Flow from the secondary clarifiers is disinfected by injecting liquid chlorine (sodium hypochlorite) into the wastewater at the beginning of the chlorine contact tank. The serpentine configuration of the tankĀ  improves the disinfection efficiency by maximizing the contact time between the wastewater and the chlorine. Sodium bisulfite is added prior to discharge to neutralize any residual chlorine.

Chlorine contact tank.