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r - -. <br /> <br />DIVISION OF MINERALS AND GEOLOGY <br />Deiaanmem of Nawral Resources <br />1713 Sherman 51., Room 215 <br />Denver, ColoraAo Et0207 <br />Phone: U031 866-3567 <br />FA7(: 17031 872-810(, <br />April 13, 1995 <br />Mr. John Hardaway <br />Manager Environmental Affairs <br />Cripple Creek & Victor Gold <br />P.O. Box 191 <br />Visor, CO 80860 <br />RE: Reevaluation of Amendment No. 6 -Leaching Tests, Cresson Mine, <br />Permit No. M-80-244 <br />Dear Mr. Hardaway: <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />RoY Romer <br />Gwemor <br />)amen 5. Lochhead <br />Ezeculiv¢ DirMOr <br />Michael B. Long <br />Division Dueclor <br />The Division has reviewed and reevaluated the leaching test results for Amendment No. 6. <br />In addition, the Division has also reviewed CC & VG response, Mr. Kim Lapakko's letter <br />and Dr. David Hyatt's third party evaluation, The Division evaluated the results of <br />leaching studies based on surface water standards - (1) Segment 21 of the Arkansas River as <br />described in the January 31, 1995 letter from WQCD, (2) Cripple Creek as described in <br />Appendix 11 of the September 30 response to OMLR Technical Review, (3) State <br />Agricultural Standards, (4} State drinking water standards, and (5) Standards for the Carlton <br />Discharge. Table TII -from the WQCD Rationale for Permit No. CO-0043648 identifies <br />which standards were evaluated. <br />The Division's assumptions were based on simple exceedances. It was assumed that there <br />would be no dilution from other surface water, and also assumed no metals would <br />precipitate out of the solution of the process water train. <br />Review <br />Upon review of the documents by Lapakko and by Hyatt, and after recxamining the data <br />in light of the proposed surface water control standards, it is evident that all of the <br />reviewers have come to the same general conclusion. That conclusion is as follows: <br />• ~II ~I~I~~~~~~I~~~~~ <br />sss <br />STATE OF COLORf~DO <br />1. Ore and waste rock covered under Permit No. M-80-244 have the potential <br />to generate acid and metals if allowed to weather (oxidic) in a manner <br />simulated by the weathering tests. <br />