Sunday - Apr 21, 2019

When the river turned yellow


by David Bacon

In the afternoon of Aug. 6, 2014, the water in the Bacanuchi River turned yellow. At Tahuichopa, where the Bacanuchi flows into the larger Sonora River, Martha Agupira was one of the first to see it.

“We had no warning,” she remembers. “We just saw the river change color-yellow, with a really terrible smell, like copper or chemicals. All the fish died. A bull drinking in the river died right away. Other animals died, too.”

Tahuichopa is a small Mexican town of about 200 people, situated where the foothills of La Elenita mountain begin to flatten out into the high plain of the Sonora Desert, about 60 miles south of the Arizona border. The town’s cornfields line the banks of both rivers. “So people had to go through the river to get to them. The people were contaminated too,” she says.  

From Tahuichopa, the Sonora River flows southwest through wide green valleys separated by narrow canyons. The yellow water arrived next at Banamichi, then Baviacora, and then Ures.  

Two days after Martha Agupira saw the fish die, Luz Apodaca was visiting San Felipe de Jesus, the next town downstream.  Like many valley residents, she liked going along the riverbank to collect watercress. “I went into the water,” she laments. “That day, the river was dark brown, like chocolate. But I didn’t pay much attention because we’re used to going in and bathing there.”

In fact, the river is a big tourist attraction, or it was. Families on weekends would drive up from Hermosillo, Sonora’s capital city of 700,000, which lies farther, between two big reservoirs. Visitors would fill the restaurants in the river towns, or picnic on the sandbars.  

But the river began to smell like ammonia, Apodaca says, and by evening her face began to swell. “Over the next two days, my skin began to break out, and ever since I’ve had sores on my face and arms and legs. My fingernails all fell off. For many days I couldn’t sleep because of the pain in my face, and my knees and bones and nerves all hurt.”

What the two women experienced, along with the other 20,000 inhabitants of the Sonora and Bacanuchi River valleys, was one of the worst toxic spills in the history of mining in Mexico. In her report on the incident, Dr. Reina Castro, a professor at the University of Sonora, said, “A failure in the exit pipe from a holding pond at the mine led to the spill of approximately 40,000 cubic meters of leached material, including acidified copper sulfate.” On August 9, the Mexican agency overseeing water quality, CONAGUA, found elevated levels of heavy metals in the water, including aluminum, arsenic, cadmium, copper, chromium, iron, manganese, nickel, and mercury.

The contamination did more than harm the health of river residents. It undermined the economic survival of their communities, and damaged the ecology of the valleys in ways that could be permanent.  

But the spill also created a political movement of townspeople in response, in alliance with miners involved in one of the longest strikes in Mexico’s history. That alliance is bringing to light the impact that corporate giants on both sides of the U.S.-Mexico border have on the people of this binational region.

The headwaters of both rivers rise in La Elenita, where the Cananea copper mine, one of the world’s largest, has been slowly pulverizing the mountain for more than a century. By the time of the spill, the mine’s workers had been on strike for nearly seven years, since July 2007. Since 2010, the mine has been operated by strikebreakers hired by the mine’s owner, Grupo Mexico, a global mining corporation. Some workers are hired directly by the subsidiary that runs Cananea’s mine operations, Buenavista del Cobre. Others work for contractors.  

In a press statement issued September 1, 2014, three weeks after the spill, Grupo Mexico blamed a contractor for causing it. “We recognize that, among other factors, a relevant cause was a construction defect in the seal of a pipe in the Tinajas 1 system … [which had been] contracted to a specialized company in the region, TECOVIFESA.” Grupo Mexico announced it was sending workers to clean up the river, and later agreed with the Mexican government to set up a fund, or fidecomiso, to compensate residents for damage from the spill.

Hiring contractors to replace the mine’s skilled workforce, however, has been going on for many years, according to the miners’ union, Section 65 of the National Union of Mine, Metal, Steel and Allied Workers. The Cananea mine contains 13 ponds holding millions of gallons of liquid left over from leaching metal from the rock. The work of maintaining them was originally performed by members of the union, before the company contracted it out. The use of contractors is one of the principle reasons for the strike.  

Grupo Mexico today owns mines in Mexico, Peru, and the United States. In the first quarter of 2016, the corporation earned profits of $406 million, on revenue of $1.9 billion. Even with the recent decline in China’s vast appetite for metal and raw materials, the company is still one of the most profitable in mining.

The company was originally the Mexican division of ASARCO, the American Smelting and Refining Company, started by the Guggenheim family in 1899. Until 1965, ASARCO owned many mines in Mexico. Under nationalist development policies, however, ASARCO sold its Mexican subsidiary to Mexican investors, among them Jorge Larrea Ortega, Mexico’s “King of Copper.” Today, his son German Larrea Mota controls Grupo Mexico.

The Cananea mine, Mexico’s largest, originally belonged to a U.S. owner, Colonel William C. Greene. In 1906, miners rebelled against the “Mexican Wage”-an arrangement paying white miners from the United States higher wages than Mexicans. In the violent insurrection that followed, the Arizona Rangers crossed the border into Mexico and put down the strike. The battle is considered the first conflict of the Mexican Revolution.

Cananea afterward belonged to the Anaconda Copper Company until the Mexican government took it over in 1971. During the last years it owned the mine, Anaconda ended the old method of shaft mining, and began open-pit operations. That decision had an enormous impact on the area’s ecology.  

In an open-pit mine, huge chunks of rock are blown out of the mountain, loaded onto giant trucks, and taken to a crusher. There, the ore is ground down into fine particles, and laid out on huge “benches.” The crushed rock is then sprayed with acid that leaches out the metal, which is collected below in ponds. Big electrodes pull the metal from the solution, and the leftover liquid is channeled into those 13 ponds. The 2014 spill originated in one of them.  

Today, benches of tailings tower over miners’ homes in Cananea. Part of the old town now lies buried beneath them. On a hot windy day, dust from pulverized rock blows into doorways, and miners’ families breathe the minerals the wind carries. On Cananea’s outskirts, the giant ponds line the southbound highway, parallel to the Sonora River.

- Due to lack of space, we were not able to run the whole story. We will try to continue it on next week edition.
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