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Page 11 May 5, 2009 Mine area. In addition, sodium, calcium, potassium, chloride, sulfate, selenium, and uranium show increased levels, generally two or more times greater in the 2007 and 2008 samples compared to the 1993 BLM samples. Sulfate, in particular, exhibits concentrations 180 mg/L higher in the December 2008 sample compared to one of the August 1993 BLM samples. Conversely, arsenic concentrations and radium-226 activity levels in the 2007/2008 samples are at least 10 times less than the 1993 levels. Assuming appropriate sampling quality control measures were practiced, the difference in concentrations may be due to differences in the climate and hydrologic regime, dilution effects related to flow rates, and field and laboratory methods used. A review of PR Spring and Lumsden Canyon Mouth water quality data reveal significant differences in TDS, and common ions. The Lumsden Canyon Mouth water has a TDS concentration of approximately 100 mg/L greater than the PR Spring sample. This is primarily due to higher concentrations of calcium, magnesium, potassium and sulfate. Chloride, a particularly conservative metal, shows concentrations at PR Spring are consistent and are in the range of the most recent samples collected at the Lumsden Canyon Mouth site. Other metals concentrations, primarily arsenic, selenium and uranium, are of considerable higher concentrations in the PR Spring water. Also, uranium metal concentrations and uranium and radium activities are considerably higher in the PR Spring water samples. It is apparent that while the PR Spring water reflects a mineralized source, the overall water quality of the Lumsden Canyon Mouth site is of higher TDS, reflected by the increase in common ions. The water quality at the Lumsden Canyon Mouth site implies a relatively long residence time exposed to the alluvium and bedrock of Lumsden Canyon. The presence of metals and radionuclides in the Lumsden Canyon Mouth water may be the combined result of upgradient water sources such as PR Spring, and ore materials in the alluvium from erosion of upgradient mine dumps. Monitoring Well MW-WI Water quality data for monitoring well MW-W I is shown in Table 2. In general, the data indicate that groundwater at MW-WI is of sodium bicarbonate type. Chloride and sulfate concentrations are relatively high, but metals, with the exception of uranium, are of low concentrations. The data also indicate that TDS and elemental concentrations have been decreasing with each sample collected. This indicates that the well is continuing to develop with each pumping event associated with sampling procedures. Groundwater Type and Potential Evolution A Piper diagram was prepared for the various sampling site data from the Whirlwind Mine area. This diagram is shown in Figure 3. The plotted data represent the average concentrations for the elements shown for data presented in Table 2 and other data provided by EFR in the quarterly reports and permit documents. The Piper plot shows the proportion or relative abundance of common ion elements and compounds in percent milliequivalents per liter (meq/L) for each sample plotted. Figure 3 shows two general groups of water chemistries that are identified by distinct proportions of calcium and sodium. The plot indicates the basic water types of calcium bicarbonate and sodium bicarbonate are present in the Whirlwind Mine area. These two main water types correlate with source water occurrences from the Burro Canyon/Upper Brushy Basin Formations (calcium bicarbonate water) and the Lower Brushy Basin Member (sodium bicarbonate water). The Burro Canyon/Upper Brushy Basin sites include DP Spring (DPS), the BLM well (BLMW), the Cherokee wells (CW), Lumsden Canyon UP (LCUP), and Lumsden Canyon DN (LCDN). The Lower Brushy Basin sites Weans032709.doc