Rosemont Mine opponents failed to prove that the mine would harm groundwater supplies, an administrative law judge has ruled.

Law Judge Thomas Shedden upheld the mine's aquifer protection permit from the state, saying opponents didn't show that the Arizona Department of Environmental Quality's granting of the permit was "arbitrary, unreasonable, unlawful or based upon a technical judgment that was clearly invalid."

Shedden's ruling last week dismissed 19 issues raised by 11 individuals and five environmental groups opposing the proposed mine. They contended the state permit will allow Rosemont Copper to pollute local groundwater supplies.

If Shedden's decision is upheld by the state Water Quality Appeals Board, litigation will be the opponents' only recourse on the water permit, which ADEQ issued a little more than a year ago.

The permit allows the company to discharge materials if it can show that it's using the best-known technology to prevent pollutants from reaching groundwater.

The appeals board will hear the case on July 8.

The company seeks to mine 243 million pounds of copper annually in an open pit in the Santa Rita Mountains southeast of Tucson.

Rosemont Copper also needs a favorable decision from the U.S. Forest Service and a federal Clean Water Act permit from the Army Corps of Engineers.

"We are gratified the judge made a thoughtful and detailed decision regarding the appeal and upholding ADEQ's permit," said Kathy Arnold, Rosemont Copper's vice president of environmental and regulatory affairs. "During the hearing, the appellants were given every opportunity to back up their assertions with evidence, but failed to do so. The bottom line is that Rosemont's permit is amply supported by scientific studies and data, and meets all legal requirements."

Opponents said they were disappointed with Shedden's decision, particularly because he agreed with ADEQ's allowing the mine do construction work for more than two years before setting formal discharge limits. That period gives time for the company to monitor existing water quality and for ADEQ to determine appropriate limits.

"That this permit could be issued demonstrates what a sham the so-called aquifer protection process is in Arizona," said Greg Shinsky, a neighboring resident and one of those appealing.

During hearings on the appeal, Dave Chambers, a geophysicist, engineer and an expert witness for opponents, testified that before discharge limits are issued, exploratory drilling and mine and road construction could damage groundwater quality, particularly construction work that exposes ore.

An ADEQ witness testified that such monitoring periods are typical for new mines. But Chambers said ADEQ has authority to require "best practices" beyond what the law says.

Tom Myers, a hydrologist and another expert witness for opponents, testified that during the two years, waste rock buttresses surrounding the mine will be 50 feet thick, far less than the 300 to 400 feet they'll be later. So stormwater falling on the buttresses won't have far to travel to reach the ground and seep into groundwater, he said.

ADEQ hydrologist Jeff Emde, however, testified that there won't be significant water-quality impacts during that two-year period.

He cited the small size of a mine's presence during the first two years. Groundwater would move too slowly, he said, to carry any pollutants from the mine in two years to what's known as the "point of compliance," the site in the aquifer where the state determines if a discharge meets water-quality standards.

Karen Herther, a geologist and Rosemont Copper's water resources superintendent, testified that before the company builds the mine, it will scrape the soil down to bedrock and stockpile it for use in reclamation. Any rainwater that seeped through waste rock buttresses during those two years would hit exposed bedrock and run off - not seep into groundwater, she said.

At every step of the state and federal permitting process, opposition groups have appealed rulings and filed lawsuits, said Jamie Sturgess, a senior vice president for Augusta Resource Corp., Rosemont Copper's parent company.

"To date, none have been successful because the federal and state agencies are conducting thorough and detailed analyses through transparent and open public processes," he said.

Contact reporter Tony Davis at or 806-7746.