KLANT ― DEME AND PARTNERS | LOCATIONS ― ZELZATE, EVERGEM AND GENT (B)
Terranova is a public-private partnership project which, after remediation and redevelopment, led to the Terranova Zonneberg (87 ha), the Callemansputte nature reserve (20 ha) and the CR2 industrial site on the Ghent-Terneuzen sea canal (50 ha). In this project, DEME is the initiator, main investor and project manager, managing all the steps of the vision itself. With its know-how and experience, DEME has transformed a looming environmental disaster on the Terranova site into a sustainable site where ecology, economy and social fabric go hand in hand.
― Avoiding an environmental disaster
Behind the Klein Rusland district in Zelzate, you can now see the largest interconnected solar park in the Benelux rising up to 60 metres high above the landscape. This ‘solar mountain’ was, not so long ago, a giant, uncapped stockpile of gypsum. This legacy of a bankrupt chemical company posed a major risk to people and the environment.
In 2010, DEME was awarded the urgent task of stabilising the site, in order to avoid an environmental disaster. However, the whole scheme was at a standstill and a definitive solution was nowhere in sight.
As such, DEME took the reins with a particularly ambitious plan to create added value for all stakeholders, including the environment and nature.
The stockpile of gypsum was a massive, unstable 87-acre landfill with open basins containing acidic, phosphorous-containing wastewater deposited by the now bankrupt company Nilefos Chemie, and it was ready to rupture. It was particularly challenging to develop a rapid and efficient remediation technique to eliminate the acute safety risk. DEME immediately mobilised 20 machines to stabilise the gypsum stockpile and the necessary installations to treat the water. A new access point was then created to avoid trucks having to drive through the residential area of Klein Rusland. The unfilled portion of the gypsum deposit area is still an authorised landfill.
To cover the landfill, a sealing concept was developed with geo-composite consisting of two layers of geotextile, with bentonite in between.
‘DEME is always aiming for a repurposing with a strong economic or environmental added value.’
In order to drain and consolidate the 30-metre-thick layer of soft mud, no fewer than 300,000 running metres of vertical drains were laid.
DEME prepared a logistics master plan for the supply of 6 million tonnes of recycled covering material, requiring 400,000 logistical movements simultaneously respecting the environment.
― The Callemansputte
At the edge of the gypsum stockpile was a second former landfill site for disposal of maintenance dredging spoil from the Gent-Terneuzen canal. This 20-hectare landfill still had to be covered with a sealing layer and an organic layer. As the landfill had been filled-in wet, on the one hand, and was adjacent to the gypsum stockpiled on the other, the sealing to make it stable was a technically complex operation. In order to drain and consolidate the 30-metre-thick layer of soft mud, no fewer than 300,000 running metres of vertical drains were laid. Once consolidated, the covering could start.
― Logistics master plan
Due to the size of the project, a special plan of execution was necessary for each phase. DEME prepared a logistics master plan for the supply of 6 million tonnes of recycled covering material, requiring 400,000 logistical movements simultaneously respecting the environment. Ship transport via inland waterways was used as much as possible.
― Energy transition
DEME and its partners gave the gypsum stockpile a new function: generating energy. The 55,000 solar panels installed on the deposits generate green power for more than 4,000 families. A new wind turbine will also be installed at the edge. This will be built at a sufficient distance from the adjacent residential areas. Terranova and partner Terranova Solar are also planning an extension of the renewable energy generation centre, as part of an innovative project involving the production of green hydrogen from the energy supplied by the solar panels.
The surrounding area will also be put to good use. The new business park of approximately 50 hectares will create additional job opportunities and roughly three hectares of forest will provide a green buffer. The gypsum stockpile was christened ‘Zonneberg’ with good reason - it means ‘Solar Mountain’.
The green maintenance at Zonneberg Terranova is done in cooperation with a local shepherd. Over the summer, the project team is joined by 150 sheep.
― Watery nature reserve
Following complete remediation, the adjoining sludge dump will be landscaped into a closed nature reserve. Forest, grassland and wetlands. This wet area will have overflowing ponds, which will create mudflats and salt marshes, resulting in a unique biotope. DEME appointed a nature expert to this end, and is working closely with Natuurpunt. The area will also become accessible: footpaths will be built that connect to the Zonneberg.
― Fabriek Energiek
‘Fabriek Energiek’ has been built at the base of the Zonneberg. In the first phase, this was a small-scale initiative for schools and stakeholders who wanted to visit the site and learn more about the future plans, the nature reserve and the largest solar park in the Benelux. It has now become a successful network for nature and environmental education (NME in Dutch) in which various organisations work together to enhance the nature and environmental curriculum in East Flanders.
‘With Zonneberg, DEME is making a clear statement in the area of circularity and the energy transition.’
‘DEME is an ideal partner in a public-private context, going much further than simple remediation. It proposes integrated solutions that take people, the environment, society and the economy into account. Major remediation projects such as Zonneberg-Terranova have a heavy impact on the surrounding area and local residents. By allowing residents to co-invest in Zonneberg via cooperative shares, and by sharing the returns, more support was created for the energy transition in East Flanders.’
FRANK DE MULDER, CHAIRMAN OF ZONNEBERG