A  portion of the facilities at an upper-tier Seveso plant were flooded by the Saône River during a series of winter flood events. The water level inside the facilities reached the benchmark of 176 NGF.1 The operator gradually shut down the facilities as the water level rose and as per the site’s flooding procedure. The retention pits used to collect effluents and firewater, a recovery sump, the surface water and polluted water drainage systems, the retention pits under the production facilities, and the weighbridge were flooded. Production was halted for four days and supplies of raw materials were decreased. There were no impacts on people or the environment. The operator noted an increase in the site’s internal workload.

Following this event, the operator updated the instructions to be followed in case of flood and added extra backup sump pumps.