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<br />- ~ ~' • ~ • III IIIIIIIIIIIII Ilh <br />CC Cripple Creek And victor Gold Mining Company <br />n A dant Venture - Prkes Peak Mining Company, Manager <br />XT`J Operations Office Englewood Office <br />lX. Y P.O. Box 191, 2755 State Highway 67 P.O. Box 5078, 5251 DTC Parkway, Suite 700 <br />(V7i,]ctggor, CO 80860 Englewood, CO 80155 <br />AUgUSt 2, 19YJ) 689-2977 • FAX (719) 689-3254 (303) 889.0700 • FAX (303) 889-0707 <br />SENT BY FACSIMILE AND CERTIFIED RETURN RECEIPT REQUESTED <br />Mr. Berhan Keffelew <br />Environmental Protection Specialist <br />Colorado Department of Natural Resources <br />Division of Mines and Geology <br />Office of Mined Land Reclamation <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 <br />RECEi~.!EI`? <br />AUG p 7 1995 <br />Division o+ f,llflt'15i~ a IUrCIGq) <br />Reference: Cresson Project: Permit M-80-244: Placement of Carlton Mill Tailing Material <br />in Arequa Gulch -Lift Thickness. <br />Dear Mr. Keffelew: <br />In Cripple Creek & Victor Gold Mining Company's ("CC&V") response of February 28, 1994 <br />to the third-party reviewer's observations regarding placement of the Carlton Mill Tailing <br />material in Arequa Gulch, it was stated, in response to the reviewer's comment: <br />"Comment <br />"(Page 14) <br />"Will the tailings be placed in thin lifts from the valley floor up or spread across in succeeding <br />end-dumped lifts? Please outline the planned placement procedure. Based on the planned <br />procedure, are the parameters of 110 pcf dry density and ~-33° used in the stability analyses <br />still applicable? <br />"Response <br />"The lifts will be 18 inch (loose thickness) and will be track-walked by a dozer <br />during placement. The unit .weights and friction angle select for the stability <br />analyses were based on the Vector (June 1993) report. The Carlton tails were <br />admixed with 6 percent bentonite to determine their applicability to function as <br />a liner for that report. The soil mixture exhibited a friction angle of 34°. The <br />~=33° still appears conservative for the unamended tailings based upon the 34° <br />for the amended tailings and 38° reported by Woodward-Clyde for unamended <br />tailings. The optimum density and moisture content for the standard Proctor tests <br />performed were found to be approximately 100 pcf dry density and 20 percent <br />moisture content. The value of 110 pcf was selected by Golder Associates for the <br />