San Manuel area may get new underground mine

Could cause less dispute than open pit for copper
2013-02-23T00:00:00Z 2014-07-15T17:49:38Z San Manuel area may get new underground mineTony Davis Arizona Daily Star Arizona Daily Star
February 23, 2013 12:00 am  • 

Another new, major Southern Arizona copper mine is in the planning stages near San Manuel, where copper was mined for many decades.

Redhawk Resources Inc. is conducting an economic study for Copper Creek, an underground mine in the Galiuro Mountains foothills that would extract about 154 million pounds of copper annually.

The company has spent "several tens of millions" of dollars in recent years on the project and hopes to seek permits to mine the area in a couple of years, said Joe Sandberg, Redhawk's president and CEO.

The new mine will employ between 100 and 400 people, depending on the size of the mine, which hasn't been determined, Sandberg said.

The Canadian company has acquired federal mining claims and state prospecting permits and bought land outright for a total of 35 square miles, including three square miles it owns.

The site lies in Pinal County, about 75 miles northeast of Tucson, 15 miles northeast of San Manuel and about eight miles northeast of the lower San Pedro River. The now-closed San Manuel mine run by Magma Copper Co. and BHP lay west of the river.

But while an underground mine may bring the company less controversy than the open pit mine planned by Rosemont Copper in the Santa Rita Mountains southeast of Tucson, this project could still face opposition from environmentalists concerned that its groundwater pumping could dry up the San Pedro.

Based in Vancouver, B.C.

Redhawk, like Rosemont Copper's parent, Augusta Resource Corp., is based in Vancouver, B.C.

Copper Creek would produce a little less than two-thirds as much copper annually as Rosemont's projected 243 million pounds. Redhawk hopes to finish its economic analysis by the end of March or in the second quarter of 2013.

The area Redhawk targets "has a considerable area of mineralization," said Nyal Niemuth, chief of the Arizona Geological Survey's economic geology section.

With copper prices topping $3.50 a pound, "it's likely they'll be able to show it's profitable," Niemuth said, adding that he can't make that statement unequivocally because he's not conducting the study.

Redhawk has drilled 75 exploratory holes, bringing the total drilled to 500, since the area had historical mining activity.

"There's certainly a full understanding of the geology," Niemuth said.

Redhawk recently announced it had decided on an underground mine over an open pit because building underground takes less time and costs less. An open pit would have produced nearly five times as much copper ore annually as the 25,000 tons per day from an underground mine.

An open pit's controversy was also a factor, since "with an open pit, there's more reclamation and more permitting involved," CEO Sandberg said. "Underground has a pretty small footprint. If you leave, when you're done, that's pretty much all that's left."

He said he hopes the mine's more remote location would reduce controversy compared with the Rosemont Mine, which lies 30 miles from Tucson.

"Any time you get a bigger population base, there's a bigger chance you'll get some kind of opposition," Sandberg said. "The towns closest to this are the little town of Mammoth, which was highly dependent on mining (in the past), and San Manuel.

"San Manuel is a mining town also - Magma built it," said Sandberg. That mine closed about a decade ago.

Endangered bird habitat

The Tucson-based Center for Biological Diversity, which has fought Rosemont, is concerned about Copper Creek because of its proximity to a stretch of the San Pedro that is prime habitat for an endangered bird.

About 78 miles of the lower San Pedro, ending in Winkelman near the Gila River, is critical habitat for the endangered Southwestern willow flycatcher, an insect-eating, riparian-dwelling bird, said Robin Silver, the center's board chairman.

The Sierra Club is also concerned about this mine project due to the river and the wildlife habitat in and near the Galiuros, said Sandy Bahr, director of its Grand Canyon chapter.

"We're concerned about the mine's stealing water from the river and polluting the river," said Silver, noting that under federal law critical habitat isn't supposed to be seriously harmed.

In response, Sandberg said the company has hydrologists looking at the area's aquifers, to determine if the proposed mine's groundwater supply is connected to aquifers under the San Pedro.

"We're aware of those kinds of issues. We don't want to do anything to harm anything," said Sandberg, adding that historical studies of the area suggest that the aquifer under the mine could be separate from the one feeding the San Pedro. Silver is skeptical of that, saying that just about all aquifers near one another are ultimately connected.

Christina McVie, a Tucson environmentalist, said she hopes the mining company will consider burying the tailings in mine tunnels underground. That method won't create the piles of tailings that lie at many mine sites, she said.

Rainfall would have a harder time reaching and leaching pollutants out of underground tailings to send them into the aquifer, she said.

Company officials are indeed looking at that idea, for economic as well as environmental reasons, Sandberg said. Tailings placed underground in tunnels provide more support for the ground surface, meaning that the company can then mine more raw material and not have to leave as much of it underground for support purposes.

"Any time you get a bigger population base, there's a bigger chance you'll get some kind of opposition. "

Joe Sandberg, Redhawk's president and CEO

Contact reporter Tony Davis at tdavis@azstarnet.com or 806-7746.

Copyright 2014 Arizona Daily Star. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Most Popular

Deals, offers & events

View more...