underground water stored between rocks or sediment that is drawn upon by wells and streams. Deep-water aquifers are a non-renewable source of fresh water and are being depleted, although how much water remains is unknown. See http://ga.water.usgs.gov/edu/earthgwaquifer.html for more information.
layers of rock or soil able to hold or transmit much water.
Water bearing strata of the ground
Porous, water-saturated layers of sand, gravel or bed rock through which groundwater flows that can yield an economically significant amount of water.
A water bearing soil or rock formation that is capable of yielding enough water for human use.
soil or rock formations that hold substantial quantities of water
A naturally occurring underground geologic formation which stores a significant amount of water.
One or more geologic formations containing sufficient saturated porous and permeable material to transmit water at a rate sufficient to feed a spring or for economic extraction by a well.
The special underground rock layers that hold groundwater, which are often an important source of water for public water supply, agriculture and industry.