The Arizona Department of Environmental Quality announced on Feb. 21 that it has terminated Minerals Research, Inc.’s consent order, which revokes the company’s authorization to operate.
MRI has been engaged in processing a copper slag pile located at 705 E. Birch Street to produce roofing granules, abrasive blasting media and pavement aggregate.
On Sept. 11, 2023, ADEQ issued a notice of violation to MRI for failing to obtain the correct permit. MRI subsequently submitted an air quality permit application to ADEQ on Oct. 31.
On Oct. 5, MRI voluntarily ceased operations, and on Oct. 12, MRI and ADEQ entered into a consent order that outlined operational requirements for MRI’s facility and required the development of a fugitive dust control plan. Operations resumed under the consent order the following day. The consent order was not a substitute for a permit and did not eliminate the need for one. Effective Feb. 21, MRI is no longer authorized to operate its facility until ADEQ reaches a decision on the pending air quality permit application.
The consent order was terminated based on the facility’s failure of a performance test on Jan. 31 that indicated that the facility was not meeting the emissions limit specified in the consent order.
Following a community meeting involving ADEQ and city of Cottonwood representatives on Dec. 13, ADEQ agreed to conduct ambient air quality monitoring for particulate matter and heavy metals in the vicinity of MRI’s facility. The department placed trailers at the Cottonwood kids’ park and the VFW to take samples for PM-10 and PM-2.5 particulate matter sizes and lead beginning on Feb. 15.
ADEQ has also initiated a preliminary investigation under the state Water Quality Assurance Revolving Fund program. This investigation will focus on the MRI facility’s potential effects on groundwater and soil. ADEQ is in the process of obtaining access to the facility’s property, surrounding areas and groundwater wells in the area to take soil and groundwater samples. The investigation will take an estimated six to eight months to complete.
ADEQ is also reviewing MRI’s air quality permit application and expects to make the documentation available to the public for review and comment in the following months.
There will then be an informal community meeting and a formal public hearing on the draft air quality permit before ADEQ makes a decision.
