Skilled laborers dig up to 15 – 40 meters by hand to reach aquifers below. 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. If ground water is present, a dug well will yield results. Water is extracted from the reservoir and replenished naturally from the aquifer. The well’s recharge and use capacities are causally 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 well’s method of construction and shallow depth, contamination from surface drainage and sub surface seepage is common.