Treatment Process Description

The sewage or Raw Influent is screened by a bar screen to remove course debris. It then flows to the Aeration Tanks where it receives biological treatment. In these tanks the sewage is mixed with the millions of living microorganisms which use the sewage as a food source. In this manner, the dissolved pollutants are removed from the water. From the Aeration tanks the Mixed Liquor (microorganisms and treated water) flow to the Clarifier, where the microorganisms are separated from the water and settle to the floor. They are then collected and returned to the aeration tanks. The treated water, free of pollutants, is conveyed to the Chlorine Contact Tank where it is disinfected with chlorine. At the end of the chlorine contact tank, sodium bisulfate is added to remove the vast majority of any residual chlorine left remaining in the water before it flows to the Brush Run stream.

Since the microorganisms feed on the sewage while in the Aeration Tanks, they grow and reproduce. To keep the process in balance, the amount grown each day is removed from the process and sent to the Digesters. Here, where there is hardly any food, they begin to consume themselves. In this manner they break down into simpler compounds (carbon dioxide, water, and inert stable solids). This digested sludge, or using the more politically correct term, biosolids, is pumped to the Belt Filter Press where excess water is squeezed out and the resulting Sludge Cake is hauled to a landfill for disposal. The water which is squeezed from the sludge, called Filtrate, is returned to the Aeration Tanks for processing.