There was an oil spill Thursday evening in the St. Clair River.
Imperial said it happened at about 5 p.m. near the Imperial Oil berth on Clifford Street.
In a release through Sarnia-Lambton Alerts, Imperial said the spill was isolated and was not active.
"Imperial is responding to an oily water release from a service line adjacent to the marine dock," read the release. "This is not a release from the vessels currently at our docks."
Imperial's spill response team responded and containment booms were also deployed.
The company also said downriver water monitoring was being conducted as a precaution.
The all clear was issued at around 11:15 p.m.
The Ministry of Environment, Conservation and Parks was notified.