63-year-old gas line that blew had a 'smart pig' check in '12

A boat navigates the swollen Arkansas River over a natural gas pipeline that ruptured Sunday morning about a mile east of the Interstate 30 bridge. Pipeline owner Spectra Energy Corp. has sent a crew to survey the line.
A boat navigates the swollen Arkansas River over a natural gas pipeline that ruptured Sunday morning about a mile east of the Interstate 30 bridge. Pipeline owner Spectra Energy Corp. has sent a crew to survey the line.

The 63-year-old pipeline that burst Sunday and released 3.9 million cubic feet of natural gas into the surging Arkansas River was last inspected in 2012, a spokesman for pipeline owner Spectra Energy Corp. said Thursday.

The age of the pipeline -- it was put in place in 1952 -- should not be a factor in the line's rupture, said Phil West, spokesman for Spectra Energy.

"Age is not the indicator of pipeline suitability," he said. "It really boils down to how it's maintained."

The 24-inch pipeline ruptured Sunday about 9:30 a.m., according to witnesses who saw two large spouts of water shooting skyward when the line released natural gas.

Spectra Energy said no residual natural gas was left in the river. Company officials and others in the industry have said that the gas released would have dissipated.

The cause of the break remains unknown. Spectra Energy sent divers to inspect the pipeline twice this week, but the swift current of the flooding river prevented them from checking the pipe, West said.

The company had a boat on the Arkansas River on Thursday with equipment to scan the riverbed.

The results so far have been inconclusive, said Lt. Brian Porter, spokesman for the U.S. Coast Guard in Memphis.

He said a 2-mile section of the river remains closed to traffic as the company tries to determine what caused the rupture.

The pipeline is part of the Texas Eastern Transmission system, which crosses the river between Little Rock and North Little Rock about a mile east of the Interstate 30 bridge.

The line that failed is a backup pipeline to the system's main transmission line, which runs from Texas to New Jersey. The parallel lines are about 10 feet apart.

Spectra Energy ran a "smart pig" through the backup pipeline in 2012. The device is used to find irregularities in pipelines, such as corrosion or cracks. The company also had divers check for exposed sections of pipe in 2011. In both instances, Spectra Energy found no problems with the pipeline, West said.

The 24-inch primary transmission line was operating normally after the parallel line ruptured, but Spectra Energy has shut it down until it can be inspected. The company said there is no indication that it was damaged.

Inspections of the main pipeline in 2003 and 2009 found no problems, according to Spectra Energy.

West said the company is required to inspect the pipeline every seven years by the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration.

The agency, which regulates interstate pipelines, is investigating the rupture. A spokesman for the agency could not be reached Thursday.

Spectra Energy has come under scrutiny for the delay in alerting city officials and other agencies about the Sunday gas leak.

The company notified the National Response Center, a federal agency that records hazardous-substance spills, on Monday. Spectra Energy informed the Little Rock and North Little Rock mayors' offices Tuesday morning.

"We try to notify officials as early in the process as possible," West said. "We started that process once we became aware and had information to share."

Spectra Energy was notified of the pipeline break Monday when it was contacted by a company that said when the line broke and gas was released, debris thrown by the eruption damaged a nearby boat.

Photos of the towboat, which belongs to Jeffrey Sand Co., show what appeared to be damage caused by chunks of concrete and other debris.

Spectra Energy's pipeline was coated in concrete, West said.

The Coast Guard is investigating how the towboat was damaged, Porter said.

Because the pipeline is a backup line, it was not being remotely monitored by the company. Instead, the company "manages risk" by keeping valves at both ends of the 41/2-mile pipeline shut, West said.

"The two valves were closed," he said. "Which is what a remote valve would do. They did their job to limit additional gas flow."

West wouldn't speculate on how much more natural gas could have been released if the valves had been open.

But, he said, if the valves were open, the main pipeline's monitoring system would have noticed a drop in pressure caused by a leak.

"And we would have reacted to that part of the procedure," West said.

The natural gas in the pipe does not flow to the main transmission line. It is in place in case the primary pipeline is shut down for maintenance or if there is a big increase in demand.

The backup line was pressurized and ready for service, said Catherine Landry, spokesman for The Interstate Natural Gas Association of America in Washington, D.C.

Pressure in the ruptured pipeline could have been a maximum of 700 pounds per square inch, West said.

"That's typical operating pressure," he said, adding that it wouldn't have led to the break.

Metro on 06/05/2015

Upcoming Events