"The McLaughlin Mine enjoyed a reputation as one of the most ecologically sensitive gold mining operations in the world. Nevertheless, during its last year of operation in 2002, the mine emitted 32,396 pounds of mercury into the environment."

Wow that's really saying something.

Eh. Moving rock that contains low concentrations of mercury into a pile is considered "releasing" it.

Whether it carries any risk to the environment depends on local factors.

It did say that it was methylated and made bioavailable. Not great I think.

That's from the old mercury mines in the area and erosion from naturally enriched mercury soil/runoff from naturally enriched geothermal springs, not the McLaughlin gold mine.

(The Wikipedia article is for the Sulfur Bank Mercury Mine. The McLaughlin mine is referenced due to how gold was discovered, but it's about 15 miles away)