A new high-tech pipe cleaning technique known as Ice Pigging is set to be introduced into Yarra Valley Waters’ water main maintenance toolkit.

The new technique will save millions of litres of water each year and be the key technique employed as part of Yarra Valley Waters’ mains cleaning program. The program aims to improve water quality by removing any naturally occurring sediment that accumulates in the pipes as a result of Melbourne’s predominately unfiltered supply sources.

The new technology works by scrubbing the water main with a thick slurry of ice, which is then ejected out of a hydrant further down the line.

Ice Pigging can remove around 17 times more sediment from water mains than traditional flushing techniques which only use water. Yarra Valley Water had a goal of reducing the amount of water used throughout the cleaning process and as such their Research and Innovations department came across the innovative processes during a global search.

The method has been used by various water companies throughout Europe, with the technology winning the global grand prize in the Small Project Innovation category from the International Water Association (IWA) in 2010.

According to Mr Tony Kelly, Managing Director of Yarra Valley Water, water mains cleaning using traditional methods were suspended during the drought because of the high use of drinking water.

“Ice Pigging allows for more effective sediment removal so that we are able to use a more targeted approach to selecting mains for cleaning. Pipes are identified for cleaning using computer hydraulic models of the water supply network which predict where naturally occurring sediments are most likely to accumulate.

“To ensure we use the most efficient and effective low water use mains cleaning technique, Yarra Valley Water has been investigating new methods. After a very successful trial, we’ve engaged the licensed providers of the Ice Pigging service so that we can use the advanced mains cleaning method across our service area,” says Mr Kelly.

The method does not reduce the man hours for their mains cleaning program, but it does reduce the amount of water used.
Prior to the start of the Yarra Valley Water program in November 2013, the technique is being demonstrated to a number of water utilities throughout Australia in order to encourage others to adopt the technology.