Ozone 8-hour 4th-highest daily max
Ozone 8-hour 4th-highest daily max in Hartford County reached 0.074 ppm in 2024, 6% above the EPA NAAQS of 0.07 ppm.
County · TRI 2024
Hartford County, Connecticut Pollution
10 top TRI facilities tracked here. PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) fell meaningfully year over year (-19%). PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 46% since 2010.
FIPS 09003 · population 0
Anomaly engine
Notable Signals
Top facilities mapped
Where Chemicals Are Released In Hartford County
Each red dot is one of the top TRI facilities. Size reflects 2024 total releases. County boundary outlined in blue.
Pollutant pathways
Hartford 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 46% 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 49% 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 41% 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 have more than halved 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 roughly unchanged from 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 have fallen 11% since 2010.
Top facilities · 2024
Where The Chemical Releases Are Concentrated
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Pratt & WhitneyRtx CORP | East Hartford | 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) | 95k lb | +15% |
| Metal Finishing Technologies LLC | Forestville | 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) | 61k lb | +143% |
| Har-Conn Chrome CO | West Hartford | 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) | 47k lb | -9% |
| Connecticut Galvanizing Corp | Glastonbury | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 41k lb | +17% |
| Ahlstrom Nonwovens LLCAhlstrom USA INC | Windsor Locks | AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA) | 33k lb | +11% |
| Marmon Industrial Energy & Infrastructure GroupBerkshire Hathaway INC | East Granby | Ozone | 26k lb | -5% |
| Armoloy Of Ct INC. | Bristol | Chromium and Chromium Compounds(except for chromite ore mined in the Transvaal Region)Health riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA) | 14k lb | — |
| Scapa Na LLCScapa North America LLC | Windsor | TolueneHealth riskCentral-nervous-system depressant. Chronic high exposure causes hearing loss and developmental effects. (EPA, ATSDR) | 11k lb | -12% |
| Clean Harbors Of Connecticut INCClean Harbors INC | Bristol | ArsenicHealth 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) | 11k lb | -95% |
| Idex Health & Science LLCIdex CORP | Bristol | DichloromethaneHealth riskIARC Group 2A probable carcinogen; central-nervous-system depressant; banned for most consumer paint-stripper uses. (IARC, EPA) | 10k lb | +0% |
Superfund / NPL sites
Federal Cleanup Sites In Hartford County
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 |
|---|---|---|---|---|
| Solvents Recovery Service Of New England | Southington | NPL FINAL | No | 1,1,1-TrichloroethaneHealth riskMethyl chloroform. CNS depressant; ozone-depleting substance phased out under Montreal Protocol. EPA MCL 200 µg/L. (EPA, ATSDR) |
| Old Southington Landfill | Southington | DELETED | No | BenzeneHealth riskIARC Group 1 carcinogen. Long-term inhalation causes leukemia and bone-marrow disorders. (IARC, EPA) |
Equity context
County Population Characteristics
All block groups in Hartford County County, CT.
Demographic shares, national-percentile rankings (PM2.5, ozone, NO₂, diesel particulate, lead-paint risk, NPL/RMP/TSDF/NPDES proximity, drinking-water non-compliance), and EJ disparity scores will render here once the EJScreen-clone ingest completes for this geography. Why this section matters →
Browse
All 14 Hartford County Cities With TRI Data
Pollution trends and TRI 2024 pages for every tracked city in this county. Alphabetical.
- Bristol pollution· 5 facilities
- Broad Brook pollution· 0 facilities
- East Hartford pollution· 4 facilities
- Hartford pollution· 0 facilities
- Kensington pollution· 0 facilities
- Manchester pollution· 0 facilities
- New Britain pollution· 7 facilities
- Newington pollution· 4 facilities
- Plantsville pollution· 1 facility
- Simsbury Center pollution· 2 facilities
- Tariffville pollution· 0 facilities
- West Hartford pollution· 5 facilities
- Wethersfield pollution· 0 facilities
- Windsor Locks pollution· 2 facilities
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.