Dewey-Humboldt, AZ
Iron King Mine - Humboldt Smelter is listed in the EPA Superfund Enterprise Management System with an NPL status of NPL Site and a Hazard Ranking System (HRS) score of 52.69. The site is located in Dewey-Humboldt, AZ. Superfund National Priorities List inclusion is the EPA's formal designation that a contaminated site qualifies for long-term federal cleanup authority under the Comprehensive Environmental Response, Compensation, and Liability Act.
EPA Superfund records catalog 36 contaminants associated with this site, documented through the remedial investigation process. Construction of the cleanup remedy has not yet been designated as complete in the EPA record.
NPL listing does not, by itself, establish a health risk to nearby residents, it triggers federal authority to investigate, score, and remediate. HRS scores of 28.50 or above qualify a site for the NPL; the ranking weighs contaminant toxicity, release pathways, waste quantity, and affected population. For current site conditions and community health guidance, contact the Arizona environmental or health agency and the EPA Regional Superfund office listed on the official site profile.
What is the cleanup status of this Superfund site?
Contaminants
| Contaminant | Media |
|---|---|
| ALUMINUM | Surface Water |
| ANTIMONY | Soil |
| ANTIMONY | Solid Waste |
| ARSENIC | Groundwater |
| ARSENIC | Soil |
| ARSENIC | Solid Waste |
| BARIUM | Surface Water |
| BERYLLIUM | Surface Water |
| CADMIUM | Soil |
| CADMIUM | Solid Waste |
| CADMIUM | Surface Water |
| CHLORINATED DIOXINS AND FURANS | Soil |
| CHLORINATED DIOXINS AND FURANS | Solid Waste |
| COBALT | Soil |
| COBALT | Surface Water |
| COPPER | Soil |
| COPPER | Solid Waste |
| COPPER | Surface Water |
| CYANIDE | Surface Water |
| DIOXINS AND DIBENZOFURANS | Soil |
| IRON | Surface Water |
| LEAD | Groundwater |
| LEAD | Soil |
| LEAD | Solid Waste |
| MANGANESE | Soil |
| MANGANESE | Surface Water |
| MERCURY | Surface Water |
| NITRATE | Groundwater |
| SELENIUM | Soil |
| SELENIUM | Solid Waste |
| SELENIUM | Surface Water |
| THALLIUM | Soil |
| VANADIUM | Surface Water |
| ZINC | Soil |
| ZINC | Solid Waste |
| ZINC | Surface Water |
Location
Other Superfund Sites in Arizona
| Site Name | Status | HRS Score |
|---|---|---|
| Apache Powder Co. | NPL Site | 39.09 |
| Hassayampa Landfill | NPL Site | 42.79 |
| Indian Bend Wash Area | NPL Site | 42.24 |
| Lukachukai Mountains Mining District | NPL Site | 50.00 |
| Luke Air Force Base | Deleted NPL Site | 37.93 |
| Motorola, Inc. (52nd Street Plant) | NPL Site | 40.83 |
| Mountain View Mobile Home Estates | Deleted NPL Site | - |
| Nineteenth Avenue Landfill | Deleted NPL Site | 54.27 |
| Phoenix-Goodyear Airport Area | NPL Site | 45.91 |
| Tucson International Airport Area | NPL Site | 57.80 |
Frequently Asked Questions
What is the Iron King Mine - Humboldt Smelter Superfund site? ▼
Is Iron King Mine - Humboldt Smelter dangerous to live near? ▼
What is the HRS score for Iron King Mine - Humboldt Smelter? ▼
What contaminants are at the Iron King Mine - Humboldt Smelter site? ▼
What is the cleanup status of Iron King Mine - Humboldt Smelter? ▼
About Superfund
The National Priorities List (NPL) is the list of sites of national priority among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States. The NPL is intended primarily to guide the EPA in determining which sites warrant further investigation.
The Hazard Ranking System (HRS) score is the principal mechanism the EPA uses to evaluate sites for placement on the NPL. Sites with an HRS score of 28.50 or greater are eligible for the NPL. Higher scores indicate greater potential risk.
The EPA's Superfund cleanup process typically follows these phases: preliminary assessment, site inspection, NPL listing, remedial investigation/feasibility study, remedy selection, remedial design/action, construction completion, post-construction completion, and NPL deletion. Some sites remain on the NPL for decades.
PlainEnviro presents this data without advocacy framing. The presence of a site on the NPL does not by itself indicate an immediate health risk to nearby residents. For site-specific health questions, consult your local environmental or health agency.
Read our methodology - how this data is sourced, computed, and verified.