Mexico’s Environment Ministry (Semarnat) has filed a criminal complaint against mining consortium Grupo México for a devastating 2014 spill of hazardous waste into the Sonora River, Semarnat confirmed on Thursday.
In a statement, Semarnat reiterated that the spill of 40,000 cubic meters of an acidic copper sulfate solution into a tributary of the Sonora River on Aug. 6, 2014, was directly caused by Grupo México’s poorly-designed dam system.
“It was not an accident, it was negligence,” Environment Minister María Luisa Albores said at a press conference.
Semarnat filed a criminal complaint on Aug. 17 this year against three companies of Grupo México — Mexicana de Cananea, Buenavista del Cobre and Operadora de Minas e Instalaciones Mineras — for failing to address the environmental and health damage caused by the spill.
An estimated 22,000 people in at least eight municipalities were affected, making it the worst environmental disaster in Mexican mining history.
Albores explained that Grupo México had agreed following the spill to contribute at least 2 billion pesos (US $110 million) to environmental remediation via the Sonora River Trust. However, only half of these funds were ever delivered, and multiple irregularities were found in their distribution, including nine water treatment plants that closed after one month due to lack of resources, and another that closed after two years. Since 2020, Grupo México has ignored court orders to reactivate the fund.
In a report published earlier this month, Semarnat concluded that the remediation paid by the company “in no way covered the [spill’s] direct, indirect and cumulative effects on the population, ecosystems and economy.”
Many of these effects are ongoing, including above-recommended levels of mercury in the air, heavy metals in the water and acidity in the soil.
Grupo México responded with a statement dismissing the report’s findings and insisting that “the remediation of the Sonora River was successful.”
At Thursday’s press conference, Albores said that the company has been ordered to present a new remediation program, which must be approved by the affected communities and authorized by Semarnat.
The affected communities, represented by the Sonora River Basin Committees (CCRS), have put forward their own list of demands. These include 36 operational water treatment plants, in line with Grupo México’s original commitment; a poison center to monitor and treat the effects of heavy metals exposure; and guarantees for the health of local children.
The CCRS also call for urgent attention to issues found in Grupo México’s new tailings dam, which they say represents a latent risk, and an early warning system to alert communities of hazards related to mining companies in the region.
