Pollution
Humain
Environnement
Economique

In a household waste incineration plant, a domestic fuel oil leak occurred in the room housing the generator set. The genset’s 500-litre tank had been in the process of being filled since the morning (the process usually takes 2 hours) from a 3 m³ underground storage tank. The technician in charge of the operation forgot to stop the process at the end of his shift. The tank overflowed into its 500-litre retention tank and then spread into the genset room, flowed under the front door (despite the presence of a liquid collection pit) and then outdoors.

The leak was detected at noon during an inspection of the facilities at the end of the shift. Intervention by the personnel made it possible to limit the spread of the fuel oil and to confine it on the roadway and in the sludge-oil separator. The filling pump was switched off, and absorbent socks were installed at the door, and absorbent granules were spread out on the fuel oil spills on the roadway. The gutter was blocked off, and the knife gate valve on the sludge-oil separator was closed. A specialised company pumped the fuel oil contained in the retention tank and on the surface of the sludge-oil separator. The soil was cleaned up and rinsed, and pumps were used to recover the liquid. A ventilation system was installed to disperse the fuel oil vapours in the generator room.

An estimated 600 litres of fuel oil was spilt, including the volume pumped out of the retention tank.

An inspection was conducted by inspection authorities for classified facilities 3 days after the incident. The operator has undertaken the following corrective measures:

  • installation of a lockout padlock on the fuel transfer pump: the padlock shall only be removed to conduct the filling operation;
  • installation of a two-level security system on the genset tank, with alarm reporting in the control room:

    • a high-level sensor triggering an audible alarm;

    • a very high-level sensor causing filling operations to stop automatically.

The operator also took measures to raise awareness among staff, regarding:

  • the configuration that led to the incident and the risks of environmental pollution in the event of a spill;
  • the use of new equipment installed on the site.