A quiet, sunny afternoon in New England quickly turned to chaos and tragedy as a series of 80 fires and explosions erupted across three communities in the Merrimack Valley north of Boston on September 13. Extreme overpressure in a Columbia Gas distribution system caused uncontrollable natural gas venting over a wide area, and the resulting blasts killed one and injured more than two dozen.
In the wake of this disaster, scientists and environmentalists are raising questions about the safety and climate impacts of Massachusetts’ aging natural gas infrastructure and the wisdom of continuing to rely on this fossil fuel.
Margaret Cherne-Hendrick, lead author of a 2016 Boston University study of natural gas leaks, cautioned, “This is a very delicate system. It’s a system that is piping a combustible gas into everybody's homes and businesses.”
‘Ticking time bombs’
Experts have repeatedly warned about the dangers of Massachusetts’ pipelines. The Conservation Law Foundation (CLF) calls them “ticking time bombs.” According to the Pipeline and Hazardous Materials Safety Administration (PHMSA), 38 percent of the system distributing natural gas was installed prior to 1970. Massachusetts utilities still operate more than 8,300 miles of old, risky cast-iron and steel pipe, which includes those in the recent explosions.
But brand-new pipes don’t guarantee safety. Just a few days before the disaster in Massachusetts, a pipeline transporting natural gas from wells to a processing plant exploded in Pennsylvania. It had only been in service for seven days.
“Gas is climate damaging, has public health implications and concerns, and it very clearly has safety concerns as well,” said Greg Cunningham, director of the clean energy and climate change program at CLF. “Those may arise infrequently, but they're devastating when they do.”
Records kept by PHMSA show that most significant pipeline disasters result from human error. Not including this latest event, Columbia Gas has been linked to 11 pipeline incidents in Massachusetts since 2010, resulting in 19 injuries.
Missing Gas, Warming Climate
Natural gas leaks from distribution pipes and equipment are common, creating potential hazards and releasing the powerful greenhouse gas methane into the atmosphere.
Cherne-Hendrick designed custom devices to accurately measure 100 identified leaks from the natural gas distribution network in Boston during a several-month period in 2015. Her key finding: Just seven percent of leaks, dubbed super-emitters, were responsible for more than half of total emissions. Almost a sixth of the natural gas leaks she studied were deemed to be “potentially explosive.”
She explained that it’s easy for utility workers to miss small leaks in urban areas where vehicle traffic and micro-winds off tall buildings can quickly dissipate tiny pockets of gas arising from underground pipes.
Sources of methane emissions in the U.S. as of 2016. Short-lived methane is an approximately 84 times more powerful greenhouse gas than carbon dioxide over a 20 year period. Credit: EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2016
In 2013, Sen. Edward Markey commissioned a report showing that 99 billion cubic feet of natural gas was “lost and unaccounted for” in Massachusetts from 2000-2011, costing ratepayers up to $1.5 billion. But studies, such as this, that rely on utility-reported losses and U.S. Environmental Protection Agency (EPA) greenhouse gas inventories, use numbers that are “not based in very sound data,” according to Kathryn McCain, author of a separate 2016 Harvard University study.
“We found that the amount of methane emissions from natural gas in Boston was two to three times larger than were estimated from the inventory type method,” she said. McCain monitored atmospheric methane at two sites in Boston, as well as one on the coast of Massachusetts and one northwest of Worcester.
Natural gas accounts for 100 percent of methane in the air over Boston except during summer, when natural sources and landfills contribute up to 40 percent.
McCain’s data show that Boston is responsible for eight percent of natural gas emissions in the U.S., but the data is really telling another story.
“If the inventory for the entire U.S. were correct, that would imply that Boston is an outsized source. But there's no reason to think that the U.S. inventory is correct,” McCain explained.
It isn’t that Boston is recklessly shooting out natural gas, it’s that current estimates for methane emissions from natural gas distribution systems across the country are likely far too low. A study published this June in the peer-reviewed journal Science suggests EPA numbers underestimate methane leaks by roughly 60 percent.
That has impacts for current estimates of greenhouse gas emissions, and for Massachusetts, where, the CLF’s Cunningham said, “They are at risk of not achieving their 2020 climate goal.”
Adequate Industry Oversight?
Following the disaster, Columbia Gas committed to replacing 45 miles of cast iron pipeline and 6,100 service lines in the three Merrimack Valley communities by November 19. Utilities are largely responsible for inspecting their own work, but on September 26, the Massachusetts Department of Public Utilities (DPU) said it would appoint an independent investigator to examine the safety of the natural gas distribution network throughout the state.
In PHMSA’s most recent annual evaluation, conducted just two weeks before the tragedy north of Boston, the DPU itself was faulted for having only two available inspectors. The DPU said it is now staffing up, with plans to bring the total to 14 qualified inspectors. In the meantime, the department has borrowed five certified inspectors from New York state to help oversee work in the communities affected by the recent disaster.
The Future of Gas in Massachusetts
Residents of Merrimack Valley have been given hot plates to cook on and electric space heaters, but most remain without hot water for cooking and washing. And winter is approaching. “In light of what they've been through,” asked Cunningham, “is natural gas what they want to go back to?”
Natural gas supplies more than half the homes in Massachusetts and fuels more than two-thirds of the electricity generated in the state. The U.S. Energy Information Administration (EIA) says that “virtually all” the planned non-renewable electricity generation in Massachusetts will be fueled by natural gas. That means that even if residents switched to all-electric homes, they would still be largely relying on a fossil fuel.
Cherne-Hendrick also pointed out that there are economic barriers for homeowners to switch from natural gas, though Columbia Gas currently is offering to reimburse some of those costs for affected residents. Still, Cherne-Hendrick suggested that a broader transition could be regulated and incentivized properly, creating “an electrification strategy that makes sense for people and their wallets as well as the environment.”
Dan Zukowski is an environmental journalist and photographer whose work appears in Sierra magazine, Hakai magazine, CityLab, and elsewhere.
Main image: The damage done to a home in North Andover, Massachusetts due to a gas explosion on September 13, 2018. Credit: Original photo by Whoisjohngalt, CC BY-SA 4.0