What are chloramines and when are they used?

Chloramines are disinfection compounds that result from the reaction between chlorine and ammonia. They are primarily used in the water treatment process to provide a longer-lasting residual disinfectant effect in the distribution system compared to free chlorine alone. This characteristic is crucial for maintaining water quality over longer distances as it helps prevent the regrowth of bacteria and other pathogens in the water supply.

When chloramines are formed, they create a stable compound that is less likely to produce disinfection by-products, which can be a concern with higher levels of free chlorine. Utilities often use chloramines as a secondary disinfectant, especially during periods when chlorine might be less effective, such as in certain environments or specific water characteristics. Their use serves to enhance safety and quality as the water travels from treatment plants to consumer taps, ensuring a reliable disinfectant presence throughout the distribution network.