South32 (ASX: S32) moved closer to securing federal approval for its Hermosa zinc-silver project in Arizona after the US Forest Service released a Final Environmental Impact Statement and Draft Record of Decision indicating it intends to allow development on National Forest land.
The draft decision marks a key step in the federal permitting process because parts of the proposed mine and supporting infrastructure would sit on land within the Coronado National Forest. If finalized, the authorization would allow the company to expand development beyond privately held property and build key infrastructure on federal land.
The documents also trigger a formal review period for eligible stakeholders who previously submitted public comments. After that process, the agency may issue a final decision that would clear the way for construction of several project components.
The Final Environmental Impact Statement supports the agency’s preferred development alternative and includes technical analysis completed during years of environmental review. The plan would allow South32 to build a primary access road, a secondary dry-stack tailings facility and part of a 138 kV transmission line on National Forest land, with the power line to be constructed by UniSource Energy Services.
Hermosa was the first mining development accepted into the federal FAST-41 permitting program, which accelerates reviews for large infrastructure projects deemed strategically important to the US economy.
“This Draft Record of Decision reflects years of listening, collaboration and real changes shaped by community input,” said Pat Risner, president of South32 Hermosa. “The draft decision affirms our design and development approach, including mitigation measures described in the Final Environmental Impact Statement that were informed through agency and public consultation.”
As part of the review process, the Forest Service conducted an independent analysis of Hermosa’s Mine Plan of Operations released in 2024 alongside baseline environmental data collected over several years and feedback gathered during the National Environmental Policy Act comment period.
The agency concluded that the selected development alternative best meets the project’s objectives while minimizing environmental impacts. The plan includes a primary access road designed to avoid traffic near the town of Patagonia, a section of the 138 kV transmission line, an updated dry-stack tailings facility and a direct water discharge system high in the Patagonia Mountains intended to recharge the aquifer and support wildlife.
According to the Forest Service, the selected alternative would produce the smallest land surface disturbance while reducing impacts to air quality, water resources, cultural sites, recreation areas, wildlife habitat and nearby communities compared with other options studied.
State permits secured
South32 has already secured required state permits from the Arizona Department of Environmental Quality for initial surface infrastructure located on private land.
“This outcome reflects a thorough, transparent process that affirms South32 Hermosa’s design and commitments are compatible with the long-term management of public lands and sets the stage for the final authorization process ahead,” Brent Musslewhite, Hermosa’s director of environment and permitting, said.
Beyond regulatory requirements, the company has committed to nearly 140 additional conservation, mitigation and monitoring measures developed with federal agencies, Indigenous Nations and community stakeholders. South32 plans to operate the project under an adaptive management framework and a no-net-loss biodiversity standard designed to strengthen environmental protections as scientific understanding evolves.
The commitments also underpin ongoing negotiations toward a Community Protection and Benefits Agreement with local governments.
The Draft Record of Decision begins a 45-day objection period followed by a potential 45-day resolution process before the Forest Service issues a final decision. South32 expects the Final Record of Decision in July and said it will continue engaging with regulators and communities during the review period.
Designed with a surface footprint of about 750 acres, the Hermosa project is expected to use roughly 90% less water than many regional mining operations and could support up to 900 jobs at peak production while generating long-term investment in surrounding communities.
