JANICE K. BREWER 

GOVERNOR 

STATE OF ARIZONA 

May 25,2011 

Jared Blumenfeld, Regional Administrator 

EP A Region IX 

75 Hawthome Street 

San Francisco, CA 94105-3901 

ExECUTIVE OFFICE 

SUBJECT; Designation Recommendations for the 2010 Primary Sulfur Dioxide National 

Ambient Air Quality Standard 

Dear Mr. Blumenfeld: 

Pursuant to Section 107(d) of the Clean Air Act and your correspondence dated March 29,2011 , 

Arizona recommends the following designations for the 2010 primary national ambient air 

quality standard (NAAQS) for sulfur dioxide (S02). These recommendations exclude Indian 

Country (as defined in federal law, 18 USC 1151), over which Arizona does not have 

jurisdiction. 

Arizona recommends that the following complete counties (except for Indian Country) be 

designated unclassifiable for the primary sulfur dioxide NAAQS: 

Apache County 

Cochise County 

Coconino County 

Graham County 

Greenlee County 

La Paz County 

Maricopa County 

Mohave County 

Navajo County 

Pima County 

Santa Cruz County 

Yavapai County 

Yuma County 

In addition, Arizona recommends that Gila County and Pinal County (except for Indian 

Country), except those portions described below, be designated un classifiable for the primary 

sulfur dioxide NAAQS. 

1700 WEST WASHINGTON STREET, PHOENIX, ARIZONA 85007 

602-542 -4331 • FAX 602-542-7602 
Jared Blumenfeld, Regional Administrator 

May 25,2011 

Page 2 of3 

Arizona recommends that two separate and distinct areas, the existing Hayden and Miami S02 

planning areas be designated non attainment as follows: 

Hayden S02 Planning Area (Gila County [part] and Pinal County [part]) -

T4S, R14E 

T4S, R15E 

T4S, R16E (except that portion in Indian Country) 

T5S, RI4E 

T5S, RI5E 

T5S, RI6E (except that portion in Indian Country) 

T6S, RI4E 

T6S, R15E 

T6S, RI6E (except that portion in Indian Country) 

Miami S02 Planning Area (Gila County [part]) -

T2N, RI4E 

T2N, RI5E 

TIN, R13E (only that portion in Gila County) 

TIN, RI4E 

TIN, RI5E 

TIS, RI4E (only that portion in Gila County) 

TIS, RI4 1I2E 

TIS, RI5E 

Arizona's unclassifiable recommendations are based on those areas that have no monitored 

violations but are without current modeling information. Arizona's two recommended 

nonattainment areas include all areas with monitored violations of the new standard as well as 

the primary emissions sources that likely contribute to those violations. Additional information 

and analysis to support the recommendations are contained in the enclosed Arizona Air Quality 

Designations, Final Proposed Boundary Recommendationsfor the 2010 Primary National 

Ambient Air Quality Standard for Sulfur Dioxide, April 25, 2011. 
Jared Blumenfeld, Regional Administrator 

May 25,2011 

Page 3 of3 

Should you have further questions, please contact Henry Darwin, Director, Arizona Department 

of Environmental Quality, at (602) 771-2204 or Eric Massey, Air Quality Division Director at 

(602) 771-2208. 

Janice K. Brewer 

Governor 

CC: Deborah Jordan, EPA Region IX 

Colleen McKaughan, EPA Region IX 

William Wiley, Maricopa County Air Quality Department 

Ursula Kramer, Pima County Department of Environmental Quality 

Don Gabrielson, Pinal County Air Quality Control District 
Janice K. Brewer 

Governor 

May 2,2011 

ARIZONA DEPARTMENT 

OF 

ENVIRONMENTAL QUALITY 

1110 West Washington Street • Phoenix, Arizona 85007 

(602) 771-2300 • www.azdeq.gov 

The Honorable Janice K. Brewer, Governor 

State of Arizona 

1700 West Washington 

Phoenix, AZ 85007 

Re: Sulfur Dioxide Non-attainment Area Boundary Recommendations 

Dear Governor Brewer: 

Henry R. Darwin 

Director 

In 2010, EPA established the I-hour National Ambient Air Quality Standards (NAAQS) for 

sulfur dioxide and revoked the previous 24-hour and annual NAAQS for sulfur dioxide 

established in 1971. Under Clean Air Act Section 107(d), states must make recommendations for 

areas that meet, cannot be classified, or do not meet new or revised NAAQS within one year 

following the promulgation of such standards. 

Under A.R.S. § 49-405(C)(4), the Arizona Department of Environmental Quality must finalize 

its proposed recommendations and supporting documents and submit them to· you not later than 

one month before your recommendations are due to EPA. The EPA deadline for the submission 

of proposed boundary recommendations is June 2, 2011; 

Attached to this letter are ADEQ's analysis of, and proposed boundary recommendations for, the 

2010 I-hour NAAQS for sulfur dioxide, as well as the responses to public comments that have 

been received. Based on monitored violations of the new standard, two separate areas are 

proposed for designation as non-attainment: the Hayden sulfur dioxide planning area in Gila and 

Pinal Counties and the Miami sulfur dioxide planning area in Gila County. Both areas are 

centered on operating copper smelters, the primary emissions sources in their respective areas, 

and cover the same areas ofland as the sulfur dioxide non-attainment areas for the previous 1971 

sulfur dioxide NAAQS. All other areas of the State are proposed as unclassifiable. 

If you have any questions, please contact me at (602) 771-2204, or Eric Massey, the Director of 

the Air Quality Division, at (602) 771-2288. 

Northern Regional Office 

1801 W. Route 66 • Suite 117 • Flagstaff, AZ 86001 

(928) 779-0313 

Southern Regional Office 

400 West Congress Street· Suite 433· Tucson, AZ 85701 

(520) 628-6733 

Printed on recycled paper 
Introduction 

Arizona Air Quality Designations 

Final Proposed Boundary Recommendations 

for the 

2010 Primary National Ambient Air Quality Standard for Sulfur Dioxide 

This document contains the current analysis of, and proposed boundary recommendations for, the 2010 1-

hour sulfur dioxide primary Na~ional Ambient Air Quality Standard (NAAQS). These recommendations 

follow an extensive public review process to solicit comment on the boundary recommendation. 

The proposed recommendations are based on currently available ambient monitoring data. At this time 

the Arizona Department of Environmental Quality proposes that the Governor recommend to the U.S. 

Environmental Protection Agency (EPA) that most counties within the' State be designated as 

unclassifiable. Due to monitored violations, two areas of the State are proposed as not meeting the new 

standard. ,The proposed nonattainment areas are the Hayden sulfur dioxide planning area in Gila and 

Pinal Counties (except that portion that is in Indian Country) and the Miami sulfur dioxide planning area 

in Gila County. 

Arizona does not make recommendations for any tribal lands as tribal lands are not within the State's 

jurisdiction. ADEQ respects tribal sovereignty and has worked to develop cooperative relationships with 

tribal air quality programs throughout the State. Nothing in this document should be interpreted to affect 

the designation of Indian Country. 

Background 

The U.S. Environmental Protection Agency is charged with developing air quality standards for the 

protection of human health and the environment. As required by the Clean Air Act (CAA), EPA set 

primary and secondary National Ambient Air Quality Standards for six' common air pollutants.! 

Maximum pollution levels or limits that are based on human health are called primary standards. Limits 

intended to prevent environmental and property damage are called secondary standards. EPA is also 

required to periodically evaluate those standards and revise them if scientific analyses indicate new 

standards would be more protective of public health and welfare. 

Among the pollutants for which EPA has set air quality standards is sulfur dioxide (S02). Sulfur dioxide 

is part of a group of highly reactive gasses known as "oxides of sulfur" or SOx. The air quality standards 

for S02 are designed to protect against exposure to the entire group of sulfur oxides. S02 is linked to a 

number of adverse effects on the respiratory system, particularly for at-risk populations, including 

children, the elderly, and asthmatics. Examples of sources of S02 emissions include fossil fuel 

combustion and the extraction of metal from ore. 

In 2010 EPA completed a review of the primary S02 standards and replaced the existing annual and 24-

hour standards with a,-l-hour standard to better protect public health by reducing exposure to elevated 

short-term concentrations of S02 (see 75 FR 35520; June 22, 2010).1 Table 1 compares the level of the 

2 

See http://www.epa.gov/air/criteria.html for a complete list of National Ambient Air Quality Standards. 

A review of the secondary S02 standard is expected to be completed in 2012. 

Final Proposed S02 Boundary Recommendations April 25, 2011 
1971 primary sulfur dioxide standards to the new 2010 standard. EPA also revised the ambient air 

monitoring requirements for S02. Additional information about EPA's, action is available at 

http://www.epa.gov/ttnlnaaqs/standards/s02/s _ s02 _ index.html. 

0.14 parts per million 

(365 llg/m3) 

75 parts per billion (ppb) 

(0.075 parts per million) 

Area Designation Approach 

annual 

24 hours 

1 hour 

year 

Not to be exceeded more than 

once in a calendar year 

Three-year average of the 99th 

percentile of the annual 

distribution of daily maximum 1-

hour average concentrations, 

calculated for each monitor 

Under Clean Air Act Section 1 07( d), states must make recommendations for 'areas that meet, cannot be 

classified, or do not meet new or revised National Ambient Air Quality Standards within one year 

following the promulgation of such standards. State recommendations for the 2010 I-hour sulfur dioxide 

standard are due to EPA byJune 2, 2011. EPA anticipates promulgating final area designations by June 

2,2012.3 

Specifically, states must submit to EPA, attainment (meets or does not contribute to ambient air quality in 

areas that do not meet the air quality standard), unclassifiable (cannot be classified as meeting or not 

meeting the standard based on availabie information), and nonattainment recommendations for all areas 

of the state. Section 107(d)(1)(A)(i) of the Clean Air Act defines a nonattainment area as " ... any area 

that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the 

national primary or secondary ambient air quality standard/or the pollutant... " 

EPA anticipates a hybrid monitoring and modeling approach for implementing the new'standard and as a 

process for assessing and designating areas relative to the new standard. In the final rule EPA states that 

"for a short term I-hour S02 standard, it is more technically appropriate, efficient, and effective to use 

modeling as the principal means of assessing compliance for medium to large sources, and to rely more 

on monitoring for groups of smaller sources and sources not as conducive to modeling." EPA also 

expects " ... to issue further guidance regarding implementation, particularly concerning issues that may 

arise regarding the application of refined dispersion modeling under this revised approach ... II On the 

subject of initial designations EPA explains -

"For initial designations that will be finalized in June 2012, States should use monitoring 

data from the existing S02 network for the years 2008-2010, as well as any refined S02 

See Primary National Ambient Air Quality Standardfor Sulfur Dioxide, 75 FR 35520; June 22, 2010. 

Final Proposed S02 Boundary Recommendations April 25, 2011 2 
dispersion modeling·(see Appendix W to 40 CFR Part 51) for sources that may have the 

potential to cause or contribute to a NAAQS violation, provided that it is recent and 

available. EPA will then issue designations based on the record of information for that 

area. Under our anticipated approach, an area that has monitoring data or refined 

modeling results showing a violation of the NAAQS would be designated as 

"nonattainment." An area that has both monitoring data and appropriate modeling 

results showing no violations would be designated as "attainment." All other areas, 

including those with S02 monitors showing no violations but without modeling showing 

no violations, would be designated as "unclassifiable." Areas with no S02 monitors at 

all i.e., "rest of State," would be designated as "unclassifiable" as well." 

"Any area initially designated "nonattainment" or "unclassifiable" could request 

redesignation to "attainment" after an assessment based on air quality modeling, 

conducted in accordance with the new guidance, and available monitoring data indicates 

that the standard has been met, as well as meeting all other requirements of the CAA for 

redesignation to attainment." 

Bec.ause EPA has only recently finalized the designation guidance necessary to conduct dispersion 

modeling analyses, and because there is no other modeling analyses of which ADEQ is aware, Arizona 

can only make initial designation recommendations based on available monitoring information. The 

proposed designations include nonattainment recommendations for two separate areas of the state with 

monitored violations. Modeling analyses to refine the recommended nonattainment area boundaries, if 

necessary, and to evaluate unclassifiable areas will be completed following the release of EPA's expected 

implementation guidance.4 

Ambient Monitoring Network 

Currently fourteen sulfur dioxide ambient monitoring sites are operated in six counties across Arizona. 

Six of these sites are operated by the Arizona Department of Environmental Quality (ADEQ), Maricopa 

County Air Quality Department (MCAQD), and the Pima County Department of Environmental Quality 

(PDEQ). The remaining sites are operated by the National Park Service (NPS) and industrial sources. 

These ambient data provide information on population exposure, source impacts, and pollutant transport. 

Monitor locations are illustrated in Figure 1. 

4 On March 24, 2011, EPA released guidance entitled Area Designations/or the 2010 Revised Primary Sulfur 

Dioxide National Ambient Air Quality Standards. The guidance contains information on factors EPA intends to 

evaluate in determining boundaries for areas designated nonattainment as well as modeling guidance for states to 

use to support designation recommendations. EPA plans to issue additional guidance for developing plans for 

implementing the standard following t1,le initial designation process. 

Final Proposed S02 Boundary Recommendations April 25, 2011 3 
Figure 1: Arizona Sulfur Dioxide Ambient Monitoring Networks 

502 MONITOR OWNER 100 

II ADEQ 

• ADEQ/SOURCE 

II MCDEQ 

lID PDEQ 

A NPS 

II SOURCE ~PJrg~ December 21. 2010 Aulhor- N Caroll 

Final Proposed S02 Boundary Recommendations April 25, 2011 4 
Ambient data from ADEQ, MCAQD, and PDEQ monitors are collected and reported to EPA's Air 

Quality System (AQS) database by each responsible agency. Design values are the statistics that are 

compared to the level of the air quality standards to determine compliance with the NAAQS. The design 

value for the new primary S02 NAAQS is the 3-year average of annual 99th percentile daily maximum 1-

hour values for a monitoring site. The 2007-2009 design values for agency monitors are shown in Table 

2. Design values for 2008-2010 will be provided upon completion of required quality assurance 

procedures. Data for the I-hour S02 standard from source operated sites are not currently available. NPS 

monitors in Coconino County are related to the Regional Haze IMPROVE program and are not federal 

reference or equivalent method monitors. 

Monitoring sites in the metropolitan areas of Phoenix (Maricopa County) and Tucson (Pima County) 

recorded design values of less than 14 percent of the I-hour NAAQS. Two source impact monitors in 

Gila County, located near the Hayden and Miami copper smelters, show violations of the new NAAQS. 

The number of days when the maximum hourly S02 concentrations at the Miami Ridgeline monitor 

exceeded 75 ppb totaled more than 20 for each year in the 2007-2009 analysis period. The number of 

days when the maximum hourly S02 concentration at the Hayden Old Jail monitor exceeded 75 ppb 

totaled more than 100 for each year in the same 3-year period. A monitor that records less than four 

exceedances per year ensures attainment of the standard. 5 . 

The Ridgeline monitor is located within the eight townships that comprise the Miami sulfur dioxide 

planning area. The planning area, centered on the Miami primary copper smelter, the dominant source of 

S02 emissions in the area, was designated by operation of law as nonattainment for the 1971 primary 

standards following the Clean Air Act amendments of 1990. Due to implementation of permanent and 

enforceable control measures, the area achieved attainment in 1984. A plan demonstrating maintenance 

of the standards was submitted to EPA in 2002. EPA subsequently redesignated the area to attainment in 

2007 (see 72 FR 3061; January 24,2007). 

Similar to Miami, the Hayden Old Jail monitor is located within the Hayden sulfur dioxide planning area 

near the Hayden primary copper smelter. Due to implementation of permanent and enforceable control 

5 Assumes 100% data collection. 

Final Proposed S02 Boundary Recommendations April 25, 2011 5 
measures, the area achieved attainment in 1989. A plan demonstrating maintenance of the 1971 primary 

standards in the area's nine townships was submitted to EPA in 2002. EPA action on the plan is still 

pending. 

The new S02 standard also requites changes to the ambient air monitoring network. ill the final rule EPA 

is relying on "monitoring for groups of smaller sources and sources not as conducive to modeling" as a 

means of assessing compliance with the standard. 

As such, the final monitoring regulations require monitors to be placed in Core Based Statistical Areas 

(CBSAs) based on a population weighted emissions index (PWEI) as follows: 

- 3 monitors in CBSAs with index values of 1,000,000 or more, 

- 2 monitors in CBSAs with index values less than 1,000,000 but greater than 100,000, and 

1 monitor in CBSAs with index values greater than 5,000. 

The PWEI is calculated by mUltiplying the popUlation of the CBSA by its tons per year sulfur dioxide 

emissions and dividing the product by 1,000,000. Table 3 shows Arizona CBSAs and the calculated 

PWEI for each. Currently, minimum monitoring requirements are met. 

Final Proposed S02 Boundary Recommendations April 25, 2011 6 
Table3:Ev,a1uatioliot1.b.ieDi-Moi:ii(onn2tReqUii.em"D.fs~f()i;AifiZ6ilit ' ....•.. ?< ...• <: ... 

Co~~~~t'~~>i)(fi~~~]~I~~.~';"I:~cv1;,=~~f ,;~i~.,· None 20,747 71,118 'I(A~ache} 1,475 o o o 

Sierra Vista-Douglas 

I (Cochise) 3,826 127,757 489 o o o 

Flagstaff 

I (Coconino} 4,772 124,953 596 o o o 

Payson 

I (Gila) 20,342 52,209 1,062 o 2 o 

Safford 139 41,398 (Graham & Greenlee} 6 o o o 

None 148 20,256 I (La Paz} 

3 o o o 

Phoenix-Mesa-Scottsdale 5,276 4,039,182 l(Marico~a & Pinal) 24,370 1 3 o 

Lake Havasu City-Kingman 

I (Mohave} 

901 193,035 174 o o o 

Show Low 24,062 111,399 I (Navajo) 2,680 o o o 

Tucson 6,157 946,362 I (pima} 5,826 1 1 o 

Nogales 

I(Santa Cruz} 115 43,080 5 o o o 

Prescott 1,912 208,014. (Yavapai) 398 o o o 

Yuma 

I (Yuma) 555 187,555 104 o o o 

* Includes only those monitors operated by ADEQ, MCAQD, and PDEQ. 

Final Proposed S02 Boundary Recommendations April 25, 2011 7 
Emissions 

Section 107 of the Clean Air Act requires that, in addition to violating areas, areas that contribute to 

violations of ambient air quality standards in a nearby area be included as part of a nonattainment area. 

Table 4 is presented to characterize county level emissions and sources. . 

Counties with the highest emissions rates are associated with· electric generating facilities and the 

smelting of sulfide copper ore. For example, more than 98 percent of total emissions in Apache County . 

and more than 91 percent in Navajo County are attributable to the "Fuel Combustion Electric Utility" 

source category of the 2005 National Emissions Inventory. In Gila County, the location of the Hayden 

and Miami copper smelters, greater than 98 percent of total emissions are in the "Metals Processing" 

category. 

By contrast, the largest source category in the most populated county, Maricopa County, is "OffHighway," contributing 58 percent of the total County emissions inventory. 

Because there is no currently available modeling information for the I-hour standard, sources that may be 

contributing to nonattainment in areas where there is no ambient monitoring data will be analyzed in 

future using EPA guidance. 

Source: U.S. Environmental Protection Agency, National Emission Inventory (NEI) database for 2005 

(Version 2, created in January 2009). 

Summary of Monitoring and Emissions Information and Next Steps 

Based on available ambient monitoring data and absence of current modeling analyses, the proposed 

designation for the majority of the State is "unclassifiable" for the 2010 I-hour primary sulfur dioxide 

Final Proposed S02 Boundary Recommendations April 25, 2011 8 
NAAQS. ADEQ is proposing to recommend that two separate and distinct areas, the existing Hayden 

and Miami S02 planning areas be designated nonattainment. 

As in the past, EPA's expected approach is to use the' county boundary as the "presumptive" 

nonattainment boundary. Because of ADEQ's previous planning area determinations, ADEQ is proposing 

to recommend that the Payson CBSA (Gila County) is not an appropriate nonattainment area boundary. 

EPA's March 24, 2011, guidance lists five factors to consider in evaluating alternative boundaries for 

nonattainment areas: 

1) air quality data; 

2) emissions-related data (location of sources and potential contribution to ambient S02 

concentrations); , 

3) meteorology (weather/transport patterns); 

4) geography/topography (mountain ranges or other air basin boundaries); and 

5) jurisdictional boundaries (e.g., counties, air districts, pre-existing nonattainment areas, 

reservations, metropolitan planning organizations). 

The recommended Hayden and Miami nonattainment areas: 

- include all monitors violating the I-hour S02 standard for the period 2008-2010, 

- include the primary emissions sources that likely contribute to monitored violations of the I-hour 

S02 NAAQS (the Hayden and Miami primary copper smelters), 

include mountainous complex terrain that separates the emissions sources from other areas of the 

County, and impacts dispersion (elevations range from 2,000 to 7,000 feet above sea level). 

- are identical to the existing S02 planning areas (except that portion of the Hayden planning area 

that is in Indian Country) and therefore include the area of applicability for S02 emissions control 

measures designed to bring the Hayden and Miami areas into attainment for the 1971 standards. 

Additional information that warrants consideration in relation to emissions impacts in the Hayden and 

Miami areas include: 

- the size of Gila County (Gila County at 4,796 square miles nearly equals the land area of the state 

of Connecticut at 4,845), and 

- the location of emissions sources and violating monitors relative to the County boundaries (the 

distance from the violating monitor in Hayden is less than 1/2 mile from the southwest Gila 

County border and more than 100 miles from the northern Gila County border). 

As an example of size disparity, a violating monitor in Middlesex County, Connecticut, would result in a 

presumptive nonattainment area boundary of 369 square miles. A violating monitor in Gila County 

would result in a presumptive nonattainment area boundary of 4,796 square miles. Conceivably, 

emissions sources of similar type and magnitude could create a presumptive nonattainment area boundary 

in Arizona that is thirteen times larger than one in Connecticut. 

Based on available information it cannot be determined whether the recommended non attainment areas 

should be larger or smaller than the existing S02 planning areas. Additional analysis and modeling will 

be performed following the completion of the designation process and release of EPA's implementation 

guidance and, if appropriate, the recommended boundaries of the Hayden and Miami planning areas may 

be revised at that time. Per EPA's final rule, future analysis and modeling will also be performed .with 

EPA's guidance to determine the attainm,ent status of other counties in the State recommended as 

unclassifiable during this "initial" designation process. 

Final Proposed S02 Boundary Recommendations April 25, 2011 9 
Proposed Boundary Recommendations 

ADEQ proposes to recommend that all of the following counties (except for Indian Country) be 

designated unclassifiable for the I-hour sulfur dioxide NAAQS: 

Apache County 

Cochise County 

Coconino County 

Graham County 

Greenlee County 

La Paz County 

Maricopa County 

Mohave County 

Navajo County 

Pima County 

Santa Cruz County 

Yavapai County 

Yuma County 

In addition, ADEQ is proposing to recommend that Gila County and Pinal County (except for Indian 

Country), except those portions described below, be designated unclassifiable for the I-hour sulfur 

dioxide NAAQS. Figure 2 illustrates the draft recommended I-hour sulfur dioxide nonattainment areas. 

Table 5 describes by county and township the areas of the State ADEQ is proposing to recommend for 

unclassifiable and nonattainment designations. 

Final Proposed S02 Boundary Recommendations April 25, 2011 10 
Figure 2: Draft Recommended Sulfur Dioxide Nonattainment Area Boundaries 

?' 

N, R11E 

N,R11E T1N, R12E 

, R11E T1S, R12E 

S, R11E 

S,R11E T3S, R12E 

S, R11E T4S, R12E 

6S, R11E T6S,R12E! 

w 

S 

'" Ii: 

T5S,R13E T5S, R14E 

T6S,R13E T6S, R14E T6S, R15E T6S, R17E 

T7S, R13E T7S, R14E T7S, R15E T7S, R E T7S, R17E 

DRAFT RECOMMENDATION 

Hayden & Miami S02 Nonattainment Areas 

For the 2010 1-Hour Primary Standard 

./ .. 

::jist 

T6S, R18E T6S, 

T7S, R18E T7S, 

~QfQQtJ of Environmental QuaIi~ JanaK.Brt:Wv,~ur 

HetlJyR. DoltWin,Atling Direclnr I I Draft Recommended S02 NonattainmentAreas 

~~ ~ Urban Areas o 2.5 5 10 Miles 

E-----3 County I I I I I I I 

V·:/·::<I San Carlos Apache Nation January 10,2011 - Aulhor N. Caroll 

Final Proposed S02 Boundary Recommendations April 25, 2011 11 
Hayden Area: 

Gila County (part) and Pinal County (part) ................. . 

T4S, RI4E 

T4S, RISE 

T4S, R16E (except that portion in Indian Country) 

TSS, RI4E 

TSS, RISE 

TSS, RI6E (except that portion in Indian Country) 

T6S, R14E 

T6S, RISE 

T6S, R 16E (except that portion in Indian Country) 

Miami Area: 

Gila County (part) ............................................... ; ....... . 

T2N, R14E 

T2N, RISE 

TIN, RI3E (only that portion in Gila County) 

TIN,RI4E 

TIN,RISE 

TIS, R14E (only that portion in Gila County) 

TIS, RI4 1I2E 

TIS, RISE 

Rest of State (exceptthose portions in Indian 

Country) .................................................................. . 

Apache County 

Cochise County 

Coconino County 

Gila County (part) 

Remainder of County 

Graham County 

Greenlee County 

La Paz County 

Maricopa County 

Mohave County 

Navajo County 

Pima County 

Pinal County (part) 

Remainder of County 

Santa Cruz County 

Yavapai County 

Yuma County 

Final Proposed S02 Boundary Recommendations April2S, 2011 

Nonattainment 

N onattainment 

Unc1assifiable 

12 
RESPONSfVENESSS~Y 

to 

Testimony Taken at Oral Proceeding and Written Comments Received on 

Arizona Air Quality Designations, Draft Boundary Recommendations/or the 2010 Primary National 

Ambient Air Quality Standard/or Sulfur Dioxide, February 1,2011 

A public notice appeared on the Arizona Depaqment of Environmental Quality's (ADEQ) Website 

announcing the opening of a public comment period on February 3,2011, and in The Arizona Republic on 

March 10 and 11, 2011. Notice was provided to counties, municipalities, and other interested parties that 

would be included in a nonattainment area under the draft proposed recommendations via the U.S. Postal 

Service on February 2, 2011. Subsequent notice was provided to counties and other stakeholders 

statewide via e-mail. 

A stakeholder meeting was held on Thursday, March 17, 2011, and an oral proceeding on the draft 

recommendations was held on Tuesday, April 12, 2011, at the Arizona Department of Environmental 

Quality, Conference Room 145, 1110 West Washington Street, Phoenix, Arizona. The pubiic comment 

period closed on Tuesday, April 12, -2011, at 5:00 p.m. Oral and written comments received and the 

Arizona Department of Environmental Quality's responses are described below. 

1) Comment: A representative of ASARCO LLC, operator of the Hayden copper smelter, 

commented at the public hearing that ASARCO has "reviewed ADEQ's proposed nonattainment 

boundary designation and pending the outcome of litigation we do not have any objections to the 

proposed boundaries." 

Response: ADEQ appreciates the positive comments regarding the proposed recommended 

boundaries. 

2) -Comment: Written comment was received from Freeport-McMoRan Miami Inc. (FMMI), 

operator of the Miami copper smelter, in support of two separate nonattainment areas for the 

Hayden and Miami areas. FMMI noted that the Hayden and Miami Copper smelters are the 

primary sources of sulfur· dioxide (S02) emissions in their respective proposed nonattainment 

areas and experience with attaining the previous primary S02 standards demoristrates that the 

smelters have no effect on the other's S02 area. FMMI further stated that attainment of the 

previous primary S02 standards was achieved by permanent and enforceable control measures at 

the Miami smelter and maintaining the existing planning area boundaries provides consistency 

with proven boundaries. 

Response: ADEQ appreciates the positive comments regarding the proposed recommended 

boundaries. 

3) Comment: Written comment was received from the Gila County Division of Health and 

Emergency Services in support of two separate nonattainment areas for Hayden and Miami. The 

commenter noted that separate areas would allow issues particular to an area to be better 

addressed. . 

Response: ADEQ appreciates the positive comments regarding the proposed recommended 

boundaries. 

4) Comment: A written comment from Pinal County included a request that ADEQ advise the 

Governor to recommend to the U.S. Environmental Protection Agency (EPA) that Pinal County 

May 2, 2011 
receive an "unclassifiable" designation because there are no monitored or modeled violations of 

the 2010 primary standard in Pinal County. 

Response: ADEQ is proposing nonattainment boundaries for the 2010 primary S02 standard that 

are identical to the existing Hayden S02 nonattainment area. The existing nonattainment area 

was established (and approved by EPA) for the 1971 primary S02 standards as the area impacted 

by emissions from the Hayden copper smelter, the principal source of S02 emissions in the area. 

The existing and proposed boundaries are comprised of nine townships in Gila and Pinal Counties 

centered on the Hayden smelter. The smelter is located in southern Gila County approximately 

one mile from the Pinal County border. A violation nearly four times the level of the 2010 

standard has been recorded at an ADEQ operated monitor more than 112 mile from the smelter. 

Because of past boundary determinations, the proximity of the smelter to the GilaJPinal County 

line, and the lack of data supporting a smaller boundary recommendation, ADEQ has determined 

that it is reasonable to include the portion of the existing Hayden nonattainment area that is within 

Pinal County in the recommended nonattainment area boundary for the 2010 standard. 

May 2, 2011 2