The invention relates to a pump device for operating vacuum drainage systems and for pumping sewage, in particular on watercrafts. This pump device comprises a drive device having a drive shaft that comprises a first shaft end and a second shaft end and can be rotated by means of the drive device. The pump device further comprises a centrifugal pump which has at least one impeller that is connected in a torque-proof manner to the drive shaft in the region of the first shaft end.