Roughly 10,800 tons of toxic material from the “Two Gentlemen” mine in the northern Mexican state of Sinaloa leaked into the Chupaderos stream, which flows into the Baluarte River in the town of Concordia, local authorities reported Friday.
State and federal authorities have taken emergency measures to prevent wastes pollutants from contaminating ground water and affecting inhabitants of the region.
According to officials a retention dam was breached at the mine which primarily extracts gold and silver.
The Federal Attorney for Environmental Protection (Profepa), said the discharge of the the toxic materials occurred Thursday morning due to a “collapse” at the mine’s dam, however the agency was not notified until three hours later. The composition of the toxic materials has yet to be disclosed.
In a statement, the agency explained that the chemical material has thus far covered a distance of 900 meters down the slope of the outside of the dam, which is located just north of the Sinaloan capital Culiacan, some 900 miles north of Mexico City.
Profepa also noted that it will open an administrative proceeding so as to plan for eventual remediation of the site which will be authorized by the Ministry of the Environment and Natural Resources (Semarnat).
On August 8, 40 thousand cubic meters of sulfuric acid spilled from the Cananea mine in Sonora, Mexico, polluting the Bacanuchi and Sonora rivers and affecting the water supply of more than 22,000 people. SEMARNAT’s director, Juan Jose Guerra Abud, called the spill the country’s “worst industrial mining disaster”.
That spill caused public outrage and protest, with organizations and politicians calling for hard sanctions and costs be paid by mining giant Grupo Mexico.
In that spill organization such as Greenpeace warned that remediation will not fully clean up the spill and heavy metals will remain, causing prolonged and possibly permanent environmental damage and serious health risks to neighboring populations.