Which Pipe First? Using Evidence-Based Condition Assessment and Desktop Modeling to Optimize Pipe Replacement

Most water systems across North America are struggling with managing the required renewal plans of their buried water assets that have reached the end of their service life. One of the primary concerns of water utility asset managers is prioritizing renewal of these buried assets to ensure that the right pipes get replaced first. The Regional Municipality of Peel found that by exclusively using their current desktop model they were replacing water mains in good condition. The region’s desktop model was missing a critical parameter: evidence-based condition information. The region engaged Echologics in a pilot study to gain condition assessment measurements on metallic water mains in Mississauga and Brampton. Wall thicknesses were measured on 133 segments (16 kilometers) of buried water mains with no interruption to service, costly excavations, or extensive support from utility crews and all at a cost of less than 1.4 percent of the cost of water main replacement. Three non-surfacing leaks were also pinpointed during the study. This paper discusses the results of the pilot and how condition assessment information was used to target spending on assets that only truly required replacement and deferred the cost of replacement on assets in good condition.