Inadequate record keeping means councils do not know whether former waste sites contain toxic substances

More than 100 old landfills in England that may be contaminated with toxic substances have flooded since 2000, potentially posing a serious safety risk, it can be revealed.

Some of these former dumps containing possibly hazardous materials sit directly next to public parks and housing estates with hundreds of households, the analysis by the Greenpeace-funded journalism website Unearthed , in partnership with the Guardian, found.