AWWA DSS63727

Proven transmission pipeline diagnostic tools developed to obtain an accurate evaluation are essential in a bottom-up condition-based asset management approach. In addition, without prior information on the actual existing condition of an essential pipeline, it is very difficult to determine how to effectively interpret the severity, and future decisions required, after an unexpected pipeline service interruption. The "Remote Field Eddy Current / Transformer Coupling" electromagnetic inspection method is capable of detecting prestressing wire condition in concrete pressure pipes 24" diameter and larger and has a proven record for accuracy in identifying baseline pipeline conditions. Combined with a proven leak location survey specifically developed for 12' and larger diameter pipes, all ferrous and non-ferrous transmission pipelines can now be assessed to determine advanced stages of deterioration through the identification and localization of each and every leak of any magnitude. The Sahara® leak survey pinpoints the location and estimates the magnitude of leaks in pipelines of any material construction type. Inserted into a live pipeline, the tethered sensor head identifies and signals each leak as it is found, facilitating accurate surface locating for subsequent rehabilitation. These non-destructive evaluation methods enable the selective repair or replacement of distressed and deteriorated pipe sections, and can alleviate the prohibitive cost of complete pipeline replacement. Repeat inspections and surveys can then be used to determine deterioration rates for effective maintenance programs to maintain acceptable levels of water supply. Monitoring critical water pipeline assets for signs of deterioration, either through leak monitoring programs or active corrosion monitoring without the prior knowledge of the baseline condition can lead to false sense of security. Utilizing an effective combination of leak surveys and electromagnetic inspection identified in this paper provides a system of determining current baseline conditions upon which further pipeline rehabilitation or monitoring programs can be properly designed and implemented. Includes 6 references, figures.