good question meshkinfam:
how big is the plant? If you have the staff and work the plant on three work shifts and its union, you would nost likes not need one. Not that the equipment wont suffer, but rather people will look at repairing the equipment as a part of their job. These plants usually avoid macerators since they keep things from cloggong and take repair work away from them.
If you are not in this situation, I would say you should consider one. The capital cost and o and m cost are relatively little compared to the savings on wear and tear on a plant.
BobPE