Three conservation groups filed suit Monday to block the first proposed uranium mine in northern Arizona in more than a decade, north of the Grand Canyon.

The Center for Biological Diversity, Grand Canyon Trust and Sierra Club sued the Bureau of Land Management in federal court.

They asserted the agency was violating multiple federal laws by using 21-year-old planning documents to approve reopening a mothballed mine on the Arizona Strip.

The environmental groups say mining possibly poses a risk to seeps and springs at the Grand Canyon, and the animals that live there, because the mine shaft could puncture an aquifer or speed up the rate at which uranium moves into nearby water.

"If there's the potential for the mine to deplete or contaminate aquifers that discharge into the canyon, that's not a risk worth taking," said Taylor McKinnon, public lands campaign director for the Center. "… Neither the mining company nor the BLM can guarantee that aquifer depletion or pollution won't happen."

The company that owns the mine, however, wants to begin mining it in the first three months of 2010. The environmental groups are attempting to prevent that by seeking an injunction.

The environmental groups are saying violations of the Endangered Species Act and National Environmental Policy Act would result from the BLM's approval to mine, are calling for more comprehensive environmental reviews than were done in the 1980s, and are asking the BLM to get the opinion of the agency that oversees endangered species.

The Arizona 1 Mine, as this is called, changed ownership three times since the 1980s and was permitted for mining in 1988, but was never mined amid sinking prices for uranium.

Located 45 miles from Fredonia, it is now owned by Denison Mines Corp., which plans to begin mining in the first quarter of 2010 following the last couple years of preparatory work, said Ron F. Hochstein, Denison president and chief executive officer.

The 1,300-foot mine shaft at Arizona 1 parallels an underground geologic formation known as a breccia pipe, or a collapsed cavern filled with different sediments and uranium ore.

The breccia pipe is about 300 feet wide and 1,500 feet deep, with the uranium ore segments located hundreds of feet below the ground surface.

About 30 employees to be paid a total of $2.1 million annually would work at the site, going down a mine shaft to excavate the ore at 1,300 feet, and down some ramps to 1,500 feet.

Ventilation would be required, and each worker is limited to 8 hours underground per day, according to the state mine inspector's office.

Miners would use explosives and a small front-loader underground to excavate ore and load it into buckets in the mine shaft for hauling to the surface.

It would next be trucked 307 miles to the White Mesa Mill near Blanding, Utah, for refinement into yellowcake and sold, after which uranium is refined 3 or 4 more times before it becomes nuclear fuel headed for utilities in the United States or other countries, Hochstein said.

Altogether, the company proposes to mine a known 67,000 tons of ore (or more if other deposits are discovered deeper), which would be enough to produce about 900,000 pounds of yellowcake.

"The breccia pipe mines are some of the highest-grade mines in the United States," Hochstein said.

Environmental groups litigating Monday are attempting to get Congress to put about 1 million acres of public land surrounding the Grand Canyon off-limits to new uranium mining for 20 years, citing 1,100 uranium mining claims within five miles of the Grand Canyon.

Because of temporary action on the issue, owners of existing mines also now must prove their claims are viable, and this one hasn't done that, say the groups litigating.

Uranium mining poses little threat to groundwater, Hochstein said, especially because miners are removing it.

"If the uranium was going to get in the groundwater, it would have done that a long time ago," he said.

A Northern Arizona University hydrologist providing information to a U.S. House committee in 2008 and another hydrologist from Nevada who has done research on springs in the canyon urged caution.

Cyndy Cole can be reached at 913-8607 or at ccole@azdailysun.com.