Hydrologic modeling of pathogen fate and transport.
A watershed-scale fate and transport model has been developed for Escherichia coli and several waterborne pathogens: Cryptosporidiumspp., Giardiaspp., Campylobacter spp, and E. coli O157:H7. The objectives were to determine the primary sources of pathogenic contamination in a watershed used for drinking water supply and to gain a greater understanding of the factors that most influence their survival and transport. To predict the levels of indicator bacteria and pathogens in surface water, an existing hydrologic model, WATFLOOD, was augmented for pathogen transport and tested on a watershed in Southwestern Ontario, Canada. The pathogen model considered transport as a result of overland flow, subsurface flow to tile drainage systems, and in-stream routing. The model predicted that most microorganisms entering the stream from land-based sources enter the stream from tile drainage systems rather than overland transport. Although the model predicted overland transport to be rare, when it occurred, it corresponded to the highest observed and modeled microbial concentrations. Furthermore, rapid increases in measured E. coli concentrations during storm events suggested that the resuspension of microorganisms from stream sediments may be of equal or greater importance than land-based sources of pathogens.
Dorner
Sarah M
SM
NSERC Chair in Water Treatment and Waterloo Hydrology Lab, Department of Civil Engineering, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1. sdorner@tei.umass.edu
Anderson
William B
WB
Slawson
Robin M
RM
Kouwen
Nicholas
N
Huck
Peter M
PM
D000818:Animals; D002167:Campylobacter / Q000302:isolation & purification / Q000378:metabolism; D003198:Computer Simulation; D003458:Cryptosporidium / Q000302:isolation & purification / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification / Q000378:metabolism; D019453:Escherichia coli O157 / Q000302:isolation & purification / Q000378:metabolism; D005872:Giardia / Q000302:isolation & purification / Q000378:metabolism; D008962:Models, Theoretical; D009864:Ontario; D014871:Water Microbiology; D014872:Water Movements; D014873:Water Pollutants / Q000378:metabolism*
D014873:Water Pollutants