The 5.45m diameter EPBM that will bore New Zealand’s largest ever wastewater tunnel, the Central Interceptor Project, has officially been ordered from Herrenknecht. The Ghella Abergeldie Joint Venture, which was awarded the contract to construct the $1.2bn tunnel, will use the EPBM to bore the 13km long, 4.5m i.d. tunnel underneath Auckland, at depths of between 15 and 110m.
The Central Interceptor will run between Western Springs and the Mangere Wastewater Treatment Plant.
The Works also include two underground links with an overall 4.3km length, to be excavated with two pipe-jacking machines, of ca 3m diameter each. The line will encounter 16 shafts reaching up to 80m depths, as well as numerous connecting sewers, chambers, control facilities and air treatment facilities.
The new sewer line is expected to reduce wastewater overflows in the central city by 80 per cent, improving water quality at some of the city’s beaches, and to provide capacity in the wastewater network for future growth and development on the Auckland Isthmus for the next 50 years and beyond.
The tunnel is due to come on-line in 2025.