In freezing weather, we de-ice planes before take-off. This ensures that mechanical parts like wing flaps do not become icebound. The de-icing process uses chemical products and water … so where does the waste water go?
De-icing is done with a mixture of water and glycol (anti-freeze). The product is heated and sprayed over the aircraft. Then, the de-icing waste water flows from the sewer system along the piers to the water treatment facility. And the waste water from the central de-icing platform? That goes first to underground storage tanks and then it’s transferred to our water treatment facility. The highly concentrated de-icing water serves as a source of nutrients for the micro-organisms during the summer. When the storage tanks are 60% full, we take the de-icing water to the water treatment facility to prevent the untreated water from overflowing and running into the streams around the airport.
In 2017, despite our strict precautionary measures, some de-icing water flowed into Steenokkerzeel’s watercourses. And because de-icing water is classified as industrial waste water, discharge without pre-treatment is absolutely prohibited. Brussels Airport Company was not aware of this discharge until the municipality of Steenokkerzeel informed us. What happened? Due to a combination of circumstances, the de-icing water was accidentally discharged into the rainwater collector, a regrettable incident.
Of course, we do everything possible to avoid such an incident. We discussed this incident thoroughly with the local authorities, the Environmental Inspectorate and the Flemish Environmental Agency and have updated our communication procedure accordingly. We’ve also made operational adjustments to accommodate de-icing water in larger volumes. And we’re investing in a central de-icing platform that will be directly connected to our water treatment facility by 2020.