A study was conducted to assess the occurrence and availability of groundwater in the crystalline rocks of the Piedmont area in northeastern Georgia and to determine whether groundwater is a viable alternative or supplemental source for industrial, public and private supplies. The area is underlain by a variety of metamorphic and igneous rocks. The quantity of water that a rock unit can supply to wells is determined by the number, capacity, and interconnection of the secondary openings. Of an estimated 10,000 successful wells drilled in the Athens Region, 972 wells are reported by drilling contractors to supply from 20 to 300 gal/min. Studies of well sites revealed that high yielding wells can be developed only where the water bearing units have undergone significant increases in secondary permeability. This occurs mainly in association with (1) contact zones between rock units of contrasting character, (2) contact zones within multilayered rock units, (3) fault zones, (4) stress-relief fractures, and (5) shear zones. Groundwater may be a viable alternative or supplemental source for industrial, public, and private supplies in much of the Athens Region. In 1980, groundwater made up 38% (18 million gal/day) of the total water used in the area. Yields of 20 to more than 200 gal/min are obtained from wells throughout most of the region, and the water is generally of good chemical quality and is suitable for drinking and many other uses. Concentrations of dissolved constituents are fairly consistent throughout the area. Except for iron, manganese, and fluoride, dissolved constituents rarely exceed drinking water standards. (Lantz-PTT)
