Sewage Ejector Pumps
Updated February 20, 2026
Pump sewage and wastewater up to the main sewer line when fixtures are below the sewer level. Required for basement bathrooms and laundry rooms.
Overview
Sewage ejector pumps handle solid waste from below-grade bathrooms, laundry rooms, or any fixture that sits below the main sewer line. Unlike sump pumps (which handle clean groundwater), ejector pumps grind or pass solid waste and pump it up to the main drain. They sit in a sealed basin with a vented lid to contain odors. Required by code for any toilet or fixture installed below the sewer line elevation. A critical distinction: grinder pumps pulverize solids; solids-handling pumps pass them whole through a 2-inch discharge.
Pros & Cons
- Enables below-grade bathrooms
- Handles solid waste
- Reliable operation
- Expensive
- Requires sealed basin
- Professional installation
Key Features
- Handles solid waste, toilet paper, and wastewater from below-grade fixtures
- Sealed basin with vented lid contains sewer gas and odors
- Available as grinder (pulverizes solids) or solids-handling (passes solids whole)
- 2-inch discharge line connects to the main sewer or septic line
- Float switch activates the pump automatically when the basin fills
Sizing & Selection
1/2 HP handles a half-bath (toilet and sink). 3/4 HP to 1 HP for a full bathroom with shower. The basin size (typically 18-30 gallon) must accommodate the peak flow from all connected fixtures. Grinder pumps cost more but work with smaller discharge pipes and handle more waste types. Solids-handling pumps are simpler and less expensive but need a 2-inch minimum discharge.
Installation
Professional installation recommended. The basin is set below the floor (usually in a pit dug during construction or remodel). Waste lines from fixtures connect to the basin. The pump sits inside the basin. A 2-inch discharge line runs from the pump up to the main sewer line with a check valve to prevent backflow. A vent pipe connects to the existing vent stack. Requires a dedicated 20-amp electrical circuit.
Maintenance
- Test the float switch monthly by pouring water into the basin until the pump activates.
- Do not flush wipes, feminine products, or anything that says flushable -- they clog ejector pumps.
- Check the check valve annually -- a failed check valve allows sewage to flow back into the basin.
- Listen for unusual pump noise -- grinding, rattling, or humming without pumping indicates a problem.
- Ejector pumps last 7-10 years on average. Budget for replacement proactively.
Buying Tips
- Liberty Pumps and Zoeller are the two most trusted brands for residential sewage ejector pumps.
- Buy a complete kit (pump, basin, lid, check valve) rather than piecing together components.
- Grinder pumps (-800) are necessary if the discharge line runs more than 50 feet or has significant vertical lift.
- Solids-handling pumps (-500) are sufficient for most basement bathroom installations with short runs.
- Install a high-water alarm on the basin -- if the pump fails, you want to know before sewage overflows.