Toxic landfill liquid mixed with sewage and spread on farmland

More than 750,000 tonnes of liquid from landfills are mixed with sewage at water treatment works and spread on farmland across England each year, it can be revealed.

- Rachel Salvidge

Generated by hundreds of landfills across the country, leachate—the liquid that drains through landfill waste carrying a cocktail of chemicals—is regularly taken by tankers to sewage treatment works, where it mixes with domestic sewage and industrial effluent to create sludge, or "biosolids".

The process produces treated liquid, discharged into rivers and seas, and solid sludge, sold by the water companies to farmers as fertiliser. But many toxic chemicals escape treatment, ending up in waterways or accumulating on fields. All of England's rivers fail to meet legal standards for chemical pollution.

Analysis by the Guardian and Watershed Investigations shows about 3.5m tonnes of leachate are generated each year, with more than 750,000 tonnes sent to sewage works unable to deal with chemicals found in leachate such as PFAS "forever chemicals", some of which are carcinogenic, as well as PCBs, dioxins, flame retardants, solvents, endocrine disruptors, microplastics and other hazardous chemicals.