Illinois Water Report Card: Worst Water Systems
The most contaminated public water systems in Illinois, ranked by PFAS levels, lead, and EPA violations from official EPA data.
Quick Answer
Il American - Lincoln has the highest PFAS in Illinois at 233.2 ppt (58x the EPA limit). Gilman has the highest lead at 140 ppb. The tables below rank the worst systems in each category so you can see how your water compares.
Highest PFAS Levels in Illinois
Public water systems in Illinois with the highest peak PFAS ("forever chemical") reading in EPA UCMR5 testing (2023-2025). The EPA enforceable limit for PFOA and PFOS is 4 ppt.
| # | Water System | Location | Peak PFAS (ppt) | Compounds | vs 4 ppt limit |
|---|---|---|---|---|---|
| 1 | Il American - Lincoln | Godfrey · 15,200 served | 233.2 | 4 | 58x |
| 2 | Galesburg | Galesburg · 31,620 served | 85 | 5 | 21x |
| 3 | Crest Hill | Crest Hill · 21,169 served | 52.1 | 7 | 13x |
| 4 | Abingdon | Monmouth · 3,275 served | 50 | 4 | 13x |
| 5 | North East Central Pwd | Edwardsville · 3,975 served | 27 | 4 | 7x |
| 6 | East Moline | East Moline · 21,374 served | 24 | 1 | 6x |
| 7 | Brighton | Brighton · 5,041 served | 23 | 3 | 6x |
| 8 | Millstadt | Swansea · 4,071 served | 23 | 4 | 6x |
| 9 | Moline | Moline · 44,500 served | 22 | 1 | 6x |
| 10 | Collinsville, Il | Collinsville · 29,500 served | 22 | 8 | 6x |
| 11 | Romeoville | Romeoville · 50,458 served | 21.2 | 3 | 5x |
| 12 | Mitchell Pwd | Granite City · 5,253 served | 21 | 4 | 5x |
Highest Lead Levels in Illinois
Community water systems in Illinois with the highest 90th-percentile lead result under the EPA Lead and Copper Rule. The EPA action level is 15 ppb; there is no safe level of lead for children.
| # | Water System | Location | Lead 90th-pctile (ppb) | vs 15 ppb |
|---|---|---|---|---|
| 1 | Gilman | Gilman · 1,793 served | 140 | 9.3x over |
| 2 | Aqua Illinois-Kankakee | Kankakee · 80,000 served | 131 | 8.7x over |
| 3 | Erie | Erie · 1,600 served | 130 | 8.7x over |
| 4 | Aqua Illinois-University Park | Kankakee · 7,002 served | 130 | 8.7x over |
| 5 | Mounds | Mounds · 1,135 served | 130 | 8.7x over |
| 6 | South Holland | South Holland · 22,000 served | 107 | 7.1x over |
| 7 | Maywood | Maywood · 24,090 served | 83 | 5.5x over |
| 8 | St Elmo | St Elmo · 1,272 served | 81.5 | 5.4x over |
| 9 | Chenoa | Chenoa · 1,785 served | 80 | 5.3x over |
| 10 | Hamilton | Hamilton · 2,753 served | 80 | 5.3x over |
| 11 | Highwood | Highwood · 5,335 served | 76 | 5.1x over |
| 12 | Windsor | Windsor · 1,200 served | 61.3 | 4.1x over |
Most EPA Violations in Illinois
Community water systems in Illinois with the most health-based EPA Safe Drinking Water Act violations on record. A health-based violation means a contaminant exceeded its federal limit or required treatment was not applied.
| # | Water System | Location | Health-based violations |
|---|---|---|---|
| 1 | Danvers | Danvers · 1,183 served | 43 |
| 2 | Chrisman | Chrisman · 1,273 served | 22 |
| 3 | Greenfield | Greenfield · 1,097 served | 20 |
| 4 | North Tazewell Pwd | East Peoria · 8,300 served | 13 |
| 5 | Coal City | Coal City · 5,749 served | 10 |
| 6 | Milan | Milan · 4,945 served | 9 |
| 7 | Rochelle | Rochelle · 9,446 served | 8 |
| 8 | Mount Zion | Mount Zion · 5,833 served | 8 |
| 9 | Pinckneyville | Pinckneyville · 5,804 served | 8 |
| 10 | Chenoa | Chenoa · 1,785 served | 8 |
| 11 | Sparta | Sparta · 4,395 served | 8 |
| 12 | Atlanta | Atlanta · 1,692 served | 8 |
How This Report Card Is Built
PFAS rankings use EPA UCMR5 monitoring (2023-2025), showing each system's peak detection above the 4 ppt EPA limit. Lead rankings use the EPA Lead and Copper Rule 90th-percentile tap results. Violation counts come from the EPA Safe Drinking Water Information System (SDWIS) and count health-based violations. Lead and violation lists are limited to community water systems serving 1,000 or more people. Figures are the most severe on record and do not necessarily reflect current treated water.
Frequently Asked Questions
What is the most PFAS-contaminated water system in Illinois?
In EPA UCMR5 testing (2023-2025), Il American - Lincoln in Godfrey had the highest recorded PFAS level in Illinois at 233.2 ppt - about 58x the EPA's 4 ppt limit for PFOA and PFOS.
Which Illinois water system has the highest lead levels?
Gilman in Gilman had the highest 90th-percentile lead result in Illinois under the EPA Lead and Copper Rule at 140 ppb - 9.3x the 15 ppb action level.
Which Illinois water system has the most EPA violations?
Danvers in Danvers has the most health-based EPA Safe Drinking Water Act violations on record in Illinois, with 43 violations.
Where does the Illinois water report card data come from?
PFAS figures come from EPA UCMR5 monitoring (2023-2025), lead from the EPA Lead and Copper Rule 90th-percentile tap results, and violations from EPA SDWIS health-based violation records. Figures are the most severe on record and do not necessarily reflect current treated water. Check your exact address at knowyourexposure.com.
What Illinois Residents Should Do
- Look up your exact address at knowyourexposure.com for your system's data
- See the full Illinois water quality overview
- If your system is listed, a certified filter (reverse osmosis for PFAS, NSF-53 for lead) reduces exposure at the tap. See the best water filters.