The most common way to drain washing machine water is by routing the washing machine drainage line directly to your sewer line. This way, water from your washing machine joins the other wastewater from your shower, sinks, and toilets. This is a great choice if you are living in a home that is linked to a municipal sewer system. However, if you have a septic system it is best to drain your washing machine water into a separate gray water system, which will safely disperse the water underground. Finally, you can drain washing machine water to a utility sink in your laundry room, but this should only be used for temporary purposes or as backup drainage in case of an overflow.
Where Does Water From Your Washing Machine Drain To?
Where your washing machine water drains depends on whether your home is linked to a municipal wastewater system or if you have a standalone septic system. If your home is connected to a municipal sewer system and you do not have a septic tank, your washing machine drains to the sewer. This means your washing machine water drains into the same main sewer line that your showers, bathtubs, sinks, and toilets drain to.
- If your home does not have a septic system then washing machine water will drain to the sewer main in your home.
- The sewer main also handles wastewater from sinks, showers, and toilets.
- If your home does have a septic system, your washing machine may drain to a separate gray water system, such as a belowground dry well.
- If you have a septic system, it is best to not drain your washing machine into your septic tank.
If your home does have a septic system, in most cases your washing machine drains to a gray water system. This is usually a belowground dry well that allows the water from your washing machine to gradually disperse into the soil at a safe distance from your home. This system allows you to safely drain your washing machine water without filling your septic tank.
Can Washing Machine Water Drain into Your Yard?
Although washing machine water will not harm your yard or garden, it is not a good idea to drain washing machine water into your yard. Doing so can cause flooding, erosion near your home’s foundation, washouts, and unsightly pools of water with soap scum floating in them. Do not drain your washing machine to an aboveground outlet in your yard.
- You should never drain washing machine water to an aboveground area in your yard.
- Draining washing machine water in your yard can cause flooding and erosion.
- An underground gray water system can be used to safely drain washing machine water into your yard, well below the soil surface.
The safe and effective way to drain washing machine water in your yard is to install a belowground gray water system. We will discuss gray water systems in more detail below. For now, keep in mind that a gray water system involves running a pipe from your washing machine, underground, to an underground water dispersal system at least 12 feet (3.7 meters) from your home, but it is a better solution than just draining outside.
3 Useful Washing Machine Drainage Options
The dirty water in your washing machine can be drained in a couple of ways. The best way depends on your home. It is best to work with professional plumbers to design and install a safe washing machine drainage option that meets the building code.
Sewer Line
The default choice for draining your washing machine is to direct the water flow to the sewer line. This means a pipe must run from your washing machine and connect to the sewer main. The pipe will direct the dirty water from the washing machine to the main sewer line.
- Run a drain pipe from your washing machine that empties into the sewer main for your home.
- This installation will safely direct water from your washing machine to the wastewater system in your home.
- Installing a new washing machine drain in an existing home is best done by a professional plumber, since it requires precise work.
Installing a new washing machine drain pipe requires plumbing expertise. It is best to hire a licensed plumber if you want to add a washing machine drain pipe where there is no existing drain line. Several building codes must be met in order to prevent washing machine water from backing up, backfilling the washing machine, or flooding your home. Making sure your washing machine P-trap is at the correct height is a crucial step.
Dedicated Gray Water System
Instead of draining your washing machine to a sewer line, you can instead direct the water into a gray water system on your property. “Gray water” is the term for used water that is not sewage but is not clean water either. It includes water from washing machines, sinks, and baths, but not toilets. Gray water is not drinkable, but it is safe for use in irrigation and can be released onto your property. Like other washing machine drainage systems, gray water systems should be designed and installed by licensed professionals. An improperly built gray water system can back up, flood, or cause standing water on your property.
- Your washing machine can drain to a gray water system on your property, which safely disperses the water belowground.
- Gray water systems should be installed by professionals, to ensure proper drainage and prevent flooding.
- Most gray water systems involve running underground pipe connections from the washing machine to an underground dry well a safe distance from your home.
A gray water system for a washing machine requires you to run an underground pipe from your washing machine to a belowground gray water dispersal system, such as a dry well. This system must direct water at least 12 feet (3.7 meters) away from your home, to prevent erosion near the home’s foundation. A dry well or another belowground dispersal system will allow the water from your washing machine to safely percolate into the surrounding soil without causing flooding, erosion, or sinkholes. For more information on how dry wells are used to control water, check out our article on dry wells and french drains.
Overflow to Utility Sink
If your laundry room has a utility sink, you can drain your washing machine into this sink temporarily. Draining directly to a sewer line or a gray water system are the best permanent solutions. However, you can treat a utility sink as a backup in case of a plumbing issue or an overflow.
- For temporary or emergency purposes, you can drain your washing machine to a nearby sink in the laundry room.
- Run the washing machine drain hose up and over the edge of the sink, so the end of the hose is pointing toward the sink drain.
- Secure the hose in place with tape, zip ties, or other implements to make sure it does not come loose when water begins to forcefully drain.
- The hose must come up at least 6 inches (15 cm) higher than the drainage outlet on the back of the washing machine to allow proper drainage.
To drain your washing machine into a sink, run the drainage hose on the rear of your washing machine up and over the edge of the sink. Then, secure the hose so that it will remain in place when water begins to drain from the washing machine. It is essential that the sink is at least 6 inches (15 cm) higher than the drain outlet on the rear of your washing machine. This will prevent premature drainage and other problems. A sink drainage system is not permanent and is prone to problems, so it should not be treated as a true drainage solution for your washing machine.
Should Washing Machine Water Go into Your Septic Tank?
It is not a good idea for your washing machine water to drain into your septic tank. The large amounts of water drained from your washing machine can overwhelm your septic system, causing clogs and contamination. This installation can even cause waste to be released from your septic tank, into the drain field, before it has been processed. Instead, it’s best to route your washing machine to a dedicated gray water system that is separate from your septic tank.
- Washing machine water can overwhelm a septic system, causing clogs, premature release of material into the drain field, and contamination of your property.
- Instead of routing your washing machine drain to your septic tank, consider a gray water system.
- Work with a professional contractor to install a gray water system for your home.
Because septic tanks can easily become overwhelmed by washing machine water, it’s best to avoid draining your washing machine into your sewer line or a sink if you have a septic system. When installing a new washing machine drain line in your home, contact a professional plumber and ask if they can help install a gray water system for your home.
How Should a Washing Machine Drain Be Hooked Up?
When you are planning to install a washing machine drain, keep the following facts in mind:
- Drain your washing machine to the main sewer line if your home DOES NOT have a septic system.
- If your home DOES have a septic system, drain your washing machine to a gray water system.
- In an emergency or for a temporary fix, you can drain your washing machine to a utility sink in your laundry room.
- It is not advisable to drain your washing machine to your septic tank—this can cause overflows and clogs.
- Always work with a professional plumber to install a new washing machine drain or gray water system.
By following the right steps for your home and wastewater system, you’ll be able to safely use your washing machine without the risk of flooding. Getting the job done right initially will save you from plumbing problems in the future.
