Second mine spill this week in Mexico contains cyanide-laced solution

A Canadian-owned mine in northern Mexico spilled over a half-million gallons of a cyanide solution used in heap-leach gold mining, after heavy rains caused a retaining pond to overflow.

The accident occurred at the Proyecto Magistral mine in the northern state of Durango. The mine is owned by a subsidiary of Toronto, Canada-based McEwen Mining Inc.

The Attorney General for Environmental Protection said Wednesday that the cyanide-laced solution contaminated an area of about a half-kilometer (quarter mile).

The office ordered the company to install membranes in holding ponds and raise the height of containment . . .