During the treatment process, chlorine is added to water as a disinfectant. Before the water leaves the treatment plant, ammonia is added to form chloramines to keep the water disinfected while it is distributed to homes and businesses. Chloramines may impart a chlorinous, or medicinal, taste or odor to your drinking water. Chloramines, rather than chlorine, are used to maintain a disinfectant residual because they are more stable, form fewer disinfection by-products, and tend to produce less offensive tastes and odors.
Small amounts (levels below 4 mg/L) of added chlorine are not harmful to your health. However, chlorine can be smelled (and often tasted) at just 1 mg/L. If your tap water’s bleach/chlorine taste is particularly strong, it may be due to your water supplier distributes water over vast distances and needs to add extra chlorine in order to keep the water clean over the longer travel time.