AWWA WQTC59017

Variability has been examined in the speciation and concentration of disinfection byproducts (DBPs) at two drinking water treatment plants in the United States. The two plants treat surface waters with sufficiently different bromide concentrations to impact DBP speciation. Although both plants utilize chloramination as the terminal disinfectant, there is a significant difference between the brominated DBP distributions at the two sites. Comparative analysis has been conducted to evaluate this variability in concentration and speciation of halogenated DBPs at the two sites, specifically for total trihalomethanes (THM4) and total haloacetic acids (HAA9). The differing DBP speciation is not currently accounted for through the quarterly DBP monitoring program mandated by the U.S. Environmental Protection Agency. Although it is suspected that the health risks associated with individual DBP species vary, the current regulatory approach does not account for the speciation within each byproduct group. The results presented in this paper explore the individual constituent concentrations at two utilities and show how they vary in relation to the byproduct group summations, THM4 and HAA9. Includes 13 references, figures.