Regional towns turn to mobile desal plants to fix salty drinking water supplies
Jan 27 2020
Towns along the dwindling Barwon-Darling River system, in the state’s parched north-west, hope that mobile desalination plants will provide relief from brackish drinking water as the drought tightens its grip.
Some locals in the small outback towns of Brewarrina, Bourke and Walgett have resorted to using bottled water as their main source of drinking water, despite assurances from health authorities that the tap water, though extremely salty, is safe to drink.
Brewarrina, which sources its water supply from a weir on the Barwon River, will on Tuesday become the first of the three towns to switch on a desalination plant, which the council has borrowed from Tenterfield Council, more than 600 kilometres away.
Mayor Phillip O’Connor said the town’s raw water supply was purified at the local treatment plant, but this process could not remove the high sodium content that resulted from the lack of inflow into the river system.
“The longer the river doesn’t run, the saltier the water gets. The water is drinkable but it has got a bad taste to it,” Cr O’Connor said.
The mobile plant, which was originally donated to Tenterfield council by charity Rural Aid, will filter the water from the treatment plant through a process of reverse osmosis. It has the capacity to provide up to 70,000 litres of drinking water a day.
However, the plant will not connect directly to Brewarrina’s water supply, and will instead function as a refilling station, located in the town’s Visitor Centre car park, where residents can bring containers and bottles to fill up and take back to their homes.
The Berejiklian government is spending $10 million to install similar desalination plants in Bourke and Walgett, but these will be attached to the towns’ water supplies, meaning residents will be able to access the water directly from their taps.
Both towns are forced to rely on emergency bore water when their river supplies run low or cease, but testing has revealed higher sodium levels than those specified in the Australian Drinking Water Guidelines on aesthetic (taste) grounds.
Walgett, on the junction of the Namoi and Barwon rivers, has been surviving on emergency bore water for much of the plast three years. Bourke’s supply, which is drawn from a weir on the Darling River, was boosted by 100 millimetres of rain in November, but without further replenishment it will be forced to switch to bore water in the coming months.
Bourke Shire Council general manager Ross Earl said the plant would have the capacity to generate as much as one megalitre of water a day, sufficient for the demands of Bourke’s 1900 residents.
That will be enough water to look after Bourke’s needs,” Mr Earl said. “All houses will be connected to the desalination supply.”
NSW Water Minister Melinda Pavey said the government was also considering reverse osmosis plants for coastal communities, including Forster on the state’s Mid North Coast.
“The recent rain has improved both water quality and supply for the coast, however we remain on standby should this change,” Ms Pavey said.