Partial Approval and Disapproval of Air Quality Implementation Plans; Arizona; Regional Haze and Visibility Impacts of Transport, Ozone and Fine Particulates
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.
Table of Contents Back to Top
- FOR FURTHER INFORMATION CONTACT:
- SUPPLEMENTARY INFORMATION:
- Table of Contents
- I. General Information
- A. Docket
- B. Instructions for Submitting Comments
- C. Submitting Confidential Business Information
- D. Tips for Preparing 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 (RPGs)
- D. Best Available Retrofit Technology (BART)
- E. Long-Term Strategy (LTS)
- F. Coordination of Regional Haze and RAVI
- G. Monitoring Strategy
- H. SIP Revisions and Progress Reports
- I. State Consultation With Federal Land Managers (FLMs)
- 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
- 1. Chiricahua National Monument, Chiricahua Wilderness Area and Galiuro Wilderness Area
- 2. Grand Canyon National Park
- 3. Mazatzal Wilderness Area and Pine Mountain Wilderness Area
- 4. Mount Baldy Wilderness Area
- 5. Petrified Forest National Park
- 6. Saguaro National Park (East Unit and West Unit)
- 7. Sierra Ancha Wilderness Area
- 8. Sycamore Canyon Wilderness Area
- 9. Superstition Wilderness Area
- VII. EPA's Evaluation of Arizona's BART Analyses and Determinations
- A. Arizona's Identification of BART Sources
- 1. Arizona's Identification of Sources Potentially Eligible for BART
- 2. Arizona's Determination of Sources Not BART-Eligible
- 3. Arizona's Identification of Sources Exempt From BART
- 4. Sources Subject to BART in Arizona
- B. EPA's Evaluation of ADEQ's Subject-to-BART Analysis
- C. Arizona's BART Control Analysis
- D. Arizona's BART Determinations
- 1. Catalyst Paper
- 2. Miami Smelter
- 3. Hayden Smelter
- 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 Apportionment of Emission Reductions
- D. Anthropogenic Sources of Visibility Impairment
- E. Mandatory Factors To Consider for the Long-Term Strategy
- 1. Ongoing Air Pollution Control Programs
- 2. Construction Activities
- 3. Emissions Limitations and Schedules for Compliance
- 4. Source Retirement and Replacement Schedules
- 5. Smoke Management Programs
- 6. Enforceability of Measures in the Long-Term Strategy
- 7. Net Effect on Visibility Impairing Emissions Through 2018
- F. Summary of EPA's Evaluation of the LTS
- X. Monitoring Strategy and Other Requirements
- A. Monitoring Strategy
- B. State and Federal Land Manager Coordination
- C. Periodic SIP Revisions and 5-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 FIP 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, Coordination With Indian Tribal Governments
- G. Executive Order 13045, Protection of Children From Environmental Health Risks and Safety Risks
- H. Executive Order 13211, Actions 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 Population
- List of Subjects in 40 CFR Part 52
Tables Back to Top
- Table 1—Consent Decree Deadlines for EPA To Act on Arizona's RH SIP
- Table 2—Class I Areas in Arizona Potentially Affected by Arizona Emissions
- Table 3—Class I Areas Outside of Arizona Potentially Affected by Arizona Emissions52
- Table 4—Visibility Calculations for Arizona Class I Areas57
- Table 5—Baseline and 2018 Visibility Conditions for Arizona Class I Areas58
- Table 6A—Emissions Inventory for Arizona Regional Haze Pollutants by Source Category for 2002 and 2018
- Table 6B—Emissions Inventory for Arizona Regional Haze Pollutants by Source Category for 2002 and 2018
- Table 7—Assessment of the Emissions Inventory67
- Table 8—Percent of Total Aerosol Light Extinction Contributed by Each Pollutant
- Table 9—Potentially BART-Eligible Sources in Arizona
- Table 10—Sources Exempt From BART (ADEQ)
- Table 11—Sources Subject to BART (ADEQ)
- Table 12—Sources Not Subject to BART (ADEQ)
- Table 13—Summary of Arizona's BART Determinations
- Table 14—Pollutant-Specific Contribution to Visibility Impairment on the Best 20 Percent of Days at CHIR1 and SAGU1136
- Table 15—Largest Sources of SO 2 in Arizona145
- Table 16A—SO 2 Reasonable Progress Analysis for TEP Springerville (Units 1 and 2)
- Table 16B—SO 2 Reasonable Progress Analysis for Sundt Units 1-3
- Table 16C—SO 2 Reasonable Progress Analysis for Douglas Lime Plant
DATES: Back to Top
Written comments must be received by the designated contact at the address below on or before February 4, 2013.
ADDRESSES: Back to Top
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: Back to Top
Gregory Nudd, U.S. EPA, Region 9, Planning Office, Air Division, Air-2, 75 Hawthorne Street, San Francisco, CA 94105. Gregory Nudd can be reached at telephone number (415) 947-4107 and via electronic mail at email@example.com.
SUPPLEMENTARY INFORMATION: Back to Top
Definitions Back to Top
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 NH 3 mean or refer to ammonia.
(16) The initials NO X 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 PM 2.5 mean or refer to fine particulate matter with an aerodynamic diameter of less than 2.5 micrometers.
(22) The initials PM 10 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 SO 2 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 Back to Top
I. General Information
B. Instructions for Submitting Comments to EPA
C. Submitting Confidential Business Information
D. Tips for Preparing Your Comments
II. Overview of Proposed Actions
A. Regional Haze
B. Interstate Transport of Pollutants That Affect Visibility
III. Regional Haze Program and Interstate Transport Background
A. Description of Regional Haze
B. History of Regional Haze Regulations
C. Roles of Agencies in Addressing Regional Haze
D. Interstate Transport of Pollutants
IV. Requirements for Regional Haze Implementation Plans
A. Regional Haze Rule
B. Determination of Baseline, Natural and Current Visibility Conditions
C. Determination of Reasonable Progress Goals
D. Best Available Retrofit Technology
E. Long-Term Strategy
F. Coordination of Regional Haze and Reasonably Attributable Visibility Impairment
G. Monitoring Strategy
H. SIP Revisions and Progress Reports
I. State Consultation With Federal Land Managers
J. The Grand Canyon Visibility Transport Commission and Section 309
V. Overview of State and EPA Actions on Regional Haze
A. EPA's Schedule To Act on Arizona's RH SIP
B. Summary of EPA's Final Rule Affecting Three BART Sources
C. History of State Submittals and EPA Actions
VI. EPA's Evaluation of Visibility Conditions in Arizona's Class I Areas
A. Affected Class I Areas
B. Determination of Visibility Conditions and Uniform Rate of Progress
C. Arizona's Emissions Inventories
D. Sources of Visibility Impairment
VII. EPA's Evaluation of Arizona's BART Analyses and Determinations
A. Arizona's Identification of BART Sources
B. EPA's Evaluation of Arizona's Subject-to-BART Analysis
C. Arizona's BART Control Analysis
D. Arizona's BART Determinations
VIII. EPA's Evaluation of Arizona's Reasonable Progress Goals
A. Reasonable Progress Goals for the Best Days
B. Reasonable Progress Goals for the Worst Days
C. Summary of EPA's Evaluation
IX. EPA's Evaluation of Arizona's Long-Term Strategy
A. Interstate Consultation on Emission Management Strategies
B. Measures To Obtain Allotted Emissions Reductions
C. Technical Basis for the Apportionment of Emission Reductions
D. Anthropogenic Sources of Visibility Impairment
E. Mandatory Factors To Consider for the Long-Term Strategy
F. Summary of EPA's Evaluation of the Long-Term Strategy
X. Monitoring Strategy and Other Requirements
A. Monitoring Strategy
B. State and Federal Land Manager Coordination
C. Periodic SIP Review and Five-Year Progress Reports
XI. EPA's Evaluation of Arizona's Provisions for Interstate Transport of Pollutants
XII. EPA's Proposed Action
A. Regional Haze
B. Interstate Transport of Visibility
C. Sanctions and Federal Implementation Plan Duties
XIII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments
G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks
H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations
I. General Information Back to Top
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: firstname.lastname@example.org.
- 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 Back to Top
A. Regional Haze
EPA is proposing to approve in part and disapprove in part the remaining portion of Arizona's Regional Haze Plan (ARHP)  submitted to EPA Region 9 on February 28, 2011, to meet the requirements of Section 308 of the Regional Haze Rule (RHR). We propose to take action on Arizona's Best Available Retrofit Technology (BART) control analysis and determinations, Reasonable Progress Goals (RPG) for each of the 12 Class I areas, and Long-term Strategy (LTS). We are also proposing to take action on the requirements that support these major components of the plan, namely, the identification of Class I Areas impaired by Arizona's emissions, estimated visibility conditions, emission inventories, and the State's monitoring strategy. Today's proposal follows our recent final action on three BART sources in Arizona  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:
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.  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.
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 NO X at Hayden smelter, and for PM 10 at Miami smelter. We propose to disapprove Arizona's conclusion that a BART determination is not required for PM 10 at the Hayden smelter and for NO X at the Miami smelter. We are proposing alternatively to approve or disapprove the State's BART determination for SO 2 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 (PM 2.5), and in 2006, EPA revised the 24-hour PM 2.5 NAAQS. Each of these actions triggered the requirement for states to address the interstate transport visibility requirement of section 110(a)(2)(D)(i)(II).
In 2007 and 2009, Arizona submitted SIP revisions for the 1997 ozone and PM 2.5, and 2006 PM 2.5 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 PM 2.5 NAAQS, and 2006 PM 2.5 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.  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 PM 2.5, and 2006 PM 2.5 NAAQS, nor a demonstration that the existing Arizona SIP already includes measures sufficient to meet the interstate transport visibility requirement.
III. Regional Haze Program and Interstate Transport Background Back to Top
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 (NH 3) and volatile organic compounds (VOC)). Fine particle precursors react in the atmosphere to form PM 2.5, which impairs visibility by scattering and absorbing light. Visibility impairment reduces the clarity, color, and visible distance that one can see. PM 2.5 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  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. 
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  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.”  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.
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.  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. 
C. Roles of Agencies in Addressing Regional Haze
Successful implementation of the regional haze program will require long-term regional coordination among states, tribal governments and various federal agencies. As noted above, pollution affecting the air quality in Class I areas can be transported over long distances, even hundreds of kilometers. Therefore, to effectively address the problem of visibility impairment in Class I areas, states, or the EPA when implementing a FIP, need to develop strategies in coordination with one another, taking into account the effect of emissions from one jurisdiction on the air quality in another.
Because the pollutants that lead to regional haze can originate from sources located across broad geographic areas, EPA has encouraged the states and tribes across the United States to address visibility impairment from a regional perspective. Five regional planning organizations (RPOs) were developed to address regional haze and related issues. The RPOs first evaluated technical information to better understand how their states and tribes impact Class I areas across the country, and then pursued the development of regional strategies to reduce emissions of particulate matter and other pollutants leading to regional haze.
The Western Regional Air Partnership (WRAP) RPO is a collaborative effort of state governments, tribal governments, and various federal agencies established to initiate and coordinate activities associated with the management of regional haze, visibility and other air quality issues in the western United States. WRAP member State governments include: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. Tribal members include Campo Band of Kumeyaay Indians, Confederated Salish and Kootenai Tribes, Cortina Indian Rancheria, Hopi Tribe, Hualapai Nation of the Grand Canyon, Native Village of Shungnak, Nez Perce Tribe, Northern Cheyenne Tribe, Pueblo of Acoma, Pueblo of San Felipe, and Shoshone-Bannock Tribes of Fort Hall.
D. Interstate Transport of Pollutants
EPA promulgated new NAAQS for 8-hour ozone and fine particulate matter (PM 2.5)  on July 18, 1997, and revised the 24-hour PM 2.5 NAAQS to a more protective level  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.
EPA issued on April 25, 2005, a “Finding of Failure to Submit SIPs for Interstate Transport for the  8-hour Ozone and PM 2.5 NAAQS.”  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. 
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  8-Hour Ozone and PM 2.5 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. 
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.  EPA reiterated this connection between the regional haze and the visibility prong of section 110(a)(2)(D)(i) for the 2006 PM 2.5 NAAQS in guidance entitled “Guidance on SIP Elements Required Under Sections 110(a)(1) and (2) for the 2006 24-hour Fine Particle (PM 2.5) 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.  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.
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.  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).
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 PM 2.5 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.  ADEQ submitted on October 14, 2009, its “Arizona State Implementation Plan Revision under Clean Air Act Section 110(a)(1) and (2); 2006 PM 2.5 NAAQS, 1997 PM 2.5 NAAQS, and 1997 8-hour Ozone NAAQS,” which addressed the requirements of section 110(a)(2)(D)(i) with respect to the 2006 PM 2.5 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. 
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.  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.  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.
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 PM 2.5 NAAQS, and 2006 PM 2.5 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 Back to Top
A. Regional Haze Rule
The Regional Haze Rule (RHR) sets out specific requirements for states' initial regional haze implementation plans.  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.
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. 
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,  hereinafter referred to as “EPA's 2003 Natural Visibility Guidance”, and Guidance for Tracking Progress Under the Regional Haze Rule, September 2003,  hereinafter referred to as “EPA's 2003 Tracking Progress Guidance”.
For the first regional haze SIPs that were due by December 17, 2007, “baseline visibility conditions” were the starting points for assessing “current” visibility impairment. Baseline visibility conditions represent the degree of visibility impairment for the 20 percent least impaired days and 20 percent most impaired days for each calendar year from 2000-2004. Using monitoring data for 2000 through 2004, states are required to calculate the average degree of visibility impairment for each Class I area, based on the average of annual values over the five-year period. The comparison of initial baseline visibility conditions to natural visibility conditions indicates the amount of improvement necessary to attain natural visibility, while the future comparison of baseline conditions to the then current conditions will indicate the amount of progress. In general, the 2000-2004 baseline period is considered the time from which improvement in visibility is measured.
C. Determination of Reasonable Progress Goals (RPGs)
The mechanism for ensuring continuing progress toward achieving the natural visibility goal is the submission of a series of regional haze SIPs that establish two RPGs (i.e., two distinct goals, one for the “best” and one for the “worst” days) for every Class I area for each ten-year implementation period. The RHR does not mandate specific milestones or rates of progress, but instead calls for states to establish goals that provide for “reasonable progress” toward achieving natural (i.e., “background”) visibility conditions. In setting RPGs, states must provide for an improvement in visibility for the most impaired days over the ten-year period of the SIP, and ensure no degradation in visibility for the least impaired days over the same period.
States have significant discretion in establishing RPGs, but are required to consider the following factors established in section 169A of the CAA and in EPA's RHR at 40 CFR 51.308(d)(1)(i)(A): (1) The costs of compliance; (2) the time necessary for compliance; (3) the energy and non-air quality environmental impacts of compliance; and (4) the remaining useful life of any potentially affected sources. States must demonstrate in their SIPs how these factors are considered when selecting the RPGs for the best and worst days for each applicable Class I area. States have considerable flexibility in how they take these factors into consideration, as noted in EPA's Guidance for Setting Reasonable Progress Goals under the Regional Haze Program, July 1, 2007, memorandum from William L. Wehrum, Acting Assistant Administrator for Air and Radiation, to EPA Regional Administrators, EPA Regions 1-10 (pp. 4-2, 5-1) (“EPA's Reasonable Progress Guidance”). In setting the RPGs, states must also consider the rate of progress needed to reach natural visibility conditions by 2064 (referred to as the “uniform rate of progress” (URP) or the “glide path”) and the emission reduction measures needed to achieve that rate of progress over the ten-year period of the SIP. Uniform progress towards achievement of natural conditions by the year 2064 represents a rate of progress that states are to use for analytical comparison to the amount of progress they expect to achieve. In setting RPGs, each state with one or more Class I areas (“Class I state”) must also consult with potentially “contributing states,” i.e., other nearby states with emission sources that may be affecting visibility impairment at the Class I state's areas. 
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  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.
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 SO 2, NO X and PM. EPA has indicated that states should use their best judgment in determining whether VOC or NH 3 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.  The Regional Haze SIP must also contain a requirement for each BART source to maintain the relevant control equipment, as well as procedures to ensure control equipment is properly operated and maintained.  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. 
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. 
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.  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).
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. 
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.  The first progress report is due five years from submittal of the initial regional haze SIP revision. At the same time a 5-year progress report is submitted, a state must determine the adequacy of its existing SIP to achieve the established goals for visibility improvement.  The RHR contains more detailed requirements associated with these parts of the Rule.
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.  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.
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.  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 SO 2 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.  The Annex was submitted in 2000, and EPA revised 40 CFR 51.309 in 2003. 
V. Overview of State and EPA Actions on Regional Haze Back to Top
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.  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.  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. 
|EPA Actions||Proposed rule||Final rule|
|BART determinations for Apache, Cholla and Coronado||July 2, 2012||November 15, 2012.|
|All remaining elements of Arizona's RH SIP||December 8, 2012||July 15, 2013.|
|FIP for disapproved elements of Arizona's RH SIP (if required)||March 8, 2013||October 15, 2013.|
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 NO X 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.”  When these regulations were first promulgated, 309 submissions were due no later than December 31, 2003. Accordingly, the Arizona Department of Environmental Quality (ADEQ) submitted to EPA on December 23, 2003, a 309 SIP for Arizona's four Class I Areas on the Colorado Plateau. ADEQ submitted a revision to its 309 SIP, consisting of rules on emissions trading and smoke management, and a correction to the State's regional haze statutes, on December 31, 2004. EPA approved the smoke management rules submitted as part of the 2004 revisions,  but did not propose or take final action on any other portion of the 309 SIP.
In response to an adverse court decision,  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.  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. 
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.  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.
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.  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. 
VI. EPA's Evaluation of Visibility Conditions in Arizona's Class I Areas Back to Top
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).
|Class I area||IMPROVE monitor code|
|1Chiricahua National Monument||CHIR1|
|4Grand Canyon National Park||GRCA2|
|6Pine Mountain Wilderness||IKBA1|
|7Mount Baldy Wilderness||BALD1|
|8Petrified Forest National Park||PEFO1|
|9Saguaro National Park||SAGU1, SAWE1|
|10Sierra Ancha Wilderness||SIAN1|
|12Sycamore Canyon Wilderness||SYCA1|
|Class I area||State||IMPROVE monitor code|
|Mesa Verde National Park||Colorado||MEVE1|
|Black Canyon of the Gunnison NP, La Garita WA, Weminuche WA||Colorado||WEMI1|
|Great Sand Dunes NM||Colorado||GRSA1|
|Eagles Nest WA, Flat Tops WA, Maroon Bells-Snowmass WA, West Elk WA||Colorado||WHRI1|
|Gila Wilderness Area||New Mexico||GICL1|
|Bosque del Apache National Wildlife Refuge||New Mexico||BOAP1|
|San Pedro Parks Wilderness Area||New Mexico||SAPE1|
|Bandelier National Monument, Pecos WA||New Mexico||BAND1|
|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
ADEQdeveloped 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. 
Baseline and Natural Visibility Conditions: Baseline visibility conditions represent the degree of visibility impairment for the 20 percent least impaired days and 20 percent most impaired days for each calendar year from 2000-2004. Using monitoring data for 2000 through 2004, states are required to calculate the average degree of visibility impairment for each Class I area based on the average of annual values over the five-year period. Chapter 6.2 and Appendix C of the ARHP provide the details of the deciview calculations of the baseline and natural conditions for each Class I area during 2000-2004.
For each Class I area, ADEQ calculated, in deciviews, the current visibility conditions (worst 20 percent of days) for the 2000-2004 baseline period (Table 4, column A) and the future natural conditions for 2064 (Table 4, column D), the long-term goal of the regional haze program. These correspond to tables 6.1 and 6.2 in the ARHP. ADEQ calculated the dv value representing the best visibility days during 2000-2004 baseline conditions, a value that must be maintained in future years.  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.  This used time-varying Class I area-specific data and more robust statistical assumptions, along with the revised IMPROVE equation  for translating pollutant concentrations into extinction, in order to derive more refined visibility estimates that remain consistent with the approach in EPA's Guidance.
|Class I area||Baseline 2000-2004||Reasonable Progress Goal (RPG) 2018||Uniform Rate of Progress (URP) estimate||Natural conditions 2064||Years required to reach natural conditions at RPG rate of improvement|
|[20 percent worst days in deciviews]|
|Chiricahua NM, Chiricahua WA, Galiuro WA (CHIR1 monitor)||13.43||13.35||11.98||7.20||1,038|
|Grand Canyon NP (GRCA2 monitor)||11.66||11.14||10.58||7.04||125|
|Mazatzal WA, Pine Mountain WA (IKBA1 monitor)||13.35||12.76||11.79||6.68||159|
|Mount Baldy WA (BALD1 monitor)||11.85||11.52||10.54||6.24||234|
|Petrified Forest NP (PEFO1 monitor)||13.21||12.85||11.64||6.49||258|
|Saguaro NP—East Unit (SAGU1 monitor)||16.22||14.82||12.88||6.46||8,370|
|Saguaro NP—West Unit (SAWE1 monitor)||14.83||15.99||13.90||6.24||624|
|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 monitor)||15.25||15.00||13.25||6.65||478|
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 areaare listed in Table 4, column C of this proposal.
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.
|Class I area||2000-04 Baseline||2018 Reasonable Progress Goal (RPG)|
|[Best 20% days in deciviews]|
|Chiricahua NM, Chiricahua WA, Galiuro WA (CHIR1 monitor)||4.91||4.94|
|Grand Canyon NP (GRCA2 monitor)||2.16||2.12|
|Mazatzal WA, Pine Mountain WA (IKBA1 monitor)||5.40||5.17|
|Mount Baldy WA (BALD1 monitor)||2.98||2.86|
|Petrified Forest NP (PEFO1 monitor)||5.02||4.73|
|Saguaro NP—East Unit (SAGU1 monitor)||6.94||7.04|
|Saguaro NP—West Unit (SAWE1 monitor)||8.58||8.34|
|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.  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: NO X, SO 2, VOC, PM 2.5, PM coarse  and NH 3. 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.
|Category||SO 2[tpy]||NO X[tpy]||VOC [tpy]||NH 3[tpy]|
|[Tons per year]61|
|Category||PM 2.5[tpy]||PM coarse[tpy]|
|[Tons per year]63|
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.  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. 
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.
|Pollutant||Anthropogenic share in 2002 (percentage)||Change in total emissions (2002-2018) (percentage)|
Table 7shows that the majority of VOC and PM 2.5 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 PM coarse and fine soil emissions are similarly from uncontrollable sources. NO X, SO 2 and NH 3 are predominantly anthropogenic in origin. Table 7 also shows that inventory projections indicate significant decreases in NO X and SO 2 emissions. EPA expects that 2018 emissions will be even lower than projected in the plan due to our FIP actions.  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 PM coarse emissions is a potential concern. However, EPA concludes that, for the reasons explained above, these 2018 emissions estimates may not be reliable.
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.  Based on this analysis, EPA proposes to find that the 2002 and 2018 inventories are adequate for the regional haze plan.
However, the RHR also requires that Arizona to provide the most recent inventory available.  Under the Consolidated Emissions Reporting Rule, states are required to compile and submit to EPA comprehensive statewide emissions inventories every three years.  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.
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.  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.
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.  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.
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.  Most significantly, the contribution from organic carbon has decreased by 2.2 inverse megameters (Mm −1)  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 tovisibility impairment, and the recent trends in more detail.
|IMPROVE SITE/Class I area||Ammonium nitrate||Ammonium sulfate||Organic carbon||Elemental carbon||Coarse mass||Fine soil||Sea salt|
|[Worst 20 percent of days, averaged over the baseline period]76|
|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|
1. Chiricahua National Monument, Chiricahua Wilderness Area and Galiuro Wilderness Area
Visibility impairment at Chiricahua National Monument, and Chiricahua and Galiuro Wilderness Areas are represented by the conditions at the IMPROVE monitor in the Chiricahua National Monument (CHIR1). Average monitored concentrations over the period of 2000-2004 indicate that coarse mass, organic carbon and ammonium sulfate are the most significant contributors to visibility impairment, together accounting for 79.9 percent of the light extinction. Fine soil is the next largest contributor to light extinction with 8.9 percent, and is correlated with periods of high coarse mass impact.
IMPROVE data averaged over 2005-2010 show measurable decreases in the light extinction due to organic carbon and coarse mass of over 3 Mm −1 each. There was a slight increase in light extinction due to ammonium sulfate measured during these years of 1.1 mM −1, but overall the total light extinction has decreased significantly between the two periods by 6.7 Mm −1.
2. Grand Canyon National Park
Visibility impairment at Grand Canyon National Park is represented by the conditions at the IMPROVE monitor at Hance Camp (GRCA2). Average monitored concentrations over the period of 2000-2004 indicate that 39.8 percent of the light extinction is due to organic carbon alone. The next significant contributor is ammonium sulfate accounting for 22.1 percent of the light extinction. Coarse mass and fine soils contribute 17.6 percent and ammonium nitrate contributes 11 percent of the light extinction. Elemental carbon accounts for 9.2 percent of light extinction, and is correlated with periods of high organic carbon impact.
IMPROVE data averaged over 2005-2010 show a slight decrease in the light extinction due to organic carbon of 1.1 Mm −1. The changes in contribution to light extinction from the other aerosol components were small or negligible between the two periods, with a very slight decrease in total aerosol light extinction of 0.8 Mm −1.
3. Mazatzal Wilderness Area and Pine Mountain Wilderness Area
Visibility impairment at Mazatzal and Pine Mountain Wilderness Areas is represented by the conditions at the IMPROVE monitor at Ike's Backbone (IKBA1). Average monitored concentrations over the period of 2001-2004 indicate that coarse mass, organic carbon and ammonium sulfate are the most significant contributors to visibility impairment, each contributing similarly to 69.0 percent of the light extinction. Ammonium nitrate contributes 14.1 percent, and fine soil and elemental carbon each contribute about 8 percent, and are correlated with periods of high coarse mass and organic carbon impact, respectively.
IMPROVE data averaged over 2005-2010 show a slight decrease in light extinction due to ammonium nitrate of 1.2 Mm −1 and a slight increase in light extinction due to ammonium sulfate of 1.0 Mm −1 since the average values of the baseline period.
4. Mount Baldy Wilderness Area
Visibility impairment at Mount Baldy Wilderness Area is represented by the conditions at the IMPROVE monitor in the wilderness area (BALD1). Similar to Grand Canyon National Park, average monitored concentrations over the period of 2000-2004 in Mount Baldy Wilderness indicate that nearly half of the light extinction is due to organic carbon alone and the next significant contributor is ammonium sulfate accounting for 22.0 percent of the light extinction. Coarse mass and fine soils contribute over 16.5 percent of the light extinction. Elemental carbon contributes 10.5 percent to the light extinction and is correlated with periods of high organic carbon impact.
IMPROVE data averaged over 2005-2010 show a measurable decrease in light extinction due to organic carbon of 2.0 Mm −1 and a overall decrease in total aerosol light extinction of 1.1 Mm −1 since the average values of the baseline period.
5. Petrified Forest National Park
Visibility impairment at Petrified Forest National Park is represented by the conditions at the IMPROVE monitor in the National Park (PEFO1). Average monitored concentrations over the period of 2000-2004 indicate that organic carbon, coarse mass, and ammonium sulfate are the most significant contributors to visibility impairment, together accounting for 76.3 percent of the light extinction. Elemental carbon is the next largest contributor to light extinction at 10.3 percent, and is correlated with periods of high organic carbon impact.
IMPROVE data averaged over 2005-2010 show that light extinction due to organic carbon and coarse mass decreased by 2.6 and 1.2 Mm −1, respectively since the baseline period. Total aerosol light extinction decreased by 3.0 Mm −1 since the average values of the baseline period.
6. Saguaro National Park (East Unit and West Unit)
There are IMPROVE monitors in both the East and West Units of Saguaro National Park that represent the visibility impairment throughout the National Park (SAGU1 and SAWE1). Average monitored concentrations over the period of 2002-2004 indicate that organic carbon, coarse mass, and ammonium sulfate are the most significant contributors to visibility impairment, together accounting for 67.0 to 67.5 percent of the light extinction. Ammonium nitrate contributes 10.6 to 14.3 percent and fine soil, correlated with coarse mass, contributes 9 to 15 percent.
IMPROVE data averaged over 2005-2010 show that light extinction due to organic carbon decreased since the baseline period by 5.5 and 2.9 Mm −1, at SAGU1 and SAWE1, respectively. Also, SAGU1 measured a decrease in contribution from ammonium nitrate of 2.2 Mm −1 and SAWE1 measured a decrease in contribution of coarse mass and fine soil together of 5.7 Mm −1. These monitors indicate that the total aerosol light extinction has improved at these two areas more than at any area in Arizona, with decreases of 8.2 and 9.8 Mm −1 at the East and West Units, respectively.
7. Sierra Ancha Wilderness Area
Visibility impairment at Sierra Ancha Wilderness Area is represented by the conditions at the IMPROVE monitor in the Wilderness Area (SIAN1). Average monitored concentrations over the period 2001-2004 indicate that 37.0 percent of the light extinction is due to organic carbon. Coarse mass and fine soil together account for almost 24.4 percent and ammonium sulfate accounts for 20.1 percent of the light extinction.
IMPROVE data averaged over 2005-2010 show that light extinction due to ammonium nitrate and coarse mass decreased by 1.3 and 1.5 Mm −1, respectively since the baseline period. Slight increases in the contribution from ammonium sulfate, as well as from organic and elemental carbon lead to a total aerosol light extinction that is decreased only slightly, by 1.3 Mm −1, since the average values of the baseline period.
8. Sycamore Canyon Wilderness Area
Visibility impairment in the Sycamore Canyon Wilderness Area is represented by the conditions at the IMPROVE monitor in the Wilderness Area (SYCA1). Average monitored concentrations over the period 2001-2004 indicate that 32.5 percent of the light extinction is due to organic carbon. Other significant contributors are coarse mass (22.6 percent), fine soil (16.9 percent), and ammonium sulfate (13.0 percent). Fine soil is often correlated with coarse mass, but there are also times when the two are not correlated. For example, July 13 and November 22, 2002 have high concentrations of fine soil but not coarse mass. Elemental carbon contributes 9.4 percent to the light extinction and is correlated with periods of high organic carbon impact.
IMPROVE data averaged over 2005-2010 show that light extinction due organic carbon and fine soil decreased by 1.3 and 1.2 Mm −1, respectively since the baseline period. The contribution from coarse mass increased between the two time periods by 1.4 Mm −1. Total aerosol light extinction decreased only slightly, by 0.8 Mm −1, since the baseline period.
9. Superstition Wilderness Area
Visibility impairment in the Superstition Wilderness Area is represented by the conditions at the IMPROVE monitor in the Tonto National Monument (TONT1). Average monitored concentrations between 2001 and 2004 indicate that 30 percent of the light extinction is due to organic carbon. Coarse mass and fine soil together account for 27.9 percent and ammonium sulfate accounts for 21.0 percent of the light extinction. Finally, ammonium nitrate contributes 12.2 percent of the light extinction.
IMPROVE data averaged over 2005-2010 show that light extinction due organic carbon and ammonium nitrate decreased by 4.1 and 1.0 Mm −1, respectively since the baseline period. This site exhibited the largest increase in light extinction from ammonium sulfate in Arizona: 1.7 Mm −1. However, total aerosol light extinction still decreased by 3.4 Mm −1, since the baseline period.
VII. EPA's Evaluation of Arizona's BART Analyses and Determinations Back to Top
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.”  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.  These facilities are listed in Table 9 below.
|Facility name||Source category||Number of BART-eligible units|
|Tucson Electric Power (TEP) Sundt Generating Station||Fossil-fuel fired steam electric plants of more than 250 million British thermal units per hour heat input||1|
|Arizona Electric Power Cooperative (AEPCO) Apache Generating Station||3|
|Arizona Public Service (APS) Cholla Power Plant||3|
|Salt River Project (SRP) Coronado Generating Station||2|
|APS West Phoenix Power Plant||3|
|CalPortland Rillito Cement Plant||Portland cement plant||1|
|Chemical Lime Nelson Plant||Lime Plant||2|
|Catalyst Paper Snowflake Mill||Fossil-fuel boilers of more than 250 million British thermal units per hour heat input||1|
|ASARCO Hayden Smelter||Primary Copper Smelter||10|
|Freeport McMoRan (FMMI, formerly Phelps-Dodge) Miami Smelter||9|
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.  As a result, the BART determinations for these three facilities are not discussed in today's proposal.
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 SO 2 and PM 10 emissions. In response, ASARCO provided a letter to ADEQ on October 1, 2007, in which it stated that only three converters and two anode furnaces were BART-eligible based on operation dates prior to 1962 in the case of two converters, and a construction (“in existence”) date of 2001 in the case of one of the anode furnaces. In addition, ASARCO stated that ADEQ's estimate of its potential to emit (PTE) was overestimated, as it was based on facility-wide PTE estimates which included the PTE of non BART-eligible sources. In its letter, ASARCO provided information re-apportioning the fraction of the facility-wide PTE attributable to the BART-eligible sources.
ADEQ performed its own research of historical smelter logs and agreed with ASARCO's assertion that only three converters and two anode furnaces are BART-eligible. It took no action regarding ASARCO's PTE apportionment information, citing a lack of documentation. However, as part of the Title V permit renewal process, ADEQ subsequently revised its estimate of facility-wide PM 10 PTE downward. ADEQ concluded that the BART-eligible units do not have a PM 10 PTE greater than 250 tpy, and determined that the units at the Hayden smelter are not BART eligible for PM 10.  This did not alter ADEQ's determination that the Hayden smelter was subject to BART for SO 2.
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.  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.  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.
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.  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.
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.”  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.”  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.
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.  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.
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.
|Facility||Class I area with highest impact||Visibility impact at 98th percentile (dv)||Notes|
|1Based on September 21, 2007 modeling report provided by Chemical Lime.|
|2Based on October 4, 2007 modeling report provided by Arizona Public Service.|
|3Based on May 25, 2007 WRAP RMC BART Modeling Results for Arizona.|
|Nelson Lime Plant||Grand Canyon National Park||0.452||0.419||0.624||0.498||1|
|West Phoenix Power Plant||Superstition Wilderness||0.28||0.21||0.23||0.24||2|
|Rillito Cement Plant||Saguaro National Monument||0.37||0.48||0.34||0.40||3|
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 th