Clearing sludge from a retention basin

Our client needs to drain the sludge from the retention basin on its production site every year, to ensure its plant runs smoothly, while complying with the standards for discharges into the natural environment.

The basin contained 850 m³ (1 112 yd³) of mineral sludge, which was too harsh to use a conventional method, such as a centrifuge or a mobile press filter.

CTP environnement suggested pumping and dewatering this sludge using a more suitable technique of dewatering with a geotextile membrane. The very hard sludge at the bottom of the tank required the use of an appropriate power shovel.

With several geotextile membranes, measuring 120 m³ (157 yd³) arranged over a specific and specially created area, the work was carried out successfully in the summer.

In the end, all the sludge was removed from the tank and the hard sludge was stored alongside the dedicated area for the dewatering membranes.