Garbage disposals are residential and commercial appliances designed to shred food waste so that it can fit through plumbing. They are usually electrically powered (although occasionally powered by water pressure) and are installed beneath sinks. Despite the convenience afforded by garbage disposals, the strain they can place on septic systems should be weighed against any potential benefits they might provide.
Why Use a Garbage Disposal?
When food waste is discarded into the trash, it places an enormous burden on waste management systems and harm the environment. Garbage disposals reduce the severity of these problems by routing food waste into septic systems or sewers instead of landfills. The following are a few specific problems associated with food waste that can be curbed through the use of a garbage disposal:
- It must be collected and transported long distances to landfills and waste treatment facilities.
- In landfills, food scraps decompose and produce methane gas, which contributes to global warming.
Garbage Disposals and Septic Systems
If a garbage disposal discharges into a septic tank, it can place significant strain on the septic system. The amount of waste that enters the tank, particularly grease and suspended solids, will increase considerably. This load increase requires that the septic tank be pumped more often than would otherwise be required. The New York Septic Code counts the presence of a garbage disposal the same as an extra room in a house when they estimate the load placed on a septic tank. The additional strain will also reduce the life span of the septic system. Septic systems can be designed to accommodate food waste but, in general, they are not.
The garbage disposal should only be used to grind non-fibrous, leftover food. If in doubt as to whether something can be put in the disposal, err on the side of caution and put it in the trash instead. The following items should never be put in a disposal:
- items that are hard enough to dull the blades, such as shells from shellfish or bones;
- food that is highly fibrous, such as corn husks, artichokes, pineapples, potato peels, asparagus, or celery should enter a disposal only in small quantities or avoided entirely. These foods take a long time to grind and can clog the disposal or the plumbing.
- grease or household oils; or
In summary, garbage disposals have the potential to limit the amount of household trash that must be taken away to waste management facilities. They can also place additional strain on septic systems and, for this reason, they should be used infrequently. Inspectors can test disposals for leaks and proper wiring, but they should beware not to do anything that might cause them to break. Inspectors should be prepared to communicate all of this knowledge to their clients.