Fig. 2 shows the Cu leachable concentrations. All 138 leachable concentrations were
far less than 10 mg/l. The top layer Cu mean (51 samples) leachable concentration was reduced to 3.9 mg/l from the untreated sample 172 mg/l (>97% reduction). The mean Cu concentration for both the middle and bottom layerswas less than 0.4 mg/l (>97% reduction).