Sketch of a common sewage grinder pump used in a modern basement Septic & Sewage Pumps
Buy, Install & Repair Guide for Sewage Pumps, Septic Pumps, Effluent Pumps & Sump Pumps

  • POST a QUESTION or READ FAQs about buying, installing, and repairing sewage ejector pumps and pump controls and about sewage and sump pump safety

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This article explains the differences between Septic System Pumps and Sump Pumps , Sewage Ejector Pumps, Septic Grinder Pumps, Sewage Pumping Stations, & Septic Pump Alarms.

Advice is given for septic tank effluent or sewage pump selection and use.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

What are Septic Pumps, Sewage Grinders, Sewage Effluent Pumps, & Sump Pumps

Discussed here: Septic tank pumps, septic grinder pumps, septic effluent pumps - Septic Pump Alarm & Septic Alarm demo video; Definitions of types of septic system pumps; Warning of items that will clog septic pumps and grinder pumps & Warning about trip and fall and health hazards of exposed sewage ejector pumps.

Our septic tank alarm video at right demonstrates the operation of a septic tank pump system alarm. More videos on septic system maintenance are


Septic alarms indicate when the septic tank pump is not operating. Repair is needed promptly.

Readers have asked the difference between a sump pump, simplex and duplex sump pumps, a septic effluent pump, a sewage grinder pump, and an effluent pump. This article explains the various types of pumps and their purchase, installation, inspection, and maintenance.

Here we use "sewage pump" and "septic pump" as synonyms. Both classes of pumps handle blackwater or sewage. It is their destination that is different.

Duplex sump pump installationA sewage pump, speaking strictly, is pumping blackwater (toilet waste) to a public sewer line.

A septic pump, strictly speaking, is pumping blackwater (toilet waste) to a private septic tank and drainfield system.

But people use these terms loosely, and even among manufacturers it is important to ask, or read the manufacturer's description of what a particular pump model is intended to handle.

In addition, even among sewage pumps and grinder pumps that are intended to either pass solids or grind solids up and pump them, the vulnerability of different pump models to damage, clogging, or motor burn-up from debris that people may flush down drains and toilets varies - a problem we discuss further in this separate article:


First let's define the different types of pumps handling wastewater.

What is a Sump Pump?

Definition of Sump pumps, which we discuss on this page, are designed to remove unwanted water, such as surface or ground water that leak into a building. Sump pumps only have to pump water, never solids.

A sump pump is normally installed in a pit at the low end of a basement or crawl space floor.

In a bad building water entry situation water runs across the basement/crawl space floor into the sump pit where it is pumped away (after already wetting the building and inviting a mold contamination problem). This condition pertains when water is entering a building through foundation walls, often because the roof drainage or surface runoff are directed right against the building foundation itself.

Keeping gutters and leaders working and correcting outside drainage errors are critical in keeping water out of a building. Doesn't it make more sense to prevent water from coming into a building than to let it in and then pump it out?

In a good situation, openings in the sides and bottom of the sump pit, or an under-floor drainage system direct subsurface water into the sump pit before the ground water level rises enough to send water into the building.

Over several years of operation, and partly by pumping a little soil silt as it operates, a sump pump may actually improve the flow of under-floor water into the sump pit, thus reducing building water entry.

What is a Septic Pump, Sewage Pump, or Grinder Pump? Definitions of the Types of Septic Pumps & Grinder Pumps

Typical home sewage grinder pump

Septic pumps, sewage pumps, or sewage ejector pumps are designed to remove sewage from a building where plumbing fixtures and their drains are lower than the building sewer line and/or septic tank.

Septic pumps have to move solids, either by being able to pass large solid objects through the pump without clogging, or by grinding the solids into fine debris.

Municipal lift stations, duplex sewage pumps, septic alarms, grinder pumps, submersible pumps, are discussed in more detail in this article.

A sewage pump may be designed to either pass solids up to a certain size, or it may be a sewage grinder pump designed to macerate solid waste so that it can be pumped through a sewer line, perhaps a smaller diameter "force main" sewer line to a public sewer or septic tank.

Sewage grinder/ejector pumps are available in various horsepower models, typically from .5 to 1hp for residential applications, and are sold to operate at various voltages including 110-120V, 220-240V, 440-480V, and even 600V models using either single phase (most common) and three-phase motors.

Typically the piping connection from the ejector pump to the building sewer line is 2" and incorporates a check valve (the white valve shown in the front-right pipe in our photo at left).

What is a Septic Effluent Pump?

Septic effluent pumps are used to move clarified septic effluent out of a pumping chamber to a drainfield.

Septic effluent pumps do not have to move solids, but are built to standards of durability and duty cycle more demanding than a typical sump pump used to remove ground water from a building.

Typical examples of applications where septic effluent pumps are used include raised bed, mound, or sand-bed filtration septic systems in which the absorption bed is located higher than the septic tank.

In these installations septic effluent is pumped from a final chamber in the septic tank or from a second effluent chamber up to the absorption system.

Watch out: PUMP MANUFACTURERS may show that the same pump models can serve as a sump pump, effluent pump, and de-watering pump.

But that is not universally the case - in other words, there are some sump pumps that work just fine as effluent pumps, but other sump pump models (such as low-cost sump pumps using a vertical float and rod switch and intended for indoor de-watering in basements) may not be suitable for septic effluent pumping and may not be designed to be used in a septic effluent tank or drywell.

Be Sure to Select the Proper Septic or Sump Pump Type

Sewage pump (C) Daniel Friedman

The distinction among sewage pumps or septic pump types is important when installing or repairing a septic system that uses pumps since choosing the wrong pump can mean a short operating life for the pump, an unreliable septic system, and unnecessary expense.

In addition to explaining these different septic pump types, in this article we also describe a community sewage pumping station and septic pump alarms as well as the inspection and installation details for this equipment.

Beware, there may be some confusion, depending on with whom you speak, because people don't always use just the right terms for construction or septic system parts - and the right sewage pump term, or right septic handling product versus the wrong one can be an important distinction.

Sewage ejector pump installation and maintenance are discussed in detail 


Septic pumps used for pumping air in aeration systems and septic pumps used to move effluent in a drip dispersion system are discussed under the appropriate septic system type which are outlined


Water removal pumps: In a pinch we've seen people use SUMP PUMPS for septic tank effluent pumping but that is not a durable nor a recommended solution.


Sewage Pumps Clogging Failures

Details about cause and prevention of sewage pump clogging and damage have been moved to a separate article at SEWAGE PUMP DAMAGE & REPAIR.

Watch out for the following conditions that cause clogging and even burnup of various types of sewage pumps, grinder pumps, ejector pumps, and septic pumps:

Don't Flush These Items Down the Toilet - They Clog or Burn Up the Grinder Pump

For complete details about stuff that ought to be kept out of drains and waste systems see our complete TOILETS, DON'T FLUSH LIST

Septic Pump Drain Venting

Depending on the lift height and other site conditions there are two sorts of vents one may find on any lift, grinder, or ejector pump or sump pump:

  1. a small drain hole specified by the manufacturer drains back wastewater from the vertical drain line, below the check valve, into the sump or pumping pit or chamber

  2. a separate vent may vent the sewage ejector piping to the open air outdoors

Model plumbing codes define a sump vent:

A vent from pneumatic sewage ejectors, or similar equipment, that terminates separately to the open air. - UPC 2006 

Sewage or Septic Pump Safety Warnings

Sump pit accident (C) D Friedman / T.C. Reader Question: dog and daughter fell into sump pit; dog died.

I recently moved in a house with this nasty hole in the basement.the first night my dog fell in and my daughter fell in the get the dog.2 hrs later the poor dog died but my daughter in ok.what can be put over this sump pump hole firmly so this does not happen again?

I am devastated for my dog but what if it was my 3yr landlord was uncaring can you help! - T.C.

[A photo of the sump pit was subsequently provided by the reader - shown at left]

Reply: consult your doctor, inform your landlord in writing, look for other unsafe conditions

A competent onsite inspection by an expert usually finds additional information that can help understand just what the hazards are in your home, not just around the sump pit. Your email raises these concerns in my mind:

  1. What kind of "sump" are you talking about? If this was a groundwater ejector pump or typical "sump pump" installation, the hazards may include injury, even drowning, as well as exposure to possible contaminants in groundwater;

    if you are talking about a sewage ejector pump the hazards of bacterial and other pathogenic infections to your daughter and family are significant; in either case you should consult your family doctor immediately if your daughter was exposed to potential contaminants or sewage.
  2. The inexperience or inattention that causes a building owner to leave a sump pit open, exposing occupants to a trip and fall hazard even if there are no other biological health hazards involved, leads me to suggest that there could be other safety hazards at the property.

While the topic is different, our advice to renters who encounter mold contamination at a property includes the importance of making sure that the building owner and manager know, in writing, of your concerns.



  1. Block or rope off access around this hazard; depending on the type of sump pit that was installed, there may be a prefabricated and safe cover that can be installed over the opening. Such covers are sold at building supply stores such as Home Depot and Loews.

    Normally I'd expect that correction to be the responsibility of the building owner. But your first priority is to prevent another accident.
  2. Inform your landlord of the accident and of this unsafe condition.

Please keep me posted on how things progress, and send along photos of the sump hole if you can. Such added details can help us understand what's happening and often permit some useful further comment. What we both learn may help me help someone else.

Reader Follow-Up:

Hello, these are the pics i have. And i have no idea what kind of pump it me please. im scared for my kids.also little fly nat bugs are coming from it.


Sump pit with cover off - sudsy © D Friedman at Your photos show an ordinary sump pump used to remove groundwater from below a basement slab and to carry off water that leaks into the basement, runs across the floor and enters the sump pit.

It also looks as if in most of the photos a sump pit cover was in place - so it would be useful to know if the cover has just been added, or was it left off, or how else did your daughter and pet fall into the pit?

From your photo [see covered sump pup pit photo above] it looks as if the pump and controls are so high in the sump pit that the cover, perhaps a home-made one, includes a large opening in its top through which a child or pet could step.

Also, one of your photos [photo of open sump pit shown at left] shows the sump pit with the cover off - and the water in your photo (it's a bit blurry picture) looks sudsy.

If the building dumps a laundry sink or washer into the pit and is then pumping that washer drainage to the ground surface outside, that'd most likely be a health and plumbing code violation.

Finally, it also looks as if the floor is broken up around the sump pit, perhaps to improve water entry into the pit from the floor surface? Is that uneven surface also a trip hazard.

Meanwhile, make sure the sump cover is secure and block off access to this corner to protect your family from trip and fall hazards.


List of Producers of Septic Pumps, Sewage Pumps, Grinder Pumps, Effluent Pumps

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Septic Pump Articles


Continue reading at SEWAGE EJECTOR / GRINDER PUMPS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see SEPTIC PUMP FAQs - questions & answers posted originally at the end of this page.

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SEPTIC SYSTEM PUMPS at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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