Anaerobic Digester Inspection, Repair and Refurbishment Framework

Thames Water Utilities Limited is establishing a multi-supplier framework agreement worth approximately £70 million to deliver inspection, repair, refurbishment and upgrade works to anaerobic digester assets across its operational estate. The framework will support ongoing maintenance, regulatory compliance and enhancement of Thames Water's critical sludge treatment operations. Scope includes: decommissioning and preparation of digesters; sludge, grit and waste removal and disposal; internal and external structural inspections with defect reporting; cleaning and enabling works; structural repairs to roofs, walls, bases and civil infrastructure; repair and replacement of mechanical, electrical, control and instrumentation systems; regulatory and environmental upgrades including emissions control and gas management; temporary works and access solutions; testing, commissioning and handover; and provision of documentation, manuals and staff training. Works will be delivered as discrete packages across multiple Thames Water sites, with call-off contracts varying in scope and value. Initial inspection findings will inform the full extent of refurbishment required, so suppliers must be flexible and work collaboratively to develop solutions. The framework operates within operational constraints, as digesters must remain largely online to maintain network performance. Suppliers must demonstrate capability in complex, safety-critical works within live operational environments, strong collaborative working practices, and commitment to regulatory compliance and value for money. No minimum workload or exclusivity is guaranteed. Full technical requirements and contractual details will be provided at the Invitation to Negotiate stage.