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• nearest upgradient mining activity in the initial cuts of the A East pit. Mining in this area has to date had no <br />obvious effect on flows at this site. Flow from this spring is not expected to be impacted during post-mine <br />conditions. This spring exists near the southern limits of the Third White Sandstone outcrop and has been <br />thought to emanate from the Third White Sandstone. A travertine deposit has been noted to exist on the <br />surface at the site of the Fox Den Spring. This deposit may indicate that water quality from this spring was <br />significantly different in ttie past for some period, or that the source of this spring is from a deeper aquifer <br />containing more highly mineralized water. Sulfate and TDS concentrations measured at the Fox Den <br />spring are similar to levels documented in Third White Sandstone wells GC-2 and GP-9. <br />A deeper source for the l=ox Den spring would require that a permeable zone exists to transmit the water <br />to the land surface. Though no obvious geologic structural features have been identified in the immediate <br />vicinity of the Fox Den Spring, some subtle indications are present. A similar travertine deposit was noted <br />to exist at springs to the ~sast in Flume Gulch (Spring 99-2 and Spring 99-3). The alignment of these <br />springs and the Fox Den Spring roughly paralleled anorthwest/southeast trending regional fault system, <br />the Cedar Mountain fault system, north of the project area. This is the dominant geologic feature in the <br />area. The Big Bottom S~mcline may have smaller displacements or slips associated with it that could <br />conceivably transmit wabsr. This type of feature could account for flows at the Fox Den Spring. The <br />lithologic units at Trapper have numerous layers of very fine-grained material that would be expected to <br />• have sealed any significant vertical fracture zones or displacements. However, a small displacement on <br />the order of tens of feet may have occurred without the extensive sealing or smearing of the fracture zone <br />associated with a larger fault. <br />The springs in Flume Gulch (Spring 99-2 and 99-3) were near the southern limits of saturation in the Third <br />White Sandstone aquifer and were also thought to be discharges from this groundwater system. <br />However, TDS and sulfal:e concentrations measured at these features occurred at lower levels than those <br />documented at Third White Sandstone wells GC-2 and GP-9. Spring 99-2 flowed from a vertical pipe at <br />an old homestead location. Details regarding the installation of the pipe are unknown, however, field <br />measurements showed the pipe extended down roughly 180 feet from the surface. The H seam is known <br />to lie about 30 feet deep at this location. The structural model for the site indicated the pipe at Spring 99-2 <br />extended nearly to the M seam. Based upon this information it is possible the flow from Spring 99-2 <br />stemmed from waters derived from the KLM interval. An exploration drill hole was established roughly 40 <br />feet west of Spring 99-2. This hole (99-AE23) was drilled to a total depth of 60 feet and was initiated near <br />the base of the Third White Sandstone. During drilling, the flow from spring 99-2 was observed to stop as <br />flow from the exploration drill hole commenced, suggesting the shallow exploration borehole was providing <br />an alternative flow path for the water normally discharged from the spring. Once the exploration hole was <br />sealed, flow from the spring was reestablished. This may indicate that water from Spring 99-2 was <br />• derived from a shallow source. Springs 99-2 and 99-3 were both disturbed by mining activities during the / <br />fall of 2000. <br />Ap~roEr,~ ~: (~ 0 <br />4-238a <br />