National Geographic News

Published March 14, 2014

The deaths of at least eight people in a natural gas explosion in New York's East Harlem on March 12 has put a spotlight on the nationwide problem of aging infrastructure. (See related, "East Harlem Explosion Highlights Risk of Natural Gas Leaks.")

A few older U.S. metropolitan areas still rely heavily on old cast iron pipes, which are more prone to leaks than plastic or protected steel are. For example, half of Philadelphia's pipes are cast iron.

Most systems that rely on cast iron pipes report higher amounts of fuel lost—what governments and the gas industry calls "unaccounted for" gas—than the national average of 1.3 percent for large natural gas systems.

On average, cast iron pipes make up just 3.5 percent of large distribution systems in U.S. cities. Here's a look at the systems with the highest risk of leaks due to cast iron pipes:

Julie C. Beer; Lauren E. James, Xaquín G.V., Marianne Lavelle, Kelsey Nowakowski and Alex Stegmaier, NG Staff. Sources: U.S. Pipeline and Hazardous Materials Safety Administration; Platts GIS
Roiikka-Ta P Globetrotter
Roiikka-Ta P Globetrotter

i could be wrong, but, the first thing that came to mind when i saw this was all that fracking going on .. it might be upsetting the earth a bit .. i heard they dig pretty deep, i mean, any miner does, dont they .. ?

David Allen
David Allen

"A chicken in every pot and a flatulent cow in every backyard!"  JUST KIDDING!!!

David Campbell
David Campbell

Ah, and the Republicans in congress insist we can't spend money even on our deadly and failing infrastructure.  How is that for the party of "Life"'

Patrick Anderson
Patrick Anderson

@David Campbell  Everything has to be about politics doesn't it with some of you people? Also all these cities are run by Democrats, and most states are run by Democrats. Illinois is solid Blue, Massachusetts is solid blue, etc. So think next time before you spout worthless nonsense.

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