The largest enviromental project in North Norway

Tromsø Harbour’s clean-up action for Tromsøy sound

Over many decades, sewage from the town, anti-fouling paint from ships and water running off landfills have polluted the seabed in the Tromsøy sound. This area has therefore been allocated priority by the Norwegian government in their plan of action for clearing up seabed pollution. Tromsø Harbour has now implemented its strategy to recreate a clean harbour environment in Tromsø centre, in order to prevent the spread of environmental toxins on the seabed to plants, animals and humans. The main goal for this strategy is to provide future generations in Tromsø with a cleaner sound than that left behind by former generations. The cleaning-up process in Tromsø sound will involve depositing contaminated material in secured, sealed steel cells which will then be used as foundations for a new quay in Tromsø.

This process will require several stages:

• We start by installing the steel cells in front of the existing quays in the town centre. These cells are then bound together using solid steel plates. The cells and their interlinking walls are clad internally with a fibre mesh to prevent seepage.

• The individual cells and the space between the cells thus become sealed disposal containers for the polluted material which is excavated from the bed of the sound. This means that we only have to transport the material a very short distance, while also preventing any negative impact on people and animals in the future.
 
• In order to prevent new contamination by polluted sediments in the overflow water from the dredging process, we have already set up a sedimentation basin in the area. Once the cells have been filled with polluted material, all excess water is pumped into the basin. Contaminated particles will be deposited into the basin while the clean water can be returned to the Tromsøy sound. We have also established physical barriers which extend right down to the seabed in order to protect the areas where we intend to install the cells and the disposal site walls.

• Finally, the disposal sites provided in and between the steel cells will become the foundations for a new and wider quay and a harbour promenade in Tromsø centre.