The contents of a domestic fuel-oil tank at an oil terminal were being transferred into an adjacent tank in preparation for its decennial inspection. While the residual volume was being transferred by a mobile pump, one of the two hoses between the two tanks burst, causing 6 m³ of fuel oil to spill into the first tank’s retention basin. The terminal operator halted the transfer and closed the drain valves on both tanks. The basin was filled with water to dilute the fuel oil and reduce seepage into the soil. A specialist contractor pumped out the basin and recovered 4 m³ of fuel oil. The basin was left filled with water. A sheen could be seen on the slabs around the tank and there was a backflow of fuel oil in the basin. Fuel oil was also found beyond the slab path.

The hose was resting on a low wall when the incident occurred. Vibrations generated by the transfer pump caused the outer spiral reinforcement of the hose to burst. This is turn caused the hose to tear apart. The hose was certified to withstand working pressures greater than the 2 bar required by the mobile pump.

The terminal operator changed the tank transfer procedure. All transfers must be monitored from start to finish by a designated supervisor, additional hose checks are also now required, and the entire pumping system must be checked by a manager prior to transfers in order to make sure that the position of the hose does not generate any friction areas or pressure points. Soil samples are also collected to check for pollution.