Jan De Nul renovates water basin near Port of Ghent

Close to the Port of Ghent, Belgium, Jan De Nul is renovating the oldest of two reservoirs at the water production center. Both basins can produce up to 60,000 cubic meters of drinking water per day, playing an important role in the water supply of northern East Flanders.

The largest and oldest basin was in need of a complete overhaul. It was leaky and contains phosphate-rich sludge.

“We started the renovation works, along with our partners, in early 2024. Over a 2.5-year period, we will remove sludge and sand, install a new foil with leak detection system and take on the technical issues,” Jan De Nul said.

“Once we had drained the water basin, we could start the real work: excavating sludge and sand, removing, cleaning and reusing the bank revetment and replacing the old foil.”

At the bottom of the reservoir, the sealing foil is covered with a protective layer of sand. Over the years, phosphate-rich sludge has accumulated. In summer, this causes algae blooms, making drinking water production more difficult.

“We excavate and remove the phosphate-rich sludge. Then we also excavate the sand. To avoid releasing harmful substances from the old foil, we use excavators that can work very precisely,” the company said.

“Once we have excavated the sludge and sand, removed the bank revetment and reshaped the basin, we will lay a new and thicker HDPE foil with leak detection system.”

This system can detect water leaks both during the works and afterwards.