What are Aquifers?
A zone of material capable of supplying ground water at a useful rate from a well is called an aquifer. Gravel, sand, soils, and fractured sandstone, as well as granite and metamorphic rocks with high porosity due to connected open fractures, are good aquifers if ground water is present. A zone of earth material that will hold water but not transmit fast enough to be pumped is called and aquiclude or aquitard. Aquitards often form a confining layer through which little water moves. Clay soils, shale, and igneous or metamorphic rocks with little interconnected porosity and or fractures are likely to form aquitards An aquifer is called an unconfined aquifer if there is no confining layer restricting the upper surface of the zone of saturation at the water table. If a confining layer is present the aquifer is called a confined aguifer and the water beneath it may be under pressure, forming artesian conditions. Similar to the effect that a water tower that produces water pressure for homes
