Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource,the U.
S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are primary sources of drinking water (Burow and Belitz, 2014). The Piedmont and Blue Ridge crystalline-rock aquifers constitute one of the primary areas being evaluated.
Source: usgs.gov