If you're a property manager, facility manager, or part of a watershed management or public works team for a municipality, discovering an underground water line leak can be a difficult task. Leaks not only result in non-revenue (NRW) water loss but can also lead to costly damage and unnecessary labor as a result of problems like sinkholes, water main breaks, or contaminated drinking water.
Fortunately, there is a systematic approach to detecting these underground water leaks effectively and safely in your municipality, campus, or property.
Here are six steps for how you can locate an underground water line leak on your site with the technology and expertise of the industry’s leading leak detection professionals.
Step 1: Do a Site Walk
Start your leak investigation by doing a site walk. On this walk, check for all contact points for the water line. This will lead to step two. If you are at a certain facility or property on a fire loop system, inspect any mechanical rooms available and time the jockey pump where applicable to see how long it takes for the pump to kick on and off. This will help give you a general estimate of how large the leak you are dealing with is.
Step 2: Minimizing Ambient Noise
A crucial part of the leak detection process is minimizing ambient noise in the surrounding area. This ensures that the equipment can accurately pick up the sound of the leak without interference. Limiting external noise sources allows for a more precise identification of the leak's location, increasing the chances of a successful detection. This is why some acoustic water leak detector professionals work at night to eliminate all possible noise in the area they are performing work.
Step 3: Listen To All Contact Points
Once all contact points have been identified, begin to use acoustic leak detection equipment to listen to all contact points on site, discerning if any distinct leak sounds stand out at each contact point. This critical step helps eliminate the distance needed to listen on each line by pinpointing a leak noise between contact points. With this step alone, potential hours can be saved in determining the location of the suspected water line leak.
Step 4: Locate the Suspected Leaking Line
Using utility locating technology such as ground penetrating radar (GPR) and an electromagnetic (EM) utility locator you can create a visual representation of what's beneath the surface, identifying any anomalies that could indicate the presence of the underground water line or other subsurface infrastructure. The EM utility locator is then used to trace the specific path of the water line, making it easier to narrow down the search area. This information is mapped on the surface with spray paint in blue, per APWA color code standards.
Step 5: Perform a Ground Microphone Investigation
After locating the water line above ground and pinpointing its exact location, began to make direct contact with the pipe using grounding rods. If the water line is under concrete, place the ground mic’s round bottom plate that magnetizes to the microphone of the DXMic or S30 unit directly on top of the water line and begin to listen for the distinct sound of a leak. If the water line is underneath soil or grass, you may need to pound the grounding rod into a hole above the line to get direct contact to the pipe itself and listen for the leak. This step helps focus the search on a more manageable area. The ability to listen directly to the pipe's activity is crucial in differentiating between normal water flow and the sound of a leak.
Step 6: Pinpoint the Leak
Finally, the "elephant foot" method is employed. This piece of equipment can be moved every couple of feet from contact point A to contact point B to help pinpoint the exact location of a leak. This tool helps pinpoint the suspected location where an 'X,' can be placed with paint, chalk, or crayon for excavation, saw cutting, or drilling to carefully begin to expose the exact location of the water line leak. Successfully pinpointing the leak is essential to avoid unnecessary digging and reduce the overall repair cost.
Step 6: Validate The Suspected Leak Location & Repair The Line
Once the leak is located, verify its position by minimal excavation or exposing through saw cutting, concrete coring, or drilling to the pipe. Proceed with the necessary repairs to fix the leak and restore the integrity of the water system so that no further damage is caused.
Benefits of Acoustic Leak Detection
This process is highly reliant on the expertise of a well-trained Leak Detection Project Manager. Their ability to discern between various noises and focus on the distinct sound of an underground leaking pipe is key to a successful operation. Utilizing this method offers significant advantages, saving facility and property managers, as well as watershed management and public works departments, thousands of dollars in Non-Revenue Water Loss. It also prevents the need for extensive excavation along the entire water line. This method is particularly effective on pressurized metallic lines like cast iron but can also be adapted for use with other pressurized lines composed of other materials. By accurately locating leaks, it avoids the cost and labor of unnecessary digging and repairs.
GPRS Project Example: Dallas Fort Worth Mall
A great example of the effectiveness of this process comes from a GPRS project in the Dallas-Fort Worth area, where Leak Detection Project Manager Erick Morales investigated a leak on a local mall's main water line in an underground parking garage. Using a combination of GPR, EM Utility Locators, leak detection equipment, and his well-trained ear, Morales was able to pinpoint a smaller leak on the line—far from where the customer initially suspected.
The mall had no visible signs of water surfacing in the garage, but the water meter indicated a significant loss of water, with the jockey pump activating more frequently than it should. The customer was unaware of the exact amount of water being lost per minute, but it was clear that the leak was substantial.
Morales’ detailed and thorough approach included the visit of different pump rooms on site to gather correlations from various points to ensure a comprehensive investigation. Ultimately, he was able to locate a smaller leak on the line for the Site Engineer and the mall's Maintenance/Facility Director. The customer was pleased with Erick’s dedication and attention to detail.
How to Prevent Underground Water Line Leaks
To mitigate the risk of ongoing non-revenue water loss and damages that can result from issues like the one from the example above, three key strategies cam keep you on the right path.
These include:
• Regular Inspections: Schedule routine water loss inspections and maintenance of your water distribution system (especially if you work within the water shed management or public works department of a municipality)
• Pressure Management: Maintain optimal water pressure to reduce stress on pipes and fittings within your system or facility
• Pipeline Monitoring: Use remote monitoring systems to detect early signs of leaks or pressure drops, and verify them by calling out a company that performs underground leak detection services like GPRS.
Have a Water Line Leak But Don't Know Who To Call?
GPRS has a nationwide team of leak detection Project Managers located across the United States, ready to help locate underground water line leaks for your facility, property, or municipality. We've worked with nationwide manufactures like Mersen, to eliminate non-revenue water loss on their fire loop systems, performed annual water loss surveys for large municipalities such as the Town of New Castle, and helped historic universities such as the 100-year-old University of Toledo, protect their workers, residents, and students from the dangers that underground water leaks can cause.
By combining cutting-edge technology with expert knowledge, we can help you quickly and safely address leaks, minimizing water loss, and avoid unnecessary excavation costs.
To learn more about how we can assist you in protecting your water infrastructure reach out to GPRS team member today by clicking the links below!
Frequently Asked Questions
How Do I Map My Underground Water Infrastructure?
Great question! As mentioned in the article above, mapping underground water infrastructure can be accomplished utilizing multiple forms of technology such as GPR and EM Utility Locators by a utility locating professional from GPRS. This information collected in the field, can then be mapped and uploaded into the cloud in a Water System Mapping Platform such as SiteMap®. The data provided within the system is geolocated, and accessible 24/7 from any tablet or mobile device so you can have an accurate and up to date underground map of your entire water line system for your facility, campus, or municipality. The same technique and SiteMap® platform can be applied to your entire underground infrastructure, including, sewer, power, telecommunications, gas, irrigation, and more.
How Much Do Leak Detection Services Cost?
It depends. The cost to purchase equipment to perform the service on your own can range anywhere between $10,000-$35,000. The cost to have a professional leak detection Project Manager from GPRS come out and do it for you varies by project. To request a quote, click here.
What Is Water & Sewer Damage Awareness Week?
Water & Sewer Damage Awareness Week (WSDAW) is an annual safety initiative sponsored by GPRS that aims to connect Water and Wastewater Engineers, Facility Managers, Public Works Officials, and Property Management Organizations with the knowledge and resources they need to better maintain and mitigate threats to the underground assets and systems they care for.
