Supplemental oxygen is sometimes used above 26,000' for climbing and sleeping.

For climbing, oxygen is consumed at 2 liters per minute with most bottles lasting about 6½ hours (filled to 260 Barr for 20°C).

Each bottle weighs almost 6lbs, is 19" long, and 4¼" in diameter.

New oxygen systems, purchased mostly in Russia, weigh half as much as those even 5 years ago.

4 bottles fit inside a medium sized pack.

An expedition can expect to pay around $360 per bottle.

If all goes well, 3 bottles are used on a summit bid and two for sleeping at the South Col.

Expeditions usually stock about 10 bottles per person to account for emergencies or waiting out bad weather up high.

A large deposit must be placed on the number of bottles brought onto the mountain. It is returned only if the same number is taken off.

The part of the South Col littered with climbing debris is actually a small fraction of the total area.

Burleson

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Hi, this is Todd from Everest Base Camp. Thought I'd talk for just a minute about the clean-up. I've had a few questions concerning the oxygen bottles. What's happened is over the last 10 to 15, 20 years, I guess, or more, oxygen bottles have been left in high-camp [the South Col at 26,300'], and some trash but mostly oxygen bottles. Actually, over the years, we've accumulated probably a couple thousand of them.

The South Col at 26,300' on Everest

In 1994, Scott Fischer and Brent Bishop kind of joined together as a team and started making efforts to clean up the mountain. They picked up a lot of trash in base, quite a bit in Camp II, and started moving bottles off the South Col.

What they did is set up a program where instead of doing it all themselves, because all these expeditions are here and everybody can help, what they do is they pay the Sherpa when they bring down bottles. [Sherpas get 700 rupees or about $13 dollars per oxygen bottle.] So, the Sherpa literally sell bottles that they pick up from the South Col. So, they're picking up trash on the South Col and selling it in Base Camp to us. And we buy it, and we ship it back to Kathmandu and dispose of it there.

I believe since 1994, our expedition itself has taken down over 500, but I think in total there's about 1,000 bottles that have been brought off the Col. A lot of effort has been put into it. It's worked well. It's never seemed to propose a real safety issue.

What happens is before we summit, the Sherpa carry full to the Col — full loads — and so they come down empty. So, when they're coming down, they grab a couple of bottles and bring them down. Then after we summit, we all bring down our own bottles. So, it works out well, and it's been a really good way of cleaning the mountain, and it's pushed everyone to be a lot more environmentally conscious.

Destroyed old tents and empty oxygen bottles left behind on the South Col by climbers descending under sometimes desperate conditions.

Brent Bishop was really the guy behind the scenes on this. He's raised the money, and what he does is he gives us the money every year, and we come over here and clean it. But basically all I do is facilitate the transfer of the money to the Sherpas and make sure it's all taken back to Kathmandu and disposed of.

So, it's worked out really well, and we owe a lot of thanks to Barrel Mountaineering in Montana, and to Brent, and Scott Fischer's memory for putting this thing all together. We hope the fund continues in the future too, and it'd be great if it continued in other places in Nepal besides Everest.

— Todd Burleson, Expedition Leader