Located in Bedfordshire, Poppy Hill Water Recycling Centre (WRC) provides an essential wastewater treatment service for the surrounding communities, receiving and treating flows before safely returning treated water back into the environment.
Across the East of England, wastewater infrastructure faces increasing challenges from population growth, changing rainfall patterns and more frequent periods of intense weather. During heavy rainfall events, additional surface water entering the network can significantly increase flows arriving at treatment works. Storm storage plays a vital role in managing these peaks by temporarily holding excess flows until they can be safely treated.
As part of Anglian Water’s AMP8 investment programme, the Anglian Water’s @one Alliance is delivering a major storm storage upgrade at Poppy Hill WRC to improve the site’s ability to manage increased flows and reduce the environmental impact of storm overflow operation.
On completion, the scheme will provide an additional 1,324m³ of storm storage capacity through the installation of a new above-ground glass-coated steel storm tank. And the upgrade will increase the site’s total working storm storage capacity from 984m³ to approximately 2,308m³, providing the additional storage capacity required under the site’s AMP8 regulatory programme.
The project brings together civil, mechanical, electrical and process engineering disciplines to deliver a resilient solution that improves environmental performance while supporting the long-term operational capability of the treatment works.
The issue
Storm tanks are a critical part of wastewater treatment infrastructure, providing temporary storage when incoming flows exceed the capacity of the treatment process during periods of heavy rainfall.
At Poppy Hill WRC, existing storm storage capacity was assessed against updated Environment Agency requirements as part of the AMP8 regulatory programme. The assessment identified that the site required additional storage capacity to meet the required total working volume.
The existing site provided approximately 984m³ of storm storage, while hydraulic modelling determined that 2,308m³of total working storm capacity was required. This created a requirement for an additional 1,324m³ of storage to ensure the site could effectively manage increased flows during storm events.
The additional storage capacity will strengthen the site’s resilience during periods of heavy rainfall and support the effective management of increased flows.
The challenge for the project team was to deliver additional storage capacity while ensuring the solution:
- Achieved Environment Agency compliance requirements.
- Integrated effectively with existing treatment infrastructure.
- Maintained operational continuity during construction.
- Provided a robust, low-maintenance asset with a long operational lifespan.
- Supported improved resilience against future climate pressures.
The solution needed to provide more than additional capacity; it needed to create a reliable and efficient storm management system that could continue supporting the site for decades.
The solution
Following hydraulic assessment and detailed design development, the selected solution was the installation of a new first-fill above-ground glass-coated steel storm tank, providing approximately 1,324m³ of additional stormwater storage capacity.
The new tank, measuring approximately 17.07m in diameter and 7.07m high, has been designed to operate alongside the existing storm storage infrastructure, increasing the total working storm storage capacity at Poppy Hill Water Recycling Centre from 984m³ to approximately 2,308m³. The glass-coated steel construction provides a durable and corrosion-resistant solution designed for long-term operational use. The prefabricated modular approach also supports improved quality control, reduced on-site construction activity and a more efficient installation process.
The new asset has been integrated into the existing stormwater management system, with the existing DN300 inlet pipework diverted to feed the new storm tank. The tank will be pump-fed using the existing Gorman Rupp T10 storm pumps, with stored stormwater returned through a new gravity return system incorporating a DN150 actuated valve. A new bellmouth overflow connection between the new and existing storm tanks enables both assets to operate together, maximising available hydraulic capacity during storm events.
Supporting infrastructure works include a new ultrasonic level monitoring system, actuated LCP , approximately 150 metres of new cable installation and a Type 1 footpath around the tank to support future inspection, maintenance and tanker access.
The scheme also includes a Xylem mixer jet automatic cleaning system, improving operational efficiency and reducing future maintenance requirements. The system uses stored stormwater to create an automated cleaning cycle, circulating flows through jet nozzles to remove settled material from the tank floor. This reduces the need for manual cleaning and confined space access, improves health and safety, enables faster return of the tank to service and supports improved long-term asset reliability.
The project is being delivered within a live operational water recycling centre, requiring careful coordination to maintain existing treatment processes throughout construction. The delivery approach combines civil engineering activities with modular construction methods, with the glass-coated steel tank manufactured off-site before assembly at Poppy Hill WRC.
Multiple disciplines have been coordinated throughout delivery, including civil works, mechanical installation, electrical infrastructure, control systems, process integration and commissioning. Detailed sequencing has ensured existing storm storage capacity remains available during construction, maintaining operational resilience while the upgrade is delivered.
The completed scheme will improve environmental performance by providing additional storage capacity to reduce the likelihood of storm overflow operation during periods of high rainfall. By retaining greater volumes of stormwater within the treatment system until capacity becomes available, the project supports improved protection of the receiving environment and greater compliance reliability.
The increased storage capacity also strengthens resilience against future rainfall pressures, helping future-proof the site against changing weather patterns. By integrating the new tank with existing infrastructure, the project maximises the value of current assets while avoiding unnecessary redevelopment.
The combination of increased hydraulic capacity, durable materials, modular construction and automated cleaning technology provides a long-term solution that improves operational reliability, reduces maintenance requirements and supports Anglian Water’s wider environmental objectives.
Supply chain
The Poppy Hill Storm Storage Upgrade is being delivered through the collaborative @one Alliance model, bringing together expertise from across engineering, construction and operational teams.
This project required key collaboration between:
| Supplier / Partner | Role |
| AVK | Valve supply |
| AVRS | Generic EICA and mechanical partner |
| Barhale | Principal Contractor |
| DLO | Direct delivery plant, labour and fuel |
| TES | Panel & Telemetry outstation |
| Hayes | Glass-coated steel storm storage tank supplier |
| Xylem | Pump supplier |
| SCS | Coring subcontractor |
| FT Ductile | Pipe and fittings suppliers and fabricators |
Working together across the supply chain has enabled the project team to develop a solution that delivers long-term environmental and operational benefits while maintaining safe and efficient construction.
Conclusion
The Poppy Hill Water Recycling Centre Storm Storage Upgrade represents a significant investment in improving wastewater resilience across Bedfordshire.
Through the installation of a new storm storage tank, the project will increase the site’s total working storage capacity, enabling compliance with Environment Agency requirements and reducing the frequency of storm overflow operation. The team are now putting the final touches to the £2 million project, which is nearing completion.
The scheme demonstrates how targeted engineering investment can deliver measurable environmental improvements while strengthening the resilience of critical wastewater infrastructure.
By combining increased hydraulic capacity, intelligent process integration, automated cleaning technology and durable construction methods, the project provides a long-term solution that supports reliable operation, protects the environment and delivers benefits for customers and communities for years to come.
