Harvard researchers say millions of dollars' worth of natural gas escapes from the Boston area's aging pipes and tanks each year.
The study by atmospheric scientists at Harvard's School of Engineering and Applied Sciences was published Thursday in the Proceedings of the National Academy of Sciences.
The scientists estimate about 15 billion cubic feet of natural gas, worth some $90 million, escapes the regional delivery system annually. That represents about 2.7 percent of the gas that is brought to the Boston region, or more than twice the loss rate that government regulators and utilities estimate, according to the study.
The team conducted their study by placing air monitoring equipment in four locations -- two atop buildings in Boston and two at upwind locations outside the city.
Leaking natural gas from aging pipes and tanks accounts for 60 percent to 100 percent of the region's methane emissions, the researchers said.
The scientists said the steady release of natural gas negatively impacts the region's economy, health and environment. They said the findings could have implications for regions like New England that are older and rely on natural gas for a significant portion of their energy needs.