(1) Location.
(a) The pumping station shall be designed
such that:
(i) the proposed site will meet
the requirements for sanitary protection of water quality, hydraulics of the
system, and protection against interruption of service by fire, flood or any
other hazard;
(ii) the access to
the pump station shall be six inches above the surrounding ground and the
station located at an elevation which is a minimum of three feet above the
100-year flood elevation, or three feet above the highest recorded flood
elevation, which ever is higher, or protected to such elevations;
(iii) the station is readily accessible at
all times unless permitted to be out of service for the period of
inaccessibility;
(iv) surrounding
ground is graded so as to lead surface drainage away from the station;
and
(v) the station is protected to
prevent vandalism and entrance by animals or unauthorized persons.
(2) Pumping Stations.
(a) Building structures for both raw and
drinking water shall:
(i) have adequate space
for the installation of additional pumping units if needed, and for the safe
servicing of all equipment;
(ii) be
of durable construction, fire and weather resistant, with outward-opening
doors;
(iii) have an interior floor
elevation at least six inches above the exterior finished grade;
(iv) have any underground facilities,
especially wet wells, waterproofed;
(v) have all interior floors drained in such
a manner that the quality of drinking water contained in any wet wells will not
be endangered. All floors shall slope at least one percent (one foot every 100
feet) to a suitable drain; and
(vi)
provide a suitable outlet for drainage from pump glands without discharging
onto the floor.
(b)
Suction wells shall:
(i) be
watertight;
(ii) have floors sloped
to permit removal of water and entrained solids;
(iii) be covered or otherwise protected
against contamination; and
(iv)
have two pumping compartments or other means to allow the suction well to be
taken out of service for inspection, maintenance, or repair.
(c) Servicing equipment shall
consist of:
(i) crane-ways, hoist beams,
eyebolts, or other adequate facilities for servicing or removal of pumps,
motors or other heavy equipment;
(ii) openings in floors, roofs or wherever
else needed for removal of heavy or bulky equipment; and
(iii) a convenient tool board, or other
facilities as needed, for proper maintenance of the equipment.
(d) Stairways and ladders shall:
(i) be provided between all floors, and in
pits or compartments which must be entered; and
(ii) have handrails on both sides, and treads
of non-slip material. They shall have risers not exceeding nine inches and
treads wide enough for safety.
(e) Heating provisions shall be adequate for:
(i) the comfort of the operator;
and
(ii) the safe and efficient
operation of the equipment.
(f) Ventilation shall:
(i) conform to existing local and/or state
codes; and
(ii) forced ventilation
of at least six changes of air per hour shall be provided for all rooms,
compartments, pits and other enclosures below ground floor, and any area where
unsafe atmosphere may develop or where excessive heat may be built
up.
(g) Lighting.
Pump stations shall be adequately lighted throughout. All
electrical work shall conform to the requirements of the relevant state and/or
local building codes.
(h)
Sanitary and other conveniences.
Plumbing shall be so installed as to prevent contamination of
a public water supply. Wastes shall be discharged in accordance with the
plumbing code, R317-4, or
R317-1-3.
(3) Pumps.
(a) Capacity.
Capacity shall be provided such that the pump or pumps shall
be capable of providing the peak day demand of the system or the specific
portion of the system serviced.
The pumping units shall:
(i) have ample capacity to supply the peak
day demand against the required distribution system pressure without dangerous
overloading;
(ii) be driven by
prime movers able to meet the maximum horsepower condition of the pumps without
use of service factors;
(iii) be
provided readily available spare parts and tools; and
(iv) be served by control equipment that has
proper heater and overload protection for air temperature
encountered.
(b) Suction
Lift.
Suction lift, where possible, shall be avoided. If suction
lift is necessary, the required lift shall be within the pump manufacturer's
recommended limits and provision shall be made for priming the pumps.
(c) Priming.
Prime water shall not be of lesser sanitary quality than that
of the water being pumped. Means shall be provided to prevent back siphonage.
When an air-operated ejector is used, the screened intake shall draw clean air
from a point at least 10 feet above the ground or other source.
(4) Booster Pumps.
(a) Booster pumps shall be located or
controlled so that:
(i) they will not produce
negative pressure in their suction lines;
(ii) automatic cutoff pressure shall be at
least 10 psi in the suction line;
(iii) automatic or remote control devices
shall have a range between the start and cutoff pressure which will prevent
excessive cycling; and
(iv) a
bypass is available.
(b)
Inline booster pumps (pumps withdrawing water directly from distribution lines
without the benefit of storage and feeding such water directly into other
distribution lines rather than storage), in addition to the other requirements
of this section, shall have at least two pumping units (such that with any one
pump out of service, the remaining pump or pumps shall be capable of providing
the peak day demand of the specific portion of the system serviced), shall be
accessible for servicing and repair and located or controlled so that the
intake pressure shall be at least 20 psi when the pump or pumps are in normal
operation.
(c) Individual home
booster pumps shall not be allowed for any individual service from the public
water supply main.
(5)
Automatic and remote controlled stations.
All remote controlled stations shall be electrically operated
and controlled and shall have signaling apparatus of proven performance.
Installation of electrical equipment shall conform with the applicable state
and local electrical codes and the National Electrical Code.
(6) Appurtenances.
(a) Valves.
Valves shall be used to permit satisfactory operation,
maintenance, and repair of the equipment. If foot valves are necessary, they
shall have a net valve area of at least 2 1/2 times the area of the suction
pipe and they shall have a positive-acting check valve on the discharge side
between the pump and the shut-off valve.
(b) Piping.
Piping within and near pumping stations shall:
(i) be designed so that the friction losses
will be minimized;
(ii) not be
subject to contamination;
(iii)
have watertight joints;
(iv) be
protected against surge or water hammer; and
(v) be such that each pump has an individual
suction line or that the lines shall be so manifolded that they will insure
similar hydraulic and operating conditions.
(c) Gauges and Meters.
Each pump shall:
(i)
have a standard pressure gauge on its discharge line;
(ii) have a compound gauge (capable of
indicating negative pressure or vacuum as well as positive pressure) on its
suction line; and
(iii) have
recording gauges in the larger stations.
(d) Water Seal.
Where pumps utilize water seals, the seals shall:
(i) not be supplied with water of a lesser
sanitary quality than that of the water being pumped; and
(ii) when pumps are sealed with potable water
and are pumping water of lesser sanitary quality, the seal shall be provided
with a break tank open to atmospheric pressure, and have an air gap of at least
six inches or two pipe diameters, whichever is greater, between the feeder line
and the spill line of the tank.
(e) Controls.
Controls shall be designed in such a manner that they will
operate their prime movers, and accessories, at the rated capacity without
dangerous overload. Where two or more pumps are installed, provision shall be
made for alternation. Provision shall be made to prevent energizing the motor
in the event of a backspin cycle. Electrical controls shall be protected
against flooding. Equipment shall be provided or other arrangements made to
prevent surge pressures from activating controls which switch on pumps or
activate other equipment outside the normal design cycle of operation.
(f) Standby Power.
Standby power, to ensure continuous service when the primary
power has been interrupted, shall be provided from at least two independent
sources or a standby or an auxiliary source shall be provided. If standby power
is provided by onsite generators or engines, the fuel storage and fuel line
must be designed to protect the water supply from contamination.
(g) Water Pre-Lubrication.
When automatic pre-lubrication of pump bearings is necessary
and an auxiliary direct drive power supply is provided, the pre-lubrication
line shall be provided with a valved bypass around the automatic control so
that the bearings can, if necessary, be lubricated manually before the pump is
started or the pre-lubrication controls shall be wired to the auxiliary power
supply.