Pollution Analyst
How it works→
Superfund / NPL site · EPA Superfund SEMS through latest publishNPL Final

Iron King Mine - Humboldt Smelter

This site is currently on the EPA Superfund National Priorities List and remains under federal cleanup oversight. Most-cited contaminant of concern: Aluminum.

Parts Of Secs 15,16&22, Twp 13N, Rng 1E, Dewey-Humboldt, Arizona · ZIP 86327 · EPA ID AZ0000309013

See Yavapai ContaminantsEquity contextHow we read Superfund data
CLEANUP TIMELINE

Listing-date and cleanup-phase enrichment from EPA's per-site SEMS profile is queued for a follow-up ingest pass. Until then, this section will populate from EPA's published timeline data.

Anomaly engine

Notable Signals

No notable signals at this Superfund site for the current ingest. Cleanup-phase and SEMS-action flags are deferred to a follow-up engineering pass.

Contaminants of concern · per EPA SEMS

What's In This Site

Each row pairs a contaminant with the medium it was found in (the exposure pathway). Hover any named contaminant for an agency-cited health-risk summary. Cited count = number of SEMS decision records (RODs and related) that name the pair.

ContaminantPathwayCited
AluminumHealth riskInhaled aluminum fumes can cause lung scarring (aluminosis); high cumulative exposure has been linked to neurological effects. (NIOSH)Surface Water1
AntimonyHealth riskInhaled antimony trioxide is an IARC Group 2B possible carcinogen; respiratory and cardiovascular effects from long-term exposure. EPA MCL 6 µg/L. (IARC, EPA)Soil1
AntimonyHealth riskInhaled antimony trioxide is an IARC Group 2B possible carcinogen; respiratory and cardiovascular effects from long-term exposure. EPA MCL 6 µg/L. (IARC, EPA)Solid Waste1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Groundwater1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Soil1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Solid Waste1
BariumHealth riskSoluble barium compounds are toxic if ingested, affecting the heart, kidneys, and nervous system. Insoluble forms (e.g. barium sulfate) are far less toxic. (EPA)Surface Water1
BerylliumSurface Water1
CadmiumSoil1
CadmiumSolid Waste1
CadmiumSurface Water1
Chlorinated Dioxins And FuransSoil1
Chlorinated Dioxins And FuransSolid Waste1
CobaltSoil1
CobaltSurface Water1
CopperHealth riskInhaled copper fumes cause metal-fume fever; chronic ingestion above EPA's 1.3 mg/L action level damages the liver. (EPA)Soil1
CopperHealth riskInhaled copper fumes cause metal-fume fever; chronic ingestion above EPA's 1.3 mg/L action level damages the liver. (EPA)Solid Waste1
CopperHealth riskInhaled copper fumes cause metal-fume fever; chronic ingestion above EPA's 1.3 mg/L action level damages the liver. (EPA)Surface Water1
CyanideHealth riskAcutely lethal at high doses by blocking cellular respiration; chronic low-dose exposure damages the thyroid and nervous system. (EPA, ATSDR)Surface Water1
Dioxins And DibenzofuransSoil1
IronSurface Water1
LeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)Groundwater1
LeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)Soil1
LeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)Solid Waste1
ManganeseHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)Soil1
ManganeseHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)Surface Water1
MercuryHealth riskNeurotoxin. Methylmercury bioaccumulates up the food chain and damages the developing nervous system. (EPA, ATSDR)Surface Water1
NitrateHealth riskDrinking-water nitrate causes methemoglobinemia ('blue-baby syndrome') in infants; EPA MCL is 10 mg/L as N. (EPA)Groundwater1
SeleniumSoil1
SeleniumSolid Waste1

Showing the top 30 pairs by SEMS citation count. 6 additional (contaminant, pathway) pairs are recorded for this site.

Drinking-water linkage · SDWIS

No Groundwater PWSes Serving Communities Within 3 Miles

No SDWIS public water systems drawing groundwater (or mixed sources) serve a community whose centroid sits within 3 miles of this site. Empty results are not a guarantee of non-impact — distance is computed to served-place centroids, and SDWIS does not expose individual wellhead locations.

Methodology: served-city centroid (TIGER 2020) is used as the PWS coordinate. Source-water classification from SDWIS primary_source_code; only groundwater and mixed-source systems are queried. Click any system above for its full SDWIS profile.

Equity context · ACS 2018-2022 block-group demographics

Who Lives Near This Site

Dewey-Humboldt, Arizona (no Census block groups within 1 mile — falling back to host city; disparity scores aggregated by centroid containment): a population of 4,363. Why we surface this →

POPULATION SHARE
12.3%

Low-income

POPULATION SHARE
11.1%

People of color

POPULATION SHARE
5.2%

Under age 5

POPULATION SHARE
41.3%

Over age 64

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror). NPL site proximity contributes to the national EJ pattern; indicator-level percentile and disparity scores are surfaced on the county page and the state page.

Source. EPA Superfund Enterprise Management System (SEMS) · retrieved 2026-05-07. SEMS is a federal public-domain dataset under 17 USC §105.

What this is not. We report EPA's published Superfund record — site listing, status, and contaminants of concern as named in EPA's decision documents. We do not perform site visits, independent air or water sampling, or current-state health-risk assessment. NPL listing reflects EPA's Hazard Ranking Score at a point in time; it does not by itself describe present-day exposure.