1 Answer

The NEC and the majority of local codes require two 20 amp circuits to supply kitchen appliances from countertop receptacles. These kitchen countertop appliance circuits are not allowed to serve any other loads not associated with countertop type appliances such as toasters, electric skillets, mixers etc... The waste disposal is a fastened in place appliance and very well may be required to have its own dedicated circuit by your local code.  If your local code allows for a dedicated circuit you will need to add a circuit breaker to the panel and bring a new line to the garbage disposal. One thing to look for is if the contractor installed a receptacle under the sink, if so this was for any future appliance like instant hot water or a waste disposal.

Best thing to do is find out what local code requires and also what the manufacturer of the disposal requires. If the maker requires a dedicated circuit then technically you are required to do so unless local inspectors will allow otherwise. It is getting to where the disposal has its own circuit in most areas from my experience. One other thing to consider is if you were to install it on the receptcle you mention then the disposal would have gfci protection. This is not required and may lead to nuisance trips of the gfci over time.