Dŵr Cymru proposes new location and a smaller site for Merthyr water treatment works

The investment is needed as three water treatment works in the area, Pontsticill, Cantref and Llwyn-onn, are ageing and nearing the end of their operational life and a new legal duty has been placed on Welsh Water by the Drinking Water Inspectorate to build a new treatment works.

The revised proposals have come following a 2-year review by the company to develop an alternative solution, to the original proposal they consulted on with the local community in 2022. They have since taken additional time to conduct further surveys, take on board the community’s feedback, and consider the options to provide a sustainable upgrade to supply safe, clean drinking water to customers well into the future.

In 2022, Welsh Water consulted on early plans to replace the three works by building a single new water treatment works on Gurnos Farm, near Pontsarn. Welsh Water’s proposals now involve proposing to construct a smaller water treatment works in the Merthyr Tydfil area, on Dan-y-Castell Farm (adjacent to the A465 Heads of the Valleys Road, in Merthyr Tydfil), to replace the existing water treatment works at Pontsticill, whilst upgrading the existing Llwyn-onn Water Treatment Works.

The two proposals now offer a new split-site approach, which together, removes the need to build a single-site works on Gurnos Farm, as well as removing the need to lay new pipework around Gurnos, Cyfarthfa Park and Georgetown, addressing the community’s feedback that it wasn’t an appropriate site for the development of a water treatment works and would impact on the local heritage.

Ian Christie, Managing Director of Water, Asset Planning and Capital Delivery at Welsh Water said:  “We greatly appreciated the feedback that we received following our 2022 consultation and would like to thank the community for their patience as we carried out our review. We have listened and challenged ourselves to develop a new solution which we believe will provide an innovative solution to our ageing water treatment works as well as making sure our assets and network are resilient to the effects of climate change and future population growth.

“It has not been an easy challenge as an investment of this size and importance requires careful planning, which is why we have taken the additional time to balance the many considerations and be as informed as possible. We’re now pleased to be sharing the progress we have made and gain the views from the local community which will help us shape our proposals further before they are finalised. We have to build a new treatment works in the area and believe that these plans now provide the right balance between our operational needs to provide a safe, reliable supply of drinking water to our customers in the area at an affordable price, together with local community and environmental concerns raised during our initial consultation. We will make a formal planning application in due course.”

Welsh Water has been issued with a legal notice from the Drinking Water Inspectorate (DWI) requiring them to upgrade the treatment processes in the area by March 2030. Much of the drinking water network in the Bannau Brychieniog National Park was constructed in the early 20th century and the company has said that these water treatment works, in particular, are becoming increasingly challenging and expensive to operate due to their age. Without major investment, there is an increased risk that they will not be able to continue to meet high drinking water standards, and customers will be at risk of increased interruptions to drinking water supplies in the future.