Relining water mains a future concern for water utilities
The development of water main relining techniques to replace ageing assets will be crucial to keeping costs within a manageable range for water utilities in future.
That's the advice from Barwon Water – just one utility facing ballooning costs as it looks to replace 1270km of asbestos cement (AC) pipes over coming years.
“The issue is, those of us that do have a lot of AC mains – particularly those constructed in the 1940s and 1950s period – are going to be facing an increasing replacement program into the future,” said Barwon Water Infrastructure Services Manager Paul Northey.
“So while we can do 10 to 20km [per year] now, in years to come we will have to increase our program and that obviously comes at a cost.”
The Water Services Association of Australia estimates that it will cost $8 billion to safely remove the 40,000km of AC water pipelines which are starting to wear out around the country.
Northey said it was time to focus on rehabilitation methods.
“It's quite established now for sewer relining [rather than replacement] and it works really well – it's saved the industry a lot of money and saved neighbourhoods a lot of disruption” he said.
“We'd be hoping that similar technologies could be developed for water mains into the future – that's certainly an opportunity for the industry.”
Northey admitted there were unique challenges when it came to extending the lives of water mains.
“The difficulty obviously with water mains is they're under pressure and you'd have to take them off service while you did it,” he said.
“And then there's the connection, so it's not quite the same as a gravity sewer but that would certainly be something to look at into the future.”
Barwon Water's experience was that the directional drill method was currently the safest and most economic way of replacing AC mains.