Frequently asked questions about Chloramination

What is chloramination?

Chloramination is the process of adding an ammonia product to drinking water, which already has chlorine added as a disinfectant. The ammonia combines with the existing chlorine, which is called free chlorine, to create chloramines.

Is chloramination new?

No, we already use chloramination in large parts of the Anglian Water region.

Why is my water supplier making the change to chloramination?

Anglian Water uses chloramines as they have a longer life span within the water network, for their lack of taste and odour, and for their safety.

How will we be chloraminating the water?

We will be adding a small amount of ammonium sulphate, which will combine with the chlorine we already use, to produce chloramines. The predominant type of chloramines will be monochloramine (NH2Cl) and will be approximately in the ratio of 5 parts chlorine to one part ammonia-nitrogen.

What will water taste and smell like with chloramines?

If you notice any change at all, you may find your water has less of a chlorine odour or taste than previously.

Are chloramines safe?

Yes. Chloramines have been used safely in the UK, U. S. and Canada for many years. Water companies are legally required to disinfect the water that is supplied to customers to ensure that it is safe for customers to drink/use. Chloraminated water is safe for bathing, drinking, cooking and all uses we have for water every day. However, there are some groups of people who need to be aware of the change to chloraminated water such as kidney dialysis patients, fish owners and industrial users.

Why do kidney dialysis patients have to take precautions?

In the dialysis process, water comes in contact with the blood across a permeable membrane. Both chlorine and chloramines in that water would be toxic in the dialysis process, and must be removed from water used in kidney dialysis machines. However, dialysis patients can drink, cook, and bathe in chloraminated water.

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

We would advise that customers with home dialysis units contact their dialysis administrator for further information about any changes that may be required to their machine.

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

Yes, we have been in contact with Public Health England to make them aware of the treatment changes.

Can people and pets safely drink the water?

Chloraminated water is essentially no different to chlorinated water and is totally safe to drink.  The digestive process neutralises chloramines before they reach the bloodstream. Chloramines are only harmful when they go directly into the bloodstream - as in kidney dialysis or through a fish's gill structure.  In these instances, chloramines must be removed. 

How about washing an open wound, such as a cut, with chloraminated water?

Certainly. Even large amounts of water used in cleaning a cut would have no effect because virtually no water actually enters the bloodstream that way.

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 no more than 1.5 parts per million parts of water. If you are concerned that this concentration might cause problems for you, check with your doctor.

How do chloramines affect fish?

Chloramines are toxic to fish and must be removed from water, just as chlorine is toxic and must also be removed. Chloramines affect salt-water fish just as they affect freshwater fish. You may not have had to remove chlorine from your aquarium water, however, because it disappears rapidly on its own.

This is not the case with chloramines and steps should be taken to remove chloramines. Most pet shops supply de-chlorinating agents and can recommend  how to use them. The chemicals used to remove chlorine should work just as well for chloramines. Some manufacturers add chloramine information to the labels on their products.

Can Koi assimilate chloramines unlike other fish?

No. Koi are just as susceptible to chloramines as any other fish.  

Won't letting water sit for a few days remove chloramines from tank or pond water?

No. Unlike chlorine, which dissipates when water sits for a few days, chloramines may take weeks to disappear. If you don't want to use a dechloraminating chemical, the next best solution is to install a granular activated cardon filter and allow sufficient contact time. 

If only a small amount of water is added to an aquarium or pond to make up for evaporative loss, do chloramines still have to be removed?

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. Instead of removing chloramines they can be controlled by monitoring for a total chlorine residual in the aquarium or pond while adding the chloraminated water, rather than a free chlorine residual. For both chlorine and chloramine residuals, the total chlorine in the water used to keep fish should be kept below 0.1 mg/l. Total chlorine test kits are available from pet shops and pool supply shops.

What are the effects of ammonia on fish?

Ammonia can be toxic to fish, although all fish produce some ammonia as a natural byproduct. Ammonia is also released when chloramines are chemically removed. Although ammonia levels may be tolerable in individual tanks or ponds, commercial products are available at pet shops to remove excess ammonia. Biological filters, natural zeolites, and pH control methods are effective in reducing the effects of ammonia.

Will chloramines change the pH of the water?

No. The pH of the water will remain the same as before.

Does bottled water contain chloramines?

It could if it is a table water rather than a natural spring or mineral water, as table water can be supplied from a mains water supply that is chloraminated.