Problems with the water treatment system at the wastewater treatment plant of a poultry abattoir were noted at around 1:50 p.m. Wastewater from the abattoir is sent to a collection pond, which supplies the plant. The first part of this pond is a buffer pond. The level in the collection pond was high and the level in the buffer pond was low, suggesting that the pipe between the ponds was blocked. The collection pond threatened to overflow and pollute the stormwater network. The operator decided to install a bypass. The plant’s operations were halted and the water supply was cut off. A submersible pump was installed to supply the buffer pond. A manhole leading to the biological treatment lagoon was opened, making it possible to see that the top of the pipe was cracked (5–7 cm). However, most of the pipe was inaccessible. A temporary seal was fitted in case the bypass proved insufficient. The facility was restarted at around 3:30 p.m. A construction company examined the non-visible portion of the pipe and modified the network to secure the line leading to the buffer pond. The observable portion of the pipe passes over the pipe used to discharge water from the clarifier to the natural environment.

The crushing and/or cracking of the pipe may be due to repeated heavy-goods vehicle traffic in this spot. The operator inspected the nearby river at 4:00 p.m. and again at 6:00 p.m. at two points located 3–4 km and 7–8 km away to ensure that there was no pollution. The next day, the WWTP operated normally with the bypass in place.