Laserfiche WebLink
accumulating in the cracks and clay in the overburden, would ultimately seal <br />the tension cracks from the surface inflow. <br />Continued monitoring of Red Wash has confirmed the permittees' <br />predictions. As projected, subsidence in Red Wash initially resulted in water <br />ponding in the stream-bottom. The high content of silt and clay carried by <br />Red Wash rapidly fills these stream-bottom ponds and seals any cracks that <br />formed in the alluvium as a result of the subsidence. Water continues to flow <br />in the surface channel at Red Wash while piezometric levels in the basal <br />alluvial gravel have dropped, indicating that the basal alluvium is not <br />recharged by surface flow infiltration. <br />Minimal subsidence impacts are expected in Scullion Gulch, similar to those <br />observed in Red Wash. The overburden under Scullion Gulch is less than <br />that of Red Wash. Tension cracks could cause several stock ponds in <br />Scullion Gulch basin to lose impounded water. Tension cracks characteristic <br />of longwall mining are expected to occur at Halandres Reservoir and Raven <br />Park Reservoir. Although the stock ponds are normally dry, a loss of water <br />could occur where water is present as a result of damage to the dams or pond <br />bottom that would allow seepage loss. Prior to the advancement of mining <br />that could potentially impact the ponds, monitoring is required to be initiated, <br />and the ponds repaired or replaced by the operator if water retention <br />capability of the ponds is diminished due to subsidence. The operator will <br />haul water for stock in the event of pond repair or construction. <br />2. Ground Water Impacts <br />Water encountered within the mine will be utilized underground for dust <br />suppression. As a result, only those inflows that temporarily exceed storage <br />capacities and mine use requirements would potentially be discharged to the <br />surface and lost from the ground water system. Pumping from approved <br />mine water discharge locations ceased upon the sealing of the D seam <br />northern longwall district in 1996. Although dewatering could be <br />accomplished by installation of a submersible pump, dewatering is not <br />currently anticipated. If mine water discharge were to occur, there would be <br />no loss to the hydrologic system, being that ground water in the area is <br />tributary to the White River. <br />Since January, 1997, prep plant thickener water has been disposed <br />underground within down-dip, sealed sections of the D seam mine. No <br />discernible effects on surface water or ground water quality are anticipated, <br />although water levels will be reestablished sooner than would otherwise be <br />the case. <br />Subsidence effects include fracturing of the material overlying the coal for a <br />distance of 30 to 40 feet due to caving of the roof material and surface <br />Deserado Mine 23 September 19, 2008