Tuesday, April 21, 2009

Water in the backcountry

Going to be in the woods for a few days? Got that 6-pack of bottled water ready to go in your backpack? Ready to get dehydrated and cut your trip short?

A typical person needs to take in around 2.5 liters of liquid every day to replace fluids lost to sweat, breathing, and going to the bathroom. Around 20% of that comes from food. The remaining amount (~2 liters) comes from liquid intake. Assuming you've got 1-liter bottles in a 6-pack, you've got 3 days of water. If we're talking about being outdoors, where you'll have a lot of increased activity, and (in my case) at high altitudes, the needed amount of water will sky-rocket. Let's assume an hour of exercise per day (you are outdoors, right?), a reasonable weight of 150lb., and a warm environment. This handy dandy calculator says such a person would need ~3 liters every day. I'm at 170lbs, so I need about 3.2. I'm also at high altitudes, so let's factor in another half liter for 3.7. That's more than 3 bottles of water / day.

For an extended stay in the backcountry, you probably won't want to carry all of that water with you. You do, after all, need space and strength for food, camping supplies, clothes, etc. The only option you really have is to learn how to purify water. Why purification? How about a nice helping of giardia-infested water that gives you really messy digestion problems? Giardia is increasingly common in many parts of the world, and unless you've got a nice microscope with you, you can't tell if the water you found in a pond or river carries it. And, yes, it does live in flowing water, too.

So, what to do? Fear not, there are several companies out there that make water purification chemicals. There are also ways of using heat to kill the organisms living in your water. We'll talk about iodine first.

IMPORTANT NOTE: Have thyroid problems? Alergic to seafood? Iodine may not be your prefered solution. Consult your doctor before trying it.

For purification via iodine, carry a 2% iodine tincture with you. You can find this in some first aid kits and drug stores. Make sure you're carrying it in a dark bottle, as exposure to light will lessen its effectiveness. To kill most organisms in 20-degree Celsius (~68 Farenheit) water, add 5 drops of your iodine solution to every quart (.95 liters) of water, if the water is clear. If the water is murky, use 10 drops. Once added and thoroughly mixed, let it sit for 30 minutes. If the water is colder than 40 Farenheit (10 Celsius), make it an hour, as a lack of heat inhibits all chemical reactions.

Sounds easy, huh? It is! Of course, it's not as thorough as boiling the water for a minute. Boiling can be inconvenient, requiring fuel for heat, a suitable container (you should have a pot, though), and the time to put it all together and start a fire. Boiling will kill everything living in that water, though, unless you somehow got your water from one of those crazy undersea volcanic ecosystems. Then, maybe you're screwed, but under most circumstances you'll be fine.

I'll be giving other purification methods a go when I take a long-ish hike. I'm really interested in solar stills and other more DIY distillery methods. Not sure when that will be, though. That rabies case I posted about a while back? There have been a few more. Most recently some kid wandered out of the woods in Lyons (kind of close to where that first case was reported), and walked right out into the busy traffic of a highway. Luckily he was moving slowly and the drivers there were able to avoid him, but I heard there were a a couple of fender benders. Someone was nearby on foot and ran out into the road to collect him once it was safe to do so. She reported that he was incoherent and sickly looking, and was bleeding from his leg. Ambulances showed up soon and whisked him off to a local hospital, and the rumors are flying that there's rampant infestation of rabid animals in the area.

I hope the kid's ok. I think I'll be looking into that conceal/carry permit soon.

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