Underground Water Mains Leak Detection in Shipston on Stour

Symptoms

The customer at a property in CV36 was experiencing a significant water loss, estimated at approximately 1,000 litres per day. The scale of the loss pointed clearly to a fault on the incoming mains supply rather than any internal plumbing.

The 25mm MDPE blue pipe enters the property through the kitchen wall beneath the kitchen units, and the suspected fault lay somewhere along its route before entry.

Methods Used

The investigation began by tracing the route of the 25mm MDPE incoming main supply from where it enters the kitchen through the wall beneath the units. Acoustic equipment was deployed across the external ground to listen for anomalies, and one was detected outside the kitchen, beneath the patio near the drain.

Pressure testing was then applied in conjunction with the acoustic equipment to intensify the signal, which confirmed and pinpointed the suspected leak area to the same location — where the incoming main passes between the kitchen and the drain.

Investigation Process

1. 1
   Customer briefing on arrival

   On arrival, the customer explained they were experiencing a significant water leak estimated at approximately 1,000 litres per day.

2. 2
   Incoming main supply located

   The 25mm MDPE blue incoming main supply was traced entering the kitchen through the wall beneath the kitchen units.

3. 3
   Acoustic survey conducted

   Acoustic equipment was used across the external ground, detecting an anomaly outside the kitchen beneath the patio and near the drain.

4. 4
   Pressure testing applied

   Pressure testing was carried out in conjunction with acoustic equipment, intensifying the anomaly and pinpointing the suspected leak to the same location where the incoming main passes between the kitchen and the drain.

5. 5
   Excavation and leak confirmed

   With the homeowner's permission, the area around the drain was carefully excavated, exposing the incoming main supply pipework and directly confirming the leak at the point where it runs through the wall and behind the drain.

6. 6
   Semi-permanent repair completed

   A semi-permanent repair was carried out on the 25mm MDPE pipework using a Philmac repair coupling and pipe supports, with the customer advised that full remediation requires the pipe to be re-laid at a minimum depth of 750mm.

Result & Outcome

The repair is classified as semi-permanent because the pipework is laid too shallow and does not meet the required minimum burial depth of 750mm before entering the property. Until the main supply is re-laid at the correct depth, the installation remains at risk. For a water mains leak detection case like this, where shallow pipework is a contributing factor, a permanent fix requires more than stopping the active leak, the underlying installation issue must also be addressed.