UKWIR leakage projects underway at Sheffield University's new state-of-the-art facility

UK Water Industry Research (UKWIR) is working in partnership with the University of Sheffield on two analytical and experimental research projects to reduce leakage levels.

The experimental work is taking place at a new testing facility at the University’s Integrated Civil and Infrastructure Research Centre (ICAIR). Both will be carried out by PhD students.

The projects, which are part of the UKWIR Big Question – How do we achieve zero leakage by 2050? – are both looking at how leakage in pipes occurs and increases. One is focusing on the impact that different environmental factors such as soil type, external loading and water quality have on the deterioration of cast iron pipes and joints, and how this eventually leads to leakage.

The other is investigating pressure transients to identify how these lead to pipe and joint degradation, and water loss.

A purpose-designed rig will be used, and sections of cast iron pipe will be buried in different types of transparent soil before being subjected to a range of loads and pressures. This will allow the students to observe and measure the pipe deterioration that occurs and the point at which leakage begins. Pipes at different stages of degradation will be assessed against a range of simulated in-service conditions.

This will help the industry understand how and when pipe degradation starts to result in leakage so it can target investment in mains renewal using more scientific evidence and allow operational staff to take action to minimise new leaks occurring on cast iron pipes.

Professor Luca Susmel, chair in structural integrity at the Civil and Structural Engineering department at the University of Sheffield, said: “Water distribution systems are a vital infrastructure for society, but are comprised of ageing, deteriorating buried assets. Despite large amounts of investment in the networks by the UK water companies, leakage of treated water from buried pipes remains a major problem for the UK water industry.

“In this challenging scenario, this project will provide, for the first time, an insight into the physical mechanisms by which cast iron pipe networks degrade and deform, and in particular, how this results in water loss through leakage. This project will be implemented with support from UKWIR, who are the ideal partner to collaborate with to answer this very complex research question.”

The pressure transient study will also be carried out on buried pipes which will be subjected to repeated pressure waves of low and medium amplitudes. This will investigate the type of transients that cause pipes to fatigue and degrade and the rate at which this happens so water companies can mitigate against this.

Dr Richard Collins, Senior Lecturer in Water Engineering in the same department, said: “This project will undertake a novel experimental programme to understand how repeated transient pressure waves cause degradation of pipes and joints in water distribution systems. By combining high quality experiments in the new ICAIR facility, with analysis of previously collected real world transient data the project will determine mechanisms through which transients can cause and increase leakage.

“The derived understanding will have a transformative impact on our water systems, enabling water companies to highlight problematic transients, mitigate them and ultimately drive down leakage.”

Jeremy Heath, UKWIR programme lead and innovation manager at SES Water said: “These projects are an important step on our journey to achieving zero leakage as they will help us to understand why and when leakage starts to occur on existing pipework. There has been a lot of research done into the causes of water main bursts but much less on leakage and we need to address this so we can prevent it from happening.

“Using the state-of-the-art facilities at the University of Sheffield means we can simulate real-life conditions and test how pipes respond so we can build the scientific evidence needed to inform our operational activities and investment decisions.”