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ELKO — To add another 12 years to the Cortez Hills operation mine life and access additional gold and silver, Barrick Gold Corp. is proposing an expansion that would be a boon to Elko County’s economy.

The Bureau of Land Management published a draft environmental impact statement on the Deep South Expansion Project and accepted public comments through Dec. 5. Elko County was among the project’s supporters.

Kevin Hurrell, BLM project manager for the Mount Lewis field office, said the process has taken two years so far, but the project now falls under an executive order to streamline permitting to be done in a year. A record of decision is expected in March or April 2019.

The plan of operations encompasses 54,825 acres of public lands, and the proposed expansion would require an increase to the plan boundary by 4,279 acres and result in about 3,800 acres of new disturbance. The mine in Eureka and Lander counties is on mostly BLM-administered land and some private land.

Economic impact

Barrick employs approximately 1,250 people from Elko, Battle Mountain, Winnemucca, Eureka, Carlin and surrounding areas at the Cortez operations. An estimated 75 percent of the mine’s workforce comes from Elko County.

The expansion would sustain the present workforce, which nets a total payroll of approximately $128 million, according to a Barrick letter requesting Elko County’s support for the project. For the Cortez Hills operation, Barrick also pays about $4 million a year in sales tax, $35 million in property taxes and $11 million in business taxes, the company stated.

Because Elko County is heavily reliant on the mining industry, county commissioners supported the proposed action. It “would provide increased financial stability for Elko County, and the environmental impacts would be either minimal or mitigated by reclamation efforts after the mine’s operations cease,” according to comments prepared by Elko County Natural Resources Director Curtis F. Moore.

Complex expansions

The proposed action would expand all four of the complexes within the Cortez operations and allow general site-wide changes.

“We’re proposing an expansion to all areas,” said Steve Schoen, manager of permitting for Barrick. “Between all of those expansions, it will give us another 12 years of operations.”

Mineral extraction began in the Cortez Mining District in 1862, with silver and gold mining occurring almost continuously through the 1900s. Barrick acquired a partial interest in the Cortez operations when it took over Placer Dome in 2006, then acquired the remaining interest from Rio Tinto in 2008.

Deep South is in the southern portion of the existing Cortez Hills Complex, and the proposal aims to expand existing underground operations, partially backfill the existing pit, and construct new ore stockpiles and ancillary facilities.

The expansion includes the deepening of the Cortez Hills underground mine by 1,300 feet to a depth of 2,500 feet, according to Barrick.

At the Pipeline complex, the mine proposes reconfiguring the authorized pit backfill areas and expanding an existing oxide ore stockpile, according to the BLM.

The expansion would include developing three new satellite pits at the Gold Acres Complex, while increasing the existing waste rock facilities, and constructing new ore stockpiles and additional facilities.

The Cortez Complex would see the expansion of the existing pit and a waste rock facility and the partial backfill of two pits. Backfilling pits prevent the formation of post-mining pit lakes, Barrick stated.

Site-wide changes

Overall, the proposed expansion would require the construction of additional water management facilities such as a reservoir, rapid infiltration basin and water reinjection wells, while continuing dewatering.

Hurrell said a major topic of concern is groundwater draw. The mine must remove water from around an open pit to access ore, but the water is reinjected back into the ground. Water that cannot be absorbed by the reinjection wells will be stored in the temporary reservoir — the Rocky Pass Reservoir — only if needed, according to Barrick.

Impacts to water levels are not projected to occur near the town of Crescent Valley or near the Humboldt River, the BLM states. Yet as a precaution, the mine would monitor surface and groundwater and implement a mitigation plan if necessary.

Ore from Cortez is processed at an oxide mill on-site and on leach pads, and refractory ore is shipped to Barrick’s Goldstrike operations.

The plan would also increase off-site refractory ore shipments to the mill at Goldstrike, and backhaul oxide ore from the Arturo Mine to the Pipeline Complex for processing.

Barrick hauls about 2 million tons of ore per year to Golstrike, and haulage would increase to about 2.5 million tons per year under the expansion plan, Schoen said.

Trucks hauling ore follow State Route 306 from the Cortez operations through Crescent Valley, east along Interstate 80 then northwest on State Route 766 from Carlin, according to a BLM map of the transportation route.

“Barrick started working with [the Nevada Department of Transportation] to develop a maintenance plan and help with funding for maintenance three years ago,” Barrick stated in the letter to Elko County. “Barrick will continue to do so as road haulage is increased.”

Environment

The BLM studied Barrick’s plans to offset impacts on greater sage-grouse and mule deer habitat through remediation and a credit system. The mine operator also has plans to preserve cultural resources and Native American values.

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