AWWA DSS63739

This slide presentation outlines a case study in Beaverton, Oregon, on using a tracer study to evaluate a hydraulic model for use in preparing Initial Distribution System Evaluation (IDSE). The project objective was to identify the best IDSE compliance option, to evaluate an existing hydraulic model for use in preparation of IDSE, and to decide which route to take: a standard monitoring plan or a system specific study. Step 1 involved a hydraulic model verification, Step 2 was to simulate a tracer study model. Tracer study conclusions included: Beaverton system operations included a system operations change on a daily basis based on expected demand reported to JWC, many PRVs (over 50) in the system with limited flow data makes model calibration challenging, ASR operation adds layer of complexity to system operation, and assumption of uniform demand in model not adequate for IDSE; tracer study showed model predicts fluoride transport fairly well with the exception of two locations in the northeast part of town; tracer study confirmed poor mixing in 5 MG tank; and, use the Standard Monitoring Plan approach to perform IDSE. Further topics covered include: preparing an IDSE plan; identify IDSE sampling sites; candidate IDSE monitoring locations; and, select IDSE monitoring sites. Includes tables, figures.