Optimization and Design Criteria of Vegetative Buffer Strips for Removal of Waterborne Cryptosporidium parvum from Animal Agricultural Runoff

Cryptosporidium parvum, a protozoal parasite, is capable of waterborne transmission from livestock to humans. Furthermore, the fecal-oral parasite is readily mobilized with agricultural runoff during rainfall conditions where it can become a waterborne hazard if discharged in streams or lakes. Vegetative or grass buffer strips are often recommended as a means to remove microbial pathogens from runoff end thereby minimize the risk of waterborne transmission to humans and other ecological systems. Unfortunately, it is unknown how to design buffers strips that consistently remove pathogens such as Cryptosporidium parvum from runoff that are economically feasible to agricultural producers. The long-term goal is to minimize waterborne transmission of microbial pathogens from animal agriculture to human communities. This project will result in the development of practical guidelines regarding buffer widths and percent vegetative cover necessary for effective removal of Cryptosporidium parvum in animal agricultural runoff. The effect of percent vegetative cover on a buffer's filtration efficiency will be calculated for agricultural soils of differing properties (infiltration rate, organic matter, bulk density), differing slopes, and differing rainstorm intensities (1.5 and 4.0 ml/hr/cm2 over 4 hours). This project should result in cost-effective management strategies for reducing the risk of point and non-point source microbial contamination of water from animal agriculture.