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interspersed with shale layers which act as barriers to groundwater movement. Results of pumping tests <br />• during baseline studies and analyses of water level data indicated the three stratigraphic zones (Upper <br />Sandstone facies, Siltstone-Coal facies, and Lower Sandstone facies) should be classified as aquitards in <br />that they will yield water but at very slow rates. Consequently groundwater inflows into the mine are <br />expected to be very low. There are no known faults in the area. Of course, there is a possibility that some <br />faults will be encountered giving local short-tens flows. Leakers are not expected to produce more than five <br />or ten gallons per minute. If fractured zones are encountered, flows of from 50 to 100 gallons per minute <br />may be encountered for a short time. Part of the water produced in the mine is discharged to Scullion <br />Gulch or Red Wash after treating it in a process pond to meet affluent limitations under the CDPS permit, or <br />simply stored in the longwall gob area. Part of the water may be recycled for use in the mine and part may <br />be used on the surface for preparation plant makeup, dust control, etc. <br />The construction of surface facilities associated with the mine will result in temporary increases in the <br />suspended solids concentration of the adjacent and receiving stream. <br />The concentration of chemical constituents, such as total iron and total manganese and other dissolved <br />solids, will also increase slightly due to the association of various chemicals with sediment. However, <br />regulations require that sediment control be provided for all areas of surface disturbance. Thus all runoff <br />from disturbed areas will pass through sedimentation ponds or other sediment control devices prior to <br />discharge from the area. It is expected that these sediment control devices will actually lower the sediment <br />• yield of the area to the White River to some degree since the permissible effluent limitation from disturbed <br />areas is far below what naturally occurs in the area. <br />Longwall mining under Red Wash, Scullion Gulch, Halandras Reservoir, and Raven Park Reservoir will <br />result in subsidence. The amount of subsidence to be expected is described in Section III.A.7.c. The effect <br />will be a lowering of the surface over the longwall panels. Lincoln Reservoir is totaled over a room and <br />pillar panel and pillar dimensions and extraction ratio will be altered directly under Lincoln Reservoir to <br />prevent subsidence. Pillar spacing as that used in the main entries which is non-subsiding in nature will be <br />used to prevent damage to Lincoln Reservoir. <br />Overlying longwall panels, tension cracks up to several inches in width form at the surface and are usually <br />parallel to the length of the panels. Fine silt present in the drainage systems hides and quickly seals off any <br />openings in the stream bottoms. It is generally believed that any cracks that develop are discontinuous. <br />Cracks observed thus far appeared to extend to a depth not greater than a few feet. The cracks fill initially <br />with water during flow events but do not appear to tarty any significant amounts of water out of the stream. <br />In course, as these cracks fill with debris, their capacity to fill with water greatly diminishes. The tension <br />cracks characteristic of longwall mining are expected to occur at Halandrds Reservoir and Raven Paris <br />Reservoir. These cracks may result in the loss of water, provided water is present in these reservoirs as <br />they are normally dry. Loss of water could occur as a result of damage to the dams or bottom that would <br />allow seepage loss. It is not considered possible for water to flow from the surface and enter the mine area. <br />• When the coal is extracted the roof caves immediately behind the longwall. The swell of the shales and <br />Permit Renewal #3 (Rev. 1/00) II.C-82 <br />