Pollution
Humain
Environnement
Economique

Following a complete overhaul, a 100,000 m³ crude oil tank was brought back into operation on 27/08 at an offshore terminal. The gauge indicated an abnormal loss of 300 m³ of product: oil appeared in the valve chamber sight-hole. An excavation carried out on 02/09 revealed the presence of product around an 8” drainage pipe used for draining water from the bottom of the tank. The tank’s operation was stopped, the pipe was cleared and the floating product was recovered. In addition, the local water table was lowered by pumping (for information, 950 m³ were recovered on 24.09). A soil clean-up plan was implemented following an analysis campaign using the site’s piezometers.

Several hypotheses were put forward: damage to the pipe when filling the tank with water at the end of inspection work, corrosion of the piping despite being equipped with protections (inner and outer lining, cathodic protection) and which had been replaced in 1997.

According to feedback, earthworks are being created around the other 7 tanks, whose piping had also been replaced by the same service provider. Furthermore, liners allowing visual inspection were installed and a stricter tank monitoring procedure has been implemented. Finally, a section integrating the hydraulic tests has been added to the procedure for tank acceptance following work.