Ice ‘slushie’ flushes out underwater pipe blockage in Murray Bridge

A giant slushy “ice pig” has been being sent through a 9-kilometre recycled water pipeline in the Murray Bridge area, to clear sediment build-up and improve supply to local recycled water users.

SA Water used the ice pigging technology – which is an alternative to the conventional pigging method – to gently scrub the inside of the pipe, including a sensitive section under the River Murray, without placing extra pressure on the existing infrastructure.

The clean-out removed sediment that had been limiting flows within the pipeline, causing recycled water to be released near SA Water’s Brinkley Wastewater Treatment Plant instead of being stored in a lagoon for irrigation use on local farms.

Over time, sediment can accumulate in sections of the pipeline and reduce the plant and connecting pipeline’s ability to supply recycled water as quickly as possible.

Completed over 9 days, the project has improved recycled water reliability for producers across the region.

SA Water’s Senior Manager of Field Operations Matt Minagall said ice pigging provided a safe, low-risk way to clean the pipe while protecting the river environment.

“Ice pigging allowed us to clean this important pipeline effectively without disrupting customers or placing additional strain on the pipe,” Matt said.

“Because the ice is pliable, it can move through bends and narrowed sections, gently wiping away build-up as it goes.”

Ice pigging technology – developed and delivered by SUEZ, who are also SA Water’s Production and Treatment Alliance partner - was chosen because part of the pipeline runs beneath the River Murray. If the ice encounters a blockage, it simply melts rather than forcing its way through.

The pipeline was cleaned in sections, taking less than 2 hours each for approximately 10-tonnes of ice to move through the pipes. Areas containing larger amounts of sediment treated twice.

All material removed during the process was captured in tankers, ensuring it did not enter the environment.

Matt said ice pigging works in a similar way to sending a scrubber through a pipe, but without the force or mechanical pressure of traditional cleaning methods.

“It’s essentially a thick, slushy ice mixture that gently wipes the inside of the pipe as it moves along,” he said.

“The project shows how using different methods can help get more value from existing infrastructure and support customer outcomes.”