Filtering and Cleaning Water for Drinking
After shelter and fire, finding water to drink is the next essential thing you must do if you want to stay alive in a survival situation. And, assuming you haven’t got a water filter or purification system with you, you’ll need to know what to do to ensure that the water you collect is as clean as possible, otherwise you can become very ill and weak by drinking unsafe water which could possibly mean the difference between life and death.
Water FiltrationIt’s important that you understand that water filtration and water purification are two entirely different things. Water filtration simply removes all the ‘visible’ particles from the water such as insects, leaves and dirt. However, this does not make the water safe to drink as it’s the ‘invisible’ elements, i.e. the parasites and bacteria which you can’t see that will cause severe illnesses such as dysentery and giardiasis to name but two.
Assuming you don’t have a ready-made container, you can make a water filter quite easily. Using what you have around you, perhaps a hollow log or an old T-shirt or some birch bark; this can form the base of your filtering system. You need to place filtering material in several layers on top. This could be comprised of crushed rock, charcoal, pebbles, sand or gravel. Then you need to find or make some other kind of container which is going to be used to collect your filtered water underneath. Pour the unclean water through your makeshift water filter and you should find that it comes out clearer when collected in the other container. Depending on how good your makeshift filter is, you may need to repeat this practice several times.
Water PurificationBefore attempting to drink the water you have filtered, you must purify it first and the easiest method is by boiling it. There are different theories of how long you should boil water depending on how high you are above sea level but, to be on the safe side in a survival situation, you should boil it for around 20 minutes or so. This will kill any micro-organisms which may have been present.
If you suspect that chemicals may have infiltrated the water supply, boiling the water on its own will not be enough and you’ll need to add water purification tablets which, hopefully, you’ll have included in your survival kit or some iodine tablets. Iodine tablets can make the clean water taste unpleasant but at least it’s safe water to drink and will keep you alive.
It may well be that you cannot find a container to put the water in that can be put safely on top of a burning fire to boil it. That’s not a problem. Simply place some rocks in your fire and heat them up well then place the red hot rocks into your container of water. This will take longer and you’ll need to warm up another set of rocks in readiness for when the first ones no longer have their heating powers but it does work.
Assessing the Purity of WaterIn a survival situation, you may get lucky and have a number of sources from which to collect water and collecting fresh rainwater in ways demonstrated in the article Finding Water Sources will always be safe to drink without having to go through purification. If you are fortunate to have several sources of water from which to choose the basic rules are that fast flowing water is almost always better than still, stagnant water. Water coming straight out of the ground is better than water running along the ground. Try to look for clear water and to avoid water that is discoloured, has algae growing on it or water which is located in marshes or swamp land.
In a survival situation, you are definitely going to need water to stay alive and although there should be no logical reason why you can’t purify it as you’ll have obviously built a fire, if purification is simply not an option, you will have no choice but to drink the cleanest water you can find. Drinking potentially unsafe water is better than dying from dehydration, after all.