A series of fires and explosions caused by a natural gas system overpressurization near Boston has pushed regulators, consumer advocates and lawmakers to take a closer look at the safety and operations of gas distribution systems, even as more pipeline-related accidents occurred in the same month.
After the disastrous Sept. 13 overpressurization of Columbia Gas of Massachusetts' distribution system, stakeholders in states where other NiSource Inc. subsidiaries operate are asking whether something similar could happen elsewhere.
The Maryland Public Service Commission's engineering division prepared an information request in light of the explosions for all Maryland gas distribution companies, including NiSource subsidiary Columbia Gas of Maryland Inc. The letter asked for additional information about whether and how the companies' pipeline risk ranking systems, integrity management programs and pipeline replacement plans take into account overpressurization.
The Indiana Utility Regulatory Commission also asked for more information from operators in its state, including NiSource subsidiary Northern Indiana Public Service Co. because of the Massachusetts explosions, commission spokeswoman Stephanie Hodgin said Oct. 3. In Virginia, the State Corporation Commission has not requested additional information from the companies it regulates, but NiSource subsidiary Columbia Gas of Virginia Inc. "has proactively kept SCC staff apprised of the Massachusetts event," SCC spokesman Ken Schrad said. An Ohio consumer watchdog has reached out to the state's utility regulator asking for more information on local NiSource subsidiary Columbia Gas of Ohio Inc.'s pipeline safety record.
Massachusetts' U.S. senators have chastised Columbia Gas of Massachusetts, saying the utility was not prepared for a disaster on the scale of the Sept. 13 explosions and fires. "[T]he company underestimated the possibility of an extremely serious incident, did not adequately build redundancies into its operations or put in place key safety measures to prevent it, and was utterly unprepared to respond to it," Democratic Sens. Edward Markey and Elizabeth Warren wrote in an Oct. 4 letter.
The lawmakers also questioned whether Columbia Gas of Massachusetts' emergency preparedness and incident prevention plans were detailed enough in addressing human error and whether the emergency shutdown protocols adequately accounted for how to handle a significant system overpressurization. "It raises serious questions as to why these policies were not previously in place for Columbia Gas' systems and whether that failure was the result of negligence, cost considerations or incompetence," the letter said.
Nearly a month after the explosions and fires, a preliminary report from the National Transportation Safety Board found that human error likely played a critical role in the overpressurization on Columbia Gas of Massachusetts' system. Prior to the fires, a utility-contracted work crew took an old pipe out of service and installed a new one but left key pressure-sensing equipment active on the old line. The sensors were in communication with nearby regulator equipment that determines how much gas should flow through the system. Because the sensors — which were monitoring the now-abandoned pipeline — detected abnormally low pressure, they prompted the regulator to send increasing amounts of gas through the active system.
In the same state where the fatal explosions occurred, a National Grid USA technician accidentally released "excess gas" into part of its gas system during routine maintenance in a city north of Boston, the gas and electric utility disclosed Oct. 8. Following the incident, the Massachusetts Department of Public Utilities ordered National Grid to stop all system work that is not emergency- or compliance-related until the department reviews the company's safety practices.
Across the continent, an Enbridge Inc. gas transmission pipeline ruptured Oct. 9 near Prince George, British Columbia, requiring the evacuation of a First Nation community. Multiple natural gas utilities in the northwestern U.S. asked customers to limit their energy use after the pipeline rupture as it cut into gas access in the region. Enbridge on Oct. 9 shut down its ruptured 36-inch pipeline, as well as a 30-inch pipeline that runs parallel to it. Both pipelines, located near Prince George in British Columbia, deliver gas to the U.S. Pacific Northwest region.