A study undertaken by Cranfield University has found there are huge deposits of valuable metals in landfill sites.
Scientists analysed samples from up to 30 metres deep from four different landfill sites.
After removing large objects, the samples were analysed for the content of rare earth metals and other valuable metals.
Around £5 million worth of the rare earth metal neodymium is estimated to be in just the four landfill sites, while £92 million of palladium is expected to be buried in the sampled sites.
The combined value of copper and aluminium in the four landfill sites is estimated to be worth £260 million.
Cranfield University scientists Dr Stuart Wagland and Dr Frédéric Coulon worked on the study.
Stuart Wagland said: “There is clearly potential value in our landfills, considering we only looked at the soil-like materials within the landfill sites.
“It is unlikely that the recovery of rare earth metals and critical metals would be economically viable. However, recover copper and aluminium and it starts to make sense.
“Further resource recovery is possible with the extraction of larger metal items and the reprocessing of plastics, adding even more value to the operation.
“Landfill mining has benefits beyond resource recovery though, as land can be reclaimed and the long-term management issues of the landfill sites are removed.”