The National Transportation Safety Board (NTSB) has joined Colorado investigators who are examining what caused a fatal home explosion last month that is linked to a severed natural gas flowline in Firestone.
The Colorado Bureau of Investigation, state regulatory officials along with local fire and police investigators already are scrutinizing the explosion of the one-inch diameter gas pipeline, which killed two men and severely injured the wife of one man.
The NTSB joined the investigation because pipelines are considered a mode of transportation for materials including oil and gas, according to spokesman Keith Holloway.
Investigators do not yet know “if there are any issues that have a national impact,” he told NGI’s Shale Daily. “It is very early in the NTSB’s investigation and no conclusions have been drawn. There are not many details available at this time.
“Also, there is a possibility that this is an isolated event and does not have a national significance,” he said. “However, that will be part of the investigation.”
The NTSB had an investigator on scene beginning last weekend, Holloway said.
“I do not have the specifics as to exactly when the NTSB was notified about the accident, but as part of the NTSB mandate, the agency investigates all modes of transportation, which includes pipeline as it may warrant. We are also working closely with the local authorities in that area.”
Typically, he said, an NTSB accident investigation may take 12-18 months before a probable cause is determined.
Gov. John Hickenlooper on May 2 called for a statewide review of oil and natural gas operations after an initial investigation determined that an abandoned and severed unrefined gas flowline was linked to the explosion in Weld County. The abandoned line, which ran about 170 feet from a nearby Anadarko Petroleum Corp. oil and gas well to the foundation of the home in Firestone, had not been capped, Frederick-Firestone Fire Protection District Chief Ted Poszywak said. Investigators determined that fugitive gas penetrated the ground near the home’s foundation and entered the French drain, where it found its way through the sump pump. The mix of gas and air then found “an ignition source” and exploded around 4:30 p.m. on April 17, Poszywak said.
In response, Anadarko shut in 3,000 vertical oil and gas wells in the northeastern part of the state and Great Western Oil & Gas Co. followed suit, shutting in 61 wells in Weld County.