August 2018 | Sharon Webb
DELORAINE RESIDENTS and businesses at 1,250 addresses boiled their drinking water for a week in July because dirty water overflowed from a holding tank into the town’s reticulated water supply.
Water is now back to normal with TasWater having reviewed its processes to ensure the problem is not repeated.
It is unknown whether anyone became ill from the water; Taswater said tests detected no E.coli, toxins or other pathogens.
But it moved quickly on 6th July to advise residents via the media about the risks of drinking the water, and to letterbox residents and businesses. The alert was lifted on 12th July.
Describing how the incident happened, Taswater incident controller for the boil water alert, Peter Januba, said when high rainfall in the first week of July caused “water in excess of acceptable turbidity limits” to leave the treatment plant, the plant automatically shut down.
“Water which did not meet specification was diverted and stored in a tank and the plant was manually restarted and normal treatment resumed,” Mr Januba said.
But the tank was too small for the dirty water and it overflowed, polluting Deloraine’s drinking water.
As a ‘precaution’ Taswater advised Deloraine people to:
Boil all water used for consumption and food preparation and cleaning of teeth;
Discard any salads prepared or food or fruit washed to be eaten uncooked in either the home or commercial premises;
Dispose of food and beverages including ice and prepared baby formula prepared using water from 10.00am Friday 6th July.
TasWater’s general manager of service delivery Bennie Smith announced his organization was investigating technical causes of the event, while the whole reticulation network was flushed and scoured to clear the system of any compromised water.
By 12th July non-compliant water was no longer in the system and Taswater had changed its protocols to prevent overflow occurring again.
Mr Januba said in future any out-of-specification water would be discharged directly into the storm water system, avoiding any chance of it entering the reticulation network.
He said test results confirmed Deloraine’s drinking water now meets the standards of the Tasmanian Drinking Water Quality Guidelines and the Australian Drinking Water Guidelines and is therefore safe to drink.
TasWater will continue to provide ongoing monitoring and testing to demonstrate water quality meets the drinking water guidelines. It is not aware of Deloraine’s problem occurring at any other Tasmanian water treatment plant.