As the largest single-site capital works wastewater infrastructure project in New Zealand in almost 20 years, the upgrade of the Watercare Mangere Wastewater Treatment Plant can justifiably claim its title as an iconic development.
Already the largest wastewater treatment plant in New Zealand and Auckland’s main wastewater treatment facility, the Mangere plant needed expansion to meet the rising demands of the city’s population growth.
Crucially, Watercare also needed to ensure the ongoing environmental preservation of the Manukau Harbour, next to which the plant is located.
This resulted in a multifaceted five-year project, which is now one of three finalists in contention for the Psoda Project of the Year Award. The award, which is part of the annual Project Management Institute of New Zealand (PMINZ) Awards, recognises superior performance and execution of exceptional project management.
Involving an international team of designers, engineers and consultants, the project was led by CH2M Beca – a joint-venture between New Zealand engineering consultancy firm, Beca and US-based engineering company, CH2M.
One million manhours
Following over 40,000 hours of design and procurement work across four countries, and a million hours of labour on-site by 2,500 people, the project delivered a complex programme of works worth $180 million.
The centrepiece of this work was the construction of a new state-of-the-art biological nutrient removal facility capable of treating wastewater at a rate of 2m3/second – increasing the capacity of the plant to cater for an additional 250,000 people.
The facility includes one of the largest water retaining structures in the country with large process pump stations and new advanced turbo aeration blowers. The facility was constructed by a joint venture of McConnell Dowell and HEB Construction, with early works completed by Fulton Hogan.
By removing far more biological material during the wastewater treatment process, the facility has also helped to reduce the amount of these waste material released into the Manukau Harbour, helping to improve water quality in the harbour and preserve its ecosystem.
Meanwhile, the project also created the opportunity for Watercare to develop and landscape 10 hectares of public access land adjoining the plant. This involved building a new 530-meter access road, relocating a 2km stretch of the Watercare Coastal Walkway and planting 10,000 native plants.
A unique collaborative approach
While the size and scale of the project is certainly impressive, this is not the most standout feature of the project, according to project manager Rob Burchell.
“What set this project apart was the unique collaborative approach to risk management between the designers, client and contractors, which started from the design phase of the project and was carried all the way through the construction and commissioning phases,” he says.
“The approach to risk management was a true partnership model – and became the heart of communication and collaboration throughout the delivery of the project.”
With a diverse project team drawn from Watercare, CH2M Beca, and environmental planning and design consultancy, Boffa Miskell, plus several different construction firms involved, such a collaborative approach was crucial, says Burchell.
“There was an intentional culture of collaboration with monthly meetings between all the parties involved from the design to the construction phase. This is what made the project a success and serves as a model for other large infrastructure projects.”
Delivering on Watercare’s vision to combine highly complex wastewater treatment processes with leading landscape architecture to improve the quality of Manukau Harbour and Watercare’s award winning coastal foreshore, was another unique aspect of the project.
Overall, for Burchell the project was outstanding due to the intensive planning throughout the early phases, clear project delivery methodology, well-orchestrated communication and collaboration between stakeholders, and the creation of a high-performance team culture.
“Incorporating robust and resilient global best-practice process technology, ensuring the ongoing environmental stewardship of the Manukau Harbour, integrated with 10 hectares of public access coastal walkways – this project demanded exceptional project management skills to ensure its successful delivery,” says Burchell.
The PMINZ Awards will be announced at the 2018 Project Management Conference in Auckland on 20 September. The two other Psoda Project of the Year finalists are Mercury for its Maraetai Dam Intake Rehabilitation project and the Ministry of Education’s Education Sector Logon upgrade.