During the experimental program, IGT conducted a series of laboratory-scale supercritical CO extraction tests to evaluate the effects of CO flow rate, temperature, and the addition of a modifier on the extraction of polynuclear aromatic hydrocarbons (PAHs) from soil. The laboratory-scale tests were conducted with supercritical CO in once-through mode. The bench-scale tests were conducted in CO recirculation mode with activated carbon absorption of the PAHs. Overall, the results of these tests show that the extent of PAH extraction from soil increases with temperature to a maximum at about 65 deg. At temperatures above 65 deg. the extent of PAH extraction from soil increases with temperature to a maximum about 65 deg. the extent of PAH extraction decreases. In PAH absorption tests with activated carbon, the results showed that lower, rather than higher, temperatures of the activated carbon increased the capture of PAHs from supercritical CO. A temperature of about 45 deg. showed that a concentration of three percent yielded the highest PAH extractions in the range of methanol concentrations, up to 10 percent in CO.