Abstract |
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 the 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. 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. (Copyright (c) 1994 ASCE.) |