Science Fair Project Encyclopedia
A well is an artificial boring in the earth through which water, oil or gas can be obtained. This article discusses water wells. For information on oil or gas wells, the article oil well should be consulted.
Different types of water well
Two classes may be distinguished:
- shallow or ordinary wells, sunk through a permeable stratum (aquifer) until an impermeable stratum is reached; or
- deep and artesian wells, the latter named from Artois in France, which are sunk through an impermeable stratum down into a water-bearing stratum which overlies an impermeable stratum.
Obviously ordinary wells can supply water very cheaply, but, since impurities readily reach them, there is great risk of contamination. The same does not apply to deep wells, such water being usually free from organic impurities. In ordinary wells, and in deep wells, the water requires pumping to the surface; in artesian wells, on the other hand, the water usually spouts up to a greater or less height above it.
The earliest wells are known from the Neolithic. In the submerged Pre-Pottery Neolithic B settlement of Atlit Yam in Israel, dated to 8100-7500 BC, a well has been found, which so far is the oldest known. Other PPNB wells (7-8 m deep) are known from Kissonerga-Mylouthkia on Cyprus and maybe shallower examples from Shillourokambos as well.
Wood-lined wells are known from the early Neolithic Linearbandkeramic culture, for example in Kückhoven and Eythra in Germany and Schletz in Austria. The early Mesolithic site of Friesack in Germany has yielded a shallow pit with the remains of a birch-bark container that may have been a shallow artificial well as well.
From the Iron Age onwards, wells are common archaeological features, both with wooden shafts and shaft-linings made from wickerwork .
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