Digging for answers from the Appomattox explosion

Officials could be months away from determining the exact cause of a natural gas pipeline rupture that sparked an explosion and devastating fireball in Appomattox on Sunday, an executive for the company that operates the pipeline said Friday.

“We will make sure it is safe before it goes back into service,” said Larry Hjalmarson, vice president of operations for Williams Gas Pipeline.

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The mangled metal pipeline, flung across Virginia 26 in the explosion, has been sent to a metallurgy lab in Houston to help determine what caused the fireball that destroyed two homes, damaged several more and injured five people.

On Friday, meanwhile, Williams workers unearthed two other pipelines that run parallel to the one that ruptured, inspecting them for any damage from the explosion.

“I feel safer out here than I do in my own home,” Hjalmarson said.

The cause of the explosion is still under investigation, but Hjalmarson said damage done by someone digging near the pipeline has been ruled out. That, he said, is the biggest threat to pipeline safety.

The three lines — the A line built in 1949, the B line in 1955 and the C line in the early 1960s — are now under scrutiny by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration, the Virginia Corporation Commission and Williams officials.

The A line was inspected for problems in 2000. The C line was inspected early this year and repaired. The B line — the one that failed — had just been inspected, but Williams’ officials had not been able to analyze the results when the blast happened.

In the wake of the explosion, the coating has been removed on the A line and inspectors are looking over the 59-year-old pipe.

Bill Deaton, an integrity inspector for Williams, said there appears to be no damage on the line from the explosion. It sits 47 feet from the hole that used to be a portion of the B line. There is also little corrosion for a line that has been in the earth since its installation, he said.

The walls of the pipeline are about one-third of an inch thick. Inspection of the A line showed about 10 percent corrosion on the bottom, which Deaton said is better than normal for many lines.

“The strength has not been compromised,” he said.

The C line runs 25 feet from the B line. It has been dug up but inspectors have not yet examined it. A portion of that line was replaced about six months ago after an inline inspection tool showed damage.

A 300-foot section of the line that ruptured will have to be replaced, said Hjalmarson. Before that line is put back into service, it will be will be filled with water and tested at 1,200 pounds per square inch for eight hours. The line is only operated at 800 psi, he said.

“When it is all built and installed, we do a hydrostatic pressure test before we ever put the line in service,” Hjalmarson said.

The welds on the pipe are also X-rayed prior to operation.

Hjalmarson said the A and C lines are running at 670 psi rather than their rated 800 psi until they are fully inspected.

The pipelines move 1.6 billion cubic feet of natural gas per day from the Gulf of Mexico north to New York, Hjalmarson said.

“We can’t turn the clock back and change it,” Hjalmarson said. “I am thankful that it wasn’t worse. Looking at it is sobering.

“We know confidence has been shattered. We want to build that back. Please give us a chance to build back that trust that Williams is a safe operation.”