An aquitard is a zone within the earth that restricts the flow of groundwater from one aquifer to another. An aquitard can sometimes, if completely impermeable, be called an aquiclude or aquifuge. Aquitards comprise layers of either clay or non-porous rock with low hydraulic conductivity.

An aquifuge is an absolutely impermeable unit that will not transmit any water. An aquiclude is a formation that has very low hydraulic conductivity and hardly transmits water. See also Wikipedia.

An aquifuge is an impermeable geological formation which is neither porous nor permeable – which means it cannot store water in it and at the same time it cannot permit water through it. Compact rock is an example of aquifuge.

An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology.

Groundwater supplies drinking water for 51% of the total U.S. population and 99% of the rural population. Groundwater helps grow our food. 64% of groundwater is used for irrigation to grow crops. Groundwater is a source of recharge for lakes, rivers, and wetlands.

Most important source of water for public water supply is groundwater.

precipitation

Water that collects or flows beneath the Earth’s surface, filling the porous spaces in soil, sediment, and rocks. Groundwater is formed due to rain and melting of snow, it is also a source of water for aquifers, springs, and wells.

Groundwater is contained in what are called ‘aquifers’. Groundwater is (naturally) recharged by rain water and snowmelt or from water that leaks through the bottom of some lakes and rivers. Groundwater also can be recharged when water supply systems leak and when crops are irrigated with more water than required.

The water that your well draws from under the ground is an example of groundwater. Water that exists beneath the earth’s surface in underground streams and aquifers. Water beneath the earth’s surface, often between saturated soil and rock, that supplies wells and springs.