Leachability and toxicity of hydrocarbons, metals and salt contamination from flare pit soil

Although composite chemical analyses, such as total petroleum hydrocarbons and total metals, are often used to assess the extent of contamination at a n industrial site, it is difficult to relate chemical analyses to the envir onmental and toxicological effects of soil contamination. Since toxicity is related to contaminant bioavailability and solubility, identification and quantification of leachable contaminants should provide an indication of th e environmental hazard of the site contaminants. Experiments were performed to determine the leachability and toxicity of contaminants from a flare pi t soil which was extensively contaminated with hydrocarbons, metals and sal t. Toxicity bioassays included earthworm mortality (Lumbricus terrestris), seed germination and root elongation (Lactuca sativa and Panicum miliaceum L.), algal growth inhibition (Selenastrum capricornutum) and bacterial lumi nescence inhibition (Pseudomonas fluorescens). Although this soil would req uire remediation according to chemically based soil criteria, neither the c ontaminated soil nor leachate generated from the contaminated soil were par ticularly toxic.