Judge reopens investigation against Grupo Mexico's subsidiary for toxic spill

Aerial view of the 2014 spill at the Buenavista del Cobre mine. (Image by @Noti_SONORA, Twitter).

A federal judge ordered Mexico's General Prosecutor to reopen a criminal investigation against Buenavista del Cobre, a subsidiary of mining giant Grupo Mexico (BMV:GMEXICOB), responsible for the 2014 spill of close to 40,000 cubic meters of wastewater into the Bacanuchi River, a tributary of the Sonora River located in the northwestern state of the same name.

According to court documents accessed by Reforma newspaper, Judge Jes??s Alberto Ch??vez Hern??ndez's appeal nullifies a couple of decisions made by the Prosecutor's office back in 2017 and in 2018, which called for the investigations to cease and be archived.

Buenavista is located about 40 kilometres from the U.S. border and it is undergoing an expansion process that will turn it into the third-largest copper mine in the world

Ch??vez Hern??ndez's move follows a challenge against those decisions introduced by a number of Sonora residents and by the Mining, Metallurgical, Siderurgical and Similar Workers Union, known as Los Mineros. Both groups claim they are victims of the spill.

Also, in early December, Mexico's Federal Attorney for Environmental Protection accused Grupo M?(C)xico of not fulfilling a number of commitments related to clean-up, restoration and reparation after the spill, an allegation that the company denies.

Following the spill, Grupo M?(C)xico created a $106 million fund to cover the damages caused by the toxic leak that started at the Buenavista copper mine, reached waterways along a 420-kilometre stretch, affected seven municipalities and left 22,000 people without drinking and irrigation water.

The total estimated cost for the environmental damage, however, was estimated by the Federal Attorney for Environmental Protection (Profepa) in more than $133.7 million.