Arrangement for driving out volatile impurities from ground water

Claim 1

An arrangement for driving out volatile impurities from a ground water and a ground region through which the ground water passes by introducing air or another gas into an opening in the ground region and subsequent aspiration of the air or the gas with entrained contamination substances, the arrangement comprising a cup insert arranged to close an opening formed in a ground region at its lower end and provided with a closed wall; two pipes arranged concentrically in the opening for supplying the air or gas and withdrawing the air or gas, respectively, said pipes including an outer pipe extending above a water level in the opening and having an upper end and a lower region, an inner pipe extending into an interior of said cup insert, said inner pipe having an upper end and a lower end; a pressure pump connected with said upper end of said inner pipe; a distributor head provided at said lower end of said inner pipe and having a plurality of openings; a suction pump connected with said upper end of said outer pipe, said outer pipe having a wall provided in said lower region and having a plurality of perforations.