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The King Coal operation has predominately mined the upper coal seam from the Menefee during the <br />course of its operations. <br />Ground Water Hydrology <br />Two aquifers have been identified within the azea potentially affected by the King Coal operation: <br />the Hay Gulch alluvial aquifer; and, the Point Lookout Sandstone. <br />The Hay Gulch alluvial aquifer, which is adjacent to the operation, averages 20 feet in depth and had <br />a cross sectional area of 25,200 squaze feet, with an estimated transmissivity of 70,400 gallons per <br />day per foot (gpd/ftJ. The water table surface in this alluvial aquifer vazies with season from above <br />ground surface to about 3 feet below the surface. The direction of flow in this unconfined system is <br />downstream, parallel to the strike of Hay Gulch. Rechazge to the alluvium is from snowmelt and <br />precipitation infiltration, and from the Menefee Formation contact along the north side of Hay Gulch. <br />Sampling of this alluvial water by National King Coal indicates that the water is high in total <br />dissolved solids. The poor quality of the water makes it unsuitable for domestic and irrigation <br />purposes, but usable for stock watering. <br />An analysis of the probable effects of mining to this aquifer indicate that very little effect would be <br />observed. Future operations in the Upper Menefee coal seam aze not expected to disrupt aquifers, <br />streams, waters systems, or the small watershed up slope of the mine site. Hydrologic data obtained <br />from existing workings, core drill holes, and other reseazch studies show that the mining operations <br />have had only a mild impact on the water sources of Hay Gulch. The mine is not located in a maj or <br />groundwater recharge azea. Reseazch has shown this portion of the basin has had very little ground <br />water development. Most ofthe wells in the general azea have been completed in the unconsolidated <br />alluvial gravels and terrace deposits of the La Plata River and its tributaries (including Hay Gulch), <br />or in consolidated aquifers further south (down dip) in the basin. The Point Lookout Sandstone <br />aquifer, neazly 275 feet below the mine floor, to date has been unaffected by mining operations. <br />With the exception of a very brief period in eazly 1986, all mine workings have been dry. All coal <br />within the permit azea lies above the potentiometric surface of Hay Gulch; therefore, it is not <br />expected there will be any hydrologic consequences due to mining. <br />Ground water use in the vicinity of the mine is limited. Within aone-mile radius of the facilities <br />azea, one spring and three water wells have been identified. <br />The Huntington Spring is located on the north side of Hay Gulch west of the La Plata No. 1 Mine <br />area (File No. C-87-072). This spring, which may issue from either the lower Menefee Formation or <br />the Hay Gulch alluvium, has been adjudicated for a water right. La Plata Coal Corporation <br />demonstrated during permitting of the La Plata No. 1 Mine that this water right has been abandoned; <br />therefore, no further investigations or monitoring aze being required. <br />Two water supply wells aze located in the immediate vicinity of the facilities azea: one at the King <br />Coal Mine and one at the La Plata No. 1 Mine. A third water well, located in an up slope tenace <br />deposit, has been capped and abandoned. Although no completion data have been submitted, it <br />appears that the abandoned well was completed in the underlying Point Lookout Sandstone. The <br />4 <br />