Laserfiche WebLink
Selected Major-Element Trends <br />Burke leachate had very low calcium concentration that ranged from <0.2 mg/L in the 5-minute <br />leach to 0.4 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 Burke mine-waste leachate. <br />Aluminum (A1).-This leachate had aluminum concentration that ranged from 19.5 µg/L in the <br />5-minute leachate and increased to 182 µg/L after 18 hours. <br />Cadmium (Cd).-Minor concentration of cadmium was found in the Burke mine-waste <br />leachate with values of <0.02 gg/L after 5 minutes, rising to 0.38 pg/L after 18 hours. <br />Copper (Cu).-Minor leachate copper concentration was found and the concentration rose <br />over time. Values ranged from 0.97 pg/L in the 5-minute leachate to 1.6 gg/L after 18 hours. <br />Iron (Fe).-Iron was found in moderate concentration in leachate from the Burke mine-waste. <br />Leachate concentration increased over time from 96 gg/L in the 5-minute leachate to 563µg/L <br />after 18 hours. <br />Manganese (Mn). Low concentration of manganese was found in the leachate. 5-minute <br />leachate concentration was 1.5 gg/L and increased to 6.3 µg/L after 18 hours. <br />Mercury (Hg). Mercury was not detected in the Burke leachate. <br />Nickel (Ni).-Very minor concentration of nickel was found. The 5-minute leachate <br />concentration was <0.4 gg/L, increasing to 0.5 gg/L after 18 hours. <br />Lead (Pb). Low leachate lead concentration was found and concentration increased over <br />time from 1.5 µg/L after 5 minutes to 15.4 gg/L after 18 hours. <br />Zinc (Zn).-Minor concentration of zinc was found in the Burke leachate, and zinc <br />concentration increased over time. The 5-minute leachate concentration was 11.3 µg/L; this <br />value rose slightly to 12.6 µg/L after 18 hours. <br />Jack Pine Mine <br />The Jack Pine mine is located in Stevens Gulch in the Clear Creek watershed. The mine is hosted <br />in the Idaho Springs Formation. <br />Net-Acidity <br />17.5 kg CaCO,/ton. <br />pH Trend <br />There was a slight decrease in pH over time in the Jack Pine mine-waste leachate. pH dropped <br />from 5.1 after 5 minutes to 5.0 after 18 hours. (-0.1 pH units). This indicates net-acid production in the <br />leachate over time. <br />Specific Conductance Trend <br />Jack Pine leachate had low specific conductance with measurements of 163 µS/cm after 5 minutes, <br />rising to 261 µS/cm after 18 hours. <br />Hageman_SIR_2508.doc 19 7/21/20042:50 PM