If a person engages in, conducts, manages, or carries on at the same time, more than one of the activities for which a fee is required by this chapter, he or she shall be deemed to be engaging in, conducting, managing, and carrying on each activity separately and apart from the other such activity, and a separate fee shall be paid for each activity, except in those cases specifically mentioned in the Medical Waste Management Act. (Prior gen. code 3-260.4)