Shell Canada is investigating an incident at their Corunna facility on Tuesday evening.
The company released the information on the Community Awareness and Emergency Response line that a sheen was spotted in Talfourd Creek, which runs directly into the St. Clair River.
A code 10 was issued by the company shortly after 9 p.m.
Shell says the spill was immediately contained and removed from the water by their vacuum trucks. Shell continues to monitor the situation.
There will be an investigation into the cause of the spill.
