ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 81 

[EPA-R09-OAR-2010-0718; FRL-] 

Determinations of Attainment by the Applicable Attainment Date 

for the Hayden, Nogales, Paul Spur/Douglas PM10 Nonattainment 

Areas, Arizona

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Direct final rule. 

SUMMARY: EPA has determined that the Hayden, Nogales, and Paul 

Spur/Douglas nonattainment areas in Arizona attained the 

National Ambient Air Quality Standard (NAAQS) for particulate 

matter with an aerodynamic diameter of less than or equal to a 

nominal ten micrometers (PM10) by the applicable attainment date 

of December 31, 1994. On the basis of this determination, EPA 

concludes that these three “moderate” nonattainment areas are 

not subject to reclassification by operation of law to 

“serious.” Lastly, on the basis of a review of more recent 

ambient monitoring data, EPA has determined that the Hayden, 

Nogales, and Paul Spur/Douglas nonattainment areas are not 

currently attaining the PM10 standard. 

DATES: This action is effective on [Federal Register: Insert 

date 60 days after the publication date] without further notice, 

unless EPA receives adverse comment by [Federal Register: Insert 

date 30 days after the publication date]. If EPA receives 
2 

adverse comment, we will publish a timely withdrawal in the 

Federal Register informing the public that the rule will not 

take effect. 

ADDRESSES: Submit comments, identified by docket number EPAR09-OAR-2010-0718, by one of the following methods: 

1. Federal eRulemaking Portal: www.regulations.gov. Follow 

the on-line instructions. 

2. E-mail: tax.wienke@epa.gov. 

3. Mail or deliver: Wienke Tax, Air Planning Office, EPA 

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 

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 www.regulations.gov or e-mail. 

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 an e-mail 

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

captured and included as part of the public comment. If you 
3 

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 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: Wienke Tax at telephone 

number: (415) 947-4192; e-mail address: tax.wienke@epa.gov, or 

the above EPA, Region IX address. 

SUPPLEMENTARY INFORMATION: Throughout this document, wherever 

“we”, “us” or “our” are used, we mean EPA. Information is 

organized as follows: 
4 

Table of Contents 

I. Background 

A. PM10 NAAQS 

B. Designation and Classification of PM10 Nonattainment Areas 

C. How Does EPA Make Attainment Determinations? 

D. What PM10 Planning has Occurred for the Hayden, Nogales, and 

Paul Spur/Douglas PM10 Nonattainment Areas? 

1. Hayden PM10 Nonattainment Area 

2. Nogales PM10 Nonattainment Area 

3. Paul Spur/Douglas PM10 Nonattainment Area 

II. EPA's Analysis 

A. What Does the Air Quality Data Show as of the December 31, 

1994 Attainment Date? 

1. Hayden PM10 Nonattainment Area 

2. Nogales PM10 Nonattainment Area 

3. Paul Spur/Douglas PM10 Nonattainment Area 

B. Does More Recent Air Quality Data Also Show Attainment? 

1. Hayden PM10 Nonattainment Area 

2. Nogales PM10 Nonattainment Area 

3. Paul Spur/Douglas PM10 Nonattainment Area 

III. EPA’s Final Action 

IV. Statutory and Executive Order Reviews 

I. Background 

A. PM10 NAAQS 
5 

The NAAQS are levels for certain ambient air pollutants set 

by EPA to protect public health and welfare. PM10, or particulate 

matter with an aerodynamic diameter less than or equal to a 

nominal 10 micrometers, is among the ambient air pollutants for 

which EPA has established health-based standards. On July 1, 

1987 (52 FR 24634), EPA promulgated two primary standards for 

PM10: a 24-hour standard of 150 micrograms per cubic meter 

(μg/m3

) and an annual PM10 standard of 50 μg/m3. EPA also 

promulgated secondary PM10 standards that were identical to the 

primary standards. 

Effective December 18, 2006, EPA revoked the annual PM10

standard but retained the 24-hour PM10 standard. 71 FR 61144 

(October 17, 2006). The 24-hour PM10 standard is attained when 

the expected number of days per calendar year with a 24-hour 

concentration in excess of the standard (referred to herein as 

“exceedance”), as determined in accordance with 40 CFR part 50, 

appendix K, is equal to or less than one.1 See 40 CFR 50.6 and 40 

CFR part 50, appendix K. 

B. Designation and Classification of PM10 Nonattainment 

 

1

 An exceedance is defined as a daily value that is above the 

level of the 24-hour standard (150 μg/m3) after rounding to the 

nearest 10 μg/m3

 (i.e., values ending in 5 or greater are to be 

rounded up). Thus, a recorded value of 154 μg/m3

 would not be an 

exceedance since it would be rounded to 150 μg/m3

 whereas a 

recorded value of 155 μg/m3 would be an exceedance since it would 

be rounded to 160 μg/m3. See 40 CFR part 50, appendix K, section 

1.0. 
6 

Areas 

Areas meeting the requirements of section 107(d)(4)(B) of 

the Clean Air Act (CAA or “Act”) were designated nonattainment 

for PM10 by operation of law and classified “moderate” upon 

enactment of the 1990 Clean Air Act Amendments. These areas 

included all former Group I PM10 planning areas identified in 52 

FR 29383 (August 7, 1987), as further clarified in 55 FR 45799 

(October 31, 1990), and any other areas violating the NAAQS for 

PM10 prior to January 1, 1989. A Federal Register notice 

announcing the areas designated nonattainment for PM10 upon 

enactment of the 1990 Amendments, known as “initial” PM10

nonattainment areas, was published on March 15, 1991 (56 FR 

11101) and a subsequent Federal Register document correcting the 

description of some of these areas was published on August 8, 

1991 (56 FR 37654). 

As former “group I” areas, the Hayden/Miami2 and Paul 

Spur/Douglas3 areas were included in the list of initial moderate 

 

2

 On March 28, 2007, EPA approved a request by the State of 

Arizona to split the Hayden/Miami PM10 nonattainment area into 

two separate PM10 nonattainment areas. See 72 FR 14422 (March 28, 

2007). In our March 28, 2007 direct final rule, we also 

determined that the Miami PM10 nonattainment area had attained 

the PM10 NAAQS. In today’s action, we have determined that the 

Hayden PM10 nonattainment area attained the PM10 NAAQS by the 

applicable attainment date. The Hayden planning area straddles 

Gila and Pinal counties at the confluence of the Gila and San 

Pedro rivers in east central Arizona. The nonattainment area 

covers roughly 700 miles of mountainous terrain. Cities and 

towns within this area include Kearney (population roughly 
7 

PM10 nonattainment areas. Nogales, a former “Group II” area, was 

included in the initial list of moderate PM10 nonattainment areas 

based on monitored violations of the PM10 NAAQS prior to January 

1, 1989.4 Later in 1991, we codified the PM10 nonattainment 

designations and moderate area classifications in 40 CFR part 

81. See 56 FR 56694 (November 6, 1991). For “moderate” 

nonattainment areas such as the three Arizona areas that are the 

subject of this document, CAA section 188(c) of the 1990 Amended 

Act establishes an attainment date of December 31, 1994. The 

designations, classifications, and boundaries of these three 

Arizona nonattainment areas are codified at 40 CFR 81.303. 

C. How Does EPA Make Attainment Determinations? 

Section 188(b)(2) of the Act requires EPA to determine 

within six months of the applicable attainment date whether, 

based on air quality data, PM10 nonattainment areas attained the 

PM10 NAAQS by that date. Generally, EPA determines whether an 

 

2,800), Hayden (population roughly 800), and Winkelman 

(population roughly 400). 

3

 The Paul Spur/Douglas planning area covers approximately 220 

square miles along the border with Mexico within Cochise County. 

Cities and towns within this area include Douglas (population 

roughly 20,000) and Pirtleville (population roughly 1,500). The 

population of Agua Prieta, Mexico, which lies just across the 

border from Douglas is roughly 70,000. 

4

 The Nogales planning area covers approximately 70 square miles 

along the border with Mexico within Santa Cruz County. The only 

significant population center in this area is the city of 

Nogales with a population of roughly 21,000. The population of 

Nogales, Mexico, which lies just across the border from Nogales, 

Arizona is roughly 160,000. 
8 

area’s air quality is meeting the PM10 NAAQS based upon complete 

(minimum of 75 percent of scheduled PM10 samples recorded), 

quality-assured data gathered at established state and local air 

monitoring stations (SLAMS) and national air monitoring stations 

(NAMS) in the nonattainment area and entered into the EPA Air 

Quality System (AQS) database. Data from air monitors operated 

by State/local/tribal agencies in compliance with EPA monitoring 

requirements must be submitted to AQS. EPA relies primarily on 

data in AQS when determining the attainment status of an area. 

See 40 CFR 50.6; 40 CFR part 50, appendix J; 40 CFR part 53; 40 

CFR part 58, appendix A. EPA will also consider air quality data 

from other air monitoring stations in the nonattainment area 

provided that the stations meet the Federal monitoring 

requirements for SLAMS, including the quality assurance and 

quality control criteria in 40 CFR part 58, appendix A. 40 CFR 

58.14 (2006) and 58.20 (2007);5 71 FR 61236, 61242 (October 17, 

2006). All valid data are reviewed to determine the area's air 

quality status in accordance with 40 CFR part 50, appendix K. 

Attainment of the 24-hour PM10 standard is determined by 

calculating the expected number of exceedances of the standard 

in a year. The 24-hour PM10 standard is attained when the 

 

5

 EPA promulgated amendments to the ambient air monitoring 

regulations in 40 CFR parts 53 and 58 on October 17, 2006. See 

71 FR 61236. The requirements for Special Purpose Monitors were 

revised and moved from 40 CFR 58.14 to 40 CFR 58.20. 
9 

expected number of exceedances averaged over a three-year period 

is less than or equal to one at each monitoring site within the 

nonattainment area. Generally, three consecutive years of air 

quality data are required to show attainment of the 24-hour PM10

standard. See 40 CFR part 50 and appendix K.6

To demonstrate attainment of the 24-hour PM10 standard at a 

monitoring site, the monitor must provide sufficient data to 

perform the required calculations in 40 CFR part 50, appendix K. 

The amount of data required varies with the sampling frequency, 

data capture rate and the number of years of record. In all 

cases, three years of representative monitoring data that meet 

the 75 percent criterion of the previous paragraph should be 

utilized, if available, and would suffice. More than three years 

may be considered, if all additional representative years of 

data meeting the 75 percent criterion are utilized. Data not 

meeting these criteria may also suffice to show attainment; 

however, such exceptions must be approved by the appropriate 

Regional Administrator in accordance with EPA guidance. See 40 

CFR part 50, appendix K, section 2.3. 

D. What PM10 Planning has Occurred for the Hayden, Nogales, and 

Paul Spur/Douglas PM10 Nonattainment Areas? 

 

6

 Because the annual PM10 standard was revoked effective 

December 18, 2006, see 71 FR 61144 (October 17, 2006), this 

document discusses only attainment of the 24-hour PM10 standard. 
10 

Along with the new designations, classifications, and 

attainment dates, the CAA as amended in 1990 also established 

new planning requirements. All initial moderate PM10

nonattainment areas had the same applicable attainment date of 

December 31, 1994. States containing initial moderate PM10

nonattainment areas were required to develop and submit to EPA 

by November 15, 1991, a state implementation plan (SIP) revision 

providing for implementation of reasonably available control 

measures (RACM) for the control of PM10, and either a 

demonstration that the plan would provide for attainment by the 

applicable attainment date (December 31, 1994) or a 

demonstration that attainment by such date was impracticable. 

See CAA section 189(a). 

1. Hayden PM10 Nonattainment Area

 By November 15, 1991, States were required to submit SIP 

revisions addressing certain CAA requirements for initial PM10

nonattainment areas. The State of Arizona relied upon a SIP 

revision (“Final PM10 State Implementation Plan for the Hayden 

Group I Area,” September 1989) (herein referred to as the “1989 

Hayden PM10 Plan”) that it had submitted on October 16, 1989 to 

meet the requirements of the CAA as amended in 1990 for the 

Hayden/Miami moderate PM10 nonattainment area. See letter from 

Edward Z. Fox, Director, Arizona Department of Environmental 

Quality (ADEQ), to Daniel W. McGovern, Regional Administrator, 
11 

EPA Region IX, dated February 3, 1992. The inventory in the 1989 

Hayden PM10 Plan identifies the ASARCO copper smelter and related 

sources, such as the smelter stack, copper ore tailings, ore 

crushing, the slag dump, road dust, smelter building fugitives, 

and copper ore, as the principal sources of PM10 emissions in the 

Hayden portion of the Hayden/Miami PM10 nonattainment area. 

In 1994, we proposed a limited approval and limited 

disapproval of the 1989 Hayden PM10 Plan. See 59 FR 36116 (July 

15, 1994). In our 1994 proposed action, we identified 

deficiencies in the 1989 Hayden PM10 Plan including the failure 

of the plan to address the Miami portion of the Hayden/Miami PM10

nonattainment area and the failure to meet the general 

monitoring requirements for the entire nonattainment area. (As 

noted above in footnote 2, we have since approved ADEQ’s request 

to split the Hayden and Miami portions of the area into separate 

PM10 nonattainment areas.) We have not finalized our 1994 

proposed limited approval/limited disapproval or otherwise taken 

action on the 1989 Hayden PM10 Plan. 

2. Nogales PM10 Nonattainment Area

 Arizona did not submit the required moderate PM10 plan by 

the November 15, 1991 deadline for the Nogales nonattainment 

area, and on December 16, 1991, we made a finding of failure to 

submit the moderate PM10 plan for Nogales. See letter from Daniel 

W. McGovern, Regional Administrator, EPA Region IX, to Fife 
12 

Symington, Governor of Arizona, dated December 16, 1991. See 57 

FR 19906 (May 8, 1992). In response, on June 14, 1993, ADEQ 

submitted the “Final State Implementation Plan for the Nogales 

PM10 Nonattainment Area,” June 1993 (herein referred to as the 

“1993 Nogales PM10 Plan”), to EPA as a SIP revision. We found the 

plan to be complete and notified the State of our finding by 

letter dated November 30, 1993. 

 The 1993 Nogales PM10 Plan identifies emissions sources 

located in Mexico as the principal sources affecting ambient PM10

concentrations in the area, and includes an analysis which 

concludes that the plan would be adequate to attain the PM10

NAAQS but for emissions emanating from outside the United 

States. Section 179B (“International Border Areas”) of the CAA 

provides EPA with the authority to approve such a demonstration. 

We have not taken action to approve or disapprove the 1993 

Nogales PM10 Plan. 

3. Paul Spur/Douglas PM10 Nonattainment Area

 Similar to the situation in Hayden, the State of Arizona 

relied upon a SIP revision (“Final PM10 State Implementation Plan 

for the Paul Spur Group I Area,” July 1990) (herein referred to 

as the “1990 Paul Spur PM10 Plan”) that it had submitted prior to 

the CAA Amendments of 1990 (in this instance, June 25, 1990) to 

meet the requirements of the CAA as amended in 1990 for the Paul 

Spur portion of the Paul Spur/Douglas moderate PM10 nonattainment 
13 

area. See letter from Edward Z. Fox, Director, ADEQ, to Daniel 

W. McGovern, Regional Administrator, EPA Region IX, dated 

February 3, 1992. The 1990 Paul Spur PM10 Plan identifies the 

lime plant located at Paul Spur as the only significant source 

of emissions in the immediate vicinity and includes control 

measures for this source of emissions. 

ADEQ did not submit the required plan for the Douglas 

portion of the Paul Spur/Douglas nonattainment area by the 

November 15, 1991 deadline, and thus, on December 16, 1991, we 

made a finding of failure to submit a moderate PM10 plan for 

Douglas portion of Paul Spur/Douglas PM10 nonattainment area. See 

letter from Daniel W. McGovern, Regional Administrator, EPA 

Region IX, to Fife Symington, Governor of Arizona, dated 

December 16, 1991. See 57 FR 19906 (May 8, 1992). In response, 

on June 17, 1993, ADEQ submitted the “Final State Implementation 

Plan for the Douglas PM10 Nonattainment Area,” April 1993 (herein 

referred to as the “1993 Douglas PM10 Plan”), to EPA as a SIP 

revision. We found the plan to be complete by letter dated 

November 30, 1993. Similar to the Nogales plan, the 1993 Douglas 

PM10 plan identifies emissions sources located in Mexico as the 

principal sources of emissions affecting ambient PM10

concentrations in the area, and includes an analysis which 

concludes that the plan would be adequate to attain the PM10
14 

NAAQS but for emissions emanating from outside the United 

States. 

A decade later, and based on a number of years of ambient 

data showing that the standard had been attained, ADEQ withdrew 

the 1993 Douglas PM10 Plan. See letter from Stephen A. Owens, 

Director, ADEQ, to Wayne Nastri, Regional Administrator, EPA 

Region IX, dated December 22, 2004. Recently, ADEQ revoked the 

2004 withdrawal of the 1993 Douglas PM10 Plan; thus, once again, 

the plan is subject to EPA approval or disapproval action as a 

revision to the Arizona SIP. See letter from Benjamin H. 

Grumbles, Director, ADEQ, to Jared Blumenfeld, Regional 

Administrator, EPA Region IX, dated September 13, 2010. We have 

not taken action to approve or disapprove either the 1990 Paul 

Spur PM10 Plan or the 1993 Douglas PM10 Plan. 

II. EPA's Analysis

A. What Does the Air Quality Data Show as of the December 31, 

1994 Attainment Date? 

ADEQ is responsible for monitoring ambient air quality 

outside the metropolitan areas in Arizona. ADEQ submits 

monitoring network plan reports to EPA on an annual basis. These 

reports discuss the status of the air monitoring network, as 

required under 40 CFR part 58. Beginning in 2007, EPA reviews 

these annual plans for compliance with the applicable reporting 

requirements in 40 CFR 58.10. With respect to PM10, we have found 
15 

that ADEQ’s annual network plans meet the applicable 

requirements under 40 CFR part 58. See EPA letters to ADEQ 

concerning ADEQ’s annual network plan reports for years 2007, 

2008, and 2009 that have been placed in the docket for this 

rulemaking. Furthermore, we concluded in our Technical System 

Audit Report (September 2010) for ADEQ’s ambient air quality 

monitoring program (a copy of which has been placed in the 

docket) that ADEQ’s ambient air monitoring network currently 

meets or exceeds the requirements for the minimum number of 

monitoring sites designated as SLAMS for all of the criteria 

pollutants, and that all of the monitoring sites are properly 

located with respect to monitoring objectives, spatial scales 

and other siting criteria. 

1. Hayden PM10 Nonattainment Area

ADEQ has operated a PM10 monitor at the Old Town Jail site, 

which is near the center of the Town of Hayden, for many years, 

including the period 1992 through 1994. The Old Town Jail 

monitoring site is part of the ADEQ’s SLAMS network and is 

located roughly one-half mile west of the ASARCO smelter. During 

the 1992-1994 period, ADEQ used a filter-based method (lowvolume dichotomous monitor) to monitor ambient PM10

concentrations, sampling PM10 concentrations every sixth day. The 

Old Town Jail monitor was sited to provide PM10 concentration 
16 

data at a neighborhood scale7 for the purpose of determining 

source impacts from ASARCO operations. Table 1 below summarizes 

the PM10 concentration data collected at the Old Town Jail site 

over the 1992-1994 period. 

Table 1: Summary of PM10 Monitoring Data, Hayden Nonattainment 

Area, 1992-1994a

Monitoring Site 

Highest 24-hour PM10

Concentration (μg/m3

) 

Expected 

Exceedances 

 Per Year 

1992 1993 1994 1992-1994

Hayden Old Jail 85 68 67 0.0 

PM10 NAAQS = 150 μg/m3. a Source: AQS QuickLook report dated June 23, 2010. 

As noted above, to be considered “complete,” valid 

measurements must be made for 75% of all the scheduled sampling 

dates in each quarter of the year, and generally, three years of 

representative monitoring data that meet the 75 percent 

criterion should be utilized, where available. 

During the 1992-1994 period, the data collected by ADEQ 

meets the completeness criterion for all quarters except for the 

fourth quarter of year 1994, when the number of valid samples 

was one short of constituting a complete quarter. EPA may find 

that data not meeting the completeness criterion suffice to show 

attainment. See 40 CFR part 50, appendix K, section 2.3(b). 

 

7

 In this context, “neighborhood scale” refers to conditions 

throughout some reasonably homogeneous urban sub-region with 

dimensions of a few kilometers. See 40 CFR part 58, appendix D, 

section 4.6. 
17 

Relevant considerations that we take into account when 

evaluating whether data not meeting the completeness criterion 

would suffice include, but are not limited to, monitoring site 

closures/moves, monitoring diligence, consistency and levels of 

the valid concentration measurements that are available, and 

nearby concentrations. See, e.g., considerations taken into 

account for analogous circumstances involving evaluating of 

ambient lead (Pb) concentrations at 40 CFR part 50, appendix F, 

section 4(d). 

In this instance, we find that data that is available is 

sufficient to determine whether the area attained the standard 

by the applicable attainment date. First, we note the large 

extent to which the maximum monitored levels during the 1992-

1994 period (67 to 85 μg/m3 – see table 1 above) fall below the 

applicable standard (150 μg/m3). We also note that 11 of the 12 

quarters in question were complete (based on the 75% criterion), 

and that the one quarter that did not meet the criterion was but 

one sample short. Further, we have reviewed the monitoring data 

for year 1995, which is comprised of four quarters of data 

meeting the completeness criterion, and during which the maximum 

24-hour concentration was, at 108 μg/m3

, well below the standard, 

providing further evidence that the area attained by the 

applicable attainment date. 
18 

Based on our rationale presented above, we find the 

available data sufficient to determine whether the Hayden 

nonattainment area met the PM10 standard by December 31, 1994 

(i.e., the applicable attainment date), and based on our review 

of the air quality data during the three-year period ending with 

the December 31, 1994 attainment date (and summarized above in 

table 1), we find that the expected number of exceedances per 

year for the Hayden PM10 nonattainment area for 1992 to 1994 was 

0 days per year. With less than an annual expected exceedance 

rate for the 24-hour PM10 NAAQS of 1.0, these data represent 

attainment of the standard. Therefore, EPA has determined that 

the Hayden PM10 nonattainment area attained the PM10 NAAQS by the 

applicable attainment date. 

2. Nogales PM10 Nonattainment Area

ADEQ has operated a PM10 monitor at the Nogales Post Office 

site (300 North Morley Avenue) for many years, including the 

period 1992 through 1994. The Nogales Post Office monitoring 

site is part of the ADEQ’s SLAMS network and is located roughly 

0.4 mile north of the border with Mexico. During year 1994, ADEQ 

also collected a total of 120 samples of 24-hour-average ambient 

PM10 concentrations at three additional locations in Nogales, all 

of which were located north of the Post Office Site. 

During the 1992-1994 period, ADEQ used a filter-based 

method (low-volume dichotomous monitor) to monitor ambient PM10
19 

concentrations in the Nogales area. At the Nogales Post Office 

site, the sampling schedule was every sixth day. The Nogales 

Post Office monitor was sited to provide PM10 concentration data 

at a neighborhood scale for the purpose of determining 

population exposure. Table 2 below summarizes the PM10

concentration data collected in the Nogales area over the 1992-

1994 period. 

Table 2: Summary of PM10 Monitoring Data, Nogales Nonattainment 

Area, 1992-1994a

Monitoring Site 

Highest 24-hour PM10

Concentration (μg/m3

) 

Expected 

Exceedances 

 Per Year 

1992 1993 1994 1992-1994

Nogales Post Office 153 119 116 0.0 

885 North Carrillo 

Place 

-- -- 52 -- 

156 West Mariposa 

Road 

-- -- 59 -- 

1852 North Mastick 

Way 

-- -- 83 -- 

PM10 NAAQS = 150 μg/m3

. The 153 μg/m3 concentration measured in 

1992 does not represent an exceedance due to rounding 

conventions. See footnote 1 of this document for a description 

of the rounding conventions. Measurements at the North Carrillo, 

West Mariposa, and North Mastick sites were not collected in 

1992 or 1993. 

a Source: AQS QuickLook report dated June 23, 2010. 

As noted above, to be considered “complete,” valid 

measurements must be made for 75% of all the scheduled sampling 

dates in each quarter of the year, and generally, three years of 
20 

representative monitoring data that meet the 75 percent 

criterion should be utilized, where available. 

During the 1992-1994 period, 150 samples were collected at 

the Nogales Post Office site out of a total of 183 scheduled 

sample days. However, on a quarter-by-quarter basis, a number of 

quarters (one in 1992, three in 1993, and 1 in 1994) failed to 

meet the 75% completeness criterion. For three of the quarters 

that failed to meet the 75% criterion, the criterion was missed 

by a single sample day, and for the two other quarters that 

failed to meet the 75% criterion, the criterion was missed by 

two sample days. In summary, a substantial amount of data was 

collected during the quarters that failed to meet the 75% 

criterion, but not enough to meet the test. As noted above for 

the Hayden area, EPA may find that data not meeting the 

completeness criterion suffice to show attainment. See 40 CFR 

part 50, appendix K, section 2.3(b). 

Like Hayden, again, we find that data is available and 

sufficient to determine whether the Nogales area attained the 

standard by the applicable attainment date. First, despite a 

number of quarters that did not meet the 75% criterion, we note 

that a substantial amount of data was collected; and, other than 

two samples taken in year 1992 (1st high of 153 μg/m3

 and 2nd high 

of 147 μg/m3

), the ambient concentrations that were collected 

were consistently well below the 150 μg/m3 standard. Second, we 
21 

take note of the supplemental ambient PM10 monitoring data 

collected by ADEQ during 1994 showing ambient concentrations at 

sites north of the Post Office site well below the 150 μg/m3

standard (the maximum was 83 μg/m3 – see table 2, above). Lastly, 

we have reviewed the monitoring data for year 1995, which is 

comprised of 53 samples out of a total number of scheduled 

sample days of 61, and during which the maximum 24-hour 

concentration was, at 123 μg/m3

, well below the standard, 

providing further evidence that the area attained by the 

applicable attainment date. 

Based on our rationale presented above, we find the 

available data sufficient to determine whether the Nogales 

nonattainment area met the PM10 standard by December 31, 1994 

(i.e., the applicable attainment date), and based on our review 

of the air quality data during the three-year period ending with 

the December 31, 1994 attainment date (and summarized above in 

table 2), we find that the expected number of exceedances per 

year for the Nogales PM10 nonattainment area for 1992 to 1994 was 

0 days per year. With less than an annual expected exceedance 

rate for the 24-hour PM10 NAAQS of 1.0, these data represent 

attainment of the standard. Therefore, EPA has determined that 

the Nogales PM10 nonattainment area attained the PM10 NAAQS by the 

applicable attainment date. 

3. Paul Spur/Douglas PM10 Nonattainment Area
22 

ADEQ has operated PM10 monitors near the lime plant at Paul 

Spur (“Paul Spur monitor”) and within the City of Douglas 

(“Douglas monitor”) for many years, including the period 1992 

through 1994. Both sites are part of the ADEQ’s SLAMS network. 

The Paul Spur monitor is located near the intersection of Paul 

Spur Road and State Route 80. During the 1992-1994 period, the 

Douglas monitor was located at 15th Street Park, approximately 

one mile north of the border with Mexico. In 1998, ADEQ relocated the Douglas monitor to its current location, the Red 

Cross building just across from the park on 15th Street. 

During the 1992-1994 period, ADEQ used a filter-based 

method (low-volume dichotomous monitor) to monitor ambient PM10

concentrations at both the Paul Spur and Douglas sites, sampling 

PM10 concentrations every sixth day. The Paul Spur monitor was 

sited to provide PM10 concentration data at a middle scale8 for 

the purpose of determining source impacts from the chemical lime 

plant. The Douglas monitor was sited to provide PM10

concentration data at a neighborhood scale for the purpose of 

determining population exposure. Table 3 below summarizes the 

PM10 concentration data collected at the Paul Spur and Douglas 

monitors over the 1992-1994 period. 

 

8

 In this context, “middle scale” refers to conditions 

characteristic of areas from 100 meters to several kilometers. 

See 40 CFR part 58, appendix D, section 4.6. 
23 

Table 3: Summary of PM10 Monitoring Data, Paul Spur/Douglas 

Nonattainment Area, 1992-1994a

Monitoring Site 

Highest 24-hour PM10

Concentration (μg/m3

) 

Expected 

Exceedances 

 Per Year 

1992 1993 1994 1992-1994

Paul Spur Chemical 

Lime Plant 

132 69 77 0.0 

Douglas (15th Street 

Park) 

138 66 96 0.0 

PM10 NAAQS = 150 μg/m3

. a Source: AQS QuickLook report dated June 23, 2010. 

As noted above, to be considered “complete,” valid 

measurements must be made for 75% of all the scheduled sampling 

dates in each quarter of the year, and generally, three years of 

representative monitoring data that meet the 75 percent 

criterion should be utilized, where available. 

During the 1992-1994 period, the data collected by ADEQ 

meets the completeness criterion for all quarters at both the 

Paul Spur and Douglas monitors except for the second quarter of 

year 1992 at the Paul Spur monitor and the fourth quarter of 

year 1992 at both monitors. During the second quarter of 1992, 

the Paul Spur monitor was two samples short of the 75% 

criterion, and in the fourth quarter of 1992, both monitors were 

one sample short of the criterion. As noted for Hayden and 

Nogales, EPA may find that data not meeting the completeness 
24 

criterion suffice to show attainment. See 40 CFR part 50, 

appendix K, section 2.3(b). 

In this instance, we find that the available data is 

sufficient to determine whether the area attained the standard 

by the applicable attainment date. First, we note the large 

extent to which the maximum monitored levels during the 1992-

1994 period (132 μg/m3 at the Paul Spur monitor and 138 μg/m3 at 

the Douglas monitor – see table 3 above) fall below the 

applicable standard (150 μg/m3

). We also note that 10 of the 12 

quarters in question were complete (based on the 75% criterion) 

at the Paul Spur monitor and 11 of the 12 quarters in question 

were complete at the Douglas monitor, and that the quarters that 

did not meet the criterion were but one or two samples short. 

Further, we have reviewed the monitoring data for year 1995, 

which is comprised of three quarters of data meeting the 

completeness criterion at the Paul Spur monitor and four 

quarters of data meeting the completeness criterion at the 

Douglas site, and during which the maximum 24-hour concentration 

was, at 77 μg/m3

, (Paul Spur) and 63 μg/m3 (Douglas), well below 

the standard, providing further evidence that the area attained 

by the applicable attainment date. 

Based on our rationale presented above, we find the 

available data sufficient to determine whether the Paul 

Spur/Douglas nonattainment area met the PM10 standard by December 
25 

31, 1994 (i.e., the applicable attainment date), and based on 

our review of the air quality data during the three-year period 

ending with the December 31, 1994 attainment date (and 

summarized above in table 3), we find that the expected number 

of exceedances per year for the Paul Spur/Douglas PM10

nonattainment area for 1992 to 1994 was 0 days per year. With 

less than an annual expected exceedance rate for the 24-hour PM10

NAAQS of 1.0, these data represent attainment of the standard. 

Therefore, EPA has determined that the Paul Spur/Douglas PM10

nonattainment area attained the PM10 NAAQS by the applicable 

attainment date. 

B. Does More Recent Air Quality Data Also Show Attainment? 

1. Hayden PM10 Nonattainment Area

 Since 1994, ADEQ has continued to operate a PM10 monitor at 

the Old Town Jail in Hayden. ADEQ has, however, changed 

monitoring methods, and, for awhile, operated a second monitor 

for precision measurement (audit) purposes. Since the second 

quarter of 2009, ADEQ has operated a single TEOM (i.e., tapered 

element oscillating microbalance) monitor on a continuousrunning basis at the Old Town Jail site in Hayden. In addition, 

since 2003, the Pinal County Air Quality Control District (AQCD) 

has operated a PM10 hi-volume sampler on an every sixth day 

schedule along the Florence-Kelvin Highway near Riverside, 
26 

Arizona, in the western portion of the Hayden PM10 nonattainment 

area (“Riverside monitor”). 

While not all years since 1994 have complete data (based on 

the 75% criterion), only one exceedance (158 μg/m3 in 1997) at 

the Hayden site was monitored until year 2006, when ADEQ added 

the TEOM working in parallel with the one-day-in-six partisol 

sampler at the Old Town Jail site. In 2006 and 2007, four and 

five exceedances were measured by the TEOM, respectively. ADEQ 

did not operate the TEOM in 2008, and in 2009, ADEQ resumed 

operation of the TEOM beginning in the second quarter. Only one 

exceedance (225 μg/m3

) was measured by the TEOM over the final 

three quarters of 2009. Meanwhile, ADEQ continued operating the 

partisol sampler over the 2006-2008 period but discontinued the 

sampler after the end of the first quarter of 2009. At the 

Riverside monitor, Pinal County AQCD has measured no exceedances 

of the PM10 standard, and maximum 24-hour PM10 concentrations 

measured there are well below the standard. 

During the most recent three-year calendar period (2007-

2009), at the Hayden monitoring site, neither the partisol 

sampler nor the TEOM provide a complete data set for the purpose 

of determining whether the area is in currently attaining the 

standard. The partisol sampler provides data for 9 of the 12 

quarters, while the TEOM provides data for 7 of the 12 quarters. 

Based on the partisol sampler, this incomplete data set suggests 
27 

that the area is currently attaining the standard because no 

exceedances were measured. The samples collected using the TEOM, 

however, suggest otherwise, with a total of six exceedances over 

the discontinuous course of its operation. Based on the TEOM, 

six exceedances over the course of this period of time is 

sufficient for us to conclude that the Hayden PM10 nonattainment 

area is not currently attaining the standard. In 2010, through 

the first two quarters, the TEOM has not recorded any 

exceedances; if this trend continues, then, next year, based on 

2008-2010 data, the current attainment status of the Hayden area 

may change once again. 

2. Nogales PM10 Nonattainment Area

 Since 1994, ADEQ has continued to operate a PM10 monitoring 

site at the Post Office in Nogales, but has replaced the dichot 

sampler with a partisol sampler, and has added a continuousrunning beta attenuation monitor (BAM). 

The data from AQS indicates that, while the area attained 

the standard by the applicable attainment date, ambient PM10

concentrations worsened in the late 1990’s to the point where 

exceedances under current conditions have been measured nearly 

every year. Based on the past three calendar years (2007-2009) 

of complete quality-assured data, we find that the annual 

expected exceedance rate for the 24-hour PM10 NAAQS for the 

Nogales area is 9.7 (based on the BAM). Based on the partisol 
28 

sampler, the annual expected exceedance rate for the 24-hour PM10

NAAQS of 4.2, but the higher of the two samplers is used to 

determine whether the area is attaining the standard. Because 

the annual expected exceedance rate for the area (9.7) is 

greater than 1.0, we conclude that the area is not currently 

attaining the PM10 standard. 

EPA’s determination that the Nogales area is not currently 

attaining the PM10 standard does not result in reclassification 

of this “moderate” area to “serious” by operation of law because 

such reclassification is tied to air quality conditions “as of 

the attainment date,” (see CAA sections 179(c)(1) and 

188(b)(2)), and, as discussed in section II.A.2 of this 

document, we have concluded that the Nogales area attained the 

standard by the attainment date. We do, however, plan to address 

the PM10 planning needs for the Nogales area over the next few 

years. We also note that the Nogales planning area has been 

designated as nonattainment 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) (74 FR 58688, November 13, 

2009), which has triggered a separate air quality planning 

process. 

3. Paul Spur/Douglas PM10 Nonattainment Area

Since 1994, ADEQ has continued to operate PM10 monitoring 

sites near the Paul Spur Chemical Lime Plant (“Paul Spur 
29 

monitor”) and in the City of Douglas (“Douglas monitor”). At the 

Paul Spur monitoring site, ADEQ replaced the dichot sampler with 

a partisol sampler, and added a second partisol sampler for 

precision measurement purposes. Both monitors continue to run on 

a one-day-in-six monitoring schedule. At the Douglas monitoring 

site, ADEQ replaced the dichot sampler with a partisol sampler 

and, in 1998, re-located the monitor to a nearby location, the 

Red Cross building just across from the park on 15th Street, 

where it continues to operate today. 

The data from AQS indicates that only two exceedances of 

the PM10 standard have been measured in the Paul Spur/Douglas 

nonattainment area over the past 15 years. Both were measured at 

the Paul Spur monitoring site. One exceedance, 206 μg/m3

, was 

measured in 2003 and the other (159 μg/m3) was measured in 2008.9

Based on the past three calendar years (2007-2009) of complete 

quality-assured data, we find that the annual expected 

exceedance rate for the 24-hour PM10 NAAQS for the Paul 

Spur/Douglas area is 2.0 (which is calculated by taking into 

account the one-day-in-six monitoring schedule).10 Because the 

annual expected exceedance rate for the area (2.0) is greater 

 

9

 Both of these exceedances were flagged by ADEQ as exceptional 

events, but EPA has not concurred on the flags. 

10 The collocated (audit) monitor measured two exceedances 

during 2008, but on both sample-days, the primary monitor also 

took valid samples, and thus, the measurements from the colocated samplers are not used to report air quality from the 

site. See 40 CFR part 58, appendix A, section 3.2.5. 
30 

than 1.0, we conclude that the area is not currently attaining 

the PM10 standard. 

EPA’s determination that the Paul Spur/Douglas area is not 

currently attaining the PM10 standard does not result in 

reclassification of this “moderate” area to “serious” by 

operation of law because such reclassification is tied to air 

quality conditions “as of the attainment date,” (see CAA 

sections 179(c)(1) and 188(b)(2)), and, as discussed in section 

II.A.3 of this document, we have concluded that the Paul 

Spur/Douglas area attained the standard by the attainment date. 

We do, however, plan to address the PM10 planning needs for the 

Paul Spur/Douglas area over the next few years. 

III. EPA’s Final Action 

Under section 188(b)(2) of the Clean Air Act, and based on 

sufficient, quality-assured data, we find that the Hayden, 

Nogales, and Paul Spur/Douglas PM10 nonattainment areas attained 

the 24-hour PM10 NAAQS by the applicable attainment date, 

December 31, 1994. On the basis of this determination, EPA 

concludes that these three “moderate” nonattainment areas are 

not subject to reclassification to “serious” by operation of 

law. This action is not a redesignation to attainment under CAA 

section 107(d)(3) because we have not yet approved maintenance 

plans for these areas as meeting the requirements of section 
31 

175A of the CAA or determined that the areas have met the other 

CAA requirements for redesignation. 

On the basis of a review of more recent ambient monitoring 

data, EPA has determined that the Hayden, Nogales, and Paul 

Spur/Douglas nonattainment areas are not currently attaining the 

PM10 standard. EPA’s determination that the Hayden, Nogales, and 

Paul Spur/Douglas areas are not currently attaining the PM10

standard does not result in reclassification of these “moderate” 

areas to “serious” by operation of law because such 

reclassification is tied to air quality conditions “as of the 

attainment date,” (see CAA sections 179(c)(1) and 188(b)(2)), 

and EPA has determined that both areas attained the standard by 

the applicable attainment date. 

 We are publishing this rule without prior proposal because 

the Agency views this as a noncontroversial action and 

anticipates no adverse comments. However, in the proposed rules 

section of this Federal Register publication, EPA is publishing 

a separate document that will serve as the proposal should 

adverse comments be filed. This action will be effective 

[Federal Register: Insert date 60 days after the publication 

date], without further notice unless the EPA receives relevant 

adverse comments by [Federal Register: Insert date 30 days after 

the publication date]. 
32 

 If we receive such comments, then we will publish a 

document withdrawing the final rule and informing the public 

that the rule will not take effect. All public comments received 

will then be addressed in a subsequent final rule based on the 

proposed rule. We will not institute a second comment period. 

Parties interested in commenting should so at this time. If no 

such comments are received, the public is advised that this rule 

will be effective on [Federal Register: Insert date 60 days 

after the publication date] and no further action will be taken 

on the proposed rule. 

IV. Statutory and Executive Order Reviews 

This action merely makes a determination based on air 

quality data and does not impose any additional Federal 

requirements. For that reason, this 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.); 
33 

• 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); 

• 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, as appropriate, disproportionate human health or 

environmental effects, using practicable and legally 

permissible methods, under Executive Order 12898 (59 FR 

7629, February 16, 1994). 

In addition, this rule does not have tribal implications as 

specified by Executive Order 13175 (65 FR 67249, November 9, 

2000), because it will not impose substantial direct costs on 

tribal governments or preempt tribal law. 
34 

The Congressional Review Act, 5 U.S.C. 801 et seq., as 

added by the Small Business Regulatory Enforcement Fairness Act 

of 1996, generally provides that before a rule may take effect, 

the agency promulgating the rule must submit a rule report, 

which includes a copy of the rule, to each House of the Congress 

and to the Comptroller General of the United States. EPA will 

submit a report containing this action and other required 

information to the U.S. Senate, the U.S. House of 

Representatives, and the Comptroller General of the United 

States prior to publication of the rule in the Federal Register. 

A major rule cannot take effect until 60 days after it is 

published in the Federal Register. This action is not a “major 

rule” as defined by 5 U.S.C. 804(2). 

Under section 307(b)(1) of the Clean Air Act, petitions for 

judicial review of this action must be filed in the United 

States Court of Appeals for the appropriate circuit by [Federal 

Register: Insert date 60 days after the publication date]. 

Filing a petition for reconsideration by the Administrator of 

this final rule does not affect the finality of this action for 

the purposes of judicial review nor does it extend the time 

within which a petition for judicial review may be filed, and 

shall not postpone the effectiveness of such rule or action. 

Parties with objections to this direct final rule are encouraged 

to file a comment in response to the parallel notice of proposed 
rulemaking for this action published in the proposed rules 

section of today's Federal Register, rather than file an 

immediate petition for judicial review of this direct final 

rule, so that EPA can withdraw this direct final rule and 

address the comment in the proposed rulemaking. This action may 

not be challenged later in proceedings to enforce its 

requirements. (See section 307 (b) (2) . ) 

List of Subjects in 40 CFR Part 81 

Environmental protection, Air pollution control, National 

parks, Particulate matter, Wilderness areas. 

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

1 

Dated: ed Blumenfel 

gional Administrator, 

%PA Region IX.