Water Leak Locating Case Study - Chasing Water
One of our municipal customers called with a water leak dilemma. Leaks tend to come from water lines and may be detectable through our leak locating service. However, this was not a water line. They were experiencing unexplained water coming out of a fiber line conduit. This excess water pouring up from this fiber line was undermining a nearby retaining wall by the Brandywine Creek in Wilmington, potentially causing issues for the structure that would prevent protection against rising water. The biggest challenge was that there were no active water lines anywhere near the surfacing water. Where could the water be coming from? It tested positive for chlorine and other chemicals associated with treated water, so it was not ground water coming up to the surface. Acoustic detection could help determine the location of the leak by listening for the sound of water. However, this water was coming from somewhere else nowhere near the surface water. This required a bit more investigation outside of just using acoustic leak detection.
The first step was to trace the leaking fiber line. We were looking for where the water was originating from. If there weren’t any active water lines near the surface water, the water must be coming from somewhere else further down the line. In order to locate the nonmetallic fiber, we used a combination of electromagnetic (EM) scanning paired with a locatable duct rod. Duct rods are incredibly useful in determining utilities that would otherwise be much harder to trace, such as nonmetallic fiber cables. Pushing a duct rod through the fiber line allowed us to get a better idea of the direction This fiber line stretched across multiple city blocks, leading us down the street and around two corners uphill.
As we located the fiber line, we passed three handholes blocks apart. Handholes are surface features that make it easier to access utilities, similar to a manhole. These handholes made it easier to access the fiber cable for maintenance. The first two handholes had water pouring from uphill and passing through the handhole. The third handhole wasn’t flowing with water - it was dry! A pole drop from across the street was the other origin point for the fiber line. By following the fiber to the point where water wasn’t spilling out, we were able to determine the general area where the leak was taking place. Locating the city water line was next to determine where it crossed or came near the fiber conduit, overlapping the area where the fiber was installed. Once that was done, acoustic testing revealed the leak source, not too far from the dry handhole. This allowed for our client to alert the city of the source of the leak and have it repaired.
If you need a leak located, our team at Trinity Subsurface can help determine where it’s taking place by not only listening for the leak through acoustic leak detection, but also uncovering the locations of the utilities through non-destructive testing and soft dug test holes if needed. Visit our website to find out more information about our leak detection services.
