Essex & Suffolk Water commissioned a new DN800 raw water transmission main serving Langford Water Treatment Works in Essex, United Kingdom.

A 7.9 km pipeline increases supply capacity and reinforces the resilience of the water network, however, repeated pre-commissioning pressure tests revealed the possible presence of defects that conventional leak detection methods had been unable to locate.

To address the issue, SUEZ’s leakage and condition assessment team worked with Aganova to inspect the pipeline using Nautilus®, Aganova’s free-swimming in-line inspection technology.

The pipeline’s rural location and the absence of visible signs of leakage made it particularly difficult to determine the source of the pressure losses. Nautilus® travelled inside the pipeline with the water flow, recording acoustic data to identify leaks and other anomalies that could not be detected from the surface.

The inspection, carried out last summer, identified two high-severity leaks, one medium-severity leak, one low-severity leak, and one anomaly consistent with an incipient leak. The two most significant leaks alone were estimated to be responsible for about one megalitre of water loss per day, explaining the repeated failure of the pressure tests.

Aganova and SUEZ specialists analyzed the inspection data and delivered a detailed report to Essex & Suffolk Water. The precise location of the incidents allowed repairs to be focused on the affected areas, avoiding further investigations and unnecessary excavation along the nearly 8-km pipeline.

Following the completion of the remediation work, the pipeline successfully met its commissioning requirements.