Since gas utilities began operating in the early 1800s, pipelines were originally built with cast iron, and later wrought iron. In the early 1930s, bare steel pipes began to replace outdated cast iron pipelines. Legacy cast iron and bare steel pipes make up 3% of the nearly 2 million miles of utility pipes in use, but account for most of the leaks and failures. As you know, every time a pipeline needs to be replaced, it needs to be dug up. Which is often not convenient for those whose property the pipeline crosses. Trucks, trenches, digging, noise. Not a fun thing. And increasingly every pipeline project, including critical replacements, are opposed by crackpot “environmentalists.” So the U.S. government had a brainstorm (no really, this is not a joke setup). What if someone could figure out a way to “replace” old pipelines in the ground, without digging them up?