A hunk of tar sands oil as mined   Photo credit Argonne National Laboratory

At about 6 PM, July 25, 2010, engineers in the Edmonton, Alberta control room were monitoring Enbridge’s Keystone Pipeline.  They were about to take the pipeline offline for routine work when an alarm went off.  The workers decided there must be a bubble somewhere blocking the flow of the tar sands and took the pipeline offline. 

The next morning, July 26th, the controllers attempted to burst the bubble by twice restarting the pipeline. 

It wasn’t until after 11 AM when a Michigan utilities worker called the Enbridge emergency line to inform the company that they had a burst pipeline that was pouring more than 1,100,000 gallons of tar sands oil into Talmadge Creek, a tributary of the Kalamazoo River in Marshal, Michigan.

The spill drove 150 families from their homes for weeks.

Keystone Pipeline tar sands oil spill in Kalamazoo River  Photo credit Michigan Department of Environmental Quality

Cleanup began immediately, and the EPA was confident it would have the mess cleaned up in a couple of months.  Today, two years later, cleanup is still continuing. 

Not until several weeks after the spill did the EPA realize the severity of the problem.  Cleanup workers noticed that as they walked through the river in their hip waders, flakes of oil floated up from the bottom and created an oil seen on the surface. 

Curious, workers stirred up the sediment with poles, which caused gushes of oil to surface.

In all the interactions with Enbridge, the company had not told the EPA that they weren’t dealing with conventional oil in a conventional spill.  What their pipeline 6B carried was tar sands oil, which is diluted bitumen, aka dilbit, something the EPA had no experience with.

The substance is either steamed or strip-mined from tarry soil and must be diluted because it’s too thick to flow through pipelines.  One of the liquid chemicals used in the thinning process is Benzene, a known carcinogen.

Diluted bitumen is the type of oil that might someday be carried by the Keystone XL pipeline across the Ogallala aquifer, which supplies drinking water for eight states as well as 30% of the US’s irrigation water.

The National Resources Defense Council and other environmentalist organizations say dilbit is so acidic and abrasive that it’s more likely to weaken and corrode pipelines than is conventional oil.

Enbridge and other oil companies insist dilbit is not different from conventional crude.

Surely they are honorable men, whose word we can take at face value.

Tomorrow:  How the bungling of the “Keystone Kops” created the worst US oil spill since the US began keeping records in 1968. 

Sources:  Huffington Post  July 5, 2012           New York Times, July 2, 2012   Geology.com #79       Transcript of PRI’s Living on Earth, July 6, 2012        MLive  July 18, 2012   Bloomberg News, July 24, 2012



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