In recent years, there has been increasing occurrence of environmentally associatedillness caused by pathogenic organisms, such as Escherichia coli O157, introducedthrough faecal pollution. The presence of E. coli and other coliform bacteria in surfacewaters is an indication of possible contamination with faecal material, which may containthese pathogenic organisms. Understanding the behaviour of E. coli is key to provideaccurate data for monitoring and regulatory purposes. This would allow improvedassessment of health risk and, potentially, implementation of mitigation measures. Thisthesis investigates both survival and transport aspects of E. coli behaviour in the aquaticenvironment.The transport of E. coli within the environment is very complex with many influentialenvironmental factors. One aspect investigated was the native stream biofilm that provedto have little influence over the transport of E. coli during the short term. Over the longterm, these native biofilms did accumulate E. coli as part of their community and thusprovide in-stream stores that may be mobilised during high flow events.
Binding of E. coli to clays also proved to be an important in the transport of the organismwithin the aquatic environment as this processes reduces distance travelled and improvessurvival. Electrostatic forces seemed to have some influence on this process undercontrolled conditions but would be unlikely to have a large impact in the environment.The clays themselves may also play a small role with some providing a more hospitablesurface to bind on than others. The differences in binding behaviour and survival between E. coli found in manure andthose found living in the stream environment suggest that the latter group have become adapted to living under these hostile conditions. These naturalised E. coli potentiallycause problems for monitoring and regulatory efforts as they are a constant source of E.coli within this environment and relatively little is known about potential pathogens inthis group.