1

---------------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------------

Template for Techni cal Support Document

Definition of important t erms used in this document:

1) Designated “unclassifiable”

– an area where EPA could not determine if there was a

violation of the 2008 Lead NAAQS or a contribution to a violation in a nearby area, because

t h ere was insufficient air quality data for both 2006

- 2008 and 2007

- 2009 and where additional monitoring data for 2010 could not result in a different designation

.

2) Designated “attainment”

– an area which EPA has determined

, based on the most recent 3

yea rs of certified air quality data from 2006

- 2008 or 2007

- 2009

, has no violations of the 2008 Lead NAAQS during 36 consecutive valid 3

- month site means ; and which EPA has further

determine d does not contribute to a violation of the 2008 Lead NAAQS in a nearb y area and that additional monitoring data from 2010 could not result in a different designation

.

3 ) Designated nonattainment area

– an area which EPA has determined

, based on a State

recommendation and/ or on the technical analysis included in this docume nt

, has a violation of

the 2008 Lead NAAQS during the most recent three consecutive years of quality

- assured, certified air quality data.

4 ) Prior nonattainment area

– an area that is currently designated as nonattainment or maintenance for the 1978 Lea d Standard (including both current nonattainment areas and maintenance areas).

5 ) Recommended nonattainment area

– an area a State or Tribe has recommended to EPA be designated as nonattainment

.

6 ) Violating monitor

– an ambient air monitor whose design value exceeds 0.15 micrograms per cubic meter ( μg/m3 ). As described in Appendix R of part 50, a violation can be based on either

Pb

- TSP or Pb

- PM 10 data and only three months of data are necessary to produce a valid violating design value.

7 ) 19 78 Lead NAAQS

– 1

. 5 μg/m 3

, N ational Ambient Air Quality S tandard for lead promulgated in 1978. Based on Pb

- TSP indicator and averaged over a calendar quarter.

8 ) 2008 Lead NAAQS

- 0. 1 5 μg/m 3

, National Ambient Air Quality Standard for lead promulgated in 2008

. Based on Pb

- TSP indicator and a t hree

- month roll ing average. Pb

- PM 10 data may be used in limited instances

, including to show nonattainment.2 ARIZONA Area Designations For the

2008 Lead National Ambient Air Quality Standard s

The Environmental Protection Agency ( EPA ) has revised the level of the primary (health

- based) National Ambient Air Quality S tandard (NAAQS) for lead (Pb) from 1.5 micrograms per cubic meter (μg/m3) to 0.15 μg/m3 measured as total suspended particles (TSP). EPA has revised the secondary (welfare

- based) standard to be identic al in all respects to the primary standard

.

Pursuant to section 107(d) of the Clean Air Act (CAA) , EPA must designate as “ nonattainment ” those areas that violate the NAAQS and those nearby areas that contribute to violations. The

table below identifies t he portion of counties in Arizona (AZ ) that EPA intends to designate

“nonattainment” for the 200 8 lead national ambient air quality standard (2008 Lead NAAQS)

.

Table 1 . Designation Recommendations

Area AZ Recommended Nonattainment

Counties EPA’s Desi gnated

Nonattainment Counties Nonattainment area

for 19 78 Lead NAAQS
Hayden None* Gila County (partial) Pinal County (partial) na

* Governor of Arizona recommended delayed designations

. EPA’s recommended boundary is identical to the boundary described i n ADEQ’s December 2009 Boundary Recommendation Technical Support Document.

Technical A nalysis for Hayden, Arizona and Surrounding A reas

Introduction

Th is technical analysis for Hayden, Arizona identifies the monitor that violate s the 2008 Lead

NAA QS and evaluates nearby areas for contributions to ambient lead concentrations in the area.

EPA has evaluated the surrounding area based on the weight of evidence of the following factors

recommended in previous EPA guidance :

Air quality in potentially included versus excluded areas ;
Emissions and emissions

- related data in areas potentially included versus excluded from

the nonattainment area , including population data

, growth rates and patterns and emissions controls; Meteorology (weather/transport pat ter n s) ; Geography/topography (mountain ranges or other air basin boundaries) ; Jurisdictional boundaries (e.g., counties, air districts, reservations, etc.) ; and Any other relevant information submitted to or collected by EPA (e.g., modeling where done appr opriately)

.3

Figure 1 is a map showing the state’s recommended nonattainment area and the surrounding

counties

. Figure 2 shows the lead monitors in the area.

Figure 1. Violating Monitor and Surrounding Area

O n December 15, 2009, the G overnor of Arizona recommended that all portions of the State, excluding Indian Country, 1 be designated as unclassifiable/attainment for the Pb standard, with the exception of the Hayden area of Gila and Pinal Counties, which is violating the standard.

C iting a c ommitment from the main source of Pb emissions in the area, ASARCO LLC, to improve Pb controls on its facility , the Governor requested that EPA delay its designation of the Hayden area . If exceedances are recorded between March 2010

– October 2010, or if ASARCO fails to agree to enforceable controls, the letter recommends promulgating a nonattainment boundary as shown in Figure s 1 and 2. 2 The basis for the boundary is discussed in Arizona Department of Environmental Quality’s (ADEQ’s) boundary recommendat ion technical support

document. 3

1 “Indian country” as defined at 18 U.S.C. 1151 refers to: “(a) all land within the limits of any Indian reservation under the jurisdiction of the United States Government, notwithstanding the issuance of any patent, and, including rights

- of

- way running through the reservation, (b) all dependent Indian communities within the borders of the United States whether within the original or subsequently acquired territory thereof, and whether within or without the limits of a state, and (c) all Indi an allotments, the Indian titles to which have not been extinguished, including rights

- of

- way running through the same.”

2 December 2009 Arizona Recommendation

3 ADEQ December 2009 Boundary Recommendation Technical Support Document * Named sources emitted > 0.05 tpy of Pb according to 2005 NEIv2, 2008 TRI,

and /or ADEQ emissions estimates.

**Un nam ed airp orts emitted < 0.05 tpy
of Pb according to the draft 2008 NEI.

(draft 2008 NEI) ** Pb Point Source* Freeport McMoRan

BHP Copper

ASARCO Copper Smelter & Concentrator

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov5

EPA is not delaying designation of the Hayden area as sufficient data are available to make a

nonat tain ment determination at this time

.

Based on EPA's technical analysis and currently available information, which is described below, EPA intends to designate the Hayden area of Gila and Pinal Counties a s nonattainment

for the 2008 Pb NAAQS

.

Air Q ualit y D ata

This factor considers the Pb design values (in μg/m 3 ) for air quality monitors in the Hayden, AZ

area and the surrounding area based on 200 6

- 200 8 data

. A monitor’s design value indicates whether that monitor attains a specified air quality standa rd. The 2008 Pb NAAQS are met at a monitoring site when the identified design value is valid and less than or equal to 0.15 μg/m 3

. A design value is only valid if minimum data completeness criteria are met. A Pb design value that meets the NAAQS is gener ally considered valid if it encompasses 36 consecutive valid 3

- month

site means (specifically for a 3

- year calendar period and the two previous months)

. For this purpose, a 3

- month site mean is valid if valid data were obtained for at least 75 percent of the scheduled monitoring days in the 3

- month period. For purposes of assessing data capture, data collected before January 1, 2009 will be treated with an assumed scheduled sampling frequency of every sixth day, as specified by 40 CFR part 50 Appendix R, section 4(c)(i). A Pb design value that does not meet the NAAQS is considered valid if at least one 3

- month mean that meets the same 75 percent requirement is above the NAAQS. That is, a site does not have to monitor for three full calendar years in orde r to have a valid violating design value; a site could monitor just three months and still produce a valid (violating) design value

.

Pb monitors that collected data in Arizona for all or part of 2006 through 2008 are listed in Table

2.

As detailed in 40 CFR part 50 Appendix R, all FRM/FEM Pb

- TSP and Pb

- PM 10 data collected in accordance with the requirements of 40 CFR part 58, including Appendix A (quality assurance), Appendix C (federal reference methods/federal equivalent methods (FRM/FEM)), and Appendix E (siting criteria), are comparable against the Pb NAAQS. In addition, Pb

- TSP and Pb

- PM 10 data representing sample collection periods prior to January 1, 2009 (i.e., "pre

- rule" data) will be considered valid for NAAQS comparisons and related attainment/n onattainment determinations

if the data were submitted to EPA’s Air Quality System (AQS) database prior to September 1, 2009, and the sampling and analysis methods used to collect the data were consistent with (1) previous or newly designated FRMs or FEMs, and (2) the provisions of 40 CFR part 58 that were

in effect either at the time of original sampling or at the time of the attainment/nonattainment

determination. 40 CFR part 50, Appendix R contains the requirement for data used for comparison with the P b NAAQS.

In October 2006, EPA Region 9’s Superfund Division began collecting Pb

- PM 10 monitoring data

at the Hayden Maintenance Building monitor just west of the ASARCO copper concentrate and smelting facility in Hayden, AZ. EPA’s Superfund Division also collected Pb

- PM 10 monitoring data at the Winkelman site, located to the southeast of the ASARCO facility . (See Figure 3.)6

Values from July, August, and September 2008 resulted in a 3

- month average design value of 0.17 μg/m3 at the Hayden Maintenance Building monitor.

EPA has reviewed the quality assurance and quality control documents collected during this sampling time. As required by 40 CFR part 58, Appendix A, a quality assurance project plan was in place at the time of sampling, as was a field sampling and data management plan. The information was entered into AQS in August 2009. Review of calibrations, flow checks, field data sheets, chain of custody forms and laboratory reports show data collected at Hayden from July through September 2008 to be valid.

Partisol

- Plus Model 20205 Sequential Air Samplers were used at both Winkelman and the Hayden Maintenance Building sites . At the time, these monitors were designated as EPA PM 10 reference method monitors (RFPS

- 1298

- 127). 4 On June 2, 2009, EPA published a Federal Register notice designating these monitors as federal reference monitors for PM Coa rse (PM 10c ). 5

The moni tors therefore meet the Federal Reference Method/Federal Equivalent Method (FRM/FEM) requirements as specified in 40 CFR part 50, Appendix R. Filters were analyzed using Energy Dispersive X

- ray Fluorescence Spectroscopy (EDXRF) consistent with EPA Compendi um Method IO

- 3.3 and 40 CFR Part 50 Appendix R

. 6

The Hayden Maintenance Building monitoring site meets all siting and network design requirements specified in 40 CFR 58 Appendices D and E. L ocated on the roof of a maintenance building , the monitor compli es with the requirement in 40 CFR 58 App. D 4.5 (i) which states
that "a monitor must be sited...where the Pb concentrations from all sources combined is expected to be at its maximum". It is appropriate for the monitor to capture contributions from

ASARC O as well as any other Pb sources. This site is located in close proximity to a number of public residences and is an appropriate location for monitoring ambient air and population

exposure.

EPA’s review shows the data collected at the Hayden Maintena nce Building between July

– September 2008 to be valid for comparison against the Pb NAAQS.

Values from July, August, and September 2008 resulted in a 3

- month average of 0.17 μg/m3 for the Hayden Maintenance Building monitor. For 2006

- 2008, the Winkelma n site’s design value (highest 3 month average that meets data completeness requirements) is 0.04 μg/m3

.

4 69624 Federal Register / Vol. 63, No. 242 / Thursday, December 17, 1998 / Notices

5 26395 Federal Register / Vol. 74, No. 104 / Tuesday, June 2, 2009 / Notices

6 66964 Federal Register / Vol. 73, No. 219 / Wednesday, November 12, 2008 / Rules and Regulations

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov8

T able 2. Air Quality Data

- Pb monitors in Arizona *
County State

Recommended

Nonattainment? Monitor Name Monitor Air Quality
System ID Monitor Location Lead Design
Value,

2006

- 2008 (μg/m 3 )

Gila
County No** Hayden

Maintenance Building 04

- 007

- 8020

- 01 2 nd Street and
Garfield Ave,
Hayden 0.17

Winkelman High

School 04

- 007

- 8021

- 01 824 Thorne Ave.,

Winkelman 0.04

FMMI Ridgeline 04

- 007

- 0009

- 01 4030 Linden St,

Miami 0.07

FMMI Golf

Course 04

- 007

- 8000

- 01 SR 188 and US 60,

Globe 0.04

Maricopa
County No

J LG Supersite 04

- 013

- 9997

- 01 4530 N. 17 th Ave,

Phoenix 0.01 *Monitors in Bold have the highest 2006

- 2008 design value in the respective county.

* * Governor of Arizona recommended delayed designations. The Hayden and Winkelman monitors fall within the

boun dary described in ADEQ’s December 2009 Boundary Recommendation Technical Support Document. The remaining monitors are outside of the boundary.

All five sites in Arizona collected Pb

- PM 10 data from 2006

- 2008. The revised 2008 Pb NAAQS

is 0.15 μg/m3 , collected as Pb

- TSP. Total suspended particulate (TSP) monitors collect both

small

- sized particles which may be inhaled, as well as larger

- sized particles which are too large to be inhaled but may affect human health through ingestion. Monitors th at collect p articulate

matter of 10 microns and smaller ( PM 10 ) capture inhalable

- sized lead, but do not capture the larger, ingestible lead particles. Ingestion can be a significant Pb exposure pathway, particularly for young children, and larger particle s may, through weathering or mechanical action, become respirable at some point. 7 Because what is captured by a PM 10 monitor may not account for the

full Pb

- TSP concentration, 40 CFR part 50 Appendix R, section 2(a)(i) specifies that Pb

- PM 10 data may be used to show nonattainment

, but it cannot be used to show attainment. ADEQ is also required to install a Pb

- TSP monitor near the ASARCO, Hayden smelter.

As shown in Figure 2, the San Carlos Apache tribal lands lie to the east of the recommended

nonattain ment area. There are no Pb ambient air monitors operating within the tribal lands, nor do the tribal lands have any sources emitting 0.1 tons per year of Pb or more (see Emissions and

Emissions

- Related Data section below). The Winkelman High School Pb

- PM 10 monitor is

located to the east of the sole Pb source located within the nonattainment area (the ASARCO copper and smelting facility ) , and west of the tribal lands. Being a Pb

- PM 10 monitor , the Winkelman monitor does not capture any Pb particles larger than 10 microns that may be present

in the ambient air. However , it s design value of 0.04 μg/m3 is well below the standard. EPA does not require Pb

- PM 10 monitors to be replaced by Pb

- TSP monitors until a 3

- month mean

exceeds 0.10 μg/m3

. 8 Available air data therefore indicate that areas to the east of the monitor, including the San Carlos Apac he tribal lands, are not causing the violation at the Hayden Maintenance Building monitor

.

7 66964 Federal Reg ister / Vol. 73, No. 219 / Wednesday, November 12, 2008 / Rules and Regulations.

8 40 CFR Part 58 Appendix C, section 2.10.2.9

The Hayden Maintenance B uilding monitor

, sited in Gila County, close to the border of Pinal County, is in violation of the 2008 Pb NAAQS. Therefore some portion of Gila County and possibly additional areas in surrounding counties must be designated nonattainment

. We evaluate nearby counties because for each monitor or group of monitors that exceed a standard, nonattainment boundaries must cover a large enough area to include not only the area judged to be violating the standard but also the source areas that are determined to be contributing to the

violations. Each area has been evaluated based o n the weight of evidence of eight factors and

other relevant informati on.

Emissions and Emissions

- Related Data

Evidence of lead emissions sources surrounding a violating monitor are an important factor for determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluated county level emission s data for lead

, population data , and emissions controls

.

Emissions

Emissions data were derived from the 2005 National Emissions Inventory, version 2 (NEI v2)

, which is the most up

- to

- date version of the national inventory. See http://www.epa.gov/ttnchie1/net/2005inventory.html

. EPA recognize s that for certain counties, emissions may have changed since 2005. For example, certain large sources of emissions in or

near this a rea may have installed emission controls or otherwise significantly reduced emissions

since 2005. EPA therefore also considered 2008 TRI information for Arizona. 9 In addition, Arizona provided updated emissions for the ASARCO Hayden smelter. 10 Table 3 re flects data from the state, the 2005 NEI v2 , and the 2008 TRI.

There are approximately 20,000 airport facilities in the U.S. at which leaded aviation gasoline is

consumed. To evaluate the potential impact of emissions at and near these facilities, EPA

rec ommends that States use the draft 2008 NEI. The Arizona airports which emit over 0.10 tons per year of Pb according to the draft 2008 NEI are listed in Table 4.

9 TRI available at http://www.epa.gov/triexplorer/

10 ADEQ December 2009 Boundary Recommendation Technical Support Document, p 710

Table 3. Arizona Facilities with Pb Emissions > 0.10 tpy.*

County Facility in State

Re commended

Nonattainment

Area ? Facility Address City Facility Total

Air Releases (tpy)

Gila No Freeport

- McMoR an Miami Inc Hwy 60 And New St. Claypool 4.90

Gila No ** Asarco LLC Ray Complex/ Hayden

Smelter & Concentrator 640 Asarco Ave Hayden 4.82

Gila No BHP Coppper Inc Pinto Valley
Operation Hwy 60 And Pinto Valley

Rd Miami 0.13

Cochise No Aacco Cast Products Inc 401 N Aacco Trails Benson 0.23

Greenlee No Freeport

- Mcmoran Morenci Inc 4521 Us Hwy 191 Morenci 0.44

Maricopa No Goodrich Corp Universal

Pro pulsion Co 25401 N. Central Ave. Phoenix 0.13

Navajo No Cholla Power Plant 4801 Frontage Rd Joseph City 0.14 *Emissions reflect highest value from ADEQ, 2008 TRI, and 2005 NEI version 2.

* * Governor of Arizona recommended delayed designations. Facility falls within the boundary described in ADEQ’s December 2009 Boundary Recommendation Technical Support Document.

Table 4. Airports in Arizona Emitting > 0.10 tpy Pb according to the draft 2008 NEI.

County Airport in State

Recommended

Nonattainment

Are a ? * Facility Type City Facility Total Air Releases (tpy)

Gila No Payson Airport Payson 0.12

Pinal No Casa Grande Muni Airport Casa Grande 0.27

Cochise No Cochise College Airport Douglas 0.13

Cochise No Sierra Vista Muni

- Libby A AF Airport Fort Huachuca Sierra

Vista 0.11

Coconino No Grand Canyon National Park Airport Grand Canyon 0.29

Coconino No Flagstaff Pulliam Airport Flagstaff 0.11

Maricopa No Phoenix Deer Valley Airport Phoenix 1.35
Maricopa No Falcon Fld Airport Mesa 1.23
Maricopa No Chandler Muni Airport Chandler 0.93
Maricopa No Phoenix

- Mesa Gateway Airport Phoenix 0.67
Maricopa No Phoenix Goodyear Airport Goodyear 0.61
Maricopa No Scottsdale Airport Scottsdale 0.50
Maricopa No Glendale Muni Airport Glendale 0.39
Maricopa No Phoenix Sky Harbor Intl Airport Phoenix 0.32
Maricopa No Pleasant Valley Airport Peoria 0.21
Maricopa No Gila Compressor Station Airport Arlington 0.18
Maricopa No Lakeside Airpark Airport Buckeye 0.18
Maricopa No Goldfield Ranch Airport Fountain Hills 0.18

Maric opa No Gila Bend AF Aux Airport Gila Bend 0.18
Maricopa No Luke A FB Airport Glendale 0.18
Maricopa No Mobile Airport Mobile 0.18
Maricopa No Roesner Ranch Airport Morristown 0.18
Maricopa No Paloma Ranch Airport Paloma 0.18

Maricopa No Airscrew Perfor mance Flightpark Ultralight Glendale 0.18
Maricopa No Wickenburg Muni Airport Wickenburg 0.13
Maricopa No Buckeye Muni Airport Buckeye 0.1111

Maricopa No Stellar Airpark Airport Chandler 0.11
Maricopa No Eagle Roost Airpark Airport Aguila 0.11

Mohave No Grand Canyon West Airport Peach Springs 0.27

Mohave No Kingman Airport Kingman 0.16

Mohave No Lake Havasu City Airport Lake Havasu City 0.14

Pima No Ryan Field Airport Tucson 0.72

Pima No Tucson Intl Airport Tucson 0.44

Pima No Marana Rgnl Airport Tu cson 0.25

Yavapai No Ernest A. Love Field Airport Prescott 0.92
Yavapai No Sedona Airport Sedona 0.13

Yuma No Yuma M. C. A. S. Airport Yuma M. C. A. S. 0.16

* Governor of Arizona recommended delayed designations. No airports in Table 4 fall within the boundary described in ADEQ’s December 2009 Boundary Recommendation Technical Support Document.

Figure 4 shows airports and point sources in the area near the violating monitor. According to the information sources listed above, other than the ASARCO cop per smelter there are no

sources that emit over 0.10 tons of Pb per year within 25 miles of the violating monitor.

There are no known Pb sources emitting 0.1 tons per year of Pb or greater in the San Carlos Apache tribal lands. Without any sources emit ting over 0.1 tons per year of Pb, it is unlikely the San Carlos Apache tribal lands are causing or contributing to the violation at the Hayden Maintenance Building monitor. As discussed in the Air Qu ality Data section above, data from the Winkelman High School monitor supports this conclusion. Air quality and emissions data support excluding the San Carlos Apache tribal lands from the nonattainment area.

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov13

Population Data , Growth Rates and Patterns

Table 5 shows the 200 8 population and population density for counties in the area. Table 6 provides projected population growth for towns near Hayden. These data help assess the extent

to which the concentration of human activities in the area and concentration of population

oriented commercial development may indicate emissions

- based activity contributing to elevated ambient lead levels. This may include ambient lead contributions from activities that would

disturb lead that has been deposited on the ground or on other surfaces. Re

- entrainment of historically deposited lead is not reflected in the emissions inventory

.

Table 5 . Population Data
County State

Recommended

Nonattainment? 2008

Population 2008

Population
Density (pop/sq mi ) Population

Change

2000

- 2008 Population %

Change 2000

- 2008

Gila No* 52,166 11 807 2

Graham No 36,452 8 2,910 9
Maricopa No 3,954,598 429 857,098 28

Pinal No* 327,301 61 146,025 81

* Governor of Arizona recommended delayed designations.

Source of dat a:U.S. Census Bureau estimates for 200 8 ( http://www.census.gov/popest/datasets.html ) and estimati on of the area of U.S. Counties

While data contained in Table 5 indicates considerable growth in P inal County fr om 2000

- 2008, this growth occurred primarily south and west of the Hayden area. ADEQ ’s December 2009 Boundary Recommendation Technical Support Document shows the Hayden area’s population is projected to remain between 0

- 50 people per square mile through 2030. 11 As shown in Table 6, towns near Hayden are also projected to have little to no growth over the coming years. The locations of nearby towns are shown in Figure 5.

Table 6 . Historical and Projected Population for Gila and Pinal Counti es, and selected towns near Hayden. 12

2000 2008 2015 2031

Pinal County 116,397 316,899 486,363 876,091
Gila County 51,335 56,427 61,128 70,358

Globe 7,486 7,603 7,974 8,647

Miami 1,936 1,973 2,022 2,104

Kearny 2,449 2,085 2,630 3,774

Winkelman 443 43 0 430 430
Hayden 892 860 860 860

Sources: Historical data

– U.S. Census Bureau; Projections

– Arizona Department of Commerce.

11 ADEQ December 2009 Boundary Recommendation Technical Support Document, pp 8

- 12.

12 ADEQ December 2009 Boundary Recommendation Technical Support Document , p 18.

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov15

Specific to ASARCO, required control measures and technologies are listed in the operating permit issued by ADEQ. See ADEQ ’s December 2009 Boundary Recommendation Technical Support Document for more details.

Meteorology (weather/transport patterns)

Due to the constraints imposed by the complex terrain in the Hayden area (see Geography/Topography factor), the extent of the area exceeding the Pb standard is confined to a relatively small area around the main source of lead emissions, the ASARCO Hayden smelter. For the same reason, locations outside the particular valleys intersecting at Hayden do not

contr ibute to NAAQS exceedances there. Therefore, the meteorology factor did not play a significant role in determining a boundary for the nonattainment area.

Meteorological data is available from the very nearby Winkelman 6 S station, part of the

National We ather Service Cooperative Observer Program. There is typically only 14 inches of rain each year, with nearly half occurring July through September, coinciding with the Arizona "monsoon" season. There is less than an inch of snow each year. Daily tempera ture highs range from 64 to 91°F depending on seaso n, and lows range from 31 to 69 °F.

General wind information for Gila County is presented in Figure 6 . Varied elevations in and around Hayden cause complex local wind flow. Within and adjacent to the Gil a River and San Pedro River valleys, drainage winds tend to dominate at night under stable conditions, toward the

west on the south and west side of the smelter, and toward the south on the east side of the facility. These conditions cause air pooling in low

- lying areas at night, causing pollutants within the air to settle in these areas. During the day under convective conditions, good vertical mixing causes polluted air to reach the ground. The vertical mixing also causes the flow to be coupled

with wi nds aloft, which generally flow toward the east.

ADEQ's boundary recommendation technical support document further describes wintertime

conditions.

During the wintertime, relatively strong inversions (where cold air becomes trapped at the surface by warm er air aloft) create extremely stable atmospheric conditions. Depending on the strength of the inversion and amount of daytime surface heating, the inversion may break by the early afternoon, permitting the air to mix vertically. Sometimes, however, the in version may not break at all. Under these conditions, vertical and horizontal movement of the air is very limited, causing pollutants in the air to accumulate up to several days with little dispersion. 13

As described in the Geography and Topography factor below, Hayden's complex terrain limits the extent of the area exceeding or contributing to the violation.

13 ADEQ December 2009 Boundary Recommendation Technical Support Document, p 21.16

Figure 6 . Average Wind Direction Frequencies in Gila County, AZ.

Source: A three

- dimensional bar chart shows the wind frequencies in eight dir ections for the four seasons. This data

is taken from 1960

- 1992 Solar and Meteorological Surface Observation Network information issued jointly by the U.S. Department of Commerce: National Climatic Data Center and the U.S. Department of Energy: National

Re newable Energy Laboratory. The chart frequencies reflect the directions from which the winds come.

Geography/topography (mountain ranges or other air basin boundaries)

The geography/topography analysis evaluates the physical features of the land that mi ght have an effect on the air shed and, therefore, on the distribution of lead over Hayden, Arizona. As shown in Figure 7 , the ASARCO Hayden smelter is located in very complex terrain, with the Gila Riv er making a winding semi

- circle south of the facility , and intersected by the San Pedro River valley from the south. The facility itself is elevated relative to the valleys; there is a 200 foot hill just south of the facility, and mountains rising toward the north/northeast. ADEQ's boundary

recommendation technical support document contains the following terrain description.

Hayden lies in the Gila River Valley, approximately 2,044 feet above sea level. The town sits at the base of the Dripping Springs Mountains which rise to a height of approximately 5,09 6 feet. The Mescal and Pinal Mountain ranges rise to the east beyond the Dripping Springs range to approximately 7,848 feet in elevation at the highest point. To the west of Hayden, the Tortilla Mountains rise to a height of 4,273 feet. The complex terrai n forms natural boundaries that isolate the Hayden area from most of Gila and Pinal Counties

. 14

In all directions there is a mountain side, limiting the extent of the area exceeding the Pb standard to a relatively small area around the smelter, the main so urce of Pb emissions. For the same reason, locations outside the particular valleys intersecting at Hayden do not contribute to NAAQS exceedances there. This supports a relatively small nonattainment area, comprising the nearby valleys and mountains, and including a buffer zone.

14 ADEQ December 2009 Boundary Recommendation Technical Support Document, p 21.

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov18

ADEQ has overall jurisdiction over environmental programs in the state of Arizona, as well as jurisdiction over certain source types, including smelters, refineries, and coal

- fired power plants, and retains authority for regulating emissions from agricult ural operations. Three Arizona

counties , Maricopa, Pima, and Pinal, have their own air pollution control programs and operate pursuant to agreements with ADEQ . The lead air quality planning agencies responsible for state implementation plans (SIPs) for Mar icopa County and Pima County are the metropolitan planning organizations (MPO), the Maricopa Association of Governments (MAG) and the Pima Association of Governments (PAG), respectively. There is no MPO and thus no air quality planning agency for SIP purpo ses in Pinal County or Gila County . Therefore, ADEQ is responsible for developing SIPs for these counties

. As shown in Figure 8, t he San Carlos Apache tribal lands lie to the east of the recommended

nonattainment area in both Pinal County and Gila County

. Neither ADEQ nor the counties have jurisdiction over tribal lands.

With the exception of the eastern boundary , the intended Pb nonattainment area boundary coincides with that of the existing Hayden SO 2 nonattainment area 15

. Arizona recommended

excludi ng Indian Country from the nonattainment area, as the state has no jurisdiction over

Indian lands. 16 As discussed in previous sections of this document, t he Winkleman monitor, located just east of Hayden and west of the San Carlos Apache tribal lands , has a design value of

0.04 μg/m 3 , well below the standard. There are no known Pb sources emitting 0.1 tons per year of Pb or greater in the San Carlos Apache tribal lands. Given the air quality data, lack of sources, the low monitored concentrations, and the state's lack of jurisdiction, EPA supports excluding the San Carlos Apache tribal lands from the recommended Hayden Pb nonattainment

area.

15 44 FR 21261, April 10, 1979

16 ADEQ December 2009 Boundary Recommendation Technical Support Document, p 2

## Copyrighted page(s) have been removed from

this document.

Please contact the EPA Docket Center, Public Reading Room to view this document.

Address: 1301 Constitution Ave, NW

Room 3334 Washington, DC 20004

Telephone:

202-566-1744

Fax:

202-566- 9744

Email: docket-customerservice@epa.gov20

Other Relevant Information

See A DEQ’s submittal documents for further details.

Conclusion

After considering the factors described above, EPA believes it is appropriate to include the Hayden portions of Gila and Pinal Counties in the Hayden 2008 Pb NAAQS nonattainment area

.

The Hayde n Maintenance Building air quality monitor near the ASARCO copper smelting and concentrate facility in Gila County shows a violation of the 2008 Pb NAAQS, based on 200 6

- 200 8 air quality data. All other Pb monitors in Arizona currently attain the standard, including those north and east of the violating monitor. Given the heavy weight of Pb , emissions are not expected to transport long distances. Instead, Pb emissions fall out of the atmosphere relatively close to their emission point. The topography and geography of the Hayden area further support the boundaries identified by the state

. Based on its consideration of all the relevant, available information, as described above, EPA believe that the boundaries described herein encompass

the entire area tha t does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the 2008 Pb NAAQS.21

Citations

December 2009 Arizona Recommendation Letter from Janice K. Brewer, Governor, to Laura Yoshii, U.S. Environmental Protection Agency Region 9, December 15, 2009 transmitting recommendations for the 2008 Pb NAAQS,

with enclosures.

ADEQ December 2009 Boundary Recommendation Technical Support Document “Arizona Air Quality Designations Technical Support Document: Boundary Recommend ation for the 2008 Revision to the National Ambient Air Quality Standard for Lead,” Air Quality Division, Arizona Department of Environmental Quality, December 9 , 2009.

References

BGI Incorporated. June 17, 2008. Certificate of Calibration, tetraCal, s erial number 000176.

CH2M Hill. November 2005. Final Field Sampling Plan, ASARCO LLC Hayden Plant Site, Remedial Investigation. Prepared by CH2M Hill for U.S. EPA Region 9.

Chester LabNet. August 20, 2008. Lab Analysis Report #08

- 266 for Client #C 033. Prepared

for CH2M Hill.

Chester LabNet. August 22, 2008. Lab Analysis Report #08

- 284 for Client #C033. Prepared

for CH2M Hill.

Chester LabNet. September 8, 2008. Lab Analysis Report #08

- 302 for Client #C033. Prepared

for CH2M Hill.

Chester L abNet. June 1, 2010. Lab Analysis Report #10

- 134 for Client #I012. Prepared for Innovative Technical Solutions, Inc.

Chester LabNet. March 2010. Certifications and Calibrations.

Chinook Engineering. February 7, 2006. Certificate of Calibration, St reamline Pro MultiCal System, serial number M060102.

Lee, Josephine. June 24, 2008. Meteorological and PM10 Monitoring Performance Audits at Winkelman, AZ and Hayden, AZ Air Quality Monitoring Stations (ASARCO LLC Hayden Plant Site), June 24, 2008. P repared for John Hillenbrand/U.S. EPA by CH2M Hill.

Lindelof, Doug. December 29, 2008. Memorandum: Tier 1 Data Evaluation Memo for the Asarco Hayden project, SDGs: 08

- 059, 08

- 169, 08

- 182, 08

- 206, 080

- 266, 08

- 284, 08

- 302, 08

- 361, 08

- 373, 08

- 394, and 08

- 408. Prepared by Region 9 Environmental Services Assistance Team (ESAT) for John Hillenbrand, U.S. EPA Region 9.22

Monthly Quality Control Maintenance Check Sheets, Hayden, AZ monitor. November 2006

– December 2008.

Wardwell, Sandra. November 13, 2009. Freeport McMoRan (FMMI) Golf Course Monitor

data.

Wardwell, Sandra. November 13, 2009. Freeport McMoRan (FMMI) Ridgeline Monitor data.

Wardwell, Sandra. December 1, 2009. Memorandum: Evaluation of QA/QC Information for Pb Samples Collected by EPA in Hayden and Winkelman. Prepared by Sandra Wardwell, Unit Manager, Arizona Department of Environmental Quality ’ s (ADEQ ’ s ) Data Management & QA

Unit

, t o Ira Domsky, D eputy D irector, ADEQ ’ s Air Quality Division.

Yoshimura, Gwen. November 30, 2009. Completeness Calculation, Hayden Maintenance Building Monitor, July

– Septem ber 2008.