Mining gold from sewage

18 November 2015

Gold bars in a row

University study uncovers a goldmine in Britain’s sewer systems

Research undertaken by the University has unveiled a “consistently high” amount of gold in the UK’s sewers.

A team led by Dr Hazel Prichard, from the School of Earth and Ocean Sciences, has been working with Thames Water to analyse the leftover solids, or sludge, from wastewater treatment plants.

The researchers estimate that incinerated sewage ash is made up of at least one part per million of gold, and could be as high as seven parts per million, which is well within the range of an economically feasible goldmine.

The team estimate that the UK gold could potentially be worth £13.6 million a year.

Speaking to The Times about the research project, Dr Prichard said she was “stunned” with the amount of gold they found in the incinerators that are used to burn off sludge. “They were all consistently high in gold,” she said.

The source of the gold is unknown but has been found on pavements and in front of schools where people walk wearing jewellery. From there it is washed down drains and either into rivers and out to sea, or into sewage works.  A simple task such a washing up could rub off bits of gold from jewellery, which could eventually end up down the sink and into the drains.

The research project is currently in its early stages, and Dr Prichard and her team from the University are now looking at ways to efficiently remove the gold from the sludge on a large scale.

The mining and crushing of rocks are two of the biggest costs associated with gold mining, so obtaining the precious metal from incinerated sewage ash could be a much cheaper, and more environmentally friendly, alternative.