Illinois Guide
PFAS Contamination in Illinois — What You Need to Know
Illinois has some of the most significant PFAS contamination in the country. Here is where it has been found, what the state is doing about it, and how to protect your drinking water right now.
Last updated: April 2026 · By the PFASFilterGuide team
Illinois PFAS Standard
4 ppt PFOA / 4 ppt PFOS (EPA MCL) — Illinois EPA follows federal limits
Illinois EPA follows the federal EPA maximum contaminant levels finalized in April 2024: 4 ppt for PFOA and PFOS individually, with additional limits for PFHxS, PFNA, and HFPO-DA. Illinois has not adopted state-specific PFAS MCLs more stringent than the federal standard. Illinois EPA has actively monitored PFAS in public water systems under the UCMR5 program. Chicago operates one of the largest public water systems in the US — drawing from Lake Michigan — and publishes PFAS testing data in its Consumer Confidence Reports.
Known Contamination Sites
These are publicly documented PFAS detections in Illinois. This is not a complete list — new sites are found regularly as testing expands.
| Location | Source | PFAS Level |
|---|---|---|
| Belleville / O'Fallon (St. Clair County) | Scott Air Force Base — AFFF firefighting foam contamination of surrounding groundwater | PFAS detected in multiple monitoring wells above EPA notification levels; off-base residential area testing ongoing; treatment provided to affected properties |
| Rantoul (Champaign County) | Chanute Air Force Base (closed 1993) — historical AFFF use, ongoing groundwater remediation | PFAS detected in groundwater plume affecting Vermilion County downstream; long-term remediation program active under EPA Superfund processes |
| DuPage County (western Chicago suburbs) | Industrial legacy manufacturing — PFAS in DuPage River tributaries from former manufacturing facilities | Some small DuPage County utilities exceeded old EPA advisory limits; treatment upgrades installed; ongoing UCMR5 monitoring |
| Chicago / Cook County | Industrial corridor — various manufacturing sites using PFAS in processes; Chicago River system | PFAS detected in Chicago River and tributary monitoring; Chicago public water meets EPA MCL but includes detectable PFAS levels in source water monitoring |
| Rock Island (Rock Island County) | Rock Island Arsenal — military industrial complex on the Mississippi River; historical PFAS use in manufacturing and fire suppression | PFAS detected in on-site groundwater; Mississippi River monitoring ongoing; investigation under DoD environmental restoration program |
| Glenview (Cook County) | Former Glenview Naval Air Station (closed 1995) — PFAS plume in North Shore suburban Chicago groundwater | PFAS detected in groundwater plume affecting Glenview and neighboring communities; ongoing remediation; some North Shore water systems have installed treatment |
Military Base Contamination
AFFF firefighting foam used on military bases is one of the largest sources of PFAS groundwater contamination. The Department of Defense has identified these Illinois bases:
Scott Air Force Base (Belleville / O'Fallon, St. Clair County)
Active installation with documented PFAS contamination from historical AFFF use at fire training areas. Multiple monitoring wells show elevated PFAS in surrounding residential areas. DoD has connected some affected homes to municipal water. Remediation and groundwater monitoring ongoing under the DoD Environmental Restoration Program.
Chanute Air Force Base (Rantoul, Champaign County)
Closed base with one of the longer-running PFAS remediation histories in Illinois. AFFF use contaminated groundwater affecting the Vermilion County watershed. Long-term remediation is active. Residents in surrounding Rantoul area should check with Champaign County Health Department about testing options.
Former Glenview Naval Air Station (Glenview, Cook County)
Closed installation now redeveloped as a mixed-use community (The Glen). PFAS groundwater plume persists in the North Shore area. Ongoing remediation managed by the Navy. Some neighboring water systems have installed treatment in response to detections.
Rock Island Arsenal (Rock Island County)
Active Army installation on the Mississippi River with documented PFAS use in manufacturing and fire suppression. Environmental investigation ongoing. Mississippi River monitoring active. Community members should check with Rock Island County Health Department.
Illinois PFAS Regulations
- Illinois EPA follows the federal EPA MCL: 4 ppt PFOA, 4 ppt PFOS, 10 ppt for PFHxS, PFNA, and HFPO-DA
- Illinois has not adopted state-specific PFAS MCLs more stringent than the federal standard
- Illinois public water systems tested under UCMR5 — results in Consumer Confidence Reports
- Illinois EPA works with DoD on Scott AFB, Chanute, and Glenview NAS cleanup programs
- Chicago draws from Lake Michigan — the utility tests under UCMR5 and publishes PFAS data annually
- Private well owners near documented contamination sites should contact county health departments for guidance
How to Test Your Water in Illinois
Illinois EPA oversees PFAS testing for public water systems under the EPA UCMR5 program, which covered all systems serving 3,300+ residents by 2025. Chicago and suburban Cook County systems publish PFAS data in their Consumer Confidence Reports. For private well owners near Scott AFB in St. Clair County, Chanute in Champaign County, or Glenview in Cook County, contact your local county health department about available testing. Illinois EPA maintains a certified lab directory for residents who want independent PFAS testing. Mail-in kits from Tap Score or SimpleLab ($150-$300) test your actual tap water — not just the utility's source water — and are available to any Illinois resident.
Recommended Filters for Illinois Residents
Any NSF P473 certified filter removes PFAS. The right type depends on whether you rent or own, and how many taps you want filtered.
Renters / Budget
Clearly Filtered Pitcher — $80 + $60/yr filters. NSF P473. No install.
See full reviewHomeowners / Kitchen
Under-sink RO system — $200-$400. Filters all drinking + cooking water at one tap.
See full reviewWhole-House
SpringWell PFAS system — $1,500+. Filters every tap including showers and laundry.
See full reviewCommon Questions
Is Chicago tap water safe from PFAS?+
Chicago's water comes from Lake Michigan and goes through extensive treatment. Chicago has tested under UCMR5 and publishes its PFAS data. As of 2026, Chicago's finished tap water is below the EPA MCL. That said, detectable PFAS levels are present in Lake Michigan from industrial and urban runoff. Adding an NSF P473 certified filter at your tap provides an extra layer of protection even if your utility meets the legal standard.
Which Illinois suburbs have PFAS contamination?+
The highest documented risk is near former and active military installations. Glenview in Cook County has a known PFAS plume from the former Naval Air Station. The O'Fallon and Belleville area in St. Clair County is affected by Scott AFB groundwater. Rantoul in Champaign County has documented contamination from Chanute AFB. Some DuPage County small utilities have exceeded old advisory levels from industrial sources. For specific suburb-by-suburb data, check the Illinois EPA PFAS page and your utility's Consumer Confidence Report.
What is Illinois doing about PFAS contamination?+
Illinois EPA monitors public water systems under the federal UCMR5 program and enforces EPA MCLs. The agency works with DoD on military base remediation at Scott, Chanute, and Glenview NAS. Illinois has not set state-specific PFAS limits beyond the federal floor, which critics note leaves private well owners without strong state protections. Chicago and some suburban utilities have invested in treatment upgrades. Illinois EPA maintains a PFAS resource page with testing guidance and lab directories.
How do I test my Illinois well for PFAS?+
Private well owners in Illinois can use a mail-in test from Tap Score or SimpleLab ($150-$300) — you collect a sample at home and mail it to a certified lab for results in 7-14 days. If you live near Scott AFB in St. Clair County, Chanute in Champaign County, or Glenview NAS in Cook County, contact your county health department about free or subsidized testing. Illinois EPA's website provides a list of state-certified drinking water labs.
Does Lake Michigan water have PFAS?+
Yes, Lake Michigan has detectable PFAS from industrial and urban runoff throughout the watershed. The Great Lakes basin has documented PFAS contamination from historical industrial use, particularly from 3M manufacturing in the Minnesota area that discharged PFAS into tributaries that eventually reach Lake Michigan. Chicago's water treatment process reduces PFAS levels in finished water, and the city's treated water meets the EPA MCL. However, for complete confidence, an NSF P473 certified filter or reverse osmosis system at your tap adds meaningful protection.
Protect Your Water Now
You do not need to wait for your state to act. An NSF P473 certified filter removes PFAS from your tap water today. Start with a test to know your levels, then pick the filter that fits your home.