A 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. Originally, a spokeswoman for the Toronto-based McEwen Mining Inc said the company owned the mine, but later said that it owns a mine with a similar name in another state.
The Attorney General for Environmental Protection said yesterday that the cyanide-laced solution contaminated an area about a half-kilometer square.
The office ordered the company to install membranes in holding ponds and raise the height of containment dams.
It was the second mine spill in as many weeks in Mexico. Earlier this month, a mine in Sonora state spilled 40,000 cubic meters of mining acids into a river.