Scope
Reference
DCWW1994
Description
Dwr Cymru Cyfyngedig (DCC) / Welsh Water is the largest water and sewerage company in Wales and the sixth largest operating in England and Wales. Responsible for providing high-quality drinking water for over three million customers and for taking away, treating and properly disposing of the wastewater that is produced.
DCC/Welsh Water is committed to securing water supplies for future generations while protecting the environment. Our primary responsibility is to operate, maintain and upgrade this large network of assets to ensure a safe and reliable drinking water supply and to deal effectively with discharges so as to protect the environment.
As part of its Cwm Taf Supply Strategy, DCC/Welsh Water is seeking to progress a major investment project to design and build a new water treatment works and develop an existing water treatment works (the Cwm Taf Scheme). The Cwm Taf Scheme has been designated under Ofwat's Direct Procurement for Customers (DPC) programme. The Cwm Taf Scheme is intended to be delivered primarily on two separate sites, one located in the Merthyr Area of South Wales and one in the Bannau Brycheiniog National Park. The scheme is about to enter a planning application stage following statutory consultation. Further details can be found on our website:
https://corporate.dwrcymru.com/en/community/investment-projects/cwm-taf-water-supply-strategy
DCC/Welsh Water is looking to utilise a Competitively Appointed Provider (CAP) through a Design-Build-Finance (DBF) model. The scheme includes design and build of a new water treatment works on a brownfield site at Dan-y-Castell Farm, along with a raw water pumping station at Pontsticill (referred to as the Dan-y-Castell project) and upgrading Llwyn-onn water treatment works (referred to as the Llwyn-onn project). The Cwm Taf Scheme is therefore a two-site project comprising Dan-y-Castell (with an estimated value of £362,000,000 excluding VAT) and Llwyn-onn (with an estimated value of £194,000,000 excluding VAT).
This notice seeks market engagement from suitably qualified parties capable of delivering a secure, sustainable, and value-oriented solution for customers for this major project aligned to DCC/Welsh Water's Cwm Taf Water Supply Strategy and the sustainable and environmental objectives of the Welsh Assembly Government including but not limited to the Well-being of Future Generations (Wales) Act 2015.
Contract award is envisaged to be August 2028. Milestone dates include DWI Regulatory Completion (envisaged to be March 2032) followed by an estimated 12 month period for testing, and a 25 year term from completion of testing.
All values and dates set out in this preliminary market engagement notice are indicative and reflect current analysis.
Total value (estimated)
- £667,200,000 including VAT
Above the relevant threshold
Contract dates (estimated)
- 31 August 2028 to 30 August 2058
- 30 years
Main procurement category
Works
CPV classifications
- 45000000 - Construction work
- 65100000 - Water distribution and related services
- 66100000 - Banking and investment services
Contract locations
- UKL - Wales
Engagement
Engagement deadline
14 November 2025
Engagement process description
DCC/Welsh Water is issuing this Preliminary Market Engagement Notice as part of the early market consultation for the Cwm Taf Scheme.
DCC/Welsh Water seeks to engage with market participants who may be interested in delivering the scheme through a DBF model. At this stage we have not circulated the questionnaire that was referred to in the original version of this notice. Activity to date has involved suppliers registering interest in the project in response to the original notice The deadline for initial registration was 22 September 2025 and DCC/Welsh Water is now updating this Notice to provide details of its first market engagement activity.
Since September we have been working on our technical documentation as part of our preparation for statutory planning consultation. We launched our statutory pre-application planning consultation at the end of October 2025. DCC/Welsh Water intends to share key technical documentation associated with the Cwm Taf Scheme and relevant to the future procurement process, as part of the market engagement process. Alongside the release of this information, DCC/Welsh Water intends to host a launch in-person event for registered organisations on the 19th of November 2025 in Cardiff which will focus on technical requirements and take the opportunity to present on our emerging reference design for the scheme. At the launch event we will also provide an overview of our procurement timeline.
We are seeking feedback as part of market engagement on the viability of the procurement plan against the backdrop of investment in the UK and constructability of the two projects to meet regulatory commitments, sustainability, social value, and plans to manage environmental impact.
For more information about the event, market participants must register via email (see contact details below).
DCC/Welsh Water intends to undertake further market engagement event(s) between December 2025 and February 2026 to discuss DCC/Welsh Water's preferred commercial and contracting models. The focus at these events will be on the main aspects of the contractual agreement, risk allocation, incentivisation, funding duration and financing models and opportunities within the procurement process to offer value for money for DCC/Welsh Water's customers. Details in relation to the further event(s) will be provided to registered organisations.
The Cwm Taf Scheme includes (but is not limited to):
• Water Treatment Works
• Pumping stations
• Transfer pipelines
• Environmental and mitigation measures
• Treated Water Storage
DCC/Welsh Water is looking to appoint a CAP through an open, fair, and transparent competitive procurement process and anticipates that the CAP will be responsible for the design, build, and financing of the scheme for a defined contract term of 25 years.
This market engagement is intended to focus on:
• Assessing market capacity and capability
• Obtaining market feedback on commercial models best suited to deliver value for money for customers
• Informing procurement strategy and timeline
• Identifying innovations and barriers to entry
The scope of this market engagement is intended to include seeking feedback on:
• Design handover
• Technical feasibility and constructability insights
• Financing models
• CAP Agreement
• Commercial risk allocation and delivery timelines
• Market constraints
• Market innovation opportunities
• Environmental or regulatory factors
DCC/Welsh Water encourages responses from:
• Infrastructure investors and major infrastructure financing bodies
• Design, Construction and Engineering firms
• Joint ventures or consortia
Please email amanda.edwards@dwrcymru.com to register/participate in the market engagement process. The deadline for initial registration for market engagement was 22/09/2025. The deadline to register for the in-person event in Cardiff is 14th November 2025. Further market engagement activities in relation to the Cwm Taf Scheme this project and associated deadlines will be provided in updates to this notice.
This notice is not a call for competition, a tender notice, or a commitment to procure.
DCC/Welsh Water reserves the right to alter or terminate the market engagement process at any time without notice.
DCC/Welsh Water is not liable for any costs or expenses incurred by any party in responding to this market engagement.
Submission of a response does not guarantee inclusion in any future procurement process.
DCC/Welsh Water reserves the right to enter into further rounds of pre-market engagement.
All future procurement opportunities will be published through the Central Digital platform (CDP).
DCC/Welsh Water will process your personal data, such as your name and contact details, in accordance with its obligations under the UK General Data Protection Regulation and Data Protection Act 2018. Your personal data will be used for the purposes contacting you for further information and to invite participation in future market engagement activities connected with the Cwm Taf Scheme only. Any information you provide may be shared with our Cwm Taf Scheme commercial and or legal advisors.
Procedure
Special regime
Utilities
Contracting authority
Dwr Cymru Cyfyngedig
- Companies House: 02366777
Linea, Fortran Road,
Cardiff
CF3 0LT
United Kingdom
Contact name: Amanda Edwards
Email: amanda.edwards@dwrcymru.com
Region: UKL22 - Cardiff and Vale of Glamorgan
Organisation type: Private utility
Devolved regulations that apply: Wales