Deep wells are used primarily in the field of site dewatering.
Deep wells are created by drilling a borehole with a diameters ranging from 300 to
2000 mm at depths ranging from a few meters to several hundred meters. Depending on the diameter, the site’s geological conditions and the intended depth, the borehole can be drilled using dry drilling or straight-flush rotary drilling. The borehole is drilled and then lined with a wellscreen/casing assembly. The annular void around the assembly is filled with gravel. A Bentonite seal is placed above the gravel to prevent the ingress of surface water or contaminants into the borehole. Groundwater abstraction is realized by a multi-stage submersible pump installed in the completed well. Discharge lines carry the groundwater to a discharge point at the surface, therefore lowering the water table to the desired depth.