Friday 30 October 2015
Bega Valley Shire Council is working to resolve problems of discoloured drinking water in Bega and Tathra areas.
To reduce the incidence of dirty water, Council is carrying out an extensive flushing program in the Bega and Tathra reticulation areas.
Targeted flushing of particular areas is being carried out, although this can adversely impact water quality in other parts of the system and is likely to be the cause of some of the widespread discoloured water problems now being experienced.
On Monday 2 November Council will also commence cleaning of the larger trunk water mains supplying Bega and Tathra areas using a process known as “ice-pigging”. This aggressive process will remove accumulation of sediment using an ice slurry pumped through the water mains.
Council’s Manager Water and Sewerage Services, Jim Collins, said the predominant source of the discolouration is iron from the Bega River source water and corrosion of water main fittings.
“The issue is not a health concern, rather an aesthetic one. There is no health based guideline value for iron in drinking water.
“The water is disinfected, safe to drink and of a high quality in terms of most indicators,” Mr Collins said.
"However, when the water is discoloured it can be unpleasant and annoying for people, particularly when laundry is affected,” he said.
Council periodically samples the deposited material in the supply network for analysis. The analysis shows iron to be the predominant deposited metal (up to 99% in some areas) followed by manganese and aluminium.
Much of the Bega water supply system is quite old and fittings such as hydrants, stop valves, unlined tees and bends have a degree of rust, or iron oxide, on the inner surface that breaks loose and deposits in the pipe network.
Iron is also naturally present in the water from the Bega River and this flows through and deposits in the system, particularly those areas where the water flow is low.
Periodically these iron deposits become resuspended and flow out of taps, giving the water an undesirable rust-brown appearance and sometimes staining laundry.
In the medium term Council has an annual pipe and fitting replacement program and over time all the old unlined fittings will be replaced with new epoxy-coated fittings.
A water treatment plant at South Bega is planned in the longer term to improve source water quality however this initiative is presently constrained by the availability of subsidy funding.
Residents experiencing discoloured town water should phone Council on 6499 2222.