The project was to extend the port of Vuosaari which involved the dredging out of TBT (tributyltin) contaminated sludge. The dredged material would then be used as construction material once stabilized.
The sludge was placed into four lagoons and was stabilized using the ALLU Soil Improvement System. The stabilized area was approximately 11 ha down to a depth of 6 m, with the total stabilized area being around 500 000 m3.
As the dredged and stabilized material could be used once processed as a construction material, huge savings were made on natural resources. There was a reduced need for stones and crushed gravel to be bought and brought in, as well as the stabilization resulting in improved strength and load bearing capacity of the ground.