Cleaner ports
NGI has been commissioned to design solutions for cleaning up contaminated sediments in the Port of Trondheim and then to follow up on the work.
Contaminated seabed
Sediments in the Port of Trondheim have been contaminated with organic compounds and heavy metals due to previous industrial and sewage discharge into the sea. Sediment dispersion has occurred, governed by diffusion, maritime traffic and dispersion via organisms.
One goal is that environmental toxins from the seabed in the port do not lead to an unacceptable environmental or health risk. Four areas must be improved in order to reach the goals. These are Ilsvika, Brattøra, Kanalen and Nyhavna.
Solution method
In the Kanalen, Brattørbassenget and Nyhavna areas the sediments will be covered. Where the sailing depth is insufficient, the sea will be dredged prior to covering. Dredged soil will be placed in a waste disposal facility comprising a waterside waste disposal site and seabed waste disposal site in Nyhavna.
The operation will be carried out in the period January 2015– May 2016.
Result
Based on calculations and observations made, the environmental budget shows that dredging and covering contaminated sediments in Kanalen, Brattørbassenget and Nyhavna, establishing a waste disposal facility in Nyhavna, as well as covering the seabed in Ilsvika will have a positive environmental effect.
Silt curtain - waste disposal site
