Williamson County, IL
The federal environmental record for Williamson County (population 66,706): what is on file, where it is, and what remains open. Sources and retrieval dates are on the methodology page.
1
Superfund NPL sites
3
federal cleanup sites
5
PFAS-detecting water systems
8
TRI facilities
41
open tank releases
Superfund NPL sites
| Site | City | Status | Listed |
|---|---|---|---|
| Sangamo Electric Dump/Crab Orchard National Wildlife Refuge (USDOI) | Carterville | on the NPL | 07/22/1987 |
Drinking water: PFAS testing
Public water systems serving Williamson with at least one PFAS detection under UCMR5. The federal limit for PFOA and PFOS is 4 ng/L; EPA proposed in May 2026 to rescind the limits for the other compounds, which are shown for information.
| System | Highest results | Reading |
|---|---|---|
| CARTERVILLE IL1990150 | PFBA: 5.7 ng/L | detected |
| HERRIN IL1990400 | PFBA: 11 ng/L | detected |
| JOHNSTON CITY IL1990500 | PFBA: 5.2 ng/L | detected |
| MARION IL1990550 | PFBA: 5.6 ng/L | detected |
| CORINTH PWD IL1995120 | PFBA: 5.6 ng/L | detected |
On a system with detections? Testing and treatment options
Facilities reporting toxic releases (2024)
8 facilities in Williamson filed TRI reports for 2024, totalling 231k lb released.
| Facility | City | Top chemicals | Total released |
|---|---|---|---|
| WILLIAMSON ENERGY | MARION | Lead, Mercury | 142k lb |
| SOUTHERN ILLINOIS POWER COOPERATIVE | MARION | Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size), Hydrogen fluoride | 86k lb |
| AISIN MANUFACTURING ILLINOIS LLC | MARION | Copper, Manganese | 1k lb |
| DIAGRAPH MARKING & CODING | MARION | Xylene (mixed isomers) | 843 lb |
| U.S.P. MARION | MARION | Lead | 724 lb |
| GENERAL DYNAMICS ORDNANCE & TACTICAL SYSTEMS INC I AREA | MARION | - | 0 lb |
| GENERAL DYNAMICS ORDNANCE & TACTICAL SYSTEMS INC BFP AREA | MARION | - | 0 lb |
| REACO BATTERY SERVICE | JOHNSTON CITY | Lead And Lead Compounds | 0 lb |
Underground fuel tanks
EPA's UST Finder records 211 tank facilities in Williamson: 135 tanks in service and 493 closed. 149 fuel releases are on record, of which 41 remain open. Open releases are cleanups that have not reached "no further action".
Radon
EPA maps Williamson as Zone 2, moderate predicted indoor radon (2 to 4 pCi/L average). Radon and air quality are covered in depth on lung.com.
The record for one specific address
County figures blur what matters: distance. The Address Environmental Report runs these same federal datasets against one address and reports every site, tank, polluter and water result around it, with distances, in about a minute.
Get the report - $39All federal cleanup sites on file
The wider Superfund enterprise inventory (SEMS) for Williamson, including sites assessed but never listed. Presence here records that EPA had reason to look, not a finding of danger.
- MARION DRUMS SITEMARION
- PERMA-TREAT OF ILLINOIS, INCMARION
- SANGAMO ELECTRIC DUMP/CRAB ORCHARD NATIONAL WILDLIFE REFUGE (USDOI)CARTERVILLE