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• • iii iiiiiiiiniiiiii Cripple Creek And victor Gold Mining Company 999 C C A Joinl Venture -Pikes Peak Mining Company. Manager ~Y~ Operations Office Englewood Office lX. P.O. Box 191, 2755 State Highway 67 P.O. Box 5078, 5251 DTC Parkway, Suite 700 Victor, CO 80860 Englewood, CO 80155 (719) 689-2977 • FAX (719) 689-3254 (303) 889-0700 • FAX (303) 889-0707 August 11, 1995 SENT BY FACSIMILE AND CERTIFIED RETURN RECEIPT REQUESTED 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 RECEIVED AUG 15 1995 Division Of Minerals is cieology Reference: Cresson Project: Permit M-80-244: Re-Revision of Underdrain Layer Sequence. Dear Mr. Keffelew: On August 3, 1995 we submitted to you a proposal to modify the underdrain sequence involving the geotextile material. Our objective was to enhance containment of the select fill located above the underdrain and to obtain the benefits of the well-sorted select material that produces a smooth surface by repositioning the geotextile. Upon discussions with Dr. Pendleton, we have revised our proposal of August 3 to revert to the original design which places the 12 ounce non-woven geotextile under the geomembrane in the area over the limits of the underdrain. In addition, we propose to place the same 12 ounce non- woven geotextile under 20 feet on both sides of the 40-foot geomembrane overlap that extends up to 40 feet from the underdrain. This geotextile will be leistered to the 12 ounce geotextile at the boundary of the underdrain. The sequence is shown in the attached drawing (Attachment 1). Though the geotextile could be of lighter weight based on the need only for cushioning in the overlap area, for logistical reasons we have not chosen to reduce the weight of the geotextile in the overlap azea. The geotextile is to be placed on top of the lower 6 inches of select structural fill and thus immediately beneath the geomembrane that responds to the request of your Office. The geotextile does not extend to the full width of the geomembrane overlap because, once outside the area of the underdrain rock fill itself, the potential for migration of the select structural fill is eliminated and, therefore, the need for the geomembrane to flex in response to such migration is eliminated and the need for cushioning is thereby reduced.