Seven m³ of domestic fuel overflowed and spilled into a drain before spreading onto the ground of the boiler room when a tank outside a radioprotection institute was being filled by a supplier in the morning.

After having passed trough the site’s rainwater collector, the spill polluted the SEINE river and the soil around the underground tanks. The drawing of water from the SEINE river and the adjoining water catchments to produce drinking water was stopped for 2 days. An internal investigation was carried out in the institute. The tanks were old and not fitted with stop valves. A prefectural order required cleaning of the internal rainwater network, disposal of polluted soil, soil tests and clearing of the facility’s administrative situation. The conducted studies revealed a soil polluted by hydrocarbons to a depth of 10 m. However the ground water for drinking water supply was not effected. A prefectural order required several measures to be taken: partial removal of polluted land, implementation of a water tight cover over the polluted area and monitoring the quality of ground water.