Pegasus pipeline accident one of 14

Correction: A barrel of oil is 42 gallons. This story incorrectly reported the amount.

The Exxon Mobil pipeline that spilled thousands of gallons of oil in a Mayflower neighborhood in March has had at least 13 other minor leaks since 2002, according to accident reports kept by the federal Pipeline and Hazardous Materials Safety Administration.

Documents obtained by the Arkansas Democrat-Gazette through a Freedom of Information Act request indicate that corrosion caused six of those leaks.

Of the 13 spills, the largest was a 15-barrel spill in Illinois. Other spills ranged from 10 gallons to four barrels and occurred in Illinois and Texas, according to the reports. There are 31.5 gallons in a barrel.

The 20-inch-wide pipeline stretches 850 miles from Patoka, Ill., through Arkansas to Nederland, Texas. It passes through the Lake Maumelle watershed - the drinking-water source for about 400,000 people in central Arkansas - on its 300-mile run across the state.

Exxon Mobil spokesman Aaron Stryk said the 13 leaks did not take place on the main Pegasus pipeline.

“They were within our facilities and generally involved small releases from pumps, valves, fittings or from ancil-lary piping,” he said in an e-mail. “Three of the events … involved a pipeline other than Pegasus.”

A letter from the Pipeline and Hazardous Materials Safety Administration accompanying the FOI request response said the 14 reports - including the Mayflower spill - “have been filed by both Mobil and Exxon-Mobil for the Pegasus System.”

The March rupture of the 65-year-old pipeline leaked more than 100,000 gallons of oil into the Mayflower neighborhood and a cove of Lake Conway.

It was the largest spill on the pipeline since 2002 and the only spill in Arkansas.

A spill of 600 barrels - about 18,900 gallons - in Garland County in 1995 was caused by a maintenance crew doing road work that accidentally cut a 2-inch gash in the Pegasus pipeline. Oil from the spill did not reach a water source, according to a report.

The 15-barrel spill in Illinois in 2008 near a Patoka tank farm was caused by internal corrosion. According to the accident report, the oil spilled on Exxon Mobil’s property near a drinking-water source, but did not contaminate the water.

“Corrosion is very common for pipelines,” said James Williams, an energy analyst who operates WTRG Economics near Russellville, “[Companies] try to catch the stuff ahead of time; sometimes they don’t.”

About 25 percent of pipeline accidents are caused by corrosion, according to the pipeline agency. Most pipeline incidents - 36 percent - are caused by welding or equipment failure.

Williams said the Wabasaca heavy Canadian oil the pipeline was carrying likely did not make it more vulnerable to corrosion.

A report by the National Research Council released Tuesday found that the Canadian diluted bitumen in the Pegasus line does not increase the likelihood of accidents when compared with other crude oils.

Williams said corrosion inside a pipeline is the result of water mixed with the oil.

Companies can prevent spills by running a device called a “smart pig” through the pipeline to detect flaws, he said.

“The big problem [with the 14 spills] is that there is a flaw, and it went undetected,” Williams said.

The pipeline is subject to inspections by Exxon Mobil and the pipeline agency. No state agency inspects it.

Exxon Mobil last ran a “smart pig” through the Mayflower section of the pipeline on July 21, 2010. Its last inspection of the pipeline was in February.

The results of the inspections “should be available in the coming months,” Stryk said.

He said the company has already shared preliminary results with the pipeline agency but is still conducting a final analysis.

Leaders from Little Rock, Pulaski County, North Little Rock and members of the Arkansas congressional delegation recently asked the pipeline agency to release the results of inspections conducted in 2010 and 2013 on the section of the line in the Lake Maumelle watershed.

But the agency said Exxon Mobil has asked that the records be protected from disclosure under the federal Freedom of Information Act.

Stryk said the pipeline passed inspections performed by Exxon in 2006 and 2010.

“Immediately prior to the [Mayflower spill], the pipeline met all requirements as outlined by [the Pipeline and Hazardous Materials Safety Administration] and for operating under normal pressure and flow conditions,” he said.

Reports from the agency also show that Exxon Mobil was fined $26,200 in 2010 for not inspecting a section of the pipeline beneath the Mississippi River between Missouri and Illinois within the five-year time frame required by federal regulations.

Damon Hill, spokesman for the agency, said the five-year inspections are required of pipelines that carry hazardous materials.

“We are currently considering regulations to expand that,” he said.

Hill said the agency inspects pipelines “all the time” but said it depended on the schedule drafted for the pipeline.

“We could be inspecting an operator once a year,” he said. “Some operators receive inspections more often than that.”