`U.S. Army Underground Storage Tank Corrosion Study`

25,000-tank study, 5–25 years to perforation depending on soil conditions. Used to quantify why the 1930s buried steel gas pipes leak.

It replaced black iron pipe. In the early eighties the American Gas Association or the Gas Research Institute — I can't remember which, they're both located in Ohio if I remember — decided they wanted to promote more use of gas. You can understand why. They were also concerned that most of the steel piping they'd been putting in in the twenties and thirties and forties and fifties was corroding. They buried the steel pipe in the ground, and particularly in New England — in Arizona it's not so bad because it doesn't rain that often, but in New England it rains a lot, the ground is wet, and this stuff corrodes. It's about an eighth of an inch thick in small diameters, but it takes a while to corrode. The U.S. Army did a study of 25,000 underground storage tanks, and they showed the typical corrosion rate: you'll perforate an eighth of an inch of steel in 5 to 25 years, depending on soil conditions, part of the country, amount of rainfall, pH of the soil, electrical resistivity of the soil because of the corrosion currents that can be carried through. Typical time to perforation of a pipe is 5 to 25 years.