NTSB Slams Columbia Gas for Merrimack Valley Gas Disaster

SEATTLE (Oil Monster):  Federal officials have pinned last September’s Merrimack Valley gas disaster on Columbia Gas of Massachusetts, citing “engineering errors” that failed to account for pressure-sensing lines in aging pipeline being replaced in South Lawrence — and are criticizing the utility company for inadequate risk management and protections against over-pressurization of gas lines.

When asked if the Sept. 13, 2018, blasts could have been prevented had Columbia Gas’ parent company, NiSource, had a comprehensive safety management program, Robert Hall, director of the NTSB’s railroad, pipeline and hazardous materials office, said, “Yes, I do.”

The National Transportation Safety Board held a nearly four-hour hearing Tuesday morning into the probable cause of the gas explosions and fires that killed a Lawrence teenager, injured nearly two dozen other people, damaged or destroyed more than 100 homes, and left 11,000 customers without gas service.

NTSB officials attributed the probable cause to Columbia Gas of Massachusetts’ “weak engineering management that did not adequately plan, review, sequence and oversee the construction project that led to the abandonment of a cast-iron main without first relocating sensor lines to the new polyethylene main.” Officials also said the low-pressure natural gas system was “designed and operated without adequate over-pressure protection,” contributing to the blasts.

The NTSB previously said sensor lines were left out of a Columbia Gas work order for a subcontractor tasked with removing old cast-iron piping and replacing it with plastic mains in South Lawrence. Regulators sensed a drop in pressure in the abandoned line and increased pressure in the system to 12 times the safe limit.

New Tuesday was the incredulity of NTSB officials at some of the lapses that contributed to, and followed, the blasts in Lawrence, Andover and North Andover — from the failure to include the sensing lines in the project plans, to Columbia Gas’ poor communication and inability to provide a map of its own gas system to first responders.

“It’s amazing to me that a company that operated this system for more than 100 years could not produce a map, a readily made map, to firefighters to show them the extent of the system and their emergency planning did not have information on valves as to how to shut the system down,” Hall said.

And with construction stretching back to 2016, officials said Columbia Gas should have known then that sensing lines needed to be relocated. They said the company “failed to comprehend that the work package, upon being executed, would have a catastrophic impact on pressure.”

The NTSB issued 14 findings and five new safety recommendations at the hearing, including to require over-pressurization protection for low-pressure natural gas distribution systems nationally.

Officials praised NiSource for following through on four recommendations it issued last November, thanking the utility company for showing “willingness to change direction and improve safety.”

U.S. Sen. Edward Markey released a statement saying the hearing confirmed to him “that this disaster was not inevitable, it was preventable.” He also said the NTSB would visit Lawrence in October to discuss its findings.

Courtesy: www.bostonherald.com