Currently, leak monitoring involves systematic inspection whereby water mains teams carry out thorough acoustic assessment of pipelines below road level. This work is done using acoustic leak detectors which, on contact with the ground, are able to detect sound generated by water leaking out of a buried pipeline; with additional equipment (acoustic correlators), it is possible to correlate the signals and achieve a more precise indication of location. This type of leak location is time-consuming (on average, 50% of the mains network can be monitored in a year); it can be susceptible to operator error or disturbance from other sources of sound; it requires the opening of roadworks (local authority permits) and cannot be carried out in adverse weather conditions.
The Noisy Leaks project aims to test a new leak detection process, transforming the system of spot inspections carried out by operatives into a system of continuous monitoring on a dedicated platform. The project involves the detection of leaks using a system of sound logging at set points in combination with a processing and leak visualization platform.
The system comes from the Israeli start-up Aquarius-Spectrum, a leader in cloud technology solutions for the monitoring of urban water distribution networks and the detection of underground leaks from their earliest stages (1.5mm holes) using both fixed and mobile acoustic sensors. The Aquarius-Spectrum solution can monitor an entire water distribution network and provide complete updated GIS representation of every breakage point, ensuring a high level of network maintenance and functioning.
There are numerous advantages, ranging from the reduction in water losses to time-cost optimization.
In detail, the main benefits fall within these areas:
The outcome of the project was positive, with a hidden leak detection efficiency of around 80% in just seven days from detection of the first anomaly (against an average leakage life of about 115 days). This was achieved with a limited level of false positives (38%).
The technology has already been rolled out on 60 km of the water distribution network in the centre of Brescia with planned coverage of a further 50 km in 2022. Overall, this will result in a forecast containment of almost 8 million cubic metres of drinking water and the saving of around 2.3 tonnes of CO2.