Marlas rising main

We know many people are concerned about the recent issues affecting the River Kenfig following a burst on the Marlas rising main near Port Talbot. We’re sorry for the impact this is having on local communities and the environment, and we want to keep you updated on the work taking place to improve the situation.

What happened?

The condition of the Marlas rising main deteriorated much faster than we expected, causing bursts and leading to a discharge impacting on the River Kenfig. In April 2026, we declared a Gold Incident due to the increasing difficulty in managing the impact to the River Kenfig.

Our initial response involved using over 20 tankers to remove wastewater from the network and reduce pressure on the system. While this helped manage the immediate problem, it was only a temporary measure.

To help manage the situation and support river health, we undertook several short-term activities to try and mitigate the impact on the River Kenfig. This included:

• Installing a temporary wastewater treatment process at Marlas Pumping Station to allow wastewater to be treated on site.
• Tankering from upstream pumping stations to help relieve the pressure on Marlas Pumping Station.
• Introduction of additional aeration equipment to support the River Kenfig, with the aeration nearest to our outfall operating 24/7.

To help mitigate the impact whilst we carry out our long-term investment work, we also installed 4.9km of temporary overland pipe which currently transfers all the wastewater to Afan Wastewater Treatment Works for treatment. What this means is that all wastewater flows go through the new pipework to Afan Wastewater Treatment Works and as a result, the flows longer impact the River Kenfig. 

Long-term Investment

To address the root cause of the issue, we’re investing £13 million to replace 6km of the existing sewer main across the Kenfig and Port Talbot area.This investment will help to:

• Improve the resilience of the network
• Reduce the risk of future failures
• Better protect the local environment for the long term

The temporary overland pipe will remain in place until we have completed our £13 million investment work. 

We are also developing plans to rehabilitate a further 3km of the pipeline where additional deterioration has been identified which will mean the entire wastewater main affected by this incident will ultimately be upgraded.

River Kenfig

We recognise that there is significant work to do to support the health of the River Kenfig. That’s why we’re working with South East Wales Rivers Trust (SEWRT) to develop a recovery plan, so we can restore and enhance the River Kenfig following this incident. SEWRT brings extensive experience in river restoration and catchment management across South East Wales, making it well placed to help develop a recovery plan rooted in local environmental expertise.

SEWRT will engage with the local community to share its findings and better understand local priorities. This collaborative approach will help identify opportunities for improvement and inform the development of future restoration ideas, which will in turn shape the recommendations for the River Recovery Plan.

Stay updated

We’ve been sharing updates with customers, local groups and stakeholders through newsletters, social media and the In Your Area section of our website, and we’ll continue to provide regular information as work progresses.

We understand how worrying this situation has been for local people and we’re sorry for the disruption and environmental impact it has caused. Our teams are working hard to improve the situation and deliver a long-term solution for the community and the river.