Document ID: EPA-R09-OAR-2006-0558-0038
Agency: epa
Document Type: Rule
Title: Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality Planning Purposes; State of Arizona; Boundary Redesignation; Finding of Attainment for Miami Particulate Matter of 10 Microns or Less (PM10) Nonattainment Area; Determination Regarding Applicability of Certain Clean Air Act Requirements; Correction
Posted Date: 2007-03-28T04:00Z

[Federal Register: March 28, 2007 (Volume 72, Number 59)]
[Rules and Regulations]               
[Page 14422-14432]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28mr07-12]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 81

[EPA-R09-OAR-2006-AZ-0558; FRL-8292-6]

 
Approval and Promulgation of Implementation Plans; Designation of 
Areas for Air Quality Planning Purposes; State of Arizona; Boundary 
Redesignation; Finding of Attainment for Miami Particulate Matter of 10 
Microns or Less (PM10) Nonattainment Area; Determination Regarding 
Applicability of Certain Clean Air Act Requirements; Correction

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA is taking direct final action to approve the State of 
Arizona's boundary redesignation of the Hayden/Miami PM10 
nonattainment area into two separate PM10 nonattainment 
areas: Hayden and Miami. EPA is also finding that the Miami 
PM10 nonattainment area is attaining the PM10 
national ambient air quality standard, and, based on this attainment 
finding, EPA is determining that certain Clean Air Act requirements are 
not applicable for so long as the Miami area shows continued attainment 
of the standard based on current, publicly available, quality-assured 
monitoring data. EPA is taking this action consistent with obligations 
under the Clean Air Act to act on State redesignations. Lastly, EPA is 
correcting two errors in previous rulemakings that involved the 
designations of PM10 areas within the State of Arizona.

DATES: This rule is effective on May 29, 2007, without further notice, 
unless EPA receives adverse comments by April 27, 2007. If adverse 
comment is received, EPA will publish a timely

[[Page 14423]]

withdrawal of the direct final rule in the Federal Register informing 
the public that the rule will not take effect.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2006-AZ-0558 by one of the following methods:
     Federal eRulemaking portal: http://www.regulations.gov. 

Follow the on-line instructions for submitting comments.
     E-mail: tax.wienke@epa.gov.
     Fax: (415) 947-3579 (please alert the individual listed in 
the FOR FURTHER INFORMATION CONTACT if you are faxing comments).
     Mail: Wienke Tax, Office of Air Planning, Environmental 
Protection Agency (EPA), Region 9, Mailcode AIR-2, 75 Hawthorne Street, 
San Francisco, California 94105-3901.
     Hand Delivery: Wienke Tax, Office of Air Planning, 
Environmental Protection Agency (EPA), Region 9, Mailcode AIR-2, 75 
Hawthorne Street, San Francisco, California 94105-3901. Such deliveries 
are only accepted Monday through Friday, 8 a.m. to 4:55 p.m., excluding 
federal holidays. Special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-R09-OAR-
2006-AZ-0558. EPA's policy is that all comments received 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 information claimed 
to be Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. Do not submit information 
that you consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site 

is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA, without 
going through http://www.regulations.gov, your e-mail address will be 

automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm
.

    Docket: All documents in the docket are listed in the http://www.regulations.gov
 index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy 
form. Publicly available docket materials are available either 
electronically in http://www.regulations.gov or in hard copy at the 

Office of Air Planning, Environmental Protection Agency (EPA), Region 
9, Mailcode AIR-2, 75 Hawthorne Street, San Francisco, California 
94105-3901. EPA requests that if at all possible, you contact the 
individual listed in the FOR FURTHER INFORMATION CONTACT section to 
view the hard copy of the docket. You may view the hard copy of the 
docket Monday through Friday, 8 a.m. to 4 p.m., excluding Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Wienke Tax, Office of Air Planning, 
Environmental Protection Agency (EPA), Region 9, Mailcode AIR-2, 75 
Hawthorne Street, San Francisco, California 94105-3901, (520) 622-1622, 
tax.wienke@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document, wherever ``we,'' 
``us,'' or ``our'' is used, we mean the EPA.

Table of Contents

I. Background
    A. What NAAQS are Considered in this Action?
    B. What is the Designation and Classification of this 
PM10 Nonattainment Area?
II. Boundary Redesignation
    A. What Did the State Submit?
    B. How Does EPA Evaluate Boundary Redesignations?
    C. What is EPA's Evaluation of the State's Submittal?
    D. What Are the Implications of EPA's Approval of the State's 
Boundary Redesignation?
III. Finding of Attainment for Miami Area and Determination 
Regarding Applicability of Certain Clean Air Act Requirements
    A. How do we Make Attainment Determinations?
    B. What is the Basis for EPA's Determination that the Miami Area 
is Attaining the PM10 NAAQS?
    C. What Are the Applicable Planning Requirements for the Miami 
Area as a Result of EPA's Attainment Determination?
IV. Corrections to the Arizona PM10 Table in 40 CFR Part 
81
V. EPA's Final Action
VI. Statutory and Executive Order Reviews

I. Background

A. What NAAQS Are Considered in this Action?

    National ambient air quality standards (NAAQS) are thresholds for 
certain ambient air pollutants set by EPA under the Clean Air Act (CAA 
or ``Act'') to protect public health and welfare. Particulate matter 
with an aerodynamic diameter less than or equal to 10 micrometers, or 
PM10, is the subject of this action. PM10 is 
among the ambient air pollutants for which EPA has established NAAQS. 
PM10 causes adverse health effects by penetrating deep in 
the lungs, aggravating the cardiopulmonary system. Children, the 
elderly, and people with asthma and heart conditions are the most 
vulnerable.
    In 1971, EPA promulgated the first NAAQS for particulate matter 
(PM) and defined the standard in terms of an indicator referred to as 
``total suspended particulate,'' or ``TSP,'' which roughly included all 
particles with diameters of 30 microns or less. In 1987, EPA 
established new PM NAAQS and defined the new standards in terms of 
PM10 instead of TSP. See 52 FR 24634 (July 1, 1987). Ten 
years later, in 1997, EPA established another PM NAAQS and defined this 
new standard in terms of particulate matter with an aerodynamic 
diameter less than or equal to 2.5 micrometers, or PM2.5, 
but in our 1997 final rule, we decided to retain a PM10 
NAAQS as well. See 62 FR 38652 (July 18, 1997). In 2006, EPA completed 
a review of both the PM2.5 NAAQS and PM10 NAAQS 
and, among other actions, decided to retain the 24-hour-average 
PM10 standard at its current level but to revoke the annual-
average PM10 standard. See 71 FR 61144 (October 17, 2006). 
The level of the primary (i.e., public health) PM10 standard 
is 150 micrograms per cubic meter ([mu]g/m \3\), 24-hour average 
concentration.\1\ See 40 CFR 50.6. The secondary PM10 
standard, promulgated to protect against adverse welfare effects, is 
identical to the primary standard.

[[Page 14424]]

B. What is the Designation and Classification of this PM10 
Nonattainment Area?
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    \1\ The effective date of EPA's October 17, 2006 final rule 
revoking the annual-average standard was December 18, 2006. Thus, we 
make no finding in this direct final rule relative to the annual-
average PM10 NAAQS but have included annual-average 
PM10 concentration data for informational purposes only. 
The now-revoked annual-average PM10 NAAQS was set at a 
level of 50 [mu]g/m \3\.
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    Under the Clean Air Act Amendments of 1977, and due to recorded 
violations of the former TSP-defined NAAQS and the location of major 
industrial sources, EPA designated one township in each of the Hayden 
and Miami areas as separate nonattainment areas for TSP (44 FR 21261, 
April 10, 1979, as corrected at 44 FR 53081, September 12, 1979).\2\ As 
noted above, in 1987, we revised the PM NAAQS to include only 
particulate matter of a size range less than or equal to a nominal 10 
microns (PM10). As part of the implementation policy for the 
new standards, where insufficient PM10 data were available, 
EPA categorized areas based on their probability of violating the 
standard using TSP data. The categories were: Group I, areas with a 
high probability of violating the standards; Group II, areas with a 
moderate probability of violating; and Group III, areas that were 
likely to be attaining the standards.
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    \2\ Hayden and Miami are towns located near significant mining 
and copper smelting activities in east central Arizona, roughly 70 
to 80 miles east-southeast of Phoenix. Miami is located in Gila 
County; Hayden straddles the boundary between Gila County and Pinal 
County approximately 27 miles south of Miami.
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    In 1987, EPA identified the ``Hayden/Miami area'' as one of the 
Group I areas for PM10. See 52 FR 29383 (August 7, 1987). In 
a 1990 clarification, we defined the geographic area of the combined 
Hayden/Miami Group I area as including all or part of 26 contiguous 
townships in and around the towns of Hayden and Miami (55 FR 45799, 
October 31, 1990).\3\
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    \3\ The Hayden/Miami ``Group I'' area encompassed the following 
townships: T1N, R13E; T1N, R14E; T1N, R15E; T1S, R13E; T1S, R14E; 
T1S, R14\1/2\2E; T1S, R15E; T2S, R13E; T2S, R14E; T2S, R15E; T3S, 
R13E; T3S, R14E; T3S, R15E; T3S, R16E (except that portion in the 
San Carlos Indian Reservation); T4S, R13E; T4S, R14E; T4S, R15E; 
T4S, R16E; T5S, R13E; T5S, R14E; T5S, R15E; T5S, R16E; T6S, R13E; 
T6S, R14E; T6S, R15E; and T6S, R16E.
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    Subsequent to our 1990 clarification and upon enactment of the 
Clean Air Act Amendments of 1990, all ``Group I'' areas, such as the 
Hayden/Miami planning area, were designated as ``nonattainment'' for 
the PM10 NAAQS by operation of law and classified as 
``moderate.'' See CAA sections 107(d)(4)(B) and 188(a). In March 1991, 
EPA announced the designations and classifications of areas with 
respect to PM10 NAAQS that occurred by operation of law upon 
enactment of the 1990 Amendments to the CAA. See 56 FR 11101 (March 15, 
1991). In August 1991, EPA rejected challenges made by the State of 
Arizona and industry to the geographic size of the Hayden/Miami 
PM10 nonattainment area. See 56 FR 37654 (August 8, 1991). 
Later that same year, we codified the PM10 nonattainment 
designations and moderate area classifications in 40 CFR part 81. See 
56 FR 56694 (November 6, 1991). For ``moderate'' nonattainment areas 
such as the Hayden/Miami PM10 nonattainment area, CAA 
section 188(c) of the 1990 Amended Act establishes an attainment date 
of December 31, 1994.
    Along with the new designations, classifications, and attainment 
dates, the CAA as amended in 1990 also established new planning 
requirements. In accordance with section 189(a) of the CAA, Arizona was 
required to submit a state implementation plan (SIP) revision by 
November 15, 1991 demonstrating attainment of the PM10 
standards and providing for implementation of reasonably available 
control measures (RACM) by December 31, 1994 for the Hayden/Miami area. 
The State of Arizona relied upon a SIP revision (``Final PM-10 State 
Implementation Plan for the Hayden Group I Area'' dated September 1989) 
that it had submitted on October 16, 1989 to meet the requirements of 
the CAA as amended in 1990 for ``moderate'' PM10 
nonattainment areas.
    In 1994, we proposed a limited approval and limited disapproval of 
Arizona's 1989 SIP revision. See 59 FR 36116 (July 15, 1994). The 
primary reason for the proposed limited disapproval was that the plan 
addressed only the Hayden portion of the Hayden/Miami PM10 
nonattainment area. In response, by letter dated November 10, 1994, the 
Governor's designee for CAA matters, the Arizona Department of 
Environmental Quality (ADEQ), submitted a formal petition for 
rulemaking to realign the Hayden/Miami PM10 nonattainment 
area boundary. Specifically, ADEQ requested that EPA correct the 
purported error the Agency had made in including the Miami area in the 
original Group I area in 1987 and called for exclusion of the northern 
third of the area (i.e., the Miami portion) from the nonattainment 
area. We have not taken final action on our 1994 proposed limited 
approval/limited disapproval of ADEQ's 1989 SIP revision. In today's 
direct final rule, we again are taking no action on ADEQ's 1989 SIP 
revision but will address applicable CAA requirements for the Hayden 
area in a future rulemaking. For the Miami area, in this direct final 
rule, we are making an attainment finding and a determination regarding 
applicability of certain CAA requirements (see section III, below).
    On June 20, 2006, under CAA section 107(d)(3)(D), ADEQ submitted a 
request for a boundary redesignation of the Hayden/Miami 
PM10 nonattainment area to EPA for approval. In contrast 
with ADEQ's 1994 petition, ADEQ's 2006 boundary redesignation would not 
reduce the overall size of the area designated as nonattainment for 
PM10 but would simply divide a single PM10 
nonattainment area into two PM10 nonattainment areas. We 
consider ADEQ's June 20, 2006 boundary redesignation (discussed in the 
following section of this direct final rule) to supersede the State's 
1994 petition and thus plan no further action on that earlier request.

II. Boundary Redesignation

A. What Did the State Submit?

    On June 20, 2006, ADEQ submitted to EPA under CAA section 
107(d)(3)(D) a request for a boundary redesignation of the Hayden/Miami 
PM10 nonattainment area into two separate, but adjoining, 
PM10 nonattainment areas, namely, the Hayden nonattainment 
area and the Miami nonattainment area. ADEQ enclosed a technical 
justification report entitled, ``Request to Revise the Hayden/Miami 
PM10 Nonattainment Area Boundary'' (May 2006), in support of 
this boundary redesignation. ADEQ's technical justification report 
includes a discussion of the regulatory background and the 
topographical and meteorological characteristics of the Hayden and 
Miami areas. The report also includes tables summarizing emission 
inventory and ambient air quality data and maps showing the existing 
nonattainment area boundaries, topographical features, the locations of 
permitted emissions sources, and the boundary delineating the new Miami 
and Hayden PM10 nonattainment areas. Together, these two new 
PM10 nonattainment areas would cover the same geographic 
area as the original Hayden/Miami PM10 nonattainment area. 
ADEQ's boundary separating the Miami and Hayden PM10 areas 
runs east-west in steps using township and section identifiers to 
roughly trace the ridgeline of the Pinal Mountains.

B. How Does EPA Evaluate Boundary Redesignations?

    Under section 107(d)(3)(D) of the CAA, the Governor of any State 
may, on the Governor's own motion, submit to EPA a revised designation 
of any area or portion thereof within the State.\4\ EPA is required to 
approve or deny a submittal

[[Page 14425]]

for redesignation within 18 months of receipt. The type of 
redesignation that ADEQ submitted on June 20, 2006 involves just a 
boundary change and does not involve a change in status (i.e., does not 
involve a change from ``nonattainment,'' for example, to ``attainment'' 
or ``unclassifiable'') of any area. In this notice, we refer to the 
former type of redesignation as a ``boundary redesignation.''
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    \4\ Boundary changes are an inherent part of a designation or 
redesignation of an area under the CAA. See CAA section 
107(d)(1)(B)(ii).
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    In determining whether to approve or deny a State's submittal of a 
boundary redesignation under section 107(d)(3)(D), EPA uses the same 
factors Congress directed EPA to consider when the Agency initiates a 
revision to a designation of an area on its own motion under section 
107(d)(3)(A). These factors include ``air quality data, planning and 
control considerations, or any other air quality-related considerations 
the Administrator deems appropriate.'' See CAA section 107(d)(3)(A). In 
addition, because ADEQ's redesignation involves a nonattainment area, 
we also take into account CAA section 107(d)(1)(A), which provides that 
nonattainment areas are to include the geographic area that does not 
meet, or that contributes to ambient air quality in a nearby area that 
does not meet, the NAAQS for a given pollutant.

C. What is EPA's Evaluation of the State's Submittal?

    We have reviewed and evaluated ADEQ's technical justification 
report and conclude that ADEQ has adequately demonstrated that the 
Miami and Hayden PM10 nonattainment areas lie in separate 
airsheds in which air quality is determined by topographical and 
meteorological factors and local emissions sources specific to each 
airshed with no significant PM10 transport between the two 
areas. We also conclude that ADEQ's division of the two areas 
essentially along the ridgeline of the Pinal Mountains follows 
logically from the identification of these separate airsheds. As such, 
each new PM10 nonattainment area encompasses the geographic 
area of historic PM10 (or, in the case of Miami, TSP) NAAQS 
violations as well as the sources which contributed to those 
violations. Therefore, we are approving the State's boundary 
redesignation of the Hayden/Miami PM10 nonattainment area 
and are thereby establishing separate Hayden and Miami PM10 
nonattainment areas. We provide further detail on our evaluation in the 
paragraphs that follow.
Topography
    As noted previously, the Hayden/Miami PM10 nonattainment 
area is located in east central Arizona. The town of Hayden is situated 
in the southern portion of the nonattainment area, approximately 27 
miles south of the town of Miami, which is located in the northern 
portion of the nonattainment area. Between the two towns lie the 
predominant geographic features of the nonattainment area: the Pinal, 
Mescal, and Dripping Spring Mountain ranges.
    Airsheds refer to areas with common weather or meteorological 
conditions and sources of air pollution. Generally speaking, an airshed 
contains source and receptor areas. The Pinal and Mescal Mountains, the 
highest of the three mountain ranges in this area, form a boundary 
between the Lower Salt River Airshed and the Gila River Airshed. These 
two interconnecting ranges separate the southern or Hayden portion of 
the nonattainment area from the northern or Miami portion. Figure 1 in 
the State's technical justification report illustrates the 
topographical features in the region.
    Elevations in the Pinal and Mescal Mountains are well over 5,000 
feet above sea level with numerous peaks above 6,000 feet. Pinal Peak 
is the highest point at 7,848 feet. Elevational differences between 
lower elevations in the southern portion of the nonattainment area and 
the airshed boundary (i.e., the ridgeline of the Pinal Mountains) 
generally range between 4,000 and 6,000 feet. Elevational differences 
between the northern portion of the nonattainment area and the airshed 
boundary (ridgeline of the Pinal Mountains) generally range between 
2,000 and 4,000 feet.
Meteorology
    The speed and direction of air pollutant transport in both the 
Lower Salt River Airshed (Miami area) and the Gila River Airshed 
(Hayden area) are greatly influenced by local topography. Both airsheds 
contain extensive areas of complex terrain that is responsible for 
complicated wind patterns.
    Hayden is located in a relatively narrow portion of the Gila River 
valley, immediately downstream from the confluence of the Gila and San 
Pedro Rivers. The Dripping Spring Mountains are located northeast of 
Hayden. In ADEQ's technical justification report, wind patterns in 
Hayden, where a number of stationary sources are located, are described 
as distinctly up-valley/down-valley. Such patterns are typical of 
mountainous areas, and are characterized by up-valley or up-slope flows 
during the day and down-valley or down-slope winds during the night. 
ADEQ notes that low southeasterly winds in the Gila River valley from 
nighttime down-slope or drainage flow can combine with stable 
atmospheric conditions to cause elevated pollutant concentrations 
within low lying areas. Up-slope convection during the day increases 
dispersion and flow out of the low lying areas. Under normal daytime 
conditions, surface winds become west-southwesterly to west-
northwesterly (up-valley) in the Hayden area, replacing nighttime down-
slope winds as the atmosphere becomes less stable. This pattern is 
repeated locally throughout much of the complex terrain found in the 
southern portion of the Hayden/Miami PM10 nonattainment 
area.
    Due to widespread areas of complex terrain, a similar up-valley/
down-valley pattern is found throughout much of the northern portion of 
the Hayden/Miami PM10 nonattainment area, where Miami is 
located. Miami is located along U.S. Highway 60 in a steep canyon of 
the Pinal Mountains. As described for Hayden, Miami is similarly 
influenced by up-slope/down-slope wind patterns. Generally, the Miami 
area exhibits a diurnal pattern of having a stronger average easterly 
component to nighttime airflow with a westerly component evident during 
the day.
    ADEQ's technical justification report notes that stronger regional 
air flow can at times override local patterns and overcome elevational 
differences, and that, under these conditions, direction of flow can 
vary. However, ADEQ notes also that mixing, dispersion, and dilution of 
emissions are increased under these conditions, especially with 
distance. Thus, localized complex terrain windflow patterns are the 
primary forces affecting dispersion from sources within each of the 
Hayden and Miami areas. We agree with ADEQ's conclusion that the 
greater emissions impacts are local, and any cross-airshed boundary 
contributions that may occur are minimal relative to local impacts.
Locations of Emissions Sources
    The topographical and meteorological characteristics described 
above support the conclusion that Hayden and Miami lie in separate 
airsheds with minimal PM10 pollutant transport between the 
two. However, ADEQ also provides information on the locations and 
magnitude of permitted PM10 sources in the two areas that 
lends further support to this conclusion.
    ADEQ notes that the majority of permitted sources in the Hayden/
Miami PM10 nonattainment area are associated with mining and 
smelting activities. These sources are located primarily in the extreme 
south and north of the

[[Page 14426]]

Hayden/Miami nonattainment area near the two mining towns, Hayden and 
Miami.\5\ Hayden area sources are clustered primarily in lower 
elevation areas in the southern portion of the nonattainment area, 
south of the Township 2 South/Township 3 South boundary. Miami area 
sources are located generally north of the Township 1 North/Township 1 
South line. The central portion of the nonattainment area, dominated by 
the Pinal and Mescal Mountain ranges that divide the lower elevation 
areas to the north and south, contains no permitted stationary sources. 
This buffer between the two concentrations of emissions sources to the 
south and north further minimizes the possibility of significant 
PM10 pollutant transport between the Hayden and Miami areas.
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    \5\ ADEQ estimates that, in 2004, permitted sources in Hayden 
emitted 1,974 tons of PM10 or 84 percent of total 
nonattainment area PM10 emissions. Emissions for Miami 
area sources totaled 375 tons or 16 percent of total nonattainment 
area emissions, and about one-fifth of Hayden area emissions. As 
expected in areas where local topographical and meteorological 
factors are the primary determinants of ambient air conditions and 
given the relative PM10 source strengths in the two 
areas, PM10 monitors in the Hayden area record higher 
PM10 concentrations than those in the Miami area. For 
example, whereas violations of both the 24-hour and now-revoked 
annual PM10 NAAQS have been recorded in the Hayden area 
(although none in recent years), no PM10 violations have 
ever been recorded in the Miami area.
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Planning Considerations
    ADEQ notes that dividing the single PM10 nonattainment 
area into two areas would facilitate air quality management by enabling 
separate analyses that reflect local air transport patterns and the 
development of control strategies and planning processes specific to 
each area. While we find that the existence of a single PM10 
air quality planning area does not preclude separate analyses and 
development of subarea-specific control strategies, we do recognize 
that dividing the single area into two would allow for de-coupling of 
the air quality planning processes for the Hayden and Miami areas, 
thereby allowing one of the two areas to seek redesignation and to 
begin the maintenance phase of CAA planning sooner than might otherwise 
be possible.
Conclusion
    Based on our review of ADEQ's technical justification report and 
other available information, we find that ADEQ has sufficiently 
demonstrated that the Miami and Hayden areas lie in separate airsheds 
in which local topographical and meteorological factors and local 
emissions sources determine ambient PM10 conditions and 
between which PM10 pollutant transport is minimal. The 
concentration of PM10 emissions sources to the south and 
north ends of the Hayden/Miami PM10 nonattainment area adds 
separation distance to the list of factors that minimize the potential 
for PM10 pollutant transport between the Miami and Hayden 
areas. We also find that dividing the single area into two would be 
beneficial from a planning perspective by allowing one of the areas to 
proceed to the maintenance phase of air quality planning under the CAA 
sooner than might otherwise be possible.\6\
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    \6\ We note that our action here today is consistent with prior 
EPA rulemakings redesignating PM10 nonattainment areas 
into multiple nonattainment areas that together cover the same 
geographic area as the original nonattainment area. See, e.g., 63 FR 
59722 (November 5, 1998), involving the division of a 
PM10 nonattainment area in Idaho into two areas 
delineated by the boundary between State lands and the Fort Hall 
Indian Reservation; and 67 FR 50805 (August 6, 2002), corrected at 
67 FR 59005 (September 19, 2002), involving the division of a 
PM10 nonattainment area in California into three areas 
delineated by the boundaries of Inyo, Kern and San Bernardino 
counties.
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D. What Are the Implications of EPA's Approval of the State's Boundary 
Redesignation?

    In approving ADEQ's boundary redesignation of the Hayden/Miami 
PM10 nonattainment area into two areas, we approve ADEQ's 
boundary, which roughly traces the ridgeline of the Pinal Mountains.
    The new Miami PM10 nonattainment area encompasses all or 
part of the following seven townships: T1N, R13E; T1N, R14E; T1N, R15E; 
T1S, R13E (sections 1-6); T1S, R14E (sections 1-24); T1S, R14\1/2\E; 
and T1S, R15E. The new Hayden PM10 nonattainment area 
encompasses all or part of the following 21 townships: T1S, R13E 
(sections 7-36); T1S, R14E (sections 25-36); T2S, R13E; T2S, R14E; T2S, 
R15E; T3S, R13E; T3S, R14E; T3S, R15E; T3S, R16E (except that portion 
in the San Carlos Indian Reservation); T4S, R13E; T4S, R14E; T4S, R15E; 
T4S, R16E; T5S, R13E; T5S, R14E; T5S, R15E; T5S, R16E; T6S, R13E; T6S, 
R14E; T6S, R15E; and T6S, R16E.
    Together, the two new PM10 nonattainment areas cover the 
same geographic area as the original Hayden/Miami PM10 
nonattainment area. Both of the new PM10 nonattainment areas 
retain the ``moderate'' classification associated with the Hayden/Miami 
PM10 nonattainment area.

III. Finding of Attainment for Miami Area and Determination Regarding 
Applicability of Certain Clean Air Act Requirements

A. How Do We Make Attainment Determinations?

    Generally, we will determine whether an area's air quality meets 
the PM10 NAAQS based upon data gathered at established state 
and local air monitoring stations (SLAMS) and national air monitoring 
stations (NAMS) in the nonattainment area and entered into EPA's Air 
Quality System (AQS) database. Data entered into AQS have been 
determined to meet Federal monitoring requirements (see 40 CFR 50.6; 40 
CFR part 50, appendix J; 40 CFR part 53; 40 CFR part 58, appendices A 
and B) and may be used to determine the attainment status of areas. We 
will also consider air quality data from other air monitoring stations 
in the nonattainment area, such as Special Purpose Monitors (SPM), some 
of which are run by industrial sources, provided that the stations meet 
the Federal monitoring requirements for SLAMS and that the data is 
publicly available.\7\ All data are reviewed to determine the area's 
air quality status in accordance with our guidance at 40 CFR part 50, 
appendix K.
---------------------------------------------------------------------------

    \7\ See EPA Memorandum, ``Use of Special Purpose Monitoring 
Data,'' from John S. Seitz, Director, Office of Air Quality Planning 
and Standards, August 22, 1997.
---------------------------------------------------------------------------

    Attainment of the 24-hour standard is determined by calculating the 
expected number of days in a year with PM10 concentrations 
greater than 150 [mu]g/m3. The 24-hour standard is attained 
when the expected number of days with levels above 150 [mu]g/
m3 (averaged over a three-year period) is less than or equal 
to one. Three consecutive years of air quality data are necessary to 
show attainment of the PM10 NAAQS. See 40 CFR part 50, 
appendix K. A complete year of air quality data, as referred to in 40 
CFR part 50, appendix K, is composed of all four calendar quarters with 
each quarter containing data from at least 75 percent of the scheduled 
sampling days.

B. What Is the Basis for EPA's Determination that the Miami Area Is 
Attaining the PM10 NAAQS?

    Beginning in 1987, PM10 has been monitored at seven 
different sites in the Miami area. ADEQ operated some of these 
PM10 monitoring sites and the owner and operator of the 
primary copper smelter (i.e., Phelps-Dodge Miami, Inc. or ``Phelps-
Dodge''), which is the largest single industrial source of emissions in 
the area, operated others. Different monitoring locations were

[[Page 14427]]

selected in an effort to locate the maximum PM10 impacts 
from the smelter. Since 1991, two monitors have remained at their 
current locations: the Golf Course monitor and the Ridgeline monitor. 
Both are operated by Phelps-Dodge and are considered Special Purpose 
Monitors (SPMs). ADEQ ended PM10 monitoring at its Nolan 
Ranch site (also known as ``Miami South'' or ``Jones Ranch'') in 1994 
and no longer operates any PM10 monitor in the Miami area. 
No violations of the PM10 NAAQS have been monitored at any 
of the seven monitoring sites in the Miami area since monitoring began 
in 1987.
    The PM10 data collected by Phelps-Dodge at the two SPMs 
(i.e., the Golf Course and Ridgeline sites) are not normally certified 
by ADEQ and entered into AQS, but to provide for this attainment 
finding, ADEQ worked with Phelps-Dodge to certify PM10 
monitoring data collected over the past several years and to enter the 
certified data into AQS. Table 1 provides a summary of the data 
collected at the Golf Course and Ridgeline sites during the 2003-2005 
period.
    Phelps-Dodge collected the PM10 data shown in Table 1 
below using Graseby-Anderson Dichotomous samplers, devices designated 
by EPA as a manual reference method sampler. The samplers operated on 
an approved operating schedule of once every six days and the data sets 
meet EPA requirements for 75 percent data capture as discussed in 40 
CFR 50, appendix K. ADEQ has reviewed the operation and maintenance 
records for these monitors and has certified that the data collected by 
Phelps-Dodge meets EPA's quality assurance requirements.

                               Table 1.--Summary of 24 Hour and Annual PM10 Concentrations ([mu]g/m3) for Miami, 2003-2005
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                PM10 Concentrations
                                                         -----------------------------------------------------------------------------------------------
                                                                             Ridgeline                                      Golf Course
                          Year                           -----------------------------------------------------------------------------------------------
                                                                              Annual       3 year annual                      Annual       3 year annual
                                                             24-hr max        average         average        24-hr max        average         average
--------------------------------------------------------------------------------------------------------------------------------------------------------
2003....................................................              59            14.6  ..............              53            20.7  ..............
2004....................................................              26            10.2  ..............              40            16.4  ..............
2005....................................................              23            12.4            12.4              40            21.0            19.4
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Note: Data for the annual-average are included in this table for 
informational purposes only because the annual-average 
PM10 standard has been revoked. The former annual-average 
PM10 standard was attained when the annual arithmetic 
mean PM10 concentration over a three-year period is equal 
to or less than 50 [mu]g/m3. We note that the Miami area 
would have been found to attain the annual standard as well as the 
24-hour standard had the former not been revoked.

    As noted above, the 24-hour PM10 standard is attained 
when the expected number of days with levels above 150 [mu]g/
m3 (averaged over a three-year period) is less than or equal 
to one. Based on the data summarized in table 1, above, we find no 
exceedances of the 24-hour PM10 standard for the 2003 to 
2005 period and thus the expected number of days with levels above 150 
[mu]g/m3 (averaged over that three-year period) is zero. As 
such, we find that Miami is attaining the 24-hour PM10 
NAAQS.

C. What Are the Applicable Planning Requirements for the Miami Area as 
a Result of EPA's Attainment Determination?

    The air quality planning requirements for moderate PM10 
nonattainment areas, such as the Miami PM10 nonattainment 
area, are set out in part D, subparts 1 and 4 of title I of the Act. We 
have issued guidance in a General Preamble \8\ describing how we will 
review SIPs and SIP revisions submitted under title I of the Act, 
including those containing moderate PM10 nonattainment area 
SIP provisions.
---------------------------------------------------------------------------

    \8\ ``General Preamble for the Implementation of Title I of the 
Clean Air Act Amendments of 1990'' (57 FR 13498, April 16, 1992, as 
supplemented 57 FR 18070, April 28, 1992).
---------------------------------------------------------------------------

    In some designated nonattainment areas, monitored data demonstrates 
that the NAAQS has already been achieved. Based on its interpretation 
of the Act, EPA has determined that certain requirements of part D, 
subparts 1 and 2 (of title I) of the Act do not apply and therefore do 
not require certain submissions for an area that has attained the 
NAAQS. These include reasonable further progress (RFP) requirements, 
attainment demonstrations and contingency measures, because these 
provisions have the purpose of helping achieve attainment of the NAAQS.
    EPA's Clean Data Policy is the subject of two memoranda setting 
forth our interpretation of the provisions of the Act as they apply to 
areas that have attained the relevant NAAQS. EPA also finalized the 
statutory interpretation set forth in the policy in a final rule, 40 
CFR 51.918, as part of its ``Final Rule to Implement the 8-hour Ozone 
National Ambient Air Quality Standard--Phase 2'' (Phase 2 Final Rule). 
See discussion in the preamble to the rule at 70 FR 71645-71646 
(November 29, 2005). EPA believes that the legal bases set forth in 
detail in our Phase 2 Final Rule; our May 10, 1995 memorandum from John 
S. Seitz, entitled ``Reasonable Further Progress, Attainment 
Demonstration, and Related Requirements for Ozone Nonattainment Areas 
Meeting the Ozone National Ambient Air Quality Standard'' (Seitz memo); 
and our December 14, 2004 memorandum from Stephen D. Page entitled 
``Clean Data Policy for the Fine Particle National Ambient Air Quality 
Standards'' (Page memo) are equally pertinent to the interpretation of 
provisions of subparts 1 and 4 applicable to PM10. EPA's 
interpretation of how the provisions of the Act apply to areas with 
``clean data'' is not logically limited to ozone and PM2.5, 
because the rationale is not dependent upon the type of pollutant. Our 
interpretation that an area that is attaining the standard is relieved 
of obligations to demonstrate RFP and to provide an attainment 
demonstration and contingency measures pursuant to part D of the CAA, 
pertains whether the standard is PM10, ozone, or 
PM2.5.
    The reasons for relieving an area that has attained the relevant 
standard of certain part D, subparts 1 and 2 obligations, applies 
equally to part D, subpart 4, which contains specific attainment 
demonstration and RFP provisions for PM10 nonattainment 
areas. As we have explained in the Phase 2 Final Rule and our ozone and 
PM2.5 clean data memoranda, EPA believes it is reasonable to 
interpret provisions regarding RFP and attainment demonstrations, along 
with related requirements, so as not to require SIP submissions if an 
area subject to those requirements is already attaining the NAAQS 
(i.e., attainment of the NAAQS is demonstrated with three consecutive 
years of complete, quality-

[[Page 14428]]

assured air quality monitoring data). Three U.S. Circuit Courts of 
Appeals have upheld EPA rulemakings applying its interpretation of 
subparts 1 and 2 with respect to ozone. Sierra Club v. EPA, 99 F.3d 
1551 (10th Cir. 1996); Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 
2004); Our Children's Earth Foundation v. EPA, No. 04-73032 (9th Cir. 
June 28, 2005) (memorandum opinion). It has been EPA's longstanding 
interpretation that the general provisions of part D, subpart 1 of the 
Act (sections 171 and 172) do not require the submission of SIP 
revisions concerning RFP for areas already attaining the ozone NAAQS. 
In the General Preamble, we stated:

    [R]equirements for RFP will not apply in evaluating a request 
for redesignation to attainment since, at a minimum, the air quality 
data for the area must show that the area has already attained. 
Showing that the State will make RFP towards attainment will, 
therefore, have no meaning at that point. 57 FR at 13564.

    EPA believes the same reasoning applies to the PM10 
provisions of part D, subpart 4.
    With respect to RFP, section 171(1) states that, for purposes of 
part D of title I, RFP ``means such annual incremental reductions in 
emissions of the relevant air pollutant as are required by this part or 
may reasonably be required by the Administrator for the purpose of 
ensuring attainment of the applicable NAAQS by the applicable date.'' 
Thus, whether dealing with the general RFP requirement of section 
172(c)(2), the ozone-specific RFP requirements of sections 182(b) and 
(c), or the specific RFP requirements for PM10 areas of part 
D, subpart 4, section 189(c)(1), the stated purpose of RFP is to ensure 
attainment by the applicable attainment date. Section 189(c)(1) states 
that:

    Plan revisions demonstrating attainment submitted to the 
Administrator for approval under this subpart shall contain 
quantitative milestones which are to be achieved every 3 years until 
the area is redesignated attainment and which demonstrate reasonable 
further progress, as defined in section 7501(1) of this title, 
toward attainment by the applicable date.

    Although this section states that revisions shall contain 
milestones which are to be achieved until the area is redesignated to 
attainment, such milestones are designed to show reasonable further 
progress ``toward attainment by the applicable attainment date'', as 
defined by section 171. Thus, it is clear that once the area has 
attained the standard, no further milestones are necessary or 
meaningful. This interpretation is supported by language in section 
189(c)(3), which mandates that a state that fails to achieve a 
milestone must submit a plan that assures that the state will achieve 
the next milestone or attain the NAAQS if there is no next milestone. 
Section 189(c)(3) assumes that the requirement to submit and achieve 
milestones does not continue after attainment of the NAAQS.
    In the General Preamble, we noted with respect to section 189(c) 
that ``the purpose of the milestone requirement is to `provide for 
emission reductions adequate to achieve the standards by the applicable 
attainment date' (H.R. Rep. No. 490 101st Cong., 2d Sess. 267 
(1990)).'' 57 FR 13539 (April 16, 1992). If an area has in fact 
attained the standard, the stated purpose of the RFP requirement will 
have already been fulfilled.\9\ EPA took this position with respect to 
the general RFP requirement of section 172(c)(2) in the April 16, 1992 
General Preamble and also in the May 10, 1995 memorandum with respect 
to the requirements of sections 182(b) and (c). We are extending that 
interpretation to the specific provisions of part D, subpart 4. In the 
General Preamble, we stated, in the context of a discussion of the 
requirements applicable to the evaluation of requests to redesignate 
nonattainment areas to attainment, that the ``requirements for RFP will 
not apply in evaluating a request for redesignation to attainment 
since, at a minimum, the air quality data for the area must show that 
the area has already attained. Showing that the State will make RFP 
towards attainment will, therefore, have no meaning at that point.'' 
(57 FR 13564). See also our September 4, 1992 memorandum from John 
Calcagni, entitled ``Procedures for Processing Requests to Redesignate 
Areas to Attainment'' (Calcagni memo), p. 6.
---------------------------------------------------------------------------

    \9\ Thus, we believe that it is a distinction without a 
difference that section 189(c)(1) speaks of the RFP requirement as 
one to be achieved until an area is ``redesignated attainment'', as 
opposed to section 172(c)(2), which is silent on the period to which 
the requirement pertains, or the ozone nonattainment area RFP 
requirements in sections 182(b)(1) or 182 (c)(2), which refer to the 
RFP requirements as applying until the ``attainment date,'' since 
section 189(c)(1) defines RFP by reference to section 171(1) of the 
Act. Reference to section 171(1) clarifies that, as with the general 
RFP requirements in section 172(c)(2) and the ozone-specific 
requirements of section 182(b)(1) and 182(c)(2), the PM-specific 
requirements may only be required ``for the purpose of ensuring 
attainment of the applicable national ambient air quality standard 
by the applicable date.'' 42 U.S.C. section 7501(1). As discussed in 
the text of this rulemaking, EPA interprets the RFP requirements, in 
light of the definition of RFP in section 171(1), and incorporated 
in section 189(c)(1), to be a requirement that no longer applies 
once the standard has been attained.
---------------------------------------------------------------------------

    Similarly, the requirements of section 189(c)(2) with respect to 
milestones no longer apply so long as an area has attained the 
standard. Section 189(c)(2) provides in relevant part that:

    Not later than 90 days after the date on which a milestone 
applicable to the area occurs, each State in which all or part of 
such area is located shall submit to the Administrator a 
demonstration * * * that the milestone has been met.

    Where the area has attained the standard and there are no further 
milestones, there is no further requirement to make a submission 
showing that such milestones have been met. As noted above, this is 
consistent with the position that EPA took with respect to the general 
RFP requirement of section 172(c)(2) in the April 16, 1992 General 
Preamble and also in the May 10, 1995 Seitz memorandum with respect to 
the requirements of section 182(b) and (c). In the May 10, 1995 Seitz 
memorandum, EPA also noted that section 182(g), the milestone 
requirement of Subpart 2, which is analogous to provisions in section 
189(c), is suspended upon a determination that an area has attained. 
The memorandum, also citing additional provisions related to attainment 
demonstration and RFP requirements, stated:

    Inasmuch as each of these requirements is linked with the 
attainment demonstration or RFP requirements of section 182(b)(1) or 
182(c)(2), if an area is not subject to the requirement to submit 
the underlying attainment demonstration or RFP plan, it need not 
submit the related SIP submission either.

1995 Seitz memorandum at 5.
    With respect to the attainment demonstration requirements of 
section 189(a)(1)(B), an analogous rationale leads to the same result. 
Section 189(a)(1)(B) requires that the plan provide for ``a 
demonstration (including air quality modeling) that the [SIP] will 
provide for attainment by the applicable attainment date * * *.'' As 
with the RFP requirements, if an area is already monitoring attainment 
of the standard, EPA believes there is no need for an area to make a 
further submission containing additional measures to achieve 
attainment. This is also consistent with the interpretation of the 
section 172(c) requirements provided by EPA in the General Preamble, 
the Page memo, and the section 182(b) and (c) requirements set forth in 
the Seitz memo. As EPA stated in the General Preamble, no other 
measures to provide for attainment would be needed by areas seeking 
redesignation to attainment since ``attainment will have been 
reached.'' (57 FR at 13564).
    Other SIP submission requirements are linked with these attainment

[[Page 14429]]

demonstration and RFP requirements, and similar reasoning applies to 
them. These requirements include the contingency measure requirements 
of sections 172(c)(9) and 182(c)(9). We have interpreted the 
contingency measure requirements of sections 172(c)(9) and 182(c)(9) as 
no longer applying when an area has attained the standard because those 
``contingency measures are directed at ensuring RFP and attainment by 
the applicable date.'' (57 FR at 13564); Seitz memo, pp. 5-6.
    Both sections 172(c)(1) and 189(a)(1)(C) require ``provisions to 
assure that reasonably available control measures'' (i.e., RACM) are 
implemented in a nonattainment area. The General Preamble, 57 FR at 
13560 (April 16, 1992), states that EPA interprets section 172(c)(1) so 
that RACM requirements are a ``component'' of an area's attainment 
demonstration. Thus, for the same reason the attainment demonstration 
no longer applies by its own terms, the requirement for RACM no longer 
applies. EPA has consistently interpreted this provision to require 
only implementation of potential RACM measures that could contribute to 
reasonable further progress or to attainment. General Preamble, 57 FR 
at 13498. Thus, where an area is already attaining the standard, no 
additional RACM measures are required.\10\ EPA is interpreting section 
189(a)(1)(C) consistent with its interpretation of section 172(c)(1).
---------------------------------------------------------------------------

    \10\ The EPA's interpretation that the statute only requires 
implementation of RACM measures that would advance attainment was 
upheld by the United States Court of Appeals for the Fifth Circuit 
(Sierra Club v. EPA, 314 F.3d 735, 743-745 (5th Cir. 2002), and by 
the United States Court of Appeals for the D.C. Circuit (Sierra Club 
v. EPA, 294 F.3d 155, 162-163 (DC Cir. 2002)).
---------------------------------------------------------------------------

    Here, as in both our Phase 2 Final Rule and ozone and 
PM2.5 clean data memoranda, we emphasize that the suspension 
of a requirement to submit SIP revisions concerning these RFP, 
attainment demonstration, RACM, and other related requirements exists 
only for as long as a nonattainment area continues to monitor 
attainment of the standard. If such an area experiences a violation of 
the NAAQS, the basis for the requirements being suspended would no 
longer exist. Therefore, the area would again be subject to a 
requirement to submit the pertinent SIP revision or revisions and would 
need to address those requirements. Thus, a determination that an area 
need not submit one of the SIP submittals amounts to no more than a 
suspension of the requirements for so long as the area continues to 
attain the standard. However, once EPA ultimately redesignates the area 
to attainment, the area will be entirely relieved of these requirements 
to the extent the maintenance plan for the area does not rely on them.
    Therefore, we believe that, for the reasons set forth here and 
established in our prior ``clean data'' memoranda and rulemakings, a 
PM10 nonattainment area that has ``clean data,'' should be 
relieved of the part D, subpart 4 obligations to provide an attainment 
demonstration pursuant to section 189(a)(1)(B), the RACM provisions of 
section 189(a)(1)(C), and the RFP provisions established by section 
189(c)(1) of the Act, as well as the aforementioned attainment 
demonstration, RACM, RFP and contingency measure provisions of part D, 
subpart 1 contained in section 172 of the Act.\11\
---------------------------------------------------------------------------

    \11\ In some prior rulemakings involving the Clean Data Policy 
and PM10, EPA has applied criteria in addition to that of 
attainment of the standard. See, e.g., 67 FR 43020 (June 26, 2002). 
EPA does not believe that those additional criteria are required by 
statute or are necessary for application of the policy for 
PM10 areas, and does not employ them in applying the 
policy to ozone and PM2.5 areas. EPA intends to make its 
application of the policy consistent for ozone, PM10, and 
PM2.5, and does not intend to require an area to meet 
additional criteria for PM10.
---------------------------------------------------------------------------

    Should EPA at some future time determine that an area that had 
clean data, but which has not yet been redesignated as attainment for a 
NAAQS, has violated the relevant standard, the area would again be 
required to submit the pertinent requirements under the SIP for the 
area. Attainment determinations under the policy do not shield an area 
from other required actions, such as provisions to address pollution 
transport.
    As set forth above, EPA finds that because the Miami area is 
attaining the PM10 NAAQS, the requirement of an attainment 
demonstration, reasonable further progress, reasonably available 
control measures and contingency measures no longer applies for so long 
as the area continues to monitor attainment of the PM10 
NAAQS.\12\
---------------------------------------------------------------------------

    \12\ We note that our application of the Clean Data Policy to 
the Miami PM10 nonattainment area is consistent with 
actions we have taken for other PM10 nonattainment areas 
that were also attaining the standard. See 71 FR 6352 (February 8, 
2006)(Ajo, Arizona area); 71 FR 13021 (March 14, 2006)(Yuma, Arizona 
area); 71 FR 40023 (July 14, 2006)(Weirton, West Virginia area); 71 
FR 44920 (August 8, 2006)(Rillito, Arizona area); and 71 FR 63642 
(October 30, 2006) (San Joaquin Valley, California area).
---------------------------------------------------------------------------

    This determination is contingent on the existence of monitoring 
data showing continued attainment of the PM10 NAAQS in the 
Miami area. Normally, we would simply rely on the continuation of a 
State's or local air district's monitoring network to provide the data 
necessary for the public and EPA to verify continued attainment because 
a State or local air district administering such a network must, under 
applicable Federal regulations, use reference methods, meet quality 
assurance requirements, and enter data periodically into AQS.
    In the Miami area, however, the only monitors collecting 
PM10 data are Special Purpose Monitors (SPMs) run by Phelps-
Dodge. Historically, these data have not been submitted to the State 
for certification and subsequent entry into EPA's Air Quality System 
(AQS) database. Thus, we have requested that ADEQ provide us with 
evidence that ADEQ and Phelps-Dodge ensure that PM10 data 
continues to be collected at Phelps-Dodge's two monitoring sites in the 
Miami area in a manner that meets Federal monitoring requirements for 
state and local air monitoring stations (SLAMS) and that ADEQ commits 
to entering the data into AQS on a periodic basis. ADEQ has submitted 
sufficient evidence supporting such commitments in the form of two 
letters: a letter dated May 15, 2006 from Alan H. Binegar, Smelter 
Manager, Phelps-Dodge Miami Inc. to Nancy Wrona, Director, Air Quality 
Division, ADEQ, and a letter dated January 19, 2007 from Nancy C. 
Wrona, Director, Air Quality Division, ADEQ, to Deborah Jordan, 
Director, Air Division, EPA-Region IX.
    Specifically, in its May 15, 2006 letter, Phelps-Dodge agrees to 
submit calibration records and supporting documentation for its 
PM10 monitors to ADEQ with future quarterly PM10 
reports. In its January 19, 2007 letter, ADEQ commits to begin entering 
data collected during 2006 by March 1, 2007, to complete the entry of 
2006 data into AQS by the end of June 2007, and to continue entry of 
2007 and subsequent data following applicable EPA quality assurance 
procedures and validation. We interpret ADEQ's commitment to mean that 
by the end of 2007, ADEQ will be entering Miami PM10 
monitoring data collected by Phelps-Dodge on the same quarterly 
schedule as required for SLAMS.
    If Phelps-Dodge or ADEQ fails to fulfill the monitoring-related 
commitments set forth in the letters dated May 15, 2006 and January 19, 
2007, then we can no longer be assured of the continued attainment of 
the PM10 NAAQS in the Miami area, and a failure to provide 
current, valid, publicly available PM10 data will have the 
same consequence as a measured violation of the PM10 NAAQS. 
In either event, the rationale for determining that the CAA

[[Page 14430]]

requirements discussed above no longer apply in the Miami area will no 
longer exist, and as a result, we will take action to withdraw our 
finding that the Miami area is attaining the standard and withdraw our 
related determination with respect to certain CAA requirements 
discussed above. Then, the State of Arizona would again be required to 
submit the pertinent CAA requirements for this nonattainment area.

IV. Corrections to the Arizona PM10 Table in 40 CFR Part 81

    In today's notice, we are also correcting two errors in the table 
found in 40 CFR part 81 (specifically, 40 CFR 81.303) listing the area 
designations within the State of Arizona for the PM10 NAAQS. 
CAA section 110(k)(6) provides EPA with authority to correct errors in 
rulemakings involving, among other things, area designations and 
classifications.
    First, we are fixing a typographical error in the listing for 
Payson in the PM10 table. This error was introduced into the 
table in a final rule redesignating the Payson area to attainment. See 
67 FR 43013 (June 26, 2002). In the June 2002 final rule, we 
inadvertently listed one of the townships that comprise the Payson air 
quality planning area as ``T01N, * * *'' while intending ``T10N, * * 
*.'' See 67 FR 43013, at 43019. We are correcting the listing in this 
notice.
    Second, we are correcting the erroneous deletion of the designation 
for ``rest of state'' in the Arizona PM10 table in 40 CFR 
81.303. This error occurred in two stages. First, in a 1996 final rule, 
we inadvertently included ``rest of state'' under the listing for 
Mohave County. See 61 FR 21372, at 21378 (May 10, 1996). Then, in a 
final rule published on February 15, 2002, we inadvertently deleted the 
``rest of state'' listing entirely. See 67 FR 7082, at 7085 (February 
15, 2002). In this notice, we are correcting this error by restoring 
the ``rest of state'' designation (``unclassifiable'') as a separate 
listing in the Arizona PM10 table.

V. EPA's Final Action

    Under section 107(d)(3)(D) of the Clean Air Act, EPA is approving 
the State of Arizona's redesignation of the Hayden/Miami 
PM10 nonattainment area into two separate but adjoining 
PM10 nonattainment areas (Hayden and Miami) as submitted on 
June 20, 2006 and making the changes to the table in 40 CFR part 81 
that shows Arizona PM10 area designations accordingly. EPA 
is approving this boundary redesignation based on topographical, 
meteorological, and other air quality-related factors that demonstrate 
that Hayden and Miami areas lie in different airsheds with little or no 
cross-airshed transport of PM10. Together, the two new 
PM10 nonattainment areas cover the same geographic area as 
the original Hayden/Miami PM10 nonattainment area and retain 
a ``moderate'' classification with respect to the PM10 
NAAQS. The approved boundary between the two new areas roughly traces 
the ridgeline of the Pinal Mountains.
    We also find that the Miami PM10 nonattainment area is 
attaining the PM10 NAAQS. Our finding of attainment is based 
on quality-assured data that meet the requirements of 40 CFR part 50, 
appendix K for the period 2003-2005.\13\
---------------------------------------------------------------------------

    \13\ The two actions we are taking today, the boundary 
redesignation and the finding of attainment, should be distinguished 
from an action to redesignate an area from ``nonattainment'' to 
``attainment'' under CAA section 107(d)(3). There are a number of 
prerequisite conditions that must be met before we can approve a 
State's request to change (i.e., ``redesignate'') the air quality 
planning status of an area from ``nonattainment'' to ``attainment,'' 
including, among other conditions, approval of a maintenance plan 
meeting the requirements of section 175A of the CAA. See section 
107(d)(3)(E) of the Act. Thus, the classification and designation 
status in 40 CFR part 81 will remain moderate nonattainment for the 
Miami PM10 area until such time as the State of Arizona 
meets the CAA requirements under section 107(d)(3)(E) for 
redesignation of the Miami area to attainment.
---------------------------------------------------------------------------

    EPA also finds that, because the Miami area is attaining the NAAQS, 
the following CAA requirements are not applicable for so long as the 
Miami area continues to attain the PM10 standard: the part 
D, subpart 4 obligations to provide an attainment demonstration 
pursuant to section 189(a)(1)(B), the RACM provisions of 189(a)(1)(C), 
the RFP provisions established by section 189(c)(1), and the attainment 
demonstration, RACM, RFP and contingency measure provisions of part D, 
subpart 1 contained in section 172 of the Act. Because our 
determination with respect to the above CAA requirements relies on the 
existence of current, valid, publicly-available monitoring data, we are 
making our determination contingent upon fulfillment of commitments 
made by Phelps-Dodge and ADEQ in letters dated May 15, 2006 and January 
19, 2007 to submit such data from the two current PM10 
monitoring sites in the Miami area to EPA's AQS. If the commitments 
made by Phelps-Dodge and ADEQ are not fulfilled or if the data shows a 
violation of the standard, then EPA will act to withdraw the attainment 
finding and withdraw the related determination with respect to the CAA 
requirements listed above.
    Lastly, under CAA section 110(k)(6), we correct two errors that 
were introduced into the ``Arizona--PM10'' table in 40 CFR 
81.303 in previous rulemakings. First, we correct a typographical error 
in the listings of townships that define the Payson air quality 
planning area. Second, we correct the erroneous deletion of the 
designation for ``rest of state'' by restoring the ``rest of state'' 
designation (``unclassifiable'') as a separate listing in the Arizona 
PM10 table.
    We are publishing this rule without prior proposal because the 
Agency views this as a noncontroversial action and anticipates no 
adverse comments. However, in the proposed rules section of this 
Federal Register publication, EPA is publishing a separate document 
that will serve as the proposal should adverse comments be filed. This 
action will be effective May 29, 2007, without further notice unless 
the EPA receives relevant adverse comments by April 27, 2007.
    If we receive such comments, then we will publish a document 
withdrawing the final rule and informing the public that the rule will 
not take effect. All public comments received will then be addressed in 
a subsequent final rule based on the proposed rule. We will not 
institute a second comment period. Parties interested in commenting 
should do so at this time. If no such comments are received, the public 
is advised that this rule will be effective on May 29, 2007 and no 
further action will be taken on the proposed rule.

VI. Statutory and Executive Order Reviews

    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 redesignates a boundary of an air quality planning area, makes a 
determination based on air quality data, and suspends certain 
requirements that otherwise would apply and does not impose any 
additional requirements. 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 does not impose any additional 
enforceable duty, it does not contain any unfunded mandate or 
significantly or uniquely affect small governments, as

[[Page 14431]]

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 97249, November 9, 2000). 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 redesignates a boundary 
of an air quality planning area, makes a determination based on air 
quality data, and suspends certain requirements that otherwise would 
apply and does not alter the relationship or the distribution of power 
and responsibilities established in the CAA. 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.
    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 CAA, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by May 29, 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 in 40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas, Intergovernmental relations, Particulate matter, 
Reporting and recordkeeping requirements.

    Dated: March 20, 2007.
Wayne Nastri,
Regional Administrator, Region 9.

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--PM10'' is 
amended by revising the entries for Pinal and Gila Counties and Gila 
County and by adding an entry for ``rest of state'' to read as follows:

Sec.  81.303  Arizona.

* * * * *

                                                  Arizona--PM10
----------------------------------------------------------------------------------------------------------------
                                                 Designation                           Classification
          Designated Area          -----------------------------------------------------------------------------
                                         Date                Type               Date                Type
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Pinal and Gila Counties:
Hayden planning area..............        11/15/90  Nonattainment........        11/15/90  Moderate.
T1S, R13E (sections 7-36); T1S,
 R14E (sections 25-36);T2S, R13E;
 T2S, R14E; T2S, R15E; T3S, R13E;
 T3S, R14E; T3S, R15E; T3S, R16E
 (except that portion in the San
 Carlos Apache Indian
 Reservation); T4S, R13E; T4S,
 R14E; T4S, R15E; T4S, R16E; T5S,
 R13E; T5S, R14E; T5S, R15E; T5S,
 R16E; T6S, R13E; T6S, R14E; T6S,
 R15E; and T6S, R16E.
Miami planning area...............        11/15/90  Nonattainment........        11/15/90  Moderate.
T1N, R13E; T1N, R14E; T1N, R15E;
 T1S, R13E (sections 1-6); T1S,
 R14E (sections 1 24); T1S, R14\1/
 2\E; and T1S, R15E.
Gila County (part):
Payson: T10N, sections 1-3,.......        08/26/02  Attainment...........  ..............  .....................
10-15, 22-27, and 34-36 of R9E;
 T11N, sections 1-3, 10-15, 22-27,
 and 34-36 of R9E; T10-11N, R10E;
 T10N, sections 4-9, 16-21, and 28-
 33 of R11E; T11N, sections 4-9,
 16-21, and 28-33 of R11E.

                                                  * * * * * * *
Rest of State.....................        11/15/90  Unclassifiable.......  ..............  .....................
----------------------------------------------------------------------------------------------------------------

[[Page 14432]]

* * * * *
 [FR Doc. E7-5663 Filed 3-27-07; 8:45 am]

BILLING CODE 6560-50-P