Development and testing of active groundwater samplers

Active groundwater sampling techniques are methods where the aquifer is flushed by pumping. The methods developed and tested represent non-dedicated methods for use in existing water wells. This paper describes two different sampling techniques: the Separation Pumping Technique (SP) and the Packer Baffle System (PBS). The methodology and design of the two systems is presented and the operational application is demonstrated by examples from full-scale field experiments. The methods are validated and their sensitivity to the well construction and the hydrogeological environment is assessed based on numerical modelling and controlled laboratory experiments. Active groundwater sampling techniques can be used for remedial pumping optimization and in obtaining hydraulic data and represent a fast operational and reliable sampling tool, also under heterogeneous and low permeability conditions.