A 300–500 t heap of compost that was maturing at a composting facility caught fire at around 7:40 a.m. The firefighters, notified by the operator, displaced some nearby wooden pallets to protect them. An excavator was used to dig a trench in the waste to separate a portion of it and form a mound of earth around the fire in order to contain it and open and turn the rows of waste over so as to reach the seat of the fire and cool the mass. After the flames were extinguished, the waste was sprayed with water until midnight. At around 7:30 a.m. on the following Monday, a second fire started, this time on a heap of green waste that was to be shredded. The firefighters responded to this fire in the same way.
An inspection by the authorities for classified facilities revealed several non-conformities. As the soil under the storage and composting areas was permeable, the firewater stagnated on the site but did not contaminate the drinking water network. However, the soil may have been contaminated by organic compounds. The operator stored the pumped water on site.
Administrative and criminal penalties for a similar fire in May 2010 (ARIA 38556) had already been imposed on the operator. However, the facility had continued operating sporadically despite being the subject of prefectural order requiring its cessation, closure, evacuation, and sealing. As a result, the inspection authorities for classified facilities requested that the facility be effectively sealed and that the operator regularise its administrative status.
The operator suspected that the fires were malicious due to the fact that they occurred at the same time on two consecutive business days and on two heaps located 6 m apart. It pressed charges. The facility was fenced off, but not protected by a security firm. The operator hired a security firm to guard the facility over the following weeks and inform it of anything unusual. The inspection authorities for classified facilities considered that a cause inherent in the composting process itself cannot be ruled out (heating followed by combustion within the organic waste masses).
