Mercury contamination to last 10,000 years in SF

The researchers also predict that the mining sediments will continue to release mercury into waterways over at least the next 10,000 years. Furthermore, as climate change intensifies the area’s rainstorms, then the flood-driven discharges could become even more frequent.
The analysis was undertaken at the University of St. Andrews in Scotland. The findings have been published in the journal Proceedings of the National Academy of Sciences. The paper is titled "Enduring legacy of a toxic fan via episodic redistribution of California gold mining debris."
http://www.digitaljournal.com/article/361381