You want to live, right?

If you find yourself in an emergency situation, the last thing you need is to get sick from polluted water.

We recommend that you keep 72 hours worth of purified, clean water in your bug-out-bag. But what will you do after the first three days? Here are five different ways to purify water that you can plan and prepare for in advance. With some basic survival skills, and the ability to use whatever tools you find at your disposal, you’ll be able to turn almost any dubious water source into safe drinking water.


Just because you’re in a survival situation, doesn’t mean you’ve come unprepared. If you packed your bug out bag well, you should have 3 ways to start a fire, and a pot suitable for boiling water.

TRENDING NOW >> Best Reading Material For When The World Ends

How to boil water to kill germs effectively:

Pour water into a pot, place over a heat source, and bring to a rolling boil. Once the water is bubbling, keep boiling for 5 minutes, plus 1 extra minute for every 1000 feet you are above sea level.

Placing a lid over the pot will allow you to bring the water to the boil faster, prevent precious pure H20 from escaping as steam, and use your energy source more efficiently (whether it’s gas cartridges, wood, or electricity).

If your water source contains debris, you may want to filter the macro pollutants out of it first. You can strain out big leaves and sticks easily enough with a metal/plastic strainer (or even a clean t-shirt), but if you want to turn dirty, brackish river water into what looks like clean drinkable water, you’ll want to make yourself a gravity filter. These can be as small as a 1.25 liter soda bottle, or as big as a 5-gallon pail.


You can use a UV purifier, also known as a Steri-Pen, to radiate all the harmful bacteria in the water to death. With a UV purifying wand, you can sterilize a quart of water in just 90 seconds. This option will require a little forward thinking and investment prior to the survival scenario. You can pick up a UV purifier kit online and combine it with a set of rechargeable batteries. One set of AA batteries will allow you to purify 150 liters of water, theoretically enough to provide safe drinking water for three months.

UV purifiers are probably the easiest to use all-weather option for purifying your water. It can be difficult to build a fire in high winds or when fuel is scarce, and it’s difficult to hide the light and smoke produced. Making a charcoal and sand filter takes time and you won’t always find the right materials. A store-bought gravity filter with cartridges is easy to use and stealthy, but won’t destroy serious pathogens.


Liquid or tablet-form water purification chemicals are easy to use, store and carry. There are a few different active ingredients depending on the brand you use, but iodine and chlorine are the most common. Like UV purifiers, these chemicals kill any bacteria that are living in the water, although they leave the dead bacteria inside, along with an extra weird taste. We bet you’ll gladly suffer the taste of iodine, though, if it means you can avoid catching the solanum virus.

How to use chemical water purifiers:

The tablets or drops you buy should have specific instructions to follow, but some universal rules of thumb are:

  • Strain macro pollutants out first. You can use a plastic or metal strainer, or any clean woven cloth. A proper cheesecloth is great, but a spare t-shirt will work just as well. Stretch it over the mouth of the container you’ll be pouring the water into.
  • Water purification chemicals work better when the water is not too cold. Try and allow your water to warm up to 68 degrees Fahrenheit if possible. Unless it’s summer, or you’re fairly far south, letting it stand at air temperature may not be enough. This may mean placing jars of water a little closer to your heat source, if you have one, or carrying the unpurified water in bottles inside your pockets for a while before you mix it with the chemicals.
  • If you’ve found tablets or drops but can’t find the instructions, the general rule is to mix one tablet per quart of water. Check for an expiration date, too – these tablets do go out of date and they do lose efficacy after they expire.
  • If the taste is too off-putting, you can mix water flavoring in to make it more palatable. Stuff like powdered ice tea, or tang. This may be especially important if you’re helping kids or elderly to adjust to chemically purified water.


How to make a solar still:

  • Put a big bowl, preferably of shiny metal, somewhere in the sun.
  • Place a smaller jar or cup inside it.
  • Fill the larger bowl with impure water, being careful not to get any inside the cup.
  • Stretch clear plastic sheeting (maybe even cling film) over the top, seal around the edges, and place a gentle weight in the center. The plastic should have a definite collection point above the cup, but shouldn’t sit so low as to seal the edges of the cup.
  • The sun will cause the impure water to evaporate and collect on the inside of the plastic sheet, and gravity will then direct it to drip into the cup.
  • At the end of the process, whatever’s in the cup is water, and impurities are left behind in the big bowl.
  • Downsides to this method: it’s gonna take a long time.


This method is possibly the one least likely to help against virulent pathogens (though I think a solar still could be worse if the pathogen can go from the water in the bowl through the air to the ‘purified’ water in the cup). However, charcoal filtration is incredibly useful for getting muddy water to look and taste like healthy water, and that’s an important step in the process.

If you’re collecting freshwater from a lake or river or a dirty roof, you’ll probably want to use this water filtration method in addition to your water purification method.

Useful tip: Using your own hand-made water filter to filter any water before you put it through a higher-tech gravity filter (i.e. a ceramic filter or a Brita jug) will extend the life of your precious cartridges.

Step-by-step instructions (with pictures) for making your own charcoal filter can be found at, and here is an excerpt (click for full article with pictures):

    1. Obtain FRESH charcoal that has cooled completely. To create a good supply of charcoal, create a camp fire and when you have a good coal bed, bank your fire by covering it with dirt or ash and come back in a day or two. Uncover the charcoal and allow to cool completely before removing.
    2. Crush your charcoal into small bits, from powder up to the size of aquarium gravel.
    3. Obtain or fashion a cylindrical container (taller is better than wider) with open ends. Julie is using a 2-liter soda bottle with the end cut off.
    4. Fill the smaller opening with tightly-packed grass or a piece of fabric (if both ends are the same diameter choose either one) to prevent the charcoal from falling out or running through with the water. Or if you are using a bottle that still has it’s cap, as we are, poke a small hole in the cap before placing your fabric/grass.
    5. Pack the crushed charcoal into the container TIGHTLY.  The idea here is to create as fine a matrix as possible for the water to DRIP through slowly, thus trapping more sediment and “wee beasties”. If the water runs rather than drips through the filter, you will need to pack your charcoal tighter. You should have enough crushed charcoal to fill your cylinder up about halfway.
    6. It is a good idea to place a couple of inches of packed-down grass or sand, or another piece of cloth on top of the charcoal to prevent it from becoming displaced when you add your water.
    7. Place your filter atop a container to catch your water. We are using a glass jar so you can see the changes easily, but in a wilderness situation it is a good idea to filter directly into the pot you are going to boil the water in rather than the one you will be drinking from (in the event they are not one in the same).
    8. Slowly pour the untreated water into your filter (being careful not to displace your sand) filling the remainder of your cylinder with water and allowing it to slowly percolate through. Remember, the water should DRIP SLOWLY out the bottom of your filter
    9. After all of the water has run through the filter, pour it back through as many times as needed to make it clear. I usually run it through at least two, preferably three, times
    10. Once the desired clarity has been achieved, bring water to a boil for a few minutes in order to make sure it is completely sterilized. Remember, boiling is the only way to ensure safety from pathogens. (Taste can be further improved by adding a small lump of charcoal to the boiling water.) Enjoy your clean water!