One afternoon, a leak was found on a pipe used to transport effluent from a whey production plant to the wastewater treatment plant. The effluent, which came from whey that had been treated to concentrate it, polluted a canal of the River Saône. The operator stopped the leak at around 10:00 a.m. the next day.

A tee-piece with a round opening had been placed on the pipe to allow any necessary maintenance. The opening was closed by a plug consisting of a PVC gasket and metal plate. Over time, the gasket became punctured, allowing the metal plate to come into contact with the effluent. This corroded the plate, ultimately puncturing it. The operator plans to fit a manhole so that the tee-piece can be regularly checked.

During a visit by the inspection authorities for classified facilities on 25 October, cracks had been seen in the aeration tank and revealed the age of the site’s facilities. The authorities had requested that the integrity of the tank be assessed by February 2018. On 25 November, another leak occurred, this time on a pipe used to transport flush water from the whey tanks to the site’s anaerobic digestion facility. In light of this, the inspection authorities suggested to the prefect that he issue a formal order requiring the operator to implement the following measures:

• within three months, provide a summary of the maintenance operations performed on the underground collecting pipes as well as the examination schedule;
• within six months, check the integrity and strength of the pipes. If a risk of pipe rupture is identified, maintenance must be scheduled for within two months;
• within 10 months, check the devices used to transport and treat effluent;
• within 12 months, establish a procedure for checking pipes and equipment that could cause untreated effluent to be discharged to the natural environment.