Operator terms · Wastewater
What is a wet well?
A wet well is the tank at a lift station that collects incoming wastewater until the pumps move it on. Level controls start and stop the pumps as the wet well fills and empties, keeping the collection system flowing where gravity cannot carry it.
Last reviewed 2026-08-03
What it does
Wastewater flows into the wet well by gravity and collects there. When the level rises to a set point, a control starts a pump that sends the wastewater onward; when the level drops, the pump stops. This cycle keeps flow moving past a low point.
What operators watch
Grease, rags, and debris can foul pumps and floats, and a stuck float or failed pump can cause an overflow. Operators check controls, alarms, and pump run times to catch problems before the wet well backs up.
Common questions
- Where is a wet well found?
- At a lift station in the wastewater collection system.
- What starts the pumps?
- Level controls that sense when the wet well has filled to a set point.
- What can go wrong?
- Grease and debris fouling pumps or floats, which can lead to overflows.