Revised on: Aug. 26, 2024 - 1:45 p.m.
This permit of interest online resource provides interested parties easy access to information about the Hermosa Project, owned by South32 Hermosa Inc., formerly Arizona Minerals Inc. (AMI).
Facility Information
The Hermosa Project, owned and operated by South32 Hermosa Inc. (formerly AMI), is located approximately five miles south of the Town of Patagonia, Arizona in Santa Cruz County. The Hermosa Project includes underground mining of two deposits:
- Taylor sulfide deposit (Taylor), zinc-lead-silver deposit, and will be mined for zinc and lead.
- Clark oxide deposit (Clark), zinc-manganese-silver deposit, and will be mined for manganese.
Location
749 Harshaw Road
Patagonia, Arizona 85624
Permitting
The Hermosa Project has the potential to emit nitrogen oxides, carbon monoxide and hazardous air pollutants greater than major source thresholds established by state and federal regulations. It is classified as a major source and is required to obtain a Class I Air Quality permit. This permit is subject to review by the Environmental Protection Agency (EPA) pursuant to 40 Code of Federal Regulations (CFR) 70.8 and Arizona Administrative Code R18-2-307.
On June 10, 2024, ADEQ issued the proposed final permit to authorize South32 Hermosa Inc. to begin actual construction, but not operation, of the Hermosa Project. On the same day, ADEQ submitted the proposed final permit and the response to public comments to EPA for its 45-day review period. ADEQ addressed comments on the proposed final permit received from EPA on July 24, 2024, and issued the final air quality permit to South32 Hermosa Inc. on August 26, 2024.
Public Participation
The public notice comment period began on January 5, 2024 and was extended to February 26, 2024 | View >
On January 11, 2024, ADEQ held an informal community meeting to discuss the draft air quality permit | View Fact Sheet >
On February 26, 2024, ADEQ held a public hearing for the public to comment in person on the draft air quality permit. Both the informal community meeting and public hearing were held at Patagonia Elementary and High School located at 200 W. Naugle Avenue, Patagonia, AZ 85624.
Facility Archives
On October 24, 2022, ADEQ received a Class I Air Quality Permit application from South32 Hermosa Inc.
- Initial Application
- Permit Application | View >
- Modeling Report | View >
- Emission Calculation Spreadsheets
- Plan I Road Emissions | View >
- Plan II Road Emissions | View >
- Plan I Emission Calculations | View >
- Plan II Emission Calculations | View >
- Compliance Assurance Monitoring (CAM) Applicability Review | View >
- Draft Permit | View >
- Draft Technical Support Document | View >
- Proposed Final Permit (June 2024) | View >
- Proposed Final Technical Support Document (June 2024) | View >
- Response to Public Comments (June 2024) | View >
- Hazardous Air Pollutants Metal Mass Fractions from the 2019 USGS Report | View >
Looking for water quality permitting related to this facility? | View >
