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BulG1oR Mine TailinRS Pon<is Evallamon <br />EXECUTIVE SUMMARY <br />• This report presents the results of geochemical and geotechnical evaluations of the Upper and <br />Lower Tailings Ponds at the Bulldog Mine site near Creede, Colorado. These evaluations were <br />conducted by Shepherd Miller, Inc. at the request of Homestake Mining Company (Homestake) <br />to assess the potential for the tailings to impact ground water resources in the tailings pond site <br />azeas. <br />During a January 1996 meeting with the Colorado Division of Minerals and Geology (DMG), <br />Homestake agreed to review azchived files for information pertaining to: (1) the effectiveness of <br />the corrective action measures implemented in the 1980's, and (2) the results of ground water <br />monitoring during that period. This review was conducted by P.M. De Dycker and Associates, <br />Inc., with the findings presented to the DMG in April 1996. The DMG concluded that the <br />information provided in the summary report (P.M. De Dycker and Associates, 1996) did not <br />provide sufficient information to conclude that tailings pore water does not have the potential to <br />affect ground water resources in the azea. The DMG and Homestake agreed that the placement <br />• of monitoring wells in a fracture flow system would be unpredictable and unreliable. This is <br />exemplified by the wells installed downgradient of the Lower Tailings Pond in the 1980's. In <br />June 1996, DMG concurred that an acceptable alternative was to conduct a tailings <br />chazacterization program on the Lower Tailings Pond. Homestake decided to conduct a <br />concurrent evaluation of the potential impact of the Upper Tailings Pond as well. <br />The tailings characterization program included combined geochemical and geotechnical <br />evaluations using field and laboratory tests. Field investigations were performed between July <br />26 and 28, 1996, with supplemental field investigations on September 16 and 17, 1996. These <br />investigations consisted of: (I) drilling, logging, sampling, and collecting tailings samples of <br />three test holes in the Lower Tailings Pond and rivo test holes in the Uppec Tailings Pond, (2) <br />collecting tailings pore water from the Upper Tailings Pond, (3) measuring oxygen profiles and <br />oxygen consumption rates in the neaz-surface tailings in the Upper and Lower Tailings Ponds, <br />and (4) collecting samples of natural soils for use in laboratory attenuation tests. <br /> <br />Nameslake Alining Company Shepherd .Llil(er, lnc. <br />y:v-drne.rcr„~..,~, l Apri!l~, 1997 <br />