Laserfiche WebLink
Formation. The Williams Fork contains the ten coal seams to be <br />mined and is the surface outcrop on the permit area. Ground water <br />within the permit area occurs under perched conditions in the <br />interbedded and lenticular sandstones of the Williams Fork <br />Formation. These sandstones are predominately fine to medium <br />grained, poorly sorted and calcareous. The thickness of the <br />sandstones is estimated to be 1,600 feet. There is no continuous, <br />regional ground water system on the property within the <br />stratigraphic section of the Williams Fork Formation. This was <br />documented in the 1979 report prepared by Leonard Rice Consulting <br />Water Engineers' study (LRCWE>. The report concluded that there <br />was an absence of ground water from the site (see Exhibit 7A of the <br />permit application). In addition, 17 test holes were drilled and <br />their corresponding records collected when the property was <br />originally explored. All well data confirmed that where water was <br />encountered, it was limited both vertically and laterally and <br />encountered under perched conditions. For further information on <br />the well test data, see pages 2.04.7-5 and 6 of the permit. <br />In the local area there is little development of the ground water <br />resource. The few wells that have been completed in the Williams <br />Fork interbedded sandstones yield less than five gallons per minute <br />and their uses are limited to domestic and/or livestock use. <br />Nearby residents haul drinking water supplies from Craig and Meeker. <br />Saturation of the Williams Fork sandstones is weak to nonexistent, <br />with the flow controlled by the geologic structure of the Collum <br />Syncline in a downdip direction. Ground water direction follows <br />the geologic structural trend and flows to the northeast. <br />Following the downdip direction, where the ground water flow meets <br />the land surface, infrequent discharges from the Williams Fork are <br />seen as seeps and springs on the valley walls of Goodspring and <br />Taylor Creeks, both intermittent streams. Further analysis of the <br />Goodspring and Taylor Creek basins show the recharge rate to be 0.2 <br />to 0.35 inches per year from the Williams Fork surface outcrop <br />area. Annual precipitation in the area averages 18 inches. <br />Beneath the Williams Fork Formation and the coats to be mined, lies <br />the Iles Formation, sources for a regional aquifer. Thicknesses of <br />the Iles varies, with the aquifer sandstone member (the Trout <br />Creek) reaching thicknesses of up to 75 feet. The Trout Creek <br />sandstone is fine, well sorted, calcareous, and is a continuous <br />unit that can be correlated over a large area. It is mainly from <br />this sandstone member that the two creeks on the permit area, <br />Goodspring and Taylor, receive their flow. The Trout Creek <br />sandstone is believed to contain water due to a saturation zone <br />found beneath Goodspring Creek. The recharge areas for the <br />sandstone are south of the permit area in the higher elevations or <br />where the Trout Creek sandstone is exposed at the ground level and <br />subsequently has been eroded above the Goodspring Creek elevation. <br />_27_ <br />