The oil leaked from a transformer that was in transit on the back of a flatbed truck yesterday afternoon.
Drivers alerted police, who followed the trail of oil to the source.
Environment Quebec workers were called in to clean up the mess. They recovered more than 200 liters of oil.
Officials can't tell yet how the leak started, but said the spill poses no threat to public.
Environment Quebec won't confirm that the oil spilled contained dangerous PCBs — chemicals that are known to cause skin lesions and have effects on the liver.