FOR IMMEDIATE RELEASE
August 25, 2025
Additional record-keeping and reporting details provided in limited ADEQ permit reopening
South32 Hermosa – the only advanced mine development project in the United States that could produce two federally designated critical minerals, manganese and zinc – has submitted information to the Arizona Department of Environmental Quality (ADEQ) in response to its limited reopening of the Hermosa air quality permit. This action was taken to address the five non-substantive petitioner claims upheld in the Environmental Protection Agency (EPA)’s May 30th, 2025, decision.
“We worked diligently with ADEQ to respond to the EPA’s ask while keeping the permit amendment process on schedule,” said Pat Risner, President of South32 Hermosa. “Our day-to-day did not change with this request, and we have continued to safely construct and work on site under the currently approved air permit, which meets all substantive Clean Air Act requirements.”
In its decision, the EPA rejected 15 of the 20 claims raised by petitioners, confirming the permit met all substantive requirements under the Clean Air Act. The five claims upheld were procedural, focusing on improving recordkeeping and reporting clarity.
Public comments can be made only on the specific sections of the permit that were revised in response to EPA’s request.
Public Comment Period:
August 26 – September 25, 2025
Public Hearing:
Thursday, September 25, 2025 | 6:00 PM
Patagonia Elementary and High School Multipurpose Room
200 Naugle Avenue
Patagonia, Arizona 85624
The draft permit and related documentation are available for public review at azdeq.gov/publicnotices.
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About South32 Hermosa
Located in a historic mining district in the Patagonia Mountains of Southern Arizona, Hermosa is currently the only advanced mine development project in the United States that could produce two federally designated critical minerals — manganese and zinc — both of which are essential minerals for powering the nation’s energy future. Learn more at www.south32hermosa.com.
Hermosa is a polymetallic development comprised of a zinc-lead-silver sulfide deposit, a battery-grade manganese deposit and an extensive, highly prospective land package with the potential for further polymetallic and copper mineralization.
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