Two basic types of lift stations are: wet pit-dry pit and wet pit-submersible.

• A. Dry pit and wet pit
• B. Wet pit-dry pit, wet pit-submersible
• C. Submersible only
• D. Gravity-fed

Answer: (B)

Understanding how lift stations are configured comes down to where the pump and drive are located relative to the wastewater. There are two common ways: a wet-well setup where the pump is in the wet pit, and a variation of that where the pump is not submerged in the wastewater but sits in a dry pit adjacent to the wet well. In the first case, the pump is submerged and typically powered by a submersible motor. In the second case, the pump is in a dry chamber and connected to the wet well via piping and a seal, so the motor isn’t in contact with the sewage.

The option that lists those two practical variations—wet-pit with a dry-pit pump arrangement and wet-pit with a submersible pump—best reflects the two primary lift-station configurations engineers use in practice. The other choices don’t capture this common dichotomy: gravity-fed isn’t about lift stations’ pump arrangements, and saying submersible only omits the dry-pit alternative.