An aeration basin that is on line applying air to the micro-organisms.

Picture of a basin on standby. Air and water added to prevent freezing in winter time.

Picture of a diffuser used to supply the air needed for the micro-organisms.

In this step of the process, sometimes referred to as "Secondary" or "Biological" treatment, bacteria and micro-organisms growing in the aeration basins remove organic matter (waste material that comes from animal and/or vegetable sources) by consuming (eating) it as food.

The aeration systems utilize a process commonly known as the activated sludge process. The effluent from the primary clarifiers flow into any one of the six aeration basins we have at GBMSD. Here we provide the ultimate conditions for the micro-organisms (bugs) to do their work. Just like us, the bugs need food and air to survive. In the aeration basins we provide both.

The air is supplied from a compressor through diffusers that lay near the bottom of the basin. These diffusers are similar to a diffuser used in an aquarium (see photo).

The activated sludge process currently utilized by GBMSD is commonly known in the wastewater field as "single stage nitrification/denitrification with biological phosphorus removal".

To properly operate the aeration systems, the operators at GBMSD must insure sufficient numbers of microorganisms are present to completely breakdown the influent waste, ammonia, and phosphorus.