US Patent 7896578 Mapping of contaminants in geologic formations

An apparatus and method for evaluating chemicals of interest in a subsurface bore hole, such as a groundwater sampling well. An absorbent member is attached to a flexible liner, and the liner is everted by fluid pressure down the borehole. The everted liner presses the absorbent member against the wall of the borehole. Any chemicals of interest are absorbed into the absorbent member from the media surrounding the borehole. The liner, with associated absorbent member thereon, is then extracted from the borehole. The absorbent member may then be subjected to any suitable laboratory analysis to evaluate the type, spatial distribution, and concentration of chemicals of interest, such as water contaminants occurring in the borehole.