Garbage disposals address the often disparate demands of convenience and conservation by grinding up kitchen scraps, especially noncompostable leftovers, like meat and poultry, and sending them down the drain to a sewage treatment plant or septic system for handling, rather than to the landfill for slow decomposition. 

In addition to eliminating the mess, a garbage disposal shifts food waste from your trash can to a wastewater treatment system, discouraging bugs and other pests.

That has prompted some cities to require disposals in new homes. Plus, many towns charge by volume for waste removal, making it easy to see why almost half of American homes have a garbage disposal.

Before choosing a model, answer these four questions:

Is a garbage disposal appropriate in my area? If you use a municipal sewer system, call your local sewer authority to find out its disposal policy. Some require a permit to use one, and some discourage them because of limited water and sewer capacity.

Is my septic tank big enough? Your municipality may require an upgrade if you have a septic system and use a garbage disposal. Check with your local building inspector or environmental health official. Alternatively, you may need to empty the existing tank more frequently.

Is the extra water use worth it? Figure on about 2.5 gallons of water per minute for most faucets, or some 900 gallons per year based on usage of 1 minute per day. In addition to potentially increasing your water bill, a disposal’s added water consumption is a concern in drought areas.

Is the plumbing up to the task? Don’t install a garbage disposal if plumbing clogs or backups are frequent, because a disposal’s added waste can make both more likely. Have a problem septic system fixed, emptied, or enlarged before buying a garbage disposal.

Our testers found that differentiating features you’ll typically see at the store might not deliver the durability they imply. We also found that some models with fewer features and a shorter warranty cost more than similar competitors. Home garbage disposals typically last about 10 to 12 years, according to InSinkErator, though not all reach the decade mark. A longer warranty does not guarantee longer life and can make some models cost more than otherwise similar machines. Here are the garbage disposal features to consider.

Electric Cord
An electric cord allows the machine to be used with typical outlets; those without the cord need to be hardwired.

Auto-Reverse Mode
This can help a garbage disposal’s spinning blades clear jammed waste, the bane of many disposals. Some models include a blade-oscillating “jaminator” feature for clearing.

Horsepower Ratings
Even models with the least powerful, ½-hp motor can handle bones and softer waste, such as carrots and corn kernels. But if your kitchen waste typically includes tougher stuff, look for a more powerful ¾-hp or 1-hp model. Those we tested ground bones fastest and finest, reducing the chance of clogged plumbing traps.

Quick-Mount Neck
Most garbage disposals have a quick-mount neck that encourages do-it-yourself installation. But because ¾- and 1-hp models weigh between 16 and 30 pounds, putting one beneath your sink may be a two-person job.

Dimensions
There is no standard size for garbage disposals, so measure the space underneath your sink before you go shopping to make sure you find one that fits.

Warranty
Coverages range from as little as one year to as long as 10 years, or even the life of the unit. But a longer warranty doesn’t guarantee longer life or better performance, and can add to the price.