Imperial is reporting a diesel leak in the St. Clair River.
In a notice through Sarnia-Lambton Alerts at around 10 p.m. Wednesday, Imperial said the company had responded to a small leak at its dock.
The source of the leak was quickly isolated, and the spill response team deployed containment booms in the river.
"Recovery and clean-up efforts are ongoing, and the sheen on the river has been fully contained," read the alert.
Imperial said as a precaution, downriver water quality monitoring was conducted, and no detectable levels of hydrocarbon have been observed.