Below is the response from Elyn Stephens AM, to questions from the Trust about the ongoing pollution of the Kenfig River, which runs alongside the Nature Reserve, and is now virtually dead. The Trust is continuing to pressurise the organisations concerned, in order to resolve this very damaging situation.
Good evening Ceri,
Thank you for your patience in waiting for me get back to you, while I'm still working without staff.
Please find below a summary of questions provided by yourself and others. Where I didn't get the chance to ask a question I have emailed Dwr Cymru separately.
1. Access for independent monitoring
Question:
Will Dŵr Cymru allow A Peace for Nature continued access to the affected areas for independent environmental monitoring, including sections now fenced off where previous testing has already taken place? A Peace for Nature has the landowner's express permission to be on the land and is willing to comply with any reasonable risk assessment or site safety requirements.
Answer / meeting notes:
I have sent this question to Dwr Cymru by email.
2. Scale, duration and current status of pollution
Question:
What levels of discharge have been recorded or reported, when did the discharges begin, and what levels are currently being recorded? In addition, how does Dŵr Cymru currently assess the ecological condition of the Afon Kenfig, and is there any basis for describing it as one of, or the most, polluted rivers in Wales?
Answer / meeting notes:
The first burst was recorded in August 2023. The River Kenfig is around 9km long and runs from North Cornelly to Port Talbot.
Around 16,000 people are connected into the Marlas system. An ammonia level of 6.5 was recorded, which Dŵr Cymru said is higher than levels they would normally have in treatment works.
Dŵr Cymru considers the incident to be a "gold incident", meaning it is being managed at the highest level within the organisation. It was also recognised that this is a long-term event and that further investment will be required.
3. Mitigation measures and public statements
Question:
What environmental recovery operations are currently being undertaken, including aeration, and are these operating continuously or only during specific periods? If aeration or other mitigation equipment is removed or inactive outside working hours, how does this align with public statements referring to continuous or "24/7" environmental mitigation?
Answer / meeting notes:
HIS contractors are operating 24/7 to reduce the amount of waste entering the river. Dŵr Cymru stated that the previous reference to 24/7 aeration related to the treatment process rather than river aeration.
Aeration is used to keep oxygen in the river. A risk assessment is currently taking place so that aeration can move to 24/7 operation. Temporary mitigation is also in place.
4. Adequacy of the current response
Question:
Is Dŵr Cymru satisfied that current mitigation measures are sufficient, given continuing reports of visual pollution, sewage odour and an apparent absence of aquatic life across an estimated 3.2km stretch of river?
Answer / meeting notes:
Dŵr Cymru appears to recognise that this is a long-term event and that more investment is needed. Temporary mitigation is currently being used, and an overland pipe is being installed as a medium-term solution.
A temporary treatment works is also in place.
5. Ecological monitoring and impact assessment
Question:
What ecological monitoring is currently being undertaken to assess fish mortality, water quality, habitat damage and the wider ecological impact on the River Kenfig?
Answer / meeting notes:
Ricardo has been appointed to sample the river upstream and downstream. The company will help draft a river recovery plan once the solution is in place.
Dŵr Cymru said the recovery plan will be discussed with Natural Resources Wales. Otters have reportedly been spotted in the river.
Biochemical Oxygen Demand was also discussed. This refers to the amount of oxygen required to neutralise sewage pollution.
6. Prevention, restoration and support
Question:
What is the timeline for stopping the outflow and preventing further pollution, and what actions will Dŵr Cymru Welsh Water take to restore the river and support the recovery of flora and fauna?
Answer / meeting notes:
A temporary overland pipe is being installed as the medium-term solution. The work is due to be completed by 16 June.
Once the temporary pipework is in place, the temporary treatment works will be removed and the discharge into the river will stop. Plastic pipe is being installed.
Dŵr Cymru said the full permanent replacement is expected to be completed by January 2027. They also stated that the pipe has an expected lifespan of around 40 years.
River quality is expected to be restored by 25 June. Dŵr Cymru said it would take around two months for bacteria to reach their most effective level in the seeding process.
Cofion gorau,
Elyn
Elyn Stephens AS Plaid Cymru - The Party of Wales
=====================================================
Oddi wrth: Trust Clerk <trustclerk@kenfignaturetrust.co.uk>
Anfonwyd: 20 May 2026 19:50
At: Stephens, Elyn (Aelod o'r Senedd - Member of the Senedd) <Elyn.Stephens-AS@senedd.cymru>
Pwnc: Re: ATB/RE: Pollution in the Kenfig River
Good Evening Elyn,
Thank you so much for replying, it means a lot to the Trust that you have taken an interest. There are several questions the Trust would like Dwr Cymru to answer and I imagine our questions will be the similar to the others who have contacted you as well.
1. Is it true that the Afon Kenfig is the most polluted river in Wales?
2. What levels of discharge have been reported?
3. When did this begin?
4. What are current levels being recorded?
5. Is the river life officially degraded to the point of a dead river?
6. What is the timeline of work to stop outflow?
7. What actions are they going to take to restore the river?
8. What support will they offer the Trust to restore the flora and fauna?
9. Will that support be financial, material or a mixture of both?
10. How much compensation will they provide.
The Trust has also asked if the Senedd and members of the local Councils will look to prosecute Welsh Water for this deliberate act of polluting the river. And would like to raise that while the Afon Kenfig is perhaps the most polluted it is not the only river within Wales that Dwy Cymru are polluting without consequence.
---
Cofion gorau | Kind regards
Ceri Davies
Clerc | Clerk
Ymddiriedolaeth Natur Cynffig | Kenfig Nature Trust
Ebost | Email: trustclerk@kenfignaturetrust.co.uk