Acoustic detection of external underground leaks

Have you had an unexpectedly high water bill, an atypical drop in pressure, or suspicious settling of the ground around your property? When it comes to a leak in the open — under asphalt, concrete, paving or green space — infrared thermography does not apply. Locating faults on external buried networks calls for entirely different technologies and serious field expertise.

ProKanal EOOD offers professional acoustic detection of external underground leaks in Sofia and across the country. Thanks to our modern equipment and deep technical experience, we find the exact location of the breach without needless, costly and large-scale excavation.

How the acoustic method of leak detection works

Behind this technology lies precise physics and highly sensitive electronics. When a pressurised underground pipe fractures, the water escaping from it generates two specific types of sound wave:

• Friction noise: The water leaves through the breach at high speed. This makes the material of the pipe itself vibrate. The structural noise travels along the entire length of the pipeline.
• Cavity noise: The water collides with the surrounding soil or surfacing. This creates a characteristic rumble and turbulence in the ground mass. The sound rises entirely vertically towards the surface.

The acoustic equipment picks up precisely these microscopic sound frequencies and vibrations, which are entirely invisible and inaudible to the human ear, allowing us to pinpoint the precise position of the fault.

World leaders in equipment for external diagnosis

ProKanal EOOD’s success in field diagnosis is due to the combination of deep practical experience and investment in latest-generation certified equipment from the leaders in the sector:

1. Echologics technology

Echologics is the absolute global technological pioneer and world market leader in the acoustic management of water resources and the detection of hidden underground leaks without interrupting the water supply. As part of the American giant Mueller Water Products, the company dictates the standards of the sector at international level.

• Leader on plastic (polyethylene) pipe: Traditional acoustic instruments and geophones fail en masse on modern plastic pipes (PVC, PE, HDPE), because plastic absorbs and muffles the sound of escaping water exceptionally quickly. Echologics brought about a genuine revolution by developing patented sensors and software algorithms that capture the low-frequency sound waves specific to plastic pipelines. They guarantee precise accuracy where standard equipment remains entirely “blind”.
• Non-invasive technology: The system allows our expert certified in Germany to carry out a full diagnosis of the water main without any need to drill into the pipes or insert internal probes. The sensors attach externally to existing fittings, fire hydrants or stop valves. The whole investigation proceeds without shutting off the water supply to the property, the warehouse or the production plant.
• Isolating urban and industrial noise: In an urban setting or in a working factory, background noise (traffic, heavy machinery, ventilation) drowns out the sound of an underground leak. Echologics systems use unique patented algorithms for digital signal processing. They isolate external interference entirely and literally “filter” the noise, so as to concentrate solely on the frequency of the breach. This allows leaks to be detected to centimetre accuracy even in the noisiest industrial zones.
• Proven world-class quality: Echologics technology is not merely a standard plumbing instrument but an intelligent engineering system, trusted by the water operators of some of the largest metropolises in the world — London, New York, Las Vegas, Toronto and Singapore — to reduce water losses across their trunk networks.

2. SebaKMT acoustic correlators (Seba Dynatronic)

The correlator is the most powerful digital weapon for detecting leaks over long distances underground. We use high-technology correlators from the German leader SebaKMT.

The method requires placing two ultra-sensitive transmitters (sensors) at two accessible points on the pipeline (for example valves, hydrants or water meters) between which a fault is suspected. The sensors pick up the noise of the leak and send the data by radio to the central computer, which calculates the exact difference in the arrival time of the sound. Based on the material of the pipe and its length, the correlator calculates the position of the breach to centimetre accuracy.

3. Highly sensitive electro-acoustic microphones (SebaKMT geophones)

This is specialised equipment for ground-level measurement on site. Once the correlator has indicated the approximate zone, the operator uses a geophone with an ultra-sensitive ground sensor placed directly on the surfacing.

The instrument has intelligent digital filters that isolate and exclude extraneous urban noise entirely (traffic, wind, footsteps). It amplifies only the frequency of the underground water impact. The closer the microphone is to the breach, the stronger and clearer the graphic signal on the operator’s display.

Key benefits by property and infrastructure

Acoustic diagnosis applies across a wide spectrum of sites, saving enormous sums on restoring infrastructure:

• For the home and garden: We locate leaks under garden paths, lawn or paving without turning your garden into a building site.
• For warehouses and logistics centres: We find faults under heavy-duty industrial power-floated concrete or asphalt ramps, without halting the movement of machinery and lorries.
• For production halls and factories: We find leaks in the supply mains around production buildings without interrupting the technological process.
• For schools and nurseries: Fast, accurate intervention stops hidden water losses that can undermine the foundations of buildings, fences or play areas, guaranteeing the safety of the children.

ProKanal EOOD’s advantages on external underground leaks

• International expertise: The analysis of the noise and the frequency graphs from the SebaKMT and Echologics correlators is carried out by our expert certified in Germany, which guarantees there are no errors in the measurements.
• Minimal excavation: A digger or hand excavation is planned solely and only at the point of the defect. Instead of digging up 50 metres of route, you dig just 1 square metre.
• Preventing settlement: Catching it in time halts the process of ground being washed out beneath the asphalt, which protects against sudden collapses of roads, fences or foundations.
• National coverage: We are based in Sofia, but our mobile field acoustics team travels and serves sites across the country.

Don’t let a leak hidden underground inflate your water bills and compromise your infrastructure. Put your trust in the modern equipment and long experience of ProKanal EOOD!