NRW investigates sewage pollution in one of Wales’ most important wildlife sites

Mark Mansfield

Natural Resources Wales is investigating a series of sewage pollution incidents that have affected the River Kenfig, including sections that run through one of Wales’ most important wildlife sites.

The environmental watchdog said repeated discharges linked to Marlas Sewage Pumping Station near North Cornelly and a pipeline operated by Dŵr Cymru Welsh Water have polluted the river, which flows through the Kenfig National Nature Reserve.

NRW said the incidents have caused pollution, unpleasant odours and damage to fish and other wildlife, with the impact extending downstream into the internationally important conservation area.

The problems stem from a nine-kilometre pipeline carrying sewage to the Afan Wastewater Treatment Works, which has suffered a number of bursts since August 2023.

NRW officers have attended sites affected by the spills to gather evidence, assess environmental damage and require Welsh Water to take action to address the failures.

The situation worsened in February this year when a continuous discharge began from the pumping station. In response, Welsh Water commissioned a temporary sewage treatment plant at the site.

A temporary overland pipeline was completed on June 9, allowing the continuous discharge from the pumping station and the temporary treatment plant to cease.

NRW said the measure should significantly reduce the risk of further pollution incidents, although there remains the possibility of additional problems until a permanent solution is in place.

Huwel Manley, NRW’s Head of Operations for South West Wales, said: “This issue is extremely serious. The scale of environmental impact on the River Kenfig is unacceptable, and we understand the concern and frustration this has caused for local communities, as well as the damage to wildlife and the wider environment, including Kenfig National Nature Reserve.

“We are undertaking detailed investigations into these incidents and will take the appropriate action in line with our Enforcement and Sanctions Policy.”

Mr Manley said NRW could not provide detailed information while formal investigations were ongoing, but stressed that officers were continuing to monitor the site and assess the environmental impact.

He added: “We want people to be assured that we are closely monitoring the situation as we build our case. Our officers are attending the site regularly to undertake important monitoring work, to continually assess the environmental impact and are ensuring DCWW delivers the necessary improvements.

“We have informed DCWW that we expect them to undertake remedial work to clean up affected stretches of the River Kenfig along with a plan for longer term enhancement of the river and its biodiversity.”

Environmental permit

Marlas Sewage Pumping Station operates under an environmental permit that allows emergency or storm sewage discharges under specific conditions.

NRW said it is examining all incidents connected to the site, including the environmental impact and any suspected breaches of permit conditions.

Dŵr Cymru Welsh Water, which operates the pumping station and pipeline, is responsible for complying with the site’s permit conditions and managing the impact of any discharges.

A spokesperson for the company said: “We are currently working on a project to replace 6km and renew 3km of sewer main in the Kenfig and Port Talbot area, at a cost of more than £13m, following the escalated deterioration of the current main.

“To minimise the impact this had on the environment, we installed a full wastewater treatment process at Marlas Sewage Pumping Station.

“This was done while 4.9km of temporary overland pipe was laid to link to the treatment works in Port Talbot. This has been operational since Monday and the spill to the Kenfig, which consisted of water treated at the temporary works, has ceased.

“While we are continuing to manage the situation, looking at a river recovery plan for the Kenfig and the wider catchment, this work would improve biodiversity and restore water quality. An aeration system will remain in the river on a 24/7 basis to increase oxygen levels to support fish and wildlife and improve river health.

“We are continuing to work with NRW, who are being provided with results from our sampling in the river.

“We would like to apologise to the community for the disruption this work is causing and for the impact we have had on the local environment.”