On Nov. 13, 2026, the comment period begins for the proposal to issue a significant permit revision to an air quality control permit to South32 Hermosa, Inc., for its zinc, silver, and manganese mine located in Santa Cruz County, Arizona. The comment period ends Dec. 14, 2026.

Significant Permit Revision No. 114492

Permittee:

South32 Hermosa, Inc.

Facility:

South32 Hermosa, Inc.

749 Harshaw Road
Patagonia,
Arizona 85624
Santa
Cruz County

The facility is subject to the requirements of federal and state clean air regulations. The facility emits the following air contaminants: coarse particulate matter with diameters 10 micrometers or less  (PM₁₀), fine particulate matter with diameters 2.5 micrometers or less (PM_2.5), volatile organic compounds (VOCs), nitrogen oxides (NO_X), sulfur dioxide (SO₂), carbon monoxide (CO) and hazardous air pollutants (HAPs).

Review Documents:

• Original Published Public Notice | View Notice > 
• Draft Permit  | View Permit > | View Track Changes >
• Draft Technical Support Document (TSD) | View TSD > 
• Permit Application | View App. >
• ADEQ’s South32 Air Quality Webpage | Visit Page >
• In person at:
  • ADEQ Record Center | Learn How >
  • Patagonia Town Clerk's Office, 310 McKeown Avenue, Patagonia,

Public Comment Period:

Dates:  Nov. 13, 2026 – Dec. 14, 2026

Comments may be submitted as follows:  

• By Email | Send Email >
• By Mail (Must be postmarked or received by Dec. 14, 2026):

ADEQ
Air Quality Division, Air Permits

Attn: Karla Murrieta
1110 W. Washington St.
Phoenix, AZ  85007

• At Public Hearing on Dec. 10, 2026, 6 p.m. | View Details >

EPA Petition Process: 

This permit is subject to review by EPA pursuant to 40 CFR 70.8 (Code of Federal Regulations) and Arizona Administrative Code R18-2-307. If EPA does not object to the issuance of this permit, you may petition to EPA within 60 days after the expiration of EPA's 45-day review period. A petition shall be based only on objections to the permit that were raised with reasonable specificity during the public comment period, unless the petitioner demonstrates that it was impracticable to raise such objections within such period, or unless the grounds for such objection arose after such period. Any person who petitions to EPA pursuant to 40 CFR 70.8(d) shall notify ADEQ by certified mail within 10 days after such petition.

Comments may be submitted to EPA according to the process for Title V Petitions | Learn More >