Watchem (Victoria) – Chlorite
Chlorite: ADWG Health 0.3mg/L.
Chlorite and chlorate are disinfection by-products of chlorine dioxide disinfection process.
Highest level recorded in Victoria 2007-10 was in the western Victorian community of Watchem 4.2mg/L.
“Chlorite levels in the Watchem supply regularly exceeded 0.3 mg/L, as a result of
high levels of organic material in this channel-fed, unfiltered water supply. Results
ranged up to 4.2 mg/L. As a result, the Watchem supply was declared as regulated
water on 14 March 2008, until such time as the water can comply with all quality
standards for drinking water. Grampians Wimmera Mallee Water is required to
prepare a risk management plan that considers the non-potable nature of this
supply and take all reasonable steps to ensure that the water is not confused with
drinking water.” Annual Report on Drinking Water Quality in Victoria 2007-08
“… industry are having serious problems meeting chlorite/chlorate limits that were proposed in the new Australian Drinking Water Guidelines, especially for disinfection in long distance pipelines that are dosed with sodium hyptochlorite” pers comm 18/5/11.