Laserfiche WebLink
;. - <br />~ M <br />III IIIIIIIIIIIII III <br />999 <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Depanmem of Natural Resources <br />1313 Sherman 51.. Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (3031 8I2-8106 <br />April 13, 1995 <br />r <br />~~ ~~ o' <br />h <br />Mr. John Hardaway <br />Manager Environmental Affairs <br />Cripple Creek & Victor Gold <br />P.O. Box 191 <br />VICLOC, CO 80860 <br />RE: Reevaluation of Amendment No. 6 -Leaching Tests, Cresson Mine, <br />Permit No. M-80-244 <br />Dear Mr. Hardaway: <br />~~~~~ <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />Roy Romer <br />Governor <br />lame: s.1«nneaa <br />Executive Director <br />michael B. Long <br />Division Du«Inr <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 III -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 re-examining 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 />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 (oxidize) in a manner <br />simulated by the weathering tests. <br />