The Vengeron pond has successfully passed its first winter. For several months, it intercepted the icing residues projected onto the planes, preventing them from being released into the nearby creek.
From the outside, the Vengeron retention pond is completely invisible. Yet, you can imagine a storage space as large as four Olympic swimming pools, adjoining the Colovrex road, almost fifteen metres below the surface. Put into operation in January 2019 after two years of construction, it has just successfully passed its first winter. Focus on a key environmental project at Genève Aéroport.
Specifically, the Vengeron pond is a giant compartment of 9,500 m3, whose construction amounted to over 25 million francs. Its mission is to receive contaminated water from the airport and thus comply with the Water Protection Ordinance during the winter. Indeed, at that time, airplanes must be regularly de-iced before take-off to avoid ice formation. A mixture of water and propylene glycol is thus sprayed on the devices. When they roll and then take-off, part of the de-icing products drips on the runway and discharges into the drain of the airport network.
Protection of the watercourse
« Until last year, these substances ended up in the Vengeron creek, located downstream of the airport and thus indirectly in Lake Geneva. De-icing products biodegraded, but they were harming the health of the watercourse. Now a network of collectors and a retention pond intercept polluted water », says Emily Tombet, Head of Environmental Projects at Genève Aéroport.
These are stored on site and sent to the treatment plant of the Industrial Services of Geneva, located in Aïre. In total, 27,700m3 of water have been treated since its commissioning. « We are in a learning process and it will take us some time to fully master the operation of the pond. Overall, the commissioning and the first months of operation went well », says Françis Graber, Head of Maintenance and Winter Operations.
This is what happens during the winter season. « In summer, the pond is also used to regulate the flow during heavy rains to prevent watercourse overflow », Emily Tombet adds. Throughout the year, it also reduces the inflow of suspended particles in the river. In the case of an accident on the runway, its mission is also to catch accidental pollution such as a kerosene leak.