At around 2:00 p.m., a fire broke out on the lower left corner of a membrane-based composting facility at an agricultural co-operative containing seeded pomace combined with untreated stalks. Firefighters, assisted by staff and loaders to smother the burning compost, brought the fire under control and limited its spread. The firewater was contained and pumped to the site’s pond. To prevent the fire reigniting, monitoring rounds were carried out over the weekend.

Rain that had fallen a few days earlier increased the moisture content inside the windrows, causing the soggy seeded pomace to ferment and self-heat. Gusty winds that rose up immediately following the rain dried the surface of the windrows, creating the conditions needed for the fire to start. Embers carried by the winds ignited the dry grass bordering the facility. The winds then spread the flames to a fallow field and a grassy vineyard.

The operator put the following corrective actions in place:

• someone goes to the facility once a day;
• composted products are handled more regularly;
• screening is now performed at least twice a year instead of just once.

The operator announced that once self-heating is detected in a windrow, a loader must be able to access it so that the hot portions can be sorted, removed, and either spread out or wetted so that they do not heat up the rest of the windrow.