A geologic formation, a group of formations, or a part of a
formation that is water bearing. A geological formation or
structure that stores or transmits water, or both, such as to
wells and springs. An underground layer of porous rock, sand, or
gravel containing large amounts of water. Use of the term is
usually restricted to those water-bearing structures capable of
yielding water in sufficient quantity to constitute a usable
supply. A sand, gravel, or rock formation capable of storing or
conveying water below the surface of the land. A geologic
formation, group of formations, or part of a formation that
contains sufficient saturated permeable material to yield
significant quantities of water to wells and springs.