Thursday, May 23, 2013

TUTORIAL - Water Purification

In almost every survival situation, it is essential to have access to a healthy water source, whether it be for drinking, cleaning of utensils, cooking or keeping yourself clean.

Finding a regular access point to water is essential. I'll cover the process of finding water when not near a water body in a future post. For now, try searching for a water body such as a stream, creek, lake or river. Try and see if you can spot any animal tracks in the loamy soil near the edges of the water - even small ones such as those from rats or possums. Animals are very good at detecting contaminants in water and won't drink at a water body that has them. Signs of animals drinking there regularly generally indicate a safe water source. Healthy vegetation growing in and around the water body is also a good sign, as plants have difficulty growing in polluted water.

Check to see whether the water has a current. Water with a decent current will, generally, be cleaner than still water, as insects - such as mosquitos - will be unable to lay eggs in it, and the churning effect as it moves over the uneven bed will cleanse the water to an extent. If it is a moving water body and you have found animal tracks, try to move further upstream from the tracks to a point that doesn't have them. Then, gather as much water as you can and take it to your camp/base.

There are many readily accessible filtration systems that you can buy, such as plunger pumps or the LifeStraw (which is particularly good, and I highly recommend having one for each person in your charge) but these do eventually stop working, and it's important to know how to do it for yourself.

The first thing you need to do is filter out any large particles. You can do this quite simply by pouring the water through coarse fabric such as a t-shirt or bandana into another container. This will gather out much of the dirt, pebbles or other debris in the water. If you have charcoal in your kit/supplies, then you should crumble some of it up and smear it over the filter cloth at this point, as charcoal makes an excellent filter. Though this, on its own, is not enough to make the water safe.

At this point you need to start the purification process. Before you add anything such as bleach or peroxide, you'll need to filter out any small particles in the water. You can do this by building a rudimentary filtration system.

Get a large plastic bottle and cut the bottom off of it, then push some cloth or cotton wool balls down inside until it blocks up the mouth of the bottle. This is to stop the filter materials from falling out into your purified water container.

On top of the cotton/fabric, place a couple of handfuls of clean sand. This will be your last stage in the system, as the sand granules churn the water minutely, leaving any particulate at the top and allowing only water at the bottom.

On top of the sand, place a couple of handfuls of charcoal. This just needs to be regular wood charcoal from your fire. Very easy to make if you don't have any on hand. Charcoal is incredibly good at absorbing minute particles and bacteria from water, and allowing the water to pass by cleanly, so put a good amount on there to catch as much as you can.

On top of the charcoal, place a wide layer of small pebbles and rocks. Rock surfaces absorb much of the larger partciles from the water, but also prevent your other filters from coming out with wind and other elements, allowing you to make good use of the filter for a good while.

You will notice with this system that even pouring muddy water in at the top will produce crystal clear water at the bottom, however, this filter will not remove all of the water-borne viruses or bacteria that may be in the source water. At this point, the water will still be fairly clean, however, especially if you got it from a RUNNING water source rather than a still one.

If, however, you're still unsure about the cleanliness of the water, you can treat it with bleach (see my post on using bleach) or by using Hydrogen Peroxide, which is considered to be safer than using bleach to purify water anyway, despite it not being as strong of a bactericide. Add a few drops of it to a liter of water and watch it fizz and bubble like crazy. Any and all particulate will move to the top of the water, and after several hours, the water will be fairly clear and clean. The process is actually quite fun to watch.

Once you're done, regardless of whether or not you used the chemical phase, the last stage is to boil the water. Bring it to a rolling boil and hold it there for several minutes. Once cooled, the water will be as safe to use as you can realistically make it.

Hopefully this has been informative! For a quick and easy water filter system to throw in your bag, though, definitely grab one of the LifeStraws. I can't recommend them enough, and they're quite well priced.

Until next time!

- CumQuaT

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