National Water-Quality Assessment (NAWQA) Project
Approximately 40 percent of the land in the United States is used for agriculture. Understanding the movement of water and chemicals is critically important in setting the expectations of agricultural best management practices on water quantity and water quality. The holistic study design focuses on the catchment scale and study areas highlighted represent major agricultural settings and, therefore, findings are relevant throughout much of the nation.
The full study can be accessed at: http://in.water.usgs.gov/NAWQA_ACT/