MEXICO CITY—Mexico’s top environmental official says a mining company lied about a spill of millions of litres of acids and heavy metals.
Environment Secretary Juan Jose Guerra Abud says the mine falsely claimed the spill was caused by unusually heavy rain.
Officials say a construction defect at a holding pond allowed mining waste to flow into two rivers and a dam downstream.
Holding ponds hold the overflow of acids used to extract metal from crushed rock.
Guerra Abud says the Buenavista copper mine could face fines of as much as US$3 million for violations of safety and environmental standards.
The mine is owned by the Grupo Mexico consortium.
National water commission head David Korenfeld says acids and pollutants like arsenic have been so diluted they are now within acceptable limits at a dam that supplies water to the capital of the northern state of Sonora.
Last week, a civil defence official claimed the mine didn’t immediately report the acid spill.