Thousands of older landfills across the UK and Europe sit in flood-prone areas, raising growing concerns that climate-driven storms and rising water levels could release harmful chemicals into rivers, groundwater and ecosystems. Many of these sites predate modern pollution controls, increasing the likelihood that toxins — including heavy metals and “forever chemicals” such as PFAS — could leach into the environment.
A large-scale mapping effort has identified more than 61,000 landfill sites, with nearly 30% located in zones vulnerable to flooding. Experts warn the real number of high-risk sites could be far higher due to incomplete and inconsistent landfill records across EU member states. Many mapped landfills are in areas where groundwater already fails chemical quality standards, suggesting long-term contamination may already be occurring.
Researchers have documented toxic leakage at several historic sites. Tests in the UK found PFAS levels far above drinking-water limits, while investigations in Greece revealed PFAS, mercury and cadmium entering local rivers. Thousands of landfills also lie within drinking-water protection zones, underscoring the potential threat to public health.
Coastal erosion presents an additional danger, with more than 250 landfills across Europe located close to shorelines. Early studies show pollutants such as arsenic and lead being released as sites erode. Experts stress the urgent need for systematic identification, risk assessment and funding to address the most hazardous landfills before climate-related flooding exposes more toxic waste.