Garbage Disposals

Garbage disposals are electrical appliances that mount between a kitchen sink drain and the water-filled, U-shaped "trap" under the sink. The first garbage disposal, the InSinkErator, was introduced in the U.S. in 1940. Half of U.S. homes now have disposals.

How does a garbage disposal work?

Food wastes are dropped onto a plate that spins the food with centrifugal force, against a shredder ring with sharp slots. Water helps push the shredded particles through the plumbing pipes to the sewer lines or a septic system.

Garbage disposal units require anywhere from 200 to 700 watts of power. They deliver one-quarter to one horsepower. Continuous flow units operate without a lid, so waste can be added without interruption. Batch-feed units offer extra safety, because the lid must be closed before the unit will operate.

Dos and don'ts

Here's a healthy diet for your garbage disposal: Always feed small pieces into the appliance. Use cold water to keep any fat residues solid. And follow these 7 rules to remember for good luck with the garbage grind:

1. Disposals accept soft, non-fatty wastes from most fruits and vegetables, meat, fish and poultry. Cut rinds from citrus, melons, cooked squash and the like into smaller pieces.
2. Scrapings from dinner plates, dirty pots and pans, leftover foods and non-fat dairy products are okay to enter.
3. Grind up citrus to refresh the unit.
4. Avoid adding anything man-made.
5. Say "Heck no!" to hard items like coffee grounds, nut shells, seafood shells, bones, pits, hard seeds, eggshells and unpopped popcorn kernels.
6. Forgo fibrous food waste, like artichoke leaves, corn cobs and husks, raw celery, onion skins and banana peels.
7. Forget about dumping fat, butter, cream or oil into the disposal.

Brands, pricing and installation

InSinkErator, Waste King, Kenmore, KitchenAid and Viking are some of the most popular brands for garbage dispoals. Budget models start around $100, while heavy-duty models may cost more than $400. Check warranty lengths and noise ratings before making the purchase.

Some homeowners tackle installation themselves or ask a friend for local plumber recommendations. Because septic systems require different models than city sewer lines, it is important that disposals are installed correctly. Fill out the form on this page to meet local contractors with installation expertise.