Sarnia

Town in Ontario, Canada, on the St Clair River, 80 km/50 mi west of London, on the Canada–USA border; population (1990) 73,400. It is the centre of a petrochemical industry. Oil was first discovered in this area in 1858, but it was only with the completion of the oil pipeline from Alberta that the great expansion of the refining and petrochemical industry began. The oil has served as a base for ammonia, ethylene, synthetic rubber, and insecticide plants.