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<br /> <br />STATE OF III IIIIIIIIIIIIIIII <br />999 <br />COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Deparimenl of Natural Resources <br />131 3 Bherm. n 51., Room '_15 <br />Denver, Colurado 80203 D I v 15 l O N O F <br />Phone: 1303) 866-3567 MINERALS <br />FAX: (3031 832-8106 & <br /> GEOLOGY <br /> R E C L A M A T I O N <br /> MINING•SAFETY <br />June 6, 2000 <br /> Bill Owens <br />To: Berhan Keffelew c°`ern°' <br /> <br />/ Greg E. lValchcr <br /> E xeculive Ducnor <br />Qk., <br />From: Harry Posey ~,e~~i y.., <br />~ ~ Michael B. Long <br /> ~~ Di.-ision Direrlnr <br />. <br />Subject: Review: Cnpple Creek & Vlctor Gold, Inc., Cress Mi ne, Amendment #8 <br />This report constitutes my review of the Amendment 8 for the captioned operation. This review <br />focuses on Volume II of the Amendment application. <br />SPECIFIC COMMENTS Vol II: <br />Section 4.0 Overburden Geochemistry and following. <br />Page 21, 25 and elsewhere. <br />The text indicates that "a total sulfur content of 0.8% was previously determined to be a <br />cutoff value below which overburden does not generate acidic leachates." This statement does <br />not displant that the 0.8% cutoff was negotiated with the Operator to address waste handling <br />qualitatively to minimize acid generation in the AGOSA on the basis of the minimal tests <br />conducted for Amendment #6. At the time Amendment 6 was approved, the 0.8% cutoff was to <br />be an interim measure for waste rock control, field results from which were to have provided <br />information on the possible need for overburden capping in the post-mining setting. Whether the <br />0.8% S presumption was used in calculations of overall NNP predictions is not evident from the <br />text. <br />Unless the presumption that rock with <0.8% sulfur x~as used to characterize NNP <br />calculations for surface a• groundwater, it could be removed ~-om the text. /f the Operator <br />has used the assumptive: in a~rv ARD predictive context, the statement should be verified. <br />Page 22. <br />The AGP formula indicates that 67% of the sulfur was sulfide sulfur. The footnote, <br />indicates 69%. <br />Please clarify which sulfide sulfur va/rte is the correct percentage of total sulfur. Please <br />indicate how the 67% (or 69%) vahte was derived. <br />