Copper-mine boom raises AZ water worries
Regulators fear strain on limited resource as thirsty industry expands
azcentral.com
Max Jarman
The Arizona Republic
Jun. 13, 2007 12:00 AM
After a long decline punctuated by mine closures and layoffs, Arizona's copper industry is making an unprecedented comeback.
Soaring metals prices have companies scrambling to open mines and expand existing ones to take advantage of the boom.
But mines consume huge amounts of water and could put tremendous pressure on the state's limited water supply.
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Water regulators, county planners and environmentalists are increasingly worried about the effect on aquifers, already suffering from decades of overpumping.
At least seven new mining projects are being planned around the state, and that doesn't count the ongoing expansion of existing mines. The new projects will require 40,000 acre-feet of water annually. That's enough to support a city larger than Tempe.
State and federal laws favor mining, and regulators say they often have little authority to deny a project based on its potential impact on the water supply.
"Basically, most mining companies can use whatever water they need," said Jack Lavelle, spokesman for the Arizona Department of Water Resources. "All that is required is a notice of the intent to drill a well."
Although some mining companies are looking for alternative water sources, most will rely on groundwater wells.
Drawing more water out of the ground than is replenished by nature can dry up existing wells, affect stream flows and wildlife and cause the ground above to sink.
The planned Resolution Copper mine near Superior will need as much as 20,000 acre-feet of water annually. That's enough to support 100,000 people.
Yearly water needs for other new mines range from 5,500 acre-feet for the new Phelps Dodge mine near Safford to 1,200 acre-feet for the proposed Carlota mine outside Miami.
An acre-foot is the amount of water needed to cover an acre of land 1 foot deep, or roughly 326,000 gallons.
Some of the mining companies are concerned about the impact on groundwater and are looking for other sources that could include the Central Arizona Project, effluent and contaminated water from old mines.
"We know full well that water is an incredibly sensitive issue in Arizona," said Mark Blakely, project manager for the Carlota mine.
An industry rebounds
Two decades ago, as Arizona developed a comprehensive groundwater-management plan, "people thought mining would eventually go away in Arizona," said Sharon Medgal, associate director of the University of Arizona Water Resources Research Center.
"But with new technology and rising (metals) prices, it's continuing and expanding," she said.
International demand has also soared, pushing the price of copper to $3.27 per pound Tuesday from 65 cents in January 2000. Mining companies have reaped the profits, and the state's mines have become valuable again. The new mines, which will produce copper and some molybdenum, also mean thousands of jobs in poor rural areas and billions of dollars pumped into the state's economy.
No special permits
Arizona's mines sit on a mix of private, state and federal land.
Although state law requires specific rights for surface water, it does not require mines to obtain any special permits to drill for groundwater.
In addition, the Arizona Department of Water Resources maintains it has little authority over most of the mining projects because they are outside what are called active water management areas. In such areas, groundwater supplies are so threatened that use is regulated.
The state then requires users to obtain rights and permits to pump the groundwater or insist it be replaced or recharged with excess CAP water.
But even in active management areas, the department has limited authority over mines. Mining companies can easily obtain a permit to pump groundwater because other sources are typically not available or too expensive.
The Rosemont Ranch mine near Tucson is within an active water management area.
"Our discretion is somewhat limited," said Ken Seasholes, director of the Tucson management area.
Federal agencies also find their hands tied.
Beverley Everson, a forest geologist with the Coronado National Forest near Tucson, explained that mining is a permitted use in the national forest. The Forest Service can work to reduce a mine's impact on the environment but can't deny a project.
"That would take congressional action," Everson said.
Above and beyond
Both Seasholes and Everson are working with the developers of the proposed Rosemont Ranch mine in the Santa Rita Mountains, 30 miles southeast of Tucson.
The mine would require about 5,000 acre-feet of water per year.
The developer is proposing to pump water from an aquifer near the mine and replenish it with excess CAP water it plans to buy. The commitment to recharge CAP water is above and beyond what Arizona law requires.
The company also has agreed to use a dry-tailings process that would cut the mine's water demand in half.
Pima County opposition
Still, the plan has drawn opposition from Pima County, which is concerned the mine will endanger streams in the area, and from environmental groups such as Earthworks.
Pima County has no legal authority over the project but has asked Congress to remove mining as an accepted use for the property.
Industry cooperation
Outside active management areas, the state can encourage mining companies to develop water-conservation and aquifer-recharging plans but can't force them to do so.
Fortunately, the mines have been cooperative, according to Herb Guenther, director of the Arizona Department of Water Resources.
"For the most part, it's been a responsible industry that recognizes that water is a precious commodity in Arizona," he said.
Resolution Copper hopes to avoid pumping groundwater to supply its planned underground mine.
"It's our last resort," said John Rickus, president of Resolution Copper Mining, a partnership between British Rio Tinto PLC and Australia's BHP Billiton Ltd.
Resolution is considering buying excess CAP water that it could exchange for rights to pump and transport surface water from lakes and rivers.
The company also is looking for sources of contaminated water inside old mines that could be used in the new facility.
Twenty miles east of the planned Resolution Copper mine is Pinto Valley, where Quadra Mining Ltd. of Vancouver, British Columbia, is developing the Carlota copper mine and BHP Copper is preparing to reopen its Pinto Valley mine after almost a decade in moth balls.
Carlota project manager Blakely said the company plans to develop a well field near the mine that would produce 1,200 acre-feet of water per year.
But up to 318 acre-feet of that could be dumped directly into nearby Pinto Creek to prevent its flows from being diminished by the groundwater pumping.
Stations would monitor the level and temperature of the creek, and water would be automatically released to maintain both at a constant level.
"We did everything we could to reduce the impact our pumping would have on surface water," Blakely said.
'A balancing act'
Water Resources official Guenther would like to have more authority over mines' water use but added that, so far, they have been willing to cooperate with department suggestions.
"We haven't had any confrontations," he said.
Although Guenther acknowledges mining can have a negative impact on the state's groundwater, he noted the industry also provides jobs and boosts the state's economy.
"It's a balancing act," he said, adding that the state can't eliminate the impact of mining on the state's groundwater, but it can try to minimize it through cooperation and conservation.
Reach the reporter at (602) 444-7351. |
