Request for Time-Critical Removal Action for Residences Most Affected by Asarco Hayden Plant Site, Hayden &
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SFUND RECORDS CTR 2141506 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105 MEMORANDUM DATE: March 10,2008 SUBJECT: Request for a Time-Critical Removal Action for Residences most affected by the Asarco Hayden Plant Site, Hayden and Winkelman, Gila County, Arizona FROM: Martin Powell, On-Scene Coordinator Emergency Response Section (SFD-9-2) THROUGH: Steve Calanog, Acting Chief ^> Emergency Response Section (SFD-9-2) TO: Daniel Meer, Chief Response, Planning & Assessment Branch (SFD-9) I. PURPOSE The purpose of this Action Memorandum is to obtain approval to spend up to $1,440,000 in direct costs to mitigate threats to human health, welfare, and the environment posed by the presence of high concentrations of arsenic, copper, and lead in residential soils in the Towns of Hayden and Winkelman, Gila County, Arizona. This Action will address those yards with concentrations of arsenic, copper, and lead in excess of Removal Action Objectives (RAOs) which are explained below. The Action Memorandum would serve as approval for the expenditure required for U.S. EPA to take actions described herein to abate imminent and substantial endangerment to residents of properties contaminated by hazardous substances. The proposed removal of hazardous substances would be undertaken pursuant to Section 104(a)(1) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), 42 U.S.C. § 9604(a)(1), and Section 300.415 of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR § 300.415. II. SITE CONDITIONS AND BACKGROUND Site Status: Non-NPL Category of Removal: Time-Critical CERCLIS ID: AZD008397127 SITE ID: 09JS A. Site Description 1. Physical Location ASARCO, LLC owns and operates a set of facilities known as the Asarco Hayden Plant Site, which includes a crusher, a concentrator, an overhead conveyor, an active smelter, an inactive smelter, property with tailings piles, and other nearby properties in Hayden and Winkelman, Arizona. The facilities surround the town of Hayden, with a population of 900, and they are on two sides of the town of Winkelman, with a population of 450. Kearny, Arizona, with a population of approximately 2,250, is approximately 9 miles northwest of the facility. Hayden is located near the intersection of Highway 177 and Route 77, approximately 100 miles southeast of Phoenix and 52 miles northeast of Tucson. Winkelman is located approximately one mile southeast of Hayden. Releases from the Asarco facilities have caused hazardous substances, including arsenic, copper, and lead, to come to be located within the residential portions of Hayden and Winkelman. This Removal Action addresses contamination in the soil of the 15 residential properties in Hayden and Winkelman which have been shown to have the highest concentrations of these hazardous substances (the Removal Site). 2. Site characteristics Removal Site consists of fifteen residential properties within Hayden and Winkelman. The residences are listed below: Summary of Hayden Winkelman Removal Residential Locations Parcel ID Address 101-07-035AS 71 0& 71 4 North Drive 101-07-040 767 Hayden Avenue 101-07-066 577 Utah Avenue 101-07-089Q 7 Warner Drive 101-07-089S Warner Drive 101-07-089T Warner Drive 101-07-091 765 Cottonwood Road 101-09-004 186 4th Street 101-09-036 1 74 2nd Street 101-09-039 1 63 1 st Street 101-09-070 589 Garfield Avenue 101-09-077 548 Velasco Avenue 101-09-088 455 Terrace Drive 101-09-140 562 Hillcrest Avenue 101-12-149 2nd Street (Hwy 177) The Asarco Hayden Plant Site in Hayden, Arizona, is an active copper ore processing, concentrating, and smelter facility located in Gila County, near the confluence of the Gila River and San Pedro River. The active portion of the Asarco Plant consists of Asarco's crusher, concentrator, smelter, and tailings impoundments areas. The crusher is located on the north side of State Route 177 and provides primary crushing of ore arriving via the Copper Basin Railway from the Ray Mine (and historically from other sources). An overhead conveyor (No. 9 conveyor), approximately 2,000 feet long, has an overhead portion (about 400 feet in length) that passes over some of Hayden's residential streets and directs ore from the crusher to the mill building at the concentrator facility. The 27,400 ton/day concentrator facility includes milling operations and two thickener tanks. The 720,000 ton/year smelter facility is located approximately 2,000 feet east- northeast of Hayden and includes an oxygen flash furnace, converters, anode casting, oxygen plant, and acid plant (Asarco website, www.asarco.com, 2006). Although closely related, Asarco manages the concentrator and smelter operations separately, with each operation having a separate entrance. The active smelter is approximately 11 stories tall and treated air emissions are released to the atmosphere through a 1,000 foot tall stack. Slag from active smelter operations is deposited in an open dump area located immediately southeast of the smelter. The former Kennecott smelter area, located on the north edge of Hayden and north of the concentrator facility, underwent demolition work beginning in 2004. It currently consists of miscellaneous building debris, storage tanks, foundations, and an abandoned slag dump northwest of the former smelter. The former Kennecott smelter stack was not subject to the demolition activity. Tailings Impoundment AB/BC is located south of State Route 177 and north of the Gila River, extends for a length of approximately two and one-half miles, and has a maximum width of one mile and a maximum height of 200 feet. The newer Tailings Impoundment D is located south of the Gila River, extends for a length of approximately two miles, has a maximum width of 1,500 feet, and a maximum height of 150 feet. Process/storm water management facilities consist of several small surface water impoundments located throughout the concentrator and smelter areas: Power House Wash (bisecting the active smelter area and concentrator/Hayden residential areas), retention ponds located south-southeast of Tailings Impoundment AB/BC, a large retention pond (Last Chance Basin) at the northwest edge of Tailings Impoundment AB/BC, and containment berms in selected areas of the tailings impoundments areas. Hayden's drinking water is supplied by a well field, which is operated by Asarco and is located south of Hayden and east of Tailings Impoundment AB/BC. Winkelman's drinking water is supplied by three wells, which are operated by the Arizona Water Company, located east of town within the community park adjacent to the Gila River. 3. Removal site evaluation In 2004, the EPA Emergency Response Section (ERS) under the authority of CERCLA, contracted Ecology & Environment Inc. to perform additional sampling in the Hayden area. Specific details of the scope of work, results, and conclusions from the removal assessment (RA) are provided in the ASARCO Hayden Removal Assessment: Final Report (Ecology & Environment, Inc., 2004). The objective of the RA was to continue to identify and address levels of metals contaminants contained in soil resulting from operations at the Asarco Hayden Plant Site, and specifically to evaluate impacts on the communities of Kearny, Hayden, and Winkelman. The investigation was focused on determining levels of metals contamination within residential, commercial, and public areas of the three towns. The summary in the following paragraphs focuses on the approach and results of sampling in Hayden and Winkelman. Soil samples were collected at a total of 51 locations in Hayden and 69 locations in Winkelman from randomly selected locations within an established grid. Background samples were collected at six locations along State Route 77 south of Winkelman. Surficial samples were collected to depths of approximately two inches below ground surface (bgs). Of the 51 samples in the Hayden area, the total metals analyses revealed metals contamination above the Residential Soil Remedial Levels (R-SRL) at 40 locations including the following: • Arsenic levels exceeded the R-SRL of 10 mg/kg at 40 locations (maximum of 91 mg/kg); • Copper levels exceeded the R-SRL of 2,800 mg/kg at 29 locations (maximum of 11,400 mg/kg); and • Lead levels exceeded the R-SRL of 400 mg/kg at one location (463 mg/kg). Sample locations revealing elevated copper and lead concentrations generally coincided with locations showing high arsenic concentrations, with the highest concentrations typically concentrated close to Asarco facilities, including particularly the No. 9 conveyor belt. Of the 69 samples from the Winkelman area, the total metals analyses revealed the following exceedances of R-SRLs: • Arsenic levels exceeded the R-SRL of 10 mg/kg at 16 locations (maximum of 320 mg/kg); • Copper levels exceeded the R-SRL of 2,800 mg/kg at seven locations (maximum of 19,000 mg/kg); and • Lead levels exceeded the R-SRL of 400 mg/kg at three locations (maximum of 485 mg/kg). The RA concluded that surficial soil contamination is present in the towns of Hayden and Winkelman, and that a soil sampling effort focused on residential yards is warranted as part of a Remedial Investigation (Rl). As part of the Rl, residential soil sampling activities were conducted and included the collection of soil samples from 130 habitable homes within Hayden and Winkelman. This total consisted of 99 homes in Hayden and 31 homes in Winkelman. The residential soil sampling activities were conducted between January 30, 2006 and February 24, 2006. Sample locations were selected within the town limits of Hayden and Winkelman based on the potential human risk of exposure to metals. To aid with this process, Hayden and Winkelman were divided into 26 separate zones. These zones were then separated into two categories termed Category 1 and Category 2. Category 1 includes areas in closer proximity to facility operations, which have a greater potential to be affected by aerial deposition, surface water runoff, or waste disposal activities, while Category 2 includes areas more distant from facility operations, which are likely to be affected primarily by aerial deposition.