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silt, and clay that was deposited by stream flow in Hay Gulch during the last several thousand <br /> years. The alluvium is several tens of feet thick and approximately 1,000 feet wide. GCC <br /> has monitored the Hay Gulch alluvium for more than 30 years in a monitoring well (the <br /> Wiltse well) next to the King I Mine. Ground water in the alluvium is unconfined. The <br /> alluvium is recharged by snowmelt and precipitation, and by seepage from the Menefee <br /> Formation subcrop along the north side of Hay Gulch. The elevation of the water table varies <br /> seasonally, ranging from just above the ground surface to a few feet below the surface. <br /> Ground water in the alluvium probably flows downstream along Hay Gulch. Ground water in <br /> the Hay Gulch alluvium generally has a high concentration of total dissolved solids (TDS) <br /> and sulfate. <br /> The Cliff House Sandstone is a fine-grained marine sandstone, and is more than 200 feet <br /> thick. The mine workings lie approximately 22 feet below the Cliff House (in the Menefee <br /> Formation). Based on information from exploration drilling, this is an unsaturated formation <br /> in the vicinity of the King Coal Mine. <br /> The Menefee Formation is a fine-grained interbedded sequence of sandstone, siltstone, <br /> mudstone, and coal, and is more than 200 feet thick. The operator mines coal from the top of <br /> the Menefee. Based on information from exploration drilling and several decades of <br /> underground mining, this is generally an unsaturated formation. However, lenticular <br /> sandstones in this formation have produced viable amounts of groundwater. <br /> The Point Lookout Sandstone is approximately 400 feet in total thickness. The upper unit of <br /> the Point Lookout sandstone is a massive, medium-grained sandstone approximately 100 feet <br /> thick, while the lower member is made up of thin sandstone beds with interbedded shale. <br /> Stratigraphically, the Point Lookout sandstone lies more than 200 feet below the King Coal <br /> Mine workings. Water has been encountered in this formation in places, and the water quality <br /> has been characterized as good by a professional geologist. <br /> The only natural springs located within one mile of the King I and II Mines are the <br /> Huntington Springs, located on the north side of Hay Gulch, west of the reclaimed La Plata <br /> No. 1 Mine (File No. C-1987-072). This spring may flow from either the lower Menefee <br /> Formation or the Hay Gulch alluvium. The Huntington Springs are beyond the area of <br /> influence of the King I and I1 Mines. <br /> Additional information on ground water hydrology can be found in the permit application in <br /> Sections 2.04.7, 2.05.3 and 2.05.6 and on Maps King I-004, King I-008, King II-004, and <br /> King II-008. <br /> Surface Water Hydrology (4.05 and 4.07) <br /> There are no perennial streams within the King Coal permit area. The surface facilities of the <br /> King I and II Mines are located in ephemeral drainages that are tributary to Hay Gulch. Hay <br /> Gulch does not have a stream channel in the vicinity of the permit area. Historically, surface <br /> flow in Hay Gulch has been diverted into the irrigation ditch on the north side of the Gulch. <br /> 6 <br />