Swiss sewage carries 43 kilograms of gold a year
Researchers at the Swiss water institute Eawag looked at 64 wastewater plants. They found about 43 kg of gold and 3,000 kg of silver passing through every year, each worth around 1.5 million Swiss francs. Some sludge in Ticino held enough gold that recovery might pay off. Overall, they said it was scarcely worthwhile.
Source: Eawag ↗