There's Gold In Them Thar Sewage Plants

A sewage treatment plant in Japan has turned out to be a gold mine — literally. Officials say they've retrieved nearly 2 kilograms of gold per metric ton of ash from the sludge they incinerate. That's almost 50 times what miners find in Japan's Hishikari Mine — one of the world's top gold mines. Plant officials believe they're getting so much gold because of manufacturers in the area that use the precious metal in making precision instruments.

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