AWWA JAW48138

This article discusses how the concentration of disinfection by-products (DBPs) changes in the distribution system. To systematically determine whether the concentrations of DBPs varied in a central New Jersey drinking water distribution system, concentrations of trihalomethanes (THMs), haloacetonitriles (HANs), haloketones (HKs), chloropicrin (CP), and haloacetic acids (HAAs) were determined. The system was disinfected with chloramine by adding ammonia to convert all but approximately 0.5 mg/L of the free chlorine; a free chlorine residual was released into the distribution system. DBP concentrations were measured at four locations with nominal residence times of zero, one, two, and three days, approximately every tenth day for one year. Water parameters known to influence DBP formation (pH, temperature, nonpurgeable organic carbon [NPOC] concentration, and free and total chlorine residual) were also measured. Includes 39 references, tables, figures.