What should a system using free chlorine with water disinfected by chloramines adjust when receiving the water?

In a water treatment system that relies on free chlorine for disinfection but uses chloramines in the water supply, it is crucial to adjust the amount of ammonia that is combined with free chlorine. This is because chloramines are formed when ammonia is added to chlorine, and the ratio of ammonia to free chlorine must be optimized to ensure effective disinfection, particularly if the goal is to maintain residual chloramines in the distribution system.

If not properly balanced, the reaction can lead to insufficient disinfection byproducts and may affect water quality and safety. Monitoring and adjusting the amount of ammonia allows operators to maintain the desired levels of chloramines without compromising the efficacy of free chlorine for disinfection or causing any undesirable reactions. This adjustment is essential for maintaining a balance that ensures both effective disinfection and water safety standards are met.

Choosing the correct ammonia concentration is vital when chloramines are involved, as it impacts not just disinfection efficacy but also the overall water quality in the distribution system.