Cwm Taf Water Supply Strategy
Investing in new and resilient water treatment works and associated facilities which will provide our customers with a safe, reliable supply of clean drinking water for decades to come.
Welcome to our consultation
30th October – 10th December 2025
The information on this consultation site outlines our proposal to construct a new water treatment works in Merthyr Tydfil, at Dan-y-Castell Farm, along with a raw water pumping station at Pontsticill Water Treatment Works and new pipeline networks.
Once constructed these new facilities will replace the existing Pontsticill works, which will be decommissioned.
This is a statutory pre-application consultation and is designed to share with you the need for the investment, our proposals, draft planning application documents, and receive your feedback ahead of us submitting out planning application to the relevant local planning authorities – Merthyr Tydfil County Borough Council and Bannau Brycheiniog National Park.
We’ve created a virtual consultation room where you will find information about the proposal and how you can provide your views. Please make sure you visit the additional information on the main table within the virtual room and provided on the screens.
Our virtual
consultation
Cwm Taf Water Supply Strategy - Dan-y-Castell Water Treatment Works
A separate virtual consultation room is available for our Llwyn-onn Water Treatment Works upgrade: www.dwrcymru.com/llwynonnproposal.
Click here for a guide to the technical documents below.
Draft drawing pack
Draft Brine Tanks Plans Elevations Sections
Draft Chlorine Contact Tank - Ground Floor Plan
Draft Chlorine Contact Tank - Roof Plan
Draft Chlorine Contact Tank - Sections A-A B-B
Draft Chlorine Contact Tank -Elevations
Draft Chlorine Contact Tank Sections CC DD
Draft Clean Water Tank - Elevations
Draft Clean Water Tank Sections
Draft Clean Water Tank- Roof Plan
Draft Clean Water Tank- Submerged Floor Plan
Draft Dan-y-Castel Site Elevations
Draft Dan-y-Castell WTW Overview of Proposed Development
Draft Dan-y-Castell WTW Pontsticill Pumping Station Existing Location Plan
Draft Dan-y-Castell WTW Pontsticill Pumping Station Existing Site Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Elevations
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Ground Floor Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Proposed Site Layout Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Proposed Site Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Retained and Demolished Site Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Roof Plan
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Sections
Draft Dan-y-Castell WTW Proposed Pontsticill Pumping Station Site Elevations
Draft Dan-y-Castell WTW Site Location Plan
Draft Dan-y-Castell WTW Site Location Plan 1 to 2500
Draft Dirty Backwash Tank Elevations Sections
Draft Dirty Backwash Tank Plans
Draft DyC 3D Views No1
Draft DyC Existing Site Plan
Draft DyC Site Plan
Draft DyC Site Roof Plan
Draft GAC Elevations
Draft GAC Ground Floor
Draft GAC MCC Plans Elevations Sections
Draft GAC Roof Plan
Draft GAC Sections
Draft Generators Fuel Store Plans Elevations Sections
Draft HLPS Elevations
Draft HLPS Ground Roof Plans
Draft HLPS MCC Sections
Draft HV Room Plans Elevations Sections
Draft Inlet Chemical Building Elevations
Draft Inlet Chemical Building Ground Floor
Draft Inlet Chemical Building Lower Ground Floor
Draft Inlet Chemical Building Roof Plan
Draft Inlet Chemical Building Sections
Draft LOX Silos Plans Elevations Sections
Draft Manganese Lime Ortho Elevations
Draft Manganese Lime Ortho Ground Floor
Draft Manganese Lime Ortho Roof Plan
Draft Manganese Lime Ortho Sections
Draft OSED Building Plans Elevations
Draft Ozone Generation Plans Elevations Sections
Draft Plant Substation Surge Vessels Above Ground Plan Elevations Section
Draft Polyelectrolyte Building Plans Elevations Sections
Draft RGF Ozone Building Ground Floor
Draft RGF Ozone Building Roof Plan
Draft RGF Ozone Tank Elevations
Draft RGF Building Sections
Draft Sodium Hydroxide Building Plan Sections
Draft Supernatant Lamellas Sludge Tanks Centrifuge Building Elevations
Draft Supernatant Lamellas Sludge Tanks Centrifuge Building Ground Floor
Draft Supernatant Lamellas Sludge Tanks Centrifuge Building Roof Plan
Draft Supernatant Lamellas Sludge Tanks Centrifuge Building Section DD
Draft Supernatant Lamellas Sludge Tanks Centrifuge Building Sections AA BB CC
Draft Workshop Plans Elevations Sections
Draft WTW 3D Views No2
Draft Minerals Assessment
Draft Minerals Assessment - Appendix B to the Planning statement
Draft Planning Statement
Draft Minerals Assessment - Appendix B to the Planning statement
Draft Design and Access Statement - Dan-y-Castell Water Treatment Works
Draft Design and Access Statement - Dan-y-Castell Water Treatment Works
Draft Design and Access Statement - Pontsticill Pumping Station
Draft Design and Access Statement - Pontsticill Pumping Station
Draft Habitat Regulations Assessment
Draft Habitats Regulation Assessment
Draft Arboricultural Impact Assessment
Draft Arboricultural Impact Assessment
Draft Outline Lighting Strategy
Draft Outline Lighting Strategy
Draft Green Infrastructure Report
Draft Green Infrastructure Statement
Draft Environmental Statement and Non-Technical Summary
Draft Volume 1 - Main Report
Draft Volume 2 - Technical Appendices - Appendix 1-A - 5-A
Draft Volume 2 - Technical Appendices - Appendix 5-B - 9-A
Draft Volume 2 - Technical Appendices - Appendix 10-A part 6
Draft Volume 2 - Technical Appendices - Appendix 10-A part 5
Draft Volume 2 - Technical Appendices - Appendix 10-A part 4
Draft Volume 2 - Technical Appendices - Appendix 10-A part 3
Draft Volume 2 - Technical Appendices - Appendix 10-A part 7
Draft Volume 2 - Technical Appendices - Appendix 10-A part 1
Draft Volume 2 - Technical Appendices - Appendix 10-B - 18-A
Draft Volume 2 - Technical Appendices - Appendix 10-A part 2
Draft Volume 3 - Figures - Part 1
Draft Volume 3 - Figures - Part 2
Draft Volume 3 - Figures - Part 3
Draft Volume 3 - Figures - Part 4
Have your say
We want to hear your views.
Please take the time to read our consultation materials and then complete our forms to share your feedback.
There are separate forms for each proposal so we can ensure that any feedback received will be specific to each proposal. We have colour coded the forms for clarity. We welcome and encourage feedback on both proposals, for those who wish to comment on both you will need to complete the two feedback forms.
How to submit feedback
You can provide feedback online here.
Thursday 6th November - 3pm-6pm at Pontsticill Memorial Hall, Vaynor Road,CF48 2RU.
Thursday 13th November - 2pm-7pm at Cefn Coed Community Hall, New Church Street, CF48 2NA.
Wednesday 26th November - 3pm-6pm at Nant Ddu Lodge & Spa, CF48 2HY.
Thursday 4th December - 1pm-5:30pm at Merthyr Tydfil Central Library, High Street, CF47 8AF.
Our forms are available to download on the supporting documentation section.
You can pick up a copy of our forms at our in-person events or at Merthyr Tydfil Central Library High Street, CF47 8AF.
Or you can request a hardcopy by emailing us cwmtafproject@dwrcymru.com.
Post your response form to: Freepost, Dŵr Cymru Welsh Water.
If you prefer to email us your feedback to email us at cwmtafproject@dwrcymru.com.
If you are unable to respond via one of the above channels, please call us on 0800 052 0130 to discuss alternative ways of sharing your feedback. (General enquiries 8am-6pm Mon-Fri, 9am-1pm Sat).
The closing date for responses is 23:59 on Wednesday 10th December 2025.
Your feedback is important to us. The feedback received as part of this consultation will be taken into consideration as we finalise our application. The comments raised, and how we considered them, will form part of our final planning application submission - set out in the Pre-application Consultation Report.