Page 23 - Water Engineering Hydraulics, Distribution and Treatment

Chapter1
Introduction to Water Systems
In the United States 95% of the population that is served
The right to water is an implicit part of the right to an ade-
quate standard of living and the right to the highest attainable by community water systems receives drinking water that
standard of physical and mental health, both of which are meets all applicable health-based drinking water standards
protected by the United Nations’ International Covenant on through effective treatment and source water protection. In
Economic, Social and Cultural Rights, which was established 2007, approximately 156,000 US public drinking water sys-
in 1976. However, some countries continue to deny the legit- tems served more than 306 million people. Each of these sys-
imacy of this right. In light of this fact and because of the tems regularly supplied drinking water to at least 25 people
widespread noncompliance of states with their obligations or 15 service connections. Beyond their common purpose,
regarding the right to water, the United Nations’ Committee the 156,000 systems vary widely. Table 1.1 groups water
on Economic, Social and Cultural Rights confirmed and fur- systems into categories that show their similarities and dif-
ther defined the right to water in its General Comment No. ferences. For example, the table shows that most people in the
15 in 2002. The comment clearly states that the right to water United States (286 million) get their water from a commu-
emanates from and is indispensable for an adequate standard nity water system. Of the approximately 52,000 community
of living as it is one of the most fundamental conditions for water systems, just 8% of those systems (4048) serve 82%
survival: of the people.
Water is used in population centers for many purposes:
The human right to water entitles everyone to (a) for drinking and culinary uses; (b) for washing, bathing,
sufficient, safe, acceptable, physically accessible and laundering; (c) for cleaning windows, walls, and floors;
and affordable water for personal and domestic (d) for heating and air conditioning; (e) for watering lawns
uses. An adequate amount of safe water is neces- and gardens; (f) for sprinkling and cleaning streets; (g) for
sary to prevent death from dehydration, reduce filling swimming and wading pools; (h) for display in foun-
the risk of water-related disease and provide for tains and cascades; (i) for producing hydraulic and steam
consumption, cooking, personal and domestic power; (j) for employment in numerous and varied industrial
hygienic requirements. processes; (k) for protecting life and property against fire; and
(l) for removing offensive and potentially dangerous wastes
According to the World Health Organization (WHO), from households, commercial establishments, and industries.
1.1 billion people (17% of the global population) lack access To provide for these varying uses, which total about 100 gal-
to safe drinking water, meaning that they have to revert to lons per capita per day (gpcd) or 378 liters per capita per
unprotected wells or springs, canals, lakes, or rivers to fetch day (Lpcd) in average North American residential commu-
water; 2.6 billion people lack adequate sanitation; and 1.8 nities and 150 gpcd (568 Lpcd) or more in large industrial
million people die every year from diarrheal diseases, includ- cities, the supply of water must be satisfactory in quality and
ing 90% of children under age 5. This situation is no longer adequate in quantity, readily available to the user, relatively
bearable. To meet the WHO’s Water for Life Decade (2005– cheap, and easily disposed of after it has served its many
2015), an additional 260,000 people per day need to gain purposes. Necessary engineering works are waterworks, or
access to improved water sources. water supply systems, and wastewater works, or wastewater
In 2004 about 3.5 billion people worldwide (54% of the management systems.
global population) had access to piped water supply through Waterworks withdraw water from natural sources of
house connections. Another 1.3 billion (20%) had access supply, purify it if necessary, and deliver it to the con-
to safe water through other means than house connections, sumer. Wastewater works collect the spent water of the
including standpipes, “water kiosks,” protected springs, and community—about 70% of the water supplied—together
protected wells. with varying amounts of entering ground and surface waters.

Water Engineering: Hydraulics, Distribution and Treatment, First Edition. Nazih K. Shammas and Lawrence K. Wang.
© 2016 John Wiley & Sons, Inc. Published 2016 by John Wiley & Sons, Inc.

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