Trenchless operators in South Australia have been assisting in flood relief and expanding infrastructure ahead of a potential game-changing innovation in the world of wastewater pipe corrosion prevention.
In service to people SA Water and Interflow’s efforts to support flooded towns and communities throughout Australia in 2022 haven’t ceased.
After heavy rain in Queensland, New South Wales and Victoria caused exceptional flooding late last year in several towns along the length of the Murray River in Southern Australia, SA Water and Interflow’s help towards the impacted communities continue.
With the water only now starting to recede in the last few weeks, this help is more than necessary today.
Located 84 kilometres east of Adelaide lies the historic town of Mannum, on the west bank of the river, where a number of properties became inundated with floodwaters.
“Some of these low-lying properties feed into the common wastewater main, and if nothing was done the river could have freely flowed into the wastewater network, inundating pump stations and impacting SA WaterCorp’s ability to provide wastewater services to some of their local customers,” shared the Interflow team.
“Early on in the event, SA Water put several actions in place to help mitigate this challenge, including calling on some of its contract partners, such as Interflow.”
Interflow welcomed its ongoing collaboration with SA Water to support local communities.
“Working consistently over three weeks, together with SA Water, we isolated required properties from the local wastewater network, through patching and sealing, and continue to work with the utility now, gradually restoring services as the floodwaters recede,” said the Interflow team.
“We’re proud of the SA Water and Interflow teams’ quick response through the floods, and for supporting the local communities.”
Healthy expansion
SA Water is investing $155 million in a water main management program that is affecting its extensive network.
The utility has begun works to replace 55 metres of water mains in Mount Barker, around the heritage SteamRanger tracks.
In order to minimise the environmental and community impacts of the work, the utility company has decided to use horizontal directional drilling (HDD) at a depth of 2.4 metres underneath Mount Barker’s heritage SteamRanger tracks.
The section of pipe being replaced is critical to the water service in Mt Barker and surrounds.
Amanda Lewry, SA Water’s General Manager of Sustainable Infrastructure said that HDD is considered to be safer and more efficient for the project.
“These works are part of our efforts to continually improve water services for our customers, with this section of pipe critical to transporting water to residents and businesses in and around Mount Barker,” she said.
“Together with our contractors, we’re committed to minimising any impacts to the community during the works, such as dust or noise caused by the use of heavy machinery and increased vehicle movement in and out of our worksite.”
Work will be timed for periods in which the SteamRanger is not operating.
Bright future
Researchers from The University of South Australia and the University of Queensland have developed self-healing concrete that may use waste to mitigate corrosion in Australia’s sewer pipes.
Professor Yan Zhuge, Professor of Structural Engineering from the University of South Australia, is leading the trial of a an innovative solution for dealing with the corrosion of concrete pipes.
Developed alongside researchers from the University of Queensland, the trial will use pipes that are manufactured from concrete that contains microcapsules filled with a mix of alum sludge and calcium hydroxide, which are added in the final step of mixing the concrete.
The microcapsules have a pH-sensitive shell that will respond to acidic buildup by breaking own and releasing the contents, which act as healing agents and makes the concrete highly resistant to microbially-induced corrosion.
The capsules have a pH-sensitive shell so that they can respond when the pH of the pipes reaches a certain point – a change caused by the corrosive acid from sulphur-oxidising bacteria in wastewater.
“This technology will not only extend the lifetime of concrete structures, saving the Australian economy more than $1 billion, but it will promote a circular economy as well by reusing sludge that would normally end up in landfill,” Zhuge said.
This reuse of waste will be essential to the carbon-neutral aspirations of many industry operators.
“Mainland Australia alone has about 400 drinking water treatment plants, with a single site annually generating up to 2000 tonnes of treated water sludge,” said Zhuge. “Most of that is disposed of in landfill, costing more than $6 million each year, as well as causing severe environmental issues.”
By utilising waste product from wastewater treatment plants in the sludge, the research has the potential to generate a circular economy – an essential element as all industries attempt to decrease their carbon footprint as much as possible.
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This article will appear in the April edition of Trenchless Australasia.