With a GCW it is possible to remove non-miscible liquids of lower density than water (LNAPL) from an aquifer.  In order to remove light non aqueous liquids floating on the groundwater, the GCW is operated in a reverse mode.  The LNAPL is  removed by means of a sensor-controlled, pneumatically-driven submersible pump. Thus it is made sure that just pure phase and no groundwater is extracted. lnapl-neu-englisch-180608.jpg