Water
Water is covered first here for a reason. People can die in as little
as three days without water. How much do you need? In a shortage situation,
try to get at least 15-20 litres per person per day. The “absolute
survival minimum” according to the United Nations is 7 litres
per person per day for wash and drinking water. People who are ill
may need more. Some sources put minimal drinking water requirements
as low as 2-3 litres per person per day for a healthy person in cool
weather without strenuous physical exercise, but there may be significant
health problems as a result of only drinking such small quantities. Wash
water is needed to avoid serious health problems from infections and
disease. If you are unable to meet that demand in potable (safe for
drinking) water, you can use non-potable, brackish or salty water
for some wash purposes. However, you should purify water used for
washing the face or hands, or for brushing teeth.
Drinking alcohol, urine, blood, or salty water will increase your
water requirements and should be avoided. Also, if you have extremely
little to drink, consider minimizing your protein intake, as protein
takes water to digest. If you have no water, you should not eat at
all. On a limited supply of water, watch for signs of dehydration
including: dark urine with a very strong odour; dark, sunken eyes;
low urine output; fatigue; loss of skin elasticity; emotional instability;
thirst; a “trench line” down center of the tongue; and
delayed capillary refill in the fingernail beds. If you are in a survival
situation without other sources of water, digging a well for water
is not usually worth the energy and sweat.
Contamination
It doesn’t matter how much water you have if the water is too
contaminated to be drinkable. The contamination of water can be pathogenic,
chemical, or physical.
Pathogenic organisms are “disease-causing organisms”,
so pathogenic contamination refers to the presence
of certain types of bacteria, amoebas, worms, or viruses. Giardia,
or “beaver fever,” and cholera, are examples.
Chemical contamination includes contamination from
pesticides and industrial chemicals, or natural chemicals from rocks.
DDT is a pesticide example, and salts and iron are examples of natural
chemicals. (Of course, if you were a fish living in the ocean, you
wouldn’t consider salt a “contaminant,” so it is
relative.)
Physical contaminants are not usually harmful, but
can make the water unappealing to drink because of taste, colour or
smell. “Cloudiness” (turbidity) is one example.
Avoiding contamination in the first place is always preferable to
having to treat water. In almost every conceivable situation, it is
easier to keep water clean than to clean it.
Sources of Water
There are three main water sources: groundwater, rainwater and surface
water. We will also look at survival sources which don’t quite
fit into any one of those categories.
Groundwater, as the name implies, is present in
the ground, below the surface. This includes water from wells and
springs. As the water flows underneath the ground, it is filtered
and purified by the soil. The United Nations considers groundwater
the preferred source of water in refugee situations. A spring is considered
the ideal source of groundwater, since you don’t have to dig
a well. Groundwater is generally free of pathogens, although contamination
can occur from latrines which are too close.
Rainwater is also an excellent source of water,
since it is generally free of contamination, although the supply varies
widely according to climate. Assuming that the containers, evestrough
and roof are clean, rainwater can be used safely without treatment.
(See page 4)
Surface water can be a good source of water, but
in most cases is contaminated from a variety of sources. Though surface
water is easily accessible in many places, it generally requires some
sort of treatment.
Survival sources of water are sources which are
present in small quantities, and often “embodied” in soil
or plants. You might look at a lake and think “water”,
but you can also get small quantities of water where it is not visible.
These sources are not generally suitable for a large, concentrated
population.
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