On a July morning in 2010 in rural Michigan, a 30-inch pipeline owned by Calgary-based Enbridge Energy Partners burst and disgorged an estimated 843,000 gallons of thick crude into a tributary of the Kalamazoo River. This was no ordinary crude -- it was the first ever major spill into water of diluted bitumen from the Alberta oil sands.

The cleanup challenges and health impacts around Kalamazoo were unlike anything the U.S. Environmental Protection Agency had ever dealt with, and raise serious questions about the preparedness in British Columbia to respond to such a disaster on the B.C. coast -- or the Vancouver harbour.  ...

Enbridge now estimates that clean up costs of the bitumen spill will cost more than $720 million. The company exceeded their insured clean-up coverage of $600 million last fall and the clean up is far from over. Compared to other spills of heavy oil, this Kalamazoo bitumen spill has been colossally expensive. A study of historic oil spills in the U.S. reported the average clean-up cost for heavy crude of $18.95 per litre. The Kalamazoo spill has so far cost over 10 times that much and counting.

[h/t Mother Jones. This one reason why opponents of the Keystone are so worried about the Ogallala aquifer.]