State drinking water records
Illinois drinking water systems
1,788 community water systems serve Illinois and are listed below under 102 counties and on the pages of 1,255 cities and towns. Their own population figures add up to 12,123,368 people, a sum that counts people twice where one system sells water to another.
404 of them (23%) had at least one health-based violation in the last 10 years. 644 systems still have one unresolved.
1,140 rely mainly on groundwater and 648 on surface water, counting water bought from other systems.
1,692 systems filed a lead service line inventory listing 423,982 lead lines, 52,940 galvanized lines that must be replaced and 938,954 lines of unknown material.
173 systems are placed by the county their records name: EPA has no service area map for 158 of them, and 15 have one that does not line up with their own records.
- Community water systems
- 1,788
- People served, sum of each system's own figure
- 12,123,368
- Systems with a health-based violation, last 10 years
- 404
- Systems with one unresolved
- 644
- Lead service lines in inventories
- 423,982
Counties
102 countiesEach county counts the systems whose service area map reaches it. Systems placed only by a mailing address are listed on the county pages but not counted here.
| County | Systems | People served | With a health-based violation, 10 years | With one unresolved |
|---|---|---|---|---|
| Adams County | 15 | 55,558 | 4 | 3 |
| Alexander County | 6 | 7,545 | 0 | 3 |
| Bond County | 10 | 19,646 | 5 | 5 |
| Boone County | 6 | 37,807 | 0 | 3 |
| Brown County | 5 | 5,721 | 0 | 1 |
| Bureau County | 25 | 26,592 | 15 | 12 |
| Calhoun County | 4 | 1,709 | 1 | 2 |
| Carroll County | 8 | 9,698 | 2 | 3 |
| Cass County | 7 | 11,133 | 1 | 1 |
| Champaign County | 30 | 204,126 | 7 | 11 |
| Christian County | 15 | 28,703 | 5 | 7 |
| Clark County | 6 | 19,356 | 2 | 4 |
| Clay County | 6 | 10,106 | 0 | 0 |
| Clinton County | 20 | 35,497 | 5 | 8 |
| Coles County | 10 | 57,768 | 1 | 4 |
| Cook County | 145 | 5,260,647 | 14 | 78 |
| Crawford County | 7 | 20,733 | 1 | 3 |
| Cumberland County | 4 | 4,683 | 1 | 0 |
| De Witt County | 8 | 11,228 | 2 | 2 |
| DeKalb County | 20 | 100,888 | 6 | 6 |
| Douglas County | 11 | 20,668 | 2 | 2 |
| DuPage County | 47 | 1,109,748 | 2 | 13 |
| Edgar County | 7 | 12,268 | 2 | 6 |
| Edwards County | 5 | 7,858 | 0 | 3 |
| Effingham County | 10 | 22,418 | 4 | 1 |
| Fayette County | 7 | 12,317 | 3 | 3 |
| Ford County | 10 | 10,464 | 4 | 2 |
| Franklin County | 20 | 42,298 | 2 | 3 |
| Fulton County | 17 | 30,909 | 2 | 2 |
| Gallatin County | 7 | 4,803 | 0 | 3 |
| Greene County | 10 | 12,563 | 4 | 4 |
| Grundy County | 19 | 56,433 | 3 | 9 |
| Hamilton County | 4 | 7,864 | 1 | 2 |
| Hancock County | 11 | 11,851 | 3 | 3 |
| Hardin County | 5 | 4,051 | 1 | 1 |
| Henderson County | 8 | 10,212 | 0 | 2 |
| Henry County | 32 | 37,467 | 9 | 19 |
| Iroquois County | 23 | 20,833 | 6 | 11 |
| Jackson County | 16 | 55,707 | 7 | 7 |
| Jasper County | 4 | 33,249 | 0 | 2 |
| Jefferson County | 13 | 39,530 | 0 | 1 |
| Jersey County | 4 | 22,008 | 0 | 2 |
| Jo Daviess County | 14 | 15,063 | 2 | 6 |
| Johnson County | 7 | 18,803 | 5 | 2 |
| Kane County | 38 | 625,600 | 6 | 8 |
| Kankakee County | 20 | 92,328 | 4 | 9 |
| Kendall County | 10 | 105,253 | 3 | 2 |
| Knox County | 16 | 45,685 | 4 | 5 |
| LaSalle County | 34 | 90,695 | 13 | 12 |
| Lake County | 87 | 650,244 | 11 | 29 |
| Lawrence County | 8 | 12,860 | 1 | 4 |
| Lee County | 16 | 27,905 | 5 | 5 |
| Livingston County | 16 | 45,897 | 4 | 3 |
| Logan County | 12 | 21,419 | 6 | 3 |
| Macon County | 14 | 103,222 | 4 | 7 |
| Macoupin County | 30 | 45,067 | 14 | 14 |
| Madison County | 33 | 260,643 | 6 | 13 |
| Marion County | 13 | 39,527 | 1 | 1 |
| Marshall County | 11 | 9,155 | 3 | 4 |
| Mason County | 6 | 8,108 | 2 | 3 |
| Massac County | 3 | 7,484 | 1 | 2 |
| McDonough County | 13 | 33,034 | 4 | 1 |
| McHenry County | 33 | 259,521 | 5 | 13 |
| McLean County | 35 | 157,846 | 14 | 16 |
| Menard County | 7 | 12,061 | 1 | 3 |
| Mercer County | 15 | 10,635 | 1 | 4 |
| Monroe County | 6 | 27,001 | 3 | 4 |
| Montgomery County | 18 | 23,993 | 9 | 11 |
| Morgan County | 14 | 36,302 | 7 | 3 |
| Moultrie County | 6 | 12,582 | 1 | 2 |
| Ogle County | 25 | 35,132 | 5 | 7 |
| Peoria County | 21 | 170,061 | 4 | 8 |
| Perry County | 6 | 17,620 | 3 | 3 |
| Piatt County | 9 | 12,587 | 3 | 2 |
| Pike County | 14 | 17,481 | 1 | 6 |
| Pope County | 1 | 630 | 1 | 0 |
| Pulaski County | 7 | 4,989 | 1 | 5 |
| Putnam County | 8 | 4,004 | 3 | 1 |
| Randolph County | 14 | 29,363 | 7 | 8 |
| Richland County | 6 | 10,884 | 2 | 1 |
| Rock Island County | 44 | 144,669 | 10 | 19 |
| Saline County | 11 | 25,507 | 4 | 5 |
| Sangamon County | 39 | 182,452 | 5 | 8 |
| Schuyler County | 5 | 7,415 | 2 | 2 |
| Scott County | 6 | 4,422 | 2 | 1 |
| Shelby County | 9 | 11,938 | 3 | 4 |
| St. Clair County | 26 | 260,741 | 7 | 8 |
| Stark County | 4 | 3,419 | 2 | 3 |
| Stephenson County | 13 | 34,150 | 2 | 5 |
| Tazewell County | 27 | 120,275 | 3 | 8 |
| Union County | 9 | 13,172 | 5 | 3 |
| Vermilion County | 20 | 55,496 | 6 | 8 |
| Wabash County | 5 | 9,881 | 1 | 0 |
| Warren County | 6 | 12,109 | 2 | 2 |
| Washington County | 10 | 8,077 | 1 | 3 |
| Wayne County | 10 | 16,129 | 6 | 3 |
| White County | 9 | 13,916 | 1 | 4 |
| Whiteside County | 11 | 37,015 | 6 | 6 |
| Will County | 49 | 819,016 | 5 | 20 |
| Williamson County | 22 | 71,438 | 9 | 11 |
| Winnebago County | 21 | 239,323 | 4 | 5 |
| Woodford County | 17 | 25,286 | 4 | 7 |
Largest systems
| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| Chicago | Cook County | 2,746,388 | Surface water | 0 | 2 | 150,767 |
| Aurora | Kane County and 1 other county | 183,000 | Surface water | 0 | 0 | 16,463 |
| Joliet | Will County | 160,000 | Groundwater | 1 | 0 | 367 |
| Naperville | DuPage County and 1 other county | 156,406 | Purchased surface water | 0 | 0 | 265 |
| IL American-Champaign | Champaign County | 150,000 | Groundwater | 0 | 0 | 4 |
| Rockford | Winnebago County | 147,051 | Groundwater | 0 | 0 | 14,240 |
| IL American-Peoria | Peoria County | 137,575 | Surface water | 0 | 0 | 10,823 |
| IL American-East St Louis | St. Clair County | 131,368 | Surface water | 0 | 0 | 784 |
| Springfield | Sangamon County | 117,444 | Surface water | 0 | 0 | 400 |
| Elgin | Kane County | 114,797 | Surface water | 0 | 0 | 10,206 |
| Waukegan | Lake County | 87,149 | Surface water | 0 | 1 | 4,589 |
| Cicero | Cook County | 83,000 | Purchased surface water | 1 | 3 | 13,087 |
| Aqua Illinois-Kankakee | Kankakee County | 80,000 | Surface water | 1 | 1 | 323 |
| Bloomington | McLean County | 77,610 | Surface water | 0 | 1 | 5,866 |
| Decatur | Macon County | 76,122 | Surface water | 0 | 0 | No inventory |
Systems with unresolved health-based violations
644 systemsThe 100 with the most unresolved violations are listed. The county pages list the other 544.
| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| Fields Hill Improvement Association | LaSalle County | 312 | Purchased groundwater | 2 | 31 | No inventory |
| Criswell Court MHP | Will County | 94 | Groundwater | 0 | 26 | No inventory |
| Benton | Franklin County | 8,104 | Purchased surface water | 1 | 19 | No inventory |
| East Moreland Wtr Service Assn | Will County | 1,320 | Groundwater | 1 | 16 | No inventory |
| Southeast Joliet SD | Will County | 2,000 | Groundwater | 1 | 11 | No inventory |
| North Meadow Village MHP | McLean County | 495 | Purchased groundwater | 1 | 11 | No inventory |
| Cortland Corners MHP | DeKalb County | 250 | Groundwater | 1 | 11 | No inventory |
| Robbins | Cook County | 5,415 | Purchased surface water | 0 | 10 | 1,303 |
| Henderson | Knox County | 375 | Purchased groundwater | 1 | 10 | No inventory |
| Uaw Senior Citizens Center | Tazewell County | 240 | Purchased groundwater | 1 | 10 | No inventory |
| Menard Correctional Center | Randolph County | 2,950 | Purchased surface water | 0 | 9 | No inventory |
| Hilltop MHP | McLean County | 1,360 | Purchased surface water | 1 | 9 | No inventory |
| Lafayette | Stark County | 250 | Groundwater | 1 | 9 | No inventory |
| Grantfork | Madison County | 1,766 | Purchased surface water | 1 | 8 | 0 |
| Fci-Marion | Williamson County | 1,544 | Purchased surface water | 0 | 8 | 0 |
| Mound PWD | St. Clair County and 1 other county | 1,500 | Groundwater | 1 | 8 | No inventory |
| Round Lake Park | Lake County | 4,900 | Purchased surface water | 1 | 7 | No inventory |
| Alma | Marion County | 336 | Purchased surface water | 1 | 7 | 0 |
| Winthrop Harbor | Lake County | 6,565 | Purchased surface water | 0 | 6 | 0 |
| Gillespie | Macoupin County | 3,737 | Surface water | 1 | 6 | No inventory |
| Rockdale | Will County | 2,012 | Groundwater | 0 | 6 | 50 |
| Steeleville | Randolph County | 1,960 | Groundwater | 7 | 6 | 0 |
| St Rose PWD | Clinton County and 1 other county | 1,688 | Purchased surface water | 2 | 6 | No inventory |
| Erie | Whiteside County | 1,600 | Groundwater | 3 | 6 | 0 |
| Silvis Heights Water Corp | Rock Island County | 1,450 | Groundwater | 4 | 6 | 0 |
| New Windsor | Mercer County | 740 | Groundwater | 3 | 6 | No inventory |
| Kansas | Edgar County | 707 | Groundwater | 0 | 6 | 0 |
| Damiansville | Clinton County | 602 | Purchased surface water | 1 | 6 | No inventory |
| Winslow | Stephenson County | 350 | Groundwater | 2 | 6 | 12 |
| Brocton | Edgar County | 288 | Groundwater | 1 | 6 | 0 |
| Sims | Wayne County | 244 | Purchased surface water | 1 | 6 | 0 |
| Hettick | Macoupin County | 174 | Purchased surface water | 7 | 6 | No inventory |
| Dolton | Cook County | 20,510 | Purchased surface water | 0 | 5 | 1,817 |
| Lawrenceville | Lawrence County | 4,524 | Groundwater | 2 | 5 | 134 |
| McLeansboro | Hamilton County | 2,812 | Purchased surface water | 1 | 5 | 0 |
| Ford Heights | Cook County | 1,813 | Purchased surface water | 0 | 5 | 10 |
| Eaton PWD | Crawford County | 1,655 | Purchased groundwater | 1 | 5 | No inventory |
| Blue Mound | Macon County | 1,300 | Groundwater | 3 | 5 | 0 |
| Chrisman | Edgar County | 1,273 | Purchased groundwater | 22 | 5 | No inventory |
| Pocahontas | Bond County | 697 | Purchased surface water | 1 | 5 | No inventory |
| Westfield | Clark County | 678 | Purchased groundwater | 3 | 5 | No inventory |
| Neponset | Bureau County | 450 | Groundwater | 1 | 5 | 0 |
| Secor | Woodford County | 351 | Groundwater | 11 | 5 | 0 |
| Panama | Bond County and 1 other county | 343 | Purchased surface water | 1 | 5 | No inventory |
| Loraine | Adams County | 300 | Purchased groundwater | 1 | 5 | No inventory |
| Cabery | Ford County and 1 other county | 266 | Groundwater | 0 | 5 | 0 |
| Forest City | Mason County | 222 | Groundwater | 1 | 5 | No inventory |
| Harvard Hills Water Corporation | Tazewell County | 215 | Groundwater | 2 | 5 | 0 |
| Springerton | White County | 176 | Purchased surface water | 1 | 5 | No inventory |
| Duck Lake Well Owners Association | Lake County | 141 | Groundwater | 1 | 5 | No inventory |
| SMG - Lynnville | Morgan County | 130 | Purchased groundwater | 1 | 5 | 1 |
| Ophiem PWS | Henry County | 110 | Groundwater | 3 | 5 | No inventory |
| Buffalo Hollow Farms Water Assoc | Peoria County | 45 | Groundwater | 0 | 5 | 0 |
| Crest Hill | Will County | 21,169 | Groundwater | 1 | 4 | No inventory |
| Richton Park | Cook County | 12,504 | Groundwater | 2 | 4 | 224 |
| Broadview | Cook County | 7,847 | Purchased surface water | 0 | 4 | 957 |
| Silvis | Rock Island County | 7,473 | Purchased surface water | 1 | 4 | 308 |
| Dixmoor | Cook County | 2,973 | Purchased surface water | 0 | 4 | 34 |
| St Jacob | Madison County | 1,835 | Purchased surface water | 2 | 4 | 0 |
| Orion | Henry County | 1,754 | Groundwater | 1 | 4 | 6 |
| Green Oaks | Lake County | 1,470 | Purchased surface water | 1 | 4 | No inventory |
| Assumption | Christian County | 1,315 | Groundwater | 4 | 4 | No inventory |
| Albers | Clinton County | 1,231 | Purchased surface water | 0 | 4 | 0 |
| Sheldon | Iroquois County | 900 | Groundwater | 0 | 4 | 0 |
| Pearl City | Stephenson County | 790 | Groundwater | 0 | 4 | 0 |
| Aqua Illinois-Eastwood Manor | McHenry County | 728 | Groundwater | 0 | 4 | 0 |
| Potomac | Vermilion County | 685 | Groundwater | 1 | 4 | 0 |
| Cutler | Perry County | 463 | Groundwater | 8 | 4 | 0 |
| Sorento | Bond County | 429 | Purchased surface water | 1 | 4 | 0 |
| Hecker | St. Clair County and 1 other county | 429 | Purchased surface water | 1 | 4 | 0 |
| BLM GW MHP, LLC | McLean County | 390 | Purchased surface water | 1 | 4 | 0 |
| Latham | Logan County | 380 | Purchased groundwater | 0 | 4 | 0 |
| Woodland | Iroquois County | 319 | Groundwater | 3 | 4 | 97 |
| Rustic Acres Water Association | Henry County | 260 | Groundwater | 1 | 4 | 0 |
| Donnellson | Bond County | 213 | Purchased surface water | 29 | 4 | 0 |
| Towners Subdivision | Lake County | 206 | Groundwater | 1 | 4 | No inventory |
| Dover | Bureau County | 200 | Groundwater | 1 | 4 | No inventory |
| Eagarville | Macoupin County | 127 | Purchased surface water | 1 | 4 | No inventory |
| East Lynn Community Water System | Vermilion County | 112 | Groundwater | 2 | 4 | No inventory |
| Van Orin Water Company | Bureau County | 100 | Groundwater | 1 | 4 | No inventory |
| Hillview | Greene County | 94 | Purchased groundwater | 1 | 4 | 0 |
| Broadview Estates East Peoria | Tazewell County | 89 | Groundwater | 0 | 4 | 0 |
| Cropsey Mutual Water Association | McLean County | 65 | Groundwater | 2 | 4 | No inventory |
| Skyview Estates | Kankakee County | 56 | Groundwater | 1 | 4 | 0 |
| Cicero | Cook County | 83,000 | Purchased surface water | 1 | 3 | 13,087 |
| Lansing | Cook County | 29,076 | Purchased surface water | 0 | 3 | 3,002 |
| Maywood | Cook County | 24,090 | Purchased surface water | 1 | 3 | 459 |
| Matteson | Cook County | 18,293 | Purchased surface water | 0 | 3 | 1,295 |
| La Grange | Cook County | 16,200 | Purchased surface water | 0 | 3 | 1,542 |
| Taylorville | Christian County | 12,806 | Surface water | 0 | 3 | 1 |
| Summit | Cook County | 10,875 | Purchased surface water | 0 | 3 | 1,403 |
| Harrisburg | Saline County | 8,524 | Purchased groundwater | 1 | 3 | 9 |
| Calumet Park | Cook County | 8,442 | Purchased surface water | 0 | 3 | 2,241 |
| Marseilles | LaSalle County | 5,061 | Groundwater | 1 | 3 | No inventory |
| Sparta | Randolph County | 4,395 | Surface water | 8 | 3 | 0 |
| Burnham | Cook County | 3,989 | Purchased surface water | 0 | 3 | 531 |
| Lake Barrington Shores Subdivsion | Lake County | 2,300 | Groundwater | 1 | 3 | No inventory |
| Mount Olive | Macoupin County | 2,193 | Purchased surface water | 3 | 3 | 324 |
| Prophetstown | Whiteside County | 2,100 | Groundwater | 1 | 3 | 0 |
| Port Byron | Rock Island County | 1,678 | Groundwater | 0 | 3 | 27 |
Counties come from the counties EPA lists each system serving, matched to 2024 Census counties; where EPA lists none, from the county coded in the system's ID, its service area map, or its mailing address. A county holding at least a fifth of a system's service area map is added when at least a fifth of that map lies in those counties. Towns are the ones EPA lists and the Census places such a map covers, always inside those counties. In New England, where EPA's town names a whole Town, it is not matched to the village of the same name. A system is not listed in a county holding less than a fifth of its map, or in a county or town its map reaches when the map lies mostly outside the counties EPA lists, so a page can leave out a system that serves part of the area. Methodology and limitations