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The Brief

Woodhams delivered a specialist mechanical and structural installation package as part of the installation of an Integrated Fixed Film Activated Sludge system for Wessex Water at Holdenhurst Water Recycling Centre.

The project formed part of a major treatment upgrade and involved the largest Membrane Aerated Biofilm Reactor system in the UK. The IFAS process combines conventional activated sludge treatment with fixed-film biofilm technology, allowing additional biological treatment capacity to be introduced within existing treatment assets rather than requiring new tankage.

Woodhams’ scope focused on the process pipework, steelwork substructure and central access walkway required to support the new MABR module arrangement — all of it within an existing anoxic/contact zone on a live wastewater treatment site.

The works required careful planning, coordination and sequencing to allow a new support structure and pipework to be installed safely inside a live treatment environment.

The Solution

Steelwork substructure. A key element of the scope was the fabrication and installation of a new steelwork substructure within the existing process tank. The structure was designed and installed to support the new MABR module frames while maintaining access for operation and maintenance, and had to be planned carefully around the existing anoxic/contact zone. Installing new support steelwork inside an existing treatment structure demanded accurate setting out, lifting coordination and sequencing within a constrained working environment.

Central access walkway. The central walkway formed an important part of the completed installation, providing a safe route through the module arrangement and enabling practical access to the new process assets. The walkway and its supporting steelwork required accurate fabrication and installation to ensure correct alignment with the module frames and the surrounding process pipework.

Process pipework. Woodhams was responsible for the process pipework associated with the new MABR system. The pipework formed a critical part of the integration between the new module arrangement and the existing treatment process, and was coordinated with the support steelwork and walkway installation so that pipe routes, supports and access requirements were fully considered before installation. The package required accurate fabrication, careful installation and close coordination with existing assets to ensure the completed system was practical, maintainable and suitable for long-term operation.

Live-site delivery and flow diversion. The works were delivered within a live wastewater treatment environment, requiring careful planning to minimise disruption to Wessex Water’s ongoing operations. A significant challenge was a complex flow diversion, needed to allow the anoxic/contact zone to be drained before the steelwork substructure could be installed. This required close coordination with the site operations team so the works could be carried out safely and within the agreed programme, with sequencing, access and interface management critical to delivery.

The Result

Woodhams delivered the process pipework, steelwork substructure and central walkway package for the Wessex Water IFAS/MABR upgrade, supporting a major treatment process upgrade and helping enable the integration of MABR technology within an existing anoxic/contact zone.

By combining process pipework installation with structural steelwork capability, Woodhams was able to deliver a coordinated package that supported the new MABR module arrangement and provided safe long-term access through the central walkway. Experience in live wastewater environments allowed the team to plan works around operational constraints, support the flow diversion strategy and deliver the installation safely within a complex existing treatment structure.

The scheme demonstrates Woodhams’ capability to deliver technically demanding process pipework and structural installation packages for major wastewater treatment projects — safely, collaboratively and efficiently, within an operational environment.

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