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to the ground water regime. <br /> Though the Sanborn Creek operation mined both the B and C seams that had <br /> been mined before at the old Somerset Mine, the Sanborn Creek Mine was not <br /> connected to the old workings and was protected by a 100-foot buffer. The old <br /> Somerset mine is thought to be flooded and that buffer was apparently <br /> successful in protecting the newer operation from inundation from the old <br /> workings. The 100-foot buffer was maintained by advance drilling to find the <br /> location of the old workings. <br /> Mine water inflow into the Sanborn Creek workings is estimated to be 425 <br /> gpm or less. The old Somerset Mine had an inflow rate of 0.15667 gpm/acre <br /> for the 1,500 acres of development in the mine that was below the level of the <br /> North Fork River. Projecting this rate to the 2,600 acres of the Sanborn Tracts <br /> yields an inflow of 407 gpm. The operator has rounded this figure to 425 gpm <br /> in the PAP. It is not known at the time of this findings document what the <br /> source of the mine inflow water was during the spontaneous combustion event <br /> in 1999. The operator has also projected an additional 235 gpm discharge from <br /> the old Somerset Mine, which has the potential to reach the North Fork of the <br /> Gunnison via the alluvial system. This is considered to be extremely unlikely; <br /> however, the projection is used in the CHIA to allow for absolute worst-case <br /> prediction. The following are potential sources for inflow: <br /> (a) The North Fork of the Gunnison River is 750 feet to the south and 100 feet <br /> above the proposed B-seam workings and 40 feet above the C-seam <br /> workings. Groundwater is expected to travel down dip from the river <br /> through the coal and overburden into the mine workings. Because of the <br /> low permeability of the coal and overburden, calculations have shown that <br /> these flows should be minor. The flows can be expected to occur with a <br /> considerable lag time. There will be a comparable diminution of flow in <br /> the North Fork, but mine pumping will return this amount to the river, <br /> minus that used in the mine. The cone of depression from dewatering of <br /> the strata will only extend to the boundary of the North Fork and will not <br /> adversely impact any wells. <br /> (b) The potential exists that the mine may encounter water inflow from faults <br /> and fractures. No particular faults have been identified. The largest fault <br /> that the old Somerset Mine encountered had a sustained inflow of 120 <br /> gpm, which contributed 50 percent of the total inflow. <br /> (c) The Sanborn Creek workings undermined portions of two abandoned <br /> mines - the Oliver Mine and the Hawk's Nest Mine. The Oliver Mine was <br /> mined in the 1930's and is thought to be flooded. An exposure of the <br /> workings adjacent to the old county road formerly discharged water at a <br /> rate of a few gallons per minute. About 90 percent of the workings of this <br /> mine lie downdip of the discharge point. <br /> 20 <br />