|Mark McDonald used a device to check for gas leaks in Dorchester. (John Tlumacki/Globe Staff)|
Thousands of gas leaks in Boston area
As use of methane increases, old pipes pose risks, group says; utility companies see no danger
When Nathan Phillips started driving the streets of Boston looking for natural gas leaks, he was stunned to find they numbered in the thousands.
The Boston University associate professor of geography and the environment wanted to document the extent of leaks because of concerns that the gas could harm trees and add to greenhouse gases that cause global warming. Then he found a leak that posed a more immediate danger, and it was near his home.
Phillips found the leak at a manhole in front of the West Newton Cinema. Twice in the past month, he detected the levels of methane in the atmosphere there to be about 6 percent, which regulators and gas companies consider a potential explosion hazard.
“I tended to downplay’’ the explosion risk of gas leaks at first, said Phillips. “But now that I have seen with my own eyes at least one case . . . I do think that is actually part of the overall problem now.’’
Natural gas is one of the fastest growing forms of energy in the United States, embraced as an abundant resource and a better alternative to coal-fired power plants, which emit far more greenhouse gases. But aging pipelines in Massachusetts that deliver natural gas to more than 1.2 million homes have more than 21,000 leaks, according to gas company records.
While gas companies and regulators say most leaks pose no immediate danger and do not need to be repaired, some legislators and former gas company workers disagree. Minor, Grade 3 leaks not only harm the environment, they say, but if not properly monitored, they can become Grade 1 leaks that are an immediate hazard. The West Newton leak is one example.
Representative Lori Ehrlich, a Democrat from Marblehead, has proposed legislation calling for all the leaks to be repaired within three years, regardless of how they are labeled.
“It’s a waste of money, a waste of a natural resource, and there’s public safety hazards as well,’’ said Ehrlich, who started looking into the issue after former gas workers and environmental activists contacted her two years ago with their concerns.
The legislation, which has nearly 40 cosponsors, was heard by the Joint Committee on Telecommunications and Energy in June, but has not received a vote.
Phillips detects gas leaks using a new device called a cavity ring-down spectrometer, which he puts in the trunk of his car so he can take measurements as he drives.
He has been surprised at how leaky the Boston area is, and he estimates that he has only explored about 1 percent of its streets.
“Cambridge Street between Storrow Drive and Government Center: very leaky,’’ he said. “Harvard Street in Brookline between Commonwealth Avenue and Coolidge Corner is also very leaky. . . . Beacon Street from Coolidge Corner out through Newton to Newton Center, that’s very leaky.’’
Massachusetts gas companies reported that 8.2 billon cubic feet of natural gas was unaccounted for in 2007. Phillips calculates that is the equivalent of about 4 to 5 percent of the greenhouse gas emissions in Massachusetts that year, since methane’s contribution to global warming is 25 times greater than the same amount of carbon dioxide.
Gas companies and the state Department of Public Utilities acknowledge that there is a problem with the state’s aging gas infrastructure that poses environmental concerns, but say there is no safety hazard.
“We feel that we operate a very safe system,’’ said David Graves, spokesman for National Grid, the largest gas company in Massachusetts. “We are very cognizant of the need to maintain public safety, and we feel that we do that on a regular basis.’’
But Mark McDonald, a former gas leak investigator for the company who worked with Ehrlich on the proposed legislation, contends that most companies do not regularly monitor gas leaks.
While he was out with a Globe reporter last month, McDonald’s combustible gas indicator, the same equipment that gas companies use, beeped above a manhole beside Las Americas Market on Blue Hill Avenue in Dorchester. The level of gas in the air was 8 percent; between 4 and 14 percent is considered an explosion hazard.
As McDonald double-checked the reading, a young man in a red T-shirt lit a cigarette nearby. If he had done so about 10 feet to his left, where the methane levels were higher, the ignition could have caused a blast.
The leak had been initially reported in December 2009 and was classified as Grade 3. Another Grade 3 leak across the street was first reported in 1995.
“It’s just ridiculous that these leaks have been leaking that long,’’ said McDonald, president of the New England Gas Workers’ Association, a group of gas workers and industry-related partners across the region that advocates for tougher utility regulations.
Asked about minor leaks that become more dangerous, Graves said Grade 1 leaks are fixed immediately. A National Grid van arrived 15 minutes after the leak on Blue Hill Avenue was called in and confirmed McDonald’s finding.
“The last time we checked it may well have been a Grade 3, and it may have accelerated to a Grade 1,’’ Graves said. “It could have been a Grade 3 yesterday and gone to a Grade 1 today.’’
National Grid said it checks Grade 3 leaks once a year.
Ehrlich and McDonald’s push for gas companies to fix all leaks within three years has met resistance from gas companies, which say such a requirement would create an unnecessary burden on their employees and raise rates for customers.
Instead, they are replacing cast-iron pipelines, particularly susceptible to corrosion and cracking in cold weather, with the help of money from the Department of Public Utilities.
“I believe it would be quite expensive’’ to replace all the Grade 3 leaks, said Ann G. Berwick, chairwoman of the DPU. “We’re inevitably balancing cost to rate-payers and wanting to keep utility rates down.’’
National Grid is on track to replace 140 miles of cast iron gas mains this year, said Graves. At that rate, it would take more than 30 years for all the aging pipeline to be replaced.
Ehrlich said laws she has proposed do not interfere with replacement programs like National Grid’s.
“When they go in and replace the oldest pipes, they’re going to get a lot of the leaks anyhow,’’ she said. “But there’s plenty more throughout the system.’’
Neena Satija can be reached at firstname.lastname@example.org.