Dispelling the Myths

There are many myths around the use of a food waste disposer. The videos and document below dispel some of the myths.

Each year in New Zealand, 700,000 tonnes of organic waste is trucked to landfills

according to information from the NZ Ministry for the Environment1. Organic waste is the single largest component of municipal solid waste sent to landfills. Once there, it quickly decomposes and produces methane, an environmentally harmful greenhouse gas at least 21 times more potent than carbon dioxide. Landfills are considered the third largest sources

of methane in the world.

“While composting and kerbside food bin schemes have received a lot of attention as of late, it’s not for everyone,” said Michael Keleman, manager of environmental engineering for InSinkErator, the world’s leading manufacturer of food waste disposers. “Food waste disposers offer one alternative to composting, but only 36% percent of New Zealand homes have an installed disposer.”

What’s keeping over half of NZ homes from installing a disposer?

There are several common myths that might be holding people back.

Myth: Food waste disposers will clog sewerage pipes.


Modern disposers grind food waste into very fine particles. Also, food waste is essentially the same density as water, so properly used disposers allow plumbing to efficiently transport particles to the wastewater treatment plant. FOG (Fats Oils & Grease) can create soap-like deposits in sewers, a phenomenon seen around the world, however these deposits occur in locations where disposers are virtually non-existent, demonstrating the problem is not directly associated to their use. InSinkErator recommends that people never pour grease or fat into your disposer, kitchen sink, drain or the toilet.

Myth: Food waste disposers overload the sewerage system.


The amount of additional loading to wastewater infrastructure is well studied and understood with textbook references indicating a 20-30% increase in the strength of the wastewater. Modern design standards account for the modest increase in loading expected from disposers, yet even in places where there is a very high penetration of disposers, the actual impacts are negligible.

Myth: Food waste disposer use a lot of water and electricity.


Although operating a food waste disposer does involve running water and using electricity, the environmental impact is minimal. Disposers use only about one percent or less of a household’s total water consumption (about as much water per day as one flush of a toilet) and cost on average less than 50 cents a year in electric usage.

A review of ten studies found that water consumption for food waste disposers is less than five (5) liters per household each day. The five liters per household conclusion was the typical finding from five of the studies. The other five studies concluded that water use decreased where disposers are used, or no statistically significant difference in water consumption could be associated with their use. Further, one recent study by DeOreo et al determined that residential disposers save 13 gallons of water per household per day and suggested they should not be considered “water wasting appliances.”

Myth: Food waste disposers are noisy.


InSinkErator Sound Limiter™ insulation and Anti-vibration mount® technology mean Evolution disposer models can operate with very little noise versus a standard disposer. We also recommend installing a good quality sink with your food waste disposer, which can eliminate vibration and noise.

Myth: Food waste disposers have blades and are dangerous to use.


InSinkErator food waste disposers do NOT have blades. Instead they have small lugs fixed to a grinding plate that act like hammers breaking down the food whilst spinning 360 degrees.

Once small enough, food waste particles pass through small holes in a stationary grind ring, out of the disposer and into the sewerage system. If users are not confident operating a food waste disposer they can always use a dish brush or wooden spoon to help push food down the mouth of the disposer.

Myth: Using a food waste disposer means that energy and water from food can’t be harnessed or used.


Modern wastewater treatment plants throughout New Zealand capture methane gas generated during processing and convert it to renewable energy in the form of heat and electricity. In addition, the water content of food (on average70-80%) is also recaptured and processed at the wastewater treatment plant.

Myth: You need a double sink bowl to have a food waste disposer installed.


A food waste disposer can be installed with both a single bowl sink or a double bowl sink, this is a personal preference. Check sink and food waste disposer dimensions for details. InSinkErator recommend installing a good quality sink with your food waste disposer, which can eliminate vibration and noise.

Myth: Using a food waste disposers means you can’t compost food.


InSinkErator food waste disposers are complementary to home composting systems. Food types such as meat, dairy and citrus which are not compostable can be placed down the food waste disposer and ultimately kept out of landfills.

Myth: Food waste disposers can’t be used on a septic tank.


InSinkErator food waste disposers are compatible with properly sized and maintained septic systems. For example, if your system is sized for a dishwasher or clothes washer, it can handle a disposer. After all, a disposer uses only about as much water per day as one flush of a toilet.

Myth: Food waste disposers are an old technology from the 80’s.


Food waste disposers have been around since the 1930’s, however the grind and sound technology is always evolving. The top of the range Evolution models (100 & 200) can grind 99% of food types and are ultra-quiet versus a standard disposer when in use.

Myth: Certain food waste items can’t go down a disposer.


The truth is that most food can go down a disposer. High performance models can even handle virtually any waste, including bones and fibrous materials like celery. As long as consumers follow these best practices, they should have nothing to fear:

  1. Run a moderate flow of cold water
  2. Turn on the disposer
  3. Gradually feed food waste while disposer and water are both running
  4. Continue to run cold water for a few seconds after grinding is complete
  5. Never pour grease or fat into your disposer or drain