The contract is for the E6 project, part of a major undertaking by the City of Oslo Municipality to provide water supply security through a new clean water tunnel from Holsfjord, west of the capital, and an underground treatment plant at Huseby. At present, a single water source and one treatment plant supply around 90% of the capital.
The AF Gruppen and Ghella joint venture will build the water distribution network between Huseby, Oset and Stubberud in Oslo. A 7m diameter tunnel, approximately 11 km long, will be drilled by a double shield hard rock TBM and 7km excavated by drill and blast. Ground conditions are sedimentary rock formation and Norwegian precambrian gneisses.
JV AF Ghella will also build clean water basins and a pump station.
Work is scheduled to start in April this year and be completed in November 2027.
The contract is the biggest in AF Gruppen’s history. The company has a 60% share of the joint venture.
AF Gruppen and Ghella previously collaborated on the Follo Line, a 22.5km high-speed railway between Oslo and Ski.
Oslo’s water supply project comprises eight major contracts. In July last year Skanksa was awarded the E5 contract to build the19km tunnel from Holsfjord to the new underground water treatment plant at Huseby.
