ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R10-OAR-2010-1072, FRL-       ]

Approval and Promulgation of Implementation Plans; State of Idaho;
Regional Haze State Implementation Plan and Interstate Transport Plan 

AGENCY: Environmental Protection Agency (EPA)

ACTION: Proposed rule.

SUMMARY: EPA is proposing to approve a State Implementation Plan (SIP)
revision submitted by the State of Idaho on October 25, 2010, as meeting
the requirements of Clean Air Act (CAA) section 110(a)(2)(D)(i)(II) as
it applies to visibility for the 1997 8-hour ozone and 1997 particulate
matter (PM2.5) National Ambient Air Quality Standards (NAAQS).  EPA is
also proposing to approve a portion of the revision as meeting certain
requirements of the regional haze program, including the requirements
for best available retrofit technology (BART). 

  

DATES: Written comments must be received at the address below on or
before [insert date 30 days from the date of publication in the Federal
Register] 

ADDRESSES: Submit your comments, identified by Docket ID No.
EPA-R10-OAR-2010-1072 by one of the following methods:

•   HYPERLINK http://www.regulations.gov www.regulations.gov . Follow
the on-line instructions for submitting comments.

• E-mail: R10-Public_Comments@epa.gov

• Mail: Steve Body, EPA Region 10, Suite 900, Office of Air, Waste and
Toxics, 1200 Sixth Avenue, Seattle, WA 98101

• Hand Delivery: EPA Region 10, 1200 Sixth Avenue, Suite 900, Seattle,
WA 98101.  Attention: Steve Body, Office of Air, Waste and Toxics,
AWT-107.  Such deliveries are only accepted during normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.  

Instructions: Direct your comments to Docket ID No.
EPA-R10-OAR-2010-1072. EPA's policy is that all comments received will
be included in the public docket without change and may be made
available online at   HYPERLINK http://www.regulations.gov
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 www.regulations.gov or e-mail. The  
HYPERLINK http://www.regulations.gov 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   HYPERLINK http://www.regulations.gov 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. 

Docket: All documents in the docket are listed in the   HYPERLINK
http://www.regulations.gov www.regulations.gov  index. Although listed
in the index, some information is not publicly available (e.g., CBI or
other information whose disclosure is restricted by statute). Certain
other material, such as copyrighted material, will be publicly available
only in hard copy form. Publicly available docket materials are
available either electronically at   HYPERLINK
http://www.regulations.gov www.regulations.gov  or in hard copy at the
Office of Air, Waste and Toxics, EPA Region 10, 1200 Sixth Avenue,
Seattle, WA 98101. EPA requests that if at all possible, you contact the
individual listed below to view a hard copy of the docket. 

FOR FURTHER INFORMATION CONTACT:  Steve Body at telephone number (206)
553-0782, body.steve@epa.gov, or the above EPA, Region 10 address.

SUPPLEMENTARY INFORMATION:  Throughout this document whenever “we,”
“us,” or “our” is used, we mean the EPA.  Information is
organized as follows:

Table of Contents

I.  Background for EPA’s Proposed Action 

A. Definition of Regional Haze 

B. Regional Haze Rules and Regulations

C. Roles of Agencies in Addressing Regional Haze

D. Interstate Transport for Visibility

II.  Requirements for the Regional Haze SIP  

A. The CAA and the Regional Haze Rule 

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

C. Consultation with States and Federal Land Managers 

D. Best Available Retrofit Technology

III.  EPA’s Analysis of the Idaho Regional Haze SIP 

A. Affected Class I Areas 

B. Baseline and Natural Conditions

C. Idaho Emissions Inventories 

D. Sources of Visibility Impairment in Idaho Class I Areas 

E.  Best Available Retrofit Technology 

F. TASCO BART Analysis

G. Monsanto/P4 BART Analysis

H.  Improvement in Visibility from BART at TASCO, Nampa and Monsanto/P4

IV.  EPA’s Analysis of Whether Regional Haze SIP Submittal Meets
Interstate Transport Requirements   

V.  What Action is EPA Proposing? VI.  Scope of Action

VII.  Statutory and Executive Order Reviews 

I. Background for EPA’s Proposed Action

	In the CAA Amendments of 1977, Congress established a program to
protect and improve visibility in the national parks and wilderness
areas.  See CAA section 169(A).  Congress amended the visibility
provisions in the CAA in 1990 to focus attention on the problem of
regional haze.  See CAA section 169(B).  EPA promulgated regulations in
1999 to implement sections 169A and 169B of the Act.  These regulations
require states to develop and implement plans to ensure reasonable
progress toward improving visibility in mandatory Class I Federal areas
(Class I areas).  64 FR 35714 (July 1, 1999); see also 70 FR 39104 (July
6, 2005) and 71 FR 60612 (October 13, 2006).   

	In this action, EPA is proposing to approve certain provisions of
Idaho’s Regional Haze SIP submission addressing the requirements for
best available retrofit technology (BART), the calculation of baseline
and natural visibility conditions, and the statewide inventory of
visibility-impairing pollutants.  EPA is also proposing to approve the
provisions of Idaho’s SIP submittal addressing BART as meeting
Idaho’s obligations under section 110(a)(2)(D)(i)(I) of the Act for
visibility. EPA is not taking action today on those provisions of the
Regional Haze SIP submittal related to reasonable progress goals and the
long term strategy. 

A.  Definition of Regional Haze 

Regional haze is impairment of visual range or colorization caused by
emission of air pollution produced by numerous sources and activities,
located across a broad regional area.  The sources include but are not
limited to, major and minor stationary sources, mobile sources, and area
sources including non-anthropogenic sources.  Visibility impairment is
primarily caused by fine particulate matter (PM2.5) or secondary aerosol
formed in the atmosphere from precursor gasses (e.g., sulfur dioxide,
nitrogen oxides, and in some cases, ammonia and volatile organic
compounds).  Atmospheric fine particulate reduces clarity, color, and
visual range of visual scenes.  Visibility reducing fine particulate is
primarily composed of sulfate, nitrate, organic carbon compounds,
elemental carbon, and soil dust, and impairs visibility by scattering
and absorbing light.  Fine particulate can also cause serious health
effects and mortality in humans, and contributes to environmental
effects such as acid deposition and eutrophication.  

	Data from the existing visibility monitoring network, the
“Interagency Monitoring of Protected Visual Environments” (IMPROVE)
monitoring network, show that visibility impairment caused by air
pollution occurs virtually all the time at most national parks and
wilderness areas.  Average visual range in many Class I areas in the
Western United States is 100-150 kilometers, or about one-half to
two-thirds the visual range that would exist without manmade air
pollution.    Visibility impairment also varies day-to-day and by season
depending on variation in meteorology and emission rates.

B.  Regional Haze Rules and Regulations

In section 169A of the 1977 CAA Amendments, 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 Class I areas which impairment results from
manmade air pollution.”  CAA section 169A(a)(1).  On December 2, 1980,
EPA promulgated regulations to address visibility impairment in Class I
areas that is “reasonably attributable” to a single source or small
group of sources, i.e., “reasonably attributable visibility
impairment”.  45 FR 80084.  These regulations represented the first
phase in addressing visibility impairment.  EPA deferred action on
regional haze that emanates from a variety of sources until monitoring,
modeling and scientific knowledge about the relationships between
pollutants and visibility impairment were improved.  

Congress added section 169B to the CAA in 1990 to address regional haze
issues.  EPA promulgated a rule to address regional haze on July 1, 1999
(64 FR 35713)(the RHR).  The RHR revised the existing visibility
regulations to integrate into the regulation provisions addressing
regional haze impairment and established a comprehensive visibility
protection program for Class I areas.  The requirements for regional
haze, found at 40 CFR 51.308 and 51.309, are included in EPA’s
visibility protection regulations at 40 CFR 51.300-309.  Some of the
main elements of the regional haze requirements are summarized in
section III of this rulemaking.  The requirement to submit a regional
haze SIP applies to all 50 states, the District of Columbia and the
Virgin Islands.  40 CFR 51.308(b) requires states to submit the first
implementation plan addressing regional haze visibility impairment no
later than December 17, 2007.  

C.  Roles of Agencies in Addressing Regional Haze 

Successful implementation of the regional haze program will require
long-term regional coordination among states, tribal governments and
various Federal agencies.  As noted above, pollution affecting the air
quality in Class I areas can be transported over long distances, even
hundreds of kilometers.  Therefore, to effectively address the problem
of visibility impairment in Class I areas, states need to develop
strategies in coordination with one another, taking into account the
effect of emissions from one jurisdiction on the air quality in another.


Because the pollutants that lead to regional haze impairment can
originate from across state lines, EPA has encouraged the States and
Tribes to address visibility impairment from a regional perspective.   
HYPERLINK "http://www.epa.gov/air/visibility/regional.html" \l
"thefive#thefive"  Five regional planning organizations  (RPOs) were
created nationally to address regional haze and related issues.  One of
the main objectives of the RPOs is to develop and analyze data and
conduct pollutant transport modeling to assist the States or Tribes in
developing their regional haze plans. 

	The Western Regional Air Partnership (WRAP), one of the five 

RPOs nationally, is a voluntary partnership of State, Tribal, Federal,
and local air agencies dealing with air quality in the West.  WRAP
member States include: Alaska, Arizona, California, Colorado, Idaho,
Montana, New Mexico, North Dakota, Oregon, South Dakota, Utah,
Washington, and Wyoming.  WRAP 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 Shoshone-Bannock Tribes of
Fort Hall.

D.  Interstate Transport for Visibility

	On July 18, 1997, EPA promulgated new NAAQS for 8-hour ozone and for
PM2.5.  62 FR 38652.  Section 110(a)(1) of the CAA requires states to
submit a plan to address certain requirements for a new or revised NAAQS
within three years after promulgation of such standards, or within such
shorter time as EPA may prescribe.  Section 110(a)(2) of the CAA lists
the elements that such new plan submissions must address, as applicable,
including section 110(a)(2)(D)(i), which pertains to the interstate
transport of certain emissions.

	On April 25, 2005, EPA published a “Finding of Failure to Submit SIPs
for Interstate Transport for the 8-hour Ozone and PM2.5 NAAQS.”  70 FR
21147.  This included a finding that Idaho and other states had failed
to submit SIPs to address interstate transport of emissions affecting
visibility and started a 2-year clock for the promulgation of a Federal
Implementation Plan (FIP) by EPA, unless the state made a submission to
meet the requirements of section 110(a)(2)(D)(i) and EPA approves such
submission.  Id.  

	On August 15, 2006, EPA issued guidance on this topic entitled
“Guidance for State Implementation Plan (SIP) Submissions to Meet
Current Outstanding Obligations  Under section 110(a)(2)(D)(i) for the
8-Hour Ozone and PM2.5 National Ambient Air Quality Standards” (2006
Guidance).  We developed the 2006 Guidance to make recommendations to
states for making submissions to meet the requirements of section
110(a)(2)(D)(i) for the 1997 8-hour ozone standards and the 1997 PM2.5
standards.

	As identified in the 2006 Guidance, the “good neighbor” provisions
in section 110(a)(2)(D)(i) of the CAA require each state to have a SIP
that prohibits emissions that adversely affect other states in ways
contemplated in the statute.  Section 110(a)(2)(D)(i) contains four
distinct requirements related to the impacts of interstate transport. 
The SIP must prevent sources in the state from emitting pollutants in
amounts which will:  (1) contribute significantly to nonattainment of
the NAAQS in other states; (2) interfere with maintenance of the NAAQS
in other states; (3) interfere with provisions to prevent significant
deterioration of air quality in other states; or (4) interfere with
efforts to protect visibility in other states.

	With respect to establishing that emissions from sources in the state
would not interfere with measures in other states to protect visibility,
the 2006 Guidance recommended that states make a submission indicating
that it was premature, at that time, to determine whether there would be
any interference with measures in the applicable SIP for another state
designed to “protect visibility” until the submission and approval
of regional haze SIPs.  Regional haze SIPs were required to be submitted
by December 17, 2007.  See 74 FR 2392.  At this later point in time,
however, EPA believes it is now necessary to evaluate such
110(a)(2)(D)(i) submissions from a state to ensure that the existing
SIP, or the SIP as modified by the submission, contains adequate
provisions to prevent interference with the visibility programs of other
states, such as for consistency with the assumptions for controls relied
upon by other states in establishing reasonable progress goals to
address regional haze.

The regional haze program, as reflected in the RHR, recognizes the
importance of addressing the long-range transport of pollutants for
visibility and encourages states to work together to develop plans to
address haze.  The regulations explicitly require each state to address
its “share” of the emission reductions needed to meet the reasonable
progress goals for neighboring Class I areas.   States working together
through a regional planning process, are required to address an agreed
upon share of their contribution to visibility impairment in the Class I
areas of their neighbors.  40 CFR 51.308(d)(3)(ii).  Given these
requirements, we anticipate that regional haze SIPs will contain
measures that will achieve these emissions reductions, and that these
measures will meet the requirements of section 110(a)(2)(D)(i).

As a result of the regional planning efforts in the West, all states in
the WRAP region contributed information to a Technical Support System
(TSS) which provides an analysis of the causes of haze, and the levels
of contribution from all sources within each state to the visibility
degradation of each Class I area.  The WRAP States consulted in the
development of reasonable progress goals, using the products of this
technical consultation process to co-develop their reasonable progress
goals for the Western Class I areas.  The modeling done by the WRAP
relied on assumptions regarding emissions over the relevant planning
period and embedded in these assumptions were anticipated emissions
reductions in each of the States in the WRAP, including reductions from
BART and other measures to be adopted as part of the State’s long term
strategy for addressing regional haze.  The reasonable progress goals in
the draft and final regional haze SIPs that have now been prepared by
States in the West accordingly are based, in part, on the emissions
reductions from nearby States that were agreed on through the WRAP
process.   

Idaho submitted a Regional Haze SIP on October 25, 2010, to address the
requirements of the RHR and the good neighbor provisions of section
110(a)(2)(D)(i) regarding visibility for the 1997 8-hour ozone NAAQS and
the 1997 PM2.5 NAAQS.  EPA has reviewed the submittal and concluded at
this time to propose to take action on only certain elements of
Idaho’s Regional Haze SIP.   EPA is required at this time, to propose
to take action either to approve Idaho’s SIP submittal, or otherwise
to take action to meet the requirements of section 110(a)(2)(D)(i)(II)
regarding visibility.  EPA is proposing to find that certain elements of
Idaho’s Regional Haze SIP submittal meet these requirements.  In
particular, as explained in section IV of this action, EPA is proposing
to find that the BART measures in Idaho’s Regional Haze SIP submittal,
which EPA is proposing to approve in this action, will also mean that
the Idaho SIP meets the requirements of section 110(a)(2)(D)(i)(II)
regarding visibility for the 1997 8-hour ozone and 1997 PM2.5 NAAQS.

II. Requirements for Regional Haze SIPs

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

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

The RHR establishes the deciview (dv) as the principal metric for
measuring visibility.  This visibility metric expresses uniform changes
in haziness in terms of common increments across the entire range of
visibility conditions, from pristine to extremely hazy conditions. 
Visibility is determined by measuring the visual range (or deciview),
which is the greatest distance, in kilometers or miles, at which a dark
object can be viewed 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 at one
deciview. 

The deciview is used in expressing reasonable progress goals (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 manmade air
pollution by reducing anthropogenic emissions that cause regional haze. 
The national goal is a return to natural conditions, i.e., manmade
sources of air pollution would no longer impair visibility in Class I
areas.  

To track changes in visibility over time at each of the 156 Class I
areas covered by the visibility program (40 CFR 81.401-437), and as part
of the process for determining reasonable progress, states must
calculate the degree of existing visibility impairment at each Class I
area at the time of each regional haze SIP submittal and periodically
review progress every five years midway through each 10-year
implementation period.  To do this, the RHR requires states to determine
the degree of impairment (in deciviews) for the average of the 20% least
impaired (“best”)  and 20% most impaired (“worst”) visibility
days over a specified time period at each of their Class I areas.  In
addition, states must also develop an estimate of natural visibility
conditions for the purpose of comparing progress toward the national
goal.  Natural visibility is determined by estimating the natural
concentrations of pollutants that cause visibility impairment and then
calculating total light extinction based on those estimates.  EPA has
provided guidance to states regarding how to calculate baseline, natural
and current visibility conditions in documents titled, EPA’s Guidance
for Estimating Natural Visibility Conditions Under the Regional Haze
Rule, September 2003, (EPA-454/B-03-005 located at   HYPERLINK
"http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf" 
http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf ),
(hereinafter referred to as “EPA’s 2003 Natural Visibility
Guidance”), and Guidance for Tracking Progress Under the Regional Haze
Rule (EPA-454/B-03-004 September 2003 located at   HYPERLINK
"http://www.epa.gov/ttncaaa1/t1/memoranda/rh_tpurhr_gd.pdf" 
http://www.epa.gov/ttncaaa1/t1/memoranda/rh_tpurhr_gd.pdf )),
(hereinafter referred to as “EPA’s 2003 Tracking Progress
Guidance”).

For the first regional haze SIPs that were due by December 17, 2007,
“baseline visibility conditions” were the starting points for
assessing “current” visibility impairment.  Baseline visibility
conditions represent the degree of visibility impairment for the 20%
least impaired days and 20% 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 time period is considered the time from which improvement in
visibility is measured.

C.  Consultation with States and Federal Land Managers

The RHR 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 visibility impairment 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. 

D.  Best Available Retrofit Technology

Section 169A of the CAA directs states to evaluate the use of retrofit
controls at certain larger, often uncontrolled, older stationary sources
in order to address visibility impacts from these sources. 
Specifically, section 169A(b)(2)(A) of the CAA requires states to revise
their SIPs to contain such measures as may be necessary to make
reasonable progress towards the natural visibility goal, including a
requirement that certain categories of existing major stationary sources
built between 1962 and 1977 procure, install, and operate the “Best
Available Retrofit Technology” as determined by the state.    States
are directed to conduct BART determinations for such 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. 

On July 6, 2005, EPA published the Guidelines for BART Determinations
Under the Regional Haze Rule at appendix Y to 40 CFR Part 51
(hereinafter referred to as the “BART Guidelines”) to assist states
in determining which of their sources should be subject to the BART
requirements and in determining appropriate emission limits for each
applicable source.  In making a BART applicability determination for a
fossil fuel-fired electric generating plant with a total generating
capacity in excess of 750 megawatts, a state must use the approach set
forth in the BART Guidelines.  A state is encouraged, but not required,
to follow the BART Guidelines in making BART determinations for other
types of sources. 

States must address all visibility-impairing pollutants emitted by a
source in the BART determination process.  The most significant
visibility impairing pollutants are SO2, NOx, and PM.  EPA has indicated
that states should use their best judgment in determining whether VOC or
NH3 compounds impair visibility in Class I areas.  

The RPOs provided air quality modeling to the states to help them in
determining whether potential BART sources can be reasonably expected to
cause or contribute to visibility impairment in a Class I area.  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.  Generally, an
exemption threshold set by the state should not be higher than 0.5
deciview.  

In their SIPs, states must identify potential BART sources, described as
“BART-eligible sources” in the RHR, and document their BART control
determination analyses.  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.  States are free to determine the weight and
significance to be assigned to each factor.  

A regional haze SIP must include source-specific BART emission limits
and compliance schedules for each source subject to BART.  Once a state
has made its BART determination, the BART controls must be installed and
in operation as expeditiously as practicable, but no later than five
years after the date EPA approves the regional haze SIP.  CAA section
169(g)(4)).  40 CFR 51.308(e)(1)(iv).  In addition to what is required
by the RHR, general SIP requirements mandate that the SIP must also
include all regulatory requirements related to monitoring,
recordkeeping, and reporting for the BART controls on the source. 
States have the flexibility to choose the type of control measures they
will use to meet the requirements of BART.

III. EPA’s Analysis of Idaho Regional Haze SIP 

A.  Affected Class I Areas 

	There are five mandatory Class I areas, or portions of such areas,
within Idaho.  Craters of the Moon National Monument, Sawtooth
Wilderness Area, and Selway-Bitterroot Wilderness Area lie completely
within Idaho State borders.  Hells Canyon Wilderness Area is a shared
Class I area with Oregon, and Yellowstone National Park is a shared
Class I area with Wyoming.  See 40 CFR 81.410.  Oregon and Wyoming
respectively will address reasonable progress goals, monitoring, and
other core requirements for these Class I areas.  Idaho consulted with
Oregon and Wyoming to determine Idaho’s contribution to regional haze
in those Class I areas and to determine appropriate measures for
Idaho’s long-term strategy. See chapter 13, section 13.2 of the Idaho
Regional Haze SIP submittal.  See also the WRAP Technical Support
Document (WRAP TSD) supporting this action 

The Idaho SIP submittal addresses the three Class I areas that are
completely within the State border and, as appropriate, Class I areas
with shared jurisdiction with Oregon and Wyoming and Class I areas in
neighboring states.

B.  Baseline and Natural Conditions

	Idaho, using data from the IMPROVE monitoring network and analyzed by
WRAP, established baseline and natural visibility conditions as well as
the uniform rate of progress (URP) to achieve natural visibility
conditions in 2064 for all Idaho Class I areas within its borders. 
While Idaho is responsible for establishing baseline and natural
conditions for three Class I areas, the SIP also included these values
for Hells Canyon Wilderness Area and Yellowstone National Park, as
determined by WRAP and established by Oregon and Wyoming.  

	Baseline visibility was calculated from monitoring data collected by
IMPROVE monitors for the most-impaired (20 % worst) days and the
least-impaired (20 % best) days.  Idaho used the WRAP derived natural
visibility conditions.  In general, WRAP based their estimates on EPA
guidance, Guidance for Estimating Natural Visibility Conditions Under
the Regional Haze Program (EPA-45/B-03-0005 September 2003) but
incorporated refinements which EPA believes provides results more
appropriate for western states than the general EPA default approach. 
See section 2.E of the WRAP TSD.

	Craters of the Moon National Monument:  An IMPROVE monitor is located
in Craters of the Moon National Monument.  Based on baseline 2000 to
2004 data, the average 20% worst days visibility is 14 dv and the
average 20% best days visibility is 4.3 dv.  Natural visibility for the
average 20% worst days is 7.53 dv.

	Hells Canyon Wilderness Area:  Hells Canyon Wilderness Area has an
IMPROVE monitor located within the Wilderness Area at Oxbow Dam.  Based
on baseline 2000 to 2004 data, Oregon determined the average 20% worst
days visibility is 18.55 dv and the average 20% best days visibility is
5.52 dv.  Natural visibility for the average 20% worst days is 8.32 dv.

	Sawtooth Wilderness Area:  Sawtooth Wilderness Area has an IMPROVE
monitor located within the Wilderness Area.  Based on baseline 2000 to
2004 data, the average 20% worst days visibility is 13.78 dv and the
average 20% best days visibility is 3.99 dv.    Natural visibility for
the average 20% worst days is 6.42 dv.

	Selway-Bitterroot Wilderness Area:  Selway-Bitterroot Wilderness Area
visibility is represented by an IMPROVE monitor located 20 km east of
the Wilderness Area in Sula, Montana.  This site also represents
visibility in the Anaconda-Pintler Wilderness Area.  Based on baseline
2000 to 2004 data, the average 20% worst days visibility is 13.41 dv and
the average 20% best days visibility is 2.58 dv for both areas.  Natural
visibility for the Selway-Bitteroot and the Anaconda-Pintler Wilderness
Areas average 20% worst days is 7.43 dv.

	Yellowstone National Park:  Yellowstone National Park has an IMPROVE
monitor located within the park. Based on baseline 2000 to 2004 data
Wyoming determined the average 20% worst days visibility is 11.76 dv and
the average 20% best days visibility is 2.58 dv.  Natural visibility for
the average 20% worst days is 6.24 dv.

	Based on our evaluation of the State’s baseline and natural
conditions analysis, EPA is proposing to find that Idaho has
appropriately determined baseline visibility for the average 20% worst
and 20% best days and natural visibility conditions for the average 20%
worst days in each Class I area within the state.  See the WRAP TSD
supporting this action (section 2.D and 2.E).

	

C.  Idaho Emission Inventories 

	There are three main categories of air pollution emission sources: 
point sources, area sources, and mobile sources.  Point sources are
larger stationary sources that emit pollutants through a stack or duct. 
Area sources are large numbers of small sources that are widely
distributed across an area, such as residential heating units or
re-entrained dust from unpaved roads or windblown dust form agricultural
fields.  Mobile sources are sources such as motor vehicles, locomotives
and aircraft.  

	The RHR requires a statewide emission inventory of pollutants that are
reasonably anticipated to cause or contribute to visibility impairment
in any mandatory Class I area.  40 CFR 51.308(d)(4)(v).  The WRAP, with
data supplied by the states, compiled emission inventories for all major
source categories in Idaho for the 2002 baseline year and estimated
emission inventories for 2018.  Emission estimates for 2018 were
generated from anticipated population growth, growth in industrial
activity, and emission reductions from implementation of control
measures, e.g., implementation of BART limitations, and motor vehicle
tailpipe emissions.  Appendix D of the Idaho Regional Haze SIP discusses
how emission estimates were determined and contains the emission
inventory. Detailed estimates of the emissions, used in the modeling
conducted by the WRAP and Idaho, can be found at the WRAP website:
http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx

There are a number of emission inventory source categories identified in
the Idaho SIP: point, area, on-road mobile, off-road mobile,
anthropogenic fire (prescribed forest fire, agricultural field burning,
and residential wood combustion), natural fire, road dust, fugitive dust
and windblown dust.  The 2002 baseline and 2018 projected emissions, as
well as the net changes of emissions between these two years, are
presented in Tables 8-1 through 8-8 in the SIP submittal for SO2, NOx,
Volatile Organic Carbon (VOC), Organic Carbon (OC), Elemental Carbon
(EC), fine particulate (PM2.5), coarse particulate (PM coarse) and
ammonia. The methods that WRAP used to develop these emission
inventories are described in more detail in the WRAP TSD.  As explained
in the WRAP TSD, emissions were calculated using best available data and
approved EPA methods. See WRAP TSD section 12.

SO2 emissions in Idaho come mostly from coal combustion at industrial
boilers and from other industrial activities.  SO2 emissions estimates
for point sources came either from source test data (where available) or
calculations based on fuel type and quantity burned.  These industrial
point sources contribute 45% of total statewide SO2 emissions. The
second largest contributor to SO2 emissions in Idaho is fire:  31% from
natural fire and 2% from anthropogenic fire.  

Idaho projects a 45% statewide reduction in point source S02 emissions
by 2018 due to implementation of BART emission limitations.  Idaho also
projects total 2018 statewide SO2 emissions to be reduced by 33.9% below
2002 levels as a result of BART and additional reductions from mobile
sources and anthropogenic fire emissions.  According to the State’s
analysis, overall point source emissions, the largest source category in
2002, are projected to be reduced by 46.7%.  Area source emissions (8%
of statewide SO2 emissions) are projected to increase 7.9% between 2002
and 2018 due to population growth.  Idaho projects SO2 emissions
associated with natural fire, the second largest source category in
2002, to remain unchanged and would become the largest source category
in 2018. 

NOx emissions in Idaho come mostly from mobile sources, both from
on-road and off-road mobile sources, which contribute 46% of total
statewide NOx emissions.  The second largest source category of NOx
emissions is area source emissions from combustion to heat buildings. 
Area source emissions account for 19% of statewide NOx emissions.  Idaho
projects that 2018 total statewide emissions of NOx will be 20.6% lower
than 2002 levels.  Idaho also projects on-road and off-road mobile
source emissions to be reduced by 72.4% and 38.3% respectively by 2018,
due to new Federal motor vehicle emission standards and fleet turnover. 
Idaho projects area source NOx emissions to increase by 38.8% to become
the largest source category in 2018 due to population growth and new
industrial sources.  Idaho projects natural fire emissions to remain
unchanged and become the second largest NOx source category in 2018.

Volatile organic compounds (VOC) in Idaho come mostly from area sources
such as industrial solvent use, paints, pharmaceuticals, and
refrigerants, which contribute 46% of total VOC emissions.  The second
largest source category in VOC emissions is non-anthropogenic fire which
contributes 25% of total VOC emissions, while the second largest source
category of anthropogenic VOC is mobile sources.  Idaho projects 2018
statewide VOC emissions to increase by 19.2% over 2002 levels even
though on-road mobile, off-road mobile and anthropogenic VOC emissions
are projected to decrease 61.7%, 32.2% and 52.3% respectively.  This
increase in VOC emissions is due to a projected 64.2% increase in area
source VOC emissions primarily due to population growth and increased
business activity.

Organic carbon in Idaho comes from natural fire, anthropogenic fire and
mobile sources.  Natural fire is the largest source category, which
contributes 82% of organic carbon emissions.  The second largest source
category is anthropogenic fire which contributes 15% of the total
organic carbon emissions.  Idaho projects 2018 statewide organic carbon
emissions to decrease 7.6% from 2002 emission levels due to reductions
in on-road mobile, off-road mobile, and anthropogenic fire of 10.8%,
43.1% and 51.6% respectively.

Elemental carbon is associated with incomplete combustion. The largest
source category is natural fire, which contributes 72% of total
elemental carbon emissions.  The second largest source category is
off-road mobile sources (diesel) which contributes 14% of total
elemental carbon emissions.  Idaho projects 2018 statewide elemental
carbon emissions to decrease by 50.7% from 2002 emission levels.  These
projected reductions are the result of anticipated emission reductions
in on-road mobile and off-road mobile emissions of 73.8% and 64.3%
respectively.

Fine particulate, particles with an aerodynamic diameter of less than
2.5 micrometers, is emitted from a variety of area sources.  Point
sources account for only 2% of statewide fine particulate.  Wind blown
dust is the largest source category contributing 26% of total fine
particulate.  Wood stoves and small manufacturing and industrial sources
contribute 24% of total fine particulate.  Natural fire, anthropogenic
fire, road dust and other fugitive dust sources also emit approximately
equal amounts of fine particulate.  Idaho projects that 2018 fine
particulate emissions will increase by 12.1% over 2002 emission levels
due to population and industrial growth.  Emissions increases are
projected from point, area, road dust, fugitive dust at 26.8%, 33.6%,
32.0%, and 30.1% respectively. Fine particulate emissions associated
with anthropogenic fire are expected to decrease by 53.6%.  

Coarse particulate is particulate with an aerodynamic diameter between
2.5 and 10 micrometers.  It is composed of larger particles in wind
blown dust, natural fire and other particulate from industrial grinding
sources.  The largest source category is wind blown dust which
contributes 40% of total coarse particulate emissions.  The second
largest source is natural fire which contributes 22% of coarse
particulate emissions.  Idaho projects that 2018 emissions of coarse
particulate to increase by 11.9% over 2002 emission levels.  Idaho
projects course particulate emissions from most categories to increase,
with the exception of anthropogenic fire which will decrease by 51.7%.

Ammonia does not directly impair visibility but can be a precursor to
the formation of particulate in the atmosphere through chemical reaction
with SO2 and NOx to form a “secondary aerosol“.  Area sources are
the primary source category contributing to ammonia emissions and
account for 85% of total ammonia emissions.  The second largest source
category is natural fire which contributes 10% of ammonia emissions. 
Idaho projects ammonia emissions in 2018 to increase by 1.3% over 2002
emission levels with increasing emissions in all categories with the
exception of anthropogenic fire which Idaho projects to decrease by
53.4%. 

D.  Sources of Visibility Impairment in Idaho Class I Areas 

Each pollutant species has its own visibility impairing property; 1
ug/m3 of sulfate, for example, is more effective in scattering light
than 1 ug/m3 of organic carbon and therefore impairs visibility more
than organic carbon.  Following the approach recommended by the WRAP and
as explain more fully below, Idaho used a two step process to identify
the contribution of each source or source category to existing
visibility impairment.  First, ambient pollutant concentration by
species (sulfate, nitrate, organic carbon, fine particulate, etc) was
determined from the IMPROVE sampler in each Class I area.  These
concentrations were then converted into deciview values to distribute
existing impairment among the measured pollutant species.  This
calculation used the “improved IMPROVE equation” (See section 2.C of
the WRAP TSD) to calculate extinction from each pollutant specie
concentration.  Extinction, in inverse megameters, was then converted to
deciview using the equation defining deciview.  Second, the
Comprehensive Air Quality Model with Extensions (CAMx) and PM Source
Apportionment Technology (PSAT) models were used to determine which
sources and source categories contributed to the ambient concentration
of each pollutant species.  Thus, impairment was distributed by source
and source category.

After considering the available models, the WRAP and Western States
selected two source apportionment analysis tools. The first source
apportionment tool was the Comprehensive Air Quality Model with
Extensions (CAMx) in conjunction with PM Source Apportionment Technology
(PSAT).  This model uses emission source characterization, meteorology
and atmospheric chemistry for aerosol formation to predict pollutant
concentrations in the Class I area.  The predicted results are compared
to measured concentrations to assess accuracy of model output.  CAMx
PSAT modeling was used to determine source contribution to ambient
sulfate and nitrate concentrations. The WRAP used state-of-the-science
source apportionment tools within a widely used photochemical model. 
EPA has reviewed the PSAT analysis and considers the modeling,
methodology, and analysis acceptable.  See section 6.A of the WRAP TSD.

The second tool was the Weighted Emissions Potential (WEP) model, used
primarily as a screening tool to decide which geographic source regions
have the potential to contribute to haze at specific Class I areas.  
WEP does not account for atmospheric chemistry (secondary aerosol
formation) or removal processes, and thus is used for estimating inert
particulate concentrations.  The model uses back trajectory wind flow
calculations and resident time of an air parcel to determine source and
source category and location for ambient organic carbon, elemental
carbon, PM2.5, and coarse PM concentrations.  These modeling tools were
the state-of-the-science and EPA has determined that these tools were
appropriately used by WRAP for regional haze planning. Description of
these tools and our evaluation of them are described in more detail in
section 6 of the WRAP TSD. 

Figure 7-1 in the Idaho Regional Haze SIP submittal presents the light
extinction for the base year at each Class I area by visibility
impairing pollutant species for the average of the 20% worst days.  The
visibility impairing pollutant species identified are:  fine particulate
(i.e. sea salt, fine soil, elemental carbon, organic carbon, ammonium
sulfate and ammonium nitrate) and coarse material.  In addition the SIP
submission identifies in Figures 7.2 through Figure 7.52, light
extinction by pollutant species for the average of the 20% worst and
average of the 20% best days for each of the Class I areas.

	Figure 7-1 of the SIP indicates that on the 20% worst days organic
carbon is the primary pollutant impairing visibility in the Sawtooth and
Selway-Bitterroot Wilderness Areas.  In Craters of the Moon National
Monument the primary pollutant impairing visibility on the 20% worst
days is ammonium nitrate.

	Idaho also analyzed the monthly variation of light extinction and
pollutant specie concentrations for the 20% worst days.  See Idaho SIP
Figures 7-6 and 7-7, Figures 7-24 through 7-27, Figures 7-35 through
7-38.  Each Class I area shows a distinct monthly and seasonal variation
in impairment.  For example, the 20% worst days in Craters of the Moon
National Monument occur during the winter months of December through
February.  The 20% worst days in the Sawtooth and Selway-Bitterroot
Wilderness Areas occur from April through November.  This variation in
impairment is due to monthly and seasonal variation in meteorology and
emission rates.     

	To determine potential impacts of emission sources in Idaho on Class I
areas in other states, Idaho considered the WRAP analysis of interstate
impacts.  Ambient air sulfate and nitrate concentrations for the 20%
worst and best days for baseline (2002-2004) and 2018 at each western
Class I area is distributed among all states in the WRAP using PSAT
modeling.  The SIP submittal provides an analysis of the Class I areas
in nearby states.  See chapter 9.3 of the Idaho Regional Haze SIP
submission.  These Class I areas are:

Shared Class I Areas with Oregon and Wyoming

Hells Canyon Wilderness Area

Yellowstone National Park

Class I Areas outside Idaho

Glacier National Park in Montana:  Idaho is ranked 3rd behind Montana
and Washington in contribution of visibility impairing pollutants on the
20% worst days

Cabinet Mountain Wilderness Area in Montana:  Idaho is ranked 3rd behind
Oregon and Washington in contribution to visibility impairing pollutants
on the 20% worst days 

Bob Marshall Wilderness Area in Montana:  Idaho is ranked 3rd behind
Montana and Washington in contribution to visibility impairing
pollutants on the 20% worst days

Gates of the Mountain Wilderness in Montana:  Idaho is ‘ranked 3rd’
behind Montana and Washington in contribution to visibility impairing
pollutants on the 20% worst days

North Absaroka Wilderness in Wyoming:  Idaho is ranked 2nd behind
Wyoming in contribution to visibility impairing pollutants on the 20%
worst days

Bridger Wilderness in Wyoming:  Idaho is ranked 2nd behind Wyoming in
contribution to visibility impairing pollutants on the 20% worst days

Eagle Cap Wilderness Area Oregon:  Idaho is ranked 3rd behind Oregon and
Washington in contribution to visibility impairing pollutant on the 20%
worst days

Jarbidge Wilderness Area in Nevada:  Idaho is ranked 1st in contribution
of sulfate and nitrate to the Jarbidge Wilderness area.  

	EPA is proposing to find that Idaho has appropriately identified the
primary pollutants impacting its Class I areas.  EPA is also proposing
to find that the SIP contains an appropriate analysis of the impacts of
emissions from Idaho on nearby Class I areas. 

E.  Best Available Retrofit Technology

	The first phase of a BART evaluation is to identify all the
BART-eligible sources within the State’s boundaries.  Table 10-1 in
the SIP submission presents the list of all BART-eligible sources
located in Idaho.  These sources are:  The Amalgamated Sugar Company
(TASCO) in Twin Falls, TASCO in Nampa, TASCO in Paul, NU West/Agrium in
Soda Springs, the J.R. Simplot Don Plant in Pocatello, the Monsanto/P4
Production LLC facility at Soda Springs, and the Potlatch Pulp & Paper
mill in Lewiston Idaho.  

The second phase of the BART determination process is to identify those
BART-eligible sources that may reasonably be anticipated to cause or
contribute to any impairment of visibility at any Class I area and are,
therefore, subject to BART.  As explained above, EPA has issued
guidelines that provide states with guidance for addressing the BART
requirements.  40 CFR Part 51 appendix Y; see also 70 Fed. Reg. 39,104
(July 6, 2005).   The BART Guidelines describe how states may consider
exempting some BART-eligible sources from further BART review based on
dispersion modeling showing that the sources contribute below a certain
threshold amount.   Idaho conducted dispersion modeling for the
BART-eligible sources to determine the visibility impacts of these
sources on Class I areas with the exception of the Monsanto/P4
Production LLC facility which was categorized as subject to BART without
analysis.  

The BART Guidelines require States 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.  Generally,
States may not establish a contribution threshold that exceeds 0.5 dv
impact.  70 Fed. Reg. at 39,161.  Idaho established a contribution
threshold of 0.5 dv through negotiated rulemaking with industry, FLMs,
and the public.  In its SIP submittal, Idaho notes that the 0.5 dv
threshold is also consistent with the threshold used by all other states
in the WRAP.  Any source with an impact of greater than 0.5 dv in any
Class I area, including Class I areas in other states, would be subject
to a BART analysis and BART emission limitations.

The explanation given by Idaho for adopting a 0.5 dv threshold for
determining whether a BART source may be reasonably anticipated to cause
or contribute to any visibility impairment in a Class I area is not
adequate to justify the selection of such a threshold.   Although a
number of stakeholders may have agreed that a 0.5 dv threshold is
appropriate, and other states in the Region may have adopted such a
threshold, such agreement does not provide sufficient basis concluding
that such a threshold was appropriate in the case of Idaho.   Based on
EPA’s review of the BART-eligible sources in Idaho, however, EPA is
proposing to find that a 0.5 dv threshold is appropriate, given the
specific facts in Idaho.    

In the BART Guidelines, EPA recommended that States “consider the
number of BART sources affecting the Class I areas at issue and the
magnitude of the individual sources’ impacts.   In general, a larger
number of BART sources causing impacts in a Class I area may warrant a
lower contribution threshold.”  70 FR 39104, 39161 July 6, 2005.   In
developing its regional haze SIP, Idaho modeled the impacts of six of
the seven BART-eligible sources on Class I areas within a 300 km radius.
 (See Table 10-3 through Table 10-8 of the SIP submittal).  As noted
above, the State and Monsanto/P4 Production mutually agreed that
Monsanto/P4 was subject to BART.  Of these BART-eligible sources, only
TASCO, Nampa exceeded the 0.5 dv threshold, based on consideration of
the 22nd highest impact during 2003-2005.   For the remaining five
BART-eligible sources, the modeling showed maximum impacts below 0.4 dv.
  These sources are generally widely distributed across the State, and
only TASCO Twin Falls and TASCO Paul showed modeled impacts affecting
the same Class I area.  Given the relatively limited impact on
visibility from these sources, Idaho could have reasonably concluded
that a 0.5 dv threshold was appropriate for capturing those
BART-eligible sources with significant impacts on visibility in Class I
areas.  For these reasons, EPA is proposing to approve the 0.5 dv
threshold adopted by Idaho in its Regional Haze SIP.   

	To determine those sources subject to BART, Idaho used the CALPUFF
model.  The dispersion modeling was conducted in accord with the BART
Modeling Protocol7.  This Protocol was jointly developed by the states
of Idaho, Washington, Oregon and EPA and has undergone public review. 
The Protocol was used by all three states in determining which
BART-eligible sources are subject to BART.  See appendix F of the SIP
submission for details of the modeling protocol, its application and
results.  As noted above, Idaho determined through modeling that one, of
the six modeled BART-eligible sources in Idaho, was subject to BART: 
the TASCO facility in Nampa.  In addition, the Monsanto/P4 Production
LLC facility in Soda Springs was determined to be subject to BART based
on agreement by the source and the State.

F.  TASCO BART Analysis:

	TASCO Nampa is a sugar beet processing facility that operates a 350
million BTU per hour, coal-fired boiler known as the Riley boiler.  The
Riley boiler emits sulfur dioxide, oxides of nitrogen and particulate
matter.  It is anticipated to operate into the foreseeable future, thus
expected life of the source is not a factor in the BART determination.  

	The first step in a BART analysis is the identification of all
available retrofit control options.  Available retrofit control options
are those air pollution control technologies with a practical potential
for application to the emission unit.  40 CFR 51, appendix Y provides
guidance on identifying available options that includes review of
EPA’s Clean Air Technology Center RACT/BACT/LAER clearinghouse, state
and local Best Available Control Technology Guidelines, and a number of
other documents.  See 40 CFR 51 appendix Y(IV)(D)(1).  Generally EPA
does not expect states to consider control technologies that have not
already been demonstrated in practice to be technically feasible.

	Idaho identified the pollutants of concern for the BART determination
at the Riley boiler to be sulfur dioxide, oxides of nitrogen and
particulate matter.  BART controls for each pollutant will be discussed
below.  Following an evaluation of available controls, described below,
Idaho determined that the following emission limits represent BART for
the Riley Boiler:

	SO2		104 lb/hr  

	NOx		131 lb/hr

	PM		12.4 lb/hr

The Idaho Regional Haze SIP submittal includes the federally enforceable
Tier II operating permit for TASCO, Nampa, (permit No. T2-2009.0109)
that contains these emission limits.  See letter and attachments dated
September 7, 2010, from Mike Simon, Stationary Source Manager, Idaho Air
Quality Division, to Kent Quinney, Plant Manager, The Amalgamated Sugar
Company, LLC-Nampa Factory.  The BART emission limits in the Tier II
operating permit are slightly higher than those limits in the SIP
submittal to allow for slight variation in test method results. 

	The emission limits for NOx and SO2 can be achieved respectively
through use of low NOx burners with overfire air and spray dry gas
desulfurization.  BART will result in a 65% reduction in SO2 emissions
and 80% reduction in NOx emissions.  Idaho found that the bag house
currently in place at the facility will result in compliance with the PM
BART limitation.

1.  TASCO SO2 BART Evaluation

	The TASCO Riley boiler currently burns low-sulfur coal limited to 1%
sulfur by weight.  The alternative control options considered for SO2
include: low- sulfur coal limited to 0.6% sulfur by weight that would
provide an additional 15% control efficiency, wet flue gas
desulfurization (Wet FGD) with a 95% control efficiency, spray dryer
flue gas desulfurization (Spray Dry FGD) with an 80% control efficiency,
dry lime flue gas desulfurization (Dry Lime FGD) with a 55% control
efficiency, dry Trona flue gas desulfurization (Dry Trona FGD) with a
65% control efficiency.  Idaho found that all these technologies are
technically feasible, but, as explained below, that wet FGD and spray
dry FGD were the best options for further evaluation.

	With a removal efficiency of 95% or greater, wet FGD systems offer one
of the highest SO2 removal efficiencies of the available control
technologies. However, the installation of wet FGD at TASCO Nampa would
require significant modification of the facility that would increase the
cost of this option.  As explained in the SIP submittal, wet FGD results
in a saturated exhaust stream.  The resulting condensation that would
form in the stack would likely have a very low pH that would require
installation of a stack liner to protect the integrity of the stack. 
Idaho concluded that installation of a stack liner would cost
$2,000,000.  Cost effectiveness of wet FGD was accordingly estimated at
$3353/ton, with an incremental cost of $6940/ton as compared to the next
most efficient control technology, spray dry FGD.

	Spray dry FGD typically has an estimated control efficiency of 80-90%
depending on exit flue gas temperature as it approaches the adiabatic
saturation temperature.  Idaho used 80% control efficiency in this
evaluation.  Cost effectiveness of spray dry FGD is $2163/ton and the
incremental cost over the next most efficient control technology, dry
Trona FGD is $360/ton.

	Idaho also evaluated the energy and non-air related environmental
impacts of the SO2 control options.  Waste-water treatment from wet FGD
is a major concern to Idaho and would need to be treated onsite.  The
SIP submittal explains that it would be difficult and expensive to
expand the TASCO on-site treatment facility due to limited available
land and the City of Nampa water treatment system might not be able to
handle the increased water volume.  See State of Idaho Department of
Environmental Quality, Regional Haze Plan, 10/8/10, appendix F, 

	Table 32 of appendix F of the SIP submittal provides the estimated
visibility impact of the five control options.  Wet FGD would reduce the
number of days with greater than 0.5 dv impact over a three year period
from 127 days to 43 days.  Spray dry FGD would reduce the number of days
with greater than 0.5 dv from 127 days to 51 days.  Considering the
incremental cost of wet FGD over spray dry FGD of $6940/ton, the waste
water treatment limitations, and achieving a reduction of only 8 more
days with impact greater than 0.5 dv over a three year period, Idaho
concluded that wet FGD is not warranted.

	Idaho has determined that spray dry FGD is the appropriate control
technology for SO2 and established 104 lb/hr as BART based on cost
effectiveness and improvement in visibility.  EPA agrees with Idaho’s
BART determination for SO2.

2.  NOx BART Evaluation

	Idaho identified potential control options for oxides of nitrogen (NOx)
for the Riley boiler as:  low NOx burners (LNB) with a 50% control
efficiency, low NOx burners with overfire air (LNB/OFA) with a 65%
control efficiency, ultra low NOx burners (ULNB) which was determined to
be infeasible, selective catalytic reduction (SCR) with a 90% control
efficiency, and selective non-catalytic (SNCR) determined to be
infeasible.  Idaho evaluated the technical feasibility of each control
option.  Idaho found that ULNB is not technologically feasible as the
fire box at the Riley boiler is not large enough to accommodate the
flame management system necessary for this type of control.  Idaho also
concluded that SNCR is also not technologically feasible as the boiler
exhaust path does not have enough residence time for reliable control. 
Idaho accordingly identified three technically feasible control options:
 LNB, LNB/OFA, and SCR.

	Idaho determined the cost effectiveness and incremental cost
effectiveness for the three technically feasible control options.  See
Table 35 of appendix F of the SIP submittal.  Idaho concluded that
LNB/OFA provides a reasonable cost effectiveness of $1270/ton and
incremental cost effectiveness of $2430/ton over low-NOx burners.  SCR
would provide a 90% reduction in NOx emissions at a cost effectiveness
of $3768 and incremental cost of $10,245/ton over LNB/OFA.  LNB/OFA
would reduce the number of days with impacts greater than 0.5 dv over a
three year period from 127 days to 56 days.  SCR would reduce the number
of days with impact greater than 0.5 dv over a three year period from
127 days to 40 days.  Considering the incremental cost of SCR over
LNB/OFA of $10,245/ton and achieving an incremental reduction of 16 days
with impact greater than 0.5 dv over a three year period, Idaho
concluded SCR is not warranted and that LNB/OFA represents BART.  In
addition, as described below in section F(d), TASCO argued that it could
not afford to install an SCR.  In view of this and Idaho’s conclusion
that the incremental cost of $10,245/ton for reducing the number of days
with an impact greater than 0.5dv by 16 over a three year period EPA is
proposing to approve Idaho’s determination of BART for NOx TASCO.

3.  PM BART Evaluation

	The TASCO Nampa Riley boiler has a baghouse to control particulate
matter.  In its PM BART evaluation Idaho considered other alternative
control technologies including: an enhanced baghouse with a control
efficiency of 99%, wet electrostatic precipitator with a control
efficiency 0f 99%, and dry electrostatic precipitator with a control
efficiency of 99%.  Idaho compared these technologies to the control
efficiency of the current baghouse.  The existing baghouse with a
control efficiency of 99% emits 0.036 lbs/MMbtu  (350 MMbtu/hour boiler
with a limit of 0.036 lbs/MMbtu the emissions are 12.6 lbs/hour).  

	Idaho determined that the existing baghouse is the best BART control
technology since it will not incur additional cost and has control
efficiency comparable to the identified alternate control technologies. 
The existing baghouse has the added environmental benefits of not
requiring additional water or electricity.  The benefit of adding an
additional baghouse is so small the benefits are outweighed by the
costs.  In conclusion, the best BART alternative for particulate is the
existing baghouse.  

	Idaho determined that the current baghouse and an emission limitation
of 12.4 lbs/hr is BART.  EPA agrees with this determination.

4.  TASCO Affordability

	TASCO appealed to Idaho that the company could not afford the
identified BART (Spray Dry FGD and LNB/OFA) and remain viable.  At
Idaho’s request, EPA conducted an evaluation and analysis of TASCO’s
financial status and health.  Based on this evaluation, EPA determined
TASCO could afford implementation of the identified BART.  EPA also
concluded that TASCO could not reasonably afford the more costly control
options of Wet FGD for SO2 control and SCR for NOx control.  See Idaho
Regional Haze Plan 10/8/10, appendix F, page F-317:  Executive Summary
excerpt from: An Affordability Analysis of The Amalgamated Sugar Company
LLC's Affordability Claim with respect to the Best Available Retrofit
Technology (BART) for the Riley Boiler at the Nampa, Idaho facility,
February 12, 2010.

	Based on EPA’s review and evaluation we propose to approve the BART
determination for TASCO.

G.  Monsanto/P4 BART Analysis

	Monsanto/P4 Production is a thermal process elemental phosphorus
production facility.  Idaho identified two BART units at the facility:
the #5 Rotary Kiln and the #9 Furnace Exhaust and carbon monoxide Flare.
 Phosphate ore is processed in a high temperature electric arc furnace
in a reducing atmosphere produced by the introduction of coke.  Carbon
monoxide gas from the arc furnace is used as fuel for the #5 Rotary
Kiln.  Excess carbon monoxide is flared to the atmosphere.  

	Idaho concluded, as discussed below, that the following emissions limit
is BART for #5 Rotary Kiln:

	SO2 		143 lb/hr

	Idaho determined, as discussed below, that there are no technically
feasible NOx control options for the #9 Furnace Exhaust and CO Flare.

1.  #5 Rotary Kiln, SO2 Evaluation:

	Idaho conducted a thorough SO2 BART evaluation for the #5 Rotary Kiln. 
The #5 Rotary Kiln heats phosphate ore to remove volatile impurities and
harden ore nodules for further handling and introduction into the
electric arc furnace. Carbon monoxide from the furnace off gasses is the
primary fuel with coal and natural gas as backup.  Existing
federally-enforceable process and air pollution controls for the kiln
are included in the facility’s current Tier I (title V) operating
permit No. T1-2009.0121, issued July 24, 2009.  These requirements
consist of:

A limit on the sulfur content of the coal to no more than 1% by weight.

A dust knockout chamber, spray tower, four parallel Hydro-Sonic©
scrubbers, and four parallel cyclonic separators.  The tandem nozzle
fixed-throat free-jet scrubbers are required for control of PM/PM10 and
polonium-210 emissions (a radionuclide) found in the phosphate ore.

The initial SO2 control device is a settling chamber where large
particles are removed. The exhaust flow is then routed to a concrete
tower where it passes through water sprays to remove soluble gases and
particulate matter. The exhaust flow is then routed to four parallel
Hydro-Sonic© scrubbers for removal of submicron particles and entrained
particle-laden water. The exhaust gases exit the scrubbers and pass
though cyclonic separators and fans prior to exiting to the atmosphere
though four stacks.

	A lime concentrated dual alkali (LCDA) scrubber to control SO2
emissions from the kiln was installed by Monsanto/P4 in 2005.  The LCDA
scrubbing process uses the existing Hydro-Sonic© scrubbers to absorb
SO2 with a solution of sodium salts comprised of sodium sulfite and
bisulfite, the active absorbent species. Some sodium sulfate will also
be produced.  The spent solution of sodium sulfite/bisulfite/sulfate is
continuously withdrawn to a dual-reactor system, where it is treated
with hydrated lime. The lime regenerates the scrubbing solution and
precipitates calcium sulfite/sulfate solids. The solids are removed from
the system through thickening and filtration, and the regenerated
solution is returned to the scrubber as feed material. 

	Additional SO2 controls would be add-on (or retrofit) control to the
existing control technology.  Idaho analyzed the technically feasible
retrofit control technologies for SO2 emissions from the #5 Rotary Kiln.
 These alternative controls included; wet FGD with lime and amine
scrubbing.  

	Idaho evaluated the control efficiencies of these feasible technologies
and found that both are capable of 97% control.  As determined by Idaho,
the costs of these controls are $466/ton for wet FGD and $881/ton for
amine scrubbing. See appendix F, Table 5.1.1 (page 338) of the Idaho
Regional Haze SIP.   The energy impacts were evaluated and both options
require more energy, but not disproportionate amounts.  Neither of the
available options constitute significant adverse non-air environmental
effects.  The #5 Rotary Kiln is expected to remain in operation for the
life of the P4 facility.

	Idaho selected wet-FGD with lime as the most suitable control
technology based on the fact that control efficiency is comparable to
amine scrubbing, has a lower cost, and is a proven mature technology. 
Idaho determined that 143 lb/hr is BART for the #5 Rotary Kiln.  EPA
agrees with this determination. 

2.  #5 Rotary Kiln NOx BART Evaluation

	Idaho searched EPA’s RACT/BACT/LAER clearinghouse (RBLC) for
potential NOx control options.  The available options include:
combustion control, LNB, and SNCR.  

	Idaho determined that NOx combustion controls are technically
infeasible due to the temperatures required for sintering the phosphate
ore and the change in temperature resulting from combustion control. 
Thermal NOx is formed at approximately 1300 oC (2372 oF) and above. The
minimum temperature at which sintering of the phosphate ore occurs is
1400 oC to 1459 oC (2552 oF to 2658 oF).  Therefore, it is not feasible
to lower the temperature in the kiln to minimize or prevent the
formation of thermal NOx and still sinter the ore.

	Likewise, LNB was eliminated because the temperature required for a low
NOx burner is too low to sinter the phosphate ore and form the required
nodules. Sintering of the ore takes place at 1400 oC to 1459 oC, and low
NOx burners must be controlled to operate at temperatures well below
1300 oC (2372 oF), the temperature at which thermal NOx is formed.

	SNCR was eliminated because the kiln off gas temperature at the exit of
the kiln and prior to the existing Hydro-Sonic© particulate control is
too low for operation of SNCR.  

	EPA agrees that there are no technically feasible NOx control options
for the #5 Rotary Kiln.  The current emission limitation is 3750.7
ton/yr.

3.  #5 Rotary Kiln Particulate Matter BART Evaluation  

	As described above, the #5 Rotary Kiln emissions are currently
controlled with Hydro-Sonic© high energy venture scrubbers to control
particulate matter.  The Tier I operating permit includes a federally
enforceable limit of 89.4 tons of PM/year. 

	Idaho conducted a brief evaluation of alternative PM control
technologies but concluded, and EPA agrees, that there are no other
technically feasible alternative control technologies with greater
control efficiency than the existing Hydro-Sonic© high energy venturi
scrubbers.  Thus, the existing PM emission limit of 98.4 t/yr
constitutes BART for this source. 

4.  BART for the #9 Furnace CO Flare Evaluation

	Ore nodules from the #5 Rotary Kiln are combined with coke and
quartzite and heated in the #9 electric arc furnace.  The resulting
thermal process releases elemental phosphorus (as a gas), carbon
monoxide and entrained particulate matter.  The furnace off gas is
cooled to liquefy and collect the elemental phosphorus and the remaining
gasses are ducted to the #5 Rotary Kiln as fuel.  Excess furnace off gas
is treated in a thermal oxidizer and flared to the atmosphere. The
source of concern is the furnace flare, since most of the furnace gasses
fuel the #5 Rotary kiln and are controlled by technology applied to that
source.

	A review of the RBLC Clearinghouse revealed there are no available
control technologies for particulate matter, SO2, or NOx for the #9
Furnace CO Flare.  The RBLC Clearinghouse flare control options are
exclusively for organic fuels and are not applicable for carbon monoxide
fueled flares. 

	EPA agrees with Idaho’s conclusion because there are no known
retrofit control technologies that are technically feasible for the
Monsanto/P4 #9 Furnace Exhaust and CO Flare.   EPA is proposing to
approve the BART determination for Monsanto/P4.

	The Monsanto/P4 BART emission limits are contained in federally
enforceable Tier I and Tier II operating permits.  The BART requirements
are contained in the Tier II operating permit, T2-2009.0109, issued
November 17, 2009. 

H.  Improvement in Visibility from BART at TASCO, Nampa and Monsanto/P4

	Table 10-14 of the SIP submittal presents the visibility improvement at
several Class I areas in Idaho and surrounding states from
implementation of BART at TASCO Nampa and Monsanto/P4.  The metric used
to measure improvement is the number of days (or reduction in number of
days) with a deciview impact larger than 0.5 dv from each BART facility
over a three year period.   

	The greatest improvement from BART controls at Monsanto/P4 is seen in
the Teton Wilderness Area in Wyoming.  Idaho estimated a reduction in
the number of days with visibility impairment greater than 0.5 dv from
Monsanto/P4 of 50 days over a three year period.    Table 10-15 of the
SIP submittal presents the visibility improvement at several other Class
I areas in Idaho and surrounding states from implementation of BART at
the Monsanto/P4 facility in Soda Springs.  

The greatest improvement from BART controls at TASCO Nampa is seen in
the Eagle Cap Wilderness Area in Oregon, with a reduction in days with
greater than 0.5 dv of 127 days over a three year period. 

	Idaho included in the SIP submittal, federally enforceable Tier I and
Tier II operating permits for TASCO Nampa and Monsanto/P4 which contain
the necessary emission limitations representing BART and schedules for
compliance. 

IV.  EPA’s Analysis of Whether Regional Haze SIP Submittal Meets
Interstate Transport Requirements   

	In its October 25, 2010, transmittal letter, Idaho also indicated that
it intends the Regional Haze SIP submittal also to be a SIP submission
for purposes of the visibility requirements of section 110(a)(2)(D)(i)
with respect to the 1997 8-hour ozone and 1997 PM2.5 NAAQS.  In the
submission, Idaho stated that:  “Idaho’s Regional Haze SIP also
satisfies the Clean Air Act Interstate Transport requirements of section
110(a)(2)(D)(ii).  Chapters 2 and 13 and the associated appendix for
chapter 2 describe Idaho’s consultation with other states through the
WRAP.  Chapter 9 identifies Idaho’s contribution and future visibility
improvements at mandatory Class I Federal Areas impacted by Idaho’s
emissions.”   In its SIP transmittal letter, the state referred to
section 110(a)(2)(D)(ii), but from the context it is clear that the
state intended this reference to be to section 110(a)(2)(D)(i), and more
particularly to section 110(a)(2)(D)(i)(II).

Section 110(a)(2)(D)(i)(II) of the Act requires SIP revisions to
“contain “adequate provisions  …prohibiting …any source or other
types of emission activity within the State from emitting any air
pollutant in amounts which will …interfere with measures required to
be included in the applicable implementation plan for any other State
… to protect visibility.”  EPA is proposing to find that the SIP
submitted by Idaho to address regional haze contains adequate provisions
to meet the “good neighbor” provisions of section
110(a)(2)(D)(i)(II) with respect to  visibility.

	As an initial matter, EPA notes that section 110(a)(2)(D)(i)(II) does
not explicitly specify how EPA should ascertain whether a state’s SIP
contains adequate provisions to prevent emissions from sources in that
state from interfering with measures required in another state to
protect visibility.  Thus, the statute is ambiguous on its face, and EPA
must interpret that provision.

	Our 2006 Guidance recommended that a state could meet the visibility
prong of the transport requirements for section 110(a)(2)(D)(i)(II) by
submission of the regional haze SIP, due in December 2007.  EPA’s
reasoning was that the development of the regional haze SIPs was
intended to occur in a collaborative environment among the states, and
that through this process states would coordinate on emissions controls
to protect visibility on an interstate basis.  In fact, in developing
their respective reasonable progress goals, WRAP states consulted with
each other through the WRAP’s work groups.  As a result of this
process, the common understanding was that each state would take action
to achieve the emissions reductions relied upon by other states in their
reasonable progress demonstrations under the RHR.  This interpretation
is consistent with the requirement in the regional haze rule that a
state participating in a regional planning process must include “all
measures needed to achieve its apportionment of emission reduction
obligations agreed upon through that process.”  40 CFR
51.308(d)(3)(ii).  

We believe that with approval of the portions of the Idaho RH SIP that
we are proposing to take action on today, Idaho’s SIP will also
contain adequate provisions to prevent interstate transport that would
interfere with the measures required in other states to protect
visibility.  Chapter 13 of the Idaho SIP submittal explains the
consultation process followed by Idaho and its neighboring states to
meet the requirements in the regional haze rule to address the
interstate transport of visibility impairing pollutants and the outcome
of that process.  Section 13.2.3 indicates that Idaho and neighboring
states agreed that “no major contributions were identified that
supported developing new interstate strategies, mitigation measures, or
emissions reductions obligations,” and that each state could achieve
its share of emission reductions through the implementation of BART and
other existing measures in state regional haze plans.  The state agreed
that future consultation would address any new strategies or measures
needed.  The measures addressing BART in the Idaho SIP submittal
accordingly would appear to be adequate to prevent emissions from source
in Idaho from interfering with the measures required to be in the
regional haze SIPs of its neighbors.  

This conclusion is consistent with the analysis conducted by the WRAP,
an analysis that provides an appropriate means for further evaluating
whether emissions from sources in a state are interfering with the
visibility programs of other states, as contemplated in section
110(a)(2)(D)(i)(II).  As described below, EPA’s evaluation shows that
the BART measures of the Regional Haze SIP submittal, that we are
proposing to approve today, are generally consistent with the emissions
reductions assumptions of the WRAP modeling from Idaho sources. 
Accordingly, EPA is proposing to approve Idaho’s SIP as ensuring that
emissions from Idaho do not interfere with the reasonable progress goals
of other states.

In developing their visibility projections using photochemical grid
modeling, the WRAP states assumed a certain level of emissions from
sources within Idaho.  The visibility projection modeling was in turn
used by the states to establish their own reasonable progress goals.  We
have reviewed the WRAP photochemical modeling emissions projections used
in the demonstration of reasonable progress towards natural visibility
conditions and compared them to the emissions limits that will result
from the imposition of BART on sources in Idaho.  We have concluded that
with the emissions reductions achieved by these measures, the emissions
from Idaho sources in the projected inventory for 2018 (which included
both reductions and increases) will be below that assumed in the WRAP
analysis.  In addition, EPA notes that these projections also included
estimated emissions from a new coal fired power plant to be located in
Jerome, Idaho.  The Governor of Idaho subsequently issued a ban on the
construction of new coal fired power plants that is still in effect. 
Thus, EPA anticipates that the actual emissions in 2018 may be
significantly less than the emissions used in modeling 2018 conditions
because the Jerome, Idaho facility will likely not be constructed during
the time period covered by the Regional Haze SIP.  

	As a result of the foregoing determination, EPA is proposing to find
that the Idaho Regional Haze SIP submission contains the emission
reductions needed to achieve Idaho’s share of emission reductions
agreed upon through the regional planning process.  As reflected in its
Regional Haze SIP submittal, Idaho committed to achieve these emission
reductions to address impacts on visibility on Class I areas in
surrounding states.  The portions of the Idaho Regional Haze SIP that we
are proposing to approve ensure that emissions from Idaho will not
interfere with the reasonable progress goals for neighboring state’s
Class I areas.  EPA is accordingly proposing to find that these emission
reductions also meet the requirements of section 110(a)(2)(D)(i)(II) of
the Act with respect to the visibility prong for the 1997 8-hour ozone
and 1997 PM2.5 NAAQS.

V. What Action is EPA Proposing?

EPA is proposing to approve portions of the Idaho Regional Haze plan,
submitted on October 25, 2010, as meeting the requirements set forth in
section 169A of the Act and in 40 CFR 51.308(e) regarding BART.  EPA is
also proposing to approve the Idaho submittal as meeting the
requirements of 51.308(d)(2) and (4)(v) regarding the calculation of
baseline and natural conditions for Craters of the Moon National
Monument, Sawtooth Wilderness Area, and Selway-bitterroot Wilderness,
and the statewide inventory of emissions of pollutants that are
reasonably anticipated to cause or contribute to visibility impairment
in any mandatory Class I Federal Area.  In addition, EPA is proposing to
find that the BART measures in the Idaho Regional Haze plan meet the
requirements of section 110(a)(D)(ii)(II) of the CAA with respect to the
1997 8-hour ozone and 1997 PM2.5 NAAQS

VI.  Scope of Action

Idaho has not demonstrated authority to implement and enforce IDAPA
chapter 58 within “Indian Country” as defined in 18 U.S.C. 1151. 
Therefore, EPA proposes that this SIP approval not extend to “Indian
Country” in Idaho.  See CAA sections 110(a)(2)(A) (SIP shall include
enforceable emission limits), 110(a)(2)(E)(i) (State must have adequate
authority under State law to carry out SIP), and 172(c)(6)
(nonattainment SIPs shall include enforceable emission limits).  This is
consistent with EPA's previous approval of Idaho's prevention of
significant deterioration (PSD) program, in which EPA specifically
disapproved the program for sources within Indian Reservations in Idaho
because the State had not shown it had authority to regulate such
sources.  See 40 CFR 52.683(b).  It is also consistent with EPA’s
approval of Idaho’s title V air operating permits program.  See 61 FR
64622, 64623 (December 6, 1996) (interim approval does not extend to
Indian Country); 66 FR 50574, 50575 (October 4, 2001) (full approval
does not extend to Indian Country). 

VII. Statutory and Executive Order Reviews

Under the Clean Air Act, 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 Clean Air Act.  Accordingly,
this proposed action merely approves state law as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by state law.  For that reason, this proposed 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 (Public Law 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
Clean Air Act; 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 dioxide, Particulate matter, Reporting and
recordkeeping requirements, Sulfur oxides, visibility, and Volatile
organic compounds.

Dated: ________________			______________________

Region 10. 

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.  42 U.S.C. 7472(a).  In accordance with section 169A
of the CAA, EPA, in consultation with the Department of Interior,
promulgated a list of 156 areas where visibility is identified as an
important value.  44 FR 69122 (November 30, 1979).  The extent of a
mandatory Class I area includes subsequent changes in boundaries, such
as park expansions.  42 U.S.C. 7472(a).  Although states and tribes may
designate as Class I additional areas which they consider to have
visibility as an important value, the requirements of the visibility
program set forth in section 169A of the CAA apply only to
‘‘mandatory Class I Federal areas.”  Each mandatory Class I
Federal area is the responsibility of a ‘‘Federal Land
Manager.’’  42 U.S.C. 7602(i).  When we use the term “Class I
area” in this action, we mean a “mandatory Class I Federal area.”

 See 64 FR at 35715.

 Id.

Albuquerque/Bernalillo County in New Mexico must also submit a regional
haze SIP to completely satisfy the requirements of section 110(a)(2)(D)
of the CAA for the entire State of New Mexico under the New Mexico Air
Quality Control Act (section 74-2-4).

 Wildearth Guardians v. Jackson, Case No. 4:09-CV-02453-CW (N.D. Calif).

The preamble to the RHR provides additional details about the deciview. 
64 FR 35714, 35725 (July 1, 1999).

The set of “major stationary sources” potentially subject to BART is
listed in CAA section 169A(g)(7).

 EPA evaluated the technical work products of the WRAP used by Idaho in
support if this Regional Haze SIP submittal.  The results of that
evaluation are included in the document “WRAP Technical Support
Document” or WRAP TSD.

   Monsanto agreed to forego exemption modeling and to move directly to
a BART determination.

   The 22nd highest impact during 2003-2004 corresponds to the 98th
percentile of modeling results, an approach to applicability that EPA
concluded was appropriate in the BART Guidelines.  70 FR at 39,123.

     “Indian country” is defined under 18 U.S.C. 1151 as: (1) all
land within the limits of any Indian reservation under the jurisdiction
of the United States Government, notwithstanding the issuance of any
patent, and including rights-of-way running through the reservation, (2)
all dependent Indian communities within the borders of the United
States, whether within the original or subsequently acquired territory
thereof, and whether within or without the limits of a State, and (3)
all Indian allotments, the Indian titles to which have not been
extinguished, including rights-of-way running through the same.  Under
this definition, EPA treats as reservations trust lands validly set
aside for the use of a Tribe even if the trust lands have not been
formally designated as a reservation.  In Idaho, Indian country
includes, but is not limited to, the Coeur d’Alene Reservation, the
Duck Valley Reservation, the Reservation of the Kootenai Tribe, the Fort
Hall Indian Reservation, and the Nez Perce Reservation as described in
the 1863 Nez Perce Treaty.

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