[Federal Register Volume 77, Number 246 (Friday, December 21, 2012)]
[Proposed Rules]
[Pages 75703-75737]
[FR Doc No: 2012-30702]

Vol. 77

Friday,

No. 246

December 21, 2012

Part II

Environmental Protection Agency

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40 CFR Part 51

Partial Approval and Disapproval of Air Quality Implementation Plans;
Arizona; Regional Haze and Visibility Impacts of Transport, Ozone and
Fine Particulates; Proposed Rules

Federal Register / Vol. 77 , No. 246 / Friday, December 21, 2012 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[EPA-R09-OAR-2012-0904, FRL-9763-2]

Partial Approval and Disapproval of Air Quality Implementation
Plans; Arizona; Regional Haze and Visibility Impacts of Transport,
Ozone and Fine Particulates

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve in part and disapprove in part a
revision of Arizona's State Implementation Plan (SIP) to implement the
regional haze program for the first planning period through July 31,
2018. This proposed action includes all portions of the SIP except for
three electric generating stations that were addressed in a final rule
published in the Federal Register on December 5, 2012. Today, EPA is
taking action on Arizona's Best Available Retrofit Technology (BART)
control analysis and determinations, Reasonable Progress Goals (RPGs)
for the State's 12 Class I areas, Long-term Strategy (LTS), and other
elements of the State's regional haze plan. If EPA takes final action
to disapprove any portion of the SIP, EPA will work with the State to
develop plan revisions to address the disapproved provisions. Regional
haze is caused by emissions of air pollutants from numerous sources
located over a broad geographic area. The Clean Air Act (CAA) requires
states to adopt and submit to EPA SIPs that assure reasonable progress
toward the national goal of achieving natural visibility conditions in
156 national parks and wilderness areas designated as Class I areas.

DATES: Written comments must be received by the designated contact at
the address below on or before February 4, 2013.

ADDRESSES: See the General Information section for further instructions
on where and how to learn more about this proposed rule, and how to
submit comments.

FOR FURTHER INFORMATION CONTACT: Gregory Nudd, U.S. EPA, Region 9,
Planning Office, Air Division, Air-2, 75 Hawthorne Street, San
Francisco, CA 94105. Gregory Nudd can be reached at telephone number
(415) 947-4107 and via electronic mail at<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Definitions

    For the purpose of this document, we are giving meaning to certain
words or initials as follows:

    (1) The words or initials Act or CAA mean or refer to the Clean
Air Act, unless the context indicates otherwise.
    (2) The initials ADEQ mean or refer to the Arizona Department of
Environmental Quality.
    (3) The words Arizona and State mean the State of Arizona.
    (4) The initials ARHP mean or refer to the Arizona Regional Haze
Plan submitted by the State of Arizona on February 28, 2011.
    (5) The initials BART mean or refer to Best Available Retrofit
Technology.
    (6) The term Class I area refers to a mandatory Class I Federal
area.
    (7) The initials CBI mean or refer to Confidential Business
Information.
    (8) The words EPA, we, us or our mean or refer to the United
States Environmental Protection Agency.
    (9) The initials FGD mean or refer to flue gas desulfurization.
    (10) The initials FIP mean or refer to Federal Implementation
Plan.
    (11) The initials FLMs mean or refer to Federal Land Managers.
    (12) The initials IMPROVE mean or refer to Interagency
Monitoring of Protected Visual Environments monitoring network.
    (13) The initials LTS mean or refer to Long-term Strategy.
    (14) The initials NAAQS mean or refer to National Ambient Air
Quality Standards.
    (15) The initials NH3 mean or refer to ammonia.
    (16) The initials NOX mean or refer to nitrogen oxides.
    (17) The initials NM mean or refer to National Monument.
    (18) The initials NP mean or refer to National Park.
    (19) The initials OC mean or refer to organic carbon.
    (20) The initials PM mean or refer to particulate matter.
    (21) The initials PM2.5 mean or refer to fine particulate matter
with an aerodynamic diameter of less than 2.5 micrometers.
    (22) The initials PM10 mean or refer to particulate matter with
an aerodynamic diameter of less than 10 micrometers (coarse
particulate matter).
    (23) The initials ppm mean or refer to parts per million.
    (24) The initials PSD mean or refer to of Significant
Deterioration.
    (25) The initials PTE mean or refer to Potential to Emit.
    (26) The initials RAVI mean or refer to Reasonably Attributable
Visibility Impairment.
    (27) The initials RHR mean or refer to the Regional Haze Rule,
originally promulgated in 1999 and codified at 40 CFR 51.301-309.
    (28) The initials RMC mean or refer to Regional Modeling Center.
    (29) The initials RP mean or refer to Reasonable Progress.
    (30) The initials RPG or RPGs mean or refer to Reasonable
Progress Goal(s).
    (31) The initials RPOs mean or refer to regional planning
organizations.
    (32) The initials SIP mean or refer to State Implementation
Plan.
    (33) The initials SO2 mean or refer to sulfur dioxide.
    (34) The initials SRP mean or refer to Salt River Project
Agricultural Improvement and Power District.
    (35) The initials SSJF mean or refer to the Stationary Sources
Joint Forum of the Western Regional Air Partnership.
    (36) The initials tpy mean tons per year.
    (37) The initials TSD mean or refer to Technical Support
Document.
    (38) The initials VOC mean or refer to volatile organic
compounds.
    (39) The initials WA mean or refer to Wilderness Area.
    (40) The initials WEP mean or refer to Weighted Emissions
Potential.
    (41) The initials WRAP mean or refer to the Western Regional Air
Partnership.

Table of Contents

I. General Information
    A. Docket
    B. Instructions for Submitting Comments to EPA
    C. Submitting Confidential Business Information
    D. Tips for Preparing Your Comments
II. Overview of Proposed Actions
    A. Regional Haze
    B. Interstate Transport of Pollutants That Affect Visibility
III. Regional Haze Program and Interstate Transport Background
    A. Description of Regional Haze
    B. History of Regional Haze Regulations
    C. Roles of Agencies in Addressing Regional Haze
    D. Interstate Transport of Pollutants
IV. Requirements for Regional Haze Implementation Plans
    A. Regional Haze Rule
    B. Determination of Baseline, Natural and Current Visibility
Conditions
    C. Determination of Reasonable Progress Goals
    D. Best Available Retrofit Technology
    E. Long-Term Strategy
    F. Coordination of Regional Haze and Reasonably Attributable
Visibility Impairment
    G. Monitoring Strategy
    H. SIP Revisions and Progress Reports
    I. State Consultation With Federal Land Managers
    J. The Grand Canyon Visibility Transport Commission and Section
309
V. Overview of State and EPA Actions on Regional Haze
    A. EPA's Schedule To Act on Arizona's RH SIP
    B. Summary of EPA's Final Rule Affecting Three BART Sources
    C. History of State Submittals and EPA Actions
VI. EPA's Evaluation of Visibility Conditions in Arizona's Class I
Areas
    A. Affected Class I Areas
    B. Determination of Visibility Conditions and Uniform Rate of
Progress
    C. Arizona's Emissions Inventories
    D. Sources of Visibility Impairment
VII. EPA's Evaluation of Arizona's BART Analyses and Determinations

    A. Arizona's Identification of BART Sources
    B. EPA's Evaluation of Arizona's Subject-to-BART Analysis
    C. Arizona's BART Control Analysis
    D. Arizona's BART Determinations
VIII. EPA's Evaluation of Arizona's Reasonable Progress Goals
    A. Reasonable Progress Goals for the Best Days
    B. Reasonable Progress Goals for the Worst Days
    C. Summary of EPA's Evaluation
IX. EPA's Evaluation of Arizona's Long-Term Strategy
    A. Interstate Consultation on Emission Management Strategies
    B. Measures To Obtain Allotted Emissions Reductions
    C. Technical Basis for the Apportionment of Emission Reductions
    D. Anthropogenic Sources of Visibility Impairment
    E. Mandatory Factors To Consider for the Long-Term Strategy
    F. Summary of EPA's Evaluation of the Long-Term Strategy
X. Monitoring Strategy and Other Requirements
    A. Monitoring Strategy
    B. State and Federal Land Manager Coordination
    C. Periodic SIP Review and Five-Year Progress Reports
XI. EPA's Evaluation of Arizona's Provisions for Interstate
Transport of Pollutants
XII. EPA's Proposed Action
    A. Regional Haze
    B. Interstate Transport of Visibility
    C. Sanctions and Federal Implementation Plan Duties
XIII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. Docket

    The proposed action relies on documents, information and data that
are listed in the index on http://www.regulations.gov under docket
number EPA-R09-OAR-2012-0904. Although listed in the index, some
information is not publicly available (e.g., Confidential Business
Information (CBI)). Certain other material, such as copyrighted
material, is publicly available only in hard copy form. Publicly
available docket materials are available either electronically at
http://www.regulations.gov or in hard copy at the Planning Office of
the Air Division, AIR-2, EPA Region 9, 75 Hawthorne Street, San
Francisco, CA 94105. EPA requests that you contact the individual
listed in the FOR FURTHER INFORMATION CONTACT section to view the hard
copy of the docket. You may view the hard copy of the docket Monday
through Friday, 9-5:00 PST, excluding Federal holidays.

 B. Instructions for Submitting Comments

    Written comments must be received at the address below on or before
February 4, 2013. Submit your comments, identified by Docket ID No.
EPA-R09-OAR-2012-0904, by one of the following methods:
     Federal Rulemaking portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER> (Attention: Gregory Nudd).
     Mail, Hand Delivery or Courier: Gregory Nudd, EPA Region
9, Air Division (AIR-2), 75 Hawthorne Street, San Francisco, California
94105. Hand and courier deliveries are only accepted Monday through
Friday, 8:30 a.m. to 4:30 p.m., excluding Federal holidays. Special
arrangements should be made for deliveries of boxed information.
    EPA's policy is to include all comments received in the public
docket without change. We may make comments available online at http://www.regulations.gov, including any personal information provided,
unless the comment includes information claimed to be CBI or other
information for which disclosure is restricted by statute. Do not
submit information that you consider to be CBI or that is otherwise
protected through http://www.regulations.gov or email. 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 email comment
directly to EPA, without going through http://www.regulations.gov, we
will include your email address 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 not include
special characters or any form of encryption, and be free of any
defects or viruses.

C. Submitting Confidential Business Information

    Do not submit CBI to EPA through http://www.regulations.gov or
email. Clearly mark the part or all of the information that you claim
as CBI. For CBI information in a disk or CD ROM that you mail to EPA,
mark the outside of the disk or CD ROM as CBI and identify
electronically within the disk or CD ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, you must submit a copy of the
comment that does not contain the information claimed as CBI for
inclusion in the public docket. We will not disclose information so
marked except in accordance with procedures set forth in 40 CFR part 2.

D. Tips for Preparing Comments

    When submitting comments, remember to:
     Identify the rulemaking by docket number and other
identifying information (e.g., subject heading, Federal Register date
and page number).
     Explain why you agree or disagree; suggest alternatives
and substitute language for your requested changes.
     Describe any assumptions and provide any technical
information and/or data that you used.
     If you estimate potential costs or burdens, explain how
you arrived at your estimate in sufficient detail to allow for it to be
reproduced.
     Provide specific examples to illustrate your concerns, and
suggest alternatives.
     Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
     Make sure to submit your comments by the identified
comment period deadline.

II. Overview of Proposed Actions

A. Regional Haze

    EPA is proposing to approve in part and disapprove in part the
remaining portion of Arizona's Regional Haze Plan (ARHP) \1\ submitted
to EPA Region 9 on

February 28, 2011, to meet the requirements of Section 308 of the
Regional Haze Rule (RHR). We propose to take action on Arizona's Best
Available Retrofit Technology (BART) control analysis and
determinations, Reasonable Progress Goals (RPG) for each of the 12
Class I areas, and Long-term Strategy (LTS). We are also proposing to
take action on the requirements that support these major components of
the plan, namely, the identification of Class I Areas impaired by
Arizona's emissions, estimated visibility conditions, emission
inventories, and the State's monitoring strategy. Today's proposal
follows our recent final action on three BART sources in Arizona \2\
and completes our review of the State's plan. EPA takes very seriously
a decision to propose disapproval of provisions in Arizona's plan, as
we believe that it is preferable that all emission control requirements
needed to protect visibility be implemented through the Arizona State
Implementation Plan (SIP). EPA must be able to find that the state plan
is consistent with the requirements of the Clean Air Act (CAA).
Further, EPA's oversight role requires that we assure fair
implementation of CAA requirements by states across the country, even
while acknowledging that individual decisions from source to source or
state to state may not have identical outcomes. EPA believes this
partial approval and partial disapproval is consistent with the CAA at
this time, while full approval of the SIP would be inconsistent with
the CAA. We look forward to working with ADEQ to address the issues
identified in our action. Our proposed actions are summarized as
follows:
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    \1\ ``Arizona State Implementation Plan, Regional Haze Under
Section 308 Of the Federal Regional Haze Rule,'' February 28, 2011.
    \2\ See 77 FR 72512, December 5, 2012.
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    Supporting Elements: EPA is proposing to approve Arizona's
identification of Class I areas that may experience visibility
impairment due to emissions from sources within the State; Arizona's
estimated visibility conditions for baseline, 2018 and 2064; Arizona's
uniform rate of progress for each Class I area; Arizona's emission
inventories for 2002 and 2018; and Arizona's identification of the
sources of visibility impairment. Because the submittal does not
include the most recently available emission inventory, as required
under the RHR, we are proposing to disapprove the ARHP with respect to
this requirement.
    BART-Eligible: EPA is proposing to approve Arizona's determination
that specific units at the following six sources are eligible for BART:
ASARCO Hayden Smelter (Hayden smelter), Freeport-McMoRan Inc. Miami
Smelter (Miami smelter), Chemical Lime (a subsidiary of Lhoist) Nelson
Plant (Nelson Lime Plant) Kilns 1 and 2, Arizona Public Service West
Phoenix Power Plant (West Phoenix Power Plant) Combined Cycle Units 1
through 3, CalPortland Rillito Cement Plant (Rillito Plant) Kiln 4, and
Catalyst Pulp Mill in Snowflake (Catalyst Paper) Power Boiler 2.\3\ We
propose to disapprove Arizona's determination that Tucson Electric
Power Sundt Generating Station (Sundt) Unit 4 is not eligible for BART.
Finally, we propose to approve the State's determination that no other
units in the State are BART-eligible. In particular, we propose to
approve the State's finding that Cholla Power Plant Unit 1 and Sundt
Unit I3 are not BART-eligible.
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    \3\ We have already approved ADEQ's determination that Arizona
Electric Power Cooperative (AEPCO) Apache Generating Station
(Apache) Units 1-3, Arizona Public Service Cholla Power Plant
(Cholla) Units 2-4, and Salt River Project Coronado Generating
Station (Coranado) 1-2 are BART-eligible. See 77 FR 72512.
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    BART-Exempt: EPA is proposing to approve Arizona's decision to set
0.5 dv as the threshold for determining whether sources are subject to
BART, but we are seeking comment on whether this threshold is
reasonable. We propose to approve Arizona's determination that two
eligible sources are exempt from BART based on this threshold. These
BART-exempt sources are West Phoenix Power Plant and Rillito Plant. We
propose to disapprove Arizona's determination that Nelson Lime Plant is
exempt from BART, but we are seeking comment on whether this
determination was reasonable and should be approved.
    BART-Subject: EPA is proposing to approve Arizona's determination
that three eligible sources are subject to BART. These sources are
Hayden smelter, Miami smelter, and Catalyst Paper.
    BART Determination: EPA is proposing to approve Arizona's BART
determinations for NOX at Hayden smelter, and for
PM10 at Miami smelter. We propose to disapprove Arizona's
conclusion that a BART determination is not required for
PM10 at the Hayden smelter and for NOX at the
Miami smelter. We are proposing alternatively to approve or disapprove
the State's BART determination for SO2 at the Hayden and
Miami smelters depending on a more detailed BART demonstration from the
State. We propose not to act on the State's BART determination for
Catalyst Paper because this facility is no longer in operation.
Further, we propose to disapprove the compliance schedules and
requirements for equipment maintenance and operation related to BART
controls at the Hayden smelter and the Miami smelter because these were
not included in the State's SIP submittal.
    Reasonable Progress Goals: EPA is proposing to disapprove Arizona's
RPGs for 2018 on the 20 percent least impaired (``best'') and 20
percent most impaired (``worst'') days at all of the State's Class I
areas. We propose to find that the State has not demonstrated that
these goals constitute reasonable progress by 2018 toward the goal of
natural conditions by 2064. For both the best and worst days, we expect
actual visibility conditions in 2018 to be better than predicted by the
State as a result of the economic recession and EPA-required controls.
    Long-term Strategy: EPA is proposing to approve Arizona's
interstate consultation process, the technical basis for its
apportionment of emission reductions, and the identification of all
anthropogenic sources of visibility impairment. Regarding the seven
mandatory factors a state must consider for the LTS, we propose to find
that Arizona considered emissions reductions due to ongoing air
pollution control programs, measures to mitigate the impacts of
construction activities, source retirement and replacement schedules,
smoke management techniques, and the anticipated net effect on
visibility due to projected changes in emissions through 2018. However,
we propose to find that the Arizona SIP does not include all measures
needed to achieve the State's apportionment of emission reduction
obligations with respect to out-of-state Class I areas. We also propose
to find that Arizona did not adequately consider emissions limitations
and schedules of compliance to achieve the RPGs or the enforceability
of emissions limits and control measures.

B. Interstate Transport of Pollutants That Affect Visibility

    When EPA promulgates a new or revised National Ambient Air Quality
Standard (NAAQS), states must submit SIP revisions that, among other
things, contain adequate provisions to prohibit the emission of any air
pollutant in amounts that will interfere with SIP measures required of
other states to protect visibility. CAA section 110(a)(2)(D)(i)(II). In
1997, EPA promulgated a revised NAAQS for 8-hour ozone and a new annual
and 24-hour NAAQS for particulate matter less than 2.5 microns
(PM2.5), and in 2006, EPA revised the 24-hour
PM2.5 NAAQS. Each of these actions triggered the requirement
for states to address the

interstate transport visibility requirement of section
110(a)(2)(D)(i)(II).
    In 2007 and 2009, Arizona submitted SIP revisions for the 1997
ozone and PM2.5, and 2006 PM2.5 NAAQS,
respectively, each of which indicated that it would be appropriate to
assess Arizona's interference with other states' measures to protect
visibility in conjunction with the state's regional haze SIP. Due to
the sequence of Arizona's regional haze submissions, we interpret
Arizona's 2007 and 2009 Transport SIPs to mean that Arizona intended
its Regional Haze Plan to address the interstate visibility requirement
of section 110(a)(2)(D)(i) for the 1997 8-hour ozone, 1997
PM2.5 NAAQS, and 2006 PM2.5 NAAQS.
    As explained elsewhere in this notice, EPA is proposing to
disapprove several elements of Arizona's Regional Haze Plan. In a prior
final rule, EPA disapproved certain aspects of Arizona's BART
determinations for three sources.\4\ Accordingly, Arizona's SIP lacks
enforceable emissions limitations for certain air pollutants necessary
to achieve RPGs for all Class I areas within, or affected by emissions
from, Arizona. As such, we are proposing to find that Arizona's 2007
and 2009 Transport SIPs and ARHP do not contain adequate provisions to
meet the ``good neighbor'' provisions of section 110(a)(2)(D)(i)(II)
with respect to visibility for the 1997 8-hour ozone, 1997
PM2.5, and 2006 PM2.5 NAAQS, nor a demonstration
that the existing Arizona SIP already includes measures sufficient to
meet the interstate transport visibility requirement.
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    \4\ 77 FR 72512.
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III. Regional Haze Program and Interstate Transport Background

A. Description of Regional Haze

    Regional haze is visibility impairment that is produced by a
multitude of sources and activities that are located across a broad
geographic area and emit fine particulates (e.g., sulfates, nitrates,
organic carbon (OC), elemental carbon (EC), and soil dust), and their
precursors (e.g., sulfur dioxide, nitrogen oxides, and in some cases,
ammonia (NH3) and volatile organic compounds (VOC)). Fine
particle precursors react in the atmosphere to form PM2.5,
which impairs visibility by scattering and absorbing light. Visibility
impairment reduces the clarity, color, and visible distance that one
can see. PM2.5 can also cause serious health effects and
mortality in humans and contributes to environmental effects such as
acid deposition and eutrophication.
    Data from the existing visibility monitoring network, the
``Interagency Monitoring of Protected Visual Environments'' (IMPROVE)
monitoring network, show that visibility impairment caused by air
pollution occurs virtually all the time at most national parks (NPs)
and wilderness areas (WAs). The average visual range \5\ in many Class
I areas (i.e., NPs and memorial parks, WAs, and international parks
meeting certain size criteria) in the western United States is 100-150
kilometers, or about one-half to two-thirds of the visual range that
would exist without anthropogenic air pollution. In most of the eastern
Class I areas of the United States, the average visual range is less
than 30 kilometers, or about one-fifth of the visual range that would
exist under estimated natural conditions.\6\
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    \5\ Visual range is the greatest distance, in kilometers or
miles, at which a dark object can be viewed against the sky.
    \6\ 64 FR 35715 (July 1, 1999).
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B. History of Regional Haze Regulations

    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 \7\ which
impairment results from manmade air pollution.'' EPA promulgated
regulations on December 2, 1980, 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.'' \8\ These regulations represented the first phase in
addressing visibility impairment. EPA deferred action on regional haze
that emanates from a variety of sources until monitoring, modeling and
scientific knowledge about the relationships between pollutants and
visibility impairment were improved.
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    \7\ 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.''
    \8\ 45 FR 80084 (December 2, 1980).
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    As part of the 1990 Amendments to the CAA, Congress added section
169B to focus attention on regional haze issues. EPA promulgated a rule
to address regional haze on July 1, 1999.\9\ The primary regulatory
requirements that address regional haze are found at 40 CFR 51.308 and
51.309 and are summarized below. Under 40 CFR 51.308(b), all states,
the District of Columbia and the Virgin Islands are required to submit
an initial SIP addressing regional haze visibility impairment no later
than December 17, 2007.\10\
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    \9\ 64 FR 35714 (July 1, 1999) codified at 40 CFR part 51,
subpart P (Regional Haze Rule).
    \10\ EPA's regional haze regulations require subsequent updates
to the regional haze SIPs. 40 CFR 51.308(g)-(i).
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C. Roles of Agencies in Addressing Regional Haze

    Successful implementation of the regional haze program will require
long-term regional coordination among states, tribal governments and
various federal agencies. As noted above, pollution affecting the air
quality in Class I areas can be transported over long distances, even
hundreds of kilometers. Therefore, to effectively address the problem
of visibility impairment in Class I areas, states, or the EPA when
implementing a FIP, need to develop strategies in coordination with one
another, taking into account the effect of emissions from one
jurisdiction on the air quality in another.
    Because the pollutants that lead to regional haze can originate
from sources located across broad geographic areas, EPA has encouraged
the states and tribes across the United States to address visibility
impairment from a regional perspective. Five regional planning
organizations (RPOs) were developed to address regional haze and
related issues. The RPOs first evaluated technical information to
better understand how their states and tribes impact Class I areas
across the country, and then pursued the development of regional
strategies to reduce emissions of particulate matter and other
pollutants leading to regional haze.
    The Western Regional Air Partnership (WRAP) RPO is a collaborative
effort of state governments, tribal governments, and various federal
agencies established to initiate and coordinate activities associated
with the management of regional haze, visibility and other air quality
issues in the western United

States. WRAP member State governments include: Alaska, Arizona,
California, Colorado, Hawaii, 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
Shoshone-Bannock Tribes of Fort Hall.

 D. Interstate Transport of Pollutants

    EPA promulgated new NAAQS for 8-hour ozone and fine particulate
matter (PM2.5) \11\ on July 18, 1997, and revised the 24-
hour PM2.5 NAAQS to a more protective level \12\ on
September 21, 2006. Section 110(a)(1) 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
air pollutants.
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    \11\ The 8-hour averaging period replaced the previous 1-hour
averaging period, and the level of the NAAQS was changed from 0.12
parts per million (ppm) to 0.08 ppm (62 FR 38856). The annual
PM2.5 standard was set at 15 micrograms per cubic meter
([mu]g/m\3\), based on the 3-year average of annual arithmetic mean
PM2.5 concentrations from single or multiple community-
oriented monitors and the 24-hour PM2.5 standard was set
at 65 [mu]g/m\3\, based on the 3-year average of the 98th percentile
of 24-hour PM2.5 concentrations at each population-
oriented monitor within an area (62 FR 38652).
    \12\ The final rule on the 24-hour NAAQS for PM2.5
published on October 17, 2006 revised the standard from 65 [mu]g/
m\3\ to 35 [mu]g/m\3\ (71 FR 61144).
---------------------------------------------------------------------------

    EPA issued on April 25, 2005, a ``Finding of Failure to Submit SIPs
for Interstate Transport for the [1997] 8-hour Ozone and
PM2.5 NAAQS.'' \13\ This included a finding that Arizona and
other states had failed to submit SIPs to address interstate transport
of emissions affecting visibility and started a two-year clock for EPA
to promulgate a FIP, unless the state made a submission to meet the
requirements of section 110(a)(2)(D)(i) and EPA approved such
submission.\14\
---------------------------------------------------------------------------

    \13\ 70 FR 21147.
    \14\ Id.
---------------------------------------------------------------------------

    EPA issued guidance on August 15, 2006, entitled ``Guidance for
State Implementation Plan (SIP) Submissions to Meet Current Outstanding
Obligations Under Section 110(a)(2)(D)(i) for the [1997] 8-Hour Ozone
and PM2.5 National Ambient Air Quality Standards'' (``2006
Guidance''). 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 the ways contemplated in the statute. Section 110(a)(2)(D)(i)
contains four distinct requirements (or ``prongs'') related to the
impacts of interstate transport. The SIP must prevent sources in the
state from emitting pollutants in amounts that 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 SIP measures required of other states to prevent significant
deterioration of air quality; or, (4) interfere with SIP measures
required of other states to protect visibility.\15\
---------------------------------------------------------------------------

    \15\ EPA previously took final action on SIP revisions from
Arizona to address section 110(a)(2)(D)(i) requirements for the 1997
8-hour ozone and 1997 PM2.5 NAAQS, but deferred action on
the fourth requirement regarding visibility. See 72 FR 42629 at
42632-42633 (July 31, 2007). Also, EPA recently finalized action on
the first three requirements of section 110(a)(2)(D)(i) for the 2006
PM2.5 NAAQS. See 77 FR 66398.
---------------------------------------------------------------------------

    With respect to the fourth prong regarding interference with other
states' measures 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.\16\ EPA reiterated this connection between the regional haze and
the visibility prong of section 110(a)(2)(D)(i) for the 2006
PM2.5 NAAQS in guidance entitled ``Guidance on SIP Elements
Required Under Sections 110(a)(1) and (2) for the 2006 24-hour Fine
Particle (PM2.5) National Ambient Air Quality Standards
(NAAQS)'' (``2009 Guidance''). For instance, the 2009 Guidance noted
that states are obliged to submit SIP measures to address regional
haze, including a long-term strategy to address Class I area visibility
impairment.\17\ A state's long-term strategy must address how it will
ensure that the emission control assumptions that other states relied
on in developing their RPGs are met.
---------------------------------------------------------------------------

    \16\ 74 FR 2392, January 15, 2009.
    \17\ 2009 Guidance at page 6.
---------------------------------------------------------------------------

    The regional haze program, as reflected in the RHR, recognizes the
importance of addressing the long-range transport of pollutants to
protect 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
RPGs for neighboring Class I areas. Working together through a regional
planning process, states are required to address an agreed upon share
of their contribution to visibility impairment in the Class I areas of
their neighbors.\18\ Given these requirements, we anticipated that
regional haze SIPs would contain measures that would achieve these
emissions reductions, and that these measures would meet the visibility
requirements of section 110(a)(2)(D)(i).
---------------------------------------------------------------------------

    \18\ 40 CFR 51.308(d)(3)(ii).
---------------------------------------------------------------------------

    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 RPGs, using the products of this
technical consultation process to co-develop their RPGs 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 installation of BART at
appropriate sources and other measures to be adopted as part of the
state's long-term strategy for addressing regional haze. The RPGs 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.
    ADEQ submitted on May 24, 2007, its ``Revision to the Arizona State
Implementation Plan Under Clean Air Act Section 110(a)(2)(D)(i)--
Regional Transport'' (``2007 Transport SIP'') to address the
requirements of section 110(a)(2)(D)(i) for the 1997 8-hour ozone and
1997 PM2.5 NAAQS. EPA approved this submission with respect
to the first three transport prongs, but deferred action on the fourth
prong (i.e. interference with SIP measures required to protect
visibility) until we received Arizona's final Regional Haze SIP.\19\

ADEQ submitted on October 14, 2009, its ``Arizona State Implementation
Plan Revision under Clean Air Act Section 110(a)(1) and (2); 2006
PM2.5 NAAQS, 1997 PM2.5 NAAQS, and 1997 8-hour
Ozone NAAQS,'' which addressed the requirements of section
110(a)(2)(D)(i) with respect to the 2006 PM2.5 NAAQS in
Section 2.4 and Appendix B of the submittal (``2009 Transport SIP'').
As with the 2007 Transport SIP, EPA acted on the first three prongs,
but deferred action on the fourth prong.\20\
---------------------------------------------------------------------------

    \19\ 72 FR 41629, July 31, 2007. In that notice, EPA noted that
``the Arizona [2007 Transport SIP] concurs with EPA in concluding
that is currently premature to determine whether or not SIPs for 8-
hour ozone or PM2.5 contain adequate provisions to
prohibit emissions that interfere with measures in other states'
SIPs designed to address regional haze.'' 72 FR 41629 at 41632.
    \20\ 77 FR 66398 (November 5, 2012).
---------------------------------------------------------------------------

    Both of these submittals refer to EPA's 2006 Guidance and state
that Arizona agrees with the 2006 Guidance inasmuch as it would be
appropriate to assess a state's interference with other states'
measures to protect visibility in conjunction with the state's regional
haze SIPs.\21\ For Arizona's regional haze program, the 2007 and 2009
Transport SIPs both indicate that Arizona submitted a regional haze SIP
under 40 CFR 51.309 in December 2003 for the four Class I areas on the
Colorado Plateau in Arizona and that the State would submit a SIP under
40 CFR 51.309(g) for the remaining eight Class I areas in Arizona.\22\
As described in prior sections of this notice, ADEQ ultimately
submitted its final regional haze SIP on February 28, 2011 under 40 CFR
51.308.
---------------------------------------------------------------------------

    \21\ 2007 Transport SIP, p. 12, and 2009 Transport SIP, Appendix
B, p. 11.
    \22\ Id.
---------------------------------------------------------------------------

    We interpret Arizona's 2007 and 2009 Transport SIPs to mean that
Arizona intended its Regional Haze Plan to address the interstate
visibility requirement of section 110(a)(2)(D)(i) for the 1997 8-hour
ozone, 1997 PM2.5 NAAQS, and 2006 PM2.5 NAAQS.
Accordingly, our evaluation of Arizona's 2007 and 2009 Transport SIPs
and whether they meet the CAA section 110(a)(2)(D)(i) visibility
requirements relies on our evaluation of Arizona's 2011 Regional Haze
Plan. Specifically, we interpret the ``good neighbor'' provisions of
section 110(a)(2)(D)(i) as requiring states to include in their SIPs
either measures to prohibit emissions that would interfere with the
RPGs required to be set to protect visibility in Class I areas in other
states, or a demonstration that emissions from the state's sources and
activities will not have the prohibited impacts under the existing SIP.

IV. Requirements for Regional Haze Implementation Plans

A. Regional Haze Rule

    The Regional Haze Rule (RHR) sets out specific requirements for
states' initial regional haze implementation plans.\23\ In particular,
each state's plan must establish a long-term strategy that ensures
reasonable progress toward achieving natural visibility conditions in
each Class I area affected by the emissions from sources within the
state. In addition, for each Class I area within the state's
boundaries, the plan must establish a reasonable progress goal (RPG)
for the first planning period that ends on July 31, 2018. The long-term
strategy must include enforceable emission limits and other measures as
necessary to achieve the RPG. Regional haze 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.
These sources, where appropriate, are required to install BART controls
to eliminate or reduce visibility impairment. Although such BART
determinations can be a part of a reasonable progress strategy, BART is
also an independent requirement that can be assessed separately from
the other requirements of the RHR.
---------------------------------------------------------------------------

    \23\ Pursuant to 40 CFR 51.301, ``implementation plan'' is
defined as ``any State Implementation Plan, Federal Implementation
Plan, or Tribal Implementation Plan.'' Therefore, although the
requirements of the RHR are generally described in relation to SIPs,
they are also relevant where EPA is promulgating a regional haze
plan.
---------------------------------------------------------------------------

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 expressed in deciviews is determined by using air quality
measurements to estimate light extinction and then transforming the
value of light extinction to deciviews using a logarithmic function.
The deciview is a more useful measure for tracking progress in
improving visibility than light extinction because each deciview change
is an equal incremental change in visibility as perceived by the human
eye. Most people can detect a change in visibility at one deciview.\24\
---------------------------------------------------------------------------

    \24\ The preamble to the RHR provides additional details about
the deciview. 64 FR 35714, 35725 (July 1, 1999).
---------------------------------------------------------------------------

    The deciview is used to express reasonable progress goals, define
visibility conditions, and track changes in visibility. To track
changes in visibility 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 and periodically
review progress midway through each ten-year implementation period. To
do this, the RHR requires states to determine the degree of impairment
(in deciviews) for the average of the 20 percent least impaired
(``best'') and 20 percent most impaired (``worst'') visibility days
over a specified time period at each of their Class I areas. In
addition, states must 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,\25\ hereinafter referred to as
``EPA's 2003 Natural Visibility Guidance'', and Guidance for Tracking
Progress Under the Regional Haze Rule, September 2003,\26\ hereinafter
referred to as ``EPA's 2003 Tracking Progress Guidance''.
---------------------------------------------------------------------------

    \25\ EPA-454/B-03-005 located at http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf.
    \26\ EPA-454/B-03-004 September 2003 located at http://www.epa.gov/ttncaaal/tl/memoranda/rh_tpurhr_gd.pdf.
---------------------------------------------------------------------------

    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 2000-2004. 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. In general, the

2000-2004 baseline period is considered the time from which improvement
in visibility is measured.

 C. Determination of Reasonable Progress Goals (RPGs)

    The mechanism for ensuring continuing progress toward achieving the
natural visibility goal is the submission of a series of regional haze
SIPs that establish two RPGs (i.e., two distinct goals, one for the
``best'' and one for the ``worst'' days) for every Class I area for
each ten-year implementation period. The RHR does not mandate specific
milestones or rates of progress, but instead calls for states to
establish goals that provide for ``reasonable progress'' toward
achieving natural (i.e., ``background'') visibility conditions. In
setting RPGs, states must provide for an improvement in visibility for
the most impaired days over the ten-year period of the SIP, and ensure
no degradation in visibility for the least impaired days over the same
period.
    States have significant discretion in establishing RPGs, but are
required to consider the following factors established in section 169A
of the CAA and in EPA's RHR at 40 CFR 51.308(d)(1)(i)(A): (1) The costs
of compliance; (2) the time necessary for compliance; (3) the energy
and non-air quality environmental impacts of compliance; and (4) the
remaining useful life of any potentially affected sources. States must
demonstrate in their SIPs how these factors are considered when
selecting the RPGs for the best and worst days for each applicable
Class I area. States have considerable flexibility in how they take
these factors into consideration, as noted in EPA's Guidance for
Setting Reasonable Progress Goals under the Regional Haze Program, July
1, 2007, memorandum from William L. Wehrum, Acting Assistant
Administrator for Air and Radiation, to EPA Regional Administrators,
EPA Regions 1-10 (pp. 4-2, 5-1) (``EPA's Reasonable Progress
Guidance''). In setting the RPGs, states must also consider the rate of
progress needed to reach natural visibility conditions by 2064
(referred to as the ``uniform rate of progress'' (URP) or the ``glide
path'') and the emission reduction measures needed to achieve that rate
of progress over the ten-year period of the SIP. Uniform progress
towards achievement of natural conditions by the year 2064 represents a
rate of progress that states are to use for analytical comparison to
the amount of progress they expect to achieve. In setting RPGs, each
state with one or more Class I areas (``Class I state'') must also
consult with potentially ``contributing states,'' i.e., other nearby
states with emission sources that may be affecting visibility
impairment at the Class I state's areas.\27\
---------------------------------------------------------------------------

    \27\ 40 CFR 51.308(d)(1)(iv).
---------------------------------------------------------------------------

 D. Best Available Retrofit Technology (BART)

    Section 169A of the CAA directs states to evaluate the use of
retrofit controls at certain larger, often uncontrolled, older
stationary sources in order to address visibility impacts from these
sources. Specifically, section 169A(b)(2)(A) of the CAA requires states
to revise their SIPs to contain such measures as may be necessary to
make reasonable progress towards the natural visibility goal, including
a requirement that certain categories of existing major stationary
sources \28\ built between 1962 and 1977 procure, install, and operate
the ``Best Available Retrofit Technology'' as determined by the state.
Under the RHR, states are directed to conduct BART determinations for
such ``BART-eligible'' sources that may be anticipated to cause or
contribute to any visibility impairment in a Class I area. Rather than
requiring source-specific BART controls, states also have the
flexibility to adopt an emissions trading program or other alternative
program as long as the alternative provides greater reasonable progress
towards improving visibility than BART.
---------------------------------------------------------------------------

    \28\ The set of ``major stationary sources'' potentially subject
to BART is listed in CAA section 169A(g)(7).
---------------------------------------------------------------------------

    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'') on July 6, 2005. The Guidelines
assist states in determining which of their sources should be subject
to the BART requirements and in determining appropriate emission limits
for each such ``subject-to-BART'' source. In making BART determinations
for fossil fuel-fired electric generating plants with a total
generating capacity in excess of 750 megawatts, states must use the
approach set forth in the BART Guidelines. States are 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.
    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. In setting
their exemption threshold values, states should consider the number of
emission sources affecting the Class I areas at issue and the magnitude
of the individual sources' impacts. 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 in the RHR as ``BART-eligible sources,'' and document their
BART control determination analyses. In making BART determinations,
section 169A(g)(2) of the CAA requires that states consider the
following factors: (1) The costs of compliance; (2) the energy and non-
air quality environmental impacts of compliance; (3) any existing
pollution control technology in use at the source; (4) the remaining
useful life of the source; and (5) the degree of improvement in
visibility which may reasonably be anticipated to result from the use
of such technology. States are free to determine the weight and
significance assigned to each factor, but must consider all five
factors and provide a reasoned explanation for adopting the technology
selected as BART, based on the five factors.
    A regional haze SIP must include source-specific BART emission
limits and compliance schedules for each source subject to BART, unless
the SIP includes an alternative program that provides greater
reasonable progress towards improving visibility than BART and meets
the other requirements of 40 CFR 51.308(e)(2). 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.\29\ The Regional
Haze SIP must also contain a requirement for each BART source to
maintain the relevant control equipment, as well as procedures to
ensure control equipment

is properly operated and maintained.\30\ 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 emissions limitations.\31\
---------------------------------------------------------------------------

    \29\ CAA section 169(g)(4); 40 CFR 51.308(e)(1)(iv).
    \30\ 40 CFR 51.308(e)(1)(v). See also CAA section 302(k)
(defining ``emission limitation'' as ``a requirement established by
the State or the Administrator which limits the quantity, rate, or
concentration of emissions of air pollutants on a continuous basis,
including any requirement relating to the operation or maintenance
of a source to assure continuous emission reduction * * *'')
(emphasis added).
    \31\ See CAA section 110(a)(2) (requirements for SIPs).
---------------------------------------------------------------------------

 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 10-15 year strategy for
making reasonable progress, section 51.308(d)(3) of the RHR requires
that states include a long-term strategy in their regional haze SIPs.
The LTS is the compilation of all control measures a state will use
during the implementation period of the specific SIP submittal to meet
applicable RPGs. The LTS must include ``enforceable emissions
limitations, compliance schedules, and other measures needed to achieve
the reasonable progress goals'' for all Class I areas within and
affected by emissions from the state.\32\
---------------------------------------------------------------------------

    \32\ 40 CFR 51.308(d)(3).
---------------------------------------------------------------------------

    When a state's emissions are reasonably anticipated to cause or
contribute to visibility impairment in a Class I area located in
another state, the RHR requires the impacted state to coordinate with
contributing states to develop coordinated emissions management
strategies.\33\ In such cases, the contributing state must demonstrate
that it has included in its SIP, all measures necessary to obtain its
share of the emission reductions needed to meet the RPGs for the Class
I area. The RPOs have provided forums for significant interstate
consultation, but additional consultation between states may be
required to sufficiently address interstate visibility issues (e.g.,
where two states belong to different RPOs).
---------------------------------------------------------------------------

    \33\ 40 CFR 51.308(d)(3)(i).
---------------------------------------------------------------------------

    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 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 RPG; (4) source retirement and
replacement schedules; (5) smoke management techniques for agricultural
and forestry management purposes including plans as currently exist
within the state for these purposes; (6) enforceability of emissions
limitations and control measures; and (7) the anticipated net effect on
visibility due to projected changes in point, area, and mobile source
emissions over the period addressed by the LTS.\34\
---------------------------------------------------------------------------

    \34\ 40 CFR 51.308(d)(3)(v).
---------------------------------------------------------------------------

 F. Coordination of Regional Haze and RAVI

    As part of the RHR, EPA revised 40 CFR 51.306(c) regarding the
long-term strategy 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 LTSs, and periodic progress
reports evaluating progress towards RPGs, must be submitted consistent
with the schedule for SIP submission and periodic progress reports set
forth in 40 CFR 51.308(f) and 51.308(g), respectively. The periodic
review of a state's LTS must report on both regional haze and RAVI
impairment and must be submitted to EPA as a SIP revision.

 G. Monitoring Strategy

    Section 51.308(d)(4) of the RHR requires a monitoring strategy for
measuring, characterizing, and reporting on regional haze visibility
impairment that is representative of all mandatory Class I areas within
the state. The strategy must be coordinated with the monitoring
strategy required in 40 CFR 51.305 for RAVI. Compliance with this
requirement may be met through ``participation'' in the Interagency
Monitoring of Protected Visual Environments (IMPROVE) network, i.e.,
review and use of monitoring data from the network. The monitoring
strategy is due with the first regional haze SIP, and it must be
reviewed every five years. The monitoring strategy must also provide
for additional monitoring sites if the IMPROVE network is not
sufficient to determine whether RPGs will be met. The SIP must also
provide for the following:
     Procedures for using monitoring data and other information
in a state with mandatory Class I areas to determine the contribution
of emissions from within the state to regional haze visibility
impairment at Class I areas both within and outside the state;
     Procedures for using monitoring data and other information
in a state with no mandatory Class I areas to determine the
contribution of emissions from within the state to regional haze
visibility impairment at Class I areas in other states;
     Reporting of all visibility monitoring data to the
Administrator at least annually for each Class I area in the state, and
where possible, in electronic format;
     Developing a statewide inventory of emissions of
pollutants that are reasonably anticipated to cause or contribute to
visibility impairment in any Class I area. The inventory must include
emissions for a baseline year, emissions for the most recent year for
which data are available, and estimates of future projected emissions.
A state must also make a commitment to update the inventory
periodically; and
     Other elements, including reporting, recordkeeping, and
other measures necessary to assess and report on visibility.

 H. SIP Revisions and Progress Reports

    The RHR requires control strategies to cover an initial
implementation period through 2018, with a comprehensive reassessment
and revision of those strategies, as appropriate, every ten years
thereafter. Periodic SIP revisions must meet the core requirements of
section 51.308(d) with the exception of BART. The requirement to
evaluate sources for BART applies only to the first regional haze SIP.
Facilities subject to BART must continue to comply with the BART
provisions of section 51.308(e), as noted above. Periodic SIP revisions
will assure that the statutory requirement of reasonable progress will
continue to be met.
    Each state also is required to submit a report to EPA every five
years that evaluates progress toward achieving the RPG for each Class I
area within the state and outside the state if affected by emissions
from within the state.\35\ The first progress report is due five years
from submittal of the initial regional

haze SIP revision. At the same time a 5-year progress report is
submitted, a state must determine the adequacy of its existing SIP to
achieve the established goals for visibility improvement.\36\ The RHR
contains more detailed requirements associated with these parts of the
Rule.
---------------------------------------------------------------------------

    \35\ 40 CFR 51.308(g).
    \36\ 40 CFR 51.308(h).
---------------------------------------------------------------------------

 I. State Consultation With Federal Land Managers (FLMs)

    The RHR requires that states consult with Federal Land Managers
(FLMs) before adopting and submitting their SIPs.\37\ States must
provide FLMs an opportunity for consultation, in person and at least 60
days prior to holding any public hearing on the SIP. This consultation
must include the opportunity for the FLMs to discuss their assessment
of impairment of visibility in any Class I area and to offer
recommendations on the development of the RPGs and on the development
and implementation of strategies to address visibility impairment.
Furthermore, 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.
---------------------------------------------------------------------------

    \37\ 40 CFR 51.308(i).
---------------------------------------------------------------------------

 J. The Grand Canyon Visibility Transport Commission and Section 309

    In addition to the general requirements of the regional haze
program, the RHR also includes 40 CFR 51.309, which contains the
strategies developed by the Grand Canyon Visibility Transport
Commission (GCVTC), established under Section 169B(f) of CAA.\38\
Certain western States and Tribes were eligible to submit
implementation plans under section 309 as an alternative method of
achieving reasonable progress for Class I areas that were covered by
the GCVTC's analysis--i.e., the 16 Class I areas on the Colorado
Plateau. In order for States and Tribes to be able to utilize this
section, however, the rule provided that EPA must receive an ``Annex''
to the GCVTC's final recommendations. The purpose of the Annex was to
provide the specific provisions needed to translate the GCVTC's general
recommendations for stationary source SO2 reductions into an
enforceable regulatory program. The rule provided that such an Annex,
meeting certain requirements, be submitted to EPA no later than October
1, 2000.\39\ The Annex was submitted in 2000, and EPA revised 40 CFR
51.309 in 2003.\40\
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    \38\ 42 U.S.C. 7492(f).
    \39\ 40 CFR 51.309(d)(4) and 51.309(f).
    \40\ 68 FR 33764 (June 5, 2003).
---------------------------------------------------------------------------

V. Overview of State and EPA Actions on Regional Haze

A. EPA's Schedule To Act on Arizona's RH SIP

    EPA received a notice of intent to sue in January 2011 stating that
we had not met the statutory deadline for promulgating Regional Haze
FIPs and/or approving Regional Haze SIPs for dozens of states,
including Arizona. This notice was followed by a lawsuit filed by
several advocacy groups (Plaintiffs) in August 2011.\41\ In order to
resolve this lawsuit and avoid litigation, EPA entered into a Consent
Decree with the Plaintiffs, which sets deadlines for action for all of
the states covered by the lawsuit, including Arizona. This decree was
entered and later amended by the Federal District Court for the
District of Columbia over the opposition of Arizona.\42\ Under the
terms of the Consent Decree, as amended, EPA is currently subject to
three sets of deadlines for taking action on Arizona's Regional Haze
SIP as listed in Table 1.\43\
---------------------------------------------------------------------------

    \41\ National Parks Conservation Association v. Jackson (D.D.C.
Case 1:11-cv-01548).
    \42\ National Parks Conservation Association v. Jackson (D.D.C.
Case 1:11-cv-01548), Memorandum Order and Opinion (May 25, 2012) and
Minute Order (July 2, 2012).
    \43\ National Parks Conservation Association v. Jackson (D.D.C.
Case 1:11-cv-01548) Minute Order (November 13, 2012).

  Table 1--Consent Decree Deadlines for EPA To Act on Arizona's RH SIP
------------------------------------------------------------------------
         EPA Actions              Proposed rule          Final rule
------------------------------------------------------------------------
Phase 1:
    BART determinations for   July 2, 2012........  November 15, 2012.
     Apache, Cholla and
     Coronado.
Phase 2:
    All remaining elements    December 8, 2012....  July 15, 2013.
     of Arizona's RH SIP.
Phase 3:
    FIP for disapproved       March 8, 2013.......  October 15, 2013.
     elements of Arizona's
     RH SIP (if required).
------------------------------------------------------------------------

B. Summary of EPA's Final Rule Affecting Three BART Sources

    As indicated in Table 1 above, the first phase of EPA's action on
Arizona's Regional Haze SIP addressed three BART sources. The final
rule for this phase (a partial approval and partial disapproval of the
State's plan and partial FIP) was signed by the Administrator on
November 15, 2012 and published in the Federal Register on December 5,
2012. We estimate that the emission limits on the three sources will
improve visibility by reducing NOX emissions by 22,700 tons
per year. Phase 2 is our action on the remainder of the regional haze
plan submitted by the State. Phase 3 will be a partial FIP that will
address any portions of the State's plan that are disapproved in Phase
2.

 C. History of State Submittals and EPA Actions

    Since four of Arizona's twelve mandatory Class I Federal areas are
on the Colorado Plateau, the State had the option of submitting a
Regional Haze SIP under section 309 of the Regional Haze Rule. A SIP
that is approved by EPA as meeting all of the requirements of section
309 is ``deemed to comply with the requirements for reasonable progress
with respect to the 16 Class I areas [on the Colorado Plateau] for the
period from approval of the plan through 2018.'' \44\ When these
regulations were first promulgated, 309 submissions were due no later
than December 31, 2003. Accordingly, the Arizona Department of
Environmental Quality (ADEQ) submitted to EPA on

December 23, 2003, a 309 SIP for Arizona's four Class I Areas on the
Colorado Plateau. ADEQ submitted a revision to its 309 SIP, consisting
of rules on emissions trading and smoke management, and a correction to
the State's regional haze statutes, on December 31, 2004. EPA approved
the smoke management rules submitted as part of the 2004 revisions,\45\
but did not propose or take final action on any other portion of the
309 SIP.
---------------------------------------------------------------------------

    \44\ 40 CFR 51.309(a).
    \45\ 71 FR 28270 and 72 FR 25973.
---------------------------------------------------------------------------

    In response to an adverse court decision,\46\ EPA revised 40 CFR
51.309 on October 13, 2006, making a number of substantive changes and
requiring states to submit revised 309 SIPs by December 17, 2007.\47\
Subsequently, ADEQ sent a letter to EPA dated December 14, 2008,
acknowledging that it had not submitted a SIP revision to address the
requirements of 309(d)(4) related to stationary sources and 309(g),
which governs reasonable progress requirements for Arizona's eight
mandatory Class I areas outside of the Colorado Plateau.\48\
---------------------------------------------------------------------------

    \46\ Center for Energy and Economic Development v. EPA, 398 F.3d
653 (D.C. Circuit 2005).
    \47\ 71 FR 60612.
    \48\ Letter from Stephen A. Owens, ADEQ, to Wayne Nastri, EPA
(December 14, 2008).
---------------------------------------------------------------------------

    EPA made a finding on January 15, 2009, that 37 states, including
Arizona, had failed to make all or part of the required SIP submissions
to address regional haze.\49\ Specifically, EPA found that Arizona
failed to submit the plan elements required by 40 CFR 309(d)(4) and
(g). EPA sent a letter to ADEQ on January 14, 2009, notifying the state
of this failure to submit a complete SIP. ADEQ later decided to submit
a SIP under section 308, instead of section 309.
---------------------------------------------------------------------------

    \49\ 74 FR 2392.
---------------------------------------------------------------------------

    ADEQ adopted and transmitted its Regional Haze SIP under Section
308 of the Regional Haze Rule (hereafter the Arizona Regional Haze Plan
or ARHP) to EPA Region 9 in a letter dated February 28, 2011. The plan
was determined complete by operation of law on August 28, 2011.\50\ The
SIP was properly noticed by the State and available for public comment
for 30 days prior to a public hearing held in Phoenix, Arizona, on
December 2, 2010. Arizona included in its SIP responses to written
comments from EPA Region 9, the National Park Service, the U.S. Forest
Service, and other stakeholders including regulated industries and
environmental organizations. The Arizona Regional Haze Plan (ARHP) is
available to review in the docket for this proposed rule.\51\
---------------------------------------------------------------------------

    \50\ CAA section 110(k)(1)(B).
    \51\ ``Arizona State Implementation Plan, Regional Haze Under
Section 308 Of the Federal Regional Haze Rule,'' February 28, 2011.
---------------------------------------------------------------------------

VI. EPA's Evaluation of Visibility Conditions in Arizona's Class I
Areas

 A. Affected Class I Areas

    Arizona has 12 Class I areas as listed in Table 2. ADEQ identified
eighteen other Class I areas located outside the State that may be
affected by its emissions. These other Class I areas are in Colorado,
New Mexico, and Utah as listed in Table 3. Each Class I area has an
associated IMPROVE monitor sited to be representative of visibility
conditions in that area. EPA proposes to find that ADEQ has identified
all Class I areas within and outside the State that are potentially
affected by its emissions, as required pursuant to 40 CFR 51.308(d).

    Table 2--Class I Areas in Arizona Potentially Affected by Arizona
                                Emissions
------------------------------------------------------------------------
               Class I area                    IMPROVE  monitor code
------------------------------------------------------------------------
1 Chiricahua National Monument...........  CHIR1
2 Chiricahua Wilderness..................  CHIR1
3 Galiuro Wilderness.....................  CHIR1
4 Grand Canyon National Park.............  GRCA2
5 Mazatzal Wilderness....................  IKBA1
6 Pine Mountain Wilderness...............  IKBA1
7 Mount Baldy Wilderness.................  BALD1
8 Petrified Forest National Park.........  PEFO1
9 Saguaro National Park..................  SAGU1, SAWE1
10 Sierra Ancha Wilderness...............  SIAN1
11 Superstition Wilderness...............  TONT1
12 Sycamore Canyon Wilderness............  SYCA1
------------------------------------------------------------------------

    Table 3--Class I Areas Outside of Arizona Potentially Affected by
                         Arizona Emissions \52\
------------------------------------------------------------------------
                                                       IMPROVE  monitor
          Class I area                  State                code
------------------------------------------------------------------------
Mesa Verde National Park.......  Colorado..........  MEVE1
Black Canyon of the Gunnison     Colorado..........  WEMI1
 NP, La Garita WA, Weminuche WA.
Great Sand Dunes NM............  Colorado..........  GRSA1
Eagles Nest WA, Flat Tops WA,    Colorado..........  WHRI1
 Maroon Bells-Snowmass WA, West
 Elk WA.
Gila Wilderness Area...........  New Mexico........  GICL1
Bosque del Apache National       New Mexico........  BOAP1
 Wildlife Refuge.
San Pedro Parks Wilderness Area  New Mexico........  SAPE1
Bandelier National Monument,     New Mexico........  BAND1
 Pecos WA.
Zion NP........................  Utah..............  ZION1
Bryce Canyon NP................  Utah..............  BRCA1
Capitol Reef National Park.....  Utah..............  CAPI1
Canyonlands NP, Arches NP......  Utah..............  CANY1
------------------------------------------------------------------------

 B. Determination of Visibility Conditions and Uniform Rate of Progress

    ADEQ developed the visibility estimates in the ARHP using models
and analytical tools provided by the WRAP. We have reviewed the models
and analytical tools used by the WRAP and those used by ADEQ in
developing the ARHP. As explained below, we found that the models were
used appropriately, and monitoring data were processed appropriately,
consistent with EPA guidance in effect at the time of their use. The
models used by the WRAP were state-of-the-science at the time the
modeling was conducted and model performance was adequate for the
purposes for which they were used.\53\
---------------------------------------------------------------------------

    \52\ Source ARHP Section 12.4 and Appendix B, Section 2.
    \53\ For our detailed review and discussion, please see
``Technical Support Document for Technical Products Prepared by the
Western Regional Air Partnership in Support of Western Regional Haze
Plans'', Final, February 2011 (WRAP TSD).
---------------------------------------------------------------------------

    Baseline and Natural Visibility Conditions: 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 2000-2004. 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. Chapter 6.2 and
Appendix C of the ARHP provide the details of the deciview calculations
of the baseline and natural conditions for each Class I area during
2000-2004.
    For each Class I area, ADEQ calculated, in deciviews, the current
visibility conditions (worst 20 percent of days) for the 2000-2004
baseline period (Table 4, column A) and the future natural conditions
for 2064 (Table 4, column D), the long-term goal of the regional haze
program. These correspond to tables 6.1 and 6.2 in the ARHP. ADEQ
calculated the dv value representing the best visibility days during
2000-2004 baseline conditions, a value that must be maintained in
future years.\54\ Natural conditions were calculated using a refined
approach, as allowed in ``EPA's 2003 Natural Visibility Guidance.'' As
discussed in EPA's WRAP TSD, WRAP and others developed the ``Natural
Haze Levels II'' approach.\55\ This used time-varying Class I area-
specific data and more robust statistical assumptions, along with the
revised IMPROVE equation \56\ for translating pollutant concentrations
into extinction, in order to derive more refined visibility estimates
that remain consistent with the approach in EPA's Guidance.
---------------------------------------------------------------------------

    \54\ See Table 5 of this notice for a comparison of the
visibility levels on the ``best 20 percent of days'' between 2000-
2004 and projected 2018 deciview values for the same set of days at
each Arizona Class I area.
    \55\ ``Natural Haze Levels II: Application of the New IMPROVE
Algorithm to Natural Species Concentrations Estimates; Final Report
by the Natural Haze Levels II Committee to the RPO Monitoring/Data
Analysis Workgroup'', presentation at WRAP Attribution of Haze
Workgroup Meeting, July 26-27, 2006, Denver, CO. Web page: http://vista.cira.colostate.edu/improve/Publications/GrayLit/gray_literature.htm direct link: http://vista.cira.colostate.edu/improve/Publications/GrayLit/029_NaturalCondII/naturalhazelevelsIIreport.ppt.
    \56\ Revised IMPROVE algorithm for Estimating Light Extinction
from Particle Speciation Data, IMPROVE, January 2006. Web page
http://vista.cira.colostate.edu/improve/publications/graylit/gray--
literature.htm.

                         Table 4--Visibility Calculations for Arizona Class I Areas \57\
                                      [20 percent worst days in deciviews]
----------------------------------------------------------------------------------------------------------------
                                                                                Years required
                                                                   Uniform Rate                      to reach
                                  Baseline 2000-    Reasonable      of Progress       Natural         natural
          Class I area                 2004        Progress Goal       (URP)        conditions     conditions at
                                                    (RPG) 2018       estimate          2064         RPG rate of
                                                                                improvement
                                               A               B               C               D               E
----------------------------------------------------------------------------------------------------------------
Chiricahua NM, Chiricahua WA,              13.43           13.35           11.98            7.20           1,038
 Galiuro WA (CHIR1 monitor).....
Grand Canyon NP (GRCA2 monitor).           11.66           11.14           10.58            7.04             125
Mazatzal WA, Pine Mountain WA              13.35           12.76           11.79            6.68             159
 (IKBA1 monitor)................
Mount Baldy WA (BALD1 monitor)..           11.85           11.52           10.54            6.24             234
Petrified Forest NP (PEFO1                 13.21           12.85           11.64            6.49             258
 monitor).......................
Saguaro NP--East Unit (SAGU1               16.22           14.82           12.88            6.46           8,370
 monitor).......................
Saguaro NP--West Unit (SAWE1               14.83           15.99           13.90            6.24             624
 monitor).......................
Sierra Ancha WA (SIAN1 monitor).           13.67           13.17           12.02            6.59             197
Superstition WA (TONT1 monitor).           14.16           13.89           12.38            6.54             401
Sycamore Canyon WA (SYCA1                  15.25           15.00           13.25            6.65             478
 monitor).......................
----------------------------------------------------------------------------------------------------------------

    Uniform Rate of Progress Estimate: ADEQ calculated the uniform rate
of progress (URP) estimate for each Class I area using the 2000-2004
baseline deciview and 2064 programmatic goal (natural conditions)
deciview values. The URP is represented as a straight line drawn
between a given Class I area's 2004 baseline value and 2064 natural
condition or programmatic goal value. This assumes the same increment
of progress every year for 60 years. Table 6.3 of the ARHP shows the
results of the uniform rate of progress calculation. In addition, ADEQ
also provided uniform rates of progress for the extinction due to each
pollutant contributing to visibility impairment. Tables 9.2 through
9.11 and figures 9.1 through 9.10 of the ARHP illustrate a uniform rate
of progress calculation and a graphic representation for each Class I
area, for all the individual pollutants (sulfate, nitrate, organic
carbon, elemental carbon, fine soil, coarse mass, and sea salt). ADEQ
then calculated each Class I area's URP estimate for 2018, in Table 6.3
of the ARHP. The URPs for each Class I area are listed in Table 4,
column C of this proposal.
---------------------------------------------------------------------------

    \57\ Source: Tables 6.1, 6.2, 6.3, and 11.9, ARHP.
---------------------------------------------------------------------------

    In summary, Arizona has produced the following visibility estimates
in deciviews for each Class I area: Baseline visibility conditions; a
ten-year reasonable progress estimate for 2018; a 2018 uniform rate of
progress estimate for comparison purposes; and a 2064 natural
conditions estimate. We propose to find that these estimates are
consistent with the requirements of the RHR, particularly those
requirements at 40 CFR 51.308(d)(2)(i) and (iii). Also, we propose to
find that Arizona has produced URP estimates consistent with the
requirement in 40 CFR 51.308(d)(1)(i)(B).
    Visibility Projections for 2018 and the Reasonable Progress Goals:
The RHR requires states to establish goals, expressed in deciviews, for
each Class I area within the state that provide for reasonable progress
toward achieving natural visibility conditions by 2064. The RPGs must
improve provide for an improvement in visibility for the most impaired
days, and ensure no degradation in visibility for the least impaired
days over the period of the SIP. The RPGs for the ARHP show visibility
improvement by 2018 for the ``worst 20 percent of days'' in all Class I
areas when compared to the baseline ``worst'' days. The State's RPGs
for the worst 20 percent of days can be seen in Table 4, column B. The
RPGs for the best 20 percent of days can be seen in Table 5.

  Table 5--Baseline and 2018 Visibility Conditions for Arizona Class I
                               Areas \58\
                      [Best 20% days in deciviews]
------------------------------------------------------------------------
                                                        2018 Reasonable
           Class I area              2000-04 Baseline    Progress Goal
                                                             (RPG)
------------------------------------------------------------------------
Chiricahua NM, Chiricahua WA,                    4.91               4.94
 Galiuro WA (CHIR1 monitor).......
Grand Canyon NP (GRCA2 monitor)...               2.16               2.12
Mazatzal WA, Pine Mountain WA                    5.40               5.17
 (IKBA1 monitor)..................
Mount Baldy WA (BALD1 monitor)....               2.98               2.86
Petrified Forest NP (PEFO1                       5.02               4.73
 monitor).........................
Saguaro NP--East Unit (SAGU1                     6.94               7.04
 monitor).........................
Saguaro NP--West Unit (SAWE1                     8.58               8.34
 monitor).........................
Sierra Ancha WA (SIAN1 monitor)...               6.16               5.88
Superstition WA (TONT1 monitor)...               6.46               6.22
Sycamore Canyon WA (SYCA1 monitor)               5.58               5.49
------------------------------------------------------------------------

    Also, as required by the RHR, Arizona estimated the time each Class
I area would take to reach natural conditions under the RPG rate of
visibility improvement (see Table 4, column E). While some of the time
estimates are close to the 2064 natural conditions goal, none of the
estimates shows that natural conditions will be achieved by 2064 in
Arizona's Class I areas. EPA's evaluation of these Reasonable Progress
Goals can be found in Section VIII of this document.

 C. Arizona's Emissions Inventories

    The RHR requires a statewide emissions inventory of pollutants that
are reasonably anticipated to cause or contribute to visibility
impairment in any mandatory Class I area.\59\ The ARHP provides an
emissions inventory for 2002, representing the mid-point of the 2000-
2004 baseline timeframe. Also, to chart progress in each Class I area,
the ARHP includes estimated emissions for 2018, the end of the first
planning period. The emissions inventories include estimated annual
emissions for the following haze producing pollutants: NOX,
SO2, VOC, PM2.5, PMcoarse \60\ and
NH3. The emissions inventories are summarized below in ten
source categories: Point sources, anthropogenic fire, wildfire,
biogenic, area sources, on-road mobile, off-road mobile, road dust,
fugitive dust and windblown dust. See Tables 6A and 6B.
---------------------------------------------------------------------------

    \58\ Source: Table 6.3, ARHP.
    \59\ 40 CFR 51.308(d)(4)(v).
    \60\ These are particles smaller than 10 microns, but larger
than 2.5 microns.
    \61\ Arizona Regional Haze Plan, Tables 8.1, 8.2, 8.7 and 8.8.
    \62\ The ARHP did not report any biogenic NH3.

                         Table 6A--Emissions Inventory for Arizona Regional Haze Pollutants by Source Category for 2002 and 2018
                                                                  [Tons per year] \61\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          SO2 [tpy]                 NOX [tpy]                 VOC [tpy]                 NH3 [tpy]
                    Category                     -------------------------------------------------------------------------------------------------------
                                                      2002         2018         2002         2018         2002         2018         2002         2018
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point Sources...................................       94,716       67,429       69,968       68,748        5,464        9,401          531          729
Anthropogenic Fire..............................          190          181          725          676          855          745           97           73
Wildfire........................................        4,369        4,369       16,493       16,494       36,377       36,381        3,781        3,782
Biogenic \62\...................................            0            0       27,664       27,664    1,576,698    1,576,698
Area Source.....................................        2,677        3,408        9,049       12,783      102,918      170,902       32,713       36,248
On-road Mobile..................................        2,715          762      178,009       53,508      110,424       52,872        5,035        7,606
Off-road Mobile.................................        4,223          546       66,414       43,249       56,901       36,033           48           64
                                                 -------------------------------------------------------------------------------------------------------
    Total.......................................      108,890       76,695      368,322      223,122    1,889,637    1,883,032       42,205       48,502
--------------------------------------------------------------------------------------------------------------------------------------------------------

     Table 6B--Emissions Inventory for Arizona Regional Haze Pollutants by Source Category for 2002 and 2018
                                              [Tons per year] \63\
----------------------------------------------------------------------------------------------------------------
                                                                     PM2.5 [tpy]             PMcoarse [tpy]
                          Category                           ---------------------------------------------------
                                                                  2002         2018         2002         2018
----------------------------------------------------------------------------------------------------------------
Point Sources...............................................          934        1,421        8,473        8,650
Anthropogenic Fire..........................................        1,033          927           17            9
Wildfire....................................................       61,225       61,230       10,107       10,108
Area Source.................................................        9,400       13,727        1,384        1,766
On-road Mobile..............................................        3,344        2,318        1,004        1,258
Off-road Mobile \64\........................................        4,758        3,032
Road Dust...................................................        3,059        4,371       24,381       34,799
Fugitive Dust...............................................        7,589       11,425       54,934       91,967

Windblown Dust..............................................        6,422        6,422       57,796       57,796
                                                             ---------------------------------------------------
    Total...................................................       97,764      104,873      158,096      206,353
----------------------------------------------------------------------------------------------------------------

    The 2018 inventory is based on assumptions about the rate of
population and economic growth between 2002 and 2018. These projections
were completed in 2006 and 2007, before the nationwide recession that
began in late 2008. The inventory was updated in 2009 with more up-to-
date data on projected emissions from electric generating units, but
many source categories that are sensitive to economic growth
projections (such as area sources, road dust and fugitive dust) were
not updated.\65\ A reconsideration of the emissions with more current
economic data may yield lower emissions totals for some source
categories. Nonetheless, the inventory was developed with the best
available information at the time. The 2018 projected inventory does
not reflect emissions reductions from BART determinations made by
EPA.\66\
---------------------------------------------------------------------------

    \63\ ARHP, Tables 8.3--8.6. For the purposes of this analysis,
primary organic aerosols, elemental carbon and fine soil are assumed
to be in the PM2.5 partition. These were combined for
ease of comparison with the IMPROVE monitoring data.
    \64\ The ARHP did not include any PM10 emissions
directly attributed to off-road vehicles.
    \65\ See ERG Technical Memorandum entitled ``WRAP PRP18b
Emissions Inventory--Revised Point and Area Source Projections'',
October 16, 2009.
    \66\ 77 FR 72512.
---------------------------------------------------------------------------

    Since the purpose of the regional haze program is to eliminate
human-caused visibility impairment at Class I areas, it is useful to
look at the proportion of the total emissions that are anthropogenic.
It is also useful to consider the projected change in emissions during
the planning period.

           Table 7--Assessment of the Emissions Inventory \67\
------------------------------------------------------------------------
                                                        Change in total
                                      Anthropogenic     emissions (2002-
             Pollutant                share in 2002          2018)
                                       (percentage)       (percentage)
------------------------------------------------------------------------
NOX...............................               88.0              -39.4
SO2...............................               96.0              -29.6
VOC...............................               14.6               -0.3
NH3...............................               91.0               14.9
PM2.5.............................               20.9               -0.7
Fine Soil.........................               59.4               30.1
PMcoarse..........................               57.0               30.5
------------------------------------------------------------------------

    Table 7 shows that the majority of VOC and PM2.5
emissions in Arizona are not from the anthropogenic share, and thus
most of these emissions are from natural or uncontrollable sources.
Nearly half of the PMcoarse and fine soil emissions are
similarly from uncontrollable sources. NOX, SO2
and NH3 are predominantly anthropogenic in origin. Table 7
also shows that inventory projections indicate significant decreases in
NOX and SO2 emissions. EPA expects that 2018
emissions will be even lower than projected in the plan due to our FIP
actions.\68\ The VOC emissions are projected to be relatively flat over
time, but that is not surprising, given the small portion of the
inventory that is anthropogenic. The projected increase in
PMcoarse emissions is a potential concern. However, EPA
concludes that, for the reasons explained above, these 2018 emissions
estimates may not be reliable.
---------------------------------------------------------------------------

    \67\ From ARHP, Tables 8.3-8.8. For the purposes of this
analysis, primary organic aerosols and elemental carbon are treated
as PM2.5, but fine soil is listed separately. For this
table, we have treated wildfires, biogenic emissions and windblown
dust as non-anthropogenic.
    \68\ 77 FR 72512.
---------------------------------------------------------------------------

    The inventories presented in the ARHP were developed by the WRAP.
The EPA reviewed the WRAP methodology and assumptions and determined
that they were based on the best available science and information at
the time they were developed.\69\ Based on this analysis, EPA proposes
to find that the 2002 and 2018 inventories are adequate for the
regional haze plan.
---------------------------------------------------------------------------

    \69\ See EPA document ``Technical Support Document for Technical
Products Prepared by the Western Regional Air Partnership in Support
of Western Regional Haze Plans'', Final, February 2011 (WRAP TSD).
---------------------------------------------------------------------------

    However, the RHR also requires that Arizona to provide the most
recent inventory available.\70\ Under the Consolidated Emissions
Reporting Rule, states are required to compile and submit to EPA
comprehensive statewide emissions inventories every three years.\71\
Under this emissions reporting rule, the State was required to develop
and submit inventories for 2005 and 2008. Both of these inventories
were required to have been completed by the time the ARHP was submitted
in February 2011. Yet, the State did not submit the most recent
inventory with the plan. The lack of this inventory does not affect our
ability to evaluate other elements of the plan. Nevertheless, given
this omission, EPA proposes to disapprove this element of the plan.
However, if the State submits a complete 2008 inventory in a format
consistent and comparable with the 2002 and 2018 inventories submitted
in the plan, EPA proposes to approve the plan as having met this
requirement.
---------------------------------------------------------------------------

    \70\ 40 CFR 51.308(d)(4)(v).
    \71\ 67 FR 39602.

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

D. Sources of Visibility Impairment

    Arizona evaluated the contributions of different components to
visibility impairment on the best and worst 20 percent visibility days
in chapter seven of the ARHP.\72\ In addition to the five-year average
of the baseline period (2000-2004), Arizona's analysis included monthly
and daily data for some sites that illustrate some seasonal differences
as well as the impact observed on organic carbon contributions to
visibility impairment due to nearby wildfires.
---------------------------------------------------------------------------

    \72\ Arizona State Implementation Plan: Regional Haze Under
Section 308 of the Federal Regional Haze Rule; January 2011.
---------------------------------------------------------------------------

    As explained above, Arizona's visibility projections for the worst
20 percent days in 2018 for all of the State's Class I areas represent
a slower rate of improvement in visibility than is needed to attain
natural conditions by 2064. In order to better understand why Arizona's
Class I areas are not expected to achieve greater progress during this
implementation period, EPA conducted an additional analysis of IMPROVE
monitoring data for the days with the worst 20 percent visibility
impairment, from the 2000-2004 baseline period and from the more recent
2005-2010 period.\73\ This analysis confirmed the percent contribution
of each component of the aerosol for the 2000-2004 baseline period
presented in the ARHP. In addition, the analysis of the more recent
data enabled us to evaluate trends in the relative contributions of
various components over the first several years of the implementation
period. Table 8 shows how much each pollutant contributed to light
extinction at each of Arizona's Class I areas during the period from
2000-2004. In most areas, organic carbon, coarse mass and ammonium
sulfate are the species that contribute most significantly to
visibility impairment. On average, these components account for 72.9
percent of the light extinction. In isolated cases, ammonium nitrate
can play a smaller but significant role (10.6-14.3 percent) in
visibility impairment. Elemental carbon and fine soil also can have
significant contributions in some cases, but in most of those are
correlated with organic carbon and coarse mass, respectively, and so
are assumed to come from the same sources. That is, the data usually
show significant elemental carbon in association with organic carbon,
as one would expect from fires. Elevated levels of fine soil are
usually associated with elevated levels of coarse mass, which implies a
common source of these pollutants as well.
---------------------------------------------------------------------------

    \73\ See EPA Analysis of IMPROVE Monitoring Data From 2000-2010
(December 6, 2012) in the docket for details on the data analysis
presented in this section.
---------------------------------------------------------------------------

    IMPROVE monitoring data from 2005 through 2010 indicate that the
amount of light extinction due to aerosol has decreased since the
baseline period overall, and the contribution to total light extinction
by most pollutants has decreased as well.\74\ Most significantly, the
contribution from organic carbon has decreased by 2.2 inverse
megameters (Mm-1) \75\ on a statewide average. The exception
to this pattern is a very slight but measurable increase in light
extinction due to ammonium sulfate, which increased by 0.8
Mm-1 statewide, and by 1.0 to 1.7 mM-1 at certain
monitors. The sections below outline the species-specific contributions
to visibility impairment, and the recent trends in more detail.
---------------------------------------------------------------------------

    \74\ See EPA Analysis of IMPROVE Monitoring Data From 2000-2010
(December 6, 2012) Table 5 in the docket, which shows the changes in
average light extinction for each aerosol component at each site
between the periods 2000-2004 and 2005-2010.
    \75\ Light extinction is the attenuation of light due to
scattering and absorption as it passes through a medium.
Reconstructed light extinction (often denoted as bext) is expressed
in units of inverse megameters (1/Mm or Mm-1). While the
haze index, expressed in deciviews (dv), is a useful measure for
tracking progress in improving visibility, light extinction is the
most useful measure for evaluating the relative contributions of
pollutants to visibility impairment. These metrics are related by
the equation HI = 10 ln(bext/10); where: HI is the Haze Index in dv,
ln is the natural log, and bext is the reconstructed
light extinction in Mm-1.
    \76\ Data were extracted from the ``IMPROVE Aerosol, RHR (New
Equation)'' dataset from the portal at the Web site: http://views.cira.colostate.edu/fed/QueryWizard/Default.aspx. EPA's
intermediate data files on IMPROVE Monitoring Data Analysis
(December 6, 2012) is available in the docket to today's proposed
rule.

                                    Table 8--Percent of Total Aerosol Light Extinction Contributed by Each Pollutant
                                           [Worst 20 percent of days, averaged over the baseline period] \76\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Ammonium     Ammonium     Organic     Elemental
                  IMPROVE SITE/Class I area                      nitrate      sulfate       carbon       carbon    Coarse mass   Fine soil     Sea salt
--------------------------------------------------------------------------------------------------------------------------------------------------------
CHIR1/Chiricahua NM, Chiricahua WA, Galiuro WA...............          5.0         26.1         22.9          5.8         30.9          8.9          0.5
GRCA2/Grand Canyon NP........................................         11.3         21.5         39.8          9.2         12.6          5.0          0.4
IKBA1/Mazatzal WA, Pine Mountain WA..........................         14.1         22.1         26.3          8.4         20.6          8.3          0.2
BALD1/Mount Baldy WA.........................................          4.9         22.0         46.6         10.5         11.3          5.2          0.1
PEFO1/Petrified Forest NP....................................          6.6         20.2         34.4         10.3         21.7          6.7          0.1
SAGU1/Saguaro NP (East)......................................         14.3         19.8         28.6          8.3         19.0          9.4          0.4
SAWE1/Saguaro NP (West)......................................         10.6         16.5         19.4          7.2         31.2         14.5          0.7
SIAN1/Sierra Ancha WA........................................          9.7         20.1         37.0          8.4         18.0          6.5          0.3
SYCA1/Sycamore Canyon WA.....................................          5.2         13.0         32.5          9.4         22.6         16.9          0.3
TONT1/Superstition WA........................................         12.2         21.0         29.8          8.8         21.2          6.7          0.3
                                                              ------------------------------------------------------------------------------------------
    Mean.....................................................          9.4         20.2         31.7          8.6         20.9          8.8          0.3
--------------------------------------------------------------------------------------------------------------------------------------------------------

 1. Chiricahua National Monument, Chiricahua Wilderness Area and
Galiuro Wilderness Area
    Visibility impairment at Chiricahua National Monument, and
Chiricahua and Galiuro Wilderness Areas are represented by the
conditions at the IMPROVE monitor in the Chiricahua National Monument
(CHIR1). Average monitored concentrations over the period of 2000-2004
indicate that coarse mass, organic carbon and ammonium sulfate are the
most significant contributors to visibility impairment, together
accounting for 79.9 percent of the light extinction. Fine soil is the
next largest contributor to light extinction with 8.9 percent, and is
correlated with periods of high coarse mass impact.
    IMPROVE data averaged over 2005-2010 show measurable decreases in
the light extinction due to organic carbon and coarse mass of over 3
Mm-1 each. There was a slight increase in light extinction
due to ammonium sulfate measured during these years of 1.1

mM-1, but overall the total light extinction has decreased
significantly between the two periods by 6.7 Mm-1.
 2. Grand Canyon National Park
    Visibility impairment at Grand Canyon National Park is represented
by the conditions at the IMPROVE monitor at Hance Camp (GRCA2). Average
monitored concentrations over the period of 2000-2004 indicate that
39.8 percent of the light extinction is due to organic carbon alone.
The next significant contributor is ammonium sulfate accounting for
22.1 percent of the light extinction. Coarse mass and fine soils
contribute 17.6 percent and ammonium nitrate contributes 11 percent of
the light extinction. Elemental carbon accounts for 9.2 percent of
light extinction, and is correlated with periods of high organic carbon
impact.
    IMPROVE data averaged over 2005-2010 show a slight decrease in the
light extinction due to organic carbon of 1.1 Mm-1. The
changes in contribution to light extinction from the other aerosol
components were small or negligible between the two periods, with a
very slight decrease in total aerosol light extinction of 0.8
Mm-1.
 3. Mazatzal Wilderness Area and Pine Mountain Wilderness Area
    Visibility impairment at Mazatzal and Pine Mountain Wilderness
Areas is represented by the conditions at the IMPROVE monitor at Ike's
Backbone (IKBA1). Average monitored concentrations over the period of
2001-2004 indicate that coarse mass, organic carbon and ammonium
sulfate are the most significant contributors to visibility impairment,
each contributing similarly to 69.0 percent of the light extinction.
Ammonium nitrate contributes 14.1 percent, and fine soil and elemental
carbon each contribute about 8 percent, and are correlated with periods
of high coarse mass and organic carbon impact, respectively.
    IMPROVE data averaged over 2005-2010 show a slight decrease in
light extinction due to ammonium nitrate of 1.2 Mm-1 and a
slight increase in light extinction due to ammonium sulfate of 1.0
Mm-1 since the average values of the baseline period.
 4. Mount Baldy Wilderness Area
    Visibility impairment at Mount Baldy Wilderness Area is represented
by the conditions at the IMPROVE monitor in the wilderness area
(BALD1). Similar to Grand Canyon National Park, average monitored
concentrations over the period of 2000-2004 in Mount Baldy Wilderness
indicate that nearly half of the light extinction is due to organic
carbon alone and the next significant contributor is ammonium sulfate
accounting for 22.0 percent of the light extinction. Coarse mass and
fine soils contribute over 16.5 percent of the light extinction.
Elemental carbon contributes 10.5 percent to the light extinction and
is correlated with periods of high organic carbon impact.
    IMPROVE data averaged over 2005-2010 show a measurable decrease in
light extinction due to organic carbon of 2.0 Mm-1 and a
overall decrease in total aerosol light extinction of 1.1
Mm-1 since the average values of the baseline period.
 5. Petrified Forest National Park
    Visibility impairment at Petrified Forest National Park is
represented by the conditions at the IMPROVE monitor in the National
Park (PEFO1). Average monitored concentrations over the period of 2000-
2004 indicate that organic carbon, coarse mass, and ammonium sulfate
are the most significant contributors to visibility impairment,
together accounting for 76.3 percent of the light extinction. Elemental
carbon is the next largest contributor to light extinction at 10.3
percent, and is correlated with periods of high organic carbon impact.
    IMPROVE data averaged over 2005-2010 show that light extinction due
to organic carbon and coarse mass decreased by 2.6 and 1.2
Mm-1, respectively since the baseline period. Total aerosol
light extinction decreased by 3.0 Mm-1 since the average
values of the baseline period.
 6. Saguaro National Park (East Unit and West Unit)
    There are IMPROVE monitors in both the East and West Units of
Saguaro National Park that represent the visibility impairment
throughout the National Park (SAGU1 and SAWE1). Average monitored
concentrations over the period of 2002-2004 indicate that organic
carbon, coarse mass, and ammonium sulfate are the most significant
contributors to visibility impairment, together accounting for 67.0 to
67.5 percent of the light extinction. Ammonium nitrate contributes 10.6
to 14.3 percent and fine soil, correlated with coarse mass, contributes
9 to 15 percent.
    IMPROVE data averaged over 2005-2010 show that light extinction due
to organic carbon decreased since the baseline period by 5.5 and 2.9
Mm-1, at SAGU1 and SAWE1, respectively. Also, SAGU1 measured
a decrease in contribution from ammonium nitrate of 2.2 Mm-1
and SAWE1 measured a decrease in contribution of coarse mass and fine
soil together of 5.7 Mm-1. These monitors indicate that the
total aerosol light extinction has improved at these two areas more
than at any area in Arizona, with decreases of 8.2 and 9.8
Mm-1 at the East and West Units, respectively.
 7. Sierra Ancha Wilderness Area
    Visibility impairment at Sierra Ancha Wilderness Area is
represented by the conditions at the IMPROVE monitor in the Wilderness
Area (SIAN1). Average monitored concentrations over the period 2001-
2004 indicate that 37.0 percent of the light extinction is due to
organic carbon. Coarse mass and fine soil together account for almost
24.4 percent and ammonium sulfate accounts for 20.1 percent of the
light extinction.
    IMPROVE data averaged over 2005-2010 show that light extinction due
to ammonium nitrate and coarse mass decreased by 1.3 and 1.5
Mm-1, respectively since the baseline period. Slight
increases in the contribution from ammonium sulfate, as well as from
organic and elemental carbon lead to a total aerosol light extinction
that is decreased only slightly, by 1.3 Mm-1, since the
average values of the baseline period.
8. Sycamore Canyon Wilderness Area
    Visibility impairment in the Sycamore Canyon Wilderness Area is
represented by the conditions at the IMPROVE monitor in the Wilderness
Area (SYCA1). Average monitored concentrations over the period 2001-
2004 indicate that 32.5 percent of the light extinction is due to
organic carbon. Other significant contributors are coarse mass (22.6
percent), fine soil (16.9 percent), and ammonium sulfate (13.0
percent). Fine soil is often correlated with coarse mass, but there are
also times when the two are not correlated. For example, July 13 and
November 22, 2002 have high concentrations of fine soil but not coarse
mass. Elemental carbon contributes 9.4 percent to the light extinction
and is correlated with periods of high organic carbon impact.
    IMPROVE data averaged over 2005-2010 show that light extinction due
organic carbon and fine soil decreased by 1.3 and 1.2 Mm-1,
respectively since the baseline period. The contribution from coarse
mass increased between the two time periods by 1.4 Mm-1.
Total aerosol light extinction decreased only slightly, by 0.8
Mm-1, since the baseline period.
 9. Superstition Wilderness Area
    Visibility impairment in the Superstition Wilderness Area is

represented by the conditions at the IMPROVE monitor in the Tonto
National Monument (TONT1). Average monitored concentrations between
2001 and 2004 indicate that 30 percent of the light extinction is due
to organic carbon. Coarse mass and fine soil together account for 27.9
percent and ammonium sulfate accounts for 21.0 percent of the light
extinction. Finally, ammonium nitrate contributes 12.2 percent of the
light extinction.
    IMPROVE data averaged over 2005-2010 show that light extinction due
organic carbon and ammonium nitrate decreased by 4.1 and 1.0
Mm-1, respectively since the baseline period. This site
exhibited the largest increase in light extinction from ammonium
sulfate in Arizona: 1.7 Mm-1. However, total aerosol light
extinction still decreased by 3.4 Mm-1, since the baseline
period.

VII. EPA's Evaluation of Arizona's BART Analyses and Determinations

A. Arizona's Identification of BART Sources

    Pursuant to Section 169A of the CAA and 40 CFR 51.308(e), states
are required to evaluate the use of retrofit controls at certain
larger, older stationary sources in order to address visibility impacts
from these sources. The best available retrofit technology (BART)
process, as set forth in the RHR and the final BART Guidelines,
consists of three steps. First, states identify those stationary
sources that are eligible for BART using criteria set forth in the RHR,
such as industrial source category, dates of initial construction and
operation, and potential to emit. For those sources that are considered
BART-eligible, states then determine if they ``cause or contribute'' to
visibility impairment at a Class I area through the use of visibility
modeling. For those sources that cause or contribute to Class I
visibility impairment, states must then perform a case-by-case
determination of what retrofit control measures are appropriate as
BART. This determination is performed on a pollutant-by-pollutant basis
for each visibility affecting pollutant.
1. Arizona's Identification of Sources Potentially Eligible for BART
    The first step of the BART process is to identify all of the BART-
eligible sources within the jurisdiction of the State and using the
following criteria: (1) One or more emission units at the facility are
classified in one of the 26 industrial source categories listed in CAA
section 169A(g)(7); (2) the emission unit(s) did not operate before
August 7, 1962, but was in existence on August 7, 1977; and (3) the
total potential to emit of any visibility impairing pollutant from the
eligible emission units at a single source is greater or equal to 250
tons per year.
    Using these criteria, the Stationary Sources Joint Forum (SSJF) of
the WRAP identified units at several facilities under the jurisdiction
of state and local agencies in Arizona that were considered potentially
BART-eligible. Using this information, ADEQ developed an initial list
of fourteen facilities that it identified as ``potentially subject-to-
BART.'' \77\ Based on CALPUFF modeling performed by WRAP, ADEQ refined
this initial list to include only those facilities considered to
contribute to impairment of visibility in a Class I area within 300
kilometers.\78\ These facilities are listed in Table 9 below.
---------------------------------------------------------------------------

    \77\ As identified in Table 1 of ``Summary of WRAP RMC BART
Modeling for Arizona'' Draft No. 5, May 7, 2005. Initial draft
released on April 4, 2005.
    \78\ Arizona Regional Haze SIP, Appendix D (Technical Support
Document), page 13.

          Table 9--Potentially BART-Eligible Sources in Arizona
------------------------------------------------------------------------
                                                         Number of BART-
         Facility name              Source category      eligible units
------------------------------------------------------------------------
Tucson Electric Power (TEP)     Fossil-fuel fired                      1
 Sundt Generating Station.       steam electric plants
                                 of more than 250
                                 million British
                                 thermal units per
                                 hour heat input.
Arizona Electric Power          ......................                 3
 Cooperative (AEPCO) Apache
 Generating Station.
Arizona Public Service (APS)    ......................                 3
 Cholla Power Plant.
Salt River Project (SRP)        ......................                 2
 Coronado Generating Station.
APS West Phoenix Power Plant..  ......................                 3
CalPortland Rillito Cement      Portland cement plant.                 1
 Plant.
Chemical Lime Nelson Plant....  Lime Plant............                 2
Catalyst Paper Snowflake Mill.  Fossil-fuel boilers of                 1
                                 more than 250 million
                                 British thermal units
                                 per hour heat input.
ASARCO Hayden Smelter.........  Primary Copper Smelter                10
Freeport McMoRan (FMMI,         ......................                 9
 formerly Phelps-Dodge) Miami
 Smelter.
------------------------------------------------------------------------

Please note that we have addressed ADEQ's BART determinations for
Apache Units 1-3, Cholla Units 2-4 and Coronado Units 1 and 2 in a
separate action.\79\ As a result, the BART determinations for these
three facilities are not discussed in today's proposal.
---------------------------------------------------------------------------

    \79\ See proposal at 77 FR 42834 and final action at 77 FR
72512.
---------------------------------------------------------------------------

2. Arizona's Determination of Sources Not BART-Eligible
    ADEQ contacted the potentially BART-eligible facilities identified
by SSJF in order to inform them of their status and to obtain
confirmation or, where necessary, more information. ADEQ received
responses and additional information from multiple facilities, and
subsequently revised this initial list of BART-eligible sources. These
revisions primarily affected the BART-eligibility status of two
facilities as described below.
    Hayden Smelter: ADEQ sent a letter to ASARCO on June 13, 2007
indicating that 10 units at the Hayden smelter, including five
converters and three anode furnaces, were BART-eligible for
SO2 and PM10 emissions. In response, ASARCO
provided a letter to ADEQ on October 1, 2007, in which it stated that
only three converters and two anode furnaces were BART-eligible based
on operation dates prior to 1962 in the case of two converters, and a
construction (``in existence'') date of 2001 in the case of one of the
anode furnaces. In addition, ASARCO stated that ADEQ's estimate of its
potential to emit (PTE) was overestimated, as it was based on

facility-wide PTE estimates which included the PTE of non BART-eligible
sources. In its letter, ASARCO provided information re-apportioning the
fraction of the facility-wide PTE attributable to the BART-eligible
sources.
    ADEQ performed its own research of historical smelter logs and
agreed with ASARCO's assertion that only three converters and two anode
furnaces are BART-eligible. It took no action regarding ASARCO's PTE
apportionment information, citing a lack of documentation. However, as
part of the Title V permit renewal process, ADEQ subsequently revised
its estimate of facility-wide PM10 PTE downward. ADEQ
concluded that the BART-eligible units do not have a PM10
PTE greater than 250 tpy, and determined that the units at the Hayden
smelter are not BART eligible for PM10.\80\ This did not
alter ADEQ's determination that the Hayden smelter was subject to BART
for SO2.
---------------------------------------------------------------------------

    \80\ Arizona Regional Haze SIP, page 150.
---------------------------------------------------------------------------

    Sundt Generating Station: ADEQ identified Units 3 and 4 at Sundt as
potentially BART-eligible units. On January 2, 2007, Tucson Electric
Power (TEP) provided a letter to ADEQ indicating that Unit I3 was not a
BART-eligible unit because it commenced commercial operation on June
26, 1962, which is prior to the August 7, 1962 ``in operation''
date.\81\ In addition, TEP provided information indicating that Unit I4
was reconstructed in 1987 as part of a coal conversion project. Under
the BART Guidelines, reconstructed sources are generally considered new
sources at the time of reconstruction.\82\ However, although Unit I4
was reconstructed in 1987, the reconstruction was undertaken as the
result of an order issued pursuant to Section 301(c) of the Power Plant
and Industrial Fuel Use Act of 1978 and, under Arizona's PSD rule (AAC
R9-3-304), a project undertaken pursuant to such an order did not
constitute a major modification at the time that reconstruction
occurred. As a result, the reconstruction of Unit I4 did not undergo
PSD review. TEP indicated that it considers PSD to be immaterial to
BART eligibility, stating that the RHR does not require PSD review as a
condition of being considered reconstructed.
---------------------------------------------------------------------------

    \81\ Letter from Cosimo DeMasi, TEP, to Nancy Wrona, ADEQ
(January 2, 2007), Attachment A (June 29, 1962).
    \82\ 40 CFR part 51, appendix Y, section II.A.2. (``What is a
`reconstructed source?'').
---------------------------------------------------------------------------

    ADEQ agreed with the documentation TEP supplied indicating that
Unit I3 began operation prior to August 7, 1962, and is therefore not
BART-eligible. ADEQ also concurred with TEP's position that Unit I4 is
not a BART-eligible source, stating that based on a plain reading of
EPA's guidance regarding the issue of reconstruction, it considered it
appropriate to treat reconstructed sources as new sources at the time
of reconstruction. As a result, ADEQ concurred that the reconstructed
Unit I4 at Sundt was not ``in existence'' prior to August 7, 1977.
3. Arizona's Identification of Sources Exempt From BART
    The second step of the BART process is to determine which BART-
eligible facilities may be exempted from further review because they
are not reasonably anticipated to cause or contribute to visibility
impairment at any Class I areas.\83\ ADEQ initially relied upon
visibility modeling performed by the WRAP's Regional Modeling Center
(RMC) in order to assess the potential of BART-eligible sources to
cause or contribute to Class I visibility impairment. ADEQ also
provided each of the BART-eligible sources the opportunity to
demonstrate, through the use of visibility modeling, that it does not
cause or contribute to visibility impairment at surrounding Class I
areas.
---------------------------------------------------------------------------

    \83\ Alternatively, a state may make BART determinations for all
of its BART-eligible sources, if those sources collectively cause or
contribute to visibility impairment at one or more Class I areas. 40
CFR part 51, appendix Y, section III.