Swimming Pool Leak Detection in Great Yarmouth

Symptoms

The operator of a Haven holiday site at a property in Great Yarmouth reported a suspected leak on a 33 x 16 metre indoor concrete swimming pool. The initial estimate suggested the pool was losing around 11 litres per minute, with the water level dropping relatively quickly before stabilising at approximately the midpoint of the 4-inch return grills along the side of the pool. After that point, the loss continued at a much slower rate of around a couple of millimetres per day.

Methods Used

The investigation focused first on acoustic scanning of the pool structure and all pipework penetrations to identify any audible signs of active water loss. A consistent trickling sound was detected along the shallow end of the pool during this initial phase, which directed subsequent pressure testing and acoustic work to that area of the pool.

Investigation Process

1. 1
   Initial Acoustic Survey of Pool Structure

   A hydrophone was used to listen to the pool structure and all pipework penetrations. A consistent trickling noise was audible along the shallow end of the pool, with no definitive leak location identified from penetrations alone.

2. 2
   Pressure Testing of Shallow End Return Connections

   The return connections in the shallow end were pressure tested to 10 psi for approximately 45 minutes. No measurable pressure loss occurred, confirming the pipework under test was sound at the time of testing.

3. 3
   Identification of Slide Return Pipe Connection

   During testing to identify which pipes fed the bubble pool returns, a grill beneath the slide ducting was found to be connected to a separate pipe. This pipe had not been previously identified as part of the active return circuit.

4. 4
   Pressure Test of Slide Return Pipe — Leak Signal Detected

   When the slide return pipe was pressure tested, a clear bubbling noise was audible in the floor approximately 7 metres from the pool, indicating an active leak along this pipe's route.

5. 5
   Borescope Camera Inspection of Slide Return Pipe

   A camera was inserted into the pipe from the pool end. It showed the pipe running in a straight line with one visible joint at approximately 6 metres, and an apparent termination or bend at around 7 metres, corresponding with the external wall of the building.

6. 6
   Filtration System Reactivated — Pipe Function Assessed

   The filtration pumps were switched back on and the slide return connection was tested for flow. No draw or push was detected, suggesting this pipe is likely redundant and not connected to the active filtration circuit.

7. 7
   Ground Microphone Survey Inside and Outside Building

   A ground microphone was used to listen to the floor area near the slide and shoe racks, and then externally along the building perimeter. A shoe rack was temporarily removed to improve access, and the clearest acoustic signal was traced to the gap between the low-level blockwork and the external wall cladding.

8. 8
   Plug Fitted by Pool Contractor — Monitoring Begun

   The pool contractor fitted a plug to the slide return connection at the pool wall. Water level monitoring over the following days was planned to confirm whether this pipe was responsible for the ongoing water loss. The removed shelving unit was re-secured before leaving site.

Result & Outcome

The leak was traced to a pipe connected to the slide return grill at the shallow end of the pool. During pressure testing, an audible bubbling signal was detected in the floor at approximately 7 metres from the pool wall, and subsequent ground microphone work — both internally and externally — located the clearest signal at the junction between the low-level blockwork and the external wall of the building. The pipe appears to terminate or change direction at this point, which aligns with the 7-metre distance identified during the camera inspection.