Water Wells 
Ground water in it’s natural state – in most places – is of good sanitary quality and is safe to drink. This is particularly true where the water is found in saturated strata of sand or a mixture of sand and gravel. The water found in such formations usually has had the benefit of natural filtration afforded by percolation through porous earth materials.
Constructing a sanitary well involves: the excavation of a bore hole deep enough to tap the desired source of ground water; the installation of the well casing; the installation of a well screen (where required); and the installation of the pump and pressure equipment, and any other accessories. The purpose is to bring the water to the point of use without introducing contamination into the aquifer from which it is taken.
Good well construction practices and regulations protect the health of those using the water by applying reasonable measures that will prevent contamination of supply.
The required protective measures vary with the physical surroundings and the geologic formations in each situation. These recommended practices provide a guide for good construction requirements for the conditions described in them. Such conditions are typical of the majority of situations where wells can be employed to obtain ground water for private and quai-public water supply systems. Some modifications in details can be made to meet unusual conditions in a locality so long as the fundamental steps are taken to protect the sanitary quality of the water.