Line 6b, part of a larger pipeline network in the Midwest, ruptured July 26, 2010, near Marshall, Mich., dumping more than 25,000 barrels of oil into the surrounding community. Cleanup has been ongoing for one of the worst onshore incidents of its kind.
Enbridge said last week it received notification from the Environmental Protection Agency it would have to close parts of the Kalamazoo River for more dredging operations but did not have a specific date for the closures.
The EPA said Tuesday 12 miles of the river are closed temporarily while Enbridge works to remove 350,000 cubic yards of contaminated sediment.
Line 6b was carrying oil sands from Canadian operations at the time of the incident. That type of oil is heavier than water, causing it to sink and mix with river sediment.
The EPA said more than 27,000 barrels of oil have been removed so far from the Kalamazoo River.
Enbridge asked for "patience and understanding" last week. It said it remains committed to completing the remediation operations to satisfy the best interest of the affected communities.