Following the transfer of Jet A1 jet fuel between the hydrocarbons depot of an airport (A) and an adjacent depot (B) on December 29, 2 connecting valves between the unloading booms and the tank were not closed. During unloading operation involving tanker trucks the day before, one of the semi-buried tanks was overfilled and its contents spilled out through the vents; 32,664 litres of fuel spilled onto the dome of the buried tank. Part of the fuel infiltrated the ground outside the catchpit and some spread into the adjacent parking area in the zone B. The parking area is connected to a petrol-intercepting trap that became quickly saturated (capacity: 600 l) and the jet fuel entered the rainwater network. The 2 depots operators quickly sealed off the rainwater network (between 8.40 am and 9.15 am) with sand and other oleophilic materials. However, after noting that jet fuel was present in the rainwater network, a depot B worker rinsed the network with a large quantity of water at 9.30 am, causing sand and jet fuel to be conveyed toward the sea. A drinking water supply well on property operated by the site B, 100 or 150 m from the tank that overflowed was stopped on the morning of the accident; the zone supplied by this well was temporarily interconnected to another network. Almost the entire polluted zone was covered with a tarp; 1,000 litres of jet fuel would be pumped in an opening of the tank and in the petrol interceptor trap of the depot B. Several measures were taken following the accident: excavation and treatment of the polluted soil by specialised means, installation of a piezometre between the tank concerned and the well, regular samples taken on the depot A piezometres and cleaning of the rainwater network. The three main causes for this jet fuel leak are as follows: human error in the handling of the valves, the position of connecting valves between the unloading booms and the tanks was unchecked and malfunction of the high level sensor on the tank concerned. The administration acknowledged the facts.

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