Contaminant 8000
Unresolved Revised Total Coliform Rule violation cited in 2023 (contaminant 8000).
City · TRI 2024
Gillette, Wyoming Pollution
1 TRI facilities inside the city limits and 43 public water systems serving residents. In-city TRI releases more than halved year over year (-96%). Toxic releases concentrations have more than halved since 2023.
FIPS 5631855 · population 33,158 · Campbell County
Anomaly engine
Notable Signals
Chlorine
Unresolved Disinfectants and Disinfection Byproducts (Stage 2) violation cited in 2023 (chlorine).
Contaminant 8000
Unresolved Revised Total Coliform Rule violation cited in 2025 (contaminant 8000).
Arsenic
Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2020 (arsenic).
Showing the 4 most editorially weighted signals out of 16. Lower-severity signals fold into the chemical breakdown and history charts below.
Pollutant pathways
Gillette Pollutant Multi-Year Trends
PM2.5 annual mean (NAAQS 9 µg/m³ (annual))Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.
PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 13% since 2010.
PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour))Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.
PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations are up 31% since 2010.
Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour))Health riskGround-level ozone (smog) forms when vehicle and industrial emissions react in sunlight. Inflames the airways, triggers asthma attacks, and worsens heart and lung disease.
Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations are up 28% since 2011.
NO₂ annual mean (NAAQS 53 ppb (annual))Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.
NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have more than halved since 2011.
Lifetime cancer risk all pollutants (100 in a million (EPA elevated threshold))Health riskEPA-modeled added cancer cases per million residents from a lifetime of breathing local air toxics. EPA flags 100-in-a-million as elevated.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Formaldehyde ambient mean (0.077 µg/m³ (1-in-a-million URE))Health riskAn air toxic emitted by refineries, wood products, and combustion. EPA classifies it as a known human carcinogen — long-term inhalation raises cancer risk.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Benzene ambient mean (0.13 µg/m³ (1-in-a-million URE))Health riskAn air toxic from gasoline, refineries, and tobacco smoke. A known human carcinogen — chronic exposure is linked to leukemia and other blood cancers.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
TRI air releases (5.1 fugitive + 5.2 stack)Health riskToxic chemicals reported by industrial facilities as released into the air — fugitive leaks plus smokestack emissions. Higher pounds means more inhaled exposure for nearby residents.
TRI air releases (5.1 fugitive + 5.2 stack) volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.
TRI water releases (5.3)Health riskToxic chemicals reported by industrial facilities as discharged to surface waters (rivers, lakes, the ocean). Affects fishing, recreation, and downstream drinking-water intakes.
TRI water releases (5.3) volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.
TRI land + off-site releasesHealth riskToxic chemicals released to land on-site or transferred off-site for disposal — landfills, deep-well injection, and similar. Risks groundwater contamination over time.
TRI land + off-site releases volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.
Greenhouse gases (GHGRP large emitters, through 2023)Health riskGreenhouse gases reported by large industrial emitters under EPA's GHGRP, in metric tons of CO₂ equivalent. Drives climate warming and the heat-related health effects that follow.
Greenhouse gases (GHGRP large emitters, through 2023) concentrations are up 34% since 2010.
Top facilities · TRI 2024
Largest Emitters Inside The City
| Facility | Top chemical | Total releases | YoY |
|---|---|---|---|
| 50 ButtesWestern Midstream Partners LP | n-HexaneHealth riskPeripheral neurotoxin. Chronic exposure causes numbness and paralysis in the extremities. (ATSDR) | 5k lb | -96% |
Drinking water · SDWIS
Water Systems Serving Gillette
354 unresolved violations on the SDWIS record across utilities serving this city.
43
Utilities serving
45,157
Population served
7
Health-based · 5yr
354
Unresolved
| Water system | PWSID | Population served | Health-based · 5yr | Status |
|---|---|---|---|---|
| Wrangler Estates Private | WY5601474 | 250 | 2 | UNRESOLVED |
| Lakeview Mobile Home Park Private | WY5601449 | 36 | 1 | UNRESOLVED |
| Countryside Water Users, Inc. Private | WY5600192 | 360 | 2 | Returned to compliance |
| Hoy Mobile Home Park Private | WY5600141 | 100 | 1 | Returned to compliance |
| Rozet Ranchettes I&S District Municipal | WY5601620 | 85 | 1 | Returned to compliance |
| Gillette, City Of Municipal | WY5600019 | 32,222 | 0 | UNRESOLVED |
| North Gurley Mobile Home Park Private | WY5601721 | 128 | 0 | UNRESOLVED |
| Ward Creek Landowners Association Private | WY5600850 | 77 | 0 | UNRESOLVED |
| Stroup Trailer Court Private | WY5600145 | 74 | 0 | UNRESOLVED |
| Hagens Estates Private | WY5601739 | 29 | 0 | UNRESOLVED |
Showing the 10 systems with recorded health-based or unresolved violations. 33 additional systems are in compliance with no recorded health-based violations in the past 5 years and are not individually tabulated.
A public water systemis the regulated entity, not the city. EPA's SDWIS definition covers anything serving 25+ people for 60+ days a year or with 15+ service connections — that includes municipal utilities (City of Stockton), water districts, mobile home parks operating their own wells, schools, and small private subdivisions. Each system is independently monitored. Some systems serve multiple cities; some cities are served by many systems.
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Who Lives In Gillette
Gillette, Wyoming (Census place block groups): 33,158 residents. City disparity score for pm2.5 (fine particulate) sits well below the reference (2). Why we surface this →
9.7%
Low-income
13.9%
People of color
9.1%
Under age 5
11.3%
Over age 64
- PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.2below the national median
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.55near the national median
- Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.53near the national median
- Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.31below the national median
- Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.95in the highest 5% nationally
- Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.35below the national median
- Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.33below the national median
- Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.56near the national median
- RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.34below the national median
- Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.14below the national median
- Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.88in the highest 20% nationally
- NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.48near the national median
- Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 2 | well below the reference |
| Ozone | 79 | below the reference |
| Nitrogen dioxide (NO₂) | 47 | well below the reference |
| Diesel particulate | 29 | well below the reference |
| Toxic releases (RSEI) | 84 | below the reference |
| Traffic proximity | 32 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 14 | well below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 29 | well below the reference |
| Hazardous-waste site proximity | 0 | well below the reference |
| Underground storage tanks | 64 | below the reference |
| NPDES wastewater proximity | 41 | well below the reference |
| Drinking-water non-compliance | 0 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Health context
Co-Located Health Indicators
Modeled adult-prevalence estimates published by CDC PLACES, paired with this city's pollution and demographic context. Comparisons are ecological, not causal — pollution and disease prevalence covary at the area level, but the data does not attribute any individual's diagnosis to local exposure. How this section works →
Adult asthma (current)
10.5%
CDC PLACES · 2025 release · BRFSS 2022-2023
COPD prevalence
6.4%
CDC PLACES · 2025 release · BRFSS 2022-2023
Coronary heart disease
5.1%
CDC PLACES · 2025 release · BRFSS 2022-2023
Diabetes (diagnosed)
9.1%
CDC PLACES · 2025 release · BRFSS 2022-2023
Frequent mental distress
17.5%
CDC PLACES · 2025 release · BRFSS 2022-2023
PLACES uses BRFSS-modeled small-area estimates, not individual records. Crude prevalence shown above is the local rate as published; comparators are age-adjusted vs the Wyoming mean and the US mean — both population-weighted across counties — so geographies with different age structures stay apples-to-apples. Sources: CDC PLACES · 2025 release · BRFSS 2022-2023.
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.
- EPA Safe Drinking Water Information System · retrieved 2026-05-07.