Ozone 8-hour 4th-highest daily max
Ozone 8-hour 4th-highest daily max in Chester County reached 0.078 ppm in 2010, 11% above the EPA NAAQS of 0.07 ppm.
10 top TRI facilities tracked here. Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) held roughly steady year over year (—). Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.
FIPS 45023 · population 32,171
Ozone 8-hour 4th-highest daily max in Chester County reached 0.078 ppm in 2010, 11% above the EPA NAAQS of 0.07 ppm.
Total TRI releases at Chester County have more than doubled since 2010 (through 2024).
Each red dot is one of the top TRI facilities. Size reflects 2024 total releases. County boundary outlined in blue.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.
TRI air releases (5.1 fugitive + 5.2 stack) concentrations are up 11% 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 land + off-site releases concentrations are up 14% since 2013.
Greenhouse gases (GHGRP large emitters, through 2023) concentrations are roughly unchanged from 2010.
| Facility | City | Top chemical | Total releases | YoY |
|---|---|---|---|---|
| Allvac Richburg PlantAti INC | Richburg | ChromiumHealth riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA) | 176k lb | +4031% |
| Boise Cascade Wood Products-Chester PlywoodBoise Cascade Co | Chester | MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA) | 85k lb | +3% |
| Building Materials Manufacturing LLCG Holdings INC | Chester | FormaldehydeHealth riskIARC Group 1 carcinogen. Linked to nasopharyngeal cancer; irritates the eyes, nose, and respiratory tract at low concentrations. (IARC, EPA) | 19k lb | +14% |
| Engineered Polymer SolutionsThe Sherwin-Williams Co | Chester | Methyl methacrylateHealth riskSkin and respiratory sensitizer; can trigger occupational asthma and dermatitis. (OSHA) | 11k lb | -22% |
| Guardian Industries LLCKoch INC | Richburg | AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA) | 7k lb | -71% |
| Synthomer INC.Yule Catto INC | Chester | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 5k lb | +12% |
| Coatex INCArkema Delaware INC | Chester | Ethyl acrylate | 2k lb | +59% |
| Chemtrade Performance Chemicals US LLCChemtrade Holdco US INC | Carlisle | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 2k lb | -56% |
| Giti Tire Manufacturing CO (Usa) LTDGiti Tire USA LTD | Richburg | Zinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR) | 1k lb | -20% |
| Jones-Hamilton CO.Jones-Hamilton Co | Richburg | Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)Health riskAerosolized HCl is a corrosive respiratory irritant; chronic exposure damages teeth and respiratory tissue. (NIOSH) | 176 lb | -1% |
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 |
|---|---|---|---|---|
| Carolawn, Inc. | Fort Lawn | 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) |
All block groups in Chester County County, SC: 32,171 residents. County disparity score for pm2.5 (fine particulate) sits well below the reference (38). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 38 | well below the reference |
| Ozone | 27 | well below the reference |
| Nitrogen dioxide (NO₂) | 27 | well below the reference |
| Diesel particulate | 36 | well below the reference |
| Toxic releases (RSEI) | 103 | near the reference |
| Traffic proximity | 26 | well below the reference |
| Lead-paint risk (pre-1960 housing) | 86 | below the reference |
| Superfund site proximity | 29 | well below the reference |
| RMP-facility proximity | 83 | below the reference |
| Hazardous-waste site proximity | 48 | well below the reference |
| Underground storage tanks | 94 | near the reference |
| NPDES wastewater proximity | 64 | below the reference |
| Drinking-water non-compliance | 31 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Modeled adult-prevalence estimates published by CDC PLACES, paired with this county'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 →
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
CDC PLACES · 2025 release · BRFSS 2022-2023
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 South Carolina 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.
Pollution trends and TRI 2024 pages for every tracked city in this county. Alphabetical.
Sources.
All sources are federal public-domain datasets under 17 USC §105. We aggregate but do not relabel; the underlying observations remain attributable to EPA.