Leak Detection in Auckland

The purpose of active leak detection is to find all the leaks that do not surface or come to the attention of the water utility through their standard procedures (for example, customer contact centre, insufficient supply, or loss of water). The detection process involves teams of skilled leak detection technicians actively surveying an area to find leaks—generally using acoustic sounding techniques or similar. This may be in response to an increase in the minimum night flow (MNF) if the area is sectorised into a DMA or Water Supply Zone, an increase in the output from a treatment works or supply reservoir, or simply as a result of a systematic, regular leak detection program at predetermined intervals.

Many technologies for water main leak detection utilise acoustic principles to identify and pinpoint leak locations. A pressurised water pipe will create a unique acoustic signature at the leak location due to the pressure differential between the inside and outside of the pipe. The water main acts as a medium for transmitting the acoustic signature of the water leak.

When water is escaping the pipe under pressure, it makes a distinct ‘hissing’ sound that can carry significant distances along the length of the water pipe and be detected on nearby service connections, hydrants or stop valves. Several factors influence the distance which the leak can travel, but it is primarily the pipeline material and diameter. For example, a 100mm cast iron water main will propagate the acoustic signal much better than a 300mm PVC water main. Key factors that influence leak detection capability and accuracy include:

• Pipeline material
• Pipeline diameter
• Pipeline pressure
• Leak size
• Leak type (or more specifically, leak shape)
• Backfill type
• Access to appurtenances
• Ambient & environmental noise

Aqua Analytics uses a range of technologies when undertaking active leak detection work. Acoustic technologies are the primary means of detecting and locating water main leaks. This method of acoustic leak detection is a systematic method of using acoustic equipment to survey the water network, identify leak sounds and pinpoint the exact locations of any underground leaks. It is carried out in a systematic manner, walking all streets and listening on all available fittings. For example, acoustic leak detection surveys are similar to a postman who needs to go down every street in a particular suburb to deliver the mail.

The most critical technology of a leak detection technician is an amplified microphone that determines the presence of a nearby leak on a connection or appurtenance on the water network.

To pinpoint a leak, more advanced technologies will be used, such as a leak noise correlator or ground microphone. At Aqua Analytics, we also use leak noise loggers (such as the Gutermann ZoneScan NB-IoT or Ovarro Enigma) from time to time when permanent leak detection is required in high consequence locations or when challenging leaks need to be located. A leak detection toolbox should contain the following technologies:

• Amplified acoustic listening sticks
• Manual listening stick
  Ground microphone
• Leak noise correlators
• Pipe & cable locators
• Correlating leak noise loggers
• Trunk main hydrophones
• Pressure transient monitoring devices

If you already have a water loss management program underway, we can provide specialist active leak detection services. Aqua Analytics also provides ‘Leakage-as-a-Service’. These programs see us deploy acoustic leak detection IoT devices under a fully managed agreement to ensure uptime reliability and immediate leakage insights. This approach is essential for high consequence locations, such as CBD locations or heavy pedestrian/roadway environments.

Trunk mains, typically assets that are over 350mm in diameter, require a different approach to reticulation assets when it comes to active water leak detection. These are often assets critical to operations and the current condition and presence of leaks must be well understood to reduce the likelihood of failure.

Trunk main leak detection is challenging due to the reduced sound propagation in larger diameter pipelines. Many utilities avoid trunk main leak detection activities due to a perceived lack of leakage on these assets; however, many examples in Australia and New Zealand prove this is inaccurate. Aqua Analytics can deliver trunk main leak detection using the following solutions:

• Trunk main correlators: Specialised hydrophones or accelerometers are placed on the trunk main (typically at 1-2km spacings), listening for specific frequencies and applying traditional correlation equations to detect the presence of leaks.
• Free swimming leak detection technologies: A cylindrical device is inserted into a live pipeline, propelled by the water flow and captured downstream. The captured data is downloaded, analysed and the leak location is determined.
• Tethered leak detection technologies: A device is inserted into a live pipeline, attached to a long cable and propelled by the water flow. An operator will listen for the acoustic signal from the device hydrophone and determine if any leaks are present.
• Real time trunk main monitoring: Specialised hydrophone devices can monitor large diameter pipelines in real time for changes in operating conditions that may indicate a new, developing or growing leak.

The Aqua Analytics team consists of internationally renowned experts on water leakage reduction, non-revenue water (NRW), and acoustic leak detection methodologies. Over several decades, we have developed customised water loss reduction strategies for conditions in Australia and New Zealand to ensure we achieve lower levels of water loss.

We are viewed as leaders in active leakage detection through our long-term engagements on projects in Sydney, Melbourne, Adelaide, Brisbane and throughout New Zealand. We also pride ourselves on delivering excellent customer service and finding solutions to problems that others cannot.

If you are looking to achieve results from your active leak detection project, please get in touch with us today by giving us a call, or fill out the enquiry form below.