DBP CONTROL IN DRINKING-WATER - COST AND PERFORMANCE

The U.S. Environmental Protection Agency (U.S. EPA) is currently attempting to balance the complex trade-offs in chemical and microbial risks associated with controlling disinfection and disinfection by-products (D/DBP) in drinking water. In attempting to achieve this balance, the U.S. EPA will propose three rules: an information collection (ICR); an enhanced surface water treatment rule (ESWTR) and a two-stage D/DBP rule. Controlling D/DBP will have a major impact on drinking water utilities in the United States. There are several options for D/DBP control, including moving the point of disinfection, removal of by products once they are found, removing precursor material or natural organic matter before it interacts with the disinfectant, or use of a disinfectant that minimizes the formation of by-products. The least-expensive approach to D/DBP control is to move the point of disinfection or the use of an alternative disinfectant. The least-desirable approach is to remove disinfection by-products once they are formed. Overall, the most effective approach to D/DBP control is to remove precursor before it reacts with the disinfectant. The choice of any given strategy is very site specific.