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Whirlwind Mine Groundwater Characterization Report <br /> presence of PR Spring and by observations of mine water in some of the historical mines that <br /> tunneled directly into the Top Rim from the surface; this includes the Packrat Mine, which is part <br /> of the proposed mining operations by EFR. However, while several mines that headed into the <br /> Top Rim reported mine water discharge at some time in the past, these volumes were relatively <br /> small, amounting to only a few gpm. Such mine discharge is not observed presently. In addition, <br /> other observations, at least for the Packrat Mine, stated that water was entering the mine from <br /> drill hole intercepts, originating from the overlying Burro Canyon and/or the Brushy Basin <br /> aquifers. Anecdotal information from past mining in the Top Rim sandstone indicates that the <br /> unit does not readily produce groundwater in the mines. <br /> Borehole testing at Borehole BM00-1, as conducted by Umetco in 2000, did not indicate that the <br /> Top Rim sandstone was an aquifer. If groundwater was present in the Salt Wash test interval, it <br /> did not readily yield to the borehole such that water could be pumped to the surface. Exploration <br /> holes drilled by EFR in 2007 showed at least one drill hole to be dry into the Salt Wash; other <br /> holes required injection of water at shallower depths, so the status of groundwater in the Salt <br /> Wash could not be determined. <br /> An ex-situ hydraulic test conducted on core of Salt Wash Top Rim sandstone resulted in two <br /> permeability tests showing values of 2.9 x 10-6 cm/s (0.00822 fuday) and 1.7 x 10-6 cm/s <br /> (0.00482 ft/day). Such permeability is within the mid-range of hydraulic conductivity for <br /> sandstone (Freeze and Cherry, 1979). These results are within the same order of magnitude of <br /> in-situ hydraulic tests conducted in the Salt Wash Top Rim sandstone at the Sunset Mine <br /> Complex in San Miguel County, Colorado (WWL, 2020). A permeability of this magnitude would <br /> be expected to yield groundwater to an open borehole or well, albeit slowly, if groundwater were <br /> present. <br /> The physiographic setting of the Whirlwind Mine and vicinity is somewhat unique in that the <br /> development and presence of groundwater-bearing units in the area is limited to a mesa <br /> highland where hydrostratigraphy is essentially terminated by topographic relief in all directions. <br /> This topography limits the development of substantial regional aquifers within the underlying <br /> and eroded Mesozoic rocks that make up Dolores Point mesa. Aquifers would be expected to <br /> be limited in extent due to the exposure of subsurface geologic formations in both upgradient <br /> and downgradient locations, which allows for minimal upgradient aerial recharge and substantial <br /> downgradient drainage which is predominately in the form of evapotranspiration. <br /> Western Water& Land, Inc. so <br />