Situated in the Sumner/Scarborough areas of the city, located south-east of the CBD, the renewals are part of contractor Fulton Hogan‘s wastewater catchment, with most of the work on hills where the wastewater lines run beneath private properties or along steep terrain. According to a Stronger Christchurch Infrastructure Rebuild Team (SCIRT) spokesperson, the wastewater lines were originally installed around 50 to 80 years ago when the areas were first developed. “And now often there are nearby obstacles such as retaining walls, paths, steps, gardens and mature trees above the pipelines,” said the SCIRT. Trenchless techniques such as pipe bursting have played a significant role in the rebuild of Christchurch’s underground infrastructure following the quakes. Pipe bursting has been a preferred rehabilitation technique due to it not requiring trenching along the whole length of the pipe, continued the SCIRT spokesperson. “It has fewer impacts to homeowners and property. Pipe bursting also takes less time than open trenching. “In a normal wastewater renewal project, the pipe bursting method can save a lot of disruption to the road surface and traffic, but for the Sumner/Scarborough project it is virtually the only way to renew these lines.” The wastewater repairs in this area of the city are expected to take a further six to eight months to complete.