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Waldorf Mine <br />The Waldorf mine is located in the very upper reach of Leavenworth Creek in the Clear Creek <br />watershed. The mine is hosted in Idaho Springs schist and rhyolitic intrusive rocks, although Silver Plume <br />granite is present near the adit and is exposed within the tunnel as well. Lovering (1938) reports that the <br />walls of the tunnel were coated with a copper "lime" during his visit <br />Net-Acidity <br />24.0 kg CaCO3/ton. <br />pH Trend <br />An increase in pH occurred in leachate from the Waldorf mine-waste composite that showed a rise <br />in pH from 3.1 after 5 minutes to 3.3 after 18 hours. (+0.2 pH units). This indicates some neutralization of <br />the leachate over time. <br />Specific Conductance Trend <br />Leachate from the Waldorf mine-waste had high specific conductance with measurements of <br />1,040 µS/cm after 5 minutes, rising to 1,092 µS/cm after 18 hours. <br />Sulfate <br />Waldorf leachate sulfate concentration increased over time from 443 mg/L after 5 minutes to 504 <br />mg/L after 18 hours. <br />Selected Major-Element Trends <br />Waldorf leachate had the second highest leachate concentration of calcium that ranged from 82 <br />mg/L in the 5-minute leachate to 120 mg/L after 18 hours. <br />Selected Trace-Metal Trends <br />Following are summaries of selected trace-element trends portrayed in the time study (5-minute <br />vs. 18-hour) of the Waldorf mine-waste leachate. <br />Aluminum (Al). Waldorf leachate had the highest aluminum concentration of the 13 dumps <br />included in this study. Aluminum concentration decreased slightly over time. Concentration <br />was 8,230 pg/L in the 5-minute leachate and decreased to 8,010 µg/L after 18 hours. <br />Cadmium (Cd). Elevated concentrations of cadmium were found with concentrations of 122 <br />pg/L after 5 minutes, rising to 140 pg/L after 18 hours. <br />Copper (Cu).-Waldorf leachate copper concentration was second highest of all the leachates <br />studied. Only leachate from the Santiago mine-waste had higher copper concentrations. <br />Waldorf leachate copper ranged from 4,400 in the 5-minute leachate to 4,410 µg/L after 18 <br />hours. <br />Hageman_SIR_2508.doc 24 7/21/20042:50 PM