Why must TBT be removed from the sea floor?
TBT contaminates sediment and is constantly in touch with water and organisms. During the spring and autumn turnovers TBT-contaminated sediment spreads to surrounding waters. Storms, propeller currents, anchoring and ice have similar effects. The clean-up solution developed by the Port of Helsinki will isolate the worst contaminated sediment from the surrounding waters and aquatic ecosystem. This is essential for the harbour project so that the soft clay beneath the sediment can be removed.
