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CM0001995 <br />Additionally, it was shown that the presence of the Mosquito Fault provides a hydraulic barrier <br />to lateral flow of ground water flow in the bedrock. • <br />The direction of ground water flow is coincident with the surface water drainages, where ground <br />water discharges into streams and creeks. The Climax Mine Storm Water Management Plan <br />(W.W. Wheeler, 1995) details potential discharges from mines, seeps, and springs in the <br />affected area of ground water. <br />The following sections present a discussion on the hydrogeologic conditions which are specific <br />to the three drainages at the Climax mine site. <br />Tenmile Creek valley <br />Ground water in the Tenmile Creek valley primarily occurs in a veneer of alluvium and glacial till <br />which overlay bedrock consisting of Paleozoic sedimentary and Tertiary quartz monzonite <br />formations. Data from seismic refraction surveys and monitoring well logs (Climax Molybdenum <br />Co., 1984) indicate that the alluvium and glacial till range in thickness from 0 to over 90 feet. <br />The alluvium consists of deposits ranging in size from clays and silts to boulders. Ground water <br />level data indicate that ground water occurs between 10 and 30 feet below ground surface with <br />a seasonal flux in elevation. <br />The direction of ground water flow in the Tenmile Creek valley is controlled by the bedrock <br />topography and outcroppings. Hydraulic conductivity data of the bedrock and the overlaying <br />soils are summarized in Table 1. These data were measured as part of the construction of the <br />Mayflower Tailings Dam. A total of 44 tests in eight holes were conducted using both slug and <br />packer testing methods (Kumar & Assoc., 1994). • <br />Table 1 <br />Summary of Field Hydraulic <br />Conductivity Tests <br />Unit - Hydraulic Conductivity Range (ft/yr) <br />Alluvium 2,595 - 88,378 <br />Glacial Till 22 - 1,238 <br />Paleozoic Sedimentary Bedrock 0 - 596 <br />Tertiary Quartz Monzonite Bedrock 18 - 54 <br />As shown, the field hydraulic conductivity test data indicate that the alluvium and glacial till in <br />the Tenmile drainage are significantly more permeable than the bedrock units. By comparison, <br />the bedrock units are of relatively low permeability. Therefore, the bedrock units are not capable <br />of transporting significant quantities of ground water. <br />In 1987, two ground water monitoring wells, GWM #1 and GWM #2 were installed in the • <br />Tenmile drainage, downgradient of the Mayflower Tailings Dam. Drillers' and completion logs