While out mountain walking recently, I ran out of water, so refilled my bottle from a clean looking mountain stream, which had emerged from a spring about 100 yards away, and was devoid of dead sheep, dodgy looking scum etc.
While contemplating the possible effects of this, My wife and I came to wonder:
In a survival situation (just a large bottle, no steri-tabs or similar) would we be better off:
a) Obtaining all my water from one source, on the assumption that this will limit possible sources of contamination - presumably a smaller variety of contaminants and pathogens.
b) Obtaining water from a number of sources in order to limit my intake from any one stream (the one with a dead sheep in, or the one full of lead would then only constitute a tenth of my intake rather than potentially all of it.)
A bit hypothetical, but it may be useful to know one day.
If you find water actually bubbling out of the ground (such as a spring) my guess that’s a fairly safe supply and I would use it exclusively if I could.
Since that’s pretty rare and you are normally faced with streams and rivers away from their sources I would take water wherever you can and not rely on a single source since whatever pathogens might be in a single contaminated stream would be diluted by water from uncontaminated sources your ran into… assuming some were uncontaminated of course.
Clear, clean and cold mountain streams can be contaminated with a number of micro-organisms which will cause serious illness. Conversely, water that is foul smelling and dirty can be bacteriologically safe to drink. Potable water, then, may be unpalatable, and palatable water may be unpotable. Make sense?
Of course it’s best to obtain the cleanest water available but appearences can be deceiving. I suspect part of the paranoia about drinking water is fed by the makers of water filters and purifiers, but I personally never drink raw water without disinfection or filtration, or boiling.
I recall being on a search and evasion course in the mountains of south korea, where it was extremely hot and I had long ago drank my ‘safe’ water from canteens. I was totally parched. I came along a 1 1/2 inch pipe spouting cold, clear water from the side of a mountain. Uh-oh. Yep, it proved too much to resist. I drank deep, and it was the best tasting water I’d had in a long time. I broke my rule about never drinking untreated water, but hey.
Seems to me one wouldn’t want to drink from several different sources- In a survival situation without any means of treatment I would try to stick with one source.
Put a tablespoon in a gallon of questionable water, stir, and let stand uncovered (but sheltered) for 24 hours.
you now have drinking water.
Boiling is a good idea as well.
Finally I’d have to say that if you found a spot and got water and didn’t give diarhea or cramps within 24-48 hours, I wouldn’t roll the dice and try another spot. I’d stick with that.
Shibb’s right, you can get some intestinal nasties from clean-looking water. IIRC, in alpine environments it’s rodent feces rather than big rotting carcasses that cause the most problems.
These days, you can get filters pretty cheaply that will take out these relatively big bugs. There are several good filters built into sports bottles so you just fill them from the suspect source and the water is filtered as you squeeze it out to drink. If you’re packing water anyway, it doesn’t hurt to pack it in one of these so you have the filter available when the bottle is empty.
As I understand it, dilution will only really help against poisons, not microorganisms: A handful of bacteria can quickly reproduce to any amount you might care to name, if the environment is right for them. Since poisons aren’t usually a concern in natural water (in fact, to the extent that they do matter, a little poison is usually good), I’d say just use one source.
I’ll double check (it’s on the label of Clorox bottles themselves.) That way forgetful idiots like myself don’t go “Well, I want this water to be really safe. Let’s just put a whole cup in.”
Clorox is recommended for emergency use in that it is a typical household product. Use Unscented Bleach for this purpose, however.
For water disinfection, however, Bleach has some shortcomings- it is ph dependent and loses effectiveness in water that has a large amounts of organic matter. Iodine is much superior for chemical disinfection of raw water. Potable Aqua is one brand name for tetraglycine hydroperiodide, a safe and effective product.
Persons with thyroid disorders should not ingest products containing iodine, however.
Like andygirl said, you can use iodine to purify water.
However, don’t use the iodine purification method for more than a month or two (at the most) running, because having to constantly clean sizable amounts of iodine out of your system will damage your kidneys, so 4/5 weeks at a time is about the sensible limit for drinking iodine-purified water.
I once overheard somebody saying that Koolaid mix could be used to purify water. I assume this is utter nonsense, but I can’t help but be curious. Anybody heard anything similar?
I think the Kool-Aid purifies water bit is a misunderstanding of two different practices. There is nothing in Kool-Aid that will purify the water, obviously. But Kool-Aid is often added to water that has already been purified with iodine to hide the iodine aftertaste. At least that’s what we used to do back in the mid-80’s during my backpacking days.
Filters were a little unreliable back then and so you could be out there a few days, the filter would clog up from too much sediment and organic material, and you’d have to fall back on the fairly bad tasting iodine tablets for purification.
This is a fairly comprehensive page about getting clean water in the event of, um, civil infrastructure breakdown, (when around your home, not in the wilderness). It’s tied to some sort of christian apocalyptic Y2K site, but the info seems pretty straight-forward. Among other things, they talk about purifying water with wine. Interesting.
Thanks, Scylla. All us city-dwellers who drop off our laundry and wouldn’t know a bottle of Clorox if one mugged us on the subway appreciate it.
But it looks from the link like you should wait 30 minutes to make sure the bleach has done it’s thing. And if not, double the dose and wait another 15.
If you’re in the woods hiking, and it’s fairly safe to say that you’re not immuno-compromised, I would go for the river water that is flowing over rocks. The rocks serve as a “trickling filter” and clear the water of a fair amount of the nasties. In fact, trickling filters, are one of the steps that most municipal water systems uses to purify potable water.
If there isn’t a lovely trickling stream, than I would go for the standard boiling. You can also use condensate for potable water.