NiSource Subsidiary Accused of 'Deficiencies', Caused Blast
MERRILLVILLE - The National Transportation Safety Board is accusing Columbia Gas of Massachusetts of “deficiencies in management and oversight” which resulted in a deadly explosion and series of fires last year in Merrimack Valley, an area north of Boston. The gas company is a subsidiary of Merrillville-based NiSource Inc. (NYSE: NI) which has accepted responsibility for the incident.
The NTSB said this week the management shortfall led to overpressurization of a natural gas distribution system. The agency says high-pressure natural gas was released into a low-pressure system.
Before the incident, a contract crew hired by Columbia Gas was replacing gas line pipes. NTSB says a bypass was used incorrectly, leading to the blast.
“Catastrophic tragedies like this should never happen,” said NTSB Chairman Robert Sumwalt. “When tackling major repair work that has the potential to impact a community, all precautions and planning should be considered and coordinated before, during and after the work has been done.”
One resident died and 22 other people were injured in the series of explosions and fires. The system over-pressure also damaged 131 structures and destroyed five homes, according to the NTSB.
NiSource released a statement following NTSB’s meeting which said the company’s understanding of the events “generally aligns” with that of the NTSB.
"Since last September, and based on lessons learned, we have taken a series of steps to prevent something similar from happening again, which is what our customers and our communities deserve. These include installing automatic shut-off devices, accelerating implementation of a Safety Management System, or SMS, enhancing emergency preparedness, enhanced mapping, and more.”
As a result of the investigation, the NTSB issued five new safety recommendations with two issued to the Pipeline and Hazardous Materials Safety Administration. Thirty-one states also received a safety recommendation to help prevent a similar event from occurring.
These recommendations address safety issues including adequacy of natural gas regulations, project documentation, project management, risk assessment, emergency response, and safety management systems.
"We have committed to our customers and our communities that we will continue to learn from what happened and implement changes to protect the public. We will continue to work with all stakeholders to help prevent something similar from happening again, in our system or anywhere," said NiSource in a statement.
You can read an abstract of the NTSB report by clicking here.