Aaro Group were awarded the large diameter portion of the Wide Bay Burnett Regional Organisation of Councils (WBBROC) Sewer Relining Program 18/19 & 19/20. This contract comprised of the following councils within the Wide Bay Area, Fraser Coast Regional Council, Bundaberg Regional Council, North Burnett Regional Council, South Burnett Regional Council, Gympie Regional Council and Cherbourg Aboriginal Shire Council.
Approximately 4km’s of sewer lines were rehabilitated, from DN375 to DN900, by installing a UV Cured Glass Reinforced Plastic Cured-in-Place Pipe (UV GRP CIPP) Liner. This type of liner is designed specifically for each application and does not rely on the host pipe being structural. The scope of works also included a number of lateral seals through the installation of top hats.
Our onsite team comprised of around 8 Aaro experts, who were capable of tackling a diverse range of challenges. Some of those included managing the flow of the larger diameter sewers by using temporary above ground pumping systems and piping. This was required as multiple waste water pumping stations were discharging into the rehabilitation area producing heavy flows, as well as the region experiencing unpredicted rain falls which caused the flow rate to increase dramatically. Aaro mitigated this by installing an overflow pipe into an old sewer pipe that was found at the beginning of the works, which ran directly into the Waste Water Treatment Plant, this allowed the flow to back up when isolated and then overflow into the disused line during a rain event. Aaro also encountered a number of small chamber openings on main roads, which were an older style cast triangular cover, here we redesigned and fabricated our standard equipment to prevent having to remote the cover. Lastly, Aaro encountered a concrete pipe that had been tunnelled, therefore had no ground cover above the pipe. We had to design a method to install a tight fit liner that had the ability to be pressurised without breaking the host pipe. We overcame this challenge by using a specialist bagging that was installed around the liner to take the pressure off the host pipe ensuring a tight fit for the liner