The complete official site file can be reviewed at:

EPA Region IX
Records Center
Mail Stop SFD-7C
95 Hawthorne St.
Room 403
San Francisco, CA 94105
415-536-2000 

Local repository:

Dewey-Humboldt Town Library
2735 N. Corral St.
Dewey-Humboldt, AZ 86329
928-632-5049

or 

Interested parties can review site information in person at the ADEQ Record Center | Learn More >

Site Documents:

• EPA Work Notice (April 2026) | View Notice >
• Fact Sheet (September 2016) | View 2016 FS > 
• Fact Sheet (March 2017) | View March 2017 FS > 
• Fact Sheet (August 2017) | View Aug. 2017 FS > 
• Fact Sheet (October 2019) | View 2019 FS >
• Fact Sheet (April 2025) | View 2025 FS >
• Feasibility Study (September 2022) | View Feasibility Study > 
• Proposed Plan (March 2023) | View Plan > 
• Proposed Plan Fact Sheet (March 2023) | View Plan FS >   
• Post RI/FS Assessment Humboldt Smelter Incremental Sampling Methodology Sampling Analysis Plan (August 2023) | View Aug. SAP > 
• Post RI/FS Assessment Humboldt Smelter Incremental Sampling Methodology Sampling Analysis Plan (October 2023) | View Oct. SAP >
• Record of Decision (October 2023) | View ROD >
• Explanation of Significant Differences for Manganese | View Explanation >

Related Links

• EPA's Site Page | Visit Page>