Jan De Nul Group - Zelzate Callemansputte

Callemansputte restores 30 hectares of nature in Ghent port area, Belgium

Until recently, Callemansputte was a desolate area with a deserted disposal area for dredged material, a place not accessible to anyone. Today, the consortium with Jan De Nul Group will change that. We have been working since 2019 to clean up this disposal area and transform it into a beautiful nature reserve, accessible to hikers and nature lovers.

From an open disposal area with contaminated dredged spoil to a new nature reserve in 2030

After the remediation and redevelopment in Zelzate of the gypsum landfill and the adjoining old Kuhlmann factory into a new industrial estate and a solar energy park that now provides green energy for 4,000 families, the adjacent old disposal area for dredged material 'Callemansputte' is now being dealt with. In the past, more than 2 million cubic metres of contaminated dredging material from the Ghent-Terneuzen Canal were dumped in the former sand extraction pit 'Callemansputte' by order of the Flemish Government.

For more than 10 years, the government has been studying various options for giving this disposal area a final destination. Our project proposal to seal it and integrate it sustainably into the cover and side slope of the neighbouring Terranova gypsum mountain prevailed over all other options.

As from 2019, the consortium with Jan De Nul Group owns these sites and will subsequently carry out the sealing work. By doing so, we are taking the first steps towards further valorising this area - which has been inaccessible for years - over the next 10 years. This will finally result in a 30-hectare new nature reserve, some parts of which will also be accessible to the public.


Making space for valuable wet nature and nature recreation

After the necessary clean-up and sealing of the two adjacent landfills, the old gypsum landfill and the old Callemansputte dredging landfill, we will create an area of about 30 hectares. In that area, we want to develop a maximum nature value. Our main activities within this project are:

Dewatering and covering the old landfill site

The old landfill site is filled with wet dredged material.  In order to be able to safely cover the landfill, this dredged material has to be dewatered first.  Extensive studies show that this is preferably done by installing vertical drains in the landfill.  Subsequently, soil layers will be installed. Clay and drainage mats provide a liquid-tight seal, in accordance with environmental legislation. Soil is supplied as much as possible by water and via the new connections of Rieme Noord and the Kluizendok in order to keep freight traffic out of the village centres.

Waste water treatment

The wastewater that is extracted from the old landfill via the vertical drains will be purified in a water treatment plant before being pumped into the Ghent-Terneuzen Canal.

Development of a new nature area

After the old landfill has been completely encapsulated, a new nature area will be created.  Several ponds and reed beds will be realized, thus creating an after-use wet nature area.  Parts of this new nature area will be accessible and viewing huts will be built.  All of this is taking place in close consultation with the municipalities of Zelzate and Evergem, Natuurpunt nature association and a nature consultant.  A brownfield covenant has also been concluded that includes the complete redevelopment of Callemansputte and Terranova.  

Thanks to the remediation of this disposal area, the entire site, together with the adjoining former gypsum landfill, now the 'Zonneberg', is completely transformed into a green, varied landscape.  For the design, we focused on a number of very specific biotopes, such as reed land, grassland with shrubbery and open water land in order to attract a number of very specific target species, including the red wood ant and the haybug, two animal species that used to occur very frequently in the area but have become very rare nowadays.

Besides the natural character, we also want to open up the area for soft recreational purposes. We want the area to fulfil its role as a green buffer and lung for the inhabitants of the nearby municipalities of Zelzate and Evergem to the maximum extent.

The capping and remediation of disposal areas is part of our core business. We can also call on our own construction sites for the large quantities of reusable soil that are required for capping, thereby reinforcing our objective of maximising the reuse of materials within the circular economy.

Ivo Pallemans