Logo Light

How to purify water? Best water purification methods

Last updated on February 5, 2021
If you don't know how to purify water in the wild, we have prepared a list for you. These are the best water purification methods in survival situations.

How to purify water in the wild?

There are many ways to purify water in the wild. Some methods need modern tools, while other methods only require knowledge and skill.

Here is the list of the top 10 water purification methods in survival situations.

  • Find a freshwater source
  • Boiling
  • Distillation
  • Survival Straws
  • Filters
  • UV Light Devices
  • Solar water disinfection (SODIS)
  • Disinfecting Tablets
  • Bleach
  • Build Your Own Filter

Now that you know the best water purification methods let's focus on the details and instructions. Each technique comes with its own pros and cons.

Depending on the bacteria and how dirty the water is, you may have to use two or more methods to purify the water.

Water purification methods

Find a freshwater source

This is the most convenient and easiest method to get fresh drinkable water. Of course, it depends on your location and water source.

As a great rule of thumb, no matter how clean the water looks, always use at least one purification method. It is better to be safe than sorry.

Here are some of the water sources you might encounter in the wild.

Puddles: low-quality water

Puddle water is a bad source of drinking water. Non-flowing water can ease the development of bacteria, organisms, and larvae. In the case of urban puddles, both people and cars pollute the water. Cars release harmful substances that remain in the puddle. Also, a puddle is a limited source of water, refilling only when it rains.

Slow flowing river: low-quality water

Flowing waters and streams have a higher chance of being clean. Slow-flowing rivers can also have bacteria and other organisms.

If the river is close to cities, it is more likely that the water might be contaminated and polluted.

Lakes and ponds: medium quality water

Lakes and ponds are not always the best choices for drinking water. Since the water is not flowing, it can attract insects and bacteria. If the water source is in an urban environment or close to one, it might be contaminated and polluted.

If the lake or pond is larger and higher altitude, the water is more likely to be cleaner. This is because there are fewer people that can pollute it.

Fast-flowing river: high-quality water

The faster the water flows, the cleaner it is. This is because it is less likely for bacteria and organisms to form. Insects do not stay or get close to moving water.

If the river is not close to any human establishment, this is even better. The further it is from people, the less likely it is to be contaminated.

Although the water might look clean and fresh, you should always use at least one purification method before drinking.


There are two ways to boil water: fire boiling and stone boiling. Both of these methods have the same effect. Boiling water can get rid of most of the dangerous bacteria, viruses, and other organisms.

You need to boil the water and then let it cool before consuming it. One of the main downsides of boiling water is that it takes a lot of time.

In both cases, you need a fire to boil the water or heat the stones that will boil the water.

For the best results, you should use a filtration method before boiling the water. This way, you remove any heavy metals, sediments, and other small debris.


There are many water sources contaminated with heavy metals, radiation, or other toxic substances. They can clog or even destroy portable filters. It is important to remove these contaminants from the water.

In a survival situation, the easiest way to purify the water is to build a distillation system. One of the simplest systems is the solar still. This allows you to collect the water, and the sun's rays will clean and distill the water.

Survival Straws

A more modern approach to water filtering is survival straws. These can filter and purify the water in a matter of seconds. It is the fastest way to get clean drinking water.

You can use it as a normal drinking straw. Just insert it in the water and start drinking. The internal filtering system does the hard work for you.

These are great for bug out bags, as they are lightweight and take up very little space. Considering their functionality, survival straws are a must-have in your survival bag.


In survival situations, you can use certain types of filters. Two types are more common nowadays, the pump-action and the drip filter.

The pump-action filter uses the manual pump's power to push the water through a series of filters. It is a great item for bug out bags as it is lightweight and durable.

The drip filter relies on gravity to filter the water. As the name suggests, the water drips through a filter, and impurities are removed. You can use the drip filter with your soft portable water holder.

UV Light Purification Devices

If you want to get rid of bacteria and small organisms, UV light is the way to go. Although no purification method is 100% effective, UV light does a great job.

You can get your own UV light manual purification device. These are very popular among preppers and do not need batteries. You power them by using your own force.

There are various UV light device manufacturers. It would help if you were looking for a compact device that will fit your bug out bag.

Solar water disinfection (SODIS)

Like UV light devices, SODIS allows you to purify water more naturally. You only need a clear plastic bottle filled with water and a clear sky.

The purification method is the same as the UV light devices. The sun's rays will kill most of the bacteria and other pathogens.

Once you fill your bottle with water, leave it in the sun for at least one day. It helps if you filter the water before. This way, you remove the sediments and larger particles.

This is a free method that does an excellent job. The only downside is that you have to rely on the weather. If the sky is cloudy, this method will not work.

Disinfecting tablets

Another great way to purify water is by using disinfecting tablets. There are several types of tablets. Some are chlorine-based, while other use iodine to disinfect the water.

Disinfecting tablets are one of the best ways to get rid of pathogens. Many of these tablets have a 99% efficiency against pathogens in drinking water.

The iodine tablets come with a few cons. These can change the taste of the water and give it a distinct flavor. Some people should avoid iodine.

Pregnant women and people that have thyroid problems should not use iodine tablets. People allergic to shellfish should also choose chlorine-based tablets.


A chemical-based method to purify water is by using bleach. An essential thing to mention is to pay close attention to the quantity of bleach you add.

You should add 4 drops per liter of water. That is roughly 16 drops per gallon of water. Once you add the drops of bleach, make sure you stir the water to ensure an even mix.

After 30 minutes, you should smell the water and see if it has a delicate chlorine smell. If it does, the water is safe to drink. If not, repeat the process and wait another half an hour.

If the water still doesn't have a delicate chlorine smell after the second try, you should throw it away.

An important thing to keep in mind is that the bleach's active ingredient must be sodium hypochlorite. The chemical symbol for sodium hypochlorite is NaOCl. The safe concentration has to be between 5.25% and 6%.

There are other ingredients that manufacturers add to the bleach. For example, sodium hydroxide might be present in the substance. This is a safe ingredient. Make sure you avoid substances that add scent or other additives.

For best results, you should boil the water before applying the bleach treatment. This is not mandatory, but it increases the efficiency of the treatment.

The Xylem Filter / build your own filter

The last entry on our list of "How to purify water" is the Xylem filter. This is a simple filter that you can build on your own. You need a few basic items like a piece of rubber tube, pinewood, and a zip tie to fasten the tube.

This is a simple way to build a filter that requires few materials, and it is very effective.

You can check this article about the Xylem filter out. It will teach you how to purify water using the Xylem filter.

Types of water contaminants​

There are many water contaminants. Here is a table with the most common ones and their size. The size allows you to understand what purifying technique to use.

Type: Protozoa
Contaminant: Giardia lamblia, Cryptosporidium
Size: 8-12 microns

Type: Bacteria
Contaminant: Cholera, E. coli, Salmonella
Size: 0.2-4 microns

Type: Viruses
Contaminant: Hepatitis A, rotavirus, Norwalk virus
Size: 0.004-0.1 microns

How to purify water: conclusions

Water is one of the most important survival factors. It is a priority and part of the rule of three, which says that you can survive up to three days without water.

Focus on finding a good source of water like a spring or a fast-flowing river or stream. If the only water source you can find is a stagnant one, make sure you treat your water before consuming it.

The best thing you can do is to use multiple purification methods. This way, you get the best results and avoid serious illnesses and dehydration.

Make sure you add a survival straw, lighters, and disinfecting tablets to your bug out bag. If you don't know what to pack, check out our article about effective bug out bag configurations.

MrBushcraft is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

MrBushcraft is supported by its readers. Please assume all links are affiliate links. If you purchase something from one of our links we make a small commission, at no extra cost to you. This helps us cover the costs of this website.

Thank you for your support!
Copyright © 2021. All rights reserved.