Matching vegetated buffer widths to environmental loading rates of Cryptosporidium parvum from livestock. Atwill, Rob^*,1, Tate, Ken², Harter, Thomas³, and Nat.Res. Advisors, UCCE Livestock⁴, ¹ Veterinary Medicine Teaching & Research Center, SVM-UCD, Tulare, CA² Department of Agronomy and Range Science, UCD, Davis, CA³ Department of Land, Air, and Water Resources, UCD, Davis, CA⁴ All, Over, CA

ABSTRACT- A strategy currently being advocated for minimizing overland transport of microbial pathogens from animal manure to surface water is to place vegetated buffer strips between animal agricultural operations and vulnerable surface water supplies. We found that the infective stage (oocysts) of the protozoal parasite, Cryptosporidium parvum, are readily eluted from bovine feces during rainfall and capable of being transported in high concentrations in overland flow. Optimal design criteria for using vegetated buffer strips to attenuate this pathogen load are just beginning to be developed for waterborne microbial contaminants. This talk will cover methods and results from several research projects that first quantify the rate of environmental loading of C. parvum from specific livestock operations, then demonstrate how filtration efficiencies per meter of vegetated buffers can be used to design appropriate widths for removing the pathogen load from overland flow.

KEY WORDS: buffers, pathogens, waterborne, livestock