The EPA Region 9 Acting Regional Administrator, Alexis Strauss, signed the following proposed rule on 6/26/2013, and EPA is 

submitting it for publication in the Federal Register (FR). While we have taken steps to ensure the accuracy of this Internet version of the 

rule, it is not the official version of the rule for purposes of compliance. Please refer to the official version in a forthcoming FR 

publication, which will appear on the Government Printing Office’s FDsys website (http://fdsys.gpo.gov/fdsys/search/home.action) and 

on Regulations.gov (http://www.regulations.gov) in Docket No. EPA-R09-OAR-2013-0449.

Billing Code: 6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2013-0449; FRL– ]

Determination of Attainment for the West Central Pinal 

Nonattainment Area for the 2006 Fine Particle Standard; Arizona; 

Determination Regarding Applicability of Clean Air Act 

Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to determine that the West Central 

Pinal area in Arizona has attained the 2006 24-hour fine 

particle (PM2.5) National Ambient Air Quality Standard (NAAQS). 

This proposed determination is based upon complete, qualityassured, and certified ambient air monitoring data showing that 

the area has monitored attainment of the 2006 24-hour PM2.5 NAAQS 

based on the 2010–2012 monitoring period. EPA is further 

proposing that, if EPA finalizes this determination of 

attainment, the requirements for the area to submit an 

attainment demonstration, together with reasonably available 

control measures (RACM), a reasonable further progress (RFP) 

plan, and contingency measures for failure to meet RFP and 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

2

attainment deadlines shall be suspended for so long as the area 

continues to attain the 2006 24-hour PM2.5 NAAQS.

DATES: Written comments must be received on or before [FEDERAL 

REGISTER OFFICE: Insert date 30 days after date of publication 

in the Federal Register].

ADDRESSES: Submit your comments, identified by Docket ID No. 

EPA-R09-OAR-2013-0449 by one of the following methods:

1. Federal eRulemaking Portal, at www.regulations.gov, please 

follow the on-line instructions;

2. E-mail to vagenas.ginger@epa.gov; or

3. Mail or delivery to Ginger Vagenas, Air Planning Office, 

AIR-2, U.S. Environmental Protection Agency, Region IX, 75 

Hawthorne Street, San Francisco, California 94105-3901.

Instructions: All comments will be included in the public docket 

without change and may be made available online at 

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 you consider to be CBI or 

otherwise protected should be clearly identified as such and 

should not be submitted through www.regulations.gov or e-mail. 

www.regulations.gov is an “anonymous access” system, and EPA 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

3

will not know your identity or contact information unless you 

provide it in the body of your comment. If you send an e-mail 

directly to EPA, your e-mail address will be automatically 

captured and included as part of the public comment. If you 

submit an electronic comment, EPA recommends that you include 

your name and other contact information in the body of your 

comment and with any disk or CD-ROM you submit. If EPA cannot 

read your comment due to technical difficulties and cannot 

contact you for clarification, EPA may not be able to consider 

your comment. Electronic files should avoid the use of special 

characters, any form of encryption, and be free of any defects 

or viruses.

Docket: The index to the docket for this action is available 

electronically at 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 at 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.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

4

FOR FURTHER INFORMATION CONTACT: Ginger Vagenas, (415) 972-3964, 

or by email at vagenas.ginger@epa.gov. 

SUPPLEMENTARY INFORMATION: Throughout this document, wherever 

“we”, “us” or “our” are used, we mean EPA. We are providing the 

following outline to aid in locating information in this 

proposal.

Table of Contents

I. What determination is EPA making?

II. What is the background for this action?

A. PM2.5 NAAQS

B. Designation of PM2.5 Nonattainment Areas

C. How does EPA make attainment determinations? 

III. What is EPA’s analysis of the relevant air quality data?

A. Monitoring Network and Data Considerations

B. Evaluation of Current Attainment

IV. What is the effect of a determination of attainment for the 

2006 24-hour PM2.5 NAAQS under subpart 4 of the Clean Air Act?

A. Background of the Clean Data Policy

B. Application of the Clean Data Policy to the AttainmentRelated Provisions of Subpart 4

V. EPA’s Proposed Action and Request for Public Comment

VI. Statutory and Executive Order Reviews
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

5

I. What determination is EPA making?

EPA is proposing to determine that the West Central Pinal

nonattainment area has clean data for the 2006 24-hour NAAQS for 

fine particles (generally referring to particles less than or 

equal to 2.5 micrometers in diameter, PM2.5). This determination

is based upon complete, quality-assured, and certified ambient 

air monitoring data showing the area has monitored attainment of 

the 2006 PM2.5 NAAQS based on 2010-2012 monitoring data.

Preliminary data in EPA’s Air Quality System (AQS) for 2013

indicate that the area continues to attain the 2006 PM2.5 NAAQS.

Based on this determination, we are also proposing to suspend 

the obligations on the State of Arizona to submit certain state 

implementation plan (SIP) revisions related to attainment of 

this standard for the area for as long as the area continues to 

attain the standard.

II. What is the background for this action?

A. PM2.5 NAAQS 

Under section 109 of the Clean Air Act (CAA or “Act”), EPA 

has established national ambient air quality standards (NAAQS or 

“standards”) for certain pervasive air pollutants (referred to 

as “criteria pollutants”) and conducts periodic reviews of the 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

6

NAAQS to determine whether they should be revised or whether new 

NAAQS should be established. 

On July 1, 1987 (52 FR 24634), EPA replaced the original 

NAAQS for particulate matter, measured as total suspended 

particulate matter (“TSP”)(i.e., particles roughly 30 

micrometers or less), with new NAAQS that replaced TSP as the 

indicator for particulate matter with a new indicator that 

includes only those particles with an aerodynamic diameter less 

than or equal to a nominal 10 micrometers (PM10).

On July 18, 1997 (62 FR 38652), EPA revised the NAAQS for 

particulate matter by establishing new NAAQS for particles with 

an aerodynamic diameter less than or equal to a nominal 2.5 

micrometers (PM2.5). EPA established primary and secondary1 annual 

and 24-hour standards for PM2.5. The annual standard was set at

15.0 micrograms per cubic meter (μg/m3), based on a 3-year 

average of annual mean PM2.5 concentrations, and the 24-hour 

standard was set at 65 μg/m3, based on the 3-year average of the 

98th percentile of 24-hour PM2.5 concentrations at each

population-oriented monitor within an area.

 

1 For a given air pollutant, “primary” national ambient air quality standards 

are those determined by EPA as requisite to protect the public health, and 

“secondary” standards are those determined by EPA as requisite to protect the 

public welfare from any known or anticipated adverse effects associated with 

the presence of such air pollutant in the ambient air. See CAA section 

109(b).
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

7

On October 17, 2006 (71 FR 61144), EPA revised the level of 

the 24-hour PM2.5 NAAQS to 35 μg/m3, based on a 3-year average of 

the 98th percentile of 24-hour concentrations. Herein, we refer 

to the 35 μg/m3 standard as the “2006 24-hour PM2.5 standard.” EPA 

also retained the 1997 annual PM2.5 standard at 15.0 μg/m3 based 

on a 3-year average of annual mean PM2.5 concentrations, but with 

tighter constraints on the spatial averaging criteria. 

In December 2012, EPA revised the annual PM2.5 NAAQS to a 

level of 12 μg/m3, retained the current 24-hour PM2.5 NAAQS at a 

level of 35 μg/m3, and retained the current PM10 NAAQS. See 78 FR 

3086 (January 15, 2013). The proposed determination in this 

document concerns only the 2006 24-hour PM2.5 NAAQS, not the 1997 

24-hour PM2.5 NAAQS or the 1997 or 2012 annual PM2.5 NAAQS, and 

not the PM10 NAAQS.

B. Designation of PM2.5 Nonattainment Areas

Effective December 14, 2009, EPA established the initial 

air quality designations for most areas in the United States for

the 2006 24-hour PM2.5 NAAQS. See 74 FR 58688 (November 13, 

2009). Pinal County, Arizona is located within one of three 

areas that EPA deferred from designation at that time.

2 However, 

 

2 With respect to the 1997 annual PM2.5 NAAQS, this area is designated as 

“unclassifiable/attainment.” EPA has not yet established designations for the 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

8

in a subsequent action on February 3, 2011, EPA designated a 

portion of State lands in Pinal County, Arizona (“West Central 

Pinal”) as nonattainment for the 2006 PM2.5 NAAQS based on 2006-

2008 data.3,

4 For more information on the designation of West 

Central Pinal, please see the February 3, 2011 final rule.

Within three years of the effective date of designations, 

states with areas designated as nonattainment for the 2006 PM2.5

NAAQS are required to submit SIP revisions that, among other 

elements, provide for implementation of reasonably available 

control measures (RACM), reasonable further progress (RFP), 

attainment of the standard as expeditiously as practicable but 

no later than five years from the nonattainment designation (in 

this instance, no later than March 7, 2014), as well as 

contingency measures. See CAA section 172(a)(2), 172(c)(1), 

172(c)(2), and 172(c)(9). Prior to the due date for submittal of 

these SIP revisions, the State of Arizona requested that EPA 

make a determination that the West Central Pinal nonattainment 

 

revised annual PM2.5 NAAQS. 

3 See 76 FR 6056, February 3, 2011. This action was effective March 7, 2011. 

On October 26, 2012, we designated nearby Indian lands belonging to the Ak 

Chin Indian Community and the Gila River Indian Community, which lie within 

the deferred area, as “unclassifiable/attainment” for the 2006 PM2.5 NAAQS 

based on improved air quality. See 77 FR 65310. 

4 The boundaries for the nonattainment area are described in 40 CFR 81.303.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

9

area has attained the 2006 PM2.5 NAAQS.

5 Today's proposal responds 

to the State’s request.

C. How does EPA make attainment determinations? 

A determination of whether an area’s air quality currently 

meets the PM2.5 NAAQS is generally based upon the most recent 

three years of complete, quality-assured data gathered at 

established State and Local Air Monitoring Stations (SLAMS) in a

nonattainment area and entered into the AQS database. Data from 

air monitors operated by state/local agencies in compliance with 

EPA monitoring requirements must be submitted to AQS. Monitoring 

agencies annually certify that these data are accurate to the 

best of their knowledge. Accordingly, EPA relies primarily on 

data in AQS when determining the attainment status of areas. See

40 CFR 50.13; 40 CFR part 50, appendix L; 40 CFR part 53; 40 CFR 

part 58, and 40 CFR part 58, appendices A, C, D, and E. All data 

are reviewed to determine the area's air quality status in 

accordance with 40 CFR part 50, appendix N.

Under EPA regulations in 40 CFR part 50, section 50.13 and 

 

5 On December 19, 2012, in an email to Colleen McKaughan, Associate Director, 

Air Division, U.S. EPA Region IX, Steven M. Calderon, Manager, State 

Implementation Plan Section, Air Quality Division, Arizona Department of 

Environmental Quality, requested that EPA determine whether the West Central 

Pinal PM2.5 nonattainment area qualified for a determination of attainment for 

the 2006 24-hour PM2.5 NAAQS. On January 29, 2013, ADEQ provided an AQS Design 

Value Report in support of the request. Both of these items can be found in 

the docket for today’s action.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

10

in accordance with appendix N, the 2006 24-hour PM2.5 standard is

met when the design value is less than or equal to 35 μg/m3

(based on the rounding convention in 40 CFR part 50, appendix N) 

at each monitoring site within the area.6 The PM2.5 24-hour 

average is considered valid when 75 percent of the hourly 

averages for the 24-hour period are available. Data completeness 

requirements for a given year are met when at least 75 percent

of the scheduled sampling days for each quarter have valid data.

III. What is EPA’s analysis of the relevant air quality data?

A. Monitoring Network and Data Considerations

Pinal County Air Quality Control District (PCAQCD) is the 

governmental agency with the authority and responsibility under 

state law for collecting ambient air quality data within the 

West Central Pinal nonattainment area. Annually, PCAQCD submits

monitoring network plans to EPA. These plans discuss the status 

of the air monitoring network, as required under 40 CFR part 58. 

EPA reviews these annual network plans for compliance with the 

applicable reporting requirements in 40 CFR 58.10. With respect 

to PM2.5, we have found that PCAQCD’s annual network plans meet 

 

6 The 24-hour PM2.5 standard design value is the 3-year average of annual 98th 

percentile 24-hour average values recorded at each monitoring site (see 40 

CFR part 50, appendix N, section 1.0(c)), and the 24-hour PM2.5 NAAQS is met 

when the 24-hour standard design value at each monitoring site is less than 

or equal to 35 μg/m3. 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

11

the applicable requirements under 40 CFR part 58.7 Furthermore, 

we concluded in our Technical System Audit Report concerning 

PCAQCD’s ambient air quality monitoring program that PCAQCD’s 

ambient air monitoring network currently meets or exceeds the 

requirements for the minimum number of monitoring sites 

designated as SLAMS for PM2.5 in the West Central Pinal

nonattainment area.

8 Also, PCAQCD annually certifies that the 

data it submits to AQS are quality-assured.9 

There was one PM2.5 SLAMS operating during the 2010-2012

period in the West Central Pinal PM2.5 nonattainment area. This 

site has been monitoring PM2.5 concentrations since 2005. 

Historically, this site had monitored PM2.5 concentrations on a 

one-in-six day sampling frequency. In the beginning of 2012, the 

sampling frequency was changed to a one-in-three day schedule.

 

7

 Letter from Matthew Lakin, Manager, Air Quality Analysis Office, U.S. EPA 

Region IX, to Donald Gabrielson, Director, PCAQCD (November 1, 2010) 

(approving PCAQCD’s “2010 Ambient Monitoring Network Plan and 2009 Data 

Summary”); Letter from Matthew Lakin, Manager, Air Quality Analysis Office, 

U.S. EPA Region IX, to Donald Gabrielson, Director, PCAQCD (November 1, 2011) 

(approving PCAQCD’s “2011 Annual Monitoring Network Plan and 2010 Data 

Summary”); Letter from Matthew Lakin, Manager, Air Quality Analysis Office, 

U.S. EPA Region IX, to Donald Gabrielson, Director, PCAQCD (March 27, 2013) 

(approving PCAQCD’s “2012 Annual Monitoring Network Plan and 2011 Data 

Summary”).

8

Technical System Audit Report transmitted via correspondence dated June 

10, 2013, from Deborah Jordan, Director, Air Division, EPA Region IX, to 

Donald Gabrielson, Director, PCAQCD. 

9 See, e.g., the letter from Kale Walch, Deputy Director, PCAQCD to Jared 

Blumenfeld, Regional Administrator, EPA Region IX, dated April 26, 2013 

certifying the ambient air quality data collected for year 2012.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

12

EPA defines specific monitoring site types and spatial 

scales of representativeness to characterize the nature and 

location of required monitors. The monitor’s spatial scale is 

middle scale,

10 and its monitoring objectives (site type) are 

source oriented and population exposure.

For the purposes of this proposed action, we have reviewed 

the data for the most recent three-year period (2010-2012) for 

completeness, and we determined that the data collected by 

PCAQCD meets the completeness criterion for all 12 quarters at 

the West Central Pinal PM2.5 monitor. We consider the PM2.5 data 

set for 2010-2012 to be complete for the purposes of determining 

whether the area has attained the standard. 

B. Evaluation of Current Attainment

EPA’s evaluation of whether the West Central Pinal PM2.5

nonattainment area has attained the 2006 24-hour PM2.5 NAAQS is 

based on our review of the monitoring data and takes into 

account the adequacy of the PM2.5 monitoring network in the 

nonattainment area and the reliability of the data collected by 

the network as discussed in the previous section of this 

document. 

 

10 In this context, “middle” spatial scale defines concentrations typical of 

areas up to several city blocks in size with dimensions ranging from about 

100 meters to 0.5 kilometers. See 40 CFR part 58, appendix D, section 1.2.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

13

Table 1 shows the PM2.5 design values for the West Central 

Pinal nonattainment area monitor based on ambient air quality 

monitoring data for the most recent complete three-year period 

(2010-2012). The data show that the design value for the 2010-

2012 period was equal to or less than 35 μg/m3 at the monitor. 

Therefore, we are proposing to determine, based on the complete, 

quality-assured, and certified data for 2010-2012, that the West 

Central Pinal area has attained the 2006 24-hour PM2.5 standard. 

Preliminary data available in AQS for 2013 indicate that the 

area continues to attain the standard.

Table 1. 2010-2012 24-Hour PM2.5 Monitoring Site and Design 

Values for the West Central Pinal Nonattainment Area.

Monitoring Site

98th Percentile (μg/m3) 2010-2012 

Design Values

(μg/m3) 2010 2011 2012

Cowtown Road 27.1 27.2 28.9 28

Source: Design Value Report, May 23, 2013 (in the docket to this 

proposed action).

IV. What is the effect of a determination of attainment for the 

2006 24-hour PM2.5 NAAQS under subpart 4 of the Clean Air Act?

This section of EPA’s proposal addresses the effects of a 

final determination of attainment for the West Central Pinal 

nonattainment area.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

14

For the 1997 annual PM2.5 standard, 40 CFR section 

51.1004(c) of EPA’s Implementation Rule embodies EPA’s “Clean 

Data Policy” interpretation under subpart 1. The provisions of 

section 51.1004(c) set forth the effects of a determination of 

attainment for the 1997 PM2.5 standard. 72 FR 20585, 20665 (April 

25, 2007). While the regulatory provisions of 51.1004(c) do not 

explicitly apply to the 2006 PM2.5 standard, the underlying 

statutory interpretation is the same for both standards. See 77 

FR 76427 (Dec. 28, 2012) (proposed determination of attainment 

for the 2006 PM2.5 standard for Milwaukee, WI).

On January 4, 2013, in Natural Resources Defense Council v. 

EPA, the D.C. Circuit remanded to EPA the “Final Clean Air Fine 

Particle Implementation Rule” (72 FR 20586, April 25, 2007) and 

the “Implementation of the New Source Review (NSR) Program for 

Particulate Matter Less than 2.5 Micrometers (PM2.5)” final rule 

(73 FR 28321, May 16, 2008) (collectively, “1997 PM2.5

Implementation Rule” or “Implementation Rule”). 706 F.3d 428 

(D.C. Cir. 2013). The Court found that EPA erred in implementing 

the 1997 PM2.5 NAAQS pursuant solely to the general 

implementation provisions of subpart 1 of Part D of Title I of 

the CAA, rather than the particulate-matter-specific provisions 

of subpart 4 of Part D of Title I. The Court remanded EPA’s 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

15

Implementation Rule for further proceedings consistent with the 

Court’s decision. In light of the Court’s decision and its 

remand of the Implementation Rule, EPA in this proposed 

rulemaking addresses the effect of a final determination of 

attainment for the West Central Pinal nonattainment area, if 

that area were considered a moderate nonattainment area under 

subpart 4.11 As set forth in more detail below, under EPA’s Clean 

Data Policy interpretation, a determination that the area has 

attained the standard suspends the State’s obligation to submit 

attainment-related planning requirements of subpart 4 (and the 

applicable provisions of subpart 1) for so long as the area 

continues to attain the standard. These include requirements to 

submit an attainment demonstration, RFP, RACM, and contingency 

measures, because the purpose of these provisions is to help 

reach attainment —- a goal which has already been achieved.

 

11 For the purposes of evaluating the effects of this proposed determination 

of attainment under subpart 4, we are considering the West Central Pinal 

nonattainment area to be a “moderate” PM2.5 nonattainment area. Under section 

188 of the CAA, all areas designated nonattainment areas under subpart 4 

would initially be classified by operation of law as “moderate” nonattainment 

areas, and would remain moderate nonattainment areas unless and until EPA 

reclassifies the area as a “serious” nonattainment area. Accordingly, EPA 

believes that it is appropriate to limit the evaluation of the potential 

impact of subpart 4 requirements to those that would be applicable to 

moderate nonattainment areas. Sections 189(a) and (c) of subpart 4 apply to 

moderate nonattainment areas and include an attainment demonstration (section 

189(a)(1)(B)); (3) provisions for RACM (section 189(a)(1)(C)); and 

quantitative milestones demonstrating RFP toward attainment by the applicable 

attainment date (section 189(c)). In addition, EPA also evaluates the 

applicable requirements of subpart 1.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

16

A. Background of the Clean Data Policy

Over the past two decades, EPA has consistently applied its 

“Clean Data Policy” interpretation to attainment-related 

provisions of subparts 1, 2 and 4. The Clean Data Policy is the 

subject of several EPA memoranda and regulations. In addition, 

numerous individual rulemakings published in the Federal

Register have applied the interpretation to a spectrum of NAAQS, 

including the 1-hour and 1997 ozone, PM10, PM2.5, CO and lead 

standards. The D.C. Circuit has upheld the Clean Data Policy 

interpretation as embodied in EPA’s 8-hour ozone Implementation 

Rule, 40 CFR 51.918.12 NRDC v. EPA, 571 F. 3d 1245 (DC Cir. 

2009). Other U.S. Circuit Courts of Appeals that have considered 

and reviewed EPA’s Clean Data Policy interpretation have upheld 

it and the rulemakings applying EPA’s interpretation. Sierra 

Club v. EPA, 99 F.3d 1551 (10th Cir. 1996); Sierra Club v. EPA, 

375 F. 3d 537 (7th Cir. 2004); Our Children's Earth Foundation 

v. EPA, N. 04-73032 (9th Cir. June 28, 2005 (Memorandum 

Opinion)), Latino Issues Forum, v. EPA, Nos. 06-75831 and 08-

71238 (9th Cir. March 2, 2009 (Memorandum Opinion)).

 

12 “EPA’s Final Rule to implement the 8-hour Ozone National Ambient Air 

Quality Standard--Phase 2 (Phase 2 Final Rule),” 70 FR 71612, 71645-46 

(November 29, 2005).
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

17

As noted above, EPA incorporated its Clean Data Policy 

interpretation in both its 1997 8-hour ozone implementation rule 

and in its PM2.5 Implementation Rule in 40 CFR 51.1004(c). 72 FR 

20585, 20665 (April 25, 2007). While the D.C. Circuit, in its 

January 4, 2013 decision, remanded the 1997 PM2.5 Implementation 

Rule, the court did not address the merits of that regulation, 

nor cast doubt on EPA’s existing interpretation of the statutory 

provisions.

However, in light of the Court’s decision, we set forth 

here EPA’s Clean Data Policy interpretation under subpart 4, for 

the purpose of identifying the effects of a determination of 

attainment for the 2006 PM2.5 standard for the West Central Pinal 

nonattainment area. EPA has previously articulated its Clean 

Data interpretation under subpart 4 in implementing the PM10

standard. See, e.g., 75 FR 27944 (May 19, 2010) (determination 

of attainment of the PM10 standard in Coso Junction, California); 

75 FR 6571 (February 10, 2010) and 71 FR 6352 (February 8, 2006) 

(Ajo, Arizona area); 71 FR 13021 (March 14, 2006) (Yuma, Arizona 

area); 71 FR 40023 (July 14, 2006) (Weirton, West Virginia 

area); 71 FR 44920 (August 8, 2006) (Rillito, Arizona area); 71 

FR 63642 (October 30, 2006) (San Joaquin Valley, California 

area); 72 FR 14422 (March 28, 2007) (Miami, Arizona area). Thus 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

18

EPA has established that, under subpart 4, an attainment 

determination suspends the obligations to submit an attainment 

demonstration, RACM, RFP contingency measures, and other 

measures related to attainment.

B. Application of the Clean Data Policy to the AttainmentRelated Provisions of Subpart 4 

In EPA’s proposed and final rulemakings determining that 

the San Joaquin Valley nonattainment area attained the PM10

standard, EPA set forth at length its rationale for applying the 

Clean Data Policy to PM10 under subpart 4. The Ninth Circuit 

upheld EPA’s final rulemaking, and specifically EPA’s Clean Data 

Policy, in the context of subpart 4. Latino Issues Forum v. EPA,

Nos. 06-75831 and 08-71238 (9th Cir. March 2, 2009 (Memorandum 

Opinion)). In rejecting petitioner’s challenge to the Clean Data 

Policy under subpart 4 for PM10, the Ninth Circuit stated, “As 

the EPA explained, if an area is in compliance with PM10

standards, then further progress for the purpose of ensuring 

attainment is not necessary.” 

The general requirements of subpart 1 apply in conjunction 

with the more specific requirements of subpart 4, to the extent 

they are not superseded or subsumed by the subpart 4 

requirements. Subpart 1 contains general air quality planning 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

19

requirements for areas designated as nonattainment. See section 

172(c). Subpart 4 itself contains specific planning and 

scheduling requirements for PM10 nonattainment areas, and under 

the Court’s January 4, 2013 decision in NRDC v. EPA, these same 

statutory requirements also apply for PM2.5 nonattainment areas. 

EPA has longstanding general guidance that interprets the 1990 

amendments to the CAA, making recommendations to states for 

meeting the statutory requirements for SIPs for nonattainment 

areas. See, “State Implementation Plans; General Preamble for 

the Implementation of Title I of the Clear Air Act Amendments of 

1990,” 57 FR 13498 (April 16, 1992) (the “General Preamble”). 

In the General Preamble, EPA discussed the relationship of 

subpart 1 and subpart 4 SIP requirements, and pointed out that 

subpart 1 requirements were to an extent “subsumed by, or 

integrally related to, the more specific PM10 requirements.” 57 

FR 13538 (April 16, 1992). These subpart 1 requirements include, 

among other things, provisions for attainment demonstrations, 

reasonably available control measures (RACM), reasonable further 

progress (RFP), emissions inventories, and contingency measures.

EPA has long interpreted the provisions of part D, subpart 

1 of the Act (sections 171 and 172) as not requiring the 

submission of RFP for an area already attaining the ozone NAAQS.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

20

For an area that is attaining, showing that the State will make 

RFP towards attainment “will, therefore, have no meaning at that 

point.” 57 FR at 13564. See 71 FR 40952 and 71 FR 63642 

(proposed and final determination of attainment for San Joaquin 

Valley); 75 FR 13710 and 75 FR 27944 (proposed and final 

determination of attainment for Coso Junction).

Section 189(c)(1) of subpart 4 states that:

Plan revisions demonstrating attainment submitted to the

Administrator for approval under this subpart shall contain 

quantitative milestones which are to be achieved every 3 

years until the area is redesignated attainment and which 

demonstrate reasonable further progress, as defined in 

section [section 171(1)] of this title, toward attainment 

by the applicable date.

With respect to RFP, section 171(1) states that, for 

purposes of part D, RFP “means such annual incremental 

reductions in emissions of the relevant air pollutant as are 

required by this part or may reasonably be required by the 

Administrator for the purpose of ensuring attainment of the 

applicable NAAQS by the applicable date.” Thus, whether dealing 

with the general RFP requirement of section 172(c)(2), the 

ozone-specific RFP requirements of sections 182(b) and (c), or 

the specific RFP requirements for PM10 areas of part D, subpart 

4, section 189(c)(1), the stated purpose of RFP is to ensure 

attainment by the applicable attainment date.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

21

Although section 189(c) states that revisions shall contain 

milestones which are to be achieved until the area is 

redesignated to attainment, such milestones are designed to show 

reasonable further progress “toward attainment by the applicable 

attainment date,” as defined by section 171. Thus, it is clear 

that once the area has attained the standard, no further 

milestones are necessary or meaningful. This interpretation is 

supported by language in section 189(c)(3), which mandates that 

a State that fails to achieve a milestone must submit a plan 

that assures that the State will achieve the next milestone or 

attain the NAAQS if there is no next milestone. Section 

189(c)(3) assumes that the requirement to submit and achieve 

milestones does not continue after attainment of the NAAQS.

In the General Preamble, we noted with respect to section 

189(c) that the purpose of the milestone requirement “is ‘to 

provide for emission reductions adequate to achieve the 

standards by the applicable attainment date’ (H.R. Rep. No. 490,

101st Cong., 2d Sess. 267 (1990)).” 57 FR 13539 (April 16, 

1992). If an area has in fact attained the standard, the stated 

purpose of the RFP requirement will have already been 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

22

fulfilled.13

Similarly, the requirements of section 189(c)(2) with 

respect to milestones no longer apply so long as an area has 

attained the standard. Section 189(c)(2) provides in relevant 

part that:

Not later than 90 days after the date on which a milestone 

applicable to the area occurs, each State in which all or 

part of such area is located shall submit to the 

Administrator a demonstration * * * that the milestone has 

been met.

Where the area has attained the standard and there are no 

further milestones, there is no further requirement to make a 

submission showing that such milestones have been met. This is 

consistent with the position that EPA took with respect to the 

general RFP requirement of section 172(c)(2) in the April 16, 

1992 General Preamble and also in the May 10, 1995 Seitz 

 

13 Thus, we believe that it is a distinction without a difference that 

section 189(c)(1) speaks of the RFP requirement as one to be achieved until 

an area is “redesignated attainment,” as opposed to section 172(c)(2), which 

is silent on the period to which the requirement pertains, or the ozone 

nonattainment area RFP requirements in sections 182(b)(1) or 182(c)(2), which 

refer to the RFP requirements as applying until the “attainment date,” since 

section 189(c)(1) defines RFP by reference to section 171(1) of the Act. 

Reference to section 171(1) clarifies that, as with the general RFP 

requirements in section 172(c)(2) and the ozone-specific requirements of 

section 182(b)(1) and 182(c)(2), the PM-specific requirements may only be 

required “for the purpose of ensuring attainment of the applicable national 

ambient air quality standard by the applicable date.” 42 U.S.C. 7501(1). As 

discussed in the text of this rulemaking, EPA interprets the RFP 

requirements, in light of the definition of RFP in section 171(1), and 

incorporated in section 189(c)(1), to be a requirement that no longer applies 

once the standard has been attained.
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

23

memorandum14 with respect to the requirements of section 182(b) 

and (c). In the May 10, 1995 Seitz memorandum, EPA also noted 

that section 182(g), the milestone requirement of subpart 2, 

which is analogous to provisions in section 189(c), is suspended 

upon a determination that an area has attained. The memorandum, 

also citing additional provisions related to attainment 

demonstration and RFP requirements, stated:

Inasmuch as each of these requirements is linked with the 

attainment demonstration or RFP requirements of section 

182(b)(1) or 182(c)(2), if an area is not subject to the 

requirement to submit the underlying attainment 

demonstration or RFP plan, it need not submit the related 

SIP submission either.

1995 Seitz memorandum at 5.

With respect to the attainment demonstration requirements 

of section 172(c) and section 189(a)(1)(B), an analogous 

rationale leads to the same result. Section 189(a)(1)(B) 

requires that the plan provide for “a demonstration (including 

air quality modeling) that the [SIP] will provide for 

attainment by the applicable attainment date * * *.” As with 

the RFP requirements, if an area is already monitoring 

attainment of the standard, EPA believes there is no need for an 

 

14 Memorandum from John S. Seitz, Director, Office of Air Quality Planning 

and Standards, “Reasonable Further Progress, Attainment Demonstration, and 

Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National 

Ambient Air Quality Standard,” dated May 10, 1995 (“Seitz memorandum”).
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

24

area to make a further submission containing additional measures 

to achieve attainment. This is also consistent with the 

interpretation of the section 172(c) requirements provided by 

EPA in the General Preamble, the Page memorandum,

15 and the 

section 182(b) and (c) requirements set forth in the Seitz 

memorandum. As EPA stated in the General Preamble, no other 

measures to provide for attainment would be needed by areas 

seeking redesignation to attainment since “attainment will have 

been reached.” 57 FR at 13564.

Other SIP submission requirements are linked with these 

attainment demonstration and RFP requirements, and similar 

reasoning applies to them. These requirements include the 

contingency measure requirements of sections 172(c)(9). We have 

interpreted the contingency measure requirements of section 

172(c)(9) (and section 182(c)(9) for ozone) as no longer 

applying when an area has attained the standard because those 

“contingency measures are directed at ensuring RFP and 

attainment by the applicable date.” 57 FR at 13564; Seitz 

memorandum, pp. 5-6.

CAA section 172(c)(9) provides that SIPs in nonattainment 

 

15 Memorandum from Stephen Page, Director, EPA Office of Air Quality Planning 

and Standards, “Clean Data Policy for the Fine Particle National Ambient Air 

Quality Standards,” December 14, 2004 (“Page memorandum”).
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

25

areas “shall 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. Such measures shall be included in 

the plan revision as contingency measures to take effect in any 

such case without further action by the State or [EPA].” This

contingency measure requirement is inextricably tied to the 

reasonable further progress and attainment demonstration 

requirements. Contingency measures are implemented if reasonable 

further progress targets are not achieved, or if attainment is 

not realized by the attainment date. Where an area has already 

achieved attainment by the attainment date, it has no need to 

rely on contingency measures to come into attainment or to make 

further progress to attainment. As EPA stated in the General 

Preamble: “The section 172(c)(9) requirements for contingency 

measures are directed at ensuring RFP and attainment by the 

applicable date.” See 57 FR 13564. Thus these requirements no 

longer apply when an area has attained the standard.

Both sections 172(c)(1) and 189(a)(1)(C) require 

“provisions to assure that reasonably available control 

measures” (i.e., RACM) are implemented in a nonattainment area. 

The General Preamble, 57 FR at 13560 (April 16, 1992), states 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

26

that EPA interprets section 172(c)(1) so that RACM requirements 

are a “component” of an area's attainment demonstration. Thus, 

for the same reason the attainment demonstration no longer 

applies by its own terms, the requirement for RACM no longer 

applies. EPA has consistently interpreted this provision to 

require only implementation of potential RACM measures that 

could contribute to reasonable further progress or to 

attainment. General Preamble, 57 FR at 13498. Thus, where an 

area is already attaining the standard, no additional RACM

measures are required.16 EPA is interpreting section 189(a)(1)(C) 

consistent with its interpretation of section 172(c)(1). 

The suspension of the obligations to submit SIP revisions 

concerning these RFP, attainment demonstration, RACM, 

contingency measures and other related requirements exists only 

for as long as the area continues to monitor attainment of the 

standard. If EPA determines, after notice-and-comment 

rulemaking, that the area has monitored a violation of the 

NAAQS, the basis for the requirements being suspended would no 

longer exist. In that case, the area would again be subject to a 

 

16 EPA's interpretation that the statute requires implementation only of RACM 

measures that would advance attainment was upheld by the United States Court 

of Appeals for the Fifth Circuit (Sierra Club v. EPA, 314 F.3d 735, 743-745 

(5th Cir. 2002), and by the United States Court of Appeals for the D.C.

Circuit (Sierra Club v. EPA, 294 F.3d 155, 162-163 (D.C. Cir. 2002)).
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

27

requirement to submit the pertinent SIP revision or revisions 

and would need to address those requirements. Thus, a final 

determination that the area need not submit one of the pertinent 

SIP submittals amounts to no more than a suspension of the 

requirements for so long as the area continues to attain the 

standard. Only if and when EPA redesignates the area to 

attainment would the area be relieved of these submission 

obligations. Attainment determinations under the Clean Data 

Policy do not shield an area from obligations unrelated to 

attainment in the area, such as provisions to address pollution 

transport.

As set forth above, based on our proposed determination 

that the West Central Pinal area is currently attaining the 2006 

24-hour PM2.5 NAAQS, we propose to find that the obligations to 

submit planning provisions to meet the requirements for an 

attainment demonstration, reasonable further progress plans, 

reasonably available control measures, contingency measures are 

suspended for so long as the area continues to monitor 

attainment of the 2006 24-hour PM2.5 NAAQS. If in the future, EPA 

determines after notice-and-comment rulemaking that the area 

again violates the 2006 24-hour PM2.5 NAAQS, the basis for 

suspending the attainment demonstration, RFP, RACM, and 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

28

contingency measure obligations would no longer exist.

V. EPA’s Proposed Action and Request for Public Comment

EPA proposes to determine, based on the most recent three 

years of complete, quality-assured, and certified data meeting 

the requirements of 40 CFR part 50, appendix N, that the West 

Central Pinal area is currently attaining the 2006 24-hour PM2.5

NAAQS. In conjunction with and based upon our proposed 

determination that West Central Pinal has attained and is 

currently attaining the standard, EPA proposes to determine that 

the obligation to submit the following attainment-related 

planning requirements is not applicable for so long as the area 

continues to attain the 2006 24-hour PM2.5 standard: The part D, 

subpart 4 obligations to provide an attainment demonstration 

pursuant to section 189(a)(1)(B), the RACM provisions of section 

189(a)(1)(C), the RFP provisions of section 189(c), and related 

attainment demonstration, RACM, RFP and contingency measure 

provisions requirements of subpart 1, section 172. This proposed 

action, if finalized, would not constitute a redesignation to 

attainment under CAA section 107(d)(3).

EPA is soliciting public comments on the issues discussed 

in this document or on other relevant matters. We will accept 

comments from the public on this proposal for the next 30 days. 
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

29

We will consider these comments before taking final action.

VI. Statutory and Executive Order Reviews

This action proposes to make a determination of attainment 

based on air quality and to suspend certain federal 

requirements, and thus, would not impose additional requirements 

beyond those imposed by state law. For that reason, this

proposed action:

 Is not a “significant regulatory action” subject to review 

by the Office of Management and Budget under Executive 

Order 12866 (58 FR 51735, October 4, 1993); 

 Does not impose an information collection burden under the 

provisions of the Paperwork Reduction Act (44 U.S.C. 3501 

et seq.);

 Is certified as not having a significant economic impact on 

a substantial number of small entities under the Regulatory 

Flexibility Act (5 U.S.C. 601 et seq.); 

 Does not contain any unfunded mandate or significantly or 

uniquely affect small governments, as described in the 

Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);

 Does not have Federalism implications as specified in 

Executive Order 13132 (64 FR 43255, August 10, 1999);
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

30

 Is not an economically significant regulatory action based 

on health or safety risks subject to Executive Order 13045 

(62 FR 19885, April 23, 1997);

 Is not a significant regulatory action subject to Executive 

Order 13211 (66 FR 28355, May 22, 2001); 

 Is not subject to requirements of Section 12(d) of the 

National Technology Transfer and Advancement Act of 1995 

(15 U.S.C. 272 note) because application of those 

requirements would be inconsistent with the CAA; and 

 Does not provide EPA with the discretionary authority to 

address disproportionate human health or environmental

effects with practical, appropriate, and legally 

permissible methods under Executive Order 12898 (59 FR 

7629, February 16, 1994).

In addition, this proposed action does not have Tribal 

implications as specified by Executive Order 13175 (65 FR 67249, 

November 9, 2000), because the SIP obligations discussed herein 

do not apply to Indian Tribes and thus this proposed action will 

not impose substantial direct costs on Tribal governments or 

preempt Tribal law.

List of Subjects in 40 CFR Part 52
This document is a prepublication version, signed by Alexis Strauss, Acting Regional Administrator, EPA Region 9, on 6/26/2013. We

have taken steps to ensure the accuracy of this version, but it is not the official version.

31

Environmental protection, Air pollution control,

Incorporation by reference, Particulate matter, Nitrogen oxides, 

Sulfur oxides, Reporting and recordkeeping requirements.

_ _________________ _____________________

Dated: Jared Blumenfeld

Regional Administrator,

Region IX.