Laserfiche WebLink
Selected Major-Element Trends <br />Santiago leachate had the highest concentration of calcium, ranging from 230 mg/L in the 5- <br />minute leachate to 370 mg/L after 18 hours. The high calcium concentration is probably responsible for the <br />increase in the leachate pH over time. <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 Santiago mine-waste leachate. <br />Aluminum (Al).-Found to be high in the 5-minute leachate at 2,060 pg/L but decreased after <br />18 hours to a concentration of 11.3 pg/L. <br />Cadmium (Cd). Slightly elevated concentrations of cadmium were found with <br />concentrations of 174 µg/L after 5 minutes, and 180 pg/L after 18 hours. <br />Copper (Cu).-Copper concentration was high in the 5-minute leachate at 6,590 µg/L but <br />decreased to 236 µg/L after 18 hours. <br />Iron (Fe).-Leachate iron was elevated in the 5-minute leachate at 836 µg/L and decreased to <br /><50 µg/L after 18 hours. <br />Manganese (Mn).-Very high concentration of manganese was found in leachate from the <br />Santiago. The 5-minute concentration was 44,200 µg/L increasing to 56,100 after 18 hours. <br />Mercury (Hg).-Mercury was detected in the leachate from the Santiago mine-waste pile. <br />Mercury concentration was 25 ng/L (ppt) after 5 minutes, rising to 30 ng/L (ppt) after 18 <br />hours. <br />Nickel (Ni).-Slightly elevated in the leachate with a slight increase in leachate concentration <br />over time. 5-minute concentration was 120 ttg/L; this value increased to 133 pg/L after 18 <br />hours. <br />Lead (Pb).-Leachate lead decreased from 234 µg/l, after 5 minutes to a concentration of <br />28.1 ltg/L after 18 hours. <br />Zinc (Zn). Very high concentration of zinc was found in the leachate and zinc concentration <br />decreased over time. The 5-minute concentration was 26,000 µg/Lthe 18-hour value dropped <br />to 22,600 gg/L. <br />U.S. Department of the Interior <br />Gale A. Norton, Secretary <br />U.S. Geological Survey <br />Charles G. Groat, Director <br />Posted online July 2004 <br />For more information about the USGS and its products: <br />Telephone: 1-888-ASK-USGS <br />World Wide Web: http://www.usgs.gov/ <br />This publication is only available online at: <br />hnp://pubs.usgs.gov/sir/2004/5104/ <br />Hageman_SIR_2508.doc 26 7/21/20042:50 PM