At approximately 5 p.m., an individual living next to a non-hazardous waste storage facility noticed leachate overflowing onto his property.

Firefighters and the operating crews intervened, redirecting the leachate to the site’s 910 m³ buffer storage basin. The lifting pumps in the wells of 3 storage cells were stopped to limit the infeed to this basin. A specialised company was called in to pump the pipes on the network still full of the leachate.

At 7 p.m., the overflowing of the leachate overflows had stopped, and an operation to clean-up the network was initiated. An obstructive, black and highly elastic material made the cleaning operation difficult and had to be removed manually. The leachates stored in the buffer basin were discharged by tanker lorries to a treatment plant to avoid odour nuisances. The cleaning operations lasted for several weeks.

Several plugs blocking the leachate discharge line to the sewage treatment plant caused the pipe to become overloaded which then overflowed from the various manholes on the property. Liquid seepage upstream from the manhole closest to the property suggested that the underground pipe was damaged. Heavy machinery operating on the property could have damaged the pipe, resulting in the seepage observed as a result of hydraulic loading of the network.

A video inspection of the installations was conducted to check the integrity of the network. Several problems were observed (defective gaskets, shifting and crushing of the pipe in some places, etc.). Work was undertaken before the system was put back into service.