APPLICATION OF ASSET MANAGEMENT PRINCIPLES TO THE WASTEWATER COLLECTION SYSTEM IN SALEM, OREGON

The City of Salem (City) has had an active rehabilitation and replacement (R&R) program for the wastewater collection system for more than 30 years. In the mid 1990s, the City decided to update the process used to identify sewers that become R&R capital projects and to determine if sufficient funds were being spent on the program to sustain the desired level of service. With the assistance of Brown and Caldwell, an environmental engineering consulting firm, the City initiated a process to develop new procedures and tools for improving the R&R program. Development and implementation of the new processes were phased in over a period of 8 years, adding new elements and building on the previous work as funding became available. Since each step in the process improved the way decisions were made, the costs and effects of implementing the program were distributed over several years, allowing staff and budgets to adjust to the changes. The program continues to evolve as additional information is added to the evaluation process.Many of the efforts undertaken by the City are now recognized as an integral part of good asset management. This paper presents the tools the City developed and utilizes for managing the wastewater collection system. These include the computerized maintenance management system (CMMS), the sewer (capital projects) priority ranking tool (SPRAT), a replacement planning model (RPM) to identify long-term funding needs, and an infiltration/inflow (I/I) forecasting model to monitor I/I in the collection system. The results of applying these tools will be presented to show how they have improved the way the City manages its wastewater collection system.