Yarra Valley Water has increasingly used “ice pigging” to clean its water mains, removing natural sediment that gathers in them over time.
The method pushes a slurry of ice, salt and water through water mains at high pressure, scouring the inside of the pipes to carry sediment away.
Yarra Valley Water general manager for asset services Bridie Fennessy said the recent dry weather underlined the importance of using water-efficient practices like ice pigging.
“Melbourne’s storages have dropped by more than more than 17 per cent in the past 12 months, so finding ways to save water are more important than ever,” she said.
This year, the water corporation is focusing on cleaning its mains in Woori Yallock, Silvan, Ringwood, Craigieburn, Greenvale and Mitcham.
“Every litre we save counts, and with ice pigging, we are saving up to 10 million litres a year compared to using more traditional methods of flushing water mains.
“It means we’re delivering safe, high-quality drinking water to our customers and keeping our water mains in top condition, all while saving water.”
Yarra Valley Water works with specialist contractor SUEZ to carry out the process, which is scheduled during winter and spring, to keep water flowing over warmer months when households use more water.
Yarra Valley Water acting manager for programmed and renewal works John Maher said ice pigging had numerous benefits over traditional methods.
“In the past, cleaning water mains meant flushing large amounts of water through the mains at high speeds. Ice pigging only requires about half as much water and has proved more effective as well,” he said.
“Because the mixture isn’t completely solid, there’s no risk of it getting stuck. When we clean water mains, we have to turn off the water supply, which is an inconvenience to our customers. However, ice pigging is far quicker than other methods, helping us minimise disruption and turn water supply back on after two to three hours.”
