Laserfiche WebLink
<br />EVALUATION OF WASTE ROCK LEACH TESTS <br />WEST PIT DISPOSAL AREA <br />BATTLE MOUNTAIN RESOURCES, INC. <br />Harry H. Posey <br />August 12, 1996 <br />INTRODUCTION <br />Part of Technical Revision 18 to the Battle Mountain Resources Inc. San Luis permit calls for <br />testing of rock samples that were to be petmanently placed in the West Pit. Prediotive leaching tests <br />were selected that would indicate whether metals or acid would be liberated from the rock in quantities <br />sufficient to adversely affect the quality of the groundwater that is downgradient mf the stored rock. <br />Because some of the rock leaching tests require many weeks to perform, BMRI elected to begin rock <br />placement in the West Pit prior to completion of the tests by accepting a stipulation to the permit <br />providing either for removal of the rock or application of other mitigation measures in the event the <br />leach tests indicated potential for significant release of acid or metals from the stored rock. <br />This report examines the results of metals leaching and acid-base accounting tests that were <br />performed on rocks to be placed in the West Pit. The test results are evaluated in light of the present <br />and probable groundwater configuration in the vicinity of the West Pit. The report considers the <br />probable fate and transport of metals and acid that are generated under the leach tests. <br />DATA REPORTS <br />Information that was examined for this report includes the following: <br />1. 9 May 1994: Permit Modification: West Pit Partial Backfill San Luis Project Costilla <br />County, Colorado by Steffen Robertson & Kirsten. <br />2. 17 May 1994: Geologic Characterization of Potential Backfill Waste Rock from the <br />"Gneiss Pit" area of the San Luis Mine Project, Costilla County, CO" <br />3. August 1995: Proposed Monitoring and Water Quality Evaluation Plan for the West <br />Pit; Prepared by Halepaska & Associates. <br />4. 12 July 1995: Technical Memorandum from Mark J. Logsdon (Geochimica) to H. Posey <br />& J. Dillie. <br />5. 18 October 1995: Technical Memorandum from Mark J. Logsdon (Geochimica) to J. <br />Dillie & H. Posey. <br />6. 1 February 1996: Technical Memorandum from Mark J. Logsdon (Geochimica) to J. <br />Dillie & H. Posey. <br />7. 9 February 1996: Humidity Cell tests conducted by Core Labs. <br />8. 3 August 1995: Batch Leach Tests prepared by Chemac, and analyzed by Core Labs. <br />1 <br />