Aerobic Treatment Unit (ATU)

Device that provides aerobic decomposition of wastewater by bringing the wastewater into direct contact with air via mechanical means (e.g., using air pumps, air injectors, lift pumps and biological-contact surfaces such as pipes, gravel and fabric). ATUs are not stand-alone wastewater treatment systems, but provide treatment prior to wastewater disposal in a subsurface drainfield system or provide pre-treatment to other alternative methods of wastewater treatment. <