Image Number 4 for United States Patent #6464005.
A method of remediating a site of earth and groundwater contamination includes the steps of drilling at least one injection well, and preferably a plurality of injection wells, into the groundwater in a contaminated area. At least one, and preferably a plurality of extraction wells, are drilled into the earth above the groundwater, the vadose zone, in the contaminated area. The surface of the earth above the contaminated area is sealed, such as by a layer of concrete, asphalt, or plastic sheeting. Air and nutrients are injected into the contaminated area through the injection wells. The air is injected on a substantially continuous basis while the nutrients are injected on a batch basis. Air and vapor is extracted on a substantially continuous basis from the contaminated area by the extraction wells, which may be either vertically or horizontally positioned.