The hazardous waste disposal of residues of surface cleaning andrepainting of steel bridges is costly. Costs can, however, be contained by ensuring proper classification of such wastes. This requiresa reliable, precise method for determining the leachable metal concentration of various solid wastes. The results obtained through use of 2 widely employed leaching methods are reviewed in this investigation. The investigation compared the extraction procedure toxicity test (eptox) promulgated to extract leachable organics and metals from solid wastes, and the toxicity characteristic leaching procedure (tclp) that was proposed to replace eptox. Metal concentrations in leachates from separate samples of various abrasive paint residues wasmeasured. The study included evaluating the precision and reproducibility of the two methods using data sets obtained from various participating analytical laboratories. Round robin tests showed significant differences between the tclp and eptox methods. It was found that tclp tests resulted in much higher concentrations of lead than dideptox tests. These and other study findings are discussed.
Abstract