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PRESS RELEASE | ADEQ Terminates Minerals Research, Inc. Consent Order Revoking the Facility’s Authorization to Operate


ADEQ Terminates Minerals Research, Inc. Consent Order Revoking the Facility’s Authorization to Operate

PHOENIX (Feb. 21, 2024) — The Arizona Department of Environmental Quality announced today its termination of a Consent Order with Minerals Research, Inc. (MRI). Effective immediately, this action revokes MRI's authorization to operate its facility located at 705 E Birch St. in Cottonwood, Arizona, until ADEQ reaches a decision on MRI’s pending air quality permit application, which ADEQ received on Oct. 31, 2023. 

ADEQ terminated the Consent Order based on certified results received on Feb. 13, 2024, which showed the facility failed a performance test conducted on Jan. 31, 2024. This failed performance test indicated the facility was not meeting a strict emission limit condition in the Consent Order. 

ADEQ is currently reviewing MRI’s air quality permit application and expects to make proposed air quality permit documents available to the public for review and comment in the coming months. The air quality permitting process involves a comprehensive review of emissions calculations and associated air dispersion modeling and development of a draft air quality permit and technical supporting document. ADEQ will make the permit documents available for public comment, and conduct both an informal community meeting and a formal public hearing for the draft air quality permit prior to making a final permit decision.

ADEQ Ambient Air Quality Monitoring

At a community meeting ADEQ conducted on Dec. 13, 2023, in partnership with the City of Cottonwood, ADEQ committed to conduct ambient air quality monitoring for particulate matter and heavy metals in the vicinity of MRI’s facility. ADEQ set up ambient air quality monitoring equipment at the two locations discussed at the community meeting – the Cottonwood Kids Park and the Veterans of Foreign Wars – and trained local volunteers on how to assist ADEQ with the project. Ambient air quality monitoring commenced on Feb. 15, 2024. ADEQ will conduct air quality monitoring as long as it takes to obtain the quality data necessary to provide to the Arizona Department of Health Services (ADHS) for its planned health consultation. Data collected when MRI is not operating will represent background concentrations, and serve as a baseline to compare with potential additional ambient air quality monitoring ADEQ would conduct if a new air quality permit is issued and the facility recommences operations.

ADEQ Preliminary Investigation (PI)

ADEQ has initiated a PI under our state Water Quality Assurance Revolving Fund (WQARF) program. The PI is focused on potential impacts to soil and groundwater associated with the slag pile located at the MRI facility and in the surrounding area. In addition to conducting a review of available historical reports and environmental data regarding operations and activities in the area of the MRI facility, ADEQ is in the process of obtaining access to the facility property, surrounding areas, and any groundwater wells that may be present and available to sample. Pending access, ADEQ will collect soil and groundwater samples for laboratory testing as part of the PI. ADEQ anticipates that the PI, including data evaluation, will take six to eight months to complete, following which ADEQ will determine what, if any, additional action may be warranted. ADEQ also will share all data collected for the PI with ADHS.


In September 2023, ADEQ issued a Notice of Violation (NOV) to MRI based on a determination that the company did not have the appropriate air quality permit for its operations. The NOV required the company to submit an application for a new air quality permit. Due to the extensive timeframe and process for considering and reaching a decision on an application for the new air quality permit required, ADEQ and MRI agreed to enter into a legally binding agreement called a Consent Order. The Consent Order, executed on Oct. 12, 2023, specified the interim, stringent operational limits and air pollution control requirements MRI must implement at the facility to protect public health. 


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