A sewage plant in Japan’s Nagano prefecture has started mining gold from sludge, earning a cool 5 million yen ($56,000) in its first month of operation.
On January 28, sewage plant operator Nagano Prefecture Suwa Construction Office announced that approximately 1.9 kilograms (4.2 lbs) of gold can be mined from each ton of molten fly ash generated when incinerating sludge at its facility in the town of Suwa.