Williamson, 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.
Environmental data for Williamson in Illinois · Population: 66,902
TRI sites such as Southern Illinois Power Cooperative; Williamson Energy; Aisin Manufacturing Illinois LLC; SDWIS systems such as MARION; HERRIN; LAKE OF EGYPT PWD; NPL sites such as Sangamo Electric Dump/Crab Orchard National Wildlife Refuge (USDOI) anchor Williamson, IL's EPA extract. Derived burden score 48/100 (Moderate 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 Williamson include LAKE OF EGYPT PWD; JOHNSTON CITY; DEVILS KITCHEN WATER DISTRICT, while Southern Illinois Power Cooperative leads reported TRI pounds among local Form R filers. No AQS county monitors report here.
Burden score 48/100 (Moderate 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 Williamson -- 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 Williamson, IL: EPA TRI 2023 reporting year
Same facilities, both years
-5.0%
8 facilities that filed in 2022 and 2023
Whole inventory
-5.0%
254.8 thousand lb → 242.1 thousand lb, every facility that filed
- Williamson, IL's total reported releases fell from 254.8 thousand lb in 2022 to 242.1 thousand lb in 2023, based on EPA TRI filings.
- Williamson, IL's air releases fell from 95.9 thousand lb in 2022 to 87.6 thousand lb in 2023, based on EPA TRI filings.
- Williamson, IL's land releases fell from 158.9 thousand lb in 2022 to 154.6 thousand lb in 2023, based on EPA TRI filings.
Water Systems (25)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| MARION | 16,855 | 0 |
| HERRIN | 12,747 | 0 |
| LAKE OF EGYPT PWD | 11,368 | 11 |
| CARTERVILLE | 6,528 | 0 |
| COAL VALLEY PWD | 4,023 | 0 |
| CORINTH PWD | 3,927 | 0 |
| JOHNSTON CITY | 3,509 | 1 |
| PITTSBURG | 2,948 | 0 |
| CAMBRIA | 1,727 | 0 |
| CRAINVILLE | 1,711 | 0 |
| FCI-MARION | 1,544 | 0 |
| DEVILS KITCHEN WATER DISTRICT | 1,428 | 15 |
| FERGES WATER DISTRICT | 1,185 | 0 |
| HIGHWAY 37 NORTH PWD | 1,065 | 1 |
| BUNCOMBE WATER DISTRICT | 1,030 | 11 |
| ENERGY | 984 | 0 |
| BLAIRSVILLE PWD | 807 | 9 |
| HURST | 782 | 1 |
| CREAL SPRINGS | 683 | 8 |
| COLP | 506 | 2 |
| FREEMAN SPUR | 373 | 1 |
| THE ORCHARDS MHC | 253 | 0 |
| CRAB ORCHARD ESTATES | 238 | 3 |
| WALNUT GROVE MHC | 40 | 0 |
| CRAB ORCHARD REFUGE | 25 | 2 |
TRI Facilities (9)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Southern Illinois Power Cooperative | 1.6M lbs |
| 2 | Williamson Energy | 732.4K lbs |
| 3 | Aisin Manufacturing Illinois LLC | 4.1K lbs |
| 4 | Diagraph Marking & Coding | 3.6K lbs |
| 5 | U.s.p. Marion | 2.8K lbs |
| 6 | Reaco Battery Service | 2 lbs |
| 7 | General Dynamics Ordnance & Tactical Systems Inc I Area | 0 lbs |
| 8 | General Dynamics Ordnance & Tactical Systems Inc Bfp Area | 0 lbs |
| 9 | Warren Oil Co LLC - Marion Il | 0 lbs |
Superfund Sites (1)
| Site Name | Status | HRS Score |
|---|---|---|
| Sangamo Electric Dump/Crab Orchard National Wildlife Refuge (USDOI) | NPL Site | 43.70 |
Cities in Williamson (12)
Frequently Asked Questions
What is the environmental risk level in Williamson, Illinois? ▼
Are there Superfund sites in Williamson? ▼
How many toxic release facilities are in Williamson? ▼
What is the air quality in Williamson? ▼
Is the drinking water safe in Williamson? ▼
What environmental agencies cover Williamson? ▼
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.