Sump Pump Discharge Line Underground Clogged!

Sump Pump Discharge Line Underground Clogged!

Is your sump pump discharge line underground clogged? This can happen due to a lack of regular maintenance like clearing the line of debris, large particles, and stains. Dropping the temperature can also be responsible for clogged discharge lines.

Whatever the reason is, unclogging the underground discharge line is essential to prevent basement floods, burning the motor, and costing expensive repair.

That’s why it’s necessary to figure out the exact source of this discharge line clogging problem and solve it appropriately. Read on to understand why the discharge line may clog and how to fix it to save on repair costs and restore the draining system.

Potential Reasons Behind Sump Pump Discharge Line Underground Clogged

After installing a sump pump, it also needs to run a discharge line to drain water to a safe distance. The length of the discharge line usually ranges from 20’ to 100’ and it is essential to restore the functionality of the clogged underground discharge line.

Though you can dig the clogged pipe up and install a new discharge line, it’ll cost around $3,000. Even, it won’t be a smart decision when you can easily determine and fix the issue at the cheapest price.

Following are a few troubleshooting:

Potential ReasonsPossible Solutions
Gunk or debris builds upClear out gunk or debris
Forming sedimentRemove sediment
Entering large objects in the lineRemove large objects
Iron OchreUse removable lid
Frozen discharge linesUnclog the frozen line

Let’s discuss briefly how these problems occur and how to solve them quickly and effectively:

Gunk Or Debris Builds Up

The sump pump discharge line underground is clogged mostly due to gunk or debris build-up.  This slows down or even blocks the pump from discharging. Regular maintenance of the sump pump discharge line is the best manner to avoid this hassle.

However, unclogging the underground sump pump discharge line is also easier.


You’ll need household tools to clean out your clogged drain pipe: a hose, plumber’s snake, bucket, screwdriver, and a wet/dry vacuum. 

To do so, unplug your sump pump and remove the screen at the drain pipe’s end. Then rinse off to get all the loose debris out. Before pulling the pump by the handle, remove the water from its basin with a vacuum.

After lifting the pump, disconnect the discharge line by loosening the clamps. Now push the leftover debris out of the pipe using a plumber’s snake and flush the pipe using a hose with higher pressure. Then connects the discharge line, puts back the sump pump, and turns it on.

Forming Sediment

Sediment build-up can also clog the discharge line and force water to pool in the sump pit. Along with continuing using the discharge line, the clog can get worse. Over time, it can force the pump motor to work harder and cause burnout.


Unlike clearing debris, removing sediment inside of the discharge line is a bit tougher. If the sediment clogs near the discharge line’s front, it’ll be easier to remove by hand. But if the sediment forms deep in the discharge line, you may have to use a shop vacuum or hire a licensed plumber.

Entering Large Objects Into The Line

If your sump pump discharge line underground is clogged, you should also check its entry and exit points for large objects. Sometimes the discharge pipe can clog due to tennis balls or pebbles that may prevent water from entering or exiting the discharge line.


You can prevent this type of clog with regular maintenance. But if it has already happened, simply remove the objects by hand to ensure continuous flow.

Iron Ochre Clogs System

Iron bacteria survive by oxidizing ferrous iron and causing iron ochre. Though iron ochre doesn’t have known health effects, it is smelly. If it builds up inside the discharge line, it can cause a thick stain and clog the drainage system.

Even if you notice the sump pump discharge pipe is overflowing or causing a basement flood, this iron ochre can be responsible for it.


To fix this iron ochre problem, you must use a removable lid to easily clean the clogs.

Frozen Discharge Lines

The sump pump discharge line can be frozen during cold weather, and the ice can block water from discharging.

The sump pit’s drained water gets backed up if the drainage pipe’s end is clogged with ice. Hence, the sump pit collects excess snowmelt water inside the home instead of draining it at a safe distance.

That’ll force the sump pump to run continuously while preventing water from draining out. As a result, the sump pump will become overwhelmed and end up burning out and overflowing in the basement.


To unclog the frozen discharge line, run warm water through the system. This will melt the ice and ensure continuous draining. Plus, install an ice guard at the beginning of the discharge line to prevent overflowing if the discharge pipe is frozen.

Attach a lawnscape outlet at the end of the discharge line to prevent debris or other critters from entering and clogging the line.



How to know if your sump pump discharge pipe is clogged?

If the discharge pipe is completely clogged, water won’t move from the basement to the outside. And it can cause an overflow in the basement. If the water moves slowly, it means the discharge pipe is blocked by debris.

How to thaw an underground sump pump discharge line?

You can run hot water in the sump pump discharge line so the ice can melt down quickly. If it doesn’t work, hire a professional contractor to thaw your buried sump pump discharge line.

How to inspect a sump pump discharge line?

Learning how to check the sump pump discharge line will come in handy to keep the water draining continuously. To do this, trace the discharge line until it goes through an outside wall and memorize the area. Find the opposite spot, locate the same discharge pipe, and trace it to the end while preparing a note on this condition.

Final words

Keeping the underground discharge line in good condition is essential to keep the yard dry, comfortable, and healthy. Once you notice the sump pump discharge line underground clogged, check the line for those reasons listed above.

If you discover that any of these options is to blame, follow the recommended procedure. If none of these are the culprits, talk to a licensed plumber for rescue and ensure regular maintenance to prevent repeating the hassle.


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