Evaluating Coliform Concentrations in Runoff from Various Animal Waste Management Systems

Moore, J.A., Smyth, J., Baker, S., Miner, J.R., Agricultural Experiment Stations, Department of Agricultural Engineering

This report describes the development of a computer model, called MWASTE, designed to follow organisms from the time they leave an animal until they are carried from the operation in surface runoff. A literature review examines the influence of environmental factors on die-off rates and the transport of organisms from livestock facilities and land-spreading operations. The effect of all of these factors is included in the model as it evaluates beef, dairy, horse, poultry, sheep, and swine operations. The hydrology component of the CREAMS model, a field scale model for Chemicals, Runoff and Erosion from Agricultural Management Systems developed by USDA-ARS scientists, is used to generate the runoff component. The operator inputs local weather data, soil characteristics, topography information, and specifics about the operation such as animal numbers, housing system, generation of wastewater and used bedding, and waste system components and their management. The model then generates the numbers of fecal coliform and fecal streptococcus that leave the livestock operation in runoff. The model was developed to be used with conditions found across the United States.