A sewage pumping station including a sump and above the sump a machinery compartment. A pair of sewage pumps and a priming chamber for holding sewage are provided in the machinery compartment. A feed conduit extending from adjacent the base of the sump into the priming chamber provides for the flow of sewage into the priming chamber. A vacuum pump also mounted in the machinery compartment when actuated produces a subatmospheric pressure in the priming chamber effective to draw sewage from the sump into the priming chamber. The pair of sewage pumps have their inlet sides connected to the priming chamber and sewage in the priming chamber is used to prime these pumps.
Another sewage pump mounted in said machinery compartment having an inlet side connected to said priming chamber adjacent the base of the pump and a discharge side connected to said discharge conduit, sewage level sensing means operable to sense the level of sewage in said sump, and pump control means connected to said sensing means for starting up the sewage pumps on a rise in the level of sewage in said sump, said pump control means including an alternating switch means operable to actuate said pumps alternately on successive startups of the sewage pumps.
In sewage pumping stations, of the type that are embedded in the ground, for ease of maintenance and other reasons, the pump which handles the sewage may be located in a compartment disposed above the sump from which the sewage is drawn, rather than being submerged in the sewage. A pump having such an elevated position with respect to the liquid that it pumps presents a problem of priming. Embedded sewage-pumping stations generally operate unattended over long periods of time and for this reason any means for maintaining a primed state in the pump must be reliable and trouble-free.