Robert Lee Welsh

US Patent:

56114028, Mar 18, 1997

Filed:

Oct 18, 1994

Appl. No.:

8/324673

Inventors:

Robert H. Welsh - Springboro OH

International Classification:

E21B 4300

US Classification:

166369

Abstract:

A process for removing volatile contaminants from soils and/or rock in the undersaturated or vadose zone involves drilling one or more boreholes into undersaturated soils and/or rock to a level below the delineated contaminants or to the top of the water table. A close-end, conduit having drilled holed in the sidewall in a lower section and enclosed in a sleeve of filtration material is placed into the borehole. A porous fill material is in turn placed within the borehole around the conduit. The upper portion of the borehole around the upper impermeable section of the conduit is sealed from atmospheric air by using a plug an fill material of low permeability. Additionally, a plastic sheeting seal is placed to cover the entire ground surface to prevent atmospheric air from migrating into the lower permeable section. A vacuum source is used to create suction in the borehole and the surrounding area to excavate the contaminants.