What is a Lift Station?

Wastewater lift stations are facilities designed to move wastewater from lower to higher elevation through pipes.  Key elements of lift stations include a wastewater receiving well (wet-well), often equipped with a screen or grinding to remove coarse materials; pumps and piping with associated valves; motors; a power supply system; an equipment control and alarm system; and an odor control system and ventilation system.  Lift station equipment and systems are often installed in an enclosed structure.  They can be constructed on-site (custom-designed) or prefabricated.

Lift station capacities range from 76 liters per minute (20 gallons per minute) to more than 378,500 liters per minute (100,000 gallons per minute).  Prefabricated lift stations generally have capacities of up to 38,000 liters per minute (10,000 gallons per minute).

Depending on the system, the pumps are designed to run at a reduced rate.  The pumps may also alternate to equalize wear and tear.  Additional pumps may provide intermediate capacities better matched to typical daily flows.  An alternative option is to provide flow flexibility with variable-speed pumps.  For pump stations with high head-losses, the single-pump flow approach is usually the most suitable.  Parallel pumping is not as effective for such stations because two pumps operating together yield only slightly higher flows than one pump.

If the peak flow is to be achieved with multiple pumps in parallel, the lift station must be equipped with at least three pumps:  two duty pumps that together provide peak flow and one standby pump for emergency backup.  Parallel peak pumping is typically used in large lift stations with relatively flat system head curves.  Such curves allow multiple pumps to deliver substantially more flow than a single pump.  The use of multiple pumps in parallel provides more flexibility.

United States Environmental Protection Agency Office of Water Washington, D.C. EPA 832-F-00-073
September 2000 Collection Systems Technology Fact Sheet Sewers, Lift Station