By Ars Technica » Scientific Method on April 16, 2017
(credit: Steve Harwood)
Researchers from Colorado State University have been working with Google Street View to map pervasive natural-gas leaks. These leaks come from pipes that can be buried three-to-four feet below city streets. Many of the millions of miles of piping that deliver natural gas locally to urban and suburban homes are decades old—in some cases piping can be more than a century old. Older pipes can be made of cast-iron or bare steel, and they are often corroded or broken in places. But because they’re buried and because natural gas is invisible, it’s hard to tell when a pipe is leaking underneath a sidewalk. Sometimes, digging up and replacing a pipe isn’t worthwhile for the utility that owns it if the leaks isn’t an immediate risk to life and limb.
Besides the occasional explosion, there’s not much of a health risk associated with small natural-gas leaks. But natural gas is mostly comprised of methane (CH4), a greenhouse gas. Although carbon dioxide sticks around in the atmosphere longer than methane does, it’s much more potent at warming the Earth in the short term than carbon dioxide.
That should make fixing the aging, leaking pipes under our cities a municipal priority. Although utilities will sometimes send employees out to neighborhoods to measure gas leaks from their pipes, they’re not always keen to share that data with citizens or even researchers. Even if utility workers are willing to share, making a complete census of all the leaks can be challenging.