To reach breakpoint, enough chlorine must be fed to overcome what?

To reach the breakpoint chlorination level, sufficient chlorine must be introduced to overcome both the chlorine demand presented by the water and any chloramines that may already be present. Chlorine demand refers to the amount of chlorine that is required to react with organic materials, bacteria, and other contaminants in the water before it can effectively disinfect the water. If chloramines are already formed due to the reaction of chlorine with ammonia in the water, these will also need to be addressed.

Only when chlorine is added in sufficient quantities to address both these factors can it then proceed to fulfill its role as a disinfection agent. When this "breakpoint" is reached, the free chlorine levels will increase, which confirms that all chloramines and other chlorine demands have been satisfied. Understanding this process is crucial for water operators, as it directly impacts water quality and safety.