SA Water is trialling a trenchless fix for the first time in its metropolitan sewer network to avoid unnecessary disruption to businesses and the community.
The trenchless Quick-Lock system involves a permanent stainless-steel sleeve that’s transported within the sewer main to the repair point, where it’s expanded by a small compressor to line and seal the pipe.
By deploying the sleeve into the pipe from a sewer access chamber near the intersection of Gawler Place and Rundle Mall in Adelaide’s CBD, SA Water’s crews were recently able to restore the pipe’s structural integrity and prevent a potential collapse – without the need for excavating.
SA Water senior manager of infrastructure planning and strategy Daniel Hoefel said South Australia needs to keep challenging itself to explore different ways of maintaining assets to ensure it is minimising any impact on the surrounding community from its work.
“Particularly within Adelaide’s CBD – which sees around 100,000 people each day during the work week – the potential impact can be even greater, making it the ideal location to trial the Quick-Lock system,” he said.
“Our team has successfully trialled the product during repairs in our regional sewer network, and we were keen to expand the solution to an area that would benefit from trenchless repairs due to the likelihood of disruption.
“Through our proactive CCTV monitoring program of high-risk areas in our CBD sewer network, we detected a 150-millimetre-diameter pipe was displaced from the joint, with sewage leaking out of it and forming a cavity.”
Hoefel added that if the leak was left too long it would likely increased in size and also caused soil around the pipe to wash away – increasing the likelihood of the ground and pipe to collapse.
If SA Water used traditional repair methods it would have involved removing pavers in Rundle Mall and excavating down to get access to the pipe, causing disruption to the community and local traders, along with impacting the area’s amenity.
However, but using this trenchless method, the utility only needed to access one of its nearby sewer chambers for repairs, and after one of the team was safely lowered inside the chamber, SA Water used a combination of ropes and steel rods – guided by a CCTV camera – to push the sleeve to the impacted section of pipe.
Once in place, the stainless-steel sleeve was expanded to line the inside of the pipe and form a new section.
“The sleeve’s locking system ensures it remains permanently in position and absorbs the natural movements of the pipe from external ground pressure,” Hoefel said.
“After the success of trialling it in our metropolitan network, we’ll look for more opportunities to test the product, which has proven to be a great non-invasive option for repairs to smaller sections of pipe.”
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