Gunnison Copper

The Johnson Camp Mine, operated by the Excelsior Mining Company, has received an amended Aquifer Protection Permit from the Arizona Department of Environmental Quality. The permit is one of three major permits the company needs to start the fullscale operation of the Gunnison Copper Project, located west of Willcox.

Arizona Range News Photo

WILLCOX — The first of three major permits for the Gunnison Copper Project outside of Willcox has been issued by the Arizona Department of Environmental Quality.

Excelsior Mining Corporation, owners of the project, announced that it has received an amended Aquifer Protection Permit for Johnson Camp Mine, the property north of Interstate 10 where copper processing facilities are located.

Excelsior is utilizing in situ mining to inject a weak acid solution into bedrock about 600 feet below the surface on its 9,560-acre property located east of Benson, on both the north and south sides of I-10.

The acid is recovered and equipment at the Johnson Camp Mine extracts copper from the solution. The camp got its start in the early 1880s, shortly after the Southern Pacific Railroad arrived in the area. At its peak, the town of Johnson near the site of the open-pit mine had two 30-ton smelters and was the headquarters in 1883 of the Peabody Co., which employed 150 men. The camp was named after George J. Johnson, who served as the general manager of the Cochise Copper Company.

Excelsior purchased the property in 2015 and, together with other holdings in the immediate area of the Johnson Camp Mine, has invested about $52 million in the Gunnison Copper Project. The operation is expected to produce about 2.2 billion pounds of copper oxide and generate about $2.4 billion in statewide economic impact for the next 20 years.

Excelsior is currently working with the ADEQ on issuing another, separate Aquifer Protection Permit for the wellfield component of the Gunnison Copper Project, located south of I-10 and directly across the freeway from the Johnson Camp Mine.

“This is the primary operating permit to be issued by the State of Arizona,” said Stephen Twyerould, president and CEO of Excelsior. “In parallel, Excelsior is working with the Environmental Protection Agency for the issuance of an Underground Injection Control Permit, which we anticipate will be received by later in the third quarter of this year.”

Twyerould said permits from state and federal agencies for the mine require that 100 percent of the acid be recovered in the process. He said the company is confident it will accomplish total recovery of the solution.

Twyerould said Excelsior has about 24 people working at the Gunnison Copper Project now, and when production begins, that number will grow to about 108 employees.