The remediation costs for damage to land and water caused by a copper sulfate spill from a mine in Mexico's Sonora State last August is expected to exceed $1.48 billion USD, according to an official estimate from Mexico's Ministry of Environment and Natural Resource (SEMARNAT), through the National Institute of Ecology and Climate Change (INECC).
The ministry said the economic effects of the water contamination and the cost of the immediate response plan, the monitoring system and the actions of the National Water Commission totaled over $230 million USD.
Remediation work on non-federal lands that are potentially contaminated could reach $1.25 billion USD, since pollutants "could filter into aquifers, causing pollution of bodies of water in federal jurisdictions," it said.
The $1.48 billion USD estimate does not include damage to health among those affected by the spill; those costs estimates will be made by the Federal Commission for Protection Against Sanitary Risk (COFEPRIS).
The Ministry of Agriculture, Livestock, Rural Development, Fisheries and Food (SAGARPA) will also measure the damages to economic activity in the area.
On August 6th, some 40,000 cubic meters of sulfuric acid from the Buenavista del Cobre mine spilled into the Sonora River. The spilled contaminants contained heavy metals including cadmium, lead, arsenic, and aluminum. They affected a surface area of 24,400 hectares, according to SEMARNAT.
The ministry noted that some of the impacts of the spill will only be detectable in the medium or long term, so continued monitoring is particularly important.
Grupo Mexico, the mine’s owner, has promised to pay $148 million USD to help those affected by the spill.
Secretary of Environment and Natural Resources Juan José Guerra Abud said his ministry would not initiate legal proceedings against Grupo Mexico under the country's Environmental Responsibility law, saying the legislation "lacks teeth" and can only impose a $3.2 million USD fine.
Any payments will be made through a trust instead, he said.