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Iron (Fe). Waldorf leachate iron concentration was high, especially in the 5-minute <br />leachate. A decrease in iron concentration was seen over time from 7,910 µg/L in the 5- <br />minute leachate to 744 µg/L after 18 hours. This is a decrease in iron concentration of more <br />than an order of magnitude. <br />Manganese (Mn).-Very high concentration of manganese was found in leachate from the <br />Waldorf mine-waste, second only to the Santiago. The 5-minute concentration was 31,500 <br />pg/L; this value increased to 40,900 after 18 hours. <br />Mercury (Hg).-Mercury was not detected in the Waldorf leachate. <br />Nickel (Ni).-Elevated concentrations of nickel were found in the leachate with a slight <br />increase in leachate concentration over time. The 5-minute concentration was 117 µg/L; this <br />value increased to 126 pg/L after 18 hours. <br />Lead (Pb).-Leachate lead concentration increased over time from 190 pg/L after 5 minutes <br />to 1,290 pg/L after 18 hours. <br />Zinc (Zn).-Very high concentrations of zinc were found in the Waldorf leachate and zinc <br />concentrations increased over time. The 5-minute concentration was 23,900 µg/L, increasing <br />to 25,500 after 18 hours. <br />Santiago Mine <br />The Santiago mine is located near the Waldorf mine in the Leavenworth Creek/Clear Creek <br />watershed. Host rock is Silver Plume granite and biotite-quartz-sillimanite schist. One of the largest <br />producers in the area the ore consisted of galena, sphalerite, pyrite and some chalcopyrite; quartz and <br />ankerite comprise the dominant gangue minerals and ankerite was reported to be very abundant in some of <br />the deeper workings. <br />Net-Acidity <br />73.0 kg CaCO,/ton. <br />pH Trend <br />An increase in pH occurred in leachate from the Santiago mine-waste composite that showed a <br />spike in pH from 3.6 after 5 minutes to 5.2 after 18 hours (+1.6 pH units). This indicates neutralization of <br />the leachate over time. <br />Specific Conductance Trend <br />Leachate from the Santiago mine-waste had the highest specific conductance of all the 13 dumps <br />studied, with specific conductance of 1,730 pS/cm after 18 hours. This followed the 5-minute reading of <br />1,396 pS/cm. <br />Sulfate <br />Santiago leachate had the highest concentration of sulfate, and the concentration increased over <br />time from 736 mg/L after 5 minutes to 1,040 mg/L after 18 hours. <br />Hageman_SIR_2508.doc 25 7/21/2004 2:50 PM