Water purification

I

ivan_yulaev

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Oct 20, 2003
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Suppose you are stuck in the woods for several days or more. In my BOB, I only have 2-3 liters of water, which is only enough to last a day or two. Therefore, instead of carrying more water, I think that purifying water becomes imperative. What are acceptable ways of doing this?

I have heard of putting 5 drops per liter of water from streams to clean it up. Is this effective? What other methods are there out there?
 
5 drops of unscented chlorine bleach and then allowing the solution to work for half an hour. I prefer iodine tablets.
 
I like my water on a daily basis, so I carry some gear for collecting water like 2 one gal. zip locked freezer bags for storage, surgical tubing, tarp or poncho for collecting dew and rain. I carry potable aqua tabs and a Pur Hiker water filter. We all pretty much carry fire with us and scrounging a pot or carrying a small pot for boiling is a great method.

The problem with just carrying bleach or iodine to purify drinking water is that it doesn't guarantee that your water is disease free. Cryptosportium (sp) has a fairly tough shell and sometimes aren't killed by the poisoning method. Boiling or filtration is sometimes necessary in addition to bleach or iodine.

This is what Chlorox has to say about their product and water purification.
 
Seems bleach has a limited shelf life too. I've heard as short as 6 months though that seems unrealistically short. Probably the salesmen and lawyers talking. Maximum product turnover and least liability.

Phil
 
I just got one of the new MIOX purifiers from MSR. I'm going to stock them, after using one for myself from a local lake. it claims to kill everything, so I'll try it out on my own stomach first. Pretty neat concept behind it as well.
 
See the fairly recent thread on iodine granules for the discussion we had on water purification.

longbow50 said:
Cryptosportium (sp) has a fairly tough shell and sometimes aren't killed by the poisoning method.
Click to expand...

Cryptosporidium species.
 
Ivan,

For the past several years in Brazil I have used a home-made water filter (Charcoal & fiber) and iodine. Normally I use Potable Aqua but I have also used 2% tincture of Iodine drops. To neutralize the iodine taste you can add a little vitamin C. I had a pharmacy make up 100 50 mg capsules for me for a few dollars.

You can use bleach but I have found that I tend to get spots on my clothes and gear. The iodine works well for most situations. Mac
 
depending on the length of time that i plan to be out in the wilds i carry filters, iodine tablets, polar pure or betadyne for this use. right now i seem to like the polar pure as it will do a lot of water for you, and is pretty compact to carry.
check out this site for a whole bunch of information about water purification.

http://www.high-altitude-medicine.com/water.html

alex
 
A couple of condoms and the Katadyn Micorpur tablets is all I carry for the woods.

http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?memberId=12500226&productId=30622149

I figure I know enough ways to get potable water that the tablets can get me through 2 days until I can make a container to boil water. Plus there is always dew, grapevines (Vitis spp.) are plentiful here, and I have been wanting to try collecting steam.

Read somewhere about digging a hole near a water source, could even be salt water, letting it fill, then boil the water with heated rocks. The steam that rises can be collected as condensed purified water with a cloth.

Has anyone tried that method? Anyone carry a sponge to collect dew? I believe a sponge comes in some military survival kits.
 
Quiet Bear,

In Brazil I carry a soft cloth for dew collection and I have used it several times. This method works great if you have moderate to heavy dew. You have to start early, just before dawn when the dew is the heaviest. I was able to collect about a liter and half once using this method.

I have found that the water collected is often muddy depending on the amount of dust that settles on leaves and grass. I had to filter the water and treat it with iodine and even then it was pretty nasty looking water. You can live on it. In my estimation dew is a viable water source from which to collect water in amounts that could actually hydrate a person. Since you collect it in the cool early morning the physical activity involved does not produce sweat.

I have found also that heavy dew forms in areas that are normally devoid of running water or springs like mountain tops. Dew that forms in high, rocky, cloud-covered elevations often collects on the surface of large rocks and even forms small puddles.
This water tends to be pretty clean if you don't disturb it too much.

One device I find indispensible is a 60 ml syringe and a length of plastic tube. This will enable you to suck up water out of any plant or crack in the rocks. Attach the tube to a walking stick and you can really get down to some places that are hard to reach. Mac
 
I have several filters...some at work...some at home.....pills....liquids....but I always have a US gov't issue canteen cup. Everything wears out. Given a long or short term situation..I'm gonna boil mostly because my good stuff is going to be home when I need it and I won't.....and no security types will question me having a canteen cup at my desk.... I watched the twin towers fall from right across the river......I travel by train and got lucky when my boss gave me a lift home when the blackout hit the east coast.....it was dark from Manhattan to Giant's stadium for those of you who know the area....that's 10 miles more or less.....an entire day's walk.....if you have a cup, you can have water, stew, etc.......and as an aside, anytime anyone tells you to evecuate or if you're at a desk all day.....take some toilet paper with you (put a roll in the bottom drawer)...you may have to walk for awhile....
Thanks,
Steve
 
On the iodine...try it at home before you need it. Some people have a bad reacton to it. Better to have it at home than in the field. Then you may be forced to use the chlorine.
 
I like your idea of the canteen cup Gryghon46. I carry a Olicamp space saving cup that is stainless steel and fits on the bottom of a Nalgene jar. It is available from Camphor. It serves the same function as the military canteen cup and can be used to heat up food and purify water. :p
 
If you want to clear up cloudy water that just won't clear up, put some alum in it. A pinch in a quart or so, shake, and let stand. In an hour or so (depending on dose and contaminants), pour off the clear water and disinfect it with a couple of drops of bleach, etc. You can also make a saturated alum solution for easier dispensing. You can make pretty good water this way.

The main reason for using the alum to settle out the cloudiness is safety. Germs and viruses can hide in the tiny particles and defy disinfection. You can actually remove a good fraction of pathogens just by using alum (though it is no substitute for disinfection).

Alum solution has a good shelf life, but chlorine (bleach) solution loses half its strength every few weeks. 5-6% bleach lasts longer than 12%.

Scott
 
I now carry a bottle of 2% tincture of iodine with me in my 'survival kit'. It's convenient because it's small, useful, and can even double as a disinfectant for cuts.

Another question...is it safe to drink water from a swimming pool? In our backyard, we have a small swimming pool. It is chlorinated, although, since it is not a public pool, there isn't nearly as much chlorine in it as most public and community pools.
 
Swimming pool water is probably (in general) less reliably chlorinated than municipal drinking water. When you put a little chlorine in, you can smell it, but the things that are formed in the water involving chlorine are not terribly efficient disinfectants. Sometimes these "chloramines" take a couple of hours to deactivate certain pathogens. Add more chlorine, and the chloramines go away to be replaced by "free chlorine" which is a very effective disinfectant. This works within minutes.

I guess a good rule of thumb would be, wait 3 hours after the last person got out who you would not be willing to lick ;)

Scott
 
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