Is there historical precedent for the use of chloramine as a drinking water disinfectant?
The EPA has no requirements that any system use chloramine for water treatment. However, it has been used by water systems (almost always as residual disinfectant, not as a primary disinfectant) for approximately 90 years, and its use is closely regulated. In Pennsylvania, 73 public water systems serving more than 4 million people currently receive water containing low concentrations of chloramine. The EPA estimates that nationally, approximately 60% of surface water utilities will ultimately use chloramine for secondary disinfection.
