Pesticides have been detected upstream of a reservoir that feeds Melbourne’s drinking water supply. On eight occasions in 2010-11, the levels of pesticides, including simazine, atrazine and DEET, at Sugarloaf reservoir, north-east of Melbourne, were recorded above safe European Union drinking water standards, according to Melbourne Water data obtained by Friends of the Earth through freedom of information. The pesticide levels were within Australian safety limits.
Friends of the Earth believes that this highlights problems with the Winneke treatment plant at Sugarloaf, which was not deigned treat for pesticides. They argue that as a precautionary principle the treatment process at Winneke should be upgraded to deal with these pesticides. Elsewhere in Australia, activated carbon has been used.
Australia limits are set at 20 parts per billion, compared with 0.1 parts per billion in Europe.
Advanced treatment technologies such as ozone, activated carbon, or reverse osmosis can be used remove the pesticides. Ozone has been shown to be particularly effective not just against pesticides but also other micro pollutants found in water. Besides removing these compounds ozone is a good primary disinfectant. This means it can do two jobs at once, remove organic compounds and harmful micro organisms. Unlike chlorine, it does not produce harmful disinfection by products such as chlorinated organic compounds in water such as trihalomethanes or haloacetic acids, both tightly controlled by many water regulatory agencies around the world.