BOTTOM FEEDERS Garbage disposers grind food scraps in a chamber using spinning or fixed blades before tap water washes the fragments down the drain.
Garbage disposers link the often disparate demands of convenience and conservation by grinding up kitchen scraps and sending them down the drain to a sewage-treatment plant or septic system for decomposition.
Besides eliminating messes and discouraging bugs and other pests, a disposer shifts food waste from landfills to a waste-water treatment system. That scenario has prompted some cities, such as Denver and Indianapolis, to require disposers in new homes. Add in the many towns that charge by volume for waste removal, and it's easy to see why nearly half of American homes have a garbage disposer.
Manufacturers are promoting their appeal as they try to distinguish these basically similar machines. Indeed, just four companies make all garbage disposers under different brand names, with In-Sink-Erator accounting for nearly 80 percent of disposers sold.
Several models now include an auto-reverse mode that helps their spinning blades clear jammed waste, the bane of many disposers. A model from Viking, which is better known for its pro-style kitchen ranges, adds a blade-oscillating “Jaminator” feature for clearing. As the Ratings detail, disposers with a clearing device of any kind performed better overall.
Still other differentiating features you will see at the store may not deliver the durability they imply. For example, the stainless-steel grinding chambers on two 1-horsepower models from In-Sink-Erator and Kenmore were dented during our tests by beef bones, an especially tough item disposers should rarely swallow. We also found that some models with fewer features and a shorter warranty cost more than relatively similar competitors.
Garbage disposers also have an ecological downside. Depending on where you live, a disposer's additional water use and its extra burden on sewer and septic systems may outweigh the landfill space it conserves (see Consider all costs and "The downside of disposers," below, for details).
HOW TO CHOOSE
Some are decidedly better than others at resisting jams and chewing up tougher stuff. Nearly all are noisy.
Consider all costs will help you determine whether a garbage disposer is right for your kitchen. If you decide that it is, here’s how to make choosing one easier:
Balance convenience with safety. Disposers fall into two basic groups. Continuous-feed models are easiest to use, since you can push new waste in as the old waste is ground up and washed down the drain. But their open filler necks pose a greater risk to small hands and can allow bone shards and other scraps to fly out. For those reasons, you'll need to mount the power switch in a safe place and hold the supplied stopper at an angle over the drain as a shield.
Batch-feed models cost more and can take more time to use, since you must load them with waste before turning down the stopper to activate the blades. But because the stopper keeps food in and hands out, batch-feed models are safer, especially for families with kids.
Weigh warranty against price. Home garbage disposers typically last about 10 to 12 years, according to In-Sink-Erator, though not all last that long. A longer warranty adds peace of mind. But it does not guarantee longer life and can make some models cost more than otherwise-similar machines.
Consider your food waste. Even models with the least powerful, 1/3-hp motor can handle softer waste such as carrots and corn kernels. But if your kitchen waste typically includes tougher stuff, look for a more powerful, 3/4-hp or 1-hp model. Those we tested ground bones fastest and finest, reducing the chance of clogged plumbing traps.
Get help putting it in. Most garbage disposers have a quick-mount neck that encourages do-it-yourself installation. But because most of the best-performing, 3/4- and 1-hp models weigh from 16 to 30 pounds or so, putting one beneath your sink may be a two-person job.
While the Waste King models we tested include electrical cords, others must connect to your home's wiring. You'll also need an electrician to add a switch for continuous-feed models. If you own a dishwasher, you'll probably want to connect it to the disposer so that the dirty dishwater passes through it.
The downside of disposers
The varied response to garbage disposers shows how some products can address one environmental problem while posing another, depending on your locale.
A case in point is New York City, which is considering whether to end a ban on the machines for its roughly 23,000 restaurants and food establishments, as it did for homes in 1997. Restaurants, which pay by weight or volume for hauling waste, say disposers will save them money while reducing solid waste and the mess, odor, and vermin that go with it.
But more disposers in homes and restaurants could create more costly problems, according to the city's Department of Environmental Protection. Increased food waste in the sewers would generate added nitrogen, which could rob the city's harbors of life-giving oxygen, it says.
Estimated cost: $200 to $300 million for required improvements to meet federal nitrogen-reduction mandates, plus another $30 to $40 million in annual expenses. That compares with roughly $4 million per year saved from hauling less garbage.
Grease is another disposer challenge facing New York and other cities. Austin, Texas, requires grease traps in restaurants that use disposers. “The greatest cause of sewer overflow is grease blockage, which can come from all the stuff being washed down the drain,” says Laurie Lentz, a spokeswoman for the Austin Water Utility. Austin discourages disposers in homes and restaurants, though it doesn't prohibit them.
Los Angeles also blames grease for its ban on most restaurant disposers, though it allows disposers in new homes, where grease is less of a problem. “Everybody in California is trying to reduce what we send to landfills,” explains Adel Hagekhalil, a waste-water engineering-division manager at the city's Bureau of Sanitation.
Homeowners should weigh all of those concerns before buying a disposer. If you have a septic tank, make sure it can handle a disposer's extra waste (see Consider all costs). And consider composting your kitchen waste as an alternative.
Assuming you want a disposer and it isn't a problem where you live, here's how to minimize potentially negative effects:
• Grind food waste only. Avoid grinding greasy or fatty foods, which tend to clog sewer systems as well as home plumbing.
• Run cold water while the disposer is grinding to help move stubborn waste while using less energy than heated water. Run water briefly after it's done to flush out small scraps.
• Before using a disposer-connected dishwasher, clear the disposer to enable the dishwasher to drain properly.