HOW-TO: Survival Water Purification

Note: This article may contain commentary or the author's opinion.

In much the same way that knowing how to construct a debris shelter with no tools can save your life in a survival situation, so can knowing how to get to fresh clean water without a camping water filter. While a water filter should be one of the items that’s non-negotiable in your survival kit (at least a LifeStraw) we all know that you don’t get to choose when or how well equipped you’ll be whenever disaster strikes.

First we’d like to note that the fastest and easiest way to “purify” water is to bring it up to a rolling boil for a couple of minutes. This will kill off all disease-causing organisms, including viruses, bacteria, and parasites. Also as a disclaimer, according to the CDC website, “Water contaminated with fuel, toxic chemicals, orĀ radioactive material will not be made safe by boiling or disinfection. Use bottled water or a different source of water if you know or suspect that your water might be contaminated with fuel or toxic chemicals.” If the water resources around are contaminated with these materials the best course of action would be to get as far away as possible as quickly as possible. Please note that filtering water in the following way alone does not completely remove all forms of pathogens from the water.

Now that we’ve got that out of the way, we’d like to cover another method of purifying water that could come in handy, especially if you don’t have a pot or metal tin to boil your water but you do have a two liter bottle or plastic container that you can use. Worst case you could use the bark from trees like birch, pine, cedar, elm, or basswood. If you’re using these shape the bark into a large cone, if using a 2 liter bottle cut the bottom off and us it as a funnel. From there it’s just a matter of gathering some material and beginning to filter your water through it.

In this video Survival on the SKinney demonstrates the materials you need and the 2 liter bottle method.

Layer One

Stuff the bottom of your cone or bottle with dry grass balled up into a wad so it can hold all the material you’re stacking above it or a large piece of charcoal that holds the next layer but still allows water to get through.

Layer Two

Next you’re going to fill it mostly with charcoal. You can easily make charcoal by building a fire, burning logs down into coals, and then covering these coals with dirt or sand to smother the fire before it turns it to ash. Once it’s cooled you can uncover your charcoal and break it into small pieces and filling your container with more room for your remaining layers.

Layer Three

Next you’ll add sand. This can be the trickiest material to find depending on the area you’re in. However, with some searching it’s likely that there’s a sandy area around you.



Layer Four

The top layer is more wads of grass mixed with large gravel stones.

What is happening in this filter is that the stones and grass are filtering out large contaminates such as debris. Next, the sand layer is filtering out sediment and smaller debris. Then the charcoal layer (which is full of millions of tiny pores) is capturing even smaller and smaller particles. The more you run water through this filer the cleaner and cleaner it gets.

This is a very useful method to filter water with minimal tools and only slight material gathering. We will cover further water purifying methods in future articles.

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