Condition/Criticality Assessment – A Case Study for Collection System Asset Management

The Knoxville Utilities Board (KUB) has established a Continuing Sewer System Assessment Program (CSSAP) that provides a structure for evaluation of the current condition of the wastewater collection system and identifies actions that should be taken to improve the performance of the system. One element of the CSSAP is a pump station and force main assessment which is intended to identify issues through periodic inspections. This project allowed KUB to develop a programmatic approach to managing collection system assets using condition/criticality (CC) analyses to identify system component (pump station and force main) issues and a prioritization system for addressing these issues.The benefit of using this CC prioritization process has been that the appropriate level of resources can be dedicated to inspect, maintain, and rehabilitate different areas of the collection system. Because simultaneous investigation and rehabilitation of every collection system asset is cost-prohibitive, KUB's finite resources are best used when they can be focused on immediate rehabilitation efforts on higher-priority areas of the system and monitor lower-priority areas. Using this approach, KUB has developed a long-term rehabilitation strategy to proactively identify potential problem areas and fix the problems before they result in negative impacts to the community or environment. The project approach and methodology are described in this paper along with the results of the pump station prioritization as a case study example of how this method can be applied.