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How to Purify Water 6 Different Ways

If you ever find yourself in a survival situation, you need to know how to purify water to avoid waterborne illness.

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You need clean drinking water in an emergency survival situation. Here are 6 ways to purify water in an emergency survival situation: boiling, filtering, disinfection, UV light, solar disinfection, and a sip well.

I’ve been hiking and camping for decades and successfully used several methods to purify water without ever getting sick. My favorite method is using UV light to purify my water when hiking or backpacking. I’ve also spent many years using various water filters with success. You, too, can learn how to purify water successfully in any situation.   

1) Purify Water by Boiling

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If you have built a fire or have a stove, boiling water for 1 minute is an easy and efficient way to purify water from germs [2]. You might need a rough sand or debris filter to remove silt from the raw water.

Boiling doesn’t eliminate chemicals or other toxins in the water, but most water in a wilderness survival situation just needs the bacteria, viruses, and parasites neutralized.

How to purify water by boiling in 3 steps: 

  1. Filter cloudy water with paper towels, coffee filters, gravel, or clean debris like pine needles. 
  2. Bring water to a boil for 1 minute.
  3. Let the water cool before drinking. 

2) Purify Water by a Filter

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Water filters are designed to remove germs. They also can work well for purifying water and removing some toxins. The Centers for Disease Control (CDC) recommends a filter that is <1 µm pore size, which should remove bacteria and parasites [3]. Also, filters usually have a carbon part to the filter, which can improve the taste.

Don’t assume the common pitcher or refrigerator filters can also filter out germs, as they aren’t intended for this.

There are multiple filter types to choose from, including simple straw filters, water bottle filters, gravity filters, pump filters, and other filter types [4].  For directions on how to purify water with a filter, see the manufacturer’s guidelines, as each filter works differently. 

3) Purify Water by Disinfection

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Disinfect Water with Bleach

Disinfection water purification generally means using chemicals to kill germs.

Small quantities of common household chlorine bleach can disinfect water, making it safe to drink. Hikers and campers can carry chlorine dioxide or iodine tablets for wilderness water purification. 

How to purify water by bleach in 3 steps: 

  1. Gather a medicine dropper from an emergency kit and fresh liquid chlorine bleach (the active ingredient of 6% or 8.25% sodium hypochlorite). 
  2. Use 5 drops of bleach per 1 quart or 1 liter of water. 
  3. Stir and let stand for at least 30 minutes [5].
Chart: Washington State Department of Health

Disinfect Water with Iodine

Common household iodine can also purify water, although pregnant women, people with thyroid disorders, and people with iodine allergies should avoid this method. It is also not recommended to drink iodine-treated water for more than a few weeks.  

How to purify water by iodine tincture in 2 steps: 

  1. Use 5 drops of 2% tincture of iodine per 1 quart or 1 liter of water.
  2. Stir and let stand for at least 30 minutes [6]. 

Don’t use pool tablets to purify water.

Silver is used by Europeans for disinfection but is not approved for safe water purification in the US.

Other commonly recommended household products, such as hydrogen peroxide and citrus juice, are not recommended for water purification, per the CDC [7].

4) Purify Water by a UV Light

Photo: ©Ryo Chijiiwa CC BY 2.0 Deed

Ultraviolet light can quickly and easily kill most germs in water. Handheld UV light water purification devices are affordable and available for hikers and backpackers.

UV water purification is my preferred method of purifying water as it is quick, easy, and lightweight. Unfortunately, my UV light has failed multiple times, resulting in having to boil water as a backup.

For directions on how to purify water by UV light, see the manufacturer guidelines, as each device works slightly differently.   

5) Purify Water by Sunlight

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Sunlight essentially acts as a UV source for purifying water. This is also called solar disinfection or SODIS [8].

How to purify water by solar disinfection in 3 steps: 

  1. Filter cloudy water with paper towels, coffee filter, gravel, or clean debris like pine needles. You may let the water settle and then use the clear water on top.  
  2. Fill clear bottles with clear water. 
  3. Lay bottles on their side on a dark surface in direct sunlight for at least 6 hours [9].

6) Purify Water with a Sip Well

AI Photo: Daniel Borkert/Canva Magic Media™

A sip well, also known as a coyote well or gypsy well, can work as a last resort if you don’t have access to a heat source for boiling or any other way to purify water.

The basic premise is that the water will filter through the dirt and debris in the ground from a nearby water source into a small hole you dig.

I didn’t find any research that this was effective in purifying water from the germs that make you sick (such as Giardia, Cryptosporidium, and E. coli) [10].

Use this method cautiously. If possible, I always recommend disinfecting water from a sip well with another method, such as boiling.

How to purify water by a sip well in 4 steps:

  1. Find a source of standing water (pond, large puddle, lake, spring) or stream. 
  2. Dig a small hole at least 3 feet or more from the water source that goes down below the level of the water source.
  3. Let water seep into your hole until filled.
  4. Process water from your sip well if possible (recommend further boiling or disinfection). 

You have learned how to purify water in six ways: boiling, filtering, disinfection, UV light, solar disinfection, and sip well. Each method has advantages and disadvantages, depending on your situation and available resources.

In addition to obtaining safe drinking water, you will also need to build an emergency shelter in a survival situation.

Stay prepared with the hiking essentials on your next camping or hiking trip, and avoid a wilderness survival situation altogether. 


Why bother with purifying my water when hiking or camping?

There are over 100 germs (bacteria, viruses, parasites) in the US surface water. Water purification is essential in avoiding waterborne illness. In a survival situation, you need water to live, but you also want to avoid getting seriously ill from contaminated water. 


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Daniel Borkert is the founder and editor-in-chief of Outdoor Footprints, a website that tells you everything you need to know about camping and hiking. He is an avid outdoorsman with almost four decades of experience in hiking, camping, caving, and fishing. Daniel loves to involve his wife and kids in his outdoor pursuits and inspire other families to do the same. He lives in Seattle, Washington with his family and an energetic Boston Terrier named Zion.

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