sieving tubes

A sieving tubes is a filtering device that allows ground water from unconsolidated and semiconsolidated aquifers to enter the well while at the same time keeping the majority of sand and gravel out of the well and out of the pump. A screen also supports the aquifer material and prevents the borehole from collapsing. A well developed in a porous but consolidated aquifer such as a sandstone or limestone does not need a screen.