An aerobic treatment plant or "aerator" can be added to any type of septic system including conventional. Simply put, this unit adds oxygen, converting the system from "anaerobic" to "aerobic". Since many more microbes can be sustained in an environment in which an oxygen source is provided, the waste is broken down more quickly and the water begins to be recycled at a much faster rate. An illustration of this concept is the addition of aeration to an aquarium. The additional air sustains more aquatic life in the tank and assists in keeping the water cleaner than it might be without the aeration.
Contrary to popular belief however, although this septic waste is much less of a health hazard than untreated waste, this effluent must still be discharged to some type of underground disposal septic field. Some jurisdictions, though, may allow for the septic field to be reduced in size due to the more efficient nature of an aerobic system.