Built in 2019 and commissioned in 2020, the de-sanding station in Nieuil-l’Espoir, managed by Eaux de Vienne, is dedicated to processing materials collected during sewer network cleaning. Its primary goal is to separate the different components of these materials to recover sand for reuse in network construction.
Materials arrive directly at the station or are transported from the Vouneuil-sous-Biard platform. Treatment, carried out in a 7 m³ tank requiring two to three days, begins with the materials being discharged into a 20 m³ reception pit. Recovered liquids are sent to a 180 m³ restitution basin before being directed to the adjacent wastewater treatment plant (STEP).
Solid materials are then filtered and cleaned by friction using high-pressure water jets. After treatment, materials are separated: sand is recovered for reuse as a bedding layer for pipes; coarser waste (rubble, stones) is sent to landfill; and residual sludge is sent to the STEP for treatment.
In 2025, out of 300 m³ of treated materials, 48% were transformed into reusable sand, 10% were sent for landfilling, and the remaining 42% (sludge and residual matter) were re-treated by the STEP and then valorized through spreading.
This approach offers several advantages: reduction of buried waste, conservation of natural resources by reusing sand, cost control (lower disposal and new material purchase expenses), and strengthened cooperation between services.
