Submitted to: USDA-CSREES National Water Quality Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2006
Publication Date: 1/29/2007
Citation: Jenkins, M., Fisher, D.S., Endale, D.M., Lowrance, R.R., Hubbard, R.K., Newton, L., Gay, P., Vellidis, G. 2007. Role of a pond in reducing the threat of pathogen contamination from livestock and poultry litter applications in an agricultural watershed of the Southern Piedmont. USDA-CSREES National Water Quality Conference.
Technical Abstract: Several outbreaks of gastrointestinal illness from exposure to recreational and municipal drinking waters have focused public attention on animal agriculture as a potential source of pathogens contaminating surface and ground water. Recent observations by researchers in Georgia have indicated that ponds with stream inflows and outflows reduce the concentration of fecal bacteria. A systematic study, however, is needed to substantiate these observations and establish the usefulness of ponds in watersheds. Objective: To test the hypothesis that Ponds downstream from a source of fecal pollution (e.g., grazing cattle, field application of poultry litter) reduce both fecal indicator bacteria (E. coli and fecal enterococci) and zoonotic pathogens Salmonella and E. coli 0157:H7, and can be used as a means of reducing pathogen contamination of surface waters below ponds. Specific objectives are to: 1. determine the spatial and temporal distribution of fecal indicator bacteria and pathogens in inflow, within, and outflow of pond, 2. determine load reduction efficiency during base and storm flow, and 3. determine relation between fecal indicator bacteria and the pathogens. Methods: Our field study occurs at Bishop Pond at the USDA J. Phil Campbell, Sr., Natural Resource Conservation Center which is fed by a first order stream. Pasture land with as many as 50 to 100 cow/calf pairs or 50 to 100 head of cattle and a cropped catchment to which poultry litter is applied once to twice a year drain into the stream and contribute to the pond’s load of fecal bacteria. Three sites upstream from the pond, four sites along a transect within the pond, and the pond outflow are sampled once a month and analyzed for fecal indicator bacteria, Salmonella, and E. coli 0157:H7, total direct microbial counts, nitrate, ammonia, soluble phosphorus, and chlorophyll. Results: The preliminary data presented will be based on base flow measurements taken at Bishop Pond. Results to date reveal that concentrations of fecal indicator bacteria in the inflow are significantly greater than in the outflow and that their concentrations in the pond itself are significantly reduced. Although the numbers of E. coli in the pond ranged from not detectable to 20 cells 100 ml-1, below the level of impairment, E. coli 0157:H7 was nevertheless detected at a level that ranged from 0.01 to 0.05 cell 100 ml-1. At base flow, the pond appears to attenuate the concentration of fecal indicator bacteria.