Underground Water Mains Leak Detection in Ipswich

Symptoms

No visible evidence of the leak was present when the engineer arrived. There was no obvious damp, no surface water, and no audible running water.

In a water mains leak detection situation like this, the absence of visible signs is common — underground leaks on mains pipework can run for extended periods without breaking the surface, making systematic testing essential to pinpoint the source.

Methods Used

This approach reflects how water mains leak detection progresses when there is no surface evidence: meter analysis establishes that a leak exists, pressure testing confirms it, and tracer gas narrows the search to a specific ground zone. Paving blocks on the driveway were lifted and the ground excavated based on the gas readings, which led directly to the leak point at a previous repair location in the mains pipework.

Investigation Process

1. 1
   Water meter checked

   The water meter in the public footpath was inspected with the internal stopcock closed. Movement on the meter confirmed an active leak on the external mains supply.

2. 2
   Pressure test conducted

   A pressure test kit was connected directly to the internal stopcock, confirming the presence of a leak within the system and establishing a baseline for further investigation.

3. 3
   Tracer gas introduced — initial scan

   Tracer gas investigation began, with the detector indicating a possible leak location in the main entrance door area. The suspended floor inside the property was carefully exposed, revealing lead pipework beneath.

4. 4
   Leak signal traced to driveway

   Further scanning with the tracer gas detector showed gas emanating from the driveway side of the external brick wall, indicating the leak was located outside the building.

5. 5
   Driveway excavated

   Paving blocks in the driveway were lifted and the ground excavated at the location indicated by the tracer gas readings.

6. 6
   Leak identified at previous repair point

   Excavation revealed two Philmac UTC couplings at a previous repair location. One coupling was leaking because the lead pipework had not been correctly seated within the fitting.

7. 7
   Faulty fitting replaced

   The leaking Philmac UTC coupling was removed and replaced with new Philmac UTC couplings and pipework. The repair was then pressure tested and passed with no further leakage detected.

8. 8
   Final meter check and reinstatement

   A final water meter investigation on all pipework confirmed no remaining leaks. The suspended floor area inside the property was restored, and the excavated driveway area was backfilled.

Result & Outcome

The property in IP3 was left with the driveway backfilled, the internal suspended floor reinstated, and no active leak on the mains supply. The repair addresses the root cause directly — an incorrectly installed fitting at a historic repair point that had been allowing water to escape into the ground undetected.