In the fall of 1985, Jacob Rubin and his colleagues presented their vision for the future U.S. Geological Survey National Water Quality Assessment Program (NAWQA). Their strategy involved implementing an extensive monitoring program, supplemented by later studies focused on enhancing geographic assessment and process understanding. An outcome of this vision, the Agricultural Chemicals Team (ACT), initiated studies in 2001 to develop an understanding of the sources, transport, and fate of nutrients and pesticides in agricultural settings. A major goal of ACT has been to estimate the watershed-scale nitrate mass budget in multiple agricultural watersheds: Morgan Creek, MD; Leary Weber Ditch, IN; Maple Creek, NE; and Granger Drain, WA. [...]
