What is chloramine and why is it added to the water?
Chlorine is added to water at the treatment plant to disinfect the water, which kills harmful bacteria and germs. A small amount of ammonia is added to the chlorinated water before it leaves the treatment plant to create a slightly different disinfectant called Chloramines. Chloramines can maintain a disinfectant residual longer than chlorine, which is important for large distribution systems such as the District’s (the District contains over 1,300 miles of pipe for distributing drinking water). Chloramine levels in DC WASA’s drinking water vary from about 2 parts per million (ppm) to 3.5 ppm depending on where you live relative to the water treatment plant, as well as the time of the year (chlorine and chloramines are harder to keep in the water during the summer when the temperature of the water is high). Chloramine was also chosen because of its capability to minimize potential carcinogenic chlorine byproducts (referred to as disinfection byproducts or DPBs). DC WASA monitors these
