*TM 5-813-1/AFM-88-10, Vol. 1
CHAPTER 2
WATER REQUIREMENTS
thorough justification, detailed plans of connection to
2-1. Domestic requirements
water source, estimated cost and a statement as to the
The per-capita allowances, given in table 2-1, will be
adequacy of the water supply to support the irrigation
used in determining domestic water requirements.
system. The use of underground sprinkler systems will
These allowances do NOT include special purpose water
be limited as follows: Air Force Projects-Areas adjacent
uses, such as industrial aircraft-wash, air-conditioning,
to hospitals, chapels, clubs, headquarters and
irrigation or extra water demands at desert stations.
administration buildings, and Army Projects-Areas
adjacent to hospitals, chapels, clubs, headquarters and
2-2. Fire-flow requirements
administration buildings, athletic fields, parade grounds,
The system must be capable of supplying the fire flow
EM barracks, Boo's, and other areas involving improved
specified plus any other demand that cannot be reduced
vegetative plantings which require frequent irrigation to
during the fire period at the required residual pressure
maintain satisfactory growth.
and for the required duration. The requirements of each
a.
Backflow prevention. Backflow prevention
system must be analyzed to determine whether the
devices, such as a vacuum breaker or an air gap, will be
capacity of the system is fixed by the domestic
provided for all irrigation systems connected to potable
requirements, by the fire demands, or by a combination
water systems. Installation of backflow preventers will be
of both. Where fire-flow demands are relatively high, or
in accordance with AFM 85-21, Operation and
required for long duration, and population and/or
Maintenance of Cross Connection Control and Backflow
industrial use is relatively low, the total required capacity
Prevention Systems (for Air Force facilities) and the
will be determined by the prevailing fire demand. In
National Association of Plumbing-Heating-Cooling
some exceptional cases, this may warrant consideration
Contractors (NAPHCC) "National Standard Plumbing
of a special water system for fire purposes, separate, in
Code," (see app. A for references). Single or multiple
part or in whole, from the domestic system. However,
check valves are not acceptable backflow prevention
such separate systems will be appropriate only under
devices and will not be used. Direct cross connections
exceptional circumstances and, in general, are to be
between potable and nonpotable water systems will not
avoided.
be permitted under any circumstances.
b.
Use of treated wastewater. Effluent from
2-3. Irrigation
wastewater treatment plants can be used for irrigation
The allowances indicated in table 2-1 include water for
when authorized.
Only treated effluent having a
limited watering or planted and grassed areas. However,
detectable chlorine residual at the most remote
these allowances do not include major lawn or other
discharge point will be used. Where state or local
irrigation uses. Lawn irrigation provisions for facilities,
regulations require additional treatment for irrigation,
such as family quarters and temporary structures, in all
such requirement will be complied with. The effluent
regions will be limited to hose bibbs on the outside of
irrigation system must be physically separated from any
buildings and risers for hose connections.
Where
distribution systems carrying potable water. A detailed
substantial irrigation is deemed necessary and water is
plan will be provided showing the location of the effluent
available, underground sprinkler systems may be
irrigation system in relation to the potable water
considered. In general, such systems should receive
distribution system and buildings. Provision will be made
consideration only in arid or semiarid areas where rainfall
either for locking the sprinkler irrigation control valves or
is less than about 25 inches annually. For Army
removing the valve handles so that only authorized
Projects, all proposed installations require specific
personnel can operate the system. In
authorization from HQDA (DAEN-ECE-G), WASH, DC
20314. For Air Force projects, refer to AFM 88 15 and
AFM 8810, Vol. 4. Each project proposed must include
2-1
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