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Ground Water <br />There are two ground water systems within and adjacent to the Blue <br />Flame operation; the Menefee Formation and the Hay Gulch alluvial <br />system. <br />The probable hydrologic consequences of mining to the Menefee <br />Formation are negligible. The Menefee is essentially dry at the Blue <br />Flame Coal Mine site. This has been historically documented at the <br />Blue Flame Coal Mine and at the King Coal Mine adjacent to the 81ue <br />Flame operation. Additionally, a drilling program initiated in 1980 <br />for the Shalako 14ine (about 1 mile northeast of the Blue Flame Coal <br />Mine in Hay Gulch) confirmed that the coal and overburden are <br />essentially free of water. Therefore, the only effect of mining to <br />the Menefee is the addition of water to the Formation during the <br />normal course of mining. The applicant has stated that about 20 <br />gallons of water per day will be used at the mine. This is an <br />insignificant amount to be added to the Idenefee Formation, given the <br />the semi-confining nature of the formation in this area which will <br />preclude rapid infiltration. Therefore, it has been determined that <br />the minor quantities of water expected to infiltrate into the Menefee <br />Formation will have an insignificant effect on the Formation. <br />The second ground water system identified near the permit area is the <br />Hay Gulch alluvial aquifer. This aquifer system may be potentially <br />affected in two ways. <br />a. Surface runoff from the mine bench and/or discharoe from the <br />sediment pond could infiltrate into the alluvial body. This <br />infiltration could cause localized increases in total dissolved <br />solids within the alluvium. The probability of this occurring is <br />minimal. The sediment control system at the Blue Flame Coal Kline <br />has been designed in such a manner so as to minimize impacts to <br />the prevailing hydrologic balance at and near the permit area. <br />All surface runoff from the mine area will flow, via a series of <br />conveyance ditches, to the sediment pond. This pond, which is <br />adequately sized to contain the runoff from a 10 year-24 hour <br />storm, will not discharge to the AYF unless the 10 year-24 hour <br />event has been exceeded. If surface water which has been <br />impacted by the operation does infiltrate the AYF, it is thought <br />that the effects will be minimized due to immediate dilution (see <br />Section 1'III of this document). Therefore, the effects of <br />surface drainage from the mine site to the AYF is insignificant. <br />b. It is possible that drainage from the access/haul road, which <br />crosses Hay Gulch from La Plata County Road 120 to the mine site, <br />could infiltrate the alluvial system. This infiltration could <br />diminish the quality of the AYF by adding total dissolved solids <br />to the system. <br />-13- <br />