Tom Heap discovers landfill mining: finding value in what's been thrown away. He visits Belgium to meet the first prospectors digging for treasure in trash.

For years rubbish has been thrown away and sent to landfill sites, but now there are moves to look at what's been discarded as a resource.

Metals, plastics, ceramics and minerals are all buried under ground. As waste in landfill decomposes it emits gases. All are rich pickings and valuable to those looking to recycle and reuse the waste we've thrown away as scientists and engineers look to close the circle of waste.

Presenter: Tom Heap