Wellpoint Systems ~ method of lowering the water table to a
position below the formation level to give a dry working area. The
basic principle is to jet into the subsoil a series of wellpoints which
are connected to a common header pipe which is connected to a
vacuum pump. Wellpoint systems are suitable for most subsoils and
can encircle an excavation or be laid progressively alongside as in
the case of a trench excavation. If the proposed formation level is
below the suction lift capacity of the pump a multi-stage system
can be employed † see next page.
Ground Water Control---Temporary Exclusion