Stage 2 DBPR Rule requires that each community water system conduct an evaluation of their distribution systems, known as an Initial Distribution System Evaluation (IDSE) to identify the locations with high disinfection byproduct concentrations. These locations will then be used as the sampling sites for Stage 2 DBPR compliance monitoring. The Stage 2 DBPR Rule also requires each water system to determine if they have exceeded an operational evaluation level, which is identified using their compliance monitoring results.
Here’s a step-by-step guide to help your water system stay on track to achieve compliance. This guide is based on the EPA’s Compliance Help information page and the Complying with Stage 2 Disinfectant and Disinfection Byproducts Rule: Small Entity Compliance Guide. We’ve also included the links for each state’s guidelines at the conclusion of this guide.