-combustion control options included
selective non-catalytic reduction (SNCR) and selective catalytic
reduction (SCR). Modeling for all of the additional NOX
control options evaluated indicated relatively small to no reduction in
visibility impacts. No deciview improvements were modeled for the 98th
percentile day and only 0.04-0.07 deciview improvement was modeled on
the maximum high day.
    For the control of SO2, ADEM has determined BART for
Boilers 5 and 6 to be an emissions limit of 1.40 lbs SO2/
MMBtu. Boiler 7, the largest of the emissions units subject to BART,
would be required to meet a limitation of 0.47 lb SO2/MMBtu
with the installation of a flue solvent injection (FSI) system or a
comparable technology. ADEM concluded that the addition of any controls
for the coking units would negate the viability of the coking units;
therefore, no additional controls were proposed for these units.
Solutia evaluated the utilization of lower sulfur coals, and post-
combustion flue gas desulfurization (which would include sorbent
injection or wet scrubbers). The use of low sulfur coal (1.4 lbs
SO2/MMBtu) in Boilers 5 and 6 would provide a reduction of
approximately 43 percent. Currently, Boiler No. 7 is already required
to utilize low sulfur coal. Therefore, the utilization of lower sulfur
coal would only provide a reduction of seven percent. In combination
with the ROFA system, Solutia has a manufacturer guarantee that the use
of a FSI system would reduce SO2 by as much as 60 percent in
Boiler No. 7.
    EPA proposes to agree with Alabama's analyses and conclusions for
the BART emissions units located at this Solutia facility. EPA has
reviewed the ADEM analyses and concluded 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 this source.
    EPA reviewed the ADEM BART determination for Solutia--Decatur and
proposes to concur with Alabama's analyses and conclusions for BART for
this facility. EPA believes that the analyses were conducted consistent
with EPA's BART Guidelines and EPA's Air Pollution Control Cost Manual
and

that they reflect a reasonable application of EPA's guidance to this
source.
    2. International Paper--Courtland Mill.
    International Paper's Courtland Mill has seven BART-eligible
emissions units that comprise the BART-eligible source. No. 1
Combination Boiler is a 398 MMBtu/hr combination fuel boiler that fires
bark, natural gas, and fuel oil and is operated as a swing boiler. The
boiler vents to a venturi scrubber where the gases are scrubbed with
water to remove PM. No. 2 Combination Boiler is a 679 MMBtu/hr
combination fuel boiler that fires coal, bark, and natural gas. The
primary fuel for this boiler is bark. The other primary fuel for this
boiler is coal. The No. 2 Combination Boiler is vented to two ESPs to
remove PM. The flue gas is then vented to a high pressure venturi
scrubber for the removal of SO2. The Package Boiler is a 365
MMBtu/hr boiler that is utilized as a back-up boiler and is fired by
natural gas. The Package Boiler has no external emissions control
devices. The No. 2 Recovery Furnace is a 470 MMBtu/hr recovery furnace
that is designed to fire black liquor with natural gas and fuel oil as
supplemental fuels. The combustion gases from the furnace are vented to
an ESP for PM control. The No. 2 Smelt Dissolving Tank is a recovery
operation for the No. 2 Recovery Furnace. The No. 2 Smelt Dissolving
Tank is vented through a separate scrubber system for PM control. No. 1
and No. 2 Lime Kilns convert lime mud to lime. Both the No. 1 and No. 2
Lime Kilns are fired with natural gas and/or fuel oil, have low
NOX burners, and are vented to a scrubber to control
particulate emissions.
    ADEM concluded that BART for PM is the current suite of installed
add-on controls which control particulates at the International Paper-
Courtland mill and have efficiencies of greater than 90 percent.
    For SO2, ADEM determined no additional controls to be
BART. International Paper evaluated five control options for the No. 1
Combination Boiler and the No. 2 Recovery Boiler. For International
Paper-Courtland, the 98th percentile 24-hour visibility improvement
from the SO2 controls evaluated for these two units ranged
from 0.013 deciview to 0.063 deciview. The No.2 Combination Boiler is
already well controlled for SO2 and was not evaluated
further. Although both the Package Boiler and the No. 2 Smelt
Dissolving Tank are BART-eligible sources for SO2, a control
effectiveness review was not performed since both of these sources only
emit approximately one ton per year of SO2. The No. 1 and
No. 2 Lime Kilns are also BART-eligible sources for SO2.
However, since both these lime kilns are subject to and are complying
with MACT standard 40 CFR Part 63 Subpart MM through the use of wet
scrubbers, and since the inherent nature of lime kilns minimize
SO2 emissions, the current approach to MACT compliance was
considered BART for SO2 for these lime kilns.
    For NOX ADEM concluded that the control of
NOX is only reasonable for the No. 2 Combination Boiler,
which is required to install low NOX burners to meet BART.
Installation and operation of these burners is projected to result in a
30 percent reduction in the unit's emissions. For the No. 1 Combination
Boiler, ADEM required International Paper Courtland to either install
low NOX Burners or only operate the No. 1 Combination Boiler
when any of the No. 2 Combination Boiler, the No. 2 Recovery Furnace,
the No. 3 Combination Boiler, or the No. 3 Recovery Furnace is either
not operating or in periods of start-up of shutdown. International
Paper reviewed seven additional NOX control options for the
No. 1 and No. 2 Combination boilers and the Package Boiler. For
International Paper-Courtland, the 98th percentile 24-hour visibility
improvement from the evaluated NOX controls on these two
units ranged from 0.013 deciview to 0.097 deciview. For NOX,
both the No. 1 and No. 2 Lime Kilns currently employ low NOX
burners in the form of combustion flame tuning to reduce NOX
emissions and no other controls where deemed feasible. No additional
NOX controls were identified as being available for the No.
2 Recovery Boiler or the package natural gas boiler.
    EPA reviewed the ADEM BART determination for International Paper--
Courtland and proposes to concur with Alabama's analyses and
conclusions for BART for this facility. EPA believes that the analyses
were conducted consistent with EPA's BART Guidelines and EPA's Air
Pollution Control Cost Manual and that they reflect a reasonable
application of EPA's guidance to this source.
    3. Enforceability of Limits.
    Alabama adopted the BART emissions limits for Solutia-Decatur and
International Paper Co-Courtland Mill into the State's regional haze
SIP (see Tables 6 and 7). ADEM incorporated the BART emissions limits
into state operating permits and submitted copies of these BART permit
provisions for information as part of the State's regional haze SIP
(see Appendix H-5 of the Alabama regional haze submittal). The BART
emissions limits will also be added to the facilities' title V permits
according to the procedures established in 40 CFR part 70 or 40 CFR
part 71.

                          Table 6--Summary of BART Emissions Limits for Solutia-Decatur
----------------------------------------------------------------------------------------------------------------
                                                                  Emission limitations
            Emissions unit            --------------------------------------------------------------------------
                                                 NOX                      SO2                      PM10
----------------------------------------------------------------------------------------------------------------
Boiler 5.............................  101.22 lb/hr...........  1.40 lb/MMBtu & 406 lb/  0.12 lb/MMBtu & 34.8 lb/
                                                                 hr.                      hr.
Boiler 6.............................  109.72 lb/hr...........  1.40 lb/MMBtu & 448 lb/  0.12 lb/MMBtu & 38.4 lb/
                                                                 hr.                      hr.
Boiler 7.............................  0.36 lb/MMbtu & 193 lb/  0.47 lb/MMBtu & 252 lb/  0.10 lb/MMBtu & 64.33
                                        hr.                      hr.                      lb/hr.
Coker 1..............................  104.43 lb/hr...........  3.57 lb/MMBtu & 1,370.1  0.12 lb/MMBtu.
                                                                 lb/hr.
Coker 2..............................  104.43 lb/hr...........  3.57 lb/MMBtu & 1,370.1  0.12 lb/MMBtu.
                                                                 lb/hr.
----------------------------------------------------------------------------------------------------------------

                   Table 7--Summary of BART Emissions Limits for International Paper-Courtland
----------------------------------------------------------------------------------------------------------------
                                                                  Emission limitations
            Emissions unit            --------------------------------------------------------------------------
                                                 NOX                      SO2                      PM10
----------------------------------------------------------------------------------------------------------------
No. 1 Combination Boiler.............  93.15 lb/hr or           147.3 lb/hr............  0.17 gr/SDCF\17\ @ 50%
                                        operational                                       Excess Air.
                                        limitations.
No. 2 Combination Boiler.............  338.13 lb/hr...........  1.20 lb/MMBtu & 65.5 lb/ 0.10 lb/MMBtu.
                                                                 hr.
Package Boiler.......................  0.20 MMBtu &...........  1.80 lb/MMbtu..........  0.10 lb/MMBtu.
                                       <1,200 million ft\3\ of
                                        natural gas/12 month
                                        period.
No. 2 Recovery Furnace...............  152 lb/hr..............  432 lb/hr..............  0.044 gr/SDCF* at 8% O2
                                                                                and 67 lb/hr.
No. 2 Smelt Dissolving Tank..........  Not Applicable.........  0.20 lb/hr.............  0.20 lb/ton of black
                                                                                liquor solids.
No. 1 Lime Kiln......................  3.5 lb/hr..............  0.10 lb/hr.............  1.0 lb/air dried ton of
                                                                                pulp.
No. 2 Lime Kiln......................  19.40 lb/hr............  0.23 lb/hr.............  0.067 gr/sdcf at 10%.
----------------------------------------------------------------------------------------------------------------

    ADEM also adopted BART exemption provisions for Rock-Tenn Mill
Company, LLC (previously Gulf States Paper); Escambia Operating
Company, LLC; Mobile Energy Services Company, LLC; and Tronox LLC
(previously Kerr McGee Chemical), which were added to the operating
permits of these four facilities. Copies of these operating permits
were also included for information in Appendix H-5 of Alabama's
regional haze SIP submittal.
---------------------------------------------------------------------------

    \17\ The term, ``gr/SDCF,'' is the abbreviation used in the
Alabama regional haze SIP submittal for ``grains per dry standard
cubic foot.''
---------------------------------------------------------------------------

    The compliance date for the newly adopted limitations for Solutia-
Decatur, International Paper Co-Courtland Mill, and Escambia Operating
Company-Big Escambia Creek, is January 1, 2013. The BART exemption
provisions were effective upon issuance of the state permit.
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
Alabama Class I area 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 Alabama. Any controls resulting
from those determinations will provide additional emissions reductions
and resulting visibility improvement, which give further assurances
that Alabama will achieve its RPGs. The modeling demonstrates that the
2018 base control scenario provides for an improvement in visibility
better than the uniform rate of progress for the Sipsey Wilderness Area
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.
    As shown in Table 8 below, Alabama's RPG for the 20 percent worst
days provide greater visibility improvement by 2018 than the uniform
rate of progress for the State's Class I area (i.e., 24.80 deciviews in
2018). Also, the RPG for the 20 percent best days provides greater
visibility improvement by 2018 than current best day conditions. The
modeling supporting the analysis of these RPGs is consistent with EPA
guidance prior to the CAIR remand. 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 Alabama, took into account
emissions reductions anticipated from CAIR in determining their 2018
RPGs.\18\ Reliance on CAIR as part of a state's LTS to achieve the
state-adopted RPGs is discussed in section IV.C of this action.
---------------------------------------------------------------------------

    \18\ Many of the CAIR states without Class I areas similarly
relied on CAIR emission 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 8--Alabama 2018 RPGs
                                                 [In deciviews]
----------------------------------------------------------------------------------------------------------------
                                                   2018 RPG--20    Uniform rate                    2018 RPG--20
                                     Baseline      percent worst  of progress at     Baseline      percent best
          Class I Area             visibility--        days          2018-- 20     visibility--        days
                                    20 percent     (improvement    percent worst    20 percent     (improvement
                                    worst days    from baseline)       days          best days    from baseline)
----------------------------------------------------------------------------------------------------------------
Sipsey Wilderness Area..........           29.03    23.53 (5.50)           24.80           15.57    14.22 (1.35)
----------------------------------------------------------------------------------------------------------------

    The RPGs for the Class I area in Alabama are based on modeled
projections of future conditions that were developed using the best
available information at the time the analysis was done. These
projections can be expected to change as additional information
regarding future conditions becomes available. For example, new sources
may be built, existing sources may shut down or modify production in
response to changed economic circumstances,

and facilities may change their emissions characteristics as they
install control equipment to comply with new rules. It would be both
impractical and resource-intensive to require a state to continually
revise the RPGs every time an event affecting these future projections
changed.
    EPA recognized the problems of a rigid requirement to meet a long-
term goal based on modeled projections of future visibility conditions,
and addressed the uncertainties associated with RPGs in several ways.
EPA made clear in the RHR that the RPG is not a mandatory standard
which must be achieved by a particular date. See 64 FR at 35733. At the
same time, EPA established a requirement for a midcourse review and, if
necessary, correction of the states' regional haze plans. See 40 CFR
52.308(g). In particular, the RHR calls for a five-year progress review
after submittal of the initial regional haze plan. The purpose of this
progress review is to assess the effectiveness of emissions management
strategies in meeting the RPGs and to provide an assessment of whether
current implementation strategies are sufficient for the state or
affected states to meet their RPGs. If a state concludes, based on its
assessment, that the RPGs for a Class I area will not be met, the RHR
requires the state to take appropriate action. See 40 CFR 52.308(h).
The nature of the appropriate action will depend on the basis for the
state's conclusion that the current strategies are insufficient to meet
the RPGs. Alabama specifically committed to follow this process in the
LTS portion of its submittal. Accordingly, EPA proposes to approve
Alabama's RPGs for the Sipsey Wilderness Area.

D. Coordination of RAVI and Regional Haze Requirements

    EPA's visibility regulations direct states to coordinate their RAVI