Water Purification 101

Whether or not you are in a situation you need a certain amount of water in order to function at your peak efficiency. That crystal clear stream or lake may look to be an enticingly cool drink, but think again before taking that first sip.

You should always assume that water from untested sources is unsafe to drink until it is treated. In fact, the United States Environmental Protection Agency reports that at least ninety percent of all the fresh water in the world is contaminated. No matter how crystal clear the water looks, it may very well harbor biological or chemical contaminates that can be very bad for your health and even life threatening.

It is a best practice not to trust any water in the outdoors, even if you know it was safe to drink at an earlier date. A few years ago while hiking along a crystal clear watercourse in the White Mountains of New Hampshire, I came upon an interesting scene: a dead moose at the head of a waterfall, damming up the entire stream. Any water downstream must have passed through this rotting carcass, yet to all appearances seemed clean and pure!

Water borne illnesses can easily lead to excessive bodily fluid loss due to diarrhea and even vomiting. Without proper electrolyte replacement this can lead to hypovolemic shock. In a survival situation, drinking bad water may lead to serious illness and is to be avoided at all cost.

Types of Water Contamination

When considering whether water is safe to drink we must consider two types of water contamination; biologic contaminants and chemical toxins.

One of the most common biologic contaminants of water is Giardia, a nasty little bug that is easily spread and causes intestinal disorders. There are numerous other bacteria and viruses, as well as intestinal parasites that come from drinking untreated or improperly treated water.

Water contaminated with toxic chemicals is also common. Often this water has been made toxic by the workings of man and includes animal feces from farm runoff, pesticides, heavy metals from mine waste, factory discharges, gasoline and motor oils, etc.

Water contaminated with living organisms can generally be made safe to drink by relatively simple methods. Water that is contaminated with toxic chemicals is another matter, so extra caution should be exercised when you believe this could be a possibility.

Preparing Water to Drink

There are a number of methods used to purify biologically contaminated water in order to make it safe to drink. When using these methods it is important that you do not cross-contaminate water you have purified with water that has not been treated. For example, do not collect suspect water using your canteen, pour this into a container for treatment, and then pour the treated water back into your canteen.

Of all the water treatment methods, I am a strong advocate of boiling water to make it safe to drink. Boiling your water is the number one method of ensuring you have destroyed all disease causing organisms. These organisms will not survive a boiling, but they often can survive the various chemical treatments and filters on the market today.

How to Boil Water to Make it Safe to Drink

The old adage that you should boil water for ten or 15-minutes in order to make it safe to drink is incorrect. You will only be wasting fuel.

Water temperatures above 160 degrees F will destroy all pathogens within half an hour. Add another twenty-five degrees to 185 F and that time is reduced to just a few minutes. The fact is, once you get the water to a rolling boil (212 degrees F at sea level) your task is finished: the water is now safe to drink. Even at high altitudes where the boiling point of water is below 212 F, the water is still hot enough to have completely destroyed any disease causing organisms.

For more information see the Survival Topic on "How Long Do You Need to Boil Water?".

Chemically Treating Water to make it Safe to Drink

Chemical water treatment methods are not as reliable as boiling but may come in handy when speed is of the essence or fuel is unavailable. The two most common chemicals used to treat water are chlorine and iodine.

Factors in Chemical Treatment of Water

• PH level, water clarity, and temperature influence the effectiveness of chemical disinfectants and may require higher concentrations.

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• Large particles in the water should be filtered out before treatment. This is because the disinfectant may not adequately penetrate them.

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• Be sure all the water and the water container is treated with the chemical. Swish the water/chemical mix around the brim and screw threads of the container.* The warmer the water, the more effective the chemical treatment.

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• Let the treated water sit for at least one-half hour before using. If the water temperature is below 40 degrees F (4 degrees C) let the water sit for a full hour. Treating Water with Iodine.

Iodine has the advantage of being better than chlorine at eliminating Giardia as a threat to your drinking water. However, Iodine must be stored in light-proof containers and is also not safe for use by everyone. People who are allergic to iodine, have thyroid problems, on lithium, women over 50, and pregnant or nursing women should practice caution when using iodine and consult their doctor before doing so.

There are a number of iodine water treatment products on the market. If you use one of these be sure to follow the manufacturer’s instructions.

Generally iodine works best when the temperature of the water is at least 68 degrees F. If you are using a liquid preparation of 2% tincture of iodine, add 5 drops per quart of clear water or double that if the water is cloudy. Shake well and let stand for an hour.

Treating Water with Chlorine

Regular non-scented household chlorine bleach can be use to chemically treat water to make it safe to drink. Usually household chlorine bleach is 5.25% chlorine. Simply add two drops per quart (or liter) of water and let stand for at least half an hour. If the water is cloudy double the amount of chlorine and double the amount of time you let it stand. Be sure to splash the chlorine laden water all around your water container in order to disinfect everything the water comes in contact with.

A major problem with using chlorine bleach to disinfect water is that it has a short shelf life and so should be rotated from your survival gear every 3 months or so in order to keep at full strength.

A much better alternative to chlorine bleach water disinfection is to use Calcium Hypochlorite.  Survival Topics has an article on using Calcium Hypochlorite for Disinfecting Water that you should read if you are serious about the chemical disinfection of water.

Treating Water by Filtration

Treating water with portable filters has become common. What many people do not realize is that some water filters on the market will not protect them from all the common water borne disease organisms. Caution is advised.

A water filter works by pumping the water to be treated through a microscopic filter which is rated for a certain size of organism. If the filter holes are large enough, disease organisms can get through. Of special concern are viruses, which are small enough to penetrate a number of the common water filters on the market today.

Be sure to read the filter manufacturer instructions.

One common method is to first treat the water with a water filter and then to use iodine or chlorine as a secondary treatment in order to destroy or inactive pathogens that get through the filter.

Conclusion

All water that comes from untested sources should be considered contaminated and be treated before drinking. Toxic chemicals are difficult to remove but pathogens can be destroyed, inactivated, or removed using a variety of methods that include boiling, filtering, and chemical additives.

Of all the methods used for making water safe to drink, boiling your water is the most sure way to destroy disease causing pathogens.

Original at: http://www.survivaltopics.com/survival/water-purification-101/