Document ID: EPA-R08-OAR-2011-0870-0001
Agency: epa
Document Type: Proposed Rule
Title: Approval and Promulgation of Implementation Plans; South Dakota: Regional Haze State Implementation Plan
Posted Date: 2011-12-08T05:00Z

[Federal Register Volume 76, Number 236 (Thursday, December 8, 2011)]
[Proposed Rules]
[Pages 76646-76673]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-31406]

=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2011-0870; FRL-9501-4]

Approval and Promulgation of Implementation Plans; South Dakota; 
Regional Haze State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: EPA is proposing to approve a revision to the South Dakota 
State Implementation Plan (SIP) addressing regional haze submitted by 
the State of South Dakota on January 21, 2011, as amended by a 
submittal received on September 19, 2011. This SIP revision was 
submitted to address the requirements of the Clean Air Act (CAA or Act) 
and our rules that require states to prevent any future and remedy any 
existing man-made impairment of visibility in mandatory Class I areas 
caused by emissions of air pollutants from numerous sources located 
over a wide geographic area (also referred to as the ``regional haze 
program'').

DATES: Comments: Comments must be received on or before February 6, 
2012.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2011-0870, by one of the following methods:
     http://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     Email: fallon.gail@epa.gov.
     Fax: (303) 312-6064 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT section if you are faxing 
comments).
     Mail: Director, Air Program, Environmental Protection 
Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, Denver, 
Colorado 80202-1129.
     Hand Delivery: Director, Air Program, Environmental 
Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129. Such deliveries are only accepted Monday 
through Friday, 8 a.m. to 4:30 p.m., excluding Federal holidays. 
Special arrangements should be made for deliveries of boxed 
information.
    Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-
2011-0870. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://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 information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://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 e-mail comment directly to EPA, without 
going through http://www.regulations.gov, your e-mail 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. The Regional Office's official hours of 
business are Monday through Friday, 8:30-4:30 p.m., excluding Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Gail Fallon, EPA Region 8, at (303) 
312-6281, or fallon.gail@epa.gov.

SUPPLEMENTARY INFORMATION:

Definitions

    For the purpose of this document, we are giving meaning to certain 
words or initials as follows:
    (i) The words or initials Act or CAA mean or refer to the Clean Air 
Act, unless the context indicates otherwise.
    (ii) The words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.
    (iii) The initials SIP mean or refer to State Implementation Plan.
    (iv) The initials NAAQS mean or refer to National Ambient Air 
Quality Standards.
    (v) The words South Dakota and State mean the State of South 
Dakota.

Table of Contents

I. Background
    A. Regional Haze
    B. Roles of Agencies in Addressing Regional Haze
II. Requirements for Regional Haze SIPs
    A. The CAA and the Regional Haze Rule
    B. Determination of Baseline, Natural and Current Visibility 
Conditions

[[Page 76647]]

    C. Determination of Reasonable Progress Goals
    D. Best Available Retrofit Technology (BART)
    E. Long-Term Strategy (LTS)
    F. Coordinating Regional Haze and Reasonably Attributable 
Visibility Impairment (RAVI)
    G. Monitoring Strategy and Other SIP Requirements
    H. Consultation With States and Federal Land Managers (FLMs)
III. Our Evaluation of South Dakota's Regional Haze SIP
    A. Affected Class I Areas
    B. Determination of Baseline, Natural and Current Visibility 
Conditions
    1. Estimating Natural Visibility Conditions
    2. Estimating Baseline Visibility Conditions
    3. Natural Visibility Impairment
    4. Uniform Rate of Progress
    C. BART
    1. Identification of BART-Eligible Sources
    2. Identification of Sources Subject to BART
    a. Modeling Methodology
    b. Contribution Threshold
    c. Sources Identified by South Dakota as Subject to BART
    3. BART Determinations and Federally Enforceable Limits
    a. Otter Tail Power Company, Big Stone I
    b. South Dakota's BART Results and Summary
    D. Evaluation of South Dakota's Reasonable Progress Goals
    1. WRAP Visibility Modeling
    2. Reasonable Progress ``Four-Factor'' Analyses
    3. South Dakota's Conclusions From the Four-Factor Analysis
    4. Establishment of the Reasonable Progress Goals
    5. Reasonable Progress Consultation
    6. Our Conclusion on South Dakota's Reasonable Progress Goals
    E. LTS
    1. Emissions Inventories
    2. Sources of Visibility Impairment in South Dakota Class I 
Areas
    3. Visibility Projection Modeling
    4. Consultation and Emissions Reductions for Other States' Class 
I Areas
    5. Mandatory LTS Factors
    a. Reductions Due to Ongoing Air Pollution Programs
    b. Measures To Mitigate the Impacts of Construction Activities
    c. Emission Limitation and Schedules of Compliance
    d. Source Retirement and Replacement Schedules
    e. Agricultural and Forestry Smoke Management Techniques
    f. Enforceability of South Dakota's Measures
    g. Anticipated Net Effect on Visibility Due to Projected Changes
    6. Our Conclusion on South Dakota's LTS
    F. Coordination of RAVI and Regional Haze Requirements
    G. Monitoring Strategy and Other SIP Requirements
    H. FLM Coordination
    I. Periodic SIP Revisions and Five-Year Progress Reports
IV. Proposed Action
V. Statutory and Executive Order Reviews

I. Background

A. Regional Haze

    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 particulate matter with a diameter less than 
2.5 microns (PM2.5) (e.g., sulfates, nitrates, organic 
carbon (OC), elemental carbon (EC) and soil dust) and its precursors 
(e.g., sulfur dioxide (SO2), nitrogen oxides 
(NOX), and in some cases, ammonia (NH3) and 
volatile organic compounds (VOCs)). These precursors react in the 
atmosphere to form PM2.5. PM2.5 impairs 
visibility by scattering and absorbing light. Visibility impairment 
reduces the clarity, color and visible distance that one can see. 
PM2.5 also can cause serious health effects and mortality in 
humans and contributes to environmental effects such as acid deposition 
and eutrophication.
    Data from 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 \1\ 
in many Class I areas (i.e., national parks, 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. 64 FR 35714, 35715 (July 1, 1999). 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. Id.
---------------------------------------------------------------------------

    \1\ Visual range is the greatest distance, in kilometers or 
miles, at which a dark object can be viewed against the sky.
---------------------------------------------------------------------------

    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 federal areas \2\ which 
impairment results from man-made air pollution.'' CAA Sec.  169A(a)(1). 
The terms ``impairment of visibility'' and ``visibility impairment'' 
are defined in the Act to include a reduction in visual range and 
atmospheric discoloration. Id. section 169A(g)(6). In 1980, we 
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., ``RAVI.'' 45 FR 80084 (December 2, 1980). These 
regulations represented the first phase in addressing visibility 
impairment. We 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 
had improved.
---------------------------------------------------------------------------

    \2\ Areas designated as mandatory Class I Federal areas consist 
of national parks exceeding 6000 acres, wilderness areas and 
national memorial parks exceeding 5000 acres, and all international 
parks that were in existence on August 7, 1977. See CAA section 
162(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. CAA section 162(a). Although states and tribes may 
designate as Class I additional areas which they consider to have 
visibility as an important value, the requirements of the visibility 
program set forth in section 169A of the CAA apply only to 
``mandatory Class I federal areas.'' Each mandatory Class I Federal 
area is the responsibility of an FLM. See CAA section 302(i). When 
we use the term ``Class I area'' in this action, we mean a 
``mandatory Class I federal area.''
---------------------------------------------------------------------------

    Congress added section 169B to the CAA in 1990 to address regional 
haze issues, and we promulgated regulations addressing regional haze in 
1999. 64 FR 35714 (July 1, 1999), codified at 40 CFR part 51, subpart 
P. The Regional Haze Rule revised the existing visibility regulations 
to integrate into them provisions addressing regional haze impairment 
and establish 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 our visibility protection regulations at 40 CFR 
51.300-309. Some of the main regional haze requirements are summarized 
in section II of this action. The requirement to submit a Regional Haze 
SIP applies to all 50 states, the District of Columbia and the Virgin 
Islands. States were required to submit a SIP addressing regional haze 
visibility impairment no later than December 17, 2007.\3\ 40 CFR 
51.308(b).
---------------------------------------------------------------------------

    \3\ EPA's regional haze regulations require subsequent updates 
to the regional haze SIPs. 40 CFR 51.308(g)-(i).
---------------------------------------------------------------------------

    Few states submitted a Regional Haze SIP prior to the December 17, 
2007 deadline, and on January 15, 2009, EPA found that 37 states, 
including South Dakota and the District of Columbia, and the Virgin 
Islands, had failed to submit SIPs addressing the regional

[[Page 76648]]

haze requirements. 74 FR 2392. Once EPA has found that a state has 
failed to make a required submission, EPA is required to promulgate a 
FIP within two years unless the state submits a SIP and the Agency 
approves it within the two year period. CAA Sec.  110(c)(1).

B. 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. 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, we have encouraged 
the states and tribes across the United States to address visibility 
impairment from a regional perspective. Five regional planning 
organizations (RPOs) were formed 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 Western Regional Air Program (WRAP) is a collaborative effort 
of state governments, tribal governments and various Federal agencies 
established to conduct data analyses, conduct pollutant transport 
modeling and coordinate planning activities among the western states. 
Member state governments include: Alaska, Arizona, California, 
Colorado, Idaho, Montana, New Mexico, North Dakota, Oregon, South 
Dakota, Utah, Washington and Wyoming. Tribal members include Campo Band 
of Kumeyaay Indians, Confederated Salish and Kootenai Tribes, Cortina 
Indian Rancheria, Hopi Tribe, Hualapai Nation of the Grand Canyon, 
Native Village of Shungnak, Nez Perce Tribe, Northern Cheyenne Tribe, 
Pueblo of Acoma, Pueblo of San Felipe and the Shoshone-Bannock Tribe of 
Fort Hall.

II. Requirements for Regional Haze SIPs

    The following is a summary of the requirements of the Regional Haze 
Rule. See 40 CFR 51.308 for further detail regarding the requirements 
of the rule.

A. The CAA and the Regional Haze Rule

    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 our 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 Best Available 
Retrofit Technology (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 Regional Haze Rule establishes the deciview (dv) as the 
principal metric for measuring visibility. See 70 FR 39104, 39118. This 
visibility metric expresses uniform changes in the degree of haze in 
terms of common increments across the entire range of visibility 
conditions, from pristine to extremely hazy conditions. Visibility is 
sometimes expressed in terms of the visual range, which is the greatest 
distance in kilometers or miles at which a dark object can just be 
distinguished against the sky. The deciview is a useful measure for 
tracking progress in improving visibility, because each deciview change 
is an equal incremental change in visibility perceived by the human 
eye. Most people can detect a change in visibility of one deciview.\4\
---------------------------------------------------------------------------

    \4\ The preamble to the Regional Haze Rule provides additional 
details about the deciview. 64 FR 35714, 35725 (July 1, 1999).
---------------------------------------------------------------------------

    The deciview is used in expressing reasonable progress goals (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 man-made air pollution by reducing anthropogenic emissions 
that cause regional haze. The national goal is a return to natural 
conditions, i.e., man-made sources of air pollution would no longer 
impair visibility in Class I areas.
    To track changes in visibility over time at each of the 156 Class I 
areas covered by the visibility program (40 CFR 81.401-437), and as 
part of the process for determining reasonable progress, states must 
calculate the degree of existing visibility impairment at each Class I 
area at the time of each Regional Haze SIP submittal and periodically 
review progress every five years midway through each 10-year 
implementation period. To do this, the Regional Haze Rule requires 
states to determine the degree of impairment (in deciviews) for the 
average of the 20 percent least impaired (``best'') and the average of 
the 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. We have provided guidance to 
states regarding how to calculate baseline, natural and current 
visibility conditions.\5\
---------------------------------------------------------------------------

    \5\ Guidance for Estimating Natural Visibility Conditions Under 
the Regional Haze Rule, September 2003, EPA-454/B-03-005, available 
at http://www.epa.gov/ttncaaa1/t1/memoranda/RegionalHaze _
envcurhr_gd.pdf, (hereinafter referred to as ``our 2003 Natural 
Visibility Guidance''); and Guidance for Tracking Progress Under the 
Regional Haze Rule, (September 2003, EPA-454/B-03-004, available at 
http://www.epa.gov/ttncaaa1/t1/memoranda/rh_tpurhr_gd.pdf, 
(hereinafter referred to as our ``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.

[[Page 76649]]

C. Determination of Reasonable Progress Goals

    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 reasonable progress goals 
(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. See 40 CFR 51.308(d), (f). The Regional Haze 
Rule 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 reasonable progress goals, 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. Id.
    In establishing reasonable progress goals, states are required to 
consider the following factors established in section 169A of the CAA 
and in our Regional Haze Rule 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 reasonable progress goals for the best and worst days for 
each applicable Class I area. In setting the reasonable progress goals, 
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 ``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. 
If a state establishes a reasonable progress goal that provides for a 
slower rate of improvement in visibility than the rate that would be 
needed to attain natural conditions by 2064, the state must 
demonstrate, based on the reasonable progress factors, that the rate of 
progress for the implementation plan to attain natural conditions by 
2064 is not reasonable, and that the progress goal adopted by the state 
is reasonable. In setting reasonable progress goals, 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 
emission sources that may be affecting visibility impairment at the 
state's Class I areas. 40 CFR 51.308(d)(1)(iv). In determining whether 
a state's goals for visibility improvement provide for reasonable 
progress toward natural visibility conditions, EPA is required to 
evaluate the demonstrations developed by the state pursuant to 
paragraphs 40 CFR 51.308(d)(1)(i) and (d)(1)(ii). 40 CFR 
51.308(d)(1)(iii).

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 with the potential to emit 250 tons or more per year 
of any pollutant in order to address visibility impacts from these 
sources. Specifically, section 169A(b)(2)(A) of the Act 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 \6\ built between 1962 and 1977 procure, install and operate 
BART as determined by the state or by EPA in the case of a plan 
promulgated under section 110(c) of the CAA. Under the Regional Haze 
Rule, 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.
---------------------------------------------------------------------------

    \6\ The ``major stationary sources'' potentially subject to BART 
are listed in CAA section 169A(g)(7).
---------------------------------------------------------------------------

    On July 6, 2005, we published the Guidelines for BART 
Determinations Under the Regional Haze Rule at appendix Y to 40 CFR 
part 51 (``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. 70 
FR 39104. In making a BART determination for a fossil fuel-fired 
electric generating plant with a total generating capacity in excess of 
750 megawatts (MW), a state must use the approach set forth in the BART 
Guidelines. A state is encouraged, but not required, to follow the BART 
Guidelines in making BART determinations for other types of sources. 
Regardless of source size or type, a state must meet the requirements 
of the CAA and our regulations for selection of BART, and the state's 
BART analysis and determination must be reasonable in light of the 
overarching purpose of the regional haze program.
    The process of establishing BART emission limitations can be 
logically broken down into three steps: First, states identify those 
sources which meet the definition of ``BART-eligible source'' set forth 
in 40 CFR 51.301 \7\; second, states determine which of such sources 
``emits any air pollutant which may reasonably be anticipated to cause 
or contribute to any impairment of visibility in any such area'' (a 
source which fits this description is ``subject to BART''); and third, 
for each source subject to BART, states then identify the best 
available type and level of control for reducing emissions.
---------------------------------------------------------------------------

    \7\ BART-eligible sources are those sources that have the 
potential to emit 250 tons or more of a visibility-impairing air 
pollutant, were not in operation prior to August 7, 1962, but were 
in existence on August 7, 1977, and whose operations fall within one 
or more of 26 specifically listed source categories. 40 CFR 51.301.
---------------------------------------------------------------------------

    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. We have stated that states should use their best judgment in 
determining whether VOC or NH3 compounds impair visibility 
in Class I areas.
    Under the BART Guidelines, states may select an exemption threshold 
value for their BART modeling, below which a BART-eligible source would 
not be expected to cause or contribute to visibility impairment in any 
Class I area. The state must document this exemption threshold value in 
the SIP and must state the basis for its selection of that value. Any 
source with emissions that model above the threshold value would be 
subject to a BART determination review. The BART Guidelines acknowledge 
varying circumstances affecting different Class I areas. States should 
consider the number of emission sources affecting the Class I areas at 
issue and the magnitude of the individual sources' impacts. Any 
exemption threshold set by the state should not be higher than 0.5 
deciviews. 40 CFR part 51, appendix Y, section III.A.1.
    In their SIPs, states must identify ``BART-eligible sources'' and 
``subject-to-BART sources'' and document their

[[Page 76650]]

BART control determination analyses. The term ``BART-eligible source'' 
used in the BART Guidelines means the collection of individual emission 
units at a facility that together comprises the BART-eligible source. 
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. See also 40 CFR 
51.308(e)(1)(ii)(A).
    A Regional Haze SIP must include source-specific BART emission 
limits and compliance schedules for each source subject to BART. Once a 
state has made its BART determination, the BART controls must be 
installed and in operation as expeditiously as practicable, but no 
later than five years after the date of our approval of the Regional 
Haze SIP. CAA section 169(g)(4) and 40 CFR 51.308(e)(1)(iv). In 
addition to what is required by the Regional Haze Rule, 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. See CAA section 110(a). As noted 
above, the Regional Haze Rule 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.

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 Regional Haze 
Rule requires that states include a long term strategy (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 reasonable progress goals. 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. 
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(s) located in 
another state or states, the Regional Haze Rule requires the state to 
consult with the other state(s) in order to develop coordinated 
emissions management strategies. 40 CFR 51.308(d)(3)(i). Also, a state 
with a Class I area impacted by emissions from another state must 
consult with such contributing state, and must also demonstrate that it 
has included in its SIP all measures necessary to obtain its share of 
the emission reductions needed to meet the reasonable progress goals 
for the Class I area. Id. at (d)(3)(ii). The RPOs have provided a forum 
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 reasonably 
attributable visibility impairment (RAVI); (2) measures to mitigate the 
impacts of construction activities; (3) emissions limitations and 
schedules for compliance to achieve the reasonable progress goals; (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. 40 CFR 51.308(d)(3)(v).

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

    As part of the Regional Haze Rule, we 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 and periodic progress reports 
evaluating progress towards reasonable progress goals, 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 and must be submitted to us as a SIP revision.

G. Monitoring Strategy and Other SIP Requirements

    Section 51.308(d)(4) of the Regional Haze Rule 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 Federal 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 
reasonable progress goals will be met.
    Under section 51.308(d)(4), 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;
     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 Regional Haze Rule requires control strategies to cover an 
initial implementation period extending to the

[[Page 76651]]

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). 
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 Regional Haze Rule requires that states consult with Federal 
land managers (FLMs) before adopting and submitting their SIPs. 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 reasonable 
progress goals 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.

III. Our Evaluation of South Dakota's Regional Haze SIP

    The State of South Dakota submitted a revision to its SIP to 
address the requirements for regional haze on January 21, 2011. On 
September 19, 2011, South Dakota submitted an amendment to the Regional 
Haze SIP revision for approval into the South Dakota SIP. The amendment 
incorporated changes made by the State to ensure approvability of the 
SIP revision. The changes incorporated detailed monitoring, 
recordkeeping, and reporting requirements for BART sources into state 
regulation, Administrative Rules of South Dakota (ARSD) Chapter 
74:36:21, including specifying that BART limits apply at all times and 
clarified compliance test methods for particulate matter and continuous 
emission monitoring system requirements for SO2 and 
NOX. In addition, South Dakota revised the reasonable 
progress analysis for the GCC Dacotah cement plant. The following is a 
discussion of our evaluation of the revision.

A. Affected Class I Areas

    In accordance with 40 CFR 51.308(d), South Dakota identified two 
Class I areas within its borders: Badlands National Park and Wind Cave 
National Park. South Dakota is responsible for developing reasonable 
progress goals for these two Class I areas. South Dakota emissions have 
or may reasonably be expected to have impacts at Class I areas in other 
states including: Boundary Waters Canoe Area Wilderness Area and 
Voyageurs National Park in Minnesota; Medicine Lake National Wildlife 
Refuge Wilderness Area and UL Bend National Wildlife Refuge Wilderness 
Area in Montana; Bridger Wilderness Area, Fitzpatrick Wilderness Area, 
Grand Teton National Park, Teton Wilderness Area, North Absaroka 
Wilderness Area, Washakie Wilderness Area and Yellowstone National Park 
in Wyoming; and Theodore Roosevelt National Park and Lostwood 
Wilderness Area in North Dakota. South Dakota consulted with the 
appropriate state air quality agency in each of these states through 
their involvement with the WRAP and worked with other states that are 
not members of WRAP (including Minnesota and Nebraska). Assessment of 
South Dakota's contribution to haze in these Class I areas is based on 
technical analyses developed by WRAP.

B. Determination of Baseline, Natural and Current Visibility Conditions

    As required by section 51.308(d)(2)(i) of the Regional Haze Rule 
and in accordance with our 2003 Natural Visibility Guidance, South 
Dakota calculated baseline/current and natural visibility conditions 
for its Class I areas, Badlands and Wind Cave, on the most impaired and 
least impaired days, as summarized below. The natural visibility 
conditions, baseline visibility conditions and visibility impact 
reductions needed to achieve the uniform rate of progress in 2018 for 
both South Dakota Class I areas are presented in Table 1 and further 
explained in this section. More detail is available in Section 3 of the 
South Dakota SIP.\8\
---------------------------------------------------------------------------

    \8\ The visibility and uniform rate of progress calculations 
presented in Table 1 and elsewhere in section III.B represent 
corrections EPA made to minor math errors in the visibility results 
South Dakota presented in the SIP and which the State agrees will be 
corrected with the next routine revision of the SIP. Our corrections 
are included in the docket in a spreadsheet entitled, EPA-R08-OAR-
2011-0870 South Dakota Regional Haze Proposal Section III.B 
Visibility Conditions Corrections.

  Table 1--Visibility Impact Reductions Needed Based on Best and Worst Days Baselines, Natural Conditions and Uniform Rate of Progress (URP) Goals for
                                                               South Dakota Class I Areas
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  20% Worst days                                   20% Best days
                                                         -----------------------------------------------------------------------------------------------
                South Dakota Class I area                                                 2018 Reduction   2064 Natural                    2064 Natural
                                                             2000-2004     2018 URP Goal   needed (delta    conditions       2000-2004      conditions
                                                           Baseline (dv)       (dv)             dv)            (dv)        Baseline (dv)       (dv)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Badlands................................................           17.14           15.02            2.12            8.06            6.89            2.86
National Park...........................................
Wind Cave...............................................           15.84           13.94            1.90            7.71            5.14            1.88
National Park...........................................
--------------------------------------------------------------------------------------------------------------------------------------------------------

1. Estimating Natural Visibility Conditions
    Natural background visibility as defined in our 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).

[[Page 76652]]

As documented in our 2003 Natural Visibility Guidance, EPA allows 
states to use ``refined'' or alternative approaches to this guidance to 
estimate the values that characterize the natural visibility conditions 
of 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.\9\ 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.
---------------------------------------------------------------------------

    \9\ 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 emission 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.
---------------------------------------------------------------------------

    For Badlands and Wind Cave, South Dakota opted to use the revised 
IMPROVE equation to calculate natural background conditions. This is an 
acceptable approach under our 2003 Natural Visibility Guidance. EPA has 
found the use of the revised IMPROVE equation appropriate for WRAP 
states.\10\ For Badlands, the natural visibility background for the 20 
percent worst days is 8.06 deciviews and for the 20 percent best days 
is 2.86 deciviews. For Wind Cave, the natural visibility result for the 
20 percent worst days is 7.71 deciviews and for the 20 percent best 
days is 1.88 deciviews. We have reviewed South Dakota's estimates of 
the natural visibility conditions and as the approach used by the State 
was consistent with our 2003 Natural Visibility Guidance we are 
proposing to find them acceptable.
---------------------------------------------------------------------------

    \10\ The science behind the revised IMPROVE equation is 
summarized in a document entitled, Technical Support Document for 
Technical Products Prepared by the Western Regional Air Partnership 
(WRAP) in Support of Western Regional Haze Plans, February 28, 2011, 
(hereinafter referred to as EPA WRAP Technical Support Document and 
available in the docket) and in numerous published papers. See for 
example: 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 IMPROVE, Colorado State University, 
Cooperative Institute for Research in the Atmosphere, Fort Collins, 
Colorado, available at http://vista.cira.colostate.edu/improve/publications/GrayLit/016_IMPROVEeqReview/IMPROVEeqReview.htmand 
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, available at 
http://vista.cira.colostate.edu/improve/Publications/GrayLit/029_NaturalCondII/naturalhazelevelsIIreport.ppt.
---------------------------------------------------------------------------

2. Estimating Baseline Visibility Conditions
    As required by section 51.308(d)(2)(i) of the Regional Haze Rule, 
South Dakota calculated baseline visibility conditions for Badlands and 
Wind Cave. The baseline condition calculation begins with the 
calculation of light extinction using the IMPROVE equation. The IMPROVE 
equation sums the light extinction \11\ resulting from individual 
pollutants, such as sulfates and nitrates. As with the natural 
visibility conditions calculation, South Dakota chose to use the 
revised IMPROVE equation.
---------------------------------------------------------------------------

    \11\ The amount of light lost as it travels over one million 
meters. The haze index, in units of dv, is calculated directly from 
the total light extinction, bext expressed in inverse 
megameters (Mm-1), as follows: HI = 10 
ln(bext/10).
---------------------------------------------------------------------------

    The period for establishing baseline visibility conditions is 2000-
2004, and baseline conditions must be calculated using available 
monitoring data. 40 CFR 51.308(d)(2). The South Dakota Regional Haze 
SIP employed visibility monitoring data collected by IMPROVE monitors 
located in both South Dakota Class I areas for the years 2000 through 
2004 and the resulting baseline conditions represent an average for 
2000-2004. South Dakota calculated the baseline conditions at Badlands 
as 17.14 deciviews on the 20 percent worst days, and 6.89 deciviews on 
the 20 percent best days. South Dakota calculated the baseline 
conditions at Wind Cave as 15.84 deciviews on the 20 percent worst 
days, and 5.14 deciviews on the 20 percent best days. We have reviewed 
South Dakota's estimations of baseline visibility conditions and 
propose to find these acceptable as the approach the State used was 
consistent with our 2003 Natural Visibility Guidance.
3. Natural Visibility Impairment
    To address the requirements of 40 CFR 51.308(d)(2)(iv)(A), South 
Dakota also calculated the number of deciviews by which baseline 
conditions exceed natural visibility conditions at Badlands and Wind 
Cave. For Badlands, baseline conditions exceed natural conditions by 
9.08 deciviews (17.14-8.06) for the 20 percent worst days and 4.03 
deciviews (6.89-2.86) for the 20 percent best days. For Wind Cave, 
these figures are 8.13 (15.84-7.71) and 3.26 deciviews (5.14-1.88), 
respectively.
4. Uniform Rate of Progress
    In setting the reasonable progress goals, South Dakota analyzed and 
determined the uniform rate of progress needed to reach natural 
visibility conditions by the year 2064. In so doing, South Dakota 
compared the baseline visibility conditions in Badlands and Wind Cave 
to the natural visibility conditions in Badlands and Wind Cave (as 
described above) and determined the uniform rate of progress needed in 
order to attain natural visibility conditions by 2064 in both Class I 
areas. South Dakota constructed the uniform rate of progress consistent 
with the requirements of the Regional Haze Rule 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 Badlands and Wind Cave. The 
uniform rates of progress are summarized in Table 2 and further 
described below.
    Using a baseline visibility value at Badlands of 17.14 deciviews 
and a ``refined'' natural visibility value of 8.06 deciviews for the 20 
percent worst days, South Dakota calculated the uniform rate of 
progress to be approximately 0.151 deciviews per year (deciviews/year 
or dv/yr). This results in a total reduction of 9.08 deciviews to reach 
the natural visibility condition of 8.06 deciviews in 2064. The uniform 
rate of progress results in a visibility improvement of 2.18 deciviews 
needed for the period covered by this SIP revision submittal (up to and 
including 2018).
    Using a baseline visibility value at Wind Cave of 15.84 deciviews 
and a ``refined'' natural visibility value of 7.71 deciviews for the 20 
percent worst days, South Dakota calculated the uniform rate of 
progress to be approximately 0.136 deciviews per year. This results in 
a total reduction of 8.13 deciviews to reach the natural visibility 
condition of 7.71 deciviews in 2064. The uniform rate of progress 
results in a visibility improvement of 1.89 deciviews needed for the 
period covered by this SIP revision submittal (up to and including 
2018).

[[Page 76653]]

              Table 2--Summary of Uniform Rates of Progress
------------------------------------------------------------------------
          Class I area                 Badlands            Wind cave
------------------------------------------------------------------------
Baseline Conditions.............  17.14 dv..........  15.84 dv
Natural Visibility..............  8.06 dv...........  7.71 dv
Total Improvement by 2064.......  9.08 dv...........  8.13 dv
Needed Improvement for this SIP   2.18 dv...........  1.89 dv
 by 2018.
URP.............................  0.151 dv/year.....  0.136 dv/year
------------------------------------------------------------------------

    We propose to find that South Dakota has appropriately calculated 
the uniform rates of progress.

C. BART

    BART is an element of South Dakota's LTS for the first 
implementation period. As discussed in more detail in section II.D of 
this preamble, the BART evaluation process consists of three 
components: (1) An identification of all the BART-eligible sources; (2) 
an assessment of whether those BART-eligible sources are in fact 
subject to BART; and (3) a determination of any BART controls. South 
Dakota addressed these steps as follows:
1. Identification of BART-Eligible Sources
    The first step of a BART evaluation is to identify all the BART-
eligible sources within the state's boundaries. The State identified 
the BART-eligible sources in South Dakota by utilizing the approach set 
out in the BART Guidelines (70 FR 39158); this approach provides three 
criteria for identifying BART-eligible sources: (1) One or more 
emission units at the facility fit within one of the 26 categories 
listed in the BART Guidelines; (2) the emission unit(s) began operation 
on or after August 7, 1962, and was in existence on August 7, 1977; and 
(3) potential emissions of any visibility-impairing pollutant from 
subject units are 250 tons or more per year. South Dakota initially 
screened its emissions inventory and permitting database to identify 
major facilities with emission units in one or more of the 26 BART 
categories. Following this, South Dakota used its databases and records 
to identify facilities in these source categories with potential 
emissions of 250 tons per year or more for any visibility-impairing 
pollutant from any units that were in existence on August 7, 1977 and 
began operation on or after August 7, 1962.
    The BART Guidelines direct states to address SO2, 
NOX and direct PM (including both coarse (PM10) 
and fine (PM2.5) particulate matter emissions as visibility-
impairing pollutants and to exercise their ``best judgment to determine 
whether VOC or NH3 emissions from a source are likely to 
have an impact on visibility in an area.'' See 70 FR 39162. The 
available inventory information indicates VOCs in South Dakota 
overwhelmingly come from biogenic sources, and NH3 in South 
Dakota is primarily due to area sources, such as livestock and 
fertilizer application. Because these are not point sources, they are 
not subject to BART. We have reviewed this information and propose to 
find South Dakota's focus on SO2, NOX, and PM 
acceptable.
    South Dakota identified BART-eligible sources in South Dakota as 
shown in Table 3. This information is presented in Section 6 of South 
Dakota's SIP.

                             Table 3--List of BART-Eligible Sources in South Dakota
----------------------------------------------------------------------------------------------------------------
       BART-eligible source                  Location           BART source category (SC)   Nearest class I area
----------------------------------------------------------------------------------------------------------------
1. Northern States Power Company    Sioux Falls, South Dakota.  SC 1--fossil fuel steam    N/A.\1\
 (Units 1, 2, and 3).                                            electric plants >250
                                                                 MMBtu/hr heat input.
2. Otter Tail Power Company, Big    Near Big Stone City, South  SC 1--fossil fuel steam    Boundary Waters
 Stone I (Unit 1).                   Dakota.                     electric plants >250      431 km.
                                                                 MMBtu/hr heat input.
3. Pete Lien and Sons, Inc........  Rapid City, South Dakota..  SC 12--lime plants.......  Wind Cave
                                                                                           52 km.
----------------------------------------------------------------------------------------------------------------
\1\ South Dakota did not analyze the three units at Northern States Power for distance to Class I areas as they
  have been decommissioned.

2. Identification of Sources Subject to BART
    The second step of the BART evaluation is to identify those BART-
eligible sources that may reasonably be anticipated to cause or 
contribute to any 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.
a. Modeling Methodology
    The BART Guidelines provide that states may use the CALPUFF \12\ 
modeling system or another appropriate model to predict the visibility 
impacts from a single source on a Class I area and to, therefore, 
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 BART Guidelines state that we find CALPUFF is 
the best regulatory modeling application currently available for 
predicting a single source's contribution to visibility impairment (70 
FR 39162).
---------------------------------------------------------------------------

    \12\ Note that our 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 at 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 us and their RPO to address any issues 
prior to modeling. South Dakota relied on WRAP's CALPUFF modeling for 
South Dakota BART sources as

[[Page 76654]]

recommended by the BART Guidelines.\13\ 40 CFR part 51, appendix Y, 
section III.A.3.
---------------------------------------------------------------------------

    \13\ The WRAP modeling protocol is available at http://pah.cert.ucr.edu/aqm/308/bart/WRAP_RMC_BART_Protocol_Aug15_2006.pdf.
---------------------------------------------------------------------------

    To determine if each BART-eligible source has a significant impact 
on visibility, South Dakota used WRAP's CALPUFF modeling results to 
estimate daily visibility impacts above estimated natural conditions at 
each Class I area within 300 km of any BART-eligible facility, based on 
maximum actual 24-hour emissions over a three year period (2000-2002).
b. 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.'' 70 FR 39104, 39161. 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.'' Id. 
Further, in setting a contribution threshold, states should ``consider 
the number of emissions sources affecting the Class I areas at issue 
and the magnitude of the individual sources' impacts.'' 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 to a Class I area justifies this approach.
    South Dakota used a contribution threshold of 0.5 deciviews for 
determining which sources are subject to BART. The State's decision was 
based on the following factors: (1) 0.5 deciviews equates to the 5% 
extinction threshold for new sources under the Prevention of 
Significant Deterioration (PSD) New Source Review rules, (2) 0.5 
deciviews is consistent with the threshold selected by other states in 
the west, which all selected 0.5 deciviews, and (3) 0.5 deciviews 
represents the limit of perceptible change. Although we do not agree 
that all of the factors considered by South Dakota's Department of 
Environmental and Natural Resources are relevant in determining whether 
a source can be considered to cause or contribute to visibility 
impairment, we propose to approve the State's threshold of 0.5 
deciviews. As the discussion below indicates, Big Stone I is the only 
BART-eligible source in South Dakota in operation. Given that and the 
fact that the modeling indicates that Big Stone I is reasonably 
anticipated to have an impact over the 0.5 deciview threshold at 
several Class I Areas, it is apparent that no BART-eligible sources 
were exempted from review based on the 0.5 deciviews threshold that 
could have had meaningful impact on visibility in one or more Class I 
areas. We are proposing that 0.5 deciviews is a reasonable threshold 
for South Dakota in determining whether its BART-eligible sources are 
subject to BART.
c. Sources Identified by South Dakota as Subject to BART
    South Dakota determined that the three units at Northern States 
Power were not subject to BART because the units have been 
decommissioned and are no longer permitted to operate under the 
facility's Title V air quality permit. Consistent with the BART 
Guidelines, South Dakota requested that WRAP model each of its 
remaining operating BART-eligible sources to assess the extent of their 
contribution to visibility impairment at surrounding Class I areas.
    The WRAP modeling results demonstrated that Pete Lien and Sons, 
Inc. did not cause or contribute to visibility impairment at any Class 
I area. After reviewing the modeling inputs, South Dakota determined 
that the vertical kiln should be modeled again due to several errors. 
However, before additional modeling could be done, Pete Lien and Sons, 
Inc. shut down and dismantled the kiln in 2009 per its Title V 
permit.\14\
---------------------------------------------------------------------------

    \14\ Although Pete Lien and Sons' existing Title V air quality 
permit still identifies the vertical kiln as a unit, permit 
condition 1.1 specifies in the footnote of Table 1-1 that Pete Lien 
and Sons is required to shutdown and dismantle the vertical kiln 
before the initial startup of Unit 45. Pete Lien and Sons 
fulfilled this commitment by notifying South Dakota on March 13, 
2009, that the vertical kiln was shutdown and dismantled. See SIP 
Section 6.1.2.
---------------------------------------------------------------------------

    The WRAP modeling results for Otter Tail Power Company's Big Stone 
I are summarized in Table 4. The results show that Big Stone I's 
emissions cause visibility impacts that exceed the 0.5 deciviews 
threshold at the Badlands National Park in South Dakota, Theodore 
Roosevelt National Park in North Dakota, and Boundary Waters Wilderness 
and Voyageurs National Park in Minnesota.

                                Table 4--WRAP's Modeling Results for Big Stone I
----------------------------------------------------------------------------------------------------------------
                                                                             Minimum distance   98th percentile
                  Class I area                             State             to class I area   visibility impact
                                                                                   (km)              (dv)\1\
----------------------------------------------------------------------------------------------------------------
Badlands.......................................  SD                                       470              0.683
Boundary Waters................................  MN                                       431              1.034
Bridger........................................  WY                                     1,041              0.001
Fitzpatrick....................................  WY                                     1,050              0.001
Grand Teton....................................  WY                                     1,112              0.001
Lostwood.......................................  ND                                       585              0.263
Medicine Lake..................................  MT                                       690              0.256
North Absaroka.................................  WY                                     1,013              0.011
Teton..........................................  WY                                     1,052              0.004
Theodore Roosevelt.............................  ND                                       555              0.687
UL Bend........................................  MT                                       902              0.089
Voyageurs......................................  MN                                       438              0.729
Washakie.......................................  WY                                     1,006              0.007
Wind Cave......................................  SD                                       572              0.263

[[Page 76655]]

 
Yellowstone....................................  WY                                     1,049              0.009
----------------------------------------------------------------------------------------------------------------
\1\ Modeling results represent the maximum 98th percentile impact over the modeled 3-year meteorological period
  2001-2003.

    South Dakota allowed Otter Tail Power Company to re-run the 
modeling after the company identified several errors in actual emission 
rates and stack parameters. After additional review, Otter Tail Power 
Company developed a revised modeling protocol that both the State and 
EPA approved. The modeling protocol is included in Appendix A of the 
SIP. The results from Otter Tail's modeling are summarized in Table 5. 
Otter Tail's modeling report is included in Appendix B of the SIP.

         Table 5--Otter Tail's Modeling Results for Big Stone I
------------------------------------------------------------------------
                                                               98th
                                                            percentile
                      Class I area                          visibility
                                                              impact
                                                              (dv)\1\
------------------------------------------------------------------------
Badlands................................................             0.5
Boundary Waters.........................................             1.1
Lostwood................................................             0.4
Theodore Roosevelt......................................             0.5
Voyageurs...............................................             0.7
Wind Cave...............................................             0.3
Isle Royale.............................................             0.7
------------------------------------------------------------------------
\1\ Modeling results represent the maximum 98th percentile impact over
  the modeled meteorological years 2002, 2006, and 2007.

    In reviewing Otter Tail's results, the State rounded to one 
significant figure and determined that Big Stone I emissions cause 
visibility impacts that exceed the 0.5 deciviews threshold at the same 
Class I areas identified in the WRAP modeling in addition to Isle 
Royale in Michigan. South Dakota relied on Otter Tail's modeling, 
noting that it best represented the visibility impacts from Big Stone I 
because the original WRAP modeling did not have the correct emission 
rates and stack parameters and that the modeling protocol adjustments 
improved the accuracy of the model over long distances.
3. BART Determinations and Federally Enforceable Limits
    The third step of a BART evaluation is to perform the BART 
analysis. The BART Guidelines (70 FR 39164) describe the BART analysis 
as consisting of the following five steps:
     Step 1: Identify All Available Retrofit Control 
Technologies,
     Step 2: Eliminate Technically Infeasible Options,
     Step 3: Evaluate Control Effectiveness of Remaining 
Control Technologies,
     Step 4: Evaluate Impacts and Document the Results, and
     Step 5: Evaluate Visibility Impacts.
    In determining BART, the State must consider the five statutory 
factors in section 169A of the CAA: (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. See also 40 CFR 51.308(e)(1)(ii)(A). The five-
factor analysis occurs during steps 4 and 5 of the process.
    South Dakota requested that Otter Tail Power Company complete a 
BART analysis for Big Stone I and used this analysis as a basis for its 
BART determination for this source for NOX, SO2 
and PM. The Otter Tail BART analysis is included in Appendix C of the 
SIP. Otter Tail generally followed the five steps contained in the BART 
Guidelines and evaluated the five BART factors. In some instances, 
South Dakota identified additional control technologies for evaluation 
and also added an analysis of average cost effectiveness compared to 
visibility benefit (dollar per deciview) for the various multi-
pollutant control options. We find that South Dakota, through its 
reliance on Otter Tail's BART analysis, reasonably considered the five 
BART factors and arrived at a reasonable BART determination for Big 
Stone I. We propose to approve South Dakota's BART determination 
summarized below.
a. Otter Tail Power Company, Big Stone I
Background
    Big Stone I is a steam electric generating plant located near Big 
Stone City, South Dakota with one generating unit burning Powder River 
Basin coal and a net electrical output of 475 MW. The Otter Tail Power 
Company is the operating agent for the Big Stone Plant co-owners: 
NorthWestern Energy, Montana-Dakota Utilities, Co., a division of MDU 
Resources Group, and Otter Tail Power Company. The generating unit is a 
Babcock cyclone boiler that started operating in 1975. The State 
analyzed each pollutant and its effect on the visibility in Class I 
areas. Since Big Stone I does not have a total generating capacity 
greater than 750 MW, South Dakota was not required to follow the BART 
Guidelines in determining BART, but it generally followed the approach 
for determining BART set out in the Guidelines. A summary of the 
State's analyses of existing controls and potential BART controls for 
each pollutant is set forth below. The State's BART determination for 
Big Stone I is provided in Section 6 of the SIP. The visibility and 
cost impacts noted in the following assessment are derived from the 
company's BART analysis provided in Appendix B of the SIP.\15\
---------------------------------------------------------------------------

    \15\ Otter Tail's costs rely on the CUECost model. While we are 
satisfied with the State's control technology conclusions as further 
described in this section, in general we do not recommend relying on 
the CUECost model. According to the BART Guidelines, ``cost 
estimates should be based on the OAQPS Control Cost Manual, where 
possible'' ``[i]n order to maintain and improve consistency.'' 70 FR 
39104, 39166. The OAQPS Control Cost Manual is now known as The EPA 
Air Pollution Control Cost Manual, EPA/452/B-02-001, 6th Ed., 
January 2002.
---------------------------------------------------------------------------

Unit 1 Boiler
    SO2 BART Review: Unit 1 has no existing SO2 controls. 
The baseline uncontrolled SO2 emissions that South Dakota 
reported in the SIP are 18,000 tons per year.
    Step 1: Identify All Available Technologies.
    The State identified the following SO2 control options 
as having potential application to Unit 1: Fuel switching, coal 
cleaning, coal upgrading (K-Fuel), hydrated lime injection, semi-dry 
flue gas desulfurization (FGD), wet FGD, Enviroscrub, electro catalytic 
oxidation and the Airborne process.
    Step 2: Eliminate Technically Infeasible Options.
    The State eliminated the following options as technically 
infeasible: Coal

[[Page 76656]]

cleaning, coal upgrading, hydrated lime injection, Enviroscrub, Electro 
catalytic oxidation and the Airborne process. Fuel switching is a 
viable method to reduce sulfur dioxide emissions by switching to a fuel 
with lower sulfur content. The Big Stone facility's primary fuel source 
is subbituminous coal obtained from the Powder River Basin in Wyoming. 
Powder River Basin subbituminous coal has one of the lowest sulfur 
contents available in the United States. As such, the State concluded 
that Otter Tail Power Company has already implemented fuel switching.
    Step 3: Evaluate Control Effectiveness of Remaining Control 
Technology.
    The State considered the control efficiencies listed in Table 6.

          Table 6--Summary of Big Stone I SO2 BART Analysis Control Technologies for Unit 1 Boiler \1\
----------------------------------------------------------------------------------------------------------------
                                                                                                    Emissions
             Control option                    Control        Emission rate   Emissions (tons/  reduction  (tons/
                                           efficiency  (%)     (lb/MMBtu)            yr)               yr)
----------------------------------------------------------------------------------------------------------------
Wet FGD 1......................                95             0.043               900            17,100
Wet FGD 2......................                83              0.15             3,130            14,870
Semi-Dry FGD 1.................                90              0.09             1,880            16,120
Semi-Dry FGD 2.................                83              0.15             3,130            14,870
----------------------------------------------------------------------------------------------------------------
\1\ South Dakota calculated emissions from a baseline of 18,000 tons per year of SO2. The baseline was derived
  from the highest average 24-hour average emission rate (4,832 pounds per hour) for calendar years 2001 through
  2003 and operations occurring 85% of the time or 7,746 hours per year.

    Step 4: Evaluate Impacts and Document Results.
    Factor 1: Costs of compliance.
    The State relied on Otter Tail's cost analysis for SO2 
controls and this is summarized below in Table 7. The State deemed the 
average cost effectiveness reasonable for the two remaining control 
options, semi-dry and wet FGD.

                    Table 7--Summary of Big Stone I SO2 BART Cost Analysis for Unit 1 Boiler
----------------------------------------------------------------------------------------------------------------
                                           Total installed                        Emissions           Cost
             Control option                 capital cost      Total annual    reduction  (tons/   effectiveness
                                                (MM$)          cost  (MM$)           yr)             ($/ton)
----------------------------------------------------------------------------------------------------------------
Wet FGD 1......................            $171.8            $29.05            17,100            $1,699
Wet FGD 2......................             171.8             28.90            14,870             1,944
Semi-Dry FGD 1.................             141.3             23.57            16,120             1,462
Semi-Dry FGD 2.................             141.3             23.33            14,870             1,569
----------------------------------------------------------------------------------------------------------------

    Factor 2: Energy impacts.
    The State noted increased energy demand estimates provided by Otter 
Tail of 9,500 kilowatts (2.0 percent of generation) for wet FGD and 
3,325 kilowatts (0.7 percent of generation) for semi-dry FGD. The State 
did not identify any energy requirements that would preclude the 
selection of either of the two alternatives.
    Factor 3: Non-air quality environmental impacts.
    The State described the non-air quality environmental impacts of 
the two control alternatives including the solid and aqueous waste 
streams. The semi-dry FGD system would be installed upstream of the 
existing baghouse. The baghouse would be used to collect the injected 
lime and reacted sulfur dioxide emissions along with other existing 
particulate matter emissions. Otter Tail did not identify how much 
additional particulate matter would be collected by the baghouse due to 
the use of the semi-dry FGD system. Otter Tail assumed the additional 
material collected in the baghouse would be negligible compared to the 
existing collection. Otter Tail estimated that the wet FGD system would 
generate an additional 44,700 tons of gypsum solids which would need to 
be properly disposed. The State did not identify any non-air quality 
effects that would preclude the selection of either of the two 
alternatives.
    Factor 4: Remaining useful life.
    The expected remaining useful life of the unit is greater than 30 
years.
    Factor 5: Evaluate visibility impacts.
    Table 8 presents a comparison of the visibility impacts of the two 
top control options, wet FGD and semi-dry FGD. The values are derived 
from modeling conducted by Otter Tail. For the cases presented, Otter 
Tail held the emission rates for NOX and PM constant but 
varied the SO2 emissions rates in the model as noted. In 
some cases, the modeling predicted that the semi-dry FGD would produce 
a greater visibility benefit than the wet FGD. It is not clear why the 
model predicted this result; it may relate to stack parameters. Based 
on the visibility modeling, the State found that there would be no 
discernible visibility benefit from selecting a wet FGD over a semi-dry 
FGD.

               Table 8--Visibility Impact Comparison Between Wet and Semi-Dry FGD SO2 Controls \1\
                                          [98th Percentile--Deciviews]
----------------------------------------------------------------------------------------------------------------
     Option \2\        Control equipment      Class I area \4\         2002            2006            2007
----------------------------------------------------------------------------------------------------------------
3.........  OFA and Semi-dry FGD   Boundary Waters.....           0.319           0.534           0.620
                      (0.09 lb/MMBtu).
                                            Voyageurs...........           0.307           0.391           0.450
                                            Isle Royale.........           0.363           0.287           0.323
                                            Badlands............           0.219           0.172           0.230
                                            Theodore Roosevelt..           0.087           0.234           0.173
4.........  OFA and Wet FGD        Boundary Waters.....           0.350           0.521           0.611
                      (0.043 lb/MMBtu).

[[Page 76657]]

 
                                            Voyageurs...........           0.312           0.464           0.502
                                            Isle Royale.........           0.351           0.250           0.290
                                            Badlands............           0.225           0.191           0.234
                                            Theodore Roosevelt..           0.084           0.230           0.138
                     Comparison Review \3\  Boundary Waters.....           0.031          -0.013          -0.009
                      (incremental
                      visibility impact of
                      wet FGD (in Option
                      3) compared to semi-
                      dry FGD (in Option
                      4)).
                                            Voyageurs...........           0.005           0.073           0.052
                                            Isle Royale.........          -0.012          -0.037          -0.033
                                            Badlands............           0.006           0.019           0.004
                                            Theodore Roosevelt..          -0.003          -0.004          -0.035
5a........  SOFA and Semi-dry FGD  Boundary Waters.....           0.250           0.419           0.493
                      (0.09 lb/MMBtu).
                                            Voyageurs...........           0.249           0.306           0.354
                                            Isle Royale.........           0.285           0.226           0.256
                                            Badlands............           0.165           0.133           0.180
                                            Theodore Roosevelt..           0.069           0.186           0.141
5b........  SOFA and Wet FGD       Boundary Waters.....           0.274           0.407           0.478
                      (0.043 lb/MMBtu).
                                            Voyageurs...........           0.244           0.365           0.393
                                            Isle Royale.........           0.274           0.195           0.227
                                            Badlands............           0.174           0.147           0.182
                                            Theodore Roosevelt..           0.066           0.180           0.108
                     Comparison Review \3\  Boundary Waters.....           0.024          -0.012          -0.015
                      (incremental
                      visibility impact of
                      wet FGD (in Option
                      5a) compared to semi-
                      dry FGD (in Option
                      5b)).
                                            Voyageurs...........          -0.005           0.059           0.039
                                            Isle Royale.........          -0.011          -0.031          -0.029
                                            Badlands............           0.009           0.014           0.002
                                            Theodore Roosevelt..          -0.003          -0.006          -0.033
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company conducted visibility modeling for both wet and semi-dry FGD options using combined
  controls with constant emission rates for NOX and PM. Thus, the results shown include the noted SO2 and NOX
  control options and the existing fabric filter PM control option.
\2\ An explanation of each of the numbered control options and the corresponding emission rates is included in
  Section 6 of the SIP, Table 6-13, p. 94.
\3\ A negative number means the wet FGD had a lower visibility impact than the semi-dry FGD.
\4\ These are the Class I areas that exceed the 0.5 deciview threshold as listed in Table 5.

    Step 5: Select BART.
    South Dakota determined BART to be the second ranked control 
option, semi-dry FGD at 90 percent control efficiency in Section 
6.3.5.2 of the SIP. Even though the top ranked control option, wet FGD 
at 95 percent control efficiency, reduced the SO2 emissions 
more than the second ranked option, the State determined that there is 
no discernible difference between the two options when considering 
visibility impacts. South Dakota specified BART limits of 505 lb/hour 
and 0.09 lb/MMBtu (30-day rolling average) that apply at all times 
including periods of startup, shutdown and malfunction. The estimated 
cost of the semi-dry FGD system was $1,462 per ton ($/ton) of 
SO2 removed, and the capital and annualized costs were 
estimated to be $141,300,000 and $23,570,000 per year ($/year or $/yr), 
respectively.
    We are proposing to approve the State's SO2 BART 
determination for Big Stone I. The State's assessment of costs and 
other impacts and its elimination of the wet FGD at 95% control 
efficiency was reasonable based on the five-factor analysis. While the 
average cost effectiveness values for both wet FGD and semi-dry FGD are 
reasonable, the modeling predicted that the use of a wet FGD at 95% 
efficiency rather than a semi-dry FGD at 90% efficiency would result in 
minimal, if any, visibility benefit. Thus, it was reasonable for the 
State to eliminate a wet FGD at 95% efficiency from consideration. The 
installation of a semi-dry FGD at Big Stone I will result in a 
reduction in annual SO2 emissions from the plant of 
approximately 16,120 tons.\16\ The visibility benefit for the selected 
BART controls for all pollutants combined is provided in the summary in 
Table 12 in section III.C.3.b. below.
---------------------------------------------------------------------------

    \16\ The selected SO2 emission limit of 0.09 lb/MMBtu 
(30-day rolling average) also happens to be well below the 
presumptive limit for EGU's without existing controls and over the 
750 MW generating capacity threshold described in the BART 
Guidelines.
---------------------------------------------------------------------------

    NOX BART Review: Big Stone I is already equipped with overfire air 
(OFA) for NOX control. South Dakota indicates in the SIP 
that Unit 1 has baseline controlled NOX emissions of 18,000 
tons per year with an emission rate of 0.65 lb/MMBtu.
    Step 1: Identify All Available Technologies.
    South Dakota identified the following control options as having 
potential application as BART: Selective catalytic reduction (SCR), 
oxygen enhanced combustion, catalytic absorption/oxidation, gas reburn, 
Enviroscrub, electro-catalytic oxidation, NOXStar, Cascade 
processes, selective non-catalytic reduction (SNCR), rich reagent 
injection (RRI), flue gas recirculation (FGR), separated over-fire air 
(SOFA), over-fire air (OFA), and low-NOX burners (LNB).

[[Page 76658]]

    Step 2: Eliminate Technically Infeasible Options.
    The State identified the following control options as technically 
infeasible: Oxygen enhanced combustion, absorption/oxidation, gas 
reburn, Enviroscrub, electro-catalytic oxidation, NOXStar, 
Cascade processes, and LNB. The State noted that flue gas recirculation 
is not known to reduce nitrogen oxide emissions any further when added 
with an over-fire air system. Therefore, the State and Otter Tail Power 
Company did not conduct any further review of flue-gas recirculation.
    Step 3: Evaluate Control Effectiveness of Remaining Control 
Technology.
    The State considered the control efficiencies listed in Table 9.

          Table 9--Summary of Big Stone I NOX BART Analysis Control Technologies for Unit 1 Boiler \1\
----------------------------------------------------------------------------------------------------------------
                                                                                                    Emissions
             Control option                    Control       Emission  rate   Emissions (tons/  reduction  (tons/
                                           efficiency (%)      (lb/MMBtu)            yr)               yr)
----------------------------------------------------------------------------------------------------------------
SCR and SOFA............................                89              0.10             2,000            16,000
RRI, SNCR and SOFA......................                77              0.20             4,090            13,910
SNCR and SOFA...........................                60              0.35             7,220            10,780
SOFA....................................                42              0.50            10,360             7,640
OFA.....................................                25              0.65            13,490             4,510
----------------------------------------------------------------------------------------------------------------
\1\ South Dakota calculated emissions from a baseline of 18,000 tons per year of NOX. The baseline was derived
  from the highest average 24-hour average emission rate (4,855 pounds per hour) for calendar years 2001 through
  2003 and operations occurring 85% of the time or 7,746 hours per year.

    Step 4: Evaluate Impacts and Document Results.
    Factor 1: Costs of compliance.
    The State relied on Otter Tail's cost analysis for NOX 
controls and this is summarized below in Table 10. The State deemed the 
average cost effectiveness reasonable for all of the remaining control 
options, SCR, SNCR, RRI, SOFA, and OFA, as provided by Otter Tail.

                    Table 10--Summary of Big Stone I NOX BART Cost Analysis for Unit 1 Boiler
----------------------------------------------------------------------------------------------------------------
                                          Total  installed                        Emissions       Average cost
             Control option                 capital cost      Total  Annual   reduction  (tons/   effectiveness
                                               (MM$)           cost (MM$)            yr)             ($/ton)
----------------------------------------------------------------------------------------------------------------
SCR and SOFA...........................              $81.9            $13.21            16,000              $825
RRI, SNCR and SOFA.....................               16.2             11.39            13,910               818
SNCR and SOFA..........................               11.9              3.99            10,780               197
SOFA...................................                4.8              0.65             7,640                85
OFA....................................                0                0.14             4,510                31
----------------------------------------------------------------------------------------------------------------

    Factor 2: Energy impacts.
    The State noted that all the energy impacts were less than one 
percent of the plant's generating capacity and did not identify any 
energy requirements that would preclude the selection of any of the 
alternatives.
    Factor 3: Non-air quality environmental impacts.
    The State discussed that the OFA and SOFA systems would increase 
the amount of unburned carbon in the flyash, which would increase the 
amount of flyash that needs to be properly disposed. Otter Tail Power 
Company considers this increase negligible compared to the existing 
amount of flyash being properly disposed.
    The State noted that the SNCR and the SCR systems would generate a 
small amount of unreacted ammonia or urea to be emitted. Even though 
ammonia and urea are not considered regulated air pollutants, these 
emissions are involved in the formation of ammonium sulfates and 
ammonium nitrates, which contribute to the amount of visibility 
impairment.
    The State did not identify any non-air quality environmental 
impacts that would preclude the selection of any of the control 
equipment alternatives.
    Factor 4: Remaining useful life.
    The expected remaining useful life of the unit is greater than 30 
years.
    Factor 5: Evaluate visibility impacts.
    Table 12, below, presents the visibility impacts for the State's 
selected BART controls for all pollutants. The values presented come 
from Otter Tail's modeling. The State found that SCR + SOFA would 
result in greater visibility improvement than the other options.
    Step 5: Select BART.
    South Dakota determined BART to be SCR + SOFA. South Dakota 
specified BART limits of 561 lb/hour and 0.10 lb/MMBtu (30-day rolling 
average) that apply at all times including periods of startup, 
shutdown, and malfunction. The estimated cost of the SCR + SOFA 
controls was $825 per ton ($/ton) of NOX removed, and the 
capital and annualized costs were estimated to be $81,800,000, and 
$13,210,000 per year ($/year or $/yr), respectively.
    We are proposing to approve the State's NOX BART 
determination for Big Stone I. The State's assessment of costs and 
other impacts was reasonable. The installation of SCR and SOFA at Big 
Stone I will result in a reduction in annual NOX emissions 
from the plant of approximately 16,000 tons. Table 12, below, provides 
the visibility benefit for the selected BART controls for all 
pollutants combined.
    PM BART Review: Big Stone I is already equipped with a pulse jet 
fabric filter baghouse for PM which is considered the most efficient 
control technology available. The baseline controlled PM emissions that 
South Dakota reported in the SIP are 300 tons per year with an emission 
rate of 0.015 lb/MMBtu. The State identified the following PM control 
options as having potential application to the Big Stone I boiler: 
Existing fabric filter baghouse, new fabric filter baghouse, compact 
hybrid particulate collector (COHPAC), electrostatic precipitator, wet 
scrubber,

[[Page 76659]]

and cyclones/multiclones. The State did not eliminate any of the 
control technologies as technically infeasible for controlling PM 
emissions from the boiler.
    South Dakota determined BART to be no additional controls. The 
State reviewed the five BART factors generally, but noted no further 
detailed analysis was required since Otter Tail has already installed 
and is operating a fabric filter baghouse, which is the top particulate 
control technology. South Dakota specified BART limits of 67.3 lb/hour 
and 0.012 lb/MMBtu (30-day rolling average). The latter represents a 
stringent level of control that is consistent with recent Best 
Available Control Technology determinations for PSD permits.
    We are proposing to approve the State's PM BART determination for 
Big Stone I. The State's assessment that no detailed analysis is 
required since the most stringent control option is already in place is 
consistent with the BART Guidelines. (40 CFR 51, appendix Y, IV.D.5.) 
Furthermore, since South Dakota's proposed BART emission limits does 
not explicitly exempt emissions during malfunctions, we interpret the 
SIP to require compliance with the PM limits at all times (including 
malfunctions).
b. South Dakota's BART Results and Summary
    We have summarized South Dakota's BART determinations in Table 11 
below. We have summarized the visibility impacts at the appropriate 
Class I areas for South Dakota's selected BART controls in Table 12 
below. The substantial emissions reductions in SO2 and 
NOX will result in a significant improvement in visibility 
at several Class I areas. The visibility improvement from reducing both 
pollutants at the most impacted area, Boundary Waters, is estimated to 
be 0.9 deciviews and 54 fewer days above 0.5 deciviews.\17\
---------------------------------------------------------------------------

    \17\ The 0.9 deciviews estimated visibility benefit at Boundary 
Waters is calculated by subtracting the 2007 impact of 0.17 
deciviews in Table 12 from the baseline impact of 1.1 deciviews in 
Table 5. Our calculations for 54 fewer days above 0.5 deciviews are 
included in the docket.
---------------------------------------------------------------------------

    South Dakota's Regional Haze Rule, which we are proposing to 
approve with the SIP, requires each source subject to BART to install 
and operate BART no later than five years after we approve the Regional 
Haze SIP. Administrative Rules of South Dakota (ARSD) Chapter 74:36:21. 
Given the scope of the retrofits involved, five years represents a 
schedule that is expeditious as practicable. This satisfies the 
requirement under 40 CFR 51.308(e)(1)(iv), that ``each source subject 
to BART be required to install and operate BART as expeditiously as 
practicable, but in no event later than 5 years after approval of the 
implementation plan revision.''
    As noted previously, to be approvable, the Regional Haze SIP must 
include monitoring, recordkeeping, and reporting requirements to ensure 
that the BART limits are enforceable. South Dakota has included these 
requirements in ARSD Chapter 74:36:21. We have reviewed these 
requirements and find them to be adequate as they relate to the BART 
limits we are proposing to approve. In particular, for SO2 
and NOX BART limits, the rule requires the use of continuous 
emission monitoring systems (CEMS) to determine compliance, generally 
in accordance with 40 CFR part 75. For the filterable PM BART limits, 
the rule requires stack testing. Adequate recordkeeping and reporting 
requirements are also specified.
    For the reasons discussed above, we propose to find that South 
Dakota satisfied the BART requirements of 40 CFR 51.308(e).

                    Table 11--South Dakota BART Determinations for Big Stone I Unit 1 Boiler
----------------------------------------------------------------------------------------------------------------
                 Baseline     Baseline   BART  level                    Emissions
                emissions     level of   of  control                      after       Emission
  Pollutant       (tons/    control  (%       (%       Control device    controls    reduction    Emission limit
                  yr)\1\     reduction)   reduction)                    (tons/yr)    (tons/yr)
----------------------------------------------------------------------------------------------------------------
SO2..........       18,000            0           90  Semi-dry FGD...        1,880       16,120  505 lb/hr, and
                                                                                                  0.09 lb/MMBtu,
                                                                                                  30-day rolling
                                                                                                  average.
NOX..........       18,000           25           88  SOFA + SCR.....        2,000       16,000  561 lb/hr, and
                                                                                                  0.10 lb/MMBtu,
                                                                                                  30-day rolling
                                                                                                  average.
PM...........          300      95-99.9      95-99.9  Existing Fabric  ...........  ...........  67.3 lb/hr, and
                                                       Filter.                                    0.012 lb/
                                                                                                  MMBtu, 30-day
                                                                                                  rolling
                                                                                                  average.
----------------------------------------------------------------------------------------------------------------
\1\ South Dakota calculated baseline emissions for SO2 and NOX by identifying the highest average 24-hour
  average actual emission rate for the years 2001 through 2003 and adjusted this to 85% operations level or
  7,746 hours per year.

        Table 12--Visibility Impacts for South Dakota's BART Determinations for Big Stone I Unit 1 Boiler
                                          [98th Percentile--Deciviews]
----------------------------------------------------------------------------------------------------------------
          Control options                 Class I area            2002              2006              2007
----------------------------------------------------------------------------------------------------------------
SCR, SOFA, and Semi-Dry FGD \1\....  Boundary Waters......             0.097             0.136             0.170
                                     Voyageurs............             0.086             0.107             0.123
                                     Isle Royale..........             0.092             0.077             0.098
                                     Badlands.............             0.079             0.060             0.070
                                     Theodore Roosevelt...             0.036             0.070             0.064
----------------------------------------------------------------------------------------------------------------
\1\ The results reflect the visibility impacts after installation of controls with an SCR at a NOX emissions
  rate of 0.1 lb/MMBtu, a semi-dry FGD at an SO2 emissions rate of 0.15 lb/MMBtu, and the existing pulse jet
  fabric filter baghouse at a PM emissions rate of 0.015 lb/MMBtu. The selected BART emissions limits for SO2
  and PM are lower than the modeled values, therefore, the visibility impacts after BART controls are installed
  will be lower than those presented in this table. See Table 8 for a comparison of visibility impacts for wet
  and semi-dry FGD. See Table 5 for baseline visibility impacts.

[[Page 76660]]

D. Evaluation of South Dakota's Reasonable Progress Goals

    In order to establish reasonable progress goals for Badlands and 
Wind Cave and to determine the controls needed for the LTS, South 
Dakota followed the process established in the Regional Haze Rule. 
First, South Dakota identified the anticipated visibility improvement 
in 2018 in the two South Dakota Class I areas using the WRAP Community 
Multi-Scale Air Quality (CMAQ) photochemical grid modeling results. 
This modeling identified the extent of visibility improvement from the 
baseline by pollutant for each Class I area. The modeling relied on 
projected source emission inventories, which included enforceable 
Federal and state regulations already in place and anticipated BART 
controls.
    South Dakota then identified, with input from EPA, the sources and 
source categories (other than BART sources) in South Dakota that are 
major contributors to visibility impairment and considered whether 
these sources should be controlled based on a consideration of the 
factors identified in the CAA and EPA's regulations. See CAA 169A(g)(1) 
and 40 CFR 51.308(d)(1)(i)(A). South Dakota also computed the baseline 
visibility impacts for these sources using their 2002 actual emissions 
and the CALPUFF modeling system. Next, based on this analysis, South 
Dakota set the reasonable progress goals for each Class I area and 
compared the reasonable progress goals for each area to the 2018 
uniform rate of progress. The SIP includes South Dakota's analysis and 
conclusion that reasonable progress will be made by 2018, including an 
analysis of pollutant trends, emission reductions, and improvements 
expected. The reasonable progress discussion and analyses are included 
in Section 7 of the SIP. We are proposing to approve South Dakota's 
submitted reasonable progress goals as described more fully below.
1. WRAP Visibility Modeling
    The primary tool WRAP relied upon for modeling regional haze 
improvements by 2018, and for estimating South Dakota's Reasonable 
Progress Goals, was the CMAQ model. The CMAQ model was used to estimate 
2018 visibility conditions in South Dakota and all western Class I 
areas, based on application of anticipated regional haze strategies in 
the various states' regional haze plans, including assumed controls on 
BART sources.\18\
---------------------------------------------------------------------------

    \18\ We provide a more detailed discussion on the WRAP modeling 
in section IV.E.3 below and in the EPA WRAP Technical Support 
Document available in the docket.
---------------------------------------------------------------------------

2. Reasonable Progress ``Four-Factor'' Analysis
    In determining the measures necessary to make reasonable progress, 
states must take into account the following four factors and 
demonstrate how they were taken into consideration in selecting 
reasonable progress goals for a Class I area:
     Costs of Compliance,
     Time Necessary for Compliance,
     Energy and Non-Air Quality Environmental Impacts of 
Compliance, and
     Remaining Useful Life of any Potentially Affected Sources.
    CAA 169A(g)(1) and 40 CFR 308(d)(1)(i)(A).
    As the purpose of the reasonable progress analysis is to evaluate 
the potential of controlling certain sources or source categories for 
addressing visibility from manmade sources, the four-factor analysis 
conducted by South Dakota addresses only anthropogenic sources, on the 
assumption that the focus should be on sources that can be 
``controlled.'' In its evaluation of potential sources or source 
categories for reasonable progress, South Dakota primarily considered 
point sources. South Dakota determined that the key pollutants 
contributing to visibility impairment at the two Class I areas are 
SO2, organic carbon and NOX. South Dakota also 
only considered controls for emissions of SO2 and 
NOX (i.e., sulfate and nitrate) which are typically 
associated with anthropogenic sources. South Dakota determined the 
major source of organic carbon in the two Class I areas is natural 
fire. By reviewing the WRAP modeling results, South Dakota determined 
that PM emissions from point sources contribute only a minimal amount 
to visibility impairment in the South Dakota Class I areas.
    Based on the WRAP CMAQ modeling, South Dakota's contribution of 
ammonia sulfate, organic carbon mass, and ammonia nitrate 
concentrations is approximately 1.5% for ammonia sulfate, minimal for 
organic carbon mass, and 4% for ammonia nitrate. Therefore, South 
Dakota concluded that minimal gain would be achieved from further 
reduction in sulfur dioxide, organic carbon mass, and nitrogen oxide 
emissions from point sources within South Dakota. More discussion on 
sources of sulfate and nitrate emissions and the State's rationale for 
focusing on point sources is included in Section 7 of the SIP. South 
Dakota initially asserted that a four-factor analysis was not warranted 
based on its belief that Badlands and Wind Cave would both achieve the 
needed reductions to meet the uniform rate of progress for both Class I 
areas despite the WRAP predictions. This belief was based on the 
State's conclusion that the emission estimates included in the WRAP 
modeling turned out to be too high. The emission estimates did not 
include reductions reflecting the BART emission limits for Otter Tail 
Power Company's BigStone I facility but did include anticipated 
emissions from two proposed coal-fired power plants--Big Stone II and 
NextGen. The Big Stone II facility will not be constructed and the 
NextGen facility is on hold indefinitely.
    However, South Dakota did not remodel with revised emissions 
estimates to demonstrate that the uniform rate of progress would be met 
for Badlands and Wind Cave. EPA therefore requested that South Dakota 
perform a four-factor analysis for three facilities, at a minimum: the 
Black Hills Ben French power plant, the GCC Dacotah cement plant, and 
the Pete Lien and Sons lime plant. South Dakota did perform a four-
factor analysis for Black Hills Ben French and GCC Dacotah based on the 
WRAP's report, Supplementary Information for Four-Factor Analyses for 
Selected Individual Facilities in South Dakota, May 19, 2009, authored 
by EC/R (hereinafter referred to as the EC/R Report). The EC/R Report 
is included in Appendix F of the SIP. The EC/R report did not address 
the Pete Lien and Sons lime plant.
    During our review of South Dakota's four-factor analysis, we 
analyzed actual emissions data from EPA's 2002 National Emissions 
Inventory database. We started with the emissions inventory totals for 
SO2 and NOX then divided the actual emissions (Q) 
in tons per year from the sources by their distance (D) in kilometers 
to the nearest Class I Federal area. A summary list of the largest 
sources we reviewed in our Q/D analysis is included below in Table 13.

[[Page 76661]]

                               Table 13--EPA Q/D Analysis for South Dakota Sources
----------------------------------------------------------------------------------------------------------------
                                                             SO2 + NOX 2000-     Distance to     Q/D to closest
                          Source                              2004 average     nearest Class I    Class I area
                                                                 (tons)           area (km)         (tons/km)
----------------------------------------------------------------------------------------------------------------
Black Hills, Ben French Power Plant.......................             1,782                65             27.41
GCC Dacotah...............................................             4,465                66             67.66
John Morrell & Company....................................               648               410              1.58
Merillat Industries Inc...................................               135                58              2.33
Pete Lien and Sons, Inc...................................               276                59              4.68
----------------------------------------------------------------------------------------------------------------

    South Dakota did not undertake a reasonable progress analysis of 
John Morrell & Company or Merillat Industries, Inc. Given the low Q/D 
values associated with these two sources, we are proposing to find that 
South Dakota's approach was reasonable.
    Although Pete Lien and Sons, Inc. also had a Q/D of less than 10, 
the State did consider whether controls should be required for 
reasonable progress. South Dakota opted, however, not to conduct a full 
four-factor analysis on Pete Lien and Sons but did a general review of 
the impacts of this facility. Pete Lien and Sons' SO2 
emissions are less than 1 ton/year and so have a de minimus impact on 
visibility in any Class I area. For NOX, the State has 
determined that the plant is already required to use what is considered 
Best Available Control Technology (BACT), and thus no further controls 
are required. As further explanation, the 2002 NOX emissions 
for Pete Lien and Sons were 272 tons/year. In May 2008, the company 
included a BACT analysis for NOX in a PSD application for a 
new preheater-type rotary lime kiln and ancillary equipment for this 
facility. The BACT analysis found non-selective catalytic reduction and 
selective catalytic reduction to be technically infeasible for several 
reasons including temperatures and the location of injection nozzles. 
South Dakota reviewed the application at the time and agreed with the 
conclusion that BACT for a lime rotary kiln was considered good 
combustion practices. South Dakota conducted a further review of EPA's 
RACT/BACT/LAER Clearinghouse to determine if any new rotary lime kilns 
had been permitted since Pete Lien and Sons' PSD application had been 
submitted with more stringent post-combustion BACT controls. There were 
three entries. One occurred in each of the states of Texas, Ohio, and 
Wisconsin. The Texas source only involved carbon monoxide. In Ohio and 
Wisconsin, the permitting authorities had concluded in the BACT 
analyses for NOX that no control technologies were cost 
effective and that good combustion practices were considered BACT. The 
State concluded there were no new rotary lime kilns that had been 
required to install post-combustion NOX controls for BACT. 
As a result, the State concluded that such controls would not 
constitute BART.
    South Dakota also evaluated Pete Lien and Sons' visibility impacts 
at Badlands and Wind Cave by conducting a CALPUFF modeling analysis. 
The modeling report is included in Appendix I of the SIP. A summary of 
the modeling results is provided below in Table 14.

    Table 14--Summary of Baseline Visibility Impacts From Reasonable
                   Progress Source Pete Lien and Sons
                          [98th Percentile, dv]
------------------------------------------------------------------------
                  Year                       Badlands        Wind Cave
------------------------------------------------------------------------
2002....................................            0.05            0.06
2006....................................            0.06            0.05
2007....................................            0.07            0.05
------------------------------------------------------------------------

    We propose to approve South Dakota's less detailed analysis for 
Pete Lien and conclusion that no controls are required. A Q/D value of 
10 is generally viewed as a conservative threshold for identifying 
facilities that may have significant source-specific impacts. We 
consider a Q/D threshold of 10 to be reasonable for this planning 
period based on the FLM's proposed FLAG Guidance amendments for initial 
screening criteria, as well as statements in EPA's BART guidelines.\19\ 
For Pete Lien and Sons, the Q/D of 4.68 is well below this threshold; 
the baseline visibility impacts analysis by South Dakota in Table 14 
confirms that Pete Lien and Sons does not have significant source-
specific impacts.
---------------------------------------------------------------------------

    \19\ The relevant language in our BART Guidelines reads, ``Based 
on our analyses, we believe that a state that has established 0.5 dv 
as a contribution threshold could reasonably exempt from the BART 
review process sources that emit less than 500 tons per year of 
NOX or SO2 (or combined NOX and 
SO2), as long as these sources are located more than 50 
kilometers from any Class I area; and sources that emit less than 
1000 tons per year of NOX or SO2 (or combined 
NOX and SO2) that are located more than 100 
kilometers from any Class I area.'' (See 40 CFR 51, appendix Y, 
section III, How to Identify Sources ``Subject to BART.'') The 
values described equate to a Q/D of 10.
---------------------------------------------------------------------------

    South Dakota undertook a more detailed analysis of the two sources 
that exceeded a Q/D of 10, Black Hills Ben French and GCC Dacotah. 
These sources are further described below in Table 15.

                   Table 15--South Dakota Sources for Reasonable Progress Four-Factor Analyses
----------------------------------------------------------------------------------------------------------------
                                                                                    SO2 actual      NOX actual
                                                                                      average         average
            Source                   Unit             Type           Capacity     emissions 2002  emissions 2002
                                                                                     (tons/yr)       (tons/yr)
----------------------------------------------------------------------------------------------------------------
Black Hills, Ben French Power  Unit 1 Boiler..  EGU............  25 MWe.........             785             907
 Plant.
GCC Dacotah                    Wet Kiln 4.....  Cement Plant...  550 tons                     26             707
                                                                  clinker/day.
                               Wet Kiln 5.....  Cement Plant...  550 tons                    431             388
                                                                  clinker/day.
                               Wet Kiln 6 \1\.  Cement Plant...  2,250 tons                  885           2,267
                                                                  clinker/day.
----------------------------------------------------------------------------------------------------------------
\1\ South Dakota opted not to include Kiln 6 in its four-factor analysis as further described in the State's
  conclusions in section III.D.3 below.

[[Page 76662]]

Four-Factor Analysis
    The control options and costs that South Dakota considered were 
derived, in part, from the EC/R report. EPA also requested South Dakota 
consider SNCR at GCC Dacotah which was not included in the EC/R report. 
For the Black Hills Ben French and GCC Dacotah reasonable progress 
sources, SO2 and NOX are uncontrolled, although 
the Black Hills Ben French facility uses low-sulfur coal (0.33 wt%) to 
minimize formation of SO2 during combustion.
Cost of Compliance
    Tables 16 and 17 show the cost of compliance for the control 
technologies evaluated for each of the reasonable progress sources.

                          Table 16--Control Option Costs for Reasonable Progress Source Black Hills, Ben French Power Plant \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Pollutant                Control option       2002     Control efficiency        Reductions                              Cost effectiveness
-------------------------------------------------------------------------------------------------------------  Capital     Annual       range ($/ton)
                                                                                                                 cost       cost   ---------------------
                                                       (tons/yr)      %          %      (tons/yr)  (tons/yr)   ($1000)    ($1000)    High end   Low end
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX.............................  LNB................        907         30         75        272        680      1,250        195        717        287
                                 -----------------------------------------------------------------------------------------------------------------------
                                  LNB w/OFA..........        907         50         65        454        590      1,780        298        656        505
                                 -----------------------------------------------------------------------------------------------------------------------
                                  SNCR...............        907         30         75        272        680      1,290        770      2,831      1,132
                                 -----------------------------------------------------------------------------------------------------------------------
                                  SCR................        907         40         90        363        816      3,000        754      2,077        924
                                                                                                             -------------------------------------------
                                                                                                                  4,250      1,068      2,942      1,309
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2.............................  Dry Sorbent                785         10         40         79        314      4,300      1,700     21,519      5,414
                                   Injection.
                                 -----------------------------------------------------------------------------------------------------------------------
                                  Spray Dryer                785  .........         90  .........        707     11,600      2,670  .........      3,777
                                   Absorber.
                                 -----------------------------------------------------------------------------------------------------------------------
                                  Wet FGD............        785  .........         90  .........        707     14,600      2,760  .........      3,904
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The cost analysis was based on a 30-year equipment life. Black Hills indicated the expected life of the Ben French power plant is 10 years. South
  Dakota conducted an additional analysis with a 10-year equipment life. The 10-year evaluation resulted in slightly higher average cost effectiveness
  values but did not change the outcome of the analysis. All controls are cost effective with the exception of the dry sorbent injection at the lowest
  end of the control efficiency range which would not reflect the true performance capability of the technology; we consider the high end of the range
  to be most appropriate.

                               Table 17--Control Option Costs for Reasonable Progress Source GCC Dacotah, Cement Plant \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
           Pollutant               Control option       2002     Control efficiency        Reductions                                Cost effectiveness
-----------------------------------------------------------------------------------------------------------  Capital   Annual cost      range ($/ton)
                                                                                                               cost       ($1000)  ---------------------
                                                     (tons/yr)      %          %      (tons/yr)  (tons/yr)   ($1000)                 High end   Low end
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Wet Kiln 4
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX............................  LNB (indirect)....        707         30         40        212        283        526          129        608        456
                                ------------------------------------------------------------------------------------------------------------------------
                                 LNB (direct)......        707  .........         40  .........        283      1,873          331  .........      1,170
                                ------------------------------------------------------------------------------------------------------------------------
                                 Biosolids                 707  .........         23  .........        163  .........  ...........        \2\        \2\
                                  Injection.
                                ------------------------------------------------------------------------------------------------------------------------
                                 CemStar...........        707         20         60        141        424      1,599          299      2,121        705
                                ------------------------------------------------------------------------------------------------------------------------
                                 Mid-Kiln..........        707         20         50        141        354      2,748         -315        \3\        \3\
                                ------------------------------------------------------------------------------------------------------------------------
                                 LoTOxTM...........        707         80         90        566        636  .........  ...........        \2\        \2\
                                ------------------------------------------------------------------------------------------------------------------------
                                 SCR...............        707  .........         80  .........        566     14,813        4,137  .........      7,309
                                ------------------------------------------------------------------------------------------------------------------------
                                 SNCR..............        707         30         40        212        283  .........      878 \3\      4,142      3,102
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2............................  Wet FGD...........         26         90         99         23         26      9,133        1,370     59,565     52,692
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Wet Kiln 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX............................  LNB (indirect)....        388         30         40        116        155        526          129      1,112        832
                                ------------------------------------------------------------------------------------------------------------------------
                                 LNB (direct)......        388  .........         40  .........        155      1,873          331  .........      2,135
                                ------------------------------------------------------------------------------------------------------------------------
                                 Biosolids                 388  .........         23  .........         89  .........  ...........        \2\        \2\
                                  Injection.
                                ------------------------------------------------------------------------------------------------------------------------
                                 CemStar...........        388         20         60         78        233      1,599          299      3,833      1,283
                                ------------------------------------------------------------------------------------------------------------------------
                                 Mid-Kiln..........        388         20         50         78        194      2,748         -315        \3\        \3\
                                ------------------------------------------------------------------------------------------------------------------------
                                 LoTOxTM...........        388         80         90        310        349  .........  ...........        \2\        \2\
                                ------------------------------------------------------------------------------------------------------------------------
                                 SCR...............        388         30         40        116        155  .........      878 \3\      7,569      5,665
                                ------------------------------------------------------------------------------------------------------------------------
                                 SNCR..............        388  .........         80  .........        310     14,813        4,137  .........     13,345
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2............................  Wet FGD...........        431         90         99        388        427      9,133        1,370      3,531      3,208
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ South Dakota also did an analysis based on operating scenario with 50% fewer hours based on last five years of actual operations showing all costs
  would still be economical.

[[Page 76663]]

 
\2\ The EC/R report did not list a cost per ton because it did not identify any capital or annual costs.
\3\ South Dakota did not list a cost per ton because the annual cost was a negative number.

Time Necessary for Compliance
    While the State did not provide specifics on the time necessary for 
compliance, the EC/R report upon which the State relied for other 
aspects of its four-factor analysis found that up to 6.5 years after 
SIP approval would be necessary to achieve compliance with some of the 
control options. The State did not identify the time necessary for 
compliance as a factor that would preclude selection of any of the 
analyzed control options.
Energy and Non-Air Quality Impacts
    The State did not identify any energy or non-air quality impacts 
that would preclude selection of any of the analyzed control options. 
The EC/R report upon which the state relied for other aspects of its 
four-factor analysis describes the various potential energy and non-air 
quality impacts of various control technologies in general terms for 
consideration.
Remaining Useful Life of the Source
    South Dakota found the remaining useful life would be at least 10 
years for the Black Hills, Ben French Power Plant but also considered a 
30 year life in its cost analysis. South Dakota used a remaining useful 
life of at least 30 years for the GCC Dacotah Cement Plant Kiln 4 and 
Kiln 5 but generally questioned the accuracy of this based on much 
reduced operations over the past five years.
Visibility Improvement
    In addition to evaluating the four statutory factors, South Dakota 
also considered the baseline visibility impacts for each RP source 
based on maximum 24-hour emission rates for meteorological years 2002, 
2006, and 2007 compared to natural background. The CALPUFF modeling 
results for Black Hills Ben French and GCC Dacotah are summarized in 
Tables 18 and 19 below. The modeling reports are available in 
Appendices G and H of the SIP.

    Table 18--Summary of Baseline Visibility Impacts From Reasonable
          Progress Source Black Hills Ben French Unit 1 Boiler
                          [98th Percentile, dv]
------------------------------------------------------------------------
                  Year                       Badlands        Wind Cave
------------------------------------------------------------------------
2002....................................            0.21            0.22
2006....................................            0.23            0.23
2007....................................            0.20            0.30
------------------------------------------------------------------------

    Table 19--Summary of Baseline Visibility Impacts From Reasonable
                Progress Source GCC Dacotah Kilns 4 and 5
                          [98th Percentile, dv]
------------------------------------------------------------------------
                  Year                       Badlands        Wind Cave
------------------------------------------------------------------------
2002....................................            0.32            0.36
2006....................................            0.32            0.36
2007....................................            0.31            0.46
------------------------------------------------------------------------

3. South Dakota's Conclusions From the Four-Factor Analysis
    South Dakota declined to conduct a four-factor analysis for GCC 
Dacotah Kiln 6. In addressing a concern raised by the National Park 
Service \20\ during the public comment period for the GCC Dacotah 
Cement Plant, South Dakota provided an explanation in an email to EPA 
regarding its decision not to include GCC Dacotah's Kiln 6 in its four-
factor analysis for the facility and specifically, not to impose SNCR 
controls on that unit. \21\ As the State explained, GCC Dacotah 
submitted a PSD air quality application for an upgrade to Kiln 6 in 
November 2001. In issuing the PSD permit in 2003, South Dakota 
determined NOX BACT for Kiln 6 was the installation of 
staged combustion with a thermal efficient in-line low-NOX 
calciner complimented by a LNB with indirect firing in the kiln; South 
Dakota found that SNCR was not technically feasible for Kiln 6. GCC 
Dacotah installed the required NOX BACT controls. South 
Dakota also determined SO2 BACT for Kiln 6 and imposed a 
corresponding emissions limit.
---------------------------------------------------------------------------

    \20\ The National Park Service commented that South Dakota's 
reasonable progress analysis should also include Kiln 6 at 
GCC Dacotah as the National Park Service believes SNCR technology is 
a feasible control option for cement kilns. August 17, 2011 letter 
from NPS, John Bunyak to DENR, Rick Boddicker. This letter is 
included in the docket.
    \21\ Email from Rick Boddicker, DENR to Gail Fallon, EPA Region 
8 (October 11, 2011). This email is included in the docket.
---------------------------------------------------------------------------

    Based on the baseline visibility impacts, the State concluded that 
visibility benefits from controls at Ben French and GCC Dacotah would 
be small. Given the small benefits, the State concluded that additional 
controls during this planning period would not be warranted to achieve 
reasonable progress. The State did not include a discussion of its 
four-factor analyses in explaining the basis for its conclusion that 
additional controls are unwarranted but instead based its determination 
on the modeling of baseline visibility impacts.
4. Establishment of the Reasonable Progress Goals
    40 CFR 308(d)(1) of the Regional Haze Rule requires states to 
``establish goals (in deciviews) that provide for reasonable progress 
towards achieving natural visibility conditions'' for each Class I area 
of the state. These reasonable progress goals are interim goals that 
must provide for incremental visibility improvement for the most 
impaired visibility days, and ensure no degradation for the least 
impaired visibility days. The reasonable progress goals for the first 
planning period are goals for the year 2018.
    Based on (1) The results of the WRAP CMAQ modeling; (2) the results 
of the four-factor analysis of major South Dakota sources; and (3) the 
emission controls on South Dakota BART sources, South Dakota 
established reasonable progress goals for the most impaired days for 
both of South Dakota's Class I areas, as identified in Table 20 below. 
Also shown in Table 20 is a comparison of the reasonable progress goals 
to the uniform rate of progress for both Class I areas. The reasonable 
progress goals for the 20% worst days fall short of the uniform rate of 
progress by 1.28 and 1.34 deciviews for Badlands and Wind Cave, 
respectively.

[[Page 76664]]

  Table 20--Comparison of Reasonable Progress Goals to Uniform Rate of Progress on Most Impaired Days for South
                                              Dakota Class I Areas
----------------------------------------------------------------------------------------------------------------
                                                   Visibility conditions on 20% worst days (dv)
                                                 ------------------------------------------------
                                                    Average for                                    Percentage of
            South Dakota class I area             20% worst days                     RPG (WRAP     URP achieved
                                                  (baseline 2000-  2018 URP goal    projection)
                                                       2004)
----------------------------------------------------------------------------------------------------------------
Badlands National Park..........................           17.14           15.02           16.30              40
Wind Cave National Park.........................           15.84           13.94           15.28              29
----------------------------------------------------------------------------------------------------------------

    South Dakota's reasonable progress goals for Badlands for 2018 for 
the 20% worst days represent a 0.84 deciviews improvement over baseline 
and its reasonable progress goals for Wind Cave for 2018 represent a 
0.56 deciviews improvement over baseline. South Dakota's reasonable 
progress goals establish a slower rate of progress than the uniform 
rate of progress. South Dakota has calculated that under the rate of 
progress represented by its reasonable progress goals, South Dakota 
would attain natural visibility conditions in the year 2265 for 
Badlands and 2236 for Wind Cave, or 201 and 172 years, respectively, 
beyond 2064.
    Table 21 provides a comparison of South Dakota's reasonable 
progress goals to baseline conditions on the least impaired days. This 
comparison demonstrates that South Dakota's reasonable progress goals 
will result in no degradation in visibility conditions in the first 
planning period; instead, for the 20% best days, there would be a 
slight improvement in visibility from the baseline for both Class I 
areas.

Table 21--Comparison of Reasonable Progress Goals to Baseline Conditions on Least Impaired Days for South Dakota
                                                  Class I Areas
----------------------------------------------------------------------------------------------------------------
                                                                   Visibility conditions on 20%
                                                                          best days (dv)
                                                                 --------------------------------  Achieved ``no
                    South Dakota class I area                       Average for                    degradation''
                                                                   20% best days    RPG  (WRAP         (Y/N)
                                                                  (Baseline 2000-   projection)
                                                                       2004)
----------------------------------------------------------------------------------------------------------------
Badlands National Park..........................................            6.89            6.64               Y
Wind Cave National Park.........................................            5.14            5.02               Y
----------------------------------------------------------------------------------------------------------------

    South Dakota believes the reasonable progress goals it established 
for the South Dakota Class I areas are reasonable, and that it is not 
reasonable to achieve the glide path in 2018, based on the State's 
findings from the four-factor analysis combined with its visibility 
analyses that indicate the benefit would be small.
5. Reasonable Progress Consultation
    In accordance with 40 CFR 51.308(d)(3)(i) and (ii), each state that 
causes or contributes to impairment in a Class I area in another state 
or states is required to consult with other states and demonstrate that 
it has included in its SIP all measures necessary to obtain its share 
of the emission reductions needed to meet the progress goals for the 
Class I area. If the state has participated in a regional planning 
process, the state must ensure it has included all measures needed to 
achieve its apportionment of emission reduction obligations agreed upon 
through that process.
    South Dakota consulted directly with neighboring states through the 
WRAP, and relied on the technical tools, policy documents, and other 
products that all western states used to develop their regional haze 
plans. Discussions with neighboring states included review of major 
contributing sources of air pollution, as documented in numerous WRAP 
reports and projects. The focus of this review process was interstate 
transport of emissions, major sources believed to be contributing, and 
whether any mitigation measures were needed. All the states relied upon 
similar emission inventories, results from source apportionment studies 
and BART modeling, review of IMPROVE monitoring data, existing state 
smoke management programs, and other information in assessing the 
extent to which each state contributes to visibility impairment other 
states' Class I areas.
    The WRAP Implementation Work Group was one of the primary 
collaboration mechanisms. South Dakota participated in WRAP and worked 
with other states that are not members of WRAP (including Minnesota and 
Nebraska) in developing its SIP. Otter Tail Power Company's Big Stone I 
facility is the only source in South Dakota that is reasonably 
anticipated to contribute to visibility impairment with visibility 
impacts greater than 0.5 deciviews at a Class I area. This facility is 
predicted to contribute to visibility impairment at the Badlands 
National Park in South Dakota; Theodore Roosevelt National Park in 
North Dakota; Boundary Waters Canoe Area Wilderness and Voyageurs 
National Park in northern Minnesota and the Isle Royale National Park 
in Michigan. Otter Tail Power Company developed a case-by-case BART 
analysis that South Dakota reviewed to establish the BART emission 
limits for Big Stone I. The case-by-case BART analysis and South 
Dakota's review were submitted to the appropriate states for their 
comments. South Dakota established BART procedures in the 
Administrative Rules of South Dakota that are equivalent to Federal 
regulation in 40 CFR part 51 and adopted the BART emission limits and 
monitoring recordkeeping and reporting requirements applicable to BART-
eligible coal fired power plants (which

[[Page 76665]]

includes Big Stone I) in the rule. The requirements will eventually be 
adopted in Otter Tail Power Company's Title V air quality operating 
permit for the Big Stone I facility. South Dakota believes the BART 
requirements represent South Dakota's fair share of emission reductions 
for Class I areas impacted by emissions from South Dakota sources and 
other states provided no adverse comments.
    40 CFR 51.308(d)(3)(ii) of the Regional Haze Rule requires a state 
to demonstrate that its regional haze plan includes all measures 
necessary to obtain its fair share of emission reductions needed to 
meet reasonable progress goals. Based on the consultation described 
above, South Dakota identified no major contributions that supported 
developing new interstate strategies, mitigation measures, or emission 
reduction obligations. Both South Dakota and neighboring states agreed 
that the implementation of BART and other existing measures in state 
regional haze plans were sufficient for the states to meet the 
reasonable progress goals for their Class I areas, and that future 
consultation would address any new strategies or measures needed.
6. Our Conclusion on South Dakota's Reasonable Progress Goals
    We are proposing to approve South Dakota's conclusion that it is 
not reasonable to meet the uniform rate of progress for Badlands and 
Wind Cave by 2018. Where a state has established a reasonable progress 
goal that provides for a slower rate of improvement in visibility than 
the rate that would be needed to attain natural conditions by 2064, the 
state must demonstrate, based on the four statutory factors that the 
rate of progress for the implementation plan to attain natural 
conditions by 2064 is not reasonable and that the progress goal adopted 
by the State is reasonable. While South Dakota undertook a four-factor 
analyses which it described in its SIP, the State made the 
determination not to impose additional controls for reasonable progress 
at the facilities in South Dakota most likely to have the largest 
source-specific impacts. The State based that determination on the 
modeled baseline visibility impacts for the facilities.
    EPA proposes to approve the State's determination that it is not 
reasonable to achieve the uniform rates of progress at Badlands and 
Wind Cave and that the reasonable progress goals adopted by the State 
are reasonable based on consideration of the following:
    a. Findings from the four-factor analysis along with the State's 
baseline visibility analyses indicate likely visibility benefits from 
the most cost-effective controls would be small.
    b. Sources outside South Dakota--including other states and 
Canada--contribute most of the visibility impairing pollutants at Class 
I areas in South Dakota, with South Dakota's emissions ranging from 2 
to 18 percent of the total emissions for each type of pollutant.
    c. On the 20 percent most impaired days, sulfate and organic carbon 
are the two greatest contributors to visibility impairment at both 
Class I areas. The four-factor analyses performed by the State show the 
costs for controlling SO2 at these facilities is excessive, 
given the minimal visibility benefits from such controls. Much of the 
organic carbon emissions are from natural fires that cannot be 
controlled.
    d. Although, as noted in Table 20 above, the reasonable progress 
goals for Badlands and Wind Cave fall short of the uniform rate of 
progress, these goals are based on the WRAP CMAQ modeling and the WRAP 
2018 projections. As South Dakota discussed in the SIP, the WRAP 2018 
projections overestimated emissions of visibility-impairing pollutants 
from sources in South Dakota. It is therefore likely that the actual 
rate of progress will be closer to the uniform rate of progress.
    We also agree with South Dakota's conclusion that it appropriately 
consulted with other states for this planning period. We also agree 
with South Dakota's determination that it needed no further controls 
beyond those already contained in the SIP to address impacts on Class I 
areas in other states. Finally, we are proposing to approve South 
Dakota's conclusion that no additional controls on non-BART sources are 
needed at this time. We expect South Dakota to evaluate additional 
controls for the sources below and other sources during the next 
regional haze planning period.
    Below we discuss each reasonable progress source and EPA's 
conclusions regarding the State's reasonable progress determination.
Black Hills, Ben French Unit 1
    EPA is proposing to approve the State's conclusion that no 
additional SO2 controls are warranted for this unit for this 
planning period. The cost effectiveness values range from $3,777 for a 
spray dryer absorber to $21,519 per ton for the least efficient dry 
sorbent injection option. Based on the cost effectiveness values and 
the minimal visibility benefits from controlling this unit, we find 
that South Dakota reasonably rejected additional SO2 
controls during this planning period.
    EPA is proposing to approve the State's conclusion that no 
additional NOX controls are warranted for this unit for this 
planning period. The cost effectiveness values range from $287 for LNB 
to $2,942 per ton for SCR. Some of these costs are reasonable. However, 
South Dakota also considered the visibility impacts--it modeled 
visibility impacts of 0.23 deciviews at Badlands and 0.30 deciviews at 
Wind Cave from all emissions from the source--and any visibility 
improvement that would result from additional NOX controls 
alone would be significantly less than these values. When the costs are 
weighed against visibility improvement, South Dakota's determination 
that additional controls of NOX are not warranted in this 
planning period is reasonable, and we are proposing to approve it.

    GCC Dacotah Kilns 4, 5, and 6

    EPA is proposing to approve the State's conclusion that no 
additional SO2 controls are warranted for Kilns 4 and 5 for 
this planning period. The cost effectiveness values for a new wet FGD 
system range from $52,692 to $59,565 per ton on Kiln 4 and from $3,208 
to $3,531 per ton on Kiln 5. Based on the cost effectiveness values and 
South Dakota's modeling of baseline visibility impacts from Kilns 4 and 
5, we find that South Dakota reasonably rejected additional 
SO2 controls during this planning period.
    EPA is proposing to approve the State's conclusion that no 
additional NOX controls for Kilns 4 and 5 are reasonable for 
this planning period. For Kiln 4, the cost effectiveness values range 
from $456 per ton for LNB to $7,309 per ton for SCR. For Kiln 5 the 
cost effectiveness values range from $832 per ton for LNB to $13,345 
per ton for SCR. Some of these costs are reasonable. However, South 
Dakota modeled the baseline visibility impacts from Kilns 4 and 5 
combined--0.32 deciviews at Badlands and 0.46 at Wind Cave--and any 
visibility benefits that would result from additional NOX 
controls alone would be significantly less than these values. We 
therefore propose to find that South Dakota reasonably rejected 
additional NOX controls during this planning period.
    EPA is also proposing to approve the State's determination that no 
additional NOX or SO2 controls are required on 
Kiln 6. During this planning period, it is reasonable for the State to 
rely on the relatively recent NOX and SO2 BACT 
determinations in the 2003 PSD permit for Kiln 6. However, during the 
next

[[Page 76666]]

planning period, the State should reconsider these determinations.

E. LTS

    As described in section II.E of this action, the LTS is a 
compilation of state-specific control measures relied on by the state 
for achieving its reasonable progress goals. 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. 40 
CFR 51.308(d)(3). South Dakota'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 South Dakota LTS was developed 
by South Dakota, in coordination with the WRAP, through an evaluation 
of the following components: (1) WRAP emission inventories for a 2002 
baseline and a 2018 projection (including reductions from WRAP member 
state controls required or expected under Federal and state regulations 
(including BART)); (2) modeling to determine visibility improvement and 
apportion individual state contributions; (3) state consultation; and 
(4) application of the LTS factors. The State's detailed LTS is 
included in Section 8 of the Regional Haze SIP.
1. Emissions Inventories
    40 CFR 51.308(d)(3)(iii) requires that South Dakota document the 
technical basis, including modeling, monitoring, and emissions 
information, on which it relied to determine its apportionment of 
emission reduction obligations necessary for achieving reasonable 
progress in each mandatory Class I Federal area it affects. South 
Dakota must identify the baseline emissions inventory on which its 
strategies are based. 40 CFR 51.308(d)(3)(iv) requires that South 
Dakota identify all anthropogenic (human-caused) sources of visibility 
impairment it considered in developing its LTS. This includes major and 
minor stationary sources, mobile sources, and area sources. In its 
efforts to meet these requirements, South Dakota relied on technical 
analyses developed by WRAP and approved by all state participants, as 
described below.
    Emissions within South Dakota are both naturally occurring and man-
made. Two primary sources of naturally occurring emissions include 
wildfires and windblown dust. In South Dakota, the primary sources of 
anthropogenic emissions include electric utility steam generating 
units, energy production and processing sources, agricultural 
production and processing sources, prescribed burning, and fugitive 
dust sources. The South Dakota inventory includes emissions of 
SO2, NOX, PM2.5, PM10, 
primary organic aerosol, elemental carbon, VOCs, NH3, and 
CO. See Section 5 of the SIP.
    An emissions inventory for each pollutant was developed by WRAP for 
South Dakota for the baseline year 2002 and for 2018, which is the 
first reasonable progress milestone.\22\ The 2018 emissions inventory 
was developed by projecting 2002 emissions and applying reductions 
expected from Federal and state regulations. The emission inventories 
developed by WRAP were calculated using approved EPA methods.
---------------------------------------------------------------------------

    \22\ These inventories, in addition to being available in 
Section 5 of the SIP, are also available at http://vista.cira.colostate.edu/TSS/Results/HazePlanning.aspx.
---------------------------------------------------------------------------

    There are 10 different emission inventory source categories 
identified in the South Dakota regional haze Plan: point, area, oil and 
gas, on-road, off-road, all fire, biogenic, road dust, fugitive dust 
and windblown dust. Tables 22 through 30 show the 2002 baseline 
emissions, the 2018 projected emissions, and net changes of emissions 
for SO2, NOX, primary organic aerosol, elemental 
carbon, PM2.5, PM10, NH3, VOC and 
carbon monoxide (CO) by source category in South Dakota. The methods 
that WRAP used to develop these emission inventories are described in 
more detail in Section 5 of the SIP and in the EPA WRAP Technical 
Support Document (TSD).

                        Table 22--South Dakota SO2 Emission Inventory--2002 and 2018 \1\
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide SO2 Emissions  [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................            14,037            11,996            -2,041               -15
Big Stone I \2\.........................            11,171             3,425            -7,746               -69
All Fire................................               469               465                -4                -1
Biogenic................................                 0                 0                 0                 0
Area....................................             1,198             1,789               591                49
Oil and Gas.............................                 6                 0                -6              -100
On-Road Mobile..........................               922               129              -793               -86
Off-Road Mobile.........................             6,066               199            -5,867               -97
Road Dust...............................                 4                 5                 1                25
Fugitive Dust...........................                24                26                 2                 8
Wind Blown Dust.........................                 0                 0                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................            22,726            14,609            -8,117              -36
----------------------------------------------------------------------------------------------------------------
\1\ SO2 emissions shown include both gas and particulate.
\2\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.

    In 2018, South Dakota's sulfate contribution switched mainly to 
point and area sources, and like other states and regions in the United 
States, mobile source contributions are minimal due to new changes in 
Federal emission standards from mobile sources.

[[Page 76667]]

                        Table 23--South Dakota NOX Emission Inventory--2002 and 2018 \1\
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide NOX Emissions  [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................            20,699            30,186             9,487                46
Big Stone I \2\.........................            14,552            15,323               771                 5
All Fire................................             1,713             1,694               -19                -1
Biogenic................................            52,852            52,852                 0                 0
Area....................................             2,903             3,309               406                14
Oil and Gas.............................               361               557               196                54
On-Road Mobile..........................            29,224             8,059           -21,165               -72
Off-Road Mobile.........................            39,039            23,785           -15,254               -39
Road Dust...............................                 5                 6                 1                20
Fugitive Dust...........................                27                27                 0                 0
Wind Blown Dust.........................                 0                 0                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................           146,823           120,475           -26,348              -18
----------------------------------------------------------------------------------------------------------------
\1\ NOX emissions shown include both gas and particulate.
\2\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions row but separated
  for comparison.

                Table 24--South Dakota Primary Organic Aerosol Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                      South Dakota Statewide Primary Organic Aerosol Emissions [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category               Baseline  2002      Future 2018       Net  change     Percent  change
----------------------------------------------------------------------------------------------------------------
Point...................................                10                 8                -2               -20
Big Stone I \1\.........................                 0                 0                 0  ................
All Fire................................             4,574             4,531               -43                -1
Biogenic................................                 0                 0                 0  ................
Area....................................             1,792             1,769               -23                -1
Oil and Gas.............................                 0                 0                 0  ................
On-Road Mobile..........................               278               270                -8                -3
Off-Road Mobile.........................               942               386              -556               -59
Road Dust...............................               255               325                70                27
Fugitive Dust...........................             1,317             1,322                 5                 0
Wind Blown Dust.........................                 0                 0                 0  ................
                                         -----------------------------------------------------------------------
    Total...............................             9,168             8,611              -557               -6
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.

                    Table 25--South Dakota Elemental Carbon Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                          South Dakota Statewide Elemental Carbon Emissions [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................                 0                 0                 0                 0
All Fire................................               717               715                -2                 0
Biogenic................................                 0                 0                 0                 0
Area....................................               306               314                 8                 0
Area Oil and Gas........................                 0                 0                 0                 0
On-Road Mobile..........................               339                86              -253               -75
Off-Road Mobile.........................             3,234             1,072            -2,162               -67
Road Dust...............................                18                23                 5                28
Fugitive Dust...........................                89                90                 1                 1
Wind Blown Dust.........................                 0                89                89                 *
                                         -----------------------------------------------------------------------
    Total...............................             4,703             2,389            -2,314              -49
----------------------------------------------------------------------------------------------------------------
* Greater than 100.

    As detailed in Tables 26 and 27, the primary sources of PM (both 
PM2.5 and PM10) are road, fugitive and windblown 
dust (agriculture, construction, and unpaved and paved roads).

[[Page 76668]]

                         Table 26--South Dakota PM2.5 Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                               South Dakota Statewide PM2.5 Emissions [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................               216               205               -11                -5
Big Stone I \1\.........................               209                 0              -209              -100
All Fire................................               839               821               -18                -2
Biogenic................................                 0                 0                 0                 0
Area....................................             1,804             1,920               116                 6
Area Oil and Gas........................                 0                 0                 0                 0
On-Road Mobile..........................                 0                 0                 0                 0
Off-Road Mobile.........................                 0                 0                 0                 0
Road Dust...............................             4,061             5,190             1,129                28
Fugitive Dust...........................            25,220            25,840               620                 2
Wind Blown Dust.........................            50,274            50,274                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................            82,414            84,250               -11               -5
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.

                          Table 27--South Dakota PM10 Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide PM10 Emissions [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................               727             9,847             9,120                 *
Big Stone I \1\.........................               209               318               109                52
All Fire................................               754               751                -3                 0
Biogenic................................                 0                 0                 0                 0
Area....................................               156               190                34                22
Area Oil and Gas........................                 0                 0                 0                 0
On-Road Mobile..........................               169               188                19                 0
Off-Road Mobile.........................                 0                 0                 0                 0
Road Dust...............................            38,164            48,773            10,609                28
Fugitive Dust...........................           122,914           129,009             6,095                 5
Wind Blown Dust.........................           452,470           452,470                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................           615,354           641,228            25,874                4
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.
* Greater than 100.

                          Table 28--South Dakota NH3 Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide NH3 Emissions [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category                Baseline 2002      Future 2018       Net change      Percent change
----------------------------------------------------------------------------------------------------------------
Point...................................               100               102                 2                 2
Big Stone I \1\.........................                29                 0               -29              -100
All Fire................................               562               553                -9                -2
Biogenic................................                 0                 0                 0                 0
Area....................................           118,877           118,992               115                 0
Area Oil and Gas........................                 0                 0                 0                 0
On-Road Mobile..........................               842             1,075               233                 0
Off-Road Mobile.........................                25                36                11                 0
Road Dust...............................                 0                 0                 0                 0
Fugitive Dust...........................                 0                 0                 0                 0
Wind Blown Dust.........................                 0                 0                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................           120,406           120,758               352                0
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.

[[Page 76669]]

                          Table 29--South Dakota VOC Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide VOC Emissions  [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category               Baseline  2002     Future  2018       Net  change     Percent  change
----------------------------------------------------------------------------------------------------------------
Point...................................             2,542             4,510             1,968                77
Big Stone I \1\.........................               107               112                 5                 5
All Fire................................             3,853             3,808               -45                -1
Biogenic................................           445,241           445,241                 0                 0
Area....................................            40,511            49,659             9,148                23
Area Oil and Gas........................            33,721               562           -33,159                 0
On-Road Mobile..........................            13,741             5,101            -8,640                 0
Off-Road Mobile.........................            12,764             7,686            -5,078                 0
Road Dust...............................                 0                 0                 0                 0
Fugitive Dust...........................                 0                 0                 0                 0
Wind Blown Dust.........................                 0                 0                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................           552,373           516,567           -35,806               -6
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.

                           Table 30--South Dakota CO Emission Inventory--2002 and 2018
----------------------------------------------------------------------------------------------------------------
                                South Dakota Statewide CO Emissions  [Tons/year]
-----------------------------------------------------------------------------------------------------------------
             Source category               Baseline  2002     Future  2018       Net  change     Percent  change
----------------------------------------------------------------------------------------------------------------
Point...................................             4,700            16,632            11,932                 *
Big Stone I \1\.........................               490               509                19                 4
All Fire................................            64,326            63,843              -483                -1
Biogenic................................           103,402           103,402                 0                 0
Area....................................            23,029            23,773               744                 3
Area Oil and Gas........................                11                16                 5                 0
On-Road Mobile..........................           221,726           120,041          -101,685                 0
Off-Road Mobile.........................            92,508            95,276             2,768                 0
Road Dust...............................                 0                 0                 0                 0
Fugitive Dust...........................                 0                 0                 0                 0
Wind Blown Dust.........................                 0                 0                 0                 0
                                         -----------------------------------------------------------------------
    Total...............................           509,702           422,983           -86,719               -17
----------------------------------------------------------------------------------------------------------------
\1\ Otter Tail Power Company's Big Stone I emissions are included in the ``Point'' emissions but separated for
  comparison.
* Greater than 100.

2. Sources of Visibility Impairment in South Dakota Class I Areas
    In order to determine the significant sources contributing to haze 
in South Dakota's Class I areas, South Dakota relied upon two source 
apportionment analysis techniques developed by the WRAP. The first 
technique was regional modeling using the Comprehensive Air Quality 
Model (CAMx) and the PM Source Apportionment Technology (PSAT) tool, 
used for the attribution of sulfate and nitrate sources only. The 
second technique was the Weighted Emissions Potential (WEP) tool, used 
for attribution of sources of organic carbon, elemental carbon, 
PM2.5 and PM10. The WEP tool is based on 
emissions and residence time, not modeling.
    PSAT uses the CAMx air quality model to show nitrate-sulfate-
ammonia chemistry and apply this chemistry to a system of tracers or 
``tags'' to track the chemical transformations, transport, and removal 
of NOX and SO2. These two pollutants are 
important because they tend to originate from anthropogenic sources. 
Therefore, the results from this analysis can be useful in determining 
contributing sources that may be controllable, both in-state and in 
neighboring states.
    WEP is a screening tool that helps to identify source regions that 
have the potential to contribute to haze formation at specific Class I 
areas. Unlike PSAT, this method does not account for chemistry or 
deposition. The WEP combines emissions inventories, wind patterns and 
residence times of air masses over each area where emissions occur, to 
estimate the percent contribution of different pollutants. Like PSAT, 
the WEP tool compares baseline values (2000-2004) to 2018 values, to 
show the improvement expected by 2018, for sulfate, nitrate, organic 
carbon, elemental carbon, PM2.5 and PM10. More 
information on the WRAP modeling methodologies is available in the EPA 
WRAP TSD.
    The PSAT and WEP results for South Dakota are provided in Sections 
4 and 5 of the SIP. See the EPA WRAP TSD for details on how the 2018 
emissions inventory was constructed. WRAP and South Dakota used this 
inventory and other states' 2018 emission inventories to construct 
visibility projection modeling for 2018.
3. Visibility Projection Modeling
    The Regional Modeling Center (RMC) at the University of California 
Riverside, under the oversight of the WRAP Modeling Forum, performed 
modeling for the regional haze LTS for the WRAP member states, 
including South Dakota. The modeling analysis is a complex technical 
evaluation that began with selection of the modeling system. The RMC 
primarily used the CMAQ

[[Page 76670]]

photochemical grid model to estimate 2018 visibility conditions in 
South Dakota and all western Class I areas, based on application of the 
regional haze strategies in the various state plans, including assumed 
controls on BART sources.
    The RMC developed air quality modeling inputs, including annual 
meteorology and emissions inventories for: (1) A 2002 actual emissions 
base case; (2) a planning case to represent the 2000-2004 regional haze 
baseline period using averages for key emissions categories; and (3) a 
2018 base case of projected emissions determined using factors known at 
the end of 2005. All emission inventories were spatially and temporally 
allocated using the SMOKE modeling system. Each of these inventories 
underwent a number of revisions throughout the development process to 
arrive at the final versions used in CMAQ modeling. The WRAP states' 
modeling was developed in accordance with our guidance.\23\ A more 
detailed description of the CMAQ modeling performed for the WRAP can be 
found in Section 5 of the SIP and in the EPA WRAP TSD.
---------------------------------------------------------------------------

    \23\ Guidance on the Use of Models and Other Analyses for 
Demonstrating Attainment of Air Quality Goals for Ozone, 
PM2.5, and Regional Haze, (EPA-454/B-07-002), April 2007, 
located at http://www.epa.gov/scram001/guidance/guide/final-03-p.m.-rh-guidance.pdf Emissions Inventory Guidance for Implementation of 
Ozone and Particulate Matter National Ambient Air Quality Standards 
(NAAQS) and Regional Haze Regulations, August 2005, updated November 
2005 (``our Modeling Guidance''), located at http://www.epa.gov/ttnchie1/eidocs/eiguid/index.html, EPA-454/R-05-001.
---------------------------------------------------------------------------

    The photochemical modeling of regional haze for the WRAP states for 
2002 and 2018 was conducted on the 36-km resolution national regional 
planning organization domain that covered the continental United 
States, portions of Canada and Mexico, and portions of the Atlantic and 
Pacific Oceans along the east and west coasts. The RMC 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 2002 modeling efforts were used to evaluate air 
quality/visibility modeling for a historical episode--in this case, for 
calendar year 2002--to demonstrate the suitability of the modeling 
systems for subsequent planning, sensitivity and emissions control 
strategy modeling. Model performance evaluation compares output from 
model simulations with ambient air quality data for the same time 
period to determine whether model performance is sufficiently accurate 
to justify using the model to simulate future conditions. Once the RMC 
determined that model performance was acceptable, it used the model to 
determine the 2018 reasonable progress goals using the current and 
future year air quality modeling predictions, and compared the 
reasonable progress goals to the uniform rate of progress.
4. Consultation and Emissions Reductions for Other States' Class I 
Areas
    40 CFR 51.308(d)(3)(i) requires that South Dakota consult with 
another state if its emissions are reasonably anticipated to contribute 
to visibility impairment in that state's Class I area(s), and that 
South Dakota consult with other states if those other states' emissions 
are reasonably anticipated to contribute to visibility impairment at 
Badlands or Wind Cave. South Dakota's consultations with other states 
are described in section III.D.5 above. After evaluating whether 
emissions from South Dakota sources contribute to visibility impairment 
in other states' Class I areas, South Dakota concluded that Otter Tail 
Power Company's Big Stone I facility was the only source in South 
Dakota that is reasonably anticipated to contribute to visibility 
impairment of a Class I are in another state. South Dakota's evaluation 
relied upon NOX and SO2 BART and reasonable 
progress reductions as described in the SIP. South Dakota did consult 
with other states and tribes, largely through the WRAP process, in 
order to meet the regulatory requirements. South Dakota also worked 
with states that are not members of WRAP including Minnesota and 
Nebraska.
    40 CFR 51.308(d)(3)(ii) requires that if South Dakota emissions 
cause or contribute to impairment in another state's Class I area, 
South Dakota must demonstrate that it has included in its Regional Haze 
SIP all measures necessary to obtain its share of the emission 
reductions needed to meet the progress goal for that Class I area. 
Section 51.308(d)(3)(ii) also requires that, since South Dakota 
participated in a regional planning process, it must ensure it has 
included all measures needed to achieve its apportionment of emission 
reduction obligations agreed upon through that process. As we state in 
the Regional Haze Rule, South Dakota's commitments to participate in 
WRAP bind it to secure emission reductions agreed to as a result of 
that process, unless it proposes a separate process and performs its 
consultations on the basis of that process. See 64 FR 35735.
    South Dakota accepted and incorporated the WRAP-developed 
visibility modeling into its Regional Haze SIP, and the Regional Haze 
SIP includes the controls assumed in the modeling. South Dakota 
satisfied the Regional Haze Rule's requirements for consultation and 
included controls in the SIP sufficient to address the relevant 
requirements of the Regional Haze Rule related to impacts on Class I 
areas in other states.
 5. Mandatory LTS Factors
    40 CFR 51.308(d)(3)(v) requires that South Dakota, at a minimum, 
consider certain factors in developing its LTS. The LTS factors are: 
(a) Emission reductions due to ongoing air pollution control programs, 
including measures to address RAVI; (b) measures to mitigate the 
impacts of construction activities; (c) emissions limitations and 
schedules for compliance to achieve the reasonable progress goals; (d) 
source retirement and replacement schedules; (e) smoke management 
techniques for agricultural and forestry management purposes including 
plans as currently exist within the state for these purposes; (f) 
enforceability of emissions limitations and control measures; and (g) 
the anticipated net effect on visibility due to projected changes in 
point, area and mobile source emissions over the period addressed by 
the LTS.
a. Reductions Due to Ongoing Air Pollution Programs
    In addition to its BART determinations, South Dakota's LTS 
incorporates emission reductions due to a number of ongoing air 
pollution control programs.
i. PSD/New Source Review Rules
    The two primary regulatory tools for addressing visibility 
impairment from industrial sources are BART and the PSD New Source 
Review rules. The PSD rules protect visibility in Class I areas from 
new industrial sources and major changes to existing sources. South 
Dakota's Air Pollution Control Rules (ARSD Chapter 74:36) contain 
requirements for visibility impact assessment and mitigation associated 
with emissions from new and modified major stationary sources. A 
primary responsibility of South Dakota under these rules is visibility 
protection. Chapter 74:36:09 and 74:36:10 describes mechanisms for 
visibility impact assessment and review by South Dakota, as well as 
impact modeling methods and requirements. Typically, this modeling is 
conducted for sources

[[Page 76671]]

within 300 kilometers of a Class I area. South Dakota will not issue an 
air quality permit to any new major source or major modification within 
this distance that is found through modeling to cause significant 
visibility impairment, unless the impact is mitigated.
ii. South Dakota's Phase I Visibility Protection Program
    EPA implemented a RAVI protection program in 1987 with a Federal 
Implementation Plan (FIP) for South Dakota to meet the general 
visibility plan requirements and long-term strategies of 40 CFR 51.302 
and 51.306, respectively. The existing Federal RAVI program is 
compatible with the regional haze program and no revisions are needed 
at this time. South Dakota indicated in the SIP that it will coordinate 
with EPA to conduct joint periodic reviews and revisions of the long-
term RAVI strategy as required by 40 CFR 51.306(c). South Dakota noted 
in its Regional Haze Plan that it may consider incorporation of the 
RAVI program into South Dakota's SIP in the future. See Section 8.5.1 
of the SIP.
iii. On-Going Implementation of State and Federal Mobile Source 
Regulations
    Mobile source annual emissions show a major decrease in 
NOX in South Dakota from 2002 to 2018. See Table 23 above. 
This reduction will result from numerous ``on the books'' Federal 
mobile source regulations. This trend is expected to provide 
significant visibility benefits. Beginning in 2006, EPA mandated new 
standards for on-road (highway) diesel fuel, known as ultra-low sulfur 
diesel. This regulation dropped the sulfur content of diesel fuel from 
500 parts per million (ppm) to 15 ppm. Ultra-low sulfur diesel fuel 
enables the use of cleaner technology diesel engines and vehicles with 
advanced emissions control devices, resulting in significantly lower 
emissions.
    Diesel fuel intended for locomotive, marine, and non-road (farming 
and construction) engines and equipment was required to meet a low 
sulfur diesel fuel maximum specification of 500 ppm sulfur in 2007 
(down from 5000 ppm). By 2010, the ultra-low sulfur diesel fuel 
standard of 15 ppm sulfur applied to all non-road diesel fuel. 
Locomotive and marine diesel fuel will be required to meet the ultra-
low sulfur diesel standard beginning in 2012, resulting in further 
reductions of diesel emissions.
b. Measures To Mitigate the Impacts of Construction Activities
    In developing its LTS, South Dakota has considered the impact of 
construction activities. Based on general knowledge of construction 
activity in the state, and without conducting extensive research on the 
contribution of emissions from construction activities to visibility 
impairment in South Dakota Class I areas, South Dakota found that 
current state regulations adequately address construction activities. 
Current rules addressing impacts from construction activities in South 
Dakota include ARSD 74:36:18, which regulates fugitive dust emissions 
for facilities in the Rapid City area.
c. Emission Limitation and Schedules of Compliance
    The SIP contains emission limits and schedules of compliance for 
the one source subject to BART--Otter Tail Power Company's Big Stone I. 
The schedule for implementation of BART for this source is identified 
in Section 6.4 of the SIP and in State rule ARSD 74:36:21 that we are 
proposing to approve with this SIP.
d. Source Retirement and Replacement Schedules
    The State does not anticipate major source retirements or 
replacements. Replacement of existing facilities will be managed 
according to the State's existing SIP. The 2018 modeling that WRAP 
conducted included emissions from two proposed coal-fired power plants 
and one proposed oil refinery in South Dakota. Although the PSD permit 
has been issued for one of the proposed coal-fired power plants, the 
applicant notified South Dakota that it is no longer going to build the 
plant. The second coal-fired power plant requested that South Dakota 
put its application on hold until further notice. Therefore, the next 
modeling exercise for determining visibility in 2018 will need to be 
adjusted to reflect these developments, and the current modeling 
results for 2018 are potentially conservative.
e. Agricultural and Forestry Smoke Management Techniques
    40 CFR 308(d)(3)(v)(E) of the Regional Haze Rule requires the LTS 
to address smoke management techniques for agricultural and forestry 
burning. As part of the long term strategy, South Dakota will 
investigate the impacts that a smoke management plan for wild fires and 
prescribed burns will have on the 20% most impaired days within the 
first planning period of 2013. Currently very little agricultural 
burning takes place in South Dakota and the majority of agricultural 
land lies in the eastern two-thirds of the State, while both Class I 
areas are in the western third. In addition, South Dakota did not 
observe any of the 20% most impaired days that were attributed to 
agricultural burning in the eastern half of South Dakota. Therefore, 
agricultural burning does not appear to have much of an impact on 
visibility at South Dakota's Class I areas. However, there is some 
grass burning in and around the Class I areas that South Dakota has 
committed to investigate to determine if this practice warrants being 
covered under a smoke management plan. See Section 8.5.5 of the SIP.
    Additionally, South Dakota is investigating prescribed burns 
conducted by the National Park Service and the U.S. Forest Service and 
the impact of prescribed burns on organic carbon mass, ammonia sulfide, 
and ammonia nitrate levels. South Dakota has observed there is evidence 
that fires contributed to the 20% most impaired days during the 
baseline period.
    South Dakota has taken the initial steps in developing a smoke 
management plan by contacting appropriate groups that will need to 
collaborate on this effort. South Dakota has been in contact with the 
South Dakota Division of Wildland Fire Suppression regarding their 
prescribed fire database to begin assessing the impacts from such fires 
on visibility at the State's Class I areas. South Dakota will continue 
working with the FLMs, other state agencies, and local governments 
during the development and implementation of the smoke management plan.
f. Enforceability of South Dakota's Measures
    40 CFR 51.308(d)(3)(v)(F) of the Regional Haze Rule requires states 
to ensure that emission limitations and control measures used to meet 
reasonable progress goals are enforceable. In addition to what is 
required by the Regional Haze Rule, general SIP requirements mandate 
that the SIP must also include adequate monitoring, recordkeeping, and 
reporting requirements for the regional haze emission limits and 
requirements. See CAA section 110(a). As noted, the SIP specifies BART 
emission limits and compliance schedules, and South Dakota has included 
such limits and compliance schedules in the state regional haze rule, 
ARSD 74:36:21, included in the regional haze SIP we are proposing to 
approve. These emission limits apply at all times, including periods of 
startup, shutdown, and

[[Page 76672]]

malfunction.\24\ In addition to specifying the limits and compliance 
schedules, the state rule specifies monitoring, recordkeeping and 
reporting requirements. South Dakota worked closely with EPA in 
developing these requirements. For SO2 and NOX 
limits, South Dakota has required the use of CEMS that must be operated 
and maintained in accordance with relevant EPA regulations, in 
particular, 40 CFR part 75. For PM limits, the SIP requires testing in 
accordance with EPA-approved test methods. The SIP requires that 
relevant records be kept for five years, and that sources report excess 
emissions on a quarterly basis.
---------------------------------------------------------------------------

    \24\ As noted above, with respect to the PM BART limits for Big 
Stone I Unit 1, because the SIP does not explicitly exempt emissions 
during malfunctions from the limits, we interpret the SIP to require 
compliance with the PM limits at all times (including malfunctions).
---------------------------------------------------------------------------

g. Anticipated Net Effect on Visibility Due to Projected Changes
    The anticipated net effect on visibility due to projected changes 
in point, area, and mobile source emissions during this planning period 
is addressed in sections III.E.3 above.
6. Our Conclusion on South Dakota's LTS
    South Dakota's LTS satisfies the requirements of 40 CFR 
51.308(d)(3), and we are proposing to approve it.

F. Coordination of RAVI and Regional Haze Requirements

    Our visibility regulations direct states to coordinate their RAVI 
LTS and monitoring provisions with those for regional haze, as 
explained in section II.F, above. Under our RAVI regulations, the RAVI 
portion of a state SIP must address any integral vistas identified by 
the FLMs pursuant to 40 CFR 51.304. See 40 CFR 51.302. An integral 
vista is defined in 40 CFR 51.301 as a ``view perceived from within the 
mandatory Class I federal area of a specific landmark or panorama 
located outside the boundary of the mandatory Class I federal area.'' 
Visibility in any mandatory Class I Federal area includes any integral 
vista associated with that area. The FLMs did not identify any integral 
vistas in South Dakota. In addition, there have been no certifications 
of RAVI for South Dakota Class I areas. The South Dakota Regional Haze 
SIP, in Sections 10.6.1 and 9.0, does address the two requirements 
regarding coordination of the regional haze LTS and monitoring 
provisions with the RAVI LTS and monitoring provisions. As noted in the 
Regional Haze SIP, South Dakota has made a commitment to coordinate the 
South Dakota regional haze long term strategy with EPA's RAVI FIP long 
term strategy. See Section 8.5.1 of the SIP. We propose to find that 
the Regional Haze SIP appropriately supplements and augments the EPA 
FIP for RAVI visibility provisions by updating the monitoring and LTS 
provisions to address regional haze. We discuss the relevant monitoring 
provisions further below.

G. Monitoring Strategy and Other SIP Requirements

    40 CFR 51.308(d)(4) requires that the SIP contain a monitoring 
strategy for measuring, characterizing, and reporting regional haze 
visibility impairment that is representative of all mandatory Class I 
Federal areas within the state. This monitoring strategy must be 
coordinated with the monitoring strategy required in 40 CFR 51.305 for 
RAVI. As 40 CFR 51.308(d)(4) notes, compliance with this requirement 
may be met through participation in the IMPROVE network. 40 CFR 
51.308(d)(4)(i) further requires the establishment of any additional 
monitoring sites or equipment needed to assess whether reasonable 
progress goals to address regional haze for all mandatory Class I 
Federal areas within the state are being achieved. Consistent with 
EPA's monitoring regulations for RAVI and regional haze, South Dakota 
indicates in Section 9.0 of the Regional Haze SIP that it will rely on 
the IMPROVE network for compliance purposes. The IMPROVE monitors at 
the South Dakota Class I Areas also described in Section 9.0 of the 
SIP. We propose to find that South Dakota has satisfied the 
requirements in 40 CFR 51.308(d)(4) enumerated in this paragraph.
    40 CFR 51.308(d)(4)(ii) requires that South Dakota establish 
procedures by which monitoring data and other information are used in 
determining the contribution of emissions from within South Dakota to 
regional haze visibility impairment at mandatory Class I Federal areas 
both within and outside the State. The IMPROVE monitoring program is 
national in scope, and other states have similar monitoring and data 
reporting procedures, ensuring a consistent and robust monitoring data 
collection system. As 40 CFR 51.308(d)(4) indicates, participation in 
the IMPROVE program constitutes compliance with this requirement. We 
therefore propose that South Dakota has satisfied this requirement.
    40 CFR 51.308(d)(4)(iv) requires that the SIP provide for the 
reporting of all visibility monitoring data to the Administrator at 
least annually for each mandatory Class I Federal area in the state. To 
the extent possible, South Dakota should report visibility monitoring 
data electronically. 40 CFR 51.308(d)(4)(vi) also requires that the SIP 
provide for other elements, including reporting, recordkeeping, and 
other measures, necessary to assess and report on visibility. We 
propose that South Dakota's participation in the IMPROVE network 
ensures that the monitoring data is reported at least annually and is 
easily accessible; therefore, such participation complies with this 
requirement.
    40 CFR 51.308(d)(4)(v) requires that South Dakota maintain a 
statewide inventory of emissions of pollutants that are reasonably 
anticipated to cause or contribute to visibility impairment in any 
mandatory Class I Federal 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. The State 
must also include a commitment to update the inventory periodically. 
Please refer to section III.E.1, above, where we discuss South Dakota's 
emission inventory. South Dakota states in Section 5.1 of the SIP that 
it intends to update the South Dakota statewide emissions inventories 
periodically and review periodic emissions information from other 
states and future emissions projections. We propose that this satisfies 
the requirement.

H. FLM Coordination

    Badlands and Wind Cave are both managed by the National Park 
Service, the FLM for these South Dakota Class I areas. Although the 
FLMs are very active in participating in the regional planning 
organizations, the Regional Haze Rule grants the FLMs a special role in 
the review of the regional haze SIPs, summarized in section II.H, 
above. The FLMs and the state environmental agencies are our partners 
in the regional haze process.
    Under 40 CFR 51.308(i)(2), South Dakota was obligated to provide 
National Park Service with an opportunity for consultation, in person 
and at least 60 days prior to holding a public hearing on the Regional 
Haze SIP. South Dakota sent a draft of its Regional Haze SIP to the 
National Park Service and other FLMs on January 15, 2010. South Dakota 
held a public hearing in front of the Board of Minerals and Environment 
on September 15, 2010. In July 2011, South Dakota provided the FLMs and 
others a draft of proposed amendments to the Regional Haze SIP. The 
FLMs provided comments to South Dakota's amended

[[Page 76673]]

submittal. The State held another public hearing on August 18, 2011.
    40 CFR 51.308(i)(3) requires that South Dakota provide in its 
Regional Haze SIP a description of how it addressed any comments 
provided by the FLMs. The FLMs communicated to the State (and EPA) 
their concerns on the January 15, 2010 draft Regional Haze SIP. South 
Dakota responded to the FLM's comments and concerns in Appendix D of 
the Regional Haze SIP. The National Park Service commented on the 
Regional Haze SIP amendment regarding its concerns pertaining to a 
reasonable progress four-factor analysis to evaluate controls at GCC 
Dacotah's Kiln 6 and additional consultation with Nebraska on Gerald 
Gentleman Station. South Dakota provided us with its rationale on GCC 
Dacotah's Kiln 6 which we discussed in section III.D.2. above. We also 
noted our agreement with the level of consultation with Nebraska for 
this planning period in section III.D.6. above. According to the 
Regional Haze Rule, South Dakota should consult with Nebraska during 
the next planning period.
    Lastly, 40 CFR 51.308(i)(4) specifies the regional haze SIP must 
provide procedures for continuing consultation between the state and 
FLMs on the implementation of the visibility protection program 
required by 40 CFR 51.308, including development and review of 
implementation plan revisions and 5-year progress reports, and on the 
implementation of other programs having the potential to contribute to 
impairment of visibility in mandatory Class I Federal areas. South 
Dakota commits in Section 10 of its Regional Haze SIP to continue to 
coordinate and consult with the FLMs as required by 40 CFR 
51.308(i)(4). South Dakota states that it intends to consult the FLMs 
in the development and review of implementation plan revisions; review 
of progress reports; and development and implementation of other 
programs that may contribute to impairment of visibility at South 
Dakota and other Class I areas.
    We are proposing that the State complied with the requirements of 
40 CFR 51.308(i).

I. Periodic SIP Revisions and Five-Year Progress Reports

    South Dakota commits in Section 11 of the SIP to complete items 
required in the future by the Regional Haze Rule. South Dakota 
acknowledged its obligation under 40 CFR 51.308(f) to submit periodic 
progress reports and Regional Haze SIP revisions, with the first report 
due by July 31, 2018 and every ten years thereafter.
    South Dakota acknowledged its obligation under 40 CFR 51.308(g) to 
submit a progress report in the form of a SIP revision to us every five 
years following the initial submittal of the Regional Haze SIP. The 
report will evaluate the progress made towards the reasonable progress 
goals for each mandatory Class I area located within South Dakota and 
in each mandatory Class I area located outside South Dakota that may be 
affected by emissions from within South Dakota.

IV. Proposed Action

    We are proposing to approve South Dakota's Regional Haze SIP 
revision, including ARSD Chapter 74:36:21, that was submitted on 
January 21, 2011 and an amendment to this submittal that was submitted 
on September 19, 2011.

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves state law as meeting Federal requirements, and 
it does not impose additional requirements beyond those imposed by 
state law. For that reason, this action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, this rule does not have tribal implications as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP is not approved to apply in Indian country located in 
the state, and EPA notes that it will not impose substantial direct 
costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxides, Particulate matter, Reporting and 
recordkeeping requirements, Sulfur dioxide, Volatile organic compounds.

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

    Dated: November 29, 2011.
Howard M. Cantor,
Acting Regional Administrator, EPA, Region 8.
[FR Doc. 2011-31406 Filed 12-7-11; 8:45 am]
BILLING CODE 6560-50-P