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STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80103 <br />Phone: (303) 866-3567 <br />FAX: (303) 832106 <br />August 3, 2005 <br />Mr. William A. Bear <br />Bowie Resources LLC <br />P.O. Box 483 <br />Paonia, Colorado 81428 <br />RE: Bowie No. 2 Mine, Permit No. C-96-083, Bowie Resources LLC <br />Technical Revision No. 37, Pond F Revised Discharge Structures <br />Dear Mr. Bear: <br />COLORADO <br />D[ V (5 I O N O F <br />MIN SRALS <br />GEOLOGY <br />aECll1N~TION•NINING <br />F~FFTY•FCIENCF <br />sal osvens <br />Governor <br />Russell George <br />Executive Director <br />Ronald W. Cattany <br />Division Director <br />Natural Resource Trustee <br />The Colorado Division of Minerals and Geology (Division) has finished its review of Bowie <br />Resources LLC (BRL) responses, dated July 22, 2005, to questions 6A and 6B in the Division's <br />adequacy review letter dated July l4, 2005. The following is the status of these two issues: <br />6. In item number one of BRL's adequacy response letter dated June 20, 200.1, BRL stated <br />tha[ the calculated capacity of the pump that dewaters pond F was reduced from 397 <br />gpm dolvn l0 275 gpm. As shown on page App-B-B of BRCS June 9, 2005 adequacy <br />response, this reduction in the pump capacity increases the dewatering time Jor pond F ro <br />2.9 days. The Division has two comments: <br />A. ,9lthotrgh not a specifac requirement of the Division's regulations, the <br />Division has adopted a guideline that sedimentation ponds need to be deleatered <br />lvithin .?6 hours of u precipitation event so that enough pond eapaeity Is available <br />to store the runofffrom a 10 year-ld hour precipitation event. Please install a <br />pump with the capacity to dewater pond F within 36 hours. <br />The Division has no further concerns. As shown on revised permit page App-B-$, <br />BRL will install a larger pump that can dewater the pond in 1.7 days. <br />B. On page App-B-8 of the submittal dated June 9, 200.1, BRL has calculated the <br />time needed to dewater the entire volume ojpond F that has been set aside for <br />water storage. However, us a worse case scenario, only the time needed to <br />dewater the hater volume resulting from the JO year-24 hozrr precipitation event <br />needs to he calculated In order to avoid any confusion. please revise page App- <br />B-8 to reflect This change. <br />The Division has no further concerns. Revised permit page App-B-8 shows the <br />revised dewatering volume. <br />Office of Office of Colorado <br />Mined Land Reclamation Active and Inattive Mines Geological Survey <br />