The Right Way To Use A Garbage Disposal With Septic System

One of the most common questions I get regarding septic tanks is whether or not they can be used with garbage disposal. Because garbage disposal introduces solids into the plumbing system, you should carefully consider the choice between using one if you have a septic tank system set up.

It is not advised that you use a garbage disposal if you utilize a septic tank system in your home. Garbage disposals are intended for use with municipal sewer systems and can lower the effectiveness of your septic tank. This can create additional costs associated with your plumbing system.

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If you are planning on using a garbage disposal with a septic tank, there are some precautions that you should take to ensure you don’t have any issues. These will be covered in this guide so you can make an informed decision regarding the use of garbage disposal with your septic system.

Are Garbage Disposals Bad For Septic Systems

Standard garbage disposals are not designed for use with septic tank systems. The solids that are introduced by the wastewater coming from your disposal will enter your septic tank and collect at the bottom. This collection of solids is usually broken down naturally when the amounts are small enough.

 Using a garbage disposal will introduce many more solids into your septic tank system than it can naturally break down, causing sludge accumulation. This will lower the capacity of your tank and also its effectiveness at treating wastewater.

This will cause your tank to need pumping far more frequently than normal, in some cases up to every six months. Septic tank pumping can be quite costly but generally is only needed once every year or two. Using a garbage disposal with your septic tank could lead to more expenses over time.

If you are interested in using a garbage disposal to be more eco-friendly, there are other more efficient ways to dispose of food, like composting, that you can consider. If you still plan on using a garbage disposal with your septic tank system, there are some things you should never put down the disposal.

What Not To Put In The Garbage Disposal With A Septic Tank?

There are several things that I advise not putting in the garbage disposal if you have a septic tank. Garbage disposals are designed for use with highly biodegradable food items and are not suited for:

The pits or peels of fruits in Garbage Disposal
  • The pits or peels of fruits
  • Tough, stringy vegetable scraps like celery or corn husks
  • The skins of onions.
  • Eggshells
  • Starches like pasta, rice, and oatmeal due to their ability to expand with water and clog pipes
  • Nuts
  • Any type of meat
  • Coffee grounds
  • Soils
  • Fats or oils
  • Any non-food items

Once these items enter your plumbing system leading to your septic tank, they will not decompose fast enough and cause clogs and sludge buildup. Large accumulations of these types of items will need to be pumped and removed by a technician.

If a clog in your septic system goes unaddressed for too long, it could cause significant sewage backup into parts of your home through the drains, sinks, and showers. When this happens, it will damage not only parts of your home but likely the tank as well.

It is important that you note these items that are not acceptable and avoid placing them down the disposal if you are using a septic system at your home. There are very few things that are acceptable to put down a garbage disposal that is attached to a septic system.

What Can You Put In A Garbage Disposal With A Septic Tank?

A garbage disposal can be used with a septic tank without issues if only certain items are put down the disposal. All food items you put down in the garbage disposal need to be easily biodegradable to ensure they can be broken down once they enter the septic tank system.

The following items can be safely put down the garbage disposal leading to your septic tank:

Ice cubes in Garbage Disposal
  • Peeled and pitted fruits
  • Soft vegetables low in fibre
  • Ice cubes
  • Dish soaps

The list of acceptable items that can be put down at garbage disposal connected to a septic system is quite small compared to what is acceptable with municipal sewer systems. You should keep these restrictions in mind when considering installing a garbage disposal with your septic system.

Garbage disposals that are connected to larger sewage systems can handle a wider variety of food items with no issue. This is because the sewer system is regularly cleared and is much larger in capacity than your tank is.

You may be wondering if there are special garbage disposals for use with septic systems. This will be covered in more detail below.

Do You Need A Special Garbage Disposal For Septic Systems?

If you wish to use a garbage disposal with your septic system, there are some options out there that will minimize the risk of damage to your system. These special garbage disposals will also help mitigate any non-desirable items that get poured down the garbage disposal.

They are called septic assist garbage disposals. They will be covered more in the section below.

Septic assist garbage disposal

What Is A Septic Assist Garbage Disposal?

Septic assist garbage disposals are similar to standard garbage disposals, with a few notable differences. They are designed specifically to reduce the strain on a septic tank system by introducing bacteria to help break down food items.

That being said, you should still be cautious about what you let go down the disposal, as it cannot completely eliminate the risk of sludge buildup in your septic tank system. Too much sludge accumulation will still cause issues with your tank that will require pumping to resolve.

Using a septic assist garbage disposal in addition to injections is the safest way to incorporate garbage disposal into your septic system. The design of the disposal and the added bacteria from the injections will ease the strain on the tank as much as possible.

Choosing the right garbage disposal for your septic tank system can help you avoid these types of issues in the future.

What Is The Best Garbage Disposal For Septic Systems?

While septic-assist garbage disposals have their benefits, you can still use a standard one safely without many issues if you are careful. Still, you should consider purchasing a garbage disposal for your septic system that is designed to help ease the burden on your septic tank by all of the extra food particles.

Garbage disposals that feature some form of injection technology are advised, as they will help introduce beneficial bacteria that will break down sludge easier. Choosing garbage disposal with a high-powered grinder will also benefit your septic system.

The higher the RPM rating of your disposals grinder, the finer food will be cut up before it reaches your septic tank. This will reduce to load on the tank and make it easier to break the food down. That being said, even if you use a high RPM grinder and beneficial injections, you should still avoid placing too much solid food down the disposal.

Over time, the food collected at the bottom of your septic tank will need to be emptied. How often this needs to happen will depend directly on your level of disposal usage, and the items put down into it. I advise checking the manual of your garbage disposal to see what measures are put in place to handle septic tank systems.

If you already own a garbage disposal, it is important that you consider its specifications before installing a new septic tank. If you are having it professionally installed, let them know about your garbage disposal, and they will offer you advice on whether or not it is appropriate for use with your new system.

Following these precautions, you can safely use a garbage disposal with your septic tank system without any serious issues.

Garbage Disposals And Septic Tanks

Garbage disposals and septic tanks can be used together as long as the proper precautions are taken. Septic tanks are sensitive to solids like the foods placed down a garbage disposal and are generally only intended to process liquids.

Garbage disposals that are linked to a municipal sewer system do not have the same restrictions for use that they do when used with a septic tank system. Your septic tank has a finite amount of space inside of it that can be limited when the disposal is used too much.

This can lead to large accumulations of sludge at the bottom of your tank that could cause clogs and other costly damage to your system. Because of this, it is important to only put items down the disposal that is highly biodegradable.

This will allow the beneficial bacteria built up in your tank to clear the food before it has time to cause clogs in the system. While garbage disposals are frequently used with septic tank systems, they generally require more routine maintenance and pumping to operate.

Because of the extra solids present in the tank, pumping could be needed up to twice as much as normal. As long as you use your garbage disposal sparingly and do not place items that are hard to degrade down it, you can use it with your septic system without issue.

Any issues that do arise are likely due to some form of issue caused by the excess sludge in the tank caused by the disposal. Keep in mind these restrictions are important and will be covered more in the section below.

Things To Consider If You Have A Septic Tank

There are several things that you should consider if you have a septic tank and are considering installing a garbage disposal or vice versa. The most important thing to consider is your tank’s overall capacity. If your tank is small, it will likely fill up with sludge and food particles faster than a larger one.

This means that it will need more frequent pumping, potentially doubling the overall expense of the maintenance of your system. You will also need to consider the things you are putting down at your disposal and how much you plan to utilize them.

Listed below are some tips for running your disposal with your septic system in a way that avoids issues.


  • Grind all of your food using cold water. Cold water will solidify any grease or oils that may be present so they can be transported through the system easier.
  • Use dish soap and cold water to clear out the disposal after using it or washing dishes.
  • Use your garbage disposal regularly to prevent rust and corrosion of the blades.
  • Pre-grind any larger or harder items that you wish to dispose of in your garbage disposal.


  • Use your garbage disposal for anything but easily biodegradable food items.
  • Turn off the garbage disposal motor before the grinding has been completed.
  • Grind highly fibrous material that could potentially tangle or jam in the disposal’s motor.
  • Pour any types of oils, fats, or grease down the disposal.
  • Put large amounts of any food item down the disposal at once.
  • Put any type of starches that will expand, like pasta or rice, down the disposal.
  • Put coffee grounds down the disposal.
  • Grind any non-food item.

As long as you follow these tips and avoid items that could potentially clog your septic system, you will likely have no issues using a garbage disposal with your tank. Of course, there are other alternatives to garbage disposals, and they are often eco-friendlier and more efficient at food disposal.

Garbage Disposal Alternatives

Garbage disposal alternatives are becoming increasingly popular due to their more eco-friendly nature. Alternative options are also a better option for a septic tank system. While you could pair a garbage disposal with your septic tank system, you will not be able to utilize it to its full potential.

A simple alternative that you can consider is a simple sink strainer. A sink strainer can catch any food particles left behind while still draining any liquid present. The strainer can then be emptied into the garbage can like normal.

Sink strainers are cheap and work efficiently at keeping food particles out of your septic tank system. This will help avoid clogs in the system that could cause issues. Another popular alternative to garbage disposals is compost bins.

A compost bin can be built yourself, which is a plus if you enjoy outdoor DIY projects. It can be used to help cultivate gardens and the growth of plants and trees in your yard. Even if you do not wish to cultivate using a compost pit, it is still a very efficient way to deal with food waste.

All of the food particles you place in the compost bin will be broken down and turned into compost over time. Once this happens, you can use this compost to fertilize plants or dispose of it. For most, this is a better option to consider if you have a septic tank system set up.


While you can use a garbage disposal with your septic tank system, it is generally not advised that you do so due to the issues that can arise. Because of all of the excess food particles that will be introduced to your septic tank from the disposal, it will be much more prone to clogs and sludge build-up.

This could lead to more frequent maintenance and costly repairs. That being said, if you follow the proper precautions, you can likely use a garbage disposal with your septic tank system with few issues. You should consult with a technician if you are having any problems and they will be able to tell you if a garbage disposal is suitable for your setup.