Resilience and Planned Preventative Maintenance (PPM) are becoming increasingly popular areas of investment for utilities. Given Ofwat’s advocacy of a Totex driven approach to expenditure, the water industry is beginning to recognise the importance of planning ahead to ensure they can tackle risks such as climate change, population density growth, and ageing infrastructure.
This ‘refurbish rather than replace’ approach is undoubtedly a great step forward for water companies, freeing up valuable resources and cash that could be put to better use in meeting customer outcomes, all while extending the life of critical assets and infrastructure.
What makes PPM a critical part of effective resilience is its ability to prevent issues from growing exponentially behind the scenes before culminating in the form of burst pipes, pollution incidents, or sustained periods of asset downtime. For water companies where success in AMP6 is intrinsically linked to serviceability, it has never been more important to ensure that each link of the chain is as at least as strong as the chain itself.
In light of OFWAT’S approach to PR19 which calls out the need for Water Companies to address ‘Asset Health’, water organisations need to consider just how expensive the cost of doing nothing really is. After all, the costs of an avoidable replacement or civils remediation will almost always exceed that of a resilience solution such as the spray lining of settlement tanks with Adalline® 400, which is guaranteed to extend the life of assets by decades.
Adler & Allan’s work with Thames Water is a testament to this recently undertaking the refurbishment of Sludge Digester 1 at Oxford Sewage Treatment Works. The Digester is a critical asset used to process waste and produce energy on site and a critical feature of the work undertaken was to minimise disruption to process whilst extending the life of the asset by a further ten years.
The roof of the Digester had become badly worn over its current life cycle and there was evidence of surface cracking that if untreated could have potentially compromised the containment of methane produced as part of the digestion process.
The Solution
Adler & Allan’s solution was to coat the roof area and surrounds with their specialist polyurea Adalline® 400 lining to provide robust and resilient refurbishment. Adalline® 400 is a high tensile, high elongation, high build, fast-set elastomer. It is specifically formulated to provide a tenacious bond to surfaces, providing a cost effective, flexible, tough, resilient monolithic membrane with water and chemical resistance. Adalline® 400 is an excellent choice of elastomer to topcoat structures for protection, primary containment and extension of asset life.
To enable works, Adler & Allan liaised closely with Thames Water operations and subcontractor parties to establish safe working access. This involved the provision of scaffolding to access the work site which was within a controlled area and the installation of bypass pipework to minimise pressure within the digester during preparation and coating. Once safe access had been established, work was undertaken in four stages.
1. The roof and surrounds of the digester were shot blasted to remove contaminants and prepare the surface for coating.
2. Cracks and visible defects were then repaired using conventional civils techniques.
3. Once the areas had been satisfactorily repaired, they were treated with a Stainguard primer to maximise adhesion, with existing assets sealed using a Rallithane jointing compound to soften profiles.
4. Finally, a 2mm coating of Adalline® 400 polyurea coating was applied across the treated area. Subsequent to coating, all surface areas were validated using a dielectric testing method to provide a 100% fully warrantied containment solution.
The Outcome
The protective lining has extended the life of the digester by a minimum of 10 years at a fraction of the cost of replacement or a traditional civils remediation that would have necessitated lengthy operational downtime. The quick setting properties of Adalline® 400 allowed the work to take place with minimal operational disruption and a full return to service was achieved within 24 hours. Ongoing co-operation and liaison throughout the three week project period ensured that all deliverables were met safely, efficiently and on time.
“The project has been highly successful and A&A have undertaken a very professional cost effective job.” Thames Water Project Engineer
If you’d like to find out more about Adler & Allan’s work within the water industry please visit their dedicated Asset Resilience website http://assetresilience.adlerandallan.co.uk
About Adler & Allan
Adler & Allan is the UK’s leading supplier of environmental and technical services, successfully protecting the UK’s critical infrastructure for over 30 years. With global coverage, class-leading capabilities, and a range of innovative technologies, they are relied upon to deliver critical compliance, flood protection, fuel, emergency response, and resilience solutions to the Utilities sector worldwide.
Built on leading technology and decades of industry experience, Adler & Allan’s services are specifically designed to help water companies meet the unique challenges of the industry and deliver and outperform against ODIs to secure maximum AMP7 funding.
