Dug Wells
Dug Wells
Dug Wells
Dug wells are made by constructing a large hole into the earth to a depth greater than the ground water
level. A reservoir is created by lining the walls of the hole with rocks, brick, wood, or concrete pipe to
prevent cave-in. In some conditions the hole may be back filled with coarse gravel with a feed line
installed. In this situation the gravel area acts as the reservoir. As long as ground water is present, a dug
well will yield results. Water is extracted from the reservoir and replenished naturally from the aquifer. The
wells recharge and use capacities are directly related to the permeability of the soil into which the well is
constructed . Dug wells are typically limited to a depth of 25 - 30, and are practical only when the water
table is near the surface of the earth. Because of the dug wells method of construction and shallow depth,
contamination from surface drainage and sub surface seepage is common. In many areas dug wells are
prohibited by law.
BORED WELLSBored wells are constructed by means of an auger which bores a cylindrical hole into the earth. After water
is reached , soil samples are collected to determine the permeability of the soil. If a suitable permeable soil
is encountered, a screen or filtering device is attached to a casing and lowered into the bore hole . The
casing is driven or pushed to the desired depth. The well is developed, and water is extracted from the soil.
DRIVEN WELLS
Driven wells consist of a series of tightly coupled pipe lengths installed below the water table with a well
point or screen at the lower end. The well point may be forced into the ground by a series of driven blows
directed upon the pipe above it or telescoped into the well after the pipe is driven and soil samples are
collected. The permeability of the soil is the determining factor for the feasibility of the well. Water is
extracted directly from the soil.