Massachusetts gas regulator opens Merrimack Valley investigations

Following a 2018 Massachusetts natural gas incident resulting from the overpressurization of gas distribution lines owned by utility Bay State Gas Company d/b/a Columbia Gas of Massachusetts, state utility regulators have opened a pair of investigations into the utility's responsibility for and response to the incident, as well as into its efforts to prepare for and restore service following the event.

As summarized by the Massachusetts Department of Public Utilities, on September 13, 2018, Bay State’s low-pressure natural gas distribution system serving the city of Lawrence and the towns of Andover and North Andover in the Merrimack Valley became overpressurized, allowing high-pressure gas to enter the low-pressure distribution system, which "resulted in the damage or destruction of 131 homes and businesses, the hospitalization of 22 individuals, and the death of one person".

The incident prompted a variety of investigations, including a federal probe by the National Transportation Safety Board which determined "that the probable cause of the overpressurization of the natural gas distribution system and the resulting fires and explosions was 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 regulator sensing lines to the new polyethylene main. Contributing to the accident was a low-pressure natural gas distribution system designed and operated without adequate overpressure protection." NTSB adopted its Pipeline Accident Report on the incident on September 24, 2019, and the report became final therafter.

Acting one day after NTSB's report became final, Massachusetts utility regulators have now initiated a pair of further investigations. In one docket, D.P.U. 19-140, the Department opened a "public investigation into Bay State’s responsibility for and response to the September 13, 2018 overpressurization incident, as well as its restoration efforts following the incident." The Department said this investigation will focus on Bay State’s compliance with federal minimum safety regulations and with the Department’s own state-level pipeline safety regulations.

In a separate docket, D.P.U. 19-141, the Department opened an "investigation into efforts by Bay Stateto prepare for and restore service following the September 13 Event", including its preparation for the incident and the utility's implementation of its emergency response plan (“ERP”). The Department said its inquiry will focus on Bay State’s compliance with the Department’s performance standards for emergency preparedness and restoration of service, including "(1) preparation for and management of the restoration efforts, including safe and reasonably prompt restoration; (2) public safety; (3) allocation of resources to affected municipalities; (4) timely and accurate communication with state, municipal, and public safety officials and with the Department; (5) dissemination of timely information to the public; and (6) identification of restoration practices that require improvement, if any."

In each docket, the Department said it would separately issue an order defining the procedures and opportunities for public participation in the investigation. According to a Department press release accompanying the orders, based on its findings, "DPU could impose multimillion-dollar financial penalties and take additional steps to improve the overall safety and reliability of the gas pipeline system."