Event Sampling for Cryptosporidium and Gardia in South Australian Water Sources

Publisher Summary Event-based monitoring has demonstrated that catchment areas need to be protected as they offer the chief source of contamination by Cryptosporidium and Giardia to drinking water supplies in South Australia. Major spikes of contamination to the inlets to supply reservoirs occur after spells of rain. This chapter presents data on the frequency of rain events, their effect on background levels of organisms, and the strategies in place to deal with contamination events. The data provide information on the challenges posed to water filtration plants and enables operators to assess public health risks. A protocol has been developed to deal with Cryptosporidium detections following these rain events, which involves sampling from supply reservoirs, and filtration plant inlets. The water treatment processes used in South Australia involving the multiple barrier approach is providing pathogen-free filtered water from relatively poor-quality source water.