Rising main failure analysis
Sewer rising mains represent a small proportion of the overall sewer network length
However, owing to their complex nature, they are susceptible to sudden and catastrophic failure, often impacting significantly on customers and the environment.
Critical assets require a proactive and strategic approach to main failures
As water companies strive to achieve significant reductions in pollution incidents, the high proportion of incidents caused by rising main bursts requires a proactive and strategic approach to better maintain these critical assets. Repeated failures on the same main leads to a reduction in confidence in the performance of the company and a greater risk of prosecution. Gathering asset intelligence from any rising main failure enables companies to help prevent repeat failures and accurately assess the need for any required replacement or rehabilitation, reducing the risk of any detrimental environmental impacts.
WRc
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WRc reduces main failures effectively and efficiently
We provide technical expertise to two UK water companies, carrying out a thorough rising main failure analysis service to identify the cause of rising main failure. To date, we have investigated over 100 rising main failures over two years, accruing key condition data from the collected pipe samples after failure. Our wastewater engineering team examines the samples to determine the cause of failure, its extent and the likelihood of future failure. They put in place mitigation measures to help prevent future failures.
Our failure analysis forms a key part of a water company’s asset intelligence strategy used on critical assets, providing greater insight into its network performance, required network improvements, engineering optimisation and capital design process.
Rising Main Doctor approach developed with UK water companies
In collaboration with six UK water companies, the Rising Main Doctor approach developed by WRc has seen a drop in repeat failures by 40%. For this approach, key information is collected from each of the retrieved pipe samples to enable the rising main failure analysis to be completed, providing the two key elements:
- pipe material identification and type including pressure rating
- pipe failure mechanism
Each failure report contains the type of failure and an assessment of the risk of future failure based on the identified failure mechanism. It also provides tested recommendations for further pipe investigation, such as an NDT inspection or in-pipe inspection techniques to determine the possible extent and severity of the failure within the remainder of the rising main. This informs the need for any required pipeline replacement and the required length of that replacement.
Reduce your main failuresImplementation of efficient mitigation measures
Mitigation measures are recommended to reduce the risk of any future failure, such as air valve maintenance or transient pressure reduction through surge pressure management. These individual reports are consolidated into a summary report that explains failure analysis and the approach taken and identifies any potential failure trends found within the results.
Project spotlight: Southern Water and Cappagh Browne
Rising main failure analysis (2025–ongoing)
We analysed 45 rising mains over nine months, delivering key strategic insights to inform future asset management decisions.
View our project portfolioProtect your assets
Maintenance and investment strategies and processes to keep your assets working efficiently.
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