In 2005 Tucson Water installed fiber optic monitoring systems inside large diameter pipelines that are designed to notify Tucson Water maintenance personnel of pipeline conditions that could lead to failure. Monitors recently detected a series of events on a segment of 84-inch diameter pipe that indicate a potential weakening of the pipe structure. The segment of pipe is along a transmission main that moves water from a reservoir near Starr Pass into eastern parts of the City. The weakened segment of pipe is located on San Marcos Boulevard between Mission Road and Greasewood Road. Water delivered from this reservoir is renewable Colorado River water that has been extracted from the Clearwater Facilities located in the Avra Valley.
On Tuesday, April 26, Tucson Water will be taking steps to isolate the affected segment of pipe in order to allow maintenance crews access to conduct an inspection and undertake repairs inside the pipe. This action will result in limited deliveries of renewable water supply from the reservoir. In order to ensure continued water service to customers while this segment of pipe is being repaired, groundwater wells in Central Tucson will be turned on to meet customer demands. The work on San Marcos Boulevard is scheduled to take place between May 6 and May 23.
According to Tucson Water Director Tim Thomure, the $5 million investment in the acoustic monitoring system has proven effective. “A single failure on a large transmission pipeline such as this one could easily exceed the cost of the monitoring system. This is another instance where we are able to avoid a catastrophic failure due to the investment we have made in this technology. Our continued investments in monitoring, inspecting and repairing our aging infrastructure also support meeting goals for ensuring long-term water reliability.” Director Thomure also pointed out another important factor in following through with the repair is the ability to maintain continuity of service due to the redundancy provided through maintaining the groundwater well system.
Customers may notice more air in their water during the transition to the groundwater delivery system, resulting in water having a temporary white or milky appearance. This is normal under these circumstances, and does not present any health risk.