Contamination of water supplies is usually due to poor sanitation close to
water sources, sewage disposal into the sources themselves, leakage of sewage
into distribution systems or contamination with industrial or farm waste. Even
if a piped water supply is safe at its source, it is not always safe by the
time it reaches the tap. Intermittent tap-water supplies should be regarded as
particularly suspect.#
Travellers on short trips to areas with water supplies of uncertain quality
should avoid drinking tap-water, or untreated water from any other source. It
is best to keep to hot drinks, bottled or canned drinks of well-known brand
names - international standards of water treatment are usually followed at
bottling plants. Carbonated drinks are acidic, and slightly safer. Make sure
that all bottles are opened in your presence, and that their rims are clean
and dry.#
Boiling is always a good way of treating water. Some hotels supply boiled
water on request and this can be used for drinking, or for brushing teeth.
Portable boiling elements that can boil small quantities of water are useful
when the right voltage of electricity is available. Refuse politely any cold
drink from an unknown source.#
Ice is only as safe as the water from which it is made, and should not be put
in drinks unless it is known to be safe. Drinks can be cooled by placing them
on ice rather than adding ice to them.#
Alcohol may be a medical disinfectant, but should not be relied upon to
sterilize water. Ethanol is more effective at a concentration of 50-70 per
cent; below 20 per cent, its bactericidal action is negligible. Spirits
labelled 95 proof contain only about 47 per cent alcohol. Beware of methylated
alcohol, which is very poisonous, and should never be added to drinking water.#
If no other safe water supply can be obtained, tap water that is too hot to
touch can be left to cool and is generally safe to drink. Those planning a
trip to remote areas, or intending to live in countries where drinking water
is not readily available, should know about the various possible methods for
making water safe.&