Report: Corrosion may be factor in Salem pipeline explosion
The federal agency investigating the natural gas pipeline explosion Friday in Salem that sent a fireball 300 feet into the air said a preliminary investigation suggests a pattern of corrosion indicating a possible flaw in material coating the weld joints may have been a factor.
The Pipeline and Hazardous Materials Safety Administration, which has been in Salem investigating the explosion in concert with Spectra Energy Corp., which operates the pipeline, outlined its preliminary findings in a corrective action order issued Tuesday to the Houston-based company.
The failed pipe section was sent to an independent metallurgist for analysis, and a third-party metallurgist contracted by Spectra was at the blast site Friday, according to the eight-page order.
Spectra spokesman Creighton Welch said that when the pipeline that exploded was installed in 1981, the type of tape coating applied to the line “was an accepted and preferred method of coating the pipeline weld joints.”
He said Spectra “employs a robust integrity management program that meets or exceeds all federal regulations,” and the last inspection of the line in 2012 showed no areas in need of repair.
Despite the findings, the federal agency said the cause of the blast has yet to be determined and the investigation is ongoing.
Susan Waller, Spectra vice president for stakeholder outreach and sustainability, stressed that the findings are very preliminary.
“It's key for all of us to realize this is a very complicated process,” Waller said at a news conference Wednesday afternoon convened near the blast site. She said Spectra investigators are working with federal investigators as well as third-party engineers, environmentalists and scientists testing soil and air.
“We're going to be here as long as it takes to make this right for the community and everyone involved. ... Anything that the public sees, please call us,” she said, repeating the 855-210-7732 hot line the company has established for inquiries.
The federal agency administrator, Marie Therese Dominguez, said she met with agency investigators and Spectra representatives when she visited the Salem blast site Sunday.
“This explosion was devastating — it injured one person, destroyed one home, and caused a fire that burned within a quarter-mile radius,” Dominguez said in a statement. “We have directed the operator to take several immediate actions to determine the root cause of the failure and to ensure the integrity of three nearby pipelines before they can be restarted.”
The agency gave Spectra 30 days to complete testing and analysis of the failed pipe as well as analysis of soil samples and any foreign materials.
The agency's order detailed the conditions at the blast site where the explosion sent a 24.5-foot section of 30-inch stainless steel pipe flying 100 feet and left a crater 12 feet deep, 30 feet wide and 50 feet long.
Spectra officials said as a precaution after the blast they released natural gas from three adjacent pipelines — one 30 inches wide, another 36 inches wide and the last 24 inches wide — on the right of way that runs through the Randy Gillis farm.
The blast damaged three homes, destroyed a fourth home and left a 26-year-old man with extensive burns. It charred acres of crop and pasture land surrounding the crater and left a section of Route 819 from Route 22 to Evergreen Drive closed indefinitely while PennDOT assesses damage. About 3,200 vehicles a day travel the highway.
Robert Rosatti, chief of the Forbes Road Volunteer Fire Company, said PennDOT concurred that it would be best to keep the road closed, both for public safety and to keep traffic to a minimum as nearly 50 staffers from Spectra, the federal safety agency and assorted engineers and third-party experts tackle the massive investigation and cleanup. He said Salem Township supervisors, Spectra officials and local first responders hope to host a town hall meeting next week to address questions from the community.
PHMSA's order calls for Spectra to uncover and inspect at least two sections of pipeline on either side that ruptured. If damage is discovered on those sections, “additional pipe must be exposed until at least 10 feet of undamaged pipe is exposed and examined.” The company will be required to excavate two sections of the other three lines in both directions from the blast area and examine them for damage.
The order details repair procedures and outlines a gradual return to transmission on the lines once the agency has Spectra's plans.
Debra Erdley is a Tribune-Review staff writer. She can be reached at 412-320-7996 or firstname.lastname@example.org