JANICE 

### K. BREWER GOVERNOR STATE OF ARIZONA



### May25,2011

Jared Blumenfeld, Regional Administrator EPA Region IX 75 Hawthome Street SanFrancisco, CA 94105-3901 ExECUTIVE OFFICE



### SUBJECT; DesignationRecommendations for the 2010 Primary SulfurDioxideNational AmbientAir Quality Standard DearMr. Blumenfeld: Pursuant to Section 107(d) ofthe Clean Air Act and your correspondence dated March 29,2011 , Arizonarecommends the following designations for the 2010 primarynational 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. Arizonarecommends 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 LaPaz County Maricopa County Mohave County Navajo County Pima County SantaCruz County Yavapai County Yuma County In addition, Arizonarecommends that Gila County and Pinal County (except for Indian Country), except those portions described below, be designated unclassifiable for the primary sulfur dioxide NAAQS

.

1700 WEST WASHINGTON STREET, PHOENIX, ARIZONA 85007 602-542 -4331 • FAX 602-542-7602

### Jared Blumenfeld, Regional Administrator May25,2011 Page 2 of3 Arizonarecommends that two separate and distinct areas, the existing Hayden and Miami S02 planning areas be designated nonattainment as follows: Hayden S02 PlanningArea (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 S02Planning Area (Gila County [part])

- T2N, RI4E T2N, RI5E TIN, R13E (only that portion in Gila County) TIN, RI4E TIN, RI5E TIS, RI4E (onlythat portion in Gila County) TIS, RI4 1I2E TIS, RI5E Arizona's unclassifiablerecommendations 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 withmonitored violations ofthe 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 inthe enclosedArizonaAir Quality Designations, FinalProposedBoundaryRecommendationsforthe 2010PrimaryNational AmbientAir Quality Standard for SulfurDioxide, April25, 

### 2011.

### Jared Blumenfeld, Regional Administrator May 25,2011 Page 3 of3

Should you have further questions, please contact HenryDarwin, Director, ArizonaDepartment ofEnvironmental Quality, at (602) 771-2204 orEric Massey, Air QualityDivisionDirector at (602) 771-2208.

Janice K. Brewer Governor CC: Deborah Jordan, EPARegion IX Colleen McKaughan, EPARegion IX William Wiley, Maricopa CountyAir QualityDepartment Ursula Kramer, Pima CountyDepartment ofEnvironmental Quality Don Gabrielson, Pinal CountyAir Quality Control DistrictJanice 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 HonorableJanice 

### K. Brewer, Governor State ofArizona 1700 West Washington Phoenix, AZ 85007 Re: SulfurDioxideNon-attainmentAreaBoundaryRecommendations Dear GovernorBrewer: Henry R. Darwin Director



### In 2010, EPAestablishedthe I-hourNational AmbientAir Quality Standards (NAAQS) for sulfur dioxide andrevokedthe previous 24-hour and annual NAAQS for sulfur dioxide established in 1971. Under CleanAirAct Section 107(d), states mustmake recommendations for areas thatmeet, cannotbe classified, or do notmeetnew orrevisedNAAQS withinoneyear following the promulgation ofsuch standards. Under A.R.S. 

### §49-405(C)(4), the ArizonaDepartmentofEnvironmental Quality must finalize its proposedrecommendations and supporting documents and submitthemto·younotlaterthan one monthbefore yourrecommendations are dueto EPA. TheEPA deadline for the submission ofproposedboundaryrecommendations is June 2, 2011; 

### Attached tothis letter are ADEQ's analysis of, andproposedboundary recommendations for, the 2010 I-hourNAAQS for sulfur dioxide, as well astheresponses to public commentsthathave beenreceived. Based onmonitoredviolations ofthe new standard, two separate areas are proposed for designation as non-attainment: the Hayden sulfurdioxide planning area in Gilaand Pinal Counties andthe Miami sulfur dioxide planning areainGila County. Both areas are centered onoperating copper smelters, the primary emissions sources intheirrespective areas, and coverthe same areas oflandas the sulfur dioxide non-attainment areas for the previous 1971 sulfur dioxide NAAQS. All other areas ofthe State are proposed as unclassifiable. Ifyou have any questions, please contactme 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 Printedon recycledpaper

### Introduction ArizonaAirQualityDesignations FinalProposed BoundaryRecommendations for the 2010 PrimaryNational AmbientAir Quality Standard for SulfurDioxide

This document contains the current analysis of, and proposedboundary recommendations for, the 2010 1- hour sulfur dioxide primary**Na~ional** Ambient Air Quality Standard (NAAQS). These recommendations follow an extensive publicreview processto solicit comment onthe boundary recommendation. The proposed recommendations are based on currently available ambient monitoring data. At this time the Arizona Department ofEnvironmental 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 ofthe 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 GilaCounty. 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 ofIndian Country. 

### Background The U.S. Environmental Protection Agency is charged with developing air quality standards for the protection ofhuman 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 ofpublic health and welfare. Amongthe pollutants for which EPA has set air quality standards is sulfur dioxide (S02). Sulfur dioxide is part ofa group ofhighly reactive gasses known as "oxides ofsulfur" or SOx. The air quality standards for S02 are designed to protect against exposure to the entire group ofsulfur 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 ofmetal from ore. 

### In 2010 EPA completed a review ofthe 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 ofS02 (see 75 FR 35520; June 22, 2010).1 Table 1 compares the level ofthe

2 See http://www.epa.gov/air/criteria.html for a complete list ofNational Ambient Air Quality Standards. Areview ofthe secondary S02 standard is expectedto 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 permillion (365 

### llg/m3)
75 parts perbillion (ppb) (0.075 parts permillion)



### Area Designation Approach annual
24 hours

1hour year Notto be exceeded more than once in a calendaryear Three-year average ofthe 99th percentile ofthe annual distribution ofdaily 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 ofsuch 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 submitto EPA, attainment (meets ordoes 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 ofthe state. Section 107(d)(1)(A)(i) ofthe 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 nationalprimaryorsecondaryambientairqualitystandard/orthepollutant... " 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 ofassessing 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 ofrefined dispersion modeling under this revised approach

... II 

### On the subject ofinitial 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 PrimaryNationalAmbientAirQualityStandardforSulfurDioxide, 75 FR 35520; June 22, 2010.


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

### 2dispersion 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., "restofState," 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 ofthe CAA for redesignationto 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 ofwhich 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 ofthe 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 ofEPA's expected implementation guidance.4

Ambient Monitoring Network Currently fourteen sulfur dioxide ambient monitoring sites are operated in six counties across Arizona. Six ofthese sites are operated by the Arizona Department ofEnvironmental Quality (ADEQ), Maricopa County Air Quality Department (MCAQD), and the Pima County Department ofEnvironmental 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 entitledAreaDesignations/or the 2010RevisedPrimarySulfur DioxideNationalAmbientAirQualityStandards. 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 supportdesignation recommendations. EPA plans to issue additional guidance for developing plans for implementingthe standard following t1,le initial designation process.
Final Proposed S02 Boundary Recommendations April 25, 2011 3

### Figure 1: Arizona SulfurDioxide AmbientMonitoring Networks

502 MONITOR OWNER 100

II ADEQ 

# • ADEQ/SOURCE II MCDEQ lID PDEQ A NPS II SOURCE

# ~PJrg~ December21. 2010Aulhor- NCaroll

Final Proposed 

### S02 Boundary Recommendations April 25, 2011 4Ambient 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 comparedto the level ofthe air quality standards to determine compliance with the NAAQS. The design value for the new primary S02NAAQS is the 3-year average ofannual 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. Datafor 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 orequivalentmethod monitors.

Monitoring sites in the metropolitan areas of Phoenix (Maricopa County) and Tucson (Pima County) recorded design values ofless than 14 percent ofthe I-hour NAAQS. Two source impact monitors in Gila County, located near the Hayden and Miami copper smelters, show violations ofthe 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 peryearensures attainment ofthe standard.5

. The Ridgeline monitor is located within the eight townships that comprise the Miami sulfur dioxide planning area. The planning area, centered onthe 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 ofpermanent and enforceable control measures, the area achieved attainment in 1984. A plan demonstrating maintenance ofthe standards was submitted to EPA in 2002. EPA subsequently redesignated the areato attainment in 2007 (see 72 FR3061; January 24,2007). Similarto Miami, the Hayden Old Jail monitor is located within the Hayden sulfur dioxide planning area near the Hayden primary copper smelter. Due to implementation ofpermanent and enforceable control

5 Assumes 100% data collection.
Final Proposed S02 Boundary Recommendations April 25, 2011 5measures, the area achieved attainment in 1989. A plan demonstrating maintenance ofthe 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. illthe final rule EPA is relying on "monitoring for groups ofsmaller sources and sources not as conducive to modeling" as a means ofassessing 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 indexvalues of 1,000,000 ormore, - 2 monitors in CBSAs with index values less than 1,000,000 but greaterthan 100,000, and 1monitor in CBSAs with indexvalues greaterthan 5,000. The PWEI is calculated by mUltiplying the popUlation ofthe 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 monitoringrequirements 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 SierraVista-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 (LaPaz} 

### 3 

## o 

# o o Phoenix-Mesa-Scottsdale 5,276 4,039,182

### l(Marico~a & Pinal) 24,370 1 3 

# o LakeHavasu City-Kingman 

## I (Mohave} 901 193,035 174 

## o o 

# o ShowLow 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) 

### 104 

## o 

## o 555 187,555 

## o *Includes onlythose monitors operatedbyADEQ, MCAQD, andPDEQ.

Final Proposed S02 BoundaryRecommendations April 25, 2011 7Emissions Section 107 ofthe Clean Air Act requires that, in addition to violating areas, areas that contribute to violations ofambient air quality standards in a nearby area be included as part ofa nonattainment area. Table 4 is presentedto characterize county level emissions and sources. . Counties with the highest emissions rates are associated with· electric generating facilities and the smelting ofsulfide copper ore. For example, more than 98 percent oftotal emissions in Apache County

. and more than 91 percent in Navajo County are attributable to the "Fuel Combustion Electric Utility" source category ofthe 2005 National Emissions Inventory. In Gila County, the location ofthe Hayden and Miami copper smelters, greater than 98 percent oftotal 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 ofthetotal County emissions inventory. Becausethere 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 ofMonitoring and Emissions Information and Next Steps Based on available ambient monitoring data and absence of current modeling analyses, the proposed designation for the majority ofthe 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 ofADEQ'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 orother 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 violatingthe I-hour S02 standard for the period 2008-2010,

- include the primary emissions sources that likely contribute to monitored violations ofthe I-hour S02NAAQS (the Hayden and Miami primary copper smelters), include mountainous complex terrain that separates the emissions sources from other areas ofthe 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 ofthe Hayden planning area that is in Indian Country) and therefore includethe area ofapplicability for S02 emissions control measures designedto bringthe 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 ofGila County (Gila County at 4,796 square miles nearly equals the land area ofthe state ofConnecticut at 4,845), and

- the location ofemissions 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 Countyborder and more than 100 miles from the northern Gila County border). As an example ofsize 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 ofsimilartype and magnitude could create a presumptive nonattainment area boundary in Arizonathat is thirteen times largerthan one in Connecticut. Based on available information it cannot be determined whether the recommended nonattainment areas should be larger or smaller than the existing S02 planning areas. Additional analysis and modeling will be performed following the completion ofthe designation process and release ofEPA's implementation guidance and, ifappropriate, the recommended boundaries ofthe 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 BoundaryRecommendations April 25, 2011 9Proposed BoundaryRecommendations ADEQ proposes to recommend that all of the following counties (except for Indian Country) be designated unclassifiable for the I-hour sulfurdioxide NAAQS: Apache County Cochise County Coconino County Graham County Greenlee County LaPaz County Maricopa County Mohave County Navajo County Pima County SantaCruz 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 ofthe State ADEQ is proposing to recommend for unclassifiable and nonattainment designations.

Final Proposed S02 Boundary Recommendations April 25, 2011 10

### Figure2: DraftRecommended SulfurDioxide NonattainmentAreaBoundaries 

# ?'

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 NonattainmentAreas Forthe 2010 1-Hour Primary Standard ./ .. 

## ::jist

T6S, R18E T6S,

T7S, R18E T7S,

# ~QfQQtJ ofEnvironmental

## 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 CarlosApache Nation January 10,2011

- Aulhor N. Caroll

Final Proposed S02 Boundary Recommendations April 25, 2011 11HaydenArea: Gila County (part) and Pinal County (part)

.................. T4S, RI4E T4S, RISE T4S, R16E (exceptthatportion in Indian Country) TSS, RI4E TSS, RISE TSS, RI6E (exceptthatportion in Indian Country) T6S, R14E T6S, RISE T6S, R16E (exceptthatportion in Indian Country) Miami Area: GilaCounty (part)

...............................................;........ T2N, R14E T2N, RISE TIN,RI3E (onlythat portion in Gila County) TIN,RI4E TIN,RISE TIS,R14E (onlythat portion in GilaCounty) TIS,RI4 1I2E TIS,RISE Rest ofState (exceptthoseportions in Indian Country)

................................................................... ApacheCounty Cochise County Coconino County Gila County (part) Remainder ofCounty Graham County Greenlee County LaPaz County Maricopa County Mohave County Navajo County PimaCounty Pinal County (part) Remainder ofCounty Santa Cruz County Yavapai County Yuma County

Final Proposed S02 Boundary Recommendations April2S, 2011 Nonattainment

Nonattainment

Unc1assifiable

12**RESPONSfVENESSS~Y** 

### to TestimonyTaken at OralProceeding andWritten CommentsReceived on 

### ArizonaAirQualityDesignations, DraftBoundaryRecommendations/orthe 2010PrimaryNational AmbientAir QualityStandard/orSulfurDioxide, February 1,2011 A public notice appeared on the Arizona Depaqment of Environmental Quality's (ADEQ) Website announcingthe opening ofa public commentperiod on February 3,2011, and in 

### TheArizona

### 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 underthe draft proposed recommendations viathe U.S. Postal Service on February 2, 2011. Subsequent notice was provided to counties and other stakeholders statewideviae-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 ofEnvironmental 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 oflitigation 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 ofthe 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 oftwo 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, 2011receive an "unclassifiable" designation because there are no monitored or modeled violations of the 2010 primary standard in Pinal County. Response: ADEQ is proposing nonattainmentboundaries 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. Theexisting and proposed boundaries are comprised ofnine 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 beenrecorded at an ADEQ operated monitormore than 

### 112 mile from the smelter. Because ofpast boundary determinations, the proximity ofthe smelter to the GilaJPinal County line, and the lack ofdata supporting a smaller boundary recommendation, ADEQ has determined thatit is reasonable to include the portion ofthe existingHayden nonattainment areathat is within Pinal County in the recommended nonattainment areaboundary for the 2010 standard.

May 2, 2011 

### 2