How To Treat Water For Drinking

Once you have reasonably clean water, it has to be treated before it is safe to drink. The purpose of this is to kill all the germs that may be in the water. The Federal Emergency Management Agency and the American Red Cross agree on three acceptable ways to treat drinking water: boiling, chlorine bleach, or distilling. Distillation and treatment systems from the camping store have problems if you are trying to provide water for a household. In general, boiling and bleach are the best.


Water should be boiled for at least 5 minutes to sanitize it. Some agencies recommend boiling for 10 minutes just to be safe. If you live at high altitudes, add a minute for every 1000 feet above sea level. Remember that there will be evaporation. You probably want to cover the pot to retain as much of the water as possible. Once the water is boiled, let it cool in the same container. It can be put in storage bottles when it is cool.

Boiled water tends to taste flat because there is no air in it. You can add air by pouring the water back and forth between two clean containers. Doing this will also improve the taste of your stored or bottled water.

Boiling requires that there be a source of fuel and a safe way to store the water while it cools. If your kitchen is working, this is not a problem. If you are cooking over a grill or campfire, use bleach to purify the water.

If you are treating the water to cook with, do not add the food until the water has boiled for the amount of time needed to treat the water. There is no need to boil the water, cool it and then reheat it for cooking, but you may contaminate the food if the water has not boiled long enough before using it to cook. If you put food in contaminated water, it gives the germs a place to hide and they may not be killed in the amount of time needed to cook vegetables or pasta.

The biggest problem with boiling for water treatment is that you can't treat very much water at a time. Most kitchens don't have any pots bigger than 6 or 8 quarts and you can't fill them more than about half or two thirds full. Remember that boiling water is also a safety issue. Even fairly small burns can make you very sick if they get infected.


Treating water with bleach is very effective at killing germs, and it doesn't taste funny to most of us because this is basically what most city water supplies do. You need to have a bottle of plain liquid chlorine bleach and a dropper. The bleach should be 5 to 6 percent sodium hypochlorite with no preservatives and no additional ingredients. Do not use scented bleaches, color safe bleaches, powdered bleaches, or bleaches with added cleaners. You want the good old fashion stuff that smells like chlorine and burns holes in your clothes if you pour it right on them. Even this is hard to choose because it is now available in different concentrations. Ultra Clorox is a 6% solution instead of 5.25% but it is the same stuff. Keep a bottle of 5.25% or 6% chlorine bleach with no additives in the laundry room to use for water purification. Change bottles once a year if you don't use it in the washer much, since bleach loses potency fairly quickly. Get an eyedropper and/or a medicine syringe at the drug store and keep it with the bleach where it won't be used for anything else.

To treat water with chlorine bleach, put the water in a clean container and add 16 drops of bleach for every gallon of water. Stir in the bleach and let the water stand for 30 minutes. If the water does not have a little smell of bleach, repeat the dosage of 16 drops per gallon and let it sit for another 15 minutes. If it smells of bleach now it is OK to drink. If it doesn't smell of bleach after two treatments, the water is too dirty to use. Throw it away and treat a new batch of water.



1 quart bottle

4 drops of bleach

2 liter bottle

10 drops of bleach

1 gallon jug

16 drops (Ĺ ml) of bleach

2 gallon cooler

ľ teaspoon (1 ml) of bleach

5 gallon bottle

Ĺ teaspoon (2.5ml) of bleach


Distillation requires boiling the water and catching the vapor as it condenses back to water. It is a method you can use in dire circumstances for a person who is at greatest danger from bad water such as a small baby or someone who is sick or very old. Although, anyone who is this susceptible should not try to stay home in a disaster situation. It is the only way to make salt water drinkable.

Distillation has all the same problems as boiling and produces very small amounts of usable water. In addition, although distilled water is virtually free of germs, it is not necessarily free of chemicals. You have to use very clean water for distillation. Unless you are a moon-shiner or a chemist who has the tools and the knowledge to set up a real distillation column, this is probably not worth trying.

If this is your only choice, you can distill water in the kitchen. Fill a covered pot half full of water. Tie a cup to the center handle of the pot lid and put the lid on the pot upside down. The cup should be hanging right side up inside the pot. Do not let the cup touch the water. Boil the water for 20 minutes. Water will boil up and condense on the lid and fall back into the cup. After 20 minutes, you should collect the water from the cup and start again. You should change the water in the pot frequently, otherwise, the water in the pot will get more and more concentrated with contaminants and the water in the cup will not be as good. Clean any contaminants off the sides of the pot and the lid before starting each new batch.

If there is no safe drinking water
donít stay.

Other Water Treatments

There are other ways to treat water for drinking. Camping stores sell water treatment kits that use chemicals or filters to purify water and tincture of iodine has been used in emergencies and by campers for years. None of these is as practical and effective as using chlorine bleach so the Red Cross does not recommend them and neither do I.

However, if these are all you have, follow the instructions carefully. Whether purification tablets are chlorine or iodine, make sure that you use the right amount of clean water per tablet and let it sit like you do when using bleach.

For tincture of iodine, use 12 to 24 drops per gallon of water depending on how clear the water is and let it sit for a full 30 minutes. Do not repeat the dose. If it doesn't smell like iodine with the first try, throw it out. The danger of iodine is that it is a drug. Taking in too much iodine over several weeks can suppress your thyroid gland and make you really sick. It also makes the water taste bad.

You can also buy filtering systems to purify water. These are not the filters you put on your faucet to make your water taste better. They are special filters that are designed to make unsafe water pure enough to drink. Some use resins or charcoal to hold the germs and others have pores so small that bacteria canít pass through them. Obviously, filters are not going to purify a lot of water and they quickly become used up or clogged up.