
[Federal Register: September 9, 2010 (Volume 75, Number 174)]
[Proposed Rules]               
[Page 54806-54821]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09se10-21]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2010-0715; FRL-9200-3]

 
Approval and Promulgation of Implementation Plans--Maricopa 
County (Phoenix) PM-10 Nonattainment Area; Serious Area Plan for 
Attainment of the 24-Hour PM-10 Standard; Clean Air Act Section 189(d)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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    EPA is proposing to approve in part and disapprove in part State 
implementation plan (SIP) revisions submitted by the State of Arizona 
to meet the Clean Air Act (CAA) requirements applicable to the serious 
Maricopa County (Phoenix) nonattainment area (Maricopa area). These 
requirements apply to the Maricopa area following EPA's June 6, 2007 
finding that the area failed to meet its December 31, 2006 serious area 
deadline to attain the national ambient air quality standards (NAAQS) 
for particulate matter of ten microns or less (PM-10). Under CAA 
section 189(d), Arizona was required to submit a plan by December 31, 
2007 providing for expeditious attainment of the PM-10 NAAQS and for an 
annual emission reduction in PM-10 or PM-10 precursors of not less than 
five percent per year until attainment (189(d) plan). EPA is proposing 
to disapprove provisions of the 189(d) plan for the Maricopa area 
because they do not meet applicable CAA requirements for emissions 
inventories as well as for attainment, five percent annual emission 
reductions, reasonable further progress and milestones, and contingency 
measures. EPA is also proposing to disapprove the 2010 motor vehicle 
emission budget in the 189(d) plan as not meeting the requirements of 
CAA section 176(c) and 40 CFR 93.118(e)(4). EPA is also proposing a 
limited approval and limited disapproval of State regulations for the 
control of PM-10 from agricultural sources. Finally, EPA is proposing 
to approve various provisions of State statutes relating to the control 
of PM-10 emissions in the Maricopa area.

DATES: Any comments must arrive by October 12, 2010.

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-
2010-0715, by one of the following methods:
    1. Federal eRulemaking Portal: http://www.regulations.gov. Follow 
the on-line instructions.
    2. E-mail: nudd.gregory@epa.gov.
    3. Mail or deliver: Gregory Nudd (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 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: Gregory Nudd, U.S. EPA Region 9, 415-
947-4107, nudd.gregory@epa.gov or http://www.epa.gov/region09/air/
actions.

SUPPLEMENTARY INFORMATION: Throughout this document, the terms ``we,'' 
``us,'' and ``our'' mean U.S. EPA.

Table of Contents

I. PM-10 Air Quality Planning in the Maricopa Area
II. Overview of Applicable CAA Requirements
III. Evaluation of the 189(d) Plan's Compliance With CAA 
Requirements
IV. Summary of Proposed Actions
V. Statutory and Executive Order Reviews

I. PM-10 Air Quality Planning in the Maricopa Area

    The NAAQS are standards for certain ambient air pollutants set by 
EPA to protect public health and welfare. PM-10 is among the ambient 
air pollutants for which EPA has established health-based standards. 
PM-10 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.
    On July 1, 1987 EPA revised the health-based national ambient air 
quality standards (52 FR 24672), replacing the standards for total 
suspended particulates with new standards applying only to particulate 
matter up to ten microns in diameter (PM-10). At that time, EPA 
established two PM-10 standards, annual standards and 24-hour 
standards. Effective December 18, 2006, EPA revoked the annual PM-10 
standards but retained the 24-hour PM-10 standards. 71 FR 61144 
(October 17, 2006). The 24-hour PM-10 standards of 150 micrograms per 
cubic meter ([mu]g/m\3\) are attained when the expected number of days 
per calendar year with a 24-hour average concentration above 150 [mu]g/
m\3\, as determined in accordance with appendix K to 40 CFR part 50, is 
equal to or less than one. 40 CFR 50.6 and 40 CFR part 50, appendix K.
    On the date of enactment of the 1990 Clean Air Act Amendments (CAA 
or the

[[Page 54807]]

Act), many areas, including the Maricopa area, meeting the 
qualifications of section 107(d)(4)(B) of the amended Act were 
designated nonattainment by operation of law. 56 FR 11101 (March 15, 
1991). The Maricopa area is located in the eastern portion of Maricopa 
County and encompasses the cities of Phoenix, Mesa, Scottsdale, Tempe, 
Chandler, Glendale, as well as 17 other jurisdictions and 
unincorporated County lands. The nonattainment area also includes the 
town of Apache Junction in Pinal County. EPA codified the boundaries of 
the Maricopa area at 40 CFR 81.303.
    Once an area is designated nonattainment for PM-10, section 188 of 
the CAA outlines the process for classifying the area as moderate or 
serious and establishes the area's attainment deadline. In accordance 
with section 188(a), at the time of designation, all PM-10 
nonattainment areas, including the Maricopa area, were initially 
classified as moderate.
    A moderate PM-10 nonattainment area must be reclassified to serious 
PM-10 nonattainment by operation of law if EPA determines after the 
applicable attainment date that, based on air quality, the area failed 
to attain by that date. CAA sections 179(c) and 188(b)(2). On May 10, 
1996, EPA reclassified the Maricopa area as a serious PM-10 
nonattainment area. 61 FR 21372.
    As a serious PM-10 nonattainment area, the Maricopa area acquired a 
new attainment deadline of no later than December 31, 2001. CAA section 
188(c)(2). However CAA section 188(e) allows states to apply for up to 
a 5-year extension of that deadline if certain conditions are met. In 
order to obtain the extension, there must be a showing that: (1) 
Attainment by the applicable attainment date would be impracticable; 
(2) the state complied with all requirements and commitments pertaining 
to the area in the implementation plan for the area; and (3) the state 
demonstrates that the plan for the area includes the most stringent 
measures (MSM) that are included in the implementation plan of any 
state or are achieved in practice in any state, and can feasibly be 
implemented in the specific area. Arizona requested an attainment date 
extension under CAA section 188(e) from December 31, 2001 to December 
31, 2006.
    On July 25, 2002, EPA approved the serious PM-10 plan for the 
Maricopa area as meeting the requirements for such areas in CAA 
sections 189(b) and (c), including the requirements for implementation 
of best available control measures (BACM) in section 189(b)(1)(B) and 
MSM in section 188(e). In the same action, EPA granted Arizona's 
request to extend the attainment date for the area to December 31, 
2006. 67 FR 48718. This final action, as well as the two proposals 
preceding it, provide a more detailed discussion of the history of PM-
10 planning in the Maricopa area. See 65 FR 19964 (April 13, 2000) and 
66 FR 50252 (October 2, 2001).
    On June 6, 2007, EPA found that the Maricopa area failed to attain 
the 24-hour PM-10 NAAQS by December 31, 2006 (72 FR 31183) and required 
the submittal of a new plan meeting the requirements of section 189(d) 
by December 31, 2007.
    On December 19, 2007, the Maricopa Association of Governments (MAG) 
adopted the ``MAG 2007 Five Percent Plan for PM-10 for the Maricopa 
County Nonattainment Area.'' In this proposal, we refer to this plan as 
the ``189(d) plan.'' On December 21, 2007 the Arizona Department of 
Environmental Quality (ADEQ) submitted the 189(d) plan and two Pinal 
County resolutions.\1\ MAG adopted and ADEQ submitted this SIP revision 
in order to address the CAA requirements in section 189(d).
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    \1\ Subsequently, in June 4, 2008 and February 23, 2009 letters 
from Nancy C. Wrona, ADEQ, to Deborah Jordan, EPA, the State 
submitted ``Supplemental Information to Section 189(d) 5% Reasonable 
Further Progress PM-10 SIP Revisions for the Maricopa County and 
Apache Junction (Metropolitan Phoenix) Nonattainment Area.''
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    CAA section 110(k)(1) requires EPA to determine whether a SIP 
submission is complete within 60 days of receipt. This section also 
provides that any plan that has not been affirmatively determined to be 
complete or incomplete shall become complete within 6 months by 
operation of law. EPA's completeness criteria are found in 40 CFR part 
51, appendix V. The 189(d) plan submittal became complete by operation 
of law on June 21, 2008.

II. Overview of Applicable CAA Requirements

    As a serious PM-10 nonattainment area that failed to meet its 
applicable attainment date, December 31, 2006, the Maricopa area is 
subject to CAA section 189(d) which provides that the state shall 
``submit within 12 months after the applicable attainment date, plan 
revisions which provide for attainment of the PM-10 air quality 
standard and, from the date of such submission until attainment, for an 
annual reduction of PM-10 or PM-10 precursor emissions within the area 
of not less than 5 percent of the amount of such emissions as reported 
in the most recent inventory prepared for the area.''
    The general planning and control requirements for all nonattainment 
plans are found in CAA sections 110 and 172. EPA has issued a General 
Preamble \2\ and Addendum to the General Preamble \3\ describing our 
preliminary views on how the Agency intends to review SIPs submitted to 
meet the CAA's requirements for the PM-10 NAAQS. The General Preamble 
mainly addresses the requirements for moderate nonattainment areas and 
the Addendum, the requirements for serious nonattainment areas. EPA has 
also issued other guidance documents related to PM-10 plans which are 
cited as necessary below. In addition, EPA addresses the adequacy of 
the motor vehicle budget for transportation conformity (CAA section 
176(c)) in this proposed plan action. The PM-10 plan requirements 
addressed by this proposed action are summarized below.
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    \2\ ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 
57 FR 13498 (April 16, 1992) (General Preamble) and 57 FR 18070 
(April 28, 1992).
    \3\ ``State Implementation Plans for Serious PM-10 Nonattainment 
Areas, and Attainment Date Waivers for PM-10 Nonattainment Areas 
Generally; Addendum to the General Preamble for the Implementation 
of Title I of the Clean Air Act Amendments of 1990,'' 59 FR 41998 
(August 16, 1994) (Addendum).
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A. Emissions Inventories

    CAA section 172(c)(3) requires that an attainment plan include a 
comprehensive, accurate, and current inventory of actual emissions from 
all sources of the relevant pollutants.

B. Attainment Demonstration

    The attainment deadline applicable to an area that misses the 
serious area attainment date is as soon as practicable, but no later 
than 5 years from the publication date of the nonattainment finding 
notice. EPA may, however, extend the attainment deadline to the extent 
it deems appropriate for a period no greater than 10 years from the 
publication date, ``considering the severity of nonattainment and the 
availability and feasibility of pollution control measures.'' CAA 
sections 179(d)(3) and 189(d).

C. Five Percent (5%) Requirement

    A 189(d) plan must provide for an annual reduction of PM-10 or PM-
10 precursor emissions within the area of not less than 5% of the 
amount of such emissions as reported in the most recent inventory 
prepared for the area.

[[Page 54808]]

D. Reasonable Further Progress and Quantitative Milestones

    CAA section 172(c)(2) requires that implementation plans 
demonstrate reasonable further progress (RFP) as defined in section 
171(1). Section 171(1) defines RFP as ``such annual incremental 
reductions in emissions of the relevant air pollutant as are required 
by this part [part D of title I] or may reasonably be required by the 
Administrator for the purpose of ensuring attainment of the applicable 
national ambient air quality standard by the applicable date.''
    Section 189(c)(1) requires the plan to contain quantitative 
milestones which will be achieved every 3 years and which will 
demonstrate that RFP is being met.

E. Contingency Measures

    CAA section 172(c)(9) requires that implementation plans provide 
for ``the implementation of specific measures to be undertaken if the 
area fails to make reasonable further progress, or to attain the 
[NAAQS] by the attainment date applicable under this part [part D of 
title I]. Such measures are to take effect in any such case without 
further action by the State or the Administrator.''

F. Transportation Conformity and Motor Vehicle Emissions Budgets

    Transportation conformity is required by CAA section 176(c). Our 
conformity rule (40 CFR part 93, subpart A) requires that 
transportation plans, programs, and projects conform to state air 
quality implementation plans and establishes the criteria and 
procedures for determining whether or not they do so. Conformity to a 
SIP means that transportation activities will not produce new air 
quality violations, worsen existing violations, or delay timely 
attainment of the NAAQS or any interim milestone. Once a SIP that 
contains motor vehicle emissions budgets (MVEBs) has been submitted to 
EPA, and EPA has found it adequate, these budgets are used for 
determining conformity: emissions from planned transportation 
activities must be less than or equal to the budgets.

G. Adequate Legal Authority and Resources

    CAA section 110(a)(2)(E)(i) requires that implementation plans 
provide necessary assurances that the state (or the general purpose 
local government) will have adequate personnel, funding and authority 
under state law. Requirements for legal authority are further defined 
in 40 CFR part 51, subpart L (51.230-51.232) and for resources in 40 
CFR 51.280. States and responsible local agencies must also demonstrate 
that they have the legal authority to adopt and enforce provisions of 
the SIP and to obtain information necessary to determine compliance. 
SIPs must also describe the resources that are available or will be 
available to the State and local agencies to carry out the plan, both 
at the time of submittal and during the 5-year period following 
submittal of the SIP.

III. Evaluation of the 189(d) Plan's Compliance With CAA Requirements

A. Emissions Inventories

    CAA section 172(c)(3) requires all nonattainment area plans to 
contain a comprehensive, accurate, and current inventory of emissions 
from all sources of the relevant pollutants in the geographic area 
encompassed in the plan. EPA believes that the inventories submitted by 
Arizona as part of the 189(d) plan for the Maricopa area are 
comprehensive and current, but are not sufficiently accurate as 
discussed below.
    MAG developed the 189(d) plan using the ``2005 Periodic Emissions 
Inventory for the Maricopa County, Arizona Nonattainment Area,'' May 
2007 (2005 Periodic Inventory). 189(d) plan, appendices, volume one, 
appendix B, exhibit 1. This inventory was developed by the Maricopa 
County Air Quality Department (MCAQD) as the baseline inventory for the 
area. 189(d) plan, p. 3-2.
    MAG used economic growth estimates to project 2007, 2008, 2009 and 
2010 emissions inventories for the area from the 2005 Periodic 
Inventory baseline. MAG then used these projected inventories to 
calculate the 5% reduction target required by section 189(d) and as the 
baseline for the RFP demonstration required by section 189(c).\4\ See 
189(d) plan, appendices, volume three, ``Technical Document in Support 
of the MAG 2007 Five Percent Plan for PM-10 for the Maricopa County 
Nonattainment Area,'' (189(d) plan TSD), chapter II.
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    \4\ The 189(d) plan projects that the Maricopa area will attain 
the PM-10 standard by December 31, 2010. For the 5% demonstration, 
the plan projects emission reductions in 2008, 2009 and 2010. The 
RFP demonstration shows annual emission reductions in a downward 
linear trend from 2007 to 2010. See 189(d) plan, chapters 7 and 8, 
and discussions of these demonstrations below.
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    The 2005 Periodic Inventory prepared for the Maricopa area 
describes and quantifies the annual and daily emissions of PM-10 from 
point, area, nonroad, on-road, and nonanthropogenic sources in the 
2,880 square mile nonattainment area.\5\ The 2005 Periodic Inventory 
indicates that the dominant sources of PM-10 emissions in the Maricopa 
area are construction-related fugitive dust, including residential, 
commercial, road and other land clearing (38 percent); paved road dust, 
including trackout (16 percent); unpaved roads (10 percent); and 
windblown dust (9 percent). 2005 Periodic Inventory, table 1.6-11.
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    \5\ The 2005 Periodic Inventory in the 189(d) plan also includes 
data on PM-10 precursors. However, a scientific analysis of the 
particulate matter found on filters on exceedance days indicates 
that the vast majority of PM-10 on these days is directly emitted 
PM-10 such as soil dust. See attachment, ``On speciated PM in the 
Salt River industrial area in 2002,'' dated January 22, 2010, to E-
mail from Peter Hyde, Arizona State University, to Gregory Nudd, 
EPA, July 30, 2010. Therefore, the 189(d) plan appropriately focuses 
on directly emitted PM-10.
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    EPA has evaluated the base year inventory relied on by MAG in light 
of the three criteria in section 172(c)(3) and our conclusions follow.
    Current: The base year, 2005, is a reasonably current year, 
considering the length of time needed to develop an inventory and 
thereafter to develop a plan based on it. The 2005 Periodic Inventory 
was the most recent inventory available when the 189(d) plan was 
developed.
    Comprehensive: The 189(d) plan's inventories are sufficiently 
complete. All of the relevant source categories are quantified.
    Accurate: The 2005 Periodic Inventory is not sufficiently accurate 
for the purposes of the 189(d) plan. As discussed below, this inventory 
and the subsequent year inventories that MAG derived from it 
overestimate the baseline emissions for construction and other sources. 
The accuracy of the baseline inventory is particularly important for 
this plan because it relies heavily on reductions from improving the 
effectiveness of existing rules \6\ for construction and other sources 
in order to meet the CAA's 5%, RFP and attainment requirements. See 
189(d) plan, chapters 7 and 8.
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    \6\ Rule effectiveness is an estimate of the ability of a 
regulatory program to achieve all of the emission reductions that 
could have been achieved by full compliance with the applicable 
regulations at all sources at all times. EPA requires a state to 
account for rule effectiveness when estimating emissions from source 
categories that are subject to regulations that reduce emissions. 
See ``Emissions Inventory Guidance for Implementation of Ozone and 
Particulate Matter National Ambient Air Quality Standards (NAAQS) 
and Regional Haze Regulations,'' EPA-454/R-05-001, November 2005 
(2005 Emissions Inventory Guidance), p. B-3.
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    MCAQD Rule 310 requires control measures for dust generating 
activities such as excavation, construction, demolition and bulk 
material handling. According to the 2005 Periodic Inventory, the 
majority of emissions subject to control under Rule 310 are from 
residential, commercial and road

[[Page 54809]]

construction. Measure 8 in the 189(d) plan is a commitment to 
implement proactive and complaint based inspections during night-time 
and on weekends and is a telling example of how the 189(d) plan depends 
primarily on improving Rule 310 effectiveness to demonstrate the 
required annual 5% reductions and RFP. The plan asserts that Measure 
8 will reduce PM-10 emissions by 1,884 tons per year (tpy). 
189(d) plan, p. 7-3. Of that, 1,694 tpy are attributed to increases in 
compliance, and therefore in the effectiveness, of Rule 310. 189(d) 
plan TSD, p. III-5. This pattern is repeated in Measures 2, 
3, 9, 10, 16, and 44, with 
a large majority of the 189(d) plan's total emissions reductions 
derived from increased compliance with Rule 310. This pattern is 
further detailed in table 2 below.
    For the 2005 Periodic Inventory, MCAQD used a set of 63 sample 
inspections of sources subject to Rule 310 in order to estimate its 
effectiveness.\7\ An analysis of these inspections yielded an estimated 
rule effectiveness of 51 percent. However, an analysis conducted by 
MCAQD of the entire database of over 11,000 relevant inspections during 
the time period of the sample inspections yielded an estimated rule 
effectiveness of 64.5 percent. In other words, examination of the 
larger database suggests that a significantly higher percentage of 
sources were in compliance, and accordingly the aggregate emissions 
inventory for this source category could be proportionately smaller 
than that suggested by the smaller set of sample inspections. While 
MCAQD conducted this analysis in 2010, after the development of the 
189(d) plan, the data and the method were available at the time it 
produced the 2005 Periodic Inventory.\8\ Table 1 below shows the impact 
of these two different rule effectiveness values on the estimate of 
fugitive dust emissions from construction sources in the Maricopa area. 
The data in table 1 are from the emission rate back-casting analysis 
conducted by MCAQD in 2010.\9\
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    \7\ 2005 Periodic Inventory, appendix 2.2, ``Rule Effectiveness 
Study for the Maricopa County Rules 310, 310.01, and 316.''
    \8\ The data from the 2010 analysis were from inspections 
conducted at the time the original rule effectiveness calculation 
was being developed, so that information should have been in the 
MCAQD's database. The analytical method was a hybrid of a simple 
average of the results in the inspection database and the 2005 
Emissions Inventory Guidance.
    \9\ E-mail from Matthew Poppen, MCAQD, to Gregory Nudd, EPA, 
``Back-casting of RE rates,'' April 19, 2010 (Poppen E-mail).

     Table 1--Impact of Rule 310 Effectiveness Methodology on Estimated Emissions From Construction Activity
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                                                                                                 Estimated 2005
                                                                                    Rule          emissions for
                              Estimation method                                 effectiveness     construction
                                                                                  (percent)      activity  (tons
                                                                                                    per year)
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Sample Rule 310 inspections (63 total inspections between July and December                 51            32,130
 2006)......................................................................
All Rule 310 inspections (over 11,000 between July 2006 and June 2007)......              64.5            24,968
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Difference in emissions.......................................................................             7,162
                                                                                                          (-22%)
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    EPA believes that analysis of the full database of 11,000 Rule 310 
inspections provides a more accurate measure of rule effectiveness than 
using a sample of 63 inspections. This is because the 63 inspections 
may not be representative of the entire population of sources covered 
by the rule. The larger data set is much more likely to be free of 
sample biases. Therefore, based on this analysis of the larger data 
set, EPA has determined that the initial estimate of rule effectiveness 
for Rule 310 was not accurate.
    There is a similar inaccuracy in the rule effectiveness 
calculations for MCAQD Rule 310.01\10\ for unpaved parking lots, 
unpaved roads and similar sources of fugitive dust emissions. For the 
2005 Periodic Inventory, MCAQD used a set of 124 sample inspections to 
estimate the effectiveness of Rule 310.01. 2005 Periodic Inventory, 
appendix 2.2. An analysis of these inspections yielded an estimated 
rule effectiveness of 68 percent. However, an analysis conducted by 
MCAQD of the entire database of over 4,500 relevant inspections during 
the time period of the sample inspections yielded an estimated rule 
effectiveness of 90 percent. See Poppen Email.
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    \10\ EPA is also concerned that the method MCAQD used to 
estimate rule effectiveness for non-metallic mineral processing and 
other sources subject to Rule 316 is dependent on qualitative 
factors rather than compliance data.
    \11\ This data summary was compiled from the emission reduction 
calculations found in the 189(d) plan TSD, chapter III.
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    The significance of the inventory inaccuracies discussed above is 
graphically depicted in table 2:

  Table 2\11\--Measures To Improve Compliance With Rules 310 and 310.01
     Compared to All Measures Supporting the Attainment, 5% and RFP
                             Demonstrations
------------------------------------------------------------------------
                                              2008      2009      2010
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Total reductions from attainment, 5% and       6,603    15,422    19,840
 RFP measures [tpy].......................
Reductions from measures to improve rule       4,658    11,292    15,244
 effectiveness of Rule 310................
Reductions from measures to improve rule         360     1,061     1,063
 effectiveness of Rule 310.01.............
% of reductions from such measures........       76%       80%       82%
------------------------------------------------------------------------

    As shown in table 2, the 189(d) plan is designed to achieve the 
additional reductions in emissions required for the attainment, 5% and 
RFP demonstrations primarily through improvements in rule effectiveness 
for the sources regulated

[[Page 54810]]

by Rules 310 and 310.01. The inaccuracies in the baseline emissions 
inventory were carried through into the future year emission 
inventories and the calculations of emission reductions for those 
demonstrations.
    Moreover, the underestimation of the effectiveness of Rules 310 and 
310.01 resulted in a control strategy with a high probability of 
failure because the over-emphasis on achieving emission reductions from 
the sources regulated by these rules likely resulted in a corresponding 
de-emphasis on emission reductions from other sources contributing to 
the nonattainment problem in the Maricopa area. In table 3 below we 
compare the projected percentage of 2010 emissions attributable to 
certain source categories before implementation of the 189(d) plan's 
controls to the projected percentage of emission reductions attributed 
to controls for these categories in 2010. The source categories are 
those contributing more than 5% to the projected 2010 inventory of 
annual PM-10 emissions. See 189(d) TSD, pp. II-17 and chapter III.

 Table 3--Comparison of the 2010 Emissions Reductions Expected From the
   Control Measures to the Proportion of 2010 Emissions for Principal
               Sources of PM-10 in the Nonattainment Area
------------------------------------------------------------------------
                                                          Percentage of
                                        Percentage of    estimated 2010
           Source category               pre-control        emission
                                       2010 emissions      reductions
------------------------------------------------------------------------
Construction........................              33.1              82.5
Paved Roads (including trackout)....              19.1               5.1
Unpaved Roads.......................              17.4               0.0
Fuel Combustion and Fires...........               5.6               0.2
Windblown dust from vacant land.....               5.4               7.7
Other Sources (<5% each)............              19.4               4.5
------------------------------------------------------------------------

    As can be seen from this comparison, the plan's emphasis on 
reducing emissions from the construction industry is out of proportion 
to that source category's relative contribution to the projected 2010 
inventory.
    For the reasons discussed above, EPA is proposing to disapprove 
under CAA section 110(k)(3) the 2005 baseline emissions inventory in 
the 189(d) plan and all of the projected inventories as not meeting the 
requirements of section 172(c)(3).

B. Measures in the 189(d) Plan

1. Introduction
    The 189(d) plan contains 53 measures designed to reduce emissions 
of PM-10. A detailed description and implementation schedule for each 
measure is provided in chapter 6 of the plan. Of the 53 measures, 25 
measures are intended to support the attainment, RFP and 5% 
demonstrations provided in the plan, and 9 are contingency measures. 
These measures incorporate differing strategies to target emissions 
from a variety of activities within the Maricopa area. The remaining 
measures are included to represent additional efforts by the State and 
local jurisdictions to reduce emissions beyond those quantified in the 
plan. As those measures are implemented, the 189(d) plan provides that 
a more detailed assessment of the air quality benefits may be developed 
and reported in the future.
    EPA is proposing action on the measures in the 189(d) plan that 
constitute mandatory directives to the regulated community or to 
various local jurisdictions to adopt certain legislative requirements. 
These measures typically involve emissions reductions that can be 
reasonably quantified, and/or regulatory components that are 
enforceable. The 189(d) plan does not take specific emission reduction 
credits for the additional measures referred to above where the ability 
to quantify emission reductions was considered to be limited.
    In reviewing a statute, regulation, or rule for SIP approval, EPA 
looks to ensure that the provision is enforceable as required by CAA 
section 110(a), is consistent with all applicable EPA guidance, and 
does not relax existing SIP requirements as required by CAA sections 
110(l) and 193. Guidance and policy documents that we use to evaluate 
enforceability and PM-10 rules include the following:
    1. ``Issues Relating to VOC Regulation Cutpoints, Deficiencies, and 
Deviations; Clarification to Appendix D of November 24, 1987 Federal 
Register Notice,'' (Blue Book), notice of availability published in the 
May 25, 1988 Federal Register.
    2. ``Guidance Document for Correcting Common VOC & Other Rule 
Deficiencies,'' EPA Region 9, August 21, 2001 (the Little Bluebook).
    3. ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 57 
FR 13498 (April 16, 1992) (General Preamble); 57 FR 18070 (April 28, 
1992).
    4. ``State Implementation Plans for Serious PM-10 Nonattainment 
Areas, and Attainment Date Waivers for PM-10 Nonattainment Areas 
Generally; Addendum to the General Preamble for the Implementation of 
Title I of the Clean Air Act Amendments of 1990,'' 59 FR 41998 (August 
16, 1994) (Addendum).
    5. ``PM-10 Guideline Document,'' EPA 452/R-93-008, April 1993.
2. Measures Proposed for Approval
    EPA has identified the State statutory provisions submitted with 
the 189(d) plan that implement the directives in each measure for which 
we are proposing action. Many of the 189(d) plan measures refer to 
Arizona Senate Bill 1552 (SB 1552). In 2007, the Arizona Legislature 
passed SB 1552, which includes several air quality provisions designed 
to reduce PM-10. SB 1552 adds new and amends existing provisions of the 
Arizona Revised Statutes (ARS) and is included in the 189(d) plan 
submittal. 189(d) plan, chapter 10, ``Commitments for Implementation,'' 
volume two. We are proposing to approve the sections of the ARS that 
implement the plan measures identified in table 4 below. For ease of 
discussion, the statutory provisions that we are proposing to approve 
are associated with measures that can be generally grouped into seven 
categories: on-site dust management, certification programs, vehicle 
use, leaf blowers, unpaved areas, burning and agriculture. A brief 
discussion of each category is provided after the table.

[[Page 54811]]



    Table 4--189(d) Plan Measure Categories and Associated Statutory
                               Provisions
------------------------------------------------------------------------
                                 Measure numbers    Associated statutory
           Category              from 189(d) plan        provisions
------------------------------------------------------------------------
On-site management............  2, 3, 16.........  ARS 49-474.05.
Certification programs........  5*, 24*..........  ARS 9-500.04, ARS 49-
                                                    457.02,
                                                    ARS 49-474.01.
Vehicle Use...................  19*, 23, 31, 46..  ARS 9-500.04, ARS 9-
                                                    500.27, ARS 49-
                                                    457.03, ARS 49-
                                                    457.04, ARS 49-
                                                    474.01.
Leaf blowers..................  18, 21, 22, 45...  ARS 9-500.04, ARS 11-
                                                    877, ARS 49-457.01.
Unpaved areas.................  25, 26*, 28, 33..  ARS 9-500.04, ARS 28-
                                                    6705, ARS 49-474.01.
Burning.......................  35, 47...........  ARS 49-501.
Agriculture...................  50*..............  ARS 49-457.\12\
------------------------------------------------------------------------
* The State submitted these measures as contingency measures pursuant to
  CAA section 172(c)(9). See section III.F below for further discussion.

    With the exception of ARS 49-457, discussed in section III.B.3 
below, and ARS 49-474.01, the ARS sections listed above are not 
currently in the Arizona SIP. On August 10, 1988, we approved an 
earlier version of ARS 49-474.01 that was submitted by the State to EPA 
on May 22, 1987. 53 FR 30224. In comparison to this previously approved 
version, the newly submitted version of ARS 49-474.01 contains several 
additional requirements regarding unstabilized areas and vehicle use 
that make the statutory provision more stringent. Therefore, we believe 
the current submitted version of ARS 49-474.01 represents a 
strengthening of the SIP and is consistent with the relevant policy and 
guidance regarding SIP relaxations.
---------------------------------------------------------------------------

    \12\ Measure 50 concerns the State statutory and 
regulatory program for the control of PM-10 from agricultural 
sources in the Maricopa area. The program is codified in ARS 49-457 
and Arizona Administrative Code (AsAC) R18-2-610 and R18-2-611. ARS 
49-457 established the program and authorized a committee to adopt 
implementing regulations. While we are proposing to fully approve 
the amendment to ARS-457 which was submitted with the 189(d) plan, 
we do not describe it further in this section because we address the 
agricultural program in detail in section III.B.3 below.
---------------------------------------------------------------------------

On-Site Management
    Many of the 189(d) plan measures are related to the reduction of 
PM-10 emissions through dust control training and on-site management by 
trained personnel. Measures 2 and 3 address 
development of basic and comprehensive training programs for the 
suppression of emissions. The program requires completion of dust 
control training for water truck and water pull drivers, and on-site 
representatives of sites with more than one acre of disturbed surface 
area subject to a permit requiring control of PM-10 emissions. Any site 
with five or more acres of disturbed surface area subject to a permit 
requiring control of PM-10 emissions will be required to have a trained 
dust control coordinator on site. Measure 16 involves the 
requirement for subcontractors engaged in dust generating operations to 
be registered with the control officer. These measures are implemented 
through ARS 49-474.05. See 189(d) plan, pp. 6-20, 6-24, 6-42, and 6-46.
Certification Programs
    Some of the 189(d) plan measures seek to achieve emissions 
reductions through certification of equipment or personnel. In certain 
cases, the certification program is intended to provide an incentive 
for voluntary emission reductions and good operating practices. In 
other cases, the certification program seeks to maintain an appropriate 
level of emissions control from regularly used equipment. Measure 
5 directs ADEQ to establish the Dust-Free Developments 
Program. The purpose of this program is to certify persons and entities 
that demonstrate exceptional commitment to the reduction of airborne 
dust. See ARS 49-457.02 and 189(d) plan, p. 6-29. Measure 24 
directs cities and towns to require that new or renewed contracts for 
sweeping of city streets must be conducted with certified street 
sweepers. Street sweepers must meet the certification specifications 
contained in South Coast Air Quality Management District (SCAQMD) Rule 
1186. See ARS 9-500.04, ARS 49-474.01, and 189(d) plan, p. 6-72.
Vehicle Use
    Because vehicle use often generates PM-10 emissions, the 189(d) 
plan addresses several different activities related to vehicle use. 
Measures 19, 23, and 46 restrict off-road 
vehicle use in certain areas and on high pollution advisory days, and 
prescribe outreach to off-road vehicle purchasers to inform them of 
methods for reducing generation of dust. See ARS 9-500.27, ARS 49-
457.03, ARS 49-457.04, and 189(d) plan, pp. 6-53, 6-71 and 6-190. 
Measure 31 restricts vehicle use and parking on unpaved or 
unstabilized vacant lots. See ARS 9-500.04, ARS 49-474.01 and 189(d) 
plan, p. 6-141.
Leaf Blowers
    The 189(d) plan seeks to reduce PM-10 emissions from the operation 
of leaf blowers. Measures 18 and 45 restrict the use 
of leaf blowers on high pollution advisory days or on unstabilized 
surfaces. Measure 21 involves the banning of leaf blowers from 
blowing landscape debris into public roadways. Measure 22 
requires outreach to buyers and sellers of leaf blowing equipment to 
inform them of safe and efficient use, methods for reducing generation 
of dust, and dust control ordinances and restrictions. See ARS 9-
500.04, ARS 11-877, ARS 49-457.01 and 189(d) plan, pp. 6-50, 6-69, 6-70 
and 6-189.
Unpaved Areas
    The 189(d) plan contains several measures that seek to reduce PM-10 
emissions by reducing the number of unpaved or unstabilized areas. 
Measures 25, 26, and 28 direct cities and 
towns to pave or stabilize parking lots, dirt roads, alleys, and 
shoulders. Measure 33 allows counties the ability to assess 
fines to recover the cost of stabilizing lots. See ARS 9-500.04, ARS 
49-474.01, ARS 28-6705 and 189(d) plan, pp. 6-86, 6-103, 6-124, and 6-
169.
Burning
    Several measures are designed to regulate burning activities. 
Measure 35 bans the use of outdoor fireplaces in the 
hospitality industry on ``no burn'' days. Measure 47 bans open 
burning during the ozone season. See ARS 49-501 and 189(d) plan, pp. 6-
174 and 6-190.
3. Measure Proposed for Limited Approval/Disapproval
    Measure 50 is included in the 189(d) plan as a contingency 
measure and is designed to achieve emission reductions

[[Page 54812]]

from agricultural sources of PM-10. 189(d) plan, pp. 6-191 and 8-73. 
Measure 50 is implemented through SB 1552 which amended ARS 
49-457 and requires in section 20 that the best management practices 
(BMP) committee for regulated agricultural activities adopt revised 
rules. These rules, AAC R18-2-610 and R18-2-611, were revised pursuant 
to amended ARS 49-457 and submitted with the 189(d) plan. 189(d) plan, 
chapter 10, ``Commitments for Implementation,'' volume two. See also 
189(d) plan, Measure 41, p. 6-185. On May 6, 2010, Arizona 
again submitted the revised versions of AAC R18-2-610 and R18-2-611 
with additional documentation and the ``Agricultural Best Management 
Practices Guidance Booklet and Pocket Guide'' (Handbook). Letter from 
Benjamin Grumbles, ADEQ, to Jared Blumenfeld, EPA, with enclosures, May 
6, 2010. The Handbook provides regulated sources with guidance on how 
to implement BMPs and provides information to the public and farm 
organizations about AAC R18-2-610 and R18-2-611 (Handbook, p. 5).
    We describe the history of agricultural PM-10 controls in the 
Maricopa area and we evaluate amended ARS 49-457 and revised AAC R18-2-
610 and R18-2-611 below.
a. History
    The analysis done for the ``Plan for Attainment of the 24-hour PM-
10 Standard--Maricopa County PM-10 Nonattainment Area,'' May 1997--
(Microscale Plan)--revealed the contribution agricultural sources make 
to exceedances of the 24-hour PM-10 standard in the Maricopa area. See 
Microscale plan, pp. 18-19. In order to develop adequate controls for 
this source category, Arizona passed legislation, the original version 
of ARS 49-457, in 1997 establishing the agricultural BMP committee and 
directing the committee to adopt by rule by June 10, 2000, an 
agricultural general permit specifying best management practices for 
reducing PM-10 from agricultural activities. The legislation also 
required that implementation of the agricultural controls begin by June 
10, 2000, with an education program and full compliance with the rule 
to be achieved by December 31, 2001.
    In September 1998, the State submitted ARS 49-457 and on June 29, 
1999 we approved the statute as meeting the reasonably available 
control measure (RACM) requirements of the CAA.\13\ 64 FR 34726.
---------------------------------------------------------------------------

    \13\ Prior to its classification as serious, the Maricopa area, 
as a moderate PM-10 nonattainment area, was required to implement 
RACM pursuant to CAA section 189(a)(1)(C).
---------------------------------------------------------------------------

    After a series of meetings during 1999 and 2000, the agricultural 
BMP committee in 2000 adopted the original versions of AAC R18-2-610, 
``Definitions for R18-2-611,'' and AAC R18-2-611, ``Agricultural PM-10 
General Permit; Maricopa PM10 Nonattainment Area'' (collectively, 
general permit rule). 66 FR 34598. The BMPs are defined in AAC R18-2-
610. AAC R18-2-611 groups the BMPs into three categories (tilling and 
harvest, noncropland, and cropland). The original version of AAC R18-2-
611 required that commercial farmers select one practice from each of 
these categories. AAC R18-2-611 also requires that commercial farmers 
maintain records demonstrating compliance with the general permit rule.
    In July 2000, the State submitted the general permit rule. The 
State also submitted an analysis quantifying the emission reductions 
expected from the rule and the demonstration that the rule meets the 
CAA's RACM, BACM and MSM requirements. We approved the general permit 
rule as meeting the RACM requirement in CAA section 189(a)(1)(C) on 
October 11, 2001. 66 FR 51869. We approved the general permit rule as 
meeting the requirements for BACM and MSM in CAA sections 189(b)(1)(B) 
and 188(e) on July 25, 2002. 67 FR 48718.
b. Amendments to ARS 49-457 and Revisions to the General Permit Rule
    SB 1552 amended ARS 49-457 to increase the number of required BMPs 
from one to two in the general permit rule by December 31, 2007. SB 
1552 also expanded the scope of the applicability of the general permit 
rule by amending the definition of regulated area to include any 
portion of Area A \14\ that is located in a county with a population of 
two million or more persons.
---------------------------------------------------------------------------

    \14\ Area A is defined in ARS 49-541. The 189(d) plan does not 
take any credit for emission reductions from the general permit 
rule's expansion to Area A because it extends beyond the boundaries 
of the Maricopa area. 189(d) plan, p. 8-73. ARS 49-451 was not 
submitted for inclusion into the SIP. While not a basis for our 
proposed action here, we recommend that ADEQ either insert the 
definition from ARS 49-451 into the general permit rule or submit 
ARS 49-451 to EPA.
---------------------------------------------------------------------------

    The agricultural BMP committee added definitions for the following 
terms to AAC R18-2-610: ``Area A,'' ``cessation of night tilling,'' 
``forage crop,'' ``genetically modified,'' ``genetically modified 
organism,'' ``global position satellite system,'' ``green chop,'' 
``high pollution advisory,'' ``integrated pest management,'' ``night 
tilling,'' ``organic farming practices,'' ``precision farming,'' and 
``transgenic crops.'' The definitions for ``commercial farm'' and 
``regulated agricultural activity'' were amended to include Area A.
    The agricultural BMP committee also amended AAC R18-2-611. Section 
C of AAC R18-2-611 was amended to require commercial farmers to 
implement two BMPs each from the categories of tillage and harvest, 
noncropland, and cropland. The following additional BMPs were added to 
the tillage and harvest category in Section E of AAC R18-2-611: Green 
chop, integrated pest management, cessation of night tilling, precision 
farming, and transgenic crops. The cropland category in Section G was 
augmented with the following additional options: Integrated pest 
management and precision farming.
c. Evaluation of Amendments to ARS 49-457 and Revisions to the General 
Permit Rule
    As stated above, in reviewing a statute, regulation, or rule for 
SIP approval, EPA looks to ensure that the provision is enforceable as 
required by CAA section 110(a), is consistent with all applicable EPA 
guidance, and does not relax existing SIP requirements as required by 
CAA sections 110(l) and 193. ARS 49-457 and the general permit rule 
generally meet the applicable requirements and guidance. We are 
proposing to approve amended ARS 49-457 because it strengthens the SIP 
by requiring an increase in the number of required BMPs and expanding 
the geographical scope of the agricultural BMP program. With regard to 
the general permit rule, we are proposing a limited approval and 
limited disapproval and we discuss the bases for that proposal below.
    As stated above, we approved the general permit rule as meeting the 
CAA requirements for BACM in 2002. Since then, several air pollution 
control agencies in California, including the San Joaquin Valley 
Unified Air Pollution Control District (SJVAPCD) and the Imperial 
County Air Pollution Control District (ICAPCD), have adopted analogous 
rules for controlling PM-10 emissions from agricultural sources. The 
relevant State and local rules in Arizona, California and Nevada are 
summarized in our recent action on ICAPCD's Rule 806. 75 FR 39366, 
39383 (July 8, 2010).
    Since the adoption of controls for agricultural sources in the 
Maricopa area, other State and local agencies which have adopted such 
controls, as well as EPA, have acquired additional expertise about how 
to control

[[Page 54813]]

emissions from these sources and implement regulations for them. As a 
result, we no longer believe that the requirements in the general 
permit rule that we approved in 2002 for the Maricopa area fully meet 
CAA requirements.
    AAC R18-2-611 Sections E, F and G list BMPs intended to control 
emissions from tillage and harvest, noncropland and cropland, and the 
BMPs on these lists are defined in AAC R18-2-610. However, as discussed 
below, the definitions in AAC R18-2-610 are overly broad. Moreover, 
there is no mechanism in the rule to provide sufficient specificity to 
ensure a BACM level of control.\15\
---------------------------------------------------------------------------

    \15\ For example, SJVAPCD's Rule 4550 has an application 
submittal and approval process. Great Basin Unified Air Pollution 
Control District's (GBUAPCD) Rule 502 has a similar application 
submittal and approval process. SJVAPCD's and GBUAPCD's application 
forms require sources to select conservation management practices 
(CMPs), the analogue to Arizona's BMPs, and to describe the 
specifics of the practices chosen. Such an application submittal and 
approval process provides a mechanism to ensure that controls are 
implemented at a BACM level.
---------------------------------------------------------------------------

    As an example of the breadth of the BMPs, one of the BMPs in AAC 
R18-2-611 Section E, the tillage and harvest category, is ``equipment 
modification.'' This term is defined in AAC R18-2-610 Section 18 as 
``modifying agricultural equipment to prevent or reduce particulate 
matter generation from cropland.'' The types of equipment modification 
are not specified in the rule, and according to the Handbook, examples 
of this practice include using shields to redirect the fan exhaust of 
the equipment or using spray bars that emit a mist to knock down PM-10. 
Handbook, p. 10. Because most of the PM-10 generated during active 
agricultural operations is due to disturbance from parts of 
agricultural equipment that come into direct contact with the soil, we 
expect that using appropriately designed spray bars would be far more 
effective at reducing PM-10 than redirecting a machine's fan exhaust. 
However, there is no provision in the general permit rule that requires 
a source or regulatory agency to evaluate whether the more effective 
version of this BMP is economically and technologically feasible. 
Moreover, while AAC R18-2-611 Section I requires that a farmer record 
that he has selected the ``equipment modification'' BMP, it does not 
require the farmer to record what type of equipment modification he 
will be implementing. Hence, neither ADEQ nor the public can verify 
whether what is being implemented is a best available control measure.
    An example from AAC R18-2-611 Section F, the category for 
noncropland, is the ``watering'' BMP. AAC R18-2-610 Section 52 defines 
watering as ``applying water to noncropland.'' The level of control 
achieved would depend on the amount of water that was applied, the 
frequency with which it was applied, as well as the size and conditions 
of the area to which it was applied. However, the rule does not specify 
the frequency or amount of water application or otherwise ensure that 
watering under this measure is effective. Moreover, the definition for 
``noncropland'' in Section 31 of AAC R18-2-611 states that it 
``includes a private farm road, ditch, ditch bank, equipment yard, 
storage yard, or well head.'' It is not clear which of these areas a 
farmer would need to control upon selecting the ``watering'' BMP. As 
written, the rule allows regulated sources to implement the 
``watering'' BMP in a manner that may not be as effective as best 
available controls. Furthermore, while AAC R18-2-611 Section I requires 
that a farmer record that he has selected the ``watering'' BMP, it does 
not require the farmer to record how he will be implementing this BMP. 
Hence, neither ADEQ nor the public can verify whether the BMP that is 
being implemented is in fact a best available control measure.
    An example from AAC R18-2-611 Section G, the category for cropland, 
is the ``artificial wind barrier'' BMP. AAC R18-2-610 Section 4 defines 
``artificial wind barrier'' as ``a physical barrier to the wind.'' The 
control effectiveness of the barrier will depend on what the barrier is 
constructed of, the size of the barrier, as well as the placement of 
the barrier. In fact, the Handbook suggests that certain materials 
(e.g., board fences, burlap fences, crate walls, and bales of hay) be 
used, notes that the distance of 10 times the barrier height is 
considered the protected area downwind of a barrier, and states that 
the barrier should be aligned across the prevailing wind direction. 
Handbook, p. 20. However, the general permit rule does not specify any 
parameters that need to be met for the implementation of the 
``artificial wind barrier'' BMP. Hence a source can construct a barrier 
that is not a best available control and still be in compliance with 
the general permit rule.
    The absence of sufficiently defined requirements makes it difficult 
for regulated parties to understand and ensure compliance with the 
requirements, and makes it difficult for ADEQ or others to verify 
compliance with the general permit rule. The general permit rule needs 
to be revised to ensure that the BMPs are enforceable as required by 
CAA section 110(a) and are implemented at a BACM level as required by 
section 189(b)(1)(B).
4. Summary of Proposed Action on Measures in 189(d) Plan
    EPA believes the statutory provisions associated with the 189(d) 
plan measures in table 4 in section III.B.2 above are consistent with 
the relevant policy and guidance regarding enforceability and SIP 
relaxations. Therefore, we are proposing to fully approve under CAA 
section 110(k)(3) the following Arizona statutory provisions, as 
submitted with the 189(d) plan:

ARS 9-500.04
ARS 9-500.27
ARS 11-877
ARS 28-6705
ARS 49-457
ARS 49-457.01
ARS 49-457.02
ARS 49-457.03
ARS 49-457.04
ARS 49-474.01
ARS 49-474.05
ARS 49-501

    EPA is also proposing pursuant to CAA section 110(k)(3) to approve 
the ``Agricultural Best Management Practices Guidance Booklet and 
Pocket Guide'' as submitted on May 6, 2010.
    EPA is also proposing pursuant to CAA section 110(k)(3) a limited 
approval and limited disapproval of AAC R18-2-610 and AAC R18-2-611, as 
submitted in the 189(d) plan. We are proposing a limited approval 
because AAC R18-2-610 and AAC R18-2-611 strengthen the SIP. We are 
proposing a limited disapproval because the general permit rule does 
not meet the enforceability requirements of CAA section 110(a) and no 
longer ensures that controls for agricultural sources in the Maricopa 
area are implemented at a BACM level as required by section 
189(b)(1)(B).

C. Attainment Demonstration

    CAA section 189(d) requires the submittal of plan revisions that 
provide for expeditious attainment of the PM-10 NAAQS. The attainment 
deadline applicable to an area that misses the serious area attainment 
date is as soon as practicable, but no later than five years from the 
publication date of the notice of a nonattainment finding unless 
extended by EPA as meeting certain specified requirements. CAA section 
179(d)(3). Because, as stated previously, EPA published the 
nonattainment finding for the Maricopa area on June 6, 2007 (72 FR 
31183), the attainment deadline for the area is as expeditiously

[[Page 54814]]

as practicable but no later than June 6, 2012.
    The 189(d) plan projects through a modeled attainment demonstration 
that the Maricopa area will attain the PM-10 standard by December 31, 
2010. 189(d) plan, chapter 8. According to the plan, modeling was 
conducted for the two areas, the Salt River area and the Higley 
monitor, that have the mix and density of sources that caused the 
highest 24-hour PM-10 monitor readings in the Maricopa area from 2004 
through 2006. The Salt River area includes the three monitors (West 
43rd Avenue, Durango Complex and Bethune Elementary) that recorded 
violations during those years. The Higley monitor did not violate the 
PM-10 standard for that period but had one exceedance in 2004 and one 
in 2006 and the surrounding area has a different mix of sources than 
the Salt River area. The plan also provides a modeled attainment 
demonstration for the remainder of the nonattainment area. AERMOD was 
used for the attainment demonstration for the Salt River area. 
Attainment for the Higley monitor area and the remainder of the 
nonattainment area was shown using a proportional rollback approach.
    AERMOD is an EPA-approved model and was appropriately used in the 
189(d) plan. The proportional rollback approach was also appropriate 
because of the lack of good models for PM-10 on large geographic 
scales. However, EPA cannot approve an attainment demonstration for PM-
10 nonattainment areas based on modeled projections of attainment if 
actual ambient air quality monitoring data show that the area cannot 
attain by the projected date. Under 40 CFR 50.6(a), the 24-hour PM-10 
standard is attained when the expected number of exceedances per year 
at each monitoring site is less than or equal to one. The number of 
expected exceedances at a site is determined by recording the number of 
exceedances in each calendar year and then averaging them over the past 
3 calendar years. 40 CFR part 50, appendix K. Thus, in order for the 
Maricopa area to attain the standard by December 31, 2010, there can be 
no more than one exceedance at any one monitor in the nonattainment 
area in calendar years 2008, 2009 and 2010.
    There were 11 recorded exceedances of the PM-10 standard in 2008 in 
the Maricopa area. Five of these exceedances were recorded at the West 
43rd Avenue monitor, two at the Durango Complex monitor, two at the 
South Phoenix monitor, and two at the Coyote Lakes monitor. In 2009, 
there were 22 exceedances recorded in the Maricopa Area. Seven of these 
exceedances were recorded at the West 43rd Avenue monitor, three at the 
Durango Complex monitor, three at the South Phoenix monitor, two at the 
Higley monitor, two at the West Chandler monitor, one at the West 
Phoenix monitor, one at the Glendale monitor, one at Greenwood monitor, 
one at the Dysart monitor, and one at the Bethune Elementary School 
monitor.\16\
---------------------------------------------------------------------------

    \16\ ``USEPA Quick Look Report for Maricopa County (01/01/2008-
12/31/2010) Air Quality System database, run date: August 26, 2010'' 
(AQS 2008-2010 Quick Look Report). The Air Quality System Identifier 
numbers for the monitors referenced in this section are as follows: 
West 43rd Avenue (04-013-4009), Durango Complex (04-013-9812), South 
Phoenix (04-013-4003), Coyote Lakes (04-013-4014), Higley (04-013-
4006), West Chandler (04-013-4004), West Phoenix (04-013-0019), 
Glendale (04-013-2001), Greenwood (04-013-3010), Dysart (04-013-
4010), Bethune Elementary School (04-013-8006).
---------------------------------------------------------------------------

    Of the eleven 2008 exceedances, ten were flagged by the State as 
due to exceptional events under EPA's Exceptional Events Rule (EER) 
\17\ which allows the Agency to exclude air quality monitoring data 
from regulatory determinations related to exceedances or violations of 
the NAAQS if the requirements of the EER are met. All of the 2009 
exceedances were flagged as exceptional events under the EER.\18\
---------------------------------------------------------------------------

    \17\ See ``Treatment of Data Influenced by Exceptional Events,'' 
72 FR 13560 (March 22, 2007). The EER is codified at 40 CFR 50.1 and 
50.14. For the state flagging requirements, see 40 CFR 50.14(c)(2).
    \18\ AQS 2008-2010 Quick Look Report.
---------------------------------------------------------------------------

    Under the EER, EPA may exclude monitored exceedances of the NAAQS 
from regulatory determinations if a state adequately demonstrates that 
an exceptional event caused the exceedances. 40 CFR 50.14(a). Before 
EPA will exclude data from these regulatory determinations, the state 
must flag the data in EPA's Air Quality System (AQS) database and, 
after notice and an opportunity for public comment, submit a 
demonstration to justify the exclusion. After considering the weight of 
evidence provided in the demonstration, EPA will decide whether or not 
to concur on each flag.
    EPA has evaluated four of the 2008 exceedances recorded at the West 
43rd Avenue monitor in south-central Phoenix that the State claims to 
be due to exceptional events.\19\ The exceedances were recorded on 
March 14, April 30, May 21, and June 4. On May 21, 2010 EPA determined 
that the events do not meet the requirements of the EER and therefore 
do not qualify as exceptional events for regulatory purposes. Letter 
from Jared Blumenfeld, EPA, to Benjamin H. Grumbles, ADEQ, re: 
PM10 National Ambient Air Quality Standard in Phoenix; 
Request for Concurrence for Treatment as ``Exceptional Events,'' May 
21, 2010, with enclosures. As a result, EPA is not excluding the 
exceedances recorded on these dates from regulatory determinations 
regarding NAAQS exceedances in the Maricopa area.
---------------------------------------------------------------------------

    \19\ EPA has not evaluated the remaining exceptional event 
claims for 2008 or those for 2009. As discussed below, such an 
evaluation was not necessary for us to determine that the Maricopa 
area cannot attain the PM-10 standard by December 31, 2010.
---------------------------------------------------------------------------

    Under 40 CFR part 50, appendix K, because there have been four 
exceedances in 2008 at the West 43rd Avenue monitor, the area cannot 
attain the standard by December 31, 2010 as projected in the 189(d) 
plan. Therefore, EPA is proposing to disapprove under CAA section 
110(k)(3) the attainment demonstration in the plan as not meeting the 
requirements of sections 189(d) and 179(d)(3).
    Finally, we note here, as we address in more detail in section 
III.A above, that most of the emission reductions relied on in the 
189(d) plan are projected to be achieved by increased compliance with 
MCAQD Rules 310, 310.01 and 316. This is the case for the attainment 
demonstration, as well as for the 5% and RFP demonstrations discussed 
in sections III.D and III.F below. The 189(d) plan provides little or 
no support for the emission reductions attributed to these increased 
compliance measures. See, e.g., Measure 8 (Conduct Nighttime 
and Weekend Inspections) which, with no explanation, estimates that 
compliance with MCAQD Rules 310 and 316 will increase by 4 percent in 
2008, 6 percent in 2009 and 8 percent in 2010. 189(d) plan TSD, pp. 
III-4 through III-6. We recognize that calculating accurate emission 
reduction estimates for increased compliance measures is challenging. 
It is, however, important for such estimates to have a technical basis, 
especially when such measures are expected to achieve the majority of 
the emission reductions in a SIP. One way to begin to address this 
issue would be to initiate an ongoing process to verify that compliance 
rates are increasing as expected and that, as a result, the projected 
emission reductions are actually being realized.

D. 5% Requirement

    The demonstration addressing the 5% requirement of CAA section 
189(d) is presented in chapter 7 of the 189(d) plan. Chapter 7 shows 
the annual 5% emission reductions of PM-10 \20\ for

[[Page 54815]]

2008 through 2010, the projected attainment year. The plan quantifies 
emission reductions attributable to 25 of the 53 measures in the plan 
to meet the annual 5% targets. Table 7-2 in the 189(d) plan shows the 
base case PM-10 emissions from the 2005 Periodic Inventory discussed in 
section III.A above. Table 7-3 presents the controlled emissions for 
2007 through 2010, i.e., the emissions after the emission reductions 
from the 25 quantified measures have been applied. The plan explains 
that the annual target is obtained by multiplying the controlled 2007 
emissions in table 7-3 by 5% and concludes that the 5% targets are met 
in 2008, 2009 and 2010 with a surplus margin of benefit in each year. 
189(d) plan, table 7-4, p. 7-19.
---------------------------------------------------------------------------

    \20\ While the 5% requirement of section 189(d) can be met by 
emission reductions of PM-10 or PM-10 precursors, the 189(d) plan 
relies on PM-10 reductions. This reliance is consistent with the 
nature of the particulate matter problem in the Maricopa area. See 
footnote 5.
---------------------------------------------------------------------------

    EPA believes the methodology for determining the 5% targets for the 
years 2008, 2009 and 2010 is generally appropriate. However, because we 
have determined that the 2005 Periodic Inventory on which the State 
based these calculations is inaccurate, the emission reduction targets 
themselves are also necessarily inaccurate. Because the 189(d) plan 
projects emission reductions surplus to the 5% targets in each year, it 
is theoretically possible that creditable reductions from the 25 
quantified measures would still achieve the 5% reductions when 
recalculated from an accurate base year inventory. However that could 
only be determined by an EPA review of a revised plan based on adjusted 
calculations.
    Furthermore, the language of section 189(d) compels us to conclude 
that the 5% demonstration in the 189(d) plan does not meet that 
section's requirement. CAA section 189(d) requires that the plan 
provide for annual reductions of PM-10 or PM-10 precursors of not less 
than 5% each year from the date of submission of the plan until 
attainment. The 189(d) plan submitted by Arizona does not provide for 
reductions after 2010 because it projects attainment of the PM-10 
standard by the end of that year. As discussed in section III.C above, 
the Maricopa area cannot attain by December 31, 2010.
    For the above reasons, EPA is proposing to disapprove under section 
110(k)(3) the demonstration of the 5% annual emission reductions in the 
189(d) plan as not meeting the 5% requirement in CAA section 189(d).

E. Reasonable Further Progress and Quantitative Milestones

    Under section 189(c)(1), the 189(d) plan must demonstrate RFP. We 
have explained in guidance that for those areas, such as the Maricopa 
area, where ``the nonattainment problem is attributed to area type 
sources (e.g., fugitive dust, residential wood combustion, etc.), RFP 
should be met by showing annual incremental emission reductions 
sufficient generally to maintain linear progress towards attainment. 
Total PM-10 emissions should not remain constant or increase from 1 
year to the next in such an area.'' Further, we stated that ``in 
reviewing the SIP, EPA will determine whether the annual incremental 
emission reductions to be achieved are reasonable in light of the 
statutory objective to ensure timely attainment of the PM-10 NAAQS.'' 
Addendum at 42015-42016.
    PM-10 nonattainment SIPs are required by section 189(c) to contain 
quantitative milestones to be achieved every three years and which are 
consistent with RFP for the area. These quantitative milestones should 
consist of elements which allow progress to be quantified or measured. 
Specifically, states should identify and submit quantitative milestones 
providing for the amount of emission reductions adequate to achieve the 
NAAQS by the applicable attainment date. Id. at 42016.
    The 189(d) plan provides a graph showing a RFP line representing 
total emissions in the Maricopa area after emission reduction credit is 
applied for the 25 measures described in chapter 6 of the plan which 
are quantified for the purpose of meeting the section 189(c) 
requirements. 189(d) plan, figure 8-25; pp. 8-65 through 8-66. The 
graph shows an annual downward linear trend in emissions from 2007 
through 2010, the modeled attainment date in the plan. The plan 
explains that the appropriate milestone year is 2010. Id.
    The statutory purpose of RFP is to ``ensure attainment'' and the 
quantitative milestones are ``to be achieved until the area is 
redesignated to attainment'' under CAA sections 171(1) and 189(c) 
respectively. As discussed in section III.C above, we are proposing to 
disapprove the attainment demonstration in the 189(d) plan because, as 
a result of exceedances of the PM-10 standard recorded at the West 43rd 
Avenue monitor in 2008, the area cannot attain the standard by 2010 as 
projected in the plan. As a result, the RFP and milestone 
demonstrations in the plan do not achieve the statutory purposes of 
sections 171(1) and 189(c). We are therefore proposing to disapprove 
these demonstrations under CAA section 110(k)(3) as not meeting the 
requirements of section 189(c).

F. Contingency Measures

    CAA section 172(c)(9) requires that the 189(d) plan provide for the 
implementation of specific measures to be undertaken if the area fails 
to make RFP or to attain the PM-10 standard as projected in the plan. 
That section further requires that such measures are to take effect in 
any such case without further action by the state or EPA. The CAA does 
not specify how many contingency measures are necessary nor does it 
specify the level of emission reductions they must produce.
    In guidance we have explained that the purpose of contingency 
measures is to ensure that additional emission reductions beyond those 
relied on in the attainment and RFP demonstrations are available if 
there is a failure to make RFP or to attain by the applicable statutory 
date. Addendum at 42014-42015. These additional emission reductions 
will ensure continued progress towards attainment while the SIP is 
being revised to fully correct the failure. To that end, we recommend 
that contingency measures for PM-10 nonattainment areas provide 
emission reductions equivalent to one year's average increment of RFP. 
Id.
    In interpreting the requirement that the contingency measures must 
``take effect without further action by the State or the 
Administrator,'' the General Preamble provides the following general 
guidance: ``[s]tates must show that their contingency measures can be 
implemented with minimal further action on their part and with no 
additional rulemaking actions such as public hearings or legislative 
review.'' General Preamble at 13512.\21\ Further, ``[i]n general, EPA 
will expect all actions needed to affect full implementation of the 
measures to occur within 60 days after EPA notifies the State of its 
failure.'' Id. The Addendum at 42015 reiterates this interpretation.
---------------------------------------------------------------------------

    \21\ EPA elaborated on its interpretation of this language in 
section 172(c)(9) in the General Preamble in the context of the 
ozone standard: ``The EPA recognizes that certain actions, such as 
notification of sources, modification of permits, etc., would 
probably be needed before a measure could be implemented 
effectively.'' General Preamble at 13512.
---------------------------------------------------------------------------

    We have also interpreted section 172(c)(9) to allow states to 
implement contingency measures before they are triggered by a failure 
of RFP or attainment as long as those measures are intended to achieve 
reductions over and beyond those relied on in the attainment and RFP 
demonstrations. Id., and see

[[Page 54816]]

LEAN v. EPA, 382 F.3d 575 (5th Cir. 2004).
    The 189(d) plan addresses the section 172(c)(9) contingency measure 
requirement in chapter 8, pp. 8-65 through 8-74. Of the 53 measures in 
the plan, nine are designated and quantified as contingency measures: 
Measures 1, 5, 19, 24, 26, 
27, 43, 50 and a measure identified as 
``multiple'' which consists of Measures 14, 15 and 
17. Chapter 8 of the 189(d) plan includes a discussion of each 
of these measures along with associated emission reductions for each of 
the years 2008, 2009 and 2010. Additional information on the emission 
reductions claimed is in the 189(d) plan TSD, chapter IV. The measures 
are also individually discussed in chapter 6 of the 189(d) plan.
    In calculating the target emission reductions that the contingency 
measures must meet, the 189(d) plan cites EPA's recommendation that 
they provide reductions equivalent to one year's average increment of 
RFP. The plan subtracts the total controlled emissions in 2010 from the 
total controlled emissions in 2007 and divides this sum by three years 
to produce an annual average of 4,869 tpy as the target for the 
contingency measures to meet in each of the years 2008, 2009 and 2010. 
189(d) plan, p. 8-67. Table 8-14 in the 189(d) plan lists the projected 
emission reductions for the nine contingency measures for each of these 
years and shows emission reductions in excess of the target for each of 
them. Table 5 below shows the contingency measures in the plan 
identified by number and reproduces the corresponding projected PM-10 
reductions as depicted in table 8-14 in the plan:

                     Table 5--Summary of PM-10 Emissions Reductions for Contingency Measures
----------------------------------------------------------------------------------------------------------------
                            Contingency measures                                 PM-10 reductions  [tons/year]
----------------------------------------------------------------------------------------------------------------
             No.                               Measure title                     2008        2009        2010
----------------------------------------------------------------------------------------------------------------
1............................  Public education and outreach program........        47.6        47.5        48.5
5............................  Certification program for dust free                  28.9        21.5        17.6
                                developments.
19...........................  Reduce off-road vehicle use..................       140.3       174.6       179.1
24...........................  Sweep streets with certified PM-10 certified      1,027.7     1,563.1     2,129.2
                                street sweepers.
26...........................  Pave or stabilize existing public dirt roads      1,488.0     2,313.3     3,723.6
                                and alleys.
27...........................  Limit speeds to 15 mph on high traffic dirt         390.4       390.2       390.2
                                roads.
43...........................  Additional $5M in FY07 MAG TIP for paving           205.2       820.9       820.9
                                roads/shoulders.
50...........................  Agricultural Best Management Practices.......       637.6       608.0       579.7
Multiple.....................  Reduce trackout onto paved roads.............     1,256.9     1,273.4     1,270.0
----------------------------------------------------------------------------------------------------------------
Total for All Quantified Contingency Measures                                    5,222.5     7,212.6     9,158.9
----------------------------------------------------------------------------------------------------------------
Contingency Measure Reduction Target                                               4,869       4,869       4,869
----------------------------------------------------------------------------------------------------------------

    As stated above, CAA section 172(c)(9) requires that the plan 
provide for the implementation of contingency measures to be undertaken 
if the area fails to attain the PM-10 standard by the applicable 
attainment date. The Maricopa area cannot attain the PM-10 standard by 
the projected date in the 189(d) plan because of monitored exceedances 
of the NAAQS in 2008.\22\ As a result, any emission reductions from 
contingency measures in the 189(d) plan that are intended to take 
effect upon an EPA finding that the area failed to attain the standard 
cannot currently be determined to be surplus to the attainment 
demonstration as required by section 172(c)(9). Therefore we are 
proposing to disapprove the attainment contingency measures under CAA 
section 110(k)(3) as not meeting the requirements of section 172(c)(9).
---------------------------------------------------------------------------

    \22\ Note that because the modeled attainment demonstration 
projected attainment by the end of 2010, the 189(d) plan does not 
address the outside applicable statutory deadline under section 
179(d)(3), June 6, 2012. See section III.B above.
---------------------------------------------------------------------------

    As also stated above, contingency measures are required to be 
implemented upon a failure of the Maricopa area to meet RFP. The 189(d) 
plan bases the emission reduction target for these measures on 
reductions between 2007 and 2010 calculated from the 2005 Periodic 
Inventory that we have determined to be inaccurate. See section III.A 
above. Thus the emission reduction target for the RFP contingency 
measures is necessarily also inaccurate.
    In addition to the inaccurate emission reduction target for the RFP 
contingency measures, many of the measures themselves do not meet the 
requirements of section 172(c)(9). These deficiencies generally fall 
into three categories: (1) Measures in the form of commitments in 
resolutions adopted by local or State governmental entities to take 
legislative or other substantial future action; (2) commitments in such 
resolutions for which implementation is conditioned on good faith 
efforts and funding availability and are therefore unenforceable; and 
(3) measures for which no basis is provided for the emission reductions 
claimed. While we illustrate these individual deficiencies below by 
reference to one or more of the 189(d) plan's designated contingency 
measures, it is important to note that many of the measures are 
deficient for multiple reasons.
    1. Some of the commitments by local governments or State agencies 
to implement measures that are intended to achieve the required 
emission reductions in 2008, 2009 and 2010 do not meet the requirement 
of section 172(c)(9) that such measures are to take effect without 
further regulatory or legislative action.
    For example, Measure 19 is intended to reduce off-road 
vehicle use in areas with high off-road vehicle activity. For this 
measure, the 189(d) plan assigns emission reduction credit to the 
requirement in ARS 9-500.27.A, as submitted in the 189(d) plan, that 
cities and towns in the Maricopa area adopt, implement and enforce 
ordinances no later than March 31, 2008 prohibiting the use of such 
vehicles on unpaved surfaces closed by the landowner. 189(d) plan, p. 
8-69; 189(d) plan TSD, p. IV-3. The 189(d) plan includes a number of 
resolutions adopted by cities and towns committing to adopt such 
ordinances to address the vehicle use prohibition in the statute. 
However, because the 189(d) plan was submitted at the end of 2007, the 
contingency measure, i.e., the vehicle use prohibition, could not be 
fully

[[Page 54817]]

implemented throughout the Maricopa area without additional future 
legislative action on the part of a number of governmental 
entities.\23\
---------------------------------------------------------------------------

    \23\ In some cases, e.g., the City of Goodyear, ordinances 
implementing the commitments in resolutions were also submitted with 
the 189(d) plan. In others, however, e.g., the City of Apache 
Junction and the Town of Buckeye, the submitted resolutions include 
a schedule for the future adoption and implementation of ordinances. 
ADEQ forwarded these ordinances to EPA in 2008 as supplemental 
information, but not as SIP submittals. See footnote 1. This 
distinction is significant because here the ordinances are the 
ultimate regulatory vehicle.
---------------------------------------------------------------------------

    Furthermore, not only do some of the contingency measure 
commitments fail to meet the requirement of section 172(c)(9) that such 
measures are to be implemented with minimal further action, but because 
they depend on future actions that may or may not occur, it is also 
impossible to accurately quantify emission reductions from them at the 
time of plan development and adoption. Thus it would not be possible to 
determine at the time of plan development and adoption whether in the 
aggregate the measures designated as contingency would meet or 
approximate the target of one year's average increment of RFP. This is 
the case with Measure 19, mentioned above. For that measure, 
the 189(d) plan claims emission reduction credit assuming that all 
jurisdictions subject to the 2008 statutory requirement will comply. 
189(d) plan TSD, p. IV-3. However, there is no way to determine at the 
time of the 189(d) plan adoption which, if any, of the multiple 
jurisdictions would in fact implement such requirements by the 
statutory deadline.
    Another example of this quantification issue is Measure 26 
regarding the paving or stabilization of existing public dirt roads and 
alleys. 189(d) plan, pp. 6-103 and 8-72; 189(d) plan TSD, p. IV-9. This 
measure includes commitments in resolutions adopted by 11 cities and 
towns to pave roads from 2007 through 2010 and claims emission 
reduction credit assuming full compliance. See also Measure 5 
which quantifies as a contingency measure a requirement in ARS 49-
457.02 that ADEQ establish a dust-free development program by September 
19, 2007.\24\ 189(d) plan TSD, p. 8-69. However, a 2010 report prepared 
by MAG addressing the 2008 implementation status of the 53 measures in 
the 189(d) plan states that ``[t]his measure was not implemented 
because ADEQ delayed the certification program indefinitely due to 
budgetary constraints.'' Letter from Lindy Bauer, MAG to Jared 
Blumenfeld, EPA, March 9, 2010, enclosing ``2008 Implementation Status 
of Committed Measures in the MAG 2007 Five Percent Plan for PM-10 for 
the Maricopa County Nonattainment Areas,'' February 2010, MAG (2008 
Status Report), table 1, p. 4.
---------------------------------------------------------------------------

    \24\ While the 189(d) plan refers to a deadline in ARS 49-457.02 
for the establishment of this program, that statutory provision, as 
submitted with the 189(d) plan, does not contain a deadline.
---------------------------------------------------------------------------

    See also Measure 24 which includes, among others, a 
commitment by the Arizona Department of Transportation (ADOT) to 
require in the contract awarded in January 2008 that contractors use 
PM-10 certified street sweepers on all State highways in the Maricopa 
area. 189(d) plan, p. 8-70; 189(d) plan TSD, p. IV-5; ADOT ``Resolution 
to Implement Measures in the MAG 2007 Five Percent Plan for PM-10 for 
the Maricopa County Nonattainment Area.'' 189(d) plan, chapter 10, 
``Commitments for Implementation,'' volume two. The 2008, 2009 and 2010 
emission reductions claimed for Measure 24 assume 
implementation of the ADOT component of the measure. However, the 2008 
Status Report states that ``ADOT's current contract * * * does not 
require the use of PM-10 certified street sweepers * * *.'' 2008 Status 
Report, p. 15.
    2. In addition to the above issue regarding commitments to take 
future action, a number of the commitments quantified for credit in the 
189(d) plan as contingency measures are in the form of city, town and 
county resolutions that specifically recognize that the funding or 
schedules for such actions may be modified depending on the 
availability of funding or other contingencies. These commitments are 
also qualified by the statement that the agency making the commitment 
``agrees to proceed with a good faith effort to implement the 
identified measures.'' \25\ See, e.g., Measure 1 regarding 
public education and outreach, 189(d) plan, pp. 6-2 through 6-20 and 
related resolutions in chapter 10, ``Commitments for Implementation,'' 
volumes one and two. See also id., p. 8-67. See also Measure 
26 regarding the paving or stabilization of existing public 
dirt roads and alleys, id., pp. 6-103 and 8-72; 189(d) plan TSD, p. IV-
7.
---------------------------------------------------------------------------

    \25\ While EPA has approved the commitments with this language 
into the Arizona SIP in past plan actions as strengthening the SIP, 
we did not approve specific emission reduction credits for them.
---------------------------------------------------------------------------

    The language in the above commitments regarding good faith efforts 
and funding availability makes the measures that are intended to 
achieve the required emission reductions virtually impossible to 
enforce. Section 110(a)(2) of the Act requires that SIPs include 
``enforceable emission limitations and other control measures'' and ``a 
program to provide for the enforcement of the measures'' in the plan. 
As we have explained, ``[m]easures are enforceable when they are duly 
adopted, and specify clear, unambiguous, and measurable requirements. 
Court decisions made clear that regulations must be enforceable in 
practice. A regulatory limit is not enforceable if, for example, it is 
impractical to determine compliance with the published limit.'' General 
Preamble at 13568. In the case of most of the contingency measure 
commitments in the 189(d) plan, the implementation of the underlying 
measure cannot be ensured because the entity making the commitment can 
avoid having to implement it by asserting that it made good faith 
efforts, but failed to do so and/or that implementation did not occur 
due to insufficient funds.
    3. The 189(d) plan provides no methodology or support for the PM-10 
emission reductions credited to a number of the contingency measures. 
For example, the group of Measures 14, 15 and 
17 designated in the plan as ``multiple'' is intended to 
reduce trackout onto paved roads. 189(d) plan, p. 8-74. The 189(d) plan 
TSD, p. IV-13, states that ``[t]he reduction in trackout emissions in 
the PM-10 nonattainment area due to the impact of these three committed 
measures is expected to be at least 15 percent in 2008-2010'' and 
credits these measures with the following emission reductions: 1256.9 
tpy in 2008, 1273.4 tpy in 2009 and 1270 tpy in 2010. No information is 
provided in the 189(d) plan regarding how the 15 percent was 
determined. Furthermore, the reductions from each measure are not 
disaggregated so it is impossible to determine the source of the 
claimed emission reductions or how they were calculated for each 
measure.
    Similarly, for Measure 1, the plan identifies annual 
emission reductions from seven source categories resulting from public 
education and outreach in various local jurisdictions but does not 
explain how these reductions were calculated. 189(d) plan TSD, p. IV-1. 
See also Measure 5 which provides annual emission reduction 
credits without any supporting information. The 189(d) plan TSD merely 
states: ``[d]ue to the implementation of this program [certification 
program for dust-free developments to serve as an industry standard], 
the construction emissions are expected to decline by 0.10% in 2008-
2010.'' 189(d) plan TSD, p. IV-2.

[[Page 54818]]

    For the reasons discussed above we are proposing to disapprove 
under CAA section 110(k)(3) the contingency measures in the 189(d) plan 
as not meeting the requirements of section 172(c)(9).

G. Transportation Conformity and Motor Vehicle Emissions Budgets

    Transportation conformity is required by CAA section 176(c). Our 
conformity rule (40 CFR part 93, subpart A) requires that 
transportation plans, programs, and projects conform to state air 
quality implementation plans and establishes the criteria and 
procedures for determining whether or not they do so. Conformity to a 
SIP means that transportation activities will not produce new air 
quality violations, worsen existing violations, or delay timely 
attainment of the NAAQS or the timely achievement of interim 
milestones.
    The 189(d) plan specifies the maximum transportation-related PM-10 
emissions allowed in the proposed attainment year, 2010, i.e., the 
MVEB. 189(d) plan, p. 8-75. This budget includes emissions from road 
construction, vehicle exhaust, tire and brake wear, dust generated from 
unpaved roads and re-entrained dust from vehicles traveling on paved 
roads. This budget is based on the 2010 emissions inventory that was 
projected from the 2005 Periodic Inventory and reflects emission 
reductions that the plan expects will result from the control measures. 
The budget is consistent with the attainment, 5% and RFP demonstrations 
in the 189(d) plan. However, as explained elsewhere in this proposed 
rule, the area cannot attain by the end of 2010 as projected in the 
plan and we are, in addition to the attainment demonstration, proposing 
to disapprove the plan's emissions inventories, 5% and RFP 
demonstrations. Therefore we must also propose to disapprove the MVEB.
    In order for us to find the emission level or ``budget'' in the 
189(d) plan adequate and subsequently approvable, the plan must meet 
the conformity adequacy provisions of 40 CFR 93.118(e)(4) and (5). For 
more information on the transportation conformity requirement and 
applicable policies on MVEBs, please visit our transportation 
conformity Web site at: http://www.epa.gov/otaq/stateresources/
transconf/index.htm. The 189(d) plan includes the PM-10 MVEB shown in 
table 6 below.

          Table 6--189(d) Plan, Motor Vehicle Emissions Budget
        (Annual-average emissions in metric tons per day (mtpd))
------------------------------------------------------------------------
                             Year                                 MVEB
------------------------------------------------------------------------
2010..........................................................     103.3
------------------------------------------------------------------------

    On March 13, 2008, we announced receipt of the 189(d) plan on the 
Internet and requested public comment on the adequacy of the motor 
vehicle emissions budget by April 14, 2008. We did not receive any 
comments during the comment period. During that time we reviewed the 
MVEB and preliminarily determined that it met the adequacy criteria in 
40 CFR 93.118(e)(4) and (5). We sent a letter to ADEQ and MAG on May 
30, 2008 stating that the 2010 motor vehicle PM-10 emissions budget for 
the Maricopa area in the submitted 189(d) plan was adequate. Our 
finding was published in the Federal Register on June 16, 2008 (73 FR 
34013), effective on July 1, 2008.
    As explained in the June 16, 2008 Federal Register notice, an 
adequacy review is separate from EPA's completeness and full plan 
review, and should not be used to prejudge EPA's ultimate approval 
action for the SIP. Even if we find a budget adequate, the SIP and the 
associated budget can later be disapproved for reasons beyond those in 
40 CFR 93.118(e).
    Because we are proposing to disapprove the emission inventories, 
and the attainment 5% and RFP demonstrations, we are also now proposing 
to disapprove the 189(d) plan's 2010 PM-10 MVEB. Under 40 CFR 
93.118(e)(4)(iv), we review a submitted plan to determine whether the 
MVEB, when considered together with all other emissions sources, are 
consistent with applicable requirements for RFP, attainment, or 
maintenance (whichever is relevant to a given SIP submission). Because 
we have now concluded that the area cannot attain by 2010 as projected 
in the 189(d) plan, the MVEB cannot be consistent with the attainment 
requirement. In addition, because we are proposing to disapprove the 5% 
and RFP demonstrations, the MVEB is not consistent with the applicable 
requirements to show 5% annual reductions and RFP. Given the 
overemphasis in the plan on reducing emissions from construction 
activities, it is quite possible that more reductions in onroad 
emissions will be required to meet the applicable requirements. 
Consequently, we find that the plan and related budget do not meet the 
requirements for adequacy and approval.
    The consequences of plan disapproval on transportation conformity 
are explained in 40 CFR 93.120. First, if a plan is disapproved by EPA, 
a conformity ``freeze'' takes effect once the action becomes effective 
(usually 30 days after publication of the final action in the Federal 
Register). A conformity freeze means that only projects in the first 
four years of the most recent conforming Regional Transportation Plan 
(RTP) and Transportation Improvement Program (TIP) can proceed. See 40 
CFR 93.120(a). During a freeze, no new RTPs, TIPs or RTP/TIP amendments 
can be found to conform. The conformity status of these plans would 
then lapse on the date that highway sanctions as a result of the 
disapproval are imposed on the nonattainment area under section 
179(b)(1) of the CAA. See 40 CFR 93.120(a)(1). Generally, highway 
sanctions are triggered 24 months after the effective date of the 
disapproval of a required SIP revision for a nonattainment area. During 
a conformity lapse, no new transportation plans, programs, or projects 
may be found to conform until another SIP revision fulfilling the same 
CAA requirements is submitted and conformity of this submission is 
determined.
    If EPA were proposing to disapprove the plan for administrative 
reasons unrelated to the attainment, 5% and RFP demonstrations, EPA 
could issue the disapproval with a protective finding. See 40 CFR 
93.120(a)(3). This would avoid the conformity freeze. Because this is 
not the case, EPA does not believe that a protective finding should be 
proposed in connection with our proposed disapproval action on the 
189(d) plan. Therefore, a conformity freeze will be in place upon the 
effective date of any final disapproval of the 189(d) plan.

H. Adequate Legal Authority and Resources

    Section 110(a)(2)(E)(i) of the Clean Air Act requires that 
implementation plans provide necessary assurances that the state (or 
the general purpose local government) will have adequate personnel, 
funding and authority under state law. Requirements for legal authority 
are further defined in 40 CFR part 51, subpart L (section 51.230-232) 
and for resources in 40 CFR 51.280.
    States and responsible local agencies must demonstrate that they 
have the legal authority to adopt and enforce provisions of the SIP and 
to obtain information necessary to determine compliance. SIPs must also 
describe the resources that are available or will be

[[Page 54819]]

available to the state and local agencies to carry out the plan, both 
at the time of submittal and during the 5-year period following 
submittal. These requirements are addressed in chapter 10 of the 189(d) 
plan. We evaluate these requirements for the plan in general and for 
those measures for which we are proposing approval or limited approval.
    MAG derives its authority to develop and adopt the 189(d) plan and 
other nonattainment area plans from ARS 49-406 and from a February 7, 
1978 letter from the Governor of Arizona \26\ designating MAG as 
responsible for those tasks. ADEQ is authorized to adopt and submit the 
189(d) plan by ARS 49-404 and ARS 49-406.
---------------------------------------------------------------------------

    \26\ Letter from Wesley Bolin, Governor of Arizona, to Douglas 
M. Costle, Administrator of EPA, February 7, 1978, found in the 
189(d) plan, chapter 10, ''Commitments for Implementation,'' Volume 
one, ``Maricopa Association of Governments.''
---------------------------------------------------------------------------

    We are proposing for full approval statutes that have been adopted 
by the Arizona legislature, signed by the Governor and incorporated 
into the Arizona Revised Statutes. We are also proposing a limited 
approval of regulations authorized and mandated by Arizona statute. See 
section III.B above. Because the requirements in these statutes and 
regulations are directly imposed by State law, no further demonstration 
of legal authority to adopt emission standards and limitations is 
needed under CAA section 110(a)(2)(E)(i) and 40 CFR part 51, subpart L.
    Section 51.230 of 40 CFR also requires that the State have the 
authority to ``[e]nforce applicable laws, regulations, and standards, 
and seek injunctive relief.'' ARS 49-462, 49-463 and 49-464 provide the 
general authorities adequate to meet these requirements. We note that 
EPA, in undertaking enforcement actions under CAA section 113, is not 
constrained by provisions it approves into SIPs that circumscribe the 
enforcement authorities available to state and local governments.
    Several of the State statutory provisions proposed for full 
approval and the regulations proposed for limited approval are direct 
mandates to the regulated community and require ADEQ to implement and 
enforce programs in whole or in part. See, e.g., ARS 49-457, 49-457.01, 
49-457.03 and 49-457.04. There is no description in the 189(d) plan of 
the resources available to the State to implement and enforce these 
statutory and regulatory provisions. Thus it is not possible for EPA to 
ascertain whether the State has adequate personnel and funding under 
CAA section 110(a)(2)(E)(i) and EPA's related regulations to carry out 
these State statutes.
    Many of the Arizona statutory provisions proposed for approval are 
directives to local governmental entities to take action. For example, 
ARS 49-474.05 requires specified local jurisdictions to develop 
extensive dust control programs. Developing such programs will require 
resources and legal authority at the local level. However, we are not 
proposing approval of such programs at this time. This action is merely 
proposing approval of the statutory mandate to develop the program. 
Therefore, for these statutory provisions, a demonstration that 
adequate authority and resources are available is not required.
    Section 110(a)(2)(E)(iii) requires SIPs to include necessary 
assurances that where a state has relied on a local or regional 
government, agency or instrumentality for the implementation of any 
plan provision, the State has responsibility for ensuring adequate 
implementation of such plan provision. We have previously found that 
Arizona law provides such assurances. 60 FR 18010, 18019 (April 10, 
1995).
    For the reasons discussed above, we propose to find that the 
requirements of section 110(a)(2)(E) and related regulations have been 
met with respect to legal authority. However, we propose to find that 
the 189(d) plan does not demonstrate that ADEQ has adequate personnel 
and funding to implement the State statutes and regulations proposed 
for full or limited approval for which the State has implementation and 
enforcement responsibility and authority.

IV. Summary of Proposed Actions

    EPA is proposing to approve in part and disapprove in part, the 
189(d) plan for the Maricopa County (Phoenix) PM-10 nonattainment area 
as follows:
    A. EPA is proposing to disapprove pursuant to CAA section 110(k)(3) 
the following elements of the ``MAG 2007 Five Percent Plan for PM-10 
for the Maricopa County Nonattainment Area'':
    (1) The 2005 baseline emissions inventory and the projected 
emission inventories as not meeting the requirements of CAA sections 
172(c)(3);
    (2) The attainment demonstration as not meeting the requirements of 
CAA sections 189(d) and 179(d)(3);
    (3) The 5% demonstration as not meeting the requirements of CAA 
sections 189(d);
    (4) The reasonable further progress and milestone demonstrations as 
not meeting the requirements of CAA section 189(c);
    (5) The contingency measures as not meeting the requirements of CAA 
sections 172(c)(9); and
    (6) The 2010 MVEB as not meeting the requirements of CAA section 
176(c) and 40 CFR 93.118(e)(4).
    B. EPA is proposing a limited approval and disapproval of AAC R18-
2-610 and AAC R18-2-611 as submitted in the ``MAG 2007 Five Percent 
Plan for PM-10 for the Maricopa County Nonattainment Area'' pursuant to 
CAA section 110(k)(3). EPA is proposing a limited approval because 
these regulations strengthen the SIP and a limited disapproval because 
they do not fully meet the requirements of CAA sections 110(a) and 
189(b)(1)(B) for enforceable BACM for agricultural sources of PM-10 in 
the Maricopa area.
    C. EPA is proposing to approve pursuant to CAA section 110(k)(3) 
the following sections of the Arizona Revised Statutes as submitted in 
the ``MAG 2007 Five Percent Plan for PM-10 for the Maricopa County 
Nonattainment Area'' as strengthening the SIP: ARS 9-500.04, ARS 9-
500.27, ARS 11-877, ARS 28-6705, ARS 49-457, ARS 49-457.01, ARS 49-
457.02, ARS 49-457.03, ARS 49-457.04, ARS 49-474.01, ARS 49-474.05, and 
ARS 49-501.
    D. EPA is proposing to approve pursuant to CAA section 110(k)(3) 
the ``Agricultural Best Management Practices Guidance Booklet and 
Pocket Guide'' as submitted on May 6, 2010.
E. Effect of Finalizing the Proposed Disapproval Actions
    If we finalize disapprovals of the emissions inventories, 
attainment demonstration, RFP and milestone demonstrations, 5% 
demonstration and contingency measures, the offset sanction in CAA 
section 179(b)(2) will be applied in the Maricopa area 18 months after 
the effective date of any final disapproval. The highway funding 
sanctions in CAA section 179(b)(1) will apply in the area 6 months 
after the offset sanction is imposed. Neither sanction will be imposed 
if Arizona submits and we approve prior to the implementation of the 
sanctions SIP revisions meeting the relevant requirements of the CAA. 
See 40 CFR 52.31 which sets forth in detail the sanctions consequences 
of a final disapproval.
    If EPA takes final action on the 189(d) plan as proposed, Arizona 
will need to develop and submit a revised plan for the Maricopa area 
that again addresses applicable CAA requirements, including section 
189(d). While EPA is proposing to approve many of the measures relied 
on in the submitted 189(d) plan,

[[Page 54820]]

additional emission reductions will be needed. In pursuing such 
reductions, we expect Arizona to investigate all potential additional 
controls for source categories in the Maricopa area that contribute to 
PM-10 exceedances. This investigation should include, but not be 
limited to, analysis of BACM controls in other geographic areas. We 
also note that CAA section 179(d)(2) provides EPA the authority to 
prescribe specific additional controls for areas, such as the Maricopa 
area, that have failed to attain the NAAQS.
    If we finalize a limited disapproval of AAC R18-2-610 and 611, the 
offset sanction in CAA section 179(b)(2) will be applied in the 
Maricopa area 18 months after the effective date of the final limited 
disapproval. The highway funding sanctions in CAA section 179(b)(1) 
will apply in the area 6 months after the offset sanction is imposed. 
Neither sanction will be imposed if Arizona submits and we approve 
prior to the implementation of the sanctions a measure for the control 
of agricultural sources meeting the requirements of CAA sections 110(a) 
and 189(b)(1)(B).
    In addition to the sanctions, CAA section 110(c)(1) provides that 
EPA must promulgate a Federal implementation plan addressing any full 
or limited disapproved elements of the plan, as set forth above, two 
years after the effective date of a disapproval should we not be able 
to approve replacements submitted by the State.
    Finally, if we take final action disapproving the 189(d) plan, a 
conformity freeze takes effect once the action becomes effective 
(usually 30 days after publication of the final action in the Federal 
Register). A conformity freeze means that only projects in the first 
four years of the most recent RTP and TIP can proceed. During a freeze, 
no new RTPs, TIPs or RTP/TIP amendments can be found to conform.

V. Statutory and Executive Order Reviews

A. Executive Order 12866, Regulatory Planning and Review

    The Office of Management and Budget (OMB) has exempted this 
regulatory action from Executive Order 12866, entitled ``Regulatory 
Planning and Review.''

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b).

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions.
    This rule will not have a significant impact on a substantial 
number of small entities because SIP approvals or disapprovals under 
section 110 and subchapter I, part D of the Clean Air Act do not create 
any new requirements but simply approve or disapprove requirements that 
the State is already imposing. Therefore, because the proposed Federal 
SIP partial approval/partial disapproval and limited approval/limited 
disapproval actions do not create any new requirements, I certify that 
this action will not have a significant economic impact on a 
substantial number of small entities.
    Moreover, due to the nature of the Federal-State relationship under 
the Clean Air Act, preparation of flexibility analysis would constitute 
Federal inquiry into the economic reasonableness of state action. The 
Clean Air Act forbids EPA to base its actions concerning SIPs on such 
grounds. Union Electric Co., v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 
42 U.S.C. 7410(a)(2).

D. Unfunded Mandates Reform Act

    Under sections 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate; or to 
the private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that the partial approval/partial disapproval 
and limited approval/limited disapproval actions proposed do not 
include a Federal mandate that may result in estimated costs of $100 
million or more to either State, local, or tribal governments in the 
aggregate, or to the private sector. This Federal action proposes to 
approve and disapprove pre-existing requirements under State or local 
law, and imposes no new requirements. Accordingly, no additional costs 
to State, local, or tribal governments, or to the private sector, 
result from this action.

E. Executive Order 13132, Federalism

    Executive Order 13132 (64 FR 43255, August 10, 1999) revokes and 
replaces Executive Orders 12612 (Federalism) and 12875 (Enhancing the 
Intergovernmental Partnership). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' Under Executive Order 13132, EPA may not issue a 
regulation that has federalism implications, that imposes substantial 
direct compliance costs, and that is not required by statute, unless 
the Federal government provides the funds necessary to pay the direct 
compliance costs incurred by State and local governments, or EPA 
consults with State and local officials early in the process of 
developing the proposed regulation. EPA also may not issue a regulation 
that has federalism implications and that preempts State law unless the 
Agency consults with State and local officials early in the process of 
developing the proposed regulation.
    This rule will not have substantial direct effects on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government, as specified in Executive Order 13132, because it 
merely proposes to approve or disapprove a State rule implementing a 
federal standard, and does not alter the relationship or the 
distribution of power and responsibilities established in the Clean Air 
Act. Thus, the requirements of section 6 of the Executive Order do not 
apply to this rule.

[[Page 54821]]

F. Executive Order 13175, Coordination With Indian Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' This proposed rule does not 
have tribal implications, as specified in Executive Order 13175. It 
will not have substantial direct effects on tribal governments, 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. Thus, Executive Order 13175 does not 
apply to this rule.
    EPA specifically solicits additional comment on this proposed rule 
from tribal officials.

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

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997) 
as applying only to those regulatory actions that concern health or 
safety risks, such that the analysis required under section 5-501 of 
the Executive Order has the potential to influence the regulation. This 
rule is not subject to Executive Order 13045, because it approves a 
state rule implementing a Federal standard.

H. Executive Order 12898, Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898, ``Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations'' (February 
16, 1994) establishes federal executive policy on environmental 
justice. Its main provision directs federal agencies, to the greatest 
extent practicable and permitted by law, to make environmental justice 
part of their mission by identifying and addressing, as appropriate, 
disproportionately high and adverse human health or environmental 
effects of their programs, policies and activities on minority 
populations and low-income populations in the United States. The 
Executive Order has informed the development and implementation of 
EPA's environmental justice program and policies. Consistent with the 
Executive Order and the associated Presidential Memorandum, the 
Agency's environmental justice policies promote environmental 
protection by focusing attention and Agency efforts on addressing the 
types of environmental harms and risks that are prevalent among 
minority, low-income and Tribal populations.
    This action will not have disproportionately high and adverse human 
health or environmental effects on minority, low-income or Tribal 
populations because the partial approval/partial disapproval and 
limited approval/limited disapproval actions proposed increase the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population.

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

    This proposed rule is not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001) because it 
is not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act

    Section 12 of the National Technology Transfer and Advancement Act 
(NTTAA) of 1995 requires Federal agencies to evaluate existing 
technical standards when developing a new regulation. To comply with 
NTTAA, EPA must consider and use ``voluntary consensus standards'' 
(VCS) if available and applicable when developing programs and policies 
unless doing so would be inconsistent with applicable law or otherwise 
impractical.
    EPA believes that VCS are inapplicable to this action. Today's 
action does not require the public to perform activities conducive to 
the use of VCS.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Particulate matter, Reporting and recordkeeping 
requirements.

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

    Dated: September 3, 2010.
Jared Blumenfeld,
Regional Administrator, Region IX.
[FR Doc. 2010-22616 Filed 9-8-10; 8:45 am]
BILLING CODE 6560-50-P

