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Siskiyou County, California: environmental and disease records

Cancer mortality in Siskiyou County is 161.6 deaths per 100,000 people per year against a U.S. rate of 143.2, a statistically significant excess. Federal databases place 632 regulated facilities, sites and hazards inside the county, led by Rail grade crossing (180), Wastewater plant (mapped facility) (117), NPDES wastewater discharge permit (109). EPA AirToxScreen estimates a lifetime cancer risk from outdoor air toxics of 20 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: 41.5016, -122.5446.

How this county ranks in California

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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 Siskiyou County compared with the United States
Cancer	Measure	County rate	U.S. rate	Times U.S.	95% interval	Years
Kidney & renal pelvis	Deaths	5.6	3.4	1.65x	3.3 to 9.2	2020-2024
Bladder	Deaths	6.3	4.1	1.54x	4 to 9.9	2020-2024
Leukemia	Deaths	8.2	5.7	1.44x	5.4 to 12.3	2020-2024
Brain & nervous system	Deaths	6.3	4.4	1.43x	3.7 to 10.2	2020-2024
Pancreas	Deaths	14	11.3	1.24x	10.2 to 18.9	2020-2024
Brain & nervous system	New cases	7.1	6.2	1.15x	4.4 to 11.1	2019-2023
All cancer	Deaths	161.6	143.2	1.13xSignificant	148.2 to 176.2	2020-2024
Esophagus	New cases	4.8	4.6	1.04x	2.6 to 8.3	2019-2023
Esophagus	Deaths	3.8	3.7	1.03x	2.1 to 6.7	2020-2024
Lung & bronchus	Deaths	30.2	30.2	1x	24.8 to 36.8	2020-2024
Bladder	New cases	17.7	18.7	0.95x	13.5 to 23.2	2019-2023
Melanoma of the skin	New cases	22.1	23.8	0.93x	16.8 to 28.7	2019-2023
Liver & bile duct	Deaths	6.1	6.6	0.92x	3.9 to 9.5	2020-2024
Pancreas	New cases	12.6	13.9	0.91x	9 to 17.2	2019-2023
Kidney & renal pelvis	New cases	15.1	17.9	0.84x	10.7 to 20.8	2019-2023
Liver & bile duct	New cases	7.3	8.7	0.84x	4.7 to 11.1	2019-2023
Lung & bronchus	New cases	42.4	51.8	0.82x	36.1 to 49.8	2019-2023
All cancer	New cases	357.4	453.4	0.79x	336.5 to 379.5	2019-2023
Leukemia	New cases	11.4	14.5	0.79x	7.9 to 16.2	2019-2023
Non-Hodgkin lymphoma	Deaths	3.6	4.8	0.75x	2.1 to 6.5	2020-2024
Non-Hodgkin lymphoma	New cases	12	18.5	0.65x	8.4 to 16.8	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 Siskiyou County
Measure	County	U.S. median	Difference	Unit
Premature death	13,488.2	9,842.6	+37%	years of life lost before age 75 per 100,000
Life expectancy	73.1	75.3	-3%	years
Child mortality	85.5	59.8	+43%	deaths under age 18 per 100,000
Infant mortality	7.8	6.2	+25%	deaths under age 1 per 1,000 live births
Injury deaths	133.8	96.9	+38%	deaths per 100,000
Drug overdose deaths	38.9	28.6	+36%	deaths per 100,000

Air toxics and air quality

EPA AirToxScreen 2020

Lifetime cancer risk from outdoor air toxics: 20 in a million. EPA treats 100 in a million as the upper end of acceptable risk and 1 in a million as the goal.

Formaldehyde15.96 per million
Carbon Tetrachloride2.64 per million
Acetaldehyde2.06 per million
Pahpom0.98 per million

EPA Air Quality Index 2025

Monitored on 363 days: 284 good, 4 unhealthy for sensitive groups or worse. Median AQI 37, peak 166.

Regulated facilities, sites and hazards by type

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

Rail grade crossing180
Wastewater plant (mapped facility)117
NPDES wastewater discharge permit109
Small hazardous waste generator45
Gas station (mapped facility)38
Large hazardous waste generator30
Brownfield property26
Industrial wastewater discharge21
Hazardous waste transporter20
Auto repair or body shop (mapped facility)12
Public airport9
Hydroelectric plant5
Toxic chemical release facility (TRI)4
Scrapyard (mapped facility)3
TRI reporting facility3
EPA air quality monitor2
Superfund (NPL) site2
Major air pollution source1
Air permit holder (minor source)1
Commercial airport1
Heliport1
Landfill (mapped facility)1
Biomass power plant1

Highest-severity records

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

J.H. Baxter & Co., Weed
Superfund (NPL) site. Hazard Ranking System score 34.8. NPL Site.
EPA site ID CAD000625731 (U.S. EPA Superfund (SEMS/NPL)) Agency record
Severity 10
Blue Ledge Mine, Rogue River - Siskiyou National Forest
Superfund (NPL) site. Hazard Ranking System score 50.3. NPL Site.
EPA site ID CAN000906063 (U.S. EPA Superfund (SEMS/NPL)) Agency record
Severity 10
Roseburg Forest Products Co. - Weed Facility, Weed
Toxic chemical release facility (TRI). Chemicals: Lead compounds, Lead And Lead Compounds, Dioxin and dioxin-like compounds, Propylene. Reports carcinogens. 32 lbs released over 5 years.
TRI facility ID 96094RSBRG98MIL (U.S. EPA Toxics Release Inventory)
Severity 5.7
Shasta Valley Asphalt, Yreka
Toxic chemical release facility (TRI). Chemicals: Polycyclic aromatic compounds. Reports carcinogens.
TRI facility ID 9609WSHSTV1251S (U.S. EPA Toxics Release Inventory)
Severity 4.5
Timber Products Co., Yreka
Toxic chemical release facility (TRI). Chemicals: Lead. Reports carcinogens.
TRI facility ID 9609WTMBRP13NPH (U.S. EPA Toxics Release Inventory)
Severity 4.5
Roseburg Forest Products, Weed
TRI reporting facility.
EPA FRS registry ID 110002794753 (U.S. EPA ECHO) Agency record
Severity 4.5
Yreka, Yreka
EPA air quality monitor.
Record ID 060932001 (U.S. EPA AirData)
Severity 4.4
J.H. Baxter & Co., Weed
TRI reporting facility.
EPA FRS registry ID 110000486251 (U.S. EPA ECHO) Agency record
Severity 4
Mt. Shasta Wwtp, Mount Shasta
NPDES wastewater discharge permit.
EPA FRS registry ID 110006657411 (U.S. EPA ECHO) Agency record
Severity 4
Southern Pacific Transportation Co, Dunsmuir
Large hazardous waste generator. Penalties $66,000.
EPA FRS registry ID 110018951393 (U.S. EPA ECHO) Agency record
Severity 4
Timber Products Co., Yreka
TRI reporting facility.
EPA FRS registry ID 110060334687 (U.S. EPA ECHO) Agency record
Severity 4
Siskiyou Exploration Project, Dorris
NPDES wastewater discharge permit.
EPA FRS registry ID 110070094785 (U.S. EPA ECHO) Agency record
Severity 4
Nor-Cal Products Inc., Yreka
Large hazardous waste generator.
EPA FRS registry ID 110038863218 (U.S. EPA ECHO) Agency record
Severity 3.8
Roseburg Forest Products, Weed
Major air pollution source.
EPA FRS registry ID 110002794753 (U.S. EPA ECHO) Agency record
Severity 3.5
Mccloud C.S.D., Mccloud
NPDES wastewater discharge permit.
EPA FRS registry ID 110013170451 (U.S. EPA ECHO) Agency record
Severity 3.3
Roseburg Commerce Park, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110038748335 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Roseburg Orchard Property, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110039062153 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Old Mt. Shasta Lumber Mill Property, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110039219618 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Former Truck Repair Shop, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110039219627 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Former Roseburg Lumber Mill Property, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110039219654 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Roseburg Mill, Mt. Shasta
Brownfield property.
EPA FRS registry ID 110039531147 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Mccloud Timber County Ranch Road, Mccloud
Brownfield property.
EPA FRS registry ID 110039531183 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
County Yard, Yreka
Brownfield property.
EPA FRS registry ID 110054625269 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Former Hi-Ridge Lumber Mill Site #2, Yreka
Brownfield property.
EPA FRS registry ID 110060849827 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
311 South Main St, Yreka
Brownfield property.
EPA FRS registry ID 110071964145 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3

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 Siskiyou County

California 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 Siskiyou County, and their findings.
California vital statistics office
Death certificate counts by cause of death and residence tract or ZIP code, and the years behind the mortality measures above.
California health department, environmental epidemiology
Health consultations or assessments by ATSDR or the state health department covering the county, and any exposure investigations.
California 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.
California 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.

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