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Pipeline that exploded was not a 'high consequence area'

CHARLESTON, W.Va. -- The natural gas pipeline that exploded last month near Sissonville was spared heightened safety scrutiny because of its size, the nation's top pipeline regulator said Monday.

The 20-inch diameter transmission line that exploded was not in what federal regulators considered a "high consequence area," even though two pipelines owned by the same company and within a stone's throw of the exploded line were.

When the line exploded on Dec. 11, it destroyed three homes, damaged several others and scorched Interstate 77 -- miraculously killing no one.

Because it was not "high consequence," the exploded line did not have to be checked for corrosion using one important pipeline safety tool. The tool -- known as a "smart pig" -- travels through a pipeline to check the pipe for irregularities, including cracks and corrosion. The tool could perhaps have found that the exploded line had corroded in places to about a third of the thickness it ought to have been.

Other details emerged about the explosion during a special hearing of the Senate's commerce committee on Monday in Charleston's federal courthouse. Sen. Jay Rockefeller, D-W.Va., is the committee's chairman and convened the special hearing here.

But Rockefeller and Sen. Joe Manchin, D-W.Va., both at times focused on the scrutiny pipelines receive.

Columbia Gas Transmission, a subsidiary of Indiana-based NiSource, owned the 20-inch line. It also owned a 30-inch pipeline 53 feet to the exploded pipeline's north and another 26-inch pipeline within 200 feet of the exploded pipeline.

Those two larger pipelines were considered to be in high consequence areas because of an equation that regulators use.

"If there are 20 residences within a bubble, it is considered a high consequence area," said Cynthia Quarterman, the head of the U.S. Pipeline and Hazardous Materials Safety Administration.

One key factor in the equation to calculate the size of the bubble is the diameter of the pipeline.

The 20-inch pipeline's bubble extended 495 feet away from the pipe in all directions, while the bubble extended 626 feet from 26-inch line and 713 feet from the 30-inch line. The two larger bubbles included nearby homes, while the smaller bubble did not, according to a chart prepared by federal regulators. Because the bubbles included more people, the two larger lines faced more scrutiny.

Quarterman said the agency is "very, very seriously" considering making changes to its rules for calculating high consequence areas.

The effort that Columbia workers had to go through to shut off the flow of gas after the explosion also became clearer during the hearing.

Deborah Hersman, the chairwoman of the National Transportation Safety Board, which is investigating the explosion, said Columbia workers had to hand crank the valves to get them closed.

In a brief interview after the hearing, Hersman said two Columbia employees took turns applying 10-20 pounds of pressure to the valves "scores" of times to shut off the flow of gas. That happened at a nearby compressor station. The station, which is to the west of the explosion, sends pressurized gas eastward to customers nearer to the coast. The station supplies gas to all three nearby lines and all valves for all three lines were closed.

There were six valves to shut off at the compressor station. Two of the valves at the station required hand cranking, two were hydraulic and two were electric, Hersman said.

It took about an hour to shut off the flow of gas.

During the hearing, Rockefeller and Manchin both heard about the merits of automatic or remote shutoff valves. The valves automatically shut off the flow of gas to a pipeline under certain conditions. The remote valves allow the gas company to remotely shut off the flow of gas.

Rick Kessler, the president of the board for the Pipeline Safety Trust, an advocacy group, said companies should invest in technology to ensure they can quickly stop the flow of gas to damaged lines. He noted that cars, TVs, garages and drones the United States uses to kill people in foreign countries all use remote control technology.

"Yet somehow we find it acceptable that an industry can use 1960s technology," Kessler said, referring to the gas transmission industry.

Columbia had trouble identifying which of the three nearby pipelines had exploded, Hersman said.

The company's Charleston control room saw pressure drop but could not tell why because the information was not specific enough. Hersman said the configuration of the gas transmission system was "masking the drop in pressure."

NiSource executive vice president Jimmy Staton said his company was committed to preventing future accidents. Just days ago, Columbia received federal approval for a multi-billion upgrade of its aging pipeline system.

The NTSB is continuing to investigate the December explosion. Contact writer Ry Rivard at or 304-348-1796. Follow him at


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