Anaconda Mine

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, and from approximately 1952 to 1978 conducted mining and milling operations at the open-pit, low-grade copper mine. Anaconda processed both copper oxide and copper sulfide ores. They removed the overburden, and dug the ore out of the pit which required pumping water 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, and all activities were shut down in 1982. When Anaconda operations ceased, groundwater pumping stopped, resulting in the 180 acre Pit Lake. It is now 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 10 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

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 a risk assessment, 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 may be due to either contaminant migration from the site or due to naturally occurring uranium in the area. A series of groundwater monitoring wells have been installed to better determine the source of the uranium.

In a September 2009 public meeting, EPA released information on groundwater conditions near the former mine site. Our current information shows that there is shallow groundwater contamination from the mine near 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 is planning 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 has submitted the results to EPA for review. ARC will also conduct a baseline human health risk assessment to determine whether the contaminants pose a chronic threat to human health. In the meantime, ARC will conduct an interim action involving capping the inactive evaporation ponds and a portion of the sulfide tailings to further reduce dust migration under an agreement with EPA signed in April 2009.

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, four Arimetco heap leach drainage fluids collection ponds, three 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 will take 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 of the site and is working with other federal agencies as well as 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 (OU1), Pit Lake (OU2), Process Areas (OU3), Evaporation Ponds/Sulfide Tailings (OU4), Waste Rock Areas (OU5), Oxide Tailings (OU6), Wabuska Drain (OU7), and Arimetco (OU8).
Each of these OUs will have their own investigation and cleanup plans. The cleanup approaches for the various hazards at the site will be determined after these investigations have 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.

Prior to 2000

Since 1978, evidence has shown that the groundwater beneath the site has 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” 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 pump contaminated water from the plume into three lined evaporation ponds on-site. The purpose of this system is to prevent shallow groundwater from contaminating private and municipal drinking water wells in Yerington and the local community. The system also stops contamination from reaching the Walker River via the Wabuska Drain.

In the late 1990s, the 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, 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.

2000-2005

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

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 if that approach did not prove effective. EPA negotiated a Scope of Work and Memorandum of Understanding with the 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.

2005-Present

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 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.

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 additional radiation survey of the process areas in the summer of 2007. (See also Initial Actions paragraph below). ARC also conducted air quality monitoring from January 2005 to April 2008, and has submitted an Air Quality Monitoring Program Data Summary Report (May 2008) and a Baseline Human Health Assessment Work Plan for the Inhalation Pathway (June 2008). The results of the monitoring are currently under review by EPA. (See also 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 (March 2009). ARC also initiated well installations at an additional 14 groundwater monitoring well locations, and completed the installations in early 2008. In addition to this work, ARC has continued to conduct quarterly and annual groundwater monitoring of monitoring wells, quarterly and annual domestic well sampling for radionuclides and metals, and provides bottled water to residents with well water exceeding 25ug/L Uranium. (See also Groundwater under the Threats and Contaminants section above.)

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 up the site into manageable operable units (OUs) that will each require their own investigation and cleanup strategy: Site-Wide Groundwater (OU1), Pit Lake (OU2), Process Areas (OU3), Evaporation Ponds/Sulfide Tailings (OU4), Waste Rock Areas (OU5), Oxide Tailings (OU6), and Wabuska Drain (OU7). EPA will concurrently conduct a “fund-lead” remedial investigation and feasibility study for the Arimetco operated portions of the site, designated as OU8.

Under the 2007 EPA Order, ARC has submitted a 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 Planaddressing 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 (OU1), a Draft Process Areas Work Plan (OU3) and a Draft Pit Lake(OU2) Work Plan. The Health and Safety and Data Management Plans have been finalized. The other Plans are currently undergoing review by EPA, and are being revised as needed until final versions are approved.

ARC will submit these additional Work Plans over the next couple years for the remaining OUs according to the schedule agreed to by EPA and ARC: Evaporation Ponds/Sulfide Tailings (OU4), Waste Rock Areas (OU5), Oxide Tailings (OU6), and Wabuska Drain (OU7). The original schedule was tied to the completion of the initial Process Areas characterization; however, as EPA is still reviewing ARC's Work Plan, EPA and ARC have initiated characterization activities to support interim removal action at OU3 to address radiological materials and on OU4 to address the wildlife and fugitive dust threats (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. Results from the characterization of the evaporation ponds have been provided and are under review.

In 2006, EPA performed emergency removals to mitigate dust from blowing off the site, remove PCB containing transformers, and repair and upgrade a couple of the leaking Arimetco fluid collection ponds. In late 2006, ARC proposed to conduct removal of radiological contamination to remove access restrictions for site workers in a 30 ft square area of the 230 acre Process Areas. 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 be based on a complete assessment of the area. ARC declined, therefore EPA conducted a radiological removal assessment in the Process Areas 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 areas that pose a threat to on-site workers.

Also 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 and recommends additional removals as funding becomes available. 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 completed the Public Review Draft of the Arimetco Remedial Investigation Report in July 2008 and is currently evaluating public input. In 2009, EPA conducted supplemental investigations to evaluate groundwater, soils and processing facilities at Arimetco. In 2010, EPA plans to initiate the evaluation of alternatives for cleanup.

EPA and ARC signed an agreement in April 2009 requiring an update to the Pumpback System and Evaporation Ponds O&M Manual, and 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. Work Plans have been submitted for EPA review, and pending approval time frames and work is expected to be on-going through the end of 2011. To date, the electrical hazards removal work has been approved, and planned to be initiated in early 2010.

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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 are currently being managed by 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

Administrative Records
		Non-Time Critical Removal
		Remedial
		Remediation Site AR
		Removal
		Removal # 2
		Removal #3
Fact Sheets
	10/01/99	Water Sampling To Take Place Near Old Copper Mine
	10/02/02	Community Relations Plan
	02/01/03	Community Meeting Thursday, February 27, 2003 AT 7:00 P.M. at Weed Heights Community Center, Yerington, Nevada
	10/01/04	Update on Activites at Yerington Mine
	01/01/05	Site Overview and Update on Activities
	04/01/05	EPA "SCANNER VAN" to Look for Radiation in Yerington Area
	07/01/05	UPDATE ON ACTIVITIES
	02/01/06	EPA To Conduct Removal Action to Address Polychlorinated Biphenyls (PCBs) and Fugitive Dust
	04/01/06	Site Security to be Improved
	09/01/06	Site Update Community Meeting September 19
	10/01/07	Site Update
	01/07/09	Technical Assistance Plan for the Anaconda Mine Site
	03/18/09	Groundwater Monitoring to Expand
	09/15/09	Upcoming Removal Actions
Legal Documents
	03/28/02	Memorandum of Understanding (MOU)
	12/10/04	EPA Response to NDEP Request for Change to EPA Oversight of the Yerington Minder Under Section 106.
	03/31/05	Unilateral Administrative Order for Initial Response Activities, as 2005-0011
	01/12/07	Administrative Order For Remedial Investigaiton And Feasibility Study, 2007-0005
	06/12/08	Anaconda Copper Mine Site, AOC 2008-005
	08/05/08	Request for a Time-Critical Removal Action at the Anaconda Yerington Mine Site, Yerington, Lyon County, Nevada
	04/21/09	Administrative Order on Consent And Settlement Agreement For Removal Action And Past Response Costs, 2009-0010
		Administrative Settlement Agreement For Response Costs And Technical Assistance Plan
Technical Documents
	07/01/05	Arco Groundwater Data Summary Report For Process Areas And Groundwater Conditions
	11/01/05	Data Summary Report For Process Areas Soils Characterization
	11/01/05	Second Quarter 2005 Air Quality Monitoring Report Yerington Mine Site
	11/28/05	Addendum To First Quarter 2005 Air Quality Monitoring Report, Yerington Mine Site
	11/28/05	Addendum To Second Quarter 2005 Air Quality Monitoring Report, Yerington Mine Site
	12/15/05	Radiological Data Compilation Yerington Mine Site
	12/19/05	Air Quality Monitoring Work Plan For The Yerington Mine Site
	01/03/06	December 2006 Monthly Report
	01/11/06	Third Quarter 2005 Air Quality Monitoring Report, Yerington Mine Site
	04/03/06	Fourth Quarter 2005 Air Quality Monitoring Report Yerington Mine Site
	04/04/06	Request for Air Quality Monitoring Scope Reduction at the Yerington Mine Site
	05/18/06	Monthly Status Reports - January, February, March 2006
	06/01/06	June 2006 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Unilateral Administrative Order for Initial Response Activities, EPA Docket No. 9-2005-001
	06/02/06	Inerim Data Summary Report Hydrogeologic Framework Assessment
	06/23/06	First Quarter 2006 Air Quality Monitoring Report
	07/01/06	July 2006 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Unilateral Administrative Order for Initial Response Activities, EPA Docket No. 9-2005-0011
	08/22/06	Health Consultation - Agency for Toxic Substances and Disease Registry (ATSDR)
	09/18/06	Second Quarter 2006 Air Quality Monitoring Report
	09/28/06	Work Plan For The Characterization And Removal Of Selected Materials In The Radiological Control Area, Yerington Mine Site
	10/04/06	September 2006 Monthly Report
	11/03/06	October 2006 Monthly Report
	11/03/06	Work Plan For The Characterizaiton And Removal Of Selected Materials In The "Radiological Control Area:
	11/21/06	Draft Revised Air Quality Monitoring Work Plan For The Yerington Mine Site
	12/07/06	November Monthly Status Report
	12/12/06	3rd Quater Air Quality Monitoring Report Yerington Mine Site
	12/19/06	Rationale for Recommended Analyte Suite
	01/04/07	December 2007 Monthly Report
	01/26/07	Draft Interim Work Plan For The Anaconda Ponds
	02/01/07	January 2007 Monthly Report
	02/04/07	January 2008 Monthly Report
	02/28/07	Final - Second Step Hdrogeologic Framework Assessment Work Plan
	03/06/07	February 2008 Monthly Report
	03/07/07	Proposed Submittals of Air Quality Monitoring Data and Work Plan for the Baseline Human Health Risk Assessment for the Inhalation Pathway.
	03/09/07	February 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Unilateral Administrative Order For Initial Response Activities, Epa Docket No. 9-2005-0011
	03/16/07	Fourth Quarter 2006 Air Quality Monitoring Report Yerington Mine Site
	04/09/07	March 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-005
	04/30/07	Fourth-Quarter 2006 - Air Quality And Meteorological Monitoring Audit Report
	05/03/07	April 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-005
	06/04/07	May 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility, EPA Docket No. 9-2007-0005
	06/06/07	First Quarter 2007 Air Quality Monitoring Report Yerington Mine Site
	07/06/07	June 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	08/08/07	Draft Site-Wide Groundwater Monitoring Plan Yerington Mine Site
	08/08/07	July 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibilty Study, EPA Docket No. 9-2007-0005
	08/30/07	Draft Process Areas (OU-3) Remedial Investigation Workplan
	09/05/07	August 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	09/12/07	Air Quality Monitoring Work Plan Yerington Mine Site - Revision 2
	09/20/07	Second Quarter 2007 Air Quality Monitoring Report
	10/05/07	Draft Revised - Conceptual Site Model
	10/05/07	September 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	11/06/07	October 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	11/16/07	Remedial Investigation Work Plan For Site-Wide Groundwater (Operable Unit 1)
	12/04/07	November 2007 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	12/06/07	Draft Remedial Investigation Work Plan For Yerington Pit Lake (Operable Unit 2)
	12/12/07	Third Quarter 2007 - Air Quality Monitoring Report Yerington Mine Site Report
	02/05/08	Request to Terminate Air Quality Monitoring Activities at the Yerington Mine Site.
	02/22/08	Request to Modify the Second-Step Hydrologic Framework Assessment Work Plan.
	02/28/08	Fourth Quarter 2007 Air Quality Monitoring Report Yerington Mine Site
	03/01/08	Draft Data Evaluation Report Armetco Heap Leach Pads Remedial Investigation Anaconda Copper Yerington Mine Site
	03/20/08	EPA Response to Request to Terminate Air Quality Monitoring Activities, dated Feburuary 5, 208.
	03/27/08	Draft Background Soils Data Summary Report
	03/27/08	Draft Background Soils Data Summary Report - Appendix A to D-2 (Continuation)
	03/27/08	Draft Background Soils Data Summary Report - Cover Sheets (Continuation)
	03/27/08	Draft Background Soils Data Summary Report - Lab Reports (Continuation)
	03/27/08	Draft Background Soils Data Summary Reports - Appendix F (Continuation)
	03/31/08	Draft Technical Memorandum Survey of Wildlife Activity in the Evaporation Ponds Areas at the Yerington Mine Site
	05/28/08	Anaconda Ponds Assessment Report
	06/05/08	May 2008 Monthly Report
	07/01/08	Public Review Draft Remedial Investigation Report Arimetco Facilities Operable Unit 8
	07/09/08	Monthly Report June 2008 - Yerington Mine Site, Lyon County, Nevada
	08/06/08	July 2008 Monthly Report, Yerington Mine Site, Lyon County, Nevada: Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	08/15/08	Anaconda Mine Radiation Assessment
	09/03/08	August 2008 Monthly Report, Yerington Mine Site, Lyon County, Nevada Administrative Order for Remedial Investigation and Feasibility Study, EPA Docket No. 9-2007-0005
	09/11/08	Second Quarter 2008 Groundwater Monitoring Report Yerington Mine Site
	09/15/08	Anaconda Evaporation Ponds Removal Action Characterization Work Plan
	10/03/08	September 2008 Monthly Report
	11/24/08	Technical Assistance Plan
	12/02/08	November 2008 Monthly Report
	12/18/08	Aconda Mine Pond Removal Support Old Raffinate Pond Report Former Anaconda Copper Mine
	01/03/09	Conceptual Site Model For The Yerington Mine Site, Lyon County, Nevada
	02/06/09	January 2009 Monthly Report.
	02/19/09	2008 Annual Groundwater Monitoring Report Yerington Mine Site
	03/02/09	Hydrogeologic Assessment for the Anaconda -Yerington Copper Mine
	03/06/09	February 2009 Monthly Report
	03/09/09	Background Soils Data Summary Report - Yeringston MIne Site 9 (Revision 1)
	05/20/09	Quality Assurance Project Plan Yerington Mine Site - (Revision 5)
	05/28/09	Draft Transite Pipe Work Plan Yerington Mine Stie
	06/01/09	DOCUMENTS UNDER REVIEW
	06/10/09	Responses to EPA Comments Process Areas OU3 RI Work Plan
	06/12/09	Anaconda Evaporation Ponds Removal Action Characterization Data Summary - Yerington Mine Site
	07/01/09	Groundwater Monitoring Report, 1st Quarter 2009 Appendix G-3
	07/01/09	Groundwater Monitoring Report, 1st Quarter 2009
	08/19/09	Transite Pipe Removal Action Work Plan Revision 1 - Yerington Mine Site
	09/04/09	Base Human Health Risk Assessment Work Plan For The Inhalation Pathway - Yerington Mine Site
	10/15/09	Anaconda Evaporation Ponds Removal Action Characterization Data Summary Report Revision 1
	11/04/09	DRAFT - IMPLEMENTATION WORK PLAN ANACONDA EVAPORATION POND REMOVAL ACTION YERINGTON MINE SITE (Cover letter, submittal letter, report contents)
	11/04/09	DRAFT - IMPLEMENTATION WORK PLAN ANACONDA EVAPORATION POND REMOVAL ACTION YERINGTON MINE SITE (Figures: Site Maps)
	11/04/09	DRAFT - IMPLEMENTATION WORK PLAN ANACONDA EVAPORATION POND REMOVAL ACTION YERINGTON MINE SITE (Appendix A to E)
	11/13/09	Revised VLT Characterization Work Plan Using X-Ray Fluorescence, Yerington Mine Site, Lyon County, Nevada: Administrative Order on Consent, EPA Docket No. 09-2009-0010
	12/07/09	THIRD QUARTER 2009 - DOMESTIC WELL MONITORING REPORT
	12/11/09	DRAFT ADDENDUM TO THE SITE-WIDE QUALITY ASSURANCE PROJECT PLAN DOMESTIC WELL MONITORING PROGRAM YERINGTON MINE SITE
	12/15/09	SITE-WIDE GROUNDWATER MONITORING PLAN YERINGTON MINE SITE – REVISION 1
	12/23/09	BASELINE HUMAN HEALTH RISK ASSESSMENT WORK PLAN FOR THE INHALATION PATHWAY YERINGTON MINE SITE REVISION 3
		Jan, Feb., Mar. 2006 Monthly Status Report, Yerington Mine Site, Lyon County, Nevada: Unilateral Administrative Order for Initial Response Activities, EPA Docket No. 9-2005-0011
		NDEP Documents 2002 through 2004 Available On CD by Request.

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Community Involvement

Public Meetings:
OUTREACH MATERIALS

Open Letter to Yerington Community, mailed 1-29-2010.

PUBLIC AND STAKEHOLDER MEETINGS

EPA and NDEP have held general public and stakeholder meetings. These meetings are announced in the local paper and open to the public. For the public meetings, EPA also provides notices to our entire mailing list.

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.

Stakeholder Meetings: Aug. 17, 2004; Feb. 15, 2005; June 8, 2005; Nov. 8, 2005; Feb. 22, 2006; May 24, 2006; Jan. 16, 2007; May 9, 2007; August 22, 2007; December 4, 2007; May 15, 2008; August 19, 2008; May 28, 2009;January 7, 2010.

Next Public meeting is to be determined.

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Public Information Repositories

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Additional Links

US EPA On-Scene Coordinator website: http://www.epaosc.org/site/site_profile.aspx?site_id=2183

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Contacts

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