I thought this was an interesting find:
Although almost everyone in Toronto, Canada never knew it was there, hydrogeologists have discovered an ancient river dating from the ice age that flows beneath the city. It's a real river, too--wide, deep, and cold, reports Reuters.
It's been there for as long as 5 million years, but it wasn't until workers were trying to cap two artesian wells as part of a storm water runoff project in one of the city's largest parks near Lake Ontario that evidence for the long-rumored glacial river was finally discovered. This is what happened: The workers capped off one of the wells. As they were in the process of capping the second, the first well blew out, shooting water 15 feet in the air. So they repaired that cap. And then the second one blew off. It shot up water and gravel. The experts were called in. They soon realized the workers had tapped into the largely unknown Laurentian River system running underneath the city.
The existence of the bedrock was documented in the early 1900s, but no one could figure out the exact location. Now they've done just that--by accident. "We've discovered where it probably comes out into Lake Ontario," Bill Snodgrass, the senior engineer responsible for groundwater quality management for the city of Toronto, told Reuters. "What we never really knew before was where it connected to Lake Ontario." The ancient river is technically known as an artesian aquifer and flows exceedingly slowly--at the rate of just one centimeter a year--in sand and gravel. Reuters notes that the water is drinkable, although it has a distinct iron taste. There are no plans to use it as a source of drinking water.