Authorities in northern Mexico have issued a new alert of a river spill from a copper mine operated by Grupo Mexico, the state director of civil protection said Sunday.

The Associated Press reported that the agency is urging people to avoid using water from the Sonora River after local municipalities complained of a toxic plume, said Carlos Arias, civil protection director for the border state of Sonora, where the spill occurred.

Groupo Mexico said 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 it contained the spill with pumps and suction. It didn’t identify the leaked substance.
Grupo Mexico 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 Aug. 7 spill of millions of gallons of acids and heavy metals that contaminated two rivers and a dam downstream.

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,

The spill sent about 10 million gallons 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 Mexico will set up a roughly $151 million trust to pay for damage caused by the earlier spill.

The company still faces fines.