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Appendix E. Groundwater Monitoring <br />Aquifers in the Paradox Basin typically behave as unconfined where the formations outcrop at <br />the surface which is the case in the project area. Recharge is typically from precipitation through <br />surface outcrops along the edge of valleys and infiltration along river channels (Topper et al., <br />2003). Typically, groundwater flows from the outcrop toward the direction of major streams <br />(Robson and Banta, 1995). <br />Bedrock of the Morrison formation underlies the project area. The Salt Wash member of the <br />Morrison is the target zone for mining exploration at the Last Chance site. The Salt Wash <br />member consists primarily of interbedded sandstones, siltstones, and mudstones. In the Paradox <br />Basin, these sandstones can serve as aquifers separated by the siltstone and mudstone beds. <br />However, Salt Wash sandstones at the project site are relatively dry probably because they are <br />located on the relatively small Davis Mesa where recharge would be minimal. Since the Salt <br />Wash outcrops along the edges of the mesa, any groundwater would not be easily contained for <br />long within these sandstones. In fact, no groundwater has been encountered in existing shafts at <br />the Last Chance Mine. <br />The Salt Wash member is underlain by the Summerville formation which consists of relatively <br />impermeable shale that is several hundred feet thick. Thus, the Summerville acts as an aquitard <br />inhibiting downward percolation of most groundwater from the Salt Wash sandstones to aquifers <br />which are several hundred feet below. <br />Nuvemco contracted the drilling of two groundwater monitoring wells on the east end of Davis <br />Mesa to investigate potential groundwater under their claims that might be impacted by drilling <br />and/or mining operations in the area. Locations and design were chosen with the assistance and <br />agreement of Mr. David Bird, DRMS Hydrologist. Wells were drilled by Little Maverick <br />Drilling Company and constructed by Nuvemco under the direction of professional geologist E. <br />Thomas Cavanaugh (CPG 10493). The monitoring holes drilled on October 1, 2008 are located <br />in the SEA Section 18, T. 46 N., R. 17 W as shown on a portion of the USGS Bull Canyon <br />Quadrangle on the next page. Monitoring Hole Number 1 (MMW 1) was drilled in the NE 1 /4 <br />SETA under Colorado Division of Water Resources (CDWR) Notice of Intent to Construct <br />Monitoring Hole permit 48088-MH, and MMW2 was located in the NW1/4 SE1/4 pursuant to <br />NOI 48032-MH. Both monitoring holes were converted to monitoring wells in accordance with <br />CDWR in January 2010. The wells have been measured and found to be dry for the last five <br />consecutive quarters. <br />Note that MMW 1 initially had about 20 feet of water in the casing. As water was hand bailed for <br />samples, it did not recharge. All of the water bailed was collected and submitted to Evergreen <br />Analytical, Inc. for analysis in spite of not being able to purge the well. Water quality was poor <br />and shown to exceed drinking water standards in Iron, Manganese, Molybdenum, Uranium, <br />Vanadium, Sulfate, and total dissolved solids (TDS). The preliminary results follow.