A leak was discovered in a sugar factory at around 5:30 p.m. following an operation to load a 21-year old tank containing 55 m³ of sulphuric acid. The leak originated from a crack located above the manhole. The acid from the leak flowed into the 70 m³ retention basin. Considering the crack’s development and the expected climatic conditions (heavy rains), the risk of tank failure and acid fumes were possible. The internal contingency plan was initiated at 6:00 p.m.

Two specialized companies were called in to pump the acid contained in the retention basin, i.e. 2 m³, as well as in the tank, below the crack (39 m³). The tank still contained 10 to 12 m³ of acid, which was required to operate the distillery, which consumes 2 m³ per day. No new filling operations were performed. The expert analysis report indicated that the acid level was lower than that of the crack and that no further cracking was to be feared in the immediate future. A 10 to 20 m³ container with retention basin was installed in order to take over.

The operator replaced the cracked tank. Visual inspections conducted prior to each loading operation have been reinforced and extended to all chemical storage tanks. Furthermore, during their visit to the facility, the inspection authorities for classified facilities noted that the retention basin associated with the unloading area was full. In addition, the drip collection area under the chemical product filling feeder tanks was not large enough to collect all the drips. The inspector requested that the operator empty the retention basin and carry out the necessary maintenance work.