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located above the mined seam, will be dewatered during the course of mining <br />operations. The perched aquifers above the mine are probably limited both in <br />number and in areal extent: There is no documented use of any of these <br />aquifers; nor is there any evidence to suggest that these aquifers supply base <br />flow to any local streams or springs: Therefore; impacts to perched aquifers, <br />and the Menefee formation as a whole; will be minimal: <br />The second ground water system identified near the permit area is the <br />Hay Gulch alluvial aquifer: This aquifer system may be potentially affected <br />by surface runoff from the mine bench or discharge from the sediment pond <br />infiltrating into the alluvial body: This infiltration Could cause localized <br />increases in total dissolved solids within the alluvium: The probability of <br />this occurring is minimal: The sediment control system at the King Coal Mine <br />has been designed to minimize impacts to the prevailing hydrologic balance at <br />and near the permit area. All surface runoff from the mine area will flow, <br />via a series of conveyance culverts and ditches; to the sediment ponds, which <br />are located on either side of the combination haul/access road adjacent to the <br />alluvial valley: The sediment ponds, which are adequately sized to contain <br />the runoff from a 10-year, 24-hour storm; will not discharge until a storm <br />event of this magnitude has been exceeded. National King Coal has committed <br />to an extensive water quality sampling plan; should the ponds discharge due to <br />mine portal discharges: The sampling plan should be an effective method of <br />determining the extent, if any; of impacts which are occurring to the alluvial <br />aquifer system: <br />It is thought that; due to the great quantity of water transported within the <br />alluvial aquifer; the effects of surface drainage to the AVF will be <br />immediately mitigated. <br />B. Cumulative Hydrologic Impact Assessment <br />The Division has made an assessment of the probable cumulative hydrologic <br />impacts of anticipated and permitted mining operations within the ground water <br />and surface water study areas: The purpose of the assessment is to determine <br />the cumulative impacts to the hydrologic system from all existing and <br />anticipated coal mining operations within the ground and surface water study <br />areas: <br />The surface water study area is defined as the Hay Gulch drainage basin from <br />Hesperus, Colorado; to its confluence with the La Plata River, near Kline, <br />Colorado: The ground water study area is defined as the Menefee Formation and <br />Hay Gulch alluvial aquifer in the immediate vicinity of the existing and <br />anticipated mining activities: <br />The coat mining operations which are considered in this cumulative assessment <br />include the La Plata No: 1 Mine (permit issuance pending; inactive); King Coal <br />Mine (permit issued, active); and the Blue Flame Coal Mine (permit issuance <br />aQnding, inactively <br />-14- <br />