Scope
Reference
Prj_7120 / pqq_907
Description
The Request for Information is available for download at
southernwater.bravosolution.co.uk
Look for "pqq_907 Kent Bioresources Project Request for Information"
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Introduction
This RFI follows on from, and has been informed by, the market engagement activities undertaken in early 2024, details of which can be found here www.find-tender.service.gov.uk/Notice/004012-2024.
These earlier sessions, including a market engagement event and subsequent one-to-one discussions, provided valuable insights into market capacity, delivery preferences, and potential partnership models. The feedback received has helped shape the current approach and the areas of focus set out in this Request for Information.
Project Purpose
Southern Water Services Limited (SWS) is initiating the Kent Bioresources Project to modernise and consolidate its sludge treatment operations across Kent. The project forms a key part of SWS's long-term bioresources strategy to deliver a more efficient, resilient, and compliant asset base aligned with future environmental standards and the company's AMP8 priorities.
Background
Southern Water currently treats approximately 6 million m³ of sewage sludge per year across its wastewater treatment network, operating 16 sludge treatment centres (STCs) supported by a large transport and recycling operation. In Kent, the current system comprises seven STCs processing around 42,000 tonnes dry solids (TDS) annually.
A combination of ageing infrastructure, evolving regulation, and tightening environmental standards - including restrictions on landbank use, air-emission limits, and emerging contaminants such as PFAS - necessitates a shift toward advanced, centralised treatment solutions.
Project Vision
The Kent Bioresources Project proposes to consolidate seven existing sludge treatment centres into three new "super-sites" that will employ Advanced Anaerobic Digestion (AAD), CHP biogas utilisation, or biomethane upgrading for grid injection. The indicative preferred sites are:
• Ashford STC (South Kent)
• Ham Hill STC (North Kent)
• Motney Hill WTW (Medway) - this has been added since the last market engagement.
Sites are expected to require full redevelopment, including new reception, digestion, dewatering, and energy recovery infrastructure.
We also have commenced feasibility studies for plants in Hampshire and Sussex to be upgraded to AAD too.
Delivery Approach
Southern Water is exploring delivery through a single third-party DBFOM (Design, Build, Finance, Operate, Maintain) contract, though alternative contracting structures remain open for market input.
Indicative features include:
• Long-term, performance-based contract structure.
• Off-balance-sheet treatment of capital investment preferred.
• Potential Special Purpose Vehicle (SPV) or consortium delivery model.
• Opportunities for collaboration among civil contractors, technology providers, funders, and operators.
Market Engagement Objectives
Through this RFI, Southern Water seeks to:
• Gauge market appetite across the investor, construction, and technology supply chain.
• Understand preferred contracting and financing models.
• Explore innovative technical solutions (e.g., alternative advanced treatment processes, resource recovery, or third-party waste integration).
• Identify key delivery risks, interfaces, and opportunities for resilience.
Contract dates (estimated)
- 1 April 2027 to 30 March 2055
- 27 years, 11 months, 30 days
Main procurement category
Works
CPV classifications
- 45252000 - Construction works for sewage treatment plants, purification plants and refuse incineration plants
Contract locations
- UK - United Kingdom
Engagement
Engagement deadline
31 March 2026
Engagement process description
Group and 1-2-1 sessions are expected to be held in the 1st quarter of 2026
Participation
Particular suitability
- Small and medium-sized enterprises (SME)
- Voluntary, community and social enterprises (VCSE)
Submission
Publication date of tender notice (estimated)
1 September 2026
Procedure
Special regime
Utilities
Contracting authority
Southern Water Services Limited
- Public Procurement Organisation Number: PBJQ-2231-ZRPG
Southern Water, Southern House
Worthing
BN13 3NX
United Kingdom
Region: UKJ27 - West Sussex (South West)
Organisation type: Private utility