Introduction


In order to gain insights into how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment, the U.S. Geological Survey (USGS) National Water-Quality Assessment Program’s Agricultural Chemicals Team (ACT) conducted in-depth investigations at seven agricultural study areas across the United States from 2002 to 2009 (Capel and others, 2004; Capel and others, 2008a). Samples collected were analyzed for a wide variety of constituents that served as indicators of agricultural contamination and as tracers of environmental and hydrologic processes. Four different groups of constituents were measured—(1) pesticides, (2) pesticide transformation products, (3) nutrients, and (4) major ions, field parameters, organic carbon, and physical parameters. Study areas included the Merced River basin in California, the Sugar Creek basin in Indiana, the South Fork Iowa River basin in Iowa, the Morgan Creek basin in Maryland, the Bogue Phalia basin in Mississippi, the Maple Creek basin in Nebraska, and the Granger Drain basin in Washington (fig. 1). 


This report provides the data obtained during the course of the ACT studies described above.


First posted June 23, 2011