(CBS SF) – What goes down the drain might be more valuable than people think. Scientists with the U.S. Geological Survey are looking at the possibility of recovering gold, along with rare elements from feces and sewage.

USGS scientist Kathleen Smith said metals are in many products, from hair care products to detergents. Those metals often end up in wastewater treatment plants, ending up in solid waste. Half of the waste is used as fertilizer, while the other half is either burned or sent to landfills.

“If you can get rid of some of the nuisance metals that currently limit how much of these biosolids we can use on fields and forests, and at the same time recover valuable metals and other elements, that’s a win-win,” Smith said in a USGS statement.

Using chemicals that pull metals out of rock, Smith and her team found microscopic sized particles of platinum, silver and gold in the waste.

“The gold we found was at the level of a minimal mineral deposit,” Smith said. According to Smith, if that metal were in rock, it might be viable to mine.

Their work echoes another study which found waste from 1 million Americans could contain metals worth $13 million.

The scientists will talk about their work at a meeting of the American Chemical Society in Denver on Thursday.