How It Works

    • 1


The control center houses an air pump and a control panel in one convenient weatherproof housing. It is able to conduct all operations and is powered by only a single wire.

    • 2

Aeration Process

When effluent arrives, the ATU immediately starts to work. The aeration compartment is where the cleanup action takes place. The air pump injects air through the diffuser lines and into (remove to) the wastewater, where oxygenation begins. This encourages the growth of aerobic bacteria, which feed on the organic waste and decompose it.

    • 3


The oxygenated effluent enters the ATU’s clarification compartment, a conically shaped area that separates clarified water from any remaining solids, which settle back to the aeration compartment for further treatment. Clear effluent leaves the clarification chamber through the outlet baffle.

    • 4

Re-aeration Chamber

During the aeration process the effluent loses some of its oxygen. Therefore the re-aeration chamber diffuses additional oxygen into the pre-treated effluent, using the same air compressor. This is how the dissolved oxygen gets increased. (Only needed for NPDES discharging)

    • 5

UV Disinfection Process

After re-aeration the pre-treated effluent passes through the UV chamber and around the bulb where ultraviolet rays strike the bacteria, which breaks it down and keeps it from reproducing. This results in the reduction of fecal coliform bacteria meeting EPA/NPDES discharging systems. (Only needed for NPDES discharge)







Advanced Aerobic Treatment Unit(ATU)

Hydro-Action Tank Options

Model NO. Waste Processing Bedrooms

GPD=Gallons Per Day