Kennecott hopes to expand copper mine

MAGNA — The largest man-made pit in the world may get even bigger in the next couple of decades, Kennecott Utah Copper announced Monday morning.

The incredible pit, one of the only man-made structures visible from space, could be crawling with tractors and dump trucks for the "Cornerstone Project" after its current project is completed in 2021.

Kennecott, which was purchased by mining giant Rio Tinto in 1989, hopes to retrieve about 700 million tons of ore by expanding the pit 1,000 feet to the southeast and digging 300 feet deeper.

The vast surface mine is already 2.75 miles wide and .75 miles deep.

If Cornerstone is successful, the company may ask for an additional expansion that could keep workers on the job — and dollars flowing into Utah — until 2034, according to Kennecott President and CEO Kelly Sanders. As of Monday afternoon, the copper company employs about 2,400 employees with an average of $93,000 in pay and benefits.

Corporate funding for the expansion has yet to be secured, and the mine still has a few years of permit renewal ahead before Kennecott goes forward with its planned expansion. The public will be allowed to comment during the state permit process and can ask for a public hearing on the matter, said Division of Air Quality permitting branch manager Regg Olsen. Permits from the U.S. Environmental Protection Agency and the Utah Department of Environmental Quality are also required, totaling 70 separate licenses.

In the Division of Air Quality, the first permit application is expected this week, Olsen said. The public process could begin within the next few months.

Standing over the amphitheater-like pit in a white hard hat and yellow sunglasses, Sanders said the public is unlikely to notice a major change if the expansion goes through. Newly unearthed waste rock from the project will be added to the current tailings site on the east-facing side of the Oquirrh Mountains, making the pile taller but not wider, Sanders said.

Beyond minor changes in the viewshed, the Salt Lake Valley is most likely to be impacted economically, Sanders said. In 2009, the company spent about $900 million in Utah for company wages, benefits, taxes and purchases. Similar sums are expected to be added to the state annually if the expansion is approved.

Kennecott points to its programs that prohibit trucks from idling, save water and power and protect wildlife as signs of its commitment to environmental protection.

Since 1903, the mine has produced about 18.7 million tons of copper, 500,000 ounces of gold, 4 million ounces of silver and 25 million pounds of molybdenum, a metal used to strengthen steel alloys. It has also produced 1.1 million tons of sulfuric acid, a by-product of the smelting process and rhenium, which is used in high-heat circumstances.

Data collected through extensive drilling shows that similar material resides in the proposed expansion area.

"I'm very excited about it," Sanders said of the proposal. "It's an interesting role to be taking, thinking 20 years on the future."

e-mail: rpalmer@desnews.com