Soil and fecal coliform trapping by grass filter strips during simulated rain
Journal of Soil and Water Conservation , 50 , 1995
Coyne, M.S., Gilfillen, R.A., Rhodes, R.W., Blevins, R.L.
Poultry production is increasing in Kentucky. The wastes produced are typically added to soil but surface runoff from agricultural soils treated with poultry waste may exceed water quality standards for fecal indicator bacteria and contribute to agricultural nonpoint-source pollution. While soil erosion in surface runoff is frequently managed by grass filter strips, this management practice may not be an equally effective control for fecal bacteria. We measured soil and fecal coliform trapping in surface runoff from two poultry manure-amended plots in a simulated rain study. The simulation reflected a worst-case event in which poultry waste application was followed by high intensity rain. Grass filter strips, 9 meters long trapped more than 99% of the soil in surface runoff but fecal coliform trapping was less effective. The efficiency of fecal coliform removal from surface runoff was 74% and 43% in the two plots studied. Fecal coliforms in surface runoff always exceeded primary contact water standards of 200 fecal coliforms/100 mL. These data indicated that grass filter strips which adequately controlled sediment runoff were inadequate to bring surface water contaminated with fecal bacteria into compliance with current primary water contact standards.