City of Manhattan's Drinking Water Quality

Drinking Water Disinfection Method
In June of 2005, the City of Manhattan improved the overall treatment process and quality of water by changing the city's drinking water disinfection method from free chlorine to chloramines. Chloramines are a combination of chlorine and ammonia that are considered a better drinking water disinfectant than free chlorine. The reason for the change in the water disinfection method is to ensure that the City complies with water quality regulations. Additionally, chloramines disinfection will provide higher quality water because of a longer residual life of chloramines in the water distribution system compared to chlorine.

Health Standards
While the city already complies with all current water quality regulations, this change was made in advance of new, more stringent health standards, which the United States Environmental Protection Agency will phase in over the next few years. Chloramines addition was selected as the disinfection method of choice because it is the most cost-effective way of maintaining compliance under the new regulations.

Chloramines for Disinfection
The use of chloramines for disinfection has been used for decades in many cities across the country. Chloramines are recognized as a proven, safe drinking water disinfectant. Cities such as Tampa, Denver and Minneapolis have been using chloramines disinfection since World War II. The cities of Topeka and Wichita also use chloramines for drinking water disinfection. The number of cities using chloramines is expected to continue to grow due to new drinking water regulations.

By-Product Reduction
The change to chloramines will reduce the level of some regulated disinfection by-products formed when chlorine mixes with trace quantities of naturally occurring organic substances found in water. This is particularly significant because the use of chloramines will reduce the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). THMs and HAAs are two types of disinfection by-products that highly regulated by the Environmental Protection Agency.

Water Safety
Water disinfected with chloramines is safe for people and animals to drink. It is also safe for all other general uses. As with chlorine, precautions must still be taken to remove or neutralize chloramines in the kidney dialysis process, in the preparation of water for fish tanks and ponds, and in businesses requiring highly treated water. Learn more about these precautions.

Related Items