Chlorine and Chloramines – Their Role in the Drinking Water Treatment Process

Chlorine and Chloramines – Their Role in the Drinking Water Treatment Process

Chlorination of drinking water is widely considered to be one of the most significant public health benefits since it was first used for this purpose in the late 1890s in Europe. Prior to this time, thousands of U.S. residents in the U.S. died annually from waterborne diseases.

Chlorine and chloramines (a mix of chlorine and ammonia) work to disinfect water during the treatment process, neutralizing contaminants that could pose a danger to humans who consume it.

Water Treatment with Chlorine and Chloramines

Chlorine and chloramines are added to water during the treatment process to disinfect it. The use of these chemicals, the most common methods for disinfecting drinking water, kills potentially harmful contaminants, such as viruses and bacteria, and protect public health.

EPA Mandates

The U.S. Environmental Protection Agency (EPA) and the Indiana Department of Environmental Management (IDEM) require a minimum level of chlorine and chloramines to be maintained within water as it comes from our treatment facilities to your water tap. Indiana American Water works to minimize these levels while protecting the quality of water delivered to our customers through consistent monitoring and adjustment of concentrations as needed.

Household Effects of Chlorine and Chloramines

Higher levels of chlorine and chloramines may exist in your tap water if you live close to an Indiana American Water treatment facility. Although you may notice the taste or smell of chlorine in your water, we closely monitor these levels to ensure tap water is always safe to consume.

If the taste or smell of chlorine in your water is bothersome to you, you can take a few steps to minimize it.

  • Refrigerate tap water in an uncovered container overnight to allow chlorine to dissipate.
  • Boil drinking water for five minutes, and allow to cool prior to drinking.
  • Add a lemon slice or a few drops of lemon juice to a glass of drinking water.

Chloraminated water typically produces less of the smell and/or taste associated with water treated with chlorine. Certain customers should be mindful and exercise precaution when utilizing chloraminated water.

  • Patients undergoing kidney dialysis should remove chlorine and chloramines before consuming, as dialysis brings water into contact with the blood stream. Ascorbic acid can be added to water to neutralize these chemicals, or water should be filtered using activated carbon prior to using it for this purpose.
  • If you own a fish aquarium, be mindful that chlorine and chloramines are toxic to fish, even when levels are quite low.  Most pet stores sell a disinfectant removal product that can be added to the water prior to introduction of the fish into a tank or pond.

Protecting the health of the public is of the utmost importance to Indiana American Water. By utilizing and monitoring chlorine and chloramine levels in our water treatment process we are helping to ensure the water that flows through your home’s taps is clear of harmful bacteria and viruses. To learn more about the use of chlorine and chloramines in our drinking water systems across the state, visit us online at