Condition Assessment of Portland, Oregon, Water Bureau's Three Primary Supply Mains

The city of Portland gets its water primarily through three (3) large diameter lock-bar steel transmission pipelines, colloquially referred to as “The Conduits.” These pipelines transport water from the Portland Water Bureau’s (PWB) Headworks facility in the Bull Run watershed approximately 25-miles to in-town reservoirs through a mix of forested terrain and urban areas. In March of 2017, PWB began an inspection and condition assessment project with Pure Technologies on these pipelines in order to gain a better understanding of their existing condition. The team is using the latest internal pipe visual inspection methods, applying non-destructive pipe wall thickness examination technologies, conducting structural and remaining service life analyses, and developing maintenance, rehabilitation, and replacement strategies. Analyses on the collected data and results from the assessment will be presented, as well as the risk-based logic behind which parts of the conduits were chosen to inspect with which tools and methods.