A. Lift Stations. A lift station consists of a tank, pump, pump controls, and alarm system. The tank can be a separate unit, or it can have common wall construction with the pretreatment unit. The tank shall have sufficient volume to provide the desired dosing volume, space for controls, space for setting the pump, plus a reserve volume. The reserve volume is the volume of the tank between the high water alarm switch and the invert of the inlet pipe; it provides storage during power outages or pump failure. A reserve capacity equal to the estimated daily domestic sewage flow is required. Duplex pump units can be used as an alternative to provide reserve capacity. No reserve capacity is necessary when siphons are used.
B. Pumps. Where it is necessary to pump sewage to the system, a separate leak-proof sump and pump shall be required.
C. Pump Specifications. Pumps shall meet the following requirements:
1. The pump shall be submersible, designed to handle domestic sewage and a minimum of 1/2 inch diameter solids, capable of delivering the required flow at the design total dynamic head.
2. The discharge pipe shall be the same size or larger than the discharge of the pump.
3. The pump shall be constructed of corrosion resistant materials. Performance curves and specification sheets indicating the above criteria have been met shall be submitted with the plan review application when pumps are to be used in a system.
D. Pumping Chamber. The pumping chamber shall be watertight. Watertight shall consist of sealing all joints. The pumping chamber shall be filled with water after being installed and backfilled to prevent the pumping chamber from floating out of position due to hydrostatic pressures, unless the tank is installed in dry soil.
E. Access Riser. An access riser with a minimum dimension (width or diameter) of 12 inches shall be installed on the pumping chamber, and extend at least 6 inches above the ground surface.
F. Dosing Volume. The dosing volume shall be at least 5 times the pipe volume of the dosing network plus provide for filling and drainback of the network. The average flow shall be used to determine the dosing volume.
G. Pump and Alarm Control. The pump control device shall be adjustable so that the required dosing volume is discharged during each pumping cycle. The control system for the pumping chamber shall consist of a control for operating the pump and an alarm system to detect when the system is malfunctioning. Pump controls shall allow flexibility in adjusting the on-off depth. An example of acceptable controls is shown in Appendix A: Illustration Q of the Illinois Private Sewage Disposal Code.
H. Electrical and Alarm System. A high water alarm shall be provided with audible and visual signals and a test function. The alarm shall be on a separate circuit and located outside the home or facility served. The alarm control device shall be a sealed float or diaphragm switch and shall be located to activate 2 to 3 inches above the pump turn-on level. Electrical devices installed after January 1, 2014 shall be provided with an electrical disconnect that is located within sight of, and not more than 50 feet away from, the device.
I. ANCILLARY EQUIPMENT.
1. Quick Disconnect. A quick disconnect device shall be included in the discharge piping to facilitate removal of the pump for inspection, repair,
or replacement. The disconnect device shall be a threaded union, pitless adapter, or lift-out rail system.
2. Pump Cable. A corrosion resistant rope or cable of adequate strength shall be affixed to the pump to facilitate installation and removal, so that personnel need not enter the chamber to disconnect the pump.
3. Pump Control Device. A pump control device must be adjustable so that the desired dosing volume can be discharged during each pumping cycle. The control device may consist of one or more sealed float or diaphragm switches, which may cooperate with a relay or contactor. Any separate control panels located outside the chamber must be protected from the weather and must provide no air path between the panel and the pump chamber.
4. Check Valve. A check valve between the pump and the piping network shall not be allowed unless this piping system is below the frost line. A check valve is required when dual pumps are utilized.
(Ord. O-201711-51-031, passed 11-14-2017)