There's Gold In Them Sewers

[Morlock 1,724]

 I wonder how many pounds of other heavy metals make it into the sewers. 

http://nypost.com/2017/10/11/1-8-million-in-gold-discovered-in-swiss-sewage-sludge

Here's another article about some guy supposedly making a living mining the sidewalks and gutters in the New York Diamond district.

http://nypost.com/2011/06/20/got-his-mined-in-the-gutter/

I doubt if you could make a good living off this given the cities high cost of living but would make a nice hobby. You got to admire his prospecting skills.

Edited October 11, 2017 by Morlock