VAV shall construct new clean water basins with a storage capacity of 100 000 m³ connected to Oset water treatment facility. This will be done by blasting 4 rock halls that will be fitted out with free-standing basins in concrete cast on site. In addition a traverse hall shall be established for pipes and access between the new and existing installations and for new access from the open air into the new clean water basins. The project also includes technical installations such as pipes, valves, drainage pumps, HVAC, electro and SRO.

This procurement is for the rock and concrete work in the project, called the main contract and executed as an execution contract in accordance with NS 8405.

The main contract will include the following site work:

— The establishment of an access tunnel of approx. 250 m, with securing, road and drainage.

— Blasting rock halls and a traverse hall with a total volume of approx. 290 000 m³.

— Sawing the execution of the existing installations.

— Construction of 4 free-standing concrete basins, including cover and coating. Volume approx. 17 000 m³ concrete.

— Concrete foundations in the traverse hall and completion work at the end of the development.

— All the necessary securing work, bolts and injections in the rock halls.

— Establishment of barracks.

— Completion work for the existing site road between Oset and Maridalsveien, footpath and parking area.

The site start for the main contract is provisionally set to the end of June 2017.