Austin Water Condition Assessment Water Network Smartball
The inspections are part of AWU’s proactive condition assessment program that focuses on leak detection and structural condition assessment through the use of advanced non-destructive technologies.
Focusing leak detection efforts on large-diameter pipelines is an excellent method to reduce Non-Revenue Water (NRW) and gather baseline condition information. While leaks on small-diameter distribution mains are the most common, leaks on large-diameter transmission mains account for a significantly higher percentage of the total water lost; repairing even one leak on a transmission main can achieve a significant reduction in NRW.
Identifying air pockets reduces pressure on pumps that are attempting to pump water past an air pocket. As pockets grow in size, they can adversely affect the flow and capacity of a pipeline.
In addition a reducing water loss, early identification of leaks helps reduce pipeline ruptures, as leaks are often a preliminary sign that a pipeline may eventually fail due to pipeline corrosion or loss of bedding support due to soil erosion. By identifying leaks early on, AWU is effectively reducing NRW, reducing their risk of failure, and gathering valuable baseline condition information on its pipelines.
The inspections completed in June 2013 were completed on two separate pipelines, the Ulrich 72-inch Prestressed Concrete Cylinder Pipe (PCCP) potable water transmission main and the Airport Road 24-inch C-303 Bar Wrapped Pipe (BWP) and Cast Iron potable water transmission main.
AWU used SmartBall® technology for both inspections. The SmartBall tool is a free-swimming inline leak detection platform that identifies the acoustic anomalies associated with leaks and air pockets that operates while the pipeline remains in service. The tool is tracked via fixed or portable receivers that are positioned strategically throughout the planned inspection distance. Following an inspection, the collected data is analyzed to determine if the acoustic anomalies represent leaks or air pockets and verified by AWU staff.
The Ulrich inspection covered a total of 6.6 miles in 6 hours and located no leaks or gas pockets. In order to successfully complete the inspection, AWU staff had to overcome one major operational constraint to ensure the tool could complete the inspection distance. Shortly after the insertion near the Ulrich WTP, the pipeline travelled beneath the Colorado River before making a 200-foot vertical climb, which can be difficult for free-flowing technologies without proper preparation. To overcome the challenge, AWU and Pure Technologies completed comprehensive flow simulations during the project planning phase to ensure the tool could traverse the vertical incline; this allowed the SmartBall tool to successfully travel up the steep hill.
In the Airport Road inspection, 2.4 miles of inspection was completed, successfully locating three leaks and giving AWU confidence that there are no air pockets restricting flow capacity in this line.
During both inspections, AWU and Pure Technologies worked closely to overcome operational challenges that allowed for successful leak detection surveys.
AWU supplies water to nearly 890,000 customers within and outside the corporate city limits of Austin, as well as the communities of Rollingwood, Sunset Valley, one water control and improvement district, five water supply corporations, seven municipal utility districts, and three private utilities. To ensure reliable service to its customers, AWU proactively addresses its infrastructure needs through regular inspection and rehabilitation to prevent service disruption and costly emergency repairs.
Highly accurate inline leak detection systems that can detect leaks and gas pockets in operational pipelines. These systems are used primarily on larger diameter water and wastewater transmission mains of all materials as well as oil & gas pipelines.