Can I Have a Garbage Disposal With a Septic Tank?

In the United States, there are an estimated 27 million homes that operate off of septic systems; however, only 22% of these homes are equipped with a garbage disposal.


Most homeowners forgo installing a garbage disposal in their home because they mistakenly believe that the two are not compatible, or because they believe it might be against their city’s regulations.

In reality, the U.S. Federal Housing Authority has stated, along with other key industry groups, that garbage disposals work quite well with septic tank systems. The key is to ensure that the septic system is properly sized and that it receives routine maintenance.

How Septic Systems Work

Septic systems are specifically designed to properly treat and dispose of waste originating from a home’s bathrooms and kitchens. If a home’s septic system is sized to handle a washing machine or dishwasher in addition to the toilets and sinks, then it is more than likely capable of handling a garbage disposal.

Water and waste flows into a septic tank. In the tank, any solids that weigh more than water, like oil and grease, float to the top of the tank where it creates a fine layer of scum. Solids that weigh more than water sink to the bottom of the tank, where a layer of sludge eventually develops. The layer of water between the scum and sludge flows through one or two distribution boxes where it is evenly dispersed into the tank’s drain field. Soil and gravel are then used to naturally filter out bacteria and other pollutants.

The decomposition of solid matter is assisted by naturally occurring bacteria that can be found in a septic tank, but it’s not capable of handling it all. This is why septic systems require periodical draining. The sludge is pumped from the system’s tank to prevent the drain field from being contaminated by solid overflow.

Tread Carefully

Your garbage disposal is not a trashcan. If your home has a septic system and you currently have a garbage disposal (or are planning to install one), most experts will recommend pretending like it is not there. Infrequent or occasional use will lessen the chances that the disposal will have an adverse effect on your septic tank.

Here are a few dos and don’ts you should follow:


  • Do pretend like your garbage disposal is not there.
  • Do pump your septic tank more often if you use your garbage disposal on a daily basis.
  • Do consider starting a compost pile for the majority of your food scraps.
  • Do consult with a professional to make sure that your septic tank is properly sized for the garbage disposal you are considering purchasing.


  • Don’t treat it like it is a trash can.
  • Don’t pour items like grease, oil, bones, or other hard to dissolve objects down your garbage disposal.
  • Don’t use your garbage disposal to clean out your refrigerator.

A Word on Additives…

Chances are that, while you are shopping for a new garbage disposal, the salesperson or website that you purchase the disposal from will try to convince you to buy system and septic tank additives with the promise that they will help break down food waste in your septic tank.

Don’t fall for it.

Over half of all these products on the market today are harmful to your septic tank’s biological activity. In fact, many of these products will outright kill the helpful bacteria in your septic tank.

When this occurs, it can rapidly ruin your entire septic system because solid bits of food waste are carried directly to the drain field. Should this happen, you can plan on buying an entirely new septic system. Drain fields that are clogged with debris force the water to the ground’s surface or to travel through the soil, which puts other groundwater resources at risk for being polluted.

If you use your garbage disposal moderately and ensure that your home’s septic system is properly maintained, your septic system will take care of the decomposing work all on its own – without any outside help from additives.

In Conclusion

Do your homework. Be smart. Make an informed buying decision when it comes to purchasing a new garbage disposal. When you take all of these considerations into account, there is no reason why you cannot find a garbage disposal unit that will be compatible with your home’s septic system.

Justin Curtis

I am not a professional plumber, but I do feel like I am pretty handy :). I would love to hear your comments about this post or others. Thanks for reading!

Click Here to Leave a Comment Below 3 comments
Laurie - January 11, 2017

I do think that if your home has a septic system you should be well informed about how it works and how to maintain it properly. Great information, thanks for sharing!

Braden Bills - April 13, 2017

I wish I had known the effects that a garbage disposal has on a septic tank before I used mine so much! I’ll make sure I get my system cleaned out. I don’t want to have to worry about it getting blocked up from all of the solid waste.


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