comments_image Comments

6 Things You Need to Know About the Arkansas Oil Spill

For starters, this is not your average crude; but there is a whole lot more you should know.

Photo Credit: Karen McCall/Greenpeace


This article was published in partnership with  GlobalPossibilities.org.

By now, you already know that at least 84,000 gallons of crude spilled from an ExxonMobil pipeline, swamping an Arkansas subdivision on Friday, and causing the evacuation of 22 homes. In addition to the loss of wildlife, damage to property, and environmental and human health hazards posed by the spill, it may have implications for the Keystone XL pipeline currently under consideration by the Obama administration.

There is a lot more to the story that's important to understand. Here are six crucial things.

1. Not Your Average Crude

InsideClimate News reported shortly after the spill that an Exxon official confirmed the pipeline was "transporting a heavy form of crude from the Canadian tar sands region." Specifically, it has been identified as Wabasca Heavy, Lisa Song writes, "which is a type of diluted bitumen, or dilbit, from Alberta's tar sands region" although you won't hear any Exxon folks calling it tar sands. 

Dilbit is some seriously nasty stuff. She writes about a previous dilbit spill by Enbridge in Michigan's Kalamazoo River in 2010: 

Dilbit is a mixture of heavy bitumen and diluents--light hydrocarbons used to thin the bitumen so it can flow through pipelines. While most conventional crude oils will float on water, the bitumen began sinking into the river as the diluents evaporated, leaving a sludge of submerged oil that defied traditional cleanup methods. ...

Earlier this month, the EPA ordered Enbridge, Inc., the Canadian company that owns the pipeline, to dredge sunken oil from the riverbed. The cleanup has cost more than $820 million to date and could top $1 billion once the order is carried out.

The Arkansas spill wasn't as big as the Michigan spill and it was farther from main water bodies, but it's still serious business. If you want to know more about how dangerous tar sands/dilbit can be, the Dilbit Disaster is a must-read. 

2. Not Your Average Pipeline

The Pegasus pipeline running more than 850 miles between Patoka, Illinois and Nederland, Texas, is 20 inches in diameter and was built in the 1940s to carry crude from Texas to Illinois. But in 2006 the flow was reversed in order to carry Canadian tar sands to Texas. As Ben Jervey wrote for DeSmog blog, the flow was reversed to "help relieve the tar sands crude bottleneck in Cushing, Oklahoma. (The same reason given by proponents for the construction of Keystone XL.)"

The pipeline was built to carry 65,000 barrels a day, but Exxon was allowed to expand that to 95,000 barrels a day just a few years ago.

All of these facts bring up some basic questions. What effect does a higher capacity have on the pipeline? What effect does reversing the flow have on the pipeline? And what effect does switching from conventional crude to dilbit have on the pipeline, considering it was built to have a much thinner crude flowing through it?

John H. Cushman Jr. wrote for InsideClimate News:

... seven years ago, when Exxon, the pipeline's operator, turned it into a higher-volume line for diluted bitumen from Canada flowing under greater pressure to refineries on the Gulf Coast, federal rules did not require a new permit application or safety reviews, according to federal officials.

"Our regulations don't specify how much product a pipeline carries. There is no regulation if they want to change the type of crude they carry," said Damon Hill, a spokesman for the Pipeline and Hazardous Materials Safety Administration, a part of the Transportation Department. "As far as reversing the flow of a pipeline, it is not a safety issue."

See more stories tagged with: