Summary:

ADEQ amended parts of A.A.C. Title 18, Chapter 2, Articles 1, 3, and 5 for the following purposes: 

1. to continue to allow permitted facilities to adopt voluntary permit conditions to protect ambient air quality; 
2. to make technical corrections to ADEQ’s new source review rules to improve clarity; 
3. to correct the gaps between ADEQ’s rules and the U.S. Environmental Protection Agency’s Title V requirements regarding portable Title V sources as well as procedural requirements; and 
4. to fulfill a five-year rule review commitment to the Governor’s Regulatory Review Council (GRRC). 

Documents:

Notice of Docket Opening | View NDO >

Notice of Proposed Rulemaking | View NPRM >

Notice of Comment Period & Public Hearing

• Comment Period: Nov. 15, 2024 – Dec. 16, 2024
• Virtual Public Hearing
  Date: Dec. 16, 2024
  Time: 1 p.m. (Arizona)
  Location: GoToWebinar

Notice of Public Information | View >

ADEQ reopened its record, extending the comment period and held an additional public hearing for the notice of proposed rulemaking.

Notice of Extended Comment Period & Additional Public Hearing

• Comment Period: May 20, 2025 – June 20, 2025
• Virtual Public Hearing
  Date: June 20, 2025
  Time: 11 a.m. (Arizona)
  Location: Online via GoToWebinar

Notice of Final Rulemaking (NFRM) (filed with the Secretary of State: January 2, 2026) |  View NFRM >

Effective Date: Feb. 7, 2026

Additional Information:

• Governor’s Regulatory Review Council (GRRC) Study Session and Council Meeting Agendas, Meeting Documents, including PDF copies of materials provided to GRRC for rulemakings, and Minutes will be available on GRRC's website | Visit Website > 
• State Implementation Plan and State Operating Permit Program Revision | View >

Summary:

ADEQ amended existing rules and adopted new rules in Arizona Administrative Code (A.A.C) Title 18, Chapter 2, Article 13 (State Implementation Plan Rules for Specific Locations) to codify the permitting conditions included in the 2023 Hayden sulfur dioxide (SO₂) State Implementation Plan (SIP) revision and the 2024 Hayden lead (Pb) SIP revision.

Documents: 

Notice of Docket Opening | View NDO >

Notice of Proposed Rulemaking | View NPRM >

Notice of Comment Period & Public Hearing

• Comment Period: Sept. 12, 2025 – Oct. 14, 2025 
• Virtual Public Hearing:
  • Date: Oct. 14, 2025
  • Time: 10:30 a.m.
  • Location: Online via GoToWebinar

Notice of Final Rulemaking (submitted to the Secretary of State on Dec. 9, 2025) | View NFRM >

Effective Date: Feb. 7, 2026

Additional Information: 

• Governor’s Regulatory Review Council (GRRC) Study Session and Council Meeting Agendas, Meeting Documents, including PDF copies of materials provided to GRRC for rulemakings, and Minutes will be available on GRRC's website | Visit Website >
• 2023 SIP Appendix C Modeling Technical Support Document for the Hayden SO₂ Nonattainment Area | View Appendix >
• On Dec. 10, 2025, ADEQ submitted the 2025 SIP Revision: Rules Incorporating Hayden Smelter Permit Conditions to Supplement Arizona’s 2023 SO₂ SIP to EPA | View SO₂ SIP Revision >
• On Dec. 10, 2025, ADEQ submitted the 2025 SIP Revision: Rules Incorporating Hayden Smelter Permit Conditions to Supplement Arizona’s 2024 Pb SIP to EPA  | View Pb SIP Revision >

Summary:

ADEQ amended A.A.C. Title 18, Chapter 2, Articles 1, 3, 6, 7, and 15 to improve consistency in language between state and federal regulations. In addition, ADEQ amended A.A.C. Title 18, Chapter 2, Article 8 to eliminate requirements no longer necessary for the operation of state government due to preemption of ADEQ's statutory authority to regulate air emissions from certain mobile sources. These amendments fulfilled a Five Year Rule Review commitment to the Governor’s Regulatory Review Council.

Documents:

• Notice of Docket Opening | View >
• Notice of Proposed Expedited Rulemaking | View >
• Notice of Rulemaking  | View >

Additional Information: 

Governor’s Regulatory Review Council (GRRC) Study Session and Council Meeting Agendas, Meeting Documents, including PDF copies of materials provided to GRRC for rulemakings, and Minutes | Visit GRRC Page >

Effective Date: Jul. 3, 2024