TRI air releases
TRI air releases at Maine have more than halved since 2010 (through 2024).
State · TRI 2024
Maine Pollution
62 TRI facilities, 359 public water systems, and 16 Superfund / NPL sites across 15 counties. Statewide TRI releases held roughly steady year over year (+2%). Toxic releases concentrations have fallen 24% since 2010.
FIPS 23 · population 1,362,359 · 16 counties total
Anomaly engine
Notable Signals At The State Level
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.
Statewide pollutant pathways
Maine 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 36% since 2013.
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 2013.
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 have fallen 14% since 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 35% 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) concentrations have fallen 23% since 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.
TRI land + off-site releases concentrations are up 28% 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 have more than halved since 2010.
| County | Population | Facilities | Total releases | YoY | Top chemical |
|---|---|---|---|---|---|
| Somerset CountyFIPS 23025 | 50,656 | 1 | 2.5M lb | +5% | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) |
| Aroostook CountyFIPS 23003 | 67,237 | 6 | 2.0M lb | +12% | 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) |
| Oxford CountyFIPS 23017 | 58,276 | 1 | 1.8M lb | -13% | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) |
| Washington CountyFIPS 23029 | 31,096 | 1 | 666k lb | +35% | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) |
| Cumberland CountyFIPS 23005 | 303,357 | 17 | 164k lb | +1% | Certain glycol ethersHealth riskReproductive toxicants; some cause testicular damage and developmental harm. (EPA) |
| Androscoggin CountyFIPS 23001 | 111,532 | 6 | 67k lb | -10% | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) |
| Knox CountyFIPS 23013 | 40,729 | 5 | 32k lb | -6% | StyreneHealth riskIARC Group 2A probable carcinogen; central-nervous-system effects from inhalation. (IARC, EPA) |
| Sagadahoc CountyFIPS 23023 | 36,868 | 1 | 24k lb | 0% | n-Butyl alcoholHealth riskEye and respiratory irritant; high exposure causes hearing loss and central-nervous-system effects. (NIOSH) |
| York CountyFIPS 23031 | 212,691 | 11 | 19k lb | -61% | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) |
| Kennebec CountyFIPS 23011 | 124,003 | 3 | 15k lb | +5% | StyreneHealth riskIARC Group 2A probable carcinogen; central-nervous-system effects from inhalation. (IARC, EPA) |
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Sappi N.A. INC. - Somerset OperationsSdw Holdings CORP | Skowhegan | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 2.5M lb | +5% |
| Mccain Foods USA INCMccain Foods USA INC | Easton | 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) | 1.9M lb | +13% |
| Nd Paper INC. - Rumford DivNd Paper LLC | Rumford | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 1.8M lb | -13% |
| Woodland Pulp LLCInternational Grand Investment CORP | Baileyville | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 666k lb | +35% |
| Sappi N.A. - Westbrook OperationsSdw Holdings CORP | Westbrook | Certain glycol ethersHealth riskReproductive toxicants; some cause testicular damage and developmental harm. (EPA) | 81k lb | +20% |
| Pioneer Plastics CorpPanolam Industries International INC | Auburn | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 40k lb | +6% |
| Twin Rivers Paper CO LLCBlue Wolf Capital | Madawaska | 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) | 39k lb | -10% |
| Huber Engineered Woods LLCJ M Huber CORP | Easton | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 36k lb | +36% |
| Bath Iron Works-Structural Fabrication Facility (Formerly HaGeneral Dynamics CORP | Brunswick | Xylene (mixed isomers)Health riskEye, skin, and respiratory irritant; central-nervous-system effects from chronic exposure. (EPA) | 33k lb | +17% |
| Bath Iron WorksGeneral Dynamics CORP | Bath | n-Butyl alcoholHealth riskEye and respiratory irritant; high exposure causes hearing loss and central-nervous-system effects. (NIOSH) | 24k lb | 0% |
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.
| Water system | PWSID | Population served | Health-based · 5yr | Status |
|---|---|---|---|---|
| Lisbon Water Department Municipal | ME0090870 | 6,643 | 5 | UNRESOLVED |
| Ellsworth Water Department Municipal | ME0090520 | 3,910 | 22 | UNRESOLVED |
| Pittsfield Water Dept Municipal | ME0091280 | 3,228 | 7 | UNRESOLVED |
| Livermore Falls Water District Municipal | ME0090880 | 2,995 | 6 | UNRESOLVED |
| Berwick Water Department Municipal | ME0090150 | 2,845 | 3 | UNRESOLVED |
| Southwest Harbor Water & Sewer District Municipal | ME0091490 | 2,480 | 2 | UNRESOLVED |
| Gray Water District Municipal | ME0090620 | 2,468 | 7 | UNRESOLVED |
| Fort Fairfield Utilities District Municipal | ME0090550 | 2,025 | 2 | UNRESOLVED |
| Sugarloaf Water Association Private | ME0091690 | 1,730 | 19 | UNRESOLVED |
| Milo Water District Municipal | ME0091000 | 1,720 | 3 | UNRESOLVED |
Superfund / NPL sites
Federal Cleanup Sites In Maine
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 |
|---|---|---|---|---|
| Brunswick Naval Air Station | Brunswick | NPL FINAL | FEDERAL | 1,1-DichloroethaneHealth riskSuspected carcinogen (EPA C/likely); CNS depressant. Common at solvent-contaminated sites as a degradation intermediate. (EPA, ATSDR) |
| Callahan Mining Corp | Brooksville (Cape Rosier) | NPL FINAL | No | Aroclor 1242Health riskPCBs. IARC Group 1 carcinogen; immune, reproductive, and neurological effects; bioaccumulate in fish and breast milk. Banned in 1979; persist as legacy contamination. (IARC, EPA) |
| Eastern Surplus | Meddybemps | NPL FINAL | No | 1,1,2-Trichloroethane |
| Eastland Woolen Mill | Corinna | NPL FINAL | No | 1,2,4-Trichlorobenzene |
| Keddy Mill | South Windham | NPL FINAL | No | 1,4-DichlorobenzeneHealth riskIARC Group 2B possible carcinogen; common in mothballs and air fresheners. EPA MCL 75 µg/L. (IARC, EPA) |
| Leeds Metal | Leeds | NPL FINAL | No | — |
| Loring Air Force Base | Limestone | NPL FINAL | FEDERAL | Benzo[A]AnthraceneHealth riskPAH; IARC Group 2B possible carcinogen; common combustion byproduct and creosote constituent. (IARC) |
| Saco Municipal Landfill | Saco | NPL FINAL | No | 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) |
| West Site/Hows Corners | Plymouth | 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) |
| Winthrop Landfill | Winthrop | NPL FINAL | No | 2-Butanone (Methyl Ethyl Ketone) |
Showing the top 10 sites by status priority. 6 additional NPL-relevant sites in Maine 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 Maine block groups: 1,362,359 residents. Statewide disparity score for pm2.5 (fine particulate) sits well below the reference (3). 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.
10.9%
Low-income
8.6%
People of color
5.0%
Under age 5
21.5%
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.2below the national median
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.7below 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.18below 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.9below 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.39below 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.36below 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.69above 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.57near 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.48near 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.54near 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.48near 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.62above 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.80above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 3 | well below the reference |
| Ozone | 9 | well below the reference |
| Nitrogen dioxide (NO₂) | 19 | well below the reference |
| Diesel particulate | 9 | well below the reference |
| Toxic releases (RSEI) | 17 | well below the reference |
| Traffic proximity | 21 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 48 | well below the reference |
| Superfund site proximity | 11 | well below the reference |
| RMP-facility proximity | 20 | well below the reference |
| Hazardous-waste site proximity | 28 | well below the reference |
| Underground storage tanks | 30 | well below the reference |
| NPDES wastewater proximity | 19 | well below the reference |
| Drinking-water non-compliance | 21 | well 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 15 Maine Counties With TRI Data
Pollution trends and TRI 2024 pages for every tracked county. Alphabetical.
- Androscoggin County pollution· 6 facilities
- Aroostook County pollution· 6 facilities
- Cumberland County pollution· 17 facilities
- Franklin County pollution· 1 facility
- Hancock County pollution· 1 facility
- Kennebec County pollution· 3 facilities
- Knox County pollution· 5 facilities
- Lincoln County pollution· 1 facility
- Oxford County pollution· 1 facility
- Penobscot County pollution· 4 facilities
- Sagadahoc County pollution· 1 facility
- Somerset County pollution· 1 facility
- Waldo County pollution· 3 facilities
- Washington County pollution· 1 facility
- York County pollution· 11 facilities
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.