Over 45,000 potentially contaminated land sites across Wales

View our findings and methodology

We reviewed publicly available data, and together with our network of local activists, we submitted Freedom of Information (FOI) requests to all 22 Welsh councils, asking them to release their register of contaminated land. 

18 out of 22 councils responded to the FOI request. These responses, together with Friends of the Earth Cymru’s own research, revealed 45,157 potentially contaminated sites. Since not all councils responded, the true figure across Wales could be higher.

Our new investigation finds:

• Over 45000 potentially contaminated land sites in Wales are not being fully inspected
• Only 82 sites in Wales are designated as contaminated
• Just six out of 22 councils provide a full public register online
• 15 councils have an inspection strategy, but only four have updated it in the past five years, and one dates to 2002
• The oldest strategy dated back over two decades, to 2002, while the most recent was updated in 2024, averaging a publication year of 2014.

4 councils that did not have a publicly available register told campaigners that they had identified sites that should appear on one. One council stated on its website that it had not identified any contaminated land yet revealed 18 sites of likely contamination to Friends of the Earth, noting that it lacked the funds to investigate these fully.

This leaves the public with little or no information about the safety of land that could sit beneath homes, schools, parks, and nature areas. Many of these sites are believed to be legacies of Wales’ industrial past, but the risks to human health and wildlife remains unknown.

Kirsty Luff, Friends of the Earth Cymru spokesperson, said:

“We must make sure the land beneath our feet is safe for people and wildlife. It’s shocking that so much land could be contaminated and yet isn’t being properly inspected.

“People in Wales deserve to know whether the places where they live, work, and play are free from pollution. Without proper inspection, these sites remain a mystery – a hidden toxic legacy from our industrial past that could still be harming communities today.

“Councils are legally required to identify and assess contaminated land, but they don’t have the funding, resources, or political support to do the job. That’s why we’re calling for a public inquiry and urgent action from both the Welsh and UK Governments.

“This issue must not be ignored – the longer the delay, the greater the risk to our health, the environment and future generations.”

Friends of the Earth Cymru is calling for a public inquiry into the scale and impact of contaminated land in Wales. We are urging joint action from the Welsh and UK governments to provide councils with the funding and resources to identify, assess, and remediate contaminated sites.