State · TRI 2024
Wyoming Pollution
54 TRI facilities, 317 public water systems, and 3 Superfund / NPL sites across 16 counties. Statewide TRI releases fell modestly year over year (-11%). Toxic releases concentrations have fallen 19% since 2010.
FIPS 56 · population 576,851 · 23 counties total
Where the burden sits
County-Level TRI Choropleth
A color-shaded map of pollution data. Darker counties report more pounds of toxic chemicals released to the EPA's Toxics Release Inventory (TRI).
Shaded by total reported releases for 2024. Counties without a published page render as “no TRI data”. Red dots mark this state's top emitters.
Statewide pollutant pathways
Wyoming 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 47% 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 have fallen 19% 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 roughly unchanged from 2010.
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 fallen 17% 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) concentrations are up 30% since 2010.
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 concentrations have fallen 24% since 2010.
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 roughly unchanged from 2010.
| County | Population | Facilities | Total releases | YoY | Top chemical |
|---|---|---|---|---|---|
| Laramie CountyFIPS 56021 | 100,316 | 6 | 6.5M lb | +6% | Nitrate compounds (water dissociable; reportable only when in aqueous solution)Health riskDrinking-water nitrate causes methemoglobinemia ('blue-baby syndrome') in infants; EPA MCL is 10 mg/L as N. (EPA) |
| Campbell CountyFIPS 56005 | 46,857 | 7 | 3.9M lb | -2% | Barium And Barium CompoundsHealth 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) |
| Sweetwater CountyFIPS 56037 | 42,079 | 7 | 3.8M lb | -3% | Hydrogen fluoride |
| Platte CountyFIPS 56031 | 8,618 | 2 | 1.9M lb | -48% | Barium And Barium CompoundsHealth 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) |
| Converse CountyFIPS 56009 | 13,729 | 6 | 1.4M lb | -29% | Barium And Barium CompoundsHealth 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) |
| Lincoln CountyFIPS 56023 | 19,794 | 3 | 564k lb | -10% | Barium And Barium CompoundsHealth 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) |
| Carbon CountyFIPS 56007 | 14,609 | 3 | 403k lb | -19% | TolueneHealth riskCentral-nervous-system depressant. Chronic high exposure causes hearing loss and developmental effects. (EPA, ATSDR) |
| Washakie CountyFIPS 56043 | 7,725 | 1 | 260k lb | -3% | Certain glycol ethersHealth riskReproductive toxicants; some cause testicular damage and developmental harm. (EPA) |
| Natrona CountyFIPS 56025 | 79,506 | 7 | 45k lb | -10% | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) |
| Albany CountyFIPS 56001 | 37,525 | 2 | 39k lb | +2973% | Hydrogen cyanideHealth riskAcutely lethal at high doses by blocking cellular respiration; chronic low-dose exposure damages the thyroid and nervous system. (EPA, ATSDR) |
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Dyno Nobel Inc-Cheyenne PlantDyno Nobel INC | Cheyenne | Nitrate compounds (water dissociable; reportable only when in aqueous solution)Health riskDrinking-water nitrate causes methemoglobinemia ('blue-baby syndrome') in infants; EPA MCL is 10 mg/L as N. (EPA) | 6.5M lb | +6% |
| Simplot Phosphates LLCJ R Simplot Co | Rock Springs | Hydrogen fluoride | 2.4M lb | +12% |
| Basin Electric Laramie River StationBasin Electric Power Cooperative | Wheatland | Barium And Barium CompoundsHealth 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) | 1.9M lb | -48% |
| Black Hills Corp - Neil Simpson ComplexBlack Hills CORP | Gillette | Barium And Barium CompoundsHealth 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) | 1.7M lb | +11% |
| Basin Electric Dry Fork StationBasin Electric Power Cooperative | Gillette | Barium And Barium CompoundsHealth 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) | 1.3M lb | -1% |
| Pacificorp Dave Johnston PlantBerkshire Hathaway INC | Glenrock | Barium And Barium CompoundsHealth 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) | 1.3M lb | +4% |
| Blacks Fork Gas PlantMarathon Petroleum CORP | Granger | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 964k lb | +11% |
| Pacificorp Wyodak PlantBerkshire Hathaway INC | Gillette | Barium And Barium CompoundsHealth 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) | 796k lb | +42% |
| Pacificorp Naughton PlantBerkshire Hathaway INC | Kemmerer | Barium And Barium CompoundsHealth 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) | 455k lb | -12% |
| Pacificorp Jim Bridger Plant & Bridger Coal COBerkshire Hathaway INC | Point Of Rocks | Barium And Barium CompoundsHealth 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) | 422k lb | -53% |
Water utilities to watch
Largest Water Systems With Unresolved Health-Based Violations
Sorted to surface utilities serving the most people that still have an active health-based SDWIS violation on the record. Systems in compliance with no unresolved issues fall to the bottom of the ranking.
| Water system | PWSID | Population served | Health-based · 5yr | Status |
|---|---|---|---|---|
| Rawlins Water Supply, City Of Municipal | WY5600045 | 9,006 | 7 | UNRESOLVED |
| Ynp-Old Faithful Federal | WY5680085 | 7,675 | 24 | UNRESOLVED |
| Lander, City Of Municipal | WY5600176 | 7,615 | 4 | UNRESOLVED |
| Buffalo, City Of Municipal | WY5600005 | 4,419 | 20 | UNRESOLVED |
| Mills, City Of Municipal | WY5600036 | 4,050 | 9 | UNRESOLVED |
| Wheatland, Town Of Municipal | WY5600187 | 3,659 | 3 | UNRESOLVED |
| Kemmerer-Diamondville Jpb Municipal | WY5600028 | 3,348 | 33 | UNRESOLVED |
| Star Valley Ranch, Town Of Municipal | WY5600287 | 2,030 | 1 | UNRESOLVED |
| Leisure Valley Inc/ Star Valley Rv Park Private | WY5601471 | 1,910 | 4 | UNRESOLVED |
| Dubois, Town Of Municipal | WY5600177 | 1,822 | 1 | UNRESOLVED |
Superfund / NPL sites
Federal Cleanup Sites In Wyoming
Sites on EPA's Superfund National Priorities List, plus deleted sites whose cleanup objectives EPA has finalized. Federal-facility sites (defense, DOE, etc.) are flagged separately. Each link routes to a per-site page.
| Site | City | Status | Federal facility | Primary contaminant |
|---|---|---|---|---|
| F.E. Warren Air Force Base | Warren AFB | NPL FINAL | FEDERAL | TrichloroetheneHealth riskTCE. IARC Group 1 carcinogen — kidney cancer; suspected liver cancer and non-Hodgkin lymphoma. EPA MCL 5 µg/L; common DNAPL groundwater plume contaminant. (IARC, EPA, ATSDR) |
| Baxter/Union Pacific Tie Treating | Laramie | DELETED | No | 1,2,3,4,6,7,8-Heptachlorodibenzo[B,E][1,4]Dioxin (Hpcdd) |
| Mystery Bridge Rd/U.S. Highway 20 | Brookhurst | DELETED | No | 1,1,1-TrichloroethaneHealth riskMethyl chloroform. CNS depressant; ozone-depleting substance phased out under Montreal Protocol. EPA MCL 200 µg/L. (EPA, ATSDR) |
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Statewide Population Characteristics
All Wyoming block groups: 576,851 residents. Statewide disparity score for pm2.5 (fine particulate) sits well below the reference (1). Why we surface this →
State-level percentiles are aggregated from block-group EJScreen data. The EJ pattern within the state will be sharper at the county level — drill down for the meaningful spatial detail.
10.7%
Low-income
17.5%
People of color
6.4%
Under age 5
17.5%
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.1below the national median
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.62above 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.47near 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.22below 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.79above the national median
- 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.26below 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.58near 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.65above 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.37below 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.29below 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.75above the national median
- 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.88in the highest 20% nationally
- 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.79above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 1 | well below the reference |
| Ozone | 78 | below the reference |
| Nitrogen dioxide (NO₂) | 46 | well below the reference |
| Diesel particulate | 25 | well below the reference |
| Toxic releases (RSEI) | 17 | well below the reference |
| Traffic proximity | 23 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 40 | well below the reference |
| Superfund site proximity | 11 | well below the reference |
| RMP-facility proximity | 19 | well below the reference |
| Hazardous-waste site proximity | 17 | well below the reference |
| Underground storage tanks | 48 | well below the reference |
| NPDES wastewater proximity | 29 | well below the reference |
| Drinking-water non-compliance | 13 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror). EJ disparity scores via the USEPA-clone GitHub mirror after EPA deprecated the public EJScreen tool in 2025; demographics from Census ACS.
Browse
All 16 Wyoming Counties With TRI Data
Pollution trends and TRI 2024 pages for every tracked county. Alphabetical.
- Albany County pollution· 2 facilities
- Big Horn County pollution· 2 facilities
- Campbell County pollution· 7 facilities
- Carbon County pollution· 3 facilities
- Converse County pollution· 6 facilities
- Fremont County pollution· 1 facility
- Laramie County pollution· 6 facilities
- Lincoln County pollution· 3 facilities
- Natrona County pollution· 7 facilities
- Park County pollution· 1 facility
- Platte County pollution· 2 facilities
- Sheridan County pollution· 1 facility
- Sweetwater County pollution· 7 facilities
- Uinta County pollution· 4 facilities
- Washakie County pollution· 1 facility
- Weston County pollution· 1 facility
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.