City · TRI 2024

Nampa, Idaho Pollution

8 TRI facilities inside the city limits and 40 public water systems serving residents. In-city TRI releases rose sharply year over year (+37%). Toxic releases concentrations are up 49% since 2010.

FIPS 1656260 · population 102,598 · Canyon County

IN-CITY TRI RELEASES · 20102024
Bar chart of annual values from 2010 to 2024, in lb. Most recent year (2024): 807k.807k'10'12'14'16'18'20'22'24807k
Anomaly engine

Notable Signals

UNRESOLVED VIOLATION · SDWIS VIOLATION

Beryllium

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2023 (beryllium).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Arsenic

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2023 (arsenic).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Contaminant 8000

Unresolved Revised Total Coliform Rule violation cited in 2025 (contaminant 8000).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Contaminant 8000

Unresolved Revised Total Coliform Rule violation cited in 2025 (contaminant 8000).

EPA SDWIS record

Showing the 4 most editorially weighted signals out of 54. Lower-severity signals fold into the chemical breakdown and history charts below.

Pollutant pathways

Nampa Pollutant Multi-Year Trends

CRITERIA AIRSINCE 2010

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.

6.22 µg/m³ · -5% YoY · -37% since 2010

PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 37% since 2010.

CRITERIA AIRSINCE 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.

22.60 µg/m³ · +26% YoY · -33% since 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 33% since 2010.

HAZARDOUS AIR2020 VINTAGE

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.

43.6 per million · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

HAZARDOUS AIR2020 VINTAGE

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.

1.87 µg/m³ · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

HAZARDOUS AIR2020 VINTAGE

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.

0.45 µg/m³ · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

TRI AIRSINCE 2010

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.

766k lb · +38% YoY · +54% since 2010

TRI air releases (5.1 fugitive + 5.2 stack) concentrations are up 54% since 2010.

TRI WATERSINCE 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.

0 lb · YoY · since 2010

TRI water releases (5.3) volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.

TRI LANDSINCE 2010

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.

40k lb · +25% YoY · -11% since 2010

TRI land + off-site releases concentrations have fallen 11% since 2010.

GHGSINCE 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.

0.5M metric tons CO₂e · -14% YoY · +37% since 2010

Greenhouse gases (GHGRP large emitters, through 2023) concentrations are up 37% since 2010.

Top facilities · TRI 2024

Largest Emitters Inside The City

FacilityTop chemicalTotal releasesYoY
Amalgamated Sugar CO NampaAmalgamated Sugar CoAmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)806k lb+37%
Performix Nutrition Systems LLCAgribeef CoZinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR)312 lb-2%
Oldcastle Infrastructure & Idaho Sand & GravelCrh Americas INCPolycyclic 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%
Idaho Asphalt Supply INC Nampa PlantIdaho Asphalt Supply INCPolycyclic aromatic compoundsHealth riskPAH class includes IARC Group 1 carcinogens (e.g., benzo[a]pyrene); long-term exposure raises cancer risk. (IARC, EPA)34 lb+711%
Plexus Manufacturing Solutions (Boi)Plexus CORPLead And Lead CompoundsHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)17 lb+22%
Hart & CooleyDuravent INCChromiumHealth riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA)7 lb0%
Oldcastle Nampa MadisonCrh Americas INCLead compoundsHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)1 lb
Lippert Components Inc.- Plant 84Lci IndustriesLeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)0 lb-4%
Drinking water · SDWIS

Water Systems Serving Nampa

729 unresolved violations on the SDWIS record across utilities serving this city.

SDWIS · 5-YR WINDOW
40

Utilities serving

SDWIS · 5-YR WINDOW
104,646

Population served

SDWIS · 5-YR WINDOW
56

Health-based · 5yr

SDWIS · 5-YR WINDOW
729

Unresolved

Water systemPWSIDPopulation servedHealth-based · 5yrStatus
Indian Village PrivateID314019322529UNRESOLVED
Sunnyridge I Subd PrivateID31401193510UNRESOLVED
Northstar Subdivision PrivateID3140278507UNRESOLVED
Locust Subd PrivateID3140066423UNRESOLVED
Evergreen Mobile Park PrivateID31400352842UNRESOLVED
Westview Shervik Subd PrivateID3140137782UNRESOLVED
Sky Ranch Estates PrivateID31402211041UNRESOLVED
Shipman Place Subd PrivateID3140109401UNRESOLVED
M & T Water Corp PrivateID31400971001Returned to compliance
Nampa City Of MunicipalID3140080100,2000UNRESOLVED
Belle Aire Acres 2 PrivateID31400093500UNRESOLVED
Covert Water Users Association PrivateID31400242500UNRESOLVED
Rolling Hills Estates Water Company PrivateID31401002500UNRESOLVED
Lakeview Hills Water Users Association PrivateID31400621600UNRESOLVED
Camelot Water Assn Inc PrivateID31400141570UNRESOLVED
Clark Theurer Water Assn PrivateID31401401550UNRESOLVED
Leisure Heights Homeowners Association PrivateID31400631420UNRESOLVED
Ok Water Assn PrivateID31400851400UNRESOLVED
Apache Heights Subdivision (2) PrivateID31400051100UNRESOLVED
Verde Hills Water Users Assn Inc PrivateID3140134950UNRESOLVED
Mangum Heights Subd PrivateID3140068750UNRESOLVED
Valley View Water PrivateID3140130570UNRESOLVED
Burnie Subd PrivateID3140011550UNRESOLVED
Dahl Subd PrivateID3140025510UNRESOLVED
Lakeridge Second Subd PrivateID3140056500UNRESOLVED
Lindenwood Water Assn PrivateID3140010480UNRESOLVED
Country Meadows Subd PrivateID3140200350UNRESOLVED
Sunnyridge Subd 2 PrivateID3140120340UNRESOLVED
Aurora Subd PrivateID3140007300UNRESOLVED
Twin Bridges Subd PrivateID3140125280UNRESOLVED

Showing the 30 systems with recorded health-based or unresolved violations. 10 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 Nampa

Nampa, Idaho (Census place block groups): 102,598 residents. City disparity score for pm2.5 (fine particulate) sits moderately above the reference (118). Why we surface this →

POPULATION SHARE
10.9%

Low-income

POPULATION SHARE
32.0%

People of color

POPULATION SHARE
7.8%

Under age 5

POPULATION SHARE
14.3%

Over age 64

NATIONAL PERCENTILE · vs all US block groups (population-weighted; ranked against the national EJScreen indicator distribution)

  • 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.42near 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.57near 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.77above 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.22below 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.52near 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.50near 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.41near 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.42near 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.63above 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.92in the highest 10% 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
EJ disparity scores · population-weighted across city block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)118moderately above the reference
Ozone101near the reference
Nitrogen dioxide (NO₂)78below the reference
Diesel particulate96near the reference
Toxic releases (RSEI)28well below the reference
Traffic proximity69below the reference
Lead-paint risk (pre-1960 housing)46well below the reference
Superfund site proximity0well below the reference
RMP-facility proximity53below the reference
Hazardous-waste site proximity54below the reference
Underground storage tanks64below the reference
NPDES wastewater proximity120moderately above the reference
Drinking-water non-compliance132moderately 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 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)

BRFSS 2023
10.9%
+2% vs Idaho mean+9% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

COPD prevalence

BRFSS 2023
6.4%
+3% vs Idaho mean+11% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Coronary heart disease

BRFSS 2023
5.6%
-1% vs Idaho mean-0% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Diabetes (diagnosed)

BRFSS 2023
10.6%
+14% vs Idaho mean-2% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Frequent mental distress

BRFSS 2023
16.8%
+0% vs Idaho mean+1% vs US mean

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.

Sources.