Bacteria including E.coli, Listeria and Salmonella are commonly found in manure, and have the potential to become a human health risk if they contaminate food products. The die-off rates of E.coli, Listeria and Salmonella were tracked when manure spiked with the bacteria applied to soil samples in two different soil types. Sentinel vials were used to prevent the soil from washing away, and then dairy or swine manure with added bacteria was sprinkled on the samples. The vials were sampled for added or native bacteria, and bulk soil tested for coliforms and  E.coli. The die-off rate was rapid for the first three weeks following manure application. Depth impacted the die-off rate in E.coli and Salmonella, but not Listeria. For E.coli, and Salmonella the rate is reduced at depths under 6″. Soil type, season, and manure type had no impact on the rate, but the study was conducted in a year with an unusually high precipitation rate which may have had an effect on the results.