South32 outlines Hermosa mine plans: $2.2 billion investment, remote operating center in Nogales and local hiring commitments

South32 told the Nogales City Council on March 5 that it has committed roughly $2.2 billion to develop the Hermosa zinc deposit south of Patagonia and is studying a manganese deposit and an adjacent copper prospect.

Pat Reisner, a South32 representative, described the project as a strategic domestic source of critical minerals and said the company has already invested hundreds of millions of dollars. Reisner said South32 will sink two 25-foot-diameter shafts to roughly 3,000 feet to access the zinc deposit, drive a decline to access manganese and construct surface processing facilities. He said the company has between 600 and 700 construction workers now at the site with an expected ramp to about 1,000 by July, and that first zinc production is expected in 2027 with more routine revenue beginning by about 2028.

Reisner said South32 has committed that at least 80% of the long-term permanent workforce will be residents of Santa Cruz County and that more than 200 people will work at a remote operating center, called Centro, that the company will build in Nogales. “We have committed to at least 80% of our long term permanent workforce will be existing residents of Santa Cruz County,” Reisner said, adding that remote operations will allow the company to train new employees in about 18 months for roles historically requiring years of mining experience.

South32 presented economic-impact estimates prepared by Ernst & Young: roughly 8–900 direct jobs at full production, roughly 2,400 indirect jobs in Santa Cruz County and annual county tax revenue of about $26 million — roughly double the county’s current annual property tax intake, the company said. South32 also described a Hermosa Community Fund that has made grants to local nonprofits and local STEM programs that the company said will expand to support workforce development.

Reisner discussed environmental controls and permitting. He said the operation is designed to “disturb about 95% less land than a typical open-pit copper mine” and to use about 90% less water than typical mining operations, and he described a goal to reach net-zero operational greenhouse-gas emissions. South32 said it holds state permits for construction and operation on private land but that a separate federal process run by the U.S. Forest Service would conclude in mid-2026; a draft environmental impact statement was scheduled for release in May with public meetings late that month.

The company described an existing water-management program permitted through the Arizona Department of Environmental Quality (ADEQ). That program treats groundwater that has naturally high metal content and discharges permitted flows to Harshaw Creek; Reisner said the operation is permitted to discharge up to 4,500 gallons per minute but that current managed flows are roughly 1,500 gpm. He said South32 is pursuing targeted aquifer recharge (rapid infiltration basins) in the federal permitting process in response to community input so some treated water can be recharged rather than routed down Harshaw Creek.

Council members asked for regular updates, additional detail on water quality and recharge plans, traffic and infrastructure impacts, housing and training programs, and legal review of a proposed community protection and benefits agreement (a “good neighbor” agreement) that South32 said it will make legally binding for the company’s commitments. Councilwoman Montiel said she wanted the city attorney involved early to ensure municipal interests are represented; South32 said listening sessions and a refreshed community advisory panel will gather public input in the coming weeks.

South32 encouraged residents to visit the project on monthly tours and posted project information and job openings online. The company said it will require major contractors to establish maintenance and support capacity in Santa Cruz County and to develop apprenticeship and training programs for local hires.