Sewage Lift Pumps: Types, Functions & Depth Concerns

During sewage treatment, there are times when moving such wastewater from a lower to a higher level becomes necessary. This largely depends on the construction of your sewage system.

For such a task, an important piece of equipment known as the sewage lift pump is necessary.

The name alone speaks volumes as it performs the primary task of moving the waste from lower to higher levels of land. This is where most of our discussion will be focused on.

Incorporating Sewage Lift Pumps into Gravity Systems

Gravity plays a key role in the treatment of sewage with emphasis on movement. Such systems are designed to easily transfer sewage from one point (usually a septic tank or sewer line) to the next.

The action of gravity is essential to the entire process.

However, while gravity is normally sufficient for some sewage systems, it doesn’t serve all situations. In other words, some sewage systems will require the movement of the wastewater from lower to higher elevations.

This is unlike gravity systems where wastewater moves from high to low elevations.

For this to be possible, a sewage lift pump needs to be in place. The lift pump only needs to get sewage or wastewater over the elevation for the action of gravity to set in.

Functions of A Sewer Lift Pump

Although we’ve highlighted the basic operations of a sewage lift pump, it will be necessary to further explain how such operations play out.

Homes found within depressions will require sewage lift pumps to remove or get rid of sewage.

In most cases, a holding facility known as a wet well or underground hole is built to collect sewage from one or more buildings. As sewage accumulates within this holding tank, a lift pump is triggered once it reaches a point.

Of course, this requires a sensor that usually accompanies the pump.

The sewage lift pump will move such wastewater or sewage through connecting pipes that move upwards. Such pipes are known several names including sewer force main or rising main. This action aims to convey sewage to a gravity manhole.

From here, it’s moved by gravity to the treatment facility.

As expected, the role of the sewage lift pump ends when the sewage is successfully transferred or when the transfer is completed. This process is repeated whenever the wet well or sewage holding tank gets filled.

There Needs to Be Backup

For a sewer system to function effectively, all its components must be in good working condition.

Sewer systems having lift pumps need to be fitted with a backup. This is mostly done to prevent a situation where a lift pump fails.

It’s possible for sewage lift pumps to fail. When this happens, a backup pump helps complete the job. This situation helps prevent sewage from overflowing the wet well. That way, wastewater is kept under control.

Without a backup pump, it will only be a matter of time before disaster unfolds.

So, in ideal conditions, a wet well needs to be fitted with multiple pumps which will serve to prevent sewage from overflowing. Single pumps may become overburdened with frequent use, thus failing.

Such situations can be avoided by simply making provisions for backup.

Depth Matters

The depth of your wet well matters a lot in regards to the type of sewage lift pump needed.

Here, we’re simply pointing to the need for a match between the pump type and the wet well depth. When there’s a mismatch between the two, several problems may result.

Some of the issues you might face with the use of unsuitable lift pumps include high energy bills and a short lifespan. What do we really mean by high energy bills and the short lifespan of sewage lift pumps?

To better understand, we’ll need to briefly discuss each of these points as follows;

  • High Energy Bills

A sewage lift pump that doesn’t fit the depth of a wet well normally brings up several issues.

There’s the likelihood of the pump running continuously and unnecessarily. Plus, such a lift pump might cycle on or off. Both of these scenarios add up to high energy bills.

  • Short Lifespan

A sewage lift pump is designed to serve a period of time.

Now proper use, getting the right pump type as well as maintenance enables it to reach or attain its intended lifespan. Anything short of this will only limit the period it serves you.

Getting the Right Sewage Lift Pump

To get the right pump for your wet well, it’s necessary to know the different types and how they work.

Sewage lift pumps fall under two categories; those that push water to the surface as well as those which pull water.

Irrespective of the category a lift pump belongs to, it should be the right size for the job. This still boils down to the depth of the wet well. Key things will need to be identified to get the right size.

They include the recovery rate, measurement from the ground to the water surface, and static water level.

Records are usually kept for each of these key details. You might want to check with your Well Permit mostly filled by the contractor drilling the wet well. This enables you to choose a pump that fits your well’s depth.

Types of Sewage Lift Pumps

When it comes to the types of lift pumps available, there are several! These include jet pumps, shallow well-pumps, and deep well-pumps. Each of these is well suited for certain depths and use.

Let’s take a brief look at these pump types.

  • Jet Pumps

Jet pumps are mostly those found above ground. Shallow pumps are among the options found under jet pumps.

As the name suggests, shallow pumps will draw wastewater from wet wells not deeper than 25 feet.

  • Deep Well Pumps

Deep well pumps go much deeper as they pull water from depths of 110 feet. Unlike shallow pumps which are designed for above ground installation, deep well pumps are installed within or inside the well.

Sewage lift pumps play a crucial role in the transfer of sewage for onward treatment.

Here, we’ve been able to discuss several aspects of their operations including how they function with gravity systems among other things.

Leave a Comment

Your email address will not be published. Required fields are marked *