Purification Method	Quantity Required to Purify	Time Required for Purification	Microorganism, Chemicals, Radiological Material Purification?	Comments
Water Purification Tablets	Follow instructions on label, generally 2 tablets per quart.	30 minutes. Longer if water is cold. (30 minutes after tablet dissolves.) Effective after 8 hours for all types.	Kills microorganisms. Does not remove chemical toxins.	Can use neutralization tablets to improve flavor. MUST wait at least 30 minutes before using. Consult MD if you are pregnant, use Lithium, are a female over 50 are allergic to iodine or shellfish, or have thyroid problems before using this method.
Polar Pure Iodine Crystals	Fill the Polar Pure bottle with water and shake. The     solution will be ready for use in one hour. Add the number of capfuls (per quart of     water treated) listed on the bottle, based on the temperature of the iodine solution.	Let the treated water stand for 30 minutes before drinking. In order to destroy Giardia cysts, the drinking water must be at least 68° F (20° C).	Kills microorganisms. Does not remove chemical toxins.	Can add powdered drink mix (Tang, Lemonade, Koolaid) containing Vitamin C to neutralize iodine and improve taste. Must wait until water is purified before adding. Consult MD if you are pregnant, use Lithium, are a female over 50, are allergic to iodine or shellfish, or have thyroid problems before using this method.
Iodine, USP 2% tincture	For clear water- add 20 drops per gallon.  For cloudy water, add 40 drops per gallon.	Shake or stir to mix. Cover and let stand for 30 minutes, longer if cold. Effective after 8 hours.	Kills microorganisms. Does not remove chemical toxins.	Can add powdered drink mix (Tang, Lemonade, Koolaid) containing Vitamin C to neutralize iodine and improve taste. Must wait until water is purified before adding. Consult MD if you are pregnant, use Lithium, are a female over 50, are allergic to iodine or shellfish, or have thyroid problems before using this method.
Hydrogen Peroxide	Difficult to dose.
Unscented Clorox Bleach (Sodium Hypochlorite) 5.25% or 6% (may contain sodium hydroxide)	2 Liters- 8 drops Clorox. 1 gallon- 16 drops Clorox.  5 gallons- 1 teaspoon Clorox.  55 gallon drums- use 50 ml Clorox.	Shake or stir to mix.  Let stand at least 30 minutes, longer if cold. Should have slight 'chlorine' odor. If not, retreat and allow to stand 15 minutes.	Kills microorganisms. Does not remove chemical toxins.	Bleach looses 50% of its strength after a year. Taste may be improved by aerating (pouring from one container to another) or adding a hot beverage mix (cocoa or tea).
Granular Calcium Hypochlorite READ CAREFULLY!	Add and dissolve 1 heaping teaspoon of      high-test granular calcium hypochlorite (approximately 1/4 ounce) for each two gallons of water. This stock solution will be further diluted before use!	The mixture will produce a stock chlorine solution of      approximately 500 mg/L, since the calcium hypochlorite has an available      chlorine equal to 70 percent of its weight. To disinfect water, add the chlorine      solution in the ratio of one part of chlorine solution to each 100 parts of water to be treated. This is roughly equal to adding 1 pint (16 oz.) of stock chlorine to       each 12.5 gallons of water to be disinfected.	Kills microorganisms. Does not remove chemical toxins.	To remove any objectionable      chlorine odor, aerate or flavor the water as described above.
Boiling	Limited only by size of pot and fuel available	1-3 minutes vigorous boiling. Covering conserves water and fuel.	Kills microorganisms. Does not remove chemical toxins. Concentrates toxins.	If water tastes 'flat', pour between 2 containers to 'aerate' or add a pinch of salt.
Distillation			Distillation will remove microbes, heavy metals, salts, most other chemicals, and radioactive dust and dirt, called radioactive fallout.	Put 3 tuna cans on the bottom of a large pot and place a smaller pot on top of the tuna cans. Put unpurified water in the larger pot (make sure the smaller pot does not float off of the tuna cans.) Turn the lid upside down and place it on the large pot. Bring the pot to a boil. The vapor will condense on the under side of the upside-down lid and flow down the lid to drip into the smaller pot. To hasten the process, you can put a bit of cool water in the lid, but make sure the cool water can't drip through the lid into the water below.
Pasteurization		Bring water to 149 degrees F. for 6 minutes.	Kills microorganisms. Does not remove chemical toxins.
Filtering			Kills microorganisms. Does not remove chemical toxins. Will remove radioactive fallout.

1. Make sure to clean lid and threads of water bottle.
2. Do not use water from a water bed, swimming pool, home or car radiator for drinking purposes.
3. This information is provided as a general guideline. No indication is given or implied that the above methods will perform as indicated. Research the contaminants in the environment you will be in and assure that the method you select will provide the necessary protection.

References:
Distillation
Water Purification Method Results
More Water Purification Methods
Emergency Purification
How to Purify Water
Noah's Ark
Pasteurizing Water
FEMA
Backpackers Field Guide
EPA Guidelines

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