A combination of parallel processes is disclosed to provide optimal re-mediation operations for contaminated soil. Soils with high levels of heavy petroleum hydrocarbons are directed to a thermal process for destruction in a combustion process. Carbon dioxide generated and recovered in the thermal process is employed as a solvent in a solvent process to clean other soils of petroleum hydrocarbons and certain chlorinated hydrocarbon compounds. In the solvent process, contaminated soils are run through a closed soil separator where the soils are washed with carbon dioxide. The carbon dioxide is then dried from the soil and the soil is sent for segregation. Soils with the lightest forms of hydrocarbon contamination (gasoline, etc.) are subjected to a vaporization process utilizing heat energy generated in the thermal process to heat the soil, under a partial vacuum, and the vapors generated are captured, condensed, and recovered as product.