Availability and quality of ground water in the Piedmont Province of Virginia

Abstract

The Piedmont Province of Virginia has an ample supply of ground water, perhaps as much as 1.5 billion gallons are in storage per square mile, generally suitable for domestic and small supply needs. The source of this ground water is precipitation. Ground water within the crystalline rocks of the Piedmont is stored in the pore spaces of the regolith and in fractures in the underlying bedrock. Water within the sedimentary rocks of the sedimentary basins is stored in bedding planes, fractures, and in pore spaces in the rock, and in the regolith. Well yields can be maximized in both terranes by constructing wells along lineaments and in valleys. Ground water in the crystalline rocks is generally slightly mineralized and acidic (pH <7.0). Ground water in the sedimentary rocks is more mineralized and basic (pH >7.0). Dissolved solids concentration in deep wells (>500 feet) in sedimentary rock may exceed tolerable limits. Land disposal of solid wastes and sewage from domestic septic systems present the major threat to groundwater quality. A greater understanding of the groundwater system in the Virginia Piedmont could be used to anticipate future shortages so that preventive measures could be implemented to protect the groundwater reservoir. GROUND WATER SURFACE WATER