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<br />' <br /> j 2 <br /> 1.0 INTRODUCTION ~ <br /> The Colorado Mined Land Reclamation Division and Battle Mountain Go are entering <br />1 into a unique third-party monitoring program for the Battle Mountain Gold facility in San <br /> Luis, Colorado. This program will address concerns raised by citizens about xceedances of <br />' cyanide permit levels in ponds at the San Luis facility. The purpose of he third-party <br /> monitoring is to address the concerns of the citizens group and to accura ely determine <br /> cyanide levels in the collection pond, two tailings ponds, monitoring wells an surface water <br />' (Rito Seco Creek) at the Battle Mountain facility over aone-year period. This proposal <br /> provides a brief background on the facility and relevant cyanide detoxificati n procedures, <br /> and a scope of work for the third-party monitoring program. <br /> <br /> 2.0 BACKGROUND <br />' <br /> 2.1 Battle Mountain Gold Mine <br />I <br />' The Battle Mountain gold mine in San Luis is located approximately 5ve mil s northeast of <br /> the town of San Luis, Colorado. Mining began in 1989 and is planned to last for 7-10 years. <br />' Ore is mined from two open pits, which are dewatered below the level of acti <br />is crushed at the on-site milling facility, processed through flotation and a mining. Ore <br />t ryanidation <br /> circuits, and gold is recovered via acarbon-in-leach circuit. Tailings are treat d with sulfuric <br /> acid to volatilize free cyanide prior to disposal in the tailings impoundments. Process water <br /> from the milling operation drains into the collection pond for reuse. <br />' Local citizens expressed concern about aspects of Battle Mountain's ap lication for a <br />reclamation permit, and a number of written comments were received. Th Mined Land <br />Reclamation Division addressed the citizens' concerns in its adequacy revi sand held a <br />' public hearing on the application. Earlier this year (March 1992) Battle Mo ntain notified <br />the Division that high levels of free ryanide were found in the tailings slurry nd the tailings <br />impoundment. The permit level for free cyanide was 4.4 ppm, and to date oncentrations <br />' of up to b00 ppm free cyanide have been identified in the tailings impo dment. It is <br />possible that high concentrations of dissolved copper produced a positive in rference with <br />the free cyanide determination, resulting in erroneously high free cyanide val es. However, <br />' the violation of permit levels had apparently gone unreported by Battle ountain for a <br />number of months, and the company was fined by the Division for this 'olation. The <br />' violation is of particular concern because the tailings disposal areas were desi ed to handle <br />only relatively low cyanide concentrations. <br />A hearing was held before the Board, and the Board issued an order on Jun~24, 1992 that <br />mandated a number of actions, including detoxification of tailings cyanide a modification <br />' RCG/Hagler, Bailly, Inc. <br /> <br />