Viikinmäki Wastewater Treatment Plant

The Viikinmäki Wastewater Treatment Plant, built mainly inside the rock, was commissioned in 1994 and is the largest wastewater treatment plant in Finland and the Nordic countries.

The Viikinmäki Wastewater Treatment Plant process is based on the activated sludge method, in which the organic matter from the sludge is digested, producing energy.

Rockplan has been involved in both the original design of the Viikinmäki Wastewater Treatment Plant as well as in its later expansion phase. In the expansion, space was excavated for a new biological post-filter and a new treatment line, keeping the treatment plant is in operation throughout the excavation. The expansion increased the plant’s nitrogen removal capacity to the level of 70%, as required by the authorities.

Helsingin vesi (now Helsinki Region Environmental Services Authority HSY)

Rock mechanics and tunneling design

Related References

West Metro

Länsimetro Oy

With the West Metro extension, the Helsinki metro network will reach Espoo, increase in length by 21 kilometers and see 13 new stations constructed along its run.

Vuosaari Transportation Tunnels

Tiehallinto/ Vuoli-projekti

Rockplan designed Vuosaari Harbor’s Porvarinlahti road tunnels and Labbacka railway tunnel in cooperation with Finnmap Infra Oy. The 1,600-meter-long submarine road tunnel in Vuosaari is approximately 25 meters below sea level at its deepest point.

Sulkavuori Central Wastewater Treatment Plant

Tampere Region Central Wastewater Treatment Plant Ltd. / City of Tampere

The construction of a wastewater treatment plant to be built inside the rock and using the latest treatment technologies began in Sulkavuori in 2018.


For more information please contact Paula Kajava
+358 50 337 7876