British researcher strikes gold (and other precious metals) in Thames sewer system
New research from the Thames Water system in Great Britain found significant amounts of gold and precious metals in its sewage. So much, in fact, that utilities are exploring ways to mine their sewage.
Hazel Prichard, a geologist from Cardiff University, did the research for Thames Water. Here is an excerpt from her conversation with As it Happens host Carol Off.
Carol Off: Ms. Pritchard, how in the world does gold end up in people's sewage?
Hazel Pritchard: Well, gold is worn on rings and jewelry by millions of people. And as they walk around on city pavements, little bits flake off, and fall in the dust, and then they get washed down the drain and end up in the sewage. The minerals of gold that we found in the sewage are only a few microns across. So I think that's most of the source of the gold. I guess a ring might get there occasionally.
CO: You're talking about microscopic bits of gold then?
HP: Well, in the incinerated sewage ash that we've looked at, we get one or two parts per million, consistently, in all the ashes we've seen in nine incinerators in the U.K. It's very consistent. Of all the samples we've looked at we've never found an ash that doesn't have any. And that's a lot, because gold is rare and precious. A little bit, a few parts a million is really quite a lot.
CO: How does it compare with, say, mining or panning for gold?
HP: Well if I found two parts a million in a rock I'd be very pleased. And some gold mines do have those sorts of values consistently as an average, so it's similar.
CO: What has been the reaction since you have told people how much gold is in your sewage?
HP: One of the things I hear is "isn't it smelly?" Well, not incinerated ash 'cause you've got rid of all the smells, and you've got a nice, fine powder with gold grains in it.
CO: Is there enough gold there to make it worth anyone's while, or the state's while, to try and mine for gold in your poo?
HP: Well, we hope so. Certainly in Japan they do it already. They've got higher values, because I think they're in an industrial area, so they've got jewelry contribution and some industrial waste, so they already do it. I don't see why the people of Canada with their gold jewelry aren't doing exactly what the people of the UK are doing.
To hear Carol's entire interview with Hazel Pritchard, click on the Listen button above.