Water-quality data from ground- and surface-water sites near concentrated animal feeding operations (CAFOs) and non-CAFOs in the Shenandoah Valley and eastern shore of Virginia, January-February, 2004

Concentrated animal feeding operations (CAFOs) result from the consolidation of small farms with animals into larger operations, leading to a higher density of animals per unit of land on CAFOs than on small farms. The density of animals and subsequent concentration of animal wastes potentially can cause contamination of nearby ground and surface waters. This report summarizes water-quality data collected from agricultural sites in the Shenandoah Valley and Eastern Shore of Virginia. Five sites, three non-CAFO and two dairy-operation CAFO sites, were sampled in the Shenandoah Valley. Four sites, one non-CAFO and three poultry-operation CAFO sites were sampled on the Eastern Shore. All samples were collected during January and February 2004. Water samples were analyzed for the following parameters and constituents: temperature, specific conductance, pH, and dissolved oxygen; concentrations of the indicator organisms Escherichia coli (E. coli) and enterococci; bacterial isolates of E. coli, enterococci, Salmonella spp., and Campylobacter spp.; sensitivity to antibiotics of E. coli, enterococci, and Salmonella spp.; arsenic, cadmium, chromium³⁺, copper, nickel, and mercury; hardness, biological oxygen demand, nitrate, nitrite, ammonia, ortho-phosphate, total Kjeldahl nitrogen, chemical oxygen demand, total organic carbon, and dissolved organic carbon; and 45 dissolved organic compounds, which included a suite of antibiotic compounds.

Data are presented in tables 5-21 and results of analyses of replicate samples are presented in tables 22-28. A summary of the data in tables 5-8 and 18-21 is included in the report.