Mechanical aeration systems use surface or subsurface mechanical stirring mechanisms to create turbulence to mix air with the water. There are several types of aeration systems used for wastewater treatment applications that include mechanical aeration systems and diffused aeration systems. These systems effectively remove volatile organic compounds but are generally used for wastewater treatment systems. The diffused aeration system bubbles air through a contact chamber for aeration; the diffuser is usually located near the bottom of the chamber. The air introduced through the diffuser, usually under pressure, produces fine bubbles that inpart water-air mixing turbulence as they rise through the chamber. Diffused aeration systems are designed to serve either point-of-use or plant situations.