Some time ago a group of us visited the Lady Vera gold mine in a gully north of Noojee in the Victorian Highlands. A couple of us had gold pans, so we decided to see what we could find in the creek adjacent to an old stamp mill.
We didn't find any gold, but we found lots of mercury. That mine was probably well over 100 years old, but the mercury which had been used to recover the gold was still there in abundance, slowly being dissolved into the water.
All of the old gold mines used mercury as do most of the small ones in developing countries. Modern large scale mines use quite dilute Sodium Cyanide solution, which ultimately decomposes into Sodium Carbonate so contamination problems are minimal.
I suspect that most of the world's old gold mining areas will have this problem for centuries to come and there is very little that can be done about it.

Geoff of Perth note emphasis of the topic.It is the toll on wildlife and not a toll on all life.These envio nazis are anti-human and like our Maurice Strong would like to see the world's pop reduced by 90%.

Will they put their hands up to go first? We've been aware of Mercury poision for a long time and the Environ-Nazis have concentrated on the lie of CO2 causing AGW.The lie has been revealed and even the IPCC is now admitting that it got it wrong.

"Just google UN Agenda 21 and you will see that our billionaires are using the environmental movement as a tool to totally enslave us"

Carefull Arjay, you will be labelled a conspiracy nut.... I guess it will dawn on them at some time.