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Sheridan County, Montana: environmental and disease records

Cancer mortality in Sheridan County is 180.5 deaths per 100,000 people per year against a U.S. rate of 143.2. Federal databases place 146 regulated facilities, sites and hazards inside the county, led by Rail grade crossing (116), NPDES wastewater discharge permit (19), Auto repair or body shop (mapped facility) (3). 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: 48.6991, -104.5433.

How this county ranks in Montana

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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 Sheridan County compared with the United States
Cancer	Measure	County rate	U.S. rate	Times U.S.	95% interval	Years
All cancer	Deaths	180.5	143.2	1.26x	135.5 to 239.1	2020-2024
All cancer	New cases	373.1	453.4	0.82x	298.5 to 462.8	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 Sheridan County
Measure	County	U.S. median	Difference	Unit
Premature death	8,225.9	9,842.6	-16%	years of life lost before age 75 per 100,000
Life expectancy	76.6	75.3	+2%	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	163.9	96.9	+69%	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: 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.

Formaldehyde10.61 per million
Carbon Tetrachloride2.87 per million
Acetaldehyde0.75 per million
Benzene0.68 per million

EPA Air Quality Index 2025

Monitored on 91 days: 79 good, 1 unhealthy for sensitive groups or worse. Median AQI 18, peak 197.

Regulated facilities, sites and hazards by type

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

Rail grade crossing116
NPDES wastewater discharge permit19
Auto repair or body shop (mapped facility)3
Gas station (mapped facility)3
EPA air quality monitor1
Commercial airport1
Brownfield property1
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.

Us Cbp Raymond Port Of Entry Be# Mt0050, Raymond
Toxic chemical release facility (TRI). Chemicals: Lead. Reports carcinogens. 134 lbs released over 5 years.
TRI facility ID 5925WRYMNDPBX15 (U.S. EPA Toxics Release Inventory)
Severity 6.1
City Of Plentywood, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110011049640 (U.S. EPA ECHO) Agency record
Severity 4.5
Border Steel - Plentywood, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110055637958 (U.S. EPA ECHO) Agency record
Severity 4.5
Raymond Port Of Entry Be# Mt0050, Raymond
TRI reporting facility.
EPA FRS registry ID 110046122664 (U.S. EPA ECHO) Agency record
Severity 4
Old Texaco Gas Station, Plentywood
Brownfield property.
EPA FRS registry ID 110038756824 (U.S. EPA Brownfields (ACRES)) Agency record
Severity 3
Outlook Sewer And Water Wwtf, Outlook
NPDES wastewater discharge permit.
EPA FRS registry ID 110011049249 (U.S. EPA ECHO) Agency record
Severity 2.8
Sher-Wood, Plentywood
Commercial airport. O.
Record ID PWD (FAA / U.S. DOT)
Severity 2
Abraxas Petroleum Corp State 2 16, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110040077430 (U.S. EPA ECHO) Agency record
Severity 1.5
Nelcon Mdot Big Muddy Creek 318, Redstone
NPDES wastewater discharge permit.
EPA FRS registry ID 110044268538 (U.S. EPA ECHO) Agency record
Severity 1.5
Samson Resources - Montana Field, Antelope
NPDES wastewater discharge permit.
EPA FRS registry ID 110044902772 (U.S. EPA ECHO) Agency record
Severity 1.5
Us Fish And Wildlife Service (Medicine Lake Nwr), Medicine Lake
NPDES wastewater discharge permit.
EPA FRS registry ID 110055044456 (U.S. EPA ECHO) Agency record
Severity 1.5
Wildcat Properties - Pro Tank Products, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110055045160 (U.S. EPA ECHO) Agency record
Severity 1.5
Nemont Telephone Coop - Outlook Fttp Upgrade Project, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110055200982 (U.S. EPA ECHO) Agency record
Severity 1.5
Transcanada Keystone Pipeline Sheridan County 318, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110064591892 (U.S. EPA ECHO) Agency record
Severity 1.5
Kim Or Kevin Price - Pole Barn Construction Project, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110064598289 (U.S. EPA ECHO) Agency record
Severity 1.5
Southwestern Energy - Bedwell, Redstone
NPDES wastewater discharge permit.
EPA FRS registry ID 110064630298 (U.S. EPA ECHO) Agency record
Severity 1.5
Wickens Construction Mdot Redstone 318, Redstone
NPDES wastewater discharge permit.
EPA FRS registry ID 110064633936 (U.S. EPA ECHO) Agency record
Severity 1.5
Plentywood Sanitary Sewer Improvements Ph 1, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110070238808 (U.S. EPA ECHO) Agency record
Severity 1.5
Town Of Reserve Lagoon, Reserve
NPDES wastewater discharge permit.
EPA FRS registry ID 110070562009 (U.S. EPA ECHO) Agency record
Severity 1.5
Reserve East, Reserve
NPDES wastewater discharge permit.
EPA FRS registry ID 110071656362 (U.S. EPA ECHO) Agency record
Severity 1.5
Outlook Branch Line Project, Outlook
NPDES wastewater discharge permit.
EPA FRS registry ID 110071963175 (U.S. EPA ECHO) Agency record
Severity 1.5
Town Of Plentywood Phase One Water System Improvements Project, Plentywood
NPDES wastewater discharge permit.
EPA FRS registry ID 110072151550 (U.S. EPA ECHO) Agency record
Severity 1.5
Sheridan Electric New Headquarters, Medicine Lake
NPDES wastewater discharge permit.
EPA FRS registry ID 110072189413 (U.S. EPA ECHO) Agency record
Severity 1.5
Private, Homestead
Rail grade crossing.
Record ID 080206T (Federal Railroad Administration)
Severity 1.2
Private, Homestead
Rail grade crossing.
Record ID 080207A (Federal Railroad Administration)
Severity 1.2

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 Sheridan County

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