Change in Water Treatment Method to Reduce TTHM Levels

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January 27, 2003

PWC will modify its disinfection process from chlorine, to chloramines, in March 2003. This new treatment process will help reduce TTHM readings. PWC began notifiying its customers in January that its Total Trihalomethanes (TTHM) results for 2002 exceeded the standard, or maximum contaminant level (MCL) as established by the United States Environmental Protection Agency.

PWC routinely monitors for the presence of drinking water contaminants. The annual standard for TTHM is 0.080 milligrams per liter (mg/L). PWC's average level of TTHM over the last year was 0.08064 mg/L.

There is not an immediate health risk for PWC customers and there is no need to use an alternative water supply.

Elevated TTHM levels were the result of several factors. Chlorine (a commonly used water treatment process), dissolved organic concentration, as well as the temperature of water, affect TTHM levels. The historically low Cape Fear River levels we experienced last summer as the result of the drought, drove dissolved organic matter concentrations within the Cape Fear River to extrememly high levels.

Also, one of the many steps that was taken by PWC immediately following the terrorist attacks of Sept. 11, was to increase the chlorine levels within the water distribution system to protect our customers from threats of bio-terrorism.

PWC is working to reduce the TTHM levels. Our testing performed in December showed that we were below the MCL for that sample period. In addition, PWC will change its water disinfection process from chlorine, to chloramines, in March 2003.

Chloramination involves the addition of ammonia to chlorinated water. This treatment process is being modified to reduce disinfection by-products, such as TTHM. This change in our process will allow PWC to comply with EPA's drinking water standards.

Some of the utilities in our area that currently use chloramines as their disinfection method include the Cities of Raleigh, Durham and Chapel Hill as well as Fort Bragg and Harnett County.

While this change in the disinfection process of your drinking water supply will reduce formation of disinfection by-products such as TTHM, customers should be aware that this modification will require that individuals on kidney dialysis machines implement certain changes to their procedures. Additionally, owners of tropical fish or other aquatic life will need to take certain precautions to ensure the health of their fish.

KIDNEY DIALYSIS
· If you are a home user of a kidney dialysis machine, you should contact your dialysis center and complete necessary modifications of your dialysis machine before February 2003, so that it can handle chloramine residuals.

· The Chloramine residual is toxic to the dialysis user if not removed properly.

· Monitoring for chloramine compounds in the water that has been pretreated for dialysis should also be performed more frequently, so check with your dialysis center as to how often they will need to see you.

TROPICAL FISH

· If you have tropical fish or aquatic animals, you should contact your local tropical fish store and take appropriate actions prior to February 2003, to get information on methods for properly preparing the water for your fish tanks.

· The Chloramines are toxic to fish and aquatic animals if not properly treated

· Test the water for combined chlorine-chloramine and ammonia residuals to insure that you have properly treated the water before adding it to your fish tank.

Prior to the switch to chloramines in March, PWC will announce the changeover date through the local news media approximately one week before the change. If you need additional information regarding this disinfection modification please call the Public Works Commission at 910-483-1382.

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