Can a Washing Machine Drain Into a Sump Pump?

Installing a sump pump for the washing machine in the basement may not be the best option if you haven’t made it a proper room. Discharging water from your washing machine sump pump to the storm drain or sewage drain is not recommended in most regions. There are various reasons behind these restrictions that you will get to know later. Find the other eco-friendly options through which you can discharge the wash water without using a sump pump for washing machine.

Washing Machine

Can You Drain a Washing Machine to a Sump Pump?

You should not drain your washing machine into the sump pump. It is also against the regulations of most local codes to drain water from washing machines into the sanitary sewer system. Confirm this by contacting your local city office, as there could be legal restrictions on draining gray water into the sewer system. Generally, sump pumps should carry only the groundwater in the foundation drain of the house. Draining washing machine water is prevented because it contains high concentrations of soap and other chemicals that could contaminate the groundwater. This can impact the water table and the soil in various negative ways.

Negative Effects

So how could a washing machine sump pump draining water be harmful? Contamination of groundwater can harm the plants and animals that consume this water. Various chemical contaminants in soap can be toxic to both plants and animals. 

Moreover, you could be charged with breaking local codes if you go against the municipality to discharge washing machine water into the sump pump. Sometimes, the inspectors may find this issue during certain house inspections. So, you need to fix this problem before you buy or sell the house.

How to Drain Your Washing Machine?

Not having proper drainage for the washing machine can cause various issues. So, even if you cannot drain the washing machine into the sump pump, there are other ways in which you can drain your washing machine. 

Laundry Tub

A laundry tub is the best way to drain your washing machine as recommended by most washing machine manufacturers. It is similar to a large sink, made of porcelain, and used to soak clothes. The drain hole is located about 25 – 30 inches above the ground. You can drain the wash water from your washing machine into this drain hole.


You can also use the option of installing a standpipe to drain the washing machine. It is a vertical pipe that connects to a P-trap and a drain. The top of the standpipe should be above the overflow level of the washing machine and needs to be vented correctly. The standpipe should be at least two inches in diameter for the water to flow properly. Although you can also use a standpipe of 1.5 inches in diameter, it may block the water flow when the diameter gets smaller. You can try this or hire a professional plumber to install the standpipe.

Underground Pipe Connection

Despite being the most expensive drainage option out of all, this is the best. You need to install underground standpipes for this. So, it requires some digging down the concrete to lay the pipes. Then connect the pipes with the washing machine so that it removes the water out of the house into a suitable wastewater discharge.

Trash Pump and Pit

A trash pump can handle gray water with solid particles. So, you can use it to discharge washing machine water containing soap and lint. Although it can handle large amounts of water, the pressure needs to be low. You can get a trash pump installed by a professional or sewage company.

How to Run a Washing Machine Drain Outside?

For this, you need to replace the drainage pipe and connect it to the piping running in your backyard and then connect this to the gray water tank. Since the plumbing requirements differ from one washing machine to another, you need to follow the different setups closely. Before you start, plan how you are going to drain the washing machine, whether it is a barrel or a drainage system. If you are planning to drain the water into a barrel, make sure that it is large enough to hold the total amount of water given out by the washing machine. Use a hose with a diameter of 1 inch to allow water into the tubing. Check and make sure that everything is installed properly before you turn on the washing machine.

Frequently Asked Questions

Does Shower Water Go to Sump Pump?

Despite the bad consequences, in most homes, the water from the washing machine, shower, and even the dishwasher flow into the sump pit. So, yes, the shower water goes to the sump pump. However, sump pumps are assigned only to remove the groundwater that seeps into the basement through the foundation. So, there should be alternative ways to deal with gray water from your bathroom.

Why Does My Kitchen Sink Gurgle When My Washing Machine Drains?

As the water flows from the washing machine draining, it will create an air-tight seal in the pipe. Therefore, a vacuum is formed as the water pushes and removes the air ahead of it. This sound of air escaping causes the gurgling noise which you hear from the kitchen sink since the drainage systems are interconnected. You might even hear this sound from the bathtub or the toilet as your washing machine drains.

Can You Have a Washing Machine in a Basement?

Do not install a washing machine or dishwasher in an unfinished basement or cellar. If you need to have your washing machine in the basement, then make sure that you make it into a proper room. This is because basements without proper drainage mechanisms increase dampness and humidity. You should also focus on dehumidifying the basement and keeping it dry as you use the basement.


It is always better to check the legal concerns in your region before planning to install a sump pump for the washing machine in the basement. It will save you from a lot of trouble, including fines for damaging the environment. If you are unaware of finding the best way to deal with your gray water, you can contact a professional to help you with a proper drainage mechanism. Leaking sump pumps may also cause inconveniences if not installed correctly.

Related Resources