While the drain connection for a garbage disposal is nearly universal and fits standard sink drain holes of 3 1/2 to 4 inches, the size of the disposal unit itself is not. You must have enough space in the cabinet underneath your sink to accommodate the disposal's housing. A larger model may not fit in a compact cabinet or if the existing plumbing is arranged in an unusual way. Before buying a new garbage disposal, measure the available space under your sink. If you are replacing an old unit, it's often easiest to choose a new model of a similar size.

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. 

Whether it's worth repairing your garbage disposal depends on its age and the specific problem. Generally, if the unit is eight years old or younger, repair is a good option. For minor issues like a bad seal or a simple jam, a repair can be inexpensive, sometimes under $10. However, if the motor is broken (a repair that can cost $150 or more) or the unit is getting old, it's often more cost-effective to replace the entire disposal.

In some cases, it’s more cost-effective in the long run to replace a garbage disposal, but it depends on the specific issue you’re having and the age of your disposal. You should ask a garbage disposal repair tech for a quote to repair your appliance and then see if it would be more worthwhile to replace it. Additionally, garbage disposals last for around 15 years, so if you know your appliance is reaching that age, it’s likely better to pay for a new garbage disposal rather than sink money into repairs.