The well water-intake part is equipped with filters. Usually filters are made from round metal slotted pipes (also rod-shaped pipes or of other design or from other materials can be used).

Vertical drainage wells are equipped with filters the designs of which can differ from case to case. The main components of the filter are its framework and infiltration area. Rod-shaped or tubed frameworks, as well as with round or slotted perforation, from pressed plate are used. The infiltration area is made in the form of wire wrap, pressed plate, metal and non-metal nets, tubular filters made from different man-made foamed materials as well as from sand and granular backfill.

The most widespread and effective filter type is the sand-and-gravel filter type which is divided into loose-fill, shell-type, and blocked filters.

Source: www.complexdoc.ru

Vertical drainage wells made usually 0.9-1.2 m in diameter are designed for influencing the upper layer of groundwater and therefore are drilled to a depth of 50-100 m. The well’s water-intake portion is located in well permeable sand-gravel deposits and equipped with a filtering framework protected with sand-gravel envelope. The water lifting equipment is placed in the water-conducting section of the pipes, which is arranged above the filtering framework.

Steel casing, thin-wall welded, plastic and asbestos-cement pipes, up to 0.4 m in diameter, are used as the pipe column/string; slotted pipes made from the same materials or factory-made filters are used for the filtering framework.

The well servicing area depends on the hydrogeological and economic conditions and may come to 100-150 ha.

Source: Irrigated land drainage manual / Yusupov, A., Rakhimov, N., Umarov, P. [in Russian]

Monographs and brochures

Novik, N.P., Segal, G.Ya., Tsoneva, E.L. Drainage filters [in Russian] (1984)