Each cycle typically consists of three main phases; aerate, settle and decant. The basin is aerated continuously during the first half of the cycle. After the aeration phase, the system goes into a settling phase where liquid/solids separation occurs. In the final step, clear water is decanted out of the basin.

The decanter typically is installed on the basin wall supported by an effluent box on one end and by a pedestal on the other. The decanter is lowered and raised using an electro-mechanical actuator. The actuator moves between top and bottom limit switches whenever the decanter is in operation, ensuring that the decanter travels from the “park” position to the bottom water level (BWL). The decanter parks above top water level during the aeration and settling phases of the cycle, thereby eliminating any possibility of solids carryover during these periods.
The decanter speed is controlled through use of a variable frequency drive (VFD). As a result, the decanter discharge rate is relatively constant from the time the decanter enters the water to the time it reaches the BWL.