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36 <br />solids concentration observed in Ennis Draw must result from dilution <br />with better quality water flowing from the south through the sand and <br />stream deposits in the draw. Locally, water may be trapped in Ennis Draw. <br />Although the water in the coal is of significantly better quality <br />than that of the overburden, in neither case can the waters be regarded <br />as acceptable for many uses. Anticipated changes in water quality as <br />a result of mining are discussed in a subsequent section of this report. <br />IV. Subsurface Hydrolony and l•Jater Quality Durino ~tinina <br />A. Pit Inflow Estimates <br />Extraction of the coal seam 6y removing the overburden in strips <br />and backfilling in the adjacent pit will completely disrupt the natural <br />sequence of strata from the bottom of the coal seam to the surface. The <br />• existing strata will be replaced by a mixture of geologic materials in <br />the form of rubble produced by the blasting and excavation of the over- <br />burden and coal. <br />The area to be mined is divided into three suhareas, designated pits <br />A, 8, and C as shown in Figure 16. Except fora small area in the north- <br />west corner of Pit A, the overburden will be removed by drag line, exposing <br />the coal in a pit with the geometry of a trench 100 ft wide and 3000 ft <br />long on the average. Operations will begin on the north boundary of Pit <br />A and progress southward; the long axis of the pit being oriented in an <br />approximate east-west direction, Mining will be confined to Pit A for <br />the first year while a buried pipeline is removed from Pit B. After <br />removal of the pipeline, the drag line will alternate between Pits A and <br />B on each pass. Coal removal will occur in Pit B while the drag line <br />is in Pit A and vice versa. <br /> <br />i <br /> <br /> <br /> <br />