Pollutant movement to shallow ground water tables from swine waste lagoons
Th is research investigated the effect of three anaerobic swine-waste lagoons on the quality of nearby ground water. The lagoons, in the Coastal Plain region of Virginia, were located on soils with high water tables and with varying drainage characteristics. Over a 14-month period in 1974 and 1975, ground water samples were taken from wells located at various depths and distances from the lagoons. These samples then were analyzed to determine the extent of contamination due to the lagoons. The biological constituent analyzed was the number of fecal coliform bacteria; chemical constituents analyzed were concentrations of Cl, Cu, Mn, NH4-N, N03-N, P04-P, and Zn.
Research findings showed that the quality of ground water was affected least around one lagoon constructed at ground level in a poorly drained soil with a clay subsoil. No ground water contamination was found more than 3 m from this lagoon. In contrast, ground water around two lagoons constructed with embankments above ground level, one in a sandy clay loam subsoil and the other in a sandy subsoil, showed traces of swinewaste components as far away as 30 m. Pollutant levels in ground water around the former lagoon were below U.S. Public Health Service drinking water standards, while pollutant levels around the latter lagoon exceeded those standards on many occasions. These experimental results indicate that seepage may occur from lagoons with embankments above ground level in sandy soil, and that biological sealing in such lagoons may not sufficiently protect shallow aquifers from contamination.