b. Components. A typical garrison water distribution system consists of the
following components:
(1) Mains and piping. The network of mains and pipes makes up the heart
of the water distribution system. They provide the means by which the water is actually
transported from the storage or pumping faciIities to the user. They form a closed
system that protects the water from outside contamination. It is important in the respect
that the mains and pipes are free from cracks and loose joints. Maintenance of
constant water pressure is also very important because positive pressure within an
underground pipe will help to prevent contamination from entering the system if a leak
should occur.
(2) Storage. If the water distribution system includes storage faciIities, a
number of variations in types of faciIities may exist. Storage faciIities may consist of
tanks, standpipes, or reservoirs. They may be of metal or of concrete. Storage may be
elevated or at ground level. The most commonly found arrangement is elevated, steel,
covered tank located on the highest ground available.
(3) Valves and hydrants. Valves are used to regulate the flow and to enable
maintenance personnel to temporariIy stop the flow for repairs and cleaning. Hydrants
are located at various intervals along the mains to provide for fire fighting. The spacing
depends upon the area that each hydrant is to serve, but the average is about 7 1/2
hydrants per miIe of water main
(4) Pumps. Occasionally, an installation or community may have a water
supply that is located at an elevation sufficient to furnish water to consumers entirely by
gravity. More commonly, however, pumps must be used both to convey water to the
consumer and to ensure that adequate pressure is maintained. Pumps may be required
to force water through the mains, to lift it from the treatment plant to elevated storage,
and to boost the water pressure at various points throughout the system.
1-20. FIELD WATER DISTRIBUTION SYSTEMS
Field water distribution systems are much less sophisticated than municipal or
garrison systems. They normally do not provide sufficient quantities for firefighting.
They are also subject to recontamination of purified water by careless handling or
unclean equipment, because they are not closed systems. Whereas garrison or
municipal water distribution systems are intended to satisfy all of the needs of the
community for water, a field water distribution system is intended to provide potable
water for drinking, cooking, and personal hygiene. A field water distribution system may
consist of any combination of the following components:
a. Water Points. A water point is a location at which potable water is produced
and made available for pickup by using units. Figure 1-20 illustrates a typical combat
water point. The selection of a water point is the responsibiIity of Corps of Engineers
personnel.
MD0160
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