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Public Notice
Air Quality

On May 16, 2023, the public comment period begins for the proposal of three actions:

  • Revision to the Arizona State Implementation Plan (SIP) for the Hayden Sulfur Dioxide Nonattainment Area for the 1971 and 2010 National Ambient Air Quality Standards (NAAQS).
  • Significant Permit Revision to an Air Quality Control Permit to ASARCO LLC for its Hayden Operations facility located in Gila County, Arizona.
  • Revised good engineering practice (GEP) demonstration study.1

The comment period ends June 15, 2023.

Public Notice Information

Permit Revision

Class I Air Quality Permit No. 96410

The facility is subject to the requirements of the Federal Clean Air Act, Code of Federal Regulations, Arizona Revised Statute 49-426, and the Arizona Administrative Code, Title 18, Chapter 2. 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 (PM2.5), volatile organic compounds (VOCs), nitrogen oxides (NOX), sulfur dioxide (SO2), carbon monoxide (CO) and hazardous air pollutants (HAPs).

SIP Revision

EPA officially designated the Hayden area as nonattainment on Aug. 5, 2013, for the 2010 NAAQS based on existing monitoring data from 2009-2010. This proposed SIP revision demonstrates that all essential regulatory elements have been met and the Hayden SO2 Planning Area will attain the 2010 primary SO2 NAAQS. Additionally, this SIP revision will satisfy any remaining requirements for the 1971 SO2 NAAQS.

GEP Demo Study

In 1983, EPA approved a GEP stack height demonstration for the 1,000-foot (305 m) main stack at the ASARCO - Hayden Smelter located in Hayden, Arizona. At EPA’s request in mid-2015 and 2022, the GEP stack height determination was reassessed with respect to the current GEP regulations. This reassessment—included in the proposed SIP revision—confirmed that the original GEP stack height determination is consistent with the 1985 regulations and that the 1,000-foot stack remains an appropriate GEP determination.



Facility Information

Hayden Operations
100 N. Hayden Ave.
Hayden, AZ 85135

Review Documents

Original Published Public Notice | View/Download > 
Draft Permit | View/Download > 
Draft Technical Support Document | View/Download > 
Hayden SO2 Proposed SIP with Appendices | View/Download > 

You may also review the above documentation in person at the Town of Hayden, Town Clerk's Office located at 520 Velasco Ave., Hayden, Arizona, or at the ADEQ Record Center | Learn How > 

Public Comment Period 

Dates: May 16, 2023 – June 15, 2023 (Comments must be postmarked or received by June 15, 2023)

Comments on the SIP revision and GEP re-assessment may be submitted as follows:
     By Email | Send Email > 
     By Mail:

       Air Quality Division, Air Quality Improvement Planning
Zachary Dorn
       1110 W. Washington St.
       Phoenix, AZ  85007

Comments on the ASARCO Hayden Operations permit revision may be submitted as follows:
     By Email | Send Email >
     By Mail:

       Air Quality Division, Air Permits
       Attn: Karla Murrieta
       1110 W. Washington St.
       Phoenix, AZ  85007

Comments may also be offered in-person at a Public Hearing | June 15, 2023, 3 p.m. | View Hearing Information > 

People who file comments on the permit will have the right to appeal the final decision as an appealable agency action to the Office of Administrative Hearing (OAH) pursuant to §41.1092.03, and the appeal must be filed within 30 days after the issuance of the final decision. The OAH may sustain, modify or reverse the final decision.

EPA Petition Process

This permit is subject to review by the Environmental Protection Agency (EPA) pursuant to 40 CFR 70.8 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 >

1 40 Code of Federal Regulations (CFR) § 51.118 | View >