SOURCE: Mining.com | May 31, 2025
South32’s (ASX: S32) proposed zinc-manganese Hermosa mine in Arizona reached a permitting milestone on Friday following the release of its draft environmental impact statement by the US Forest Service (USFS).
Hermosa is currently the only advanced mining project in the US capable of producing two federally designated critical minerals: zinc and manganese. In 2023, under the Biden administration, it was included in the FAST-41 permitting program, the first mining project to obtain this status.
The draft EIS comes a year after the USFS initiated the federal permitting process, which includes disclosing the mine’s plans of operations for public input.
Situated in the Patagonia Mountains, about 80 km southeast of Tucson, the project comprises the zinc-lead-silver Taylor sulphide deposit and the zinc-manganese-silver Clark oxide deposit, with the former having been approved for a $2.16 billion investment, the largest in the state of Arizona.
With a surface footprint of just over 600 acres and projected to use 75% less water than other mines in the region, the operation has been designed to minimize its environmental impact.
As all of Hermosa’s mining will be conducted on private lands, the initial project development required state permits from the Arizona Department of Environmental Quality (ADEQ), which have been obtained. That construction is underway and already 40% complete, South32 said.
As part of the project’s review, the USFS identified its preferred alternative for how Hermosa should proceed with its mine plan of operations after weighing the benefits and environmental impacts. These include the construction of a 138kV power line, a primary access road, a dry-stack tailings facility updated in the latest MPO, and direct water discharge in the Patagonia Mountains.
“We are designing Hermosa from the ground up so that it is safer, more efficient and less impactful to the environment, combining state-of-the-art technology with best-in-class mining techniques, to deliver minerals America needs for its national and energy security,” said Pat Risner, Hermosa’s president
To comment on this story or for additional details click on related button above.
