Document ID: EPA-R09-OAR-2012-0904-0001
Agency: epa
Document Type: Proposed Rule
Title: Partial Approvals and Disapprovals of Air Quality Implementation Plans: Arizona; Regional Haze and Visibility Impacts of Transport, Ozone and Fine Particulates
Posted Date: 2012-12-21T05:00Z

[Federal Register Volume 77, Number 246 (Friday, December 21, 2012)]
[Proposed Rules]
[Pages 75703-75737]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-30702]

[[Page 75703]]

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  

[[Page 75704]]

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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 r9azreghaze@epa.gov.

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

[[Page 75705]]

    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: r9azreghaze@epa.gov.
     Fax: 415-947-3579 (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

[[Page 75706]]

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

[[Page 75707]]

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

[[Page 75708]]

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.
---------------------------------------------------------------------------

    \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\

[[Page 75709]]

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

[[Page 75710]]

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

[[Page 75711]]

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

[[Page 75712]]

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\
---------------------------------------------------------------------------

    \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

[[Page 75713]]

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

[[Page 75714]]

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.

[[Page 75715]]

  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

[[Page 75716]]

 
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.

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

[[Page 75717]]

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

[[Page 75718]]

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

[[Page 75719]]

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

[[Page 75720]]

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.
---------------------------------------------------------------------------

    For states using modeling to determine the applicability of BART to 
single sources, the BART Guidelines note that a state must establish a 
contribution threshold to assess whether the impact of a single source 
is sufficient to cause or contribute to visibility impairment at a 
Class I area. The BART Guidelines state that, ``[a] single source that 
is responsible for a 1.0 deciview change or more should be considered 
to `cause' visibility impairment.'' \84\ The BART Guidelines also state 
that ``the appropriate threshold for determining whether a source 
contributes to visibility impairment may reasonably differ across 
states,'' but, ``[a]s a general matter, any threshold that you use for 
determining whether a source `contributes' to visibility impairment 
should not be higher than 0.5 deciviews.'' \85\ Further, in setting a 
contribution threshold, states should ``consider the number of 
emissions sources affecting the Class I areas at issue and the 
magnitude of the individual sources' impacts. For determining whether a 
source is subject to BART, ADEQ used a contribution threshold of 0.5 
dv, based on a 3-year average of 98th percentile impacts.
---------------------------------------------------------------------------

    \84\ 40 CFR part 51, appendix Y, section III.A.1.
    \85\ Id.
---------------------------------------------------------------------------

    The BART Guidelines provide that states may choose to use the 
CALPUFF modeling system or another appropriate model to predict the 
visibility impacts from a single source on a Class I area, and 
determine whether an individual source is anticipated to cause or 
contribute to impairment of visibility in Class I areas (i.e., 
visibility impacts below the 0.5 dv threshold). The Guidelines state 
that we believe CALPUFF is the best regulatory modeling application 
currently available for predicting a single source's contribution to 
visibility impairment.\86\ The WRAP Regional Modeling Center (RMC) 
developed a modeling protocol, entitled ``CALMET/CALPUFF Protocol for 
BART Exemption Screening Analysis for Class I Areas in the Western 
United States.'' The WRAP RMC used this protocol to perform CALPUFF 
modeling for each of the western states in which it assessed the 
visibility impact of each of the sources initially identified as BART-
eligible by the SSJF. Certain sources that were identified as causing 
or contributing to Class I visibility impairment (and therefore subject 
to BART) based on WRAP RMC results performed their own CALPUFF modeling 
in order to provide results indicating they were not subject to BART. 
This modeling was performed in accordance with the WRAP protocol and 
primarily consisted of different estimates of source emission rates 
during the baseline period.
---------------------------------------------------------------------------

    \86\ 70 FR 39162.
---------------------------------------------------------------------------

    Based on CALPUFF modeling performed in accordance with the WRAP 
protocol, ADEQ determined that the facilities in Table 10 had 
visibility impacts below the contribution threshold of 0.5 dv, and were 
therefore exempt from BART.

[[Page 75721]]

                                    Table 10--Sources Exempt From BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
                                                               Visibility impact at 98th percentile (dv)
              Facility                   Class I area with   --------------------------------------------  Notes
                                          highest impact         2001       2002       2003     Average
----------------------------------------------------------------------------------------------------------------
Nelson Lime Plant...................  Grand Canyon National       0.452      0.419      0.624      0.498       1
                                       Park.
West Phoenix Power Plant............  Superstition                0.28       0.21       0.23       0.24        2
                                       Wilderness.
Rillito Cement Plant................  Saguaro National            0.37       0.48       0.34       0.40        3
                                       Monument.
----------------------------------------------------------------------------------------------------------------
\1\ Based on September 21, 2007 modeling report provided by Chemical Lime.
\2\ Based on October 4, 2007 modeling report provided by Arizona Public Service.
\3\ Based on May 25, 2007 WRAP RMC BART Modeling Results for Arizona.

    Based upon CALPUFF modeling performed by WRAP, the remaining BART-
eligible sources from Table 9 were determined to have visibility 
impacts greater than 0.5 dv.
4. Sources Subject to BART in Arizona
    Following the elimination of those sources that it determined were 
not BART-eligible or that it found to have visibility impacts below the 
0.5 dv contribution threshold, ADEQ determined that the remaining BART-
eligible sources were subject to BART for the one or more pollutants. 
These sources are summarized in Table 11.

                                    Table 11--Sources Subject to BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
                                                                                                 Pollutants
             Facility                   BART emission units           Source category             evaluated
----------------------------------------------------------------------------------------------------------------
Catalyst Paper....................  Power Boiler 2............  Fossil-fuel boilers of      NOX, SO2.
                                                                 more than 250 million
                                                                 British thermal units per
                                                                 hour heat input.
Hayden Smelter....................  Anode Furnaces 1 and 2,     Primary Copper Smelter....  SO2.
                                     Converters 1, 2, and 4.
Miami Smelter.....................  Converters 1-5, Anode       ..........................  SO2, PM10.
                                     Furnace, Shaft Furnace,
                                     Fugitives.
----------------------------------------------------------------------------------------------------------------

    A summary of the BART-eligible sources ADEQ determined not subject 
to BART is in Table 12 below.

                                  Table 12--Sources Not Subject to BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
           Facility name                        Source category                            Reason
----------------------------------------------------------------------------------------------------------------
Sundt..............................  Fossil-fuel fired steam electric       Unit 3 commenced operation prior to
                                      plants of more than 250 million        August 7, 1962
                                      British thermal units per hour heat   Unit 4 reconstructed after August 7,
                                      input.                                 1977.
West Phoenix Power Plant...........  .....................................  Exempt (visibility impact <0.5 dv).
Rillito Cement Plant...............  Portland cement plant................  Exempt (visibility impact <0.5 dv).
Nelson Lime Plant..................  Lime Plant...........................  Exempt (visibility impact <0.5 dv).
----------------------------------------------------------------------------------------------------------------

B. EPA's Evaluation of ADEQ's Subject-to-BART Analysis

    Hayden Smelter: We propose to approve ADEQ's determination that the 
Hayden smelter is a BART-eligible source and that a BART determination 
is required for SO2, but is not required for NOX. 
We propose to disapprove ADEQ's determination that a BART determination 
is not required for PM10. In its SIP submittal, ADEQ 
determined that a BART determination for PM10 was not 
required because the facility's potential to emit PM10 is 
less than 250 tons per year.\87\ This is inconsistent with the Regional 
Haze Rule. As defined in the Regional Haze Rule, a BART-eligible 
facility is one that, among other criteria, ``has the potential to emit 
250 tons per year or more of any air pollutant.'' \88\ Once a facility 
has been determined to be BART-eligible, BART must then be determined 
for all visibility-impairing pollutants.\89\ However, a state is not 
required to make a BART determination for SO2 or for 
NOX if a BART eligible source has the potential to emit less 
than 40 tons per year of such pollutant(s), or for PM10 if a 
BART-eligible source has the potential to emit less than 15 tons per 
year of such pollutant.\90\ For Hayden, the potential to emit 
PM10 of the BART-eligible sources is 70 tpy.\91\ While we do 
not necessarily agree that this figure encompasses the full potential 
to emit of all BART-eligible units at Hayden, even ADEQ's estimate of 
70 tpy exceeds the PM10 exception threshold of 15 tpy. As a 
result, we propose to find that a BART determination for 
PM10 is required. We intend to propose BART requirements for 
PM10 at Hayden as part of our Phase 3 proposal. At minimum, 
we expect that BART would require compliance with the NESHAP MACT 
Subpart QQQ control requirements and emission limits.
---------------------------------------------------------------------------

    \87\ Page 23 of 115, Arizona RH SIP, Appendix D. See Docket Item 
B-01.
    \88\ 40 CFR 51.301.
    \89\ 40 CFR 51.308(e)(1)(ii).
    \90\ 40 CFR 51.308(e)(1)(ii)(C).
    \91\ Per Table 6.5, Arizona RH SIP, Appendix D. See Docket Item 
B-01.
---------------------------------------------------------------------------

    Miami Smelter: We propose to approve ADEQ's determination that the 
Miami smelter is a BART-eligible source, and that a BART determination 
is required for SO2 and PM10. We propose to 
disapprove ADEQ's determination that a BART

[[Page 75722]]

determination is not required for NOX. In its SIP submittal, 
ADEQ did not address NOX emissions from the Miami smelter. 
As part of the visibility modeling performed for the Miami smelter, 
WRAP identified an annual NOX emission rate of 158 tpy for 
the units constituting the BART-eligible source.\92\ This exceeds the 
NOX exception threshold of 40 tpy. As a result, a BART 
determination for NOX is required.
---------------------------------------------------------------------------

    \92\ As described in ``Summary of WRAP RMC BART Modeling for 
Arizona'', Draft5, May 25, 2007.
---------------------------------------------------------------------------

    Sundt: We propose to approve ADEQ's determination that Sundt Unit 
I3 is not BART-eligible based on the startup date prior to August 7, 
1962. We propose to disapprove ADEQ's determination that Sundt Unit I4 
is not BART-eligible. Although we accept that the unit was 
reconstructed in 1987, we have determined that because the unit did not 
undergo PSD review as part of reconstruction that it is subject to 
BART.
    Under the RHR, ``BART-eligible source'' means any stationary source 
of air pollutants in one the 26 BART categories, ``including any 
reconstructed source, which was not in operation prior to August 7, 
1962, and was in existence on August 7, 1977, and has the potential to 
emit 250 tons per year or more of any air pollutant. * * *'' \93\ As 
ADEQ noted in its RH SIP, the BART Guidelines state:
---------------------------------------------------------------------------

    \93\ 40 CFR 51.301.

    The ``in operation'' and ``in existence'' tests apply to 
reconstructed sources. If an emissions unit was reconstructed and 
began actual operation before August 7, 1962, it is not BART-
eligible. Similarly, any emissions unit for which a reconstruction 
``commenced'' after August 7, 1977, is not BART-eligible.\94\
---------------------------------------------------------------------------

    \94\ 40 CFR part 51, appendix Y, Sec.  II.A.2, ``What does `in 
existence on August 7, 1977' mean?''

    However, as explained in the preamble to the Guidelines, Congress 
intended ``that the BART provision apply to sources which had been 
`grandfathered' from the new source review permit requirements in parts 
C and D of title I of the CAA.'' \95\ Consistent with this approach, 
footnote 9 of the preamble to the BART Guidelines notes that, ``sources 
reconstructed after 1977, which reconstruction had gone through NSR/PSD 
permitting, are not BART-eligible.'' \96\ By implication, reconstructed 
sources that did not go through NSR/PSD permitting, are BART-eligible. 
Therefore, EPA concludes that, even accepting ADEQ's determination that 
TEP Sundt Unit I4 was ``reconstructed'' after August 7, 1977, the Unit 
remains BART-eligible because it did not go through NSR/PSD 
permitting.\97\
---------------------------------------------------------------------------

    \95\ 70 FR at 39111.
    \96\ 70 FR at 39111 (July 6, 2005) (emphasis added).
    \97\ See ``TEP Sundt Unit I4 BART Eligibility Memo'' (November 
21, 2012) for a more detailed discussion of the BART eligibility of 
Unit I4.
---------------------------------------------------------------------------

    Threshold for Subject-to-BART: Arizona set a 0.5 dv as the 
threshold for determining whether a source ``contributes'' to 
visibility impairment. The BART Guidelines state that ``[as] a general 
matter, any threshold that you use for determining whether a source 
`contributes' to visibility impairment should not be higher than 0.5 
deciviews.\98\ In setting a threshold, states should consider the 
number of BART-eligible sources within the state and the magnitude of 
each source's impacts.\99\ Arizona did not provide a rationale for 
choosing 0.5 dv as the threshold for determining BART eligibility. We 
note that the WRAP's SSJF identified fourteen sources that it initially 
considered BART eligible, and that ADEQ determined that seven of these 
fourteen do not contribute to visibility impairment based on visibility 
impacts below 0.5 dv. The source with a modeled impact closest to the 
0.5 dv threshold is the Chemical Nelson Lime Plant facility with a 
modeled average 98th high impact of 0.498 dv at Grand Canyon NP.\100\ 
As we discuss below, this is very close to the 0.5 dv threshold and, 
depending on how that threshold is interpreted, may exceed it. The 
source with the next highest impact is Rillito Cement Plant with a 
modeled maximum impact of 0.40 dv at Saguaro NP.\101\ The source with 
the next highest impact is Salt River Project San Tan with a modeled 
maximum impact of 0.31 dv at Superstition WA. Given that reducing the 
threshold to 0.3 dv would not result in bringing into BART a 
significant number of sources impacting the same Class I area, the use 
of the 0.5 dv threshold may be appropriate. Therefore, EPA proposes to 
approve Arizona's decision to set 0.5 dv as the threshold for 
determining whether sources are subject-to-BART. However, given that 
the modeled average 98th high impact of one BART-eligible source, the 
Nelson Lime Plant, is within 0.002 dv of 0.5 dv, EPA is also seeking 
comment on whether it was unreasonable for ADEQ to set a threshold of 
0.5 dv. If, after taking into consideration any comments received, we 
determine that the State's determination was unreasonable, then we may 
disapprove the State's decision to set a threshold of 0.5 dv.
---------------------------------------------------------------------------

    \98\ BART Guidelines, 40 CFR part 51, appendix Y, section 
III.A.1.
    \99\ Id.
    \100\ From visibility modeling performed by the source, see ARHP 
Appendix D, Table 6.9.
    \101\ See ``Summary of WRAP RMC BART Modeling for Arizona'' 
Draft No. 5, May 7, 2005. Initial draft released on April 4, 2005.
---------------------------------------------------------------------------

    West Phoenix Power Plant: As seen in Table 10, the visibility 
modeling performed by APS indicates that the 98th percentile impact 
from the West Phoenix Power Plant is below 0.5 dv at the most affected 
Class I area. Based on our review of the visibility modeling performed 
by APS, we propose to approve ADEQ's determination that the West 
Phoenix Power Plant is exempt from BART.
    Rillito Cement Plant: As seen in Table 10, the visibility modeling 
performed by CalPortland indicates that the 98th percentile impact from 
the Kiln 4 at the Rillito Cement Plant is below 0.5 dv at the most 
affected Class I area. Based on our review of the visibility modeling, 
we propose to approve ADEQ's determination that the Rillito Cement 
Plant is exempt from BART.
    Nelson Lime Plant: As seen in Table 10, the visibility modeling 
performed by Chemical Lime indicates that the average 98th percentile 
impact from the Nelson Lime Plant is below 0.5 dv at the most affected 
Class I area. However the 98th percentile impact for a single year, 
2003, exceeds 0.5 dv. ADEQ based its BART-exemption determination on 
the 3-year average of 98th percentile impact. When the 2003 value is 
averaged with the 2001 and 2002 values, the facility's visibility 
impact is below the exemption threshold of 0.5 dv. This interpretation 
of the 0.5 dv threshold differs from the interpretation used in a 
similar type of analysis, namely the Prevention of Significant 
Deterioration (PSD) Class I visibility analysis. For example, the 
CALPUFF model is often used for certain aspects of the PSD Class I 
visibility analysis, and the Federal Land Managers (FLMs), who have the 
affirmative responsibility to protect visibility at Class I areas, also 
use 0.5 dv as a threshold.\102\ Guidance issued by the FLMs indicates 
that they interpret this threshold to be exceeded if the 98th 
percentile values for change in light extinction are equal to or 
greater than 0.5 dv for any year.\103\ Typically, the PSD-style method 
has been used to determine if a source exceeds the BART threshold. 
However, the BART Guidelines and the preamble to the Regional Haze Rule 
do not specify the

[[Page 75723]]

interpretation of this threshold to the same level of detail as the 
FLM's guidance for the PSD program, nor do they specify a rounding 
convention under these circumstances. Nonetheless, in this instance, 
given that the 98th percentile impact for a single year clearly exceeds 
0.5 dv and that the average of the three years is within 0.002 dv of 
0.5 dv, EPA proposes to determine that it was not reasonable for the 
State to find the Nelson Lime Plant is not subject to BART. Therefore, 
we propose to disapprove the State's determination and find that Nelson 
Lime Plant is subject to BART. However, we are seeking comment on 
whether the State's decision was, in fact, reasonable and should be 
approved. If, based on comments received, we determine that the State's 
determination was reasonable, then we may approve the State's decision 
to find this source not subject-to-BART. In addition, EPA also seeks 
comments on whether there are cost effective pollution controls at 
Nelson Lime Plant.
---------------------------------------------------------------------------

    \102\ Specifically, the FLM's threshold for concern is a 5% 
change in light extinction, which is equivalent to 0.5 dv.
    \103\ Federal Land Managers' Air Quality Related Values Work 
Group (FLAG) Phase I Report--Revised (2010) (FLAG 2010), Page 23.
---------------------------------------------------------------------------

    Cholla Unit 1: As discussed previously, we have addressed the BART 
determinations for Cholla Units 2, 3, and 4 in a separate action. For 
Unit 1, ADEQ determined it is not BART-eligible because it was in 
existence prior to August 7, 1962. The WRAP's ``Arizona BART 
Eligibility TSD'' further explains that:

    [Cholla] Unit 1 is listed as potentially date eligible as 
information shows that the emissions unit was in service only 2 
months prior to the cut-off date. Recommend requesting additional 
supporting documentation for final determination.\104\
---------------------------------------------------------------------------

    \104\ ``Supporting Documentation on Emissions Unit Bart 
Eligibility Analysis'', section 5.1.2.

    ADEQ requested and later received this additional documentation 
from APS in August 2007 in the form of a document dated May 23, 1962 
entitled ``Operating Notes For May 1962.'' \105\ This document 
indicates that, ``[o]n Tuesday, May 1, 1962, unit [1 was] 
placed into commercial operation.'' \106\ After reviewing this 
documentation, ADEQ concurred that Unit 1 was not BART eligible.\107\ 
We have requested and received from APS a copy of the ``Operating Notes 
For May 1962'' along with additional information concerning the 
operation of Cholla Unit 1.\108\ We have placed these materials in the 
docket and, based on our review, we consider this documentation to be 
sufficient to confirm ADEQ's determination that this unit is not BART-
eligible. As a result, we propose to approve ADEQ's determination that 
Cholla Unit 1 is not among the units that constitute the BART-eligible 
source at Cholla.
---------------------------------------------------------------------------

    \105\ Arizona Regional Haze SIP at page 155.
    \106\ Id.
    \107\ Id.
    \108\ Email from Sue Kidd, APS, to Colleen McKaughan, EPA 
(October 10, 2012, 9:17 a.m.) and attachments.
---------------------------------------------------------------------------

C. Arizona's BART Control Analysis

    The third step of the BART process is to perform the BART analysis 
and make a final determination. The BART Guidelines (70 FR 39164) 
describe a step-by-step procedure for performing the BART analysis. In 
performing this analysis, 40 CFR 51.308(e)(1)(ii)(A) requires that 
states consider the following factors: (1) The costs of compliance of 
each technically feasible control technology, (2) the energy and non-
air quality environmental impacts of compliance of the control 
technologies, (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. These factors are frequently 
referred to as the ``five-factor analysis'' for the RHR BART 
determination.
    The BART Guidelines recommend that a BART analysis include the 
following five steps. The Guidelines provide detailed instructions on 
how to perform each of these steps.\109\
---------------------------------------------------------------------------

    \109\ 40 CFR part 51, appendix Y, Sec.  IV.D.
---------------------------------------------------------------------------

     Step 1--Identify All Available Retrofit Control 
Technologies,
     Step 2--Eliminate Technically Infeasible Options,
     Step 3--Evaluate Control Effectiveness of Remaining 
Control Technologies,
     Step 4--Evaluate Impacts and Document the Results,\110\ 
and
---------------------------------------------------------------------------

    \110\ Step 4 includes evaluating the cost of compliance, energy 
impacts, non-air quality environmental impacts, and remaining useful 
life.
---------------------------------------------------------------------------

     Step 5--Evaluate Visibility Impacts.
    ADEQ's BART analyses mostly followed this approach, with the 
addition of a step to identify existing control technologies and a step 
concluding ``selection of BART.'' ADEQ identified a seven step process 
in its SIP submittal for determining BART:
     Step 1: Identify the Existing Control Technologies in Use 
at the Source
     Step 2: Identify All Available Retrofit Control Options
     Step 3: Eliminate All Technically Infeasible Control 
Options
     Step 4: Evaluate Control Effectiveness of Remaining 
Technologies
     Step 5: Evaluate the Energy and Non-Air Quality 
Environmental Impacts and Document Results \111\
---------------------------------------------------------------------------

    \111\ We note that, while ADEQ refers to its Step 5 as an 
evaluation of energy and non-air quality environmental impacts, this 
step also includes consideration of the costs of compliance and the 
remaining useful life of the source, consistent with the BART 
Guidelines, 40 CFR part 51, appendix Y, section IV.D.4.
---------------------------------------------------------------------------

     Step 6: Evaluate Visibility Impacts
     Step 7: Select BART

In the cases of the Hayden and Miami smelters, ADEQ performed a 
streamlined BART analysis in which it examined controls required by New 
Source Performance Standards (NSPS) and National Emission Standards for 
Hazardous Air Pollutants. In the case of PM10, ADEQ examined 
control requirements from NESHAP Maximum Achievable Control Technology 
(MACT) Subpart QQQ (Primary Copper Smelters) in its streamlined 
analysis. In the case of SO2, ADEQ examined control 
requirements from NSPS Subpart P (Primary Copper Smelters).
    EPA Evaluation: This seven step BART determination process was also 
used to determine BART for the Apache, Cholla, and Coronado. As noticed 
in the separate action addressing BART for these facilities, while we 
found that this overall approach to the five-factor analysis is 
generally reasonable and consistent with the RHR and the BART 
Guidelines, we identified certain areas of this approach that were not 
consistent with RHR and the BART Guidelines.\112\ This process was used 
for the BART determination for Catalyst Paper. However, as explained in 
further detail below, we are not proposing to take action on the 
facility's BART determinations at this time. As a result, we are not 
taking action to identify any areas of the BART determination process 
for Catalyst Paper that may not be consistent with RHR.
---------------------------------------------------------------------------

    \112\ 77 FR 42841.
---------------------------------------------------------------------------

    We propose to approve the use of a streamlined BART analysis for 
the copper smelters. The use of such a streamlined analysis is 
consistent with the RHR, which provides for streamlined analyses in 
certain instances when the affected source is subject to a MACT 
standard or other emission limitation required under the Clean Air Act. 
Our evaluation of the streamlined analyses and resulting determinations 
for the smelters are discussed in further detail below.

D. Arizona's BART Determinations

    A summary of the ADEQ's BART determinations is contained in Table 
13. Our evaluation of ADEQ's BART determinations is organized by 
source.

[[Page 75724]]

                                                   Table 13--Summary of Arizona's BART Determinations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 NOX                                PM10                               SO2
                                                --------------------------------------------------------------------------------------------------------
           Unit No.               Description                       Emission limit                      Emission limit                    Emission limit
                                                     Controls          lb/MMBtu          Controls          lb/MMBtu         Controls         lb/MMBtu
--------------------------------------------------------------------------------------------------------------------------------------------------------
Catalyt Paper, Unit 2........  1132 MMBtu/hr     No controls       0.7.............                 None                Partial FGD      0.80
                                Coal-fired        (existing).                                                            (existing).
                                Boiler.
Hayden Smelter...............  3 converters and                 None
                                2 anode
                                smelters.
                                              None
                                     Existing Controls--NSPS
Miami Smelter................  Electric                         None
                                furnace, 4
                                converters,
                                remelt/mold
                                pouring vessel.
                                    Existing Controls--NESHAP
                                     Existing Controls--NSPS
--------------------------------------------------------------------------------------------------------------------------------------------------------

 1. Catalyst Paper
    On July 30, 2012, Catalyst Paper publicly announced the permanent 
closure of the mill in Snowflake, which includes the Unit 2 power 
boiler.\113\ At present, however, Catalyst Paper has not yet canceled 
its operating permits and therefore still maintains the ability to 
operate the mill. For this reason, we are not proposing to take action 
on ADEQ's BART determinations for Catalyst Paper. Instead, we intend to 
require that Catalyst Paper notify us prior to resuming operation of 
mill, at which point we will review ADEQ's BART determination and, if 
necessary, propose a FIP in accordance with regional haze requirements, 
including the BART provisions in 40 CFR 51.308(e).
---------------------------------------------------------------------------

    \113\ http://catalystpaper.com/media/news/community/catalyst-permanently-close-snowflake-recycle-paper-mill.
---------------------------------------------------------------------------

2. Miami Smelter
    ADEQ's Analysis: For PM10, ADEQ performed a streamlined 
analysis in which it examined cost information and control requirements 
associated with NESHAP MACT Subpart QQQ (Primary Copper Smelters), 
which uses PM10 as a surrogate for certain particulate HAP 
emissions. ADEQ notes that there are currently three operating copper 
smelters: the Kennecott smelter in Utah, the ASARCO smelter in Hayden, 
Arizona, and the Freeport McMoRan Inc. smelter in Miami, Arizona, with 
the other previously operating facilities having been shut down or 
permanently dismantled. ADEQ noted that the Kennecott smelter was 
constructed in the mid-1990s and uses a flash copper converting 
technology that allows copper to be produced on a continuous basis. 
ADEQ determined that the Kennecott smelter is not comparable to the 
Miami smelter, which operates as batch process rather than as a 
continuous process. A review of EPA's RACT/BACT/LAER Clearinghouse 
(RBLC) revealed that there are no emission limitations or air pollution 
control devices that have been approved for anode furnace operations. 
As a result, ADEQ determined that the most stringent control available 
to control PM10 emissions from primary copper smelting are 
those required by NESHAP MACT Subpart QQQ.
    For SO2, ADEQ indicated it had performed a 
``streamlined'' BART determination in which it examined control 
requirements and emission standards associated with NSPS Subpart P 
(Primary Copper Smelters). Again, ADEQ noted that only three copper 
smelters are currently operating: the Kennecott smelter in Utah, the in 
Hayden smelter and the Miami smelter, with the other facilities having 
been shut down or permanently dismantled. Again, ADEQ also noted that 
the Kennecott smelter was constructed in the mid 1990s and uses a flash 
copper converting technology that allows copper to be produced on a 
continuous basis. ADEQ determined that the Kennecott smelter is not 
comparable to the ASARCO Hayden smelter, which operates as a batch 
process rather than as a continuous process. ADEQ reviewed EPA's RBLC 
and concluded that there are no emission limitations or air pollution 
control devices that have been required as BACT or LAER for anode 
furnace operations. Based only on this limited information, ADEQ's 
streamlined analysis found that the most stringent control available 
for SO2 emissions from primary copper smelting operations is 
the existing double contact acid plant and that compliance with NSPS 
Subpart P constitutes BART for SO2.
    EPA's Evaluation: We propose to approve ADEQ's BART determination 
for PM10 at the Miami smelter. As noted in the BART 
Guidelines, ``unless there are new technologies subsequent to the MACT 
standards which would lead to cost effective increases in the level of 
control, you may rely on the MACT standards for purposes of BART.'' 
\114\ Although MACT Subpart QQQ was promulgated more than 10 years 
ago,\115\ we have not identified any new control technologies for the 
Miami smelter that would achieve more stringent emission control. In 
addition, we consider ADEQ's exclusion of controls in place at the 
Kennecott smelter from consideration to be appropriate for purposes of 
BART.\116\ The BART Guidelines state that ``[w]e do not consider BART 
as a requirement to redesign the source when considering available 
control alternatives.'' \117\ Given the fundamental differences between 
operating a copper smelter (or any kind of manufacturing unit) as a 
batch process and a continuous process, we do not consider it 
appropriate to include this as a potential control option.
---------------------------------------------------------------------------

    \114\ 40 CFR part 51, appendix Y, section IV.C.
    \115\ 67 FR 40478 (June 12, 2002) (codified at 40 CFR part 63, 
subpart QQQ).
    \116\ This conclusion does not impact whether or not the level 
of control for Kennecott should be considered in a best available 
control technology analysis under the Act's prevention of 
significant deterioration program.
    \117\ 40 CFR part 51, appendix Y, section IV.D.5.
---------------------------------------------------------------------------

    At this time, we are proposing to disapprove ADEQ's SO2 
BART determination or, in the alternative, approve the SO2 
BART determination if we receive adequate additional information during 
the comment period to support the appropriateness of the streamlined 
analysis in the SIP and that the control requirements and emissions 
standards from NSPS Subpart P are enforceable at all units as BART. We 
agree with ADEQ that the Miami smelter is comparable only to the Hayden 
smelter. We also note that the Miami

[[Page 75725]]

smelter is operating the sulfuric acid plant at the facility as a 
control device rather than as a stand-alone facility.
    The BART Guidelines allow streamlined analyses that rely on 
emission standards established under other provisions of the CAA. For 
example, the BART Guidelines provide that generally states may rely on 
MACT standards for purposes of BART (70 FR 39164), but should consider 
other standards, such as the NSPS, only as starting points in 
streamlined analyses.\118\ When relying upon an NSPS in performing a 
streamlined analysis, the BART Guidelines indicate that additional 
analysis must be performed to determine if better control technology 
performance can be achieved since the promulgation of the NSPS. The 
BART Guidelines state ``where you are relying on these standards to 
represent a BART level of control, you should provide the public with a 
discussion of whether any new technologies have subsequently become 
available.''
---------------------------------------------------------------------------

    \118\ BART Guidelines, 40 CFR part 51, appendix Y, section 
IV.D.1, stating: ``[w]e do not believe that technology 
determinations from the 1970s or early 1980s, including new source 
performance standards (NSPS), should be considered to represent best 
control for existing sources, as best control levels for recent 
plant retrofits are more stringent than these older levels.''
---------------------------------------------------------------------------

    We are proposing to disapprove ADEQ's BART determination, in part, 
because ADEQ did not provide information demonstrating that NSPS 
Subpart P meets the requirements for a streamlined BART determination. 
At the time NSPS Subpart P was promulgated, the control technology 
known to be capable of meeting the SO2 standard was a 
sulfuric acid plant, which is the current control technology in place 
at the Miami smelter. ADEQ did not analyze whether the acid plant was 
operating at an optimal control level or if it could be retrofitted to 
operate at a lower emissions level. ADEQ identified the flash copper 
converting technology in place at the Kennecott smelter, but 
appropriately excluded it from consideration as a control option.\119\ 
However, we find that it was not reasonable for ADEQ to limit its 
analysis to those facilities that are specifically subject to the NSPS 
Subpart P, rather than considering emission levels that are being 
achieved at other acid plants.
---------------------------------------------------------------------------

    \119\ We consider ADEQ's decision to not consider this 
technology to be appropriate. The BART Guidelines state that ``[w]e 
do not consider BART as a requirement to redesign the source when 
considering available control alternatives.'' \119\ Given the 
fundamental differences between operating a copper smelter (or any 
kind of manufacturing unit) as a batch process and a continuous 
process, we do not consider it appropriate to include this as a 
potential control option. As a result, we conclude that in this 
instance, ADEQ's reliance on NSPS Subpart P in its streamlined 
analysis was appropriate.
---------------------------------------------------------------------------

    ADEQ's analysis did not examine whether acid plants in operation at 
a copper smelter (either at Miami or at Hayden) have demonstrated an 
ability to achieve, in practice, better levels of control since the 
promulgation of NSPS Subpart P. We note that multiple industries 
operate acid plants. An acid plant at a copper smelter, for example, 
uses the SO2 in process offgas to produce sulfuric acid 
product, whereas an acid plant at a stand-alone sulfuric acid plant, 
for example, may use SO2 from elemental sulfur and from 
spent sulfuric acid to produce sulfuric acid product. However, 
regardless of the source of the sulfur or the physical location of the 
plant, both facilities may be using the double contact acid plant 
process in which SO2 in the feed stream is converted to 
SO3 through double contact/double absorption converters. 
ADEQ has not provided any basis for limiting its examination of acid 
plant performance to only those acid plants operating at copper 
smelters.
    In addition, ADEQ does not specify whether its BART determination 
would require that all of the BART-subject gas streams at the Miami 
smelter meet all of the relevant control requirements and emissions 
standards in Subpart P. NSPS Subpart P provides that no owner or 
operator of an affected facility ``shall cause to be discharged into 
the atmosphere * * * any gases which contain sulfur dioxide in excess 
of 0.065 percent by volume.'' \120\ This requirement extends to all of 
the emissions released by the subject facilities, which include 
smelting furnaces and copper converters, and not just to those 
emissions that are vented to and controlled by an acid plant. To 
provide an adequate BART determination, ADEQ should include a finding 
about the amount of emissions being controlled by the acid plant and a 
clarification that the NSPS would apply to all emissions discharged 
from the BART-eligible units to the atmosphere.
---------------------------------------------------------------------------

    \120\ 40 CFR 60.163(a).
---------------------------------------------------------------------------

    Therefore, we are proposing to disapprove ADEQ's streamlined 
determination that SO2 BART is the existing double contact 
acid plant with the NSPS Subpart P emission standard of 650 ppm. We are 
disapproving this determination because ADEQ's streamlined analysis 
does not demonstrate that the NSPS Subpart P level of control 
represents the best level of control. We are also proposing to 
disapprove the BART determination because it does not require that all 
of the BART-eligible units meet the control requirements and emissions 
standards in NSPS Subpart P. Finally, we are proposing to disapprove 
the lack of enforceability and compliance requirements for this BART 
determination.
    In the alternative, we are proposing to approve ADEQ's 
determination that compliance with NSPS Subpart P constitutes BART for 
SO2 provided ADEQ or other commenters submit additional 
information demonstrating that the sulfuric acid plant cannot achieve a 
lower level of SO2 emissions. ADEQ's use of NSPS Subpart P 
in its streamlined analysis must be supported by additional information 
because, while the BART Guidelines provide that states generally may 
rely on MACT standards for purposes of BART, the same is not true for 
NSPS standards. NSPS standards may be outdated and may not represent 
current pollution control technology performance from acid plants 
operating at smelters and other industries.\121\ As a result, we 
propose to approve ADEQ's reliance on NSPS Subpart P in its streamlined 
analysis as a starting point provided we receive additional information 
showing the emission limit remains the most appropriate as BART, that 
the sulfuric acid plant cannot be operated cost-effectively at a lower 
level of SO2 emissions, and that all other SO2 
emissions from the BART-eligible units meet BART. Commenters should not 
rely solely on the information regarding copper smelters in the RBLC 
but should include information from other acid gas plants.
---------------------------------------------------------------------------

    \121\ BART Guidelines, 40 CFR part 51, appendix Y, section 
IV.D.1, n. 13, stating: ``EPA no longer concludes that the NSPS 
level of controls automatically represents `the best these sources 
can install.' ''
---------------------------------------------------------------------------

    Finally, Regional Haze SIPs must include requirements to ensure 
that BART emission limits are enforceable. In particular, the RHR 
requires inclusion of (1) A schedule for compliance with BART emission 
limitations for each source subject to BART; (2) a requirement for each 
BART source to maintain the relevant control equipment and (3) 
procedures to ensure control equipment is properly operated and 
maintained.\122\ General SIP requirements also mandate that the SIP 
include all regulatory requirements related to monitoring, 
recordkeeping and reporting for the BART emissions limitations.\123\ 
ADEQ did not provide any explanation of how the Arizona SIP addresses 
these requirements for the

[[Page 75726]]

Miami smelter.\124\ Therefore, we can fully approve ADEQ's BART 
determinations for this source only if they are accompanied by adequate 
compliance requirements, including a clearly defined scope for the 
applicable BART requirements, compliance deadlines, operation and 
maintenance procedures, and monitoring, recordkeeping and reporting 
requirements for all of the BART-eligible units.\125\
---------------------------------------------------------------------------

    \122\ 40 CFR 51.308(e)(1)(iv), (v).
    \123\ See, e.g. CAA section 110(a)(2)(F) and 40 CFR 51.212(c).
    \124\ NSPS Subpart P includes some provisions concerning 
monitoring, recordkeeping and reporting but ADEQ did not indicate 
whether its BART determination would require compliance with these 
provisions. EPA is also aware that the Arizona SIP currently 
includes R18-2-175. Standards of Performance for Existing Primary 
Copper Smelters; Site Specific Requirements. This SIP-approved rule 
contains requirements for the Miami smelter, including enforcement 
and compliance provisions. ADEQ did not demonstrate that compliance 
with this rule would constitute BART for the Miami smelter.
    \125\ We also note that our proposed approval, in the 
alternative, for regional haze requirements purposes should not be 
taken as a statement regarding the acceptability of this level of 
SO2 emissions at this facility or as an indication of the 
facility's compliance with other regulatory requirements. In 
addition, we wish to clarify that if we receive additional 
information adequate to finalize our proposed approval for BART for 
SO2, the BART determination does not foreclose a more 
stringent BACT limitation should this source be required to obtain a 
PSD permit in the future for any reason.
---------------------------------------------------------------------------

3. Hayden Smelter
    ADEQ's Analysis: For SO2, ADEQ identified some existing 
control technologies (i.e., primary and secondary hooding, double 
contact acid plant) currently installed and operating for the units 
that comprise the BART-subject source at the Hayden smelter. ADEQ 
indicated it had performed a ``streamlined'' BART determination in 
which it examined control requirements and emission standards 
associated with NSPS Subpart P (Primary Copper Smelters). ADEQ noted 
that only three primary copper smelting facilities are currently 
operating: the Kennecott smelter in Utah, the ASARCO smelter in Hayden, 
Arizona, and the Freeport McMoRan Inc. smelter in Miami, Arizona. In 
addition, ADEQ also noted that the Kennecott smelter was constructed in 
the mid 1990s and uses a flash copper converting technology that allows 
copper to be produced on a continuous basis. ADEQ determined the 
Kennecott smelter was not comparable to the Hayden smelter, which 
operates a batch process rather than a continuous process. ADEQ 
reviewed EPA's RBLC and concluded that there are no emission 
limitations or air pollution control devices that have been required as 
BACT or LAER for anode furnace operations. Based only on this limited 
information, ADEQ's streamlined analysis found that the most stringent 
control available for SO2 emissions from primary copper 
smelting operations is the existing double contact acid plant and that 
compliance with NSPS Subpart P constitutes BART for SO2.
    EPA's Evaluation: At this time, we are proposing to disapprove 
ADEQ's BART determination or, in the alternative, to approve the BART 
determination, if we receive adequate additional information and 
analysis during the comment period to support the appropriateness of 
the streamlined analysis in the SIP. We are also proposing to 
disapprove the lack of compliance requirements, including a compliance 
deadline, operation and maintenance requirements, and monitoring, 
recordkeeping and reporting requirements sufficient to ensure that the 
BART requirements are enforceable at all units. We agree with ADEQ that 
the Hayden smelter is comparable only to the Miami smelter. We also 
note that the Hayden smelter is operating the sulfuric acid plant at 
the facility as a control device rather than a stand-alone facility.
    The BART Guidelines allow streamlined analyses that rely on 
emission standards established under other provisions of the CAA. For 
example, the BART Guidelines provide that generally states may rely on 
MACT standards for purposes of BART (70 FR 39164), but should consider 
other standards, such as the NSPS, only as starting points in 
streamlined analyses.\126\ When relying upon an NSPS in performing a 
streamlined analysis, the BART Guidelines indicate that additional 
analysis must be performed to determine if better control technology 
performance can be achieved since the promulgation of the NSPS. The 
BART Guidelines state ``where you are relying on these standards to 
represent a BART level of control, you should provide the public with a 
discussion of whether any new technologies have subsequently become 
available.''
---------------------------------------------------------------------------

    \126\ BART Guidelines, 40 CFR part 51, appendix Y, section 
IV.D.1, stating: ``[w]e do not believe that technology 
determinations from the 1970s or early 1980s, including new source 
performance standards (NSPS), should be considered to represent best 
control for existing sources, as best control levels for recent 
plant retrofits are more stringent than these older levels.''
---------------------------------------------------------------------------

    We are proposing to disapprove ADEQ's BART determination, in part, 
because ADEQ did not provide information demonstrating that NSPS 
Subpart P meets the requirements for a streamlined BART determination. 
At the time NSPS Subpart P was promulgated, the control technology 
known to be capable of meeting the SO2 NSPS was an acid 
plant, which is the current control technology in place at the Hayden 
smelter.\127\ ADEQ did not analyze whether the acid plant was operating 
at an optimal control level or if it could be retrofitted to operate at 
a lower emissions level. ADEQ identified the flash copper converting 
technology in place at the Kennecott smelter, but appropriately 
excluded it from consideration as a control option.\128\ However, we 
find that it was not reasonable for ADEQ to limit its analysis to those 
facilities that are specifically subject to the NSPS Subpart P, rather 
than considering emission levels that are being achieved at other acid 
plants. In addition, ADEQ's analysis did not examine whether acid 
plants in operation at a copper smelter (either at Hayden or at Miami) 
have demonstrated an ability to achieve, in practice, better levels of 
control since the promulgation of NSPS Subpart P. We note that multiple 
industries operate acid plants. An acid plant at a copper smelter, for 
example, uses the SO2 in process offgas to produce sulfuric 
acid product, whereas an acid plant at a stand-alone sulfuric acid 
plant, for example, may use SO2 from elemental sulfur and 
from spent sulfuric acid to produce sulfuric acid product. However, 
regardless of the source of the sulfur or the physical location of the 
plant, both facilities may be using the double contact acid plant 
process in which SO2 in the feed stream is converted to 
SO3 through double contact/double absorption converters. 
ADEQ has not provided any basis for limiting its examination of acid 
plant performance to only those acid plants operating at copper 
smelters.
---------------------------------------------------------------------------

    \127\ Specifically, ASARCO currently operates a double contact 
acid plant, which replaced the original single contact acid plant in 
1983.
    \128\ We consider ADEQ's decision to not consider this 
technology to be appropriate. The BART Guidelines state that ``[w]e 
do not consider BART as a requirement to redesign the source when 
considering available control alternatives.'' Given the fundamental 
differences between operating a copper smelter (or any kind of 
manufacturing unit) as a batch process and a continuous process, we 
do not consider it appropriate to include this as a potential 
control option. As a result, we conclude that in this instance, 
ADEQ's reliance on NSPS Subpart P in its streamlined analysis was 
appropriate.
---------------------------------------------------------------------------

    In addition, ADEQ does not specify whether its BART determination 
would require that all of the BART-subject gas streams at the Hayden 
smelter meet all of the relevant control requirements and emissions 
standards in Subpart P. NSPS Subpart P provides that no owner or 
operator of an affected facility ``shall cause to be discharged into 
the atmosphere * * * any gases which contain sulfur dioxide in excess 
of 0.065

[[Page 75727]]

percent by volume.'' \129\ This requirement extends to all of the 
emissions released by the subject facilities and not just to those 
emissions that are vented to and controlled by an acid plant. To 
provide an adequate BART determination, ADEQ should include a finding 
about the amount of emissions being controlled by the acid plant and a 
clarification that the NSPS would apply to all emissions discharged 
from the BART-subject units to the atmosphere.
---------------------------------------------------------------------------

    \129\ 40 CFR 60.163(a).
---------------------------------------------------------------------------

    Finally, Regional Haze SIPs must include requirements to ensure 
that BART emission limits are enforceable. In particular, the RHR 
requires inclusion of (1) A schedule for compliance with BART emission 
limitations for each source subject to BART; (2) a requirement for each 
BART source to maintain the relevant control equipment and (3) 
procedures to ensure control equipment is properly operated and 
maintained.\130\ General SIP requirements also mandate that the SIP 
include all regulatory requirements related to monitoring, 
recordkeeping and reporting for the BART emissions limitations.\131\ 
ADEQ did not provide any explanation of how the Arizona SIP addresses 
these requirements for the Hayden smelter.\132\
---------------------------------------------------------------------------

    \130\ 40 CFR 51.308(e)(1)(iv), (v).
    \131\ See, e.g. CAA section 110(a)(2)(F) and 40 CFR 51.212(c).
    \132\ NSPS Subpart P includes some provisions concerning 
monitoring, recordkeeping and reporting but ADEQ did not indicate 
whether its BART determination would require compliance with these 
provisions. Additionally, ADEQ did not specify when any BART-
eligible units not currently subject to NSPS Subpart P at the Hayden 
Smelter would be required to comply with its control requirements 
and emissions standards. EPA is also aware that the Arizona SIP 
currently includes R18-2-175. Standards of Performance for Existing 
Primary Copper Smelters; Site Specific Requirements. This SIP-
approved rule contains requirements for the Miami smelter, including 
enforcement and compliance provisions. ADEQ did not demonstrate that 
compliance with this rule would constitute BART for the Hayden 
smelter.
---------------------------------------------------------------------------

    Therefore, we are proposing to disapprove ADEQ's streamlined 
determination that SO2 BART is the existing double contact 
acid plant with the NSPS Subpart P emission standard of 650 ppm. We are 
disapproving this determination because ADEQ's streamlined analysis 
does not demonstrate that the NSPS Subpart P level of control 
represents the best level of control. We are also proposing to 
disapprove the BART determination because it does not require that all 
of the BART-eligible units meet the control requirements and emissions 
standards in NSPS Subpart P. Finally, we are proposing to disapprove 
the lack of enforceability and compliance requirements for this BART 
determination.
    In the alternative, we are proposing to approve ADEQ's 
determination that compliance with NSPS Subpart P constitutes BART for 
SO2, provided ADEQ or other commenters submit additional 
information demonstrating that the sulfuric acid plant cannot achieve a 
lower level of SO2 emissions. ADEQ's use of NSPS Subpart P 
in its streamlined analysis must be supported by additional information 
because, while the BART Guidelines provide that states generally may 
rely on MACT standards for purposes of BART, the same is not true for 
NSPS standards. NSPS standards may be outdated and may not represent 
current pollution control technology performance from acid plants 
operating at smelters and other industries.\133\ As a result, we 
propose to approve ADEQ's reliance on NSPS Subpart P in its streamlined 
analysis as a starting point, provided we receive additional 
information showing the emission limit remains the most appropriate as 
BART, that the sulfuric acid plant cannot be operated cost-effectively 
at a lower level of SO2 emissions, and that all other 
SO2 emissions from the BART-eligible units meet BART. 
Commenters should not rely solely on the information regarding copper 
smelters in the RBLC but should include information from other acid gas 
plants.
---------------------------------------------------------------------------

    \133\ BART Guidelines, 40 CFR part 51, appendix Y, section 
IV.D.1, n. 13, stating: ``EPA no longer concludes that the NSPS 
level of controls automatically represents `the best these sources 
can install.' ''
---------------------------------------------------------------------------

    Finally, we can fully approve ADEQ's BART determination for this 
source only if ADEQ also submits adequate compliance requirements, 
including a clearly defined scope for the applicable NSPS requirements, 
compliance deadlines, operation and maintenance procedures, and 
monitoring, recordkeeping and reporting requirements.\134\
---------------------------------------------------------------------------

    \134\ We also note that our proposed approval, in the 
alternative, for regional haze requirements purposes should not be 
taken as a statement regarding the acceptability of this level of 
SO2 emissions at this facility or as an indication of the 
facility's compliance with other regulatory requirements. In 
addition, we wish to clarify that if we receive additional 
information adequate to finalize our proposed approval for BART for 
SO2, the BART determination does not foreclose a more 
stringent BACT limitation should this source be required to obtain a 
PSD permit in the future for any reason. Also, EPA is currently 
investigating the compliance status of this facility for other 
provisions of the CAA.
---------------------------------------------------------------------------

VIII. EPA's Evaluation of Arizona's Reasonable Progress Goals

 A. Reasonable Progress Goals for the Best Days

    The RHR requires that the RPGs ensure that there is no degradation 
on the best 20 percent of days.\135\ The projected visibility levels 
for 2018 (shown in Table 5) raise some concerns about some of the Class 
I areas on the best days. The Class I areas represented by CHIR1 are 
projected to have an increase in visibility impairment of 0.03 dv. 
Saguaro NP--East Unit (SAGU1) is projected to have an increase of 0.10 
dv.
---------------------------------------------------------------------------

    \135\ 40 CFR 51.308(d)(1).
---------------------------------------------------------------------------

    The species-specific results of the 2018 projections provide more 
details about what the computer model shows to be the driver of the 
apparent increase in degradation at these two monitors. Table 14 
provides this data.
---------------------------------------------------------------------------

    \136\ Source: WRAP TSS, http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx, Best 20% of days, (plan02d--rev and 
prp18b).

 Table 14--Pollutant-Specific Contribution to Visibility Impairment on the Best 20 Percent of Days at CHIR1 and
                                                   SAGU1 \136\
----------------------------------------------------------------------------------------------------------------
                                                         CHIR1                               SAGU1
                                         -----------------------------------------------------------------------
                                              2000-2004                           2000-2004
                Pollutant                     baseline       2018 projected       baseline       2018 projected
                                           conditions [Mm-   conditions [Mm-   conditions [Mm-   conditions [Mm-
                                                 1]                1]                1]                1]
----------------------------------------------------------------------------------------------------------------
Sulfate.................................              2.28              2.29              2.67              2.65
Nitrate.................................              0.53              0.49              0.99              1.04
Organic Carbon..........................              1.40              1.41              2.18              2.30
Elemental Carbon........................              0.67              0.57              1.27              0.88
Fine Soil...............................              0.33              0.44              1.10              1.77

[[Page 75728]]

 
Coarse Material.........................              1.22   \137\ No change              1.83         No change
Sea Salt................................              0.01         No change              0.11         No change
----------------------------------------------------------------------------------------------------------------

    At both CHIR1 and SAGU1, the increase in visibility impairment is 
caused primarily by the projected increase in impairment due to fine 
soil.
---------------------------------------------------------------------------

    \137\ WRAP elected to hold the coarse mass and sea salt 
visibility impairment levels constant.
---------------------------------------------------------------------------

    The monitoring data trends are not consistent with what the model 
is projecting. As shown in the Arizona IMPROVE trend analysis conducted 
by EPA,\138\ the monitors representing these areas showed the greatest 
improvement in visibility on the worst days when one compares monitored 
data in 2005-2010 to monitored data in the base period of 2000-2004. 
Significantly, there is no indication of increased impairment due to 
fine soil. Given these facts, and the relatively small amount of 
projected degradation, EPA is not overly concerned with the model 
results.
---------------------------------------------------------------------------

    \138\ See Table 5 of EPA Analysis of IMPROVE Monitoring Data 
From 2000-2010 in the docket.
---------------------------------------------------------------------------

    However, these projected visibility conditions on the 20 percent 
least impaired days do not account for benefits from EPA's BART 
determinations for Apache, Cholla and Coronado.\139\ EPA expects the 
visibility on the least impaired days to be better than projected in 
the ARHP. Therefore, we propose disapproval of the RPGs for the 20 
percent best days.
---------------------------------------------------------------------------

    \139\ 77 FR 72512.
---------------------------------------------------------------------------

 B. Reasonable Progress Goals for the Worst Days

    Because Arizona's RPG estimates provide for a rate of improvement 
in visibility slower than the rate needed to show attainment of natural 
conditions by 2064, the RHR requires the state to demonstrate why its 
RPGs are reasonable and why a rate of progress leading to attainment of 
natural visibility conditions by 2064 is not reasonable.\140\ The RHR 
specifies that RPGs, as well as the demonstration of the reasonableness 
of attainment beyond 2064, are to be established and evaluated taking 
into consideration four factors: costs of compliance; time necessary 
for compliance; energy and non-air quality environmental impacts of 
compliance; and remaining useful life of any potentially affected 
sources.\141\ As explained below, we propose to find that the State did 
not conduct an adequate analysis of these four factors. However, based 
on our supplementary analysis, we have come to the same conclusion as 
Arizona for some visibility impairing pollutants.
---------------------------------------------------------------------------

    \140\ The RHR also requires that the state provide to the public 
an assessment of the number of years it will take to reach natural 
visibility conditions. 40 CFR 51.308(d)(1)(ii). Arizona's estimates 
were included in its proposed SIP, which was provided to the public 
during the public review and comment process prior to ADEQ's 
adoption of the ARHP.
    \141\ 40 CFR 51.308(d)(1)(i)(A); 51.308(d)(1)(ii).
---------------------------------------------------------------------------

    Focus on NOX and SO2: The State elected to focus its reasonable 
progress analysis on NOX and SO2. EPA concurs 
that these are the primary pollutants of concern. EPA also concurs that 
it is not appropriate to focus on primary organic aerosols or sources 
of VOC emissions at this time. The WRAP emissions inventories 
demonstrate that the vast majority of these emissions are not 
controllable by the State. However, we disagree with the state's 
decision to exclude coarse mass and fine soil from their reasonable 
progress analysis. According to the State's own analysis, 57 percent of 
coarse mass emissions and 60 percent of fine soil emissions in 2002 
were anthropogenic.\142\ We propose to disapprove the State's finding 
that it was not reasonable to require additional reductions of coarse 
mass or fine soil emissions, given that the State did not conduct an 
analysis for these pollutants, given that they contribute significantly 
to visibility impairment and are mostly from anthropogenic sources.
---------------------------------------------------------------------------

    \142\ Tables 8.5 and 8.6 of the ARHP.
---------------------------------------------------------------------------

    Mobile Sources: Emissions of SO2, NOX and VOC 
from on-road and off-road mobile sources are projected to drop 
significantly over the planning period (2002-2018). This is due to the 
impact of EPA requirements for cleaner vehicles and cleaner fuels.\143\ 
Given these large reductions in emissions of these pollutants, we 
propose to approve the State's decision to not consider further control 
measures for SO2, NOX and VOC from mobile 
sources.
---------------------------------------------------------------------------

    \143\ See ARHP page 173.
---------------------------------------------------------------------------

    Fires: EPA proposes to agree with the State that emissions from 
fires should not be considered for further controls in the reasonable 
progress analysis. Efforts to reduce visibility impacts from fires are 
appropriately addressed by the smoke management plans, rather than in a 
reasonable progress analysis. EPA's analysis of the smoke management 
plans may be found in our evaluation of the State's Long Term Strategy 
in Section IX of this plan.
    Area Sources: The State did not complete an adequate analysis of 
the potential for reasonable controls from area sources of 
NOX and SO2. While a number of source categories 
are listed in Chapter 11 of the ARHP, in the case of area sources, the 
state typically judged that it was too resource intensive to conduct 
the analysis. Given the lack of supporting analysis, the EPA proposes 
to disapprove the State's finding that there are no reasonable controls 
for NOX or SO2 on area sources.
    Point Sources of SO2: The vast majority of 
SO2 emissions in Arizona are from point sources.\144\ 
Therefore, this is the most important source category to consider for 
this pollutant. Over 99 of percent point source SO2 
emissions in Arizona are from 10 stationary sources. These sources are 
shown in Table 15. Some of these facilities are subject to BART (noted 
below). For the others, the State did not adequately consider the 
possibility of additional controls, so EPA conducted its own analysis.
---------------------------------------------------------------------------

    \144\ Table 8.1 of the ARHP.

[[Page 75729]]

            Table 15--Largest Sources of SO2 in Arizona \145\
------------------------------------------------------------------------
                                                        SO2 emissions in
                        Source                           2002 (tons per
                                                             year)
------------------------------------------------------------------------
Cholla Power Plant...................................             20,770
Tucson Electric Power Springerville..................             19,862
Hayden Smelter.......................................             18,439
Coronado Generating Station..........................             17,741
Miami Smelter........................................              5,667
Apache Generating Station............................              5,167
Sundt Generating Station.............................              3,119
Catalyst Paper Mill..................................              1,519
Nelson Lime Plant....................................                893
Douglas Lime Plant...................................                755
------------------------------------------------------------------------

    The sources that ADEQ found subject to BART are described in 
Section VII of this notice. These are: Cholla (Units 2-4 only), Hayden 
smelter, Coronado, Miami smelter, Apache plant (Units 1-3 only), and 
the Catalyst Paper. EPA is proposing to find that the Sundt Generating 
Station Unit 4 is BART-eligible and the Nelson Lime Plant is also 
subject to BART.\146\ Therefore, EPA's reasonable progress analysis 
will focus on those remaining sources and units that we expect to emit 
significant quantities of SO2: TEP Springerville, Sundt 
Units 1-3, and the Douglas Lime Plant.\147\ For each source, we have 
evaluated each of the four statutory reasonable progress factors. In 
addition, where we found that there were additional potentially cost-
effective controls available (using an initial screening level of 
$5,000/ton), we conducted visibility modeling to assess the potential 
benefits of those controls.\148\ These analyses are set forth in Tables 
16A-16C below.
---------------------------------------------------------------------------

    \145\ Source: WRAP 2002 Arizona Point Source Emissions.
    \146\ If EPA determines that the Nelson Lime Plant is not 
subject-to-BART, we will evaluate it for cost effective 
SO2 controls for reasonable progress.
    \147\ We have not considered potential SO2 controls 
at Cholla Unit 1 and Apache Unit 4, since these units have 
relatively low SO2 emissions. Cholla Unit 1 currently 
uses lime injection to remove at least 80 percent of SO2 
as a result of New Source Review (Installation Permit 1247) 
and Apache Unit 4 may only be operated on pipeline quality natural 
gas, except during periods of gas curtailment not to exceed 600 
hours per year (title V operating permit 35043). These 
permits can be accessed at http://www.azdeq.gov/environ/air/permits/title_v/index.html.
    \148\ While visibility is not an explicitly listed factor to 
consider when determining whether additional controls are 
reasonable, the point of additional controls is to make reasonable 
progress toward natural visibility conditions. Therefore, the 
projected visibility benefit of the controls should be taken into 
account when determining if the controls are needed to make 
reasonable progress.
    \149\ See ``Springerville FGD costs.xls'' for a summary of 
preliminary cost estimates.
    \150\ Source: WRAP 2002 Arizona Point Source Emissions.

                Table 16A--SO2 Reasonable Progress Analysis for TEP Springerville (Units 1 and 2)
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  These coal-fired units are already equipped with dry flue gas
                                               desulfurization (FGD) units. Therefore, they are already well
                                               controlled for SO2. While it is possible to remove the dry FGD
                                               units and replace them with more effective wet FDG units, we
                                               estimate the incremental cost effectiveness of such an effort to
                                               be approximately $17,000 to $22,000/ton, which is a range of
                                               values that we do not consider cost effective.\149\
Time Necessary for Compliance...............  Any new control device would need to be installed by 2018. There
                                               would be sufficient time to comply.
Energy and Non-Air Quality Environmental      A wet FGD would require more energy than the existing dry FGD. In
 Impacts of Compliance.                        addition, it would create a new water waste stream at the
                                               facility.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given that the facility is already well controlled, EPA proposes
                                               to find that it is not reasonable to require more stringent SO2
                                               controls on this facility at this time.
----------------------------------------------------------------------------------------------------------------

                         Table 16B--SO2 Reasonable Progress Analysis for Sundt Units 1-3
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  These units are all fired with pipeline-quality natural gas. Their
                                               SO2 emissions are low and will remain low. 99.9 percent of the
                                               SO2 emissions from this facility are from Unit 4.\150\ Given the
                                               very low emission rates from these units--there are no cost-
                                               effective controls.
Time Necessary for Compliance...............  Any new control device would need to be installed by 2018. There
                                               would be sufficient time to comply.
Energy and Non-Air Quality Environmental      Any post-combustion control, such as FGD would reduce the
 Impacts of Compliance.                        thermodynamic efficiency of the plant and increase fuel
                                               consumption.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given that the low SO2 emissions from this non-BART units at this
                                               facility, EPA proposes to find that it is not reasonable to
                                               require more stringent SO2 controls on this facility at this
                                               time.
----------------------------------------------------------------------------------------------------------------

                       Table 16C--SO2 Reasonable Progress Analysis for Douglas Lime Plant
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  Emissions inventory data indicates that production at the Douglas
                                               Lime Plant essentially stopped during the recession. SO2
                                               emissions from the facility were 1,013 tpy in 2008, 42 tpy in
                                               2009 and 0 tpy in 2010. Given the lack of emissions from the
                                               plant, EPA proposes to find that requiring controls would not be
                                               reasonable at this time.
Time Necessary for Compliance...............  Any controls would need to be installed by 2018. There is adequate
                                               time to install controls.
Energy and Non-Air Quality Environmental      A wet FGD would increase energy consumption at the plant and would
 Impacts of Compliance.                        create a new waste water stream.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given the current lack of SO2 emissions, EPA proposes to find that
                                               it is not reasonable to require additional controls on this plant
                                               at this time. This plant should be considered for SO2 controls in
                                               future planning periods, as it may return to its previous levels
                                               of emissions.
----------------------------------------------------------------------------------------------------------------

[[Page 75730]]

    Based on our supplemental analyses provided in the tables above, 
EPA proposes to approve ADEQ's conclusion that it is not reasonable to 
require additional SO2 controls on non-BART sources at this 
time.
    Point Sources of NOX: The State's analysis of point sources to 
justify its RPGs did not provide sufficient supporting information to 
demonstrate the requirements of the RHR have been met. For example, the 
State's analysis of internal combustion engines and combustion turbines 
stated that ``the Department has determined that it is not possible to 
complete a four-factor analysis without a major investment of resources 
* * * which is beyond the scope and effort required in this first 
Regional Haze SIP and therefore no further analysis was conducted.'' 
Similarly, with respect to cement kilns, the ARHP contends that the 
Rillito Cement Plant does not ``appreciably diminish or impair 
visibility'', but the plan does not provide technical documentation of 
that assertion. Given the slow rate of visibility improvement on the 
worst days at all Class I areas, a thorough analysis is required before 
concluding that nothing more can be done to improve visibility. 
Therefore, EPA proposes to disapprove the State's finding that it is 
not reasonable to require additional NOX controls on non-
BART point sources in Arizona.

C. Summary of EPA's Evaluation

    EPA proposes to find that State did not demonstrate that its RPGs 
for the worst 20 percent of days in 2018 constitute reasonable progress 
toward the goal of natural visibility impairment by 2064. Specifically, 
EPA proposes to find that the State did not perform an adequate 
analysis for reasonable controls for fine soil and coarse mass. EPA 
furthermore proposes to find that the State did not perform an adequate 
analysis justifying its decision that it is not reasonable to require 
additional NOX controls on non-BART point sources. Based on 
these shortcomings, EPA proposes to disapprove the State's RPGs for the 
worst 20 percent days at all Class I Areas in the state.
    EPA also proposes to disapprove the State's RPGs for the best 20 
percent of days. We expect that visibility on these days will be better 
than the State projects, given additional controls required by the EPA.

IX. EPA's Evaluation of Arizona's Long-term Strategy

    Under section 51.308(d)(3) of the RHR, Arizona must include a 10 to 
15-year long-term strategy (LTS) as part of its regional haze plan 
(RHP). Arizona's LTS should compile all control measures the State will 
use through 2018 to meet the regional haze plan's RPGs, including BART 
required by the RHR. 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 Arizona.\151\ There are five general 
requirements for Arizona's LTS. The first general requirement concerns 
the interstate consultation process.\152\ The second concerns allotted 
emission reductions for out-of-state Class I areas.\153\ A third and 
related requirement concerns documenting the technical basis for 
determining the apportionment of emission reduction obligations needed 
for reasonable progress in reducing visibility impairment in the 
State's affected Class I areas.\154\ The fourth general requirement is 
to identify anthropogenic emissions sources causing visibility 
impairment considered by the State in developing its RHP.\155\ Finally, 
the fifth general requirement is for the State to consider the 
following factors within the LTS:
---------------------------------------------------------------------------

    \151\ See 40 CFR 51.308(d)(3).
    \152\ See 40 CFR 51.308(d)(3)(i).
    \153\ See 40 CFR 51.308(d)(3)(ii).
    \154\ See 40 CFR 51.308(d)(3)(iii).
    \155\ See 40 CFR 51.308(d) (iv).

    (A) Emission reductions due to ongoing air pollution control 
programs, including measures to address reasonably attributable 
visibility impairment;
    (B) Measures to mitigate the impacts of construction activities;
    (C) Emissions limitations and schedules for compliance to 
achieve the reasonable progress goal;
    (D) Source retirement and replacement schedules;
    (E) Smoke management techniques for agricultural and forestry 
management purposes including plans as currently exist within the 
State for these purposes;
    (F) Enforceability of emissions limitations and control 
measures; and
    (G) The anticipated net effect on visibility due to projected 
changes in point, area, and mobile source emissions over the period 
addressed by the long-term strategy.\156\
---------------------------------------------------------------------------

    \156\ See 40 CFR 51.308(d)(3)(v).

    We have reviewed Arizona's LTS against these five general 
requirements.

 A. Interstate Consultation on Emission Management Strategies

    Under 40 CFR 51.308(d)(3)(i), Arizona is required to consult with 
another state if Arizona's emissions are reasonably anticipated to 
contribute to visibility impairment at that state's Class I area and 
must consult with other states, if emissions from those other states 
are reasonably anticipated to contribute to visibility impairment Class 
I areas in Arizona. To meet these regulatory requirements for 
interstate consultation and coordination, Arizona consulted with other 
states and tribes using the WRAP forums and processes. In particular, 
Arizona consulted with California, Colorado, New Mexico, and Utah using 
the primary vehicle of the WRAP Implementation Work Group (IWG). 
Arizona describes their WRAP participation in Chapters 2, 12.2, 13.2, 
and Appendix C of the RHP.
    While Nevada was not a formal member of the WRAP and was not listed 
with WRAP member states in Arizona's discussion of interstate 
consultation, we note that Nevada did participate in WRAP workgroups 
and utilized WRAP technical analyses and source apportionment modeling 
in producing the Nevada RHP. Nevada used the WRAP's source 
apportionment modeling to demonstrate Nevada's minimal contribution of 
the State's sulfate and nitrate emissions to light extinction at 25 
Class I areas in Nevada's five neighboring states. Based on 
consultation through the WRAP, Nevada identified no major contributions 
that supported developing new interstate strategies, mitigation 
measures, or emissions reduction obligations.\157\
---------------------------------------------------------------------------

    \157\ For our review and discussion of the Nevada RHP and 
approval of Nevada's consultation procedures, see our proposed rule 
at 76 FR 36450, (June 22, 2011) and our final rule at 77 FR 17334, 
(March 26, 2012).
---------------------------------------------------------------------------

    In addition to participating with WRAP member states and Nevada in 
the WRAP forums and using WRAP analytical tools and procedures, Arizona 
provided a 30 day public comment period and a public hearing on 
December 2, 2010 to receive oral and written comments on its proposed 
RHP. No other states submitted oral or written comments or requested 
additional consultation during Arizona's public review process, 
including Nevada. See Appendix E of the RHP for the public hearing 
transcript and submitted written comments.

B. Measures To Obtain Allotted Emissions Reductions

    Pursuant to 40 CFR 51.308(d)(3)(ii), Arizona is required to 
demonstrate, where its emissions cause or contribute to impairment in 
another state's Class I area, that it has included in its RHP all 
measures needed to obtain its share of the emission reductions for 
meeting the progress goal for that state's Class I area. Also, since 
Arizona participated in a regional planning process through the WRAP, 
Arizona is required to include in

[[Page 75731]]

the LTS all measures needed to achieve its allotment of emission 
reductions agreed upon through the WRAP process.\158\
---------------------------------------------------------------------------

    \158\ 40 CFR 51.308(d)(3)(ii).
---------------------------------------------------------------------------

    Arizona's LTS for the first implementation period addresses the 
emissions reductions from federal, state, and local controls that take 
effect in the State from the end of the baseline period starting in 
2002 through 2018.\159\ Coordinating with the WRAP, ADEQ developed its 
LTS using the following components: WRAP emission inventories for a 
2002 baseline and a 2018 projection (including emission reductions from 
WRAP member states); controls required or expected under federal and 
state regulations and BART; modeling to determine visibility 
improvement and apportion individual state contributions; state 
consultation; and application of the long-term strategy factors. 
Arizona accepted and incorporated the WRAP-developed visibility 
modeling within the ARHP. However, as explained above, we have 
disapproved the State's BART determinations for NOX at the 
following units: Apache Units 2 and 3; Cholla Units 2, 3, and 4; 
Coronado Units 1 and 2.\160\ In addition, as described in section VII 
of this document, we are proposing to disapprove certain elements of 
the state's BART determinations at other sources. Accordingly, the LTS, 
as approved into the applicable Arizona SIP, will not include all of 
the emissions reductions that were assumed in the WRAP-developed 
visibility modeling. Accordingly, Arizona's LTS does not include all 
measures needed to achieve its allotment of emission reductions agreed 
upon through the WRAP process. Therefore, we propose to determine that 
the LTS does not meet the requirements of 40 CFR 51.308(d)(3)(ii).
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    \159\ See the ARHP at page 201 for examples of federal and state 
programs providing emission reductions; e.g., federal low sulfur 
diesel fuel requirement and the Arizona vehicle emissions inspection 
program (AVEIP). For our approval of the AVEIP into the Arizona SIP, 
see 68 FR 2912; (January 22, 2003). Later in this review, we discuss 
several other state and local regulations that have been approved 
into the SIP.
    \160\ See our proposed rule at 77 FR 42834, (July 20, 2012) and 
our final rule at 77 FR 72512, (December 5, 2012) which addressed 
these units.
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C. Technical Basis for Apportionment of Emission Reductions

    Pursuant to 40 CFR 51.308(d)(3)(iii), Arizona is required to 
document the technical basis that it relied upon to determine its share 
of emission reduction obligations needed to achieve reasonable progress 
in each mandatory Class I Federal area it affects, including modeling, 
monitoring, and emissions information. The State may meet this 
requirement by relying on technical analyses developed by the WRAP and 
approved by all State participants. Arizona must also identify the 
baseline emissions inventory on which its strategies are based.
    To meet these requirements, Arizona relied on several WRAP data and 
analytical systems and technical centers, such as the Technical Support 
System, the Regional Modeling Center, the Visibility Information 
Exchange Web System, the Causes of Haze Assessment Project, and the 
Emission Data Management System. Arizona provided a general overview of 
the WRAP policy and technical assistance in Chapter 12.2 and more 
specific and detailed documentation in Appendix C of the ARHP. 
Specifically, to determine the significant sources contributing to haze 
in Arizona's Class I areas, Arizona relied upon two source 
apportionment analysis techniques developed by the WRAP. The first 
technique was regional modeling using the Comprehensive Air Quality 
Model (CAMx) and the PM Source Apportionment Technology (PSAT) tool, 
used for the attribution of sulfate and nitrate sources. The second 
technique was the Weighted Emissions Potential (WEP) tool, used for 
attribution of sources of organic carbon, elemental carbon, 
PM2.5, and PM10. The WEP tool is based on 
emissions and residence time, not modeling. WEP is a screening tool 
that helps to identify source regions that have the potential to 
contribute to haze formation at specific Class I areas. Unlike PSAT, 
this method does not account for chemistry or deposition. More 
information on the WRAP modeling methodologies is available in Appendix 
C of the RHP.
    As directed by the WRAP Modeling Forum, the Regional Modeling 
Center at the University of California at Riverside performed modeling 
for the WRAP member states, including Arizona. The Regional Modeling 
Center primarily used the CMAQ photochemical grid model to estimate 
2018 visibility conditions in Arizona and all western Class I areas, 
based on application of the regional haze strategies in the various 
state plans, including assumed controls on BART sources. The Regional 
Modeling Center developed air quality modeling inputs, including annual 
meteorology and emissions inventories for the following: (1) A 2002 
actual emissions base case; (2) a planning case to represent the 2000-
2004 regional haze baseline period using averages for key emissions 
categories; and, (3) a 2018 base case of projected emissions determined 
using factors known at the end of 2005. All emission inventories were 
spatially and temporally allocated using the SMOKE modeling system. 
These inventories were revised several times throughout the development 
process to arrive at the final versions used in CMAQ modeling. The 
photochemical modeling of regional haze for 2002 and 2018 for the WRAP-
member states was conducted on the 36-kilomenter resolution national 
regional planning organization domain that covered the continental 
United States, portions of Canada and Mexico, and portions of the 
Atlantic and Pacific Oceans along the east and west coasts. Again, a 
more detailed description of the CMAQ modeling performed for the WRAP 
can be found in Appendix C of the RHP.
    To summarize, as described in Chapters 11 and 12 and Appendix C of 
the ARHP, Arizona used the technical tools and outputs provided by the 
WRAP, including the WRAP's 2002 baseline inventory, to produce the 
State's LTS. In EPA's evaluation of the WRAP's technical tools, we 
found these tools to be adequate for the analytical task to which they 
were applied and consistent with EPA guidance and suggested practice at 
the time of their use by the WRAP for its member states.\161\ 
Therefore, we propose to determine that the ARHP meets the requirements 
of 40 CFR 51.308(d)(iii).
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    \161\ See ``Technical Support Document for Technical Products 
Prepared by the Western Regional Air Partnership (WRAP) in Support 
of Western Regional Haze Plans,'' February 28, 2011, at pages 57-58 
for a summary of our review of the WRAP's analytical work.
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D. Anthropogenic Sources of Visibility Impairment

    Pursuant to 40 CFR 51.308(d)(3)(iv) Arizona is required to identify 
all anthropogenic sources of visibility impairment it considered in 
developing its LTS, including major and minor stationary sources, 
mobile sources, and area sources. As described earlier, Arizona used 
emissions inventories for 2002 and 2018 provided by the WRAP. The 2018 
emissions inventory was developed by projecting 2002 emissions and 
applying reductions expected from federal and state regulations. The 
ARHP emission inventories were developed by WRAP and distributed to 
Arizona via the Technical Support System. These emission inventories 
were calculated using approved EPA methods and we found them to be 
adequate for their use by the WRAP.\162\
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    \162\ We found the WRAP emission inventories to be complete, 
recent, and accurate, as well as, consistent with EPA Guidance; see 
EPA's February 28, 2011 TSD at page 58.
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    Across all visibility-related pollutants, there are 11 different 
emission

[[Page 75732]]

inventory source categories identified in Arizona's RHP: point, 
anthropogenic fire, natural fire, area, WRAP region oil and gas, on-
road mobile, off-road mobile, biogenic, road dust, fugitive dust, and 
windblown dust. Tables 8.1 through 8.8 of the ARHP show Arizona's 2002 
baseline emissions, the 2018 projected emissions, and net changes of 
emissions for SO2, NOX, organic carbon, elemental 
carbon, PM2.5, PM10, NH3, and VOC by 
their respective source category. In our discussion of the ARHP's 
emission inventories in section VI, we provide a summary of the 
relative contribution of anthropogenic sources for these pollutants; 
see Table 7. Furthermore, as part of its reasonable progress 
demonstration, Arizona identified the following specific source 
categories, totaling 48 facilities, as producing anthropogenic 
emissions worthy of consideration: internal combustion engines and 
turbines; external combustion boilers; asphalt plants; lime plants; 
primary copper smelters; and, nitric acid plants; see chapter 11.3 of 
the ARHP. The methods that the WRAP used to develop these emission 
inventories are described in more detail in Chapters 8, 9 and Appendix 
C of the RHP and are evaluated in the EPA's February 28, 2011 TSD.
    In summary, Arizona utilized the 2002 and 2018 WRAP emission 
inventories developed according to EPA guidance and presented those 
inventories in the RHP. Also, Arizona identified all anthropogenic 
sources of visibility impairment it considered in developing the LTS. 
Therefore, we propose to determine that the ARHP meets the requirements 
of 40 CFR 51.308(d)(3)(iv). It should be noted that our proposed 
approval for this element is based on our finding that Arizona 
identified the sources of impairment that it actually considered in 
developing the LTS. This proposed approval does not imply that Arizona 
fully or appropriately considered all anthropogenic sources of 
visibility impairment in establishing its RPGs.

E. Mandatory Factors To Consider for the Long-Term Strategy

    Pursuant to 40 CFR 51.308(d)(3)(v), Arizona must consider and 
address the following seven factors within its LTS: (1) Emission 
reductions due to ongoing air pollution control programs, including 
measures to address RAVI; (2) measures to mitigate the impacts of 
construction activities; (3) emissions limitations and schedules for 
compliance to achieve the RPG; (4) source retirement and replacement 
schedules; (5) smoke management techniques for agricultural and 
forestry management purposes; (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.
1. Ongoing Air Pollution Control Programs
    Arizona's LTS cites on-going air pollution control programs assumed 
within the RHP as part of the 2002 base year inventory and projected 
through 2018, such as Arizona's Vehicle Emissions Inspection Program 
and federal diesel fuel standards for low diesel fuels; see the RHP at 
pages 201-202. Mobile source emission reductions through 2018 are due 
to ``on-the-books'' federal controls applied to on-road mobile sources 
and non-road mobile sources and equipment; see chapter 11.4.4, page 173 
for the list of assumed federal controls.
    The LTS also lists 10 PM10 nonattainment and maintenance 
plan areas in Arizona; see page 202 of the RHP and Table 12.55. Arizona 
asserts that the emission reduction programs in these areas provide 
significant emission reduction benefits. Several fugitive dust rules 
have been approved into the SIP and are cited as providing the emission 
reductions within these areas: A.C.C. R18-2-602, A.C.C. R18-2-608, 
Maricopa County Rule 310.01, and the Agricultural Best Practices 
Program.\163\ The LTS does not describe ongoing state or local 
stationary source emission reduction programs or regulations in detail; 
however, the LTS mentions the New Source Review and the Prevention of 
Significant Deterioration stationary source programs as they relate to 
visibility impact assessment.\164\ Regarding specific stationary source 
requirements, Arizona's BART reviews and determinations are discussed 
elsewhere in the ARHP, such as Chapter 10 and Appendix D.
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    \163\ These rules were approved into the Arizona SIP as follows: 
R18-2-602 at 71 FR 28270, May 16, 2006; R18-2-608 at 47 FR 17485, 
April 23, 1982 (renumbered from R18-2-408 and R9-3-408); Maricopa 
County Rule 310.01, Fugitive Dust from Non-Traditional Sources of 
Fugitive Dust, at 75 FR 78167, December 15, 2010; and, the 
Agricultural Best Practices Program in R18-2-610 and R18-2-611 at 68 
FR 51873, October 11, 2001.
    \164\ ARHP Chapter 12.7.1.1 at pages 198-199.
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    The RHR also requires consideration of emission reductions due to 
ongoing air pollution control programs such as those derived from the 
Act's section 169A requirement for Arizona to reduce emissions from 
sources determined to cause reasonably attributable visibility 
impairment at Class I areas in the State (the RAVI program). Arizona 
has no ongoing air pollution programs providing emission reductions due 
to specific requirements of the RAVI program. In the late 1980s and 
early 1990s, EPA implemented a FIP to address the requirements of 
section 169A and EPA's RAVI rules.\165\ Ultimately, EPA found that 
certain episodes of visibility impairment at the Grand Canyon National 
Park were reasonably attributable to the Navajo Generating Station 
(NGS) and required implementation of controls at NGS to reduce oxides 
of sulfur emissions.\166\ Because NGS is located on the Navajo Indian 
Reservation, Arizona has no ongoing responsibility for regulating this 
source.
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    \165\ See our rulemaking actions at: 52 FR 45134, (November 24, 
1987); 53 FR 35956, (September 15, 1988); and, 56 FR 50172, (October 
3, 1991) (codified at 40 CFR 52.145). Also, see the summary 
discussion in the RHP at pages 199-200.
    \166\ 40 CFR 52.145(d).
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    We propose to find that Arizona has met the requirement of 40 CFR 
51.308(d)(3)(v)(A) to consider emission reductions due to ongoing air 
pollution control programs, including measures to address RAVI.
2. Construction Activities
    The LTS cites Maricopa County Rules 300 and 310 as rules for 
controlling fugitive dust emissions from construction activities. 
Maricopa County Rule 310, Fugitive Dust from Dust Generating Operations 
has been approved as a Best Available Control Measure-level rule for 
serious PM10 nonattainment areas.\167\ Also, we approved 
into the SIP Pinal County Rule 4-7, Construction Sites in Nonattainment 
Areas--Fugitive Dust.\168\ Rule 300 has not been approved into the SIP.
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    \167\ For the most recent SIP incorporated version of Rule 310, 
see 75 FR 78167; (December 15, 2010).
    \168\ See 75 FR 17307; (April 6, 2010). Pinal County also 
adopted and in this rulemaking we approved several other rules 
related to controlling fugitive dust from unpaved roads and parking 
areas.
---------------------------------------------------------------------------

    We propose to find that Arizona has met the requirement of 40 CFR 
51.308(d)(3)(v)(B) to consider measures to mitigate the impacts of 
construction activities.
3. Emissions Limitations and Schedules for Compliance
    The LTS states that, ``implementation of BART will contain emission 
limits and schedules of compliance for those sources either installing 
BART controls or taking federally enforceable permit limitations.'' 
\169\ However, as noted above, we have already disapproved the State's 
BART determinations for NOX at

[[Page 75733]]

the following units: Apache Generating Station Units 2 and 3; Cholla 
Generating Station Units 2, 3, and 4; Coronado Units 1 and 2.\170\ As 
described in section VII of this document, we are also proposing to 
disapprove certain elements of the state's BART determinations at other 
sources. In addition, all of Arizona's BART determinations lack the 
necessary compliance schedules and requirements for operation and 
maintenance of control equipment and monitoring, recordkeeping and 
reporting.
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    \169\ ARHP section 12.7.3, page 203.
    \170\ See our proposed rule at 77 FR 42834, (July 20, 2012) and 
our final rule at 77 FR 72512, (December 5, 2012) which addressed 
these units.
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    The LTS also states that Arizona ``did not identify any additional 
measures that were appropriate for this first Regional Haze plan. As a 
result, no other emission limitations or schedules of compliance are 
included in this plan.'' \171\ As explained in section VIII above, we 
are proposing to disapprove the State's reasonable progress analysis 
and its conclusion that no additional emissions controls can be 
reasonably implemented. Based on these shortcomings in the State's BART 
and Reasonable Progress analyses, we do not believe that Arizona has 
adequately considered the emission limits and schedules of compliance 
necessary to achieve reasonable progress. Therefore, we propose to 
determine that the ARHP does not meet the requirements of 40 CFR 
51.308(d)(3)(v)(C).
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    \171\ ARHP section 12.6.3, page 204.
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4. Source Retirement and Replacement Schedules
    Chapter 12.7.4 of the LTS refers to an evaluation of sources to 
provide a schedule of shutdowns, source retirements, and equipment 
replacement in an earlier section of the LTS; however, no such 
evaluation is found within Chapter 12.7.1.\172\ Appendix C of the ARHP 
does, however, discuss the 2002 and 2018 emissions inventories 
developed by the WRAP for Arizona; see pages 9--11 of Appendix C. The 
base case 2018 projected emissions inventories developed by the WRAP 
considered and accounted for source retirement and replacement for 
point and area sources.\173\ These projections were updated in 2009 to 
include new information about projected changes in electric demand and 
the resultant impact on emissions from electric generating units.\174\ 
In a similar manner, the WRAP used EPA's MOBILE emissions model and 
this model projected on-road mobile source fleet turnover and 
replacement in Arizona over the 2002 to 2018 timeframe and these 
emissions inventory estimates were incorporated in later visibility 
modeling.
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    \172\ See page 204 of the ARHP.
    \173\ See ``WRAP Point and Area Source Emissions Projection for 
the 2018 Base Case Inventory'', Version 1, January 25, 2006 at 
Chapters 4 and 5. Chapter 4 discusses projected growth to 2018, 
including EGUs. Chapter 5 discusses point source retirement and 
replacement rates used in the analysis. See: http://wrapair.org/forums/ssjf/documents/eictts/docs/WRAP_2018_EI-Version_1-Report_Jan2006.pdf.
    \174\ See ERG Technical Memorandum entitled ``WRAP PRP18b 
Emissions Inventory--Revised Point and Area Source Projections'', 
October 16, 2009.
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    We propose to find that the ARHP meets the requirements of 40 CFR 
51.308(d)(3)(v)(D) because it has considered adequately source 
retirement and replacement.
5. Smoke Management Programs
    Arizona adopted rules consistent with a state certified smoke 
management program. EPA has reviewed and approved the following rules 
in the SIP: Rule R18-2-602, Unlawful Open Burning; Rule R18-2-1501, 
Definitions; Rule R18-2-1502, Applicability; Rule R18-2-1503, Annual 
Registration, Program Evaluation and Planning; Rule R18-2-1504, 
Prescribed Burn Plan; Rule R18-2-1505, Prescribed Burn Requests and 
Authorization; Rule R18-2-1506, Smoke Dispersion and Evaluation; Rule 
R18-2-1507, Prescribed Burn Accomplishment, Wildfire Reporting; Rule 
R18-2-1508, Wildland Fire Use: Plan, Authorization, Monitoring, Inter-
agency Consultation, Status Reporting; Rule R18-2-1509, Emission 
Reduction Techniques; Rule R18-2-1510, Smoke Management Techniques; 
Rule R18-2-1511, Monitoring; Rule R18-2-1512, Burner Qualifications; 
and, Rule R18-2-1513, Public Notification Program, Regional 
Coordination.\175\ Arizona believes these rules meet WRAP criteria for 
an enhanced smoke management program; see Table 12.56, page 205 of the 
RHP.
---------------------------------------------------------------------------

    \175\ See 71 FR 28270; (May 16, 2006).
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    We propose to find that the ARHP meets the requirement of 40 CFR 
51.308(d)(3)(v)(E) to consider smoke management techniques for 
agricultural and forestry management purposes.
6. Enforceability of Measures in the Long-Term Strategy
    The RHR requires that the State consider the enforceability of 
emissions limitations and control measures included in its plan, as 
part of the LTS.\176\ Arizona has adopted and submitted, and EPA has 
approved into the SIP many rules supporting the ARHP. Maricopa County 
Rule 310 and the smoke management program rules listed above are 
examples of the federally enforceable rules supporting the reasonable 
progress goals of the ARHP.
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    \176\ 40 CFR 51.308(d)(3)(v)(F).
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    As noted earlier, however, we are have determined that Arizona's 
BART determinations lack provisions to ensure their enforceability. In 
our recent Phase 1 final rule, we found that the ARHP lacked the 
necessary compliance deadlines and requirements for equipment 
maintenance and operation, including monitoring, recordkeeping and 
reporting requirements for all pollutants at all of the eight BART 
units covered by that action.\177\ In today's action, we are proposing 
to disapprove the lack of such ``enforceability requirements'' for 
ADEQ's BART determinations at the two BART-subject copper smelters. As 
explained above, we are also proposing to disapprove other elements of 
the State's BART and reasonable progress analyses. Therefore, we 
propose to determine that the ARHP does not meet the requirement of 40 
CFR 51.308(d)(3)(v)(F).
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    \177\ 77 FR 72512, (December 5, 2012).
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7. Net Effect on Visibility Impairing Emissions Through 2018
    Pursuant to 40 CFR 51.308(d)(v)(F), the State must consider as part 
of its LTS, the anticipated net effect on visibility due to projected 
changes in point, area, and mobile source emissions over the period 
addressed by the long-term strategy. Using WRAP-provided resources as 
described in the ARHP, Arizona estimated the net effect on visibility 
through 2018 due to changes in point, area, stationary and mobile 
source emissions. Those visibility changes within each Class I area are 
presented in detail in chapter 9.3 and are discussed in aggregate in 
chapter 11 of the ARHP. In sum, 2018 visibility is projected to improve 
in all Arizona Class I areas on the worst impaired days compared to 
baseline conditions and 2018 visibility is projected to improve in all 
but two Class I areas on the least impaired days compare to baseline 
conditions. We, therefore, propose to determine that the ARHP meets the 
requirement of 40 CFR 51.308(d)(3)(v)(G).

F. Summary of EPA's Evaluation of the LTS

    We propose to approve in part and disapprove in part the LTS 
portion of the ARHP. Arizona has submitted an LTS addressing visibility 
impairment due to regional haze within Class I areas, both inside and 
outside of the

[[Page 75734]]

state. We review our proposed approvals and disapprovals below.
    Through participation in the WRAP, Arizona consulted with 
neighboring states and coordinated the ARHP, as well as developed and 
documented the technical basis for the ARHP. The State has estimated 
the 2002 base year and 2018 emissions inventories and the emission 
reductions resulting from the ARHP's control measures. The State 
identified all anthropogenic sources of visibility impairment it 
considered in developing the ARHP and LTS. The State has considered and 
addressed measures to mitigate the impacts of construction activities 
and to provide for smoke management from agricultural and forestry 
practices. Through the WRAP and its analyses, Arizona considered and 
estimated the net effect of the LTS on 2018 visibility levels. 
Consequently, we propose to find that the LTS meets the requirements of 
40 CFR 51.308(d)(3)(i), (iii), (iv), (v)(A), (v)(B), (v)(D), (v)(E), 
and (v)(G) and we propose to approve the ARHP with respect to these 
requirements.
    Because we have disapproved certain elements of the ARHP in our 
Phase 1 final rule and are proposing to disapprove other elements 
related to the implementation of enforceable BART controls and 
enforceable controls for reasonable progress, we are also proposing to 
determine that the LTS does not meet the requirements of 40 CFR 
51.308(d)(3)(ii), (v)(C) and (v)(F). Therefore, we propose to find that 
the LTS does not meet the requirements of 40 CFR 51.308(d)(3)(ii), 
(v)(C), and (v)(F) and we propose to disapprove the ARHP with respect 
to these requirements.

X. Monitoring Strategy and Other Requirements

A. Monitoring Strategy

    Arizona has elected to fulfill the requirements for a monitoring 
strategy through participation in the IMPROVE network, as permitted 
under the RHR.\178\ Arizona relies on the IMPROVE monitoring program to 
collect and report data for reasonable progress tracking for all Class 
I Areas in the state.\179\ Consequently, we propose to find that the 
state has met the requirements of 40 CFR 51.308(d)(4) for a monitoring 
strategy.
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    \178\ 40 CFR 51.308(d)(4).
    \179\ ARHP, Chapter 4, ``Regional Haze Monitoring Network'', and 
Section 12.7, pages 200-201.
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B. State and Federal Land Manager Coordination

    Arizona participated fully in the WRAP, the primary forum for 
consultation among western states, tribal nations, federal agencies, 
stakeholder groups and the public. FLMs from the National Park Service 
(NPS), U.S. Fish and Wildlife Service, Bureau of Land Management and 
the U.S. Forest Service (USFS) were actively engaged in the WRAP's 
development of technical analyses and reports that formed the basis of 
Arizona's and other western state's regional haze plans. To facilitate 
consultation as required in 51.308(i)(2), ADEQ provided a list of its 
agency contacts to the FLMs followed by its draft RH SIP on September 
20, 2010. Arizona ensured that the FLMs had an opportunity for 
consultation in person and at least 60 days prior to the public hearing 
that was held in Phoenix, Arizona, on December 2, 2010, which was also 
the deadline for public comments. NPS submitted comments dated November 
29 and December 1, 2010. The USFS submitted comments dated November 29, 
2010. ADEQ responded to the FLMs' comments through its Responsiveness 
Summary in Appendix E of the Arizona RH SIP. ADEQ outlined procedures 
for continuing consultation with the FLMs in its RH SIP \180\ and 
committed to provide the FLMs an opportunity to review and comment on 
future SIP revisions, the 5-year progress reports, and the 
implementation of other programs that may contribute to visibility 
impairment in Arizona's Class I areas. EPA proposes to find that 
Arizona has met the requirements for coordination with the FLMs under 
40 CFR 51.308(i)(1-4).
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    \180\ ARHP, Chapter 13, page 209.
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C. Periodic SIP Revisions and 5-Year Progress Reports

    In the ARHP, Arizona affirmed its commitment to submit a 
comprehensive SIP revision by July 31, 2018, and every ten years 
thereafter as required in 40 CFR 51.308(f). In these comprehensive 
revisions, the State must evaluate and reassess all of the elements 
required in 40 CFR 51.308(d), taking into account improvements in 
monitoring data collection and analysis techniques and control 
technologies. The State must also address current visibility 
conditions, actual progress toward natural conditions, effectiveness of 
the long-term strategy, and the reasonable progress goals. Arizona also 
confirmed it commitment to submit a report on reasonable progress every 
five years that will evaluate progress toward meeting the RPGs for its 
12 Class I area as well as Class I areas outside the State that may be 
affected by emissions from within the State as required in 40 CFR 
51.308(g). The first report is due five years after the State's 
submittal, which is February 28, 2016.

XI. EPA's Evaluation of Arizona's Provisions for Interstate Transport 
of Pollutants

    Section 110(a)(2)(D)(i)(II) requires that each SIP contain 
``adequate provisions * * * prohibiting * * * any source or other types 
of emission activity within the State from emitting any air pollutant 
in amounts which will * * * interfere with measures required to be 
included in the applicable implementation plan for any other State * * 
* to protect visibility.'' EPA is proposing to find that Arizona's 2007 
and 2009 Transport SIPs and Regional Haze Plan 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.
    Our 2006 Guidance recommended that a state could meet the 
visibility prong of the transport requirements for section 
110(a)(2)(D)(i)(II) with an approved regional haze SIP.\181\ EPA's 
reasoning was that the development of the regional haze SIPs was 
intended to occur in a collaborative environment among the states, and 
that through this process states would coordinate on emissions controls 
to protect visibility on an interstate basis. In fact, in developing 
their respective RPGs, WRAP states consulted with each other through 
the WRAP's work groups. As a result of this process, the common 
understanding was that each state would take action to achieve the 
emissions reductions relied upon by other states in their reasonable 
progress demonstrations under the RHR. Thus, 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 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. 
This interpretation is consistent with the requirement of the RHR that 
a state

[[Page 75735]]

participating in a regional planning process must include ``all 
measures needed to achieve its apportionment of emission reduction 
obligations agreed upon through that process.'' \182\
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    \181\ ``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'' (August 15, 2006); see also 
``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'').
    \182\ 40 CFR 51.308(d)(3)(ii).
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    Since Arizona's 2007 and 2009 Transport SIPs did not specify which 
parts of the State's regional haze program should be considered as 
meeting the visibility requirement of section 110(a)(2)(D)(i)(II), we 
considered the 2011 Regional Haze SIP as a whole in assessing whether 
Arizona has met the visibility requirement of section 
110(a)(2)(D)(i)(II). As discussed in sections VII (``EPA's Evaluation 
of Arizona's BART Analyses and Determinations'') and VIII (``EPA's 
Evaluation of Arizona's Reasonable Progress Goals'') of this proposed 
rule, EPA is proposing to disapprove several aspects of Arizona's BART 
and Reasonable Progress Analyses. Also, as previously noted, EPA has 
already disapproved Arizona's determinations for NOX 
emission limits at most of the units at Apache, Cholla, and 
Coronado.\183\ The emissions from each of these sources affect 
visibility in at least one Class I area in another state.\184\ The 
proposed partial disapprovals in today's notice, if finalized, and the 
final partial disapprovals for Apache, Cholla, and Coronado mean that 
these portions of Arizona's Regional Haze Plan will not become part of 
the Arizona SIP.
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    \183\ 77 FR 42834 (July 20, 2012) (proposal), 77 FR 72512, 
(December 5, 2012) (final).
    \184\ For example, Cholla Power Plant has been determined by 
Arizona and EPA to affect visibility in Class I areas in Colorado, 
New Mexico, and Utah. See 77 FR 42834 at 42861. Also, Arizona's RHP 
discusses Arizona's contributions to visibility impairment in 
Colorado, New Mexico, and Utah (see pages 179-181).
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    Accordingly, Arizona's long-term strategy (i.e., the compilation of 
all control measures that Arizona will implement to meet the relevant 
RPGs) lacks enforceable emissions limitations for certain air 
pollutants as necessary to achieve RPGs for all Class I areas affected 
by emissions from Arizona, as required by 40 CFR 51.308(d)(3). As noted 
above, 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. 
Because we partially disapproved Arizona's BART provisions for three 
sources (Apache, Cholla, and Coronado) and are proposing in this notice 
to partially disapprove Arizona's BART and reasonable progress 
analyses, we propose to conclude that the Arizona SIP does not include 
sufficient measures to prohibit emissions that would interfere with the 
RPGs for Class I areas in other states. Furthermore, Arizona has not 
made a demonstration that emissions from the state's sources and 
activities will not have the prohibited impacts under the existing SIP.
    Thus, we propose to find that Arizona's 2007 and 2009 Transport 
SIPs and Regional Haze Plan do not contain adequate provisions to 
prohibit emissions that interfere with SIP measures required of other 
states to protect visibility.\185\ Accordingly, we propose to 
disapprove these SIP revisions for the visibility requirement of 
section 110(a)(2)(D)(i)(II) for the 1997 8-hour ozone, 1997 
PM2.5, and 2006 PM2.5 NAAQS.
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    \185\ As noted above, we previously acted on these submissions 
with respect to the other three prongs. See 72 FR 41629 (July 31, 
2007) and 77 FR 66398 (November 5, 2012). Therefore, today's action, 
if finalized, will complete our action on these submissions.
---------------------------------------------------------------------------

XII. EPA's Proposed Action

A. Regional Haze

    EPA is proposing to approve in part and disapprove in part the 
remaining portions of Arizona's RH SIP. Specifically, we are proposing 
to approve the technical basis for the State's plan, most of the 
analyses regarding which sources are eligible and which sources are 
subject to BART, the BART determination for PM10 at the 
Miami smelter and parts of the long-term strategy. We are proposing 
alternatively to approve or disapprove the State's BART determination 
for SO2 at the Hayden and Miami smelters, and whether the 
Nelson Lime Plant is subject to BART.
    We are proposing to disapprove the State's BART determinations for 
PM10 at the Hayden smelter and for NOX at the 
Miami smelter as well as the State's finding that Unit 4 at Sundt is 
not BART-eligible. In addition, we are proposing to disapprove the 
visibility goals for the most and least impaired days, which set the 
targets for evaluating progress. Moreover, we propose to disapprove 
that part of the long-term strategy that requires enforceable emission 
limits and compliance schedules that were not included in the SIP, and 
were not adequately considered in setting the visibility goals. Our 
consent decree deadline for taking final action on Arizona's RH SIP is 
July 15, 2013.
    EPA is legally obligated to issue a FIP for the disapproved parts 
of Arizona's RH SIP pursuant to CAA section 110(c)(1) and the court's 
orders under the consent decree. Accordingly, we included a FIP in our 
recently published final rule regarding three of Arizona's BART 
sources. For today's proposed action on the SIP, we have a separate 
court-ordered schedule for a FIP to address any disapproved elements of 
the SIP. The consent decree deadlines for this FIP are to propose by 
March 8, 2013, and take final action by October 15, 2013. Our 
obligation to promulgate a FIP for those parts of the State's plan that 
we are unable to approve is based on the State's failure to submit a 
required SIP, and our subsequent failure to issue a FIP within two 
years of our finding of failure to submit. EPA takes very seriously a 
decision to disapprove all or part of a state plan. In this instance, 
we believe that Arizona's SIP meets some, but not all of the RHR 
requirements under the CAA. As a result, EPA considers that proposing 
to disapprove portions of the State's plan is the only path that is 
consistent with the Act at this time.

B. Interstate Transport of Visibility

    As discussed in section XI (``EPA's Evaluation of Arizona's 
Provisions for Interstate Transport of Pollutants'') of this proposed 
rule, EPA proposes to find that Arizona's 2007 and 2009 Transport SIPs 
and Regional Haze Plan do not contain adequate provisions to prohibit 
emissions that interfere with SIP measures required of other states to 
protect visibility. Therefore, we propose to disapprove Arizona's 2007 
and 2009 Transport SIPs and Regional Haze Plan for the visibility 
requirement of section 110(a)(2)(D)(i)(II) for the 1997 8-hour ozone, 
1997 PM2.5, and 2006 PM2.5 NAAQS.

C. Sanctions and FIP Duties

    Under section 179(a) of the CAA, final disapproval of a submittal 
that addresses a requirement of part D, title I of the CAA (CAA 
sections 171-193) or is required in response to a finding of 
substantial inadequacy as described in CAA section 110(k)(5) (SIP Call) 
starts a sanctions clock. Arizona's 2007 and 2009 Transport SIPs and 
Regional Haze Plan were not submitted to meet either of these 
requirements. Therefore, any action we take to finalize the described 
partial disapproval will not trigger mandatory sanctions under CAA 
section 179. In addition, CAA section 110(c)(1) provides that EPA must 
promulgate a FIP within two years after finding that a State has failed 
to make a required submission or disapproving a State

[[Page 75736]]

implementation plan submission in whole or in part, unless EPA approves 
a SIP revision correcting the deficiencies within that two-year period. 
Thus, our proposed disapproval of Arizona's 2009 Transport SIP with 
respect to the visibility requirement of section 110(a)(2)(D)(i)(II) 
for the 2006 PM2.5 NAAQS, if finalized, will establish a 
deadline two years from the effective date of such final rule for EPA 
to promulgate a FIP for this requirement, unless a SIP revision is 
submitted by ADEQ and approved by EPA by that deadline.\186\ We 
anticipate that any FIP designed to remedy the proposed disapprovals 
described in this notice, if finalized, along with the already-
finalized partial BART FIP for Apache, Cholla, and Coronado, would also 
remedy the disapproval, if finalized, for the interstate transport 
visibility requirement of CAA section 110(a)(2)(D)(i)(II) for the 1997 
8-hour ozone, 1997 PM2.5, and 2006 PM2.5 NAAQS.
---------------------------------------------------------------------------

    \186\ As described above, EPA is already subject to a FIP duty 
for Regional Haze in Arizona. In addition, due to a previous finding 
of failure to submit, 70 FR 21147, we are already subject to a FIP 
duty for the 2007 Transport SIP.
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XIII. Statutory and Executive Order Reviews

 A. Executive Order 12866, Regulatory Planning and Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order (EO) 12866 (58 FR 51735, October 4, 1993) and 
is therefore not subject to review under the EO.

 B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., 
because this proposed partial approval and partial disapproval of SIP 
revisions under CAA section 110 will not in-and-of itself create any 
new information collection burdens but simply proposes to approve 
certain State requirements, and to disapprove certain other State 
requirements, for inclusion into the SIP. Burden is defined at 5 CFR 
1320.3(b).

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions. For purposes of assessing the impacts of today's rule on 
small entities, small entity is defined as: (1) A small business as 
defined by the Small Business Administration's (SBA) regulations at 13 
CFR 121.201; (2) a small governmental jurisdiction that is a government 
of a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field. After considering the economic 
impacts of today's proposed rule on small entities, I certify that this 
action will not have a significant impact on a substantial number of 
small entities. This rule does not impose any requirements or create 
impacts on small entities. This proposed rule does not impose any 
requirements or create impacts on small entities. This proposed partial 
SIP approval and partial SIP disapproval under CAA section 110 will not 
in-and-of itself create any new requirements but simply proposes to 
approve certain State requirements, and to disapprove certain other 
State requirements, for inclusion into the SIP. Accordingly, it affords 
no opportunity for EPA to fashion for small entities less burdensome 
compliance or reporting requirements or timetables or exemptions from 
all or part of the rule. Therefore, this action will not have a 
significant economic impact on a substantial number of small entities. 
We continue to be interested in the potential impacts of this proposed 
rule on small entities and welcome comments on issues related to such 
impacts.

D. Unfunded Mandates Reform Act

    This action contains no Federal mandates under the provisions of 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 
1531- 1538 for State, local, or tribal governments or the private 
sector.'' This action proposes to approve certain preexisting 
requirements, and to disapprove certain other pre-existing 
requirements, under State or local law, and imposes no new 
requirements. Accordingly, no additional costs to State, local, or 
tribal governments, or to the private sector, result from this proposed 
action.

 E. Executive Order 13132, Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.'' This action 
does not have federalism implications. It will not have substantial 
direct effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government, as specified 
in Executive Order 13132, because it merely proposes to approve certain 
State requirements, and to disapprove certain other State requirements, 
for inclusion into the SIP and does not alter the relationship or the 
distribution of power and responsibilities established in the Clean Air 
Act. Thus, Executive Order 13132 does not apply to this action.

 F. Executive Order 13175, Coordination With Indian Tribal Governments

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000), because the SIP 
on which EPA is proposing action would not apply in Indian country 
located in the state, and EPA notes that it will not impose substantial 
direct costs on tribal governments or preempt tribal law. Thus, 
Executive Order 13175 does not apply to this action. However, this 
action creates the basis for future action which could impact a 
tribally-owned source. EPA will engage in consultation with the 
affected tribe to ensure that any concerns are considered during that 
process. EPA specifically solicits additional comment on this proposed 
rule from tribal officials.

 G. Executive Order 13045, Protection of Children From Environmental 
Health Risks and Safety Risks

    EPA interprets EO 13045 (62 FR 19885, April 23, 1997) as applying 
only to those regulatory actions that concern health or safety risks, 
such that the analysis required under section 5-501 of the EO has the 
potential to influence the regulation. This action is not subject to EO 
13045 because it is not an economically significant regulatory action 
based on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997). This proposed partial approval and partial 
disapproval under section 110 of the Clean Air Act will not in-and-of 
itself create any new

[[Page 75737]]

regulations but simply disapproves certain State requirements for 
inclusion into the SIP.

 H. Executive Order 13211, Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This proposed rule is not subject to Executive Order 13211 (66 FR 
28355, May 22, 2001) because it is not a significant regulatory action 
under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. NTTAA directs EPA to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards. The EPA 
believes that this action is not subject to requirements of Section 
12(d) of NTTAA because application of those requirements would be 
inconsistent with the Clean Air Act.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Population

    Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States. EPA lacks the discretionary authority 
to address environmental justice in this rulemaking.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Nitrogen dioxide, Particulate 
matter, Reporting and recordkeeping requirements, Sulfur oxides, 
Visibility, Volatile organic compounds.

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

    Dated: December 7, 2012.
Jared Blumenfeld,
Regional Administrator, Region 9.
[FR Doc. 2012-30702 Filed 12-20-12; 8:45 am]
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