Our water treatment works in the Bannau Brycheiniog National Park provide drinking water to people across Merthyr Tydfil and the surrounding areas. The investment project in this area is called the Cwm Taf Water Supply Strategy, future proofing our supply of water to our customers.
The drinking water network in this area includes a number of water treatment works, many of which were built in the early 1900s.
The water treatment works at Pontsticill, Cantref and Llwyn-onn are ageing and have become increasingly difficult to maintain. We now have a legal duty to upgrade the water treatment processes, providing a sustainable solution to supply clean drinking water well into the future.
Without major investment, we will not be able to continue to meet the high drinking water standards we must comply with, and customers will be at risk of increased water supply interruptions in the future.
We have spent time considering the options available to us, whilst also consulting with the local community and stakeholders on our proposals, to help inform our decisions.
Our consultations
Original proposal: Single-site Water Treatment Works 2022
In 2022, we held a non-statutory consultation on early proposals to replace the three existing water treatment works with a single-site new water treatment works on Gurnos Farm, Merthyr Tydfil, and invited the local community and stakeholders to comment on this proposal.
The feedback we received was extremely useful. Following the 2022 consultation, we spent time listening to the local community’s feedback and challenged ourselves to see if there were other solutions which balanced our need to meet our legal duty to improve the local water infrastructure whilst also considering the community’s feedback and environmental impacts.
Revised proposals: Split-site approach 2024
By taking additional time to review and conduct further surveys, we were able to revise our proposals offering a split-site approach, which means proposing to upgrade the existing Llwyn-onn Water Treatment Works and constructing a new smaller water treatment works at Dan-y-Castell Farm, Merthyr Tydfil, along with a new raw water pumping station at our existing Ponsticill Water Treatment Works site.
The split-site approach allows us to:
- Upgrade one of the existing water treatment works and re-use existing Welsh Water assets.
- Reduce the size of a new water treatment works required in the Merthyr Tydfil area.
- Minimise the amount of new pipework and pumping stations needed, protecting heritage and minimising traffic disruption.
- Reduce capital costs and the cost to our customers.
- Provide a lower embodied carbon solution by maximising the use of existing infrastructure.
In 2024, we held a further non-statutory consultation on these revised proposals, that together will provide new and resilient water treatment facilities, safeguarding and future proofing the supply of water to present and future generations, whilst removing the need for a larger single-site treatment works on Gurnos Farm.
Further information on these proposals is available in the Cwm Taf Water Supply Strategy Non-statutory Consultation 2024 document, which is available in the documents section below.
We would like to thank everyone who took the time to engage with the non-statutory consultation process, the feedback that we received has been greatly appreciated.
What’s happening now
We have been continuing to conduct further surveys, as well as review the feedback received, which has helped us to shape and develop the proposals we consulted on in 2024, the split-site approach.
The split-site approach provides us with a resilient solution that balances the feedback received and the environmental impacts. We’ve therefore been progressing with the designs for the following proposals:
- Dan-y-Castell Water Treatment Works and Pontsticill Pumping Station
- Llwyn-onn Water Treatment Works upgrade.
What’s next
For us to meet our legal duty and to progress with our proposals to invest in our water treatment facilities, we will need to seek planning permission.
Prior to us submitting our planning applications we will need to undertake further consultations, where we’ll present draft versions of our planning application documents, providing the opportunity for the local community and stakeholders to review and comments on our proposals. This process is known as a pre-application consultation.
The split-site solution means we will need to consult on each application separately prior to submitting separate planning applications for each proposal to the two relevant planning authorities, Merthyr Tydfil County Borough Council and Bannau Brycheiniog National Park Authority.
We are currently preparing the information for the pre-application consultation, and we’re aiming to hold these consultations Autumn 2025.
Further information
Once we have confirmed the dates for the pre-application consultation we will notify the local community and stakeholders, and we will once again welcome your feedback.
We appreciate there will be lots of questions about this project and why we need to do it, should you have any queries then please email us cwmtafproject@dwrcymru.com.
