Water Network Leak Detection: What’s Involved?
When it comes to water network leak detection, early and active intervention is crucial. While pipe leakage is relatively common occurrence, far too many people underestimate the time, money and resources that can be lost without effective leak detection in water utilities. So, what’s involved in water leak detection? In this article we will cover the various methods and solutions for identifying and remedying leaks in water pipeline networks:
The Importance of Active Leak Detection in Water Networks
Pipeline networks service an enormous volume of water to homes, commercial properties, and industrial sites. As such, even the most minor leak can have far-reaching consequences.
Underground leaks can be hard to detect without suitable training and equipment. Left unchecked, they can surface as sinkholes, structural damage, buckling pavement, and flooding. Water network detection is the first step in finding the source of the leaks and determining the best methods to remedy the situation.
Additionally, a significant amount of water can be lost through cracked or broken water networks, which wastes an essential resource and costs providers substantial amounts of money. Not only is escaping water an issue, but contaminants and bacteria can also get in and impair the quality of the water, rendering it unsafe for drinking. Water main leak detection methods are vital for pinpointing these leaks in local and major water networks and ensuring prompts and effective repairs.
Water Main Leak Detection Methods
Leak detection involves more than a visual inspection. For starters, most of the infrastructure is underground and requires state of the art technology to detect tiny leaks across kilometres of pipes. The most common and effective water main network leak detection methods involve using acoustic listening devices.
Acoustic Leak Detection
Water escaping from high-pressure water main networks through a pipe or crack makes a distinctive noise that can be identified using listening equipment. These sounds can travel a great length in a water network as the pipes act as a medium. Different pipe lengths, diameters and materials influence the pitches of the sounds and help leak detection technicians pinpoint the exact location of the leak.
A narrow metal pipe can transmit sounds up to a distance of 500 metres, while leak sound can only travel up to 30 meters on large diameter PVC pipelines.
The listening devices utilised in water utility leak detection methods are used in a range of operational modes. They can be fixed or mobile, placed internally or externally, and transmit data using radio signals or direct download to a computer.
Mobile units can be manually operated along a specific pipe segment using ground microphones. Technicians may also install fixed units along the length of a pipe network. They can also use additional equipment to pinpoint a leak, such as a noise correlator, ground microphone, or even a leak noise logger. A leak detection toolbox typically contains:
- Manual listening stick
- Amplified listening stick
- Ground microphone
- Leak noise correlator
- Pipe and cable locator
- Correlating leak noise loggers.
These devices and methods are so accurate that they can determine a leak’s location in a vast network to within 1 metre.
Once the location has been determined, technicians can dig around the piping or use non-invasive methods to identify the leak or crack.
Secondary Leak Detection – Pressure Differentials
Another way in which leaks can be detected in pipeline networks is with the strategic placement of flow meters and pressure gauges. These tools measure pressure differences and can approximate the leak’s location using the differences in readings throughout the network. Differences in flow rates between the start and finish of a pipe indicate a leak between the two points, just like a reduced water pressure indicates water escaping due to a leak. When this method is combined with acoustic sensors, technicians can efficiently and accurately find the source of a leak across complex water utility networks.
Water Main Leak Detection Solutions
Assets over 350mm in diameter are typically known as trunk mains. Due to their increased diameter and reduced sound propagation, they require a different approach to water network leak detection.
As these assets are typically critical pieces of infrastructure, a clear understanding of the state of the network and the presence of leaks is essential to reducing significant issues. Leaks are harder to detect in these larger pipes. As such, many utilities that do not conduct active leak detection are often unaware of problems in their network. Expert technicians employ water main leak detection methods specific to these more extensive networks to determine the location and severity of the leaks. These can include:
- Free Swimming Technology – The leak location can be determined using a cylindrical device inserted into the pipeline. This device then travels downstream through the network while capturing data which provides valuable information to leak detection technicians when the device is collected.
- Tethered Acoustic Leak Detection – While acoustic detection employed in smaller diameter pipes may not work in trunk mains, technicians can still utilise acoustic listening techniques to determine the leak site. A cylindrical device is tethered to the pipeline; however, unlike the free-swimming technology, the instrument is deployed on a long cable. Once in place, the operator can then listen and analyse the acoustic signal to identify any leaks.
- Trunk Main Correlators – Spaced 1 to 2 km apart on a trunk main, hydrophones or accelerometers gather information which the technician can then process using correlation equations to determine if any leaks are present.
- Real-Time Monitoring – Devices can also be inserted into large diameter pipelines to give technicians real-time feedback. The consistent stream of data provides insights into new, developing, or established leaks. These water main leak detection solutions are the most effective way to reduce downtime and lost resources. Leaks detected early on are typically easier to fix and allow for less invasive methods to be applied.
The Importance of Consistent Auditing
While the nuts and bolts of this article concern methods in water network leak detection, this is only the first step. The key is consistent, holistic management of the water utility network. Solutions such as Smart Water Metering and Real Time Pipeline Monitoring provide real-time feedback across aspects such as water quality, pressure levels and acoustic leak detection.
As water main leak detection methods are improving with advances in technology, it is the application of these methods that the real value is found. We find our customers reap the most rewards when they integrate leak detection into their water loss management. A full-scale water network audit at least once a year can provide a wealth of insights to prevent, manage, and remediate any leaks within a pipeline. An extended range of leak analysis data provides a wealth of insights into the efficiency of the network. It also improves the accuracy and reliability of both direct and indirect information collected. While some utilities may be hesitant to spend a significant amount of money towards long-term water main leak network detection, they will see a return on their investment with increased efficiency over time.
Experts in Water Utility Leak Detection Methods & Solutions
Aqua Analytics is Australia’s leading water network leak detection provider. Servicing water network assets across Australia and New Zealand, with a leading combination of state-of-the-art technology and expertise. We save our clients time, money, and resources by finding the causes of any water main leak. With over three decades of experience, we are internationally renowned for our expert services and great results. We believe in the value of early and active detection and high-quality solutions to improve water utility infrastructure.