Watercare announced that a tunnel-boring machine (TBM), dubbed Piper, has completed the final leg of a 5km pipeline installation to transport wastewater from Warkworth to the Snells Beach wastewater treatment plant in New Zealand.
According to the utility, which supplies water to Auckland, this latest development marks a significant step in its NZ$300m ($179m) wastewater upgrade programme for Warkworth, Snells Beach, and Algies Bay.
As part of the broader infrastructure enhancement programme, the new pipeline aims to enhance the performance of the local wastewater network and promote future growth.
Watercare’s investment initiatives also include the construction of this modern wastewater treatment facility at Snells Beach.
The pipeline installation was carried out in three phases, with the final leg marking the shortest and most straightforward segment for Piper. Despite two breakdowns during its 14-month journey, the pipeline’s installation proceeded smoothly, said the water utility.
Piper has excavated a variety of soft and hard ground materials. These are transported out of the tunnel and separated from water at a dedicated separation plant located at the launch site.
At this facility, the extracted materials are processed, with water then pumped back to Piper to supply bentonite for lubrication and to pump tailings back to the surface.
Since September of last year, Piper has been progressing at an installation rate of approximately 36m per day.
Operating up to 50m underground, the TBM requires careful planning to avoid disruptions, as repairs at such depths would pose risks of damage and project delays.
Upon completing this final phase, Piper will undergo a comprehensive maintenance check. Following this inspection, the TBM will be prepared for its next assignment.
Over 120 workers are now focused on completing the mechanical and electrical systems at the Snells Beach wastewater treatment plant.
Watercare said that the motor control centre has been activated, permanently connecting the facility to the local power grid.
The crews are now targeting the completion of crucial components, including the outfall tanks and ultraviolet (UV) treatment systems, to prepare for cold commissioning, scheduled to begin in early 2025.
Cold commissioning is a key step in the commissioning process and it ensures the plant’s systems operate smoothly and safely before it becomes fully operational.
Watercare project manager Casper Kruger said: “Achieving this required a coordinated effort between the contractor, power supplier, and electrical inspector following months of preparation and planning.”
The current wastewater treatment facilities at Warkworth and Snells Beach support a population of approximately 8,500 people.
Once upgraded, the new wastewater treatment plant will initially serve 18,000 residents, with capacity expansions planned to accommodate up to 35,000 people as demand grows.
