The ammunition depot in the ‘Gat van Zierikzee’ in the Oosterschelde does not pose a threat to public health. This is the conclusion of Minister Mark Harbers (Infrastructure and Water Management) in the eighth study into the presence of harmful substances in Zeeland water.
After the Second World War, an estimated thirty million kilograms of ammunition was dumped in the Oosterschelde. The bombs, bullets and grenades have rusted over the years because of the salt water, releasing TNT (explosive material).
Rijkswaterstaat checks the water quality in the Gat van Zierikzee every five years. Low concentrations of TNT came to light during the last check in 2019/2020, but also at a second measuring point 10 kilometers away at Wissenkerke. To put an end to ambiguity – it is technically possible that the concentration of TNT decreases between collecting the water sample and actually analyzing it in a lab – the then State Secretary Barbara Visser (Defence) decided to conduct a broader investigation.
In recent months, samples have been taken at eight locations – from Vlissingen to Terschelling and near Antwerp. Minister Harbers has now sent the results to the House of Representatives.
The more extensive research has now shown that there are also low concentrations of TNT in the water at the Oesterdam, Zijpe, the Lodijkse Gat (a channel in the Oosterschelde), Vlissingen and near Antwerp. The minister concluded that the TNT at Vlissingen and Antwerp (where the concentration is very low) must come from the North Sea, because there is no ammunition depot in the Western Scheldt.
Mustard gas
After the Second World War, ammunition was dumped in numerous places off the Dutch and Belgian coast. An attached map in the research indicates dozens of places where not only are bombs, grenades, torpedoes and mines, but off the Flemish coast there are also places where chemical munitions (such as mustard gas) have probably been dumped. It is unknown how much ammunition is in the different places. The minister dared to conclude that the concentrations of TNT in the Eastern Scheldt and the Western Scheldt originate from old ammunition depots in the North Sea and from the Gat van Zierikzee.