In order to develop the city’s water distribution network, the City of Oslo has opted a joint venture among Italian tunneler Ghella and Norwegian civil engineering firm AF Gruppen.
The granted contract with £730M value is for the design and build of the E6 clean water tunnel, which is due to spread treated water from a new plant at Huseby to Oslo residents.
Diverse connection points for linking it to the available water mains along the stretch, will be considered in the construction of this new water supply tunnel.
While the ground condition of the tunnel’s route will include sedimentary rocks, bedrock gneiss, and syenite, a tunnel boring machine is going to excavate almost 11km of tunnel and 7km will be done by drill and blast.
Additionally, the construction of clean water basins and a pump station will be a part of the contract and JV’s duty.
As a section of the Oslo Municipality’s wider water supply scheme, the main purpose of these works is to ensure that the city’s water supply will provide enough drinking water even in the event of a failure in vital parts of the water supply system, whereas E6 forms one of ten contracts for the scheme.
Schedule date for commencing the process is April 2022 and it is due to be completed in November 2027.
Moreover, a contract with £287M budget in order to build the 19km E5 water supply tunnel, was handed to Skanska in the previous year.