The basic aerobic septic system, aka aerobic treatment unit (ATU), aerobic wastewater treatment plant and aerobic treatment sewage disposal system, is a system that provides a suitable oxygen rich environment for organisms that can reduce the organic portion of the waste into carbon dioxide and water in the presence of oxygen.
Aerobic septic systems are similar to conventional septic systems in that they both use natural processes to treat wastewater. But unlike septic (anaerobic) treatment, the aerobic treatment process requires oxygen. Aerobic treatment units, therefore, use a mechanism to inject and circulate air inside the treatment tank.
Because aerobic septic systems use a higher rate process, they are able to achieve superior effluent quality. The effluent can be discharged to the subsurface as in a septic tank leach field or, in some cases, discharged directly to the surface.
The early aerobic systems consisted of little more than an aerator placed in a traditional septic tank. These were often referred to as an aeration septic system or aerator septic system.
The newer aerobic septic systems are pre-engineered and operate at a high level of efficiency.
The use of residential aerobic septic systems was limited, in part, because of the widespread use of conventional septic systems, which were relatively inexpensive and easy to maintain. Conventional septic systems used to be the most common onsite wastewater treatment systems in rural areas.
However, conventional septic systems are not suitable for residential applications. Homes in Liberty, Chambers, and Harris county Texas do not have the appropriate soil conditions to accommodate the soil absorption drainfield. In all communities, the water table is too high to allow the drainfield to give adequate treatment to the wastewater before it is returned to groundwater.
One of the most common reasons to choose an aerobic septic system is to replace failing conventional septic systems, which are a major source of groundwater pollution in some areas. If a failed conventional septic system needs to be replaced or if a site is inappropriate for a conventional septic system, an aerobic septic system may be a viable option.