Mississippi River oil spill: why Yazoo turn is treacherous

Oil continued to leak into the Mississippi River Tuesday from a barge containing more than 600,000 gallons of light crude, following an accident that took place early Sunday morning in Vicksburg, Miss.

The US Coast Guard says it has not yet determined how much oil escaped but that skimming operations have captured about 2,300 gallons of oily water mixture and about 7,000 gallons remain unaccounted for.

The vessel is one of two tank barges pushed downriver by a tugboat that failed to make a dangerous turn south of Vicksburg, where the Yazoo River empties into the Mississippi. The collision resulted from one barge striking a railroad bridge, damaging one of the eight onboard oil tanks.

The location of the accident represents “one of the two most difficult turns in the Mississippi River” because, when moving downstream, operators have to make a hard right, which exposes them to currents from the Yazoo, says Kavanaugh Breazeale, a spokesman for the US Army Corps of Engineers in Vicksburg. Contributing to the danger are underwater pylons supporting two bridges – one for rail cars and a second for Interstate 20 – which are separated by less than a tenth of a mile.

Navigating the Mississippi is often treacherous due to changes in elevation, cross currents from intersecting waterways, and the increasing number of barges in a single tow, which could extend to as many as 40, says Marty Lipinski, director emeritus of the Intermodal Freight Transportation Institute at the University of Memphis.

“These are enormous structures moving down the river. These pilots are highly skilled people who sometimes have to put a thread through the needle to maintain navigation of these large tows within the channels,” Mr. Lipinski says.

Last February, two barges spilled about 10,000 gallons of oil after a collision about 50 miles upriver from New Orleans. In 2008, about 300,000 gallons of oil escaped near New Orleans after a similar collision between a barge and a tanker.

Recovery operations are ongoing. Jonathan Lally, a spokesman for the US Coast Guard Eighth District based in New Orleans, could not confirm the rate at which the oil was spilling, but described the discharge as a “slow leak.” Mr. Lally says besides recovery operations, which include 2,800 feet of boom, the Coast Guard is working to transfer the oil from the vessel to another to salvage the damaged barge.

The damaged barge has been pushed to the banks of the river in downtown Vicksburg. A 16-mile stretch of the lower Mississippi remains closed, a situation that is forcing about 47 barges to idle until further notice.

Petroleum and agricultural commodities like grain or fertilizer make up about 90 percent of commodities that travel the Mississippi River.

The Louisiana Environmental Action Network, an advocacy group located in Baton Rouge, La., says that its investigators have determined that oil sheen from the spill has already contaminated the area of land located between the river’s edge and the bluff in Mississippi, and the earthen levee in Louisiana. “It’s contaminated that ecosystem and will have a long-term impact on the sediment,” says Wilma Subra, a chemist with the organization.