

[Federal Register: January 24, 2007 (Volume 72, Number 15)]
[Rules and Regulations]               
[Page 3061-3075]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24ja07-18]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R09-OAR-2006-0580; FRL-8270-3]

 
Approval and Promulgation of Air Quality Implementation Plans; 
Designation of Areas for Air Quality Planning Purposes; Arizona; Miami 
Sulfur Dioxide State Implementation Plan and Request for Redesignation 
to Attainment; Correction of Boundary of Miami Sulfur Dioxide 
Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA is taking direct final action under the Clean Air Act to 
approve the Miami Sulfur Dioxide Nonattainment Area State

[[Page 3062]]

Implementation and Maintenance Plan as a revision to the Arizona state 
implementation plan. The Arizona Department of Environmental Quality 
developed this plan to maintain the sulfur dioxide national ambient air 
quality standards in the Miami (Gila County) area. The maintenance plan 
contains various elements, including contingency provisions that will 
be implemented if measured ambient concentrations of sulfur dioxide are 
above certain trigger levels. EPA is also approving the State of 
Arizona's request for redesignation of the Miami area from 
nonattainment to attainment for the sulfur dioxide standards. Lastly, 
EPA is correcting the boundary of the Miami sulfur dioxide 
nonattainment area to exclude a noncontiguous township that was 
erroneously included in the description of the area and to fix a 
transcription error in the listing of one of the other townships.
    EPA is taking these actions consistent with provisions in the Clean 
Air Act that obligate the Agency to approve or disapprove submittals of 
revisions to state implementation plans and requests for redesignation. 
The intended effect is to redesignate the Miami, Arizona sulfur dioxide 
nonattainment area to attainment, provide for maintenance of the 
standard for the ten-year period following redesignation, and correct 
long-standing errors in the codified description of the area.

DATES: This rule is effective on March 26, 2007 without further notice, 
unless EPA receives adverse comments by February 23, 2007. If we 
receive such comments, we will publish a timely withdrawal in the 
Federal Register to notify the public that this direct final rule will 
not take effect.

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-
2006-0580, by one of the following methods:
    1. Federal eRulemaking Portal: http://www.regulations.gov. Follow the on-

line instructions.
    2. E-mail: vagenas.ginger@epa.gov.
    3. Mail or deliver: Ginger Vagenas (Air-2), U.S. Environmental 
Protection Agency Region IX, 75 Hawthorne Street, San Francisco, CA 
94105-3901.
    Instructions: All comments will be included in the public docket 
without change and may be made available online at http://www.regulations.gov, 

including any personal information provided, unless the comment 
includes Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. Information that you 
consider CBI or otherwise protected should be clearly identified as 
such and should not be submitted through the http://www.regulations.gov or e-

mail. http://www.regulations.gov is an ``anonymous access'' system, and EPA 

will not know your identity or contact information unless you provide 
it in the body of your comment. If you send e-mail directly to EPA, 
your e-mail address will be automatically captured and included as part 
of the public comment. 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.
    Docket: The index to the docket for this action is available 
electronically at http://www.regulations.gov and in hard copy at EPA Region 

IX, 75 Hawthorne Street, San Francisco, California. While all documents 
in the docket are listed in the index, some information may be publicly 
available only at the hard copy location (e.g., copyrighted material), 
and some may not be publicly available in either location (e.g., CBI). 
To inspect the hard copy materials, please schedule an appointment 
during normal business hours with the contact listed in the FOR FURTHER 
INFORMATION CONTACT section.

FOR FURTHER INFORMATION CONTACT: Ginger Vagenas, Air Planning Office, 
(415) 972-3964 or by e-mail at vagenas.ginger@epa.gov.

SUPPLEMENTARY INFORMATION: Elsewhere in this Federal Register, we are 
proposing approval and soliciting written comment on this action. 
Throughout this document, the words ``we,'' ``us,'' or ``our'' mean 
U.S. EPA.

Table of Contents

I. Summary of Today's Direct Final Action
II. Introduction
    A. SO2 NAAQS
    B. State Implementation Plan
    C. History of SO2 Planning in Arizona
    1. Development of the SO2 SIP
    2. Miami SO2 Nonattainment Area
    D. Sources of SO2 Emissions in the Miami Area
III. CAA Requirements for Redesignation Requests and Maintenance 
Plans
IV. EPA's Evaluation of Redesignation Request and Maintenance Plan 
for the Miami, Arizona SO2 Nonattainment Area
    A. The Area Must Be Attaining the SO2 NAAQS
    B. The Area's Applicable Implementation Plan Must Be Fully 
Approved Under Section 110(k)
    C. The Improvement in Air Quality Must Be Due to Permanent and 
Enforceable Reductions in Emissions
    D. The Area Must Have Met All Applicable Requirements Under 
Section 110 and Part D
    1. Section 110 Requirements
    2. Part D Requirements
    a. Section 172
    b. Section 176
    c. Subpart 5
    E. The Area Must Have a Fully Approved Maintenance Plan
    1. Attainment Inventory
    2. Maintenance Demonstration
    3. Monitoring Network
    4. Verification of Continued Attainment
    5. Contingency Plan
    6. Subsequent Maintenance Plan Revisions
    7. Conclusion
V. Boundary Correction
    A. Background
    B. Authority for Correcting Errors
    C. Evaluation and Conclusion
VI. Public Comment and Final Action
VII. Statutory and Executive Order Review

I. Summary of Today's Direct Final Action

    On June 26, 2002, the Arizona Department of Environmental Quality 
(``ADEQ'' or ``State'') submitted to EPA Region IX its Miami Sulfur 
Dioxide State Implementation and Maintenance Plan and its request for 
redesignation to attainment (``Miami SO2 Maintenance Plan'' 
or ``submittal''). The submittal summarizes the progress the State has 
made in attaining the sulfur dioxide (SO2) national ambient 
air quality standards (NAAQS) in the Miami nonattainment area (Gila 
County, Arizona) (``Miami area'') and includes a plan to assure 
continued attainment of the SO2 NAAQS for at least the next 
10 years. The June 26, 2002 submittal also includes a request for 
redesignation of the boundary of the area and for redesignation of the 
status of the area, as amended, to ``attainment'' under section 107(d) 
of the Clean Air Act (``Act'' or CAA). On June 30, 2004, ADEQ submitted 
certain replacement pages correcting errors in the June 26, 2002 
submittal. On June 20, 2006, ADEQ submitted a letter withdrawing the 
boundary redesignation request and requesting EPA to address the 
boundary issue as an error correction under CAA section 110(k)(6) 
instead.
    In today's direct final action, because we find that the Miami 
SO2 Maintenance Plan meets the requirements for maintenance 
plans under section 175A of the Act and that the Miami area qualifies 
for redesignation under CAA section 107(d)(3)(E), we are approving the 
submittal (as amended by the submittals dated June 30, 2004 and June 
20, 2006) as a revision to the Arizona SIP and redesignating the Miami 
area from nonattainment to attainment for the SO2 NAAQS. 
Also, based on a review of the relevant State and EPA materials from 
the late 1970's, we are correcting errors under CAA section 110(k)(6) 
in the listing of the townships that comprise the Miami SO2 
nonattainment area to exclude a noncontiguous township and

[[Page 3063]]

to fix a transcription error in one of the other townships so listed.

II. Introduction

    The following section discusses the NAAQS for SO2, CAA 
requirements for state implementation plans, SO2 planning in 
Arizona generally and in the Miami area more specifically, and sources 
of emissions in the Miami area.

A. SO2 NAAQS

    The NAAQS for SO2 consists of three standards: Two 
primary standards for the protection of public health and a secondary 
standard for protection of public welfare. The primary SO2 
standards address 24-hour average and annual average ambient 
SO2 concentrations. The secondary standard addresses 3-hour 
average ambient SO2 concentrations. The level of the annual 
SO2 standard is 0.030 parts per million (ppm), which is 
equivalent to 80 micrograms per cubic meter ([mu]g/m3), not 
to be exceeded in a calendar year. The level of the 24-hour standard is 
0.14 ppm (365 [mu]g/m3), not to be exceeded more than once 
per calendar year. The level of the secondary SO2 standard 
is a 3-hour standard of 0.5 ppm (1,300 [mu]g/m3), not to be 
exceeded more than once per calendar year. See 40 CFR 50.2-50.5.

B. State Implementation Plan

    The CAA requires states to implement, maintain, and enforce ambient 
air quality equal to or better than the NAAQS. A state's strategies for 
implementing, maintaining, and enforcing the NAAQS are submitted to EPA 
for approval, and, once approved, become part of the State 
Implementation Plan (or SIP) for that State. SIPs are compilations of 
regulatory and non-regulatory elements adopted, submitted, and approved 
at different times to address various types of changes in 
circumstances, such as new or revised NAAQS or amendments to the CAA. 
SIPs include, among other things, the following: (1) An inventory of 
emission sources; (2) statutes and regulations adopted by the state 
legislature and executive agencies; (3) air quality analyses that 
include demonstrations that adequate controls are in place to meet the 
NAAQS; and (4) contingency measures to be undertaken if an area fails 
to attain the standard or make reasonable progress toward attainment by 
the required date. The state must make proposed changes to the SIP 
available for public review and comment through a public hearing, and 
must formally adopt the changes before submitting them to EPA for 
approval. Upon our approval, a SIP revision becomes federally 
enforceable.

C. History of SO2 Planning in Arizona

1. Development of the SO2 SIP
    In the early 1970's, soon after the Clean Air Amendments of 1970 
were passed, Arizona began developing air quality regulations that 
applied to all Arizona primary copper smelters, including the one 
operating in the Miami area. These regulations focused on establishing 
an air quality monitoring network in the areas surrounding the smelters 
and determining the allowable emission rates from the smelters so that 
the SO2 NAAQS could be attained and maintained. Arizona 
submitted various SIP revisions during the 1970s to establish 
approvable emission limitations for the primary copper smelters 
operating in the state. On September 20, 1979, the State submitted its 
SIP revision to EPA which contained its multi-point rollback (MPR) 
technique to establish operating limitations on smelters. After EPA's 
proposed conditional approval on November 30, 1981 (46 FR 58098), 
Arizona made necessary changes which corrected identified deficiencies. 
EPA granted full approval of the MPR-based SIP submittal on January 14, 
1983 (48 FR 1717), but was not able to grant full approval to the 
SO2 SIPs for six smelter areas (including Miami) because 
they lacked a strategy for addressing fugitive\1\ sources of 
SO2.
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    \1\ ``Fugitive'' in this context refers to emissions that could 
not reasonably pass through a stack, chimney, vent for a 
functionally equivalent opening.
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    On November 1, 2004, EPA approved several revisions to the 
SO2 SIP, including site-specific requirements, compliance 
and monitoring, and fugitive emissions standards for existing primary 
copper smelters. See 69 FR 63321. In that same notice, EPA promulgated 
a limited approval/limited disapproval of R18-2-Appendix 8, which sets 
out procedures for calculating sulfur emissions using a sulfur balance 
method. ADEQ subsequently corrected the identified deficiencies and EPA 
approved the new version of R18-2-Appendix 8 as a SIP revision on April 
12, 2006. See 71 FR 18624. The effective date for our April 12, 2006 
final approval is June 12, 2006.
2. Miami SO2 Nonattainment Area
    Originally, the air quality planning area we refer to as the Miami 
SO2 nonattainment area was not separately defined but rather 
was included in a county-wide SO2 nonattainment area (see 43 
FR 8969, March 3, 1978). At the request of the state of Arizona, the 
boundaries were reduced to nine townships in and around the city of 
Miami (44 FR 21261, April 10, 1979). See also, 40 CFR 81.303.\2\ In 
addition, six adjacent townships were designated as ``cannot be 
classified''. Section 107(d)(1)(C) of the 1990 Clean Air Act Amendments 
(CAAA) brought forward, by operation of law, the nonattainment 
designations for areas, such as the Miami SO2 area, that 
continued to be designated as nonattainment at the time of enactment of 
the CAAA, i.e., areas that had not been redesignated to ``attainment'' 
prior to November 1990.
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    \2\ The nine townships that comprise the Miami SO2 
nonattainment area are: T2N, R14E; T2N, R15E; T1N, R13E (only that 
portion in Gila County); T1N, R14E; T1N, R15E; T1N, R16E; T1S, R14E 
(only that portion in Gila County); T1S, R14\1/4\E; and T1S, R15E. 
Code of Federal Regulations, title 40, part 81, section 303 (40 CFR 
81.303) also identifies six other townships as areas that ``cannot 
be classified.'' These six townships are: T2N, R13E (only that 
portion in Gila County); T2N, R16E; T1S, R13E (only that portion in 
Gila County); T1S, R16E; T2S, R14E (only that portion in Gila 
County); and T2S, R15E. All of the townships discussed in this 
notice relate to the Gila and Salt River Base Line. In section V of 
this notice, we discuss our decision to amend 40 CFR 81.303 to 
correct the boundary of the Miami area to exclude a noncontiguous 
township and to fix a typographical error.
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D. Sources of SO2 Emissions in the Miami Area

    The dominant source of SO2 emissions in the Miami area 
is the Phelps-Dodge Miami primary copper smelter (``Miami smelter''). 
Combined stack and fugitive SO2 emissions from the smelter 
are limited under the source-specific EPA-approved rule (i.e., R18-2-7-
715) to 2,420 pounds per hour annual average, which amounts to 
approximately 10,368 tons per year based on 357 days of operation (set 
forth for the permit for this facility) or approximately 10,600 tons 
per year assuming 365 days per year of smelter operation. Between 1996 
and 2000, the smelter's actual SO2 emissions ranged from 
5,737 tons per year to 7,819 tons per year and represented 97 to 99% of 
the total stationary source SO2 emissions in the Miami 
nonattainment area. See tables 4.1, 4.3, and 5.2 of the Miami 
SO2 Maintenance Plan. There are several other point sources 
of SO2 in the Miami area, all of which are relatively minor: 
BHP Copper, Pinto Valley; BHP Copper, Miami East Unit; Carlota Copper 
Company Mine; and the Phelps-Dodge Miami Mine. Viewed collectively, 
these sources are permitted to emit a total of approximately 100 tons 
per year. Actual emissions, however, are generally less than 10 tons 
per year. SO2 emissions from area and mobile sources

[[Page 3064]]

are about 150 tons per year. See sections 4.1 and 4.3 of the Miami 
SO2 Maintenance Plan and table 1, below.

 Table 1.--Point, Area, and Mobile Sources of SO2 Emissions in the Miami
               SO2 Nonattainment Area (Tons per year, TPY)
------------------------------------------------------------------------
                                                              Actual
           Source name or type               Allowable       emissions
                                             emissions        (1999)
------------------------------------------------------------------------
Stationary Sources (not including Phelps-
 Dodge primary copper smelter):
    BHP Copper, Pinto Valley Unit.......              6a              < 1
    BHP Copper, Miami East Unit.........              < 1              < 1
    Carlotta Copper Company Mine........               1               0
    Phelps-Dodge Miami Mine.............              92               7
    Area and Mobile.....................              NA             149
    Phelps-Dodge Miami Smelting                   10,368           7,819
     Operations.........................
                                         -------------------------------
        Total From All Sources..........              NA           7,975
------------------------------------------------------------------------
a When burning diesel; lower limits exist for other fuels.
NA = not applicable.
Source: Sections 4.1 and 4.3 from the Miami SO2 Maintenance Plan.

III. CAA Requirements for Redesignation Requests and Maintenance Plans

    As stated in the summary section of this rule, Arizona has 
requested that we redesignate the Miami SO2 nonattainment 
area to attainment. Any redesignation from nonattainment to attainment 
requires EPA to determine whether the requirements of Clean Air Act 
section 107(d)(3)(E), have been met. These criteria are: (1) At the 
time of the redesignation, we must find that the area has attained the 
relevant NAAQS; (2) the State must have a fully approved SIP for the 
area; (3) we must determine that the improvements in air quality are 
due to permanent and enforceable reductions in emissions resulting from 
implementation of the SIP and applicable federal regulations and other 
permanent and enforceable reductions; (4) the state must have met all 
the nonattainment area requirements applicable to the area; and (5) we 
must have fully approved a maintenance plan for the area under CAA 
section 175A.
    To evaluate the State's redesignation request for the Miami area, 
we relied upon the Clean Air Act itself, particularly section 110 and 
part D (of title I), EPA's NAAQS and SIP regulations in 40 CFR parts 50 
and 51, and guidance set forth in ``General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990'' (57 
FR 13498, April 16, 1992), and in the following EPA guidance documents: 
``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' dated September 4, 1992, from John Calcagni, (``Calcagni 
Memo''), ``Attainment Determination Policy for Sulfur Dioxide 
Nonattainment Areas,'' dated January 26, 1995, from Sally L. Shaver, 
(``Shaver Memo''), and ``Part D New Source Review (part D NSR) 
Requirements for Areas Requesting Redesignation to Attainment,'' dated 
October 14, 1994, from Mary D. Nichols (``Nichols Memo'').

IV. EPA's Evaluation of Redesignation Request and Maintenance Plan for 
the Miami, Arizona SO2 Nonattainment Area

A. The Area Must Be Attaining the SO2 NAAQS

    Under CAA section 107(d)(3)(E)(i), in order for an area to be 
redesignated, we must determine that the area has attained the 
applicable NAAQS. The air quality data should be representative of the 
area of highest concentration and should be measured by monitors that 
remain at the same location for the duration of the monitoring period 
required for demonstrating attainment. The data should be collected and 
quality-assured in accordance with 40 CFR part 58 and recorded in EPA's 
Air Quality System database (AQS) to be available for public review. 
Under 40 CFR part 58, States certify data that is entered into AQS on 
an annual basis.
    For the purposes of determining whether an area has attained the 
SO2 NAAQS, we require no fewer than two consecutive years of 
``clean'' data (i.e., no violations) as recorded in AQS. In addition, 
to qualify for attainment determination purposes, the annual average 
and second-highest 24-hour average concentrations must be based upon 
hourly data that are at least 75 percent complete in each calendar 
quarter. See 40 CFR 50.4.
    The State of Arizona initiated ambient monitoring of SO2 
in the Miami area in 1970. In order to establish coverage sufficient to 
evaluate the ambient impact of smelter emissions, this initial effort 
was expanded. Eventually more than sixteen stationary monitoring sites 
were established, with as many as seven monitors operating 
concurrently. Historic ambient SO2 monitoring site locations 
and periods of operation are provided in Table 3.1, and Figures 3.1 and 
3.2 of the State's submittal.
    Following the Miami smelter's compliance with stack emissions 
limits (using continuous control technology) as required under Arizona 
Administrative Code (AAC) R9-3-515, which was submitted and approved by 
EPA as a revision to the Arizona SIP in the 1980's (but since amended 
and re-codified as R18-2-7-715), the number of SO2 monitors 
has decreased. Between 1990 and 1996, the number of monitors varied 
from three to four and several monitoring locations changed, but since 
1997, the three presently-operating monitors have remained at their 
current locations: the Jones Ranch monitor along Cherry Flats Road, the 
Ridgeline monitor along Linden Street, and the Townsite monitor along 
Sullivan Street.
    All three presently-operating monitors are located south of the 
smelter, but vary in distance and elevation relative to smelter 
sources. The Townsite monitor lies closest to the smelter and at the 
lowest elevation among the three sites while the Jones Ranch monitor 
lies furthest from the smelter but at the highest elevation. The Jones 
Ranch and Townsite monitors are operated by Phelps Dodge using Thermal 
Electron pulsed fluorescent (TECO) samplers, and the Ridgeline monitor 
is operated by ADEQ using a Thermo pulse fluorescence analyzer.
    Table 2 below summarizes the SO2 monitoring data 
collected at the various monitors operated by ADEQ (or, in the case of 
Jones Ranch, ADEQ or the smelter operator) from 1988 through 2005. ADEQ 
ended its monitoring at Jones Ranch in 1994, but the smelter

[[Page 3065]]

operator continues to monitor SO2 at that location. Table 3 
below presents estimated annual SO2 emissions from the 
smelter over the same time period.

             Table 2.--Summary of Sulfur Dioxide Ambient Air Quality Data--Miami, Arizona: 1988-2005
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                                                          Concentrations ([mu]g/m\3\) at individual sites
                                                 ---------------------------------------------------------------
             Year               Averaging period                      Cities
                                                    Jones ranch   services bldg.   Little acres      Ridgeline
----------------------------------------------------------------------------------------------------------------
1988..........................  Max 3-hour......             655             413             153  ..............
                                Max 24-hour.....             180              73              29              --
                                Annual..........              21              13               6              --
1989..........................  Max 3-hour......             814             169              86              --
                                Max 24-hour.....             133              29              18              --
                                Annual..........              17               4               3              --
1990..........................  Max 3-hour......             715              --              --              --
                                Max 24-hour.....             136              --              --              --
                                Annual..........             *16              --              --              --
1991..........................  Max 3-hour......             767              --              --              --
                                Max 24-hour.....             143              --              --              --
                                Annual..........             *18              --              --              --
1992..........................  Max 3-hour......             875              --              --              --
                                Max 24-hour.....             128              --              --              --
                                Annual..........              *8              --              --              --
1993..........................  Max 3-hour......             721              --              --              --
                                Max 24-hour.....             123              --              --              --
                                Annual..........              10              --              --              --
1994..........................  Max 3-hour......             566              --              --              --
                                Max 24-hour.....             121              --              --              --
                                Annual..........              16              --              --              --
1995..........................  Max 3-hour......             433              --              --             244
                                Max 24-hour.....             122              --              --              89
                                Annual..........               8              --              --              10
1996..........................  Max 3-hour......             593              --              --             338
                                Max 24-hour.....             146              --              --             110
                                Annual..........              11              --              --               8
1997..........................  Max 3-hour......             820              --              --             524
                                Max 24-hour.....             138              --              --              92
                                Annual..........              10              --              --               5
1998..........................  Max 3-hour......             840              --              --             175
                                Max 24-hour.....             123              --              --              40
                                Annual..........              10              --              --               8
1999..........................  Max 3-hour......             897              --              --             198
                                Max 24-hour.....             152              --              --              65
                                Annual..........               8              --              --              14
2000..........................  Max 3-hour......             895              --              --             307
                                Max 24-hour.....             133              --              --              70
                                Annual..........              11              --              --              17
2001..........................  Max 3-hour......             577              --              --             338
                                Max 24-hour.....             145              --              --             110
                                Annual..........              19              --              --              19
2002..........................  Max 3-hour......             628              --              --             174
                                Max 24-hour.....             184              --              --              78
                                Annual..........              16              --              --              18
2003..........................  Max 3-hour......             578              --              --             250
                                Max 24-hour.....             152              --              --              70
                                Annual..........              21              --              --              13
2004..........................  Max 3-hour......             326              --              --             291
                                Max 24-hour.....              99              --              --              78
                                Annual..........              13              --              --              11
2005..........................  Max 3-hour......              --              --              --             250
                                Max 24-hour.....              --              --              --              78
                                Annual..........              --              --              --              12
----------------------------------------------------------------------------------------------------------------
Notes: The primary NAAQS for SO2 are 365 [mu]g/m3, 24-hour average, not to be exceeded more than once per
  calendar year, and 80 [mu]g/m3, annual average. The secondary NAAQS for SO2 is 1,300 [mu]g/m3, 3-hour average,
  not to be exceeded more than once per calendar year. The * indicates that the annual average does not satisfy
  summary criteria. The -- indicates little or no data in a given year from a given monitor. EPA's AQS database
  is the source of data shown in italics. ADEQ's Air Quality Annual Reports are the sources of the non-
  italicized data shown in this table.
Monitoring Sites:
 The Jones Ranch monitoring site is located along Cherry Flats Road, approximately 1.8 miles south-
  southeast of the smelter stack at an elevation of 4,100 feet above sea level. ADEQ operated a monitor at this
  site through 1994. From 1991 through 1994, the State-operated monitor at Jones Ranch was referred to as
  ``Nolan Ranch''. More recent data shown in this table for Jones Ranch was collected and compiled by the
  smelter operator.
 The Cities Services Building monitoring site was located approximately 2.2 miles east-northeast of the
  smelter stack. ADEQ operated a monitor at this site through 1989.

[[Page 3066]]


 The Little Acres monitoring site was located approximately 2 miles southeast of the smelter. ADEQ
  operated a monitor at this site through 1989.
 The Ridgeline monitoring site, which is the current ADEQ monitoring site for SO2 in the Miami area, is
  located along Linden Street at an elevation of 3,600 feet.


       Table 3.--Miami Smelter Sulfur Dioxide Emissions: 1988-2005
------------------------------------------------------------------------
                                                          Sulfur dioxide
                          Year                            emissions tons
                                                             per year
------------------------------------------------------------------------
1988....................................................           3,988
1989....................................................           6,398
1990....................................................           4,141
1991....................................................          11,145
1992....................................................           4,813
1993....................................................           7,678
1994....................................................           9,260
1995....................................................           5,108
1996....................................................           5,737
1997....................................................           6,368
1998....................................................           6,097
1999....................................................           7,819
2000....................................................           6,810
2001....................................................           9,062
2002....................................................           5,667
2003....................................................           8,005
2004....................................................           8,754
2005....................................................           7,366
------------------------------------------------------------------------
Sources: Miami SO2 Maintenance Plan, page 35; e-mail correspondence from
  Bruce Friedl, ADEQ, dated September 29, 2006.

    Review of historic data supports identification of the Jones Ranch 
monitor as the monitoring location where the highest concentrations are 
recorded among the network of monitoring locations selected to measure 
the impact of smelter-related emissions on ambient air quality. We note 
that the Jones Ranch monitoring site was determined to be the 
``limiting site'' for the purposes of establishing emissions limits for 
the smelter. ADEQ closed its monitoring site at Jones Ranch in 1994, 
and while Phelps-Dodge continues to operate an SO2 monitor 
at that site, the data is not recorded in AQS.\3\ In 1995, ADEQ began 
monitoring at the Ridgeline site, and no exceedances have ever been 
recorded there.
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    \3\ ADEQ has committed to working with Phelps-Dodge to begin 
entering SO2 monitoring data collected at the Jones Ranch 
site to AQS beginning with the first quarter of 2008. See letter 
from Nancy C. Wrona, Director, Air Quality Division, ADEQ, to 
Deborah Jordan, Air Division Director, EPA--Region IX, dated October 
18, 2006.
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    Based on a review of the data from the Miami SO2 
Maintenance Plan as well as tables 2 and 3 presented above, we find 
that the Miami nonattainment area has attained the SO2 NAAQS 
and thereby meets the first criterion for redesignation. Our conclusion 
is based on six basic interrelated facts:
     Ambient SO2 concentrations in the Miami air 
quality planning area are determined by emissions from the Phelps-Dodge 
primary copper smelter \4\ and local meteorological and topographic 
characteristics, and all other SO2 sources have essentially 
no effect on ambient levels in the planning area;
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    \4\ There is one significant point source located outside the 
Miami nonattainment area but within 50 kilometers of the Miami 
nonattainment area. The ASARCO Hayden Smelter is located 
approximately 46 kilometers south of the Miami smelter. However, 
because the ASARCO Hayden smelter is geographically separated from 
the Miami area by the 7,000 foot Pinal Mountains, its emissions do 
not have an impact on air quality in the Miami area.
---------------------------------------------------------------------------

     The monitor at the Jones Ranch site records SO2 
concentrations that are representative of the highest ambient levels in 
the nonattainment area;
     There are two consecutive and complete years of ``clean'' 
data from the Jones Ranch monitor, i.e., the limiting site, as recorded 
in AQS (1988 and 1989);
     During the 1988-1989 period, maximum concentrations were 
approximately 60% of the 3-hour-average secondary NAAQS and 
approximately 50% of the 24-hour-average primary NAAQS, and the highest 
of the annual-average concentrations measured in the area during this 
period was approximately 30% of the corresponding primary NAAQS;
     While annual emissions from the smelter have varied from 
year to year, they have generally been no higher than 50% above those 
that occurred during the 1988-1989 period; and
     No SO2 exceedances have been measured at any of 
the monitoring sites over the 1988 to 2005 period.

B. The Area's Applicable Implementation Plan Must Be Fully Approved 
Under CAA Section 110(k)

    Under CAA section 107(d)(3)(E)(ii), the SIP for the Miami area must 
be fully approved under CAA section 110(k) of the Act. We examined the 
applicable SIP for Arizona and also looked at the disapprovals listed 
in 40 CFR 52.125 and have determined that no disapprovals listed remain 
relevant to the applicable SIP. Arizona has a fully approved SIP with 
respect to SO2 in the Miami area.

C. The Improvement in Air Quality Must Be Due to Permanent and 
Enforceable Reductions in Emissions

    CAA section 107(d)(3)(E)(iii) requires that EPA determine that the 
improvement in air quality is due to permanent and enforceable 
reductions in emissions resulting from implementation of the SIP and/or 
applicable federal measures. Figure 6.1 of the Miami SO2 
Maintenance Plan (as amended in ADEQ's submittal dated June 30, 2004) 
illustrates the significant decline in emissions from the Miami smelter 
since the 1970's in inverse proportion to the level of control over 
smelter emissions sources.
    Control over the smelter's SO2 emissions has been made 
permanent and enforceable through EPA approval of State rules limiting 
such emissions as a revision to the Arizona SIP (specifically, R18-2-
715, R18-2-715.01, R18-2-715.02, and R18-2-Appendix 8) and through 
ADEQ's issuance of a title V permit for the Miami smelter. Arizona's 
primary copper smelter rules and ADEQ's title V permit contain 
enforceable emission limitations that cap emissions at a level that has 
been shown to be protective of the NAAQS. Any relaxation to the SIP-
approved limits must be approved by EPA as a revision to the Arizona 
SIP, and EPA may not approve any such SIP revision without a 
demonstration that the relaxation in the limits would not interfere 
with attainment or maintenance of the NAAQS. See CAA section 110(l). 
Therefore, we find that the improvement in ambient SO2 
concentrations in the Miami, AZ area is due to permanent and 
enforceable reductions in emissions resulting from implementation of 
the SIP.

D. The Area Must Have Met All Applicable Requirements Under Section 110 
and Part D

    Under CAA section 107(d)(3)(E)(v), we must determine whether the 
State of Arizona has met all requirements under section 110 and under 
part D (of title I) of the CAA applicable to the Miami SO2 
nonattainment area.
1. Section 110 Requirements
    CAA section 110 contains the general requirements for SIPs 
(enforceable emissions limits, ambient monitoring, permitting of new 
sources, adequate funding, etc.). EPA's guidance for implementing 
section 110 of the Act is discussed in the General Preamble to Title I 
(57 FR 13498, April 16, 1992). Over the years, we have approved 
Arizona's SIP as meeting these basic requirements. The SIP includes 
enforceable emission limitations; requires monitoring, compiling, and 
analyzing of ambient air quality data; requires preconstruction review 
of new

[[Page 3067]]

major stationary sources and major modifications to existing ones; 
provides for adequate funding, staff, and associated resources 
necessary to implement its requirements; and requires stationary source 
emission monitoring and reporting.
2. Part D Requirements
    Before an area can be redesignated to attainment, it must have 
fulfilled the applicable requirements under part D (of title I). For 
this area, the relevant requirements are found in subparts 1 and 5 of 
part D. Subpart 1 of part D specifies the basic requirements applicable 
to all nonattainment areas. Subpart 5 sets out additional provisions 
for areas designated nonattainment for SO2. As discussed 
below, EPA finds that Arizona has met the requirements of subpart 1 of 
part D, specifically sections 172(c) and 176, and subpart 5 as 
applicable for the Miami SO2 nonattainment area.
a. Section 172
    CAA section 172 contains the general requirements for nonattainment 
SIPs. A thorough discussion of the requirements of 172(c) can be found 
in the General Preamble for the implementation of title I (57 FR 13498, 
April 16, 1992). Additional guidance can be found in the Calcagni memo.
    EPA has interpreted the requirements of CAA sections 172(c)(2) 
(reasonable further progress--RFP), 172(c)(6) (other measures), and 
172(c)(9) (contingency measures) as not relevant to a redesignation 
request because they only have meaning for an area that is not 
attaining the standard (see the General Preamble and the Calcagni 
Memo), and as discussed above in section IV.A. of this notice, we find 
that the Miami area is attaining the SO2 standard. 
Furthermore, the State has not sought to exercise options that would 
trigger section 172(c)(4) (identification of certain emissions 
increases). Thus, this provision is also not relevant to this 
redesignation request. The other provisions under 172(c) are discussed 
below.
    Reasonably available control measures. Under CAA section 172(c)(1), 
reasonably available control measures (RACM), which include 
requirements for reasonably available control technology (RACT), are 
required for existing sources in nonattainment areas. In 1983, we 
approved the State's submittal of Rule R9-3-315, a predecessor to the 
State's current smelter rules codified at Arizona Administrative Code 
(AAC) R18-2-715. See 48 FR 1717 (January 14, 1983). This rule limited 
stack emissions from primary copper smelters, including the smelter in 
the Miami area. We concluded, however, that the control strategy for 
SO2 in Arizona's six SO2 nonattainment areas was 
incomplete due to the failure to address fugitive emissions problems. 
See 48 FR 1717 (January 14, 1983) and 40 CFR 52.125(a)(1).
    In 1998, 2003, and 2006, the State submitted amended rules (AAC 
R18-2-715 (sections F, G, and H), R18-2-715.01, R18-2-715.02, and R18-
2-Appendix 8).\5\ These rules address both fugitive and stack emissions 
from smelters and, in approving the rules, we found that the amended 
rules met the RACT requirement under CAA sections 172(c)(1) and 191(b). 
See 69 FR 26789 at 26788 (May 14, 2004), 69 FR 63321 (November 2, 
2004), and 71 FR 18624 at 18625 (April 12, 2006). Furthermore, because 
the area has attained the standard, no further demonstration that RACM 
has been implemented need be submitted by the State.
---------------------------------------------------------------------------

    \5\ A more extensive summary of the regulatory history of copper 
smelters in Arizona is included in EPA's proposed action on these 
rules. See 69 FR 26786 (May 14, 2004).
---------------------------------------------------------------------------

    Emissions inventory. The emissions inventory requirement of section 
172(c)(3) is satisfied by the maintenance plan inventory requirements. 
The maintenance plan inventory is evaluated below, in section IV.E.1.
    NSR permit program. Section 172(c)(5) requires new source review 
(NSR) permits for the construction and operation of new and modified 
major stationary sources located in nonattainment areas. ADEQ is the 
agency responsible for implementing the nonattainment area NSR permit 
program in the Miami area. Under ADEQ's rules, all new major sources 
and modifications to existing major sources are subject to the NSR 
requirements of these rules.
    We have not yet fully approved the ADEQ NSR rules.\6\ We have, 
however, determined that an area being redesignated from nonattainment 
to attainment does not need to have an approved NSR program prior to 
redesignation, provided that the area demonstrates maintenance of the 
standard without nonattainment NSR in effect. See memorandum from Mary 
Nichols dated October 14, 1994 (``Part D New Source Review (part D NSR) 
Requirements for Areas Requesting Redesignation to Attainment.'') We 
have determined that the maintenance demonstration for Miami does not 
rely on nonattainment NSR.
---------------------------------------------------------------------------

    \6\ ADEQ's NSR rules are included in the preconstruction review 
and permitting provisions of Arizona Administrative Code (AAC), 
Title 18, Chapter 2, Articles 3 and 4. EPA approved an earlier 
version of ADEQ's NSR requirements (AAC R9-3-302) on May 5, 1982 (47 
FR 19328) and August 10, 1988 (53 FR 30220).
---------------------------------------------------------------------------

    Prevention of significant deterioration (PSD) is the permitting 
program that applies in attainment areas. PSD was established to 
preserve air quality in areas that are meeting the NAAQS. The PSD 
program requires new, modified, or reconstructed stationary sources to 
undergo preconstruction review and to apply best available control 
technology. In addition, sources are required to review PSD increment 
consumption and undertake preconstruction modeling. ADEQ has an EPA-
approved PSD permitting program (Arizona Air Pollution Rule R9-3-304) 
for all criteria pollutants except respirable particulate matter 
(PM\10\). See 48 FR 19878 (May 3, 1983). The federal PSD program for 
PM\10\ was delegated to the State on March 12, 1999. ADEQ's partially 
approved, partially delegated PSD program will apply automatically to 
new major sources or major modifications to existing sources of 
SO2 in the Miami area once the area is redesignated to 
attainment.
    Compliance with section 110(a)(2). Under section 172(c)(7), plan 
provisions submitted to satisfy part D must meet the applicable 
provisions of section 110(a)(2) of the CAA. As noted in section IV.B. 
above, the Miami portion of the Arizona SIP meets these requirements.
    Equivalent techniques. Under section 172(c)(8), EPA may allow the 
use of equivalent modeling, emission inventory, and planning 
procedures, unless EPA determines that the proposed techniques are, in 
the aggregate, less effective than the methods specified by EPA. The 
Miami SO2 Maintenance Plan relies on an equivalent modeling 
technique referred to as Multipoint Rollback (MPR). MPR was used to 
derive emissions limits for the Miami smelter that provide for 
attainment and maintenance of the SO2 NAAQS. The State's 
rules containing MPR-derived emission limits for the Miami smelter were 
approved by EPA on January 14, 1983 (48 FR 1717) and amended versions 
of the rules were approved by EPA on November 1, 2004 (69 FR 63321).
b. Section 176
    Section 176(c) of the CAA requires states to establish criteria and 
procedures to ensure that federally supported or funded projects 
conform to the air quality planning goals in the applicable SIP. The 
requirement to determine conformity applies to transportation plans, 
programs, and projects developed, funded or approved

[[Page 3068]]

under title 23 U.S.C. or the Federal Transit Laws (``transportation 
conformity'') as well as to all other federally supported or funded 
projects (``general conformity''). Because EPA does not consider 
SO2 a transportation-related pollutant, only the 
requirements related to general conformity apply to the Miami 
SO2 area. The State of Arizona adopted general conformity 
criteria and procedures as a revision to the Arizona SIP. EPA approved 
Arizona's general conformity SIP on April 23, 1999 (64 FR 19916). Thus, 
the requirements of CAA section 176 have been satisfied.
c. Subpart 5
    Subpart 5 of part D contains additional provisions for areas 
designated nonattainment for SO2. Under CAA section 191(b), 
States with existing nonattainment areas for the primary SO2 
NAAQS where those areas lack fully approved SIPs, including part D 
plans, must submit implementation plans meeting the requirements of 
subpart 1 of part D. As discussed in section IV.D.2.a of this notice, 
the State of Arizona has met the requirements of subpart 1 of part D 
for the Miami area. Under CAA section 192(b), such areas were required 
to meet the primary SO2 NAAQS as expeditiously as possibly 
but no later than November 15, 1995. As discussed in section IV.A of 
this notice, the Miami SO2 nonattainment area met the 
primary SO2 standards well before the applicable attainment 
date of November 15, 1995 and has continued to attain since then.

E. The Area Must Have a Fully Approved Maintenance Plan

    Section 107(d)(3)(E)(iv) of the Act makes EPA approval of a 
maintenance plan meeting the requirements of section 175A another 
prerequisite to redesignation. Under section 175A, a maintenance plan 
must provide for maintenance of the NAAQS for at least 10 years after 
redesignation, and include any additional control measures as may be 
necessary to ensure such maintenance. In addition, maintenance plans 
are to contain such contingency provisions as EPA deems necessary to 
assure the prompt correction of a violation of the NAAQS that occurs 
after redesignation. The contingency measures must include, at a 
minimum, a requirement that the state will implement all control 
measures contained in the nonattainment SIP prior to redesignation.
    The Calcagni Memo contains EPA guidance on the contents of 
maintenance plans submitted for the purposes of meeting section 175A. 
Generally, such plans should address the following five topics: the 
attainment emissions inventory, maintenance demonstration, monitoring 
network, verification of continued attainment, and a contingency plan.
    Lastly, under CAA section 175A(b), states are required to submit a 
subsequent maintenance plan eight years after redesignation providing 
for maintenance of the NAAQS for an additional 10-year period beyond 
the initial 10-year maintenance period.
1. Attainment Inventory
    The Miami SO2 Maintenance Plan includes an emissions 
inventory for point sources, area sources, and mobile sources for 1999 
and 2000 as well as a projection of emissions to 2015. See table 4 
below. As discussed in section IV.A of this notice, the Miami area has 
continued to attain the SO2 NAAQS since at least 1990 and 
thus 1999 and 2000 are acceptable as the basis upon which to develop an 
``attainment emissions inventory'' for the purposes of a maintenance 
plan.
    ADEQ developed the area and mobile source estimates shown in table 
4 based on EPA's AIRData for Gila County. Point source estimates are 
based on ADEQ annual emissions inventory data. See section 4.0 and 
appendix B of the Miami SO2 Maintenance Plan. Sulfur dioxide 
emissions from the Phelps-Dodge smelter copper smelter itself are based 
on continuous emission monitoring systems and the assumption that stack 
emissions represent 25 percent of the facility's total annual (i.e., 
stack plus fugitive) SO2 emissions. The actual percentage of 
total facility emissions emanating from the stacks varies from year to 
year (e.g., from 19 percent to 33 percent over the 1996 to 2000 period) 
but the 25 percent assumption is a reasonable average annual value 
based on material balance calculation methods.

Table 4.--SO2 Emissions Inventories for 1999, 2000, and Projected Inventory for 2015 for the Miami Area (in TPY)
----------------------------------------------------------------------------------------------------------------
                           Source type                                 1999            2000            2015
----------------------------------------------------------------------------------------------------------------
Area and Mobile.................................................             149             150             162
Point (excluding Miami smelter).................................               7               4               9
Miami Smelter...................................................           7,819           6,810           8,000
                                                                 -----------------------------------------------
    Total.......................................................           7,975           6,964           8,171
----------------------------------------------------------------------------------------------------------------
Source: Miami SO2 Maintenance Plan, tables 4.4 and 4.6.

    Based on our review of the submitted plan, we conclude that the 
emissions inventory is based on reasonable methods and assumptions and 
is comprehensive and accurate.
2. Maintenance Demonstration
    EPA allows states to demonstrate maintenance of the NAAQS by either 
showing that future emissions of a pollutant or its precursors will not 
exceed the level of the attainment inventory, or by modeling to show 
that the future mix of sources and emission rates will not cause a 
violation of the NAAQS.\7\ In the case of the Miami nonattainment area, 
the demonstration of maintenance relies on both a projected emissions 
inventory for future years of 2005, 2010, and 2015 for sources in the 
Miami nonattainment area as well as SO2 emission limits for 
the Miami smelter that were developed using a variant of Multipoint 
Rollback (MPR) modeling and intended to minimize the probability of an 
exceedance of the SO2 NAAQS due to smelter emissions.
---------------------------------------------------------------------------

    \7\ See Calcagni Memo, at p. 9.
---------------------------------------------------------------------------

    The inventory from the Miami SO2 Maintenance Plan shows 
that about 98% of the total SO2 emissions in the Miami 
nonattainment area are generated by the smelter.\8\ Projections for the 
Miami smelter itself anticipate a minor increase from those in 1999 
[7,819 tons per year (tpy)] to 2005 and beyond (8,000 tpy). The 
remaining point sources in the nonattainment area have existing permits 
that limit their allowable emissions to less than 100 tpy. Projections 
for area and mobile sources

[[Page 3069]]

(increasing from 149 tpy \9\ to 162 tpy) are based on anticipated 
moderate increases in population and the assumption that SO2 
emissions from such sources are proportionate to the population. Total 
projected actual emissions of point, area, and mobile sources are 
expected to remain relatively constant, with total SO2 
emissions projected to be less than 24 tons on a daily basis and 
approximately 8,200 tons on annual basis by 2015.\10\ This represents 
an increase of only about 2 percent from 1999 levels. Thus, throughout 
the maintenance period, the Miami smelter is expected to continue to be 
the overwhelming source of SO2 emissions in the area.
---------------------------------------------------------------------------

    \8\ See appendix B of submitted plan.
    \9\ The most recent quality assured inventory is from 1996. The 
1999 SO2 inventory for area and mobile sources is based 
on economic growth activity.
    \10\ See table 4.6 of submitted plan.
---------------------------------------------------------------------------

    The emissions projections for the smelter (from 7,819 tpy) in 1999 
to 8,000 tpy in 2005 and beyond are based on the expectation that, 
through 2015, the copper industry will not expand. While the 
expectation of continued low price pressures on copper may well have 
been reasonable in 2002 when the maintenance plan was adopted, changes 
in the copper market in fact have occurred over the past several years 
raising the price for copper thereby leading to a reasonable 
expectation of higher production levels at the Miami smelter than 
anticipated in the Miami SO2 Maintenance Plan.
    Nonetheless, the demonstration of maintenance of the SO2 
NAAQS in the Miami area does not rely solely on the emissions 
projections, but also on the SO2 emission limits established 
under SIP rule AAC R18-2-715 (approved by EPA in 2004 and, as amended, 
in 2006) and incorporated into the title V operating permit for the 
Phelps-Dodge Miami smelter. These limits cap stack emissions at 604 
pounds per hour (lbs/hr) on an annual average basis and total facility 
(i.e., stacks plus fugitives) emissions at 2,420 lbs/hr on an annual 
basis. SIP rule AAC R18-2-715 also establishes a cumulative occurrence 
table that caps the number of occurrences of 3-hour average emissions 
above various levels with, for example, only two occurrences allowed 
per year of stack SO2 emissions greater than 5,900 lbs/hr, 
3-hour average. The total facility emissions cap (2,420 lbs/hr) 
corresponds to approximately 10,600 tpy assuming round-the-clock, year-
round operation (the permit however cites 10,400 tpy based on 357 work 
days in a given year).
    As explained below, ADEQ has demonstrated that the new limits are 
protective of the SO2 NAAQS. In order to increase the 
smelter's emissions limits the State would have to submit a SIP 
revision that demonstrates that, consistent with CAA section 110(l), 
the revision does not interfere with maintenance of the SO2 
NAAQS. Therefore, the emission limits for the smelter, supported by the 
emissions inventory projections that show that the smelter will remain 
the overwhelming source of SO2 emissions in the area for the 
foreseeable future, in essence provide the demonstration necessary to 
show that the Miami area will continue to attain the SO2 
standard indefinitely, and thereby comply with CAA section 175A(a), 
which requires maintenance plans to provide for maintenance of the 
NAAQS for at least 10 years after redesignation.
    Given the link then between the SO2 emission limits on 
the Phelps-Dodge Miami smelter and the demonstration of maintenance, 
the Miami SO2 Maintenance Plan provides a detailed 
explanation of how the limits were derived and how they minimize the 
probability of exceedance of the SO2 NAAQS due to smelter 
operations. See chapter 5 of the submitted plan. First, it is important 
to note that ADEQ used a variant of the Multipoint Rollback (MPR) 
method to derive these emissions limits. In brief, MPR uses the ratio 
of monitored concentrations to the NAAQS to determine how much to scale 
the smelter's existing hourly distribution of emission rates so that 
they meet the NAAQS. Unlike simple rollback, which yields a single 
maximum emission rate never to be exceeded, MPR yields limitations on 
the number of times per year that the facility may exceed each of a 
series of emission rates. In the resulting cumulative occurrence table, 
the larger the emissions rate, the fewer number of occurrences are 
allowed per year. The emission rates are chosen so that the full hourly 
distribution results in attainment of the NAAQS on a probabilistic 
basis. This approach has been approved by EPA for use with smelters 
because of their highly variable emission rates.\11\ ADEQ used a 
variant of MPR, as explained further below, to show that the new limits 
are protective of the NAAQS.
---------------------------------------------------------------------------

    \11\ See EPA Final Rule, ``Approval and Promulgation of 
Implementation Plans; Arizona Plan Revision: Sulfur Oxides Control 
Strategy and Regulations for Existing Nonferrous Smelters,'' 48 FR 
1717 (January 14, 1983); and the SO2 Guideline Document, 
EPA-452/R-94-008, February 1994, section 6.4.4.
---------------------------------------------------------------------------

    ADEQ derived the original emissions limits for the smelter in the 
late 1970's using MPR, and adopted the original smelter SO2 emissions 
rule in 1979. To derive new, enforceable limits on the smelter stacks, 
it was necessary to distinguish stack emissions from total emissions, 
which include fugitives (those emissions not vented through the stack). 
The new emissions limits were derived by apportioning the old facility-
wide emission limits between the stack emissions and fugitive 
emissions. Using mass balance, the total amount of emissions can be 
calculated from the total mass of sulfur entering the plant in raw 
materials. Stack emissions are monitored, and account for about 25% of 
the total sulfur. The fugitive emissions were then determined by 
subtracting the monitored stack emissions from the calculated total 
emissions. Because the release height of the stack and fugitive 
emissions is similar, and their emissions are fairly well-mixed by the 
time they reach the monitor, the stack also accounts for 25% of the 
observed concentration at the monitor, on average. Thus, 25% of the 
existing facility-wide limits (2,420 lb/hr) are what the stack must be 
limited to (605 lb/hr; the SIP rule caps the emissions at 604 lb/hr, 
which is slightly more conservative) in order to meet the NAAQS.
    This provides only an annual average emission rate. To derive MPR-
style limits on allowed occurrences of various emission rates (i.e., a 
cumulative occurrence table), ADEQ used the shape of the current hourly 
emission distribution \12\ and scaled it to match the required annual 
average emission rate. Since the new average limit is 1.75 times the 
current average actual emissions (604 lb/hr limit vs. 345 lb/hr current 
average), the current distribution and occurrence emission levels were 
scaled up by this factor. The result is new occurrence limits 
consistent with the new average limit of 604 lb/hr, the level needed to 
meet the NAAQS based upon the 1979 MPR analysis and the 25% stack 
fraction.
---------------------------------------------------------------------------

    \12\ Emissions from each hour of 1999 were averaged with the 
corresponding hour in 2000, which represents a minor departure from 
how original MPR was carried out; i.e., using all data in a single 
distribution. EPA believes any resulting changes to the calculations 
are insignificant in the context of the Miami MPR analysis and finds 
this to be an acceptable approach.
---------------------------------------------------------------------------

    However, scaling according to the 1979 limits assumes that the 1979 
relationship between emissions and ambient concentrations has not 
changed. There have been substantial operational and emissions changes 
at the smelter since the 1979 average

[[Page 3070]]

emission limit and occurrence table were derived, which could have 
altered the shape of the emissions curve. If the current distribution 
shape has a broader peak than the 1979 one, then there will be 
relatively more instances of high ambient impacts, and so scaling of 
the average will not guarantee NAAQS-protective limits on short-term 
emissions.
    In order to address this, ADEQ carried out a second step in the 
submittal that is more consistent with the MPR procedure, in that it 
incorporated the ambient effect of the current emissions distribution, 
rather than relying on the 1979 relationship. ADEQ used monitoring data 
from 1996-2000, and emissions during that same period. The new emission 
limits, though a decrease from the old limits, represent an increase 
over the current actual emissions, and so should be shown to be 
consistent with the NAAQS. ADEQ assumed the smelter operated at the 
higher emissions rate allowed in the new limits, and applied the 
fractional emissions increase to ambient 3-hour, 24-hour, and annual 
SO2 concentrations. This uses the current relationship 
between emissions and ambient concentration to show that the scaled-up 
emissions allowed in the new limits are consistent with the NAAQS. The 
result of this ``rollback'' scaling is shown in figure 5.4 of the Miami 
SO2 Maintenance Plan, and also in table 5 below.

                    Table 5.--Predicted Ambient SO2 Concentrations Based on Emissions Limits
----------------------------------------------------------------------------------------------------------------
                                                                     Predicted                      Percent of
                         Averaging time                           level [mu]g/m3  NAAQS [mu]g/m3       NAAQS
----------------------------------------------------------------------------------------------------------------
3-hour..........................................................           1,180           1,300              91
24-hour.........................................................             230             365              63
Annual..........................................................              25              80              31
----------------------------------------------------------------------------------------------------------------
Note: The predicted 3-hour and 24-hour average concentrations represent second-high values in a given year.
  Predicted levels listed in this table are derived from figure 5.4 of the Miami SO2 Maintenance Plan.

    With this second verification step, ADEQ used a procedure 
consistent with MPR, an EPA-approved method for smelter attainment 
demonstrations, to show that the new limits are protective of the 
NAAQS. We find that the protection of the NAAQS provided by the 
smelter's SO2 emissions limits, considered in the context of 
emissions projections that show that the smelter will remain the 
overwhelming source of SO2 emissions in the area for the 
foreseeable future, sufficient to demonstrate maintenance through the 
maintenance period and beyond.
3. Monitoring Network
    Currently, there are three monitoring sites in the Miami 
nonattainment area: the Ridgeline monitor operated by ADEQ, and the 
Jones Ranch and Townsite monitors operated by Phelps-Dodge. ADEQ and 
Phelps-Dodge Miami commit to continue monitoring ambient SO2 
concentrations at their respective sites for at least 10 years 
following the approval of the Miami SO2 Maintenance Plan. 
Phelps-Dodge has the option of shutting down the monitors if the 
smelter has not operated for more than 2 years but commits to resume 
monitoring at the two sites three months prior to restarting of 
smelting operations. In addition, ADEQ commits to discussing changes to 
monitor locations with EPA and indicates that all ambient monitoring 
data will continue to be quality-assured in accordance with the 
requirements of 40 CFR part 58, Ambient Air Quality Surveillance. See 
section 7.2 of the submitted plan. We find that the Miami 
SO2 Maintenance Plan adequately provides for continued 
monitoring of SO2 concentrations in the Miami area.
    At the present time, only the SO2 monitoring data 
collected at ADEQ's Ridgeline site is certified and entered into AQS. 
However, because the Jones Ranch site has historically measured the 
highest SO2 concentrations in the area and because the data 
from Jones Ranch is used in connection with the contingency plan, EPA 
has requested that ADEQ commit to working with Phelps-Dodge to ensure 
that SO2 monitoring data from the Jones Ranch site is 
entered into AQS. By letter to EPA dated October 18, 2006, ADEQ has 
agreed that entering SO2 monitoring data from the Jones 
Ranch site into AQS is appropriate and has committed to working with 
Phelps-Dodge to accomplish this task no later than the first quarter of 
2008. This commitment provides additional assurance that a suitable 
monitoring network will be maintained within the Miami area through the 
maintenance period and provides additional support for the contingency 
plan discussed below in section IV.E.5 of this action.
4. Verification of Continued Attainment
    ADEQ intends to track the progress of the Miami SO2 
Maintenance Plan through implementation and enforcement of the 
monitoring, reporting, and certification procedures to which permitted 
sources are subject under AAC R18-2-306 and R18-2-309. As a permitted 
source, the Phelps-Dodge Miami smelter is subject to these State 
requirements. ADEQ also notes that it has authority pursuant to Arizona 
Revised Statutes section 49-101 to monitor and ensure source compliance 
with all applicable rules and permit conditions. See section 7.3 of the 
submitted plan. Lastly, we note that ADEQ is required under 40 CFR part 
51, subpart A, to report emissions data for large stationary sources, 
such as the Phelps-Dodge Miami smelter, on an annual basis. Considered 
together, the submitted plan and relevant EPA regulations adequately 
provide for verification of continued attainment of the SO2 
NAAQS in the Miami area.
5. Contingency Plan
    Section 175A(d) of the CAA requires that maintenance plans include 
contingency provisions to promptly correct any violation of the NAAQS 
that occurs after redesignation of the area. The Calcagni memo provides 
additional guidance, noting that, although a state is not required to 
have fully adopted contingency measures that will take effect without 
further action by the state in order for the maintenance plan to be 
approved, the maintenance plan should ensure that the contingency 
measures are adopted expediently once they are triggered. Specifically, 
the maintenance plan should clearly identify the measures to be 
adopted, include a schedule and procedure for adoption and 
implementation of the measures, and contain a specific time limit for 
action by the state. In addition, the state should identify specific 
indicators, or triggers, that will be used to determine when the 
contingency measures need to be implemented.
    Because the Phelps-Dodge smelter is the overwhelming source of 
SO2 emissions in the Miami area, the

[[Page 3071]]

contingency plan contained in section 7.4 of the Miami SO2 
Maintenance Plan focuses on ambient impacts and emissions attributable 
to it. The contingency plan uses monitored ambient concentrations of 
SO2 to trigger actions designed to ensure continued 
attainment of the SO2 NAAQS. The trigger levels and 
associated notification procedures and associated actions are described 
below.
    Notification Procedure: If either of the Phelps-Dodge monitors or 
the ADEQ-operated monitor record ambient 3-hour average SO2 
levels between 0.425 ppm and 0.5 ppm (i.e., levels greater than 85%, 
but less than 100%, of the secondary SO2 NAAQS), \13\ the 
entity that operates the monitor is required to notify the other party. 
A second occurrence in a calendar year of ambient concentrations 
between 0.425 ppm and 0.5 ppm, or an exceedance of the secondary NAAQS 
is defined as the protective trigger level (PTL). The response required 
by a triggering of the PTL is divided into two action levels.
---------------------------------------------------------------------------

    \13\ See Table 5, above, which shows that the three-hour 
SO2 NAAQS is ``limiting'' in the sense of being the most 
constraining on emissions, since this averaging time has the least 
room for additional emission increases. This is consistent with past 
findings that the three-hour average requires the most stringent 
reduction in emissions. See 46 FR 58098 (November 30, 1981) at page 
58102.
---------------------------------------------------------------------------

    First Action Level: If the PTL is tripped, Phelps-Dodge must 
undertake a series of inspections and a full calibration check of the 
ambient SO2 analyzers and recording systems in order to 
validate the data. If the data are determined to be valid, Phelps-Dodge 
must perform any needed repairs or corrective actions and implement 
specified preventive measures. The source must also submit a report to 
ADEQ by the close of the second business day following an exceedance in 
which it describes the nature of the event, any corrective actions 
taken to resolve the event, and recommendations for future corrective 
actions to avoid recurrence of such an event.
    Second Action Level: If the source is unable to correct the 
triggering of the PTL by implementing the actions required under the 
first action level, Phelps-Dodge must undertake an analysis to identify 
additional control measures needed to ensure maintenance of the NAAQS. 
Phelps-Dodge is required to submit recommendations to ADEQ within 30 
business days following the triggering of the PTL. Using all available 
data, ADEQ will determine the cause and appropriate resolution of the 
event, and will require the adoption and implementation of additional 
control measures, as needed. ADEQ commits to initiating changes to the 
rules or to the permit as soon as possible.
    Special Measure: A violation of the secondary NAAQS (i.e., a second 
exceedance in a calendar year) triggers the implementation of a special 
measure within 24 hours of the monitored violation that requires the 
source to reduce its operating rate by the same percentage as that by 
which the 3-hour standard was exceeded. These circumstances also 
require that the source comply with first action level requirements 
and, if necessary, second action level requirements. A second and 
higher concentration violation of the secondary NAAQS within the same 
calendar year requires that the operating rate be recalculated 
accordingly.
    Upon review of the contingency plan in the Miami SO2 Maintenance 
Plan summarized above, we find that ADEQ has established a workable 
contingency plan, including trigger levels, notification procedures, 
and appropriate actions, for promptly correcting any violations of the 
SO2 NAAQS that occur after the redesignation of the Miami area to 
attainment and thereby satisfies the requirements of CAA section 
175A(d).
6. Subsequent Maintenance Plan Revisions
    As noted previously, CAA section 175A(b) requires states to submit 
a subsequent maintenance plan revision eight years after the 
redesignation request is approved by EPA. The subsequent maintenance 
plan is to provide for maintenance of the NAAQS for an additional 10 
years following the first 10-year maintenance period. ADEQ has made a 
commitment to submit a subsequent maintenance plan to EPA eight years 
into the initial 10-year maintenance period (see page 53 of the 
submitted plan) and thereby satisfies CAA section 175A(b).
7. Conclusion
    ADEQ's Miami SO2 Maintenance Plan adequately addresses 
the five basic topics that such plans should address, including 
attainment inventory, maintenance demonstration, monitoring network, 
verification of continued attainment, and contingency plan, and also 
provides for submittal of a subsequent maintenance plan. Therefore, we 
approve the Miami SO2 Maintenance Plan as a revision to the 
Arizona SIP and thereby satisfy the related redesignation criterion of 
CAA section 107(d)(3)(E)(iv).

V. Boundary Correction

A. Background

    Under section 107(d) of the Clean Air Act Amendments of 1977, each 
State was directed to submit to EPA a list identifying the NAAQS 
attainment status for all areas within the State. EPA was required 
under section 107(d)(2) of the 1977 Amended Act to promulgate the State 
lists, with any necessary modifications, within 60 days of their 
submittal. In 1978, in the absence of recommendations from the State of 
Arizona, EPA promulgated the original area designations for Arizona for 
each of the NAAQS. See 43 FR 8962 (March 3, 1978).\14\ EPA selected 
counties as the geographic basis for the original nonattainment area 
designations for SO2 in Arizona and designated all of Gila 
County as a nonattainment area for the SO2 NAAQS. See 43 FR 
8962, at 8968.
---------------------------------------------------------------------------

    \14\ EPA has codified the designations for air quality planning 
areas at 40 CFR part 81. The Arizona area designations are codified 
at 40 CFR 81.303.
---------------------------------------------------------------------------

    On August 15, 1978, the State of Arizona submitted its area 
designations to EPA with the intent that EPA redesignate the original 
EPA-promulgated nonattainment areas to reflect the State's 
recommendations. The State's August 15, 1978 submittal included a 
background document prepared by the Arizona Department of Health 
Services and entitled, ``Identification of Areas within Arizona that do 
or do not meet National Ambient Air Quality Standards (August 1, 
1978)'' (referred to herein as the ``State's designations background 
report''). The State's designations background report identifies 
townships, or identifiable portions thereof, as the smallest geographic 
unit defining air quality planning areas in Arizona.
    With respect to SO2 in the Miami area, the State's 
designations background report includes a map showing a nonattainment 
area comprised by a total of nine townships: two townships in which the 
major source of SO2 emissions in the area (i.e., the primary 
copper smelter) is located (T1N, R14E and T1N, R15E) and seven adjacent 
townships (or portions thereof) to the east, west, north and south. The 
State's map also shows six additional adjacent townships with the 
designation of ``cannot be classified.''
    In the State's designations background report, the State provided a 
specific list of townships defining the nonattainment and ``cannot be 
classified'' areas. However, the list of townships and the map 
illustrating the areas are not entirely consistent with

[[Page 3072]]

one another. The State's list of townships for the Miami SO2 
nonattainment area includes, among others, the following townships 
moving west to east: T1N, R13E; T1N, R14E; T1N, R15E; and T1N, R16E. 
The township immediately east of T1N, R15E, however, is T1N, R15\1/2\E 
not T1N, R16E, and thus the list inadvertently created a noncontiguous 
nonattainment area with a single township (T1N, R16E) isolated from the 
rest of the larger designated area.\15\ In contrast, the map submitted 
as part of the designations background report shows the nonattainment 
area boundary as a single contiguous area including both T1N, R15\1/2\E 
and the western half of T1N, R16E. On April 10, 1979 (44 FR 21261), we 
approved the redesignation request by Arizona for the Miami 
SO2 nonattainment area without modification and thereby 
codified the State's submitted list of townships (not the map) as the 
geographic definition for the Miami SO2 nonattainment area 
thereby creating a noncontiguous nonattainment area (i.e., one township 
isolated from the rest of the townships comprising the nonattainment 
area). In its June 26, 2002 submittal of the Miami SO2 
Maintenance Plan and supplemental June 30, 2004 submittal, ADEQ 
requested that we redesignate the boundaries under CAA section 
107(d)(3)(D) to create a single, contiguous planning area and to 
exclude tribal lands from the planning area. By letter dated June 26, 
2006, however, ADEQ withdrew the boundary redesignation request as 
previously formulated but requested that EPA act to correct the 
boundary under section 110(k)(6) of the Act instead. As explained 
further below, we agree with ADEQ that a boundary correction is 
warranted, and we make the related corrections to the boundary in 
today's notice.
---------------------------------------------------------------------------

    \15\ Township T1N, R16E straddles the boundary of the San Carlos 
Indian Reservation. Most of the township (roughly 31 or 32 of the 36 
square miles) lies within the reservation and is characterized by 
rugged mountainous terrain traversed in places by jeep trails. The 4 
to 5 square miles of land that lie within State jurisdiction have 
similar characterisics as the portion within the reservation. No 
population centers are found within this township. ADEQ indicates 
that no permits have been issued to any stationary source within the 
portion of the township that lies within State jurisdiction.
---------------------------------------------------------------------------

    Also, while our April 10, 1979 final rule redesignating 
nonattainment areas in Arizona correctly listed T1S, R14\1/2\E as one 
of the townships comprising the Miami SO2 nonattainment 
area, the 1979 version of 40 CFR part 81 included a transcription error 
and listed this particular township as ``T1S, R14\1/4\E'' instead of 
``T1S, R14\1/2\E.'' We are correcting the transcription error in this 
notice as well.

B. Authority for Correcting Errors

    Section 110(k)(6) of the Clean Air Act, as amended in 1990, 
provides, ``Whenever the Administrator determines that the 
Administrator's action approving, disapproving, or promulgating any 
plan or plan revision (or part thereof), area designation, 
redesignation, classification or reclassification was in error, the 
Administrator may in the same manner as the approval, disapproval, or 
promulgation revise such action as appropriate without requiring any 
further submission from the State. Such determination and the basis 
thereof shall be provided to the State and the public.''
    We interpret this provision to authorize the Agency to make 
corrections to a promulgated regulation when it is shown to our 
satisfaction that (1) we clearly erred in failing to consider or in 
inappropriately considering information made available to EPA at the 
time of the promulgation, or the information made available at the time 
of promulgation is subsequently demonstrated to have been clearly 
inadequate, and (2) other information persuasively supports a change in 
the regulation. See 57 FR 56762, at 56763 (November 30, 1992).
    In this instance, we have found clear error in our 1979 
consideration of the State of Arizona's submitted recommendations for 
area redesignations and believe that correction of the error to be 
appropriate at this time in support of the State's submittal of a 
redesignation request and maintenance plan for the SO2 NAAQS 
within the Miami air quality planning area.

C. Evaluation and Conclusion

    Based on a comparison of the map submitted by the State in its 1978 
designations background report that illustrates the nonattainment area 
with the accompanying list of townships defining the area, we find that 
the State erred by assuming that the township immediately east of T1N, 
R15E is T1N, R16E when it is actually T1N, R15\1/2\E and by then 
including the former instead of the latter in the list of townships 
defining the nonattainment area. Whereas T1N, R15\1/2\E lies 
immediately adjacent to one of the townships in which the major source 
of SO2 emissions is located, T1N, R16E lies mostly within 
the San Carlos Indian Reservation, is more distant from the major 
source in the area, and has no known source of SO2 
emissions. EPA then erred in failing to discover this error in our 1979 
consideration and approval of the State's recommended redesignation for 
the Miami SO2 nonattainment area. By virtue of the State's 
designations background report submitted in August 15, 1978, EPA had 
the relevant information necessary to discover this error at the time 
of our April 10, 1979 final rule but failed to do so. The State has now 
requested redesignation of the Miami SO2 nonattainment area 
to ``attainment'' and submitted a maintenance plan, which if approved 
as proposed herein, will begin the next phase (``maintenance'') of air 
quality planning in the Miami area.
    We believe that correction of the error that resulted in the 
creation of a noncontiguous area would help provide a solid regulatory 
foundation for the maintenance phase of CAA planning in the Miami area 
by eliminating the noncontiguous portion of the otherwise contiguous 
Miami air quality planning area and by removing any uncertainties as to 
the area designation status and applicable requirements for township 
T1N, R16E. Furthermore, ADEQ's redesignation request and maintenance 
plan for the Miami area do not rely on any control measure within T1N, 
R16E to demonstrate attainment and maintenance of the SO2 
standard in the Miami area. We are therefore taking direct final action 
under CAA section 110(k)(6) to correct the designation for T1N, R16E 
and thereby remove it from the list of townships comprising the Miami 
SO2 nonattainment area (which we are herein taking direct 
final action to redesignate to attainment). Specifically, we are 
correcting the error by revising the designation of T1N, R16E from 
``does not meet primary standards'' to ``cannot be classified'' in the 
listing for Miami in the Arizona SO2 table in 40 CFR 81.303. 
We are changing the designation of the township to ``cannot be 
classified'' for the SO2 standard consistent with the 
State's 1978 approach for areas that, while in the general proximity of 
a recommended SO2 nonattainment area, would be unlikely to 
experience violations of the standard because of the distance from the 
source and the terrain. For example, using this rationale, the State 
recommended, and we approved, ``cannot be classified'' designations for 
townships T2N, R16E and T1S, R16E.
    Rather than reclassifying township T1N, R15\1/2\E as part of this 
redesignation action, we have decided to retain its current air quality 
planning status of ``cannot be classified.'' First, establishing 
township T1N, R15\1/2\E as part of a future Miami maintenance area (and 
no longer as part of the ``rest of

[[Page 3073]]

state'' area) could have unintended effects on SO2 increment 
tracking under the State's prevention of significant deterioration 
permitting program. Second, no control measures in T1N, R15\1/2\E have 
been relied upon for attainment or maintenance of the SO2 
standard in the Miami area. Third, including township T1N, R15\1/2\E in 
the maintenance area would inappropriately subject projects in that 
township to certain CAA requirements, such as general conformity, that 
are intended only to apply within nonattainment areas and former 
nonattainment areas that have been redesignated to attainment. See CAA 
section 176(c)(5).
    In addition to the correction described above, we are taking direct 
final action to correct the transcription error introduced first in the 
1979 version of 40 CFR part 81 by replacing T1S, R14\1/4\E with T1S, 
R14\1/2\E in the list of townships comprising the Miami SO2 
air quality planning area.

VI. Public Comment and Final Action

    As authorized under section 110(k)(3) of the Act, EPA is approving 
the Miami Sulfur Dioxide Nonattainment Area State Implementation and 
Maintenance Plan, as submitted by ADEQ on June 26, 2002, corrected by 
the submittal dated June 30, 2004, and amended by the submittal dated 
June 20, 2006, as a revision to the Arizona state implementation plan. 
In so doing, we find that the maintenance plan meets the requirements 
for such plans under CAA section 175A.
    EPA is also approving the State of Arizona's request for 
redesignation of the Miami area from nonattainment to attainment for 
the SO2 NAAQS based on our conclusion that all of the 
redesignation criteria in CAA section 107(d)(3)(E) have been satisfied. 
Specifically, we find that (1) the Miami area has attained the 
SO2 NAAQS; (2) Arizona has a fully approved SIP for the 
Miami area; (3) the improvements in air quality in the Miami area are 
due to permanent and enforceable reductions in emissions resulting from 
implementation of EPA-approved smelter rules and title V permit 
conditions; (4) Arizona has met all of the nonattainment area 
requirements applicable to the Miami area; and (5) the State's 
submitted maintenance plan meets all relevant CAA requirements and is 
being approved in this notice.
    Lastly, under CAA section 110(k)(6) and for the reasons stated 
above in section V of this notice, EPA is correcting the boundary of 
the Miami SO2 nonattainment area to exclude a noncontiguous 
township that was erroneously included in the original description of 
the nonattainment area. Specifically, we are correcting the error by 
revising the designation of township T1N, R16E as listed in the Arizona 
SO2 table in 40 CFR 81.303 from ``does not meet primary 
standards'' to ``cannot be classified.'' We are also correcting the 
erroneous transcription of one of the townships in the Miami 
SO2 planning area in 40 CFR 81.303 by replacing ``T1S, 
R14\1/4\E'' with ``T1S, R14\1/2\E.''
    EPA is finalizing this action without proposing it in advance 
because the Agency views this action as noncontroversial and 
anticipates no adverse comments. However, in the Proposed Rules section 
of this Federal Register, we are simultaneously proposing approval of 
the same maintenance plan and request for redesignation and proposing 
the same corrections to the list of townships comprising the Miami, AZ 
SO2 area. If we receive adverse comments by February 23, 
2007, we will publish a timely withdrawal in the Federal Register to 
notify the public that the direct final approval will not take effect 
and we will address the comments in a subsequent final action based on 
the proposal. If we do not receive timely adverse comments, the direct 
final approval will be effective without further notice on March 26, 
2007. This will approve the redesignation request and maintenance plan 
submitted by Arizona on June 26, 2002, as amended by submittals dated 
June 30, 2004 and June 20, 2006, and to revise the designation of 
township T1N, R16E as listed in the Arizona SO2 table in 40 
CFR 81.303 from ``does not meet primary standards'' to ``cannot be 
classified'' and replace the township incorrectly listed as ``T1S, 
R14\1/4\E'' with ``T1S, R14\1/2\E''.
    Please note that if EPA receives adverse comment on an amendment, 
paragraph, or section of this rule and if that provision may be severed 
from the remainder of the rule, EPA may adopt as final those provisions 
of the rule that are not the subject of an adverse comment.

VII. Statutory and Executive Order Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and therefore is not 
subject to review by the Office of Management and Budget. For this 
reason, this action is also not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This action 
merely approves a state plan and redesignation request as meeting 
Federal requirements and corrects a long-standing error in the boundary 
of an air quality planning area. It imposes no additional requirements 
beyond those imposed by state law. Accordingly, the Administrator 
certifies that this rule will not have a significant economic impact on 
a substantial number of small entities under the Regulatory Flexibility 
Act (5 U.S.C. 601 et seq.). Because this rule approves pre-existing 
requirements under state law and does not impose any additional 
enforceable duty beyond that required by state law, it does not contain 
any unfunded mandate or significantly or uniquely affect small 
governments, as described in the Unfunded Mandates Reform Act of 1995 
(Pub. L. 104-4).
    This rule also does not have tribal implications because it will 
not have a substantial direct effect on one or more Indian tribes, on 
the relationship between the Federal Government and Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
Government and Indian tribes, as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000). Nonetheless, EPA has contacted the San 
Carlos Apache tribe to provide an opportunity to discuss the 
implications of exclusion of that portion of township T1N, R16E that 
lies within the reservation from the Miami SO2 nonattainment 
area. In letters dated November 20, 2006 and December 12, 2006, EPA 
transmitted a fact sheet with background information on this issue and 
a map illustrating the air quality planning area boundary change.
    This action also does not have Federalism implications because it 
does not have substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132 (64 FR 43255, August 
10, 1999). This action merely approves a state plan and redesignation 
request implementing a Federal standard and corrects a long-standing 
error in the boundary of an air quality planning area. It does not 
alter the relationship or the distribution of power and 
responsibilities established in the Clean Air Act. This rule also is 
not subject to Executive Order 13045 ``Protection of Children from 
Environmental Health Risks and Safety Risks'' (62 FR 19885, April 23, 
1997), because it is not economically significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices,

[[Page 3074]]

provided that they meet the criteria of the Clean Air Act. In this 
context, in the absence of a prior existing requirement for the State 
to use voluntary consensus standards (VCS), EPA has no authority to 
disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. This rule does not 
impose an information collection burden under the provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by March 26, 2007. Filing a 
petition for reconsideration by the Administrator of this final rule 
does not affect the finality of this rule for the purposes of judicial 
review nor does it extend the time within which a petition for judicial 
review may be filed, and shall not postpone the effectiveness of such 
rule or action. This action may not be challenged later in proceedings 
to enforce its requirements. (See section 307(b)(2).)

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Reporting and recordkeeping requirements, Sulfur oxides.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

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

    Dated: December 22, 2006.
Sally Seymour,
Acting Regional Administrator, Region IX.

0
Part 52, chapter I, title 40 of the Code of Federal Regulations is 
amended as follows:

PART 52--[AMENDED]

0
1. The authority citation for part 52 continues to read as follows:

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

Subpart D--Arizona

0
2. Section 52.120 is amended by adding paragraph (c)(132) to read as 
follows:


Sec.  52.120  Identification of plan.

* * * * *
    (c) * * *
    (132) The following plan revision was submitted on June 26, 2002, 
by the Governor's designee.
    (i) Incorporation by reference.
    (A) Arizona Department of Environmental Quality.
    (1) Final Miami Sulfur Dioxide Nonattainment Area State 
Implementation and Maintenance Plan (June 2002), chapter 7 
(``Maintenance Plan''), adopted on June 26, 2002 by the Arizona 
Department of Environmental Quality.
    (ii) Additional materials.
    (A) Arizona Department of Environmental Quality.
    (1) Final Miami Sulfur Dioxide Nonattainment Area State 
Implementation and Maintenance Plan (June 2002), excluding the cover 
page, and pages iii, 2, 3, 4, and 49; chapter 7 (``Maintenance Plan''); 
appendix A (``SIP Support Information''), sections A.1 (``Pertinent 
Sections of the Arizona Administrative Code'') and A.2 (``Information 
Regarding Revisions to AAC R18-2-715 and R18-2-715.01, `Standards of 
Performance for Primary Copper Smelters: Site Specific Requirements; 
Compliance and Monitoring' ''); and appendix D (``SIP Public Hearing 
Documentation''), adopted on June 26, 2002 by the Arizona Department of 
Environmental Quality.
    (2) Submittal of Corrections to the Final Miami Sulfur Dioxide 
Nonattainment Area State Implementation and Maintenance Plan (June 
2002), letter and enclosures (replacement pages for the cover page and 
pages iii, 2, 3, 4 and 49), dated June 30, 2004.
    (3) Letter from Stephen A. Owens, Director, Arizona Department of 
Environmental Quality, dated June 20, 2006, withdrawing a section 
107(d)(3)(D) boundary redesignation request included in the Miami 
Sulfur Dioxide Nonattainment Area State Implementation and Maintenance 
Plan and requesting a section 110(k)(6) error correction.
* * * * *

0
Part 81, chapter I, title 40 of the Code of Federal Regulations is 
amended as follows:

PART 81--[AMENDED]

0
1. The authority citation for part 81 continues to read as follows:

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

Subpart C--[Amended]

0
2. In Sec.  81.303, the table entitled ``Arizona--SO2'' is 
amended by revising the entry for Miami to read as follows:


Sec.  81.303  Arizona.

* * * * *

                                                  Arizona--SO2
----------------------------------------------------------------------------------------------------------------
                                               Does not meet    Does not meet                      Better than
               Designated area                    primary         secondary        Cannot be         national
                                                 standards        standards        classified       standards
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Miami:
    T2N, R14E...............................  ...............  ...............  ...............               X
    T2N, R15E...............................  ...............  ...............  ...............               X
    T1N, R13E \1\...........................  ...............  ...............  ...............               X
    T1N, R14E...............................  ...............  ...............  ...............               X
    T1N, R15E...............................  ...............  ...............  ...............               X
    T1S, R14E \1\...........................  ...............  ...............  ...............               X

[[Page 3075]]


    T1S, R14\1/2\E..........................  ...............  ...............  ...............               X
    T1S, R15E...............................  ...............  ...............  ...............               X
    T2N, R13E \1\...........................  ...............  ...............               X   ...............
    T2N, R16E...............................  ...............  ...............               X   ...............
    T1N, R16E...............................  ...............  ...............               X   ...............
    T1S, R13E \1\...........................  ...............  ...............               X   ...............
    T1S, R16E...............................  ...............  ...............               X   ...............
    T2S, R14E \1\...........................  ...............  ...............               X   ...............
    T2S, R15E...............................  ...............  ...............               X   ...............

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
\1\Only that portion in Gila County.

* * * * *
 [FR Doc. E7-996 Filed 1-23-07; 8:45 am]

BILLING CODE 6560-50-P
