PFAS in Drinking Water in Illinois
What residents of Illinois need to know about PFAS ("forever chemicals") in drinking water — including contamination sources, which utilities have documented violations, and how to filter PFAS from tap water.
Source: EPA SDWIS, Illinois Environmental Protection Agency, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in Illinois?
Yes. Illinois has multiple documented PFAS contamination sources, including Scott AFB near Belleville, Glenview Naval Air Station (now closed but a legacy contamination site), Rock Island Arsenal, and industrial manufacturing sites. The Chicago metro area has some of the highest PFAS detection rates for municipal water systems of any major metro in the Midwest.
Where does PFAS come from in Illinois?
Scott AFB in St. Clair County is the primary military PFAS source in Illinois, with documented contamination of surrounding groundwater. The former Glenview NAS site in suburban Chicago represents a legacy contamination issue. Industrial sources in the Chicago metro — including manufacturing facilities and fire training areas — also contribute PFAS to Lake Michigan and groundwater in northeastern Illinois.
What should Illinois residents know?
The Chicago metro area draws primarily from Lake Michigan, which has been tested for PFAS; southern Illinois communities near Scott AFB and in the Mississippi River corridor face more direct groundwater exposure concerns. Illinois EPA has conducted PFAS monitoring at numerous public water systems under UCMR5.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| MCLG | Zero |
| Primary contamination sources | Scott AFB (Metro East), former Glenview NAS (Chicago suburbs), industrial manufacturing sites |
| Chicago water source | Lake Michigan — PFAS tested; generally lower concentrations than groundwater-dependent systems |
| State regulator | Illinois Environmental Protection Agency (IEPA) |
| Health effects | Cancer (kidney, testicular), thyroid disruption, immune effects, developmental toxicity |
| Effective treatment | Reverse osmosis or GAC; Chicago metro utilities evaluating large-scale GAC treatment |
Why PFAS Matters in Illinois
Illinois' PFAS picture spans two distinct geographies: the Chicago metro with Lake Michigan surface water and suburban/industrial groundwater sources, and central/southern Illinois with military base and agricultural-area contamination. Scott AFB in the Metro East St. Louis area has generated documented PFAS plumes. The former Glenview NAS site in Cook County has required remediation for PFAS among other contaminants. Chicago's Lake Michigan water supply has been tested for PFAS; while levels are generally low in the open lake, some tributary sources show elevated concentrations.
Illinois PFAS Regulation
State MCL — Stricter Than Federal
Illinois follows federal EPA limits but enacted the PFAS Reduction Act requiring disclosure and restricting PFAS use in consumer products; no state MCL more protective than federal as of 2024.
Illinois EPA enrolled in UCMR5 monitoring and enacted the PFAS Reduction Act requiring manufacturers to disclose and phase out PFAS in consumer products. The Waukegan industrial corridor and former Joliet Arsenal site have PFAS contamination histories. Illinois does not have a state MCL more protective than the federal 4 ppt standard.
Largest Illinois Water Utilities
No PFAS violations on record in EPA SDWIS for Illinois utilities in our database. Browse the largest utilities to review their full water quality record.
What Are PFAS (“Forever Chemicals”)?
PFAS are a family of over 12,000 synthetic chemicals used in non-stick cookware, stain-resistant fabrics, food packaging, and AFFF firefighting foam. Their carbon-fluorine bonds do not break down in the environment or the body — hence the name “forever chemicals.” AFFF used at military bases is the single largest source of PFAS in U.S. drinking water.
Full PFAS overview — national data, health effects, all 50 statesWho Should Pay Closest Attention
Residents of Belleville, O'Fallon, and Scott AFB adjacent communities in St. Clair County face military-source PFAS risk. Private well users in rural downstate Illinois communities and in the former Glenview NAS area face less regulatory protection than those on public water systems.
Residents near military bases with AFFF use history
Private well owners near military or industrial sites
Pregnant residents and families with young children
Residents in communities with documented PFAS detections
Anyone who has consumed water above 4 ppt for an extended period
Residents near airports, fire training areas, or industrial manufacturers
How to Check Your Situation in Illinois
- 1
Identify your water utility using the ZIP lookup below or by browsing the Illinois utility directory on this site.
- 2
Review your utility's Consumer Confidence Report (CCR) — it must report PFAS monitoring results under UCMR5 and the new MCL.
- 3
Check the EPA's ECHO database for your utility's monitoring history. Look for PFAS, PFOA, PFOS, and related compound results.
- 4
Contact your utility directly and ask for their most recent PFAS test results and whether they are implementing treatment under the 2024 MCL.
- 5
If you use a private well near a military base, airport, or industrial facility, order a PFAS panel test from a state-certified laboratory. Tests typically cost $150–$400.
- 6
If PFAS is detected above 4 ppt in your source water, install a certified NSF/ANSI 58 reverse osmosis system or an NSF/ANSI 53-certified activated carbon filter rated for PFAS removal.
How to Remove PFAS from Tap Water
Reverse Osmosis (Best)
90–99% removal — NSF/ANSI 58 certified systems only
Certified Activated Carbon
Effective with NSF/ANSI 53 or 58 certification — verify before buying
Boiling concentrates PFAS. Standard pitcher filters and water softeners do not remove PFAS. Always verify NSF certification before purchasing.
Take Action Now
Look up your Illinois utility's PFAS monitoring history on the PFAS Watchlist below.
If your utility has detected PFAS above 4 ppt, install an NSF/ANSI 58-certified reverse osmosis system at your drinking tap.
Private well owners near military or industrial sites should order a PFAS panel test ($150–$400 at a state-certified lab).
Request your utility's most recent Consumer Confidence Report — PFAS results must be disclosed under the new 2024 MCL.
Frequently Asked Questions
Related Pages
PFAS — National Overview
All U.S. utilities with PFAS records
Illinois PFAS Watchlist
Live utility PFAS monitoring data
Illinois State Overview
All utilities and water quality data
Reverse Osmosis Guide
Removes 90–99% of PFAS
Activated Carbon Filter Guide
NSF/ANSI 53/58 certified options for PFAS
Arsenic in Drinking Water
Another priority contaminant
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Illinois Environmental Protection Agency ↗