Four geotubes spread out on a field
Cellulose was produced in Kemijärvi from the 1960s until 2008. After the pulp mill was closed, Stora Enso decided to clean up the bottom sediment of the old sludge pond. The aim was to suction dredge the bottom and to use the pumped bottom sludge for earthmoving purposes. The Finnish Transport Infrastructure Agency had built a train terminal in the vicinity of the old mill for the use of the forest products industry, and it obviously needed room to expand. Vesirakennus Ojanen is the contractor chosen by Stora Enso to suction dredge nearly 300,000 cubic meters of bottom sediment from down to six meters, and pump it into geotubes. There the sludge is dried with the help of a polymer recipe optimized through laboratory testing. Stora Enso bears its environmental responsibility by investing in the cleaning of the area – all the while looking for sensible ways to make use of the dredged masses of earth.
We estimated this technique would fit the purpose. It was developed to fulfil precisely our needs. The unit cost of this technique has dropped, and the hardware developed is suitable for the purpose and efficient.
Erkki Autio, Director, Stora Enso