AWWA DSS63721

Stage 2 of the Disinfection Byproduct Rule (DBPR) is designed to further reduce exposure to disinfection byproducts (DBP) in drinking water. The first step required under the Stage 2 DBPR is completion of an Initial Distribution System Evaluation (IDSE). The purpose of the IDSE is to identify those locations within the distribution system where DBP concentrations are anticipated to be the highest. These representative locations will then become the long-term compliance monitoring points. This paper discusses the sampling-based and hydraulic modeling-based methods by which the IDSE can be accomplished and highlight the additional benefits which can be expected through the use of an IDSE compliant hydraulic model. Includes tables.