Read the full story from NPR.
In Ticino, Switzerland, the streets aren’t paved with gold. But the sewage pipes are packed with it.
And across the country as a whole, some $3 million worth of gold and silver is thrown out in wastewater every year.
That is according to Swiss researchers who evaluated 64 municipal wastewater treatment plants across the country. Scientists have long known that small amounts of the valuable metals can wind up mixed in with sewage. In Switzerland, the researchers found, the small quantities add up — to more than 6,600 pounds of silver and nearly 100 pounds of gold, the researchers estimate.
In most cases, it would be so expensive to extract and recycle that it wouldn’t make economic sense — recovery would be “scarcely worthwhile,” as the researchers put it.