Laserfiche WebLink
The alluvium of Coal Creek and its tributaries consists of <br /> sands and gravels derived from the Mesaverde Group, Mancos Shale, <br /> and reworked glacial and terrace deposits . This alluvium is <br /> discontinuous, varies between 0 and 75 feet and is moderately <br /> permeable. The Coal Creek alluvium is isolated into separate <br /> narrow alluvial bodies by water gaps formed by the resistant <br /> sandstone strata and by layers of clay deposited from the <br /> Mancos Shale. Wells do not produce as much as would be expected, <br /> ranging from 5 to 15 GPM. The alluvial ground water is predom- <br /> inantly a calcium, sodium, magnesium bicarbonate type. The total <br /> dissolved solids concentration is about 350 mg/l. Alluvial ground <br /> water is utilized for domestic and industrial uses. The alluvial <br /> ground water discharges to Dutch, Coal, Bear and Porcupine <br /> Creeks, providing base flow in the creeks during low flow periods. <br /> The alluvium is recharged directly from the streams during snow- <br /> melt and during R4cipitation events. <br /> The impacts incurred by ground water resources as a result <br /> of the proposed mining operations are expected to be insigni- <br /> ficant. However, several slight changes in the hydrologic system <br /> are expected: the ground water quality of alluvial ground water <br /> located adjacent to the coal processing waste and tunnel rock <br /> piles will become slightly degraded; and slight mixing of ground <br /> waters from previously unconnected aquifers may occur as a result <br /> of the proposed rock tunnel. None of these potential impacts <br /> are expected to cause material damage to ground waters in the <br /> Coal Basin area. Each is discussed in greater detail below. <br /> The disposal of mine and processing waste materials at the <br /> mine have the potential to degrade the quality of the alluvial <br /> 55 <br /> I� <br />