How Deep Should a Sump Pump Discharge Line Be?

Are you trying to install a sump pump discharge line yourself but need help figuring out how deep should a sump pump discharge line be? We’ve got you covered.

Installing your drain line at the incorrect depth and not digging your trench sufficiently deep can cause terrible outcomes like a frozen line, a soggy lawn, and lines that are only partially drained. Digging your pipes at the correct depth is fundamental to ensuring they function correctly.

In this post, we will outline how deep should a sump pump discharge line be to drain sump water properly.

Discharge Piping Depth

Let’s begin with how deep should a sump pump discharge line be.


Installing the sump pump discharge line two feet below the frost line in your county is critical. This prevents water in the pipe from freezing and clogging while allowing for easy digging and access to the trench in case of problems. 

It is critical to install the lines 2 to 3 feet underground in significant parts of the United States. During heavy snowstorms, pipes that are not deep enough may freeze.

Frost LineDepth
6 inches2.5’ to 3.5’
1’3’ to 4’
2’4’ to 5’

Digging the Trench

You can dig a trench either by hand or with a trench-digging tool. These step-by-step instructions will help you construct and install your lines correctly. 

Tools You Need

  • A trench digging tool or shovel – If you require to dig a trench longer than 5 feet, we suggest using a trench digger, which will take a few days.
  • A measuring tape – You can use a measuring tape to track how far you have dug
  • A tarp to collect the dirt onto for reburial.

Depending on the ground, depth, and length, the trench might be straightforward or difficult to dig. Begin digging where the drain pipe exits the house and finish where the drain pipe discharges. 

Make sure to dig and spread the PVC pipe at a slight downslope as water flows out of it more easily. You’ll need a more powerful sump pump if you must flow uphill and fight gravity. Hopefully, now you understand how deep should a sump pump discharge line be.

Where Should The Sump Pump Discharge The Water?

Now that you know how deep should a sump pump discharge line be, it’s time to learn where the water should be discharged from the sump pump.


Every sump pump must have a discharge pipe to transport water from the sump basin to a location outside the house. Most manufacturers suggest a line of 1.5 inches for discharging water. It must be installed outside the home and discharged as far from it as possible. 

Since many homeowners would like to connect their sump pump to their sewage system, this is against the law. Because you must treat the untreated water, it is not permissible to pump it into the sewer system. 

Sump pumps may overload the sewer system and force cities to discharge untreated water into the rivers. Because of this, a sewer line might make a home difficult to sell unless it is properly inspected. 

A septic system must be safe from wastewater lines, which can cause severe damage and a giant mess. Because discharges cannot be poured into a sewer or septic tank, you must use your yard to get rid of them. 

A professional sump pump installer will help you choose a suitable place for the water to exit your house and flow away rapidly. The line will run through a hole in the foundation or rim joist. In this way, you don’t have to worry about how deep should a sump pump discharge line be and the place from where the water should exit your home.


Common Questions About Sump Pump Discharges

Here are some common questions about sump pump discharges and how deep should a sump pump discharge line be that will help you install a sump pump discharge line by yourself easily.

  • Can I connect the sump pump line to the sewer?

This is the most frequently asked question. People who ask the question: how deep should a sump pump discharge line be, also want to know if they can prevent their sump pump water from flooding their lawns by connecting it to the sewer. 

When water is discharged from the sump pump and soaked back into the ground over and over, the easiest solution (if it were legal) would be to link it to the sewer. Unfortunately, this isn’t allowed. 

Unfortunately, the sewage treatment organizations in our communities have a limited capacity. When it rains, all the water discharged by sump pumps is poured into the sewage system, creating inundation. 

Therefore, connecting sump pumps directly to the sewer became illegal to minimize water pollution. Code enforcement officers in many areas were required to ensure that all sump pumps were permanently disconnected and discharged to the exterior of buildings.

  • How far from my house should the sump pump discharge?

Another question related to how deep should a sump pump discharge line be is the distance of the discharge area.

You should arrange the sump pump discharge area, so the water does not flow back into the sump pit. The water should be discharged far away to run out from home, not towards it. 

You can create a “shooting grade” in your discharge area to determine at what point the water runs away from home in your yard rather than towards it. This is usually accomplished by grading the yards of most homes. 

As the years go by, many yards erode and cause a problem that appears to be challenging to fix. If you have a grade problem at your home, you need professional help.

  • How to locate a sump discharge line?

This question is simple to answer. You’ll discover the sump pump in the basement or crawlspace. A round trash can is buried with a steel or plastic top lid. 

Look for a vertical pipe emerging from the pit. Follow the line until it goes through an outside wall. Make mental notes of where you find it in the basement or crawlspace. Next, go to the spot outside the house where the same pipe goes through the wall. 

Follow the line from there to the end. If the water flows underground after emerging from the outside wall, look for a spot where the water flows in the yard (you may run a hose down into the pit in the basement if the pump does not have water to pump).

  • How long can my sump pump discharge pipe be?

Now that you know how deep should a sump pump discharge line be, another question that pops in your mind is how long should a sump pump discharge line be.

The pipe can be as long as you like, so long as it slopes downhill from the sump pump to the end of the line. However, if your property slopes down from the point of discharge till the end of the line, you can make the line as long as you want, keeping in mind the engineering requirements for size and drain capacity. 

The more shallow the pipe, the faster it is likely to freeze in the winter. We must remember that the colder the discharge water coming out of your sump pit, the quicker it will cool down and freeze as it travels down the underground discharge pipe. 

The water may freeze and block your line if it does not get sufficiently cold as it travels through the line. Bury it as deep as possible, keep it as short as possible, and don’t skimp on money, as a few extra bucks spent on bigger pipes and fittings will pay off in the long run.



Various factors determine how deep should a sump pump discharge line be installed, but generally, they should be no less than 3 feet deep. The pit’s depth affects how much water it can collect, but it also affects the amount of power required to drain all of the water before it overflows. 

Hopefully, this guide answers all your questions about how deep should a sump pump discharge line be.

Michael Bowen

Michael Bowen

Michael Bowen is an ambitious entrepreneur who has been in the business of building homes since he was 19. Michael's commitment to honesty, integrity, and high-quality workmanship has earned him a reputation as one of the best in the business.

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