Can You Have a Garbage Disposal on Septic?

Does a garbage disposal hurt a septic system?

It can add stress. A disposal grinds food into small pieces, but small is not the same as gone. Those pieces still have to settle in the tank. The EPA says food waste adds solids that build up as scum and sludge, and suggests homeowners eliminate or limit disposal use. If you must use one, pump the tank more often.

The EPA also warns that solids pushed into the drain field can clog pipes and thicken the biomat, the layer that forms where the pipes meet the soil. A thick biomat slows water down, and a slow field can flood.

What this means for pumping

The general EPA guidance is to inspect a household septic system at least every three years and to pump the tank every three to five years. A disposal pushes you toward the shorter end of that range, and a septic pumping company can tell you from what they see when the lid is open. Ryan repairs septic systems and does not pump tanks, so you will call a pumping company for that part.

What is okay to put in a disposal on septic

If you keep a disposal, treat it as a tool for small leftovers only. Reasonable things are:

• Small soft food scraps left on a plate after you scrape it
• Bits of cooked vegetables or fruit
• Always with plenty of cold running water, so the pieces move out of the unit and down the pipe

What to keep out of the disposal

Cooking grease, oil, fats, butter and similar items do not belong in any drain on septic. Coffee grounds, egg shells, bones and stringy or starchy food (like celery, potato peels and pasta) do not break down well and add to the sludge. Skip large amounts of food after a big meal. A better plan for those is the trash or a compost pile.

Never pour chemical drain cleaner into a clogged disposal. The EPA says to avoid chemical drain openers, and the chemicals can sit in the unit where someone may reach in later. Call or text first.

Ways to cut down what goes in

• Scrape plates into the trash before rinsing.
• Keep a small bowl by the sink for scraps and empty it into the trash or a compost pile outside, well away from the drain field and your well.
• Use a sink strainer to catch bits.
• Wipe greasy pans with a paper towel before washing.

These habits keep your tank healthier and make a disposal last longer too.

When a disposal on septic needs a plumber

A disposal that hums but will not spin is usually jammed. One that leaks under the sink or drains slowly may have a failing seal or a clogged line. If the sink backs up into the other side or into a dishwasher, the clog may be deeper in the line. Our post on garbage disposal repair or replace helps you decide, and our garbage disposal service page shows what Ryan does.

If several drains in the house slow down at once, do not blame the disposal first. Read how a septic system works and call or text Ryan, since the problem could be the tank or the field.

Choosing to install one on septic

If you are thinking about adding a disposal to a home on septic, the honest answer is to weigh it. For many households, skipping it is easier on the tank. If you want one, Ryan installs garbage disposals and can talk through whether it makes sense for your home and system. You can buy the unit yourself or he can source one for you, and the estimate is free.

Related Reading and Help

• Garbage disposal: repair or replace?
• Garbage disposal repair and installation
• How a septic system works
• What not to flush or pour down the drain on septic
• Septic system repair from The Village Plumber
• Signs your main sewer line is clogged
• Sewage smell in your house: what it means