Replacing a garbage disposal costs anywhere from $150 to $950, but the average cost is somewhere around $550. There are two types of garbage disposal units, and continuous feed disposals tend to cost more than batch feed disposals. Going for an aluminum garbage disposal is also significantly cheaper than choosing a stainless steel garbage disposal. You'll also need to factor in the horsepower of the motor, labor, and the removal and disposal of your old unit.

There are many maintenance and repair issues that lead to a malfunctioning garbage disposal. Regular clogs place wear and tear on the motors, leading to an eventual shutdown. Electrical issues at the breaker, wall outlet, or disposal itself can fry the unit. The most common cause is simply a worn-down motor. These motors can only handle so much use before powering down for good. 

When a dishwasher discharges its wastewater, it uses a pump to quickly move a lot of water. If anything in the drain line or the garbage disposal impedes the high volume of water, it will back up into the sink through the drain or the garbage disposal. Following regular dishwasher maintenance tips like clearing clogs, keeping them cleared, and occasionally running the disposal will eliminate the problem.

Garbage disposals can be considered bad for the environment due to their electricity usage, but good for the environment because they reduce the food waste sent to landfills. If everyone used a garbage disposal, it would tax the wastewater treatment facilities in that region, but if we had to choose one of the options, we’d say they are a net positive on the environment when used correctly.