Enbridge this week said it suspected heavy flooding in Alberta may have contributed to the rupture of the 11-mile Line 37 oil pipeline about 44 miles southwest of Fort McMurray.
Parts of Alberta are under a state of emergency because of flooding. The Canadian National Energy Board, which has headquarters in Calgary, said its offices remained closed Wednesday because of the situation.
About 750 barrels of oil spilled from Line 37. Enbridge said no potable water wells were affected by the release, though some of the oil spilled into a small creek and a lake.
The type of crude oil extracted from Alberta is heavier than water, making it more difficult to remove from rivers and streams.
Enbridge said Tuesday it extracted more than 100 barrels of a mixture of water and oil from the site. Fencing was set up in the region to prevent wildlife from entering the area.
The official cause of the incident is still under investigation.