During a weekly delivery at 5 pm, 3,600 litres of fuel oil spilled, polluting the lower slope of the La Serra ski area.

The driver employed by the petroleum products distributor was familiar with the ski resort site, given that it was on his regular delivery route; he also knew the tank installation, which was being filled for the first time during this winter season. The actual quantity of fuel to be transferred, which depended to a large extent on use of the slope grooming machines, could never be precisely determined ahead of time.

The driver moved towards the transfer opening located (as was usual) in the room behind the open door, in preparation for the delivery. Not accompanied by any ski resort staff, the driver connected the hose on his own and proceeded to transfer the load, while remaining next to the transfer opening to monitor the vent. Upon completion of the loading operation, he disconnected the hose when called by a member of the operator’s staff to be informed of a change in the delivery destination.

As it turned out, the transfer opening and vent had remained in the same place, but the tank had since been neutralised. The 3,600 litres of fuel infiltrated into the soil and resurfaced at the base of the resort’s rescue station, not far from the BIEF FROID watercourse. Emergency services were notified.

A retention basin was dug at the rescue station base and fire-fighters contracted a private firm to pump a maximum amount of fuel. A safety perimeter was established around the basin. Though channelled over a 100-m distance in a nozzle, the stream was protected by hay bales; fire-fighters stayed through the night to monitor the premises. The topsoil was scraped with a backhoe, and water analyses were planned.

During the night of 7th to 8th March, the retention basin filled up once again; fire-fighters used absorbent products in order to separate the fuel oil from melted snow, and the private firm returned to the site to pump the resurgent flow. The dams set into place showed no traces of fuel oil, and test results indicated no aquatic pollution of the BIEF FROID watercourse; the fuel oil seemed to be concentrated over a radius extending 15 to 30 m. Yet this pollution was located within the safety perimeter of 2 water supply extraction zones serving the town of St-Claude (Montbrillant and Serger). Both the municipality and water distribution office closely supervised the scene until 12th March, when the situation was deemed under control, as the drinking water revealed zero trace of pollution.

An elected official filed a complaint with the local gendarmerie, which dispatched officers to the site. The distribution company emphasised the fact that the company’s driver was not greeted by a client representative onsite and moreover that the client had not connected the supply hose as stipulated in the distributor’s general sales conditions. In addition, a portion of the equipment connected to the disused tank had remained in the same plac