St. Clair, IL
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Fixed caps: facilities ≤25 pts (50+ = max), log10 releases ≤25 pts, Superfund ≤25 pts (5/site), health-violation systems ≤15 pts (3/system), high-chemical facilities ≤10 pts. Bands: High ≥60, Moderate ≥30. See methodology. This is a different measure than the EJ Screening score for this county, which ranks it by percentile against other tracked counties rather than against these fixed caps.
Environmental data for St. Clair in Illinois · Population: 254,777
TRI sites such as Veolia N.a. Inc.; Afton Chemical Corp; Occidental Chemical Corp Sauget Plant; SDWIS systems such as O FALLON; CASEYVILLE; CAHOKIA HEIGHTS; NPL sites such as Old American Zinc Plant; Sauget Area 1; Sauget Area 2 anchor St. Clair, IL's EPA extract. Derived burden score 74/100 (High Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
Health-flagged SDWIS rows in St. Clair include O FALLON; CASEYVILLE; TRENTON, while Veolia N.a. Inc. leads reported TRI pounds among local Form R filers. AQS median AQI 46 / peak 112 in 2024.
Burden score 74/100 (High Risk) is the only weighted composite on this page. The tables below list every TRI facility, SDWIS system, and Superfund site EPA has on record for St. Clair -- not just the names called out above -- reproducing the disclosure history as filed, not a current-safety verdict. Extract current as of 2026-08-25.
Release-over-release change
What changed for St. Clair, IL: EPA TRI 2023 reporting year
Same facilities, both years
+15.6%
23 facilities that filed in 2022 and 2023
Whole inventory
+14.8%
682.0 thousand lb → 783.3 thousand lb, every facility that filed
Between the two reporting years, 0 facilities filed for the first time and 1 stopped filing. Facilities entering or leaving the inventory are excluded from the same-facility comparison above.
- St. Clair, IL's total reported releases rose from 677.6 thousand lb in 2022 to 783.3 thousand lb in 2023, based on EPA TRI filings.
- St. Clair, IL's air releases rose from 73.4 thousand lb in 2022 to 87.0 thousand lb in 2023, based on EPA TRI filings.
- St. Clair, IL's off-site transfers rose from 604.2 thousand lb in 2022 to 696.3 thousand lb in 2023, based on EPA TRI filings.
- St. Clair, IL's chemicals reported fell from 104 in 2022 to 99 in 2023, based on EPA TRI filings.
Air Quality History (2020–2024)
EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.
| Year | Good | Moderate | Unhealthy (SG) | Max AQI |
|---|---|---|---|---|
| 2024 | 218 (60%) | 145 | 3 | 112 |
| 2023 | 128 (35%) | 223 | 12 | 169 |
| 2022 | 165 (45%) | 199 | 1 | 105 |
| 2021 | 141 (39%) | 221 | 2 | 185 |
| 2020 | 260 (71%) | 105 | 0 | 100 |
Source: EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)
For real-time air quality readings and pollutant breakdowns in Illinois, see the EPA's AirNow.gov.
Water Systems (23)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| O FALLON | 46,603 | 2 |
| CASEYVILLE | 13,798 | 3 |
| CAHOKIA HEIGHTS | 12,528 | 0 |
| MASCOUTAH | 8,759 | 0 |
| AMERICAN WATER OPER AND MAINTENANCE, LLC | 6,779 | 0 |
| LEBANON | 4,714 | 0 |
| FREEBURG | 4,707 | 0 |
| DUPO | 4,684 | 0 |
| SMITHTON | 4,381 | 0 |
| MILLSTADT | 4,071 | 0 |
| TRENTON | 2,742 | 16 |
| NEW ATHENS | 1,970 | 3 |
| MARISSA | 1,921 | 2 |
| ST LIBORY | 628 | 0 |
| LENZBURG | 616 | 4 |
| SOUTHWESTERN IL CORRECTIONAL CENTER | 563 | 0 |
| FAYETTEVILLE | 490 | 2 |
| S L M WATER COMMISSION | 385 | 0 |
| ARAPAHO VILLAGE MHP | 368 | 0 |
| SUMMERFIELD | 347 | 0 |
| FSH WATER COMMISSION | 313 | 2 |
| GASLITE COURT MHC | 114 | 0 |
| KASKASKIA WATER DISTRICT | 0 | 2 |
TRI Facilities (27)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Veolia N.a. Inc. | 1.9M lbs |
| 2 | Afton Chemical Corp | 1.3M lbs |
| 3 | Occidental Chemical Corp Sauget Plant | 340.7K lbs |
| 4 | Flexsys America LP Krummrich | 62.5K lbs |
| 5 | Solvay Fluorides LLC | 57.4K lbs |
| 6 | Allnex USA Inc. | 35.8K lbs |
| 7 | Phillips 66 Co East St Louis Terminal | 28.2K lbs |
| 8 | Roho West | 24.3K lbs |
| 9 | Custom Marble Inc | 23.9K lbs |
| 10 | Kempen Paint Co | 9.9K lbs |
| 11 | Center Ethanol Co LLC | 8.2K lbs |
| 12 | Gateway Terminals LLC | 6.5K lbs |
| 13 | Kettler Casting Co Inc. | 4.8K lbs |
| 14 | Hawkins Inc. - Dupo | 2.3K lbs |
| 15 | Chemtrade Solutions Llc-East St Louis | 1.5K lbs |
| 16 | Videojet Technologies Inc | 1.2K lbs |
| 17 | Cerro Flow Products LLC | 559 lbs |
| 18 | US Air Force/scott Air Force Base | 504 lbs |
| 19 | Brenntag Mid-South Inc. | 65 lbs |
| 20 | Solutia Inc P2S5 Plant | 42 lbs |
| 21 | Hubbell-Wiegmann | 32 lbs |
| 22 | Belleville Shoe Manufacturing Co | 10 lbs |
| 23 | Siemens Mfg Co Inc | 2 lbs |
| 24 | Oldcastle Lawn & Garden | 0 lbs |
| 25 | Brenntag Mid-South Inc | 0 lbs |
| 26 | Century Castings Corp | 0 lbs |
| 27 | East Side Jersey Dairy | 0 lbs |
Superfund Sites (3)
| Site Name | Status | HRS Score |
|---|---|---|
| Old American Zinc Plant | NPL Site | 30.00 |
| Sauget Area 1 | Proposed NPL Site | 50.00 |
| Sauget Area 2 | Proposed NPL Site | 50.00 |
Cities in St. Clair (23)
Frequently Asked Questions
What is the environmental risk level in St. Clair, Illinois? ▼
Are there Superfund sites in St. Clair? ▼
How many toxic release facilities are in St. Clair? ▼
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Is the drinking water safe in St. Clair? ▼
What environmental agencies cover St. Clair? ▼
What does this county environmental profile show?
This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.
Read our methodology - how this data is sourced, computed, and verified.