At 7:45 am during a patrol at a household waste incineration plant, a shift manager detected an acid smell coming from a room housing a stock of hydrochloric acid in a 33% solution, which is a substance used for preparing boiler water. Alerted at 8:10 am, the emergency services arrived at the scene 10 minutes later and a safety perimeter was set up. The investigations carried out remotely due to the significant releases of acidic vapours helped to locate a small leak in the retention system associated with the acid tank. Earth dams were established to prevent the chemical from spilling into the establishment’s waste-water network. A chemical emergency squad sealed the crack in the retention system. At the beginning of the afternoon, a specialist company recovered the 1,100 l of acid present in the system and sent it to authorised treatment facilities along with the 1,000 l of washing water, the earth and soiled cloths.

The accident was caused by a sealing fault on the suction flange of a transfer pump following the breakage of 3 of the 4 attachment screws. The pump, installed in 2002, had been inspected in October 2003 during a technical shutdown. Property damage was estimated at €1,700. The operator promised to correct the sealing fault on the retention system concerned and install more reliable equipment.