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Page 13 May 5, 2009 <br />The Salt Wash Member horizon, particularly in the area of Packrat Mine has not exhibited seepage or <br />springs other than the PR Spring which has existed for many years. Based on the field observations <br />conducted for this study to date, and the associated climatic conditions, the Salt Wash Member is not a <br />significant aquifer in the area; water yield from the unit is minimal based on underground observations. <br />Groundwater of yieldable quantities is present in the lower Brushy Basin Member within Whirlwind <br />Mine and monitoring well MW-WI. The relationship of PR Spring groundwater to other strata will be <br />investigated after Packrat Mine has been made safe to enter. <br />Surface water in Lumsden Canyon is influenced by DP Spring and PR Spring in the upper canyon. This <br />surface water eventually infiltrates into the streambed alluvium. Virtually no surface water was present <br />in the mid canyon. Small reaches of the canyon show surface water in the lower canyon due to <br />variability in the relief of underlying bedrock and streambed alluvium. The hydraulic connection of <br />upper canyon water with water in the lower canyon was not confirmed, but surface observations <br />indicated that if the connection exists during base flow conditions, the flow path would involve over <br />3,000 ft of alluvium and bedrock. Water quality at the Lumsden Creek DN site in the lower canyon is <br />more mineralized (of a higher TDS) than that upper canyon water, indicating the affect of a longer flow <br />path and residence time. Ore-bearing alluvium was observed throughout Lumsden Canyon that may be <br />contributing to the dissolved constituents at the Lumsden Creek DN site. The Lumsden Creek DN <br />water also contains more dissolved solutes than the PR Spring water, which supports the hypothesis of <br />progressive degradation of water quality with flow path. Water at the Lumsden Canyon Mouth site is <br />interpreted as a mixture of waters from numerous sources, some of which have not been physically <br />delineated or quantified. A more in-depth chemical analysis may allow for further interpretation. <br />The Lumsden Creek UP and Lumsden Creek DN samples were collected above and below the <br />Dutchman Mine dump, respectively. Both the June and December 2008 sample events revealed that the <br />most obvious impact to water quality (of parameters analyzed) as a result of the Dutchman Mine waste <br />rock are the radionuclide elements of uranium and radium. Other parameter concentrations did not <br />demonstrate a consistent relationship. <br />Plotting of analytical results on a Piper diagram (Figure 3) shows that water quality types in the mine <br />area are of two main types. Calcium bicarbonate water is present in DP Spring and Lumsden Canyon <br />surface waters. Whereas, sodium bicarbonate waters are present in the Whirlwind Mine, PR Spring, <br />and monitoring well MW-W I. These water types reflect the geologic composition of materials <br />associated with the groundwater occurrences, i.e. the Burro Canyon Formation and upper Brushy Basin <br />Member, and the lower Brushy Basin Member. The hydraulic connection between Burro Canyon <br />Formation and lower Brushy Basin Member groundwater would require well installations and <br />sampling of groundwater within the strata between these geologic horizons. This is not critical <br />information that is needed at this time. Also, the chemical signature of downstream Lumsden Canyon <br />surface water (Lumsden Canyon Mouth site) does not necessarily indicate that this water is <br />hydraulically connected to upper Lumsden Canyon surface water. The composition of the downstream <br />water is likely a result of a longer flow path, and greater residence time and mineral dissolution. Mixing <br />with other subsurface waters is also a plausible explanation for the downstream chemical composition. <br />WWL recommends the following activities be conducted as a follow-up to the December 2008 <br />hydrologic reconnaissance: <br />1. Sample and analyze the PR Spring water at the confluence with Lumsden Canyon. The V <br />resulting analysis will allow for an assessment of solute attenuation from the spring emanation <br />Weans032709.doc