The cost of active leakage control on trunk mains is affordable

February 16, 2018 Categories: Articles


Active Leakage Control (ALC) on large diameter pipelines is value for money if done properly. ALC will find significant leakage volumes and provide the insights into asset health necessary to prioritise totex. 

The cost of ALC on trunk mains is affordable, but only when mains are targeted properly and leaks are located reliably and accurately.

1 Ml/d every 10 km

Even with the most basic of targeting, WRc’s Sahara® Leak Location platform typically finds 1 Ml/d of leakage every 10 km of pipeline surveyed for the first time.  But this cost-effective approach can be further improved by combining our engineering knowledge of flow measurement uncertainty with analysis of network flow data and probabilistic propensity to leak (PPL) modelling.

In-pipe acoustic leak detection techniques such as Sahara® and SmartBall® pinpoint leaks with certainty and reliability. With a location accuracy of 300mm, up to 30m deep, and a survey length of up to 2km, we guarantee no ‘dry holes’!

While other detection techniques find trunk main leaks in some cases, only in-pipe acoustics provide a reliable witness to the leakage status of a pipe, as they WILL detect EVERY leak, regardless of size.

Enabling Costs

Deployment of in-pipe acoustic leak detection through existing air valves or low-cost dedicated chambers keeps a lid on the total cost of enabling works. Once a chamber has been built it can be used as future access for subsequent cleaning and inspection,  making it cost-effective over whole-life in many cases. To prove this point, we use an economic trunk main leakage model (ETML) to determine which technique(s) are both feasible and most cost-effective to  compare the cost per Ml/d against leakage options for other parts of the water network.

Added Value

WRc’s leak location service provides ground marking, leak sizing and geospatial referencing for each leak. In turn, these survey data points provide insights to additional asset management services including:

  • Prioritisation of larger leaks for repair by our clients’ preferred contractor
  • Analysis of repeat survey results to diagnose asset deterioration and natural rate of rise of leakage
  • Quantification of real and apparent losses to support evaluation of upstream water balances
  • Appraisal and selection of the most cost-effective intervention options to mitigate operational risks, e.g.

Leak location using in-pipe survey

Leak type

Suggested action

Small leak, cast/spun iron joint 


Monitor through regular data review

Large leak, cast/spun iron joint


Plan in repair at time of lower reactive maintenance

Leak on cast/spun iron pipe barrel


Urgent repair

Small leak, ductile iron or steel


Frequent monitoring through data review. Consider regular in-pipe surveys

Large leak, ductile iron or steel


Urgent repair

Multiple leaks observed in single survey


Planned regular in-pipe inspections; determine sections which may benefit from rehabilitation rather than repair

Lifting the lid on the condition of trunk main networks doesn’t have to be scary. We regularly prove that much of these assets will be fit for purpose for many years to come. But ignoring their condition means losing the opportunity to save significant leakage and proactively plan pipeline maintenance.

To discuss your requirements please contact Keith Walker - Head of Infrastructure

SIMON AYLEY Key Account DirectorTel: +44 (0) 1793 865085