The purpose of this study is to assess the potential for nitrogen and phosphorus concentrations in Piedmont, Blue Ridge, and Valley and Ridge streams, reservoirs and lakes to be elevated because of the contribution from ground water.  Natural sources (including geologic sources) and anthropogenic sources of nutrients and will be assessed.  

Data from eight NAWQA study units are used in this study. All water-quality data used for this study were collected and compiled as part of the USGS NAWQA program from 1991 to 2000 (NAWQA cycle I). Water-quality results for water samples from 501 wells and 54 springs collected in 20 studies from selected areas in the eight NAWQA study units form the ground-water database of this study. The 20 studies include eleven major aquifer studies, five agricultural land-use studies, and four urban land-use studies. Water-quality results for surface-water samples were collected at 42 fixed-monitoring sites and 452 synoptic surface-water sites.