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AquaCensus

Illinois public water systems

4,585 active systems regulated under the Safe Drinking Water Act, serving a reported 12.6M people across 148 counties.

Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

4,585

Population served

12.6M

Community systems

1,794

Groundwater share

83.9%

System types in Illinois

1,794

Community water system

423

Non-transient non-community water system

2,368

Transient non-community water system

Largest water systems in Illinois

The largest active public water systems in Illinois by population served
#Water systemCountyPopulation servedTypeSource
1ChicagoCook2,746,388CommunitySurface water
2AuroraKane183,000CommunitySurface water
3JolietWill160,000CommunityGroundwater
4NapervilleDuPage156,406CommunityPurchased surface water
5Il American-ChampaignChampaign150,000CommunityGroundwater
6RockfordWinnebago147,051CommunityGroundwater
7Il American-PeoriaPeoria137,575CommunitySurface water
8Il American-East St LouisSt. Clair131,368CommunitySurface water
9SpringfieldSangamon117,444CommunitySurface water
10ElginKane114,797CommunitySurface water
11WaukeganLake87,149CommunitySurface water
12CiceroCook83,000CommunityPurchased surface water
13Aqua Illinois-KankakeeKankakee80,000CommunitySurface water
14BloomingtonMcLean77,610CommunitySurface water
15DecaturMacon76,122CommunitySurface water
16SchaumburgCook75,750CommunityPurchased surface water
17EvanstonCook74,486CommunitySurface water
18Il American-West SuburbanWill73,978CommunityPurchased surface water
19Arlington HeightsCook73,320CommunityPurchased surface water
20PalatineCook70,875CommunityPurchased surface water
21SkokieCook66,422CommunityPurchased surface water
22Des PlainesCook60,675CommunityPurchased surface water
23Oak LawnCook58,362CommunityPurchased surface water
24Orland ParkCook58,020CommunityPurchased surface water
25BerwynCook57,250CommunityPurchased surface water

By county

Lake494 systemsCook303 systemsMcHenry281 systemsWill279 systemsWinnebago177 systemsLaSalle161 systemsKane160 systemsDuPage158 systemsOgle107 systemsRock Island106 systemsTazewell87 systemsMcLean80 systemsHenry75 systemsPeoria69 systemsChampaign68 systemsLee62 systemsWoodford61 systemsSangamon60 systemsGrundy59 systemsWhiteside59 systemsKankakee57 systemsIroquois56 systemsBureau55 systemsKendall55 systemsMadison54 systemsDeKalb53 systemsBoone50 systemsSt. Clair47 systemsStephenson46 systemsJo Daviess45 systemsKnox42 systemsCarroll41 systemsVermilion36 systemsMacoupin34 systemsFulton30 systemsLivingston28 systemsMercer28 systemsHenderson26 systemsMason26 systemsClinton25 systemsFranklin25 systemsJackson25 systemsWilliamson25 systemsMontgomery24 systemsMarshall23 systemsAdams22 systemsMcDonough22 systemsPutnam22 systemsChristian21 systemsRandolph21 systemsLogan20 systemsMacon20 systemsDe Witt18 systemsMarion18 systemsMorgan17 systemsCass16 systemsWashington16 systemsBond15 systemsFord15 systemsPiatt15 systemsWarren15 systemsEffingham14 systemsJefferson14 systemsLawrence14 systemsMonroe14 systemsDouglas13 systemsPike13 systemsSaline13 systemsUnion13 systemsColes12 systemsHancock12 systemsMenard12 systemsShelby12 systemsStark12 systemsFayette11 systemsWayne11 systemsEdgar10 systemsGreene10 systemsWhite10 systemsClark9 systemsPerry9 systemsRichland9 systemsVan Buren9 systemsClay8 systemsCrawford8 systemsMoultrie8 systemsCalhoun7 systemsGallatin7 systemsJohnson7 systemsPulaski7 systemsSchuyler7 systemsScott7 systemsAlexander6 systemsJersey6 systemsMassac6 systemsWabash6 systemsBrown5 systemsHardin5 systemsJasper5 systemsCumberland4 systemsEdwards4 systemsHamilton4 systemsPope3 systems
Calcasieu Parish2 systems
Berrien2 systems
Grand Traverse2 systems
St. Joseph2 systems
Emmet2 systems
Hillsdale2 systems
St. Louis2 systems
Buchanan2 systems
Harris2 systems
Madera1 systems
Sonoma1 systems
Pitkin1 systems
Gunnison1 systems
Kootenai1 systems
Baltimore1 systems
Eaton1 systems
Kalamazoo1 systems
Washtenaw1 systems
Mecosta1 systems
Kalkaska1 systems
Otsego1 systems
Shiawassee1 systems
Newaygo1 systems
Hennepin1 systems
Olmsted1 systems
Ramsey1 systems
Anoka1 systems
Mille Lacs1 systems
Miller1 systems
Camden1 systems
Stone1 systems
Medina1 systems
Oklahoma1 systems
Lane1 systems
Berks1 systems
Lehigh1 systems
Bandera1 systems
Brazoria1 systems
Colorado1 systems
Frio1 systems
Guadalupe1 systems
Howard1 systems
La Salle1 systems
Llano1 systems
Wise1 systems