Ecoli Fate and Transport in Agricultural System
(Completed)
Significance:
$600 million spent annually on medical expenses
December 2018, massive recall of red/green leaf lettuce and cauliflower with the identified source of E. coli contamination being from an agricultural reservoir in California
Objectives:
Determine E. coli load during and following storm events at a continuous rotational livestock grazing operation
Estimate the contribution from bird and cow species to the measured E. coli load
Hypothesis:
When cows get close = E. coli increases
When birds arrive = E. coli increases
Conclusions:
E. coli highest when cows are closest to the stream before a rainfall event
E. coli concentrations increased as water flowed downstream
The downstream reservoir exceeded EPA freshwater quality criteria ~85% of the study period following rainfall events
Publications:
Hansen, S.2, Messer, T.L., Mittelstet, A., Berry, E.D., Bartelt-Hunt, S., Abmibola, F. 2020. Escherichia Coli Concentrations in Waters of a Reservoir System Impacted by Cattle and Migratory Waterfowl. STOTEN. 705(25), https://doi.org/10.1016/j.scitotenv.2019.135607.
Graduate Student: Samuel Hansen (MS Biological Systems Engineering; Graduated 2019)