Engineers celebrate with tea and muffins as Army Bay Wastewater Treatment Plant refurbishment is completed

07 May 2019



A low-key celebration marked the end of the $31 million upgrade to our Army Bay Wastewater Treatment Plant, located with Shakespear Regional Park, Whangaparāoa Peninsular.
 
Local Board members and councillors made up the small guest list and they applauded as a commemorative plaque was unveiled on the side of the UV disinfection treatment facility. Work began 18 months ago and upgrades have included improvements to an existing pump station, and replacement of an outfall pipe, which extends 1.2 kms into the Tiri Channel.
 
Projects manager John McCann was pleased to announce the project had been delivered on time and within budget: “We have achieved a lot in a short time, especially given the complex nature of the micro-tunnelling and the installation of the outfall pipe.       

"We are aware that all this has taken place within a sensitive ecological environment and we’ve taken care to isolate construction sites and protect local wildlife, including kiwi and lizards.”
 
John paid special tribute to all Watercare staff, including project manager Dirk Du Plessis, as well as the planning and health and safety teams who contributed to the project. He also complimented McConnell Dowell, the principal contractor.   
 
Much of the tunnelling work was done by a large tunnel boring machine called ‘Blanche’, which set a new world record for the longest stretch of pipe ever laid using the ‘direct pipe’ tunnelling method (1929 metres) in a continuous drive.
 
The marine section of the outfall pipe was assembled in the Coromandel and carefully floated across the Firth of Thames to the Waitematā Harbour, before divers guided it into place on the sea bed.
 
The refurbishments mean the plant will continue to treat wastewater to a very high standard and can manage growth from across Orewa, Silverdale and Whangaparāoa.
 
John and Dirk have now turned their attention to Snells Beach, where another wastewater tunnelling project is about to begin.