The streets of Ticino, Switzerland are not paved in gold, but the city’s sewage pipes are packed with it.
Across Switzerland in general, gold and silver worth more than $3 million is thrown out each year in wastewater.
Those statistics were released by Swiss researchers after they evaluated over 64 wastewater treatment plants in different municipalities. Scientists have known for a long time that small quantities of metals with high value can end up being mixed in with sewage.
Over 6,600 pounds of silver as well as close to 100 pounds of gold are estimated to be in the Switzerland wastewater.
In the majority of cases, it is too expensive to extract then recycle that it makes little sense economically to recover the valuable metals.
However, concentration of the metals was varied across Switzerland. In Ticino, where many gold refineries are based, there are higher amounts of gold that run through the treatment plants.
One scientists involved with the research said that in some sites, the gold concentration in sewage is sufficiently high to be recovered and possibly worthwhile economically.
Switzerland is considered a major hub for gold refining, with close to 70% of the gold in the world, passing through refineries in Switzerland annually.
As well as precious metals, researchers looked at the concentration of other elements which are useful in luminous paints and electronics.
The scientists evaluated any possible environmental hazards, and found that in the overwhelming majority of cases, there was not any known environmental risk from the high concentrations of metals.
This news of valuable metals being mixed with human waste is nothing new, but this study that the Swiss government commissioned and was conducted by Eawag a water research institute, was called by Eawag, the quantitative, systematic assessment throughout the whole of an industrialized country.
Work of a similar nature has been completed by U.S. Geological Survey. The USGS explored ways of removing the possible dangerous metals from sewage that is treated and used in fertilizer and pursued a possibility of extracting the valuable metals in sewage as a possible profitable resource.
During 2015, researchers from the U.S. evaluated sewage form more than 1 million people and were able to find $13 million in valuable metals in the sludge.
At the same time, the news that untapped wealth is in sewage across Switzerland may cause an increase in the sales of mining products.