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MOUNTAIN COAL COMPANVL.L.C. A Subsidiaq~ o! Arch \Vcslem Resources, LLC February 1, 1999 Me Jim Burnell Colorado Division of Minerals and Geology 1313 Sherman Street, Room 215 Denver, CO 80203 iii iiiiuiiiiiii iii Wes[ Elk Mine ~E P O Bo.~ 591 CEIVEp 5174 Hi~h~ray 133 Somerset, C0 81434 FE3 0 2 ~g99 Far (970) 929-5995 Division orMmerals 8 Geology RE: Technical Revision No. 88 (Hydrology Monitoring Program Reduction); West Elk Mine; Permit No. C-80-007 Dear Jim: Mountain Coal Company, LLC (MCC) submits the enclosed technical revision application to reduce the hydrology monitoring program for the West Elk Mine. The reduction is based on the enclosed report entitled "Chazacterization of Groundwater Systems in the Vicinity of the West Elk Mine, Somerset, Colorado" prepared by Mayo and Associates. Also enclosed is an evaluation of MCC's current monitoring program, also completed by Mayo and Associates, that provides recommendations of changes to the program based on a groundwater systems characterization. MCC commissioned this study by Mayo and Associates because the monitoring program has been modified several times predominately to add new resources in the new mining areas (i.e. Jumbo Mountain, Apache Rocks, etc). As a result, MCC has likely been monitoring redundant resources and/or continuing to visit sites that are no longer providing valuable data. The hydrogeologic characterization of the West Elk Mine area is based on a synthesis of existing hydrogeologic information, new isotopic data collected during 1998, and the results of a previous study completed by Mayo and Associates regarding the in-mine, fault related groundwater inflows. Mayo and Associates evaluated the shallow groundwater systems in each geologic formation and the deep groundwater systems, including those encountered within the West Elk Mine. A description of recharge and dischazge locations for the vazious groundwater systems, and an evaluation of the interconnectedness of the shallow groundwater systems encountered at the surface with the deep groundwater systems is also provided. Upon completion of these analyses and resulting characterizations, Mayo and Associates reviewed MCC's current hydrology monitoring program, including all data that has been obtained from these sites. Flow data, water levels, water quality, sources of springs, and planned mining areas were reviewed. As a result, Mayo and Associates have recommended that MCC eliminate nine wells and 18 springs, and reduce the annual laboratory analyses to only the required pazameters after five years of full-suite analyses have been completed at each site. The proposed monitoring program will retain 15 wells and 19 springs.