Probe launched into allegations of illegal toxic waste dumping at mine following revelations by Nation.Cymru

Martin Shipton

Natural Resources Wales – the nation’s environmental regulator – has confirmed it is launching an investigation into allegations that toxic waste was illegally dumped at the site of Wales’ largest opencast mine.

The failure to progress the remediation of Ffos-y-fran mine at Merthyr Tydfil has become a national scandal, with concerns that its owner, businessman David Lewis, is trying to avoid his legal responsibilities

Last week a former worker provided Nation.Cymru with a statement, setting out in detail an eyewitness account of illegal dumping carried out at Ffos-y-fran by haulage firms, including two run by Mr Lewis’ sons.

Last year a report from the Senedd’s Climate Change, Environment and Infrastructure Committee concluded that the “epic mismanagement” of the Ffos-y-Fran mine saga must not happen again to any community in Wales.

Operating illegally

The licence to extract coal from Ffos-y-Fran expired in September 2022 but local residents reported that the mine was still operating – illegally – many months after this before the site was closed in November 2023.

The company which ran the mine, Merthyr (South Wales) Ltd, owned by Mr Lewis, pledged to fully restore the site after it finished operations.

The committee heard evidence that since 2017, the company had paid out nearly £50m in dividends and royalties out of the business.

But with current restoration costs estimated at up to £120m, and despite the original restoration promises, the company now claims it is unable to afford the work.

In March 2025, however, Nation.Cymru reported how Mr Lewis’ company had set aside more than £90m in its accounts for the remediation work.

Years before, the firm had agreed to put £15m into an escrow account towards the cost of the work, but had only done so after Merthyr Tydfil council won a High Court judgement.

Last week we published a statement from a former worker at Ffos-y-fran who provided details about the illegal dumping of toxic waste at the site by companies including two owned by sons of David Lewis.

We asked Natural Resources Wales (NRW) how it was responding to our revelations.

Concerns

Fiona Hourahine, operations manager for NRW, said: “We understand the ongoing concerns in the local community regarding the Ffos-y-fran opencast mine.

“The site does not hold any permits or licences associated with waste disposal and we will be investigating this recent report of illegal activity accordingly, in line with our regulatory procedures.

“It is crucial that anyone with concerns or evidence related to how waste is being disposed – or any other suspected environmental incident – report their concerns directly to NRW without delay. If there is a delay in matters being reported to us, it limits the actions we can take. They can do this by calling our incident communications line on 0300 065 3000 or using the report-it form on our website: Natural Resources Wales / Report an incident. All reports are treated in the strictest confidence.”

Welsh Conservative Shadow Cabinet Secretary for Climate Change & Environment Janet Finch-Saunders MS, said: “I have visited the site with other members of the Climate Change Committee and was assured that there is a comprehensive plan for remediation. If these reports are accurate, Natural Resources Wales has a clear duty to thoroughly investigate and hold those responsible for any illegal activity accountable.”

A spokesperson for Delyth Jewell, Plaid Cymru’s MS for South East Wales, said she was looking to raise the issue in the Senedd at the earliest opportunity.

Battery plant

The ex-worker said in his statement: “I worked at the Ffos y Fran opencast coal mine at Merthyr Tydfil from 2016 to 2023.

“However, between 2020 and 2023 lorries belonging to SL recycling (owned by Stacey Lewis – son of David Lewis) and lorries belonging to Darren Lewis Transport ( Owned by Darren Lewis son of David Lewis) regularly visited the site fully loaded and departed empty.

“I have been excluded from the mine since 2023 but during the period mentioned I saw the movement of these lorries and even arriving and departing after midnight.

“SL Recycling had reason for its lorries to be seen in the vicinity as there is an authorised tipping facility operated by Biffa just a mile and a half from the mine.

“SL Recycling runs a scrap yard from the old Rechem site in Cwmbran.

“I am aware that SL Recycling had a disposal contract with a battery plant in Cwmbran.

“SL Recycling’s lorries would deposit their load in an area of ground at the top of the mine at the rear of a barrel coal wash plant. This waste was later moved to the restoration area of the mine on large dump trucks.

“The dumping area was subsequently covered with overburden material to completely cover the dumped waste.

“I can identify the area of dumping on a map.

“Darren Lewis directed all day-to-day operations at the mine

“In 2023 I recall looking at an area at the rear of a barrel coal wash plant. The ground was bubbling and full of fumes and I was told by the operations manager, Chris Barber, that this was battery acid. He also told me that the recycling lorries from SL recycling lorries were dumping this toxic waste and he was in no position to prevent this.

“This area of ground was later cleared and the waste buried in the restoration area and covered with overburden.

“I saw this occur on more than a few occasions.

“I was also told of the late night tipping by David Jones, a senior councillor at Merthyr Council.

“I make this statement but do not want my name to be released as I am concerned for my safety.

“David Lewis is likely to harm me if he realises I have exposed his activities.”

Mr Lewis, his two sons and Mr Barber were invited to comment, but did not do so.