Industry, enviros spar over proposed N.M. copper-mining water rule

Posted: Apr 15, 2013

Written by

April Reese, Greenwire
Chino mine

A state regulatory panel yesterday began evaluating a proposed rule that would change how copper miners manage groundwater.

The New Mexico Environment Department proposal would let companies contaminate groundwater directly under copper mining sites but require them to pump out and treat contaminated water downslope.

The rule would also allow companies to construct waste rock and tailing impoundments without synthetic liners that would protect groundwater from "acid rock drainage" -- contamination by acidic solutions released when mineral sulfides are oxidized in tailings and waste rock piles.

Industry representatives and environmentalists argued over the proposal yesterday in front of the New Mexico Water Quality Control Commission.

Industry members maintain that the rule would provide clarity and consistency on groundwater requirements. It's in line, they say, with the intent of a 2009 law passed by the Legislature and signed by then-Gov. Bill Richardson (D) that says regulations should protect groundwater while ensuring a viable copper mining industry. Copper mining contributes $326 million to the state's economy and supports 4,328 jobs a year, the New Mexico Mining Association says.

But environmentalists and the state's attorney general argued the proposal threatens groundwater resources, which provides 90 percent of the state's drinking water.

"Water resources are not sufficient to meet current demands, let alone for future growth," said Tannis Fox, who represented state Attorney General Gary King (D). "Every municipality and industrial sector in the state is looking for new supplies to meet current and future needs."

Fox said the rule violates the New Mexico Water Quality Act, which requires companies to protect groundwater during mining operations.

"The Environment Department proposes a rule that violates the [state] Water Quality Act, is inconsistent with your regulations ... and is inconsistent with over 35 years of NMED water quality act implementation," Fox told the commission.

The commission rejected Fox's request that the hearing be ended and the rule returned to the department for revisions.

Attorney General King has accused the Environment Department of making late changes to the rule that weakened groundwater protections.

The proposed rule -- drafted under a reconfigured department that includes new appointees by Gov. Susana Martinez (R), who took office in 2010 -- underwent an eight-month vetting process that included input from industry, environmental groups, technical experts and others.

The revised proposal that emerged last October was significantly different than the discussion draft floated last August.

Bruce Fredrick, an attorney with the New Mexico Environmental Law Center, said the rule is unnecessary, because companies are already allowed to receive variances to groundwater protection requirements under certain circumstances.

"We understand that some water pollution may be unavoidable at some copper mines, given today's technology, but that does not mean we should accept pollution at all copper mines," he told the commission..

The state is already dealing with massive groundwater contamination from previous copper mining operations, said hydrologist William Olson, former chief of the Environment Department's Ground Water Quality Bureau and a former member of the commission.

"Copper mining has resulted in extensive pollution of New Mexico's groundwater" that will need to be monitored for 100 years, Olson said, testifying as a private citizen.

Some groundwater under copper mine sites in New Mexico contains sulfate, nickel, cobalt and copper at 10 times over legal limits. Levels of aluminum, cadmium, manganese, iron and zinc are as much as 1,000 times higher at some sites, according to the state attorney general.

"I stress, the purpose of the rules under the Water Quality Act is to prevent pollution," Olson said. "Portions of the rule, however, specifically allow new groundwater pollution to occur."

Industry defends proposal

But Dan Moellenberg, an attorney for Freeport McMoRan Copper & Gold Inc., said the rule would sufficiently protect groundwater.

"The rules propose a detailed set of requirements to prevent groundwater pollution and how monitoring must be done," he said. For example, monitoring wells will be placed "as close as practicable" to waste rock piles and other potential pollution sources, he said.

The proposal would force mining companies to keep polluted water at mine sites, said Andrew Knight, an attorney with the state Environment Department.

"That doesn't sound like a license to pollute to me," he said.

Copper is mined through a leaching process in which weak acids dissolve the metal from rocks. Copper is then reaggregated and molded into sheets that can be turned into wiring and other products.

Olson warned the panel that approving the rule could set a precedent for other entities that have to secure groundwater permits.

"Uranium mines, molybdenum mines, power plants, wastewater treatment plants, geothermal plants, Los Alamos National Laboratory, the Waste Isolation Pilot Plant -- they could all could argue that they should also be allowed to cause pollution as long as it's contained by a groundwater pumping system," he said.

Southwestern New Mexico is home to several copper mines. One of the largest, the Chino mine near Silver City, resumed operations in 2011.

Freeport McMoRan, which inherited several mines in the Silver City area from former owner Phelps-Dodge, is currently pumping and treating contaminated groundwater from beneath the Tyrone, Chino and Cobre mines under a 2011 settlement with the state.

When the mines were opened, Phelps-Dodge assured regulators that the area's geology would provide a natural barrier to keep acid drainage out of groundwater.

The commission is expected to issue a decision on the rule this summer.

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