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• iii iiiiiiiiiiiu iii • 999 C ~ Cripple Creek & Victor Gold Mlning Company Rn' `` A Joinl Venture -Pikes Peak Mining Company. Manager ~J~. • Operations Office ~X. P.O. Box 191, 2755 State Highway 67 Viclor, CO 80860 (71 689-2977 • FAX (719) 689-3254 November 6, 19 6 Englewood Office P.O. Box 5078, 5251 DTC Parkway, Swte 700 Englewood, CO 80155 (303) 889-0700 • FAX (303) 889-0707 SENT BY FACSIMILE & CERTIFIED RETURN RECEIPT REQUESTED P 289 926 294 Mr. Berhan Keffelew Environmental Protection Specialist Colorado Department of Natural Resources Division of Mines and Geology Office of Mined Land Reclamation 1313 Sherman Street, Room 215 Denver, Colorado 80203 NOV t7 8 I.9flii - ...~, Reference: Cresson Project; Permit M-80-244: Oueaions Regarding Status of Cresson Mine Hiehwall Stability and Additional Friction Angle Information On Cresson Ore. Dear Mr. Keffelew: [n your telephone message of 23 October 1996, you reminded the Cripple Creek & Victor Gold Mining Company ("CC&V") of [he need [o close out two items that were addressed in the permit application for Amendment Number 6 to the referenced permit, namely the results of Mine highwall mapping (in relationship to highwall stability) and an "additional shear box test" to assess [he internal friction angle of crushed Cresson ore. We will address both of those items here. 1. Mine Hiahwall Stability Pre-Mining Evaluation As par[ of the original design of the Cresson Mine, a study of the rock mass strength and the highwall slope design was performed and submitted to the Office of Mined Land Reclamation (Call and Nicholas, 1994; see Enclosure 19 of Volume VIII of CC&V's Permit Amendment Application). The results of this study have been used in a continuing re-assessment of the slopes of the mine highwalls, and have been augmented with information obtained as the mine has been developed. Results of the original study are referenced, as appropriate, below. Mine Slope Evaluation During Mining With respect to mine highwall stability, CC&V has examined, in varying degrees of detail, essentially all rock faces exposed as the Cresson Mine ("Mine") advances. This examination has included the following aspects of mine highwall slope stability: 1. The geology of Mine highwall materials;