HYDROGEOLOGICAL AND CHEMICAL ANALYSIS OF SURFACE AND SHALLOW GROUNDWATER FROM A DAIRY WASTE LAGOON, BERRY COLLEGE, GA

The Berry College dairy was established in the early 1900's. Since the 1930's it has occupied a moderately sloping area draining into a small creek. A large waste lagoon (40,000ft²) catches the effluent that is washed from the facility. The waste lagoon was excavated in the Chewacla and the Townley soil series. Both soils are classified as 'severe' for waste lagoons, meaning that they are highly unsuitable for this function. Four shallow (6ft) and 3 deeper (15ft) monitoring wells were installed down gradient from the lagoon. The shallow wells are monitored on a weekly basis since March 2000. The deeper wells are monitored since October 2001. In August 2001, the dairy herd was culled to approximately 20 animals from 100. Surface water samples from 6 locations (1 up gradient from the lagoon, 1 from the lagoon and 1 from the outfall pipe, and 3 down gradient) have also been sampled. Several field parameters (pH, temperature, D.O. and NH ₄-N) and laboratory analysis (NO₂, NO₃, PO₄) are performed. Preliminary results indicate that the surface and shallow groundwater well waters contain little to no NO₂, NO₃ or PO₄. The only surface waters containing any phosphate come from the waste lagoon itself. They also contain a small amount of NH₄-N. However, the deeper wells do show high amounts of NO₃ (40-50ppm for the well (DW1) closest to the lagoon and 230-250ppm for the well (DW3) furthest from the lagoon). The soil from DW1 was also analyzed. It showed high concentrations of NH₄-N (80ppm) at the surface with decreasing concentrations down-core until another high concentration (80ppm) area was encountered in the C-horizon at 10 feet below the surface. A similar pattern was observed for phosphorus. No NO₂ was recorded, but high NO₃ values, 20 and 10ppm, are found within the A and E horizons, respectively. The bottom of the lagoon, DW1 at a depth of 10 feet and the top of DW3 are all at the same elevation (665 +/- 5ft). The high amounts of NH₄-N in the soils of DW1 at 10 feet and the very high amounts of NO₃ in the groundwater at DW3 are a possible indicator of seepage flow from the bottom of the lagoon. These data will be used to explain the flow patterns and potential impact of these contaminants to areas down gradient from the lagoon and their impact on the proposed future land use of the dairy following the relocation of the dairy to an updated facility.