How to make water safe for drinking and cooking
Surface water and water from leaking pipes and
open cisterns and wells may be contaminated with
cholera and other germs. This water should be
carefully treated before drinking!
There are different ways to
treat surface water or other
water sources that are likely
to be contaminated. The
quickest ways are boiling,
bleaching, and adding lime or
lemon. No matter how it is
treated it should be settled
and filtered first, or the
treatment may not work.
1. Settle and filter the water.
• Let water settle until solids have settled out and
water is more-or-less clear.
• Pour water through a filter made of clean fabric or a
sand and charcoal filter.
To use a fabric filter: Fold clean sari cloth 4 times
and stretch or tie it over the mouth of a clean water
jar. Pour water slowly into the jar through the cloth.
After using the cloth, wash it and leave it in the sun
to dry, or disinfect the cloth with bleach to kill germs.
2. Boil or add bleach. If you have
no bleach, use lemon or lime.
Boiling
• Bring water to a rapid boil for at least
1 minute.
• Pour water into a clean container to cool.
Use of bleach
Because household bleach is the most common form
of chlorine, this chart shows how to disinfect water
with household bleach. Household bleach may have
different amounts of chlorine. Most common are
3.5% and 5%. The easiest way to measure the amount
of bleach needed is to first make a mother solution
(about 1% chlorine) and then add this solution to the
water you want to disinfect.
First prepare the mother solution:
1. Add 1 cup of bleach to a clean,
empty beer bottle.
2. Fill the bottle with clean water.
3. Shake the bottle for 30 seconds.
4. Let it sit for 30 minutes.
Your mother solution is ready.
WAT E R
For 1 liter
or 1 quart
BLEACH
3 drops
For 1 gallon
or 4 liters
12 drops
For 5 gallons
or 20 liter
1 teaspoon
For a
200 liter barrel
10 teaspoons
Add these amounts of the mother solution to clear
water and wait at least 30 minutes before drinking the
water. If the water is cloudy, you need twice as much
of the bleach solution.
Use of lime or lemon
(This method will not kill all
germs, but is safer than no
treatment at all and can
prevent many cases of
cholera)
• Add the juice of 1 lime or
lemon per liter of drinking
water, to kill cholera germs.
• Pour water into a clean container.
3. Keep water containers clean.
• Make sure the water storage container stays
clean! Do not put dirty containers, hands or
anything else in the water container. Pour it off
into clean cups for use.
For more information on this and similar subjects, go to www.hesperian.org