The corporate parent of the Massachusetts natural gas utility that’s the focus of an investigation into explosions and fires that killed one person and injured about 25 others had links to three previous gas line blasts, a review of federal and state records and court filings shows.
Columbia Gas of Massachusetts is still providing assistance and information to residents of Lawrence, North Andover and other Merrimack Valley communities after the Thursday incidents.
The history of other accidents came to light as the National Transportation Safety Board (NTSB) launched an investigation that showed Columbia Gas pipes in the area of the explosions had been over-pressurized.
Normally, gas would flow into residences at a rate of a ½-pound per square inch, said NTSB Chairman Robert Sumwalt.
“We believe the gas did indeed flow into homes at significantly greater flow rates and pressure. The real question for this investigation is to answer why this occurred,” Sumwalt said.
A pressure increase in the disaster area also had been indicated on the pipeline controller’s console in Columbus, Ohio, around the time of the disaster, Sumwalt said.
Columbia Gas of Massachusetts is the business name of Bay State Gas Company, according to a written summary of testimony Stephen Bryant, the utility’s president and chief operating officer, provided in April for a rate hike request submitted to the Massachusetts Department of Public Utilities.
Incorporated in 1974, the company is one of seven natural gas distribution companies that are subsidiaries of NiSource, a publicly traded holding company based in Merrillville, Indiana.
Columbia Gas distributes natural gas to 321,000 residential, commercial and industrial customers in three Massachusetts areas centered in Lawrence, Springfield and Brockton, Bryant said.
NiSource’s combined utility operations serve 3.9 million customers in seven states and operate 60,000 miles of distribution pipelines.
This latest incident renewed focus on the safety of natural gas pipelines and the companies that own and maintain them. Through its subsidiaries, NiSource had links to at least three gas line explosions in three states during the last six years, including another blast in Massachusetts.
In November 2012, a Columbia Gas of Massachusetts service line explosion injured 21 and destroyed a building that housed the Scores strip club in Springfield, MA. The blast heavily damaged a dozen nearby buildings and blew out windows in others.
NiSource said in a Securities and Exchange Commission filing that the gas service line was pierced, and an explosion occurred.
In December 2012, an interstate natural gas pipeline operated by Columbia Gas Transmission, another NiSource subsidiary at that time, exploded in Sissonville, West Virginia.
Escaping high-pressure gas from the 20-inch pipeline sparked a fire that destroyed three homes in the sparsely populated area, according to a NTSB report. The explosion also propelled a 20-foot section of the pipe more than 40 feet from its original location, the report said.
In another incident, a natural gas release from an “improperly abandoned” service line was responsible for a March 2015 explosion and fire, the Public Utilities Commission of Ohio concluded in a report on the Upper Arlington disaster that caused $9 million in structural damage.
The report focused on the actions of Columbia Gas of Ohio, a NiSource subsidiary.
The state regulator’s staff concluded that the gas line was installed at a home on Sunningdale Way in 1960 and was taken out of service between 1985 and 1997. However, the line was never disconnected from the gas main and was not plugged or sealed, the report said.