TM 5-814-2/AFM 88-11, Vol. 2
manholes, backup of wastes into buildings, or any
unattended stations, temperatures will be maintained at
unlawful pollution of the environment, or health hazard
40 degrees F. Attended stations will be heated to 65
to personnel.
Pumping stations located at or in
degrees F. Although wet wells are generally unheated,
conjunction with treatment facilities, such as those
thermostatically controlled heaters may be used to
required for influent pumping, recycling or bypassing of
prevent condensation on walls and floors during cool
flows, and pumping of effluent, will require standby
weather, provided the ventilation system is shut off.
power capability if the pumping is essential to critical
b. Ventilation.
treatment processes, plant flow control, or is necessary
(1) Wet wells will be provided with a positive
to maintain compliance with the discharge permit. If
ventilation capacity of 30 air changes per hour during
fixed standby power is required, refer to paragraph 4-2
occupancy, based on the wet well volume below grade
for design criteria when selecting pump drive units, and
and above the minimum wastewater level.
descriptions of various arrangements to be used in
(2) Unattended dry wells will be provided with
providing fixed, standby power capability at wastewater
a positive ventilation capacity of 30 air changes per
pumping stations.
hour. Attended dry wells will be provided with a
continuously-operated ventilation capacity of 6 air
Water supply.
A potable water supply is
changes per hour, supplemented with additional
7-5.
ventilation in warm climates to remove pump motor heat
required at all large pump stations to supply washroom
to within 5 degrees F. of the outside air temperature.
and toilet facilities, hydrants, hose bibs and pump seal
Supply intakes and exhaust outlets must be located
systems. A wash basin and toilet facilities will be
properly to introduce fresh air and remove hazardous
provided at pump stations which are attended regularly.
gases or fumes. The wet and dry well sides of the
Hose bibs will be provided in wet wells, dry wells and
station will be provided with separate ventilation
bar screen rooms. Freeze proof wall hydrants will be
systems.
required for outdoor use. A positive separation will be
maintained between the potable water system and any
piping or appurtenances subject to contamination.
Electrical equipment and lighting. Pump
7-3.
Warning signs will be posted at all water taps not
station equipment will be suitable for operation at either
directly connected to the potable water supply. The
208V, 230V, or 480V, 60 Hz, three phase power
positive separation will be accomplished either by
supplies. However, equipment with motors smaller than
providing a break with an air gap, or by installing
0.5 horsepower, including meters, switches, timers,
backflow prevention devices. Air force facilities will
clocks, and similar equipment, will be suitable for
comply with AFM 85-21.
operation at a 125V, 60 Hz, single phase power source.
a Service transformers.
Service transformer
Flow measurement. Flow meters installed to
installations will conform to the requirements of TM 5-
7-6.
indicate and record the discharge from the pump station,
811-1/AFM 889, Chap. 1.
and from individual pumps, will be provided at all
b. Motor starters and controls. Motor starters and
medium to large sized stations. A meter installed in the
controls will be provided and housed in a factory
discharge header provides valuable information on the
assembled, free-standing control center located on the
operation of the station, and will be required where
ground floor. The center will include motor starters,
pumping capacity is expected to increase significantly in
switches or circuit breakers, instrumentation and
the future. Pressure gages are required on individual
controls. A pump station requiring a few small sized
pump discharge lines, and on the station discharge
starters is an exception, and will employ wall mounted or
header. Elapsed time clocks will be mounted on all
stand mounted equipment.
pump motor starters. For smaller stations utilizing
c. Control for submersible pumps. Enclosures for
constant speed pumps, an elapsed time clock may be
submersible pump controls will be installed above
used in lieu of a pipe mounted flow meter to measure
grade.
pump discharge. This will also aid in scheduling routine
d. Trouble alarms. Local trouble alarms will be
maintenance on the motor since most small stations are
provided at all pump stations.
Alarms will be
unattended. A noncorrodible depth gage installed in the
annunciated remotely from unattended stations. Alarm
wet well will generally suffice for very small pumps;
systems will be provided with manual silencing.
flows can be estimated from depth measurements taken
manually. The types of flow measuring devices to be
Standby power. The requirement for fixed,
7-4.
used for large wastewater pumps of the constant,
standby power at wastewater pumping stations will
adjustable or variable speed type, include flow
depend upon the type, location, and critical nature of
each pumping facility. For stations situated in low lying
areas, or in areas remote from a treatment plant,
standby capability will be provided if a power outage
would result in flooding of the station, overflows at sewer
7-2
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