Method For the Measurement of Hydrocarbon Sequestration and Availability For Microbial Decomposition

17 Method For the Measurement of Hydrocarbon Sequestration and Availability For Microbial Decomposition--META Environmental, 49 Clarendon Street, Watertown, MA 02172-2872; (617) 923-4662 Dr. David M. Mauro, Principal Investigator Dr. David M. Mauro, Business Official DOE Grant No. DE-FG02-97ER82430 Amount: $72,826 Recent research shows that when environmental contaminants, such as oils and tars, are removed from soil by natural processes or engineered systems, the initial cleanup may be rapid but cleaning up the residual contaminants may be very slow and expensive. The risks posed by the residual contamination may be much lower than is currently estimated because the residual contamination is not available to organisms, such as earthworms, for decomposition. Cleaning residual soil contamination can increase the cost of site cleanup by prolonging treatment system operations necessary to achieve stringent cleanup levels. A method is needed that can measure the amount of ¿available¿ contaminant in a soil sample so that cost-effective decisions can be made regarding soil cleanup. Phase I will focus in determining which of three chemical analysis methods may be better for the measurement of soil contaminants. The project will study solid phase microextraction, mild solvent extraction, and aggressive solvent extraction, compare those techniques to the results of microbiological assays of several contaminated soil samples under various conditions and identify which method gives the most accurate estimate of microbiologically available contaminants. In Phase II, the performance of the best chemical analysis method will be refined by testing a range of soil types containing a greater number of chemicals and chemical concentrations. The method will be automated, and commercial equipment will be designed. Commercial Applications and Other Benefits as described by the awardee: A reliable method for determining whether contaminated soil can be cleaned up by organisms would be used extensively by environmental consultants, property owners, and government agencies. The results obtained will aid engineers to design cost effective soil cleanup systems that are based on practically achievable endpoints.