The project has had a significant and positive impact on the environment. Four hundred and forty-four thousand cubic meters were dredged and deposited in a deep-water basin at Malmøykalven.
Forty-four thousand containers of contaminated seabed were removed from the city port, and small-boat harbors in Frognerkilen, Bestumkilen, and on Hovedøya.
Between ninety-five and ninety-nine percent of contaminants were removed from Pipervika, across from City Hall, and Bjørvika, in front of the Opera house.
Clean sand and clay now cover the seabed at both sites to a depth of 20 meters, an area equivalent to 77 soccer fields. Both sites achieved Class 2 certification.
70-meter landfill
The contaminated seabed was deposited in a natural basin, almost 70 meters deep, and covered with a 0.4-meter thick layer of sand. Monitoring of the basin has not shown any spread from the landfill. The site will continue to be monitored in the future.
How polluted was the seabed?
The level of environmental toxins in the dredged seabed was far below what is considered hazardous waste. Seabed remediation reduces environmental damage created by turbulence from maritime traffic and protects marine life and the food chain from toxins. The volume of waste and debris in the harbor posed a major challenge. Specially designed equipment was used to access hard-to-reach areas. Measures were established to ensure the cleanup work was as environmentally-friendly as possible.
Collaborative clean-up
The clean-up cost approximately NOK 250 million and was financed through a joint venture between stakeholders and property developers associated with Fjordbyen (Fjord City). Port of Oslo contributed NOK 70 million to the clean-up and led the project on behalf of Oslo City Council.
Project documentation
A comprehensive control and monitoring program governed the project. It is one of Norway’s best-documented projects. More than 250 publications from a variety of professional bodies report on the project’s implementation, execution and results. Despite these measures, the project, and especially the landfill solution, was controversial.
Clean Oslofjord Project
The Clean Oslofjord Project was launched to address pollution from former industrial sites along Akerselva, shipyards, dumping of dirty snow cleared from roads and sewage. Accumulation of toxins in the harbor basin stirred up by ship propellers contaminated the port’s waterways.