
Construction du filtre
Work Completed (2018–2021)
Lot 1 – Disconnection Pipeline
Installation of a pipeline beneath Allée de Madrid in Neuilly, with a major microtunneling incident in June 2019 that delayed the works. The pipeline was fully commissioned in July 2021 after sediment analysis and cleaning.
Lot 2 – Pumping Station and Storage Facility
Construction of an underground structure beneath Avenue du Mahatma Gandhi, designed to store effluents and transfer them to a planted filter. Works were slowed by the COVID-19 health crisis, particularly due to telecommunications issues and challenges in organizing tests.
Lot 3 – Macrophyte Planted Filter
Located on Route de l’Étoile, this facility treats water before it is returned to the natural environment. Commissioned in early 2021.
Challenges Encountered
A major technical incident involving the microtunneling machine
Delays caused by COVID-19, affecting coordination, testing, and communications (fiber optics and 4G)
Technical complexity of the installation, requiring extensive and in-depth testing
Environmental Results
Total volume pumped: 47,240 m³, including 34,638 m³ discharged into the storm overflow and 12,602 m³ reinjected into the aquifer
No exceedance of regulatory thresholds for groundwater extraction
Installation of a monitoring system (hydrocarbon detectors, automatic samplers) to ensure long-term performance
The project stands as a technical and environmental success, contributing to the protection of the Seine River, the relief of the wastewater network, and a more sustainable management of the Bois de Boulogne ecosystem.