Chloramines are disinfectants used to treat drinking water and in water treatment plants to kill bacteria and other pathogens. .  It is formed most commonly when ammonia is added to chlorine to treat drinking water.  It helps to provide longer-lasting disinfection as the water moves through distribution.  More than 1 in 5 Americans have water that is currently being treated with chloramines.  Since chloramines stay in the system a long time and create less byproducts, it is often chosen as an alternative to free chlorine despite it being less effective.   It seems to survive in the system a longer time which will provide further protection to your pipes and fixtures, but may give the water a bad smell and taste.


  1. Monochloramine – most common form used to disinfect drinking water
  2. Dichloramine – Formed when chlorine to ammonia-nitrogen weight ratio is greater than 5:1, however, this reaction is slow.
  3. Trichloramine – does not usually occur under normal drinking water treatment conditions.  If pH is lowered below 4.4 or the chlorine to ammonia-nitrogen weight ratio becomes greater than 7.6:1, then trichloramine can form.
  4. Organic chloramines – Formed when chlorine reacts with organic nitrogen compounds


Municipal Treatment


Chloramines do pose a risk for hemodialysis patients causing hemolytic anemia when it’s present in dialysis water.  Nitrosamines can be generated as byproducts from use of chloramines as well.  They are strongly suggested to be human carcinogens.


An effective filtration system can remove chloramines from your water.  Using a BWS CARBON FILTER SYSTEM with granular activated carbon (GAC) is the most effective way to remove chloramines from you drinking water.

WQA Chloramine Fact Sheet