Pollution Analyst
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State · TRI 2024

Iowa Pollution

377 TRI facilities, 1,078 public water systems, and 26 Superfund / NPL sites across 86 counties. Statewide TRI releases held roughly steady year over year (+2%). Toxic releases concentrations have fallen 16% since 2010.

FIPS 19 · population 3,190,369 · 99 counties total

Top counties Top facilitiesPathwaysEquity context
PM2.5 ANNUAL MEAN (NAAQS 9 ΜG/M³ (ANNUAL)) · 2010–2024
Bar chart of annual values from 2010 to 2024, in µg/m³. Most recent year (2024): 7 µg/m³.11 µg/m³'10'12'14'16'18'20'22'247 µg/m³
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.

STYLE
TRI total releases (lbs/yr)
LOW → HIGH
Statewide pollutant pathways

Iowa 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.

6.84 µg/m³ · -29% 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.

16.04 µg/m³ · -33% YoY · -44% since 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 44% since 2010.

CRITERIA AIRSINCE 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.

0.060 ppm · -20% YoY · -17% since 2010

Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations have fallen 17% since 2010.

CRITERIA AIRSINCE 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.

3.9 ppb · -2% YoY · -11% since 2010

NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have fallen 11% 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.

23.5 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.

1.21 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.

0.12 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.

18.4M lb · -5% YoY · +1% since 2010

TRI air releases (5.1 fugitive + 5.2 stack) concentrations are roughly unchanged from 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.

6.2M lb · +11% YoY · +0% since 2010

TRI water releases (5.3) concentrations are roughly unchanged from 2010.

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.

10.1M lb · +10% YoY · -41% since 2010

TRI land + off-site releases concentrations have fallen 41% 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.

61M metric tons CO₂e · -2% YoY · -19% since 2010

Greenhouse gases (GHGRP large emitters, through 2023) concentrations have fallen 19% since 2010.

Top counties · TRI 2024

Iowa Counties With Most Chemical Releases

Methodology →

CountyPopulationFacilitiesTotal releasesYoYTop chemical
Lee CountyFIPS 1911133,442104.3M lb-23%AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)
Clinton CountyFIPS 1904546,48894.2M lb+18%EthyleneHealth riskSimple asphyxiant at high concentrations; precursor to many polymers; low direct toxicity. (NIOSH)
Woodbury CountyFIPS 19193105,526153.8M lb-6%AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)
Muscatine CountyFIPS 1913942,96873.3M lb+25%Manganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)
Linn CountyFIPS 19113229,308213.1M lb+17%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)
Louisa CountyFIPS 1911510,82321.9M lb+11%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)
Monroe CountyFIPS 191357,57461.7M lb-8%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)
Pottawattamie CountyFIPS 1915593,54391.4M lb-9%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)
Wapello CountyFIPS 1917935,2925857k lb+51%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)
Allamakee CountyFIPS 1900514,0463849k lb-4%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)
Top facilities · TRI 2024

The Largest Individual Emitters In Iowa

Methodology →

FacilityCityTop chemicalTotal releasesYoY
Ssab Iowa INC.Ssab Enterprises LLCMuscatineManganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)3.1M lb+27%
Climax Molybdenum COFreeport-Mcmoran INCFort MadisonAmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)2.7M lb-25%
Cf Industries Nitrogen Llc-Port Neal Nitrogen ComplexCf Industries Holdings INCSergeant BluffAmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)2.4M lb-6%
Adm Corn ProcessingArcher Daniels Midland CoClintonBarium compounds (except for barium sulfate (CAS No. 7727-43-7))Health 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)2.1M lb+42%
Equistar Chemicals Clinton PlantLyondellbasell Finance CoClintonEthyleneHealth riskSimple asphyxiant at high concentrations; precursor to many polymers; low direct toxicity. (NIOSH)2.0M lb+1%
Tyson Fresh Meats Inc-Louisa CountyTyson Foods INCColumbus JunctionNitrate 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)1.6M lb+18%
Adm Corn ProcessingArcher Daniels Midland CoCedar RapidsBarium 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)1.4M lb+10%
Midamerican Energy CO Walter Scott Jr Energy CenterBerkshire Hathaway INCCouncil BluffsBarium 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)1.4M lb-9%
Koch Fertilizer Wever LLCKoch INCWeverAmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)1.1M lb+16%
Ajinomoto Health & Nutrition N.A. INC.Ajinomoto Health & Nutrition North America INCEddyvilleNitrate 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)852k lb-13%
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.

Methodology →

Water systemPWSIDPopulation servedHealth-based · 5yrStatus
Altoona Water Supply MunicipalIA770703019,5653UNRESOLVED
Grinnell Water Department MunicipalIA79300089,56435UNRESOLVED
Osceola Water Works MunicipalIA20380385,5039UNRESOLVED
Xenia Rwd (Boone) PrivateIA08440064,9753UNRESOLVED
Anamosa Municipal Water Supply MunicipalIA53070484,4572UNRESOLVED
Madrid Water Department MunicipalIA08480153,0902UNRESOLVED
Mitchellville Water Supply MunicipalIA77510922,5152UNRESOLVED
Lamoni Municipal Utilities MunicipalIA27400502,0295UNRESOLVED
Slater Muni Water Dept MunicipalIA85800571,5483UNRESOLVED
Danville Water Supply MunicipalIA29150009232UNRESOLVED
Superfund / NPL sites

Federal Cleanup Sites In Iowa

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.

Methodology →

SiteCityStatusFederal facilityPrimary contaminant
Des Moines TceDes MoinesNPL FINALNoAldrinHealth riskMetabolizes to dieldrin in the body. EPA classifies as 'probable human carcinogen'; banned in the US in 1987. (EPA, ATSDR)
Fairfield Coal Gasification PlantFairfieldNPL FINALNoArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)
Highway 3 PceLe MarsNPL FINALNo—
Iowa Army Ammunition PlantMiddletownNPL FINALFEDERAL2,4,6-Trinitrotoluene
Lawrence Todtz FarmCamancheNPL FINALNoArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)
Lot 46 Valley Gardens TceDes MoinesNPL FINALNo—
Mason City Coal Gasification PlantMason CityNPL FINALNoDibenzo(A,H)Anthracene
Midwest Manufacturing/North FarmKelloggNPL FINALNo1,1,1-TrichloroethaneHealth riskMethyl chloroform. CNS depressant; ozone-depleting substance phased out under Montreal Protocol. EPA MCL 200 µg/L. (EPA, ATSDR)
Pce Former Dry CleanerAtlanticNPL FINALNoTetrachloroetheneHealth riskPCE / 'perc'. IARC Group 2A probable carcinogen; central-nervous-system effects; common dry-cleaning solvent and DNAPL plume contaminant. EPA MCL 5 µg/L. (IARC, EPA)
Peoples Natural Gas Co.DubuqueNPL FINALNoBenzeneHealth riskIARC Group 1 carcinogen. Long-term inhalation causes leukemia and bone-marrow disorders. (IARC, EPA)

Showing the top 10 sites by status priority. 16 additional NPL-relevant sites in Iowa have entity pages — browse them via the host-county or host-city page rollups.

Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Statewide Population Characteristics

All Iowa block groups: 3,190,369 residents. Statewide disparity score for pm2.5 (fine particulate) sits well below the reference (33). 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.

POPULATION SHARE
11.1%

Low-income

POPULATION SHARE
16.2%

People of color

POPULATION SHARE
6.4%

Under age 5

POPULATION SHARE
17.6%

Over age 64

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

Methodology →

  • 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.34below the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.36below 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.32below 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.80above 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.67above 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.72above 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.69above 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.78above 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.37below 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.74above 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.77above the national median
EJ disparity scores · population-weighted, all state block groups (100 = national reference; higher = greater disparate burden) · Methodology →
IndicatorDisparity scoreReading
PM2.5 (fine particulate)33well below the reference
Ozone37well below the reference
Nitrogen dioxide (NO₂)45well below the reference
Diesel particulate33well below the reference
Toxic releases (RSEI)51below the reference
Traffic proximity47well below the reference
Lead-paint risk (pre-1960 housing)56below the reference
Superfund site proximity25well below the reference
RMP-facility proximity60below the reference
Hazardous-waste site proximity28well below the reference
Underground storage tanks47well below the reference
NPDES wastewater proximity37well below the reference
Drinking-water non-compliance4well 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 86 Iowa Counties With TRI Data

Pollution trends and TRI 2024 pages for every tracked county. Alphabetical.

Sources.