All water systems in Illinois
5,097 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Oswego Oswego · Kendall County |
38,169 | 1 | 0 | |
|
Addison Addison · DuPage County |
38,017 | 1 | 0 | |
|
Carpentersville Carpentersville · Kane County |
37,983 | 0 | 0 | |
|
Hanover Park Hanover Park · Cook County |
37,470 | 2 | 1 | |
|
Calumet City Calumet City · Cook County |
37,000 | 4 | 1 | |
|
North Park Pwd Machesney Park · Winnebago County |
35,580 | 0 | 0 | |
|
Northbrook Northbrook · Cook County |
34,200 | 2 | 0 | |
|
IL American-Granite City Granite City · Madison County |
33,572 | 0 | 0 | |
|
Woodridge Woodridge · DuPage County |
33,566 | 1 | 1 | |
|
Vernon Hills Lake CO PW Vernon Hills · Lake County |
33,207 | 1 | 0 | |
|
Glendale Heights Glendale Heights · DuPage County |
33,176 | 1 | 0 | |
|
ST Charles Saint Charles · Kane County |
33,081 | 2 | 2 | |
|
Elk Grove Village Elk Grove · Cook County |
31,802 | 4 | 1 | |
|
IL American-Pekin Pekin · Tazewell County |
31,731 | 0 | 0 | |
|
Galesburg Galesburg · Knox County |
31,620 | 0 | 0 | |
|
Mundelein Mundelein · Lake County |
31,500 | 1 | 0 | |
|
Algonquin Algonquin · McHenry County |
30,700 | 0 | 0 | |
|
Collinsville Collinsville · Madison County |
30,616 | 0 | 0 | |
|
Gurnee Gurnee · Lake County |
30,193 | 0 | 0 | |
|
Highland Park Highland Park · Lake County |
30,176 | 0 | 0 | |
|
Aqua Illinois-Vermilion County Danville · Vermilion County |
30,106 | 0 | 0 | |
|
Aqua Illinois-North Maine Utilities Cook County |
30,043 | 1 | 0 | |
|
South Stickny SD Burbank (south Stickney) · Cook County |
30,000 | 3 | 1 | |
|
EJ Water Cooperative Jasper County |
29,720 | 5 | 1 | |
|
Niles Niles · Cook County |
29,350 | 1 | 1 | |
|
New Lenox New Lenox · Will County |
29,200 | 0 | 0 | |
|
Lansing Lansing · Cook County |
29,076 | 4 | 3 | |
|
Montgomery Montgomery · Kane County |
28,956 | 1 | 0 | |
|
Lake in the Hills Lake In The Hills · McHenry County |
28,661 | 1 | 0 | |
|
Glen Ellyn Glen Ellyn · DuPage County |
28,500 | 1 | 1 | |
|
Huntley Huntley · McHenry County |
28,495 | 1 | 0 | |
|
Wilmette Wilmette · Cook County |
27,650 | 2 | 1 | |
|
Oak Forest Oak Forest · Cook County |
27,478 | 2 | 1 | |
|
Round Lake Beach Round Lake Beach · Lake County |
27,200 | 2 | 0 | |
|
Edwardsville Edwardsville · Madison County |
26,808 | 1 | 0 | |
|
Chicago Heights Chicago Heights · Cook County |
26,184 | 2 | 0 | |
|
Batavia Batavia · Kane County |
26,098 | 2 | 0 | |
|
Woodstock Woodstock · McHenry County |
25,630 | 3 | 0 | |
|
Belvidere Belvidere · Boone County |
25,339 | 1 | 1 | |
|
Morton Grove Morton Grove · Cook County |
25,297 | 3 | 2 | |
|
West Chicago West Chicago · DuPage County |
25,166 | 0 | 0 | |
|
Elmwood Park Elmwood Park · Cook County |
25,000 | 2 | 1 | |
|
Harvey Harvey · Cook County |
25,000 | 2 | 1 | |
|
IL American-Homer Township Will County |
24,543 | 0 | 0 | |
|
Zion Zion · Lake County |
24,442 | 3 | 1 | |
|
Lisle Lisle · DuPage County |
24,223 | 1 | 1 | |
|
Melrose Park Melrose Park · Cook County |
24,206 | 0 | 0 | |
|
Westmont Westmont · DuPage County |
24,161 | 0 | 0 | |
|
Maywood Maywood · Cook County |
24,090 | 4 | 2 | |
|
Frankfort Frankfort · Will County |
24,000 | 2 | 1 |
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.