Sydney 1998 - lessons from a drinking water crisis

From July to September 1998, high concentrations of Cryptosporidium and Giardia were detected episodically in the water supply and distribution systems of Sydney, Australia. The resulting drinking water crisis triggered three consecutive boil-water advisories and a government inquiry into the management of the water supply. The episodic nature of the detections focused attention on the veracity of the laboratory results and triggered an investigation of the transport of these pathogens in Sydney's water supply system. This article provides information submitted to the Sydney Water Inquiry that explains the episodic occurrence of pathogens in the reticulated water supply, attributing it to rapid fluctuations in the quality of the water reaching the water treatment plant