Garbage disposals require a substantial amount of running water to work effectively. The same result can be accomplished without water by disposing of kitchen waste in the garbage or adding it to the compost pile when appropriate.

Disposals can add 50% to the volume of solids in a sewer system or septic tank. Solids also add nitrogen, phosphorus, grease, and organic matter to the wastewater, decreasing water quality and shortening the life of septic systems. Because of the increased burden they impose on the wastewater system, garbage disposals are illegal in Japan.

If you do use a garbage disposal, run it at the end of cooking or cleanup periods when it is full. You can eliminate the need to use additional faucet water if you run the disposal when draining a stoppered sink.