Chloramines

Chloramine, which consists of a mixture of chlorine and ammonia, is added to the water of many cities as a substitute for free chlorine. It is often referred to in the plural, as “chloramines,” because it can take on a number of forms according to the pH and mineral content of the water. Chloramine is a disinfectant used by many cities and water districts to sterilize water. It is an alternative to chlorine. The use of chloramine has increased dramatically in recent years in large part due to the facts that it maintains its sterilization capacity longer (less likely than chlorine to degrade or dissipate – it is more stable), and it is less likely to form harmful disinfection by-products like THMs. It is estimated that close to 30% of municipal water treatment plants now use chloramine instead of chlorine.

Chloramines are perhaps the most damaging chemicals being applied to water treatment at various water treatment plants throughout the country today, and contrary to what water suppliers have attempted to say about the subject for many years, it is now apparent that these compounds are potent carcinogens. Notwithstanding this information, utility companies around the country routinely misinform their customers, telling them that chloramines are effectively neutralized by stomach acids before they can reach the blood. It is also known that chloramines cause DNA damage and are potential carcinogens. They are extremely dangerous to all forms of fresh and salt-water fish because they are absorbed directly from the gills and transported directly into the blood causing death in a short period of time.

For a variety of reasons, increasing numbers of people want chloramine out of the water they drink and bathe in. One of the big myths about chloramine is that it can’t be removed. Actually, it is removed with filter carbon (often called charcoal), the same filtering agent that very effectively removes chlorine. The difference is that chloramine is much harder to remove. Therefore, it takes more carbon and water must be given more residence time in the carbon. In other words, you need a considerably larger carbon bed and a significantly slower flow rate to remove chloramine with standard carbon.

The whole reduction discussion for chloramines can become quite complex, but the main thing you need to know is that chloramine is removed from water with essentially the same strategies that are used to remove chlorine. This means that carbon filtration is the best removal method, and, contrary to urban legends, filter carbon does indeed remove chloramine. The problem is that it takes more carbon and more contact time to do the job. In practical terms this means that if your city disinfects your tap water with chloramines you’ll need to get a larger and better carbon filter than you would need if chlorine alone were used.

If you are unsure whether your water supply is treated with chlorine or chloramine, contact your city’s utilities department, local health department, or water treatment plant. If you are unable to get a definite answer, we recommend that you use a catalytic carbon filter.