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Drilled wells can be excavated by simple hand drilling methods (augering, sludging, jetting, driven, hand percussion) or machine drilling (rotary, percussion, down the hole hammer). Drilled wells can get water from a much deeper level than by dug wells - often up to several hundred of meters.
Drilled wells with electric pumps are currently used throughout the world, typically in rural or sparsely populated areas, though many urban areas are supplied partly by municipal wells.
Drilled wells are typically created using either top-head rotary style, table rotary, or cable tool drilling machines, all of which use drilling stems that are turned to create a cutting action in the formation, hence the term 'drilling'. Most shallow well drilling machines are mounted on large trucks, trailers, or tracked vehicle carriages. Water wells typically range from 20 to 600 feet (180m), but in some areas can go deeper than 6,000 feet (1800m).
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