Safe, Environmentally-Sound Solution
for Food Waste

( Denne artikkelen er lånt fra "Plumbing-Heating-Cooling Information Bureau" sin hjemmeside.)
Whether by personal conviction or regulation, Americans are putting more emphasis than ever before on safeguarding the environment. And nowhere is that emphasis more apparent then in the heart of the home, the kitchen. According to the Plumbing-Heating-Cooling Information Bureau, an industry group, food waste disposers are the fastest way to get food waste out of the home and on the way to decomposition. Ground food scraps flow directly from the sink to a sewage treatment plant or a septic system where they break down more rapidly than they would in a landfill. "Disposers are an ideal method for diverting food wastes to treatment facilities and reducing the amount of waste targeted for landfills," said Dennis Broderick, vice president of sales, In-Sink-Erator. "In fact, disposing of food scraps with the rest of the garbage actually increases the chance of rodent and insect infestation and unpleasant odors and spills." This is especially important because food waste now comprises 15 to 18 percent of the world's landfills, according to a 1992 study by the U.S. Environmental Protection Agency. In fact, more than 90 municipalities, including Denver, Detroit and Indianapolis, require disposers to be installed in all new home construction.
What are some environmental advantages of using food waste disposers? "In addition to reducing some of the burden on landfills, disposers have other environmental advantages," said Sergio Varela, vice president of sales, Anaheim Manufacturing. "Disposers also do their own form of recycling. The sludge left after ordinary treatment at a sewage plant can be used as fertilizer. Food waste is effectively recycled back into the earth." Seattle, Los Angeles, Milwaukee and Portland, Oregon are several cities which now have active sludge recycling programs. In a 1990 study by Dr. P.H. Jones, professor emeritus at the University of Toronto's Institute for Environmental Studies, Jones concluded that disposers were the most effective, convenient and environmentally correct way to eliminate food waste in areas where sewage treatment is available. Disposers use very little water and electricity for operation. A recent study by the EPA found disposers use an average of 1.2 gallons of water per day per household, less than one flush of a low-flow toilet. On average, disposers also use about 1.5 kilowatt hours of electricity per year, which is less than the energy used by a 7.5 watt night light running continuously for a year. "In addition to being a safe alternative for disposing of biodegradable waste, disposers are a positive complement to already established recycling or composting programs," added Broderick.
Are disposers safe for my septic system? Disposers have even been proven safe to use with a septic system. According to a U.S. Public Health Service study, ground food waste does not hamper the operation of a septic tank system if the septic tank is properly sized and maintained. If a septic system is operating with a dishwasher and washing machine, the home already has a larger tank and absorption field and a disposer can be used with the system. F.H.A. guidelines allow use of disposers with septic systems if the tank and field are sized under its guidelines for washing machines and dishwashers.
How do food waste disposers operate? Food waste disposers are installed directly under the sink attached to the drain opening and the plumbing. Most models also have an optional dishwasher connection. Food waste fed through the sink falls into the disposer's chamber and onto a turntable dotted with holes to allow water and waste through. The turntable's rotation throws waste against a circular wall with a grater-like surface. Metal impellers attached to the turntable then press the food against the wall, grating the waste. Finally, the food particles are washed out of the disposer and down the drain. According to the Bureau, almost all bio-degradable food wastes can be fed into disposers including: chicken bones, melon rinds, tea bags, egg shells and coffee grounds. However, they should not be used to grind clam or oyster shells, corn husks or other materials with a high fiber content. Under no circumstances should non-food materials such as glass, plastic or metal - bottle caps, tin covers or aluminum foil - ever be put through a disposer. Maintenance is easy. Grinding small bones actually helps clean the disposer by scraping away stubborn deposits or citric acid and pulp. Grinding a little ice is another way to clean deposits and get rid of odors. Occasionally pouring a little baking soda in the disposer also helps control odors. For the most part, however, disposers are self-cleaning.

What type of food waste disposers are available? There are two types of disposers: batch-feed and continuous-feed. To operate a batch-feed disposer, fill the disposer with food scraps, then insert and push down or twist a stopper. Continuous-feed disposers are started by flipping an electrical switch. Continuous-feed disposers typically outsell batch-feed disposers. That may be because consumers like the convenience of continuously adding waste scraps to the disposer, rather than stopping to refill the batch-feed models. Batch-feed, however, are impossible to turn on without the stopper in place. This would greatly reduce the likelihood of the disposer being activated by a young child. "With either type of disposer, it is essential to run the cold water when grinding to move the waste all the way through the drain line," noted David L. Weiner, executive director of the Plumbing-Heating-Cooling Information Bureau. "Fats and grease congeal and harden in cold water and can be flushed through the system. Hot water should not be used because it can dissolve fats and grease, which may then begin to layer on drain lines."

What are the costs associated with food waste disposers? Disposers range in price from $40 to $350, not including installation, and have between 1/3 and 1 horsepower. The higher the horsepower, the more quickly the disposer can handle harder food wastes. Batch-feed disposers are slightly more expensive than their continuous-feed competitors, but are easier to install. Continuous-feed disposers require both a plumbing and an electrical hook-up. If replacing an existing continuous-feed disposer, a licensed professional p-h-c contractor can completely install a new model. However, in a new installation, a licensed p-h-c contractor will bring in an electrician to do the wiring. The disposer and the dishwasher should be installed on separate circuits. "In any plumbing installation, it is best to use a licensed plumbing-heating-cooling contractor," according to Weiner. "These professionals can install either type of disposer correctly and safely, with the least possible risk to the homeowner." Founded in 1919, the Chicago-based Plumbing-Heating-Cooling Information Bureau is the consumer information arm of the plumbing-heating-cooling industry.


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