The Cost of Our Cities' Aging Gas Pipes

Households throughout America have long relied on natural gas to keep warm through the winters, but in many cities, the network of pipes they depend on are long overdue for a facelift. Researchers from Boston and Duke Universities set out earlier this year to track down and measure how much gas is slipping through the cracks in Boston.

After a 785-mile tour of the city in a gas-analyzer-equipped van, they found some 3,300 leaks throughout the city. "We know from just dozens of chamber measurements that some of the leaks can exceed daily U.S. household usage (200 cubic feet a day)," said lead researcher Nathan Phillips. "I think the distribution is skewed with a long tail — many small leaks, and a few really big ones."

Notes Revkin, "It takes money to fix such problems. Tokyo has become a global leader in stanching water leaks, for example. A core component of that fix has been costly stainless steel pipes. Updating invisible infrastructure also takes a culture shift."

Most often, the leaks occur not along pipes themselves, but at joints where the sealant has deteriorated. Cast iron pipes, while only accounting for 3 percent of infrastructure mileage, represent the largest source of fugitive emissions. "We should be replacing underground infrastructure when we are already repaving streets," wrote Phillips in an email, "rather than addressing one infrastructure in isolation of the others. It would save a lot of money."

Phillips hopes his team's research will shed light on the environmental magnitude of the problem: "Every molecule of natural gas that floats into the air has somewhere between 20 and 30 times the greenhouse gas potential of a CO₂ molecule that would have resulted if that same natural gas molecule was burned to heat someone's home."