Boston and New York cast-iron water main failures

Aging-infrastructure case. Tom's forensic heuristic: when consulting on a NYC water-pipe break, ask when the previous nearby break occurred — usually three to five years prior, because disturbing adjacent brittle pipe during repair seeds the next failure.

Then people realized wood didn't have a very long lifespan — maybe twenty or thirty years before it rots. So people started using cast iron. We use cast iron for water mains. One of the biggest problems in cities like Boston and New York is we've got hundred-year-old cast iron water mains, and every now and then one breaks. They're so brittle that when you work on it in this block, you know about five or ten years down the road the next block is going to have a leak. Because in New York City, when you go and dig up the road to replace the pipe that broke, you're going to disturb the pipe on either side. You don't want to dig up a long section of road in New York City — it tends to disturb traffic. And it helps me a lot — now you know, when I get a job in New York City and they say we had a water pipe burst, I say, when was the last one in that area? Usually there was one about three to five years earlier.