Are Garbage Disposals Worth It?

A garbage disposal (also called a food waste disposer) sits under the sink and grinds food scraps into small particles that wash into the sewer. Whether one is worth it depends less on the appliance and more on your plumbing, your local wastewater system and what you already do with food scraps.

Pros

• Less food in the kitchen bin, so fewer smells and fewer trips to the outside bin.
• Quick clean-up after cooking: scrape plates straight into the sink.
• Can be better than landfill. Food rotting in a landfill produces methane, a powerful greenhouse gas. The EPA lists landfills as one of the largest sources of human-made methane in the US.

Cons

• Not suitable for septic systems unless the system is sized for it; food solids fill the tank faster.
• Some foods jam or clog it (see the list below).
• Uses water and a little electricity each time you run it.
• Some towns restrict or discourage disposals, usually because of the load on local sewers. Check before you install one.
• Composting is better. On the EPA’s Wasted Food Scale (which replaced its older food recovery hierarchy), composting ranks above sending food down the drain to wastewater treatment, and preventing food waste in the first place ranks above both. Landfill ranks lowest.

Are garbage disposals bad for the environment?

It depends on where the waste goes. Some wastewater treatment plants send solids to anaerobic digesters, which turn food waste into biogas and a soil product. In that case a disposal can have a smaller footprint than sending the same scraps to landfill.

Other plants are not set up to recover energy from food waste, and in older sewer systems food particles and grease can contribute to blockages. Independent research comparing disposals with landfill and composting is limited, and some of the most-cited studies were funded by disposal manufacturers, so be wary of strong claims either way.

As a rule of thumb: if you can compost, compost. If you can’t, and your area’s wastewater plant handles food waste well, a disposal is a reasonable option.

What not to put down a garbage disposal

• Fats, oils and grease (they solidify in pipes)
• Bones, fruit pits and shells
• Fibrous food such as celery, corn husks, onion skins and artichokes
• Coffee grounds and eggshells in quantity (they build up into a sludge)
• Pasta, rice and bread in quantity (they swell with water)
• Anything that isn’t food

Always run cold water before, during and for a few seconds after grinding.

Do you need a plumber to install one?

Not always. Replacing a disposal with a similar model is a common DIY job if you are comfortable with basic plumbing and the unit plugs into an existing outlet under the sink.

Hire a plumber (and possibly an electrician) if:

• there is no existing disposal and no switched outlet under the sink,
• the drain layout needs to change,
• you have a dishwasher connected to the same drain and are not sure how to connect it,
• local rules require a licensed installer.

Are garbage disposals dangerous?

Most disposals don’t have sharp blades. They use blunt impellers that fling food against a grinding ring. They can still cause serious injury, so:

• Never put your hand inside. Use tongs to remove objects.
• Switch it off, and unplug it or turn off the circuit breaker, before clearing a jam.
• Consider a batch-feed model, which only runs when the stopper lid is in place, if you have children.