First Nation seeks transparency as questions loom over Sarnia, Ont., pipeline leak

A First Nation in southwestern Ontario says the size and cause of a Sarnia pipeline leak are still unclear days after it was first reported.

Aamjiwnaang First Nation is calling for answers after it learned of a spill on March 11 along the southern fence line of Suncor’s Sarnia refinery last week, adjacent to its reserve.

In a news release this week, the First Nation says reports confirm it led fuel product to leak into the ground and St. Clair River.

Suncor says its preliminary investigation indicated the source of the release might be a third party.

Sun-Canadian, which operates a refined oil pipeline from Sarnia to the Toronto area, says it was made aware on March 12 of the suspected release and started to investigate its system.

In a statement, it says “containment and recovery measures have been deployed,” but it did not immediately respond to questions about the size or source of the leak.

Ontario’s pipeline regulator says the impacted section of the pipeline has been shut down and an investigation is ongoing.

This report by The Canadian Press was first published March 19, 2026.

Jordan Omstead, The Canadian Press