Total TRI releases
Total TRI releases at Canyon County have risen 62% since 2010 (through 2024).
County · TRI 2024
Canyon County, Idaho Pollution
10 top TRI facilities tracked here. PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) fell modestly year over year (-5%). PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 37% since 2010.
FIPS 16027 · population 235,006
Anomaly engine
Notable Signals
Top facilities mapped
Where Chemicals Are Released In Canyon County
Each red dot is one of the top TRI facilities. Size reflects 2024 total releases. County boundary outlined in blue.
Pollutant pathways
Canyon County 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 37% 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 33% since 2010.
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 61% 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 are up 73% 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 up 37% since 2010.
Top facilities · 2024
Where The Chemical Releases Are Concentrated
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Amalgamated Sugar CO NampaAmalgamated Sugar Co | Nampa | AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA) | 806k lb | +37% |
| Simplot U.S. Food Group Holdings LLCJ R Simplot Co | Caldwell | 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) | 246k lb | +20% |
| Best Bath SystemsBest Bath Systems INC | Caldwell | StyreneHealth riskIARC Group 2A probable carcinogen; central-nervous-system effects from inhalation. (IARC, EPA) | 157k lb | +5% |
| Darigold-CaldwellNorthwest Dairy Assoc | Caldwell | 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) | 6k lb | -13% |
| Icco MiddeltonCrh Americas INC | Caldwell | 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) | 2k lb | -53% |
| Simplot Western Stockmen'SJ R Simplot Co | Caldwell | Copper And Copper CompoundsHealth riskInhaled copper fumes cause metal-fume fever; chronic ingestion above EPA's 1.3 mg/L action level damages the liver. (EPA) | 688 lb | -72% |
| Performix Nutrition Systems LLCAgribeef Co | Nampa | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 312 lb | -2% |
| 301931-Stephens #2 (Nampa)Knife River CORP | Nampa | 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) | 90 lb | -80% |
| Oldcastle Infrastructure & Idaho Sand & GravelCrh Americas INC | Nampa | Polycyclic aromatic compoundsHealth riskPAH class includes IARC Group 1 carcinogens (e.g., benzo[a]pyrene); long-term exposure raises cancer risk. (IARC, EPA) | 57 lb | -24% |
| Big Tex Trailer Manufacturing Inc-CaldwellBcd Parent INC | Caldwell | ManganeseHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR) | 50 lb | -80% |
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Who Lives In Canyon County
All block groups in Canyon County County, ID: 235,006 residents. County disparity score for pm2.5 (fine particulate) sits moderately above the reference (113). Why we surface this →
10.2%
Low-income
31.7%
People of color
7.7%
Under age 5
14.2%
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.89in the highest 20% nationally
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.40below 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.45near 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.67above 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.46near 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.45near 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.49near 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.32below 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.34below 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.59near 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.98in the highest 5% 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.100in the highest 5% nationally
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 113 | moderately above the reference |
| Ozone | 95 | near the reference |
| Nitrogen dioxide (NO₂) | 62 | below the reference |
| Diesel particulate | 82 | below the reference |
| Toxic releases (RSEI) | 42 | well below the reference |
| Traffic proximity | 57 | below the reference |
| Lead-paint risk (pre-1960 housing) | 43 | well below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 29 | well below the reference |
| Hazardous-waste site proximity | 41 | well below the reference |
| Underground storage tanks | 57 | below the reference |
| NPDES wastewater proximity | 118 | moderately above the reference |
| Drinking-water non-compliance | 119 | moderately above 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 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 →
Adult asthma (current)
10.8%
CDC PLACES · 2025 release · BRFSS 2022-2023
COPD prevalence
6.6%
CDC PLACES · 2025 release · BRFSS 2022-2023
Coronary heart disease
5.9%
CDC PLACES · 2025 release · BRFSS 2022-2023
Diabetes (diagnosed)
11.2%
CDC PLACES · 2025 release · BRFSS 2022-2023
Frequent mental distress
16.6%
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 Idaho 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.
Browse
All 8 Canyon County Cities With TRI Data
Pollution trends and TRI 2024 pages for every tracked city in this county. Alphabetical.
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.
All sources are federal public-domain datasets under 17 USC §105. We aggregate but do not relabel; the underlying observations remain attributable to EPA.