Severn Trent has gone out to tender with a major AMP8 contract for digestor roof replacement design & build works with a current estimated total value of £84 million (inc VAT).
The works requirement is for the provision of new replacement fixed steel painted digester rooves. The appointed contractor(s) will be required to develop both the outline and detailed design and undertake build in the role of Principal Designer and Principal Contractor. The works include:
- Outline and detailed design
- Digestor decommissioning & purging (emptying/ cleaning/waste management)
- Demolition and disposal of existing steel roof
- Build including any remedial works (roof fabrication & installation civils/MEICA/DSEAR/ Welding Electrical & Instrumentation)
- Reinstatement & commissioning
The works will include requirements for surveys, temporary works, necessary plant, equipment, materials, site management and welfare facilities.
The framework's objective is to:
- Replace aging assets, providing new fixed roofs to digesters. The new, fixed roof is to be sealed preventing any foam and sludge leakage from digester sludge seal annulus associated with floating roofs, reducing pollution events.
- Improve safety associated with the new assets. Including upgraded lightning protection, enhanced monitoring and control around digester gas headspace, and protection against rapid volume expansion (RVE's).
- Significantly reduce the risk of serious structural failure of the roof
- Drive benefits to Net Zero efficiencies
- Comply with company digester design manual and specifications (fixed roof)
- Comply with the Environment Agency's Industrial Emissions Directive (IED), achieving compliance before end of AMP8.
Works completion date across all sites is required by 2030.
Framework duration is 8 years with current estimated start and end contract dates of 30 September 2026 to 29 September 2034. Estimated formal contract award decision date is currently 30 September 2026.
Deadline for submission of enquiries about the tender is 4.00pm on 16 June 2026 and tender submission deadline is 4.00pm on 16 July 2026.
the documents provided under Stage 1 (PQQ) & Stage 2 (RFP) listed below are the Digestor Roof Replacement tender documents which Severn Trent is making visible to interested parties during the Stage 0 Advert stage which runs from - 2 May 2026 to 16 June 2026. At Stage 0 Advert bidders are only required to register their interest with Severn Trent to bid. There is no requirement to complete the Stage 1 or 2 tender documents during this stage.
Stage 1 is the Pre Qualification Questionnaire (PQQ) where bidders will have the opportunity to complete and submit the PQQ. PQQ responses will be evaluated & shortlisted to Stage - 2 Request for Proposal (RFP). Bidders do not need to complete the RFP documents until notified of shortlisting to RFP stage.
Click here to access the Ariba portal for the submission address, associated tender documents and PQQ & RFP Briefing Packs for further guidance.
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