The Largest Environmental Prosject in the High North
The Port of Tromsø’s clean-up project for Tromsøy Sound. Over many decades, sewage from the city, anti-fouling paint from ships and water runoff from landfills have polluted the seabed in the Tromsøy Sound, the strait that separates the island from the mainland.
This area has therefore been assigned priority by the Norwegian government in their plan of action for cleaning up seabed pollution. The Port of Tromsø has implemented a strategy to recreate a clean harbour environment in the city 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 previous generations. The clean-up process in Tromsøy Sound will involve depositing contaminated material in secured, sealed steel cells which will then be used in the foundations for a new quay in Tromsø.
This process will consist of several stages:
- We start by installing the steel cells in front of the existing berths in the city 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 humans 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 form the foundation for a new and wider quay and harbour promenade in the city centre.
The project will be completed at the end of 2011.