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Whirlwind Mine Groundwater Characterization Report <br /> from the PR Spring by an impermeable mudstone layer. USES postulated that this mudstone <br /> unit serves as a barrier to vertical downward migration of groundwater from the overlying ore- <br /> zone sandstone to the underlying sandstone unit associated with PR Spring. USES further <br /> stated that any groundwater percolating downward to the mudstone unit was directed to the <br /> northwest toward the Lumsden fault where it would eventually dissipate. <br /> Umetco goes on to evaluate water chemistry data from the Packrat Mine and PR Spring <br /> concluding that there was no indication that the two waters were commingling and that they <br /> were essentially not hydraulically connected. <br /> PR Spring is located at a lower elevation than the Packrat Mine portal and emanates from a <br /> sandstone ledge a few hundred feet north of the mine within the lower portion of the ore-bearing <br /> sandstone. The concentrated flow emanates from a joint or fracture in the sandstone ledge. <br /> The joint has a strike of N65OW and dip of 80ON (USES, 2001). The relatively constant flow <br /> observed at PR Spring versus no discharge at the Packrat Mine support this concept. <br /> Umetco and BLM gathered data between 1993 and 1997 and found that the Packrat Mine <br /> discharged approximately 1 gpm at the portal until the end of 1995 when flow ceased (EFR, <br /> 2008a). The Packrat Mine is known to be partially flooded currently but the mine does not <br /> discharge water at the portal/surface. During active mining at the mine in the mid-1950's <br /> through the 1980's, water collecting in the underground sumps was pumped and discharged at <br /> the surface. Since mine operations were shut down in the early 1980's, the mine was allowed to <br /> flood and infiltrate into surrounding formations. <br /> Specific evaluation of water chemistry at PR Spring and Packrat Mine are discussed in Section <br /> 5.0 (Water Chemistry) of this report. <br /> 4.2.1.7 Monitoring Well W-1 <br /> Monitoring Well W-1 was drilled and installed in October 2008. The well was installed to monitor <br /> shallow groundwater conditions within the Brushy Basin Member in the area of a planned waste <br /> rock repository. The monitoring well is located approximately 30 ft north of County Road 5/10 <br /> and 350 ft south of the Whirlwind Mine portal (see Figure 5). Air rotary drilling methods were <br /> used. The driller reported damp conditions at 30 ft and 78 ft, but no water was produced at the <br /> Western Water S Land, Inc. 21 <br />