Due to malicious act, PCB spread in a 70-kW/h electricity production centre in operation since 1960. The electricity produced was being resold and transferred onto the electricity distribution grid after a voltage step-up from 380 V to 20 kV by use of a transformer. In accordance with the programme to gradually eliminate PCB-containing equipment, the centre’s operator anticipated the removal of this transformer, which dated from the beginning of the 1970’s and contained 179 kg of askarel dielectric fluid. Replaced during the 2nd half of September 2005, the device had been disassembled and then temporarily stored in a closed, covered and locked room adjacent to the hydroelectric plant. During the night of 29th to 30th November, 2005, 2 individuals pried open the door to this room and then opened the transformer to recover its copper parts. The upper section of this device was disassembled first, before laying the transformer on its side to empty the dielectric fluid. Two coils had already been removed when a neighbour disrupted the intruders, who fled the scene immediately. Police and fire-fighters intervened in order to limit the spreading, but the PCB migrated into the ground. The majority of the oil, however, remained confined in the room that had been built with a concrete floor, yet this did not provide for adequate retention. Some of the fluid flowed into a stormwater drain pipe that emptied into the Dadou River. Fire-fighters halted progression of the oil before it reached the watercourse by means of clogging the stormwater drain channel. Local health and safety officials ordered a nearby pumping station to cease operations as a precaution and carried out water analyses to detect eventual traces of PCB. On 29th November, 2005 around 3 pm, a firm specialised in recovering toxic industrial waste cleaned out the channel, estimating at 500 kg the weight of earth and absorbent products polluted by the PCB. These wastes were eliminated at a duly authorised facility designed for this purpose, and the paperwork justifying their successful disposal was transmitted to the Classified Facilities Inspectorate.