Revised On: Mar. 24th, 2026 - 03:38 pm
ADEQ conducted a PI under our state’s Water Quality Assurance Revolving Fund Program | Learn More >
The PI focused on potential impacts to soil and groundwater in the Cottonwood area. ADEQ conducted sampling around the slag pile located at the Minerals Research, Inc. (MRI) facility, the former smelter operations, and the surrounding area.
ADEQ completed the PI after two rounds of data collection from March 2024 to October 2025 and concluded that groundwater is not impacted, but some surface soils contain elevated levels of arsenic and a few other metals above background or screening levels in certain areas. View the PI Report Addendum for details.
6th Street and Birch Street Site | View PI Report > | View PI Report Addendum >
ADEQ shared its data with the Arizona Department of Health Services for its health consultation work | View Health Consultation > | Fact Sheet >
Community Engagement
For more information about MRI, visit the Site/Facility of Interest section within the My Community page | View Page >
