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Page 4 December 19, 2013 <br />Table 3. Summary of mine water, average leachate concentrations and resulting concentration <br />ratios for the leaching tests for common constituents of concern. <br />Analyte <br />Unit <br />Mine Water <br />Avg. Leachate <br />Ratio <br />State <br />Standard <br />Arsenic <br />µg/L <br />15 <br />7.38 <br />2.03 <br />10 <br />Boron <br />µg/L <br />5000 <br />5312.5 <br />0.94 <br />750 <br />Cadmium <br />µg/L <br />0.41 J <br />0.42 <br />0.98 <br />5 <br />Chloride <br />m <br />38 <br />38.5 <br />1.00 <br />250 <br />Chromium <br />µ <br />1.91 <br />1.65 <br />1.15 <br />100 <br />Copper <br />µg/L <br />6.2 <br />21.08 <br />0.29 <br />100 <br />Fluoride <br />m <br />2.5 <br />2.58 <br />0.97 <br />2.0 a <br />Lead <br />µg/L <br />0.069J <br />0.09 <br />0.78 <br />50 <br />Mercury <br />µg/1., <br />0.2U <br />0.2U <br />1.00 <br />2 <br />Molybdenum <br />µg/L <br />220 <br />220 <br />1.00 <br />210 <br />Nitrate <br />m /L <br />2.9 <br />2.99 <br />0.97 <br />10 <br />Nitrite <br />m /L <br />0.13U <br />0.13 <br />1.00 <br />1 <br />Selenium <br />µg/L <br />7 <br />6.6 <br />1.06 <br />20 (ag) <br />Sulfate <br />m /L <br />1300 <br />1375 <br />0.95 <br />250 <br />Note: ag = agriculture standard <br />The ratio column represents the ratio of the mine water concentration to average leachate concentration. <br />A ratio greater than one implies greater adsorption, whereas a ratio less than one implies greater <br />leaching or desorption. The solid versus dissolved fractions are implied; the adsorbed fraction has not <br />been directly measured. With exception of a few elements, the ratios are near one, indicating no <br />significant adsorption or desorption of the constituents of concern. The results for arsenic indicate that <br />the element partitions to the solid phase (adsorbs) at concentrations twice that of the dissolved phase. <br />Copper, on the other hand, appears to exist in the dissolved phase more than 3 times the concentration <br />of the adsorbed phase. <br />4. Please provide baseline data for both LWCW -JA and LW -22. The data supplied for LWCW -IA is from <br />May 10, 2011 and no data from LW -22 was provided. <br />Response: <br />Data for Well LW -22 were provided in Table 2 of the submitted Technical Revision No. 8 application. <br />For convenience, LW-22 data are presented again in this response. The attached Tables 4 and 5 provide <br />all available chemistry data for wells LWCW -IA and LW -22, respectively. Well LW -22 is an alluvial <br />well completed in the alluvium of Logan Wash, located approximately 2.4 miles downstream of the <br />mine site. The well is 86 feet deep. Well LWCW -IA is a monitoring well completed mostly in the <br />colluvium and bedrock underlying Dry Gulch. the well is located approximately 300 feet downslope of <br />the toe of the Lower Dump and approximately 1,600 feet down stream of the current 001 Outfall. The <br />well penetrated bedrock at approximately 70 feet and was completed to a depth of 100 feet. <br />S. Sulfate in LW -001 is reported at higher levels than levels found in wells in the vicinity of the site. Is it <br />possible that the increased sulfate levels could impact the ambient groundwater conditions of Dry <br />Gulch? <br />TMarshaII121713.doc <br />