We have selected Ghella-Abergeldie Harker Joint Venture as our preferred bidder for the construction of the Central Interceptor wastewater tunnel.
Ghella-Abergeldie Harker Joint Venture is one of four contractors that tendered for the project. The other three are: CPB Contractors; Pacific Networks (comprising McConnell Dowell, Fletcher Construction and Obayashi); and VINCI Joint Venture (comprising VINCI Construction Grands Projets, HEB Construction and Soletanche Bachy).
The Central Interceptor will run for 13-kilometres from Western Springs to a new pump station at the Māngere Wastewater Treatment Plant.
At 4.5 metres diameter, it will be Auckland’s largest wastewater tunnel and the biggest wastewater project ever undertaken in New Zealand.
Watercare chief executive Raveen Jaduram says the Central Interceptor is a big step forward for Auckland: “This project will improve the health of our city’s waterways by reducing wet-weather overflows and provide for population growth. Not only that, its construction will create employment and opportunities for the city.”
The contractors submitted their tenders in mid-September and over the past two months, the Central Interceptor team has been rigorously reviewing their bids while adhering to water-tight security and confidentiality measures.
Jaduram says that on 27 November, the company’s Board of Directors approved the Central Interceptor team’s request to move forward with Ghella-Abergeldie Harker Joint Venture because it represents the best overall value for Auckland.
“Over the next two months, we will continue our due diligence, working with the joint venture on a range of conditions and issues relating to their bid.
“If the conditions and issues can be successfully worked through, the Central Interceptor team will take a recommendation to our Board of Directors in the first quarter of 2019.
“If the conditions and issues cannot be successfully worked through, then we will start liaising with the second bidder – who cannot be named at this stage.”
We have run a thorough procurement process that involved prequalifying the contractors through the expression of interest stage and interacting with them during the request for proposal stage.
“Often when a company undertakes a project of this size, they tender for design and build. By contrast, we have already completed the detailed design. This means all four contractors have a very clear understanding of our project and as a result, there is better pricing and less risk for both Watercare and the contractors.”
Francesco Saibene, New Zealand representative for Ghella, says both joint venture partners are delighted to have the opportunity to further progress their tender: “The team at Watercare are running a professional and robust procurement process which makes us confident that, should we be successful, we will be able to work collaboratively together to deliver an outstanding result for Auckland and its people.”
The joint venture of Ghella and Abergeldie Harker combines more than 30 years of tunnelling expertise in New Zealand with over 150 years of Italian and international tunnelling experience and ability, to ensure the utmost skill and competence in the delivery of this landmark project.
Ghella has successfully completed numerous projects of this scale worldwide. These include the Legacy Way tunnel project in Brisbane which achieved world records in tunnel boring machine excavations. Currently, Ghella is working on some of the biggest tunnelling projects around the world, including the Follo Line in Oslo, the Sydney Metro and the Riachuelo sewage system in Buenos Aires.
Abergeldie Harker has successfully delivered complex underground construction projects across New Zealand over the past four decades and is one of New Zealand’s foremost shaft sinking and pipejacking contractors. Its parent company Abergeldie is one of Australia’s leading three waters contractors with extensive experience working on major water and wastewater assets throughout Australia.
As with the joint venture, we have a strong track record of delivering infrastructure projects. With $10.1 billion in infrastructure, we are one of New Zealand’s largest companies by asset base.
Between 2007 and 2010, we carried out $118-million Project Hobson in which we replaced a 90-year-old sewer pipe that crossed Hobson Bay with a three-kilometre-long wastewater tunnel that connects to large pump station at Orakei.
“With Project Hobson, we successfully used a tunnel boring machine to construct a 3.7m wide tunnel that connects to two shafts and a large pump station. The Central Interceptor project is similar in many ways, only on a larger scale.”
While Project Hobson has reduced overflows in Hobson and Okahu bays, the Central Interceptor will reduce overflows into central Auckland waterways that flow into Waitematā Harbour.
“Parts of the old Auckland City Council area have no stormwater system, so when it rains the stormwater goes into the wastewater pipes and then overflows into streams and beaches,” explains Jaduram.
“It was designed to do that in the early 1900s because it was acceptable back then – and with fewer houses, there was more land for the rain to soak into. But Aucklanders’ expectations have changed – we want a clean and swimmable water environment.”
The Central Interceptor will address wet-weather overflows by collecting the wastewater and stormwater from these overflow points and transporting it to Māngere for treatment.
“It’s expected to reduce the volume of overflows by at least 80 per cent,” Jaduram says. “It also provides time for Auckland Council to install stormwater pipes in areas where there are none.”
The project has been on our agenda for many years, and its funding is already catered for in our pricing plan.
“The Central Interceptor is part of the $5.8 billion we will be spending on upgrading and expanding our infrastructure over the next decade.”
Construction will begin next year and continue until 2025.