Abstract

The Barrick Mercur Mine is located in the historic Camp Floyd mining district on the western side of the southern end of the Oquirrh Mountains in Tooele County, Utah. The most recent operational period in life of the district was initiated by the Getty Mining Company in the late 1970’s. The mine was developed and constructed in the early 1980’s by Getty Mining Company as a tank leach operation for the recovery of gold, silver, and mercury metals from oxide ore. Barrick Resources (USA) Inc. purchased the mine in 1985. Production of sub-economic oxide ore warranted heap leaching operations for additional resource recovery. Valley Fill Heap Leach Area 2 (VF2) was used for cyanide leaching of low-grade gold ore from July 1986 through July 1992. Closure of the leach area is in progress and involves reclamation, revegetation, and long-term monitoring. A primary concern with closure efforts is the protection of ground-water and surface-water quality. Supporting documentation of current practices for the closure of heap leach areas in Nevada and Colorado was provided to establish precedence. Modeling was determined to be the best available technology for evaluating reclamation designs and predicting potential impacts to ground-water quality. Risks were assessed through modeling site specific conditions. Barrick successfully negotiated conditional approval of a closure plan with the State of Utah, Department of Environmental Quality, Division of Water Quality, in May 1995.