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Pacific Southwest, Region 9: Superfund

Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations

Anaconda Copper Mine

EPA #: NVD083917252

State: Nevada(NV)

County: LYON


Congressional District: 2


Bulletin Board

Please refer to the Community Involvement Documents and Reports section to see the latest materials from the Community Meeting on August 16th, 2016. This presentation includes a draft timeline for proposed listing to the National Priorities List.

Description and History

NPL Listing History

NPL Status:

Proposed Date:

Final Date:

Deleted Date:

Is the Anaconda Copper Mine a "Superfund" site?

The quick answer is "yes"; however, it is not on the National Priority List (NPL) of sites.

EPA is addressing the issues at the Anaconda Copper Mine using its authority under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which is commonly named “Superfund.” Therefore, the Anaconda Copper Mine is considered a Superfund site. EPA can use CERCLA authority to conduct investigations and removal actions, and compel work by responsible parties (in this case, Atlantic Richfield Company). The State of Nevada requested that EPA use our Superfund authority in 2005.

EPA is in the process of proposing the site for the NPL. The main difference between NPL sites and other Superfund sites is that we cannot spend Superfund money to conduct long-term cleanups. We can use Superfund money to conduct long-term cleanups on NPL sites only.

Site description and history

The Anaconda Copper Mine site covers more than 3,400 acres in the Mason Valley, near the city of Yerington, in Lyon County, central Nevada, approximately 65 miles southeast of Reno. The Singaste Range and the town of Weed Heights lie to the west, open agricultural fields and homes to the north, U.S. Bureau of Land Management (BLM) managed public land to the south, and the Walker River and the city of Yerington to the east. Portions of the site are owned by Arimetco (in bankruptcy) and portions are BLM managed public lands.

Copper was discovered in the Yerington District in 1865, and operations at this mine site began in 1918 as the Empire Nevada Mine. Anaconda purchased the mine in 1941. From approximately 1952 to 1978, Anaconda conducted mining and milling operations at the open-pit, low-grade copper mine. Anaconda processed both copper oxide and copper sulfide ores. They removed overburden and ore from the pit, which required pumping groundwater out of the pit to get to the ore. The processing of the copper oxide ore involved large quantities of sulfuric acid, made in an on-site sulfuric acid manufacturing plant. The ore processing created liquid and solid wastes, such as: tailing piles, waste rock areas, liquid waste ponds, leach vats, heap leach pads, and evaporation ponds. Anaconda mining operations generated approximately 360 million tons of ore and debris from the open pit and 15 million tons of overburden resulting in 400 acres of waste rock placed south of the Pit, 900 acres of contaminated tailings, and 300 acres of disposal ponds.

In 1977, Atlantic Richfield Company (ARC) bought Anaconda. A decrease in copper prices, lower priced foreign imports, and declining grade and amount of ore available forced the closure of Anaconda’s copper mining operations in 1978. All activities were shut down in 1982. Groundwater pumping out of the pit stopped when Anaconda operations ceased, resulting in the 180-acre Pit Lake. It is about one mile long, 800 feet deep with 500 feet of water, and contains around 40,000 acre-feet of water which increases at the rate of 2.5 feet/year.

In 1982, the property was sold to Don Tibbals, who refurbished Weed Heights, conducted some operations, and leased portions of the site to various companies. Following Anaconda’s sale of the site, portions of the site were used for extracting copper from the tailing and waste rock piles and as a metal salvage and transformer recycling facility. Arimetco bought the property from Tibbals in 1988 and pursued leaching operations on the site, eventually building an electrowinning plant and five heap leach pads to produce copper. They used tailings material left by Anaconda and added some new ore resulting in 250 acres of heap leach piles and 12 acres of heap leach solution collection ponds. Arimetco went bankrupt in 1997 and abandoned the site in 2000.

NDEP and EPA have taken several emergency removal actions at the site to address immediate concerns, and have required ARC to begin remedial investigations and feasibility studies to determine the extent of contamination and potential cleanup options for the site. EPA has initiated a remedial investigation of the Arimetco portions of the site. Please see the Response Action Status section for detailed information about the removal and investigation activities to date.

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Contaminants and Risks

Contaminated Media
  • Groundwater
  • Surface Water
  • Air
  • Soil and Sludges

The threats EPA is investigating at the site include contaminated groundwater and contaminated fugitive dust that could impact human health and surface water. Additional concerns include on-site contaminated surface water (which could impact wildlife), and physical hazards associated with abandoned buildings, debris, and unstable materials such as the waste rock, heap leach and tailings piles, and pit lake slopes.

Primary Contaminants of Potential Concern*:

Metals-Aluminum, Arsenic, Beryllium, Boron, Cadmium, Chromium, Copper, Iron, Lead, Manganese, Mercury, Molybdenum, Nickel, Selenium, Uranium, Zinc

Radioisotopes -Uranium-234, Uranium-235, Uranium-238, Thorium-230, Thorium-232, Radium-226, Radium-228

Others-Chloride, Sulfate, low pH (acidic) conditions, particulate matter

* This list may not be complete or comprehensive. EPA will establish an official list of contaminants of concern for each Operable Unit after remedial investigation activities, including risk assessments, have been completed.

Groundwater: In the late 1970’s, the U.S. Geological Survey (USGS) described a groundwater plume of arsenic, cadmium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, selenium, and zinc below the site and migrating northward. The shallow aquifer is contaminated with acidic process waters and metals potentially from the process areas, evaporation ponds, and leaking heap leach pads and tailings piles. Intermediate and deep aquifers may be degraded, and the aquifers may be interconnected.

Also, research conducted by the BLM in 2003 showed knowledge of technologically enhanced naturally occurring uranium (TENORM) on the site. Testing in 2004 by ARC confirmed the presence of uranium in off-site domestic wells located north and west of the mine and in soil samples from the process area. The uranium in the off-site domestic wells is likely due to contaminant migration from the site although there is also naturally occurring uranium in the area. A total of 353 groundwater monitoring wells have been installed to better determine the source of the uranium.

During EPA's September 2009 public meeting in Yerington, Nevada, and in subsequent public meetings, EPA provided information on groundwater conditions near the former mine site. Our current information shows that there is shallow groundwater contamination from the mine that has crossed the northern boundary of the property. This contamination does not impact the City of Yerington Water System, which is tested regularly and is in compliance with federal drinking water standards. Domestic wells north and west of the mine site that exceed the federal drinking water standard for uranium are offered bottled water by ARC. EPA has undertaken investigations to further differentiate mine-related contamination from naturally occurring contamination. We will continue to share findings from our ongoing groundwater studies.

Fugitive Dust: High wind events combined with a semi-arid environment contribute to occasional erosion of the mine tailings piles, creating potentially contaminated fugitive dust blowing off of the site. In 2004, ARC installed ambient air monitoring equipment to evaluate fugitive dust concerns. ARC sampled particulate matter with an aerodynamic diameter less than 10 microns (PM10), total suspended particulates (TSP), metals, and radionuclides at the site perimeter from 2005 to 2008. The air monitoring program evaluated air quality impacts from fugitive dust using EPA-approved sampling methods. In an effort to reduce fugitive dust from blowing off of the site, EPA capped and sealed approximately 125 acres of potentially contaminated soil in 2006. During the capping, additional air monitoring was conducted to ensure that capping procedures did not produce additional fugitive dust. In early 2007, ARC upgraded the ambient air monitoring equipment to better characterize the high wind events and associated air pollutant concentrations. The air monitoring program was temporarily discontinued on April 1, 2008 and ARC submitted the results to EPA for review. ARC conducted a baseline human health risk assessment in 2010 to determine, under current conditions, how potential for adverse health effects from the inhalation of dust at the boundary of the mine site would compare to regulatory guidelines and to evaluate risk associated with natural background. (The report can be found in the "Document and Reports" section below.)

In April 2009, ARC signed an agreement with EPA to minimize the migration of dust from the lined and unlined evaporation ponds. ARC submitted a Dust Suppression Plan to EPA, proposing the application of a dust suppressant to the ponds to reduce the emission of dust. EPA approved the Dust Suppression Plan, Revision 1, in June 2011. ARC completed the application of the dust suppressant to an area within the Process Area to minimize the emission of dust from the area where a removal action was completed in late 2010. In addition, ARC applied the dust suppressant to the unlined evaporation pond in July 2011. The dust suppression work was completed at the end of 2011. The dust suppressant application to the lined and unlined evaporation ponds was a temporary measure implemented while EPA and NDEP determine a cover design for these areas.

Surface Water: There are several areas of surface water on the site that could pose a threat to wildlife and potentially groundwater resources. These areas include the Pit Lake, Arimetco heap leach drainage fluids collection ponds, ARC pumpback collection ponds, water collecting in low lying areas of Anaconda lined and unlined evaporation ponds, and parts of the sulfide tailings area during rain events. These areas are primarily contaminated with heavy metals and low pH levels. ARC completed initial characterization of the lined and unlined evaporation ponds in October 2008 and is collecting additional data to evaluate possible interim measures to provide a cover for these areas as described above. ARC has also been monitoring wildlife since March 2007 and operating bird deterrent systems at the site's evaporation ponds and the Arimetco ponds since September 2008. Remaining areas are planned to be investigated by ARC under an EPA Order.

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Who is Involved

The U.S. EPA has regulatory lead for all privately owned land at the site. U.S. Bureau of Land Management (U.S. BLM) has regulatory lead for all publicly owned land at the Site. U.S. EPA and U.S. BLM are working together as well with state agencies and potentially responsible parties. Please see Site Contacts below for contact information.

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Investigation and Cleanup Activities

EPA has established eight Operable Units (OUs) to address the investigation and cleanup of the various components of the site: Site-Wide Groundwater (OU-1), Pit Lake (OU-2), Process Areas (OU-3), Evaporation Ponds/Sulfide Tailings (OU-4), Waste Rock Areas (OU-5), Oxide Tailings (OU-6), Wabuska Drain (OU-7), and Arimetco (OU-8).
Each of these OUs has their own investigation and will have their own cleanup plans. The cleanup approaches for the various hazards at the site will be determined after each investigation has been completed and potential risks have been evaluated. In the interim, EPA will determine whether emergency removals or other interim actions are warranted to mitigate immediate hazards.

Initial Actions

Prior to 2000
Since 1978, evidence showed that the groundwater beneath the site had been impacted by mining activities. In the late 1970s and early 1980s, initial studies by NDEP found that tailing streams contained arsenic, mercury, lead, copper, zinc, and chromium. The studies also discovered that contamination from the mining, milling, and metal salvaging operations had migrated into the groundwater forming a contaminant plume.

NDEP issued a Finding of Violation to ARC for the groundwater pollution in 1982. A second Violation was issued in 1985 and required the installation and monitoring of an interception “pumpback” well system designed to contain the groundwater contamination plume. ARC initially installed five pumpback wells on the northern end of the site from 1985 to 1986. An additional six pumpback wells were installed in 1998. The eleven wells pumped contaminated water from the plume into three lined evaporation ponds located on the northern portion of the site. The purpose of this system was to prevent shallow groundwater from contaminating private and municipal drinking water wells in Yerington and the local community. The system was meant to also stop contamination from reaching the Walker River via the Wabuska Drain.

In the late 1990s, local residents, including the Yerington Paiute Tribe, collected water samples from domestic and tribal wells located away from the site. In two of the locations sampled, they found arsenic at levels higher than the acceptable drinking water standard. The discovery of elevated arsenic levels led NDEP and EPA to conduct an Expanded Site Investigation, which was completed in October 2000. Based on the results of that investigation, EPA and NDEP determined that the extent of contamination and the potential human health risks at the site warranted a more comprehensive investigation and cleanup.


NDEP assumed maintenance of the site in 2000 and performed emergency removals at the site from 2001 until 2003.

EPA considered proposing the site for placement on the NPL in 2001; however, the State of Nevada objected since the State was working on the site under a voluntary agreement with ARC. EPA agreed to defer the process for listing the site at that time to allow the State to continue that approach, while reserving the right to reconsider proposed listing on the NPL in the future if the State's approach did not prove effective.

EPA negotiated a Scope of Work and Memorandum of Understanding with NDEP and BLM to cover further site investigations and cleanup activities. In this agreement, NDEP retained lead responsibility and EPA provided oversight. In late 2004, NDEP requested that EPA take the regulatory lead at the site due to the increased complexity of contaminants at the site, such as radioactive contamination.


EPA issued a Unilateral Administrative Order (UAO) for Initial Response Actions to ARC in March 2005. The Order required ARC to: improve site security, update the health and safety plan for on-site workers, implement air monitoring, conduct a radiation survey on and off the site, continue operating the groundwater pumpback well system and Arimetco heap leach fluids management system, prepare Operations and Maintenance (O&M) Plans, continue ongoing investigations of the Process Areas, sample domestic wells for contaminants, supply bottled water to residents, and implement a groundwater study.

ARC conducted air quality monitoring from January 2005 to April 2008, and submitted an Air Quality Monitoring Program Data Summary Report and a Baseline Human Health Assessment Work Plan for the Inhalation Pathway. ARC completed the Baseline Human Health Risk Assessment for the Inhalation Pathway in 2011. (See Fugitive Dust under the Threats and Contaminants section above.)

In early 2007, ARC modified the ambient air monitoring equipment, and also completed installation of approximately 3.5 miles of new fencing, new gates, and new signage, repairs of 10.7 miles of existing fencing, to prevent unauthorized access to the site. In summer 2007, ARC collected soil samples off-site to establish background levels of contamination in the area soils and completed a Background Soils Data Summary Report in March 2009.

In 2006, EPA performed emergency response actions to: mitigate dust from blowing off the site, remove PCB containing transformers, and repair and upgrade leaking Arimetco fluid collection ponds. In late 2006, ARC proposed to conduct a removal of radiological contamination from the Process Area in order to remove access restrictions for site workers in a 30 square ft. area of the 230-acre Process Area. To avoid repeated mobilizations, and ensure a more thorough investigation of the radiological conditions at the site prior to removal actions, EPA requested the scope of the removal action be based on a complete assessment of the area. ARC declined; therefore, EPA conducted a radiological removal assessment in the Process Area during the summer of 2007, and completed a report of the survey in August 2008. EPA completed an agreement with ARC in April 2009 for ARC to conduct additional characterization and removal of the radiological materials in the Process Area that pose a threat to on-site workers; ARC removed over 6,000 tons of soil contaminated with radiological materials in late 2010.

In the summer of 2007, EPA conducted assessments of the Arimetco heap leach fluids management system ponds to determine the scope of additional removals that may be needed, and an investigation of the Arimetco Heap Leach Pads. In the fall of 2007, EPA conducted a permanent removal of another leaking Arimetco pond. EPA conducted additional removals of inactive leach ponds, and repairs of active ponds in September and October 2008. This included removal of soil contaminated with kerosene at the Arimetco processing facilities and bioremediation treatment of the soil.

EPA and ARC signed an agreement in April 2009 requiring an update to the Pumpback Well System and Evaporation Ponds O&M Manual, and the completion of the following interim removal projects: evaporation ponds capping, removal of radiological materials in the process areas, removal of transite/asbestos pipe, and abatement of electrical hazards. EPA approved work plans for the removal of radiological materials in the process areas, removal of transite/asbestos containing pipe, and abatement of electrical hazards. All three removal actions were completed in 2010. In addition, EPA approved a work plan for capping of the thumb pond and a small area of the Process Area (referred to as Sub-Area A); ARC completed the capping project in 2010. ARC initiated dust suppression activities in 2011 by applying a dust suppressant to a portion of the Process Area. (See Fugitive Dust under the Threats and Contaminants section above.)

In 2010, EPA completed the following short-term response actions: removal of asbestos from the Anaconda Copper Mine office and off-site disposal of the asbestos containing material; demolition of the mine office and on-site landfilling of the demolition debris; radiological screening and off-site disposal of more than 300 large truck tires; repair of the heap leach fluids management system; and removal of small containers of hazardous waste left on-site. EPA also performed an evaporation pond pilot test to assess enhanced evaporation methods.

Site Studies

EPA issued a second Order to ARC in January 2007 requiring remedial investigations and feasibility studies of the Anaconda portions of the site. EPA has divided the site into manageable operable units (OUs) that each require their own investigation and cleanup strategy: Site-Wide Groundwater (OU-1), Pit Lake (OU-2), Process Areas (OU-3), Evaporation Ponds/Sulfide Tailings (OU-4), Waste Rock Areas (OU-5), Oxide Tailings (OU-6), and Wabuska Drain (OU-7). EPA conducted a “fund-lead” remedial investigation and feasibility study for the Arimetco operated portions of the site, designated as OU-8.

Under the 2007 EPA Order, ARC submitted the following documents to EPA: Draft Site-Wide Quality Assurance Project Plan (covering the general sampling and analytical procedures to be used during the investigations), a Draft Site-Wide Health and Safety Plan (addressing the health and safety procedures for on-site workers), a Draft Site-Wide Data Management Plan, a Draft Site-Wide Conceptual Site Model, a Draft Site-Wide Groundwater Work Plan (OU-1), a Draft Process Areas Work Plan (OU-3) and a Draft Pit Lake(OU-2) Work Plan. The Site-Wide Quality Assurance Project Plan, Health and Safety Plan, and Data Management Plan were finalized.


ARC has installed a total of 353 groundwater monitoring wells as of August 2016. Our current information shows that shallow groundwater contamination from the mine has crossed the northern boundary of the mine. Groundwater investigations are ongoing as EPA receives more information from the expanded groundwater monitoring well network. EPA and ARC have undertaken a groundwater background investigation to determine what levels of contaminants can be considered naturally occurring. This background investigation will help us to further differentiate mine-related contamination from naturally occurring contamination.

EPA worked with ARC to revise the Domestic Well Monitoring Program in 2009 to increase the number of domestic wells sampled and to increase the frequency of sampling. As of August 2016, over 200 domestic wells are sampled quarterly or semiannually for radionuclides and metals. In addition, ARC continues to provide bottled water to residents if well water exceeds 25 ug/L uranium during one sampling event. (See Groundwater under the Threats and Contaminants section above.)

Process Area

In 2005, ARC completed initial soil and groundwater sampling in the Process Areas, and installed new monitoring wells at 15 locations. Furthermore, ARC completed an initial radiation survey focusing on on-site worker exposure limited to work areas in 2004 and 2005. EPA conducted an additional radiation survey of the process areas in the summer of 2007. (See Initial Actions section above).

ARC provided the results of the 2004-2005 soil and groundwater sampling in the Data Summary Report for Process Areas Soils Investigation and the Data Summary Report for Process Areas Groundwater Conditions. Samples were analyzed for metals, radiochemicals, total petroleum hydrocarbons (TPH), volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), herbicides, and pesticides. ARC summarized the results and identified additional sampling locations in the Draft Process Areas OU-3 Remedial Investigation Work Plan, which was provided to EPA in 2007.

ARC initiated geophysical investigations of the Process Area in 2010 to identify subsurface utilities (i.e., pipes, dry wells, etc.), which may be ongoing sources of contamination at the site.

ARC has performed additional work to characterize the Process Area and a Remedial Investigation Report is due by the end of 2016. ARC has also begun the Human Health Risk Assessment using the data collected.

Evaporation Ponds

EPA and ARC initiated activities to address the wildlife and fugitive dust threats in OU-4 (described above in the contaminants and risks section). ARC implemented a Work Plan for Characterization of the Inactive Evaporation Ponds in September and October 2008, and initiated a Wildlife Mitigation Plan for the pumpback collection ponds at the same time. Additional field data collection was performed by ARC in 2016 which will feed into a remedy decision for the Evaporation Ponds.


EPA completed the Public Review Draft of the Arimetco Remedial Investigation Report in July 2008 and solicited public input on the report. In 2009, EPA conducted supplemental investigations to evaluate groundwater, soils and processing facilities at Arimetco. EPA initiated an evaluation of cleanup alternatives in 2010. EPA completed the Draft Feasibility Study for the Arimetco Heap Leach Pads and Drain-Down Fluids in 2011. NDEP completed a supplement to the Feasibility Study in 2015. EPA is currently working to finalize the Feasibility Study and is working in conjunction with U.S. BLM and NDEP to prepare the Proposed Cleanup Plan.

Additional Studies

ARC will submit additional work plans to EPA for the following OUs according to the schedule agreed to by EPA and ARC: Evaporation Ponds/Sulfide Tailings (OU-4), Waste Rock Areas (OU-5), Oxide Tailings (OU-6), and Wabuska Drain (OU-7). The original schedule was tied to the completion of the initial Process Area characterization which is nearly complete as of August 2016; EPA and ARC earlier initiated characterization activities of the Process Area to support interim removal actions at OU-3 to address radiological materials. (See Initial Actions section above.)

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Cleanup Results to Date

The site is currently undergoing Remedial Investigation and interim response actions to deal with immediate hazards. See section Response Action Status (above) for further details.

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Potentially Responsible Parties

Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.

Atlantic Richfield Company – Atlantic Richfield Company (ARC) is an oil company that was formed by the merger of East Coast-based Atlantic Refining and California-based Richfield Petroleum in 1966. Since 2000, ARC has been a subsidiary of British Petroleum (BP), and is officially known as BP West Coast Products LLC. ARC merged with Anaconda Copper Mining Company (ACM) of Montana in 1977. ACM/ARC owned at the Anaconda Yerington Mine from 1941 to 1982.
Don Tibbals – In 1982, local citizens Don and Joy Tibbals purchased the Mine property from ARC. Mr. Tibbals conducted some mining operations and leased portions of the property until 1988. Mr. Tibbals also developed a series of residential parcels toward the exterior of the site, known as Weed Heights.

Arimetco – Arimetco, also known as Arizona Metals Company, based out of Tucson, AZ, purchased the property from Tibbals in 1988. Arimetco built additional facilities and operated at the mine until 2000 after filing for bankruptcy in 1997. Assets owned by Arimetco were purchased by Singatse Peak Services in 2011 from the bankruptcy court.

Unison Transformer Services – Unison Transformers leased a portion of the property from Arimetco and operated for a few years in the 1990s to collect, crack and recycle transformers. Its operation left a discrete area contaminated with polychlorinated biphenyls (PCBs).

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Documents and Reports

Hide details for Administrative RecordsAdministrative Records
Non-Time Critical Removal
Remediation Site AR
Removal AR #4
Removal # 2
Removal #3
Hide details for Community InvolvementCommunity Involvement
03/24/11Draft Anaconda Community Involvement Plan
08/13/12Public Notice on Voluntary Settlement with Singatse Peak Services on Portion of ARIMETCO (Operable Unit 8)
01/31/13Groundwater Investigation Community Meeting Presentation
01/31/13Yerington Mine Site Public Meeting Groundwater Operable Unit (OU-1) Remedial Investigation (RI) Update Presentation
01/08/14EPA Presentation from January 8, 2014 Community Meeting
08/11/15Presentations from the August 6th, 2015 Community Meeting
09/06/16August 16th Community Meeting Presentation
Hide details for Fact SheetsFact Sheets
10/01/99Water Sampling To Take Place Near Old Copper Mine
10/02/02Community Relations Plan
02/01/03Community Meeting Thursday, February 27, 2003 AT 7:00 P.M. at Weed Heights Community Center, Yerington, Nevada
10/01/04Update on Activites at Yerington Mine
01/01/05Site Overview and Update on Activities
04/01/05EPA "SCANNER VAN" to Look for Radiation in Yerington Area
02/01/06EPA To Conduct Removal Action to Address Polychlorinated Biphenyls (PCBs) and Fugitive Dust
04/01/06Site Security to be Improved
09/01/06Site Update Community Meeting September 19
10/01/07Site Update
01/07/09Technical Assistance Plan for the Anaconda Mine Site
03/18/09Groundwater Monitoring to Expand
09/15/09Upcoming Removal Actions
04/22/10Groundwater Investigation Results and Next Steps
03/31/11EPA Draft Community Involvement Plan Available for Public Comment
08/18/11Arimetco Feasibility Study Released for Public Comment
10/06/11Public Comment Period Extended
02/14/12Community Update Meeting
11/07/12EPA Oversees Additional Site Work
01/18/13Community Meeting on Groundwater Investigation
08/13/14Groundwater Investigation Update Fact Sheet
Hide details for Legal DocumentsLegal Documents
03/28/02Memorandum of Understanding (MOU)
12/10/04EPA Response to NDEP Request for Change to EPA Oversight of the Yerington Minder Under Section 106.
03/31/05Unilateral Administrative Order for Initial Response Activities, as 2005-0011
01/12/07Administrative Order For Remedial Investigaiton And Feasibility Study, 2007-0005
06/12/08Administrative Settlement Agreement for Response Costs and Technical Assistance Plan, AOC 2008-0005
08/05/08Request for a Time-Critical Removal Action at the Anaconda Yerington Mine Site, Yerington, Lyon County, Nevada
04/21/09Administrative Order on Consent And Settlement Agreement For Removal Action And Past Response Costs, 2009-0010
07/16/12Settlement Agreement and Order on Consent for Removal Action
Administrative Settlement Agreement For Response Costs And Technical Assistance Plan
Hide details for Technical DocumentsTechnical Documents
07/01/05Arco Groundwater Data Summary Report For Process Areas And Groundwater Conditions
11/01/05Data Summary Report For Process Areas Soils Characterization
12/15/05Radiological Data Compilation Yerington Mine Site
05/18/06Monthly Status Reports - January, February, March 2006
06/01/06June 2006 Monthly Report
07/01/06July 2006 Monthly Report
08/22/06Health Consultation - Agency for Toxic Substances and Disease Registry (ATSDR)
10/04/06September 2006 Monthly Report
11/03/06October 2006 Monthly Report
12/07/06November 2006 Monthly Status Report
01/03/07December 2006 Monthly Report
01/04/07December 2007 Monthly Report
02/01/07January 2007 Monthly Report
03/09/07February 2007 Monthly Report
04/09/07March 2007 Monthly Report
05/03/07April 2007 Monthly Report
06/04/07May 2007 Monthly Report
07/06/07June 2007 Monthly Report
08/08/07July 2007 Monthly Report
08/30/07Draft Process Areas (OU-3) Remedial Investigation Workplan
09/05/07August 2007 Monthly Report
09/12/07Air Quality Monitoring Work Plan Yerington Mine Site - Revision 2
10/05/07September 2007 Monthly Report
11/06/07October 2007 Monthly Report
12/04/07November 2007 Monthly Report
12/06/07Draft Remedial Investigation Work Plan For Yerington Pit Lake (Operable Unit 2)
02/04/08January 2008 Monthly Report
03/01/08Draft Data Evaluation Report Armetco Heap Leach Pads Remedial Investigation Anaconda Copper Yerington Mine Site
03/06/08February 2008 Monthly Report
03/31/08Draft Technical Memorandum Survey of Wildlife Activity in the Evaporation Ponds Areas at the Yerington Mine Site
05/28/08Anaconda Ponds Assessment Report
06/05/08May 2008 Monthly Report
07/01/08Public Review Draft Remedial Investigation Report Arimetco Facilities Operable Unit 8
07/09/08Monthly Report June 2008
08/06/08July 2008 Monthly Report
08/15/08Anaconda Mine Radiation Assessment
09/03/08August 2008 Monthly Report
10/03/08September 2008 Monthly Report
11/24/08Technical Assistance Plan
12/02/08November 2008 Monthly Report
12/18/08Aconda Mine Pond Removal Support
Old Raffinate Pond Report
Former Anaconda Copper Mine
01/03/09Conceptual Site Model For The Yerington Mine Site, Lyon County, Nevada
02/06/09January 2009 Monthly Report.
02/19/092008 Annual Groundwater Monitoring Report Yerington Mine Site
03/02/09Hydrogeologic Assessment for the Anaconda -Yerington Copper Mine
03/06/09February 2009 Monthly Report
03/09/09Background Soils Data Summary Report - Yeringston MIne Site 9 (Revision 1)
04/06/09March 2009 Monthly Report
05/05/09April 2009 Monthly Report
05/20/09Quality Assurance Project Plan Yerington Mine Site - (Revision 5)
06/02/09May 2009 Monthly Report
06/10/09Responses to EPA Comments Process Areas OU3 RI Work Plan
07/06/09June 2009 Monthly Report
08/06/09July 2009 Monthly Report
09/08/09August 2009 Monthly Report
10/02/09September 2009 Monthly Report
10/15/09Anaconda Evaporation Ponds Removal Action Characterization Data Summary Report Revision 1
11/06/09October 2009 Monthly Report
11/13/09Revised VLT Characterization Work Plan Using X-Ray Fluorescence, Yerington
Mine Site, Lyon County, Nevada: Administrative Order on Consent, EPA Docket
No. 09-2009-0010
12/03/09Pumpback Well System Characterization Work Plan Addendum (Revision 1),
Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial
Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
12/04/09November 2009 Monthly Report
01/05/10December 2009 Monthly Report
01/08/10Draft Transite Pipe Removal Action Plan, Yerington Mine Site
01/22/102009 Annual Domestic Well Monitoring Report
02/02/10January 2010 Monthly Report
02/12/10Addendum To The Site-Wide Quality Assurance Project Plan
02/12/10Addendum to the Site-Wide Quality Assurance Project Plan, Domestic Well Monitoring Program - Revision 1
02/17/10Pumpback Well System Characterization Work Plan Addendum (Revision 2),
Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial
Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
03/05/10February 2010 Monthly Report
03/17/10Addendum to the Site-Wide Quality Assurance Project Plan, Domestic Well Monitoring Plan - Revision 2
04/05/10March 2010 Monthly Report
04/23/10Draft Supplemental Scale Sampling and Analysis Plan - Transite Pipe Removal Action
04/30/10Reuse Assessment: Anaconda/Yerington Mine Site - Yerington, Nevada
05/06/10April 2010 Monthly Report
06/02/10First Quarter 2010 Domestic Well Monitoring Report, Yerington Mine Site
06/07/10May 2010 Monthly Report
06/18/10Implementation Work Plan - Revision 1 - Anaconda Evaporation Pond Removal Action - Yerington Mine Site
06/25/10Draft Cover Materials Characterization Work Plan - Yerington Mine Site
07/01/10Addendum to the Site-Wide Quality Assurance Project Plan, Domestic Well Monitoring Plan - Revision 3 (Approved)
07/06/10Process Areas Radiological Materials Removal Action Plan - Yerington Mine Site
07/07/10June 2010 Monthly Report
07/23/10Data Summary Report for the Characterization of Vat Leach Tailings (VLT) Using X-Ray Fluorescence (XRF) - Yerington Mine Site
07/28/10July 2010 Drilling Summary Report
07/30/10Transite Pipe Removal Action Plan - Revision 1 - Yerington Mine Site
07/31/10Fluid Management System Operation and Maintenance Update Report
08/05/10July 2010 Monthly Report
08/10/10Responses to EPA Comments on Draft Process Areas Radiological Materials Removal Action Plan
08/19/10Draft Electrical Hazards Removal Action Completion Report - Yerington Mine Site
08/20/10Process Areas (OU-3) - Vadose Zone and Groundwater Characterization Work Plan - Revision 1 - Yerington Mine Site
09/07/10August 2010 Monthly Report
09/23/10Fugitive Dust Control and Air Monitoring Plan - Yerington Mine Site
10/01/10Historical Summary Report - Anaconda-Yerington Mine Site - Yerington, Nevada
10/06/10September 2010 Monthly Report
10/06/10September 2010 Monthly Report
11/06/10October 2010 Monthly Report
12/01/10Dust Suppression Plan, Revision 1
12/06/10November 2010 Monthly Report
01/07/11December 2010 Monthly Report
01/07/11Process Area (OU-3) Sub-Surface Utility and Dry Well Investigation, Revision 2
02/08/11January 2011 Monthly Report
03/04/11February 2011 Monthly Report
04/08/11March 2011 Monthly Report
05/01/11Removal Report - Anaconda Removal 2010 (May 2011 Revision)
05/06/11April 2011 Monthly Report
06/08/11May 2011 Monthly Report
06/10/11Data Summary Report for the Characterization of Potential Cover Materials
06/16/111Q 2011 Domestic Well Monitoring Report
07/01/111Q 2011 Groundwater Monitoring Report
07/07/11June 2011 Monthly Report
08/09/11July 2011 Monthly Report
08/15/112Q 2011 Domestic Well Monitoring Report
09/08/11August 2011 Monthly Report
10/07/11September 2011 Monthly Report
11/04/11October 2011 Monthly Report
02/08/12January 2012 Monthly Report
03/09/12February 2012 Monthly Report
04/09/12March 2012 Monthly Report
05/03/12April 2012 Monthly Report
06/08/12May 2012 Monthly Report
07/06/12June 2012 Monthly Report
08/06/12July 2012 Monthly Report
09/05/12August 2012 Monthly Report
10/05/12Final Pollution Report - VLT Pond Removal Action
10/09/12September 2012 Monthly Report
11/09/12October 2012 Monthly Report
12/06/12November 2012 Monthly Report
01/04/13December 2012 Monthly Report
02/08/13January 2013 Monthly Report
03/08/13February 2013 Monthly Report
04/08/13March 2013 Monthly Report
05/03/13April 2013 Monthly Report
06/07/13May 2013 Monthly Report
07/05/13June 2013 Monthly Report
08/06/13July 2013 Monthly Report
09/04/13August 2013 Monthly Report
10/07/13September 2013 Monthly Report
11/04/13October 2013 Monthly Report
12/09/13November 2013 Monthly Report
01/06/14December 2013 Monthly Report
02/04/14January 2014 Monthly Report
03/07/14February 2014 Monthly Report
NDEP Documents 2002 through 2004 Available On CD by Request.

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Community Involvement

Public Meetings:

Open Letter to Yerington Community, mailed 1-29-2010. Final Open Letter Acaconda 1-28-10.pdf


EPA and NDEP have held general public and stakeholder meetings. These meetings are announced via direct mailings and open to the public.

Public Meetings: October 20, 1999; May 11, 2000; January 29, 2001; February 27, 2003; Aug. 25, 2004; Aug. 3, 2005; Sept. 19, 2006; January 22, 2009; September 24, 2009; April 21, 2011. Other public meetings included a groundwater update held August 6, 2015 and a recent Community Meeting on August 16, 2016 at the Yerington Elementary School.

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Public Information Repositories

The public information repositories for the site are at the following locations:

Lyon County Library
20 Nevin Way
Yerington, NV 89447
(775) 463-6645

Nevada Division of Environmental
Protection (NDEP) website: http://ndep.nv.gov/bca/anaconda.htm

The most complete collection of documents is the official EPA site file, maintained at the following location:

Superfund Records Center

Mail Stop SFD-7C

95 Hawthorne Street, Room 403

San Francisco, CA 94105

(415) 820-4700

Enter main lobby of 75 Hawthorne street, go to 4th floor of South Wing Annex.

Additional Links

Anaconda Copper Mine Site video: http://www.epa.gov/region09/superfund/anaconda/index.html
US EPA On-Scene Coordinator website: http://www.epaosc.org/site/site_profile.aspx?site_id=2183

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EPA Site Manager
David Seter
Dante Rodriguez
Christopher Dirscherl
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Sarah Cafasso
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
(415) 947-8701
State Contact
Jeryl Gardner, Nevada Division of Environmental Protection
901 S. Stewart St., Ste. 4001 Carson City, NV 89701
PRP Contact
Jack Oman, Project Manager,
Atlantic Richfield Company
4 Centerpointe Drive
LaPalma, CA 90623-1066
Community Contact
Yerington Paiute Tribe Contacts:
Chairman Linda Howard
Environmental Director Lauryne Wright
(775) 463-3301
171 Campbell Lane, Yerington NV 89447
Environmental Office:
603 West Bridge Street Yerington, NV 89447
Other Contacts
David Davis, Bureau Of Land Management
(775) 861-6575
Bureau of Land Management
1301 Financial Blvd.
P.O. Box 12000
Reno, NV 89502
After Hours (Emergency Response)
(800) 424-8802

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