Rosemont Copper now has one of the most hotly contested permits - although not the last needed - for it to operate a mine southeast of Tucson.

The Arizona Department of Environmental Quality announced Thursday that it issued the company an air-quality permit. ADEQ said its review of Rosemont Copper's computerized air pollution forecasts found the mine's emissions would not violate any federal air standards for carbon monoxide, nitrogen and sulfur dioxide, or fine and large particles.

But the approval, which helped trigger a 17-cent-per-share rise in the stock of Rosemont Copper's parent company Thursday, comes with a caveat. Because Rosemont Copper has changed its mining plans somewhat since applying for the permit, it may need to amend the permit.

For now, "all technical issues raised by ADEQ were addressed appropriately by Rosemont Copper," ADEQ wrote in response to one of more than 230 comments it received. "The (computer) modeling analyses and emissions calculations were verified by ADEQ. The modeling approach taken was consistent with well-established methodology for modeling, and state and federal guidelines."

The permit came despite many concerns from opponents, including that the mine would send high levels of dust or hazardous pollutants into the air and reduce visibility at Saguaro National Park East. Critics said the application hadn't adequately taken into account the potential for mine tailings to blow off the property as they have, periodically, at other mine sites near Tucson.

The permit follows a two-year conflict in which Pima County first ruled the application incomplete and then denied it, only to have a Superior Court judge rule the denial arbitrary and capricious on technical grounds. The state took over the permit last summer.

Rosemont's new mining plans eliminate heap leaching and copper oxide production, and significantly boost copper sulfide. These are or have been the key parts of the mine's production processes.

If the U.S. Forest Service approves these plans in its decision on the mine, the company may have to amend its permit application. Depending on how the changes affect Rosemont's emissions patterns, that could trigger more public review and comment, ADEQ said.

Still, the permit was good news for the mining company, which needs only final approval from the Forest Service on its environmental impact statement, and a U.S. Army Corps of Engineers permit, to start construction. It will also have to survive an expected court challenge.

"Having received one of the last permits remaining represents a major achievement for the Rosemont Copper project as we near the end of the permitting process and prepare for construction this year," Gil Clausen, president and CEO of Augusta Resource Corp., Rosemont Copper's parent, said in a news release. "This success demonstrates our commitment to set high standards for environmental protection by operating with enhanced emission controls that go beyond regulatory requirements. Further, we would like to commend the ADEQ for advancing the permitting process ... thoroughly, professionally and expeditiously."

Opponents are considering an appeal, said Gayle Hartmann, president of Save the Scenic Santa Ritas. The group is awaiting a response from a state hearing officer on a separate appeal of ADEQ's aquifer protection permit for the mine, issued in April 2012. The mine would be located in the Santa Rita Mountains, about 30 miles southeast of Tucson.

"ADEQ's approval of this permit is not surprising. This agency has been decimated by budget cuts and is beholden to the regulated entities that pay the permitting fees to keep it afloat," the group said in its news release.

Citing the Forest Service's continued deliberations over endangered-species issues and the Environmental Protection Agency's criticisms of the mine proposal, the group said the mine's future is far from certain.

Mined in America, a pro-industry group, called the permit a major step toward creating environmentally friendly mining and job creation nationally.

"There have been far too many delays - with Arizona workers and businesses paying a heavy price," the Washington, D.C.-based group said in a statement. "No one can afford that. Now is the time to come together to bring this process to a conclusion and help Arizonans and our country get back to work."

To get a better handle on dust, ADEQ required that:

• The company operate a monitor for large particle emissions - known as PM-10s - to verify that it's not violating those air standards.

• The mine install high-efficiency filters and an electrostatic precipitator, and spray tailings and other dust sources with water.

• The company submit a tailings management plan, that will also require public comment and review.

• That the company pave 3.1 miles of dirt roads that it hadn't been planning to pave.

But Nancy Freeman, a Green Valley activist, said she believes there's "no way" the mine will be able to keep dust from leaving the site due to its plans to use dry instead of wet tailings as a way of conserving water and preventing seepage of tailings into the aquifer.

"The way they will be doing it is that all the toxic metals from their mill that go into the tailings will be exposed to the environment through water, storm water or through dust in the air," said Freeman, of the Groundwater Awareness League.

Contact reporter Tony Davis at or 806-7746.