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-22- <br /> of this great depth, no site-specific data has been collected regarding the <br /> hydraulic characteristics or water quality of these potential aquifers. <br /> However, the applicant has provided estimated ranges of permeabilities in the <br /> sandstone aquifers, which range from 0.01 to 1 foot per day, and of <br /> transmissivities; which range from 0.5 to 150 square feet per day. During a <br /> U.S.G.S. survey, only one well was located in the Mesaverde Group in the <br /> vicinity of the mine. It is not known specifically what stratigraphic unit <br /> this well is completed in. However, the water quality of this well was <br /> reported to be a calcium bicarbonate type with a total dissolved solids <br /> concentration of 181 mg/l . <br /> The most prominent aquifer in the vicinity of the Mid-Continent operations is <br /> the alluvial aquifer of Coal Creek. Yields in this aquifer are reported to <br /> average 20 gpm. Mid-Continent has completed 9 observation and production <br /> wells into this alluvial aquifer, and the alluvium of several of the smaller <br /> drainages (see Map IV-C-1 and Map III-E-1 of the permit application) . Depths <br /> of these wells range from 10-75 feet. The water quality of the aquifer is <br /> generally a calcium, sodium, magnesium-bicarbonate type with an average total <br /> dissolved solids concentration of 347 mg/l. Iron and magnesium concentrations <br /> are high, but the water is still suitable for domestic uses (see Section <br /> III-E-2 of this permit application). The alluvial aquifer is probably <br /> recharged from 4 sources; <br /> 1 . the direct infiltration of precipitation and snowmelt. <br /> 2. surface water streams during periods of high flow, <br /> 3. discharge of the adjacent colluvial/outwash deposits; and <br /> 4. discharge of adjacent bedrock strata <br /> The alluvial aquifer probably discharges to the following locations: <br /> 1 . the surface water during periods of low flow (contributing to base <br /> flow,) <br /> 2. the adjacent bedrock strata, and <br /> 3. the alluvial aquifer of the Crystal River, farther downstream. <br /> The colluvial/outwash deposits are minor aquifers. These deposits underly the <br /> proposed Sutey Disposal Site and are tributary to the alluvial aquifer Coal <br /> Creek. Tese boring of the outwash deposits in the disposal site indicate that <br /> these colluvial/outwash deposits are primarily composed of weathered Mancos <br /> shale. The upper part of the outwash deposits are primarily a silty clay <br /> material and the lower part clayey gravel . Ground water levels seasonally <br /> fluctuated between 15 and 4.1 feet below land surface (as indicated by <br /> monitoring well data). <br />