A household and infectious clinical waste incinerator (ICW), as well as the associated sorting centre, were flooded following very heavy rainfall. At 1 a.m., the night shift noticed the rising waters and raised the alert. Both incineration furnaces and the turbine were shut down. Following the arrival of the fire brigade, the sorting centre was also shut down, and the employees were evacuated. The electricity utility isolated the plant from the high-voltage grid. A pumping station was installed to keep the generator room above water and allow it to continue to operate. The generator stopped at 5 a.m.

The water continued to rise overnight, reaching 1.5 m in some areas.

Three high-flow pumps, which had been ordered when the flood began, arrived on site two days later. These pumps made it possible to drain the water from the site and from the various basins in the area.

Consequences and actions taken

• The incinerator pit was not flooded.
• The product storage facilities (containing acid, sodium hydroxide) were flooded, but the tanks remained intact.
• The products in small volumes, stored in cabinets, remained confined.
• The ICW bins were protected from the rising water on the unloading dock.
• The big-bags of flue gas purification residue from the household waste incineration and ashes had taken on water, though the damage did not prevent them from being sent to conventional treatment processes.

Traces of hydrocarbons from the retention basins were found in the ground after the water was pumped out, and analyses were conducted.

The operator estimated the cost of the flood at between 6 and 7 million euros (operating loss, equipment damage). The sorting centre remained shut down for 2 weeks; the incinerator was shut down for an extended period of time (restarted after 31 days for the first incineration line, 41 days for the second line, and after 52 days for the ICW furnace feed line). The energy recovery unit connected to the turbine started back up in October. For the first few weeks following the incident, the sorting site employees and the staff in charge of the ICW activity were temporarily laid off. The incinerator staff remained mobilised in order to prepare for the restart operations.

During the period when the facilities were inoperable, incoming waste was directed to other treatment facilities. Flooded waste from the sorting centre was sent to a storage facility.

Feedback

The cumulative effect of the heavy rains and runoff from the already saturated nearby forest and the malfunction of a lifting pump from an industrial estate’s rainwater basin led to the rapid rise in water levels. The site is not located in a floodplain and had never been flooded, even on a small scale, in 20 years of existence.