Business South May 2021

34 | CONTRACTING Fulton Hogan Sewer upgrade proves a massive task T Richard Loader “We had to connect on to each and every existing gravity system from every property with new gravity pipework and take that to a new tank location. From there, it was pumped to the road to a new pressurized sewer main and finally delivered to the treatment plant.” 0800 TRULINE www.trulinecivil.com Excellence in Infrastructure E ngagement with property owners played a key role in Fulton Hogan’s successful delivery of major repairs to Kaikoura’s earthquake damaged wastewater network two kilometres along Beach Road. Fulton Hogan was contracted by the Kaik- oura District Council (KDC) to renew, upgrade and replace the damaged Lyell Creek sewer running from Hawthorne Road to Mill Road. Project scope included the decommission- ing of parts of the existing network, connect- ing domestic and commercial wastewater users to low pressure wastewater tanks, then connect to a new wastewater pipeline along beach road and through to an existing waste water treatment plant. Fulton Hogan worked collaboratively with KDC along with the system’s designer Stantec, and Aquatec NZ — KDC’s nominated supplier of the low-pressure water tanks. Project Manager for Fulton Hogan, John O’Donoghue, says replacing the old gravity system with a new pumped wastewater net- work and its design was the first challenge to overcome. “We had to connect on to each and every existing gravity system from every property with new gravity pipework and take that to a new tank location. “From there, it was pumped to the road to a new pressurized sewer main and finally delivered to the treatment plant.” John explains that a new 355mm polyeth- ylene (PE) pipe along Beach Road had thirty connections feeding into it coming from the different tanks and each of those tanks were fed from two, ten or even fifteen private or commercial properties. “Tank sizing and capacity for the number of properties was important together with the pipe and pump sizing also to deliver the correct volume and flow of wastewater to the main pipe work on the road. “Each and every one of the tanks had an electrical supply that had to be routed to the locations as well. “We were basically installing underground tanks 3mx3mx3m in size that were finished flush with ground level. “We had to site them on private property away from buildings and away from any fu- ture development where possible. In conjunc- tion with all of the trenching and excavations that was required we employed the services of structural engineers to do a photographic structural survey pre and post of all of the affected properties.” With design work for the new wastewater network completed, the second challenge was gaining stakeholder agreement. “We had to work collaboratively with up to 150 private householders to gain property access to reroute and relay the new services in and close to their properties.” Before commencing any work on private property, Fulton Hogan always obtains a signed access and restoration agreement with the homeowner, outlining what work was required to be done on their property.