Relating pollutant and water quality parameters to landuse in a subwatershed in the Choptank River watershed

Abstract

Agriculture and animal feeding operations have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This survey examined a subwatershed within the Choptank River watershed for impacts of a poultry facility on its adjacent surface water. Water and sediment samples were collected May - October 2009 under mostly baseflow conditions and analyzed for antibiotics, nutrients, heavy metals, and selected bacteria. Of the antibiotics recovered, no significant difference was observed spatially, but a significant difference emerged between spring and fall/winter. For nutrients, the greatest phosphorus concentrations were at the subwatershed outlet (4) and at two branches not containing the poultry house (3 and 5); nitrogen concentrations at sites 2 and 5 were as high as site 4. Arsenic concentrations at 2 were lower than both the low-agriculture (control) site and a site neighboring 3. Bacterial counts in water and sediment remained fairly constant throughout the sampling regime.