The coverage of the 76 hectare fjord bottom takes place by using a well-proven method. The goal is to limit the risk of future spread of environmental toxins after more than 90 years of extensive industrial activity at Herøya. The pollution consists of, among other things, mercury, dioxins and furans, primarily from the chlorine plant and the magnesium plant, which were closed in 1987 and 2002, respectively.
Directive from the Norwegian Environment Agency
For many years, Hydro has been engaged in assessing the situation and researching measures to reduce the environmental impact of pollutants in Gunneklevfjorden, both in the short and long term.
In 2013, Hydro initiated investigations aimed at planning actions in Gunneklevfjorden. Two years later, the company received a directive from the Norwegian Environment Agency to develop an action plan, and in March 2018, a directive was issued to implement measures in the fjord.
Hydro places great importance on being a good neighbour wherever they operate. When leaving an area, such as Herøya, they aim to clean up responsibly and sustainably.
Commencing with the construction of a jetty
Work begins now with the construction of a jetty, or a pier, using a fall-bottom barge.
"The jetty will help stabilize the seabed. Afterward, we will commence covering the seabed with a 20 cm thick layer of clean material in the form of crushed stone. This will be done using a bottom-dumping barge," says Boško Janjušević, the project coordinator from Hydro.
Temporary closure of waterfront pedestian and cycle path
As part of the fill project, it will be necessary to relocate a sanitation pipeline along the waterfront pedestian and cycle path.
"While we relocate the sanitation pipeline, the pedestrian and cycle path along Gunneklevfjorden will be temporarily closed. This applies to the stretch along the waterfront, between the roundabout at the main gate and the roundabout at gate 4. We start on this job very soon.
The pedestrian and cycle path on the other side of the road, towards the industrial park, will remain open and accessible," informs Midtgarden.
The goal is a clean fjord
The goal is for the fjord to once again be regarded as a clean fjord, where there is no need to take special precatutions related to normal activities in a local lake.
"By covering the seabed, we prevent environmental toxins in the fjord from leaching out of the sediments and entering the food chain. This will also prevent the spread of pollutants to the surrounding areas. The solution will provide a clean seabed and form a good starting point for the reestablishment of flora and fauna," explain Eivind Midtgarden and Boško Janjušević from Hydro's project team.
Reduced access to the fjord
During the covering work, there will be limited access and the possibility of anchoring in Gunneklevfjorden at times.
The contractor responsible for the covering work is Repstad Anlegg AS.
Further information on the project
If you wish further information on this project, please see Hydros website.
18. September 2023
