AWWA INF52155

In 1985, a total of 1,600 water main breaks were recorded on Edmonton, Alberta's 758 miles of cast iron pipe resulting in significant inconvenience to many customers and high maintenance costs. At that time, a Cast Iron Water Main Replacement program was initiated. By the end of 1997, the annual number of water main breaks had decreased to 489 on a cast iron distribution system length of approximately 544 miles. In the early 1990s, the water utility began the shift from a reactive to a proactive approach to managing the remaining cast iron pipe network. While continuing to replace pipe, alternative technologies such as cathodic protection are now applied to some pipe to reduce the rate of deterioration. Non-destructive testing using the Hydroscope tool for the evaluation of pipe wall condition is also utilized by the utility. Hydroscope provides information on the pipe wall condition and improves the reliability of decisions made in the management of the cast iron infrastructure. This paper discusses Edmonton's use of these new technologies to optimize the management of cast iron pipes. Includes 10 references, figures.