Melbourne, too, has suffered through at least two such contaminations, however the Sydney drama was much worse. In Sydney, supermarkets reported panic-buying of bottled water and vendors sold small bottles of water to drivers at stoplights. Millions of people had to boil water first to make it safe to drink, but they were still at risk when taking showers. The dogs were not actually in the canals, they were outside, but we think the foxes might have been in the water. At that time, Sydney Water revealed that the water treatment plant did not filter for giardia.
Contaminants can get into the water supply at the catchment area too.
This is where the worst of the problems lies. Complicating matters is the sale and use of human waste sludge. All the deaths and 403,000 of the illnesses were linked to a 1993 bad water outbreak in Milwaukee. The Sydney outbreak showed 9 times that amount when tested. Another outbreak of contamination struck Texas in July 1998, when 160,000 gallons of raw sewage seeped into an aquifer.