Dwr Cymru Cyfyngedig (DCC) / Welsh Water, the largest water and sewerage company in Wales and the sixth largest operating in England and Wales, is inviting organisations in the wider water sector to register their interest in a major upcoming £667 million Design-Build-Finance scheme.

Welsh Water is now encouraging responses from:

• Infrastructure investors and major infrastructure financing bodies
• Design, construction and engineering firms
• Joint ventures or consortia

As part of its Cwm Taf Supply Strategy, the water company 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, which has been designated under Ofwat's Direct Procurement for Customers (DPC) programme, 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 now about to enter a planning application stage following statutory consultation.

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 a two-site project comprising Dan-y-Castell (with an estimated value of £362 million excluding VAT) and Llwyn-onn (with an estimated value of £194 million excluding VAT).

Welsh Water is looking to appoint a CAP through a 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.

Current estimated total value is £667.2 million including VAT and current estimated start and end dates for the contract.which will run for 30 years in total, are 31 August 2028 to 30 August 2058. Contract award is envisaged to be August 2028. Milestone dates include Drinking Water Inspectorate 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.

The water company has now issued a preliminary market engagement notice seeking interest from suitably qualified parties capable of delivering a secure, sustainable, and value-oriented solution for customers for the major project. The solution must be aligned to Welsh Water's Cwm Taf Water Supply Strategy and the sustainable and environmental objectives of the Welsh Assembly Government, including the Well-being of Future Generations (Wales) Act 2015.

The Cwm Taf Scheme currently includes:

• Water Treatment Works
• Pumping stations
• Transfer pipelines
• Environmental and mitigation measures
• Treated Water Storage

All values and dates set out in the preliminary market engagement notice are indicative and reflect current analysis.

Welsh Water has issued the notice as part of its early market consultation for the Cwm Taf Scheme to engage with market participants who may be interested in delivering the scheme through a DBF model. The first activity as part of the market engagement involves the response to a questionnaire to help shape the legal, commercial, technical, and delivery strategy of the project and inform the forthcoming procurement process.

DCC/Welsh Water intends to undertake further market engagement activities which may include a briefing event and 1-2-1 meetings with interested organisations. The water company will publish further updates to reflect future activities.

The 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 the 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 is now encouraging responses from:

• Infrastructure investors and major infrastructure financing bodies
• Design, Construction and Engineering firms
• Joint ventures or consortia

The water company is asking interested organisations to email This e-mail address is being protected from spambots. You need JavaScript enabled to view it to register their interest in participating in the market engagement process - deadline for registering is 22^nd September 2025.

DCC/Welsh Water is highlighting the fact that it reserves the right to alter or terminate the market engagement process at any time without notice and is not liable for any costs or expenses incurred by any party in responding to the market engagement.

The utility also points out that submission of a response does not guarantee inclusion in any future procurement process.