Pinpointing Water Main Leaks: Solving Water Loss in Roanoke, VA.

Challenge

When Western Virginia Water Authority (WVWA) approached SEH, they were facing significant water loss within their distribution system. The area of concern was a Reinforced Concrete Cylinder Pipe (RCCP) transmission main that routes directly from the water treatment plant and serves all of downtown Roanoke, VA.  This critical transmission main runs entirely under streets and highways, providing very limited access. Additionally, the line could not be taken out of service during inspections, making the situation particularly challenging.

Solution

To ensure the SEH team found the right solution, extensive research was conducted, carefully evaluating various technologies to determine the best approach for assessing the condition of the transmission main without disruption.

This research identified several critical factors that shaped the decision-making process. The type and size of the transmission main played a major role, with larger and concrete mains demanding specialized solutions. Accessibility posed another challenge, as the selected 3.55-mile section runs beneath heavily trafficked streets and highways, limiting opportunities to excavate and access the pipe. Additionally, the team needed to account for the low velocity and pressure, ensuring any solution could accurately assess the main’s condition.

Ultimately, SmartBall®, which is a product from Pure Technologies, ended up being the best fit for the job. SmartBall® is a small, spherical device, typically around the size of a baseball, with an acoustic sensor and gyroscope at its core. The SmartBall® travels through the pipeline, carried by the flow of water, and listens for the distinct sounds of leaks and gas pockets. As it moves, the device records data, which is later analyzed to pinpoint the exact location of any issues, all without disrupting pipeline operations.

Working alongside WVWA and SEH, Pure Technologies started the sensor’s journey through the 36-inch RCCP transmission main from the Carvin’s Cove Water Treatment Plant Clearwell to the Delray Pump Station. Once extracted, the acoustic data identified only one leak, which was previously known – a blow-off valve that had been visibly leaking – and confirmed that the extensive water loss was not originating from this critical section of the pipeline. This finding helped eliminate concerns of further, unidentified leaks within the entire 8-mile span of the transmission main, allowing the focus to shift to inspecting other parts of the distribution system.

Previously, communities would rely on assumptions to determine which pipes were nearing the end of their lifespan, leading to the replacement of any aging infrastructure. Now, with this technology, they can accurately identify which water mains truly need replacement, allowing them to prioritize repairs based on actual need rather than guesswork. This enables a more efficient allocation of Capital Improvement Program (CIP) funds, focusing resources on projects that require attention, leading to a more targeted and effective approach to maintenance and repairs across the distribution system.