Heavy rains flooded a petrol station, soaking the surrounding ground and ultimately seeping into the station’s underground fuel storage tanks via their poorly sealed stilling wells. As a result, the fuel became unfit for sale. A specialist company transported 80,000 l of fuel to an oil terminal but left 40,000 l of watery fuel in the tanks. A second rainfall event occurred two weeks later, again filling the underground tanks with water. A second specialist company was called in to pump out the tanks. That very same day, the town’s sewer system was found to be contaminated. Fuel had leaked into a several-kilometre stretch of the intermunicipal sewer system, affecting the operation of the wastewater treatment plant.

The water networks of the petrol station and its car wash as well as that of a nearby private home are upline of the first manhole affected by the pollution. The results of soil samples collected around the tanks showed that the tanks had not overflowed.