Grupo México and its copper mine in Cananea, Sonora, are under fire again, this time for hoarding water to feed the mine’s expansion.

And while the mining company corrals more sources of water, the Sonora River has become a toxic basin due to a mining process that uses the river as drainage for its wastes, say critics.

On August 6 of last year, a devastating toxic spill from the Buenavista del Cobre mine discharged 40,000 cubic meters of copper sulphate solution into the river systems, directly affecting 25,000 inhabitants of neighboring municipalities along the Sonora and Bacanuchi rivers.

In the past five years, Grupo México has created a monopoly on water in the region. On top of that, some 200 dams and dikes have been constructed on ranches in the area, affecting the natural flow of the river.

The annual deficit of the Sonora River is said to be 300 million cubic metres of water — enough to supply all the inhabitants of the state capital of Hermosillo for three years — as more water is extracted by the mine than that which is recovered with rain.

According to the Public Registry of Water Rights (REPDA), Buenavista de Cobre holds 14 concession agreements to its name, containing 93 wells that extract over 44 million cubic meters annually.

The company has taken at least 30 more wells previously used for agricultural, livestock and other purposes from the communal land used for agriculture in the area of Emiliano Zapata, Ignacio Zaragoza, 16 de Septiembre and Vicente Guerrero.

Information on the website of the national water commission, Conagua, states that none of the certificates issued to the company between January 1997 and September 2013 includes a drainage permit, which means it cannot legally discharge wastewater.

Humberto Robles Hoyos, owner of Rancho San José del Carrizo in Cananea, says Grupo México bought the water rights in most of the seven ejidos, or communal agriculture lands, in the municipality.

But owners who do not agree to sell are left without the resource anyway because the mining company drills down far enough that neighbors’ wells dry up.

“If you are a small owner and have a well of whatever depth, they drill deeper and of course the water level is reduced and obviously you are left without water,” the civil engineer explained.

One academic suggested that while the mine’s acquisition of wells might be legal, it is not necessarily just. While the people who live along the rivers have limits on their water consumption, the mine is free to squander the resource, said Alfonso Gardea Béjar of the Food and Development Research Center (CIAD), an arm of the National Science and Technology Council, Conacyt.

CIAD researchers have estimated that at least 10% of the wells are unregulated or exceed allowed levels of consumption. The agency estimates that one-third of the Sonora River’s deficit is caused by overuse resulting from the lack of control and monitoring.

Attempts to determine from Conagua how many wells Grupo México has and the volume of water extracted were unsuccessful. The area director claimed “election silence,” the law that prohibits government and its agencies from offering information that might be deemed political during the lead-up to elections.

Meanwhile contamination of water near the mine is also an issue, according to tests.

Recent samples taken from water on the Ojo de Agua ranch, located near the copper mine, revealed high concentrations of copper, cadmium, lead and heavy metals, which can have adverse short and long-term health effects.

The samples indicated that copper levels were 10.63 milligrams per liter, well above the maximum allowable limit of two.

Source: Excélsior (sp)