MAC: Mines and Communities

Mexican copper mine pollutes local rivers

Published by MAC on 2014-08-13
Source: Associated Press,

Following on from last week's huge tailings spill in Canada (see: Massive tailings pond breach at Mount Polley Mine in Canada), there has been another spill, but this time south of - but close to - the US border.

Mexico Says Mine Slow to Report Huge Acid Spill

By Mark Stevenson

Associated Press

12 August 2014

Mexico City - A civil defense official says a private mine in northern Mexico did not immediately report a massive acid spill, allowing it to flow into a river that supplies water to tens of thousands of people.

Carlos Arias, director of civil defense for the northern state of Sonora, said the spill at a copper mine near the U.S. border was caused by defects in newly constructed leaching or holding ponds.

Such ponds hold the overflow of acids used to leach metal out of crushed rock. But Arias said a pipe either blew out or became unseated on Aug. 7, allowing about 10 million gallons (40,000 cubic meters) of mining acids to flow downstream into a river.

"Definitely ... it was an error" in the design or construction of the retaining pond, Arias said.

He said the sulfuric acid spill was detected by residents downstream the next day, and that the mine operators hadn't notified state authorities.

Arias said tests have revealed the spill contains pollutants like arsenic above acceptable levels. Water supplies from the river have been cut off to about 20,000 people.

The Grupo Mexico company operates the Buenavista mine in Cananea, Sonora. The company did not respond to requests for comment on Tuesday.

Arturo Rodriguez, the head of industrial inspection for the Attorney General for Environmental Protection, said the mine did advise his agency almost a day after the spill, just within the 24-hour time limit for filing such reports.

He said lax supervision at the mine, along with rains and construction defects, appeared to have caused the spill. Rodriguez said mine operators should have been able to detect the leak before such a large quantity leaked into the river.

Authorities are trying to de-acidify the water in the Bacanuchi and Sonora rivers by adding calcium, Arias said. "What you can't get rid of are the heavy metals," he noted.

Mine spill forces federal officials to restrict water supply to towns along 2 rivers

Associated Press

10 August 2014

MEXICO CITY - A spill of mining wastewater in northern Mexico is forcing Mexican officials to restrict water supply to cities and towns in the country's north, including the Sonora state capital of Hermosillo.

The National Water Commission says about 40,000 cubic meters (10 million gallons) of water leached during copper mining has entered the Bacanuchi River, which feeds the Sonora River. The state's civil defense office issued a statement on its Facebook page denying rumors that the contamination from the mine in Cananea includes cyanide.

Sunday's statement by the water agency says towns affected include Arizpe, Banamichi, San Felipe de Jesus, Aconchi, Baviacora and Ures, as well as Hermosillo. However, it says the capital receives only 3 percent of its water from the river.

Mexico copper mine spill pollutes water supplies 40 km from U.S. border

Cecilia Jamasmie

12 August 2014

Close to 40,000 cubic meters of wastewater from a copper mine in northern Mexico have spilled into rivers, forcing authorities to restrict water supply to urban areas, including Sonora state's capital of Hermosillo, which has a population of about 800,000 people.

The toxic leak, reports El Proceso, came from Grupo Mexico's Buenavista copper mine, located only about 40 km from the U.S. border, and contaminated the Bacanuchi River, a tributary of the Sonora River.

The spill affected seven different municipalities, turning the 420-kilometer-long waterway orange, affecting hundreds of thousands of people.

The country's National Water Commission (PROFEPA) said it was monitoring chemicals water quality at multiple points along the Sonora river and has ordered the company to stop any further environmental damage.

"In addition to ordering the implementation of a total remediation plan, PROFEPA initiated proceedings against Buenavista del Cobre to determine possible sanctions," the agency said.

Top mining state

Sonora is home to more than a quarter of Mexico's mining industry and leads in gold, copper and graphite production.

Mexico's federal government recently opened up the country's vital energy sectors such as electricity generation and oil production to private companies.

In 2009 an American subsidiary of Grupo Mexico, Asarco, paid the U.S. government a record $1.79 billion to settle hazardous waste pollution in 19 states.

Mexico minister says Grupo Mexico account of toxic spill 'totally false'


20 August 2014

MEXICO CITY - Mexico's environment secretary said on Tuesday that Grupo Mexico gave false information about a toxic spill at its Buenavista mine in northern Mexico, a day after the environmental authority said it would file a criminal complaint against the company.

In a statement on Aug. 12, Grupo Mexico said that "unusual rainfall" had caused the spill.

But Environment Secretary Juan Jose Guerra told local radio on Tuesday that this was "totally false" and that there was zero precipitation on Aug. 6, the day the spill was detected.

"They unfortunately did not have dams. They hadn't put infrastructure there to contain leached (fluids) in case of a spill," he said.

Grupo Mexico did not immediately respond to a request for comment on Tuesday regarding the criminal complaint or the minister's comments.

Mexico's President Enrique Pena Nieto said that the damage done by the spill to the surrounding population and environment was high.

"I assume that here, small sanctions will not do," he said in a Tuesday night television interview than ran into early Wednesday.

The federal attorney general's office for environmental protection (Profepa) said in a statement on Monday night it would bring charges against Buena Vista del Cobre, the Grupo Mexico subsidiary that operates the copper mine.

Profepa said the spill pumped 40,000 cubic meters of toxic mining acid into the Bacanuchi river in northern Sonora state.

The agency said the fine for the spill could reach up to 40 million Mexican pesos, or about $3 million.

Grupo Mexico shares fell by as much as 2.5 percent on Tuesday, before recovering to close down 0.63 percent at 46.83 pesos.

Earlier in the day, traders attributed the share price drop to the charges being announced.

"Everyone knew about the spill, but now we know about the size of the fine," said Gerardo Roman, head of stock trading at Actinver brokerage in Mexico City. "It's not so much the economic impact, it's that people don't look kindly on them contaminating."

(Reporting by Tomas Sarmiento, Christine Murray, Gabriel Stargardter and Noe Torres; Editing by Diane Craft and Simon Gardner)


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