ID / county FIPS 16037 / county research

Custer County, Idaho: environmental and disease records

Cancer mortality in Custer County is 145.9 deaths per 100,000 people per year against a U.S. rate of 143.2. Federal databases place 230 regulated facilities, sites and hazards inside the county, led by Air permit holder (minor source) (147), Industrial wastewater discharge (39), NPDES wastewater discharge permit (14). EPA AirToxScreen estimates a lifetime cancer risk from outdoor air toxics of 10 in a million, driven mainly by formaldehyde.

Rates are age-adjusted per 100,000 people. A cancer signal is marked significant when the lower bound of its 95 percent confidence interval is above the U.S. rate. Facility counts use active federal records located inside the county boundary. Approximate county center: 44.2239, -114.2932.

How this county ranks in Idaho

View on the heat map Scan an address in this county

Cancer deaths and new cases versus the United States

Source: NCI and CDC State Cancer Profiles, both sexes, all ages. Sorted by the ratio of the county rate to the U.S. rate.

Cancer rates for Custer County compared with the United States
Cancer	Measure	County rate	U.S. rate	Times U.S.	95% interval	Years
All cancer	Deaths	145.9	143.2	1.02x	110.2 to 193.2	2020-2024
All cancer	New cases	356.8	453.4	0.79x	296.8 to 428.3	2019-2023
Lung & bronchus	New cases	35.5	51.8	0.69x	19.3 to 65.1	2019-2023

Mortality measures versus the U.S. county median

Source: County Health Rankings, built from CDC National Vital Statistics System death records. The comparison value is the median of all U.S. counties.

Mortality measures for Custer County
Measure	County	U.S. median	Difference	Unit
Premature death	8,306.4	9,842.6	-16%	years of life lost before age 75 per 100,000
Life expectancy	78.7	75.3	+5%	years
Child mortality	n/a	59.8	n/a	deaths under age 18 per 100,000
Infant mortality	n/a	6.2	n/a	deaths under age 1 per 1,000 live births
Injury deaths	146.9	96.9	+52%	deaths per 100,000
Drug overdose deaths	n/a	28.6	n/a	deaths per 100,000

Air toxics and air quality

EPA AirToxScreen 2020

Lifetime cancer risk from outdoor air toxics: 10 in a million. EPA treats 100 in a million as the upper end of acceptable risk and 1 in a million as the goal.

Formaldehyde7.82 per million
Carbon Tetrachloride2.43 per million
Acetaldehyde0.95 per million
Pahpom0.76 per million

EPA Air Quality Index 2025

Monitored on 96 days: 93 good, 0 unhealthy for sensitive groups or worse. Median AQI 10, peak 56.

Regulated facilities, sites and hazards by type

230 active records inside the county from EPA ECHO, TRI, Superfund, Brownfields, NPDES, EIA, FAA, FRA and corrections data.

Air permit holder (minor source)147
Industrial wastewater discharge39
NPDES wastewater discharge permit14
Public airport11
Gas station (mapped facility)8
Brownfield property4
EPA air quality monitor1
Commercial airport1
Small hazardous waste generator1
Heliport1
Scrapyard (mapped facility)1
TRI reporting facility1
Toxic chemical release facility (TRI)1

Highest-severity records

The 25 records with the highest Envyrofax severity in the county, with the agency identifier to cite in a records request.

Thompson Creek Mine, Clayton
TRI reporting facility.
EPA FRS registry ID 110000600430 (U.S. EPA ECHO) Agency record
Severity 9
Thompson Creek Mining Co, Clayton
Toxic chemical release facility (TRI). Chemicals: Nitrate compounds (water dissociable; reportable only when in aqueous solution), Copper compounds, Lead compounds. 1,724,672 lbs released over 5 years.
TRI facility ID 83227THMPSSQUAW (U.S. EPA Toxics Release Inventory)
Severity 7.8
Thompson Creek Mine, Clayton
NPDES wastewater discharge permit.
EPA FRS registry ID 110000600430 (U.S. EPA ECHO) Agency record
Severity 5.3
Mackay Wwtp, Mackay
NPDES wastewater discharge permit.
EPA FRS registry ID 110009726001 (U.S. EPA ECHO) Agency record
Severity 4.5
Garden Creek Farms, Challis
NPDES wastewater discharge permit.
EPA FRS registry ID 110070393459 (U.S. EPA ECHO) Agency record
Severity 4.5
Lost River Trout Hatchery, Mackay
NPDES wastewater discharge permit.
EPA FRS registry ID 110070694518 (U.S. EPA ECHO) Agency record
Severity 4.5
Hecla Mining Company Grouse Creek Unit, Stanley
NPDES wastewater discharge permit.
EPA FRS registry ID 110007513360 (U.S. EPA ECHO) Agency record
Severity 4.3
Thompson Creek Mine, Clayton
Small hazardous waste generator.
EPA FRS registry ID 110000600430 (U.S. EPA ECHO) Agency record
Severity 3.8
Thompson Creek Mine, Clayton
Air permit holder (minor source).
EPA FRS registry ID 110000600430 (U.S. EPA ECHO) Agency record
Severity 3.3
Idaho Department Of Fish And Game - Mackay State Fish Hatchery, Mackay
NPDES wastewater discharge permit.
EPA FRS registry ID 110070695083 (U.S. EPA ECHO) Agency record
Severity 3.3
Guffy, Clayton
Brownfield property.
EPA FRS registry ID 110071963693 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Bayhorse Mining District - Pacific Mine, None
Brownfield property.
EPA FRS registry ID 110071967448 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Bayhorse Mining District - Beardsley Mine, None
Brownfield property.
EPA FRS registry ID 110071967449 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Bayhorse Mining District - South Parcel, None
Brownfield property.
EPA FRS registry ID 110071967450 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Sawtooth State Fish Hatchery, Stanley
NPDES wastewater discharge permit.
EPA FRS registry ID 110035853993 (U.S. EPA ECHO) Agency record
Severity 2.8
Challis Mine, Challis
NPDES wastewater discharge permit.
EPA FRS registry ID 110067180455 (U.S. EPA ECHO) Agency record
Severity 2.8
Hk Contractors Inc 00207, Portable
Air permit holder (minor source). Penalties $25,000.
EPA FRS registry ID 110042093882 (U.S. EPA ECHO) Agency record
Severity 2.3
Coeur D'Alene Paving - Rathdrum 00432, Portable
Air permit holder (minor source). Penalties $300.
EPA FRS registry ID 110022408232 (U.S. EPA ECHO) Agency record
Severity 2
Copper Basin, Mackay
Public airport. O.
Record ID 0U2 (FAA / U.S. DOT)
Severity 2
Stanley, Stanley
Public airport. O.
Record ID 2U7 (FAA / U.S. DOT)
Severity 2
Cougar Ranch, Challis
Public airport. O.
Record ID D47 (FAA / U.S. DOT)
Severity 2
Challis, Challis
Commercial airport. O.
Record ID LLJ (FAA / U.S. DOT)
Severity 2
Twin Bridges, Ketchum
Public airport. O.
Record ID U61 (FAA / U.S. DOT)
Severity 2
Mackay, Mackay
Public airport. O.
Record ID U62 (FAA / U.S. DOT)
Severity 2
Upper Loon Creek Usfs, Challis
Public airport. O.
Record ID U72 (FAA / U.S. DOT)
Severity 2

Correctional facilities

Prisons, jails and corrections operations with an EPA facility record, and the drinking water and wastewater compliance attached to them.

No correctional facility with an EPA record is located in this county.

Discovery / public records

Records to request for Custer County

Idaho state cancer registry
Cancer incidence counts by census tract or ZIP code, by cancer type and year (de-identified). Any cancer cluster inquiries or investigations in Custer County, and their findings.
Idaho vital statistics office
Death certificate counts by cause of death and residence tract or ZIP code, and the years behind the mortality measures above.
Idaho health department, environmental epidemiology
Health consultations or assessments by ATSDR or the state health department covering the county, and any exposure investigations.
Idaho environmental agency and the U.S. EPA regional office
Compliance history, inspection reports, notices of violation, penalties and enforcement actions for each facility above, cited by EPA FRS registry ID.
Idaho drinking water program
Violation notices, sampling results and sanitary surveys for the public water systems serving the county, including any system serving a correctional facility.
Department of corrections or county sheriff
Water testing, grievances and environmental health inspections for the correctional facilities listed above.

Each Envyrofax address report includes a printable records request worksheet with the custodian and the exact request wording per finding.

Scan an address in Custer County View on the heat map All Idaho counties