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Page 7 September 2, 2008 <br />Water quality results for sample sites Lumsden Creek UP and Lumsden Creek DN did not differ <br />dramatically with exception of the levels of arsenic, uranium, and the radiological parameter of Ra-226. <br />Arsenic in the Lumsden Creek UP and Lumsden Creek DN samples showed concentrations of 0.008 <br />and 0.037 mg/L, respectively. Uranium in the Lumsden Creek UP and Lumsden Creek DN samples <br />showed concentrations of 0.002 and 0.071 mg/L, respectively. Ra-226 in the Lumsden Creek UP and <br />Lumsden Creek DN samples showed activity levels of 0.4 and 13.8 pCi/L, respectively. Total <br />dissolved solids (TDS) in the. Lumsden Creek UP was greater (308 mg/L) than the TDS in the <br />Lumsden Creek DN (252 mg/L) sample. At first glance, this seems contrary to what might be expected <br />in that leaching from the Dutchman Mine dump might increase TDS downstream of the mine. <br />However, TDS in upper Lumsden Creek is likely influenced by discharge from DP Spring which <br />exhibits TDS concentrations that range between 300 and 500 mg/L. <br />A comparison of the Lumsden Creek UP and Lumsden Creek DN analytical results to samples <br />collected at similar locations by the BLM in 1993 (Table 2) showed generally better water quality in the <br />June 2008 samples than in 1993. TDS concentrations in the June 2008 samples were approximately <br />100 mg/L less than the 1993 samples. Concentration differences may be related to dilution due to <br />greater flow rates observed in the June 2008 sample, or from other influences such as hydrologic <br />regime (flow paths, residence time, and the presence or absence of geologic media), and field and <br />laboratory methods used. <br />The Lumsden Canyon Mouth sample was interpreted to have been collected at the same location as <br />past "Lumsden Canyon Spring - Upper Contact" samples. Comparison of the June 2008 sample with <br />previous samples at this location show that TDS is slightly elevated from a previous high concentration <br />of 648 mg/L in the April 2007 sample to 668 mg/L in the June 2008 sample. TDS, sodium, calcium, <br />potassium, chloride, sulfate, selenium, and uranium show increased levels, generally two or more times <br />greater, in the April 2007 and June 2008 samples compared to the 1993 BLM sample. Whereas arsenic <br />and radium-226 for this site show decreased levels in the April 2007 and June 2008 samples compared <br />to the 1993 BLM sample. Sulfate, in particular, exhibits concentrations over 100 mg/L higher in the <br />2007/2008 samples. Conversely, arsenic concentrations and radium-226 activity levels in the <br />2007/2008 samples are at least 10 times less than the 1993 levels. Assuming appropriate sampling <br />quality control measures were practiced, the difference in concentrations may be due to differences in <br />the hydrologic regime, dilution effects related to flow rates, and field and laboratory methods used. <br />The current interpretation of the Lumsden Canyon Mouth sample location is that the water sampled at <br />this location is shallow groundwater that surfaces due to variability in the physical streambed. An <br />alluvial aquifer comprised of streambed colluvium of limited extent overlies the bedrock. An <br />undulating bedrock surface and surficial erosive features in the colluvium contribute to exposure of the <br />alluvial groundwater system in the streambed. In high flow times surface water may flow for longer <br />distances in Lumsden Canyon, depending on the volume and longevity of the source, such as runoff <br />associated with intense thunderstorms. The alluvial aquifer can supply water to the creek as long as <br />aquifer storage and groundwater levels are sufficiently high enough to do so. Bedrock aquifers may <br />also exist in the area that contributes recharge to the alluvium and the creek. In turn, the alluvial aquifer <br />may recharge underlying bedrock. It is possible that waste rock and possibly ore-bearing materials that <br />have become entrained in the Lumsden Creek channel from past mining activities, i.e. as observed at <br />the Dutchman Mine dump, will impact water quality of the shallow alluvial aquifer as well as surface <br />water in the creek. <br />Source waters located high in the watershed, including DP and PR springs may contribute to <br />groundwater of the alluvial aquifer in Lumsden Canyon. However, the degree of this contribution is <br />uncertain without conducting a comprehensive study that would evaluate the extent of the alluvial and <br />Weans090108.doc