Cause of Mayflower Exxon-Mobil Oil Spill Still a Mystery

It’s been almost two months and Exxon-Mobil still hasn’t released a reason why a portion of its 850-mile Pegasus pipeline in March ruptured and spilled more than 200,000 gallons of crude oil into a Mayflower neighborhood and its surrounding area.

According to the Pipeline & Hazardous Materials Safety Administration, for both oil and gas, Arkansas endured $10.4 million in property damage from pipeline incidents between 2003 and 2012. The divide between oil and gas incidents was about 50-50, with a little more coming from the gas side.

But 2013 has already dwarfed the past nine years. An estimated $20 million in damage has already occurred this year. Some $3.6 million of that came from a 5,600-barrel oil spill in March when a corroded pipe owned by Lion Oil Co. of El Dorado burst, spilling the oil into a creek near Magnolia.

In February, an equipment malfunction in some gas pipeline owned by CenterPoint Entergy Inc. caused $2,208 in damage.

The remaining $16 million was the result of the Mayflower incident.

Of the 78 incidents recorded between 2003 and 2012, 29.5 percent were from material, welding or equipment failure; 20.5 percent from corrosion; 17.9 percent from excavation damage; 10.3 percent from natural force damage; 7.7 percent each from other outside force damage and all other causes; and 6.4 percent from incorrect operations.

PHMSA still lists the Mayflower incident as “unknown cause.” Workers and police officers can still be seen toiling near Exit 145 on Interstate 40.

Amber Gardner, a spokeswoman for Exxon, said a new section of the pipeline was installed on April 15 and the damaged portion has been transported to a third party metallurgical lab. Beyond that, the company had little else to say.

“Pretty much other than that, the pipeline is shut down,” she said. “We’re truly still in the middle of this. We’re still analyzing to find out what happened and we’re not at a point where we have a plan.”

PHMSA’s Office of Pipeline Safety earlier this month asserted that some of both the northern and southern parts of the Pegasus have had seam failures during pressure tests.

The pipeline is 20 inches wide, travels 850 miles from Patoka, Ill., about 85 miles east of St. Louis, to Nederland, Texas, near Port Arthur on the Louisiana border. It can carry about 95,000 barrels of crude per day.

The northern section of the Pegasus, including the ruptured area, was built in 1947 and 1948, with the other parts built in 1954 and 1973.

Peter Lidiak, pipeline director for the American Petroleum Institute, said it’s not unusual for pipeline laid in the 1950s to still be in use. He said it will be difficult to determine any precedents for the rupture until the cause is found.

“Not really knowing what the cause of the accident is, I think it’s awfully hard to think of what kind of repairs might be needed,” he said.