TasWater is continuing to investigate taste and odour issues reported across Hobart.

Since early January, the TasWater call centre has received around 236 reports, the majority over the last two weeks and from different parts of Hobart, and investigations have been ongoing to determine the precise cause.

TasWater CEO Mike Brewster said extensive initial investigations within raw water sources, treatment plants and the reticulation system are yet to find a common cause for the taste and odour issue.

“In addition to our regular sampling regime, we have been testing water in the systems where complaints have been raised. We have conducted 319 tests in the last five weeks and results are within Australian Drinking Water Guidelines, which means the water is safe to drink,” Mr Brewster said.

“One of the biggest challenges has been that there is no definitive scientific test for taste and odour in water, and we have been investigating more than 2,500km of pipeline across affected areas.”

“We can confirm that all calls are investigated and we have been responding to these complaints through localised flushing.”

“What this investigation has found that while localised flushing is helpful, it is not enough. Our crews will now move to larger zonal flushing of water mains,” Mr Brewster said.

General Manager Works Delivery, Dr Dharma Dharmabalan said that as the cause is not obvious TasWater is considering a range of probable causes.

“We are undertaking investigations to determine if changing water flows, maintenance regimes, seasonal changes and water sources are causing the taste and odour,” Dr Dharmabalan said.

“By mapping all of these activities within the system we anticipate being able to identify the localised causes of the taste and odour issues,” he said.

TasWater will continue to inform the public via their website and Twitter as the investigation continues.

“While we are investigating the problem, we want to reiterate that routine testing of water in the distribution system consistently shows that the water meets national safe drinking water standards and is safe to drink,” Mr Brewster said.

“The increased number of calls to our call centre regarding taste and odour has helped with the investigation and we ask anyone experiencing odour or taste irregularities with their water to contact our call centre on 13 6992,” Mr Brewster said.

Background Information – Hobart’s water supply

Number of complaints received by TasWater:

 236 since 1 January; the majority in the past two weeks
Greater Hobart’s three primary water catchments:
 River Derwent, through Bryn Estyn Water Treatment Plant – around 60% of supply, supplying Greater Hobart, Glenorchy, eastern shore and Sorell, and Bridgewater, Kempton & Campania
 Lake Fenton – through Bryn Estyn Water Treatment Plant – around 20% of supply supplying parts of Glenorchy and Hobart
 Mount Wellington – around 20% of supply supplying parts of Glenorchy and Hobart an all of Kingborough
Treatment facilities
 One water treatment plant – Bryn Estyn Water Treatment Plant (located outside New Norfolk)
 16 dosing stations (disinfection)
Storages
 Nine reservoir dams in the supply system
 96 storage sites (excluding those in water treatment plants)
Bulk water mains (pipelines)
 419 km in length
 Average age 52 years; earliest records go back to 1917
Reticulation pipelines
 2,172km in length
 Average age 34 years; earliest records go back to 1920
No. of connections in greater Hobart
 85,218
Number of drinking water tests
 6,100 per annum
Number of water test sites
 80
Simon Pilkington, TasWater