An Official Pennsylvania Government Website
Translate
Begin Main Content Area

Chloramine in Drinking Water

What is chloramine?

 
  • Chloramine is a disinfectant used to treat drinking water. It is formed by mixing chlorine with ammonia. Although it is a weaker disinfectant than chlorine, it is more stable which extends its disinfectant benefits throughout a water utility's distribution system (a system of pipes that delivers water to homes).
  • Some water systems use chloramine as a secondary disinfectant to maintain a disinfectant residual throughout the distribution system so that drinking water remains safe as it travels from the treatment facility to the customer. Chloramine has been used by water systems for almost 90 years, and its use is closely regulated.

Why do public water suppliers add disinfectants to my drinking water supply?

  • Disinfecting tap water is critical to protect the public from disease-causing microorganisms. Drinking water is disinfected to kill bacteria, viruses and other organisms that can cause serious illnesses and death.
  • Disinfection of drinking water has improved public health by lowering the rates of infectious diseases (for example, typhoid, hepatitis and cholera) spread through untreated water. Common disinfectants include chlorine and chloramines.

What are the advantages of using chloramine?

 
  •  Since chloramine is not as reactive as chlorine, its use can reduce the formation of cancer-causing disinfection byproducts, such as the trihalomethanes and haloacetic acids. Because a chloramine residual is more stable and longer lasting than free chlorine, it provides better protection against bacterial regrowth in distribution systems.
  • Chloramine, like chlorine, is effective in controlling biofilm, a coating in the pipe caused by bacteria. Controlling biofilm also tends to reduce coliform bacteria concentrations and biofilm-induced corrosion of pipes. Because chloramine does not tend to react with organic compounds, many systems will experience fewer taste and odor complaints when using chloramine. Chloramine technology is relatively easy to install and operate. It also is among the less expensive disinfectant alternatives to chlorine.

What are the disadvantages of using chloramine?

  • Chloramine levels are more complicated to regulate than chlorine levels. Failure to properly control and monitor the treatment process can cause undesirable chemical reactions such as increased corrosion of pipes or nitrification in the distribution system.
  • Corrosion can cause leaching of lead and copper from pipes and solder. Nitrification can cause a loss of disinfectant residual. Proper operation and management of the treatment system and disinfectant levels prevents these potential drawbacks to the use of chloramines.
  • In addition, chloramine will deteriorate natural rubber products like toilet tank "flapper valves" faster than chlorine. Alternative synthetic products are available in plumbing and hardware stores if rubber deterioration becomes a problem.

How many people use drinking water that has been treated with chloramine?

 
  • Approximately one-third of all public water systems in the United States use chloramine for residual disinfection.
  • In a 1998 national survey, the U.S. Environmental Protection Agency (EPA) estimated that water systems serve drinking water containing chloramine residuals to more than 68 million people across the country.
  • In Pennsylvania, 73 public water systems serving more than 4 million people receive water containing these residuals.

Does chloramine cause a skin rash or irritate my lungs when I shower or bathe?

  • Drinking water chloramine levels that meet the EPA standard are associated with minimal to no risk and should be considered safe. According to Dr. Jeffrey K. Griffiths at the Tufts University School of Medicine, "There is no scientific literature to support the contention that chloramine or ammonia exposures of any significance occur because of respiration. The levels of ammonia found in chlorinated water do not act as a skin irritant given their very low levels, and the levels of ammonia found in chloraminated water are dwarfed by the amounts of ammonia found in foodstuffs."
  • Irritating effects to the eyes and nose, stomach discomfort or anemia can occur by drinking water containing chloramines well in excess of the Maximum Residual Disinfectant Levels. High levels would only occur with improper operation of the water treatment and distribution system.
  • DEP reviews and approves the use of chloramines and all other chemicals or additives in public drinking water systems. In addition, DEP reviews the suitability of all proposed equipment and its operational requirements to ensure that all facilities are effectively and reliably operated to produce finished water that meets all current Pennsylvania standards for safe drinking water.
 

Does chloramine increase lead levels in my drinking water?

  • Regardless of of whether a water system uses chlorine or chloramine for disinfection, optimum treatment for lead control is important. In some instances, water systems have experienced elevated lead levels immediately after converting to chloramine. These problems were usually attributable to unique circumstances and are avoidable if the conversion process is monitored and managed properly.
 

Will chloramine irritate my skin or lungs while swimming in a pool?

  • Proper water quality maintenance in pools will prevent skin and lung irritation. Most swimming pool owners use chlorine as a disinfectant. Inadequate chlorine addition or improper pH levels can contribute to the creation of chemical compounds, such as dichloramine and trichloramine, which are the most likely causes for irritation from swimming.
  • Maintaining a pH level of 7.2 to 7.8 is necessary to control the formation of dichloramine and trichloramine. The type of disinfectant used to treat water does not change the necessary chemical maintenance for swimming pool owners nor does it alter the effectiveness of those chemicals used for treatment.
 

How does chloramine affect dialysis patients?

  • Dialysis centers and hospitals are notified before a water system converts to chloramine. Like chlorine, chloramine residuals need to be removed from water that is used for dialysis machines.
  • As part of their standard test procedures, technicians check for total chlorine residuals (due to chloramine) to ensure the residual is zero. Some machines may need modifications depending on the method of chlorine removal that is currently used.
  • A change in the disinfectant used to treat the water should not impact or require any change in the normal operation of dialysis machines. Home dialysis users should consult their physician or dialysis machine manufacturer for instructions.

How does chloramine affect aquarium hobbyists and fishpond owners?

  • Chloramine residuals need to be removed from water that is added to aquariums and fishponds.
  • Aquarium hobbyists may obtain an inexpensive conditioner and a test kit from a local pet store or aquarium supply store. Alternatively, hobbyists may purchase a carbon filtration system that is designed to remove chloramine.
  • Pond owners may need to purchase a conditioner or ammonia binder in bulk quantities if more than one percent of the total water volume in the pond is replaced at one time.

Where can I learn more?