Edge Underground has played a driving role in a major South Australia infrastructure project.
In the rapidly growing northern suburbs of Adelaide, a bold wastewater infrastructure project is taking shape. Roughly 10km of new infrastructure is being delivered by Fulton Hogan, leaning heavily on Edge Underground’s vacuum microtunnelling technology – a choice that not only accelerates delivery, but also mitigates disruption in a highly serviced, high-density urban environment.
From the outset, Fulton Hogan’s project team recognised that conventional open-cut methods would be prohibitively complicated in many zones. As Fulton Hogan Civil Senior Project Engineer Li Dong said, even though parts of the alignment cross relatively underdeveloped areas, the presence of existing services – water, gas, electricity – made relocation difficult, risky, and costly. Trenchless microtunnelling offered a smarter solution, reducing reinstatement costs, limiting the traffic footprint, and significantly lessening the impact on the local community.
Edge Underground was initially awarded approximately half of the 10km package but was later called upon to utilise its upgraded equipment featuring AdaptX technology to complete several bores where conventional systems used by other contractors had encountered challenges.
Fulton Hogan Utilities Senior Project Manager Jithu John explained.
“There were some areas in our initial design concept that were to be done by open trenching, but when we encountered additional services that required relocation (with no commitment from the service providers), then we made the risk-based delivery-driven call that is was easier to go with microtunnelling,” he said.
“It shows that it’s not just the ground condition that determines the technology. It’s also the hindrances you are dealing with, and how challenging it is to get around them.”
Edge Underground’s parent company, OptionX Group, is led by CEO Stuart Harrison, who is acutely aware of the inherent risks involved in sewer pipeline works. His understanding comes not only from decades in the trenchless industry, but from his own family’s history in traditional trenching.
“There are risks on multiple levels – the safety of construction workers, the protection of underground infrastructure, the surrounding environment, and the well-being of the community as a whole. This goes to the very heart of why we continue to advance AdaptX technology. Our goal is to deliver the essential infrastructure the world needs, without the historical risks that open trenching brings.”
Two Edge Underground crews, in addition to a third microtunnelling contractor, were deployed on the project. Edge Underground’s advanced vacuum microtunnelling technology was able to easily handle the challenging clay ground conditions, allowing Fulton Hogan to compress its schedule significantly.
“What we observed is that Edge’s methodology and technology has better consistency and efficiency. Edge delivered consistent six-day sections, whereas the other contractor took roughly 10-11 days per section,” Li Dong said.
“They have been pretty consistent and always ahead of program.”
One of the most outstanding technical requirements of the job is the ultra-flat grade: just 0.13 percent, or 0.13 mm per metre. That level of precision is rare, even in microtunnelling projects, but Edge Underground’s system, powered by the AdaptX platform, delivered consistently.
This high degree of accuracy, paired with impressive performance even in tough ground conditions, allows Edge Underground to deliver tangible productivity benefits.
“They’re very consistent in their timing, and that consistency has cost benefits to it,” Jithu John said.
“For Edge to do its work, our team has to prepare the launch and receiver shafts for them. Doing this too early means greater disruption to the community, and increased costs. If you’re digging these shafts weeks in advance, then you’re just burning money.
“With Edge’s system, planning these digs becomes more accurate and predictable.”
Tshepo Molatedi, Fulton Hogan’s Senior Estimator – Utilities, said working with Edge Underground has been refreshingly collaborative.
“They are very good to work with – there has been continual communication and support from them,” he said.
That spirit of partnership, Tshepo believes, has helped to contribute to the success of the overall project.
“We want contractors who are willing to work together and prioritise the outcome of the project. Edge Underground is very collaborative,” he said.
Across all fronts – technical, operational, and interpersonal – Edge Underground is delivering excellence. The team’s microtunnelling works are expected to be completed in March 2026, contributing to the quality of life for north Adelaide residents for decades to come.
For more information, visit optionxgroup.com.au