Abstract: An improved method and apparatus for removing chemical contaminants from soil. Contaminated soil is loaded and hydraulically sealed in the treatment vessel. A vacuum is placed on the material, which is indirectly heated through the heat transfer plate from a natural gas of propane fired burner located under the plate. As the material is heated, contaminants are vaporized and flow through the vacuum discharge pipe toward the condenser unit. Vapors are cooled in the condenser through a series of refrigerated condensing coils where the vaporized material is converted back to a liquid and discharged to a liquid recovery vessel. After treatment, material is downloaded into a roll-off type container for post-treatment analysis and cool down prior to recycling or backfilling. Recovered liquids are recycled or sent to an appropriate facility. Process time is typically 45 minutes to an hour for a six cubic yard batch. The system is self-contained, mobile, and operable by a two-person crew.

Abstract: A method of recovering contaminants entrained in subsurface soils which includes establishing a plurality of vacuum withdrawal wells and a plurality of air injection wells adjacent to a contaminated zone of earth. The method includes operating the wells in this fashion for a predetermined time, then reversing the air flow through one or more of the wells to effect contaminant removal in previously untreated nodes in the well field.