Gay Mine | Region 10 | US EPA

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Gay Mine


Joe Wallace (
EPA Project Manager

Kay Morrison (
EPA Community Involvement Coordinator

Kelly Wright (
Manager, Shoshone-Bannock Tribes Environmental Waste Management Program

Site Summary

Southeast Idaho is home to a large deposit of phosphate called the Meade Peak Phosphatic Shales formation. In the past, and presently, the phosphate ore from this formation has been mined and processed into phosphate fertilizer and elemental phosphorus. The mining process has created releases of high levels of metals contamination, notably selenium, which have resulted in livestock deaths, surface and groundwater contamination, and other environmental effects.

JR Simplot Company and FMC Corporation mined phosphate ore at the Gay Mine on the Fort Hall Indian Reservation from 1946 to 1993. Mining activities resulted in the creation of waste rock dumps, ore stockpiles, and open pits at hundreds of locations across the nearly 8,500 acre mine site. EPA is concerned that these mining activities may have caused the release of selenium and other metals such as cadmium, vanadium, and nickel into the soil, ground water, streams, animals, plants, and air (in the form of dust).

In December of 2010, the JR Simplot Company and the FMC Corporation voluntarily agreed to study the extent of contamination at the Gay Mine by undertaking and paying for a Remedial Investigation and Feasibility Study following a Settlement Agreement under the Superfund law (the Comprehensive Environmental Response, Compensation, and Liability Act – CERCLA) with the EPA and the Tribes.

The Remedial Investigation is a detailed study of the site. It identifies if contamination is present and, if so, the extent of the contamination. It looks at whether this contamination is currently, or will later become, a threat to the environment and/or the people nearby. From this information EPA, in consultation with the Tribes, will determine if the site requires cleanup. If EPA determines that the site must be cleaned up, the Feasibility Study investigates and presents cleanup options which will protect human health and the environment.

Current activities

JR Simplot and FMC are currently engaged in pre-field work studies to determine the existence and possible extent of contamination at the Gay Mine Site. This will help determine the scope of field work necessary to complete a Remedial Investigation. During this work JR Simplot and FMC will:

  • Collect thousands of historic documents from EPA, the Tribes, US. Fish and Wildlife, Bureau of Indian Affairs, Bureau of Land Management
  • Review collected documents and write planning and scoping documents

EPA, the Tribes, and other support agencies will review and comment on all the planning and scoping documents.

Community involvement

Throughout the Superfund process there are opportunities for the community to be involved. Please review our Draft Community Involvement Plan, based on interviews conducted at Fort Hall in October 2012.

We encourage you to send your thoughts and suggestions on the Community Involvement Plan to Kay Morrison (, Community Involvement Coordinator, 800-424-4372 extension 8321

Where to find documents

Official records and other documents about the Gay Mine site investigation are at:

  • Shoshone-Bannock Library
    PO Box 306
    Fort Hall, Idaho 83203
  • EPA Region 10 Superfund Records Center
    1200 Sixth Avenue, Suite 900, ECL-076
    Seattle, WA 98101
    206-553-4494 or toll-free at 1-800-424-4372
    Please call for an appointment
Next steps

We estimate the Remedial Investigation to be completed around 2015, and, if necessary, the Feasibility Study would then likely be completed around 2016.

  • Upon Agencies approval of the preliminary planning and scoping documents, JR Simplot and FMC will write a Remedial Investigation Work Plan which will:
    • Describe field work to delineate the extent of the contamination
    • Assess the risk the contamination poses to people and the environment, including plants and animals
  • Upon approval of the Remedial Investigation Work Plan the Remedial Investigation will begin
  • After completion of the Remedial Investigation, JR Simplot and FMC will begin the Feasibility Study, identifying and describing a range of potential cleanup methods

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