Water is more important than food when it comes to surviving in the wilderness—you can survive for weeks without food, but only a maximum of about five days without water. Water that you’re likely to find in the wild can be contaminated with parasites and microorganisms that could be very harmful to your health. Knowing how to purify water could be the difference between life and death.
It’s important to find ways to purify your water in the wild—water found in the wild can cause ailments like dysentery or other serious health problems that could prove fatal in a survival situation. For this reason, you’ll want to always carry supplies which will make purifying water possible.
It’s also beneficial to purify water using a variety of methods, combining them when necessary to produce clean, drinkable water free of contaminants and dirt. You may want to practice the different methods below to ensure you have the skills necessary to produce potable water that won’t make you sick. You’ll also want to look for as wide a variety of water sources as possible, so that you not only have an abundant supply of water but a choice between water sources which may be cleaner than others.
One of the easiest ways to purify water is to boil it. Boiling water for ten minutes thoroughly kills any organisms in the water, making it safe to drink. You want to apply sufficient heat to produce a rolling boil, and keep the water at this temperature for ten minutes at a minimum. Once removed from the fire and cooled, the water will be safe to drink.
Filtration is another excellent way to purify water in the wild. Oftentimes, scavenged water will be muddy, dirty, or full of floating debris. In this situation, sand filtration is one of the simplest ways to make your water potable. You’ll need a plastic bottle you can cut the bottom off of. You’ll then want to invert the bottle, and pack several inches of pebbles or cotton into it, followed by larger pebbles or gravel. Top this layer of gravel with several inches of sand, and fill the remaining space with water. Within a few moments, clear, filtered water should flow from the bottom of the inverted bottle. If the water is cloudy or still has some dirt in it, pass it through the filter again to clear it up.
Though not the safest method of filtering water, t-shirt or cloth filtration is a good way to clean dirty water that you may be able to further purify using other methods. In a pinch, filtering water through cloth is better than not filtering it at all, and if this is the only method available to you, it’s certainly better than nothing. You’ll want several layers of cloth for this method. You can cut scrap cloth into wide strips and double them up, or fold a t-shirt or other article of clothing back on itself to create multiple layers of cloth for the water to flow through.
One of the easiest ways to effectuate this method is by using sturdy sticks to form a framework for the cloth. Wrap the cloth around the sticks, which can be handheld or anchored in the earth at an appropriate angle to allow you to collect water that flows through the layers of cloth. Simply pass the water through the layers of cloth, collect it in a bottle, and examine it for impurities. If water is cloudy or still dirty, you’ll want to pass it through the cloth filter one or more times until it’s as clear as you can get it. Though this method may not protect you against microscopic organisms, it is better than nothing—and in the best of circumstances, can be considered a good “first pass” filtration technique to be combined with boiling or sand filtration.
If you have the luxury of time, sedimentation filtration can also be a useful technique. Over time, particles in still water will settle to the bottom of a container, leaving mostly clean water above the layer of dirt and particles at the bottom. This is a particularly good method to use for muddy or murky water. Simply fill a container with untreated water and allow it to sit for a day or two. This can be aided by the sun, provided you have a way of tightly sealing the bottle or container to guard against evaporation. After a day or two, most of the particles will have settled at the bottom of the container. Carefully pour the water into another container, taking care to not disturb the layer of sediment at the bottom. This method is particularly useful when combined with either boiling or a sand filter to produce clean, potable water.
To your survival,