AWWA DSS69155

This powerpoint presentation begins by presenting study objectives that include the following: review strategies that have been used by utilities to investigate and resolve coliform occurrences; review some newer research trends associated with detection and characterization of coliform occurrences; and, discuss new Distribution System Microbial Integrity Toolbox to enhance compliance with revised Total Coliform Rule (TCR). The presentation briefly overviews actions to revise the TCR, including assessments to identify sanitary defects. A summary is provided of tools reviewed in the AwwaRF Report #3116 Utility Case Studies. Topics covered include: strategies for investigating the source and/or extent of coliform problem; strategies for mitigating coliform occurrences; and, emerging research from AwwaRF 3116 associated with coliform detection and speciation. Presentation conclusions indicate the following: more rapid identification and better characterization of coliforms will allow utilities to better determine sources/causes of occurrence such as treatment breakthrough, contamination event, or regrowth; can assess adequacy of existing O&M practices; utilities will begin to build libraries of isolates associated with different events in their systems; will help focus and tailor responses to coliform events; will provide more confidence regarding integrity of distribution system and potential threats to public health; and, guidance available to help with TCR assessments and corrective actions. Includes figures.