Areas at high risk of nitrogen contamination of groundwater

Modeling integrates information to estimate risks of nitrate contamination to shallow ground water

One USGS model, based on nationwide data, was developed to estimate the risk of nitrate contamination to shallow ground water across the United States.(30) The model integrates nitrogen inputs and aquifer vulnerability by use of Geographic Information System (GIS) technology. Nitrogen inputs include commercial fertilizer and manure application rates, atmospheric contributions, and population densities (the latter representing residential and urban nitrogen sources, such as septic systems, fertilizers, and domestic animal waste). Aquifer vulnerability is represented by soil-drainage characteristics—the ease with which water and chemicals can seep to ground water—and the extent to which woodlands are interspersed with cropland.