All water systems in Illinois
5,097 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Posen Posen · Cook County |
5,331 | 3 | 1 | |
|
Sangamon Valley Pwd Champaign County |
5,300 | 2 | 0 | |
|
Genoa Genoa · DeKalb County |
5,298 | 3 | 0 | |
|
Mitchell Pwd Madison County |
5,253 | 1 | 0 | |
|
Flora Flora · Clay County |
5,233 | 1 | 0 | |
|
Eureka Eureka · Woodford County |
5,216 | 1 | 0 | |
|
Berkeley Berkeley · Cook County |
5,214 | 0 | 0 | |
|
Monee Monee · Will County |
5,148 | 3 | 1 | |
|
Caterpillar Trail Pwd Eureka · Woodford County |
5,125 | 0 | 0 | |
|
Aqua Illinois-Willowbrook Manhattan · Will County |
5,100 | 0 | 0 | |
|
Marseilles Marseilles · LaSalle County |
5,061 | 4 | 3 | |
|
Brighton Brighton · Macoupin County |
5,041 | 3 | 0 | |
|
Byron Dragway Ogle County |
5,000 | 0 | 0 | |
|
Niabi Zoo Rock Island County |
5,000 | 1 | 1 | |
|
U of I Chicago Medical Center Cook County |
5,000 | 4 | 1 | |
|
South Highway Pwd Jackson County |
4,972 | 3 | 0 | |
|
Murdale Pwd Jackson County |
4,963 | 0 | 0 | |
|
Milan Milan · Rock Island County |
4,945 | 3 | 1 | |
|
Creve Coeur Tazewell County |
4,934 | 0 | 0 | |
|
Olympia Fields Olympia Fields · Cook County |
4,922 | 3 | 1 | |
|
Anna Anna · Union County |
4,910 | 2 | 0 | |
|
Round Lake Park Round Lake Park · Lake County |
4,900 | 4 | 1 | |
|
Tuscola Tuscola · Douglas County |
4,875 | 4 | 1 | |
|
Palos Park Palos Park · Cook County |
4,873 | 0 | 0 | |
|
Breese Breese · Clinton County |
4,772 | 4 | 0 | |
|
Watseka Watseka · Iroquois County |
4,767 | 1 | 1 | |
|
IL American-Lake Holiday LaSalle County |
4,750 | 0 | 0 | |
|
Cherry Valley Cherry Valley · Winnebago County |
4,731 | 2 | 1 | |
|
Sullivan Sullivan · Moultrie County |
4,729 | 1 | 0 | |
|
Petersburg Petersburg · Menard County |
4,725 | 0 | 0 | |
|
Eldorado Eldorado · Saline County |
4,715 | 1 | 1 | |
|
Lebanon Lebanon · St. Clair County |
4,714 | 2 | 0 | |
|
Beecher Beecher · Will County |
4,713 | 1 | 1 | |
|
Freeburg Freeburg · St. Clair County |
4,707 | 0 | 0 | |
|
Fox River Grove Fox River Grove · McHenry County |
4,702 | 0 | 0 | |
|
Pittsfield Pittsfield · Pike County |
4,697 | 1 | 0 | |
|
Dupo Dupo · St. Clair County |
4,684 | 1 | 0 | |
|
Stone Park Stone Park · Cook County |
4,576 | 1 | 1 | |
|
Athens Athens · Menard County |
4,575 | 4 | 0 | |
|
Auburn Auburn · Sangamon County |
4,574 | 3 | 0 | |
|
Lawrenceville Lawrenceville · Lawrence County |
4,524 | 7 | 2 | |
|
Oglesby Oglesby · LaSalle County |
4,500 | 1 | 0 | |
|
Calhoun County Rwd Calhoun County |
4,438 | 0 | 0 | |
|
Hillsboro Hillsboro · Montgomery County |
4,402 | 3 | 0 | |
|
Dwight Dwight · Livingston County |
4,400 | 1 | 0 | |
|
Cortland Cortland · DeKalb County |
4,398 | 1 | 0 | |
|
Sparta Sparta · Randolph County |
4,395 | 4 | 2 | |
|
Smithton Smithton · St. Clair County |
4,381 | 1 | 0 | |
|
Fountain Water District Valmeyer · Monroe County |
4,350 | 3 | 0 | |
|
Riverton Riverton · Sangamon County |
4,279 | 1 | 0 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Illinois records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.