AWWA ACE65252

The objective of this study was to evaluate alternative bromate control strategies, involving pre-oxidation (or addition) of chlorine dioxide, chlorine and then ammonia, ammonia then chlorine, or ammonia alone before ozonation. A second objective was to balance the formation of bromate with that of other regulated DBPs (i.e., chlorate, THMs). In order to reliably meet the bromate MCL of 10 µg/L, the goal was <8 µg/L. In addition, the 10-4 excess cancer risk level for bromate at 5 µg/L represented an alternative bromate goal. In order to meet the ACC, a goal of <32 µg/L of THMs (40 µg/L with a 20-percent safety factor) and <24 µg/L of HAA5 (30 µg/L with a 20-percent safety factor) was established for the testing processes. In order to meet the California notification level for chlorate, a goal of <0.6 mg/L was set (i.e., 20-percent safety factor). Includes 4 references, figures.