Icy solution for improved water

Ice might seem an unlikely ally in the provision of water in the temperate Wimmera but it is playing a role in guaranteeing quality drinking supply for Nhill.

Water managers are using a system-cleaning method called ice pigging, or scouring, which involves forcing a saline ice slurry through pipes to clear iron deposits from inside the pipe walls.

Nhill’s previous and historic groundwater supply left iron deposits in the reticulation system that subsequently built up over many years.

Nhill converted to a drinking-water supply sourced from the Grampians in October 2013 and at the time Gwmwater scoured the reticulation network to remove most of the iron from the system, which worked well.

But some hardened iron deposits remained and as they slowly dissolve, are causing occasional discolouring in supply.

Gwmwater managing director Mark Williams said since 2013, Gwmwater had used several conventional methods to clean the pipe network with varying degrees of success.

He said the corporation, to speed up this process, would adopt a water-main cleaning program employing technology used successfully by other water businesses.

“Ice pigging is highly effective, will not cause blockages and is environmentally friendly,” he said.

Gwmwater has engaged contractor Suez to start ice pigging on the system tomorrow.

The work program allows for work at night when the service will be least disrupted.

“This has been done so there is flexibili- ty to accommodate sensitive customers and commercial businesses which need a constant water supply during business hours,” Mr Williams said.

Gwmwater will distribute a ‘disruption to supply’ flyer to affected customers at least 48 business hours before ice pigging is scheduled to occur.

Mr Williams said the cleaning process led to some waste of water, but the volume was much reduced when compared with flushing alone.

Gwmwater will remove the ice slurry and any heavy sediment generated during the ice pigging process to a storage centre for further processing.

Mr Williams said only the final flush water would be discharged to the storm-water system and Gwmwater was confident there would be no environmental harm caused to the storm-water system or receiving water bodies.

“We’re confident that disruption to customers will be at a minimum and the ice-pigging works will provide much improved water to Nhill.”

Mr Williams said people with any queries about the program could call Gwmwater during business hours on 1300 659 961 or visit website www.gwmwater.org.au.

“We are confident that disruption to customers will be at a minimum and the ice-pigging works will provide much improved water to Nhill” – Mark Williams