The findings by Boston University researchers differ significantly from results gathered by gas companies and other monitoring groups, and highlight the risks that these “fugitive” gas emissions pose both for safety and the environment, says Margaret Hendrick, a PhD candidate in BU’s Earth & Environment department.
Hendrick is lead author on a paper published in Environmental Pollution, which emphasizes the need to develop standardized ways to detect leaks and prioritize their repair.
Natural gas is considered a relatively clean fossil fuel, but a substantial amount of the gas is lost in production and distribution. In addition to the safety risks, methane (the main component of natural gas) is a major contributor to atmospheric warming.
Gas pipelines may date back as early as the mid-nineteenth century in east coast cities such as Boston. About a third of the installed pipelines use leak-prone materials such as cast iron, wrought iron or unprotected steel. There are thousands of gas leaks in these cities, but how the sizes of these leaks vary in an urban area “was a big black box until this project,” Hendrick says.
She and her colleagues looked at emissions from cast iron pipelines at 100 sites in greater Boston where leaks had been detected in the air along roadways. The researchers painstakingly analyzed the release of methane inside custom-built chambers created with plastic buckets and the lids from child sandboxes. “To fully ascertain the safety hazards of leaks really does require us to get out on the ground with instrumentation,” Hendrick explains.