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III IIIIIIIIIIIIIIII 999 Wyoming !~uel Compony 12055 W. Second Place • P.O.Box15596 • Lakewood, Colorado 80215 • Telephone (303)989-5037 August 15, 1984 RECEIVED AU G 151984 Ms. Susan Mowry Reclamation Specialist 1313 Sherman Street Denver, Colorado 80203 MINED LAND RECLAMATION DIVISION Colo. Dept of Natural Resources Re: Response to Problems 84-012-04 and 84-012-07 for the New Elk Mine, Problems 84-013-01 and 84-013-03 for the Golden Eagle Mine Identified in Jim Herron's April 24, 1984 Inspection Report Dear Ms. Mowry: By this letter Wyoming Fuel Company (WFC) is responding to the above stated problems. The following responses are based on preliminary evaluations and the meeting held on August 7, 1984 with you, Jim Herron and myself. New Elk Mine Problem 84-012-04. An analyses of culvert sizing can be found in Appendix A. The basic approach was to determine if the design flow capacity could be met by using available head (difference in top of road or top of rail elevation to bottom of inlet). With the exception of CMP 2 all installed culverts in question will handle design flows without overtopping. The design flow for CMP 2 is 104.57 cfs. The existing culvert (36 inch CMP) will handle 70 cfs. WFC will bring this into compliance by constructing an Arizona crossing or improving the inlet. Construction details will be submitted as a minor revision. Since the runoff season is coming to a close I feel there is no need to do this work during 1984. WFC will commit to submitting the minor revision by the end of February 1985 and complete construction by April 15, 1985. Problem 84_012-07. Appendix B contains survey information for ponds 004, 005, 006 and 007. During the April 24, 1984 inspection, pond 007 was dewatering at a lower elevation than the maximum sediment storage volume, which under current CMLRB policy is 100%. This indicates the slots in the principal riser are below the maximum sediment level. The survey shows the principals have sufficient Height with minor pond cleaning to handle the 100% sediment level plus a !0 year 24 hour storm event. WFC plans to modify the principals as necessary to meet section 405.6(3)(c) of the CMLRB regulations. WFC will commit to this by April 15, 1985. The relative elevations presented in Appendix B shows the emergency spillways will handle design flow depths presented in the application with 1 foot of freeboard. Tn addition, based on elevations differences between the top of the principal and bottom of the emergency no discharge should occur during the 10 year 24 hour storm event.