You are on what is supposed to be an enjoyable hike during a camping trip and lose your water filter bottle down a ravine. It’s hard to enjoy the rest of your hike because you keep wondering how you are going to filter your water. Given that humankind has been filtering water as far back as 2000 B.C., it stands to reason that there are ways to do so even without modern conveniences. There are a variety of options, some of which require advanced planning because they involve specific supplies. It’s important to keep in mind that while you can survive three weeks without food, you cannot survive without water for more than three days.
How to Filter Water
Boiling: Historical records show that ancient civilizations boiled water to rid it of impurities. This is the easiest way to eliminate microorganisms from water. Make sure you bring the water to a rolling boil for at least five minutes to ensure that it is safe. While this is easy to do, the only downsides are that boiling does not remove non-living contaminants, has to be done in small batches, and you must wait for the water to cool before drinking.
Making a Simple Water Filter with Sand
1. Choose a container such as a large, empty coffee can and punch 5-10 holes in the bottom. If you use a large plastic bottle, cut the end of it off evenly. If you can’t find a container, you can create a cone of birch bark. Tie the cone with rope to keep it from opening up, but make sure there is a small hole in the bottom.
2. You’ll need something to prevent the sand from spilling out of the container. A few inches of small pebbles, a mesh made of nonpoisonous grass, or cotton material will suffice.
3. Add a layer of gravel to strengthen the filter material and prevent sand from getting into your filtered water.
4. Fill your can, bottle, or cone with sand.
5. Collect some water and pour it through the filter. You’ll need another clean container to catch the filtered water. If the water isn’t clear after one pass, repeat this step until it is clear.
Now that you have filtered the water, the next step is to purify it since the water may contain harmful bacteria that your filter did not remove. To do so, get charcoal from your campfire and crush the briquettes into gravel size pieces. Add this between the gravel and sand layer and pour the water through the filter again. While this method is not as refined as the charcoal used in commercial filters, it might help to know that the use of charcoal to purify water also harkens back to 2000 B.C.