Emergency Water: Locating Safe Water
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After a disaster, it is possible that water supplies will be temporarily
cut off or become contaminated. Because you must have water to survive,
it is important to know how to locate and purify drinking water to make
it safe.
Facts About Water
Water is the single most abundant substance in the human body, making
up to 60 percent of an adult's weight and up to 80 percent of an infant's
weight. A person can live several days without food, but just a few days
without water. It is second only to air in importance to life.
Because water is so important to human survival, never ration it. Drink
at least 2 litres per day, as long as supplies last, and look for alternative
sources.
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Water Sources
In the home
Melt ice cubes, and use water from the hot-water tank, the toilet tank
(not the bowl) and water pipes.
Hot water tank
Turn off the power that heats it, and let the tank cool. Then place a
container underneath and open the drain valve at the bottom of the tank.
Don't turn the tank on again until water services are restored.
Toilet tank
The water in the tank (not the bowl) is safe to drink unless chemical
treatments have been added.
Water pipes
Release air pressure into the plumbing system by turning on the highest
faucet in the house. Then drain the water from the lowest faucet.
Water beds
Avoid water from water beds as a source for drinking water. Pesticidal
chemicals are in the plastic casing of the bed and chemicals have probably
been added to the water to prevent the growth of algae, fungi, and bacteria.
The water is safe only for hand-washing and laundering.
Outside the home
Rain water, spring water, and water from streams, river,lakes, and coiled
garden hoses can be used after it is purified. Avoid water with floating
material, an odor our a dark colour. Use saltwater only if you distill
it first.
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Purifying Water
Note: Water that local officials report has been contaminated
with toxic chemicals or radioactive materials cannot be purified using
home decontamination methods.
Boiling and chemicals are two ways to purify water
Any water that is obtained from sources outside the home or water that
does not appear clear should be sterilized. Non-sterilized water may be
contaminated with the parasite Giardia.
Straining water
Straining water containing sediment or floating material through a cloth or
paper filter before beginning the purification process.
Heat sterilization
Boiling water is the preferred method of purification because disease-causing
microorganisms cannot survive the intense heat. Bring water to a rolling boil
for 10 minutes. Pour the water back and forth from oneclean container to another
to improve the taste. Adding a pinch of salt could also help.
Chemical sterilization
In some situations, boiling may not be an option. The alternative is to treat
the water chemically. Plain household chlorine bleach may be used. Be sure the
label states that hypochlorite is the only active ingredient. Bleach containing
soap or fragrances is not acceptable. With an eye dropper, add 8 drops of bleach
per litre of water (16 if the water is cloudy), stir and let stand. After 30
minutes the water should taste and smell of chlorine. At this time it can be used.
If the taste and smell (and appearance in the case of cloudy water) has not changed,
add another dose and let stand. If after one half hour the water does not have a
chlorine smell, do not use it.
Purification tablets
Purification tablets release chlorine or iodine. They are inexpensive
and available at most sporting goods stores and some drugstores. Follow
the package directions. Usually one tablet is enough for one quart of
water. Double the dose for cloudy water.
More Rigorous Purification Methods
While the three methods described above will remove only microbes from
water, the following two purification methods will remove other contaminants.
Distillation will remove microbes, heavy metals, salts, most other chemicals,
and radioactive dust and dirt, called radioactive fallout. Filtering will
also remove radioactive fallout. (Water itself cannot become radioactive,
but it can be contaminated by radioactive fallout. It is unsafe to drink
water that contains radioactive fallout.)
Distillation
Distillation involves boiling water and then collecting the vapor
that condenses back to water. The condensed vapor will not include salt
and other impurities. To distill, fill a pot halfway with water. Tie a
cup to the handle on the pot's lid so that the cup will hang right-side-up
when the lid is upside-down (make sure the cup is not dangling into the
water) and boil the water for 20 minutes. The water that drips from the
lid into the cup is distilled.
To make a fallout filter, punch holes in the bottom of a large
bucket, and put a layer of gravel in the bucket about 1-1/2 inches high.
Cover the gravel with a towel cut in a circle slightly larger than the
bucket. Cover soil with a towel, place the filter over a large container,
and pour contaminated water through. Then, disinfect the filtered water
using one of the methods described above.
Containers
Store the water in a clean and sanitary glass or plastic container. Plastic
containers are good because they are lightweight and unbreakable. Metal
containers should be considered as a last resort because they may corrode
and give water an unpleasant taste.
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