Leighton Linslade WRC (2026)
Repurposing the existing tanks to provide additional storage capacity - Courtesy of @one Alliance
Leighton Linslade Water Recycling Centre (WRC) serves Leighton Buzzard and Linslade in Bedfordshire. The works has a working storm storage capacity of 1,782m3; however, the required storage capacity is 4,156m. By making better use of existing infrastructure and repurposing five disused sludge holding tanks, the shortfall of 2,374m3 of storm storage could be achieved without the need to construct a new storm tank. The project forms part of Anglian Water’s £11 billion AMP8 investment programme (2025–2030), which includes significant upgrades to wastewater infrastructure across the region. Repurposing and upgrading existing assets is an important part of supporting the long-term needs of growing communities.
Solution
The @one Alliance developed a solution centred on repurposing five redundant sludge holding tanks to provide the additional storm storage capacity required at the site. By adapting existing assets rather than constructing a new storm tank, the scheme maximises the value of existing infrastructure while reducing the scale of new construction.
3D BIM model of the upgrade – Courtesy of @one Alliance
The solution combines structural alterations to the tanks with new pipework, flow control measures, automated cleaning equipment, and electrical and control system upgrades. Together, these works integrate the converted tanks into the existing storm storage network, enabling flows to be transferred, stored and returned in a controlled and efficient manner.
Key modifications include forming new openings through the internal tank walls to create hydraulic connections between the tanks, installing a new feed connection from the existing storm system, and upgrading the return arrangements through a new pumping well, associated pipework and automated valve controls.
Additional overflow infrastructure has also been incorporated to ensure the expanded storage system operates safely and effectively during storm events.
Connecting the tanks & managing flows
The converted tanks are being integrated into the site’s existing storm storage system through a series of structural, hydraulic and control system modifications. To enable flows to pass between the five tanks, openings are being cored through the internal dividing walls, with four openings formed in each wall. A new feed pipe is also being installed to connect the converted tanks to the existing storm tank’s diverted overflow weir, incorporating the additional storage capacity into the wider site network.
Repurposing the existing tanks to provide additional storage capacity – Courtesy of @one Alliance
To manage the return of stored flows, the existing sludge returns line is being diverted to a new storm return pumping well. New pipework, an actuated valve and associated control infrastructure are being installed to provide reliable flow management, while the existing storm tank gate valve is being replaced with an actuated plug valve to enhance operational control.
Further modifications include the installation of a high-level overflow weir box connected to the existing overflow line. Together, these works will provide the hydraulic connections, flow control functionality and operational resilience required to integrate the repurposed tanks into the site’s storm storage infrastructure.
Supporting operation & maintenance
Alongside the structural and pipework modifications, an automated tank-cleaning system is being installed to support the long-term operation and maintenance of the converted assets. The system will utilise the site’s existing final effluent washwater supply, supported by a new washwater booster set connected to a 135m ring main.
This infrastructure will distribute washwater to two spray nozzles supplied by Spray Nozzle People in each tank, providing a total of ten nozzles across the five tanks.
Installation of the tank cleaning system – Courtesy of @one Alliance
To support the new equipment, a range of electrical and control upgrades is also being delivered, including new ducting, six drawpits and a local control panel. Where appropriate, redundant electrical panels are being repurposed, allowing existing assets to be incorporated into the upgraded system and further maximising the value of the site’s infrastructure.
Safe access for future operational and maintenance activities is being improved through the provision of a new Type 1 footpath and handrails. Together, these mechanical, electrical and civil engineering works will provide the infrastructure required to operate, maintain and manage the expanded storm storage system efficiently throughout its design life.
Leighton Linslade WRC: Supply chain – key participants
- Project delivery: @one Alliance
- Principal contractor: Skanska
- Water jetting/cleaning: Civil Safety Drainage (CSD)
- Coring openings: Sealant & Construction Services
- Tier 2 M&E contractor: Kemada Enisca Browne
- Nozzles fitted to tank cleaning swing arms: Spray Nozzle People
- Valves: AVK UK Ltd
- Pumps: Dutypoint Ltd
- Pipework & fittings: Saint Gobain PAM UK
- Pipework & fittings: Wolseley UK
- Local control panel: TES Group
- Instrumentation: Pulsar Measurement
- Instrumentation: VEGA Controls Ltd
New electrical connections – Courtesy of @one Alliance
Benefits of the solution
By repurposing five disused sludge holding tanks, the upgrade provides an additional 2,374m3 of storm storage capacity, and reduces embodied carbon by an estimated 88% compared with a traditional new-build alternative. The scheme demonstrates how existing assets can be adapted to meet operational requirements while avoiding the need for a conventional new-build storm tank.
The solution combines structural modifications with mechanical, electrical and control system upgrades to deliver the required capacity and integrate the converted tanks into the site’s existing infrastructure. Further efficiencies have been achieved through the reuse of suitable electrical equipment and the use of the site’s existing final effluent washwater supply.
At the time of writing (October 2026), construction is nearing completion, with the project team focused on final commissioning activities and preparing the upgraded infrastructure for operation.
Delivered by Anglian Water’s @one Alliance and its supply chain partners, the scheme highlights the value of asset repurposing as a practical and lower-carbon approach to enhancing wastewater infrastructure.
The project has attracted local interest, including a site visit by Alex Mayer MP, providing an opportunity to showcase the investment being made in local wastewater infrastructure and the engineering solutions being implemented to support future storm storage requirements. Construction is scheduled to finish by the end of 2026, with full project completion expected in early 2027, subject to confirmation of the final programme.
New electrical connections to support the new storm tanks - Courtesy of @one Alliance
