CHARLESTON, W.Va. --A federal safety agency has given the OK to restart the natural gas pipeline that exploded in the Sissonville area Dec. 11, but not before the gas company responds to a list of questions.  

C.W. Sigman, Kanawha County's deputy emergency services director, said the federal Pipeline and Hazardous Materials Safety Administration included a "long list of actions the gas company has to take before they restart" the pipeline.

The list is "going to take a while" for NiSource subsidiary Columbia Gas Transmission to respond to and Sigman said he isn't sure how long it would take.

"Timing is not the issue. The issue is making sure it's safe," Sigman said. "It already had one rupture and burnt several buildings down. We want to make sure it doesn't happen again so we don't want to be in any hurry."

The pipeline exploded near Columbia Gas Transmission's Lanham Compressor Station at Rocky Fork.

The blast and resulting fires destroyed about five homes and engulfed a large section of Interstate 77. No one was killed but several people were treated for minor injuries.

New federal records contradicted NiSource's earlier statements to local officials that the pipeline dated back to only the 1990s. It was constructed in 1967.

Sigman said since the pipe is so old it has never been "pigged" before.

A pipeline inspection gauge, or "pig," is a maintenance tool that's inserted into a pipeline and travels freely through it, driven by the flow of the product inside the pipeline itself to do a specific task within it, according to the Pigging Products and Services Association's website.

In this instance, pipeline inspection gauges are used to provide information on the condition of the pipeline and the extent and location of any problem, such as corrosion.

The gas company needs to verify records to ensure that there aren't corrosion issues, Sigman said.

"They have never tested the pipe so how do they know it doesn't have thinning issues on other parts of the pipe?" Sigman said. "The valves are so old. I'm sure over the years pipe has been added to it and replaced. It needs to be verified. Digging needs to be done."

Sigman said the Pipeline and Hazardous Materials Safety Administration approved replacing the portion of the pipeline that exploded -- instead of the entire pipeline -- because "if they replaced an all-new pipe, there would be all new standards and this letter would not be necessary."

The pipeline safety agency proposed that NiSource partially test the pipeline and its valves to ensure its safety. But Sigman said he prefer that they are fully tested.

"Partially tested only verifies it partially," he said. "We are not a regulator, we cannot tell [the gas company] what they can and cannot do but we want to make sure they understand our concerns and explain how to make it safe. We want to make sure we're all on the same page and feel like it's the safe thing to do."

Also, Sigman questions why the agency told the gas company that it would allow the pipeline pressure to be at 80 percent, which would enable it to sustain pressure of 741 pounds per square inch.

When the pipeline exploded, the pipe was 70 percent thinner than it should have been, but still should have been able to sustain pressure of 921 pounds per square inch.

"One question we have is, 'How did they determine that number? Is that just an arbitrary number?'" Sigman said. "We think they need to do some other things before they put some more pressure on it."

Sigman said he'd like to see scientific engineering studies performed to "make sure the blast is not happening somewhere else."

Kanawha County Commission President Kent Carper said that since a portion of pipeline was so deteriorated before it exploded, it should be confirmed that the rest of the pipeline isn't as dangerous.

"The community has an absolute right to be safe. The traveling public driving over interstates have a right to be safe and the first responders deserve better than this," Carper said. "It's incumbent on the gas company to prove to the regulatory authorities that the line is intact from beginning to end."

Chevalier Mayes, a communications manager for NiSource, did not return phone calls Thursday.

CORRECTION: An earlier version of this story originally said the state Public Service Commission was the agency that gave approval to restart the pipeline. The PSC is only allowed to provide comments and input regarding the federal Pipeline and Hazardous Materials Safety Administration order, a PSC spokeswoman said.

Reach Megan Workman at megan.work...@wvgazette.com or 304-348-5113.