Everything You Need to Know About Sewage Ejector Pumps and How They Work

Katy Willis
Written by Katy Willis
Updated July 25, 2022
Person doing laundry at home
Photo: SolStock / E+ / Getty Images


  • Homes with basement laundry or bathroom facilities need a sewage ejector pump.

  • These pumps help move sewage waste into the main septic line.

  • Hire a pro to conduct basic annual maintenance on your pump.

  • Sewage ejector pumps cost $300 to $800, not including labor or permits.

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Sewage ejector pumps are submersible workhorses that help move solid and liquid waste from your home to the communal sewer line. Only homes with basement laundry or bathroom facilities need a sewage ejector pump, but in these homes they are vital.

What Is a Sewage Ejector Pump?

A sewage ejector pump is a submersible centrifugal pump that moves liquid and soft solid waste along the residential pipework into the main community sewer line. In normal setups, wastewater, including sewage, moves via gravity from a property's plumbing to the main septic line outside.

But things get dicey if the sewage pipework is below or not far enough above the main septic line. Gravity will need a helping hand, and that's where a sewage ejector pump comes in. It moves the waste up and along the pipes into the main sewer line.

How Does a Sewage Ejector Pump Work?

For a vital piece of equipment, the sewage ejector pump isn’t very complex; it's just a pump and float arrangement. So, the pump sits in the sump basin with a float attached. When the level of sewage in the basin lifts the float, it engages the pump's motor. When the motor turns on, it forces the solids and liquids out of the basin, down the sewer pipe to the main septic line outside of the property. 

As the basin empties, the float moves back down and, when it reaches its minimum level, it signals to the ejector pump to turn off, and the cycle begins again. 

To equalize pressure when the pump is active and to release sewer gases, the setup requires a vent that usually runs from the sump basin and connects to an existing vent stack or runs up the side of the property and out through the roof.

Do You Need a Sewage Ejector Pump?

If your home has a laundry or a bathroom where the plumbing is below the level of the communal sewer line it joins to, then yes, you absolutely need a sewage ejector pump or, in some cases, a sewage grinder pump. 

It's almost certain you'll need one of these pumps if you have a washing machine or a bathroom in your basement. If not, waste will solidify in the pipe, resulting in a sewage backup and overflow nightmare.

Where Is a Sewage Pump Typically Installed?

To work effectively, the sump basin is usually underground in a basement. The ejector pump will sit in a basin (usually plastic or steel) to keep fluids and odors contained while it moves waste up into the sewer lines. 

What Maintenance Does a Sewage Ejector Pump Need?

Ideally, sewage ejector pumps need no maintenance apart from a yearly service by a qualified plumber. During the service, the technician cleans the pump, oils the motor, and carries out a full inspection of the pump, the float, and the connections. They'll also remove any debris wedged in the sump basin. 

But homeowners need to do their part, too. It's vital that you only flush waste and toilet paper in systems with a sewage ejector pump. Other items can clog the pump and force the motor to work extra hard to move them. This will shorten the life of the pump and can cause a clog and sewage overflow in your bathroom.

How Much Does a Sewage Ejector Pump Cost?

Expect to pay between $300 and $800 for a sewage ejector pump. You'll also need to hire a local plumber for installation. Plumbers generally charge by the hour, and the cost to hire a plumber per hour varies between $45 and $200. The annual service costs in the vicinity of $130, but you may be able to save by getting a complete yearly plumbing inspection for your whole home.

Some areas may also require a permit to install an ejector pump. This is because cities will need to confirm your improvements are in compliance with local drainage points. In general, plumbing permits cost $50 to $500.

Sewage Ejector Pumps vs. Sewage Grinder Pumps

Sewage grinder pumps are more powerful than a sewage ejector pump. These pumps are able to grind up raw sewage before passing them into the sewer line. They're also able to handle tougher solids and at a higher volume. 

Note that sewage grinders aren't suitable for use with septic tanks, as they grind the sewage too finely so the liquids and solids never separate, and the liquified solids travel through the secondary system into the leaching field. 

If you have a septic tank, then you'll need a sewage ejector pump. You'll also use an ejector pump if you have a vertical lift less than 70 feet and if you're pumping the sewage less than 750 feet.

Sewage Ejector Pumps vs. Sump Pumps

The main difference between sewage ejector pumps and sump pumps is the contents they pump. Sewage ejector pumps help remove home sewage waste—both solid waste and liquid gray water—via your sewer line. Sump pumps help move excess groundwater outside and prevent flooding after a heavy rainstorm. 

Both systems are commonly used in homes built in lower elevations, such as below the water or sewer line.

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