Lessons Learned in Calibrating an IDSE Model

The Stage 2 Disinfection By-Product Rule Initial Distribution System Evaluations (IDSE) requirements have led utilities to redo their water distribution system models to conform to different standards than prior models which were created for master planning studies. This paper describes the hurdles faced in converting an older water distribution model for Scranton, Pa. into a model that could be used for IDSE studies. Some of the issues included: 1) Need to fill in the distribution grid, 2) Ability to better assign water use records to nodes, 3) Problems with data sources being in different (and nonstandard) coordinate systems, 4) Issues with boundaries between pressure zones, 5) Discontinuities in underlying CAD map, 6) Questionable or missing SCADA data, and 7) Complexity of the Scranton system. The problems encountered during the study and their solutions, which involved a mix of advanced data processing tricks to plain-old hard work, are described in this paper.