Jalur Cahaya Sdn Bhd (JCSB) is a full service environmental engineering company that is dynamically involved in helping Malaysian water utilities reduce non-revenue water (NRW).

NRW is an important issue facing water utilities, considering it has an estimated value of more than $18 billion per year worldwide. NRW is the difference between the volume of water supplied to the system and the volume of water that is billed to the customers. Simply put, NRW is water loss for which the utility receives zero revenue.

JCSB engineers were using acoustic-based leak detection systems to locate leaks on water transmission and distribution mains for a utility in central Malaysia. The systems were unable to locate leaks due to low water pressure levels in the mains and the fact that the mains were comprised of plastic and other non-ferrous materials.

Traditionally, the acoustic detection of leaks on non-ferrous mains is painstakingly difficult, especially if the mains have low pressure. This is due to the fact that leaks in such environments are typically characterized by relatively low noise frequencies and amplitudes that are almost impossible to accurately detect with typical leak noise correlators.

Desperate for a solution, JCSB turned to Mississauga, Ontario, Canada-based Echologics, a developer of acoustic-based technologies for water loss management, leak detection and pipe condition assessment.

JCSB asked Echologics to conduct a pilot leak detection survey in areas of the utility’s water system where it could not locate leaks that it knew existed. Pipes in the specific areas ranged between 150 mm to 300 mm in diameter and were comprised of high-density polyethylene (HDPE), polyvinyl chloride (PVC) and asbestos cement (AC).

For the pilot, Echologics’ leak specialists used a Windows-based leak detection system that is able to non-invasively detect underground leaks on all pipes—irrespective of their material, pressure, diameter, geometry, etc.

Unlike traditional acoustic leak detection systems, the technology is based on recent acoustical developments that include an enhanced correlation function, which dramatically improves its ability to accurately identify and locate narrow-band leak noise that is characteristic of non-ferrous pipe material, low pressures, multiple leak situations, and excessive background noise created by traffic and other environmental factors.

The technology is completely non-invasive, which means it can accurately detect leaks without breaking ground, inserting tools into the water system or disrupting service; it relies on standard pipe appurtenances such as hydrants, valves or direct attachments to the pipe’s outer wall.

To conduct the project, surface mounted sensors were placed at two locations along suspect water lines — in most cases on valves or hydrants — between 120 m and 1,300 m apart. A correlator compared the acoustic signature of the leaks it detected with their expected speed of sound in running water; a computer algorithm then calculated the data to accurately pinpoint the location of the leaks.

During the five-day project, the leak specialists acoustically surveyed more than 4,700 m of non-ferrous water mains with as little as 0.9 bar of flow pressure; sensors were placed less than 700 m apart on available fire hydrants and meter stands.

A total of five water main leaks, one illegal connection and one broken meter with a customer side leak were non-invasively pinpointed.

“At Jalur Cahaya Sdn Bhd, we are committed to serving our clients with the best and cost effective solutions that will help them to reduce non-revenue water levels,” said JCSB chief operating officer Sheikh Mazlan Sheikh Hassan. “By leveraging this type of advanced acoustic-based technology moving forward, we can bolster our current service offerings by giving our engineers the tools they need to quickly and accurately locate leaks in almost any environment they encounter — without disrupting surrounding infrastructure. Our vast experience combined with these capabilities will help us as we partner with other states in Malaysia to help them resolve their non-revenue water woes.”

This article was submitted by Echologics, based in Missassauga, Ontario, Canada.