In order to transfer treated water from a new plant at Huseby to the capital, Oslo, and also construction of new links to the available network, lately Oslo Municipality and Water Authority launched an open tender for the construction of the E6 Rentvannstunnel Clean Water Tunnel.
As a part of providing a reserve water supply project for the population of Oslo, the E6 project currently is the only water source, and one treatment plant supplies around 90% of the capital. E6 involves much tunneling in rock, with around 18km of multiple tunneling drives. The subcontracts of the procurement involve the tunnel drives; construction work in connection with tunnels; and construction work in connection with water and sewage pipelines.
The plan comprises of digging a segmentally-lined 11km tunnel using TBM is to that will involve around 423,000m3 of rock spoil. In addition, there will be a conventionally mined tunnel of around 3.5km from the existing Oset water treatment plant to Disen, and other similarly-mined tunnels. In 2020 the scheme work for the tunneling was granted to Multiconsult, the Norway-based international engineering consultancy.
The determined time duration of this contract is due to be from February 2022 to October 2027, while the enthusiasts who have completed their tenders or requests to participate should send them by 20 December 2021.