Aquifer

An aquifer is an underground layer of water-bearing rock, sediment, or soil that stores groundwater and allows water to flow through it.  These geological formations can range from permeable materials like gravel, sand, and sandstone to fractured rocks like limestone or granite.  Aquifers are crucial for providing water supplies for drinking, agriculture, and industry.  There are two main types of aquifers:

 

Unconfined Aquifer  -  Water is stored in porous rock or sediment layers, with the water table (upper level of the aquifer) exposed to atmospheric pressure.  It recharges directly from precipitation or surface water.