In British Columbia in 2014 a tailings holding dam on a tributary of the Fraser River collapsed.  This was the "worst case" scenario; however, have the salmon runs on the Fraser River been impacted?   Is the EPA and our state DEC studying this even to glean information that  be applicable to the Pebble situation? 

Link: http://www.fishermensnews.com/story/2014/09/01/features/tailings-dam-failure-hits-fraser-river-watershed-salmon-spawning-regions/275.html
 
Link: https://en.wikipedia.org/wiki/Mount_Polley_mine_disaster