The image is quite startling. The blue of the water surrounded by the recent large-scale industry which has been taking place there. But people living near it say it is dangerous and they are very worried indeed.

The people living by the UK's former biggest open cast coal mine say they are “disappointed” at the reaction to their fears that rising water levels at the site could cause contaminated water and become a drowning risk. Campaigners and local residents Chris and Alyson Austin are calling on Merthyr council to use £15m in an account involving the council and the mining company to address what they believe are pressing safety concerns over Ffos-y-Fran opencast mine.

The site, which produced two thirds of the UK’s coal, finally closed on November 30, 2023. Prior to its closure, drone footage and photos showed activity continuing at the site after it was told to stop production.

Drone footage in March by the Coal Action Network showed water forming at the bottom of the disused mine. And fresh drone footage shot by Mark Lewis for Wales Online today - April 14 - reveals that water is now a fully fledged lake on a massive scale. Local campaigners are calling for water pumps to be brought back to drain the water, but the council and Merthyr (South Wales) Limited, which own the site, say they are monitoring the situation with no current plans to reintroduce them.

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A lake which has formed in a former opencast coal site
Pumps had previously been brought to the site to remove water
A lake which has formed in a former opencast coal site
Local residents fear the water is a drowning risk and could also contaminate local supplies

According to a report by the Good Law Project, a not for profit campaign organisation, £15m was put into an escrow fund by Merthyr (South Wales) Limited. The local authority said the sum, originally in the form of a bond, was an agreed business arrangement put in place as part of the planning process around the mine to be used towards restoration, but was not set up to cover the full cost. Mr and Mrs Austin believe this money could go a long way to making the void safe.

The couple said they wished for funding to be used so that the site could be properly surveyed to check it was suitable for holding a large body of water, as well as testing for toxins and increasing security around the site. In an interview with Wales Online, Mr and Mrs Austin said they were shocked by Merthyr (South Wales) Limited "turning off the pumps and walking away".

Alyson Austin and her husband Chris want action to be taken

A statement from Merthyr Council to Wales Online said: “The council continues to work with Merthyr (South Wales) Limited. Merthyr (South Wales) Limited are continually monitoring the water levels in the void, the rate of which is decreasing, and at this time the levels are not considered to be a cause for concern.”

The local authority added: "It is, and always has been, the responsibility of the mine owner to ensure they have sufficient funds to cover the full restoration works."

But in response to the council statement, Mr and Mrs Austin said: “That's flummoxed me completely, because the weather has been awful at the moment. That worries me more to hear the levels are decreasing without being pumped out because where is that water going?”

Mr and Mrs Austin have expressed concern that the current void of water is dangerous not just because of potential toxins in the water but also that it will become a magnet for young people. They said that they worried if someone were to fall in there that they would never get out. “We need to be proactive here, not reactive. Time is not on our side."

There is plenty of infrastructure, equipment and vehicles still at the site
There is plenty of infrastructure, equipment and vehicles still at the site

A spokesman for Merthyr (South Wales) Limited told the BBC that following one of the wettest winters on record, ground water had stabilised around the levels "prior to commencing mining operations", and were currently some 200 feet below the site's lowest natural ground level.

Last October a letter from the UK Government's Coal Authority was written to John Howell, director of climate change, energy and planning for the Welsh Government. The document, shared with WalesOnline, said: “The meeting last week demonstrated there was no understanding of how to manage rising water levels, or whether they could use the restoration bond held in the escrow account.” For the latest Merthyr Tydfil news, sign up to our newsletter here

The Welsh Government said they were “in regular contact with a range of public sector partners, including the local authority, whose Leader had provided assurance that the water level was not an immediate concern.” Merthyr (South Wales) Limited has been contacted for a statement but has not responded.

Ffos-y-Fran was at one time responsible for 86% of the UK’s coal emissions but is claimed to have been a blight for the residents living in its shadow, while concerns have been raising over the years over health and safety, the despoiling of the landscape and the impact of mining coal on climate change - read more on that here. It is classed as a land reclamation area, and part of the agreement with Methyr (South Wales) Limited was that it would help restore the area for the community.

Ffos-y-Fran opencast mine when it was in operation
Pictures last year showed ongoing work at a controversial opencast coal mine months after the site's planning permission expired.
Ffos-y-Fran opencast mine when it was in operation
The site pictured in October, 2022

Mr and Mrs Austin have described the site as "a scar and a blot on the landscape that will be there till the end of our lives.” Organisations such as Friends of the Earth Cymru and Coal Action Network have voiced support for local residents.

The director of Friends of the Earth Cymru, which both Mr and Mrs Austin are part of, said: “It is disgraceful that Ffos y Fran is now a dangerous hole with water. For the safety of local people and wildlife the water pumps must be turned back on. And a proper restoration plan to be carried out urgently.”

David Therkelsen from the Coal Action Network said: “We stand alongside local residents in disbelief as yet again Merthyr (South Wales) LTD shows its reckless disregard for the population of Merthyr Tydfil.”