Current through September 21, 2024
(a) 2018 TSS, parts
6.1-6.1.1(e), location; 6.2, 6.2(b)-(e), pumping stations; 6.2.1-6.2.1(d),
pumping stations, suction well; 6.2.2-6.2.2(b), pumping stations, equipment
servicing; 6.3.2, pumps, pump priming; 6.6.1, appurtenances, valves;
6.6.3-6.6.3(d), appurtenances, gauges and meters; 6.6.4-6.6.4(b),
appurtenances, water seals; 6.6.5, appurtenances, controls; 6.6.6,
appurtenances, standby power; are herein incorporated by reference.
(b) Stairways or ladders shall be provided
between all floors and in pits or compartments that must be entered.
(c) Pumping facilities shall be heated to
maintain a minimum temperature of 40 degrees Fahrenheit if typically unoccupied
and 50 degrees Fahrenheit if normally occupied.
(d) Pumping station ventilation designs shall
demonstrate that:
(i) All areas of the pumping
station that are accessible shall be ventilated;
(ii) Ventilation may be continuous or
intermittent;
(iii) Drywell
ventilation shall provide:
(A) At least six
air changes per hour if continuous; and
(B) At least 30 air changes per hour if
intermittent with an automatic start upon operator entry into the area.
(iv) Wetwell ventilation
shall provide 12 continuous air changes per hour or 60 intermittent air changes
per hour and be designed to permit the use of portable blowers that will
exhaust the space and supply fresh air during the access
periods.
(e)
Dehumidification equipment shall be provided in below-ground pumping stations.
The equipment shall be sized to maintain a dewpoint at least two degrees
Fahrenheit below the coldest anticipated temperature of the water to be
conveyed in the pipes.
(f) All
pumping stations that are manned four or more hours per day shall be provided
with potable water, lavatory, and toilet facilities. The waste shall be
discharged to the sanitary sewer or an on-site waste treatment
system.
(g) Pump design shall
comply with the following requirements:
(i)
At least two pumps shall be provided. With the largest pump out of service, the
remaining pump or pumps shall be capable of providing the maximum pumping
capacity of the system.
(ii) Pumps
shall be selected such that the net positive suction head required (NPSHR) is
less than the net positive suction head available (NPSHA) minus four feet based
on hydraulic conditions and the altitude of the pump installation. If this
condition cannot be satisfied, a means of priming shall be provided.
(iii) A surge analysis shall be provided to
demonstrate if surge protection devices will be needed to protect the piping.
Pressure relief valves are not acceptable as surge control.
(iv) The calculated total dynamic head for
pumping units shall be based on pipe friction, pressure losses from pipe
entrances, exits, appurtenances (such as valves and bends), and static head at
the design flow.
(v) The station
shall have a flow rate indicator and totalizing meter, and a method of
recording the total water pumped.
(h) Booster pumps shall comply with the
following requirements:
(i) Booster pumps
shall not produce less than 5 psi in suction lines. If the suction line has
service connections, the pressure shall be at least 35 psi during normal
operation and shall have a low-pressure cutoff switch to maintain at least 20
psi.
(ii) For booster pumps used for
fire suppression, no person shall install or maintain a water service
connection to any premises where a fire pump has been installed on the service
line to or within such premises unless the pump is equipped with one of the
following:
(A) A low suction throttling valve
or pilot-operated valve installed in the discharge piping that maintains
positive pressure in the suction piping while monitoring pressure in the
suction piping through a sensing line. The valve shall throttle the discharge
of the pump when necessary so that suction pressure will not be reduced below
20 psi gauge when the pump is operating; or
(B) A variable-speed suction limiting control
that is used to maintain a minimum positive suction pressure at the pump inlet
by reducing the pump driver speed while monitoring pressure in the suction
piping through a sensing line. The limiting control shall be set so that the
suction pressure will not be reduced below 20 psi gauge while the pump is
operating.
(iii)
Automatic or remote-controlled pumps shall have a range between the start and
cutoff pressure that will prevent the pump from cycling more than one start
every 15 minutes.
(iv) In-line
booster pumps shall be accessible for maintenance. There shall be access
openings, as needed, to allow the removal of the pump.
(v) Individual home booster pumps shall not
be allowed for any individual service from the public water supply
main.
(vi) Un-manned or remotely
controlled pump stations shall have an alarm at an operator attended location
for any conditions that may affect the continuous delivery of water.
(i) Pumping facility
valves shall comply with the following requirements:
(i) Air release valves shall be provided
where the pipe crown is dropped in elevation. The discharge pipe from the valve
shall have a minimum of an 8-inch air gap and shall be covered with a #24 mesh
non-corrodible screen.
(ii) Each
pump shall either have an individual suction line or the suction lines shall be
manifolded such that they demonstrate similar hydraulic and operating
conditions.
