In order to maintain quality water, the Maui Department of Water Supply uses chloramines as a disinfectant in the Upper Kula system. Chloramines are a combination of chlorine and a small amount of ammonia. Here are answers to commonly asked questions about chloramines and why we use chloramines for Upper Kula.

Are chloramines new?
No. Many cities in the USA and Canada have used chloramines for decades.

Your water is surface water from the Waikamoi forest reserve, which is treated by microfiltration at the Olinda Water Treatment Facility. The Maui Department of Water Supply recognizes the need to keep disinfection as consistent and stable as possible throughout the water system. The Maui DWS uses chloramines for their ability to last in the distribution system, for their lack of taste and odor and for their safety. It has been shown that chloramines help deliver water to you with the lowest possible levels of trihalomethanes (THMs).

What are trihalomethanes (THMs)?
THMs are chemical compounds that are formed when chlorine mixes with naturally occurring organics in water. The U.S. Environmental Protection Agency (EPA) conducted tests, which determined that chloroform (one of the THMs) is carcinogenic when consumed by laboratory animals in large quantities over a prolonged period of time, and is a suspected carcinogen for people. EPA set a standard of 100 parts per billion as the safe maximum level of THMs in drinking water.

Are chloramines safe?
Yes. Chloramines have been used safely in the USA and Canada for many years. EPA accepts chloramines as a disinfectant and as a way to avoid THM formation. Were it not for some kind of disinfectant in drinking water, disease-causing organisms such as typhoid and cholera could be carried in your drinking water. Chloraminated water is safe for bathing, drinking, cooking and all uses we have for water every day. However, there are two groups of people who need to take special care with chloraminated water: kidney dialysis patients and fish owners.

Why do kidney dialysis patients have to take special precautions?

Yes. All medical facilities should know about the effects of chloramines. If you have any doubt, please ask your physician.

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

Are other areas of Maui County affected by chloramines?
No. Water for the rest of the Maui DWS system is disinfected by chlorination. This includes Central Maui, Molokai, East Maui, West Maui, Makawao, Haiku, Pukalani, and Lower Kula.

If chloramines are toxic, won't they harm people and pets?
Chloramines are harmful when they go directly into the bloodstream, as happens in kidney dialysis. Fish also take chloramines directly into their bloodstreams. That's why chloramines must be removed from water that goes into kidney dialysis machines or is used in fish tanks and ponds.




Chloraminated water is no different than chlorinated water for all of the normal uses we have for water. Water that contains chloramines is totally safe to drink. The digestive process neutralizes the chloramines before they reach the blood stream. Even kidney patients can drink and bathe in chloraminated water.

Can pregnant women and children drink chloraminated water?
Yes. Everyone can drink water that contains chloramines.

What about people who are sensitive to chemicals?
The amount of chloramines will be extremely small - no more than 2 parts per million parts of water. If you are concerned that even this low concentration might cause problems for you, check with your physician. The predominant type of chloramines will be monochloramine (NH2Cl) and will be in the ratio of 5 parts chlorine to one part ammonia-nitrogen.

Will chloramines change the pH of the water?

What will water taste like with chloramines?

Do home water softeners remove chloramines?
Most water softeners are not designed to remove chloramines.

Does bottled water have chloramines?

Will chloramines affect my swimming pool?
No. You will still need a free-chlorine residual to retard algae and bacteria growth. The chlorine chemicals and test kits you currently use can still be used with confidence. Contact your local pool supply store for any specific questions.


How do chloramines affect fish?


This will depend on the amount of water added in relation to the size of the aquarium or pond and the time period over which it's added. An alternative is to monitor for a total chlorine residual in the aquarium or pond while adding the chloraminated water. Chloramine residuals in water used to keep fish should be kept below 0.1 mg/L. Total chlorine test kits are available from pet stores, pool supply stores and chemical supply houses. Make sure that the kit is for "total chlorine" or "combined chlorine," not "free chlorine." A free chlorine test of chloraminated water would read zero but still be toxic to fish.

Are both salt and fresh water fish affected by chloramines?

Do chloramines pose a hazard to koi?
Yes. Koi are just as susceptible to chloramines as any other fish.

Will a carbon filter remove chloramines?
Yes. However, it must contain high quality granular activated carbon and you must permit sufficient contact time between the water and the carbon.

Will reverse osmosis remove chloramines?

Will chloramines be removed by boiling the water?
No. Boiling is not an effective method of removing chloramines from water. The only practical methods for removing chloramines from water are using a water conditioner which contains a dechloraminator or by using granular activated carbon.


What are the effects of ammonia on fish?



Can film development be affected by chloramines?
Yes. Chloramines have the potential to stain photographic emulsions or retard development. Please contact your equipment manufacturer and your chemical supplier to determine if chloramines will effect your set up. If you need to remove the chloramines there are two recommended methods for the removal of chloramines, use f specific reagents or a granular activated carbon (GAC) filter.

Call the Maui Department of Water Supply laboratory at (808) 270-7550.
Please view the Water Quality Report for Upper Kula for more information and details on the amount of THMs in the area's water system.