At around 4:00 p.m., a storm containment basin was found to have been polluted by hydrocarbons. The basin was confined by shutting off its supply pumps. After an inspection the following day, the employees found a leak of heavy fuel oil on an insulated, partially buried steel pipe connecting a tank to a melting furnace. The leak was stopped with a plug. As the temperature in the melting furnace had to be maintained to avoid damaging it, the pressure in the pipe was lowered from 2 to 0.7 bar. The fuel oil was pumped off the surface of the storm containment basin. The site’s stormwater runoff was sent to the town’s wastewater treatment plant until the basin could be cleaned and the water in it treated.

Environmental impact

On 17 March, an oily sheen could be seen on the surface of the River Charente at a stormwater outlet. Firefighters laid a containment boom on the water. Pumping from downstream abstraction wells was halted. Water samples were taken for analysis. The site’s stormwater systems were checked to avoid the risk of leaching. The risk of soil and water pollution was closely monitored.

Poor state of a hydrocarbon pipe

According to the operator, the leak was caused by the pipe’s structures ageing. Apparently, it had never been inspected. The inspection authorities for classified facilities asked the operator to conduct a complete examination of the pipe and hydrocarbon tank. Replacing the pipe by an overhead section that is easier to inspect was being considered.