Another Toxic Spill Alert in Sonora, Northern Mexico

HERMOSILLO, Sonora – Authorities in northern Mexico have issued a new alert of a toxic spill in the Sonora River basin from a copper mine operated by Grupo México, the state director of civil protection said Sunday.

The agency is urging some 25,000 residents of the area to avoid using the water after local municipalities complained of a toxic plume, said Carlos Arias, civil protection director for the border state of Sonora, where the spill occurred.

Arias said the tributaries affected drain into the Bacanuchi River.

A flyover of the area shows an abnormal orange stain, he added. He said his department is taking measures to ensure people or livestock don’t come in contact with the water until it can be tested.


A storm water overflow after excessive rains from Hurricane Odile caused toxic water from the Buenavista copper mine to leach into some creeks and streams, the company said in a statement Sunday. It said it contained the spill with pumps and suction. It didn’t identify the leaked substance.

Grupo México operates the $1 billion-a year Buenavista mine in Cananea, Sonora, producing 200,000 tons of copper.

Mexico’s top environmental official accused the mining company last month of lying about an early August spill of millions of gallons of acids and heavy metals that contaminated two rivers and a dam downstream.

Bacanuchi River, Sonora

Officials have said the company also lied about the measures it took to control the effects. The company blamed heavy rains for the overflow of containment ponds, but officials have said lax supervision at the mine and construction defects appeared to have caused the accident.

The spill sent about 10 million gallons (40,000 cubic meters) of copper sulfate and heavy metals into the rivers and on to a reservoir behind a dam that supplies water to the capital of Sonora.

Grupo México will set up a roughly $151 million trust to pay for damage caused by the earlier spill.


One month ago The Yucatan Times published the following article regarding a toxic spill in the Bacanuchi River: