Ozone 8-hour 4th-highest daily max
Ozone 8-hour 4th-highest daily max in Sweetwater County reached 0.071 ppm in 2024, 2% above the EPA NAAQS of 0.07 ppm.
7 top TRI facilities tracked here. PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) rose modestly year over year (+9%). PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 29% since 2011.
FIPS 56037 · population 42,079
Ozone 8-hour 4th-highest daily max in Sweetwater County reached 0.071 ppm in 2024, 2% above the EPA NAAQS of 0.07 ppm.
Each red dot is one of the top TRI facilities. Size reflects 2024 total releases. County boundary outlined in blue.
PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 29% since 2011.
PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 39% since 2011.
Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations are up 14% since 2011.
NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have fallen 18% since 2011.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
TRI air releases (5.1 fugitive + 5.2 stack) concentrations are roughly unchanged from 2010.
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 releases concentrations have fallen 34% since 2010.
Greenhouse gases (GHGRP large emitters, through 2023) concentrations have fallen 30% since 2010.
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Simplot Phosphates LLCJ R Simplot Co | Rock Springs | Hydrogen fluoride | 2.4M lb | +12% |
| 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 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% |
| Vermillion Gas PlantMarathon Petroleum CORP | Rock Springs | n-HexaneHealth riskPeripheral neurotoxin. Chronic exposure causes numbness and paralysis in the extremities. (ATSDR) | 25k lb | +5% |
| Church & Dwight CO INCChurch & Dwight Co INC | Green River | 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran | 92 lb | -17% |
| P4 Production LLCBayer US Holding LP | Rock Springs | Lead And Lead CompoundsHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR) | 29 lb | +1368% |
| Sunroc Corp - Lagoon Drive Ready MixClyde Cos INC | Rock Springs | LeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR) | 0 lb | 0% |
All block groups in Sweetwater County County, WY: 42,079 residents. County disparity score for pm2.5 (fine particulate) sits well below the reference (0). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 0 | well below the reference |
| Ozone | 81 | below the reference |
| Nitrogen dioxide (NO₂) | 54 | below the reference |
| Diesel particulate | 46 | well below the reference |
| Toxic releases (RSEI) | 20 | well below the reference |
| Traffic proximity | 26 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 31 | well below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 18 | well below the reference |
| Hazardous-waste site proximity | 6 | well below the reference |
| Underground storage tanks | 61 | below the reference |
| NPDES wastewater proximity | 29 | well below the reference |
| Drinking-water non-compliance | 16 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Modeled adult-prevalence estimates published by CDC PLACES, paired with this county'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 →
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
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.
Pollution trends and TRI 2024 pages for every tracked city in this county. Alphabetical.
Sources.
All sources are federal public-domain datasets under 17 USC §105. We aggregate but do not relabel; the underlying observations remain attributable to EPA.