New York City Water Nightmare is an Underwater Gadget Lover's Dream

The tech we see above ground in New York City is undeniably cool, but underground, where the wild things are, things are not going so smoothly. A giant aquifer, completed in 1944, is leaking up to 36 million gallons of water a day. For New Yorkers, who on average use 150 gallons per day, that's unacceptable. Trouble is, fixing the leak involves some extreme diving, 14 tractor trailer trucks worth of gear, and a 24-foot room that divers will live in for a month, breathing helium.

The five-year, $US22 million diving project is underway today, and that means six lucky divers are presently 200 metres beneath the NYC surface, trying to find where one of the bigger leaks is hiding. They're living in a 7.3 metre pressurised tube that includes "showers, a television and a Nerf basketball hoop," and they're breathing air that is 97.5% helium and 2.5% oxygen.

Why helium? Well, since these lucky ducks will be in a pressurised environment for an extended period of time, they need to employ what's known as "saturation diving." Long story short, this technique allows the divers to go 200 metres down, and return to their living quarters without having to worry about repeated decompression sessions. In fact, the only times they have to worry about pressure is when they first step into the tube, and when they exit it a month later.

When the divers aren't squeaking at one another in helium-speak, three of them use a diving bell to go 70 stories down, where they do things like strip out 1800kg bronze pipe fittings. Their twelve hour shifts are divided up into four-hour demolition sessions, one per diver, where they each take a turn breaking concrete to get at a malfunctioning valve array. After four hours, the divers "rest" for eight hours in the murky water, before returning the the cylinder.

When they're on break, the divers can have whatever meals they like, although helium tends to dull human taste buds. Tabasco sauce is their best friend, apparently, along with jalapenos and salsa.

"They lose a lot of weight because they're burning so many calories," said Robert Onesti, who is running the water rescue project via Global Diving. "It's not for everybody. It's heavy construction work, and it's deep."

And when the month is up, the divers will have another week in the tube to adjust to life without helium in their lungs. [New York Times, thanks Andy!]