ASARCO HAYDEN REMOVAL ASSESSMENT Final Report

December 2004

Prepared for:U.S. Environmental Protection AgencyRegion IX Emergency Response Section

Prepared by:Ecology and Environment, Inc.

Superfund Technical Assessment and Response TeamContract No: 68-W-01-012

TDD: 09-04-02-0002

SDMS DOCID# 1109583

Superfund Technical Assessment and Response Team

SOIL ASSESSMENT REPORTASARCO HAYDEN REMOVAL ASSESSMENT

PINAL AND GILA COUNTIES, HAYDEN, ARIZONA

TDD No.:09-04-02-0002Project No.:0443.01.RS

Submitted to:

Steve CalanogFederal On-Scene Coordinator

United States Environmental Protection AgencyRegion 9 - Emergency Response Section

Prepared by:

Iain BakerSTART Team Member

Ecology and Environment, Inc.

December 2004

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TABLE OF CONTENTS

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Site Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1 Site Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 Site History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.4 Previous Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 Field Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.1 Deviations from the Sampling and Analysis Plan . . . . . . . . . . . . . . . . . . . . . . . . 63.2 Sampling Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Analytical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134.1 Data Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134.2 Discussion of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.2.1 Kearny . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144.2.2 Winkelman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154.2.3 Hayden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164.2.4 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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TABLE OF CONTENTS (cont.)

TablesTable 4-1: Laboratory Results for Arsenic, Copper, and Lead in Samples Demonstrating

Concentrations Above R-SRLs in Kearny . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Table 4-2 Laboratory Results for Arsenic, Copper, and Lead in Samples Demonstrating

Concentrations Above R-SRLs in Winkelman . . . . . . . . . . . . . . . . . . . . . . . . . . 19Table 4-3 Laboratory Results for Arsenic, Copper, and Lead in Samples Demonstrating

Concentrations Above R-SRLs in Hayden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Table 4-4 Laboratory Results for Arsenic, Copper, and Lead in Background

Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figures

Figure 2-1 Site Location Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Figure 3-1 Hayden Sample Pont Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Figure 3-2 Winkelman Sample Point Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-3 Kearny Sample Point Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-4 Background Sample Point Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 4-1 Kearny Sample Grids With Concentrations Greater Than R-SRLs . . . . . . . . . . 23Figure 4-2 Winkelman Sample Grids With Concentrations Greater Than R-SRLs . . . . . . . 24Figure 4-3 Hayden Sample Grids With Concentrations Greater Than R-SRLs . . . . . . . . . . 25

Appendices

Appendix A Site Photographs Appendix B Kearny Analytical Result Summary TablesAppendix C Winkelman Analytical Result Summary TablesAppendix D Hayden Analytical Result Summary TablesAppendix E Background Analytical Result Summary TablesAppendix F Data Validation Reports

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1 INTRODUCTION

The U.S. Environmental Protection Agency (USEPA) Region 9 and the Arizona Department ofEnvironmental Quality (ADEQ) are participants in efforts to identify and address environmentalissues associated with the Asarco Inc.- Hayden Smelter Facility (Asarco) and their impacts onthe surrounding towns of Hayden, Kearny and Winkelman, Arizona. One of the issues ofparticular concern to the ADEQ is the potential exposure to residents from metal contaminants insoil above the Arizona residential soil remediation levels (R-SRLs). The assistance of theUSEPA Emergency Response Section (ERS) was requested to conduct expedited sampling toaddress this issue. The USEPA ERS, under the authority of the Comprehensive EnvironmentalResponse Reauthorization and Liability Act of 1980 (CERCLA) and the Superfund Amendmentand Reauthorization Act of 1986 (SARA), directed the Ecology and Environment, Inc. (E & E)Superfund Technical Assessment and Response Team (START) to perform an assessment ofsurficial soils throughout the three towns. The purpose of the assessment was to determinelevels of metal contaminants contained in soil resulting from operations at Asarco.

This report describes the field activities conducted from October 18 through October 21, 2004 bythe START for the USEPA, and the results of those activities. The specific field sampling andchemical analysis information pertaining to this assessment are addressed in the Asarco HaydenSite, Pinal and Gila Counties, Hayden, AZ Sampling and Analysis Plan (SAP), September 2004.

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2 SITE BACKGROUND

2.1 Site LocationAsarco is located at 640 Asarco Avenue in Hayden, Arizona along the Pinal and Gila Countyborder near the intersection of Highway 177 and Route 77. The geographic coordinates of themain building at the facility are 33< 00' 15.26" north, latitude and 110< 46' 30.39" west, longitude(see Figure 2-1, Site Location Map).

2.2 Site DescriptionAsarco is an active copper smelter facility, consisting of a concentrator, crusher, smelter andtailings deposition. Smelting operations (smelting area) are conducted within an approximately200-acre area, all within an approximate 1,000-acre property boundary. The remaining 800acres are undeveloped. An overhead conveyor belt which is approximately 2,000 feet longpasses directly over some of Hayden’s streets on the southeastern portion of the town. Theconveyor belt transfers concentrated copper ore to the crushing plant, adjacent to State Highway177. Two tailing piles are also associated with the facility; an approximate 1,240-acre tailingspile located along State Highway 177 on the north side of the Gila River, and an approximate500-acre tailings pile located on the south side of the Gila River. Asarco receives copper ore byrailway from the Ray Mine, located 12 miles northwest of Hayden.

The areas of concern for this assessment included the residential, commercial, and publicproperties within the city limits of Hayden, Winkelman, and Kearny, the towns surroundingAsarco. Hayden (approximately 900 residents) has a land area of approximately 1.3 squaremiles and is located between the smelting area and the tailings pile on the north side of the GilaRiver. Hayden consists primarily of residential development, community facilities and Asarco’ssmelting and concentrating operations. Many unused or abandoned residential and commercialproperties are present in the town. Asarco operations occur along the northern, southern andeastern edges of the town. The nearest residences to Asarco are adjacent to the south and west ofthe smelting area.

Winkelman (approximately 1,200 residents) has a land area of 0.7 square miles and isapproximately one mile southeast of Hayden along State Highway 177. Development withinWinkelman is primarily residential, with a school (grades K-12) on the north edge of town,

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commercial development along State Highway 177, a cemetery on the western side of town, anda community park on the eastern edge of the town. Several religious and community facilitiesare dispersed throughout the town.

Kearny (approximately 2,500 residents) has a land area of approximately 2.8 square miles and islocated approximately eight miles west north west of Hayden. Kearny consists of a school(grades K-12) on the northern edge of town, with a commercial strip adjacent to State Highway177 near the eastern edge of town, primarily residential development to the west and south, and asmall airport at the southern edge of town. Additional residences are located on the eastern edgeof town across Highway 177, and several religious and community facilities dispersedthroughout the town.

2.3 Site HistoryThe Ray Mine has been mined for copper since 1880. Asarco constructed its Hayden smelter in1911 and began to process ore from the Ray Mine in 1912. In 1958 the Kennecott CopperCompany (Kennecott) began operation of its Ray Smelter in Hayden and Asarco stoppedreceiving ore. In 1982 Kennecott stopped operating and the next year Asarco bought Kennecott,resuming control over the Ray Mine operations. This created the Asarco Ray Complex whichconsists of the Ray Mining operations and the Hayden operations. The Asarco Ray Complexoperation is currently active (ADEQ 2003).

The towns of Hayden, Winkelman and Kearny were founded in 1909, 1887, and 1849respectively. Hayden was founded by Hayden Stove and Company (a mining company),Winkelman was established by farmers migrating to the region ahead of railroad construction,and Kearny was founded as a base camp for General Stephen W. Kearny then built as a plannedcommunity in 1950 specifically for workers at the Kennecott Copper Company facility (nowAsarco). The economies of all three towns are historically related to copper mining operationsin the area (Arizona Department of Commerce 2004).

2.4 Previous InvestigationsIn 1988 E & E was tasked by the USEPA to conduct a preliminary assessment and evaluation ofthe site using the Hazard Ranking System (HRS) scoring. E & E recommended a high priorityScreening Site Inspection (SI) be conducted at the site. In 1991, the ADEQ completed a non-sampling SI and concluded that based on documented releases to the air and soil, the site

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qualified for further consideration under the CERCLA regulations (ADEQ 2003).

In 2000 the USEPA tasked E & E to review site information and previous sampling data,determine additional data needs, recommend sampling to gather necessary data, and develop aworkplan to conduct sampling. E & E determined that additional data was required toadequately document, for HRS scoring, the soil, groundwater and surface water exposurepathways associated with the site. Potential sources of soil contamination associated with theAsarco operations included wind-blown dust from tailings piles, smelter smokestack emissionsand dust from operation of the overhead conveyer belt in Hayden. E & E recommended that soilsampling be conducted in and around the towns of Hayden and Winkelman (Ecology &Environment 2000).

ADEQ performed an Expanded Site Investigation (ESI) in 2002, conducting sampling aroundAsarco operations in and near Hayden. ADEQ sampling documented elevated levels of arsenic,cadmium, copper, mercury and lead in surficial soil at residential and public sampling locationsin Hayden and from locations in Kennecott Avenue Wash and Power House Wash, which theyconcluded was a result of Asarco operations (ADEQ 2003).

A total of 27 locations in Hayden were sampled during the ESI; 26 with concentrations ofarsenic above the Arizona Residential Soil Remediation Level (R-SRL) of 10 milligrams perkilogram (mg/kg), 24 with copper concentrations above the R-SRL of 2,800 mg/kg, and threewith lead concentrations above the R-SRL of 400 mg/kg. Although cadmium and mercury weredetected at elevated levels compared to background concentrations, these constituents were notdetected above their respective R-SRLs of 38 mg/kg and 6.7 mg/kg. The concentrations ofmetals ranged from 3 to 67.4 mg/kg of arsenic, 863 to 55,100 mg/kg of copper, 24.7 to 851mg/kg of lead, 0.59 to 12.4 mg/kg of cadmium and 0.05 to 0.48 mg/kg of mercury. Backgroundsamples were collected from locations ranging from approximately two and one half to three and one half miles north of Hayden. Background concentrations ranged from 4.6 to 14 mg/kg ofarsenic, 220 to 2,700 mg/kg of copper, 20-1,700 mg/kg of lead, 0.5-4 mg/kg of cadmium and0.04 to 0.06 mg/kg of mercury. Based on the observed metals contamination in residential andpublicly accessible areas in and around Hayden, the ESI concluded that referral to the EPARegion 9 ERS for further assessment was necessary (ADEQ 2003).

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INSERT FIGURE 2-1

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3 FIELD ACTIVITIES

Field work was conducted for this assessment from October 18 through October 21, 2004. START field activities consisted of mapping the sampling locations using a global positioningsystem (GPS) and collecting surface soil samples. Photographic documentation of STARTactivities are included in Appendix A.

3.1 Deviations from the Sampling and Analysis PlanAll work was conducted in accordance with the SAP dated September 2004 with the followingexceptions:

• Section 4.1 Sample Location. The SAP specified that samples would be collected at 52 locations in Hayden, 83locations in Winkelman and 168 locations in Kearny. The USEPA was unable toobtain access agreements for several of the properties where sampling wasproposed. This was based on inability to contact property owners or propertyowners who were unwilling to participate in the study. Where possible, samplelocations were moved to randomly selected locations on town property within thesample grid to maintain a representative spread of sample locations. However,public property locations were not always available within the designated samplegrid, resulting in the reduction of the total number of locations for each town. Atotal of 51 locations in Hayden, 69 locations in Winkelman, and 89 locations inKearny were sampled.

Figure 4-1 in the SAP identified the proposed sample grid locations in the town ofHayden. Several of these grid locations were identified based on consent fromAsarco to sample on its property. During the sampling activities, Asarcorepresentatives informed the USEPA On-Scene Coordinator (OSC) that fivesamples collected at locations on Asarco property could not be submitted to thelaboratory for analysis and were to be returned to Asarco. Therefore, five samplegrids in Hayden could not be used because Asarco had disallowed sampling. Accordingly, the START added an additional five sample grids and randomsampling locations to the town of Hayden and collected samples at these locationsto attempt to maintain a representative number of sample grids.

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Additionally, the sample location for sample grid 220 in Hayden was located on asteep sloping hillside and was inaccessible. This location was move by thesampling team approximately 150 feet south to the nearest accessible location. This location was not within the sample grid but was determined to be within anappropriate distance to the grid.

• Section 6.1.3 Field MeasurementThe SAP specified that the GPS would be used to locate the precise latitude andlongitude of the sample points assigned by the ArcView 3.3 Random PointGenerator program. Due to malfunction of the GPS, the 18 sample pointscollected in Kearny on October 21, 2004 were located visually using a aerialphotograph showing the sample point locations. The START was able to recordthe precise location of the sample collected using the GPS and the sample pointswere determined to be within the proposed sample grid and within an acceptabledistance of the preassigned locations.

3.2 Sampling ActivitiesUnder the authority of USEPA OSC Steve Calanog, the START conducted soil sampling fromOctober 18 to October 21, 2004. Also present on site during the field activities were Lisa Fasanoof the USEPA Public Information Office, Hector Aguirre of the USEPA Community InvolvementOffice and John Gilbert of the USEPA Environmental Response Team.

The START sampled the designated areas of concern as specified in the SAP with deviationspreviously discussed. Sample locations for Hayden, Winkelman, Kearny and background arepresented in Figures 3-1 through 3-4 respectively. As specified in the SAP, samples werecollected at previously determined random locations. Samples were collected at 89 locations inthe town of Kearny, 69 locations in the town of Winkelman, and at 51 locations in the town ofHayden. Background samples were collected at six locations along State Highway 177, rangingfrom approximately 12 to 17 miles south of Winkelman.

Six START members were present on site for the sampling activities. A team of three STARTmembers collected samples in the towns of Winkelman and Hayden and a team of two STARTmembers collected samples in the town of Kearny. Sample team members located and recordedsample points with the GPS, collected samples, prepared samples, recorded sample information,

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and photographically documented sample locations. The START Project Manager assisted thesampling teams and performed project coordination and overall sample management duringsampling activities.

Soil samples were collected at each location by laying down a one square foot plastic templateand collecting the surficial soil to approximately 2 inches below ground surface (bgs) within thatsquare using a dedicated plastic scoop. The surficial soil was then placed into a plastic samplebag and homogenized before being poured into an 8 ounce glass jar. Samples were then labeledand transferred under chain-of-custody to the laboratory.

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INSERT FIGURE 3-1

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INSERT FIGURE 3-2

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INSERT FIGURE 3-3

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INSERT FIGURE 3-4

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4 ANALYTICAL RESULTS

Samples were submitted to Ecology and Environment Analytical Services Center (ASC) inLancaster, New York, Severn Trent Laboratories (STL) in Tacoma, Washington, and EMAXLaboratories, Inc. (EMAX) in Torrance, California for analysis by EPA Methods 6010B TotalsMetals and EPA Method 1311, the Toxicity Characteristic Leaching Procedure (TCLP) Metals. The START submitted 95 samples, 24 duplicate samples and 2 performance evaluation samplesto ASC; 63 samples, 23 duplicate samples and 2 performance evaluation samples to STL; and 57samples, 24 duplicate samples and 2 performance evaluation samples to EMAX.

4.1 Data QualityLaboratory data generated by STL and EMAX was validated by a START chemist followingQuality Assurance/Quality Control Guidance for Removal Activities, Sampling QA/QC PlanValidation Procedures, OSWER Directive 9360.4-1, April 1990. Laboratory data generated byACS was validated by Conestoga-Rovers & Associates. Laboratory data were found to beacceptable with qualification as definitive category data and determined to be usable to meetproject use objectives with the exception of silver TCLP data for 19 samples. Silver TCLP datafor samples H-1190a, K-1275a, K-137, K-153, K-154, K-164, K-167, K-169, K-177, K-186, K-189, K-238, K-256, K-275, K-276, K-277, K-293, K-373, and K-374 was rejected on the basis ofvery low relative percent differences for Matrix Spike/Matrix Spike Duplicate (MS/MSD) onduplicate samples. The START data validation reports are included as Appendix F and qualifiedsummary data are included in Appendices B, C, D and E.

During the investigation, field duplicate samples were taken at twenty-four locations. Fieldduplicates were analyzed by each of the three laboratories to determine reproducibility with theexception of two samples (W-092 and H-169) which were each submitted to two of the threelaboratories. The analysis of field duplicates showed acceptable reproducibility between alllaboratories used during this investigation with the following exceptions. Results for totalthallium and beryllium were qualified as estimated (J qualified), due to elevated results that werenot reproduced in corresponding field duplicates. Results for TCLP barium, copper, and zincappeared to be highly variable among all field duplicates and were qualified as estimated. Adetailed analysis of field duplicate samples is included in Appendix F.

4.2 Discussion of Results

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The START sampled points within 89 sample grids in the town of Kearny, 69 sample grids in thetown of Winkelman, and 51 sample grids in the town of Hayden to determine the areal extent ofcontamination within the three towns. The START compared the soil sample data to the R-SRLs,the site action levels, for arsenic (10 mg/kg), copper (2,800 mg/kg), and lead (400 mg/kg). Additionally, the results of all of the TCLP analysis for each sample were compared to the TCLPlimits for set forth in the Resource Conservation and Recovery Act (RCRA). A discussion ofsampling results for each town is presented below and includes the range of metals concentrationsin samples in the town, as well as a discussion of the sample grids which demonstratedcontaminant concentrations above an action level.

4.2.1 KearnyThe laboratory results for samples from Kearny with documented concentrations of contaminantsof concern above the R-SRLs are presented in Table 4-1 and the sample grids with concentrationsabove R-SRLs are displayed on Figure 4-1. All of the laboratory results for samples collected inthe town of Kearny are presented in a summary table as Appendix B, including TCLP results. The TCLP analysis for the samples collected in Kearny did not document concentrations abovethe TCLP limits for any of the constituents with the exception of one sample K-153 which had aTCLP concentration of 9.66 mg/L of lead. This concentration is above the TCLP limit of 5 mg/L,however, based on data validation (see report in Appendix F) this concentration was determinedto likely be biased high.

The Total Metals analysis identified contaminants of concern above the R-SRLs at 10 locations. Copper was not detected above its R-SRL at any locations in Kearny and concentrations rangedfrom 29.7 to 1740 mg/kg. Lead concentrations ranged from 10.1 to 576 mg/kg with only onesample, K-177, documenting a concentration above the R-SRL. Arsenic was detected above itsR-SRL at nine locations with concentrations ranging from 10.1 to 19.6 mg/kg. Beryllium andthallium were also detected just above their R-SRLS of 1.4 mg/kg and 6.1 mg/kg respectively inseveral samples. However, based on data validation, these concentrations were determined tolikely be biased high.

The highest concentrations of arsenic documented were within sample grids K-281, K-186 and K-95, at concentrations of 19.3, 19.6 and 26 mg/kg respectively. Sample locations K-281 and K-186 were within the main residential area of Kearny at the northern and southern ends. However,no other locations in close proximity to either of these locations demonstrated concentrations

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above the R-SRLs. K-95 was located on the school property at the northern edge of town in thevicinity of State Highway 177. Three other samples in this general area showed arsenicconcentrations just over R-SRLs with concentrations ranging from 10.1 to 11 mg/kg.

Four additional locations demonstrated concentrations of arsenic just above the R-SRL, withconcentrations ranging from 10.4 to 12.2 mg/kg. These locations were dispersed throughout thenortheastern part of Kearny with the majority of the locations in the vicinity of State Highway177. At location K-189, a duplicate sample location, arsenic was detected above the R-SRL inone duplicate sample at 10.9 mg/kg and at less than 8.6 mg/kg in the other three samplessubmitted for this location. Based on the dispersion of sample grids throughout Kearnydocumenting concentrations of contaminants above action levels, additional sampling wouldlikely be required to define the extent of contamination in the general areas where theseconcentrations were detected.

4.2.2 Winkelman

The laboratory results for samples from Winkelman with documented concentrations ofcontaminants of concern above the R-SRLs are presented in Table 4-2 and the sample grids withconcentrations above R-SRLs are displayed on Figure 4-2. All of the data for samples collectedin the town of Winkelman are presented in a summary table in Appendix C, including TCLPresults. The TCLP analysis for the samples collected in Winkelman did not documentconcentrations above the TCLP limits for any of the constituents.

The Total Metals analysis identified contaminants of concern above the R-SRLs at 16 locations. Although it was not considered a contaminant of concern, antimony was detected above its R-SRL, 31mg/kg, at one location W-151 at 50.8 mg/kg. However no other samples containedantimony at concentrations above its R-SRL. Additionally, beryllium and thallium were alsodetected at concentrations just above their R-SRLS of 1.4 mg/kg and 6.1 mg/kg respectively inseveral samples. However, based on data validation, these concentrations were determined tolikely be biased high. Copper was detected above its R-SRL at seven locations with overallconcentrations ranging from 36.4 to 19,000 mg/kg. All of these sample locations, withconcentrations above the action level, were in the southern part of the town in the vicinity of StateHighway 177. Lead was present above its R-SRL in samples collected at three locations, W-134,W-138, and W-160, at concentrations of 468 mg/kg, 489 mg/kg and 403 mg/kg respectively.

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Lead concentrations ranged from 5.87 to 4.98 mg/kg. Locations demonstrating copper and leadconcentrations above R-SRLs also had arsenic concentrations above its R-SRL.

Arsenic was present above its R-SRL in samples from 16 locations, with concentrations rangingfrom 1 to 320 mg/kg. Locations with concentrations above the action level were primarilylocated at the northern and southern edges of the town. Three locations, W-31, W-32, and W-44,on the school property at the northern tip of town showed arsenic concentrations ranging from11.3 to 12.2 mg/kg. These sample grids are the closest grids to the Asarco facility that weresampled in Winkelman. One sample, W-89, in the middle portion of the town along the westernedge revealed a concentration of 10.1 mg/kg of arsenic, however, no other samples collected inthis area demonstrated concentrations above action levels. The remaining 12 locations withconcentrations of arsenic above the action level were in the southern portion of the town in thevicinity of State Highway 177. Concentrations ranged from 10.3 to 320 mg/kg. The potentialsource of contaminants in these locations appears to be aerially dispersed from vehicles travelingalong the highway.

The sample with the highest arsenic concentration, W-160 with 320 mg/kg, also demonstrated thehighest concentration of copper, 19,000 mg/kg, and a lead concentration of 403 mg/kg. Thissample was located in a wash area adjacent to the railroad tracks and demonstrated copper andarsenic concentrations which are significantly higher than any other samples collected. Elevatedlevels at this location have two likely potential causes: the railroad cars which are used totransport copper ore and tailing may have dropped contaminated material in this area or; tailings,which are documented to have been washed into the Gila River from the two tailings piles duringheavy rains and high water levels, were deposited in this area.

4.2.3 Hayden

The laboratory results for samples from Hayden with documented concentrations of contaminantsof concern above the R-SRLs are presented in Table 4-3 and the sample grids with concentrationsabove R-SRLs are displayed on Figure 4-2. All of the data for samples collected in the town ofHayden are presented in a summary table in Appendix D, including TCLP results. The TCLPanalysis for the samples collected in Hayden did not document concentrations above the TCLPlimits for any of the constituents. Of the 51 locations sampled in Hayden for Total Metals, 40contained metals contamination above R-SRLs. Lead concentrations ranged from 19.1 to 463

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mg/kg, with a concentration above the action level at only one location, H-188. Copper wasdetected at 29 locations above its R-SRL with concentrations ranging from 418 to 11,400 mg/kg. Arsenic was detected above its action level at 40 locations with concentrations ranging from 4.69to 91 mg/kg.

Sample locations demonstrating high arsenic concentrations generally coincided with elevatedcopper levels. Although concentrations of copper and arsenic were documented throughoutHayden, the highest concentrations were typically found at locations nearest the Asarco facilityand particularly in areas near the overhead conveyor belt. Sample H-190, which is locatedadjacent to the conveyor belt, demonstrated the highest levels of both arsenic and copper, likelyfrom materials blown or dropped from the conveyor. Based on the active smelting, crushing andconcentrating operations occurring at the Asarco facility, elevated levels of contaminants ofconcern found throughout Hayden are presumably the result of aerially dispersed contaminationfrom these operations.

4.2.4 Background

Background samples were collected at locations ranging between 12 and 17 miles south ofWinkelman along State Highway 77. The results for the analytes of concern are presented inTable 4-4 and the results for all of the analytes are presented in a summary table in Appendix E . Background samples documented lead concentrations ranging from 15.5 to 45.8 mg/kg with anaverage concentration of 29.6 mg/kg. Copper concentrations ranged from 145 mg/kg to 1390mg/kg with an average concentration of 585.5 mg/kg and arsenic concentrations ranged from 2.99to 8.53 mg/kg with an average concentration of 5.72 mg/kg. These results suggest that levels ofthe constituents detected at concentrations above their respective R-SRLs, in samples from thethree towns investigated, are not naturally occurring.

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INSERT TABLE 4-1

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INSERT TABLE 4-2

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INSERT TABLE 4-3

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INSERT TABLE 4-3 P-2

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INSERT TABLE 4-4

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Insert Figure 4-1

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Insert Figure 4-2

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Insert Figure 4-3

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5 CONCLUSION

Analytical results from samples collected in the towns of Hayden, Winkelman and Kearnydocument areas with concentrations of copper, lead and arsenic above their respective R-SRLs. Arsenic was detected above action levels more frequently than the other constituents and lead wasdetected above the action level in only a limited number of sample grids in each town. Samplegrids displaying concentrations of metals above the R-SRLs in Kearny were generally dispersedthroughout the town and did not demonstrate specific regions of the town where contaminationwas likely to occur. Additionally, based on the results of this sampling event in Kearny, copperdoes not appear to be a constituent of concern in this town, as copper was not detected above theR-SRL in any of the sample grids. Sample grids with concentrations of the contaminants ofconcern above R-SRLs in Winkelman point to two main areas of concern within the town, thenorthern portion of town, closest to the Asarco facility, and the south to southwestern edge oftown along State Highway 177. Hayden samples document elevated levels of contaminantsthroughout the town, the highest concentrations in close proximity to the Asarco facility. Basedon the results of this sampling event, contamination is present in all three towns sampled. It isrecommended that the sampled grids which documented elevated levels of the contaminants ofconcern be evaluated further by the USEPA States, Tribes and Assessment Section to determine iffurther assessment of the areas of concern is necessary.

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6 REFERENCES

ADEQ, Expanded Site Inspection Report, Asarco Inc., Hayden Plant, 640 Hayden Avenue, HadenGila County, Arizona. April 25, 2003.

Arizona Department of Commerce, Kearny, Hayden, and Winkelman: Community Profile. June2004

Ecology and Environment Inc., Asarco - Hayden Copper Smelter Workplan. August 2000.

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APPENDIX ASite Photographs

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APPENDIX BKearny Analytical Result Summary Tables

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APPENDIX CWinkelman Analytical Result Summary Tables

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APPENDIX DHayden Analytical Result Summary Tables

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APPENDIX EBackground Analytical Result Summary Tables

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APPENDIX FData Validation Reports(available upon request)