The secondary clarifiers provide the necessary detention time and collection equipment to settle and remove the biological solids (sludge) from the bio-system mixed liquor.

From the Rotating Biological Contactors mixed liquor, flows from the division box through two 14-inch pipes to the 46'x10'x8' (27,526 gallon) secondary clarifiers. The biological floc settles to the bottom of the clarifiers where the rectangular sludge scraper mechanism moves it into a hopper at the inlet end of the tanks. Sludge is pumped reqularly from these hoppers to the aerobic digestors. The clarified water passes over the effluent weirs and is directed to the final chlorine contact tanks.