Imperial experienced an unplanned equipment outage at its Sarnia site Wednesday night.
In a notice issued through Sarnia-Lambton Alerts, the company said the outage impacted several process units.
Imperial said equipment safeguards functioned properly, preventing the event from escalating.
The company said there will be intermittent elevated flaring as a result over the next several days. There is also the potential of noise to be heard off-site while personnel work to return the site to normal operations.
The Ministry of Environment was notified and precautionary perimeter air monitoring was being conducted.