On Friday, April 1, OWASA will resume the disinfection of drinking water with a compound of chlorine and ammonia called chloramines.

In March, the utility only used chlorine in accord with an annual State requirement. Chlorine disinfection resulted in some chlorine taste and odor in the water.

With the return to chloramine disinfection on April 1st, some chlorine odor and taste may be noticeable in OWASA water for a few days.

Background information regarding water disinfection with chloramines

Before 2002, OWASA used chlorine in the form of sodium hypochlorite (bleach) for disinfection. 

In January, 2002, OWASA began using chloramines to disinfect drinking water. Disinfection with chloramines has improved the taste and odor and the overall quality of drinking water.

The change to chloramine disinfection in 2002 has reduced the levels of disinfection byproducts which may be harmful at high levels over a lifetime. The disinfection byproducts, which result from the chemical reaction of chlorine with organic material, are called trihalomethanes (THMs) and haloacetic acids (HAAs). Small particles of organic material are naturally present in the water from lakes.

In the Triangle region, water utilities including OWASA, the City of Raleigh and the Town of Cary use chloramines for disinfection except for one month of the year (March or a similar period). 

For more information:

Ken Loflin, Water Supply and Treatment Manager, 537-4232;

Rachel Monschein, Laboratory Supervisor, 537-4227;