Frequently Asked Questions About Chloramine Water Disinfection

Q: What is the disinfection process?

A: Disinfection is a step in the water treatment process to assure the biological safety of water. Chlorine, Chloramines and other chemicals can be used as disinfectants.  In 2000, the Washington Aqueduct, which provides drinking water for Arlington residents, changed to chloramine as the disinfectant.

Q: Is chloramine safe?

A: Chloramine is safe. EPA accepts chloramine as a disinfectant and recognizes its ability to control THM formation. Chloraminated water is safe for bathing, drinking, cooking and all everyday uses. 

Q:  Why does our water provider change back to chlorine as the disinfectant every spring while the water mains are flushed? 

A: Temporarily converting from chloramines to free chlorine is done to accompany the annual process of flushing of our drinking water distribution system.   A biological film, known as biofilm, is found in all water pipes.  It can lead to water quality problems if not controlled.   Biofilm can become accustomed to the chloramine disinfectant that is routinely used.   By switching to free chlorine for a short period of time, the biofilm is ‘shocked’ and weakened.   Using fire hydrants to conduct a system-wide flushing of our distribution mains, combined with the disinfectant change, is a very effective method for controlling biofilm that is used nationwide.

Q: What methods are available to remove chloramine?

A: Carbon filtration or water treatment products that neutralize chloramine may be used. If you use a carbon filter it must contain high quality granular activated carbon and you must permit sufficient contact time.

Q: Will reverse osmosis remove chloramine?

A: No. Salts can be caught by the permeable membranes but chloramine may pass through the membranes.

Q: Do home water softeners remove chloramine?

A: Most softeners are not designed to remove chloramine.

Q: What about fish tank owners?

A: Fish tank owners, including hobbyists, restaurants and fish markets, who now treat for chlorines in the water, should assure that they have appropriate carbon filtration equipment or use water treatment products that neutralize chloramine. These products are readily available through pet and aquarium stores, as well as from companies that service commercial fish tanks.

Q: Does letting water sit for a few days remove chloramine from tanks for pond water?

A: No. Unlike chlorine, which breaks up when water sits for a few days, chloramine may take weeks to disappear. If you choose not to use de-chloraminating chemical, install a granular activated carbon filter and allow sufficient contact time between the water and filter.

Q: Will chloramine affect the way I treat my swimming pool?

A: No. you will still need a free chlorine residual to retard algae and bacteria growths.

Q: How are kidney dialysis patients affected by chloramine?

A: Chloramine can diffuse through the reverse osmosis membrane filters utilized by some hemo-dialysis machines, and patients undergoing kidney dialysis could be adversely affected. To prevent this dialysis equipment must be adjusted to remove chloramine and the treated water must be monitored to measure the final chloramine concentration. Dialysis facilities must review their dialysis treatment equipment to determine its continued safe operation.

Q: What should people with home dialysis machines do to remove chloramine?

A: Check with your physician. Often times, home dialysis service companies can make the needed modifications.

Q: Is it safe for kidney dialysis patients to drink water containing chloramine?

A: Yes. Because the digestive process metabolizes chloramine before it reaches the bloodstream, everyone can drink chloraminated water. Kidney dialysis patients can drink, cook, and bathe in chloraminated water. It’s only when water interacts directly with the blood stream, as in dialysis or in a fish’s gill structure, the chloramine must be removed.

Q: Can children and pregnant women drink chloraminated water?

A: Yes, everyone can drink water containing chloramine.

Q: Can people on low-sodium diets, or with diabetes us chloraminated water?

A: Yes. People with those medical problems can use chloraminated water for all purposes.

Q: How about washing an open wound with chloraminated water?

A: Even large amounts of chloraminated water used in cleaning a cut would have no effect because virtually no water actually enters the blood stream that way.

Q: Who can I call if I have more questions?

A: Call your local Utility of the Water Supplier in you area.

For treatment plant questions, call the Washington Aqueduct: 202-764-0019,

For DC/WASA questions, call 202-612-3441

For Arlington County questions, call 703-228-6555

For City of Falls Church questions, call 703-248-5287

Fact Sheet For Kidney Dialysis Patients

Washington Aqueduct has changed the disinfectant used in drinking water. This change is being made to improve Washington Aqueduct water quality and meet new federal and state drinking water regulations. We have switched from chlorine disinfection to chloramine disinfection for the distribution system. While chloramines are recognized as a safe form of drinking water disinfection, like chlorine, chloramines must be removed from water used in kidney dialysis machines.

What does this mean to you as a kidney dialysis patient?

Drinking either chlorinated or chloraminated water is safe. Chlorine and chloramines are harmful only when the directly enter the bloodstream through the dialysis process. As a result, you may need to change the way water is pre-treated for dialysis. Depending on the method of chlorine removal your dialysis machine uses now, some modifications may be necessary.

If you are a home user of a kidney dialysis machine:

Like chlorine, chloramines must be removed from water use for kidney dialysis treatment. Contact you dialysis center and complete any necessary modifications to your dialysis machine.

Check with your dialysis center to find out how often they will need to see you. Monitoring for chloramine compounds in the water that has been pre-treated for dialysis may need to be performed more frequently.

Why do kidney dialysis patients need to take special precautions?

In the dialysis process, the compounds in water come in contact with the blood across a permeable membrane. Chloramines in that water would be harmful, just as chlorine is harmful and must be removed from water used in kidney machines. There are two ways to do that: either by adding ascorbic acid or by using a granular-activated carbon treatment. Medical centers that perform dialysis are responsible for preparing the water that enters the dialysis machines. They are  informed of this change.

Is it safe for kidney dialysis patients to drink water containing chloramines?

Yes. Because the digestive process metabolizes chloramines before they reach the bloodstream, everyone can drink chloraminated water. Kidney dialysis patients can drink, cook, and bathe in chloraminated water. It is a concern only when water interacts directly with blood stream, as in dialysis.

What should people with home dialysis machines do to remove chloramines?

You should first check with you dialysis physician, who will probably recommend the proper type of water treatment. Often, home dialysis service companies can make the needed modifications, but you should check with your physician to be certain.

Do medical center, hospitals, and clinic that perform kidney dialysis know about the change to chloramines?

Yes. All medical facilities have been notified of the change. All dialysis systems  prepare the water being used for dialysis. If you have any concerns about this process, talk with you physician.

Can people with kidney ailments, with diabetes, or on low-sodium diets use chloraminated water?

Yes. People with those medical problems can use chloraminated water for all everyday purposes such as bathing, drinking and cooking.