Faced with the challenge of delivering a complex maintenance operation for a key water asset, our team at United Infrastructure adopted Ice-pigging to provide an innovative, efficient and a low-disruption cleaning solution.
When our clients Northumbrian Water Group (NWG), decided to undertake a maintenance operation for a 30-inch steel main for a critical water asset in Teesside, they faced several challenges, including minimising disruption to customers, maintaining network resilience and reducing both water consumption and environmental impact.
To meet these objectives, our project team recommended Ice Pigging – an innovative no-dig, no-dismantling solution that provided a more efficient, less disruptive, and reliable method for cleaning critical trunk mains.
Initially, various conventional trunk main cleaning methods were assessed but ruled out due to their reliance on extensive temporary works, high water consumption, or rigid equipment and chemicals that risked operational disruption.
To overcome these challenges, our team at UI led the planning, design, and execution of the Ice-pigging operation, in collaboration with NWG, specialist contractors, SUEZ, and environmental regulators – with minimal disruption to customer supply and day-to-day operations.
The Ice-pigging method uses an ice slurry ‘pig’ to scour complex live trunk mains at a carefully controlled velocity, without taking them out of service. The project aimed to remove accumulated sediment and biofilm, improve hydraulic performance, and extend asset life without resorting to disruptive or costly alternatives. Throughout the process, the pig’s movement can be tracked in real time, enabling continuous performance monitoring and allowing immediate adjustments where required.
The process integrates hydraulic modelling, telemetry-driven monitoring and field testing to control pig movement, system pressures, and downstream solids mobilisation. Use of this methodology enabled controlled cleaning of live mains with no excavation, reduced water use compared with traditional flushing, and improved pressure and solids management, also helping in delivering the works in weeks rather than the months typically required by conventional methods.
Beyond addressing immediate hydraulic and water quality challenges, the project successfully demonstrated the effectiveness of Ice-pigging on a large diameter steel trunk main, providing valuable evidence to support its future strategic deployment across similar assets.
This challenged previous assumptions around scalability and reinforced confidence in its use across water-distribution networks for routine and reactive main cleaning. Following this, other clients, such as Yorkshire Water, as well as several wastewater projects, are now planning to adopt the technology.
The use of Ice-pigging has significant environmental and operational benefits, including nearly 90% reduction in water usage compared to conventional flushing methods. The technique also eliminates the need for excavation and associated waste, while avoiding unplanned interruptions and adverse impacts on customers.
In addition, real-time telemetry can be used to track pig progression, with slurry velocity adjusted dynamically to optimise performance. This enhanced control, visibility and assurance throughout the cleaning operation, enables the work to be carried out safely and effectively on a live network.
Testimonials
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"Innovation delivers the greatest value when it solves real challenges. Using Ice Pigging on this project helped us reduce customer disruption, minimise environmental impact and improve asset performance, while proving it can be scaled to support the demands of critical water infrastructure."
Kelly MacFarlane, Managing Director - Water
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