Thousands of landfills across the United Kingdom (UK) and Europe sit in floodplains, posing a potential threat to drinking water and conservation areas if toxic waste is released into rivers, soils and ecosystems.
Across the European Union (EU) there are estimated to be up to 500 000 landfills.
Roughly 90% of them, including 22 000 sites in the UK, predate pollution control regulations such as landfill linings to prevent leaching.
Modern landfills which are well managed are likely to pose a low risk.
Modelling indicates the number of flood‑risk sites could be as high as 140 000.
This mapping effort, based on requests for landfill data from 10 countries and supplemented with open-source information, highlights a deeper issue: EU institutions lack centralised landfill records, while data from individual member states remains fragmented, inconsistent and often inaccessible.
