Page 25 - Water Loss Control

W ater Loss Contr ol: A Topic of the Twenty-First Century 7

2.2 The Need for Water and Basic Facts about the Resource Water
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Human body weight is approximately 50 to 65% water , which must be replenished on
a daily basis; with a minimum of eight glasses per day recommended for each person.
A human can survive without food for several weeks but without water we die in
around 3 to 4 days! Water stands as the second most urgent body need after air. Like the
human body, many of the fruits and vegetables,
which we eat, are also mostly water. Obviously,
water is an extremely important resource even
though people in many developed countries often Water is the second most
take its relative abundance and high quality for urgent body need after air.
granted. The availability of fresh water is essential
for our societies to thrive and flourish.
The world’s surface is made up of approximately 80% water, which is an indestructible
substance. Of this water approximately 97% is salt water, 2% frozen in glaciers, and only 1%
is available for drinking water supply using traditional treatment methods. Through the
natural patterns of world climate conditions and the hydrologic cycle, the availability of this
water varies widely over time and distance. In any point in time, some part of the world is
enduring severe drought while other parts are experi-
encing floods. Rarely does this natural cycle coincide
with the routine variation in man’s use of water. The Only 1% of the earth's water
amount of water on the earth is fixed and limited. Our is freshwater that is readily
predecessors have probably drunk several times in the
available for water supply
past the water we drink today! The water cycle hasn’t using traditional treatment
really changed much since the beginning of time. The
water cycle is essentially evaporation, cloud forma- methods—we should take
more care of it!
tion, rainfall, and passage to the sea by rivers and
streams. In a 100-year period, a water molecule spends
98 years in the ocean, 20 months as ice, about 2 weeks in lakes and rivers, and less than a
week in the atmosphere. People interfere with the later stages of the cycle and redirect that
passage back to the sea through water piping or distribution systems, human bodies, sewer
systems, and then back to the sea.
Although the water cycle hasn’t changed since the passage of time, the treatment
technology used to make it usable, and the distribution technologies, have changed
considerably. This is particularly true with the advent of consolidation of populations
into major city centers; usually with increasing industry, pollution, and demands for
services. The more polluted water becomes, the more expensive it is to treat. The farther
away the source from the population center, the higher the transportation cost of water.
Given continuing worldwide population expansions and relocations, it is inevitable
that the provision of water is becoming increasingly expensive.
Recent initiatives to better utilize water resources include water conservation, recy-
cling, and the use of reclaimed water. Desalination, a way of tapping into the vast
resources of sea water, has historically been very energy intensive and costly; however,
improvements in the technology have reduced costs and pressures from supply short-
ages and population growth have resulted in a growing number of desalination plants
around the world. Still, desalination is an option largely for coastal cities at this time.
Water conservation is a proven technique for customer consumption management. It
is now realized that conservation is not just a stopgap action during drought, but an