Leak under tarmac pinpointed by ground microphone in Cricklade
Water was coming up through tarmac at the front of a house. An acoustic listening device picked up a strong leak signal on the tarmac, and a single targeted dig exposed a leaking 25mm metal supply pipe, which was repaired the same visit.
Signs of the leak in Cricklade
Water was escaping through the tarmac near the front of the property and the ground around it was wet. The supply had already been turned off at the valve in the footpath. When it was turned back on, water appeared at the edge of the tarmac within about three minutes.
How acoustic equipment found it
With the supply back on and the pipe under pressure, the engineer moved a ground microphone across the tarmac and listened for the sound of escaping water. It picked up a strong, clear leak signal at one point, and the dig was made there. This was the only locating method used before digging.
The investigation, step by step
- 01Found water surfacing through the tarmac, with the supply already turned off at the footpath valve.
- 02Turned the supply back on; water appeared at the tarmac edge within about three minutes.
- 03Listened across the tarmac with a ground microphone and picked up a strong leak signal.
- 04Lifted the tarmac and dug at that point, exposing a leak on a 25mm metal supply pipe.
- 05Replaced the damaged section with 25mm MDPE pipe and two universal fittings.
- 06Pressure tested the supply, which showed no further leaks, then backfilled and reinstated the tarmac.
What was found
- Found
- A leak on a 25mm metal water supply pipe buried under the tarmac near the front of the house.
- Repair
- The damaged section was replaced with 25mm MDPE pipe and two universal fittings, the repair passed a pressure test, and the hole was backfilled and the tarmac reinstated.
