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• 2.04.5(1) <br />of several thousand feet of sediments. This action tends*.o allow <br />the sediments near the surface to expand and exaggerate their <br />true dip. Dip measurements on the Rollins Sandstone indicate a dip <br />of seven to ten degrees. However, calculated dip from drill hole <br />logs in the permit area indicate a dip of three to four degrees. <br />No other major geological structures exist in the area. No faulting <br />or folding of significant magnitude has been located within or <br />near the permit boundaries. <br />Ground Water System. <br />Significant amounts of ground water are contained within the Red <br />Canyon # 1 Mine and proposed # 2 Mine permit boundary. These can <br />be subdivided generally into two aquifer systems. The shallowest <br />and most significant of these would be the alluvial glacial outwash <br />deposits, which reach a maximum thickness of approximately <br />• 250 feet in the area north of the permit area. A second aquifer <br />system would be the coal seams themselves (which derive their <br />permeability from secondary facturing) and other bedrock unit such <br />as the numerous lenticular, tightly cemented sandstone units. The <br />coals and sandstone units in the area both appear to have a very <br />low permeability and porosity and do not contain or transmit large <br />amounts of water to any wells in the area. The Bedrock Configuration <br />Map, 2.04.5-2, is a map ehowinq surface geology as well as the location <br />of all water wells in the vicinity of the permit area. Although <br />a number of water wells do exist in the area, their depths (as derived <br />from the State Engineers Office records, Figure 2.04.5-1) are shallow <br />and yields low enough so as to not affect the underlying bedrock <br />aquifers. Conversely, mining and dewatering of the coal seams <br />should not significantly interfere with utilization of this water <br />in the immediate area. There will be significant inflow problems <br />near the subcrop of both the "D" and "E" coal seams where they are <br />in direct contact with the base of the glacial alluvial material. <br />This problem will be addressed in a later section. <br /> <br />9~ <br />