Water Purification Facts

Water is essential to life, and all living things contain it. On average, people lose 2-3 liters of water daily and can only survive for approximately three days without water.

The concern for the wilderness traveler comes from the quality of the water in the backcountry. The U.S. Environmental Protection Agency (EPA) reports that 90% of the world’s water supply is contaminated. After drinking contaminated water, there is an increased risk of illness, resulting in a potential fluid loss due to diarrhea and vomiting. The answer – Is to purify Your Water.

There are three waterborne pathogens to eliminate from your water supply: viruses, bacteria, and parasites (such as protozoa, amoebas, tapeworms, and flatworms).

3 Methods of Water Purification

1. Boiling – Boiling is considered the safest and most complete purification method, eliminating all forms of pathogens. All that is required is to bring the water to a boil. If you feel the need or the water source is highly questionable, let the water boil for one minute to be extra safe.

2. Chemical Treatment – Chemical treatments such as iodine are effective against viruses, bacteria, and the protozoa Giardia (considered the most common cause of waterborne illness in the backcountry). Still, they are ineffective against the protozoa Cryptosporidium (“crypto”). When using a chemical treatment, you should follow the directions on the bottle, but when in doubt, allow the chemical to dissolve and sit for one hour before consumption.

It should be stated that iodine treatments do have an undesirable taste and can be neutralized by adding vitamin C or a drink mix containing vitamin C after the treatment protocol has been followed, not before.

For people allergic to iodine, there are chlorine treatments available. If you’re a woman over fifty, pregnant, have thyroid problems, or taking prescription drugs, you should consult your physician before use.

3. Filtration – Although filters can be expensive, they are considered quick and easy to use. Filtration is considered very effective against protozoa like Giardia and Cryptosporidium. To be effective against bacteria, filters must remove particles at least four-tenths of a micron. The problem with filtration is that it is ineffective against viruses. In North America, viruses are usually not a concern, but in third-world countries, viruses like Hepatitis A and B are greatly concerned. To address the problem with viruses, you can either chemically treat the water before filtering or buy a model that includes an iodine chamber through which the water passes. Different models even come with a charcoal element to clear the taste; whatever features you want, be sure to find one that is lightweight, easy to use, and clean. Also, be careful not to drop the filter; a crack can eliminate its effectiveness.

Method Pros and Cons


Pros – Effective against all pathogens

Con’s – Slow, requires fuel, and inconvenient.


Pro’s – Effective against bacteria, viruses, and Giardia. It can be combined with filtration.

Con’s – Ineffective against Cryptosporidium. Slow and tastes bad.


Pro’s – Effective against parasites and bacteria (depending on filter size). Quick and easy to use.

Con’s – Ineffective against viruses. Expensive and may break or clog.

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