Pollution
Humain
Environnement
Economique

In a chemical plant, a tank containing used flammable liquids overflowed via the vent during the transfer of 3,500 litres of used solvent. Having witnessed the release, a member of the personnel closed the valve on the transfer station, and then alerted the operator in charge of the operation. The spillage involved 200 litres of solvents recovered in the storage facility’s catchpit. The contents of the catchpit were pumped and transferred into a second tank dedicated to the storage of flammable liquids earmarked for destruction. The incident had no impact on the natural environment.

The accident occurred after the operator in charge of the transfer had checked the connection to the transfer station and registered the workshop to ensure that the volume present in the storage tank would allow the transfer without any risk of spillage. The register, however, was designed only to know the type of substances pumped into the waste solvents tank and not the available transfer capacity. Furthermore, the information regarding the fact that the tank was full was not transmitted to the operator when he came on duty, nor noted on the waste solvent transfer log; no written instructions concerning the workshop’s transfer procedures to the storage tanks were available. This type of transfer lies entirely on the personnel; there is no overfill protection system on the tank and the level indicator does not have an alarm or report reporting capability. Several measurements are taken to prevent an incident of this type from happening again: implementation of a register of the contents of the tank near the transfer station, a warning panel indicating that the connection and the volume to be transferred must be checked, instructions drawn up regarding tank management procedures defining the responsibilities of the various persons involved, improvement of personnel training, and the implementation of overfill protection devices on the waste solvent storage facilities…