This site/facility of interest is an online resource that provides interested parties easy access to information about the Minerals Research, Inc. (MRI) facility.

Air Quality Permitting

On Oct. 31, 2023, ADEQ received a Class II Air Quality Permit Application from MRI for the operation of its Cottonwood facility and deemed the application complete on Nov. 14, 2023. Under Arizona Administrative Code (A.A.C.)¹, MRI can legally operate its facility while ADEQ reviews the application, develops a draft air quality permit, and prepares a Technical Support Document for public input. As part of this process, ADEQ:

• Evaluates emissions sources within the facility’s property and estimates the potential emissions from those sources; and
• Reviews air dispersion modeling conducted by the applicant to ensure that public health will be protected from emissions from the proposed facility.

Once ADEQ completes this work, ADEQ:

• Conducts an informal community meeting to review the draft air quality permit.
• Starts the formal public participation process by publishing an official public notice in two local newspapers. This public notice seeks interested parties’ input and includes the start and end date of the public comment period (must be a minimum of 30 days) and provides interested parties with links to the draft air quality permit and Technical Support Document, including details about how to:
  • Submit comments in writing or in person, and 
  • Attend the formal public hearing.
• Reviews and considers all public comments received during the public comment period.
• Prepares a Responsiveness Summary that addresses all comments received.
• Makes a final permitting decision.

Community Engagement

• On Sept. 23, 2026, ADEQ held an informal community meeting to discuss the draft air quality permit | View Sept. 2 Community Update > | Fact Sheet > | View Sept. 23 Presentation >
• The public comment period for the draft air quality permit begins on Sept. 29, 2026, and ends on Nov. 30, 2026 | View Public Notice >
• On Nov. 18, 2026, ADEQ will hold an in-person public hearing to accept formal public comments on the draft air quality permit | View Hearing Details >

Documents

For more information about MRI, visit the Site/Facility of Interest section within the My Community page | View Page >

Looking for other activities related to this facility?

• MRI Air Quality Monitoring | View Monitoring >
• ADEQ WQARF Preliminary Investigation (PI) | View PI >
• Veterans of Foreign Wars (VFW) Post Site Voluntary Remediation Program (VRP) | View VFW VRP >

¹A.A.C. R18-2-510.D >