Chloramine is used as an alternative to chlorine for disinfecting drinking water. Canada is currently (2019) in the process of updating its guidelines for the use of chloramine in drinking water.
Chloramine is a more persistent but less effective disinfectant than chlorine. Its use is controversial.
What is Chloramine?
Chloramine is chlorine plus added ammonia. There are actually 3 species of chloramine that all occur in chloraminated water. You may see reference elsewhere to chloramines. For the sake of simplicity, in this article we make reference to chloramine in the singular.
Why is Chloramine used instead of Chlorine?
The reasons why some municipalities choose to disinfect their tap water with chloramine rather that chlorine are because the use of chloramine is more convenient due to it being more persistent in the distribution system and less expensive than chlorine, and because chloramine forms fewer of the regulateddisinfection by-products (THMs and HAAs) which are toxic chemicals formed by chlorine in drinking water.
Health Effects of Chloramine
Chloramine may form higher concentrations of unregulated disinfection by-products (DBPs), some of which may be more toxic than regulated DBPs. There are insufficient studies to date pertaining to the health effects of chloramine and its disinfection by-products. Negative health effects associated with chloraminated tap water include immune, respiratory, skin, digestive, kidney and blood issues.
Chloramine and Lead Leaching
Chloramine can cause lead to leach from lead pipes, lead solder and from some older brass plumbing fixtures. Lead poisoning causes neurological damage.
Chloramine and Rubber Corrosion
Chloramine can cause corrosion of rubber plumbing parts like toilet flappers and rubber casings.
Environmental Impact of Chloramine
Chloramine is lethal to aquatic life and must not be discharged directly into the environment. It directly enters the blood streams of, and is toxic to fish, amphibians and water-based reptiles.
Greater Vancouver Decided Against the Use of Chloramine
This negative impact on the environment was the deal breaker when Greater Vancouver held a plebiscite to decide whether to disinfect Metro Vancouver’s tap water with chlorine or chloramine. “In the early 1990’s, a comprehensive Environmental Assessment evaluated the use of both chlorine and chloramine as a secondary disinfectant. Through an extensive public consultation process in 1994, chlorine was chosen as the most favourable option.”