Endrin
Unresolved Nitrate/Nitrite violation cited in 2025 (endrin).
City · TRI 2024
Williamsport, Pennsylvania Pollution
6 TRI facilities inside the city limits and 5 public water systems serving residents. In-city TRI releases rose modestly year over year (+9%). Toxic releases concentrations have fallen 19% since 2010.
FIPS 4285312 · population 27,755 · Lycoming County
Anomaly engine
Notable Signals
Endrin
Unresolved Nitrate/Nitrite violation cited in 2025 (endrin).
Contaminant 7500
Unresolved Volatile Organic Chemical Rule violation cited in 2020 (contaminant 7500).
Arsenic
Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2024 (arsenic).
Showing the 4 most editorially weighted signals out of 6. Lower-severity signals fold into the chemical breakdown and history charts below.
Pollutant pathways
Williamsport 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 are roughly unchanged from 2019.
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 are up 42% since 2019.
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.
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 28% 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 have fallen 34% 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 doubled since 2010.
Top facilities · TRI 2024
Largest Emitters Inside The City
| Facility | Top chemical | Total releases | YoY |
|---|---|---|---|
| Ohd Thermacore INC.Overhead Door CORP | ManganeseHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR) | 20k lb | -13% |
| Prysmian Cables & Systems USA LLCPrysmian Cables & Systems (Us) INC | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 18k lb | +25% |
| High Steel Structures - Williamsport FacilityHigh Industries INC | ManganeseHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR) | 8k lb | +82% |
| Arxada LLCArxada LLC | N-Hydroxyethylethylenediamine | 2k lb | -1% |
| Lycoming Engines A Div Of Avco CorpTextron INC | ChromiumHealth riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA) | 118 lb | +202% |
| Spartronics Williamsport INC.Spartronics LLC | Lead And Lead CompoundsHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR) | 1 lb | +6% |
Drinking water · SDWIS
Water Systems Serving Williamsport
186 unresolved violations on the SDWIS record across utilities serving this city.
5
Utilities serving
51,788
Population served
8
Health-based · 5yr
186
Unresolved
| Water system | PWSID | Population served | Health-based · 5yr | Status |
|---|---|---|---|---|
| Foxcroft Manor Mobile Home Pk Private | PA4410166 | 200 | 4 | UNRESOLVED |
| Oak Lynn Manor Mobile Home Pk Private | PA4410153 | 250 | 3 | UNRESOLVED |
| American Tempo Village Park Private | PA4410002 | 88 | 1 | UNRESOLVED |
| Collomsville Mutual Waterworks Private | PA4410179 | 250 | 0 | UNRESOLVED |
Showing the 4 systems with recorded health-based or unresolved violations. 1 additional system is in compliance with no recorded health-based violations in the past 5 years and is 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.
Superfund / NPL sites
Federal Cleanup Sites In Williamsport
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 | Status | Federal facility | Primary contaminant |
|---|---|---|---|
| Avco Lycoming (Williamsport Division) | NPL FINAL | No | 1,2-Dichloroethene (Cis And Trans Mixture) |
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Who Lives In Williamsport
Williamsport, Pennsylvania (Census place block groups): 27,755 residents. City disparity score for pm2.5 (fine particulate) sits below the reference (51). Why we surface this →
25.4%
Low-income
23.4%
People of color
6.6%
Under age 5
13.5%
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.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.23below 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.29below 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.90in the highest 10% nationally
- 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.51near 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.88in the highest 20% nationally
- 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.93in the highest 10% nationally
- 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.81in the highest 20% nationally
- 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.78above 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.33below 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.76above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 51 | below the reference |
| Ozone | 74 | below the reference |
| Nitrogen dioxide (NO₂) | 47 | well below the reference |
| Diesel particulate | 50 | below the reference |
| Toxic releases (RSEI) | 117 | moderately above the reference |
| Traffic proximity | 74 | below the reference |
| Lead-paint risk (pre-1960 housing) | 120 | moderately above the reference |
| Superfund site proximity | 124 | moderately above the reference |
| RMP-facility proximity | 113 | moderately above the reference |
| Hazardous-waste site proximity | 74 | below the reference |
| Underground storage tanks | 96 | near the reference |
| NPDES wastewater proximity | 47 | well below the reference |
| Drinking-water non-compliance | 0 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Sources.
- EPA Toxics Release Inventory · retrieved 2026-05-07.
- EPA Safe Drinking Water Information System · retrieved 2026-05-07.